• Journal of radiological science and technology
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• 제22권1호
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• pp.61-66
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• 1999

The use of multileaf collimator(MLC) to replace conventional field-shaping techniques is not in itself expected to improve the local control of malignancy. The purpose for using MLCs in conventional radiation oncology is to improve the efficiency of treatment delivery. For effective clinical application of MLCs to shaped radiation field, field outline must be translated into MLC leaf position tables. The intended leaf positions contained in these tables must then be communicated to the control computer that drives the MLC. There are currently at least three techniques utilized by manufacturers of MLCs and treatment planning systems for doing this. The Varian series use a workstation employing a manual digitizer and light box especially. It has a third level MLC configuration and also has the option of placing the wedges above or below the block tray. The C language are used for development of software and three leaf coverage have been used for positioning MLC loaves at the nominal field boundary. The fit of the leaf shape to treatment target volumes are optimized by the rotation of the direction in leaf travel. The clinical application of this software are investigated for Varian MLCs used in linear accelerator of Yonsei Cancer Center. The advantage of the results with using this software is to prescribe and calculate exposed and blocked area in MLCs field.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제14권2호
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• pp.189-197
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• 1996

Digital Elevation Model, Ortho-image, and 3-D positional data of terrain features are indispensable elements for producing 3-D image information. In this research, digital pbotogrammetric studies were conducted to measure the 3-D positional data on high performance computer systems in order to replace analytical stereo-plotter-oriented tasks with those of digital workstations. Especially, technical approaches to measure these data on stereo workstation were developed and then the results were applied on SPOT satellite images. As the result of this study, the possibilities of the proposed technologies were tested and proved based on the ap-plication of the digital photogrammetric processes to extract 3-D ground coordinates of terrain features from digital satellite imagery.

• Proceedings of the Korea Contents Association Conference
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.23-29
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• 2009

Blob detection is an essential ingredient process in some computer applications such as intelligent visual surveillance. However, previous blob detection algorithms are still computationally heavy so that supporting real-time multi-channel intelligent visual surveillance in a workstation or even one-channel real-time visual surveillance in a embedded system using them turns out prohibitively difficult. In this paper, we propose a fast and precise blob detection algorithm for visual surveillance. Blob detection in visual surveillance goes through several processing steps: foreground mask extraction, foreground mask correction, and connected component labeling. Foreground mask correction necessary for a precise detection is usually accomplished using morphological operations like opening and closing. Morphological operations are computationally expensive and moreover, they are difficult to run in parallel with connected component labeling routine since they need much different processing from what connected component labeling does. In this paper, we first develop a fast and precise foreground mask correction method utilizing on neighbor pixel checking which is also employed in connected component labeling so that the developed foreground mask correction method can be incorporated into connected component labeling routine. Through experiments, it is verified that our proposed blob detection algorithm based on the foreground mask correction method developed in this paper shows better processing speed and more precise blob detection.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제24권10호
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• pp.2654-2663
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• 2000

Steam turbine rotors are the most critical and highly stressed components of a steam power plant; therefore, the life expectancy of the turbine rotor is an important consideration for the safety of a steam power plant. The objective of this paper is to develop a life estimation program for turbine rotors for all possible operating conditions. For this purpose, finite element analysis was carried out for four normal operating modes (cold, warm, hot and very hot starts) using ABAQUS codes. The results are made into databases to evaluate the life expenditure for an actual operating condition. For any other possible abnormal operating condition, the operating data are transmitted to the server (workstation) through a network to carry out finite element analysis. Damage estimation is carried out by transmitting the finite element analysis results to the personal computer, and then the life expectancy is calculated.

• Aerospace Engineering and Technology
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• 제12권2호
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• pp.91-98
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• 2013

Computing environment of space explorer including LEO (Low Earth Orbit), GEO (Geosynchronous Earth Orbit) satellite may be considered as the same category of embedded system on the ground. But with comparison with personal computing environment it is widely accepted that the space computing is outdated and behind of state of the art. Especially file system which is nearly essential item in all ground computing environment including personal computer, workstation and server is rarely used in space explorer till lately. In this paper, a study of ESA PUS (Packet Utilization Standard) and CCSDS (Consultative Committee for Space Data Systems) community's activity, international trend, and applicable technical application for applying file system in oder to use these standards for utilizing the file system to deep space explorer is described.

• Asia pacific journal of information systems
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• 제2권2호
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• pp.31-54
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• 1992

Generating an action plan and obtaining commitment to achieve it is desired in organizations, but not always achieved. Whatever the reason, there is a room for an improved approach to decision making, so that people can arrive at a common understanding of a problem and commitment to action. Those are the purposes of a Decision Conferencing(DC). A DC, one example of single workstation-based GDSSs, is a two-day session attended by a group of people who attempt to resolve important issues of concern to their organization with the help of group facilitation techniques and decision analytic computer modelling. The interchange of differing perspectives on the issues is encouraged by the facilitator who attends to group processes but does not contribute to the content of discussions. Decision analysis provides a variety of structures for modelling the differing perspectives. Information and value judgements are incorporated in these models, whose results usually reveal new, higher-level perspectives on the issues. Information technology is needed to combine the part of the model and to facilitate on-the-spot replay of results. The experimental case study in this paper shows that how a DC can help a Korea's trading company to develop new, corporate level resource allocation strategies which are based on improved consensus among competing participants.

• Proceedings of the KIEE Conference
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2325-2327
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• 2002

포항 가속기연구소(PAL)에서는 포항방사광가속기(PLS)가 가동을 시작한 1994년 이후 현재까지 사용되어 온 기존의 제어 시스템을 새로운 환경인 EPICS(Experimental Physics and Industrial Control System) 시스템으로 개발하고 있다. EPICS 시스템의 구성은 IOC(Input/Ouput Controller) 와 OPI(Operator Interface)의 2-Layer로 구성되며 이는 MIU(Machine Interfaces Unit), SCC(Subsystem Computer Control System) 그리고 HMI(Human Machine Interface)로 이어지는 기존의 3-Layer 단계 중 SCC단계를 줄여 2-Layer로 구성된다. 이들 두 계층간의 통신은 Client(OPI)/Server(IOC) 구조의 Channel Access를 통해서 이루어진다. 개발중인 EPICS 시스템은 Open Architecture 구조로 IOC와 OPI 각 부분에서 개발시에 사용된 운영체제나 Hardware 를 사용하지 않고 다른 운영체제나 Hardware를 사용하더라도 하나의 공통부분 즉, Channel Access만 있으면 이를 통해 서로 다른 Subsystem IOC의 데이터를 Access할 수 있다. 전체 EPICS 제어시스템 중 저장링 운전의 핵심이 되는 BPM(Beam Position Monitoring) 및 MPS(Magnet Power Supply) 시스템은 IOC부분에 MVME5100(Target Machine) 보드와 vxWorks(Operating System)를 이용하고 OPI부분에는 SUN Workstation(Host Machine)와 Solaris(Operating System)을 사용하여 개발하고 있다. 본 논문에서는 IOC 및 OPI의 설치 절차와 설치 방법에 대해 기술하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제14권1_2호
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• pp.40-53
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• 1992

This sutdy aimed at examining the effect of lingual frenectomy on phonation & tongue movement. Almost the patient visiting to department of oral & maxillofacial surgery for the treatment of tongue tie always complain the speech problem. Many operation was performed according to this problem. But the objective evaluation of the speech change have been deficient. The experimental group was 25 adult males. Fourteen Korean consonants & after Korean vowels was combined and seventy sound was made for speech analysis. Before & after lingual frenectomy, the speech of the above mentioned group was recorded and then analysed by the Speech Workstation computer software. And before & after operation, the lingual frenum & tongue protrusion amount vas measured. The results were as follows : 1. The pre-operative length of lingual frenum was inverse proportion with the pre-operative length of the protrusive tongue. 2. The average difference between pre & post-operative length of the protrusive tongue was about 23 mm. 3. In the comparison of consonant continuing time change, fricative consonant(r, s, h) was increased post-operatively. 4. In the comparison of the vowel frequency formant change, the "i"and "u" sound vas reliably changed. 5. There was no reliable speech changes on the other sounds.

• Proceedings of the KIEE Conference
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2504-2506
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• 2000

포항가속기(PLS) 제어시스템은 선형가속기와 저장 링 제어시스템으로 분산 독립형으로 운영되어 왔다. 각각의 제어시스템의 구성상 상이한 H/W, S/W구조로 인하여 통합제어의 실현을 구현하지 못하여, 빔 운영상의 두 곳의 운전 감시업무로 인한 인력소요의 낭비를 초래하였다. 이러한 점을 개선하기 위한 선형가속기 및 저장 링 제어시스템의 제어알고리즘의 장점만 살려, 통합운전에 필수적으로 필요한 제어 분야만 새롭게 설계된 개선된 제어시스템에 적용하였다. 개선된 제어시스템의 구성은 디바이스제어에서 GUI(Graphic User Interface)단계까지의 3단계의 제어구조에서 SCC(Subsystem Computer Control System)를 생략한 디바이스 제어 컴퓨터와 GUI실현을 위한 상위 컴퓨터로 운영되고 있다. 디바이스 제어 컴퓨터는 VMEbus 구조의 OS-9 ver3.03 real-time OS가 적용되어 있으며, 상위는 SUN Workstation 환경에 UNIX 운영체제에 Rtworks가 적용되었다.

• Proceedings of the Korea Society for Simulation Conference
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• 한국시뮬레이션학회 1997년도 춘계 학술대회 발표집
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• pp.81-85
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• 1997

In a virtual environment, agents must demonstrate some degree of realism and interactivity. This paper discusses the algorithm that enables agents to navigate a virtual road network realistically and interactively. The road description files written in this language provide the information of road environments to the navigating agents and the scene visualizer. We call this navigating agent in the road an ambient car. The ambient cars must follow the traffic rules as human does. To do this, the ambient car should continuously check its circumstances, such as, the traffic lights, lanes, road signs, and other ambient cars. Because of the huge scale of road network and the large number of ambient cars, the algorithm considers only the area where the participant is currently located. By this locality, the performance of the whole system does not fluctuate much in different situations. The behavior of ambient cars according to the predefined rules may appear monotonous. We added probability distribution functions to introduce some randomness. We implemented the above idea on silicon Graphics Indigo 2 workstation. The ambient car exhibited its awareness of lanes, traffic lights, and other cars. The participants could hardly distinguish between a human-controlled car and computer-controlled ambient car generated by the algorithm.