• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.1
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• pp.1-12
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• 2003

This paper describes a study on the abnormal behavior of the electrical characteristics of the (n)GaAs/Ti/Pt/Au Schottky contacts prepared by the two techniques of electron beam deposition and rf sputtering and after an annealing treatment. The samples were characterized by I-V and C-V measurements carried out over the temperature range of 150 - 350 K both in the as prepared state and after a 300 C, 30 min. anneal step. The variation of ideality factor with forward bias, the variation of ideality factor and barrier height with temperature and the difference between the capacitance barrier and current barrier show the presence of a thin interfacial oxide layer along with barrier height inhomogenieties at the metal/semiconductor interface. This barrier height inhomogeneity model also explains the lower barrier height for the sputtered samples to be due to the presence of low barrier height patches produced because of high plasma energy. After the annealing step the contacts prepared by electron beam have the highest typical current barrier height of 0.85 eV and capacitance barrier height of 0.86 eV whereas those prepared by sputtering (at the highest power studied) have the lowest typical current barrier height of 0.67 eV and capacitance barrier height of 0.78 eV.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.5
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• pp.460-469
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• 2010

To develop coal gasfication system, many studies have been actively conducted to describe the simulation of steady state. Now, it is necessary to study the gasification system not only in steady state but also in dynamic state to elucidate abnormal condition such as start-up, shut-down, disturbance, and develop control logic. In this study, a model was proposed with process simulation in dynamic state being conducted using a chemical process simulation tool, where a heat and mass transfer model in the gasifier is incorporated, The proposed model was verified by comparison of the results of the simulation with those available from NETL (National Energy Technology Laboratory) report under steady state condition. The simulation results were that the coal gas efficiency was 80.7%, gas thermal efficiency was 95.4%, which indicated the error was under 1 %. Also, the compositions of syngas were similar to those of the NETL report. Controlled variables of the proposed model was verified by increasing oxygen flow rate to gasifier in order to validate the dynamic state of the system. As a result, trends of major process variables were resonable when oxygen flow rate increased by 5% from the steady state value. Coal flow rate to gasifier and quench gas flow rate were increased, and flow rate of liquid slag was also increased. The proposed model in this study is able to be used for the prediction of gasification of various coals and dynamic analysis of coal gasification.

• Journal of Biomedical Engineering Research
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• v.14 no.4
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• pp.379-386
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• 1993

This paper describes design of a Chaos analyser and its applications to analysis of nonlinear characteristirs of ECG. The proposed system can easily distinguish chaotic system among the various dynamical systems by chaotic quantitative and qualitative analysis and also chaotic characteristics which represents states of nonlinear dynamical system. And we have also proposed new possibilities to recognize abnormal state of ECG signal using the chaotic characteristics.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.293-297
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• 1992

For the computerized monitoring and diagnosis of the undesirable chip chatter which are major obstacles to FMS, a pattern recognition system based on multi-layer perception neural network is developed and the performance of the system is experimentally evaluated. Experimental results show that recognition of the two class state of normal or abnormal cutting gives satisfactory results with success rate of 81`91%. Therefore, the proposed system has possibility for use in monitoring and diagnosis of automatic manufacturing system

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.39-41
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• 2006

It is important to estimate the hand skin temperature because it reveals not only physiological properties of a certain diseases but also it can estimate even human mental-stress conditions. In this study, we try to estimate the temporal skin temperature distribution of human hand by applying stress-cold test to possibly apply to estimate a subject's blood circulation condition in his or her hand in terms of normal or abnormal state.

• The Korean Journal of Pain
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• v.7 no.2
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• pp.258-262
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• 1994

Thermography is a non-invasive, comfortable, diagnostic technique to monitor successful sympathetic block. We observed abnormal thermal distribution during disease state and then followed with thermography on the process of treatment with stellate ganglion block.

• The Korean Journal of Pain
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• v.8 no.1
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• pp.139-143
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• 1995

Hyperhidrosis is the state of abnormal sweating on the palm, sole and axillary region. The main treatment of hyperhidrosis are surgical sympathectomy and a thoracic sympathetic ganglion block with neurolytics. Among them, a thoracic sympathetic ganglion block is used in pain clinic for the treatment of hyperhidrosis. I have successfully performed a thoracic sympathetic ganglion block on a 21 year old female patients with pure alcohol. I concluded that the thoracic sympathetic ganglion block was one of the most effective treatment of hyperhidrosis.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.11 no.2
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• pp.59-66
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• 2007

The oxygen distribution at steady state is analyzed mathematically in a hexagonal cylinder. The domain is penetrated by parallel cylindrical capillaries of different oxygen squirt. Asymptotic solution is used to determine the effect of axial diffusion. Oxygen concentration profiles are displayed at some positions of capillary-beds. At the venous end some tissue areas suffer from a shortage of oxygen.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.207-210
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• 2001

This Paper presents a design of the fuzzy decision maker analyzable of output result of ECG signals. The fuzzy decision maker proposed are divided into two groups whose functions are different each other. The one rules when decision of heart rates, The other decision values for an interval of each points of waveform using of which static state values and abnormal values. We have chosen several variable used for composing condition and action part by knowledge of an Expert The result of outputs with fuzzy rules suggested was a proved of satisfied with by classify ECG arrythmia signals

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.137-140
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• 1993

This paper describes a Chaos analyzer and its applications to characteristic analysis of ECG signals and the other signals. We can detect chaotic system among the various system by quantitative and qualitative analysis using the proposed system. And we also propose a new Possibility to recognize abnormal state of ECG signal using the chaotic characteristcs of signal.