• Journal of the Korean Society for Heat Treatment
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• v.24 no.5
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• pp.271-276
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• 2011

The effect of grain size on the deformation induced martensite transformation and mechanical properties in austenitic stainless steel with high amount of Mn was studied. a'-martensite was formed by deformation and deformation induced martensite was formed with surface relief. With increase of grain size, volume fraction of deformation induced martensite was increased. With the increase in degree of cold rolling, hardness, and tensile strength was rapidly increased with linear relationship, while, elongation was decreased rapidly and then decreased slowly. With increase of grain size, hardness and tensile strength was rapidly increased with linear relationship, while elongation was decreased rapidly. The hardness, tensile strengths, and elongation were more strongly influenced by deformation induced martensite than the grain size.

• Journal of Power System Engineering
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• v.11 no.1
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• pp.115-120
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• 2007

The effect of grain size on the damping capacity of Fe-26Mn-2Al alloy studied in this paper has been investigated after changing the microstructure by cold rolling and changing grain size. Micro structures in Fe-26Mn-2Al at room temperature consist of a large quantity of austenite and a small quantity of ${\varepsilon}\;and\;{\alpha}'$ martensite. And ${\varepsilon}\;and\;{\alpha}'$ martensite was increased by increasing the degree of cold rolling. The content of deformation induced martensite was increased with increasing the degree of cold rolling. Damping capacity was linearly increased with increasing ${\varepsilon}$ martensite content, which suggests that stacking faults and ${\varepsilon}$ martensite variant boundaries are the principle damping sources. With increasing the grain size in Fe-26Mn-2Al alloy, the damping capacity was increased due to increasing the volume fraction of ${\varepsilon}$ martensite by decrement in stability of austenite phase. With decreasing the grain size, the content of deformation induced martensite was decreased and the damping capacity was decreased.

• Journal of the Korean Ceramic Society
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• v.50 no.1
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• pp.70-74
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• 2013

Dependence of microwave dielectric properties on the crystallization behaviors of $CaMgSi_2O_6$ (diopside) glass-ceramics was investigated with different heat treatment methods (one and/or two-step). The crystallization behaviors of the specimens, crystallite size and degree of crystallization, were evaluated by differential thermal analysis (DTA), scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis by combined Rietveld and reference intensity ratio (RIR) methods. With an increase in heattreatment temperature, the dielectric constant (K) and the quality factor (Qf) increased due to the increase of the crystallite size and degree of crystallization. The specimens heat-treated by the two-step method had a higher degree of crystallization than the specimens heat-treated by the one-step method, which induced improvement in the quality factor (Qf) of the specimens.

• Journal of Families and Better Life
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• v.11 no.1
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• pp.35-45
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• 1993

The purpose of this study is to investigate the changes of housing characteristics and the degree of attainment of housing norms. The major findings are as follows: 1) There are significant differences in changes of housing characteristics. A size of house and the number of room have been improved according to hosing experience and housing expects. Type of tenure has been improved according to housing experience and housing expects. Type of tenure has been improved gradually according to moving. The family with higher socio-economic status prefers apartments. Although about a half of household hopes to live in a high-rising apartments. more than 40 persentage of the household still hopes to live in single detached houses. As a result apartment are though not to satisfy their housing well-being 2) As socio-economic status is higher and family life cycle is longer the degree of their attainment of housing norms appear higher. The household attaining higher housing norms has the higher housing satisfaction but needs to move is lower The family attains housing norms as the following orders: type of tenure\longrightarrowtype of house\longrightarrowthe nmber of rooms\longrightarrowa size of house.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.8
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• pp.1186-1195
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• 2002

The purpose of this study was to study the body cathexis according to the age and the degree of obesity of elderly women. The subjects were 342 elderly women aged 60 to 92. Body measurement and survey were taken from July to August 2001. The results are follows; 1) The subjects showed a tendency to be satisfied with their bodies. But they were relatively unsatisfied with the girth of torso parts. 2) The body cathexis was more influenced by the perceived body size than the actual body size. 3) There were significant differences among the age groups in the body cathexis. The 60∼69 age group was more dissatisfied with their bodies than the other age groups. 4) There were significant differences among groups according to Rohrer Index in the body cathexis. The normal group was more satisfied with their bodies than the lean and the obese groups.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.7
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• pp.62-69
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• 1992

The conventional BMA is performed with the fixed block size. For better performance at low bitrate, the block size is required to be large in relatively stationary area, while small in moving area. Thus, in this paper, a video coding technique using variable block size model is proposed. It decides the block size based on the degree of local motion defined by the local mean and variance of blocks. Computer simulation shows that the proposed method gives comparable performance to the conventional one with less bits required for motion vector coding.

• The Journal of Engineering Geology
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• v.24 no.2
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• pp.179-189
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• 2014

We analyzed the three-dimensional distribution of micropores and internal structures in both fresh and weathered granite using micro-focus X-ray computed tomography (micro-CT). Results show that the pore radius in fresh granite is mostly in the range of $17-50{\mu}m$, the throat radius is in the range of $5-25{\mu}m$, and the coordination number (CN) of pores is less than 10. In contrast, the pore radius in weathered granite is mostly in the range of $20-80{\mu}m$, the throat radius is in the range of $8-30{\mu}m$, and the CN is less than 12. In general, a positive linear relationship exists between pore radius and CN. In addition, both the size and the density of pores increase with an increasing degree of rock weathering. The size of the throats that connect the pores also increases with an increasing degree of weathering, which induces fracture propagation in rocks. Micro-CT is a powerful and versatile approach for investigating the three-dimensional distributions of pores and fracture structures in rocks, and for quantitatively assessing the degree of pore connectivity.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.2
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• pp.231-243
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• 2012

This study examines the characteristics of fat body type males aged 35 to 55 with a BMI rate higher than 25 categorized as mid-degree obesity and high-degree obesity according to the $6^{th}$ Size Korea; in addition, the study provides a sizing system for obese males. The physical characteristics of the obese male appeared to be with a shorter lower body compared to an upper body for a higher degree of obesity. Obesity appeared evenly from chest to thigh circumference compared to a normal group. Especially, their waist measurement, depth, and width were significantly larger as well as the crotch length (natural indentation) and a larger waist measurement. As for the cloth sizing system, this study suggests the sizes with higher distribution among the designated size intervals of casual tops, men's suit tops and bottoms based on standard stature, chest size and waist circumference (Omphalion) by KS.

• Journal of Korean Society of Transportation
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• v.14 no.2
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• pp.157-172
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• 1996

The long-existed licence system which has acted as one of the strong barriers to entry in the ocean shipping market in Korea is supposed to repeal in the near future. As a result, competition among the different sizes of firms which are operating under regional shield by means of the licence will be intensified. The main objective of this paper is to estimate the degree of economies of scale and economies of density for various firm sizes. For the successful estimation of economies scale and economies of density, translog cost models are developed and estimated through SURE technique which was suggested by Zeller (1963). The major findings are as follows ; All shipping firms in the sample exhibit economies of scale and density. Even small size shipping firms under licence system, they show substantial economies of scale contrary to the wide-known idea that small-size firms are subject to diseconomies of scale. For the ranked firm sizes according to owned deadweight tons, the degree of economies of scale decreases as the firm sizes are larger and larger. The degree of economies of density moderately declines from the smallest to the firm size of 30-60 thousand deadweight tons and sharply rise thereafter. And the large shipping firms with over half-million deadweight tons exhibit high economies density compared to other sizes of firm. If follows that the larger firms have great advantage in competition if the licence system is abolished.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.95-98
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• 2006

This study investigates spalling properties of high performance concrete, 60MPa clan, made with the various types of coarse aggregate and adding ratio of polypropylene(PP) fiber. As experimental parameters, totally sixteen specimens of ${\phi}100{\times}200mm$ in size are prepared: one specimen for control without fiber, ten specimens with different coarse aggregate types, along with 0.05, 0.1, 0.15 percent of PP fiber in each. 1 hour fire test is conducted and then spalling appearance, spalling degree and residual compressive strength are examined. In addition, sit specimens made with two types of coarse aggregate site, along with same adding ratio of fiber are supplementally done, and only spalling properties is examined. Test results showed that control concrete and most specimens containing 0.05% of PP fiber exhibited 4 to 3 level of spalling degree, resulting severe explosive spalling, except for the specimen using basalt aggregate(Bc) showing 2 to 3 level of that. Especially, the Bc specimen containing 0.1% of the fiber exhibited that residual compressive strength value was 32%, which is 10% higher than other specimens using limestone or granite. Spalling resistance performance was also effective as aggregate size increase.