• 한국항공우주학회지
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• 제43권12호
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• pp.1035-1047
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• 2015

고고도 장기체공 축소형 전기 동력 무인기(EAV-2H+)용 프로펠러의 성능을 평가하기 위해 풍동시험과 전산해석을 수행하였다. 3종의 프로펠러에 대해 성능 곡선을 측정하고, 운용 조건을 평가하여 EAV-2H+에 적용 가능 여부를 판단하였다. 낮은 rpm 영역에서 성능 계수의 저하 경향을 확인하였다. 프로펠러 성능에 미치는 강체 천이 테이프 부착 효과를 측정하고 분석하였다. 상용 전산유체역학 코드를 사용한 성능 해석을 수행하여 시험과 해석의 추력계수-동력계수 선도가 잘 일치함을 확인하였다. 전진비에 따른 성능 계수를 비교하고 결과 차이에 기여하는 시험장치의 영향을 평가하였다. 시험에서 관찰된 낮은 rpm 영역의 성능 감소 경향을 transition SST 모델이 유사하게 모사함을 확인하였다. 낮은 레이놀즈수에 의한 깃 요소의 공력 성능 저하가 프로펠러 성능 감소의 주원인으로 분석되었다. 고고도 조건 해석으로부터 프로펠러 성능 저하를 확인하였다.

• Structural Engineering and Mechanics
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• 제77권1호
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• pp.137-149
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• 2021

In engineering design, the axial equivalent elastic modulus of laminated FRP pipe was mostly calculated by the average elastic modulus method or the classical laminated plate theory method, which are based on relatively simplified assumptions, and may be not accurate enough sometimes. A new analytical calculation method for the axial equivalent elastic modulus of laminated FRP pipe was established based on three-dimensional stress state. By comparing the results calculated by this method with those by the above two traditional analytical methods and the finite element method, it is found that this method for the axial equivalent elastic modulus fits well not only for thin-walled pipes with orthotropic layers, but also for thick-walled pipes with arbitrary layers. Besides, the influence of the layer stacking on the axial equivalent elastic modulus was studied with this method. It is found that a proper content of circumferential layer is beneficial for improving the axial equivalent elastic modulus of the laminated FRP pipe with oblique layers, and then can reduce its material quantity under the premise that its axial stiffness remains unchanged. Finally, the meso-mechanical mechanism of this effect was analyzed. The improving effect of circumferential layer on the axial equivalent elastic modulus of the laminated FRP pipe with oblique layers is mainly because that, the circumferential fibers can restrain the rigid body rotations of the oblique fibers, which tend to cause the significant deformations of the pipe wall units and the relatively low axial equivalent elastic modulus of the pipe.

• 한국기계가공학회지
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• 제19권8호
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• pp.56-63
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• 2020

The heat transfer phenomenon in the vicinity of the irradiated region of a focused laser beam of a DMT process greatly affects both the deposition characteristics of powders on a substrate and the properties of the deposited region. The goal of this paper is to investigate the heat transfer characteristics of a single bead deposition of Inconel 718 powders on S45C structural steel using a laser-aided direct metal tooling (DMT) process. The finite element analysis (FEA) model with a Gaussian volumetric heat flux is developed to simulate a three-dimensional transient heat transfer phenomenon. The cross-section of the bead for the FEA is estimated with an equivalent area method using experimental results. Through the comparison of the results of the experiments and those of the analysis, the effective beam radius of the bottom region of the volumetric heat flux and the efficiency of the heat flux model for different powers and travel speeds of the laser are predicted. From the results of the FEA, the influence of the power and the travel speed of the laser on the creation of a steady-state heat transfer region and the formation of the heat-affected zone (HAZ) in the substrate are investigated.

• 한국초전도ㆍ저온공학회논문지
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• 제16권2호
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• pp.42-46
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• 2014

In this study we investigated ac transport current losses in the face to face stack for the anti-parallel current flow, and compared the electromagnetic properties with those of the single SC tape as well as those of the same stack for the parallel current path. The gap between the SC tapes in the stack varied in order to verify the electromagnetic influence of the neighbors when current flows in opposite direction, and the model was implemented in the finite element method program by the commercial software, COMSOL Multiphysics 4.2a. Conclusively speaking, the loss was remarkably decreased for the anti-parallel current case, which is attributed the magnetic flux compensation between the SC layers due to the opposite direction of the current flows. As the gap between SC tapes was increased, the loss mitigation became less effective. Besides, the current density distribution is very flat cross the sample width for the narrower gap case, which is believed to be benefit for the power electric system. These results are all in good agreement with those predicted theoretically for an infinite bifilar stack.

• 가정과삶의질연구
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• 제2권1호
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• pp.131-150
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• 1984

The purpose of this study is to explore the family as an interaction system, concentrating on the mutual influences between communication and family development; (1) how Communication patterns affect family relationships, and (2) how relationships among family members affect communication. In order to do this Galvin, Brommel used the following frame work; family is a system in which communication regulates cohesion and adaptability by a flow of message patterns through a defined network of evolving interdependent relationships. A family system consists of members, the relationships among them, the family attributes, the members attributes and an environment in which family functions. Within the framework of common cultural communication patterns, each family has the capacity to develop its own communication code based on the experiences of individual members and the collective family experience. Most of us develop our communication skills within the family context learning both the general cultural language and the specific familial communication code. Communication may be viewed as a symbolic, transactional process as the process of creating and sharing meanings. To say that communication is a process implies a continuous interaction of an indefinite large numbers of variables with a concomitant,. continuous change in the values taken by these variables. Finally the process implies change, Family functions include the primary functions of cohesion and adaptability, and supporting functions of family images, themes, boundaries, and biosocial issues. The primary functions reveal concepts integrated family interaction and supporting function, along with those of cohesion and adaptability, give shape to family life. the characteristics of developed relationships of richness, uniqueness efficiency, substitutability, pacing , openness spontaneity, and evaluation are reflected in the verbal and nonverbal behaviors with which family members negotiated a set of common meanings and develop thier own unique message system. The message system is the major element of communication process and influences both the form and the content of thier relationship and in create and share meanings. Family systems need to provide order and predictability for thier members, specifically focusing on communication rules and the networks by which messages are transmitted. Most rules emerge as a result of multiful interactions. There are basic rules and rules about rules, or metarules. Perceiving the rules of family system is very difficult because often family members don't think about the basic rules, much less the metarules. Breaking the rule may result in the creation of a new set because the system may recalibrate itself to accept more variety of behavior. Families develop communication networks to deal with the general issue. Family adaptability may be seen through the degree of flexibility in forming and reforming networks and networks become a vital part of the decision- making process and relate to the power dynamics operating within the family. Networks also play an integral part in maintaining the roles and rules operating with the family system. Thus networks and rules have mutual influence. The family -of -origin issues influence all aspects of family communication and account for many of the communication patterns, rules and networks and the role of the family -of-origin influences as a primary force for communication on behavior of newly forming systems. Each family system develops its own communication meanings. There is not one right way to communicate within a family but may be indefinitly large change of family life and communication behavior. Study on functional family communication helps to gain a better understanding of dynamics of family communication and ability of a new insight into the family.

• 한국건설관리학회논문집
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• 제16권2호
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• pp.12-20
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• 2015

공공프로젝트 발주자들에게 VE의 중요성이 점증되고 있다. 본 연구에서는 VE 공공발주체계의 과학화, 시스템화를 통하여 공공발주자의 의사결정을 객관화시키고 발주체계 관련자들의 상호신뢰 회복을 위한 의사결정 지원체계의 구축을 위하여, 공공발주자에게 미치는 VE 프로젝트 발주체계의 영향력 분석에 대한 DB를 구축하는데 그 목적이 있다. 이에 국내의 VE 수행현황 분석을 통하여 수행체계의 문제점을 고찰하고, 도출된 문제점의 개선을 위하여 건설VE 수행사례를 통한 프로젝트 발주 시 고려하여야 할 VE 영향요소를 추출하여 설문결과에 대한 회귀분석 및 요인분석을 통하여 전체의 60%이상의 영향력을 가지는 15개의 영향요소를 도출한다. 도출된 영향요소에 대한 AHP분석을 통하여 프로젝트 생애주기 동안의 각 단계에 미치는 영향력을 분석하여 제시하였다.

• 한국산학기술학회논문지
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• 제20권7호
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• pp.467-473
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• 2019

본 연구의 목적은 중학교 교사의 분산적 리더십이 교사효능감과 교직헌신도에 어느 정도 영향을 미치는지 알아보고, 전체적인 영향력의 크기를 알아보는데 있다. 이를 위해 J지역 중학교 교사 460명을 대상으로 빈도와 백분율을 산출하였으며, t/F 검증을 하고, 일원변량분석과 Duncan 사후검증을 실시하였다. 또한 상관의 정도를 알아보기 위해 Pearson의 적률상관분석과 회귀분석을 실시하였다. 첫째, 분산적 리더십에 대한 중학교 교사들의 배경변인에 따라 인식 수준은 여교사, 평교사, 21년 이상 교사, 사립학교 교사가 높은 것으로 나타났다. 둘째, 분산적 리더십과 교사효능감 및 교직헌신도 간에 상관관계는 통계적으로 정적인 상관관계가 있는 것으로 나타났는데, 교사효능감이 교직헌신도보다 높은 정적인 상관을 보였다. 셋째, 분산적 리더십이 교사효능감 및 교직헌신도 전체의 영향력은 통계적으로 유의미하게 나타났다(41%). 결론은 분산적 리더십의 하위요소가 교사효능감과 교직헌신도와의 하위요소에 유의미한 정적인 상관관계가 있다. 분산적 리더십의 하위요소가 교사효능감의 자기조절효능감과 자신감 요소, 교직헌신도의 교육애 요소를 긍정적으로 설명하고 있다. 분산적 리더십의 하위요소가 교사효능감과 교직헌신도에 미치는 설명력은 학교상황이 27%, 학교장의 리더십이 28%, 교사의 리더십이 28%, 교사의 상호작용이 28%로 나타났다. 추후 교사들의 능력을 학교에서 다양하게 수행할 수 있는 교육환경개선을 위한 교육정책수립이 필요하다.

• 복식
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• 제24권
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• pp.15-28
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• 1995

This thesis focuses on the study of costume and ornaments of Shilla which had been severely affected by Uighur, and those of Uighur in Uighur self-governing district located in Shin Kang. East Turkestan, in Centrals Asia. This study aims to identifty the way of intergration of Uighur's costume and ornaments into Shilla, and orgins of Shill's costume and ornaments which had amix of internationl elelemnts thoursh cross exchanges, by comparing the differences between the two, and at the same time to clarify the pedigree of Korean costume and ornaments which are said to be udner a severe Chinese influence, by highlingting its uniqueness and originality . The result of the study demonstrates and originality of SHilla by melting foreign cultures into its own style in the process of accepting them. This means that the Shilla has recreated them in t도 form of simplification, and added naturalistic abstratness which is an element of Norther culture. The costume and ornaments are divided into coronets men's costuem, women's costume, and accessories 1. Coroncts A horse-riding man, and the costume type of 유고제 착유지체형 tell the Northern culture's influence on 백화수피기마인물채화담립 and patterns of a lotus flowr and arabesque show the 백화수피기마인물채색답립 has an influence of Buddhism with cluture of bordering countries of Western China , The origin of 뱍회수피제안형건(원정형, 방정형) lies in Northern cultures which can be found in ancient tombs of the Huns in noin-Ila , and stone caves of Jizil in Kochang. The wall paintings in Alexandropol, Murutuk and 돈황 No. 409 cave show that 초화형입식계금관 is under the influence of Northern culture, and Bezerkrick No, 25 cave and 회 번 in Kocho also show 수목녹각형입식관 is under the influence of Northern culture, with its origin in Novecherkaask. In this regard, the transformed coroncts of Shilla has shows a blended culture of Shilla with Nothern, Chinese, and Western cultures. 2. Men's Costume 반령포 derives from cultures of bordering countries of Western China centering around Uighur and Turkey. 연주문 in Uighur prince's costume and in Uighur paintings of Central Asia were reflected into the arts of Shilla in a direct way, and the motive of Uighur was deviatelly expressed at Shilla's arts in the form of simplicity , and naturalistic abstract paintings as in shown at 입수쌍조문 in tiles and brick. Along with this , 고착지체형 costume originates from Eurasia's Northern horseriding costumes as was shown in a golden man in B.C.4-5C which is now possessed by Kazakstan Republic Academy Archelogy Center Museum, and a golden figure from Skitai ancient caves, an the origin is carried away into wall paintings of Kizil No.14. cave in 8c and Astana's early period ancient tomb. No.6. 3. Women's Costume The hair styles of Shilla people are either 변발 or up -style with a lot of hair around it whose origin can be seen in Astana No.216 and No.187 caves of Kochang and Uighur's wall paintings of royal princess's hair style. Astana's middle period No. 206 and No.230 tombs reveal the its origin of 고착장군 while Astana early period No. 6 tomb shows that of 광유풍만형. 4. Accessories The earrings with small golden beads is seen at earring of figure holding a sword in wall painting of figure holding a sword in wall painting of Kizil in about 5 C. and those of a offering people in Sorchuk wall paintings. The earrings with small golden beads originates from a golden pendant of Shivargan, Afganistan, and golden pendants and other golden and metal accessories from Chrioba ancient tombs in Skiti Critia peninsula. Shilla's costume derives from the costume style of horse-ridding man, which proves the fact that Shilla people are horse-ridding peoplewith excellent horse-ridding techniques, and traditions. The people of Shilla are from horse-ridding people of local mounted momads in Northern part of Siberia steppe and this origin of Northern culture had been carried into Uighur in East Turkestan. At the same time , Shilla has a wealth and power since it was rich in gold and iron , thus producing lots of materials made of them. The results of this study emphasizes Shilla's identity and self-control by creating an independent an innovative heterogeneous culture since Shill's active exchanges with East Asia allowed it to accept the most civilized Uighur culture in East Turkestan among Altai languate which had frequent cross contacts with India and Europe.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.197-197
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• 2016

Commercially pure titanium (CP Ti) and Ti-6Al-4V alloys have been widely used for biomedical applications. However, the use of the Ti-6Al-4V alloy in biomaterial is then a subject of controversy because aluminum ions and vanadium oxide have potential detrimental influence on the human body due to vanadium and aluminum. Hence, recent works showed that the synthesis of new Ti-based alloys for implant application involves more biocompatible metallic alloying element, such as, Nb, Hf, Zr and Mo. In particular, Nb and Hf are one of the most effective Ti ${\beta}-stabilizer$ and reducing the elastic modulus. Plasma electrolyte oxidation (PEO) is known as excellent method in the biocompatibility of biomaterial due to quickly coating time and controlled coating condition. The anodized oxide layer and diameter modulation of Ti alloys can be obtained function of improvement of cell adhesion. Manganese(Mn) plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. Radio frequency(RF) magnetron sputtering in the various PVD methods has high deposition rates, high-purity films, extremely high adhesion of films, and excellent uniform layers for depositing a wide range of materials, including metals, alloys and ceramics like a hydroxyapatite. The aim of this study is to research the Mn coatings on the micro-pore formed Ti-29Nb-xHf alloys by RF-magnetron sputtering for dental applications. Ti-29Nb-xHf (x= 0, 3, 7 and 15wt%, mass fraction) alloys were prepared Ti-29Nb-xHf alloys of containing Hf up from 0 wt% to 15 wt% were melted by using a vacuum furnace. Ti-29Nb-xHf alloys were homogenized for 2 hr at $1050^{\circ}C$. Each alloy was anodized in solution containing typically 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at room temperature. A direct current power source was used for the process of anodization. Anodized alloys was prepared using 270V~300V anodization voltage at room. Mn coatings was produced by RF-magnetron sputtering system. RF power of 100W was applied to the target for 1h at room temperature. The microstructure, phase and composition of Mn coated oxide surface of Ti-29Nb-xHf alloys were examined by FE-SEM, EDS, and XRD.

• 한국유통학회지:유통연구
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• 제13권2호
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• pp.1-27
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• 2008

프랜차이즈업체와 같은 비대칭적인 의존구조 하에서 의존성이 높은 경로구성원은 전적으로 거래 상대방의 행위에 의존할 수 밖에 없으며, 따라서 상호 Win-Win 체제 구축을 위해서는 파트너간 신뢰와 결속을 증가시켜 관계의 질을 향상시킴으로써 거래구성원간 장기적인 협력 관계를 지속시켜야 한다. 프랜차이즈에서 본사와 가맹점간의 관계의 질을 높이기 위해서는 우선 힘의 우위가 큰 본사의 공정성에 대한 가맹점의 지각을 높일 필요가 있다. 본 연구는 이러한 취지에서 기본 가설모형과 비교가설모형을 설정하여 힘의 불균형을 특징으로 하는 프랜차이즈 본부와 프랜차이즈 가맹점간 계약관계에서 가맹점이 바라는 본부의 행동이 가맹점의 태도와 행동에 미치는 영향을 알아보았다. 이러한 연구배경 하에 연구 대상인 외식업 프랜차이즈업체의 가맹점 점장을 대상으로 설문조사를 실시하였으며, 주요한 연구결과는 다음과 같다. 첫째, 프랜차이즈 본사와 가맹점간의 관계규범 차원 중에서 단결규범과 상호성이 분배공정성과 절차공정성에 긍정적 영향을 미치는 반면, 유연성은 부정적 영향을 미치는 것을 알 수 있었고, 둘째는 분배공정성은 계산적 결속과 경제적 결속에 모두 긍정적인 영향을 미치는 반면 절차공정성은 사회적 결속에는 유의한 영향을 미쳤지만 경제적 결속에는 유의한 영향을 미치지 못하여 관계 결속에 있어서 분배공정성이 더욱 중요한 요소임을 알 수 있었다. 하지만 절차공정성은 분배공정성 혹은 사회적 결속을 통하여 경제적 결속에 간접적인 효과를 나타내었다.