• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1083-1088
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• 2001

To do performance evaluations about inorganic permanent form mixed in admixture(fly ash, silica fume) and after placed concrete, it is examined reinforcement materials in the permanent form from shear strength, bond strength and flexural strength tests. In this study, permanent form was inserted with reinforcement metal fitting is strength-tested in several method. The result of this study is belows. ⑴ In bond strength test, Most specimens are satisfied with criterion-6 kgf/$cm^{2}$ ⑵ Irrelative with the inserted metal fitting's shape, unevenness and aggregate, Permanent form and after placed concrete have good condition in the shear strength test. ⑶ In flexural test, there is no drop out of permanent form. Most cracks are located in nearby the strain point

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.681-686
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• 2002

In this study, a high volume fly-ash substituted concrete experiments in two curing temperature circumstances - 35${\circ}$, 20.${\circ}$, High volume fly-ash concrete is tested in fresh concrete properties and hardeded concrete properties. There is slump, air contents, concrete setting tests. 3, 7, As fresh concrete test items and 28 days water curing compressive strength is measured in the hardened concrete test. The purpose of this study is to submit a various fly-ash concrete data for application to field. The result of this study is that the best strength is developed at the plain concrete cured 20 ${\circ}$, and Mixing F43 shows the best strength among specimens which cured at 35${\circ}$,

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.80-83
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• 2004

The FRP plate or sheet bonding technology was widely used for strengthening deficient RC structures. The strengthened structure using FRP bonding scheme, however, experience the complex interfacial behaviour which is difficult to predict. Therefore, the unbonded scheme using some anchorage device can be is an alternative for more reliable design. In this study, wedge-type anchor for FRP plate is developed for the unbonded flexural strengthening scheme. Some parameter study using 2D finite element method is performed. The analysis parameters are taken as wedge-guide friction coefficients, wedge- FRP ,.friction coefficient and wedge inclination angle. Based on the parameter study, more efficient anchors are designed and tested. The test result show that the developed anchor assure about $80\%$ FRP strength, which is higher performance than typical bonding scheme. Last, 3D finite element analysis is performed.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.332-335
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• 2004

Polymethyl Methacrylate(PMMA) mortars using EPS solution-based binders are prepared with various unsaturated polyester resin(UP) contents of binder, and tested for working life. heat exothorm temperature, length change. compressive strength and temperature dependence of compressive strength. As a result, the working life of PMMA mortar is lengthened with raising UP content of binder. Length change of the mortar was condensed from expansion to shrinkage with increasing UP content, and non shrinkage of the mortar is obtained at about UP content of $2.5\%$. The compressive strength of the mortar is increased with an increase in the UP content and reach maximum at UP content of $5\%$. However thermal resistance improvement of the mortar by increasing UP content was not recognized. UP resin was recommended as an effective agent for shrinkage control and strength development of PMMA mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.196-199
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• 2004

Metakaolin is a cementitious material for producing high-strength concrete. This material is now used as substitute for silica-fume. In this paper, we tested the compressive strength of concrete according to the substitute ratio of metakaolin, silica-fume. And we did the durability test such as chloride ion diffusion and chemical attack. In the compressive strength test, the result shows that $10\%$ substitute of metakaolin & silica-fume for binder is optimum. In the chloride ion diffusion test, according to the increase of substitute of metakaolin & silica-fume for binder, the diffusion coefficient is more reduced. And in the chemical attack test, according to the increase of substitute, the resistance is more excellent. In the durability test, we recognized that metakaolin is able to used as a substitute for silica-fume.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.231-234
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• 2003

This paper describes the structure, operation, image processing, and decision making techniques of a color machine vision system designed for the automatic sorting of soybeans. The system consists of feeder, conveyor belt, line-scan camera, lights. ejector, and a PC Unlike manufactured goods, agricultural products including soybeans have quite uneven features. The criteria for sorting good and bad beans also vary depending on inspectors. We tackle these problem by letting the system learn the inspecting parameters from good samples selected manually by a machine user before running the system for sorting. Real-time processing has another importance In the design. Four parallel DSPs are employed to increase the processing speed. When the designed system was tested with real soybeans and the result was successful.

• Journal of Electrical Engineering and Technology
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• v.2 no.3
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• pp.353-357
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• 2007

The bearing diagnostics method is presented in this paper using fuzzy inference based on vibration data. Both time-domain and frequency-domain features are used as input data for bearing fault detection. The Adaptive Network based Fuzzy Inference System (ANFIS) and Genetic Algorithm (GA) have been proposed to select the fuzzy model input and output parameters. Training results give the optimized fuzzy inference system for bearing diagnosis based on measured vibration data. The result is also tested with other sets of bearing data to illustrate the reliability of the chosen model.

• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1481-1490
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• 2019

Arduino makes it easy to connect objects and computers. As a result, programming learning using physical computing has been proposed as an effective alternative to SW training for beginners. In this paper, we propose an Arduino-based physical computing education method that can be applied to basic programming subjects. To this end, we propose a basic programming training method based on Arduino analog signals. Currently, physical computing courses focus on digital control when connecting input sensors and output devices in Arduino. However, the contents of programming education using analog signals of Arduino boards are insufficient. In this paper, we proposed and tested the teaching method used for programming education using low-cost materials used for Arduino analog signal-based computing.

• Journal of Korea Multimedia Society
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• v.21 no.10
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• pp.1171-1181
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• 2018

Most simulated shooting systems are TDM based method and dot type laser has been used. The proposed laser pattern based simulated shooting system is a new approach. It can distinguish shooters by calculating the angle of bar shaped laser pattern by each shooter. Unlike the existing TDM method, it is possible to distinguish shooters and lanes by patterns so that there is no time division restriction like TDM method. It is also possible to recognize overlapped impact points of laser patterns launched by multiple shooters. After the laser pattern based simulated shooting system was implemented, general shot and overlapped shot were tested for each lane. Through experiments, we confirmed the possibility of continuous shooting. In addition, it is possible to separate the pattern by each lane, and 100% recognition result was obtained even if impact points overlapped.

• The Korean Nurse
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• v.28 no.1
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• pp.77-88
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• 1989

The purpose of this study is to propose the baseline data for -developing the occupational stress measurement tool for Psychiatric nurses Working in the hospital. 135 staff nurses in psychiatric unit of 11. hospital were participated during the period from August 1 to August 20, 1988. Though the pretest and literature review a questionnaire was coristructed with 88 stressors which were experienced by the psychiatric nurses in the hospital. Subjects were given instruction to rate 1~6 likert type scale according to the level of stress experienced by each stressor described. Reliability of the tool was tested by Cronbach's Alpha and the reasult was ${\alpha}=0.94871$. Factor analysis was applied to organize 88 items together: As the result, 14 factors were obtained. The factors were; 1) Administration problem 2) Work overload 3) Role conflict as a profession 4) Lack of professional knowledge and skill 5) Conflict with nurses 6) Conflict with other health teams 7) Conflict in nurse-clint relationship 8) Conflict with supervisor 9) Conflict with suborinate 10) Low reward 11) Scheduling probrem 12) Inappropriate physical environment 13) Staff inadequate 14) Inadequate of equipment.