• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.106-109
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• 2006

It has been shown that many reinforced concrete(RC) structures designed without seismic details have experienced brittle shear failures in the beam-column joint area and may result in large permanent deformations and structural collapse. In this study, experimental investigations for RC beam-column joints strengthened with the carbon fiber-reinforced polymer(CFRP) under cyclic loadings were presented. The use of CFRP in the joint was varied to determine the effective way of improving the structural performances of RC joints. Ten RC beam-column joints were designed and tested with cyclic loadings. The experimental results showed that the use of CFRP in RC joints would be very effective solutions to improve the seismic performances of the non-seismic RC joints. All of the non-seismic design specimens strengthened with CFRP sheets showed the significant increase of strength and ductility.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.152.1-152
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• 2001

This paper presents a high performance and cost effective way by using an FPGA circuit to implement torque controller so that the SRM can operate at high speed. In order to increase the operating speed, we need to implement both the torque and the current controllers by using an FPGA. However, it is difficult to implement all of the torque controller in the FPGA. Moreover, implementation of a time critical part is sufficient for improving the performance. One of the time critical part is the switching angle control. In this study, torque controller which calculate the switching on and commutation angles is implemented in PC because these angle are a function of rotor velocity which is varied slowly, and switching angle controller ...

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.127-130
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• 1995

Fuzzy controllers have proven to be powerful in controlling dynamic processes where mathematical models are unknown or intractable and ill-defined. The way of improving the performance of a fuzzy controller is based on making up rules, constructing membership functions, selecting a defuzzification method and adjusting input-output scaling factors. But there are many difficulties in tuning those to optimize a fuzzy controller. So, in this paper, we propose the look-up table based self-orgenizing fuzzy controller (LSOFC) which optimizes look-up values resulting from the above fuzzy processes. We use the plus-minus tuning method(PMTM), scanning the value through the processes of addition and subtraction. Simulation results demonstrate that the performance of LSOFC is far better than that of a non-tuning fuzzy controller.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.165.1-165.1
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• 2011

In this paper, it is intended to study about deferences of design and operation properties between large and small hydro-power house's turbine which type is reaction. In generally, turbine of large hydro-power has a more safe and effective energy output mechanisms than small hydro-power's because the turbine of small hydro-power is more sensitive to hydraulic losses. But, it is more effective for the all energy market to improve the capability and efficiency of small hydro-power in the present status of increasing construction of small hydro-power than large hydro-power. Therefore, we intend to investigate and introduce the way to enhance the efficiencies of reaction turbine adopted to small hydro-power.

• Journal of the Korea Safety Management & Science
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• v.10 no.1
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• pp.23-31
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• 2008

Recently, there is a rise of accident by some defective products, especially it reported that a serious fact is a defect of design causing some problem since execute a product liability(PL), people who use products have been able to bo remunerated for a damage to those defects, so responsibilities of companies are rising more and more. Therefore, companies that are obligated to manufacture a safety product, and should make preparation for PL. For solving the problem, even though manufacturers tried to make a safety product ay mixed ways, it is seldom that its safety is considered from planning a design. This thesis has suggested a way aimed at improving a safety of products through considering a stage of a plan, by searching and analyzing the design-process in to each steps.

• Journal of Environmental Science International
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• v.13 no.10
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• pp.863-870
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• 2004

The main objectives of this research are to analyse and evaluate the demolishing walls initiative in Daegu city as the collaborative urban environment improvement initiative in South Korea using the actor network theory concept. Local authorities are unable to effectively and efficiently improve urban environment because of their limited statutory and financial powers. This inability crucially led to the formation of the demolishing walls initiative in Daegu city with building a coalition of the local people, interest groups and public and non-governmental organisations in the operational processes in order to improve the physical and social urban environments. Furthermore, co-ordination between local authorities and landscape architecture specialists not only to change the way in which they tackle urban environmental problems but also to make the local people aware of their potential ability in positively improving the urban environment.

• Journal of the Korean Society of Safety
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• v.26 no.6
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• pp.1-6
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• 2011

This study focuses on the control strategy for industrial safety in Korea. Specifically, the effect of safety budget such as the industrial accident prevention fund on the safety performance to prevent and reduce industrial accidents is statistically examined first and modeled as a second order system. The effectiveness of such a dynamic model is also explained with a simple PI control mechanism in a feedback loop. The simulated model, however, suggests that, without improving the efficiency of the safety system, extra safety budget needed to decrease the accident rate to a level in advanced countries is far beyond the social consensus. An efficient way of reducing industrial accidents based on such a dynamic model with more internal damping but with less elastic nature in a feedback loop framework needs to be implemented.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2429-2433
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• 2008

A rotary vane blower was developed as an air supply system for fuel cell application. As one way of improving the blower efficiency, a roller was adapted between vanes and cylinder housing. The performance of blower was investigated experimentally. The blower power input was about 115W to compress the air at normal atmospheric condition to 0.2 bar with the flow rate of 140 NLPM, resulting in the blower overall efficiency of 43%. After 400 hours of operation, the performance of blower was not changed. The result showed that developed blower was confirmed to be suitable for fuel cell application.

• Korean Journal of Agricultural Science
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• v.26 no.2
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• pp.106-115
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• 1999

It will become necessary for farmers to adopt information technology into commercialized farming system, since its productivity is increasingly linked to how to exploit the agricultural information. The purpose of this study is to examine the current status of information technology and to suggest ways to utilize the information technology for innovative farm management. Internet should become more important instruments which farmers might utilize in order to collect and mine the agricultural information because of its rapidity, reliability and precision. Also farmers should be encouraged to adopt a GIS-based farm management decision support system and to integrate the market information and geographic information such as soil, water, temperature, etc. for optimal decision making. Another way of improving farm management is to make farmers use agricultural accounting software for individual farmers and develop farming simulation system which analyze a farmer's current financial condition and suggest how to improve it. Making home page would be major marketing strategy for farmers to promote the sales of agricultural products.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.320-324
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• 2005

In this paper, the resonance characteristics of SMR-type FBAR devices annealed by three different annealing methods are investigated and compared. The resonance characteristics could be effectively improved by the proposed efficient annealing method which can optimize the annealing conditions. It seems very useful for improving the performance of the SMR-type FBAR devices in a cost-effective way.