• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.668-672
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• 2009

In wireless ad-hoc network, knowing the available bandwidth of the time varying channel is imperative for live video streaming applications. This is because the available bandwidth is varying all the time and strictly limited against the large data size of video streaming. Additionally, adapting the encoding rate to the suitable bit-rate for the network, where an overlarge encoding rate induces congestion loss and playback delay, decreases the loss and delay. While some effective rate controlling methods have been proposed and simulated well like VTP (Video Transport Protocol) [1], implementing to cooperate with the encoder and tuning the parameters are still challenging works. In this paper, we show our result of the implementation experiment of VTP based encoding rate controlling method and then introduce some techniques of our parameter tuning for a video streaming application over wireless environment.

• 한국IT서비스학회지
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• 제15권3호
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• pp.15-31
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• 2016

Sales Force Automation (SFA) is a strategic information system and one of the components of operational CRM system. SFA supports salespeople's activities such as selection of potential customers, creative value proposition, after-sales services, etc. SFA is increasingly used in many companies because it has the advantages to raise the salespeople's productivity by developing forecasting ability, value proposition ability, after sales service ability etc. Many researches have shown that implementation of SFA leads to the increase of salepeople performance, organizational performance, and quality of customer relationship. However, Some prior studies have discussed on the SFA implementation failure and pointed out that one of important causes of this failure is salespeople's resistance to SFA. Although many researches explain SFA acceptance phenomenon using Technology Acceptance Model (TAM) and Theory of Planned Behavior (TPB), these researches didn't deeply investigate the salespeople's resistance to SFA. Therefore, this study focuses on the factors influencing salespeople's resistance to SFA and the relationships among these factors. This study identified three factors (salespeople's perceived loss of power, perceived loss of autonomy, and perceived time and effort waste) influencing salespeople's resistance to SFA. The hypotheses testing results showed that salespeople's perceived loss of power and perceived time and effort waste significantly increased salespeople's resistance to SFA. And salespeople's perceived loss of power plays a mediating role between perceived loss of autonomy/perceived time and effort waste and salespeople's resistance to SFA. At the end of the paper, theoretical and managerial implications of this study and the limitations and future research directions are discussed.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.555-560
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• 2022

In this study, the insertion loss and phase delay according to the multi-layer structure radome parameters were analyzed using the boundary value solution approach, and the multi-layer structure and hexa mesh structures with low-loss electrical characteristics for the Ku-band transmission/reception frequency of 10.7 ~ 14.5 GHz were designed and manufactured. A hexa mesh was applied to minimize radio wave transmission and scattering, which lowered the transmittance refractive index according to the radio incident angle and minimized dielectric loss through high-density foam. Similar to the simulation result, the transmission loss obtained the gain in a specific receiving frequency band, and in the transmission frequency band, an excellent low loss characteristic was obtained with an insertion loss of 0.8dB or less. The results of this study can be used in radio transmission radomes of low-weight, low-cost end-system protection devices.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 전문대학교육위원 P
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• pp.52-55
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• 1999

In recent years, much attention has been paid to the voltage collapse phenomena. There has been reported many cases about the voltage collapse in many countries. These voltage collapse phenomena are known as the event that can occur due to reactive power deficits. This paper proposes an efficient method that can pursue the reactive power loss changes and gives the simple voltage collapse proximity indicator(VCPI) based on the reactive power loss sensitivities using optimal techniques. By comparing reactive power loss sensitivity with active power loss sensitivity, it is also proved that VCPI based on reactive power loss sensitivities is more effective. The developed VCPI is derived from the Jacobian matrix of Load Flow and the computational burden is very low and on-line implementation is possible. The proposed method is applied to a IEEE-14 bus test system and reliable and promising results are obtained.

• 해양환경안전학회지
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• 제16권1호
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• pp.65-69
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• 2010

선박에서 발생하는 각종 사고의 처리와 손해배상은 선박보험료에 영향을 미치게 되므로, 해양사고와 선박보험료와 증감은 선박의 국제안전관리규약(ISM Code) 도입의 효과를 측정하는 직접적인 평가척도가 될 수 있다. 따라서 본 연구에서는 ISM Code 국내도입 1년 전에서부터 도입 후 8년 동안에 변화하는 해양사고 및 선박보험요율의 분석을 통해, ISM 시행에 따른 성과를 파악하였다. 해양사고는 ISM 이행 1년 전에 비해 ISM 이행 8년차에는 약 14.4%가 감소하였고, 보험율도 감소하는 경향을 나타내었다.

• 대한인간공학회지
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• 제26권3호
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• pp.45-52
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• 2007

Shipbuilding workers are potentially exposed to ergonomic hazards in the manufacturing process. The purpose of this study is to describe the impact of an ergonomic intervention and the implementation effect of ergonomics program at a shipbuilding company. This study portrays an implementation procedure of ergonomics program over a period of two years concerning ergonomic hazard analysis and improvement, along with medical management. After implementation of the ergonomics program, the productivity improved, and the rate of accidental incidents decreased, also the loss of workdays decreased largely. The implementation effect of ergonomics program presented in this study can be used to provide baseline information for the prevention of musculoskeletal disorders in the shipbuilding industry.

• 전자공학회논문지A
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• 제32A권6호
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• pp.19-28
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• 1995

In this paper, measured iris transmission loss data and simulated data by using 3-dimension full-wave analysis S/W are presented and compared with Marcuvitz's theory. And by using measured iris data, dual-mode narrow-band channel filters can be successfully implemented. This paper shows that there is severe difference between the transmission loss of iris calculated by using Marcuvitz's equation to calculate iris dimension, if the length of slot iris is longer than .lambda./.pi., and in the long urn the response of channel filter is distorted. Experimental result shows that the characteristic response of implemented channel filter by using the iris transmission loss graph presented here matches well the design specfications. In conclusion, iris transmission loss measurement method will be very useful to design channel filter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.948-949
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• 2008

In this paper, an effect on power conversion unit in next generation high-speed train by loss of contact between a contact wire and pantograph supplied electrical power to high-speed train are investigated. One of the most important needs accompanied by increasing the speed of high-speed train is reduced that arc phenomenon by loss of contact brings out EMI. To analysis of conducted EMI source on powering mode of next generation high-speed train, it is necessary electrical modeling system between the contact wire and the pantograph according with loss of contact. Therefore analytical model of a contact wire and a pantograph is constructed to simulate the behaviour of loss of contact. The reliability of the modeling system is verified by simulation implementation on loss of contact.

• 한국컴퓨터정보학회논문지
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• 제24권2호
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• pp.103-109
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• 2019

Recently, as the number of families raising dogs has increased, cases of lost dogs have frequently occurred. According to US statistics, 5% of the total dogs are reported to be alive, with only 18% reporting to their owners. Therefore, a device for preventing the loss of dogs is needed, and the demand for the market is rapidly growing. Therefore, it is necessary to develop a lost device for dogs. In this paper, we developed a loss prevention device that combines low-power broadband wireless communication technology, LoRa communication method, and GPS positioning technology. The result of this study is expected to prevent the loss of dogs. It is also expected that social problems will reduce the problem of lost dogs.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1629-1632
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• 2003

Generally an increasing number of recent applications have found TCP too limiting. There are some characteristics in the transmission of document and binary data which some transmission delay are tolerant but the content must completely be transferred. However voice signals are more sensitive with not some packet loss but some transmission delay. Therefore, Stream Control Transmission Protocol(SCTP) is proposed to minimize the delay and packet loss in the field of delivery of voice signal. SCTP is designed to transport PSTN signalling messages over IP networks, but is capable of broader applications. In this paper, the architecture of SCTP implementation is designed and some interface of SCTP software library which are implemented are specified.