• 한국가스학회지
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• 제20권6호
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• pp.95-101
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• 2016

본 연구에서는 다양한 수소 생산 방법 중 하나인 천연가스 수증기 개질반응(natural gas steam reforming reaction)에 대해 일반적인 충전층반응기와 반응기와 수소분리기가 결합된 새로운 형태의 분리막 반응기에서의 성능에 대한 비교분석을 수행하였다. Xu 와 Froment에 의해 기존에 발표된 실험결과를 바탕으로 상업용 화학공정모사기인 Aspen $HYSYS^{(R)}$ 모델이 개발되었으며, 반응온도, $H_2$ 투과량, Ar 유량 등이 분리막 반응기에서의 반응물의 전환율 및 $H_2$ 수율 향상도에 미치는 영향에 대해 분석한 결과 분리막 반응기에서 보다 많은 양의 수소수율 및 메탄전환율이 확인되었다. 더 나아가, 전체 시스템에서 필요로 하는 열량을 공급하기 위해 요구되는 천연가스의 양에 초점을 맞춰 분리막 반응기에서의 원가절감 가능성을 평가한 결과, 분리막 반응기에서 10.94%의 원가절감이 관찰되었다.

• 대한간호학회지
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• 제40권1호
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• pp.69-77
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• 2010

This methodological research was designed to develop performance evaluation key indicators (PEKIs) for management by objectives (MBO) and to estimate their weights for hospital nurses. Methods: The PEKIs were developed by selecting preliminary indicators from a literature review, examining content validity and identifying their level of importance. Data were collected from November 14, 2007 to February 18, 2008. Data set for importance of indicators was obtained from 464 nurses and weights of PEKIs domain was from 453 nurses, who worked for at least 2 yr in one of three hospitals. Data were analyzed using $X^2$-test, factor analysis, and the Analytical Hierarchy Process. Results: Based upon Content Validity Index of .8 or above, 61 indicators were selected from the 100 preliminary indicators. Finally, 40 PEKIs were developed from the 61 indicators, and categorized into 10 domains. The highest weight of the 10 domains was customer satisfaction, which was followed by patient education, direct nursing care, profit increase, safety management, improvement of nursing quality, completeness of nursing records, enhancing competence of nurses, indirect nursing care, and cost reduction, in that order. Conclusion: PEKIs and their weights can be utilized for impartial evaluation and MBO for hospital nurses. Further research to verify PEKIs would lead to successful implementation of MBO.

• 한국정보전자통신기술학회논문지
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• 제9권6호
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• pp.566-572
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• 2016

소프트웨어 개발과정에서 소프트웨어 신뢰성은 매우 중요한 문제 중에 하나이다. 소프트웨어 고장현상을 분석하기 위하여 비동질적인 포아송과정에서 고장 발생 추이를 의미하는 위험함수가 고장시간에 독립적으로 일정하거나, 종속적인 경우, 즉 비-증가 또는, 비-감소하는 속성을 가질 수 있다. 본 연구에서는 소프트웨어 제품 테스팅 과정에서 고장 수명분포로서 어랑분포의 다양한 형상모수를 고려한 소프트웨어 개발 비용 분석에 대하여 연구되었다. 소프트웨어 고장현상을 분석하기 위하여 모수추정은 최우추정법이 사용되었다. 따라서 본 논문에서는 어랑분포의 형상모수를 고려한 소프트웨어 개발비용모형 분석을 위하여 소프트웨어 고장간격 시간자료를 이용하여 비교 및 평가하였다. 그 결과 형상모수에 따른 비용곡선을 비교 하였을 때 형상모형이 작을수록 비용이 많고 소프트웨어 최적 방출시간이 지연 됨을 알 수 있었다. 이 연구를 통하여 소프트웨어 개발자들에게 소프트웨어 형상모수에 따른 개발 비용을 탐색하는데, 기본적으로 도움을 줄 수 있는 사전정보의 역할을 할 수 있을 것으로 판단된다.

• Anatomy and Cell Biology
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• 제56권1호
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• pp.86-93
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• 2023

Age at death estimation has always been a crucial yet challenging part of identification process in forensic field. The use of human skeletons have long been explored using the principle of macro and micro-architecture change in correlation with increasing age. The clavicle is recommended as the best candidate for accurate age estimation because of its accessibility, time to maturation and minimal effect from weight. Our study applies pre-trained convolutional neural network in order to achieve the most accurate and cost effective age estimation model using clavicular bone. The total of 988 clavicles of Thai population with known age and sex were radiographed using Kodak 9000 Extra-oral Imaging System. The radiographs then went through preprocessing protocol which include region of interest selection and quality assessment. Additional samples were generated using generative adversarial network. The total clavicular images used in this study were 3,999 which were then separated into training and test set, and the test set were subsequently categorized into 7 age groups. GoogLeNet was modified at two layers and fine tuned the parameters. The highest validation accuracy was 89.02% but the test set achieved only 30% accuracy. Our results show that the use of medial clavicular radiographs has a potential in the field of age at death estimation, thus, further study is recommended.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1425-1432
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• 2010

In large construction site, although soil conversion factor is so significant to preliminary design, operation design and calculating the cost of construction that it is important to take reasonable estimation and application, the standard of soil conversion factor for weathered ground doesn't clearly suggested yet. So in this study, at first we obtain the image using DSLR - high resolution camera and Laser scanner in the Haeng-Bok city constructin site, then analysis the ratio of soil and rock using various image processing method(Sobel method, Laplace method, Highpass filter, Hue and Saturation analysis). Mutual comparation with the result of image processing analysis and manual segmentation of 5case image in the cad. As a result, best image processing method was different for each case. In case of high propotion of rock, Laplace was best and in case of high propotion of soil, Highpass was best, and mixed case Laplace was best.

• Architectural research
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• 제14권3호
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• pp.109-116
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• 2012

In order to shorten construction duration in high-rise project, construction company tried to make various system method toward simplifying construction method and shortening construction duration. Though high-rise tower-type residential project are growing, there are few case study. Then, the data for preliminary schedule planning in high-rise tower-type residential project are rare. This purpose of research shows construction method in structural work in high-rise tower-type residential project, suggests schedule planning in structural work through case studies. The structural work in high-rise tower-type residential project was divided 1) completion of form in lower part and 2) the typical floor under penthouse. The statistical analysis were done in two parts, the data from analysis were used in simulation. Finally, researcher confirmed the difference between real construction duration and the figure from simulation. The results shows that the more construction duration is long, the less ACS's cost is low. It means the effectiveness is increasing in ACS, if the floor number is high.

• 한국재난정보학회 논문집
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• 제19권1호
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• pp.18-30
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• 2023

연구목적: 본 연구는 서울시 철도터널 건설공사의 공사계측비 분석 및 개선방안을 도출하여 건설계측의 신뢰향상으로 계측기술 발전에 기여한다. 연구방법:공사계측비의 설계 및 계약 현황, 공사계측비의 적용 현황 및 분석, 안전관리비와 품질관리비 분석, 이를 개선하기 위해 계측관리용역에 대한 대가 산정기준 적용 확대와 발주처에서 직접 발주하는 방안을 제시한다. 연구결과: 그동안 건설공사에 포함하여 발주하던 계측관리용역을 입찰참가자격 사전심사를 통하여 발주처에서 계측업체를 직접 선정하여 계측을 수행하면 계측 품질을 높이고 정확한 계측데이터 확보가 가능하다. 결론:계측관리용역에 대한 대가 산정기준은 시공사에서 하도급으로 수행하게 되는 순공사비 내에 포함하는 방식이 아닌 발주처 직접 발주로 엔지니어링진흥법에 따른 실비정액가산방식과 지반조사 표준품셈의 계측관리비 산출기준의 적용을 확대해야 한다.

• 자원ㆍ환경경제연구
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• 제22권2호
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• pp.367-391
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• 2013

후쿠시마원자력발전소의 사고를 계기로 원전의 안전대책비용, 사고위험대응비용과 같은 외부비용들의 존재가 부각되고 있다. 이에 본 연구는 원전의 외부비용들 중에서 추가안전대책비용과 사고위험대응비용을 추정하고, 이를 발전원가 및 전기요금에 반영하여 변화정도를 살폈다. 원전의 추가안전대책비용은 70~90%의 이용률에서 0.53원/kWh~0.80원/kWh으로 원전의 발전원가에 큰 영향을 미치지는 않는다. 사고위험대응비용은 원전사고피해규모별, 사고발생빈도별, 이용률별로 0.0025원/kWh~26.4188원/kWh로 추정되었다. 사고위험대응비용을 포함시키면 원전발전원가는 47.58원/kWh~85.92원/kWh가 된다. 2011년을 기준으로 사고위험대응비용을 내부화한 경우의 전기요금의 증가율은 70~90%의 이용률에서 0.001%~10.0563% 로 추정되었다. 본 연구는 원전의 외부비용을 내부화하는 방법으로서 외부비용을 발전원가에 포함하여 전기요금에 반영하였다. 본 연구는 지금까지 우리나라에 논의되지 않았던 원전 외부비용을 내부화하는 방법의 하나가 될 것이다.

• 한국도로학회논문집
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• 제18권5호
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• pp.75-82
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• 2016

PURPOSES : This study was initiated to estimate the benefits from the campaign to prevent drowsy driving crashes on expressways. The study was conducted by the Korea Expressway Corporation using a contingent valuation method. METHODS : First, a questionnaire was designed for a preliminary survey. From the survey's results, the initial willingness to pay for the campaign was determined by averaging different amounts of payments chosen under virtual scenarios in the survey. The willingness to pay data was used to find a first bid price for the open-ended method used for the second survey. After that, a primary questionnaire was designed and conducted using a single dichotomous choice question (SDBCQ). Drivers at expressway resting areas were asked their willingness to pay for the campaign. Based on statistical analysis using data collected from the second survey, the mean willingness to pay was estimated using a probability utility function. Finally, the benefit from the campaign was calculated using the estimated willingness to pay and accident data on expressways. CONCLUSIONS : Based on the result from the contingent valuation method, the benefit from the campaign to prevent drowsy driving crashes was estimated to be 170.6 won per expressway trip. The benefit is to be paid as an additional toll. In addition, the traffic crash cost estimate is about 2,209,680,000 won less than the cost during the same period in 2014.

• 풍력에너지저널
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• 제13권4호
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• pp.50-57
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• 2022

Renewable energy is emerging as a way for the government to carry out its 2030 carbon-neutral policy. In this regard, the demand for wind turbine generators for renewable energy is increasing. As a result of restrictions due to civil complaints, offshore wind power generators are actively being developed. At this time, offshore wind power generation has higher maintenance costs, material costs, and installation costs compared to onshore wind power generation. So, an economic evaluation that calculates imports and costs is an important task. The levelized cost of energy (LCOE) is an economic evaluation index used in the energy field. In this paper, based on AEP calculated by windpro, the LCOE calculated by the wind power cost estimation model published in the NREL Economic Analysis Report, installing one 15 MW unit and installing one 20 MW unit and seven units were reviewed and analyzed. As a result, AEP was calculated as 0.140($/Kwh) for the installation of a single 15 MW, 0.142($/Kwh) for the installation of a single 20 MW, and 0.119 ($/Kwh) for the installation of a 20 MW farm. Therefore, it was confirmed that the installation of the single 20 MW was more economical than the installation of the single 15 MW and the installation of the 20 MW farm was most economical.