• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.113-116
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• 2003

The sustain discharge mode using various auxiliary pulses was proposed to improve both the luminance and luminous efficiency of ac-plasma display panel (ac-PDP). It was found that the various auxiliary pulses, which were applied at the rising and falling time of the sustain pulse, played a role in strengthening both the main and self-erasing discharges. As a result, the sustain waveforms with auxiliary pulse improved both the luminance of 23 % and the luminous efficiency of 36 %, when compared with the conventional sustain waveform without auxiliary pulse.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권9호
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• pp.383-387
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• 2003

In this paper, we have studied about optimal transmission efficiency characteristics of pulse energy in a coal plant for removing environmental polluted gas. The electrical efficiency of pulse power systems depends on impedance of the reactor. To obtain high efficiency, we used MPC(Magnetic pulse compressor) as the power switch and tested their characteristics as electrode length of the reactor and charging voltage of capacitor, As results, we obtained a compressed pulse such as pulse voltage of 10㎸, rising time 200ns and pulse width of 500ns. With increasing electrode length, the load impedance was decreased but the electrical efficiency was increased.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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• pp.157-161
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• 2000

The electronic ballasts for low pressure discharge lamps are produced and commercialized. However, the electronic ballasts for high pressure lamps are now in progress because of poor reliability and high cost. The major case of troubles with electronic ballasts are thermal destruction of semiconductor output switches due to non ideal i-v characteristics of switch. The loss converts to heat and rises the temperature of switch and it increases proportionally to switching frequency and value of current and voltage. This study shows the variable frequency ballasts which can suppress the heating of switches efficiently. It is used for the limitation the switch current and the rising temperature of switch by impedance variation of lamp inductor. As a result, initial warm-up time of the proposed ballasts was faster than that of magnetic ballasts about 90 msec. Power factor of tested ballasts follow as ; input and output average of magnetic ballasts are 93 [%] and 86 [%], respectively, And proposed ballasts are 97 [%] and 99 [%], respectively.

• 한국세라믹학회지
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• 제34권4호
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• pp.337-342
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• 1997

This paper describes the design and evaluation of new type piezoelectric bimorph actuator that shows much large mechanical response than those conventional types. The bimorph actuator has modified structure combined with the multilayer actuator(MLA) and the composite multilayer actuator called "Moonie". The design and performancean alysis of bimorph actuator are carried out with Finite Element Method (FEM). Theoretical calculation results show that the generating force and displacement of Moonie-modified bimorph actuator can be improved by about 130% and 150%, respectively. The overshooting and ringing phenomena of the bimorph can be effectively restrained by the pseudo step electric field having a rising time coincied with a period of the fundamental vibration mode of the bimorph.e bimorph.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1760-1763
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• 2003

In this paper, we propose a new weaving trajectory algorithm for the are welding of a articulated manipulator. The algorithm uses the theory of Bezier spline. We make a comparison between the conventional algorithms using Catmull-Rom curve and the new algorithms rising Bezier spline. The proposed algorithm has been evaluated based on the MATLAB environment in order to illustrate its good performance. The algorithm has been implemented on to the industrial manipulator of DR6 so as to show its real possibility. Through simulations and real implementations, the proposed algorithm can result in high-speed and flexible weaving trajectory planning and can reduce the processing time because it needs one-half calculation compared to the conventional algorithm using Catmull-Rom curve.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.82-84
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• 2008

A surface encoder based on the Half-shaded square pattern (HSSP) is presented. The HSSP working as reference grid is composed of the straight lines which are easy to be fabricated and make measuring time short. Since the periodic cell is separated in ON/OFF by the $45^{\circ}$ straight line, the duration from the starting point of scanning to the first rising edge and the duty cycle of the pulse train vary with respect to the position of the starting point. And the relationship between X and Y position and the duration, and duty cycle is described in the simple linear equation. Therefore, it is possible to measure X and Y position with the measured duration and duty cycle without calculating load. Through the test set-up, the feasibility of the proposed surface encoder was verified. Also the future works for improvement of performance were suggested.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.45-49
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• 2003

According to the rising of national economic level, domestic consumption of vegetables having high additive values is increased continuously due to increased consumption of meat in last decade. These vegetables are produced almost in this country and are limited to import from neighbor countries in due of high transportation expenses for storing in refrigerated container. It is very important to mechanize the harvest work, forming more than 30% for their production cost, in order to cultivate variable vegetables at the same time according to their harvesting seasons. In this state its former harvest methods, with using of human power or semi-automatic harvest, caused to increase their production cost due to high labor cost and low working efficiency.

• Advances in concrete construction
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• 제5권2호
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• pp.87-99
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• 2017

After passing through a magnetic field, the physical quality of water improves, and magnetic water (MW) is produced. There are many investigations on the effects of magnetic field on water that shows MW properties like saturation and memory effect. This study investigates the fresh and hardened properties of concrete mixed with MW, which contains silica fume (SF) and superplasticizer (SP). The test variables included the magnetic field intensity for producing MW (three kinds of water), SF content replaced cement (0 and 10 percent), water-to-cementitious materials ratio (W/CM=0.25, 0.35 and 0.45) and curing time (7, 28 and 90 days). The results of this study show that MW had a positive impact on the workability and compressive strength of concrete. By rising the intensity of the magnetic field which was used for producing MW, its positive influence on both workability and compressive strength improved. MW had greater positive impacts on samples containing SP that did not have SF. Moreover, the best compressive strength improvements of concrete achieved as W/CM ratio decreased.

• Asian Journal for Public Opinion Research
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• 제2권3호
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• pp.140-171
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• 2015

As China's economic development brings the country out of poverty and into modernity, a long-lasting debate concerns whether the Chinese public's value system is also changing toward the so-called "modern values," or whether some distinctly traditional Chinese values remain unchanged. Using empirical data collected at three points in time during the 1990s and the first two decades of the 21st Century (1993, 2002, and 2011), I found that Chinese citizens who benefitted from urbanization, rising levels of education and employment in non-farm, knowledge-based industries displayed stronger modern values. People with stronger modern values are more likely to emphasize individual autonomy, competition, gender equality, and market transaction, among others. Some characteristics of the Chinese people, most importantly family values, however, seem to remain stable amidst rapid social changes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.129-134
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• 1992

Fuzzy theory has shown good control performance for non-linear system that is difficult to be controlled by the conventional controller. Backpropagation neural network can interpolate output without the priori knowledge of its dynamics. In this paper, we proposes a Fuzzy-Neural Controller. The Fuzzy Control by deterministic rule may not be sensitive for uncertain conditions and has a disadvantage of setting the rule by repeatedly experience. To solve such problems, we construct Self organizing Fuzzy-Neural Controller which can reorganize the fuzzy rule according to the state of system. Experimental results show that proposed Fuzzy-Neural Controller has better performance than conventional controller(PID) has especially rising time and overshoot characteristics.