• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.625-630
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• 2008

In the manufacturing industries, viewing CAE analysis results is frequently required during the product development process for design verification. CAE data which include all related information of an analysis is, however, not efficiently shared among designers because CAE data size is in general large to deal with. In order to increase collaboration among designers this paper introduces the development of a CAE visualization system based on JT format exploiting for a large model visualization with a scene graph-based toolkit. Since CAE analysis results and JT format have different structure we developed a translator to convert the CAE result in binary format to the JT format. To show the effectiveness of JT format in showing the CAE result we also developed a prototype viewer offering basic functions provided by commercial systems. By using JT format we are able not only to reduce the size of analysis results, but to store a series of analysis results with several LOD in a data file.

• 한국통신학회논문지
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• 제38B권7호
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• pp.535-542
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• 2013

Coordinated multi-point transmission (CoMP) is considered to be a promising technique to improve the throughput for LTE-Advanced systems. One important approach for CoMP is Joint Transmission (JT). However, the analytical model of JT has not been fully studied, as user equipments (UEs) receiving the desired signals from an adjacent base station (BS) as well as serving BS, or only serving BS were not distinguished. We derive a new analytical model to describe the call admission control in JT based systems. The performance measures of interest are the call blocking probability, and resource utilization. Furthermore, we compare the performance of JT-based systems and non-JT- based systems. The analytical results are in reasonable agreement with the simulation results.

• 구강회복응용과학지
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• 제36권2호
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• pp.80-87
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• 2020

목적: JT-3D system를 통해 하악의 운동을 측정하고 측두 하악 장애의 진단에 참고할 수 있는 하악의 운동 범위를 제공하고자 하였다. 연구 재료 및 방법: 성인 60명을 대상으로 JT-3D system을 이용하여 최대 개구와 폐구 운동을 기록하였고, 5회의 반복 운동을 1번의 운동 주기로 간주하여 총 3회의 운동 주기를 기록하였다. 최대 개구 시 하악의 수직적 위치, 전후방 위치, 측방 편위량, 최대 개구량을 기록하였다. JT-3D system의 재현성 평가를 위해 통계분석을 시행하였다(α = 0.05). 결과: 최대 개구 시의 평균값은 수직적 위치 31.56 mm, 후방 24.42 mm, 측방 편위량 0.72 mm, 최대 개구량 40.32 mm로 나타났다. JT-3D system으로 기록한 3회의 운동 주기의 모든 측정값에서 통계적 유의성은 없었다(P > 0.05). 결론: 최대 개구 시 평균 측방 편위량에서 0.72 mm, 최대 개구량은 40.32 mm로 나타났으며, JT-3D system을 이용한 하악 운동 분석은 재현성 있는 결과를 보였다.

• Radiation Oncology Journal
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• 제35권1호
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• pp.90-100
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• 2017

Purpose: To Study the dosimetric advantage of the Jaw tracking technique in intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for Head and Neck Cancers. Materials and Methods: We retrospectively selected 10 previously treated head and neck cancer patients stage (T1/T2, N1, M0) in this study. All the patients were planned for IMRT and VMAT with simultaneous integrated boost technique. IMRT and VMAT plans were performed with jaw tracking (JT) and with static jaw (SJ) technique by keeping the same constraints and priorities for a particular patient. Target conformity, dose to the critical structures and low dose volumes were recorded and analyzed for IMRT and VMAT plans with and without JT for all the patients. Results: The conformity index average of all patients followed by standard deviation (${\bar{x}}{\pm}{\sigma}_{\bar{x}}$) of the JT-IMRT, SJ-IMRT, JT-VMAT, and SJ-VMAT were $1.72{\pm}0.56$, $1.67{\pm}0.57$, $1.83{\pm}0.65$, and $1.85{\pm}0.64$, and homogeneity index were $0.059{\pm}0.05$, $0.064{\pm}0.05$, $0.064{\pm}0.04$, and $0.064{\pm}0.05$. JT-IMRT shows significant mean reduction in right parotid and left parotid shows of 7.64% (p < 0.001) and 7.45% (p < 0.001) compare to SJ-IMRT. JT-IMRT plans also shows considerable dose reduction to thyroid, inferior constrictors, spinal cord and brainstem compared to the SJ-IMRT plans. Conclusion: Significant dose reductions were observed for critical structure in the JT-IMRT compared to SJ-IMRT technique. In JT-VMAT plans dose reduction to the critical structure were not significant compared to the SJ-IMRT due to relatively lesser monitor units.

• 한국CDE학회논문집
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• 제18권4호
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• pp.258-266
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• 2013

In shipbuilding, 2D manufacturing drawings are crucial for building a ship. Even various types of 3D models are being utilized for supporting ship manufacturing, which does not reduce the importance of 2D drawings. Recently things are changing in the shipbuilding industry. To reduce the number of 2D drawings or to reduce the quantity of information contained in 2D drawings, some attempts that can substitute for 2D drawings are being made. One of the attempts is to visualize lightweight 3D manufacturing models in a mobile device. In this paper, a method for displaying lightweight 3D models of a ship in an Android based device is introduced. To overcome the problem with parsing JT files in Android system, JT files are parsed in a Windows based server and as-simple-as-possible visualization data are transmitted to an Android based viewer. A comparison result with a commercial system is also given.

• 한국CDE학회논문집
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• 제16권5호
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• pp.344-350
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• 2011

In injection molding industries, CAE analyses are generally used to find out problems predicted during the process of manufacturing. The results of CAE analyses consist of much in formation such as meshes and stress, so that the size of data is pretty large. To reduce the size of the data and to make it easy to share, the CAE result to JT translator is proposed in this paper. The translator consists of three modules to translate CAE result to JT format; Extracting module gets ASCII data of product shape and the result values of CAE analysis. Sorting module and mapping module make an element data set and JT file with the data extracted from Extracting module respectively. To the JT files, engineers are able to append product properties and their comments, so that they can share the whole history of the analysis process. In addition, our case study shows that the size of JT format is reduced by almost 90% of its original data format.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2007년도 제33회 하계학술대회 초록집
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• pp.175-175
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• 2007

• 대한방사선치료학회지
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• 제31권1호
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• pp.33-41
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• 2019

목 적: 식도암 방사선치료 시 세기조절방사선치료(Intensity Modulated Radiation Therapy, IMRT) 및 용적세기조절회전치료(Volumetric Modulated Arc Therapy, VMAT)에서 Jaw-Tracking 기법 유 무에 따라 저선량 영역에 대한 주변 정상장기의 용적선량을 분석하여 그 유용성을 평가하고자 한다. 대상 및 방법: 본 원에서 사용하고 있는 선형가속기 VitalBeamTM(Varian Medical System, U.S.A)으로 식도암 방사선치료를 받은 27명을 대상으로 하였으며, 치료계획은 Eclipse(Ver. 13.6 Varian, U.S.A)를 이용하여 Jaw-Tracking(JT)을 사용한 치료계획과 Non Jaw-Tracking(NJT) 치료계획을 수립하였으며, 치료계획용적(Planning Target Volume, PTV)에 빗장위림프절(Supraclavicular Lymph Nodes, SCL)이 포함되어 있는 T자형 PTV를 가진 환자를 대상으로 하였다. 조사범위에 대한 영향을 확인하기 위해 복강(Celiac) 포함 여부로 비교군을 나누었다. 수립된 치료계획의 비교를 위해 손상위험장기는 양측 폐, 심장, 척수를 비교하였으며 Conformity Index(CI), Homogeneity Index(HI)를 비교하였다. 임상적용 검증을 위해 전자포탈영상장치(Electronic Portal Imaging Device, EPID)를 이용하여 Portal Dosimetry를 실시하였고, 선량 영역의 임계치(Threshold)를 10 %, 5 %, 0 %로 매개변수로 설정하여 감마분석을 실시하였다. 결 과: 모든 치료계획은 3 mm / 3 %, 감마통과율 95 % 기준에 대해 Threshold 10 %의 경우 95 % 이상으로 JT, NJT 모두 통과하였으며, IMRT는 Threshold가 5 %, 0 %로 줄어들수록 JT보다 NJT의 값이 1 % 이상 줄어 들었다. IMRT에서 양측 폐의 $V_5$와 $V_{10}$은 JT에서 Celiac을 포함하지 않을 때 최대 14.7 %, 평균 8.5 %, 5.3 % 만큼 감소했고, $D_{mean}$은 $72.3{\pm}51cGy$ 감소하였으며, Celiac을 포함할 때 JT에서 선량감소가 증가하였다. 심장의 $D_{mean}$은 $68.9{\pm}38.5cGy$, 척수의 $D_{max}$는 $39.7{\pm]30.1cGy$만큼 감소하였다. VMAT은 JT기법 사용 시 폐에서 $V_5$ 평균 2.5 % 감소하였고, 심장 및 척수에서 소량 감소하였으며, Celiac 포함 시 JT의 선량감소가 증가하였다. 결 론: 식도암 치료계획에서 IMRT가 JT 사용 시 양측 폐의 $V_5$, $V_{10}$에서 유의미한 감소가 나타났고, 저 선량영역에서 조사범위가 클수록 선량감소가 크게 나타났다. 따라서 식도암 방사선치료에는 IMRT가 VMAT보다 JT 적용 시 더 효과적이며, 저 선량영역에서의 MLC 누설 및 투과선량으로부터 정상장기를 보호할 수 있다.

• 설비공학논문집
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• 제6권1호
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• pp.11-19
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• 1994

An optimal design for Gifford-McMahon/Joule-Thomson(GM-JT) refrigerators was performed by a numerical method. The design goal was to meet the cooling requirement for MRI systems, which was 3 Watt at 4 K. A general cycle analysis program was written to calculate the cooling capacity of the GM-JT refrigerators for the givenstage GM refrigerator. The program was executed for a specific refrigerator with various design parameters. The optimal values for the maximum cooling were found for the sizes of the heat exchangers, the mass flow rate of helium, and the compression pressure.

• 한국항공운항학회지
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• 제28권1호
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• pp.106-114
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• 2020

The Lion Air JT610 accident in Indonesia in October 2018, along with the Ethiopian Airline ET302 accident in March 2019, is an significant aircraft accident that detects defects of the B737MAX aircraft. Shortly after the accident, the FAA prohibited operation of the aircraft. This action has affected the market environment of airlines and aircraft manufacturers around the world. In October 2019, Indonesian Traffic Safety Committee released an accident investigation report for Lion Air JT610, which concluded that the causes of the accident were MCAS design defects, lack of education and training, and errors in the repair process. This paper summarizes the flight control system of the B737MAX aircraft, the causes of the accident based on the final accident investigation report, and provides considerations for aircraft design and retrofit.