• Journal of the Korean Society for Heat Treatment
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• v.28 no.4
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• pp.181-189
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• 2015

Two types of advanced cold-work tool steels were characterized and compared. A higher-alloyed ledeburitic steel with primary carbides (denoted as 9Cr) and a lower-alloyed steel without primary carbides (5Cr) were fabricated by vacuum induction melting and subsequent hot forging. They were spheroidizing-annealed at $870^{\circ}C$, quenched at $1030^{\circ}C$ and tempered at 180 or $520^{\circ}C$. Their machinability after annealing and hardness, impact toughness, wear resistance after tempering were compared and interpreted in association with their characteristic microstructures. After annealing, 5Cr showed higher resistance to machining due to higher ductility and toughness in spite of lower strength and smaller carbide volume. Owing to smaller carbide volume fraction and the absence of coarse primary carbides, 5Cr showed even better impact toughness although the hardness was lower. The improved toughness of 5Cr resulted in excellent wear resistance, while smaller volume fraction of retained austenite also contributed to it.

• Journal of the Korean Home Economics Association
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• v.20 no.4
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• pp.143-153
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• 1982

The objectives of this study were as follows: 1) To describe the group of selected disabled homemakers in terms of demographic and medical variables related to organizational activities in the home and family participation in household activities. 2) To identify those demograhpic and medical variables that were related to organizational activities in the home and family participation in household activities. 3) To identify relationship between organizational activities in the home and family participation in household activities. Questionnaires were given to the selected disabled homemakers living in Seoul. The sample was small(N=35) and it was not random; therefore generalizations could not be made to the population as a whole. Data were analyzed by mean, Kruskal-Wallis one-way analysis of variance by ranks, and Spearman rank correlation coefficients. Homemaker's organizational activities were measured by 16 items about physical and mental activities from Mumaw's Organizational Activities Index. Family participation in household activities was measured by 8 items about how often family members participated in two areas of household activities: house chores and extra-activities. The results were as follows: 1) The homemaker's higher organizational activities scores were associated with younger homemaker, higher the level of education, small households, and higher the economic status. The homemaker without children performed better organizational household activities. The homemaker with shorter the duration of disability performed better organizational activities. The homemaker who needed crutches for mobility performed better organizational household activities. 2) The homemaker who was younger, higher the level of education, with smaller households, and lower the economic level was helped by husband. Husband helped better the homemaker with shorter the duration of disability in household activities. 3) Factors affecting children's participation in disabled homemaker's house chores and extra-activities were the age of homemaker and the marital status. The homemaker was single and older, the children were more helpful. 4) Task standardization score was the highest among the factors of homemaker's organizational activities and families with a disabled homemaker participated more extensively than families with abled homemaker. 5) Significant intercorrelation was found between the dependent variables.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.1
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• pp.71-82
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• 2022

Most of the predictions using machine learning are neutral predictions considering the symmetrical situation where the predicted value is not smaller or larger than the actual value. However, in some situations, asymmetric prediction such as over-prediction or under-prediction may be better than neutral prediction, and it can induce better judgment by providing various predictions to decision makers. A method called Asymmetric Twin Support Vector Regression (ATSVR) using TSVR(Twin Support Vector Regression), which has a fast calculation time, was proposed by controlling the asymmetry of the upper and lower widths of the ε-tube and the asymmetry of the penalty with two parameters. In addition, by applying the existing GSVQR and the proposed ATSVR, prediction using the prediction propensities of over-prediction, under-prediction, and neutral prediction was performed. When two parameters were used for both GSVQR and ATSVR, it was possible to predict according to the prediction propensity, and ATSVR was found to be more than twice as fast in terms of calculation time. On the other hand, in terms of accuracy, there was no significant difference between ATSVR and GSVQR, but it was found that GSVQR reflected the prediction propensity better than ATSVR when checking the figures. The accuracy of under-prediction or over-prediction was lower than that of neutral prediction. It seems that using both parameters rather than using one of the two parameters (p_1,p_2) increases the change in the prediction tendency. However, depending on the situation, it may be better to use only one of the two parameters.

• Korean journal of food and cookery science
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• v.13 no.1
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• pp.64-69
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• 1997

The experiments of rice bread processing were carried out to compare the varietal difference in processing adaptability to rice bread between brown and milled rice flour, and to analyze the interrelations among chemical properties of rice grain and some characteristics relevant to rice bread processing and quality There was varietal difference in adaptability to rice bread processing in both brown and milled rice, but there was not significant adaptability difference between brown and milled rice flours to rice bread processing. However, there was remarkable adaptability difference between brown and milled rice flours to rice bread processing in some rice varieties. Three high-amylose rices AC 27, IR 44, Suweonjo showed high quality of milled rice bread among tested rice materials. Brown rice revealed better adaptability to rice bread processing compared with milled rice in all varieties except the above three varieties. Especially, the glutinous rice Hangangchalbyeo failed to normal formation of rice bread from milled rice flour, but it showed the successful formation of rice bread from brown rice flour. The interrelations among chemical components of rice grain and some characteristics relevant to rice bread processing and quality exhibited quite different tendency between brown and milled rices. In the case of rice bread processing by brown rice flour, the larger volume expansion of dough during fermentation made the more springy rice bread and the more moist rice bread showed the more soft and cohesive physical property. In the case of rice bread processing by milled rice flour, the lower protein of rice flour was closely associated with the more moistness of rice bread and the higher lipid led to the more uniformal air pore distribution, the smaller pore size and the lower springiness of rice bread. Also, the larger volume expansion of dough during fermentation made the better loaf formation and the larger pore size of rice bread. The better loaf formation of rice bread revealed the softer hardness and the lower chewiness, and the lower springiness was closely correlated with the more uniformal size distribution of air pore and the smaller pore size in rice bread.

• Journal of Ocean Engineering and Technology
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• v.28 no.4
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• pp.338-344
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• 2014

The purpose of this study was to evaluate the dispersion degree of particles using a nanoindentation test for titanium oxide nanoparticles/epoxy resin nanocomposites. Thus, the effects of the particle size and weight fraction, dispersion agent, and position of the sample on the modulus and degree of particle dispersion in the nanocomposites were investigated. As a result, the dispersion degree of large particles was found to be better than that of smaller particles in composites. It could be found that the aggregation or agglomeration of small particles with large surface energy occurred more easily in nanocomposites because of the large specific surface area. The moduli of the upper side of the film-shaped sample obtained from a nanoindentation test were low scattering, while the values for the bottom side were high scattering. Thus, the dispersion situation of the nanoparticles on the upper side of film-shaped samples could be considered to be better than that for the bottom side. This could be concluded due to the non-uniform nanoparticle dispersion in the same sample. The modulus obtained from nanoindentation test increased slightly with the content of nanoparticles and increased with the indented depth for the same sample. The latter is presumably due to the increase in the accumulated particles facing the indenter with the indented depth. The nanoindentation test was found to be a useful method to evaluate the dispersion status of nanoparticles in nanocomposites.

• Journal of the Korean Home Economics Association
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• v.41 no.7
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• pp.185-200
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• 2003

The purpose of this study was to investigate the fitness using the draft method to develop moderate-stretch knit block pattern for young women in Korea. The subjects were three women within the range of the ages from 18 to 24 showing the average body figures. In this study, 4 different patterns were drafted for the moderate stretch knitted fabrics, that were categorised into two different types. The first type of these was made up for kilted fabrics and the other was initially drafted for woven fabrics and altered for knitted materials afterward. The major findings derived from this investigation were as follows; 1. According to each sensory evaluation for the appearance test on fitness, knit block patterns A and D were the better than the rest of them. 2. Knit block patterns A and D with higher evaluation scores were drafted with body size measurements except the waist line, whereas patterns B and C with relatively lower scores were produced including the smaller ease amounts than the woven block pattern. 3. To see the results of the functional test based on the designed ten motions for this experiment, knit block patterns A and B were concluded as better than the rest of them. In addition, concerning the arm liking motions, pattern B was scored as the best among the developed patterns.

• The Research Journal of the Costume Culture
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• v.17 no.1
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• pp.15-27
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• 2009

The purpose of this study was to find texture which suitable for the acryl knitted jacket of women in the middle age. The study was carried out 2 parts. The first part was to choose the pattern fitted in the body shape of women in the middle age, and the second part was wearing test with 3 different textured acryl knitted jacket(half milano, milano, jacquard). The usable data of the test were coded for further statistical analysis including descriptive statistics (frequency and one way-ANOVA test, Student-Newman-Keuls Multiple Range Test) by using SPSSWIN 12.0. The results were as follows: It was found that first evaluation for the appearance test on fitness, pattern B(Brand: Morado) were better than the rest of them(pattern A: Trieste, pattern C: Escalier). It was found that second evaluation for the test, jacket with jacquard were better than the rest of them. Acryl knitted Jacket of women in the middle age should made of jacquard. Therefore it should be designed as possible as considering the physical characteristics of knitted materials. It was found that third evaluation for the test, it was opposite results that a general knitted fabric pattern was made smaller than a woven jacket. So, it was necessary that the acryl knitted jacket of women in the middle age follow a similar site tolerance such as a woven jacket. This result was due to a radical change of a middle age women's body shape.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.69-77
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• 1996

To design high-effective profile in screw rotor profile using in screw compressor, we design the symmetric type changing the number of lobes and the non-symmetric type changing the neighbourhood of the top point of lobe. Then, we calculated the performance value of profile according to the scale of these non-symmetric's wrap angle. We had the results as follows. 1. About the non-symmetric case, the larger a wrap angle is the shorter seal line is and the smaller blow hole is, thus we know what the large wrap angle profile is better than the small one. 2. We know what the non-symmetric profile is better than the symmetric profile in the result of the compare of seal line's length, blow hole's area, volume curve. 3. About the non-symmetric case, the deformation of the neighbourhood of lobe's top point of the rotor profile has a large effect upon the increase of performance because the length of seal line became short and the area of blow hole is small.

• East Asian Economic Review
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• v.21 no.4
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• pp.343-384
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• 2017

We assess the outcomes for the negotiating parties in the Trans-Pacific Partnership if the remaining eleven parties go ahead with the agreement as negotiated without the United States, as compared to the outcomes under the original twelve-member agreement signed in October 2016. We find that the eleven-party agreement, now renamed as the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), is a much smaller deal than the twelve-party one, but that some parties do better without the United States in the deal, in particular those in the Western Hemisphere - Canada, Mexico, Chile, and Peru. For the politically relevant medium term, the United States stands to be less well-off outside the TPP than inside. Since provisional deals can be in place for a long time, the results of this study suggest that the eleven parties are better off to implement the CPTPP, leaving aside the controversial governance elements, the implications of which for national interests are unclear and which, in any event, may be substantially affected by parallel bilateral negotiations between individual CPTPP parties and the United States.

• Journal of Welding and Joining
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• v.22 no.4
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• pp.50-58
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• 2004

In this study, high temperature tensile properties of high strength steels(POSTEN60, POSTEN80) were investigated. The three-dimensional thermal elastic-plastic analyses were conducted to investigate the characteristics of welding residual stresses in welds of high strength steels on the basis of thermal and mechanical properites at high temperature obtained from the experiment. According to the results, high temperature tensile strength of POSTEN60 steel deteriorated slowly to 10$0^{\circ}C$. As the temperature went up, the tensile strength became better because of blue shortness, and it deteriorated radically after reaching to the maximum value around 30$0^{\circ}C$. For the POSTEN80 steel, high temperature tensile strength deteriorated slowly to 20$0^{\circ}C$. As the temperature went up the tensile strength became better and it deteriorated slowly to $600^{\circ}C$ after reached to the maximum value around 30$0^{\circ}C$. Strain of high strength steels at the elevated temperature increased radically after the mercury rose to $600^{\circ}C$. The strain hardening ratio of POSTEN60 steel was larger then that of POSTEN80 steel at the elevated temperature as in the case at the room temperature and it became smaller radically after the mercury rose to 40$0^{\circ}C$. And, in the welding of high strength steels, increasing tensile strength of the steel (POSTEN60