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Wyszukujesz frazę "Kim, Hwan-Seong" wg kryterium: Autor


Wyświetlanie 1-8 z 8
Tytuł:
Optimization of stochastic production-inventory model for deteriorating items in a definite cycle using Hamilton-Jacobi-Bellman equation
Autorzy:
Hau, Bui Minh
Kim, Hwan-Seong
Long, Le Ngoc Bao
You, Sam-Sang
Powiązania:
https://bibliotekanauki.pl/articles/2203774.pdf
Data publikacji:
2022
Wydawca:
Wyższa Szkoła Logistyki
Tematy:
production inventory model
deteriorating items
stochastic optimal control
HJB equation
model zapasów produkcyjnych
elementy niszczące
optymalna kontrola stochastyczna
równanie HJB
Opis:
Background: Inventory control is essential for a manufacturer to achieve the desired profit in successful supply chain management. This paper deals with the production-inventory system under the decrease in production rate. The model includes three stages: before the decrease in production, after the decrease in production, and after a period of inventory shortage. Throughout the stages, the stochastic inventory model is always affected by random factors and the deterioration of inventory quality. Method: The article uses the economic order quantity (EOQ) framework to evaluate costs in the production-inventory model. To optimize the manufacturer’s profit with the stochastic factor, Hamilton-Jacobi-Bellman (HJB) equation is presented to find the production rate to make the inventory model to guarantee its intended goals in a determined cycle. Result: Analytical solutions are provided for optimization of the stochastic production-inventory model. Numerical experiments show that inventory level, production rate, and profit over time are based on the optimal initial value of the production rate. Conclusion: The manufacturer’s profit comes from the stages of importing raw materials, processing and producing, storing and supplying items. Finding the initial value of the production rate can make the inventory level and production rate to ensure their desired value and get the target profit within a specified time.
Źródło:
LogForum; 2022, 18, 4; 379--411
1734-459X
Pojawia się w:
LogForum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of Ca Precipitation in Al-Mg Alloys Containing a Trace of Ca During Homogenization
Autorzy:
Ha, Seong-Ho
Shin, Young-Chul
Kim, Bong-Hwan
Yoon, Young-Ok
Lim, Hyun-Kyu
Lim, Sung-Hwan
Kim, Shae K.
Powiązania:
https://bibliotekanauki.pl/articles/2049165.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Mg system
precipitation
Mg+Al2Ca mater alloy
transmission electron microscope
phase diagram
Opis:
In this study, precipitation of Ca in Al-Mg alloys containing a trace of Ca during homogenization was investigated using a transmission electron microscope (TEM) and calculated phase diagrams. TEM result indicated that the Ca-based particles found in the examined sample are Ca7Mg7.5Si14. From the calculation of Scheil-Gulliver cooling, it was found that the Ca was formed as Al4Ca and C36 laves phases with Mg2Si and Al13Fe4 from other impurities phase during solidification. No Ca-Mg-Si ternary phase existed at the homogenization temperature in the calculated phase diagram. From the phase diagram of Al-Al4Ca-Mg2Si three-phase isothermal at 490°C, it was shown that Ca7Mg6Si14 phase co-exists with Al, Mg2Si and Al4Ca in the largest region and with only Al and Mg2Si in Al4Ca-poor regions. It was thought that the Ca7Mg6Si14 ternary phase was formed by the interaction between Mg2Si and Al4Ca considering that the segregation can occur throughout the entire microstructures.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 4; 959-962
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure Formation of Al-5 mass%Mg Alloy Melts by Interaction with Silica
Autorzy:
Kim, Sun-Ki
Ha, Seong-Ho
Kim, Bong-Hwan
Yoon, Young-Ok
Lim, Hyun-Kyu
Kim, Shae K.
Kim, Yong-Jig
Powiązania:
https://bibliotekanauki.pl/articles/2049152.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Mg system
silica
reduction
Mg2Si
phase diagram
Opis:
Dissolution of Si in Al-5 mass%Mg alloy melt by the reduction of SiO2 and its effect on microstructure formation of the alloy after solidification were investigated. Al-5 mass%Mg alloy without silica powder had approximately 0.05 mass%Si as an impurity. No significant difference in Si content was observed after the reaction with silica for 10 min, while the Si content increased up to about 0.12 mass% after 30 min. From the microstructure analysis and calculation of Scheil-Gulliver cooling, it was considered that as-cast microstructures of Al-5 mass%Mg-1 mass% SiO2 alloys had the distribution of eutectic phase particles, which are comprised of β-Al3Mg2 and Mg2Si phases. Based on the phase diagrams, only limited amount of Mg can be selectively removed by silica depending on the ratio of Si and Mg. Addition of silica of more than approximately 1.5 mass% in Al-5 mass%Mg alloy led to the formation of spinel and removal of both mg and Al from the melt.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 4; 947-950
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Cu Addition on Oxide Growth of Al-7 mass%Mg Alloy at High Temperature
Autorzy:
Ha, Seong-Ho
Shah, Abdul Wahid
Kim, Bong-Hwan
Yoon, Young-Ok
Lim, Hyun-Kyu
Kim, Shae K.
Powiązania:
https://bibliotekanauki.pl/articles/2049221.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Mg system
Cu addition
oxidation
phase diagram
Opis:
Effect of Cu addition on oxide growth of Al-7 mass%Mg alloy at high temperature was investigated. As-cast microstructures of Al-7 mass%Mg and Al-7 mass%Mg-1 mass%Cu alloys showed α-Al dendrites and area of secondary particles. The 1 mass%Cu addition into Al-7 mass%Mg alloy formed Mg32(Al, Cu)49 ternary phase with β-Al3Mg2. The total fraction of two Mg-containing phases in Cu-added alloy was higher than the β-Al3Mg2 fraction in Cu-free alloy. From measured weight gains depending on time at 500°C under an air atmosphere, it was shown that all samples exhibited significant weight gains depending on time. Al-7mass%Mg1mass%Cu alloy showed the relatively increased oxidation rate when compared with Cu-free alloy. All the oxidized cross-sections throughout the entire oxidation time showed coarse and dark areas regarded as oxides grown from the surface to inside, but bigger oxidized areas were formed in the Al-7mass%Mg-1mass%Cu alloy containing higher fraction of Mg-based phases in the as-cast microstructure. As a result of compositional analysis on the oxide clusters, it was found that the oxide clusters contained Mg-based oxides formed through internal oxidation during a long time exposure to oxidizing environments.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 3; 699-702
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Si Addition on Oxide Growth of Al-6 mass%Mg Alloy Melts
Autorzy:
Yoon, Young-Ok
Ha, Seong-Ho
Shah, Abdul Wahid
Kim, Bong-Hwan
Lim, Hyun-Kyu
Kim, Shae K.
Powiązania:
https://bibliotekanauki.pl/articles/2049203.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Mg system
Si addition
oxidation
phase diagram
Opis:
Influence of Si addition on oxide layer growth of Al-6 mass%Mg alloys in molten state was investigated in this study. After melt holding for 24 h, the melt surface of only Si-free alloy became significantly bumpy, while no considerably oxidized surface was observed even with 1 mass%Si addition. There was no visible change on the appearance of melt surfaces with increasing Si content. As a result of compositional analysis on the melt samples between before and after melt holding, the Si-added alloys nearly maintained their Mg contents even after the melt holding for 24 h. On the other hand, the Mg content in the Si-free alloy showed a great reduction. The bumpy surface on Si-free alloy melt showed a large amount of pores and oxide clusters in its cross-section, while the Si-added alloy had no significantly grown oxide clusters on the surfaces. As a result of compositional analysis on the surfaces, the oxide clusters in Si-free alloy contained a great amount of Mg and oxygen. The oxide layer on the Si-added alloy was divided into Mg-rich and Mg-poor areas and contained certain amounts of Si. Such a mixed oxide layer containing Si would act as a protective layer during the melt holding for a long duration.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 3; 695-698
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary Study of Frequency-Variable Vibration Packing Fabrication for Atomized Metallic Particulate Fuel Using Surrogate Spherical Powder
Autorzy:
Kim, Ki-Hwan
Ha, Seong-Jun
Park, Sang-Gyu
Kuk, Seoung-Woo
Park, Jeong-Yong
Powiązania:
https://bibliotekanauki.pl/articles/2049120.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
atomized powder
injection casting
metallic particulate fuel
alternative fabrication method
vibration packing
Opis:
An alternative fabrication method for metallic fuel in Gen-IV reactor was introduced with vibration packing of nuclear fuel particles to facilitate remote fabrication in a hot cell and reduce the generation of long-lived radioactive wastes. Vibration packing experiments on metallic particulate fuel using a surrogate 316L stainless steel powder were done to investigate the packing density and the uniformity of the simulated fuel according to the filling method and the vibration condition. Metallic particulate fuel filled with a pre-mixed power over all particles had the highest packing fraction and the most uniform distribution among the filling methods. The vibration packing method showed that it could fabricate the metallic particulate fuel having uniform distribution of spherical fuel particles through the adjustment of the filling method of the metallic powder and the vibration condition of the metallic particulate fuel.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 4; 1043-1047
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication of U-10wt.%Zr-RE Fuel Slugs by Recycling of Metallic Fuel Scraps
Autorzy:
Kim, Ki-Hwan
Mun, Seung-Uk
Ha, Seong-Jun
Kuk, Seoung-Woo
Park, Jeong-Yong
Powiązania:
https://bibliotekanauki.pl/articles/354614.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuel slug
scrap recycling
mechanical cleaning treatment
fabrication yield rate
radioactive wastes
Opis:
U-10wt.%Zr-5wt.%RE fuel slugs for a sodium-cooled fast reactor (SFR) were conventionally prepared by a modified injection casting method, which had the drawback of a low fabrication yield rate of approximately 60% because of the formation of many metallic fuel scraps, such as melt residue and unsuitable fuel slug butts. Moreover, the metallic fuel scraps were classified as a radioactive waste and stored in temporary storage without recycling. It is necessary to develop a recycling process technology for scrap wastes in order to reduce the radioactive wastes of the fuel scraps and improve the fabrication yield of the fuel slugs. In this study, the additive recycling process of the metallic fuel scraps was introduced to re-fabricate the U-10wt.%Zr-5wt.%RE fuel slugs. The U-10wt.%Zr-5wt.%RE fuel scraps were cleaned on the surface impurity layers with a mechanical treatment that used an electric brush under an Ar atmosphere. The U-10wt.%Zr-5wt.%RE fuel slugs were soundly re-fabricated and examined to evaluate the feasibility of the additive process compared with the metallic fuel slugs that used pure metals.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 3; 1035-1039
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Recovery of Valuable Metals in Spent Lithium-Ion Batteries by Al2O3-SiO2-CaO-Fe2O3 Slag System
Autorzy:
Moon, Tae Boong
Han, Chulwoong
Hyun, Soong-Keun
Park, Sung Cheol
Son, Seong Ho
Lee, Man Seung
Kim, Yong Hwan
Powiązania:
https://bibliotekanauki.pl/articles/2049176.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spent lithium-ion battery
smelting
Al2O3-SiO2-CaO-Fe2O3
recovery
slag
Opis:
This study investigated the recovery behavior of valuable metals (Co, Ni, Cu and Mn) in spent lithium ion-batteries based on Al2O3-SiO2-CaO-Fe2O3 slag system via DC submerged arc smelting process. The valuable metals were recovered by 93.9% at the 1250°C for 30 min on the 20 Al2O3-40SiO2-20Cao-20Fe2O3 (mass%) slag system. From the analysis of the slag by Fourier-transform infrared spectroscopy, it was considered that Fe2O2 and Al2O3 acted as basic oxides to depolymerize SiO4 and AlO4 under the addition of critical 20 mass% Fe2O3 in 20 Al2O3-40SiO2-Cao-Fe2O3 (Cao + Fe2O3 = 40 mass%). in addition, it was observed that the addition of Fe2O3 ranging between 20 and 30 mass% lowers the melting point of the slag system.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 4; 983-986
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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