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Wyszukujesz frazę "Kim, Jong" wg kryterium: Autor


Tytuł:
Measurement of surface subsidence and ground collapse caused by underground mining in the Boleo Copper District, Mexico
Autorzy:
Kim, Jong-Gwan
Powiązania:
https://bibliotekanauki.pl/articles/1839040.pdf
Data publikacji:
2020
Wydawca:
Główny Instytut Górnictwa
Tematy:
subsidence
vertical movements
copper mine
surface crack
longwall
underground mine
osiadanie
ruchy pionowe
kopalnia miedzi
pęknięcie powierzchniowe
ściana eksploatacyjna
kopalnia podziemna
Opis:
Subsidence and vertical movements in mines are a challenge in mining operations. To qualify as a controlled mine site, ground movements must be measured regularly during mining operations. Boleo Copper District mine was monitored and the movement during mining operations was measured from Oct. 31, 2018 to March 15, 2019. The evaluation of vertical and horizontal movement was determined in four locations in the mine areas M303, M303S, M303 C, and M305. The exploitation area, which measured approximately 80 £ 90 m2 with a height of 2.4 m, impacted the surface in the form of cracks. These cracks were observed on the topographic surveys and varied during the mining operations from the beginning to the end. The final results indicated that the points with the greatest displacement were those in the central zone of the mine excavation (points #3, 5, and 6) and the displacement trend of the ground was toward this zone. In theory, the subsidence is typically lesser than the thickness of the extracted ore. In this case, the maximum subsidence was 1.15 m and the ore seam thickness was 2.4 m. The maximum possible subsidence is typically 55-65% of the extracted seam thickness; however, because chain pillars are generally left in place, and provide some support, this maximum possible subsidence is rarely reached. In this case, the maximum subsidence was 52% of the seam thickness.
Źródło:
Journal of Sustainable Mining; 2020, 19, 2; 126-134
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selection mining methods via multiple criteria decision analysis using TOPSIS and modification of the UBC method
Autorzy:
Ali, Mahrous A.M.
Kim, Jong-Gwan
Powiązania:
https://bibliotekanauki.pl/articles/1839056.pdf
Data publikacji:
2021
Wydawca:
Główny Instytut Górnictwa
Tematy:
TOPSIS
UBC method
mining method selection
multiple criteria decision making
metoda UBC
wybór metod wydobycia
wielokryterialne podejmowanie decyzji
Opis:
Mine designers often face difficulties in selecting an appropriate mining method; however, such a method should be selected based on ore and rock characteristics. The selection of mining methods can be considered a type of multi-criteria decision making, and this depends on many factors used in the selection process. The general method used in this field is the University of British Columbia (UBC) method, which determines the criteria of the properties that are compared to determine the best and worst of several mining methods. In this paper we used as new technique which defines as Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The criteria considered in the UBC method include general shape, ore thickness, ore plunge, and grade distribution, beside the rock quality designation (RQD), and the rock substance strength (RSS). This paper presents an improved TOPSIS method based on experimental design. Additionally, this paper will introduce a modified version of the UBC method that can be employed based on Excel sheet. The best mining methods is cut and fill stoping and top slicing with the same rank equal 0.72, and the second-best mining method is square set stoping with rank equal 0.65.
Źródło:
Journal of Sustainable Mining; 2021, 20, 2; 49-55
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of and Prospects for Students’ Academic Performance in Polish History Education
Autorzy:
Kim, Yong-Deog
Lee, Jong-Oh
Kim, Jong-Suck
Powiązania:
https://bibliotekanauki.pl/articles/48527145.pdf
Data publikacji:
2012-06-30
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
Polska
Korea
Polish history
Korean students
Department of Polish
Opis:
For this study, an evaluation tool focusing on the Polish history was developed to measure the academic performance of college students who major in the Polish language in Korea. The purpose of this study was to investigate the effects of the tool on students’ academic performance after applying it in a classroom setting. The tool consisted of three types of questions, which were administered before and after the application of the tool to 108 students taking a Polish history course. The results of the study serve as a foundation for revitalizing research on Poland and Polish language education, as well as for improving students’ academic performance.
Źródło:
The New Educational Review; 2012, 28; 61-72
1732-6729
Pojawia się w:
The New Educational Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study on Korean History Education Plans for Children from Mixed Marriages in Korea : Focus on Korean-Vietnamese, -Chinese, and -Japanese Children
Autorzy:
Moon, Hyoung-Jin
Nam, Jong-ho
Kim, Jong-suck
Powiązania:
https://bibliotekanauki.pl/articles/2140592.pdf
Data publikacji:
2022-09-30
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
Children from mixed marriages
Korean history
history education
comparative-history teaching method
audio-visual teaching method
Opis:
This study aims to prepare the most effective Korean history education plan for children from mixed marriages in Korea using a questionnaire survey and in-depth interviews. Before the survey, the children from mixed marriages between Korea and Vietnam, China, and Japan preferred the auto-visual teaching method (ATM). However, after learning Cramming Teaching Method (CTM), Audio-Visual Teaching Method (ATM), Comparative-History Teaching Method (CHTM), and Discussion Teaching Method (DTM) for one week, Chinese and Korean – Japanese children preferred CHTM, whereas Korean-Vietnamese children preferred ATM itself. Hence, CHTM was found to be the most effective method when educating Korean history to the children from mixed marriages between Korea and countries with many historical conflicts, similar to that of their mothers (first-generation immigrants).
Źródło:
The New Educational Review; 2022, 69; 39-50
1732-6729
Pojawia się w:
The New Educational Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of an eccentric decoupled charge on rock mass blasting
Autorzy:
Kim, Jung-Gyu
Ali, Mahrous A.M.
Kim, Jong-Gwan
Powiązania:
https://bibliotekanauki.pl/articles/1839045.pdf
Data publikacji:
2020
Wydawca:
Główny Instytut Górnictwa
Tematy:
eccentric decoupled charge
fracture pattern
PFC
AUTODYN
decoupling index
wzór pęknięcia
wskaźnik odsprzęgania
Opis:
Experimental and numerical analyses were conducted to investigate the effect of an eccentric loaded contour hole on a rock mass. In the concrete blocks used for the analyses, detonating cords were placed at the centre of the blast hole and eccentrically against the wall of the blast hole. PFC2D and AUTODYN were used for the numerical analyses, and the results of these software showed that an eccentric decoupled charge can result in the directional development of fractures, thereby enabling the control of cracks in the opposite direction. Even though both types of blasting have identical decoupling indexes, the crack and fracture patterns were affected by the location of the explosive, tamping, and other conditions. The results showed that an eccentric charge holder can be applicable to control the fracture direction and the damaged zone. For an eccentric charge, the initial crack was generated at 0.01 ms and expanded in the intended direction. For the eccentric charge, the maximum pressure at the area in contact with the blast hole wall exceeded that for the central decoupled charge by a factor of 5.5. Furthermore, the pressure in the intended direction was twice of that in the opposite direction.
Źródło:
Journal of Sustainable Mining; 2020, 19, 1; 1-10
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of T6 Heat Treatment on the Scratch Wear Behavior of Extruded Al-12wt.%Si Alloy
Autorzy:
Kang, Yeon-Ji
Kim, Jong-Ho
Hwang, Jong-Il
Lee, Kee-Ahn
Powiązania:
https://bibliotekanauki.pl/articles/356776.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-12wt.%Si alloy
scratch test
wear-resistance
T6 heat treatment
Opis:
This study investigated the effect of T6 heat treatment on the microstructure and scratch wear behavior of hypoeutectic Al-12wt.%Si alloy manufactured by extrusion. Microstructural observation identified spherical eutectic Si phases before and after the heat treatment of alloys (F, T6). Phase analysis confirmed Al matrix and Si phase as well as Al2Cu and Al3Ni, Mg2Si in both alloys. In particular, Al2Cu was finer and more evenly distributed in T6 alloy. This resulted in Vickers hardness of T6 alloy that was 2.3 times greater compared to F alloy. The scratch wear test was conducted using constant load scratch test (CLST) mode and multi-pass scratch test (MPST) mode. The scratch coefficient and worn out volume obtained by such were used to evaluate wear properties before and after heat treatment. In the case of T6 alloy, its scratch coefficient was lower than F alloy in all load ranges. After 15 repeated tests to measure worn out volume, F alloy and T6 alloy measured 1.2×10-1 mm3 and 7.8×10-2 mm3, respectively. In other words, the wear resistance of T6 alloy were confirmed to be better than those of F alloy. In addition, this study attempted to identify the microstructural factors that contribute to the better scratch wear resistance of T6 alloy and wear mechanism from surface and cross-section observations after the wear tests.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 617-622
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Growth and Characterization of Indium-Doped Zinc Oxide Thin Films Prepared by Sol-Gel Method
Autorzy:
Kim, M.
Yim, K.
Kim, S.
Nam, G.
Lee, D.
Kim, Jin
Kim, Jong
Leem, J.
Powiązania:
https://bibliotekanauki.pl/articles/1491351.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Dz
81.20.Fw
78.66.Hf
Opis:
Indium-doped ZnO thin films were deposited by sol-gel spin-coating method with various In content. The effects of In content on the structural and optical properties of the indium-doped ZnO thin films were investigated by scanning electron microscopy, X-ray diffraction, and UV-visible spectroscopy. The particle-like surface morphology and the crystallinity of the indium-doped ZnO thin films were affected by change in the In content, especially at the In content of 3 at.%. The values of direct band gap were decreased with increase in the In content. The width of localized states in the optical band gap of the indium-doped ZnO thin films were changed with In content and the Urbach energy $(E_{U})$ was changed inversely with optical band gap of the indium-doped ZnO thin films.
Źródło:
Acta Physica Polonica A; 2012, 121, 1; 217-220
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ZnO Nanorods on Nanofibrous ZnO Seed Layers by Hydrothermal Method and Their Annealing Effects
Autorzy:
Yim, K.
Jeon, S.
Kim, M.
Kim, S.
Nam, G.
Lee, D.
Kim, Jin
Kim, Jong
Leem, J.
Powiązania:
https://bibliotekanauki.pl/articles/1491348.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Dz
81.15.Lm
78.55.Et
Opis:
ZnO nanorods were grown by using the hydrothermal method on p-type Si (100) substrates with nanofibrous ZnO seed layers. Before the ZnO nanorods growth, nanofibrous ZnO seed layers were spin-coated onto the Si substrates. The structural and optical properties of ZnO nanorods were characterized by scanning electron microscopy, X-ray diffraction, and photoluminescence. The fibrous ZnO nanorods is possible due to the surface morphology of the nanofibrous ZnO seed layers. To investigate annealing effects of the ZnO nanorods, the post-annealing process was carried out at various temperatures ranging from 300 to 700C under argon conditions. The structural and optical properties of the ZnO nanorods were also affected by the post-annealing treatment.
Źródło:
Acta Physica Polonica A; 2012, 121, 1; 214-216
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-performance high-speed WIM for sustainable road load monitoring using GIS technology
Autorzy:
Kim, Jong Woo
Jung, Young Woo
Utebayeva, Ainura
Kamaliyeva, Zhuldyz
Collins, Neil
Sarbassov, Dastan
Sagin, Janay
Amanzhlova, Raushan
Powiązania:
https://bibliotekanauki.pl/articles/2098176.pdf
Data publikacji:
2021
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
WIM
weight-in-motion
silk road
one belt
KAIA
ważenie pojazdów w ruchu
jedwabny szlak
jeden pas
Opis:
The increasing importance of better transport connectivity has indicated the need to develop high-speed road load monitoring technologies. The Belt and Road Initiative (BRI), Silk Road transportation programs considerable have developed the roads and highways networks in Kazakhstan and other Central Asian (CA) countries. Transportation services require proper maintenance and prompt track load monitoring. There is no holistic freight traffic management system that controls and monitors traffic flow in CA. A Weigh in Motion (WIM) technology can be used as an effective traffic management control system in the CA region. The WIM technology is designed to control axle and gross vehicle weight in motion. It has a wide range of applications, including pavement and bridge weight control, traffic legislation and state regulations. The WIM technology has advantages over conventional static weighing as it does not interrupt traffic flow by creating queues at monitoring stations. The WIM technology can be used not only as a weight control tool but also performs a comprehensive analysis of other traffic flow parameters. In cooperation with Korean UDNS experts with suport from KAIA, we test the application of WIM in Nur-Sultan city, North of Kazakhstan, with Siberian-type cold weather. These works create much challenges and innovative approach to test sensors in the harsh environment, from the extreme cold to hot temperatures, with intensive dust distortions. Our Talapker WIM pilot test site was installed in September 2020, and it performs Gross Vehicle Weight (GVW) and Axle of Weight (AOW) analyses. The Talapker WIM High Speed (HS) sensors are capable of detecting different driving patterns, including everyday driving, acceleration or deceleration more than 10km/h/s and eccentric driving (partial contact with the platform to avoid excessive weighting). The pilot Talapker HS WIM site has demonstrated a positive effect on implementing WIM technology in Kazakhstan. Every 10th car passing through the WIM site registered as an overloaded vehicle by gross weighting, and every 5th car is considered overloaded by axle weighting. GIS-based location allocation analysis (LAA) performed in the given study provided an understanding of a practical implementation of WIM sensors. Taking into consideration different geographical data, the WIM site map was developed to reveal 43 suitable locations. Further improvements for the CA road network and their WIM demand points will be the focus of future research investigations.
Źródło:
Transport Problems; 2021, 16, 4; 149--162
1896-0596
2300-861X
Pojawia się w:
Transport Problems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication and Characterization of GaN/Polymer Composite p-n Junction with PEDOT Nanoparticle Interface Layer
Autorzy:
Kim, M.
Jin, S.
Choi, H.
Kim, G.
Yim, K.
Kim, S.
Nam, G.
Yoon, H.
Kim, Y.
Lee, D.
Kim, Jin
Kim, Jong
Leem, J.
Powiązania:
https://bibliotekanauki.pl/articles/1505152.pdf
Data publikacji:
2011-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.61.Ey
81.15.Gh
Opis:
A heavily Si-doped GaN/polymer hybrid structure with p-type poly(3,4-ethylene-dioxythiophene):beta-1,3-glucan (PEDOT nanoparticle) interface layer has been fabricated. The Si-doped GaN thin film with carrier concentration of 1 × $10^{19} cm^{-3}$ was grown by metal-organic chemical vapor deposition. The PEDOT nanoparticle with various sizes ranging from 60 to 120 nm was synthesized via a miniemulsion polymerization process. The electrical conductivity of the PEDOT nanoparticle is less than 1.2 S/cm. The current-voltage (I-V) characteristic of the hybrid structure shows diode-like behavior. The I-V characteristic was examined in the framework of the thermionic emission model. The ideality factor of the structure without PEDOT nanoparticle interface layer is 12.9. However, the ideality factor of the hybrid structure with PEDOT nanoparticle interface layer is obtained as 1.9. The value of ideality factor is dramatically decreased by inserting the PEDOT nanoparticle interface layer.
Źródło:
Acta Physica Polonica A; 2011, 119, 6; 875-879
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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