• 제목/요약/키워드: closed forms

검색결과 223건 처리시간 0.026초

산성광산배수로 인한 환경오염도 조사 (Environmental Contamination from Acid Mine Drainage)

  • 강미아
    • 지질공학
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    • 제17권1호
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    • pp.143-150
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    • 2007
  • 폐광산으로부터 발생하는 산성광산배수는 인근의 물환경과 토양환경을 오염시킴으로써 사람에게 건강상 유해성을 간접적으로 나타내는 오염원이다. 본 연구에서는 45일간의 연속용출실험을 통해 폐광산 인근 토양에 함유된 As, Mn 및 Zn의 용출 및 흡착반응을 명확히 밝혔다. 용출 및 흡착반응에는 용액의 pH와 산화환원전위가 함께 작용하여 물환경내에서의 중금속류의 화학적 존재형태를 지배하고 이것이 용출 및 흡착반응에 영향을 미치는 것으로 나타났다. 그러나 매우 가까운 위치에서 시료를 채수한다 하더라도 함유되어 있는 중금속의 수준은 매우 다를 뿐 만 아니라 산화환원상태도 상이함을 알 수 있었다. 따라서 폐광산 및 광산주변의 토양으로부터 발생하는 산성배수가 미치는 환경오염의 영향을 평가하기 위해서는 pH뿐 만 아니라 산화환원상태도 함께 고려되어야 한다. 또한 경과시간에 따른 용출 및 흡착반응을 고찰하면서 적절한 산성배수의 관리를 시행한다면, 보다 경제적인 해결방안을 모색하는데 기여할 수 있을 것으로 기대한다.

분양자율화 이후 민영아파트 주동 공용공간의 디자인 특징 - 대구광역시 고층.초고층아파트를 중심으로 - (A Study on the Design Characteristic about Public Space of Privately-built Apartment Housing after the Enforcement of Price Deregulation - Focused on the high rise apartment in Daegu -)

  • 서희숙;이상홍
    • 한국주거학회논문집
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    • 제21권1호
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    • pp.79-88
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    • 2010
  • The purpose of this study is to examine the design characteristic about the public space of privately-built apartment housing after the enforcement of price deregulation in Daegu. The public space of the multi-family housing is monotonous and closed according to the position of an elevator and a stair hall by the 1990's. However, the housing has been gentrified since 2000 because of demands of residents and purpose for selling in lots. Thus, the recognition of the apartments has changed and this change has led to extend the living territory and magnify the role of the public space where help interact with neighbors. This study is based on the survey of thirty nine apartment complex. Also, by using an analysis derived from a precedent study, design elements in approach and interior space of apartment residents are comprehended. The characteristic of the porch is researched and divided according to a roof of porch, form as the door, material of roof, wall, the ceiling and floor. Interior space is analyzed by several elements; forms of core, forms, materials and lights of ceiling, materials of walls and floors, existence and nonexistence of windows, and extra interior components etc. As a result of the study, After the enforcement of price deregulation, the public space of apartments has had improved quality in materials and design and the community center for residents such as waiting rooms and spots facilities has appeared. However, the traffic line of interior space has been very intricate. Also, sports facilities and waiting areas are limited to some apartments.

선형(線形) 변단면(變斷面) I-형(型) 부재(部材)의 자유진동(自由振動) (Free Vibrations of Linearly Tapered I-Beams)

  • 이용우;민경주
    • 대한토목학회논문집
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    • 제14권5호
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    • pp.1023-1031
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    • 1994
  • 선형변단면(線形變斷面) I-형(型) 부재(部材)의 3차원(次元) 공간(空間)에서의 고유진동해석(固有振動解析)을 위하여 회전관성(回轉慣性)도 포함하는 컨시스턴트 질량행렬(質量行列)을 유도하였다. 유도과정(誘導過程)에서 정확한 형상함수(形狀函數)를 사용했다. 일반적으로 많이 사용되는 변단면부재(變斷面部材)의 경사(傾斜)는 매우 작으므로 '정형식(整形式)'으로 표현된 행렬(行列)을 사용하여 변단면(變斷面) 부재(部材)를 포함하는 구조물(構造物)을 해석할 때에 신빙성 없는 결과를 얻게 된다. 이러한 수치적(數値的) 오류(誤謬)를 피하기 위하여 '급수식(級數式)'을 유도했다. 변단면(變斷面) 부재(部材)의 구조물(構造物)을 해석하기 위하여 본 연구에서 유도된 질량행렬(質量行列)을 사용하여 구한 고유진동수(固有振動數)와 변단면(變斷面) 부재(部材)를 균일단면(均一斷面)의 탑형태(塔形態)로 표현하여 ANSYS에서 구한 고유진동수(固有振動數)를 비교하여 본 연구 결과 효율성과 정확성이 증진된 것을 확인하였다. 본 연구에서 유도된 질량행렬(質量行列)은 변단면(變斷面) 부재(部材)와 균일단면(均一斷面) 부재(部材)의 자유진동해석(自由振動解析)에 사용할 수 있다.

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테헤란 스트리트에 나타난 패션 아이템 히잡 연구 (A Study on the Hijab as a Fashion Item in the Tehran Street)

  • 김현서;김현주;나현신
    • 패션비즈니스
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    • 제24권2호
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    • pp.1-16
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    • 2020
  • Hijab as a symbol of women's oppression due to the opening and reform of Islamic State group, is becoming more diverse as younger generation begins to dress more freely than ever before, spreading the perception that it is a fashion item. In response, this research conducted a theoretical review about the history of hijab, various forms of hijab, and characteristics of hijab using relevant literature, media reports, and fashion media articles. As an empirical study, image-oriented photo data shared by Tehran Street Fashion from 2015 to November 2019 were analyzed separately by fashion majors into color, pattern, and hijab-making forms. According to the analysis, six different fashion images were categorized as romantic feminine, modern chic, natural elegant, classic formal, sporty casual and gorgeous ethnic. For Muslim women in the past, hijab was worn as a repressive and closed sense by the religious system. However, in modern times, it is a way to express one's style and ideas as a fashion item. It is also and a means to express one's thoughts and beliefs. Through aesthetic consideration of Hijab as a fashion item, it was found that it was a medium for freedom of expression and a medium for beauty and individuality.

중국 티베트족 공연의상에 관한 연구 - CCTV 춘절 특집 프로그램을 중심으로 - (A Study on Tibetan Folk Costume on the Stage - Focused on the CCTV Spring Festival Gala -)

  • 교단;소황옥
    • 복식
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    • 제60권9호
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    • pp.26-40
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    • 2010
  • The purpose of this study is the Tibetan folk costumes'characteristics and change of design in stage. The subjects are the Tibetan costumes in the Spring Festival Gala of CCTV. The basic characteristics of Tibetan folk costumes are fat waist, long sleeves, overlap, and right ren. Tibetan costumes consist of Tibetan gowns, aprons, shirts, belts, Tibetan hats, headgear, ornaments, all of these compose the traditional image of the Tibetan people. Because of the long-term closed survival, the development of Tibetan costumes has no much vertical differences and changes. The costumes of Weizang(衛藏), Ali(阿里), Gongbu(工布), Kham(康巴), Amdo(安多) have different features which are divided according to different dialects. Study the changes of design Tibetan stage costumes from 25times, we can get that during the 1986~1992, people emphasis on the activities of dancers, styles are simple, just to grasp the characteristics of the Tibetan costumes. In the 1993~1999, the dancers put on the real-life Tibetan clothing on stages. By the 2000s to now, Tibetan stage costumes have much more changes in forms and colors which are more complete and complex. The types of Tibetan costumes include Tibetan all clothing, they all express the changed forms and colors without exception. So in this period are artistic Tibetan folk costumes.

하드코팅에 의한 광변색 플라스틱 렌즈의 제조 및 특성 (Preparation and Characteristics of Photochromic Plastic Lenses by Hard Coatings)

  • 유동식;하진욱;문병연
    • 한국산학기술학회논문지
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    • 제10권7호
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    • pp.1635-1641
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    • 2009
  • 하드코팅에 의해 광변색과 경성의 성질을 갖는 플라스틱 렌즈를 제조하고, 그것들의 광학적 성질과 표면 특성을 평가하였다. 무색 상태의 자외선 스펙트럼과 유색 상태의 가시광선 스펙트럼에서 광변색 효과를 관찰할 수 있었다. 광변색 렌즈의 가시광선 투과율은 무색 상태에서 83.44%(검정)에서 87.15%(청)였으며, 유색 상태에서 71.10%(적)에서 79.98%(황)이었다. 적색 광변색 렌즈는 다른 렌즈에 비해 광학 밀도(${\Delta}$OD)와 색차(${\Delta}$$E^{\ast}_\;{ab}$)가 컸다. 하드코팅을 적용한 광변색 렌즈는 부착성, 내온수성, 내약품성 및 표면 현상이 우수하였으며, 또한 경도와 내마모성은 무코팅 렌즈에 비하여 증가하였다. 따라서 이와 같은 코팅 시스템으로 광변색과 하드코팅 성질과 같은 기능성을 안경렌즈에 부여할 수 있었다.

Spiropyran과 Spirooxazine 유도체의 열변색 현상 (Thermochromism of Spiropyran and Spirooxazine Derivatives)

  • 이윤상;김종규;허영덕;김명건
    • 대한화학회지
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    • 제38권12호
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    • pp.864-872
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    • 1994
  • 열변색 현상을 나타내는 spiropyran과 spirooxazine 유도체의 흡수 스펙트럼을 관찰하였다. 흡수 스펙트럼의 용매효과를 관찰한 결과, 치환되지 않은 spiro 화합물은 merocyanine-like form이 quinoid type이며, 전자끄는기가 치환된 spiro 화합물은 merocyanine-like form이 zwitter-ion type임을 확인하였다. 닫힌형 구조와 merocyanine-like form 사이의 엔탈피 변화량을 측정하였다. Spiro 화합물의 엔탈피 변화량은 용매의 극성이 증가할수록 감소함을 관찰하였다. Merocyanine-like form의 흡수 스펙트럼을 세 개의 Lorentzian-Gaussian 곱함수의 띠로 분해하였으며, 각 띠의 모양이 용매에 어떻게 변화하는지도 관찰하였다.

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SORET, HALL CURRENT, ROTATION, CHEMICAL REACTION AND THERMAL RADIATION EFFECTS ON UNSTEADY MHD HEAT AND MASS TRANSFER NATURAL CONVECTION FLOW PAST AN ACCELERATED VERTICAL PLATE

  • VENKATESWARLU, M.;LAKSHMI, D. VENKATA;RAO, K. NAGA MALLESWARA
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제20권3호
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    • pp.203-224
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    • 2016
  • The heat and mass transfer characteristics of the unsteady hydromagnetic natural convection flow with Hall current and Soret effect of an incompressible, viscous, electrically conducting, heat absorbing and optically thin radiating fluid flow past a suddenly started vertical infinite plate through fluid saturated porous medium in a rotating environment are taken into account in this paper. Derivations of exact analytical solutions are aimed under different physical properties. The velocity, concentration and temperature profiles, Sherwood number and Nusselt number are easily examined and discussed via the closed forms obtained. Soret effect and permeability parameter tends to accelerate primary and secondary fluid velocities whereas hall current, radiation and heat absorption have reverse effect on it. Radiation and heat absorption have tendency to enhance rate of heat transfer at the plate. The results obtained here may be further used to verify the validity of obtained numerical solutions for more complicated transient free convection fluid flow problems.

학위논문의 목록기술형식 및 검색방법 고찰 (A study of descriptive forms of catalogue and searching method for dissertations)

  • 조호일
    • 한국도서관정보학회지
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    • 제12권
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    • pp.133-160
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    • 1985
  • In college or university libraries, the data of dissertations is one of the important academic information data. But traditional cataloging rules of dissertations and the method of operation is not only didn't unify but also fit to actual circumstances of library. This reason make librarians waste of time and the situation about piling up of unprocessed data don't make library services properly. In this papers, to analyze the above mentioned problems, I have investigated with questionaries about actual examples of construction methods of call number and item describing form of dissertations which is being used now in every college library in Korea. With the replied 61 questionaries which was compared with and investigated to merits and faults about library itself, I have showed revision ways. The characteristics of the revision ways are the followings. 1) Deleted informal and unmeaning descriptions and simplified describing. 2) Recommended to operating one or two kinds describing items which are only necessary. 3) Made call number specifically and then it make us easy to identify data and simultaneously call number can do its original action. 4) shelving range of data is made to colleges, years, departments, majors but in same departments, author's name is recommended by Korean alphabetical ordering. Besides, for proper and systematic management and operating of data. It must be necessary to recommend that reading systems of closed shelves type, incoming and outgoing and shelving by fulltime exclusive charged librarian, separate management of items and data are recommended.

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열린 학교 단위학습공간의 구성유형별 건물성능평가에 관한 연구 - 대구광역시 소재 초등학교를 대상으로 - (A Study on the Post-Occupancy Evaluation of the Types of the Learning Space Unit in Elementary Schools)

  • 최재영;이상홍;최무혁
    • 교육시설
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    • 제10권2호
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    • pp.15-22
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    • 2003
  • The purpose of this study is to find problems and to provide architectural design standards of the Learning Space Unit(L.S.U.) in Elementary Schools through the Post-occupancy Evaluation(POE). In this study, we found six major problems of the type of the L.S.U. in elementary schools. More than 50% of users expressed dissatisfactions in these items : size, safety, cooling facility, noise, privacy and primary meaning for its original purpose. After the interrelation-analysis, we checked pros and cons about each forms of L.S.U. It is the result of analysis of the layout method in L.S.U. 1) "$8.4m{\times}8.4m$" classroom unit got the highest positive responses 2) "2-classroom type" and "4-classroom type" got higher score than "3-classroom type" 3) "Whole faced type" 1) made more active Multi-space than "Partial faced type" 4) prefered prepared "Open-classroom" to "Closed-classroom" 5) 'Zoning type between L.S.U.s' couldn't influence to user's responses. Designers can consult those informations when they plan a new, remodeling and additional elementary school.