• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.275-283
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• 2013

The patient radiation dose is different depending on selection of Ion chamber when taking Chest PA which using AEC. In this paper, we studied acquiring the best diagnostic images according to selection of Ion chamber on AEC mode as well as minimizing patient radiation dose. Experimental methods were selection of Ion chamber and change of sensitivity under the same conditions as Chest PA projection. At AEC mode, two upper ion chambers sensors and one lower ion chamber sensor were divided into 7 cases according to selection of on/off. after measuring five times respectively, we obtained average value and calculated exposure dose. Image assessment was done with measured Modulation Transfer Function, Peak Signal to Noise Ratio, Root Mean Square, Signal to Noise Ratio, Contrast to Noise Ratio, Mean to Standard deviation Ratio respectively. In exposure assessment results, selection of two upper chambers was the lowest. In resolution assessment results, image of two upper chambers had the second high spatial frequency at sensitivity at 625(High) was 1.343 lp/mm. RMS value of image selecting two upper chambers was low secondly. SNR, CNR, MSR were the high value secondly. As the sensitivity was increased, radiation dose was decreased but better image could be obtained on image quality. In order to obtain the best medical images while minimizing the dose, usage of two upper ion chambers is considered to be clinically useful at sensitivity 625(High).

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.71-77
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• 2011

This paper proposes a design of controller for automatic evacuation disposal system with suction, collecting, washing, and drying functions to be useful for excretion care of long-term bedridden patients. It is desirable that the system can discriminate excreta such as feces and urine severally, and dispose of them without having additional efforts of caregivers. This paper describes a method to improve the discrimination ability by using multi-sensors, and proposes disposal processes according to the type of excrements. As a result the automatic evacuation disposal system can perform an efficient operation in the excrement care. Experimental results using artificial excrements show the automatic evacuation disposal system is effective and feasible to assist the excrement care.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.451-458
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• 2001

In this paper, we propose speech control system for a various control device in the car with real time control speech. A real time speech control system is detected start-end points from speech data processing by A/D conversion, and recognize by one pass dynamic programming method. The results displays a monitor, and transports control data to control interfaces. The HMM model is modeled by a continuous control speech consists of control speech and digit speech for controlling of a various control device in the car The recognition rates is an average 97.3% in case of word & control speech, and is an average 96.3% in case of digit speech.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1022-1023
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• 2006

본 논문에서는 MATLAB/SIMULINK와 dSPACE DS1104보드를 이용하여 유도전동기의 간접백터제어 알고리즘을 구현하였다. 유도전동기의 간접벡터제어를 위한 전체 시스템 모델은 SIMULINK 그래픽 모델과 dSPACE DS1104 R&D Control 보드의 Real Time Interface(RTI)를 이용하여 구현한 후에 실험을 수행하였다. 벡터제어를 위해서 전동기 전류의 측정은 16kHz로 측정하였고, 측정된 전류를 이용하여 8Hz로 전류제어기, 4kHz로 속도제어기를 구현하였다. MATLAB과 dSPACE 보드의 컴파일러가 설계된 그래픽 모델의 C source 파일과 object 파일을 자동으로 생성시켜주기 때문에 추가적인 프로그램의 coding 없이 실제 시스템의 시뮬레이션과 실험을 동시에 수행할 수 있으며 원하는 제어성능을 얻을 수 있다.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2585-2587
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• 2005

본 논문은 전차선 급전 케이블 자동가설 로봇의 이동제어를 나타내었다. 작업로봇의 차륜 구동부를 모델링하여 이동제어 시스템이 작업로봇의 이동에 유용한 것을 구명하였다 실험을 하여 실용성을 검토하였다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.6
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• pp.45-56
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• 1999

This paper presents a method for designing an autopilot of the BTT missile using 2DOF Wiener-Hopf control technique to improve tracking performance. Linear controllers are designed based on the linearized models which are obtained from the nonlinear missile dynamic equations at various operating points. The gain scheduling technique is used to implement the final autopilot. A simulation on the flight of missiles is carried out through the use of 6DOF equation program including exact nonlinear equations of the missile and the variations of aerodynamic variables in order to check applicability of the suggested method in real situation.

• Proceedings of the Korean Society of Radiological Science
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• 1991.05a
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• pp.19.2-19.2
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• 1991

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.177-183
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• 2002

Current state-of-the-art of VMS control is based upon simple knowledge-based inference engine with message set and each message's priority. And R&Ds of the VMS control are focused on the accurate detection and estimation of traffic condition of the subject roadways. However VMS display itself cannot achieve a desirable traffic allocation among alternative routes in the network In this context, VMS display strategy is the most crucial part in the VMS control. VMS itself has several limitations in its nature. It is generally known that VMS causes overreaction and concentration problems, which may be more serious in urban network than highway network because diversion should be more easily made in urban network. A feedback control algorithm is proposed in this paper to address the above-mentioned issues. It is generally true that feedback control approach requires low computational effort and is less sensitive to models inaccuracy and disturbance uncertainties. Major features of the proposed algorithm are as follows: Firstly, a regulator is designed to attain system optimal traffic allocation among alternative routes for each VMS in the network. Secondly, strategic messages should be prepared to realize the desirable traffic allocation, that is, output of the above regulator. VMS display strategy module is designed in this context. To evaluate Probable control benefit and to detect logical errors of the Proposed feedback algorithm, a offline simulation test is performed using real network in Daejon, Korea.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.398-401
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• 2000

The effect of volatile components on cell growth and polysaccharide production in suspension cultures of Aloe saponaria was investigated using an intelligent on-line gas control system which enabled to control the concentrations of oxygen, carbon dioxide and ethylene simultaneously. Aloe production was enhanced in the presence of exogenous ethylene in the concentration range of 5ppm and 15ppm. Maintaining high tension of carbon dioxide (5% v/v) was found to enhance polysaccharide production significantly.

• Journal of Information Technology Application
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• v.1 no.3_4
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• pp.1-23
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• 1999

본 연구에서는 HMM(Hidden Markov Model) 및 Levelbuilding 알고리즘을 이용하여 인식대상 음소열의 표본 집합(훈련패턴 집합)을 입력으로 하는 음성의 자동 분할 시스템을 구현하였다. 본 시스템은 자연스럽게 발음되어진 연결음 음성으로부터 표준 음소모델을 생성한다. 본 시스템의 구성은 초기화 과정, HMM학습과정 그리고 Levelbuilding을 이용한 분리 및 CLustering 과정으로 구성되어 있다. 초기화 과정에서는 제어 정보를 이용하여 훈련패턴 집합으로부터 초기 음소 집합 군을 생성한다. Levelbuilding을 이용한 분리 및 Clustering 단계에서는 음소 모델과 제어 정보를 이용하여 훈련패턴들을 음소 단위로 분리하고, 분리된 후보 음소들을 Clustering하여 음소집합 군을 생성한다. 음소모델의 구성에 변화가 없을 때까지 이 작업을 반복 수행하여 최적의 음소모델을 생성한다. 본 연구에서는 3개 이하의 숫자단어로 구성된 연결되어 음성 패턴을 대상으로 실험하였다. 연결단어에 대한 음소의 표준모델 생성과정에서 가장 중요한 처리인 훈련패턴의 자동분할 과정을 분석하기 위하여 각 반복과정에서 분리된 정보를 그래프로 도시화하여 확인하였다.