• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.988-991
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• 2003

In this paper, we try to develop the controller which uses the block diagrams of SIMTool and internal functions CEMTool for planning the global driving controller for high efficiency AGV. We acquire the control efficiency by controlling the motor used each part of AGV driving controller. The block diagram structures provided with SIMTool is easily designed by the controller, and the monitoring and analysis of the results is researched by simulation. We expect to control AGV. robot and various plant using Ziegler-Nichols auto-tuning method and external I/O board

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.467-467
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• 2000

In this paper, a structural design method of robust motion controllers for high-accuracy positioning systems, which makes it possible to predict the performance of the whole closed-loop system, is proposed. First, a stabilizing control input is designed based on robust internal-loop compensate.(RTC) for the system in the presence of uncertainty and disturbance. Next, using the structural characteristics of the RIC, disturbance attenuation properties and the performance of the closed-loop system determined by the variation of controller gains are analyzed. Through this analysis, in some specific applications, it is shown that if the control gain of RIC is increased by N times, the magnitude of error is reduced to its 1/N. Finally, the proposed method is verified through experiments using a high-accuracy positioning system used in the semiconductor chip mounting devices.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.236-236
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• 2000

Control of Industrial processes is very difficult due to nonlinear dynamics, effect of disturbances and modeling errors. M.Morari proposed Internal Model Control(IMC) system that can be effectively applied to the systems with model uncertainties and time delays. The advantage of IMC systems is their robustness with respect to a model mismatch and disturbances. But it was difficult to apply for nonlinear systems. Adaptive Neuro-Fuzzy Inference System which contains multiple linear models as consequent part is used to model nonlinear systems. Generally, the linear parameters in neuro-fuzzy inference system can be effectively utilized to identify a nonlinear dynamical systems. In this paper, we propose new IMC design method using adaptive neuro-fuzzy inference system for nonlinear plant. Numerical simulation results show that proposed IMC design method has good performance than classical PID controller.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.650-653
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• 2001

In recent the energy efficiency of a refrigerator has been restricted extremely. A compressor consumes a great portion of input power in a refrigerator. So it is necessary to develop a more efficient compressor in these days. The existing reciprocating compressor need to a crank shaft to convert the rotating motion to the straight motion and is not efficient. But the linear compressor using mechanic resonance is efficient but need a drive instead of a crank shaft to control a position accurately. However it is impossible to apply a stroke sensor practically because of the internal circumstance of compressor. In this paper, A new sensorless stroke control method using the current and voltage of linear compressor is proposed.

• 대한핵의학회지
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• 제27권1호
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• pp.88-97
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• 1993

Anterior abdominal scintigraphy after intravenous injection of $^{99m}Tc$-human serum albumin ($^{99m}Tc$-HSA 20 mCi) was done in 16 patients with connective tissue diseases and 15 healthy control patients. Patients with proteinuria or hepatopathy were excluded. 1) 7 (44%) patients among 16 connective tissue disease patients without the apparent evidence of external protein loss showed abnormal intestinal accumulation of albumin. 6 patients with positive albumin scintigraphy showed bypoalbuminemia. 2) There was no false positive scintigraphic finding in control group. 3) The serum albumin level in connective tissue disease patients ($3.1{\pm}0.6 g/dl$, n=16) was lower than control patients ($3.9{\pm}0.3 g/dl$, n=15) (p<0.0001). 4) The serum albumin level was lower in connective tissue disease patients with positive $^{99m}Tc$-HSA scan ($2.8{\pm}0.6 g/dl$, n=7) than the connective tissue disease patients with negative scan ($3.3{\pm}0.3 g/dl$, n=9) (p<0.05). 5) The hemoglobin level in connective tissue disease patients with positive nan ($10.6{\pm}2.91 g/dl$) was lower than that of the control group ($13.6{\pm}1.5 g/dl$) (p<0.05). Mypoalbuminemia is frequently involved in chronic connective tissue diseases. Protein losing enteropathy (PLE) is also responsible for the majority of the bypoalbuminemia in these patients. But it has been ignored because the conventional method for the diagnosis of PLE was difficult to perform. $^{99m}Tc$-HSA scan also must be validated by more extended study and comparison with the quantitative study such as stool ${\alpha}-1$ antitrypsin measurement. There must be a reevaluation of PLE in various diseases especially in connective tissue diseases with easy, fast, economical, and non-invasive method.

• Structural Engineering and Mechanics
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• 제64권4호
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• pp.427-436
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• 2017

Concrete technologists have used ultrasonic pulse velocity test for decades to evaluate the properties of concrete. However, the presented research work focuses on the use of ultrasonic pulse velocity test to study the degradation in steel-concrete bond subjected to increasing loading. A detailed experimental investigation was conducted by testing five identical beam specimens under increasing loading. The loading was increased from zero till failure in equal increments. From the experimentation, it was found that as the reinforced concrete beams were stressed from control unloaded condition till complete failure, the propagating ultrasonic wave velocity reduced. This reduction in wave velocity is attributed to the initiation, development, and propagation of internal cracking in the concrete surrounding the steel reinforcement. Using both direct and semidirect methods of testing, results of reduction in wave velocity with evidence of internal cracking at steel-concrete interface are presented. From the presented results and discussion, it can be concluded that the UPV test method can be successfully employed to identify zones of poor bonding along the length of reinforced concrete beam. The information gathered by such testing can be used by engineers for localizing repairs thereby leading to saving of time, labor and cost of repairs. Furthermore, the implementation strategy along with real-world challenges associated with the application of the proposed technique and area of future development have also been presented.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.243-248
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• 1999

Ultrasonic wave technology was employed to improve filtration performance and ethanol production in a bioreactor equipped with an internal ceramic-membrane filter module. The filtration performance was found to depend on the power and the pattern of ultrasonic wave irradiation. Under the optimized conditions (irradiation time: 25 see, period: 5 min, and ultrasonic power: 60 W), the flux was improved with the periodic-pause method by 200-700％ compared with the control (with no irradiation), while the improvement was only 30 to 90％ without the periodic-pause method. The final ethanol concentration also increased slightly. However, in a more severe condition (irradiation time: 2.5 min, period: 5 min, and ultrasonic power: 110 W), the irradiation of ultrasonic waves was observed to disturb cell integrity and viability, and thus to decrease ethanol production.

• 한국수소및신에너지학회논문집
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• 제27권3호
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• pp.311-317
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• 2016

This paper presents the flow characteristics of a ball valve used for a gas pipeline. Understanding of the internal flow of a ball valve is an important to analyze the physical phenomena of the valve. Present experimental study was performed by IEC 60534-2-3, the international standard for an industrial control valve testing procedure. Pressure measured at upstream and downstream of the valve, flow-rate and gas temperature passing the inside of the gas pipeline were measured with respect to valve opening rates. Throughout the experimental measurement of the ball valve, empirical equation of the pressure drop between the ball valve according to the mass flow rates is successively obtained using a polynomial curve fitting method. In addition, flow coefficient for determining the valve capacity is also analyzed with respect to valve opening rates using the curve fitting method.

• 대한한방내과학회지
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• 제29권2호
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• pp.432-442
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• 2008

Objective : Ssanggang-tang(SGT) is noted as an effective method to treat hyperlipidemia in China. The main purpose of this study was analysis of the effects of Ssanggang-tang(SGT) on rats induced with caused hyperlipidemia. Methods : We observed 3 experimental groups: normal, control, and SGT. Rats were provided a normal diet in the normal group, and the other groups were provided a hyperlipidemic diet to induce hyperlipidemia. After 2 weeks, SGT was treated in the SGT group. For 6 weeks, values related to hyperlipidemia were observed in the 3 experimental groups. Results : SGT decreased some values related to hyperlipidemia like total cholesterol, low density lipoprotein cholesterol(LDL cholesterol), triglyceride, acetocoenzyme A acetyltransferase(ACAT), and 3-hydroxy-3-methylglutaryl coenzyme A reductase(HMG-CoA reductase). However, it showed no effect on weight change or high density lipoprotein cholesterol(HDL cholesterol). Conclusion : These results suggest that SGT might be effective in treatment and prevention of hyperlipidemia.

• 대한한방내과학회지
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• 제32권1호
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• pp.75-86
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• 2011

Objectives : This study investigated oriental diagnosis and treatment of reflex esophagitis (RE) such as syndrome differentiation and herbal medicine by reviewing Chinese journals. Methods : A journal search was performed using China National Knowledge Infrastructure (CNKI) from January 2006 to December 2010. The keywords were the various combinations of 'reflex esophagitis', 'Chinese medicine', 'syndrome differentiation', and 'herbal medicine'. All types of journal entries that explained or referred to herbal medicines and definite syndrome differentiations were included. The Types of the journals were randomized clinical trials (RCT), reviews, essays, case series and reports. Vague syndrome differentiations and experimental studies were excluded. Selected journals were extracted and summarized by two researchers independently. Results : 47 Chinese entries were finally selected. 61% of them were case-control trials that had non-randomized, active controlled clinical trials. 36 kinds of syndrome differentiations about RE were investigated. We summarized and divided them into 10 syndrome differentiation groups. 肝胃不和(syndrome of liver qi invading the stomach) in syndrome differentiation, 和胃降逆 (harmonize the stomach and direct qi downward) in method of treatment, and Jwa kum-whan (左金丸) were cited with high frequency in RE. Conclusions : We find that many kinds of syndrome differentiation groups and herbal medicines for reflex esophagitis are used in China, compared with Korea. Further studies will be required about oriental syndrome differentiation and treatment of this disease.