• 제목/요약/키워드: Element group

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몽골 서부 할잔-부룩테이 페그마타이트에 대한 지화학적 예비 연구 (A Preliminary Geochemical Study on the Khaldzan-Buregtei Pegmatite, Western Mongolia)

  • 박상준;허철호;김유동
    • 한국광물학회지
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    • 제21권3호
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    • pp.261-269
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    • 2008
  • 몽골 서부 할잔-부룩테이 알칼리 복합체에서 산출되는 페그마타이트는 Nb-Y-Zr-F의 부화가 특징적인 NYF 유형의 함희유금속 페그마타이트이다. 이들 함희유금속 페그마타이트는 할잔-부룩테이 섬장암 및 알칼리 장석 화강암의 분화물로서 알칼리 화강암류에 비해 십 배 이상의 희유금속이 농집되어 있다. 할잔-부룩테이 함희유금속 페그마타이트의 경제성은 페그마타이트맥의 연장성 및 국부적 품위 변화에 의해 좌우될 것으로 생각된다.

Characteristics of a Corona between a Wiring Clamp(Dead End Clamp) and a Porcelain Insulator Used in a 154[kV] Power Receptacle

  • Han, Un-Ki;Kim, Jong-Min;Bang, Sun-Bae;Kim, Han-Sang;Choi, Hyeong-Jun
    • 조명전기설비학회논문지
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    • 제21권9호
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    • pp.57-63
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    • 2007
  • The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154[kV] dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in 154[kV] power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method(FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

Multibody models with flexible components for inflatable space structures

  • Petrolo, Marco;Governale, Giorgio;Catelani, Daniele;Carrera, Erasmo
    • Advances in aircraft and spacecraft science
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    • 제5권6호
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    • pp.653-669
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    • 2018
  • This work has the objective to analyze multibody mechanisms of inflatable structures for manned space applications. The focus is on the evaluation of the main characteristics of MaxFlex, a new module of MSC Adams including the effect of nonlinear flexible bodies. MaxFlex integrates the nonlinear Finite Element Analysis (FEA) of Nastran-SOL400-and the Adams multibody capabilities in one unique solver, providing an improvement concerning the concept and technology based on the co-simulation among solvers. MaxFlex converts the equations of motion of the nonlinear FEA into phase-space form and discretizes them according to the multibody system integrator framework. The numerical results deal with an inflatable manned space module having rigid components and a flexible coating made of Kevlar. This paper is a preliminary assessment of the computational capabilities of the software and does not provide realistic guidelines for the actual design of the structure. The analysis leads to some recommendations related to the main issues to consider in a nonlinear simulation including both rigid and flexible components. The results underline the importance of realistic deployment times and applied forces. Also, a proper structural modeling is necessary, but can lead to excessive computational overheads.

나노구조 단분자막의 전기적 특성 (Electrical Characteristics of Nano-Structural Monolayer)

  • 최용성;조장훈;송진원;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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    • pp.166-167
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    • 2006
  • Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L-films and LB films of dendrimer and 8A5H were performed. The 8A5H organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for Impression.

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Operational Report of the Mission Analysis and Planning System for the KOMPSAT-I

  • Lee, Byoung-Sun;Lee, Jeong-Sook;Kim, Jae-Hoon;Lee, Seong-Pal;Kim, Hae-Dong;Kim, Eun-Kyou;Choi, Hae-Jin
    • ETRI Journal
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    • 제25권5호
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    • pp.387-400
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    • 2003
  • Since its launching on 21 December 1999, the Korea Multi-Purpose Satellite-I (KOMPSAT-I) has been successfully operated by the Mission Control Element (MCE), which was developed by the ETRI. Most of the major functions of the MCE have been successfully demonstrated and verified during the three years of the mission life of the satellite. This paper presents the operational performances of the various functions in MAPS. We show the performance and analysis of orbit determinations using ground-based tracking data and GPS navigation solutions. We present four instances of the orbit maneuvers that guided the spacecraft form injection orbit into the nominal on-orbit. We include the ground-based attitude determination using telemetry data and the attitude maneuvers for imaging mission. The event prediction, mission scheduling, and command planning functions in MAPS subsequently generate the spacecraft mission operations and command plan. The fuel accounting and the realtime ground track display also support the spacecraft mission operations.

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Phthalate 완충용액에서 전해 석출한 철족 원소의 산화 용해 반응 (Anodic Dissolution of Electrodeposited Iron Group Elements in Phthalate Buffer Solution)

  • 천정균;김연규
    • 대한화학회지
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    • 제51권1호
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    • pp.14-20
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    • 2007
  • 금(Au) 전극 위에 전해 석출한 철족 원소(Fe, Co, Ni)를 전극으로 phthalate 완충 용액에서 철족 원소의 부식과정을 조사하였다. Phthalate 완충용액의 pH의 변화에 대한 부식전위와 부식전류를 측정하여 각 원소(Fe, Co, Ni)전극의 산화반응과 환원반응에 대한 Tafel 기울기를 구하였으며 Tafel 기울기를 포함한 정량적인 전기화학 인자를 측정하여 전극의 산화반응과 환원반응에 대한 반응 메커니즘을 제안하였다. Phthalate 완충 용액에 존재하는 화학 종의 흡착은 철족 원소 전극의 산화반응에 영향을 미치는 것으로 보인다.

1990년대 이후 국내 대중음악 스타의 패션연출 특성에 관한 고찰 (A Specific Character of Fashion-Presentation in the Korean Music stars since 1990s)

  • 유송옥;한자영
    • 복식
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    • 제51권5호
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    • pp.61-75
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    • 2001
  • This study was intended to observe strategic fashion-presentation in Music stars according to the change of the star system in the Korean popular musics. The Korean Music stars since 1990s have been made, fabricated and have excessively depended on the demand of the teenagers. Therefore their distinctive fashion-presentation is considered as more important element than those of the past. Consequently. the characteristics of the fashion-presentation in the Korean Music star these days are as follows : First. Music stars shows fashion-presentation that has a consistent fashion theme. That is one of the key success factor to raise the recognition of star singer. Second. Music star produces fashion images which reflects identity and of subculture. Those appearance have won wild popularity of the Peeps 1990's new generation. Third. although there is no change music genre and emotion. through merely renovation of their fashion image, Music star got diversity and originality of the characteristics of contemporary cultural goods. Fourth. In case of famous dance groups, in the past they maintained a singular atmosphere as a group, but in 1990'Music star group each members of the group have individually fashion-presentation. So, they can get more fans. Fifth, Music singers borrow or duplicate fashion-presentation from each others. Such as similar fashion-presentation guarantees support of the same fans.

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Hysteresis PWM 전류 제어 기법을 사용한 독립 다상 BLDC 전동기의 효율 해석 유효성 검증 (Validation of Efficiency Analysis for Independent Multi-Phase BLDC Motor Using Hysteresis PWM Current Control Method)

  • 이준원;공영경;박선정;최호용;홍성영
    • 한국군사과학기술학회지
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    • 제17권5호
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    • pp.604-610
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    • 2014
  • In this paper, the analysis and the experiment of independent multi-phase BLDC motor are performed. The back-emf, iron loss analysis are performed by the finite element method and compared with experimental results. The independent multi-phase BLDC motor is manufactured and to measure the efficiency of the motor, evaluation system is also manufactured including the load generator. By comparing the analytic and the experimental results, the effectiveness of the analysis model is verified when calculating the efficiency of the motor.

Nutritional Assessment of the Older Population: Practical Application and Limitation

  • Yoon, Jin-Sook
    • Journal of Community Nutrition
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    • 제2권1호
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    • pp.36-49
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    • 2000
  • Evaluation of nutritional status is an essential element in providing appropriate intervention strategies to achieve the highest level of health, Nutritional assessment of the older population is complicated by many factors which do not significantly affect the nutritional status in young adults, therefore, it should be considered in two ways; community-dwelling elders group and hospitalized or institutionalized elderly group. To sort out the individuals with nutritional problems in a community efficiently, nutrition screening tools must be simple, relatively inexpensive, and applicable to a large number of subjects. Combination of tools and indicators such as 24-hour food recall, body weight and height, and questionnaires on eating practices, and the presence of chronic diseases is practically applicable as basic tools of nutritional screening of older age group. However, the lack of validated screening techniques remains a barrier in improving nutrition. Validation is only limited to energy, BMI, protein intake of the older populations living in western countries. Further refinement of nutritional assessment tools is demanded to figure out whether those are practically applicable to community-living older adults in Asian Society. A careful and systematic evaluation of nutritional assessment tools should be carried out prior to implementation of stepwise nutrition service to the heterogeneous older population. For an in-depth nutritional assessment at the individual level, we need to extend research efforts to clarify the requirements of nutrients due to aging and diseases. More cost-effective method that will allow rapid analysis of survey results are needed so that information can be readily available to policymakers.

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실시간 다물체 차량 동역학 소프트웨어 개발 Part Ⅰ: 부분시스템 합성방법에 의한 실시간 차량 모델 (Development of Real Time Multibody Vehicle Dynamics Software Part I : Real Time Vehicle Model based on Subsystem Synthesis Method)

  • 김성수;정완희;이창호;정도현
    • 한국자동차공학회논문집
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    • 제17권1호
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    • pp.162-168
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    • 2009
  • The real-time multibody vehicle model based on the subsystem synthesis method has been developed. Suspension, anti roll bar, steering, and tire subsystem models have been developed for vehicle dynamics. The compliance effect from bush element has been considered using a quasi-static method to achieve the real time requirement. To validate the developed vehicle model, a quarter car and a full vehicle simulations have been carried out comparing simulation results with those from the ADAMS vehicle model. Real time capability has been also validated by measuring CPU time of the simulation results.