• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.3
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• pp.44-51
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• 2009

It is very important to verify generated setup errors in cancer therapy by using a high energy radiation and to perform the precise radiation therapy. Specially, the verification of treatment position is very crucial in special therapies like fractionated stereotatic radiotherapy (FSRT). The FSRT uses normally high-dose, small field size for treating small intracranial lesions. To estimate the developed FSRT system, the isocenter accuracy of gantry, couch and collimator were performed and a total of inaccuracy was less than ${\pm}1mm$. Precise beam targeting is crucial when using high-dose, small field size FSRT for treating small intracranial lesions. The EPID image of the 3mm lead ball mounted on the isocenter with a 25mm collimator cone was acquired and detected to the extent of one pixel (0.76mm) after comparing the difference between the center of a 25mm collimator cone and a 3 mm ball after processing the EPID image. In this paper, the radiation treatment efficiency can be improved by performing precise radiation therapy with a developed video based EPID and FSRT at near real time

• Radiation Oncology Journal
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• v.23 no.2
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• pp.123-130
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• 2005

Purpose: We wanted to improve the setup reproducibility of breast cancer patients when utilizing a commercially available breast board for radiation therapy. The breast board was modified by using a new head rest and 2 types of board fixation devices. Materials and Methods: A conventional head/neck rest was modified to be positioned in various slots of the breast board, and it was fabricated 1 cm thinner to provide more comfort to a patient when the patient's neck was rotated. This rest improves the uncertainty of the daily setup. Also, the sagging problems at the left and right sides became negligible with the two types of board fixation devices: (1) the stair type, and (2) the arm type. The first device consists of an upper/lower holder with 4 stair-types of grooves and 4 rectangular Inserts. In order to cover the whole range of vertical setup of the breast board, 4 rectangular inserts were needed, and each covered 10 steps. The arm-type fixation device was also fabricated and attached to the breast board, It had two aluminum bars that were fixed by utilizing a lock-type of screw. These devises were evaluated with two volunteers in order to prove the effectiveness of the improved setup accuracy. Results; The developed cranio-caudal fixation device demonstrated that it could reduce the cranio-caudal error by nearly $55\%$ compared to the old device. As for left-and-right inclination, the stair-type and arm-type fixation devices can reduce the relative inclination by nearly $80\%$ and $90\%$, respectively, compared to the breast board without the fixation device. Conclusion: It was verified that the developed devices were effective for positioning the patients and for avoiding inclination of the breast board.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.98-106
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• 2012

CSD(Container Security Device) is a security device with sensors that can detect the abnormal behavior such as illegal opening of a container door. Since the CSD provides security and safety of the container, CSD should not only provide security services such as confidentiality and integrity but also cloning detection. If we can not detect the cloned CSD, an adversary can use the cloned CSD for many illegal purposes. In this paper, we propose a policy based cloned CSD detection mechanism. To evaluate proposed clone detection mechanism, we have implemented the proposed scheme and evaluated the results.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.7
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• pp.819-825
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• 2014

The diurnal range of temperature in korea is increasing. We know that the environment has deteriorated through report about railway damage and economic loss caused by climate. In these conditions, Monitoring device for railway must operate to support the operations and maintenance. Therefore, In this paper, COM-based monitoring device implemented using Industrial-Extended electronic components and made, We tested compliance about temperature environment of actual railway. We verified through testing about cold and dry heat of monitoring device. Used components in this product will be able to utilize the development of the railway industry of electronics.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.149-153
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• 2003

AC 부하를 갖는 동기전동기에 있어서, 동기전동기의 속도리플을 저감시키기 위한 문제를 풀기위해 3가지 제어기법에 대해 비교를 한 후 가장 강인한 제어기법에 대해 분석하였다. AC 부하를 갖는 특별한 제어 대상으로 엑스선 전산화 단층촬영 장치(CT)용 겐트리를 선정하였으며 시스템이 갖는 특별한 구조에 의해 이러한 시스템 특성을 갖는다. 동기전동기의 출력 축에 링(Fing) 모양의 원판 프레임을 갖으며, 이 원판 표면에 무게가 서로 다른 여러 장치(X_선 튜브, X-선 검출기, 고압발생장치, DAS 장치, 온도조절장치 등)를 부착하여 영상 획득 시스템의 회전부를 구축하기 때문이다. 이러한 시스템에서는 무게 평형을 갖지 못하는 편심 무게가 존재하게 되며 이로써 전동기 관점에서는 AC 부하처럼 인식되는 제어 조건으로 인식 될 수 있다. AC 부하를 갖는 동기전동기에 대해 일반적인 벡터제어 알고리즘으로 제어를 수행하면 정상상태에서도 속도 오차가 "0" 으로 줄어들지 않고 AC 형태의 오차 성분이 존재하며 편심 무게의 크기에 비례하여 진폭이 커지는 특성을 갖는다. 이러한 문제점을 해결하기 위하여 Sine파 보상전류를 갖는 속도제어기법, 펀심부하토크 관측기를 이용한 속도제어기법, 그리고 기준모델제어기법을 소개하였다. 각 방법에 대한 실험 결과로부터 편심무게의 변동과 편심 위치의 변동 조건에서 기준모델제어기법이 강인한 제어 특성과 리플저감 측면에서 가장 우수함을 검증하였다. 이로써 AC 부하 조건에서 고정도 속도 제어기가 요구되는 경우 좋은 선택의 지침이 될 수 있다고 본다.

• Journal of the Korean Institute of Gas
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• v.5 no.2 s.14
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• pp.1-8
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• 2001

Fault tree construction for hazard assessment requires so much time and labor, so it is very difficult to be applied to the large scale chemical plant. In this study, for the synthesis of fault tree in chemical processes, the object-oriented knowledge framework is proposed to represent the deviations of process variables in the equipment and cause-consequence relationship with equipment faults. The cause of fault is searched by using the object-oriented modeling of equipments and the connectivity among equipments, and then a fault tree is synthesized. we have discussed the performance of the methodology on nitric acid cooling process to evaluate its effectiveness.

• Journal of Korean Society of Transportation
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• v.19 no.5
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• pp.71-83
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• 2001

This paper introduces the simulation system which was developed to evaluate the effectiveness of ITS, and presents its adaptabilities to traffic signal control systems. The simulation system in this paper has a function of real-time testing and evaluating traffic control systems. It consists of Modu-RE which is a simulation operating software and Real-CID which is a controller interface device. Real-CID allows Modu-RE to communicate with traffic control hardware.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.285-290
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• 2008

Pyrotechnic shock or pyroshock is characterized as a transient vibration phenomena which shows large acceleration and high frequency range up to 10kHz during the operation of separation devices where explosives are used. During the flight of a launch vehicle, pyro-shock is mainly generated at several events such as satellite separation, fairing separation and stage separation. In this paper, characteristics of pyroshock are introduced briefly, and PEEK washer shock absorber is applied for the reduction of pyroshock in the high frequency range. With some electronic devices, reduction characteristic of pyroshock using washer type shock absorber are studied. Random vibration tests are also performed for the verification of vibrational characteristics.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.128-132
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• 2009

Digital control system for active combustion control of lab-scale combustor equipped with secondary fuel injection is designed. Controllability with adaptive law is revealed with the Cambridge Combustor model and the requirement for control system is derived. The input and output requirements of frequency estimator and fuel supply actuator for the adaptive control law is verified with cold tests. The system can be used as digital based active combustion controller having 150Hz combustion instability.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.1
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• pp.13-18
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• 2007

Human's sight holds the most extents for recognizing information among other senses. If we make much better visualized environment for human, it will become more beneficial in person's emotion or body. Human is using a lot of display units in modern society. Basic hues ate Red, Green and Blue. Using these three colors, we can change hue sense and degree of brightness of display unit. If we control hue of unit to be suitable according to individual environment, we can feel comfortable or reduce stress. In this paper, we present Human-Friendly Intelligent Hue Control System(HFIHCS) that control hue of display unit using fuzzified factors related to human's emotion and environment. The effectiveness of the proposed system is demonstrated by questionnaire.