Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Nguyen, A." wg kryterium: Wszystkie pola

  Lista filtrów
Wyrównaj
Wyświetlanie 1-50 z 140
Tytuł:
Positive bilinear discrete-time systems with delays
Dodatnie biliniowe układy dyskretne z opóźnieniami
Autorzy:
Kaczorek, T.
Nguyen, A. D.
Powiązania:
https://bibliotekanauki.pl/articles/153400.pdf
Data publikacji:
2006
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
biliniowość
sterowalność
opóźnienie
dodatni układ dyskretny
bilinear system
controllability
delay
discrete-time
positive system
Opis:
Necessary and sufficient conditions are established for the positivity of bilinear discrete-time systems with delays. Solutions to positive bilinear discrete-time systems are derived. The controllability to zero of the bilinear positive systems with delays is addressed. Necessary and sufficient conditions for the controllability to zero of positive bilinear systems with delays are formulated and proved. The considerations are illustrated by examples.
Podano warunki konieczne i wystarczające dodatności biliniowych układów dyskretnych z opóźnieniami w wektorze stanu i w wymuszeniu. Podano również metodę wyznaczania rozwiązania tych biliniowych układów dyskretnych z opóźnieniami. Wyprowadzono warunki konieczne i wystarczające sterowalności do zera tej klasy układów dodatnich. Rozwiązanie ogólne zostało zilustrowane przykładem liczbowym.
Źródło:
Pomiary Automatyka Kontrola; 2006, R. 52, nr 10, 10; 75-78
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gaze-J2K: gaze-influenced image coding using eye trackers and JPEG 2000
Autorzy:
Nguyen, A.
Chandran, V.
Sridharan, S.
Powiązania:
https://bibliotekanauki.pl/articles/309070.pdf
Data publikacji:
2006
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
eye tracking
image compression
importance map
JPEG 2000
region of interest
Opis:
The use of visual content in applications of the digital computer has increased dramatically with the advent of the Internet and world wide web. Image coding standards such as JPEG 2000 have been developed to provide scalable and progressive compression of imagery. Advances in image and video analysis are also making human-computer interaction multi-modal rather than through the use of a keyboard or mouse. An eye tracker is an example input device that can be used by an application that displays visual content to adapt to the viewer. Many features are required of the format to facilitate this adaptation, and some are already part of image coding standards such as JPEG 2000. This paper presents a system incorporating the use of eye tracking and JPEG 2000, called Gaze-J2K, to allow a customised encoding of an image by using a user's gaze pattern. The gaze pattern is used to automatically determine and assign importance to fixated regions in an image, and subsequently constrain the encoding of the image to these regions.
Źródło:
Journal of Telecommunications and Information Technology; 2006, 1; 3-10
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Software Startups – A Research Agenda
Autorzy:
Unterkalmsteiner, M.
Abrahamsson, P.
Wang, X. F.
Nguyen-Duc, A.
Shah, S.
Bajwa, S. S.
Baltes, G. H.
Conboy, K.
Cullina, E.
Dennehy, D.
Edison, H.
Fernandez-Sanchez, C
Garbajosa, J.
Gorschek, T.
Klotins, E.
Hokkanen, L.
Kon, F.
Lunesu, I.
Marchesi, M.
Morgan, L.
Oivo, M.
Selig, C.
Seppänen, P.
Sweetman, R.
Tyrväinen, P.
Ungerer, C.
Yagüe, A.
Powiązania:
https://bibliotekanauki.pl/articles/953060.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
software startup
research agenda
software-intensive systems
Opis:
Software startup companies develop innovative, software-intensive products within limited time frames and with few resources, searching for sustainable and scalable business models. Software startups are quite distinct from traditional mature software companies, but also from micro-, small-, and medium-sized enterprises, introducing new challenges relevant for software engineering research. This paper’s research agenda focuses on software engineering in startups, identifying, in particular, 70+ research questions in the areas of supporting startup engineering activities, startup evolution models and patterns, ecosystems and innovation hubs, human aspects in software startups, applying startup concepts in non-startup environments, and methodologies and theories for startup research. We connect and motivate this research agenda with past studies in software startup research, while pointing out possible future directions. While all authors of this research agenda have their main background in Software Engineering or Computer Science, their interestin software startups broadens the perspective to the challenges, but also to the opportunities that emerge from multi-disciplinary research. Our audience is therefore primarily software engineering researchers, even though we aim at stimulating collaborations and research that crosses disciplinary boundaries. We believe that with this research agenda we cover a wide spectrum of the software startup industry current needs.
Źródło:
e-Informatica Software Engineering Journal; 2016, 10, 1; 89-123
1897-7979
Pojawia się w:
e-Informatica Software Engineering Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A simulation of integral and derivative of the solution of a stochastici integral equation
Autorzy:
Nguyen, Hy
Nguyen, Minh
Powiązania:
https://bibliotekanauki.pl/articles/1312064.pdf
Data publikacji:
1992
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
A stochastic integral equation corresponding to a probability space $(Ω,Σ_ω,P_ω)$ is considered. This equation plays the role of a dynamical system in many problems of stochastic control with the control variable $u(·):ℝ^1 → ℝ^m$. One constructs stochastic processes $η^{(1)}(t)$, $η^{(2)}(t)$ connected with a Markov chain and with the space $(Ω,Σ_ω,P_ω)$. The expected values of $η^{(i)}(t)$ (i = 1,2) are respectively the expected value of an integral representation of a solution x(t) of the equation and that of its derivative $x'_u(t)$.
Źródło:
Annales Polonici Mathematici; 1992, 57, 1; 1-12
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improvement of a hydraulic self-climbing formwork
Autorzy:
Nguyen, Van Tinh
Nguyen, Kiem Anh
Nguyen, Van Linh
Powiązania:
https://bibliotekanauki.pl/articles/139495.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
climbing formwork
self-climbing formwork
hydraulic self-climbing formwork
Opis:
Nowadays, self-climbing formworks are commonly used in the construction of concrete buildings with a great height, such as high-rise buildings, silos, and bridge piers. A regular formwork can be improved to have more functions, e.g., the formwork itself can climb to the desired construction site. Climbing characteristics of the formwork as well as opening and closing characteristics of the formwork shell are essential criteria for evaluating the performance of a self-climbing formwork. The effective ones were mentioned in different studies, where most of them were published in patents of countries, e.g., the United States and China. Dissimilar from these studies, this paper presents several improvements for some certain groups to enhance the features of a hydraulic self-climbing formwork. Based on the analysis of the composition and the working principle of the actual climbing formwork types, a new opening and closing method of the formwork shells and a new rail clamping device are suggested. They are applied to design a self-climbing formwork with the shell’s working size of 4 m × 3 m. Their load capacity, as well as the flatness of the concrete surface after casting, are assessed. The proposed solutions can result in various advantages, e.g., the shorter initial alignment time, the increase of the quality concrete surface, and the maximal automation for construction operations.
Źródło:
Archive of Mechanical Engineering; 2019, LXVI, 4; 495-507
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on the Hasse principle
Autorzy:
Nguyen, Thang
Powiązania:
https://bibliotekanauki.pl/articles/1392255.pdf
Data publikacji:
1990
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Źródło:
Acta Arithmetica; 1989-1990, 54, 3; 171-184
0065-1036
Pojawia się w:
Acta Arithmetica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A remark on Nilsson type integrals
Autorzy:
Minh, Nguyen
Ziemian, Bogdan
Powiązania:
https://bibliotekanauki.pl/articles/1359520.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
We investigate ramification properties with respect to parameters of integrals (distributions) of a class of singular functions over an unbounded cycle which may intersect the singularities of the integrand. We generalize the classical result of Nilsson dealing with the case where the cycle is bounded and contained in the set of holomorphy of the integrand. Such problems arise naturally in the study of exponential representation at infinity of solutions to certain PDE's (see [Z]).
Źródło:
Banach Center Publications; 1996, 33, 1; 277-285
0137-6934
Pojawia się w:
Banach Center Publications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The contribution of geophysics to archaeology: a case study of an ancient canal of the Oc Eo culture in the Mekong Delta, Vietnam
Autorzy:
Le, Ngoc Thanh
Nguyen, Quang Dung
Nguyen, Quang Bac
Nguyen, Quang Mien
Nguyen, Dan Vu
Duong, Ba Man
Nguyen, Dinh Chau
Powiązania:
https://bibliotekanauki.pl/articles/184367.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
electromagnetic profiling
electrical resistivity tomography
hand-auger
radiocarbon dating
ancient canal
alluvial deposits
Oc Eo culture
Ba The mountain
Opis:
Generally, underground ancient canals are infilled with alluvial materials, with the canal bed and substrate often having different resistivity values. This study aimed to determine the location and morphology of Malleret’s ancient canal 16 located to the southeast of the Ba The mountain, Mekong Delta, Vietnam by means of geophysical techniques. Two geophysical methods were used: electromagnetic profile and electric resisitivity tomography. A geoelectric structure 70 m long with 70–95 mS/m of apparent conductivity was found. On the electrical resistivity tomography section, a resistivity zone of 10–20 Ω∙m, 1–4 m deep, 70 m wide corresponds to the mentioned above geoelectric structure, which is in an asymmetric U-shape extending toward the southeastern bank of canal 16. Hand-augering confirmed that the canal bed is fully incised into Holocene sediments as a substrate which stretches down to the Pleistocene. The sediments are composed of loams mixed with plant remains with a resistivity ρ ~ 10–15 Ω∙m. Both of the canal banks at a depth of 5 m are made up of Holocene sedi-ments (ρ ~ 4–10 Ω∙m). The 14C measurements determined the age of the organic matter in the canal as being equal to 1210 ±85 BP, suggesting canal 16 ceased being operational at that time. The precise positioning of canal 16 on the ground surface, as well as identifying the morphology of the canal bed, were corroborated by geophysical techniques. The obtained results are of considerable value to archaeologists.
Źródło:
Geology, Geophysics and Environment; 2019, 45, 1; 45-56
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Solution to Ensure Ventilation when Expanding the Area of Cam Thanh Underground Coal Mine, Ha Long Coal Company, Vietnam
Autorzy:
Nguyen, Cao Khai
Nguyen, Van Tinh
Nguyen, Phi Hung
Nguyen, Van Quang
Powiązania:
https://bibliotekanauki.pl/articles/2020950.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
mine ventilation
mine ventilation and safety
Cam Thanh mines area
ventilation system adjustment
fan operating points
kopalnie
wentylacja
Wietnam
Opis:
In the process of underground mining, the mining system changes for various reasons. One of the main reasons is changes in the mining production plans, especially the scales and outputs. Nowadays, coal mines in Vietnam have been expanding in width and depth, and so have the mines’ ventilation systems. Consequently, there will be changes in the alteration of the structure of the design ventilation system, which reduces the effectiveness of the ventilation and does not meet the main objective of mine ventilation, directly affect the safety of the working environment in the mine. Therefore, it is necessary to research the improvement of the ventilation system with the development and specific conditions of underground coal mines in Vietnam, improving the efficiency of the ventilation work and assuring the safety of the mine environment. Cam Thanh coal mine, Ha Long coal company, Vietnam, is the case study for this research. The article considers the plan of increases the mining output by more than 1.5 times, propose solutions to improve the ventilation system accordingly, helping the company proactively implement the production plan, ensure the working environment's safety, and reduce the costs of mine ventilation.
Źródło:
Inżynieria Mineralna; 2021, 2; 533--542
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parametric model analysis, geometrical characteristics and tool trajectories to surface roughness when machining the cycloid screw by a five-axis milling machine
Autorzy:
Pham, Van Bong
Thien, Nguyen Van
Nguyen, Van Que
Duy, Trinh Nguyen
Nguyen, Duy Khanh
Tien, Dung Hoang
Powiązania:
https://bibliotekanauki.pl/articles/2086278.pdf
Data publikacji:
2022
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
cycloid screw surface
five axis milling machine
ball nose end mill
surface roughness
Opis:
To improve the screw machining accuracy in modern air compressors. This paper investigates three main issues during the development process for cycloid screw machining methods on five-axis CNC machine tools with high precision and efficiency. First, the theoretical basis of cycloid screw surface shaping and derivative of the final profile equation is established. Then, modeling the center trajectory and feed rate according to the cycloid screw profile is given. Next is the experimental setup and simulation of the cycloid screw machining process and discussions. The obtained surface quality prediction parameters are close to the actual measured value, which can be used as a reference model for five-axis CNC milling technology processes. All experimental results obtained by the proposed mathematical model show that a surface with good surface quality is created, meeting the requirements for surface quality. The main work can be used as references for engineers and technicians in practice.
Źródło:
Journal of Machine Engineering; 2022, 22, 2; 108--124
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Luminescence Spectra of ZnAl$\text{}_{2}$O$\text{}_{4}$:Cr$\text{}^{3+}$ Spinel Nanopowders
Autorzy:
Luc, H. H.
Nguyen, T. K.
Nguyen, V. M.
Suchocki, A.
Kamińska, A.
Le, V. K.
Nguyen, V. H.
Luong, T. T.
Powiązania:
https://bibliotekanauki.pl/articles/2037040.pdf
Data publikacji:
2003-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.60.-b
72.80.Ga
81.05.Je
81.05.Mh
Opis:
The synthetic ZnAl$\text{}_{2}$O$\text{}_{4}$ spinels doped with Cr$\text{}^{3+}$ ions are prepared from ZnSO$\text{}_{4}$, Al$\text{}_{2}$(SO$\text{}_{4}$)$\text{}_{3}$, and Cr$\text{}_{2}$(SO$\text{}_{4}$)$\text{}_{3}$. The spinel single phase is detected from X-ray diffraction. Luminescence properties of Cr$\text{}^{3+}$ in ZnAl$\text{}_{2}$O$\text{}_{4}$ were studied by low temperature luminescence and decay measurements. Four luminescence lines at 14570, 14520, 14460, and 14330 cm$\text{}^{-1}$ were found to originate from structure distortion and the line at 14175 cm$\text{}^{-1}$ - from chromium pairs. The broad emission band at about 13540 cm$\text{}^{-1}$ is considered to arise from a new Cr$\text{}^{3+}$ center in ZnCr$\text{}_{2}$O$\text{}_{4}$.
Źródło:
Acta Physica Polonica A; 2003, 104, 6; 581-587
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effectiveness of a Mobile Application-Based Intervention to Improve Knowledge and Practice Regarding Silicosis Among High-Risk Workers of Dust Exposure in a Northern Province of Vietnam
Autorzy:
Nguyen, Thi Thu Huyen
Ta, Thi Kim Nhung
Pham, Thi Quan
Nguyen, Thanh Thao
Nguyen, Ngoc Anh
Nguyen, Thi Lien Huong
Le, Thi Huong
Luong, Mai Anh
Le, Thi Thanh Xuan
Powiązania:
https://bibliotekanauki.pl/articles/27323251.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
knowledge
practice
workers
silicosis
mobile application
effectiveness
praca
aplikacja mobilna
Wietnam
Opis:
Objectives: to analyze changes in knowledge and practices regarding silicosis in groups of workers at high risk of silicosis before - after an intervention. Methods: The study was conducted from 2018 to 2019 based on structured questions related to knowledge and practices of silicosis of workers directly exposed to silica dust in a Northern province of Vietnam. The mobile app-based intervention was applied to steel workers, then compared with ironworkers in improvements in silicosis knowledge and practices. Results: Significant changes in the intervention group related to workers' knowledge about the signs suggestive of silicosis, disease consequences, measures to reduce the risk of silicosis, and participation in annual occupational disease examinations were reported. Conclusion: Mobile applicationbased interventions could improve silicosis knowledge and practice among workers at high risk of exposure to silica dust.
Źródło:
Inżynieria Mineralna; 2023, 2; 295--302
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A solution for increasing data rate of Doppler-RAKE system
Autorzy:
Nguyen Nguyen, M.
Modelski, J.
Powiązania:
https://bibliotekanauki.pl/articles/307797.pdf
Data publikacji:
2003
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
diversity
Doppler-RAKE
CDMA
multi-path
fast-fading
spread-time signaling
multi-user detection
channel coding
Opis:
Doppler-RAKE detection in the CDMA system has been further developed and offers better performances in comparison to conventional RAKE detection, especially in fast-fading environments. Also, the multi-user Doppler-RAKE system works more effectively with channel coding applications. However, by means of exploring the Doppler effect, the system's data rate is decreased. We propose a simple solution to increase the data rate for the system while keeping the Doppler gain.
Źródło:
Journal of Telecommunications and Information Technology; 2003, 3; 130-134
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water Lettuce (Pistia stratiotes L.) as a Potential Material for Biogas Production
Autorzy:
Cong, Nguyen Van
Thanh, Tran Van
Kha, Le Thi Mong
Hoang, Nguyen Xuan
Powiązania:
https://bibliotekanauki.pl/articles/2105278.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
water lettuce
anaerobic digestion
renewable energy
Opis:
This study evaluated the biogas production potential of water lettuce (Pistia stratiotes L.) by batch anaerobic digestion under in-vitro conditions. Twenty-one litre-plastic jars were used to conduct 4 replications over 75 days. The results showed that solution temperature, pH and Eh were suitable for biogas production. More than 50% of the obtained CH4 was formed within 17–42 days after incubation. The maximum daily CH4 production was 0.052 L/gVS, whilst the daily H2S concentration was low, with a maximum value of 28 ppm within 14–21 d after incubation. Moreover, the peak of daily biogas production was seen at day 16 with production of 0.12 L/gVS. The results highlight that water lettuce biomass can be potentially used to produce high quality biogas in anaerobic incubation.
Źródło:
Journal of Ecological Engineering; 2022, 23, 6; 182--188
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modular intelligent fixture system for flexible clamping of large parts
Autorzy:
Möhring, H.-C.
Gessler, W.
König, A.
Nguyen, L. T.
Nguyen, Q. P.
Powiązania:
https://bibliotekanauki.pl/articles/100187.pdf
Data publikacji:
2017
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
machine tool
modular fixture
hybrid material
intelligent system
Opis:
In this work a modular intelligent fixture system for flexible clamping of large parts is presented. The fixture modules consist of a hybrid material structure involving metal frame elements and mineral casting. These modules can be combined and connected to realize fixtures adapted to the geometry of the workpiece and requirements of the machining processes. By integrated pipes and interfaces, an internal hydraulic supply and active cooling is possible even for combined modules. Temperature and acceleration sensors allow for an active thermal control and process monitoring. The modules and first test fixtures are investigated in experiments.
Źródło:
Journal of Machine Engineering; 2017, 17, 4; 29-39
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Difference in flotation behavior of galena by single and multi-step chronoamperometric oxidation
Autorzy:
Ozdemir, Orhan
Hampton, Marc A
Nguyen, Tuan
Nguyen, Anh
Powiązania:
https://bibliotekanauki.pl/articles/110510.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
surface roughness
hydrophobicity
contact angle
elemental sulfur
galena
chronoamperometry
Opis:
The relationship between electrochemical oxidation (Chronoamperometry) of galena surfaces and collocterless galena flotation was investigated in detail. The chronoamperometry (CA) micro- flotation experiments and zeta potential experiments were performed with ground galena particles (106×53 μm). In addition, contact angle measurements were carried out with a freshly cleaved galena sample at pH 4 in order to investigate any changes in galena surface hydrophobicity after the surface oxidation electrochemically. The results from this study indicated that there is a strong link between the nano/micro-physico-chemical properties of a sulphide on galena surfaces and collectorless flotation of galena particles at pH 4. The results were also supported with the electrokinetics behavior and contact angle values of galena particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 3; 812-821
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybridization of machine learning and NSGA-II for multi-objective optimization of surface roughness and cutting force in AISI 4340 alloy steel turning
Autorzy:
Nguyen, Anh-Tu
Nguyen, Van-Hai
Le, Tien-Thinh
Nguyen, Nhu-Tung
Powiązania:
https://bibliotekanauki.pl/articles/2200263.pdf
Data publikacji:
2023
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
multi-objective optimisation
machine learning
AISI 4340
NSGA-II
ANN
Opis:
This work focuses on optimizing process parameters in turning AISI 4340 alloy steel. A hybridization of Machine Learning (ML) algorithms and a Non-Dominated Sorting Genetic Algorithm (NSGA-II) is applied to find the Pareto solution. The objective functions are a simultaneous minimum of average surface roughness (Ra) and cutting force under the cutting parameter constraints of cutting speed, feed rate, depth of cut, and tool nose radius in a range of 50–375 m/min, 0.02–0.25 mm/rev, 0.1–1.5 mm, and 0.4–0.8 mm, respectively. The present study uses five ML models – namely SVR, CAT, RFR, GBR, and ANN – to predict Ra and cutting force. Results indicate that ANN offers the best predictive performance in respect of all accuracy metrics: root-mean-squared-error (RMSE), mean-absolute-error (MAE), and coefficient of determination (R2). In addition, a hybridization of NSGA-II and ANN is implemented to find the optimal solutions for machining parameters, which lie on the Pareto front. The results of this multi-objective optimization indicate that Ra lies in a range between 1.032 and 1.048 μm, and cutting force was found to range between 7.981 and 8.277 kgf for the five selected Pareto solutions. In the set of non-dominated keys, none of the individual solutions is superior to any of the others, so it is the manufacturer's decision which dataset to select. Results summarize the value range in the Pareto solutions generated by NSGA-II: cutting speeds between 72.92 and 75.11 m/min, a feed rate of 0.02 mm/rev, a depth of cut between 0.62 and 0.79 mm, and a tool nose radius of 0.4 mm, are recommended. Following that, experimental validations were finally conducted to verify the optimization procedure.
Źródło:
Journal of Machine Engineering; 2023, 23, 1; 133--153
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new environmentally friendly chemical mechanical polishing method applied for surface finishing Ti-6Al-4V alloy
Autorzy:
Quang, Nguyen Minh
Quan, Nguyen Ngoc
Mai, Nguyen Trong
Thanh, Le Thi Phuong
Tung, Nguyen Tien
Tan, Tran Ngoc
Hai, Ha Thanh
Trinh, Nguyen Duy
Powiązania:
https://bibliotekanauki.pl/articles/28407325.pdf
Data publikacji:
2023
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
chemical-mechanical polishing
hydrogen peroxide
TI-6AL-4V
silica
malic acid
Opis:
A new eco-friendly slurry has been developed for the chemical mechanical polishing process with a solution of malic acid, deionized water, and an oxidizing agent hydrogen peroxide (H2O2). The surface quality of Ti-6Al-4V workpieces with the proposed chemical mechanical polishing slurry with optimal parameters include oxidizers (H2O2), colloidal (SiO2) slurry, and deionized water by weight 8%, 45%, and 47% respectively, the pH concentration is adjusted 4 through the malic acid content present in the slurry. Experimental results obtained with the proposed chemical mechanical polishing method show a more improved surface quality than previous studies when applying for polishing Ti-6Al-4V alloy. The developed chemical mechanical polishing method's polishing results under optimal conditions obtain an ultra-fine surface quality with Ra = 0.696 nm over a measuring area of 53×70 μm2. X-ray photoelectron (XPS) and electrochemical measurements were used to study the chemical reaction mechanisms in the proposed chemical mechanical polishing process. The chemical mechanical polishing processes for the surface of the Ti-6Al-4V alloy workpiece with the H2O2 oxidizing agent showed high suitability with the reactants formed on the surface such as Ti, V, and Al oxide. With the proposed oxidant and the established chemical mechanical polishing slurry, the feasibility and surface quality of the super smooth Ti-6Al-4V workpiece formed after polishing were demonstrated. The established chemical mechanical polishing method shows high applicability in environmental protection and Ti-6Al-4V alloy ultra-precision machining industries.
Źródło:
Journal of Machine Engineering; 2023, 23, 4; 64--76
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal-mechanical coupled simulation
Autorzy:
Nguyen, H. P.
Derewońko, A.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/244229.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
thermo-mechanical coupled
simulation
plastic deformation
Opis:
Optimal design of engineering structures and technological processes requires taking into account various factors affecting the state of strain and stresses in the structure. Coupled thermo-mechanical analysis enables, among others, determination of undesirable changes in a body shape resulting from the implementation method of the initially-boundary conditions, for example, time-varying load and physical properties of the material depending on the temperature. They are also used to determine residual stresses remaining after manufacturing to prevent revalued stiffness and rigidity of the designed construction. In this study, coupled thermo-mechanical analysis illustrated by metal machining operation is presented. The commercial code MSC.Marc has been used to develop a coupled thermo-mechanical finite element model of plane-stress orthogonal metal cutting operations. Metal cutting is one of the most important and common manufacturing processes in the car industry. A thermal mechanical transient analysis is performed to convert mechanical work into heat by plastic deformation of the workpiece material and friction during metal machining operation. The finite element mesh distortion, due to large deformations, requires a remesh technique. The influence of parameters of the 2D and 3D finite element mesh adaptation on plastic deformation and temperature generated in the cutting processing is considered.
Źródło:
Journal of KONES; 2015, 22, 3; 161-168
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exchange Interaction in ZnCrSe Semimagnetic Semiconductor
Autorzy:
Mac, W.
Nguyen, The Khoi
Twardowski, A.
Gaj, J. A.
Demianiuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1924249.pdf
Data publikacji:
1992-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
Opis:
Magnetoreflectance and magnetization of ZnCrSe were measured for B ≤ 5 T and T = 2 K. A linear dependence between exciton splitting and magnetization was found. The s, p-d exchange parameter was estimated: N$\text{}_{0}$α-N$\text{}_{0}$β=0.67eV.
Źródło:
Acta Physica Polonica A; 1992, 82, 5; 902-904
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A theory of refinement structure of hedge algebras and its applications to fuzzy logic
Autorzy:
Ho, Nguyen
Nam, Huynh
Powiązania:
https://bibliotekanauki.pl/articles/1341733.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
In [13], an algebraic approach to the natural structure of domains of linguistic variables was introduced. In this approach, every linguistic domain can be interpreted as an algebraic structure called a hedge algebra. In this paper, a refinement structure of hedge algebras based on free distributive lattices generated by linguistic hedge operations will be examined in order to model structure of linguistic domains more properly. In solving this question, we restrict our consideration to the specific hedge algebras called PN-homogeneous hedge algebras. It is shown that any PN-homogeneous hedge algebra can be refined to a refined hedge algebra (RHA, for short) and every RHA with a chain of the primary generators is a distributive lattice. Especially, we shall examine RHAs with exactly two distinct generators, which will be called symmetrical RHAs. Furthermore, in the symmetrical RHAs of the linguistic truth variable, we are able to define negation and implication operation, which, according to their properties, may be interpreted as logical negation and implication in a kind of fuzzy logic called linguistic-valued logic. Some elementary properties of these operations will be also examined. This yields a possibility to construct a method in linguistic reasoning, which is based on linguistic-valued fuzzy logic corresponding to the symmetrical RHAs of the linguistic truth variable.
Źródło:
Banach Center Publications; 1999, 46, 1; 63-91
0137-6934
Pojawia się w:
Banach Center Publications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Triggering students’ learning autonomy using the combination of m-learning and gamification: a case study at Nguyen Tat Thanh University
Autorzy:
Le Nhat Pham, Linh
Tan Nguyen, Hoang
Thi Kieu Le, Van
Powiązania:
https://bibliotekanauki.pl/articles/2085224.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej w Lublinie. IATEFL Poland Computer Special Interest Group
Tematy:
gamification
m-learning
learner autonomy
language teaching
Opis:
M-learning is usually thought of as based on videos, digital materials, and high technology. Nonetheless, it is not a complete perspective of this new educational trend. Mobile devices with many functions can be an effective tool to support learning. Furthermore, learners nowadays, who were born in the 4.0 movement, are more familiar with mobile devices than notebooks. They spend much time on their mobile phones interacting on social media and playing mobile games. Hence, if educators can integrate those interests into traditional lesson plans, added value would appear for learners’ academic performance and learner autonomy. This paper proposes the idea of combining m-learning, gamification, and other factors influencing learning motivation into a mobile application to reinforce students’ learner autonomy. With a case study at Nguyen Tat Thanh University, we take a closer look at the effectiveness of the application on students’ language acquisition and a detailed description of how to best use the application along with lessons at schools. Using experimental methods with surveys and tests, this paper draws a bonding connection between students’ personal interest in the subject and their performance. The study provides thoughtful insights into utilizing m-learning and gamification to improve students’ learner autonomy and modernize language learning classrooms in this technological context.
Źródło:
Teaching English with Technology; 2021, 21, 2; 66-91
1642-1027
Pojawia się w:
Teaching English with Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of Spatial Solitons in Twisted Nematics Waveguides
Autorzy:
Karpierz, M. A.
Brzdąkiewicz, K. A.
Nguyen, Q. V.
Powiązania:
https://bibliotekanauki.pl/articles/2035666.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.65.Wi
42.70.Df
Opis:
Theoretical analysis of light beam propagation in twisted nematic liquid crystalline waveguides is presented. Due to the optical reorientation nonlinearity, the light beam changes the direction of propagation and optical spatial soliton is formed. Modeling of such behavior is presented by using (2+1)-dimensional vector beam propagation method as well as simplified (1+1)-dimensional method. Although both approaches give similar results, the differences are discussed in detail.
Źródło:
Acta Physica Polonica A; 2003, 103, 2-3; 169-175
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Global attractor of a differentiable autonomous system on the plane
Autorzy:
Nguyen, Chau
Powiązania:
https://bibliotekanauki.pl/articles/1311425.pdf
Data publikacji:
1995
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Markus-Yamabe Conjecture
asymptotically stable
Jacobian Conjecture
Opis:
We study the structure of a differentiable autonomous system on the plane with non-positive divergence outside a bounded set. It is shown that under certain conditions such a system has a global attractor. The main result here can be seen as an improvement of the results of Olech and Meisters in [7,9] concerning the global asymptotic stability conjecture of Markus and Yamabe and the Jacobian Conjecture.
Źródło:
Annales Polonici Mathematici; 1995, 62, 2; 143-154
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Building a Digital Society to Enhance the Efficiency of National Governance in Vietnam
Autorzy:
Nguyen, Quynh Nga
Chu, Thi Khanh Ly
Nguyen, Van Hau
Powiązania:
https://bibliotekanauki.pl/articles/27323275.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
digital society
digital citizen rights
digital lifestyle
digital commerce
national governance
społeczeństwo cyfrowe
styl życia
Wietnam
Opis:
The Fourth Industrial Revolution, especially the digital technology, has been rapidly transforming all aspects of social life, driving a powerful process of digital transformation across all fields. The digital transformation program in Vietnam identifies the digital society as one of the three fundamental pillars, encompassing changes in the way social interactions and connections shift from traditional methods to digital connections through modern technology and communication infrastructure. Alongside the numerous positive aspects, the process of building a digital society also presents significant challenges for each country in managing issues related to ensuring digital citizen rights, establishing digital lifestyle standards, and ensuring fairness in digital commerce. In this study, we will: (1) Clarify the concept and characteristics of the digital society; (2) Explore the current status of building a digital society in Vietnam; (3) Analyze some barriers to the digital society construction; (4) Propose some recommendations for enhancing the effectiveness of national governance in Vietnam today.
Źródło:
Inżynieria Mineralna; 2023, 2; 195--202
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Faraday Rotation and Photoionization of ZnCrSe Semimagnetic Semiconductor
Autorzy:
Mac, W.
Nguyen, The Khoi
Gaj, J. A.
Twardowski, A.
Demianiuk, M.
Stachow-Uciakowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1929663.pdf
Data publikacji:
1993-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
Opis:
The magnetoabsorption and the Faraday rotation of ZnCrSe were measured for B ≤ 5 T and T = 2 K in the region of photon energies lower than the fundamental absorption edge. The circular dichroism of the photoionization absorption bane was observed and analyzed. The Faraday rotation was interpreted as due to the sum of contributions from interband and photoionization optical transitions.
Źródło:
Acta Physica Polonica A; 1993, 84, 3; 567-570
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Melting and the Debye Temperature of for BCC and FCC Metals Under Pressure: A Calculation from the Statistical Moment Method
Autorzy:
Hoc, Nguyen Quang
Tinh, Bui Duc
Hien, Nguyen Duc
Powiązania:
https://bibliotekanauki.pl/articles/2174555.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
statistical moment method
defective cubic metals
perfect cubic metals
Debye temperature
Opis:
We build the melting theory and the theory of the Debye temperature for defective and perfect cubic metals mainly based on the statistical moment method. Our theoretical results are applied to metals Ni, Pd and Pt. Our calculations of melting temperatures agree well with experiments and other calculations. Our other calculations are highly reliable.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 4; 1227--1234
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-step Homogenization of Poroelastic Properties of a Limestone
Dwu-etapowa homogenizacja właściwości poroelastycznych wapienia
Autorzy:
Trieu, Hung Truong
Nguyen, Ngoc Bien
Pham, Duc Tho
Vu, Minh Ngoc
Do, Ngoc Anh
Nguyen, Sy Tuan
Tran, Nam Hung
Nguyen, Thi Thu Nga
Powiązania:
https://bibliotekanauki.pl/articles/318822.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
oolitic limestone
tow-step homogenization
CSA
poro-elastic properties
differential self-consistent
wapień oolityczny
homogenizacja dwuetapowa
właściwości poroelastyczne
zróżnicowana spójność własna
Opis:
This study aims at deriving the effective poroelastic properties of the oolitic limestones based on the Hashin composite sphere assemblage (CSA) micromechanical theory. The microstructure of oolitic limestones generally exhibits an assemblage of grains (oolites) surrounded by a matrix. Grain and matrix are linked via the interfacial transition zone (ITZ). Pores exist in these three material phases (oolite, ITZ and matrix). A two-step homogenization method is proposed. The first step consists of upscaling the properties of each porous phase (i.e. porous oolite, porous ITZ and porous matrix) in which each phase contains two sub-phases including pore and solid. The differential self-consistent scheme is used for the first step. At the second step, the three different porous constituents (oolite, ITZ and matrix) are assembled in a CSA model. A mathematical analogy between thermoelasticity and poroelasticity is used to obtain the effective poroelastic properties. A comparison between the proposed model and test data on the oolitic limestone from Bourgogne (France) helps to calibrate the model parameters and to highlight the role of ITZ phase.
W artykule, przedstawiono wyniki badań efektywnych właściwości poroelastycznych wapieni oolitowych w oparciu o teorię mikromechaniczną złożonego zespołu kul Hashin (CSA). Mikrostruktura wapieni oolitycznych wykazuje generalnie zbiór ziaren (oolitów) otoczonych matrycą. Ziarno i matryca są połączone za pośrednictwem międzyfazowej strefy przejściowej (ITZ). W tych trzech fazach materiału (oolit, ITZ i matryca) istnieją pory. Zaproponowano dwuetapową metodę homogenizacji. Pierwszy etap polega na zwiększeniu skali właściwości każdej porowatej fazy (tj. Porowatego oolitu, porowatej ITZ i porowatej matrycy), w której każda faza zawiera dwie podfazy: porową i stałą. W pierwszym etapie zastosowano różnicowy schemat samouzgodnienia. Na drugim etapie trzy różne porowate składniki (oolit, ITZ i matryca) są składane w modelu CSA. Matematyczne analogie między termosprężystością a poroelastycznością są wykorzystywane do uzyskania efektywnych właściwości poroelastycznych. Porównanie proponowanego modelu z danymi testowymi dotyczącymi wapienia oolitycznego z Bourgogne (Francja) pomaga skalibrować parametry modelu i podkreślić rolę fazy ITZ.
Źródło:
Inżynieria Mineralna; 2020, 1, 2; 31-39
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Marine Sediments with a Subbottom Profilers System in West Coast of Camau, Vietnam
Autorzy:
Dung, Nguyen Quang
Giang, Nguyen Van
Thanh, Le Ngoc
Powiązania:
https://bibliotekanauki.pl/articles/27323269.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
west coast of Camau
high-resolution shallow seismic
sub-bottom profiler
cross-section
Holocene-Pleistocene sediments
Sejsmika
Wietnam
profile
Opis:
The west coast of Camau (Southeast Vietnam) connects two semi-enclosed East Sea and Thailand Bays, allowing water exchange between them. Despite its importance to the oceanographic evolution of the region, it has still been poorly studied. Therefore, Subbottom profilers are used across shallow sea waters with some applications, such as sea-level studies, sedimentation process and geomorphology. In the whole survey area, 6 high-resolution shallow seismic measurements have been performed with a total length of 60.6 km, and all have recorded good reflected signals in the range 20–70 ms. In this section, physical characteristics and nature of petrology in the survey environment are quite uniformly shown. The topography of the seabed in the survey area tends to be gradually shallower from west to east, and is relatively flat. Particularly, on the cross section of the T1 line, it is visible that the first section of the line has a rather steep and deep terrain, which may be the slope of the continental shelf in the survey area. Wedge-shaped, oblique, corrugated and transverse structures all appear on the cross-sections. In the survey area, the shallow geological structure in the Holocene sediments is divided into 4 layers, and the structural boundary between the Holocene and Pleistocene sediments at the depth of 25–35 m is observed. In addition, geological faults are also detected on geological sections from seismic sections. For instance, at the section of T6 line, two faults were detected at the beginning of the line. The displacement amplitude of these faults ranges between 1.5–4 m. This new dataset will contribute to future comprehension of the geologic and oceanographic evolution.
Źródło:
Inżynieria Mineralna; 2023, 2; 215--223
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A syntactic component for Vietnamese language processing
Autorzy:
Le-Hong, P.
Roussanaly, A.
Nguyen, T. M. H.
Powiązania:
https://bibliotekanauki.pl/articles/103931.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Podstaw Informatyki PAN
Tematy:
language
parsing
segmentation
syntactic component
tagging
tree-adjoining grammar
Vietnamese
Opis:
This paper presents the development of a grammar and a syntactic parser for the Vietnamese language. We first discuss the construction of a lexicalized tree-adjoining grammar using an automatic extraction approach. We then present the construction and evaluation of a deep syntactic parser based on the extracted grammar. This is a complete system that produces syntactic structures for Vietnamese sentences. A dependency annotation scheme for Vietnamese and an algorithm for extracting dependency structures from derivation trees are also proposed. This is the first Vietnamese parsing system capable of producing both constituency and dependency analyses. It offers encouraging performance: accuracy of 69.33% and 73.21% for constituency and dependency analysis, respectively.
Źródło:
Journal of Language Modelling; 2015, 3, 1; 145-184
2299-856X
2299-8470
Pojawia się w:
Journal of Language Modelling
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On periodic oscillations for a class of feedback control systems in Hilbert spaces
Autorzy:
Loi, Nguyen
Powiązania:
https://bibliotekanauki.pl/articles/729532.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
semilinear differential inclusion
periodic solution
guiding function
Opis:
In this paper, by using the topological degree theory for multivalued maps and the method of guiding functions in Hilbert spaces we deal with the existence of periodic oscillations for a class of feedback control systems in Hilbert spaces.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2013, 33, 2; 205-219
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
General Geometric Model of GNSS Position Time Series for Crustal Deformation Studies – A Case Study of CORS Stations in Vietnam
Autorzy:
Tran, Dinh Trong
Nguyen, Quoc Long
Nguyen, Dinh Huy
Powiązania:
https://bibliotekanauki.pl/articles/2019404.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
geometric model
GNSS position time series
crustal deformation
CORS stations
Vietnam
model geometryczny
GNSS
Wietnam
Opis:
In processing of position time series of crustal deformation monitoring stations by continuous GNSS station, it is very important to determine the motion model to accurately determine the displacement velocity and other movements in the time series. This paper proposes (1) the general geometric model for analyzing GNSS position time series, including common phenomena such as linear trend, seasonal term, jumps, and post-seismic deformation; and (2) the approach for directly estimating time decay of postseismic deformations from GNSS position time series, which normally is determined based on seismic models or the physical process seismicity, etc. This model and approach are tested by synthetic position time series, of which the calculation results show that the estimated parameters are equal to the given parameters. In addition they were also used to process the real data which is GNSS position time series of 4 CORS stations in Vietnam, then the estimated velocity of these stations: DANA (n, e, u = -9.5, 31.5, 1.5 mm/year), HCMC (n, e, u = -9.5, 26.2, 1.9 mm/year), NADI (n, e, u = -10.6, 31.5, -13.4 mm/year), and NAVI (n, e, u = -13.9, 32.8, -1.1 mm/year) is similar to previous studies.
Źródło:
Inżynieria Mineralna; 2021, 2; 183--197
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and performance analysis of a mechanically coupled spring compliant to out-of-plane oscillation
Autorzy:
Nguyen, Duong Van
Nguyen, Chien Quoc
Dang, Hieu Van
Chu, Hoang Manh
Powiązania:
https://bibliotekanauki.pl/articles/27309868.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
coupled spring
mode coupling
serpentine spring
Sigitta spring theory
finite element
method
sprzężenie trybów
element końcowy
metoda
Opis:
In this paper, a spring system symmetrically arranged around a circular plate compliant to out-of-plane oscillation is proposed. The spring system consists of single serpentine springs mutually coupled in a plane. Three theoretical mechanical models for evaluating the stiffness of the spring system are built, which are based on the flexural beam, Sigitta, and serpentine spring theories and equivalent mechanical spring structure models. The theoretically calculated results are in good agreement with numerical solutions using the finite element method, with errors less than 10% in the appropriate dimension ranges of the spring. Compared to similar spring structures without mechanical coupling, the proposed mechanically coupled spring shows advantage in suppressing the mode coupling.
Źródło:
Archive of Mechanical Engineering; 2022, LXIX, 4; 629--643
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expert judgement-based tuning of the system reliability neural network
Autorzy:
Brandowski, A.
Nguyen, H.
Frąckowiak, W.
Powiązania:
https://bibliotekanauki.pl/articles/258506.pdf
Data publikacji:
2014
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
neural network
reliability
elicitation
parameter
correlation
Opis:
The neural network tuning procedure applied to reliability analyses of anthrop technical systems, based on judgements of experts - experienced operating practicians. Numerical and linguistic elicitation of the judgements, analyses of the network input and output data correlation and of the AHP method processing deviation are presented. Example of data elicitation and correlation analysis of a reliability arrangement of the seagoing ship propulsion system are included to the article.
Źródło:
Polish Maritime Research; 2014, 1; 28-34
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A simulation model of energy distribution in ship combustion engine
Autorzy:
Nguyen, H.
Powiązania:
https://bibliotekanauki.pl/articles/259168.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
computer simulation
ship diesel engine
dynamic processes
energy balance and distribution
Opis:
In the paper a model of energy flow and distribution in ship diesel engine cylinder was presented. This is a model of discrete parameters, being a continuation of the author s research on simulation of energy processing within ship main propulsion engine [2,3]. The model in question makes it possible to calculate energy flow values delivered and transferred during every working cycle of the engine cylinder. Results of application of the model for 6ZA40S Sulzer engine installed on B672 ship were also attached. The results were compared with results of test-stand measurements of the engine, performed at different load levels.
Źródło:
Polish Maritime Research; 2005, 1; 22-26
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lean experience analysis at a leading automotive manufacturer in Vietnam
Autorzy:
Nguyen, Dat-Minh
Powiązania:
https://bibliotekanauki.pl/articles/27315589.pdf
Data publikacji:
2023
Wydawca:
STE GROUP
Tematy:
Lean experience
Lean techniques
Lean principles
Lean practice
sustainable improvement
Opis:
Over the last decades, thanks to the increased pressure to reduce cost and to be more responsive to customer demands as well as improving continuously to the value provided to them, the business has been motivated for managing their operation responsibly in regards to the economical, environmental and social aspects as well. In order to fulfill this mission, encouraged companies and researchers have been finding ways to meet customer demands and sustainable requirements. Lean is one of the systematic approaches to achieving higher value for organizations by eliminating non-value-added activities. Through a case study, the research aims is to present the effectiveness of sustainable improvement on economic, social, and environmental improvement from the perspective of Lean practices. The analysis of the day-to-day Lean practices experience in a case study a good experience for enterprises in desiring applies Lean for sustainable development, can be extremely effective at developing management techniques to achieving sustainable improvement.
Źródło:
Management Systems in Production Engineering; 2023, 1 (31); 9--17
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scattering Dynamics of Excitons in ZnSe Based Semimagnetic Semiconductors
Autorzy:
Nguyen, The Khoi
Mac, W.
Gaj, J.A.
Powiązania:
https://bibliotekanauki.pl/articles/1921546.pdf
Data publikacji:
1992-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
78.30.Fs
Opis:
Resonant Raman scattering was measured for (Zn,Fe)Se and (Zn,Cr)Se with the magnetic ion mole fraction below 0.02. LO phonons and intra-Fe$\text{}^{++}$ transitions were observed. Polarization measurements versus magnetic field allowed to obtain polarization lifetimes (polariton flight times) in the sub-picosecond range.
Źródło:
Acta Physica Polonica A; 1992, 82, 4; 634-636
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A conjecture on the prevalence of cubic bridge graphs
Autorzy:
Filar, Jerzy
Haythorpe, Michael
Nguyen, Giang
Powiązania:
https://bibliotekanauki.pl/articles/744564.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Hamiltonian graph
non-Hamiltonian graph
cubic bridge graph
Opis:
Almost all d-regular graphs are Hamiltonian, for d ≥ 3 [8]. In this note we conjecture that in a similar, yet somewhat different, sense almost all cubic non-Hamiltonian graphs are bridge graphs, and present supporting empirical results for this prevalence of the latter among all connected cubic non-Hamiltonian graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2010, 30, 1; 175-179
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studying the thermo-gas-dynamic process in a muzzle brake compensator
Autorzy:
Nguyen, Dung Van
Bui, Viet Quy
Nguyen, Dung Thai
Uong, Quyen Si
Truong, Hieu Tu
Powiązania:
https://bibliotekanauki.pl/articles/27309887.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
thermo-gas-dynamic
muzzle device
muzzle brake compensator
automatic gun
dynamiczny termo-gaz
urządzenie wylotowe
kompensator hamulca wylotowego
pistolet automatyczny
Opis:
To reduce the recoil and improve the stability of small arms, a muzzle brake compensator is attached to the muzzle of the barrel. This device uses the kinetic energy of the powder gas escaping from the bore after the bullet is fired. In this paper, the authors present the determination of the thermo-gas-dynamic model of the operation of a muzzle brake compensator and an example of calculating this type of muzzle device for the AK assault rifle using 7.62x39 mm ammunition. The results of the calculation allowed for obtaining the parameters of the powder gas flow in the process of flowing out of the muzzle device, as well as the change in the momentum of the powder gas's impact on the muzzle device. The model proposed in the article provides the basis for a quantitative evaluation of the effectiveness of using the muzzle device in stabilizing infantry weapons when firing.
Źródło:
Archive of Mechanical Engineering; 2023, LXX, 2; 311--328
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Impact of Digital Leadership on Organizational Performance: A Study in Vietnams coal Mining Companies
Autorzy:
Le, Van Chien
Nguyen, Duc Thang
Pham, Kien Trung
Nguyen, Thi Hoai Nga
Powiązania:
https://bibliotekanauki.pl/articles/27323234.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
digital transformation
digital leadership
digital transformation strategy
digital skills
organization performance
coal mining company
transformacja cyfrowa
strategia
górnictwo
Opis:
Under the influence of the 4th industrial revolution and the impact of the Covid-19 pandemic, digital transformation is rapidly taking place in all aspects of society. For businesses, digital transformation is an essential and objective trend for their sustainability and development. The purpose of digital transformation for businesses is to enhance operational efficiency through factors such as accelerating market speed, gaining competitive advantage, driving revenue growth, increasing labor productivity, and expanding customer attraction and retention. Numerous studies have indicated that the process of digital transformation in businesses is influenced by leadership and digital transformation strategies, and digital transformation has an impact on business performance. This study aims to identify the relationship between digital leadership and the operational efficiency of coal mining companies in Vietnam, with the mediating role of digital transformation strategies. Additionally, the study examines the moderating role of digital skills on the relationship between digital transformation strategies and the operational efficiency of the organizations. The research surveyed 111 employees and workers currently working in coal mining companies in Vietnam. Through analysis and hypothesis testing, the results showed that digital leadership does not have a direct impact on coal companies’ operational efficiency. However, it indirectly affects business performance through the mediating role of digital transformation strategies. The study's findings also revealed that the digital skills of employees play a moderating role in enhancing the relationship between digital transformation strategies and the operational efficiency of the organization.
Źródło:
Inżynieria Mineralna; 2023, 2; 121--130
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of spontaneously generated coherence and phase of laser fields on optical bistability in a three-level atomic medium: an analytical approach
Autorzy:
Van, Doai Le
Minh, Phuong Le Thi
Tien, Dung Nguyen
Xuan, Khoa Dinh
Huy, Bang Nguyen
Powiązania:
https://bibliotekanauki.pl/articles/174730.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical bistability
electromagnetically induced transparency
spontaneously generated coherence
Opis:
The influence of spontaneously generated coherence and relative phase of laser fields on optical bistability in a three-level atomic medium under electromagnetically induced transparency was studied by using a density matrix theory. An input-output intensity relation of a probe laser field is derived as an analytical function of parameters of a controlling light field, the relative phase, and the spontaneously generated coherence. This function can be fitted with experimental values to be a semi-empirical model which is helpful for finding related applications. It is shown that thresholds and width of the optical bistability hysteresis loop can be manipulated with the controllable parameters. On the other hand, the influence of population relaxation between two ground hyperfine levels on the optical bistability behavior is significant for small coupling field intensity.
Źródło:
Optica Applicata; 2019, 49, 3; 509-522
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of Criteria for High-Technology Rice and Corn Suitability Assessment – A Case Study in the An Giang province, Viet Nam
Autorzy:
Nguyen, Phan Chi
Vu, Pham Thanh
Minh, Vo Quang
Tri, Le Quang
Khuong, Nguyen Quoc
Powiązania:
https://bibliotekanauki.pl/articles/2202337.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
An Giang province
corn production
high-tech
multi-criteria
rice production
Opis:
This study identified the zones likely to apply high-tech rice and corn technology based on criteria from different expert groups. Based on the resulting limiting factor for ability suitable, structural and non-structural solutions have been proposed to improve the suitability of rice and corn with high-tech applications. It was the basic foundation to support strategic planners in agricultural development sustainability in the future. High technology application in agricultural production is an inevitable trend in today’s society. In Vietnam, high-tech agricultural production has developed for a long time in high-tech industrial park production. However, in agricultural production, applying high technology with mass production has yet to have any specific regulations on criteria for implementation in production. On that basis, the research aimed at determining the requirements for developing high-tech agriculture with mass production. Therefore, the predefined criteria for primary and secondary data were developed, which were used for the data collected from farmers, managers, and scientists. Thereby, a production hierarchy of adaptations for rice and corn was built based on consultation results with the farmers and scientists and published studies. The results also made three land adaptation zones apply high technology in mass production for these two crops. The areas suitable for producing rice and corn with high technology applications were marginally suitable, and not suitable prevailed. No region in the An Giang province has a strong potential for cultivating high-tech rice and corn. This result also established adaptive upgrading solutions for applying high technology in the future, which helped improve agricultural production efficiency.
Źródło:
Journal of Ecological Engineering; 2023, 24, 1; 239--247
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Lasso and Elastic-Net Regularized Generalized Linear Model for Predicting Blast-Induced Air Over-pressure in Open-Pit Mines
Model Lasso i uogólniony model liniowy elastycznej siatki do prognozowania nadciśnienia wywołanego wybuchem w kopalniach odkrywkowych
Autorzy:
Bui, Xuan‑Nam
Nguyen, Hoang
Tran, Quang Hieu
Bui, Hoang‑Bac
Nguyen, Quoc Long
Nguyen, Dinh An
Le, Thi Thu Hoa
Pham, Van Viet
Powiązania:
https://bibliotekanauki.pl/articles/318532.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
Lasso model
kopalnia odkrywkowa
wybuchy
open pit mines
explosives
Opis:
Air overpressure (AOp) is one of the products of blasting operations in open-pit mines which have a great impact on the environment and public health. It can be dangerous for the lungs, brain, hearing and the other human senses. In addition, the impact on the surrounding environment such as the vibration of buildings, break the glass door systems are also dangerous agents caused by AOp. Therefore, it should be properly controlled and forecasted to minimize the impacts on the environment and public health. In this paper, a Lasso and Elastic-Net Regularized Generalized Linear Model (GLMNET) was developed for predicting blast-induced AOp. The United States Bureau of Mines (USBM) empirical technique was also applied to estimate blast-induced AOp and compare with the developed GLMNET model. Nui Beo open-pit coal mine, Vietnam was selected as a case study. The performance indices are used to evaluate the performance of the models, including Root Mean Square Error (RMSE), Determination Coefficient (R2), and Mean Absolute Error (MAE). For this aim, 108 blasting events were investigated with the Maximum of explosive charge capacity, monitoring distance, powder factor, burden, and the length of stemming were considered as input variables for predicting AOp. As a result, a robust GLMNET model was found for predicting blast-induced AOp with an RMSE of 1.663, R2 of 0.975, and MAE of 1.413 on testing datasets. Whereas, the USBM empirical method only reached an RMSE of 2.982, R2 of 0.838, and MAE of 2.162 on testing datasets.
Źródło:
Inżynieria Mineralna; 2019, 21, 2/2; 8-20
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 140

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies