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Wyszukujesz frazę "Singh, S. N." wg kryterium: Autor


Tytuł:
A collaborative strategy for a three echelon supply chain with ramp type demand, deterioration and inflation
Autorzy:
Singh, N.
Vaish, B.
Singh, S. R.
Powiązania:
https://bibliotekanauki.pl/articles/406653.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
three echelon supply chain
ramp type demand
deterioration
backlogging
inflation
Opis:
A supply chain system has been investigated in which a single manufacturer procures raw materials from a single supplier, processes them to produce finished products, and then delivers the products to a single retailer. The customer’s demand rate is assumed to be time-sensitive in nature (ramp type) that allows two-phase variation in the demand and production rate. Our adoption of ramp type demand reflects a real market demand for a newly launched product. Shortages are allowed with partial backlogging of demand (only for the retailer), i.e. the rest represent lost sales. The effects of inflation of the cost parameters and deterioration are also considered separately. We show that the total cost function is convex. Using this convexity, a simple algorithm is presented to determine the optimal order quantity and optimal cycle time for the total cost function. The results are discussed with numerical examples and particular cases of the model discussed briefly. A sensitivity analysis of the optimal solution with respect to the parameters of the system is carried out.
Źródło:
Operations Research and Decisions; 2014, 24, 3; 78-100
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study into occurrence of fire in opencast workings over developed coal pillars and evolving control parameters for its safe extraction
Badanie przypadku wystąpienia pożaru w wyrobiskach odkrywkowych ponad udostępnianymi filarami węglowymi i opracowanie parametrów kontrolnych dla zapewnienia ich bezpiecznego wydobycia
Autorzy:
Panigrahi, D.
Sinha, S. K.
Singh, G. N.
Powiązania:
https://bibliotekanauki.pl/articles/219289.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
prowadzenia odkrywki powyżej filarów podziemnych udostępnionych metodą filarowo-komorową
parametry krytyczne określające możliwość wystąpienia pożaru
parametry górnicze
przegląd krytyczny
parametry związane z wydobyciem
przedział ufności
analiza wariancji
opencast over underground bord and pillars
critical to fire
mining parameters
critical review
mine operational parameters
confidence interval and analysis of variance
Opis:
In India, a number of opencast mines are being worked over the coal pillars developed by underground bord and pillar method of mining. In these cases, the fires have occurred in most of these opencast mines causing loss of the coal reserve, production, productivity and safety. In this research work, 13 such mines have been studied over a period of three years and critical parameters for occurrence of these fires have been identified. This paper presents the details of observations for two such mines and detailed statistical analyses have been carried out by using confidence interval (C.I.) and analysis of variance (ANOVA-Two-way classification) for finding out the range of these critical parameters which can be controlled to reduce the occurrence of these fires.
W wielu kopalniach odkrywkowych w Indiach wydobycie prowadzi się w wyrobiskach ponad filarami ochronnymi udostępnianymi przy wykorzystaniu metody filarowo-komorowej. W takich warunkach powstające często w kopalniach pożary powodują utratę zasobów węglowych, zmniejszenie wydajności i poziomu wydobycia oraz negatywnie wpływają na bezpieczeństwo pracy. W artykule tym przeanalizowano przypadki 13 kopalni odkrywkowych na przestrzeni trzech lat, zidentyfikowano krytyczne parametry dla określenia możliwości wystąpienia pożaru. Artykuł przedstawia dokładne obserwacje poczynione w dwóch kopalniach, poparte szczegółową analizą statystyczną z zastosowaniem przedziałów ufności i analizy wariancji (ANOVA - klasyfikacja dwukierunkowa) do określenia wartości parametrów krytycznych w celu zminimalizowania ryzyka wystąpienia pożarów.
Źródło:
Archives of Mining Sciences; 2013, 58, 4; 1145-1162
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A three level integrated inventory model with time dependent demand and production rate under a trade credit policy for both distributor and retailer
Autorzy:
Singh, N.
Vaish, B.
Singh, S. R.
Powiązania:
https://bibliotekanauki.pl/articles/206192.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
time dependent demand
variable production rate
three echelon supply chain
trade credit
Opis:
This paper develops a three echelon supply chain inventory model with permissible delay in payment, in which distributor and retailer’s demand is time dependent and production rate for manufacturer is also time sensitive. The models consider the two level trade credit policy in manufacturer-distributor and distributor-retailer relationship in this supply chain model. A simple solution algorithm is presented to determine the optimal order quantity and optimal cycle time of the total cost function and the number of shipments for distributor and retailer. The results are discussed with numerical examples and the particular cases of the model are also discussed in brief.
Źródło:
Control and Cybernetics; 2014, 43, 3; 439-469
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Almost Unbiased Ratio and Product Type Exponential Estimators
Autorzy:
Yadav, Rohini
Upadhyaya, Lakshmi N.
Singh, Housila P.
Chatterjee, S.
Powiązania:
https://bibliotekanauki.pl/articles/465956.pdf
Data publikacji:
2012
Wydawca:
Główny Urząd Statystyczny
Tematy:
study variable
auxiliary variable
almost unbiased ratio-type and product-type exponential estimators bias
mean squared error
Opis:
This paper considers the problem of estimating the population mean Y of the study variate y using information on auxiliary variate x. We have suggested a generalized version of Bahl and Tuteja (1991) estimator and its properties are studied. It is found that asymptotic optimum estimator (AOE) in the proposed generalized version of Bahl and Tuteja (1991) estimator is biased. In some applications, biasedness of an estimator is disadvantageous. So applying the procedure of Singh and Singh (1993) we derived an almost unbiased version of AOE. A numerical illustration is given in the support of the present study.
Źródło:
Statistics in Transition new series; 2012, 13, 3; 537-550
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An investigation into the effect of rockmass properties on mean fragmentation
Autorzy:
Chandrahas, Sri
Choudhary, Bhanwar Singh
Prasad, N. S. R. Krishna
Musunuri, Venkataramayya
Rao, K. K.
Powiązania:
https://bibliotekanauki.pl/articles/2073876.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
górotwór
test wytrzymałości
kopalnia węgla
Opis:
Desired rock fragmentation is the need of the hour, which influences the entire mining cycle. Thus, most engineering segments pay attention to rock fragmentation and neglect by-products like ground vibration and fly rock. Structural and mechanical properties of rock mass like joint spacing, joint angle, and compressive strength of rock pose a puzzling impact on both fragmentation and ground vibration. About 80% of explosive energy that gets wasted in producing ill effects can be positively optimised, with a new set of blast design parameters upon identifying the behaviour of rock mass properties. In this connection, this research aims to investigate the influence of joint spacing, joint angle, and compressive strength of rock on fragmentation and induced ground vibration. To accomplish this task, research was carried out at an opencast coal mine. It was discovered from this research that compressive strength, joint spacing, and joint angle have a significant effect on the mean fragmentation size (MFS) and peak particle velocity (PPV). With the increase in compressive strength, MFS explicit both increase and decrease trends whilst PPV increased with a specific increase in compressive strength of the rock. An increase in joint spacing triggers both increase and decrease trends in both MFS and PPV. While there is an increase in joint angle, MFS and PPV decrease.
Źródło:
Archives of Mining Sciences; 2021, 66, 4; 561--578
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An investigation of ship airwakes by scale adaptive simulation
Autorzy:
Shukla, S.
Singh, S. N.
Sinha, S. S.
Vijayakumar, C.
Powiązania:
https://bibliotekanauki.pl/articles/116802.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
applications for navy
ship airwakes
Scale Adaptive Simulation (SAS)
simulation
flow phenomena
turbulent structures
investigation by simulation
ship airwakes flow characteristic
Opis:
An early assessment of the ship airwakes flow characteristic is one of the most challenging tasks associated with the designing of vessels. The presence of ship airwake creates very complex flow phenomena due to the presence of strong velocity gradients in space and time and widely varying high levels of recirculation and turbulence. Under such condition, the landing and take-off operation of a helicopter over the ship helodeck is very complex and accurate prediction represents a computational challenge. We present time-accurate scale-adaptive simulation (SAS) of turbulent flow around a simple frigate ship to gain insight into the flow phenomena over the helodeck. Numerical analysis is carried out after several grids and time-steps refinement to ensure the spatial and temporal accuracy of the numerical data. The instantaneous iso-surface of eddy flow structures and vorticity have been analysed across the vertical and longitudinal plane. Results show good agreement with experimental data. Comparisons of mean quantities and velocity spectra show good agreement, indicating that SAS can resolve the large-scale turbulent structures which can adversely impact ship-helo combined operations. Overall, the SAS approach is shown to capture the unsteady flow features of massively separated ship airwake characteristics with reasonable accuracy.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 2; 471-475
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Best Linear Unbiased Estimators of Population Mean on Current Occasion in Two-Occasion Rotation Patterns
Autorzy:
Singh, G. N.
Prasad, S.
Powiązania:
https://bibliotekanauki.pl/articles/465782.pdf
Data publikacji:
2013
Wydawca:
Główny Urząd Statystyczny
Tematy:
successive sampling
auxiliary information
unbiased
variance
optimum replacement policy
Opis:
Best linear unbiased estimators have been proposed to estimate the population mean on current occasion in two-occasion successive (rotation) sampling. Behavior of the proposed estimators have been studied and their respective optimum replacement policies are discussed. Empirical studies are carried out to examine the performance of the proposed estimators and consequently the suitable recommendations are made.
Źródło:
Statistics in Transition new series; 2013, 14, 1; 57-74
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conservation of the endangered medicinal plant Picrorhiza kurroa through in vitro multiple shoot regeneration
Autorzy:
Chaudhary, V.
Singh, S.
Sharma, R.
Singh, A.
Sharma, N.
Powiązania:
https://bibliotekanauki.pl/articles/80933.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
medicinal plant
Picrorhiza kurroa
endangered plant
shoot regeneration
micropropagation
conservation
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2019, 100, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of water supply networks for water transfer to the urban area Case study: Balikpapan city
Autorzy:
Huy, Dinh T.N.
Dwijendra, Ngakan K.A.
Poltarykhin, Andrey
Suksatan, Wanich
Nahi, Nooraldeen S.
Mahmudiono, Trias
Hai, Nguyen T.
Kadhim, Mustafa M.
Singh, Krishanveer
Ahmed, Alim A.A.
Powiązania:
https://bibliotekanauki.pl/articles/2174373.pdf
Data publikacji:
2022
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
network design
water distribution
water shortage
water supply network
water transmission
Opis:
The growing population and the development of industries in all countries of the world have created a very important and complex issue for water supply to cities. Today, many parts of the world are facing the problem of water shortage and this problem cannot be easily solved. In addition to the proper use of water resources and preventing the loss of natural water, the establishment of regional water supply networks is effective in meeting the future needs of the people. A water distribution network (water supply network) is a set of interconnected pipelines used to transport and distribute water in a complex. In designing the water distribution network, factors such as the type of water distribution network, water pressure, water velocity, design flow, minimum pipe diameter, pipe material and many other factors should be considered. In this study, we have tried to design the water supply network of a part of Balikpapan city in Indonesia. The design method led to the determination of pressure values in the connection nodes, pipe diameters, flow rate and velocity in the pipes. All the existing criteria are considered in the design of the water supply network. Although this study has been implemented for a specific study area, it can be of great help to designers in designing the water supply network.
Źródło:
Journal of Water and Land Development; 2022, 54; 251--254
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of flux composition on the percentage elongation and tensile strength of welds in submerged arc welding
Efekt składu topnika na wydłużenie procentowe i wytrzymałość na rozciąganie spawów przy spawaniu łukiem krytym
Autorzy:
Singh, B.
Khan, Z. A.
Siddiquee, A. N.
Maheswari, S.
Sharma, S. K.
Powiązania:
https://bibliotekanauki.pl/articles/140322.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultimate tensile strength
carbon equivalent
basicity index
elements transfer
delta quantity
UTS
wytrzymałość na rozciąganie
równoważnik węglowy
współczynnik zasadowości
transfer pierwiastków
wielkość delta
Opis:
This experimental study reveals the effects of CaF2, FeMn and NiO additions to the base fluxes on tensile strength and percentage elongation of the weld metal. The aim of this study is to develop suitable flux for mild steel for high tensile strength, impact strength and ductility. Bead on plate welds were made using submerged arc welding process. Mathematical model for percentage elongation and UTS of mild steel welds were made. The elements transfer to the welds have been correlated with the above mechanical performance characteristics. The effect of oxygen content on weld elongation and UTS also has been deduced. This study shows that CaF2 and NiO are the significant factors for tensile strength while FeMn is not significant for tensile strength. However, for elongation besides CaF2, the interaction of CaF2 and FeMn was also found significant. The effects of basicity index of the flux and carbon equivalent of the welds on tensile strength and percentage elongation of the welds have also been evaluated.
W studium eksperymentalnym, przedstawionym w pracy, pokazano wpływ domieszek CaF2, FeMn i NiO do podstawowego składu topnika na wytrzymałość na rozciąganie i procentowe wydłużenie metalu spawu. Celem studium było opracowanie topnika odpowiedniego dla stali niskowęglowej, który zapewnia wysoką wytrzymałość na rozciąganie, wytrzymałość na udary i plastyczność. Ściegi spawów wykonano metodą spawania łukiem krytym. Opracowano model matematyczny wydłużenia procentowego i wytrzymałości na rozciąganie (UTS) dla spawów ze stali niskowęglowej. Zbadano korelację między wymienionymi charakterystykami mechanicznymi a transferem pierwiastków do spawu. Wyznaczono także wpływ zawartości tlenu na wydłużenie spawu i ostateczną wytrzymałość na rozciąganie. W badaniach doświadczalnych wykazano, że domieszki CaF2 oraz NiO są istotnymi czynnikami wpływającymi na wytrzymałość na rozciąganie, podczas gdy domieszka FeMn nie ma istotnego wpływu. Oceniono także wpływ współczynnika zasadowości topnika i równoważnika węglowego spawu na wydłużenie procentowe spawu.
Źródło:
Archive of Mechanical Engineering; 2016, LXIII, 3; 337-354
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FPGA implementation of DPWM utility/DG interfaced solar (PV) power converter for green home power supply
Autorzy:
Singh, S. N.
Mishra, S.
Powiązania:
https://bibliotekanauki.pl/articles/229942.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
direct pulse width modulation (DPWM)
total harmonic distortion THD
field SMF: sealed maintenance
free programmable gate array (FPGA)
Opis:
In this paper, utility/DG interfaced DPWM solar (PV) power converter (SPC) has been proposed and developed to meet the growing green energy demand of household applications in a developing country like India. The use of new software based direct PWM strategy (DPWM) in the inverter circuit has resulted in to produce a very near sine-wave, most suitable for various home loads. Simulated results of proposed PWM output wave form and computation of its harmonics content in terms of THD value (upto 5% or even less) using MATLAB software has been reflected in the proposed scheme. The features like an intelligent control action to prevent battery from overcharge or undercharge, higher efficiency (> 90%), generation of grid quality green electricity, sustainability of solar renewable energy sources, cost effective hardware realization with FPGA based VLSI embedded system, shows the superiority of the proposed scheme over conventional power supply systems.
Źródło:
Archives of Control Sciences; 2011, 21, 4; 461-469
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved Separate Ratio Exponential Estimator for Population Mean Using Auxiliary Information
Autorzy:
Yadav, Rochini
Upadhyaya, Lakshmi N.
Singh, Housila P.
Chatterjee, S.
Powiązania:
https://bibliotekanauki.pl/articles/465985.pdf
Data publikacji:
2011
Wydawca:
Główny Urząd Statystyczny
Tematy:
Study variable
auxiliary variable
stratified random sampling
separate ratio estimator
separate product estimator
bias and mean squared error
Opis:
This paper advocates the improved separate ratio exponential estimator for population mean of the study variable y using the information based on auxiliary variable x in stratified random sampling. The bias and mean squared error (MSE) of the suggested estimator have been obtained upto the first degree of approximation. The theoretical and numerical comparisons are carried out to show the efficiency of the suggested estimator over sample mean estimator, usual separate ratio and separate product estimator.
Źródło:
Statistics in Transition new series; 2011, 12, 2; 401-412
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leaching of Al-Based Polygrain Quasicrystalline and Related Crystalline Surfaces
Autorzy:
Yadav, T.
Mishra, S.
Pandey, S.
Singh, D.
Lowe, M.
Tamura, R.
Mukhopadhyay, N.
Srivastava, O.
McGrath, R.
Sharma, H.
Powiązania:
https://bibliotekanauki.pl/articles/1373698.pdf
Data publikacji:
2014-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.44.Br
81.16.Hc
61.66.Dk
68.37.Hk
Opis:
In the present investigation, we have studied leaching on polygrain Al-based quasicrystalline $(i-Al_{63}Cu_{25}Fe_{12})$ as well as crystalline (B2 phase; $Al_{55}Cu_{30}Fe_{15})$ alloy surfaces using a 10 mole NaOH solution. The surface was leached at varying times from 30 min to 8 h and subsequently characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analysis. Leaching of the samples for 30 min generated a homogeneous layer. However further leaching for 1-8 h yielded nano-size particles on the surface. Spherical microstructure has been observed on the Al-Cu-Fe crystalline surface whereas on the quasicrystalline surface a petal-like microstructure appeared. The implications of the evolution of different microstructures in the context of structure, stability and activity are discussed. The results are compared with the microstructure of leached polygrained samples containing a mixture of different surface orientations.
Źródło:
Acta Physica Polonica A; 2014, 126, 2; 629-632
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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