• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.215-217
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• 2007

Recently, the demand for high definition TV is being increased by beginning of the digital broadcasting. The higher resolution of PDP is, the longer addressing time become, then, the sustain period for display image decreases. Because of the reason, dual-scan method which synchronously write information of an image on top and bottom of the screen is used for the high definition PDP. However, as the price competition of PDP becomes severe, we can`t avoid turning to a single-scan method which uses only a half of an expensive address IC. Accordingly, the sustain period becomes much shorter than prior method. In case of XGA level, it is impossible to display, eventually. In this paper, we are going to prove usefulness by realizing negative reset waveform and the driving circuit for high speed addressing.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.4
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• pp.56-60
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• 1986

The purpose of this study is to find the light intensity which induced maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by using rock trout, He.'~agrammos otakii (Jordan et starks). An experimental tank (360L x SOW x 55H cm) was set up in a dark room. An illumination system was attached to the end of one side of the tank to control horizontal light intensity. Six artificial light sources were prepared by combination of two light bulbs (5 W, 150 W) and seven filters. During the experiment water depth was maintained 50 em level in the tank. The tank was marked into six longitudinal sections each being 60 em long to observe the distribution of fish. The fish were acclimatized in dark condition for 50 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 40 times every 30 seconds. and the gathering rate was obtained from the average number of fish in each section. The light intensity inducing maximum gathering rate was O. 7 lux (0. 5~1. 1 lux) in the daytime and 5. 2/ux (3.2-7.7 lux) at night. The variation of the gathering rate of fish in illumination time was sma II and showed the decreasing trend.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.18-28
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• 2015

This study aims to understand the meaning that learning of the old age has, through old age learners who augustly live after retirement-life so called successful silver years. Qualitative research methods is used for analyzing the contents of articles about 15 old age learners and the results are follows below. First, the retirement has dual meaning for the old learners. One is they experienced psychological and emotional insecurity after retirement and the other is it is a turning point for them to realize their longtime dream. Second, the old age learners showed enthusiasm about learning and they voluntarily found the way of success in their silver years. Finally, the old age learners working in new career with provocative and enthusiastic attitude work as a role model of successful old age life and show how they progress. This study argued that we need to consider the old as active agents and the old age as the time when productive and continuous learning can be done. In addition, this study strongly insisted that we need to realize the importance of 'education by the elderly' and social and other relevant conditions are needed to be established immediately.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.98-104
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• 2003

While the impact or internet on our everyday life keeps increasing, the internet users are turning toward the value added information only that suits their purpose instead of just wandering over a sea (pool) or information. Although it is easy to locate the information using various search engines. we still finds it time and cost consuming to update the existing information or to add similar Information. There are several portal sites managed by each industrial types or associations/organizations for the purpose or strengthening the competitiveness or small and medium-sized enterprises And currently, tremendous manpower and expenses are put into the selection and quality improvement or information to satisfy the needs toward the high qualify information by the specialized users in their fields collection and updating or the information is partially available manually during He period or budget allocation by the government it becomes problematic, however, to continue this service when the project expires. This report presents the system for the information collection, analysis and classification of portal sites operated for the special purposes and automatic upload to the proper sites. In addition. expression or web robots and application of robots and several information types are suggested which will eventually accomplish currency or information and automatic updates and addition or documents with the least expenses or maintenance.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.194-200
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• 2007

The tilting train is able to tilt its body towards the center of the turning radius, preventing roll-over of the train as it runs on a curved rail at high-speed. This train, widely accepted for commercial purpose internationally is very beneficial in that the operating time is shortened without much capital investment to the infrastructure where there are many curved rails. Over several years, the Korea Railroad Research Institute(KRRI) has developed such a train. In this paper, the safety of the Korean tilting train express(TTX) is investigated using a dynamic simulation model. Since, proper safety standards have not been established for the TTX, those for the Korean train express(KTX) is employed instead to analyze the safety and ride comfort of the TTX. This study will prove useful in predicting the behavior of the TTX and ride comfort, and conforming that designed TTX measures up to the safety standards. It would be useful to recommend proper normal operating speed and determine the maximum safety speed, according to the result. Furthermore, it would be possible to provide basic reference data when analyzing the dynamic effect of the catenary system and the fatigue of the bogie.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.79-84
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• 2012

This study consist of two parts. One is development of a self-propelling vinyl remover which was already reported at the previous paper. This is the second part of the study. For the study, an attached vinyl remover was developed. It was consisted of connecting tractor to bucket, removing bucket from tractor, and the process was the tractor's assistance hydraulics. In the case of an attached vinyl remover, the vinyl was twisted 0.5times per 30~85cm length. The bobbin's diameter was 190mm and it's stable travelling speed was 1m/s. The revolution of the remover wheel was 90rpm to maintain the wheel's linear velocity. As seen at performance test at the field which had 950mm ridge intervals and 10 a area, the average working speed was 1m/s and the turning time was 20seconds. Therefore, the working performance was 24.5min/10a. The efficiency of used vinyl remover was 97% and working conditions were good.

• Journal of Welding and Joining
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• v.26 no.2
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• pp.50-54
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• 2008

The wearplate with Cr-C has been used in condition of severe abrasion. Recently, the demand of wearplate made by hardfacing with Cr-C has increased in the world, but it is lack of supply and expensive due to low productivity. CMAW (Compound Metal Arc Welding) is very useful process of several welding methods to make wearplate. In this paper, twin torch CMAW to use twin torch at the same time was developed to improve productivity and to ensure quality of wear plate. When the distance between two touches was smaller than 30mm, arc blow was occurred. However when the distance was larger than 35mm, there was no arc blow any more. If the oscillation path of each torch was overlapped together, the melt through at the overlapped zone was occurred due to concentrated heat input in substrate. On the other hand, the turning point of each torch was open more than 5mm, separated bead was generated. Therefore twin torch CMAW which has adequate conditions was able to make wearplate having flatter surface at the bead connection than single torch.

• Transactions of Materials Processing
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• v.22 no.6
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• pp.317-322
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• 2013

A radio frequency(R/F) switch connector is widely used in wireless devices such as mobile phone and navigator to check defects of the circuit board of product. The R/F switch connector shell plays a role in protecting the switch connector. Previously, this part was machined using a turning, which is time-consuming and has poor material utilization. Furthermore, the workpiece material of brass containing lead that has excellent machinability has environmentally regulated during recent years. The purpose of the current study was to develop the connector shell by forming through progressive dies including embossing, burring and forging process in order to achieve higher productivity and dimensional accuracy without tool failure. To accomplish this objective, a strip layout was designed and finite element (FE) analysis was performed for each step in the process. Try-out for the connector shell was conducted using progressive die design based on FE-analysis results. Dimensional accuracy of developed part was investigated by scanning electron microscopy. The result of the investigation for the dimensions of the formed connector shell showed that the required dimensional accuracy was satisfied. Moreover, productivity using the progressive die increased four times compared to previous machining process.

• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.48-57
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• 2014

The transient and synchronization behaviors of a TA (thermo acoustic) laser pair were investigated experimentally for various crossing angles and different separation distances between the laser openings. Sound waves generated by the lasers were measured and analyzed at or near the focusing point by means of microphones, SPL meters, and a commercial software called Signal-Express. The two TA lasers were acoustically coupled through the air mass between their openings, and the only mode-locking operation that could be achieved was the one that was nearly $180^{\circ}C$ out of phase. The time to achieve synchronization was found to be dependent upon the initial mistuning of the frequencies and the crossing angle between the laser axes. The synchronization process could also be accelerated by turning on the laser with the lower power input first.

• Magazine of the Korean Society of Agricultural Engineers
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• v.29 no.2
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• pp.30-38
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• 1987

Because the development of Korea's water resources will reach its limit in the near future, preparations should now be begun to deal with problems that may come as a result. It will be too late to start preparations when the water resources have already reach their limitation and, as the preparations cannot be done in a day, it will take a long time to provide them. Now is the great turning point to accumulate our technical experiences and attain our plans gradually. The preparations against this are summarized as follows; 1)The transitory use of water should be turn into the recurrent use for the future. 2)A cooperative water control system of an area should be arranged. 3)Water saving, control of water demand, and the multiple use of water should be encouraged. To do this effectively, people should be informed of the value and rarity of water. 4)The development of freshwater reserviors at estuaries is closely related to the development of water utilization in the whole river basin. The development of water resources by the construction of freshwater reservoirs at the estuaries should be started, when the development of upstream water resources reaches their limitation. 5)The existing water utilization structures should be reorganized by water resources exchange planning, so the effective use of water in large areas be attained.