• 한국방사선학회논문지
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• 제5권2호
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• pp.67-72
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• 2011

선형가속기에 설치된 OBI (On-Board $Imager^{TM}$ Varian Medical Systems. USA)의 정도관리는 일간 및 주간으로 하고 있으며 이때 기하학적인 정확성은 매우 중요하게 된다. 본 실험에서 4개월간 선형가속기의 OBI 장치 정도관리용 팬톰을 사용하여 일간과 주간으로 선형가속기의 기계적인 중심점(isocenter)과 가시화된 레이저의 중심점의 일치정도 및 OBI 장치 및 레이저의 중심점을 비교하여 데이터화함으로써 OBI 장치의 기계적 정확성과 정도관리용 팬톰을 사용하여 일간, 주간으로 선형가속기 환자위치 및 레이저의 등 중심점을 체크하여 데이터화함으로써 사후관리 및 환자치료 성적을 높일 수 있다고 사료된다.

• Progress in Superconductivity
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• 제10권1호
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• pp.1-5
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• 2008

Magnetocardiography (MCG) is a non-contact, non-invasive, and harmless diagnostic tool to detect the abnormal electrical conductivities of the heart caused by the various coronary artery disease or cardiac muscular disease. The purpose of this study is to identify whether MCG signals and MCG parameter values vary depending on the location of sensor assembly. It will be an important reference for the standard measurement. Four healthy male subjects (33.3$\pm$6.3 years) participated in this study. Basal recording was made at 20 mm apart from the chest surface. All subjects were requested to take a regular breathe while MCG was taken. The gap between the chest surface and the bottom of the sensor assembly was 20, 40, 60, and 80 mm. Recording was made using 64 channel MCG system (Axial type, first order gradiometer) developed by Korea Research Institute of Standards and Science (KRISS). After resting for two minutes in a supine position on the bed in magnetically shielded room, MCG were recorded for 30 s. As the sensor location is getting away from the chest surface signal, the amplitude of R and T wave peak decreases to 70% (at 40 mm gap), 50% (at 60 mm), and 37% (at 80 mm) of the reference strength measured (y = $1.3903e^{-0.0169x}$, $R^2$ = 0.99; where y=amplitude remained after reduction, x=distance between chest surface and sensor location). The regression equations may be used as a good reference to calculate how much strength will be decreased by the distance. In MCG parameters, most values of parameters were decreased as the gap was increased. As an example, the current moment at T-wave peak reduced to 52% (at 40 mm gap), 33% (at 60 mm), and 19% (at 80 mm). However, the difference caused by the gap could be reduced by considering the distance when the MCG parameters were calculated. The study results can be used as a useful reference to design the baseline and the sensor location.

• 정보처리학회논문지A
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• 제10A권4호
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• pp.279-284
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• 2003

본 논문에서는 Montgomery 알고리즘을 기반으로 시스톨릭 어레이 구조를 이용한 효율적인 Radix-4 모듈러 곱셈기 구조를 제안한다. 제안된 알고리즘을 이용하여 모듈러 곱셈을 위한 반복의 수가 감소되었으며, 따라서 n-비트의 모듈러 곱셈을 수행하기 위하여 (3/2)n+2 클럭이 소요된다. 그러나 하드웨어의 이용도를 감안할 때 두 개의 곱셈에 대한 중첩(interleaving) 연산이 가능하며, 가장 빠른 시기에 새로운 곱셈을 시작한다면 하나의 모듈러 곱셈을 수행하기 위하여 평균 n/2 클럭이 필요하다. 제안된 구조는 시스톨릭 어레이 구조의 잇점으로 규칙성과 확장성을 갖기 때문에 효율적인 VLSI 구조로 설계하기가 용이하다. 기존의 다른 구조들과 비교하여 볼 때 제안된 구조는 상대적으로 적은 하드웨어들을 사용하여 높은 수행 속도를 보여주었다.

• 대한지역사회영양학회지
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• 제9권4호
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• pp.519-527
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• 2004

This study was designed firstly to measure the job satisfaction (JS) levels of personnel engaged in contract food-service management company (CFMC), secondly to compare the job satisfaction levels by personal and company-related characteristics, and thirdly to identify the effects of JS facets on overall job satisfaction. Of 1135 respondents, there were 712 employees in the headquarters and 423 in the branch office. From an analysis on job satisfaction, overall job satisfaction level was 3.22 out of a maximum 5 and the co-worker (3.71) facet of JS was the highest job satisfaction followed by supervision (3.32), work itself (3.26), working condition (3.15), promotion (2.95) and payroll (2.74). In comparison of job satisfaction by personal characteristics, the personnel who were male (p < .01), had associate degrees (p < .01) or long-term careers in foodservice field (p < .05), or were regular employees (p < .01) perceived significantly higher than others for overall JS. In comparison of the job satisfaction by company-related characteristics, overall JS was significant by company scale (p < .01) and by work place (p < .05), but it was not significant by operating group. Finally, on the regression analysis for the effects of JS facets on overall JS, adjusted R2 was 0.534 (p < .001) and all six JS facets, especially payroll, had a positive effect on overall JS significantly (p < .001). Considering that the goal of enterprise on profit-making through customer satisfaction (CS) and the role of personnel on CS at moment of thrust (MOT), the findings confirmed the necessity for continuous internal marketing and human relation management focusing on the lower level of JS facets.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2014년도 추계학술대회
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• pp.17-18
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• 2014

파력발전기의 유형은 진동수주형, 월파형, 가동물체형으로 나누어진다. 그 중 가동물체형은 파도에너지를 기계적 운동에너지로 전환하여 발전하기 때문에 가동물체의 운동량이 증가해야 발전량이 증가 할 수 있다. 본 논문에서는 가동물체형 파력발전기를 발전시스템이 있는 구조물 본체와 가동부유체로 구성하고 바 형태의 다리로 연결하였다. 다양한 정면파 조건에서 가동부유체와 구조물 본체 간 연결 방식 변화에 따른 운동 특성을 연구하고, 발전축의 모멘트와 각속도를 계산하였다. 이 연구는 가동물체형 파력발전기의 설계시 기초 자료로 사용 될 수 있다.

• 대한안전경영과학회지
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• 제19권1호
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• pp.15-25
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• 2017

The findings were summarized as follows. The safety check by manufacturer showed that 6 of 13 companies are over the average occurrence of defects. It was expected that there would be a difference between manufacturing technology capability and production system of each manufacturer. Consequently, manufacturers should institutionally improve and strengthen certification items for the upward standardization of safety certification before factory. Second, the safety check by year showed that the results of this study accord with those of previous studies on defect time. Consequently, manufacturers should classify the 3-year-old equipment for vehicle-mounted MEWP into a special check subject to do a nondestructive test according to proven results, and also reflect the test in a safety test system to do regular preventive activities of equipment defects. Third, the safety check by part showed that the boom and outrigger parts of vehicle-mounted MEWP have the most defects. Stress concentration resulted in defects as the boom part was most frequently operated in the structural parts for a real work. To prevent this, it is suitable to improve the hardness of boom materials. The outrigger part needs improvement in safety devices with materials. As an outrigger supports the overturning moment of equipment, it is most affected by its load based on the operating radius, resulting in fatigue crack.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.119-122
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• 2007

트루텍(TRUTEC) 빌딩은 서울 마포구 상암동 DMC(Digital Media City) 단지 내에 위치한 오피스 빌딩이다. 본 건물은 독일 설계사무소의 원설계를 바탕으로 국내 실시설계가 이루어졌으며 지하 5층 지상 12층 중규모 건물로서 그 외관을 독특한 3차원 입체 유닛을 활용한 커튼월로 마감하였다. 기존의 커튼월 공사에서 보여주었던 평면적인 모델을 탈피하고 알루미늄 바를 3차원 입체 가공함으로써 사각형 박스의 단순하게 보여질 지 모르는 입면을 독특하게 구현해해는 데 성공했다. 18개월의 공기를 준수하기 위해 커튼월 공사는 공사계약시점부터 주요 공정으로 분리되어 공정관리가 이루어졌으며, 지속적인 공정 업데이트 및 유기적인 이해당사자 회의를 통해 디자인 현안들을 해결해 나갔다. 최초 시도되는 형태의 입면과 알루미늄 바의 가공방법에서 발생할 수 있는 리스크를 최소화하기 위하여 단계별 Mock-Up을 실시하였으며, 피드백을 통해 예상되는 문제점들을 도출하고 분석하였다. 이를 통해 촉박한 공기의 준수와 품질 확보를 이룰 수 있었다.

• 보존과학회지
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• 제6권2호
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• pp.141-148
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• 1997

각종 국토개발사업이 본격적으로 시작된 1970년대 이후 그에 따른 발굴조사도 매년 증가되고 있다. 다양한 재질로 이루어진 유물은 출토후 보관환경에 따라 돌이킬 수 없는 손상을 받을 수 있다. 출토 유물의 보존에 대한 중요성은 증가되고 있으나, 발굴을 담당하는 기관과 비교하여, 출토된 유물을 보존처리하는 기관은 소수에 불과한 실정이다. 일반적으로 출토된 금속유물은 불안정하여 쉽게 손상되어진다. 특히 주조철제는 발굴후 건조되지 않도록 해야 한다. 이는 출토된 주조철제가 흙, 부식층과 금속심으로 이루어진 층 사이에서 건조로 인해 유물이 순간적으로 붕괴되어지기 때문이다. 출토된 금속유물의 안전한 보존방법은 다음과 같이 요약할 수 있다. (1)먼저 발굴현장에서 금속유물은 환경변화에 따른 손상을 방지하기 위해 유물포장용 특수비닐로 밀봉처리 하거나 알칼리 용액속에 침적시키는 것이다. (2)현장에서 임시 보존처리후 유물은 보존처리실에서 안전한 방법에 의한 처리를 해야 한다. (3)처리된 유물은 일정한 온${\cdot}$습도 유지, 주기적인 상태조사, 자외선 차단 등 안정한 보관환경을 유지시켜야만 재부식을 방지할 수 있다.

• 기술혁신연구
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• 제7권1호
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• pp.151-175
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• 1999

This study develops principles for determining and managing costs applicable to grants and cooperative agreements for basic research. We investigated financial management policies of funding agencies and foundations in the United States, United Kingdom, Canada, Germany, Japan and Korea. Also we surveyed opinions of researchers and research fund administrators in Korean universities. Based on our review of funding agencies and our survey, the recommended management policies for grants and cooperative agreements are as follows: (1) Cost Structure. Cost of a sponsored agreement is comprised of the allowable direct costs and allocable portion of the allowable indirect costs. Direct costs can be further divided into salaries and wages, equipment, and other direct costs. (2) Salaries and Wages. Salaries and wages applied to a grant are paid for services rendered to the project during the period of performance of the particular agreement. In order to give researchers financial incentive, researcher allowance can be paid up to 30% of his/her regular salary. (3) Equipment. Any property purchased with grants which has an acquisition cost of 5,000,000 won or more per item and a normal life expectancy of two years or more is defined as equipment. Expenditures for special purpose equipment are allowable provided the acquisition of items is necessary for the research supported by the grant. (4) Other Direct Costs. Other direct costs are comprised of travel (both domestic and foreign), materials, other costs. Other costs may not exceed 30% of total other direct costs. (5) Indirect Costs. Since there is no clear consensus on indirect costs and additional budget is necessary to support actual indirect costs, the practical policy at the moment is to give a research support expense in lieu of indirect costs. In the future, however, some form of actual indirect costs should be supported. This study develops principles for determining and managing costs applicable to grants and cooperative agreements funded by the Ministry of Science and Technology. This research can be applied to other governmental agencies to give consistency and uniformity in administration of grants and cooperative agreements.

• Coupled systems mechanics
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• 제2권3호
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• pp.231-253
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• 2013

The impact of spar-nacelle-blade coupling on edgewise dynamic responses of spar-type floating wind turbines (S-FOWT) is investigated in this paper. Currently, this coupling is not considered explicitly by researchers. First of all, a coupled model of edgewise vibration of the S-FOWT considering the aerodynamic properties of the blade, variable mass and stiffness per unit length, gravity, the interactions among the blades, nacelle, spar and mooring system, the hydrodynamic effects, the restoring moment and the buoyancy force is proposed. The aerodynamic loads are combined of a steady wind (including the wind shear) and turbulence. Each blade is modeled as a cantilever beam vibrating in its fundamental mode. The mooring cables are modeled using an extended quasi-static method. The hydrodynamic effects calculated by using Morison's equation and strip theory consist of added mass, fluid inertia and viscous drag forces. The random sea state is simulated by superimposing a number of linear regular waves. The model shows that the vibration of the blades, nacelle, tower, and spar are coupled in all degrees of freedom and in all inertial, dissipative and elastic components. An uncoupled model of the S-FOWT is then formulated in which the blades and the nacelle are not coupled with the spar vibration. A 5MW S-FOWT is analyzed by using the two proposed models. In the no-wave sea, the coupling is found to contribute to spar responses only. When the wave loading is considered, the coupling is significant for the responses of both the nacelle and the spar.