• Journal of IKEEE
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• v.24 no.2
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• pp.592-597
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• 2020

Since SiC has 10 times higher breakdown field and 3 times higher energy gap than Si, it is possible to manufacture an excellent power MOSFET with a high breakdown voltage. However, since it has a high on-resistance due to low mobility, a Trench MOSFET has been proposed to lower it, but at the same time, it has a problem that BV decreases. The purpose of this paper is to design a 1200V trench MOSFET, and to solve this, split Epi depth, Trench depth, and Trench depth to Epi depth, which are important variables for BV and Ron, to achieve maximum electric field, BV, Ron's reliability characteristics were compared and analyzed. As the epi depth increased, the trench depth decreased, and the epi depth decreased at the trench depth, the maximum electric field decrease, BV increase, and Ron increase were confirmed. All results were simulated by sentaurus TCAD.

• Industry Promotion Research
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• v.2 no.1
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• pp.1-7
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• 2017

In the case of manufacturing companies, various types of data are collected. Many of these data can be used as useful information for product reliability evaluation. In this study, we first look at data that can be collected by a manufacturing company and related to products, technology, finance, and customers. Next, we will look at the company's business management system, scientific journals, test and marketing survey data, etc., as sources of data. Next, look at what kind of data is collected over the product life cycle to evaluate the reliability of the product. In the development stage of the product, reliability test is performed for each component, and reliability data is collected by performing reliability test at the subsystem and system level. On the other hand, at the manufacturing stage, data on the functional test and the design change test of the product are collected, and at the field stage, the problem of the product is detected in the field and collected in the form of data. Finally, let's look at what you need to do to make a reasonable analysis later in your data collection.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.2
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• pp.1-13
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• 2009

Although enormous data have been collected in major cities (Korea) by APTS(Advanced Public Transit Systems), most of studies related to bus schedule management evaluation have confined to headway adherence and on-time performance. Therefore, bus operation management have been very lack of using APTS data. This study uses coefficient of correlation to evaluate bus company's schedule management level. However, direct application of coefficient of correlation has inequitable problem because of many limitation(number of vehicle, headway, etc). and so variable calibration method was developed and applied to cope with these problems. Thus, demand-elastic management evaluation index was developed. For verifying the equity of developed index, it is applied to Seoul bus routes. It is expected for the developed index to contribute into the demand-elastic management of bus schedule.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.3
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• pp.9-15
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• 2011

The left-turn actuated signal control method has been occurred various problems under the COSMOS. one of problems is a early termination for left-turn phase by u-turn vehicles at left-turn lane. Therefore, the purpose of this study is a development of the efficient left-turn actuated signal control method to improve the problem. This study was considered that setback the left-turn vehicle detector to the start point of u-turn line and adjustment of the passage time. For effective analysis of developed method, Traffic simulation was simulated by T-7F and VISSIM under various traffic conditions. The result was proved that the developed Method improved the effectiveness.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.241-249
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• 2012

In the many countries, research about ultra wideband wireless transmission technique is widely studied for efficient utilization of frequency resource due to a sudden increase of demand of frequency resource all over the world. The ultra wideband communication system has the some specific advantages. First, it can transmit data with high speed, second short transmission range can increase the frequency reuse rate, and finally it has high security property. However, there is a interference between ultra wideband system and other communication system but study to solve this problem is insufficient. To efficient utilization of limited frequency resource, a novel frequency avoidance technique and setup the standardization of frequency interference must need. So, the purpose of this paper is that increases communication efficiency of microwave communication systems to analyze the technical trends for transmission of the low power device, and to research the implementation and technical research of wireless access network technique of wideband communication systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.7-12
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• 2014

The data forwarding transmission is an important function of the relay in cooperative communication in wireless communication systems. However, additional relay cause the waste of power consumption and cost. Therefore, in this paper, we consider how to use the user mobile devices in stead of relays to deal with this problem. In this paper, we proposed the protocol that divide each relay into two states of idle and non-idle. The receiver has two functions of base station and user mobile device. In this case, it is possible that no additional cost, and improve the spectral efficiency and network capacity. We verified BER performance for the proposed protocol over Rayleigh fading through Monte-Carlo simulation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.213-220
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• 2016

In order to drive on road safely, the type of road design and construction is basically needed to optimize driver's safety and vehicle performance. Although the heavy traffic highways were built by reflecting these factors, the national highways and local roads have still taken a lot of problems. In this study, we analyzed the behavior characteristics of a vehicle according to the speed variation of the vehicle using the PC-Crash program for the traffic accidents reconfiguration at GULUN interchange located Hongcheon in Gangwon Province. the conditions outlet surface of the road for analysis were dry road surface, wet road surface and icy road surface. As a result, we identified the fact that the friction coefficient of road surface and the speed of vehicle affected to vehicle behavior characteristics of outlet shape in GULUN interchange, and showed the possibility that we can verify a problem about road design through to this simulation in advance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.209-214
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• 2017

A plane-wave incident upon asymmetric multi-layered dielectric grating as well as symmetric grating structure generates space harmonics. Selected space harmonics among those harmonics can undergo strong resonance scattering variations known as GMR(guided-mode resonance). In this paper, to clarify these effects, the field propagation and dispersion curve inside the grating region are analyzed by using a rigorous equivalent transmission-line theory(RETT) based on eigenvalue problem. The results show that, at the peak of a scattering resonance, the reflected mode is almost identical to a leaky wave that can be supported by the grating structure. Thus, it confirms to be occurred GMR effect associated with the free-resonant character of leaky waves at asymmetric multi-layered dielectric gratings. Quantitative simulation results illustrating the behavior of typical gratings are given, and the special case of normal incidence is discussed for TE and TM modes.

• Journal of Agricultural Extension & Community Development
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• v.4 no.1
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• pp.73-89
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• 1997

The purpose of this study was to investigate the leadership style and development of agricultural organization in Korea. Specific objectives of the study were to : 1) identify the leadership style of agricultural organization though literature review, 2) survey the members' opinions about their leadership style, 3) examine the leader's self-estimation of their leadership style, 4) identify the desirable leadership style items of the leaders and members, 5) suggest effective way to the development of leadership style. The study was carried out through literature review and questionnaire survey. Total of 715 farmers were surveyed to collect data, and 501 responded. The statistical techniques applied on the data are frequency, percentile, analysis of variance, multiple regression utilizing the SPSS/WIN, and the statistical significance was tested at .05 level. The major findings of the study were: 1) the leaders motivation and problem solving abilities of agricultural organizations were not enough to satisfy the members, 2) members believed the leaders make somewhat arbitrary decisions, 3) the leaders of the organizations had difficulties to coordinate the different opinions of the members, and 4) the leaders of the organizations felt the need of skills and information on leadership style and development of agricultural organization. For improvement of leadership for agricultural organization, this study suggests; 1) the more education programs should be made and practiced to make their leadership special, 2) all members should make much efforts to have channels for rational communication, 3) the leaders have to give members well-polished incentives for active participation, 4) more governmental support should be given to empower those organizations, and 5) the agricultural organizations, universities and government must establish a strong coordinating system to realize above suggestions.

• The Journal of Korean Association of Computer Education
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• v.4 no.2
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• pp.71-83
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• 2001

The purpose of this study was to explore the status of development, dissemination, and usage of web courseware for elementary school. Also, this study investigated the problems and improvement strategies. The subjects were 52 researchers from Offices of Education and private companies and 528 teachers and 527 students from elementary schools. Questionnaires were used to collect the data. The study results indicated as follows: First, web courseware are insufficient. It is necessary to provide sufficient budgetary support for development of web courseware. Second, many of web courseware are inconsistent with the curriculum and class environment. To resolve this problem, more teachers should be involved in web courseware development. Third, web courseware usage level was very low because of the lack of information and training. In-service training program should be changed from computer literacy oriented to teaching method with web courseware.