• 설비공학논문집
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• 제10권3호
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• pp.343-347
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• 1998

The objective of this study is to manufacture the low temperature waterless container that is compact and low cost for a live fish transportation. Using the low temperature water container, it makes observations on the optimal conditions such as the amount of dissolved oxygen, total ammonia and nitrite in seawater for determining the survival rate of live fish in short and long-term transportation. Using a sole as a live fish, the temperatures of $0^{\circ}C$, 3$^{\circ}C$, 5$^{\circ}C$, 7$^{\circ}C$, 15$^{\circ}C$ were controled for there effects. The results of this investigation show that as the seawater temperature increased, the amount of oxygen decreased and there was a low temperature shock below 3$^{\circ}C$. It was observed that the fish was died with 30$m\ell/\ell$of ammonia. The optimal temperature is about 5$^{\circ}C$ for live fish transportation to maintain best survival rate.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.405-409
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• 2008

In this paper, factors affecting accuracy or grade of forged bevel gears are investigated in the experimental way. Two materials of SKD-11 and copper. two machining conditions and two machines of WIA-V50 and Roders-RFM600 are particularly investigated to reveal their effects on the grade of bevel gear forging dies in this study. It has been shown that the bevel gear grades are much affected by all the factors tested, revealing that it is of great significance to find the optimal machining process of die making to develop or manufacture a high precision bevel gear and that the bevel gear is degraded by one from the grade of its related die during forging.

• 한국기계가공학회지
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• 제3권2호
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• pp.3-9
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• 2004

The main objectives of this paper are to determine optimum cutting conditions using experimental design method to manufacture pedicle screws. Generally, titanium alloys are known as difficult-to cut materials. In the machining of titanium alloy, high cutting temperature and strong chemical affinity between the tool and the work material are generated because of Its low thermal conductivity and chemical reactivity. Such phenomenon cause increase of tool wear and deterioration of surface quality. Thus, in this paper, required experimental investigations are performed to evaluate the machinability of titanium materials With tungsten carbide tools Required simulation and experiments are performed, and the results are investigated.

• 한국공작기계학회논문집
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• 제11권1호
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• pp.32-37
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• 2002

The use of hexagonal ceramic inserts for copper extrusion dies offers significant technical and economic advantages over other forms of manufacture. In this paper the data on the loading of the tools is determined from a commercial FEM package as the contact stress distribution on the die-workpiece interface and as temperature distributions in the die. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the design and a data exchange program has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process. The stress analysis of the dies is used to determine the stress conditions on the ceramic insert by considering contact and interference effects under both mechanical and thermal loads.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.72-77
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• 2001

The use of hexagonal ceramic inserts for copper extrusion dies offers significant technical and economic advantages over other forms of manufacture. In this paper the data on the loading of the tools is determined from a commercial FEM package as the contact stress distribution on the die-workpiece interface and as temperature distributions in the die. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the design, and a data exchange program has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process. The stress analysis of the dies is used to determine the stress conditions on the ceramic insert by considering contact and interference effects under both mechanical and thermal loads.

• 한국생산제조학회지
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• 제20권1호
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• pp.60-66
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• 2011

In this paper, the computer simulation analyzed the effective plastic strain and temperature behaviors. The quantitative analyses which proposed the effective mold design of S/CAM shaft was executed. The parameters of forging shape that affected on the optimize conditions that was calculated with simple equation were investigated. it is expected that the developed analysis model and design technique would greatly contribute to the drum brake optimal design considering effective plastic strain and temperature affected behaviors. This development could save more than 20% of production cost and reduced failure rate to more than 30%. By improving the life span of mold from 15,000 to 25,000, financial difficulty of company imposed on a mold manufacture could be overcome.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 춘계학술대회논문집
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• pp.159-164
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• 1997

The optimal conditions were investigated in order to manufacture the light automotive body parts using the semi-solid forging process by the finite element nalysis. Considering about macro-segregation cause to difference of relative velocity between solid phase and liquid phase, solidificational phenomenon cause to heat transfer from die and export of the latent heat, so solid fraction updating algorithm can be proposed. The rigid thermo-viscoplastic finite element analysis was carried out according to die temperature with proposed algorithm, so availability of forming part were understood. The finite element program can be used to the analysis of semi solid forging process.

• Progress in Superconductivity
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• 제7권1호
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• pp.83-86
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• 2005

The High-Tc superconducting power cable consists of a multi-layer high-Tc superconducting cable core and a stabilizer which is used to bypass the current at fault time. Eddy current loss is generated in the stabilizer in normal operating condition and affects the whole system. In this paper, the eddy current losses are analyzed with respect to various structure of stabilizer by using opera-3d. Moreover, optimal conditions of the stabilizer are derived to minimize the eddy current losses from the analyzed results. The obtained results could be applied to the design and manufacture of the high-Tc superconducting power cable system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.345-347
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• 1995

ZnO varistor with composition of ZnO(90wt%)-$Bi_2O_3$(3wt%)-$Sb_2O_3$(3.61wt%)-$CO_2O_3$(1.16wt%)-NiO (0.88wt%)-$MnO_2$(0.71wt%)-$Cr_2O_3$(0.93wt%) according to $Al_2O_3$ addtive was fabricated by sintering methods. The optimal densification were established for the processing conditions of 8000 rpm 190$^{\circ}C$ spray drying and 1200$^{\circ}C$ 2hrs sintering. Then here investigated how additive compotions and processing variables affected the electrical and the phesical properties of these ZnO varistors.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.258-263
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• 2000

Under the optimal cutting conditions, determined the machinability difference of cutting tools are by two major factors. One is the geometric shape of the cutting tool, and the other is the tool materials or heat treatment or coating of the cutting tool. In this research, we evaluated the machinability of cutting tools with conventional HSS and P/M(powder metallurgy) which was made from the different of materials and manufacture processes. Tool wear, surface roughness, cutting force and squareness of machined workpiece were evaluated.