• 핵의학기술
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• 제13권1호
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• pp.63-66
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• 2009

Purpose: ACR (American College of Radiology) offers variable parameters to PET/CT quality control by using ACR Phantom. ACR Phantom was made to evaluate parameters which are uniformity, attenuation, scatter, contrast and resolution. Manual analysis method wasn't good for the use of QC because values of parameter were changed as it may user and it takes long time to analysis. Ki-Chun Lim, a nuclear scientist in AMC, developed program that automatically analysis values of parameter by using ACR Phantom to overcome above problems. In this study, we evaluated automatic analysis program's usability, through the comparing SUV of each method, reproducibility of SUV when repeated analysis and the time required. Materials and Methods: Using Flangeless Esser PET Phantom, the ideal ratio of 4 : 1 hot cylinder and BKG but it actually showed a ratio of 3.89 to 1 hot cylinder and BKG. SIEMENS Biograph True Point 40 was used in this study. We obtained images using ACR phantom at Fusion WB PET Scan condition (2 min/bed) and 120 kV, 100 mAs CT condition. Using True X method, 3 iterations, 14 subsets, Gaussian filter, FWHM 4 mm and Zoom Factor 1.0, $168{\times}168$ image size. We obtained Max. & Min. SUV and SUV Mean values at Cylinder (8, 12, 16, 25 mm, Air, Bone, Water, BKG) by automatic program and obtained SUV by manual method. After that, we compared manual and automatic method. we estimate the time required from opened the image data to final work sheet was completed. Results: Automatic program always showed same result and same the time required. At 8, 12, 16 and 25 m cylinder, manual method showed 6.69, 3.46, 2.59, 1.24 CV values. The larger cylinder size became, the smaller CV became. In manual method, bone, air, water's CV were over 9.9 except BKG (2.32). Obtained CV of Mean SUV showed BKG was low (0.85) and bone was high (7.52). The time required was 45 second, 882 second respectably. Conclusions: As a result of difference automatic method and manual method, automatic method showed always same result, manual method showed that the smaller hot cylinders became, the lager CV became. Hot cylinders mean region size, the smaller hot cylinder size becomes we had some trouble in doing ROI poison setting. And it means increase in variation of SUV. The Study showed the time required of automatic method was shorten then manual method.

• 한국산학기술학회논문지
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• 제19권11호
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• pp.497-505
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• 2018

대형폐기물량을 산정해야 하는 상황에서 드론을 이용하여 폐기물의 3차원 모형을 구축하여 폐기물의 정량적인 양을 산출할 수 있다. 필요에 따라서 단시간에 폐기물량을 산정해야 하는 경우가 있다. 본 연구에서는 다양한 비행변수와 지상기준점 측량을 통해 드론 기반의 3차원 모형을 구축하고 정확도와 소요되는 시간의 관계를 분석하였으며 단시간에 폐기물량 산정을 위한 적절한 드론 활용 기법을 도출하고자 하였다. 드론을 이용하여 폐기물의 영상을 촬영하여 자동정합하고 3차원 좌표를 가지는 모형을 생성하였다. 3차원 모형의 정확도는 RMSE(Root Mean Square Error) 계산을 통해 평가하였다. 총 49개 모형의 RMSE는 최고 0.08부터 최저 124.75로 나타났다. 정확도가 높은 상위 15개 모형의 소요시간과 그 특성을 분석한 결과, RMSE가 0.08로 영상의 정확도가 가장 높은 1번 모형의 소요시간이 954.87분으로 나타났다. 또한 소요시간이 98.27분으로 가장 짧은 10번 3차원 모형의 RMSE는 0.15로써 정확도가 가장 높은 모형과 큰 차이가 없음을 확인하였다. 가장 효율적인 드론 비행변수는 비행고도 150m에서 높은 촬영중복도(종중복도 60-70%, 횡중복도 30-40%)이며 영상정합에 필요한 지상기준점 개수는 최소 10개 이상인 것으로 나타났다. 본 연구의 결과는 드론을 활용하여 신속하고 효율적인 폐기물량 산정하는데 기초자료로 활용될 수 있다.

• 문화기술의 융합
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• 제7권3호
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• pp.509-515
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• 2021

이 연구는 패스파인더 시뮬레이션 프로그램을 활용하여 학교의 피난 안전성 확보를 위한 효율적인 학급 층별 배치 방안 분석을 목적으로 한다. 경사로와 계단이 함께 설치된 고등학교 5층 건물을 대상으로 층별 인원배치에 따른 REST (Required Safe Egress Time, 피난소요시간)을 분석하여 효율적인 피난 방법과 안전성을 평가하였다. 현재 상태의 인원배치는 기준 RSET을 초과함으로써 피난안전성에 문제가 있다는 결과를 얻었다. 학생들을 3층, 4층, 5층에 배치했을 때 기준 RSET보다 가장 많은 시간을 초과하는 결과를 얻었다. 학생들을 1층, 2층, 3층에 배치했을 때 기준 RSET보다 가장 짧게 피난을 완료하는 결과를 얻었다. 현재의 상태에서 위치별로 피난출구를 지정하여 피난을 유도했을 때 기준 RSET을 단축시키는 결과를 얻었다. 결과적으로 고층 학교 건물에 학생들을 배치할 때는 저층부터 배치하는 것이 피난안전성 측면에서 효과적이며, 화재 시 위치별로 가까운 출구를 활용하여 피난할 수 있도록 피난출구를 지정한 사전 훈련이 필요하다. 향후 연구과제로 특정 위치에 화재가 발생했을 때 해당 위치의 자동방화셔터의 개폐여부에 따른 RSET에 대한 추가적인 연구가 필요하다.

• Geomechanics and Engineering
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• 제28권4호
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• pp.421-435
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• 2022

The necessity of estimating the time and cost required for tunnel construction has led to extensive research in this regard. Since geological conditions are significant factors in terms of time and cost of road tunnels, considering these conditions is crucial. Uncertainties about the geological conditions of a tunnel alignment cause difficulties in planning ahead of the required construction time and costs. In this paper, the continuous-space, discrete-state Markov process has been used to predict geological conditions. The Monte-Carlo (MC) simulation (MCS) method is employed to estimate the construction time and costs of a road tunnel project using the input data obtained from six tunneling expert questionnaires. In the first case, the input data obtained from each expert are individually considered and in the second case, they are simultaneously considered. Finally, a comparison of these two modes based on the technique presented in this article suggests considering views of several experts simultaneously to reduce uncertainties and ensure the results obtained for geological conditions and the construction time and costs.

• 한국중재학회지:중재연구
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• 제27권1호
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• pp.37-57
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• 2017

An arbitrator in Pakistan is required to file an arbitral award in a civil court of competent jurisdiction for its recognition and enforcement if an arbitral award is domestic or before the concerned High Court if the arbitral award is international. The court of law is required to issue a decree upon submitted arbitral award if an interested party do not apply for modification or remission of an arbitral award and do not challenge it for setting it aside or for revocation of its recognition and enforcement within a prescribed time limit. The challenging process of an arbitral award can be started by the aggrieved party of an arbitration agreement at the seat of arbitration or at the place where recognition and enforcement of an arbitral award is sought. The aggrieved party to an arbitration agreement is required to challenge an arbitral award within a prescribed time limit if contracting parties have not excluded the right to challenge an arbitral award. Limitation for challenging an arbitral award in Pakistan is 30 days under article 158 of the Limitation Act 1908, starting from the date of service of notice of filling of an arbitral award before the court of law. Generally, 90 days are given for an appeal against decision of the civil court of law under section 96 of the Code of Civil Procedure 1908, it is therefore highly recommended that challenging time of an arbitral award should be increased from 30 to 90 days.

• 한국항공우주학회지
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• 제43권7호
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• pp.648-656
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• 2015

능동 합성개구레이더 위성의 주요기동은 SAR 안테나 방향을 바꾸기 위한 롤축 기동이다. 그리고 도플러 중심주파수 변화를 최소화하기 위하여 요축 기동이 요구된다. 따라서 토크/모멘텀 용량을 대부분 롤축으로 그 다음으로 요축으로 할당하는 것이 합리적이다. 하지만 궤도 조정 때문에 가끔씩 피치축으로 중심으로 큰 각도의 회전이 요구된다. 본 논문에서는 롤축과 요축의 연속회전을 통한 피치축 기동시간 단축 방법에 대해서 살펴본다. 이들 두 축이 피치축에 비해서 기동성능이 좋기 때문에, 피치축을 중심으로 큰 회전이 요구될 때는 기동시간 단축이 가능하다.

• 산업공학
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• 제16권4호
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• pp.450-462
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• 2003

In this paper, we deal with a process and layout design for producing a planned amount of Sikhye in a given limited time period under a reasonable production schedule. We represent a Sikhye production line as a vector N, the element of which denotes the number of tanks required in each process and our objective is to find an appropriate vector which minimizes the total investment cost. We suggest a systematic method for finding an appropriate N and an appropriate layout to N. In detail, first, we decide the required sequence of processes and the required operations for each process and we estimate standard operating times. Second, constructing a precedence diagram, we find a critical path in order to reduce the total production lead time for a batch of Sikhye. Third, given a limited N space, we manage to construct manually each production schedule using both the processing times of the critical operations and transfer times. Finally, we find an optimal vector N which gives a minimum investment cost and meets both the time constraint and quantity constraint. In addition, with the estimated relative size of each tank, we suggest an appropriate conceptual layout design including an expansion area for future demands, based on the span technique used in the field of architectural design.

• 동의생리병리학회지
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• 제19권5호
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• pp.1292-1295
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• 2005

Effects of the Seokchangpo-Wonji-Tang on recovery from disorder of stomach, liver and mental-faculty in alcoholism were studied using male Sprague-Dawley rats. The rats were assigned into 4 groups; normal, control and Seokchangpo-Wonji-Tang(SWT) group. Control group administered ethanol(25 v/v %) at a dose 3g/kg, while SWT group administered 50mg/kg of SWT 30min before treating same dose of ethanol as control group for 10 days, orally. The gastric ulceration and also GOT and GPT activities in rats were checked, and all groups were subjected to trials of straight channel on the 1st day and to those of multiple T-maze during the following 3 days. The gastric ulceration, GOT and GPT activities were increased in control group, but decreased in SWT group significantly. The time required in normal group for the straight channel of the 2nd and 3rd trials was significantly shorter than that of the 1 st, while the control group showed no significance. In the time required for the multiple T-maze trials, the control group showed no significance. But in the straight or T-maze trials, the SWT group showed significant decrease in the time required against the control group.

• Archives of Plastic Surgery
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• 제49권5호
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• pp.696-700
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• 2022

We performed distal bypass and free flap transfer in a single-stage operation to repair an extensive soft tissue defect in an ischemic foot of an 84-year-old woman. The nutrient artery of the free flap was anastomosed to the bypass graft in an end-to-side manner. Subsequently, the bypass graft became occluded on several occasions. Although intravascular and surgical interventions were performed each time, the bypass graft eventually became completely occluded. However, despite late occlusion of the nutrient artery, the free flap has remained viable and the patient is ambulatory. The time required for a transplanted free flap to become completely viable without a nutrient artery is likely longer for an ischemic foot compared with a healthy foot. However, the exact period of time required is not known. A period of month was required in our patient. We report this case to help clarify the process by which a free flap becomes viable when applied to an ischemic foot.

• 대한전기학회논문지:전력기술부문A
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• 제51권7호
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• pp.349-361
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• 2002

Occasionally, equipment in a distribution system fails due to damage from weather, vandalism, or other causes. Failures and unexpected events do not always occur as and where expected. Therefore, a good contingency plan, multi-zone or otherwise, provides flexibility by locating switches at various strategic locations so that parts of a feeder can be picked up in the event of line outages at various places. It is possible to create feeder system layout that achieve remarkable contingency support economics, even as their normal peak loading levels approach thermal capacity, by utilizing six, seven, or even nine switchable zones per feeder. But many switchable zones per feeder are of questionable practicality and effectiveness, because of the complexity and time required for the switching operation. In practice, a zonal scheme with between three and four zones will usually provide complete contingency backup for all feeders. Line switches have both capital and maintenance costs, the planning for multi-zonal schemes is considerably more difficult than or loop or single-zone systems, and the required switching operations required during contingencies take more time. But multi-zonal schemes are used because these costs come to far less than the cost of additional capacity required for loop or single-zone. In this paper, we present the optimal number of switchable zones per feeder in Kora distribution system.