• Advances in materials Research
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• 제8권1호
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• pp.47-73
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• 2019

Joining of Mg/Ti hybrid structures by welding for automotive and aerospace applications has attracted great attention in recent years due mainly to its potential benefit of energy saving and emission reduction. However, joining them has been hampered with many difficulties due to their physical and metallurgical incompatibilities. Different joining processes have been employed to join Mg/Ti, and in most cases in order to get a metallurgical bonding between them was the use of an intermediate element at the interface or mutual diffusion of alloying elements from the base materials. The formation of a reaction product (in the form of solid solution or intermetallic compound) along the interface between the Mg and Ti is responsible for formation of a metallurgical bond. However, the interfacial bonding achieved and the joints performance depend significantly on the newly formed reaction product(s). Thus, a thorough understanding of the interaction between the selected intermediate elements with the base metals along with the influence of the associated welding parameters are essential. This review is timely as it presents on the current paradigm and progress in welding and joining of Mg/Ti alloys. The factors governing the welding of several important techniques are deliberated along with their joining mechanisms. Some opportunities to improve the welding of Mg/Ti for different welding techniques are also identified.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제26권4호
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• pp.185-223
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• 2022

The classical equation of Jonathan Homer Lane and Robert Emden, a nonlinear second-order ordinary differential equation, models the isothermal spherical clouded gases under the influence of the mutual attractive interaction between the gases' molecules. In this paper, the Adomian decomposition method (ADM) is presented to obtain highly accurate and reliable analytical solutions of a class of generalised Lane-Emden equations with strong nonlinearities. The nonlinear term f(y(x)) of the proposed problem is given by the integer powers of a continuous real-valued function h(y(x)), that is, f(y(x)) = h^m(y(x)), for integer m ≥ 0, real x > 0. In the end, numerical comparisons are presented between the analytical results obtained using the ADM and numerical solutions using the eighth-order nested second derivative two-step Runge-Kutta method (NSDTSRKM) to illustrate the reliability, accuracy, effectiveness and convenience of the proposed methods. The special cases h(y) = sin y(x), cos y(x); h(y) = sinh y(x), cosh y(x) are considered explicitly using both methods. Interestingly, in each of these methods, a unified result is presented for an integer power of any continuous real-valued function - compared with the case by case computations for the nonlinear functions f(y). The results presented in this paper are a generalisation of several published results. Several examples are given to illustrate the proposed methods. Tables of expansion coefficients of the series solutions of some special Lane-Emden type equations are presented. Comparisons of the two results indicate that both methods are reliably and accurately efficient in solving a class of singular strongly nonlinear ordinary differential equations.

• Advances in aircraft and spacecraft science
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• 제9권3호
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• pp.195-215
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• 2022

The increasing interest in CubeSat platforms ant their capability of enlarging the frontier of possible missions impose technology improvements. Miniaturized electrical propulsion (EP) systems enable new mission for multi-unit CubeSats (6U+). While electric propulsion systems have achieved important level of knowledge at equipment level, the investigation of the mutual impact between EP system and CubeSat technology at system level can provide a decisive improvement for both the technologies. The interaction between CubeSat and EP system should be assessed in terms of electromagnetic emissions (both radiated and conducted), thermal gradients, high electrical power management, surface chemical deposition, and quick and reliable data exchanges. This paper shows how a versatile CubeSat Test Platform (CTP), together with standardized procedures and specialized facilities enable the acquisition fundamental and unprecedented information. Measurements can be taken both by specific ground support equipment placed inside the vacuum facility and by dedicated sensors and subsystems installed on the CTP, providing a completely new set of data never obtained before. CTP is constituted of a 6U primary structure hosting the EP system, representative CubeSat avionics and batteries. For the first test campaign, CTP hosts the ambipolar plasma propulsion system, called Regulus and developed by T4I. After the integration and the functional test in laboratory environment, CTP + Regulus performed a Test campaign in relevant environment in the vacuum chamber at CISAS, University of Padua. This paper is focused on the test campaign description and the main results achieved at different power levels for different duration of the firings.

• 패션비즈니스
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• 제27권3호
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• pp.35-49
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• 2023

The purpose is to derive its aesthetic characteristics by objectifying the visual image of the YouTube campaign into adjectives. As a result, we intend to identify advertising strategies that use them as basic data for setting fashion design concepts. A group of experts in fashion majors watched each of them, wrote adjectives, and collected 75 adjectives. By analyzing the frequency of adjectives, aesthetic characteristics were derived with adjectives recording the upper number of times, and the results were obtained that they had the characteristics of deconstruction. The conclusions of this study are as follows. First, Tamburin's Jenny appeared to be strange, scary, rambling and charming. Among the internal meanings of deconstruction due to spatial, social, and psychological distance from consumers, it can be said that T.P.O's mutual textuality and play of interaction. Second, Gucci Cruise be chosen rural, strange, wild, unharmonious, and difficult, which is a mixture of intertextuality and play of T.P.O. Third, The Excise Gucci Campaign parodies that juxtaposes six films directed by Stanley Kubrick, making them strange, retro, difficult, interesting, and wrong. Deconstructionist de-genre and de-boundary Fourth, Kenzo World is weird, dynamic, wrong, difficult, difficult, and confused, which correspond to T.P.O's interactive textuality, play of the second half, and destruction and decomposition among the external expressions of deconstruction. Fifth, Burberry Hero emphasized the aesthetic value of traditional men, so it was ostensibly wild, free, powerful, sensual, and fantastic. Compared to the lifestyle of men who usually work at work, this corresponds to play of second best.

• 한국엔터테인먼트산업학회논문지
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• 제8권2호
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• pp.283-297
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• 2014

미래 인간의 삶은 사회, 경제, 정치와 개인 등 삶의 전 영역에 걸쳐 다학제적 기술의 파급효과 증대에 의해 혁신될 것이다. 특히 로봇 분야와 로봇을 이용한 차세대 게임 분야에서는 다학제적 기여와 상호작용에 의해 더욱 더 기술간 융합화가 가속화 될 것으로 전망된다. 본 연구는 지금까지의 "인간-로봇 인터페이스 기술"의 기술적인 한계 및 시공간적 제약을 뛰어넘는 새로운 인터페이스 모델로, 기존 인간-로봇 인터페이스 기술에서 가질 수 없는 다양한 모달리티(modality)들의 융합을 통해 보다 신뢰성 있으며 편하고 자유로운 "인간-로봇 인터페이스 기술"의 연구이다. 이족보행의 휴먼로봇과 모바일 기기 화면의 3D 콘텐츠(contents) 로봇(가상로봇)의 동작과 위치 값을 실시간적으로 연동하는 동기화(Synchronization) 엔진을 개발하고, 상호간의 정보를 주고받기 위한 무선 프로토콜(Protocol) 및 효율적인 티칭(Teaching)을 위한 학습에 의한, 다이렉트 티칭앤플레이(Direct Teaching & Play)의 티칭 프로그램 개발과, 이를 이용한 로봇 게임 시스템을 연구한다.

• 영어영문학
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• 제58권5호
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• pp.903-941
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• 2012

This essay examines Edward Said's Culture and Imperialism focusing on the concepts of 'culture,' 'empire,' and 'nation'. The approach is critical, theoretical, and historical rather than explicatory. Consequently, the range of the essay is not limited to Said's own explanation and argument about Western imperialism and its culture presented in the book. In doing this, this essay finally purposes to be a discursive resistance to the current global empire, the United States, via a critical reading of Said's work. Said's notion of culture is set upon to disclose the function of culture as an apparatus of ideological consent of the dominated to the dominant. When applied to imperial practice, Western culture functions to subject the colonized to the colonizer. Said's geographical approach to imperialism complements the historical understanding of imperialism. Imperialism is not only the practice of Western-centered historicism but also the spatially mutual interaction between the West and the rest of the world. Along with European imperialism, Said poses the current global empire of the United States as his main target of criticism. Said's problem is that he takes the United States as a nation-state. When examined, the United States is not a nation-state, but today's empire. The empire in the appearance of the nation-state United States does not work for the interest of the American nation, that is, the American people. The empire is the transnational and postnational political and economic institution that works for the interest of global capital. In order to resist the current global empire, this essay suggests that the building or restoration of nation-states with its basic principle of people's sovereignty is in need.

• 지역연구
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• 제40권2호
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• pp.21-38
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• 2024

지역 인구와 경지면적 간의 상호작용을 이해하는 것은 지역 경제 활성화와 농업의 지속가능성 향상을 위해 중요하다. 기존의 연구들은 지역의 인구이동이나 경지면적 변화 각각의 주제에 중점을 두었으며, 이들의 상호작용에 관한 연구는 미흡했다. 또한, 새로운 노동 공급원인 외국인 근로자의 증가를 대상으로 한 지역 단위의 정량적 연구도 부족했다. 이에 본 연구에서는 지역의 인구 변화, 경지면적, 그리고 외국인 근로자 수 변화의 상호작용을 패널 자기 상관 모형(Panel Vector Auto Regression Model)을 활용하여 분석하였다. 분석 결과, 지역의 인구유입률과 경지면적은 서로에게 부정적인 영향을 발생시키지만, 농업부문의 외국인 근로자 증가는 경지면적을 증가시키는 것으로 나타났다. 또한, 밭 면적의 증가는 외국인 근로자를 증가시키는 것으로 나타났다. 이러한 결과는 지역의 인구감소와 경지면적 감소 현상이 상호영향을 미치고 있으며 외국인 근로자의 유입이 농촌지역의 구조적 문제해결에 긍정적인 영향을 미칠 가능성이 있음을 시사한다.

• 한국보육지원학회지
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• 제10권3호
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• pp.159-177
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• 2014

본 연구는 보육시설을 이용하는 영유아 어머니들의 양육죄책감에 영향을 미치는 변인을 분석하였다. 양육과정에서 경험하는 보편적 양육죄책감이 아닌 보육시설에 자녀를 맡기는 상황에서 경험하는 타인양육에 대한 죄책감에 연구의 초점을 두었다. 이를 위해 광주 전남지역에 거주하는 어머니 350명을 대상으로 사회인구학적 변인에 따라 양육죄책감에 차이가 있는지 분석하였다. 또한 양육죄책감에 대한 어머니의 양육효능감, 교사의 지지, 어머니의 적극적 상호작용, 보육시설 만족도의 상대적인 영향력을 분석하였다. 본 연구의 결과로 첫째, 영아 어머니가 유아 어머니에 비해, 그리고 첫째아의 어머니가 둘째이후 자녀의 어머니에 비해 높은 양육죄책감을 보고하였다. 둘째, 양육죄책감 영향요인 중, 교사의 정서적 지지가 양육죄책감을 가장 잘 설명하는 변인으로 나타났다. 또한 양육효능감과 어머니의 적극적 상호작용, 그리고 보육만족도가 유의한 설명력을 보였다. 이는 자녀를 보육시설에 맡기는 상황에서 경험하게 되는 어머니들의 양육죄책감을 줄일 수 있는 방법으로, 교사와 어머니 간의 적극적 상호협력을 통한 양육공조의 중요성을 시사한다.

• 지능정보연구
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• 제17권1호
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• pp.17-35
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• 2011

집단지성은 개인들의 협업과 경쟁을 통한 공통이해에 기반한 생산으로서 대중의 지혜를 창출하는 개별 지성들의 통합체라고 할 수 있다. 집단지성의 활용은 공개와 공유 그리고 참여의 기본 철학을 갖고 있는 웹 2.0의 주요한 설계원칙으로 자리잡은 후로, 이와 관련된 연구가 다양하게 진행되고 있다. 이 논문은 개인들간의 관계와 상호작용에 대한 인식을 기반으로 집단지성을 밝혀보려는 방법론을 제안한다. 응용대상은 정보검색과 분류 분야이며, 개인지성의 표현과 도출을 위해 개인 컨스트럭트 이론과 지식 그리드 기법에 퍼지관계이론을 적용한다. 개인의 개별적인 지성은 헤세 다이어그램의 형태로 구현된 지성 구조로 표현하여 내재된 지식적인 의미를 분석한다. 논문의 목적인 집단지성의 도출은 개인지성들의 비교를 통해 상호간 공유와 일치를 찾아낼 수 있는 유사성 이론의 도입에 의해 이루어진다. 제안하는 방법론은 퍼지관계 이론 및 퍼지 매칭 알고리즘을 기반으로 실험 데이터로부터 유사성을 측정하고, 개인지성들을 대표할 수 있는 최적의 집단지성을 이끌어내고자 한다.

• BMB Reports
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• 제39권4호
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• pp.339-345
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• 2006

The blood-neural barrier (BNB), including blood-brain barrier (BBB) and blood-retinal barrier (BRB), is an endothelial barrier constructed by an extensive network of endothelial cells, astrocytes and neurons to form functional 'neurovascular units', which has an important role in maintaining a precisely regulated microenvironment for reliable neuronal activity. Although failure of the BNB may be a precipitating event or a consequence, the breakdown of BNB is closely related with the development and progression of CNS diseases. Therefore, BNB is most essential in the regulation of microenvironment of the CNS. The BNB is a selective diffusion barrier characterized by tight junctions between endothelial cells, lack of fenestrations, and specific BNB transporters. The BNB have been shown to be astrocyte dependent, for it is formed by the CNS capillary endothelial cells, surrounded by astrocytic end-foot processes. Given the anatomical associations with endothelial cells, it could be supposed that astrocytes play a role in the development, maintenance, and breakdown of the BNB. Therefore, astrocytes-endothelial cells interaction influences the BNB in both physiological and pathological conditions. If we better understand mutual interactions between astrocytes and endothelial cells, in the near future, we could provide a critical solution to the BNB problems and create new opportunities for future success of treating CNS diseases. Here, we focused astrocyte-endothelial cell interaction in the formation and function of the BNB.