• Title/Summary/Keyword: Combined Effort

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양방향 스털링엔진의 선형발전기 설계에 관한 연구 (A Study on Design of the Linear Generator in the Double Acting Stirling Engine)

  • 박성제;고준석;홍용주;김효봉;염한길;인세환
    • 한국수소및신에너지학회논문집
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    • 제26권6호
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    • pp.638-644
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    • 2015
  • This paper describes the continuing effort to analysis and design on dynamic and electrical behavior of gamma-type free piston Stirling engine/generator with dual-opposed linear generator for domestic micro-CHP (Combined Heat and Power) system. The double acting Stirling engine/generator has one displacer and two power piston which are supported by flexure springs. Two power pistons oscillate with symmetric sinusoidal displacement and are connected with moving magnet type linear generators for power generation. To operate Stirling engine/generator, combustion heat of natural gas is supplied to hot-end and heat is rejected from cold-end by cooling water. The temperature difference across the displacer induces the oscillating motion, and it can be explained with mass-spring vibration system. The purpose of this paper is to describe the design process of linear generator for the double acting free-piston Stirling engine.

In vitro Antibacterial and Synergistic Activity of an Ecklonia cava Extract against Anti biotic-Resistant Streptococcus parauberis

  • Eom, Sung-Hwan;Santos, Jeniel A.;Kim, Ji-Hoon;Jung, Won-Kyo;Kim, Do-Hyung;Kim, Young-Mog
    • Fisheries and Aquatic Sciences
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    • 제18권3호
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    • pp.241-247
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    • 2015
  • In an effort to discover alternative phytotherapeutic antimicrobial agents to combat Streptococcus parauberis, a fish pathogenic bacterium, we evaluated the antibacterial activity of seaweed extracts in vitro. A methanolic extract of Ecklonia cava exhibited strong antibacterial activity against S. parauberis isolated from olive flounder Paralichthys olivaceus. Furthermore, the n-hexane soluble (Hexane) fraction of the E. cava methanolic extract exhibited the greatest antibacterial effect on S. parauberis strains with a minimum inhibitory concentration (MIC) ranging from 256 to $1,024{\mu}g/mL$. In addition, the MIC values of oxytetracycline against antibiotic-resistant S. parauberis were markedly reduced up to 64-fold in combination with the Hexane fraction, suggesting that the antibacterial activity of the antibiotic was restored when combined with the Hexane fraction. The interaction between both antibiotics and the Hexane fraction was assessed by the fractional inhibitory concentration (FIC) index. The Hexane fraction and oxytetracycline combination against antibiotic-resistant S. parauberis strains resulted in a median ${\sum}FIC$ range of 0.502 to 0.516. Thus, the synergistic ranges of median ${\sum}FIC$ < 1 were observed for all combinations of the Hexane fraction and oxytetracycline against S. parauberis. To the best of our knowledge, this is the first report indicating the efficacy of an E. cava extract against fish pathogenic bacterium S. parauberis.

보행 재활을 위한 신체 자중 보상용 모바일 로봇에 관한 연구 (Development of Body-Weight-Support System for Walking Rehabilitation)

  • 서승환;유승남;이상호;한창수
    • 한국산학기술학회논문지
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    • 제11권10호
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    • pp.3658-3665
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    • 2010
  • 최근 고령화 사회로의 진입 및 장애 인구의 증가로 인해, 인간의 복지를 위한 자동화 시스템에 대한 수요가 늘고 있다. 특히 재활 자동화와 관련한 로봇 시스템은 환자 본인 및 치료 보조자에 대한 수고를 덜어주면서도 기존의 전통적인 재활효과에 상응하는 성과를 얻을 수 있을 것으로 기대되고 있다. 본 연구는 하지 근력이 약화된 사용자들의 신체 자중을 보상해줌과 동시에 정상인과 같은 패턴의 보행 훈련을 수행할 수 있는 모바일형 보행 재활 시스템을 제안하고자 한다. 특히, 자중보상 시스템은 신체의 자세 변화 특징을 반영하여, 기구학적인 분석을 통해 구현하였으며 보행 가이드를 위한 제어 알고리즘과 더불어 메인 컨트롤 시스템이 내장된 모바일 플랫폼에 통합 적용되었다. 이러한 모바일 플랫폼은 사용자의 보행 속도의지를 반영하는 UCS(User Command System)와 플랫폼 자체에 내장된 자율주행 알고리즘의 병합되어 운용되도록 고안되었으며, 본 논문에서는 보행 훈련시의 BWS(Body Weight Support)의 효과에 대한 검증에 집중하고자 한다. 이를 위해 인체의 근전도 신호를 측정할 수 있는 EMG(Electromyography) 센서를 활용하여, BWS 및 모바일로봇을 활용한 자중 보상 시의 피험자의 하지 근력 패턴을 측정 및 분석하여, 정상 보행자와의 차이점을 비교함으로서 본 연구의 타당성을 검증하였다.

원발성 폐암 154례에서의 수술율 및 술후 생존 (An Analysis of the 154 Cases of Lung Cancer)

  • 손광현
    • Journal of Chest Surgery
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    • 제20권1호
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    • pp.81-91
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    • 1987
  • During the period of 10 years from July, 1976 to July, 1986, 154 cases of primary carcinoma of the lung - by the cell type, stage, operability, and survival rate in the resectable cases - are analyzed at the Dept. of Thoracic Surgery, Paik Hospital in Seoul. The results are as follows: 1] Histopathological types are squamous cell carcinoma 49% [76 cases], adenocarcinoma 25% [39 cases], undifferentiated large cell carcinoma 9% [14 cases], undifferentiated small cell carcinoma 6% [9 cases], bronchioloalveolar carcinoma 4% [6 cases] and adenosquamous carcinoma 3% [4 cases]. 2] Peak incidence is observed in the 4th decade of life [33%], then 5th [29%] and 3rd [21%] respectively. Male to female ratio is 4 to 1. 3] Evidence of inoperability is observed in 64% [99 cases] by clinical staging workup. Thirty six percent [55 cases] were operated. Of these, post-surgical stage I was 5% [3 cases], stage II, 64% [35 cases] and stage III, 31% [17 cases]. Among total 17 cases of stage III, 14 cases were unresectable with evidence of T2N2M0, while 3 cases were resectable. Resectability is 27%, [41 cases] from the total number of 154 cases. And the resectability for the ex 55 cases is 75% [41 cases]. 4] By cell type, highest resectabitity is the squamous cell carcinoma, 49% [20 cases]. Adenocarcinoma is 32% [13 cases] and bronchioloalveolar, 12% [5 cases]. 5] Survival rate is evaluated for 38 cases of 41 resectable stage I, II and III. Overall 5 year survival rate is 24%, 3 year 32% and 10 year 8%. Survival rate in stage II for 5 year is 25%. In squamous cell type for, 5 year is 42%. Authors believe when surgeons continuous effort of early detection is met with patients early visit, 5 year survival rate for the stage I K II resectable patients will improve more effectively. As well, When the efforts are added to combined modality with radiotherapy and chemotherapy for the stage III selected cases of non-small cell carcinoma patients, the enhancement in survival rate is expected.

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중년여성의 운동실천과 건강상태에 관한 연구 (A Study on the Relations between Physical Exercise and Health Status in Middle-aged Women)

  • 박재순
    • 지역사회간호학회지
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    • 제10권2호
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    • pp.400-411
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    • 1999
  • The purpose of this study was to identify the physical exercise and the effects of exercise on health. Data were collected from Oct. to Dec. 1998. The subjects were 241 middle aged women living in Seoul and near Seoul. The following instruments were used in the study: The questionniare for physical exercise and health status was combined with simple CMI and climacteric symptom. Analysis of the data was done by chi-test. t-test. and ANOVA with SAS program. The results of this study were as follows: 1. The rate of physical exercise was 59.3% of subjects. The mean number of exercise per week was 3.1. Duration at one time exercise was 25.6 minutes. The period of exercise was 18.6 months. And main objective of exercise was health promotion. 2. The physical exercise had differences according to the age. job. monthly income. period of marriage. type of family. and perceived body image. 3. Musculoskeletal and mental complaints were lower in no-exercise group than exercise group(respectively P=0.04. 0.02). According to the duration of exercise. autonomous nervous symptoms was the lowest in 20 minutes group(P=0.04) and psychologic complaints was the lowest in below 60 minutes group(P=0.03). According to the period of exercise. cardiovascular and fatigue complaints was the lowest in 7-12 months maintenance group and autonomous nervous complaint was the lowest in below 3 months maintenance group(P=0.04). This study is only a preliminary effort. so I recommend that the repeated studies be carried out including detailed. comprehensive exercise practice and developing systematic exercise program.

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한국 대학 실내디자인 관련 교육 현황 분석과 개선 방향 연구 (An Analysis and Directional Study on Current Interior Design Related Education in Korea)

  • 서수경
    • 한국실내디자인학회논문집
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    • 제19권6호
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    • pp.121-128
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    • 2010
  • Interior design education has been developed rapidly since the discipline established in Korea in 1980s but unfortunately the development was without any progressive transition until 1990's. When Korean Institute of Interior Design/KIID inaugurated in 1992, interior design education and related research activities began to be intensified. Despite its effort, there were still confusion about the discipline as there were many similar discipline tracks (architecture, design, fine art, & home economic, etc.) each having an own definition of interior design and introducing different aspects of educating the subject. Education program for interior design still not sufficiently supporting the needs of today's rapidly changing industry nor to prepare the diverse needs of the client. In order for interior design major to be effective in the future and fulfill the needs of current industry development within our society, re-evaluation of our current interior design educational programs in Korea is important. This study will be the beginning of a research series. As the first part of the research series, this particular study has been focused on reviewing of current status of interior design majors in the nation and its current condition. While making suggestion for the changes in curriculum, the following points will have to be considered as basic principle. First, understanding the duality of technology and design to accommodate the contents of design discipline. Second, understanding the need of practice and theory combined for practical education. And lastly, considering ways to adopt the human experience in order to develop creativity in oneself. The focus of this research is only on the interior design discipline, and research method as the following; first, analyze current status by reviewing admission data for 2010. Second, process a survey regarding the interior design education and practice-related issues in admissions and collect opinions from educators and professional designers in the field. Thirdly, with reference to previous studies, suggestions will be made for the discipline to be effective in the field. As mentioned earlier, this study series will continue and develop to suggest improvement in interior design program as well as to provide curriculums for students get ready for the industry with more up-to-date knowledges and creativities.

북한 핵의 맥락적 이해 (Contextual Understanding of North Korea Nuclear Problem)

  • 박봉규
    • 한국과 국제사회
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    • 제1권1호
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    • pp.97-114
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    • 2017
  • 본고의 목적은 북한 핵문제 해결의 단서를 모색하기 위하여 북한 핵 문제를 맥락적으로 이해하려는 것이다. 다양한 시도가 무산된 상황에서 북한 핵 문제를 백지 상태에서 가늠해 보자는 것이다. 북한 핵문제는 북한 내부의 전개과정과 밀접하면서 동시에 국제정치적 함의 변화와 관련된다. 북한 핵문제가 체제 생존의 노력으로부터 파생되어 학습 효과에 의해 진화한 프로젝트일 가능성이 크다는 것이다. 소련의 영향으로 발아된 북한 핵문제가 '자위의 원칙'과 결합되면서 중 소 분쟁 등 국제정치적 상황에 의해 진화되었다. 냉전체제 붕괴와 탈냉전기의 도래는 획기적인 변화를 가져왔다. 북한 안보환경의 악화와 더불어 9 11 테러 이후 소위 '악의 축'이 보유하고 있는 대량파괴무기와 테러집단의 연결 가능성은 북한 핵문제를 세계안보 차원으로 확대시켰다. 그러므로 북한 핵문제는 체제생존, 냉전체제의 붕괴, 탈냉전기 안보함의의 변화라는 맥락 속에서 다양한 가능성을 전제하고 지속적인 수렴 과정을 통해 해결의 영역을 확보해야 한다.

A complement to Hoek-Brown failure criterion for strength prediction in anisotropic rock

  • Bagheripour, Mohammad Hossein;Rahgozar, Reza;Pashnesaz, Hassan;Malekinejad, Mohsen
    • Geomechanics and Engineering
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    • 제3권1호
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    • pp.61-81
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    • 2011
  • In this paper, a complement to the Hoek-Brown criterion is proposed in order to derive the strength of anisotropic rock from strength of the corresponding truly intact rock. The complement is a decay function, which unlike other modifications or suggestions made in the past, is multiplied to the function of the original Hoek-Brown failure criterion for intact rock. This results in a combined and extended form of the criterion which describes the strength of anisotropic rock as a varying fraction of the corresponding truly intact rock strength. Statistical procedures and in particular regression analyses were conducted into data obtained in experiments conducted in the current research program and those collected from the literature in order to define the Hoek-Brown's criterion complement. The complement function was best described by a simple polynomial including only three constants to be empirically evaluated. Further investigations also showed that these constants can be related to the other readily available parameters of rock material which further facilitate determining the constants. A great and prime advantage of the proposed complement is that it is mathematically simple including the least possible number of empirical constants which are easily estimated with minimum experimental effort. Moreover, proposed concept does not suggests any change to the original Hoek-Brown criterion itself or its constants and serves whenever anisotropy does exist in the rock. This further implies on the possibility of using any other failure criterion for intact rock in conjunction with the compliment to reach the strength of anisotropic rock.

Spent Fuel and Waste Management Activities For the Cleanout of the 105F Fuel Storage Basin at HANFORD

  • Morton, Mark-R.;Rodovsky, Tomas J.;Lee, Sun-Kee
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2007년도 학술논문요약집
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    • pp.190-191
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    • 2007
  • Cleanout of the F Reactor Fuel Storage Basin (FSB) is an element of the FSB decontamination and decommissioning (D&D) and is required to complete interim safe storage (ISS) of the F Reactor. Following reactor shutdown and in preparation for a deactivation layaway action in 1970, the water level in the FReactor FSB was reduced to approximately 0.6 m (2 ft) over t]to floor. Basin components and other miscellaneous items were left or placed in the FSB. The item placement was performed with a sense of finality, and no attempt was made to place the items in an orderly manner. The F Reactor FSB was then filled to grade level with 6(20of local surface material (essentially a fine sand). The reactor FSB backfill cleanout has the potential of having to remove spent nuclear fuel (SNF) that may have been left unintentionally. Based on previous cleanout of six water-filled FSBs with similar designs (i.e., the B, C, D, and DR FSBs in the 1980's), it was estimated that up to five SNF elements could be discovered in the F FSB (I). In reality about 17 full SNF elements were found in the excavation. This paper covers the technical and programmatic challenges of performing this decommissioning effort with some of the controls used for SNF management. The paper also will highlight how many various technologies were married into a complete package to address the issue at hand and show how no one tools could complete the job, but combined, good progress is being made.

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안전 필수 시스템을 위한 안전성 분석 기법 (A Survey on Safety Analysis Techniques for Safety-Critical Systems)

  • 김의섭;윤상현;유준범
    • 중소기업융합학회논문지
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    • 제2권1호
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    • pp.11-18
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    • 2012
  • 소프트웨어의 규모가 커지고 복잡해지면서 소프트웨어의 기능적 실패(Functional Failure)를 만들어 내는 위험(Hazard) 요소들을 분석하기가 어려워지고 있다. 안전 필수 시스템(원자력 발전소, 항공관제 시스템, 철도 운영 시스템)에서 이런 기능적 실패는 곧 큰 사고 (인명피해, 환경오염) 로 이어지게 된다. 따라서 이러한 기능적 실패를 방지하고 소프트웨어의 안전성을 높이기 위해서는 소프트웨어 안전성 분석이 필요하다. 하지만 몇 가지 이유 (시간과 노력, 안전성 분석 기법의 다양한 지식 부족, 기관이나 회사의 관습적인 방법 사용) 로 적절하지 못한 안전성 분석 기법을 선택하게 되는 경우가 있다. 따라서 본 논문에서는 기존 안전성 분석 기법과 최신 안전성 분석 기법, 통합 모델 몇 가지를 소개 하겠다. 이것을 통해 전문가는 여러 종류의 안전성 기법을 간략하게 확인 할 수 있을 것이고, 시스템에 맞는 안전성 분석 기법을 선택하는데 도움을 받을 수 있을 것이다.

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