• 제목/요약/키워드: Area gap

검색결과 1,095건 처리시간 0.027초

미생물 연료전지의 전극 재료와 구조에 따른 전기적 특성 (Electric Characteristics of the MFC according to different electrode structures and materials)

  • 최규만
    • 한국정보전자통신기술학회논문지
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    • 제7권1호
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    • pp.36-39
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    • 2014
  • 폐수 속에 들어있는 미생물을 이용해서 전기를 얻을 수 있도록 고안된 것이 미생물 연료전지이다. 본 논문에서는 미생물 연료전지의 전극 재료와 구조에 따른 전기적 특성을 조사했다. 구리판을 캐소드 전극으로 사용한 연료전지는 구리판의 산화 반응에 따른 전압역전현상이 관찰되어 백금판을 전극으로 사용한 연료전지보다 낮은 출력 전압을 나타내었다. 구리판을 전극으로 사용한 경우 전극판의 간격이 작을수록 높은 전압특성을 나타내었고 면적이 넓을수록 최고출력전압이 나타나는 시간이 지연되는 특성을 보였다.

니트 의류제품의 품질요인과 품질개선속성에 관한 연구 (Quality Factor and Quality Improvement Attributes on Knitted Apparel)

  • 박재옥;안민영
    • 복식문화연구
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    • 제19권1호
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    • pp.163-175
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    • 2011
  • The purposes of this study are to identify quality factors of knitwears, to find out important attributes of knitwears quality, and to find attributes of knitwears quality which improvement are required. College students in the Seoul district participated in the study, a convenience sampling method was used. A questionnaires was arranged with three separates subject sections, importance degree of knitwears quality, satisfaction degree of purchased knitwears, and demographic factors. Data from 280 questionnaires were used for the statistical analysis. For data analysis, factor analysis, paired-samples t-test and multiple response frequency were conducted. The results were as follows. Knitwears quality factors were classified into six subdivisions by factor analysis; physical functions, yarn and fabric properties, fit, symbol, aesthetic, and usefulness. Quality attributes in purchasing knitwears were considered importantly in order of design, textures, color, price, size, and shape stability, etc. Among quality attributes on knitwears, there were significant differences in importance degree and satisfaction degree; important degree was higher than satisfaction degree to six factors on knitwears quality. Especially, in graph according to gap analysis, physical function and symbol were included in IV area, attributes that attention, required of quality improvement. In contrast, yarn and fabric properties, fit, aesthetic, and usefulness were included in I area, strengths, maintained presently quality levels.

의료서비스의 품질 및 고객만족 관련 변수들의 관계에 관한 실증적 연구 (An Empirical Study on The Relationships of Service Quality, Customer Satisfaction and Its Influencing Variables in Medical Service area)

  • 조현주
    • 한국병원경영학회지
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    • 제4권1호
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    • pp.171-189
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    • 1999
  • This study aims to investigate the determinants of service quality and the relationships of service quality, customer satisfaction, word of mouth and subsequent purchase intention of medical service. SERVQUAL, an instrument developed by the marketing area, is offered as a possible measure of medical service quality. SERVQUAL measures service dimension of tangibles, reliability, responsiveness, assurance and empathy. The questionnaire method is used in this study. A survey is conducted on patients who are randomly selected. The questionnaire are sent to 300 patients and 208 are available. The objectives of this study were: 1) to find out the influence of determinants of service quality on medical service. 2) to investigate the relationship of medical service quality and customer satisfaction. 3) to analyze the relationship of customer satisfaction and favorable word of mouth, ubsequent purchase intention 4) to find out the gap perceived service quality between secondary and tertiary hospital. The results of this study are summarized as follows: 1) Reliability, responsiveness and assurance have a positive impact on the medical service quality. 2) Medical service quality has a positive impact on the customer satisfaction. 3) Customer satisfaction has a positive impact on the favorable word of mouth and subsequent purchase intention. 4) There is no gap between secondary and tertiary hospital of perceived service quality.

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위성 DMB GF Network의 설계 기초에 관한 연구 (A study on the Base of Design of GF Network for Satellite DMB)

  • 노순국
    • 한국정보통신학회논문지
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    • 제12권1호
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    • pp.183-188
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    • 2008
  • 위성 DMB는 비가시거리 지역인 위성신호의 전파음영지역이 존재하고, 이러한 지역에 서비스를 제공하기 위해 Gap Filler(GF)를 사용한다. GF는 중계기로써 위성 DMB System은 단말기의 이동수신을 보장하기 위해 GF Network을 반드시 구축해야 하며 GF의 커버리지는 Cell or Sector를 형성하게 되어 다수의 GF가 인접하여 설치되면 간섭 등의 문제가 발생할 수 있다. 그러므로, 본 논문에서는 위성 DMB 시스템과 GF에 대해 살펴보고, 이러한 문제를 경감할 수 있는 GF Network의 설계 기초 방안에 관해 검토하였다. 그 결과, GF와 단말기간의 거리가 4.6Km을 벗어나면 상호 간섭으로 작용하여 품질열화가 발생하여 서비스 제공이 어려워짐을 확인하였다.

하천 친수환경 평가체계 구축 및 적용에 관한 연구 (A Study on Development and Application of Water-friendly Environment Assessment System)

  • 이형숙
    • 농촌계획
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    • 제24권4호
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    • pp.81-88
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    • 2018
  • With the increase of the number of riverfront development projects an objective and systematized survey and assessment tool is required to understand and identify the characteristics and potentials of river environment for human uses. The purpose of this study was to develop an assessment system for the investigation and evaluation of the water-friendly environment and to examine its effectiveness by applying the system to the selected study sites. Literature reviews, expert consultation, and preliminary survey were conducted to select highly relevant indexes to evaluate water-friendliness in rivers and, as a result, an assessment system of ten items in four areas was established. The assessment system were applied to 139 reaches of six rivers including Bykgye Cheon, Seom River, Gap Cheon, Yudeng Cheon, Naesung Cheon, and Kumho River. The scores and grade of water-friendliness were calculated per rivers and reaches, and their differences were prominent according to urban river, rural river, mountainous area and city area. Bykgye Cheon and Naesung Cheon got high scores in visual quality and Kumho River and Gap Cheon in community needs and potential uses. The scores of each section in the same river can be used as a basic data for the selection of appropriate sites for the development of hydrophilic space. In addition, it is expected that identifying the characteristics of each river help establish an appropriate management plan for the river.

Enhancement of NOx photo-oxidation by Fe-doped TiO2 nanoparticles

  • Martinez-Oviedo, Adriana;Ray, Schindra Kumar;Gyawali, Gobinda;Rodriguez-Gonzalez, Vicente;Lee, Soo Wohn
    • Journal of Ceramic Processing Research
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    • 제20권3호
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    • pp.222-230
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    • 2019
  • Microwave hydrothermal-assisted sol-gel method was employed to synthesize the Fe doped TiO2 photocatalyst. The morphological analysis suggests anatase phase nanoparticles of ~20 nm with an SBET area of 283.99 ㎡/g. The doping of Fe ions in TiO2 created oxygen vacancies and Ti3+ species as revealed through the XPS analysis. The reduction of the band gap (3.1 to 2.8 eV) is occurred by doping effect. The as-prepared photocatalyst was applied for removal of NOx under solar light irradiation. The doping of Fe in TiO2 facilitates 75 % of NOx oxidation efficiency which is more than two-fold enhancement than the TiO2 photocatalyst. The possible reason of enhancement is associated with high surface area, oxygen vacancy, and reduction of the band gap. Also, the low production of toxic intermediates, NO2 gas, is further confirmed by Combustion Ion Chromatography. The mechanism related NOx oxidation by the doped photocatalyst is explained in this study.

우간다의 도시-농촌 간 교육 불균형 해소를 위한 ICT 적정기술 (Reducing Rural-Urban Education Gap in Uganda Through ICT Appropriate Technology)

  • 노효선
    • 적정기술학회지
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    • 제7권1호
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    • pp.33-40
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    • 2021
  • 동아프리카에 속한 우간다도 농업 중심의 현 국가 상황에서 벗어나 중상위권 국가로 도약하기 위해 다양한 국가개발 계획을 세우고 진행하고 있다. 그러나 다양한 정부의 노력에도 도시-농촌간 균형적인 발전을 이루지 못하고 그 격차가 더욱 심화되고 있다. 특별히 도시-농촌간 교육 격차는 장기적으로 우간다 국가계발 계획에 부정적인 영향을 줄 수 있는 문제점으로 부각되고 있다. 본 논문에서는 우간다의 도시-농촌간 교육 불균형이 가속화되고 있는 원인들을 살펴 보고 전자도서관 시스템과 같은 ICT 적정 기술을 활용하여 교육 불균형을 감소 시킬 수 있는 방안을 소개하고자 한다.

선망어법의 어획과정에 있어서 어군행동에 관한 연구 (A Study on the Behaviour of Fish Schools in the Process of Catch of the Purse Seine Fishing Method)

  • 박정식;김석종;김삼곤
    • 수산해양기술연구
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    • 제33권3호
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    • pp.173-182
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    • 1997
  • 선망어법의 어회과정에 있어서 어군행동에 관한 기초적인 연구를 목적으로 제주 근해에서 사용하고 있는 고등어 선망어구인 파워불록용 선망(Powetblock seine)과 앞으로 예상되는 단선조작에서의고등어 선망어구인 트리플레스용 선망(Triplex seine)의 두 가지 모형망을 1/180로 제작 하고 선망에 의해 포위된 어군의 망내행동과 양쪽 선단의 개구부를 통하여 도피하는 어군의 행동을 관찰 분석함과 동시에 망단의 개구부의 면적 및 장력변화 등을 해석하였으며, 그 결과는 다음과 같다. 1. 죔줄죄기 소요시간 20분일 때, 개구부로 도피하는 아군의 평균 유영속도는 Powerblcok seine에서 9.71cm/sec, Triplex seine에서 9.97cm/sec였다. 2.죔줄죄기 소요시간 20분중 좀줄을 50% 정도 감아들었을 때, 선망내의 어군은 Powerblock seine의 경우 I section 10%, II section방향으로 10% 유영하는 행동을 보였다. 3.죔줄죄기 소요시간 20분중 10분 경과했을 때, 전면 망단 개구부의 면적 감소율은 Powerblock seine이 63.5%, Triplex seine이 어군도피에 대한 수평적 서단능력이 높았따. 그리고, 좀줄에 걸리는 최대장력은 Powerblock seine이 약 8.1톤, Triplex seine이 8.3톤으로 나타 났는데, 양자의 차이는 그다지 크지 않았다.

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흰쥐의 척수손상 후 천궁처리에 의한 피질척수로 축삭재생 반응시 Glial cells의 역할 (The Role of Glial Cells in Regenerative Responses of the Injured Corticospinal Tract Axons in Rats Treated with Cindii Rhizoma)

  • 한영수;오민석
    • 한방재활의학과학회지
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    • 제18권3호
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    • pp.19-39
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    • 2008
  • 목 적 : 천궁은 중추신경계 신경조직의 손상을 감소시키는 데에 유효한 것으로 보고되었다. 따라서 손상 척수신경에서 천궁에 의한 각각의 신경조직의 반응성을 조사하기 위하여 흰쥐의 손상된 척수 신경에 천궁 추출물을 처리하여 관찰하였다. 방 법 : 흰쥐의 척수조직에 타박손상을 가한 후 천궁을 처리하고 손상부위의 GAP-43과 Cdc2 및 Erk1/2 단백질의 수준, 축삭 및 성상세포의 수, 아교상혼의 정도를 각각 확인하여 손상부위 및 피질척수로의 재성장 여부를 관찰하였다. 결 과 : 천궁처리에 의하여 손상부위에서는 GAP-43과 Cdc2 및 Erk1/2 단백질의 수준이 증가하였다. 손상척수 부위에서 성상세포의 수는 천궁처리에 의하여 비손상대조군에 비해 증가하였다. CSPG 단백질에 의하여 확인된 아교상흔의 정도는 천궁처리에 의하여 감소하였다. Dil에 의한 정방향 염색에 의하여 피질척수로를 확인하였으며, 측방축삭의 싹돌기는 천궁처리에 의하여 손상부위 상단부 및 하단부에 각각 증가하였다. 고분자미세관을 손상척수부위에 이식하여 미세관내부로 축삭 및 비신경세포의 이주양상을 분석한 결과 천궁처리에 의하여 축삭 및 성상교세포의 이주증가를 확인하였다. 결론 : 천궁이 손상척수신경부위에서 비신경세포 특히 성상세포의 활성화에 기여함을 알 수 있었다. 이러한 활성화는 손상 피질척수로 축삭의 재성장 반응을 증가시키는 효과가 있는 것으로 판단된다.

유한요소법을 이용한 수종 2급 아말감 와동의 비교연구 (A STUDY ON COMPARISON OF VARIOUS KINDS OF CLASSII AMALGAM CAVITIES USING FINITE ELEMENT METHOD)

  • 석창인;엄정문
    • Restorative Dentistry and Endodontics
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    • 제20권2호
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    • pp.432-461
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    • 1995
  • The basic principles in the design of Class II amalgam cavity preparations have been modified but not changed in essence over the last 90 years. The early essential principle was "extension for prevention". Most of the modifications have served to reduce the extent of preparation and, thus, increase the conservation of sound tooth structure. A more recent concept relating to conservative Class II cavity preparations involves elimination of occlusal preparation if no carious lesion exists in this area. To evaluate the ideal ClassII cavity preparation design, if carious lesion exists only in the interproximal area, three cavity design conditions were studied: Rodda's conventional cavity, simple proximal box cavity and proximal box cavity with retention grooves. In this study, MO amalgam cavity was prepared on maxillary first premolar. Three dimensional finite element models were made by serial photographic method. Linear, eight and six-nodal, isoparametric brick elements were used for the three dimensional finite element model. The periodontal ligament and alveolar bone surrounding the tooth were excluded in these models. Three types model(B option, Gap option and R option model) were developed. B option model was assumed perfect bonding between the restoration and cavty wall. Gap option model(Gap distance: $2{\mu}m$) was assumed the possibility of play at the interface simulated the lack of real bonding between the amalgam and cavity wall (enamel and dentin). R option model was assumed non-connection between the restoration and cavty wall. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed the displacement, 1 and 2 direction normal stress and strain with FEM software ABAQUS Version 5.2 and hardware IRIS 4D/310 VGX Work-station. The results were as followed. 1. Rodda's cavity form model showed greater amount of displacement with other two models. 2. The stress and strain were increased on the distal marginal ridge and buccopulpal line angle in Rodda's cavity form model. 3. The stress and strain were increased on the central groove and a part of distal marginal ridge in simple proximal box model and proximal box model with retention grooves. 4. With Gap option, Rodda's cavity form model showed the greatest amount of the stress on distal marginal ridge followed by proximal box model with retention grooves and simple proximal box model in descending order. 5. With Gap option, simple proximal box model showed greater amount of stress on the central groove with proximal box model with retention grooves. 6. Retention grooves in the proximal box played the role of supporting the restorations opposing to loads.

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