• Title/Summary/Keyword: AC System

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A Study on the Safety Estimation of Wiring Connection Connector Manufactured by Housing Type (하우징 형태(Housing Type)로 제작된 배선 연결 커넥터의 안전성 평가에 관한 연구)

  • Choi, Chung-Seog
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.4
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    • pp.462-466
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    • 2010
  • The purpose of this study is to evaluate the safety of a wire connector fabricated for the effective installation of a lighting fixture including its contact resistance, insulation resistance, withstanding voltage characteristics, etc., and to provide the basis for the analysis and judgment of PL(Product Liability) dispute by presenting a damage pattern due to a general flame and overcurrent. This study applied the Korean Standard (KS) for the incombustibility test of the connector using a general flame and performed an overcurrent characteristics test of the connector using PCITS (Primary Current Injection Test System). The contact resistance of the housing connector was measured using a high resistance meter and the insulation resistance was measured using a multimeter. In addition, a supply voltage of AC 1,500V for testing the withstanding voltage characteristics was applied to both ends of the connector. Measurement was performed on 5 specimens and the measured values were used as a basis for judgment. Since the connector is fabricated in the form of a housing, it can be connected and separated easily and has a structure that allows no foreign material to enter. In addition, since it has a structure that allows wires to be connected only when their polarity is identical, any misconnection that may occur during installation can be prevented. When the incombustibility test was performed by applying a general flame to the connector, it showed outstanding incombustibility characteristics and the blade and blade holder connected to the housing remained firmly secured even after the insulation sheath (PVC) was completely destroyed by fire. In addition, the mechanism of the damaged connecting wire showed a comparatively uniform carbonization pattern and it was found that some residual melted insulation material was attached to both ends. In the accelerated life test (ALT) to which approximately 500% of the rated current was applied, the connector damage proceeded in the order of white smoke generation, wire separation, spark occurrence and carbonization. That is, it could be seen that the connector damaged by overcurrent lost its own metallic color with traces of discoloration and carbonization. The contact resistance of the connector at a normal state was 2.164mV/A on average. The contact resistance measured after the high temperature test was 3.258mV/A. In addition, the insulation resistance after the temperature test was completed was greater than $10G\Omega$ and the withstanding voltage test result showed that no insulation breakdown occurred to all specimens showing stable withstanding voltage and insulation resistance characteristics.

A Small-Angle Neutron Scattering Study for Sizes and Structures of Micelles and Vesicles Formed in Aqueous Solutions of Mixed Surfactants ADS/OTAC (ADS/OTAC 혼합 계면활성제 수용액에서 형성된 마이셀과 층막구형체의 크기 및 구조에 대한 작은 각 중성자 산란 연구)

  • Kim, Hong-Un;Lee, Jin-Kyu;Lim, Kyung-Hee
    • Applied Chemistry for Engineering
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    • v.16 no.2
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    • pp.231-237
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    • 2005
  • The sizes and structure of micelles and vesicles formed in ammonium dodecyl sulfate (ADS)/octadecyl trimethyl ammonium chloride (OTAC) mixed aqueous solutions were analyzed by small-angle neutron scattering. In micellar regions of pure ADS and OTAC aqueous solution, the spherical micelles were formed at given concentrations and their sizes were 40 and $61{\AA}$, respectively. The structure transition of pure micelles occurred above 300 mM due to the constancy of the intermicellar distance above 250 mM. The coexisting region of mixed micelles and vesicles in phase diagram of mixed system was also assured. It was investigated that vesicle formed spontaneously took a bilayer structure. The lamellar thickness of vesicles decreased with increasing concentration of vesicle samples. However, the size could not be determined for mixed micelle and vesicle above 100 nm due to limitation of low q ranges. Finally, The 9 mM solution of ADS mole fraction 0.9 (${\alpha}$=0.9) showed bilayer structure compared to phase diagram classified into mixed micelle.

Adaptive Regulators for Quality Assurance in Resistance Welding (MFDC 저항용접의 적응제어 및 SPC 기능 고찰)

  • Lee, Yong-Ki
    • Proceedings of the KWS Conference
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    • 2009.11a
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    • pp.119-119
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    • 2009
  • 인버터 DC 저항용접의 적용성 증대 : 인버터 DC 저항용접 공법이 SPOT, PROJECTON, SEAM, BUTT 등의 공정에 다양하게 적용되어 저항용접 현장에서 고효율, 친환경적 용접 환경을 만드는데 일조 하고 있다. 특히 자동차의 경량화, 충돌내성 증대, 진동 및 내구성 증대, 공간활용 극대화, 새로운 Design 개념 적용 등의 산업전반에 걸쳐 나타나는 신 Trends로 고 장력 철재의 적용 범위가 확대되고 HSS(High Strength Steel), EHSS(Extra High Strength Steel), UHSS (Ultra High strength Steel ; Hot - Formed Steel )등 다양한 철판의 SPOT 저항용접이 필요하게 되었다. 기존의 AC 단상용접의 전력 특성 상 통전 중 무 통전 시간 과 높은 PEAK 전력, 단상 대 전력 소모로 인한 전력 DROP 등의 문제로 인하여 신소재의 용접 시 매우 많은 Spatter가 발생하고, 높은 용접품질의 확보가 어려워 지므로 이를 대체하기 위한 공법으로 MFDC ( 인버터 DC 저항용접공법 )이 적용되고 있다. 인버터 DC 저항용접의 적응제어 : MFDC라는 높은 효율의 용접 전력원이 확보 됨에도 불구하고 용접현장에서는 원 자재, 도금 등의 품질 산포, 프레스 물의 가공산포, 공기압 산포, 전극 과열 및 마모 등의 요인에 의하여 저항용접 산포가 발생하고 있다. 이는 인위적인 조작이 어렵고 불규칙적이며, 어디서나 산재하고 있는 문제이다. 이를 용접전력 제어 법으로 개선하여 일정한 용접성을 확보하기 위한 노력이 적응제어 기법이다. 정 전류, 정 전력 제어는 정량 제어로 용접 물을 비롯한 용접부의 변화와는 관계없이 설정된 일정량의 전력을 공급하기만 하는데 반하여 적응제어는 적절한 용접 작업 시의 용접 물의 상태, 전극의 가압, 표면 상태 등에 따른 변화 페턴을 기억하고 이후 진행되는 용접에 대하여 정상 페턴과의 차이를 감지 이를 보상하므로 고품질의 용접성을 보장하는 제어기법이다. 따라서 다양한 용접 산포 유발 요인에 의해 용접부의 변화가 발생한다 하여도 그 변화를 감지 하고 적절한 용접전력을 공급한다면 고품질의 용접성을 확보하는데 유용한 공법이 될 수 있다. 인버터 DC 저항용접의 SPC 관리 : SPOT 용접 시 획득할 수 있는 다양한 파라메터에 대하여 모니터링 하고 이 자료를 data 화 하여 품질 관리에 응용하게 되면 양산라인에서 반복적으로 발생되는 문제점을 확인 할 수 있고 이를 통계적 방법으로 추적 개선해 나간다면 용접 불량 감소 및 생산성 향상에 도움이 되며 작업자의 공정 능력 향상 및 기업의 기술축적에도 높은 기여를 할 수 있을 것이다. 용접 적응제어와 다양한 파라메터 모니터링이 한 system에서 이루어 질 때 높은 용접성 확보와 불량률 감소, 원가절감, 생산성 향상 등의 효과가 극대화 될 것이다.

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Enhancement of the Anti-inflammatory Activities of Aralia continentalis Kitagawa Extracts Fermented by Lactobacillus plantarum (추출용액에 따른 유산균 발효 땅두릅의 항염증 효과)

  • Woo, Young Min;Kim, Ok Ju;Jo, Eun Sol;Jo, Min Young;Ahn, Mee Young;Lee, Sang-Hyeon;Ha, Jong-Myung;Kim, Andre
    • Journal of Life Science
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    • v.28 no.12
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    • pp.1438-1447
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    • 2018
  • We investigated the anti-inflammatory activities of various organic solvent extracts with and without Lactobacillus plantarum fermentation of Aralia continentalis Kitagawa which has hypotensive effects in addition to excitatory effects on the central nervous system. It has been used to treat arthritis, colds, neuralgia, rheumatism, and itchy skin. Our extracts were tested for their anti-inflammatory potential on NO production and the expression of inflammatory factors in lipopolysaccharide-stimulated RAW264.7 macrophages. Extracts with and without L. plantarum fermentation were prepared using water, ethanol, hexane, ethyl acetate, and butanol. The RAW264.7 cells were tested for toxicity and the anti-inflammatory activity of each extract was determined at a concentration with no toxicity to the cells. The extracts used in this study significantly inhibited both the production of NO and the mRNA expression of COX-2 and iNOS, the major inflammatory factors. The production of inflammation-related cytokines $IL-1{\beta}$, IL-6, and $TNF-{\alpha}$ was also significantly reduced. These results suggest that the extracts involving fermentation by L. plantarum can inhibit cytokines by controlling the expression of inflammatory cytokine genes. It is considered that the water, ethanol, and butanol extracts after fermentation with L. plantarum could be useful as functional natural materials with anti-inflammatory effects.

A Study on the Design and Rectification Method of a KW class Power Converter Unit for an Aircraft Mounted Guided Missile (항공기 장착 유도탄의 KW급 전력변환장치 설계와 정류방식에 따른 연구)

  • Kim, Hyung-Jae;Jung, Jae-Won;Lee, Dong-Hyeon;Kim, Gil-Hoon;Moon, Mi-Youn
    • Journal of Advanced Navigation Technology
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    • v.26 no.2
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    • pp.99-104
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    • 2022
  • Recently, the domestic demand for weapon systems based on aircraft platforms is gradually increasing. In particular, the demand for effective precision guided missile(PGM) which cruises for several hundred kilometers after launch to strike the ground target is rising drastically, but it is in the early stages of development, and research based on it are limited. This paper is a study on the power converter unit(PCU) within PGM which is mounted on an aircraft platform based on MIL-STD-1760, which is an interface between an aircraft and PGM. We investigated the electrical properties and structure of the umbilical connector, and the aircraft/store electrical interconnection system. Also, the focus on the design specifications of the PCU that supplies power were described. This result 3 phase AC input, which is the state for the guided simulation power supply in the state of being mounted on an aircraft that rectification method with power factor correction(PFC) compared to bridge rectifier circuit. In the future, it may be used as a basis for power supply design on aircraft mounted weapon systems.

Cloning and Expression of Bacillus thuringiensis crylAa1 Type Gene. (Bacillus thuringiensis crylAa1 Type Gene의 클로닝과 발현)

  • 이형환;황성희;권혁한;안준호;김혜연;안성규;박수일
    • Microbiology and Biotechnology Letters
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    • v.32 no.2
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    • pp.110-116
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    • 2004
  • The over-expression in E. coli of the pHLN1-SO(+) and pHLN2-80(-) plasmids cloned an insecticidal crystal protein (ICP) gene (crylAal type) from Bacillus thuringiensis var. kurstaki HD 1 was investigated through in part, the deletion of -80 bp promoter and an alternative change of cloning vector system. Two recombinant plasmids were constructed in an attempt to analyze the over-expression of the ICP in relations to its gene structure possessing only -14 bp [Shine-Dalgarno (SD) sequence of -80 bp promoter]. Also, anther two recombinant plasmids similarly cloned the icp gene in a different vector system. The amounts of ICP produced from the recombinants were measured by SDS-PAGE and confirmed by Western blot analysis. One clone, pHLRBS1-14 clone in which only the SD sequence in the inverted orientation icp gene appeared, was more evident than the pHLRBS2-14 clone in which only the -14 bp SD sequence of the right orientated icp gene was shown to exist. The pHLN2-80(-) clone produced more ICP proteins than the pHLRBS1-14 clone. In the two clones, pHLNUC1-80 right-oriented icp gene and the pHLNUC2-80 clone inverted-orientation icp gene in a new different vector, the pHLNUC2-80 produced more ICP proteins in E. coli system. These results indicate that the P/ac promoter, the inverted icp gene insertion and -80 bp promoter (-66 bp part of the icp gene promoters), were concerned with the expression of the icp gene in the recombinant plasmids. In addition, the expression mechanism might result from the disruption of the transcription-suppressing regions in the promoter regions.

Effects of Dietary Fatty Acid Composition on Level of Oleic Acid (ω9) in Brain Subcellular Fractions of Rats (식이 지방산이 흰쥐 뇌조직 Subcellular Fractions내 Oleic Acid(ω9) 조성에 미치는 영향)

  • Chung, Eon-Jung;Um, Young-Soak;Lee, Yang-Cha
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.10
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    • pp.1626-1633
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    • 2004
  • In recent, the roles of oleic acid, most abundant fatty acid in myelin, were investigated in relation to the brain functions. This study examined the effects of diets either with desirable ratios of $\omega$6/ $\omega$9 and P/M/S (mixed oil-fed group: MO) or with defficient in $\omega$3 series fatty acids (safflower oil-fed group: SO) on the oleic acid composition in RBC and brain synaptosomal, mitochondrial & microsomal phospholipids. The desirable fatty acid composition was computer-searched with different fats and oils to meet right ratios of both $\omega$6/ $\omega$3 and P/M/S. Diets were fed 3 weeks before conception and new-born pups were fed maternal milk from the same mothers and same diets until 9 wks of age. At 3 wks of age, the compositions of oleic acid in brain subcellular fractions and red blood cells were constantly remained whatever the composition of dietary fatty acids. But at 9 wks of age, the composition of oleic acid in synaptosome and mitochondria were significantly higher in MO group than SO group. The composition of oleic acid in milk was significantly higher in MO group than SO group, but in case of SO group, that of oleic acid was increased by 48%, in comparison with dietary fatty acid compositions. -9 desaturase index (18:0\longrightarrow8:1) of brain synaptosome was significantly higher in MO group than SO group at 3 and 9 weeks of ages, but that of brain microsome was higher in SO group than MO group at 9 wks of age. Taken together, the presences of oleic acid in the diet was important to maintain brain functions. The origins of oleic acid in brain may suggests two hypotheses; first, the central nervous system has priority for the uptake of oleic acid, and second the nervous system can synthesize all the oleic acid it needs, independently of its presence in the diet.

Digital Humanities, and Applications of the "Successful Exam Passers List" (과거 합격자 시맨틱 데이터베이스를 활용한 디지털 인문학 연구)

  • LEE, JAE OK
    • (The)Study of the Eastern Classic
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    • no.70
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    • pp.303-345
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    • 2018
  • In this article, how the Bangmok(榜目) documents, which are essentially lists of successful passers for the civil competitive examination system of the $Chos{\breve{o}}n$ dynasty, when rendered into digitalized formats, could serve as source of information, which would not only lets us know the $Chos{\breve{o}}n$ individuals' social backgrounds and bloodlines but also enables us to understand the intricate nature that the Yangban network had, will be discussed. In digitalized humanity studies, the Bangmok materials, literally a list of leading elites of the $Chos{\breve{o}}n$ period, constitute a very interesting and important source of information. Based upon these materials, we can see how the society -as well as the Yangban community- was like. Currently, all data inside these Bangmok lists are rendered in XML(eXtensible Makrup Language) format and are being served through DBMS(Database Management System), so anyone who would want to examine the statistics could freely do so. Also, by connecting the data in these Bangmok materials with data from genealogy records, we could identify an individual's marital relationship, home town, and political affiliation, and therefore create a complex narrative that would be effective in describing that individual's life in particular. This is a graphic database, which shows-when Bangmok data is punched in-successful passers as individual nodes, and displays blood and marital relations in a very visible way. Clicking upon the nodes would provide you with access to all kinds of relationships formed among more than 90 thousand successful passers, and even the overall marital network, once the genealogical data is input. In Korea, since 2005 and through now, the task of digitalizing data from the Civil exam Bangmok(Mun-gwa Bangmok), Military exam Bangmok (Mu-gwa Bangmok), the "Sa-ma" Bangmok and "Jab-gwa" Bangmok materials, has been completed. They can be accessed through a website(http://people.aks.ac.kr/index.aks) which has information on numerous famous past Korean individuals. With this kind of source of information, we are now able to extract professional Jung-in figures from these lists. However, meaningful and practical studies using this data are yet to be announced. This article would like to remind everyone that this information should be used as a window through which we could see not only the lives of individuals, but also the society.

Intelligent Brand Positioning Visualization System Based on Web Search Traffic Information : Focusing on Tablet PC (웹검색 트래픽 정보를 활용한 지능형 브랜드 포지셔닝 시스템 : 태블릿 PC 사례를 중심으로)

  • Jun, Seung-Pyo;Park, Do-Hyung
    • Journal of Intelligence and Information Systems
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    • v.19 no.3
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    • pp.93-111
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    • 2013
  • As Internet and information technology (IT) continues to develop and evolve, the issue of big data has emerged at the foreground of scholarly and industrial attention. Big data is generally defined as data that exceed the range that can be collected, stored, managed and analyzed by existing conventional information systems and it also refers to the new technologies designed to effectively extract values from such data. With the widespread dissemination of IT systems, continual efforts have been made in various fields of industry such as R&D, manufacturing, and finance to collect and analyze immense quantities of data in order to extract meaningful information and to use this information to solve various problems. Since IT has converged with various industries in many aspects, digital data are now being generated at a remarkably accelerating rate while developments in state-of-the-art technology have led to continual enhancements in system performance. The types of big data that are currently receiving the most attention include information available within companies, such as information on consumer characteristics, information on purchase records, logistics information and log information indicating the usage of products and services by consumers, as well as information accumulated outside companies, such as information on the web search traffic of online users, social network information, and patent information. Among these various types of big data, web searches performed by online users constitute one of the most effective and important sources of information for marketing purposes because consumers search for information on the internet in order to make efficient and rational choices. Recently, Google has provided public access to its information on the web search traffic of online users through a service named Google Trends. Research that uses this web search traffic information to analyze the information search behavior of online users is now receiving much attention in academia and in fields of industry. Studies using web search traffic information can be broadly classified into two fields. The first field consists of empirical demonstrations that show how web search information can be used to forecast social phenomena, the purchasing power of consumers, the outcomes of political elections, etc. The other field focuses on using web search traffic information to observe consumer behavior, identifying the attributes of a product that consumers regard as important or tracking changes on consumers' expectations, for example, but relatively less research has been completed in this field. In particular, to the extent of our knowledge, hardly any studies related to brands have yet attempted to use web search traffic information to analyze the factors that influence consumers' purchasing activities. This study aims to demonstrate that consumers' web search traffic information can be used to derive the relations among brands and the relations between an individual brand and product attributes. When consumers input their search words on the web, they may use a single keyword for the search, but they also often input multiple keywords to seek related information (this is referred to as simultaneous searching). A consumer performs a simultaneous search either to simultaneously compare two product brands to obtain information on their similarities and differences, or to acquire more in-depth information about a specific attribute in a specific brand. Web search traffic information shows that the quantity of simultaneous searches using certain keywords increases when the relation is closer in the consumer's mind and it will be possible to derive the relations between each of the keywords by collecting this relational data and subjecting it to network analysis. Accordingly, this study proposes a method of analyzing how brands are positioned by consumers and what relationships exist between product attributes and an individual brand, using simultaneous search traffic information. It also presents case studies demonstrating the actual application of this method, with a focus on tablets, belonging to innovative product groups.

The costume culture of China is as old and varied as her long history (중국 소수민족의 복식 연구(1))

  • 박춘순
    • Journal of the Korean Society of Costume
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    • v.26
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    • pp.175-206
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    • 1995
  • The costume culture of China is as old and varied as her long history. As China is a multiracial nation and consists of fifty-six min-ority races including Han race, there are not only fifty-six different costumes in China but each races' costume habit is very different. Therefore, Chinese penninsula can be considered an enor-mous exhibition center of the costumes. This study undertook on the assumption that the costumes' mainstream of Korea and east-northern Asia as well as that of China could be examined by investigating the minority races' costumes in the east-and west-northern areas of China. The process of evolution of the costume of a particular people, country or area is subject not only to constraints related to geography such as climate, topography or local products but is also affected by numorous environmental influences including cultural, economic, social and even pol-itical ones in terms of the selection of material, styling, color and standard of tailoring. In other words, things like philosophy of life, religious be-lief, aesthetic outlook, moral code, class system, degree of affluence, and cultural exchange will all be reflected directly or indirectly by features of a people's or country's style costume. Of course, there are several factors affecting to the style of costume of the minority people in China. However, the only three factors-geo-graphical and environmental, production method, and religious belef-will be touched in this study. First of all, the geograghical and eenviron-mental factor would be the decisive one because the costume should be designed to overcome the constraints of climate and geographical environ-ments. Accordingly, each race has an unique style of costume. The costume of the minority races in the northern parts are loose and wide, and made of warm furs. For instance, Mongolian robe has the quality of anti-wind, anti-cold and warmness, and the width of a sleeve is narrow and long. Secondly, the costume style can be said to be limited by the production pattern, when the geo-graphical environment was affected to decide the costume style, the production pattern was together affected to it . In case of Mongolian robe, they should satisfy the dual condition as the practical function. One is the condition that they should be fitted to the climate, and the other is the condition that they should be suit-able to the nomadic life. Mongolian robes are suitable to the nomadic peoples because they are designed for not only overcoming the cold wind and weather but being used as the bedquit at night. The costumes of Hoche people was made of the skin of the fish and wild animals because of their main means of living being fishing and hunting. Accordingly, their costumes are dur-able, warm and water-proof. Finally, the style of the costume is affected by the religious belief. In other words, the pattern in fashion is closely related with the religious be-lief or ancestor worship and nature worship. Ac-cordingly, the symbols of these worship are often emerged in the decoration of the costume. The design of costume of the people in the northern areas of China is very simple. It is related with their monotheism. On the other hand, the costumes of twen쇼 minority races in the east-northern parts of China can be devided into three racial groups such as the long robes of Man people and Mongols, Tunics of the peoples in the west-northern areas, and the pants and jackets of Hoche people. The minorority races all has not only the unique costume habit but their costumes are also related with their living style and production means.

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