• Title/Summary/Keyword: path loss

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The Effect of Fashion Consumer's Browsing Motives and Risk Perception on Purchase Intention in Social Commerce (소셜커머스에서 패션제품 소비자의 브라우징 동기, 위험지각이 구매의도에 미치는 영향)

  • Woo, Seung Hyun;Hwang, Jin Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.37 no.6
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    • pp.772-785
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    • 2013
  • This study investigated the effects of fashion consumer's browsing motives and risk perception on impulse buying and purchase intention in social commerce. The online survey results of 317 customers who experienced using fashion products via social commerce were used for the final analysis. Exploratory factor analysis, reliability analysis, and frequency analysis were conducted using SPSS 18.0, and confirmatory factor analysis and path analysis were performed with AMOS 18.0. Three browsing motives (hedonic motive, rational motive, and informational motive) and three risk perceptions (products-related risk, customer service risk, and opportunity loss risk) were identified. The results from the structure equation model were as follows. 1) It was deducted that the browsing motive did not have a significant effect on risk perception due to the rejection of most of the hypotheses in regards to the browsing motive influence on risk perception. 2) Product-related risk and customer service risk had a significantly negative effect on purchase intention. Opportunity loss risk had significantly positive effect on impulse buying and purchase intention. 3) Hedonic browsing motive had a significant effect on impulse buying, and rational motive had a significant effect on impulse buying and purchase intention. The informational browsing motive had a significant effect only on purchase intention.

Prediction of Transmission Loss Due to Rain Scattering (강우산란에 의한 전송손실 예측)

  • 이점수;양승인
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.3
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    • pp.310-317
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    • 1997
  • Due to the congestion of the radio spectrum, frequency bands are shared among the communication systems. Therefore for the satisfactory operation we have to predict with reasonable accuracy the levels of interference that might exist among them. Inter- ference among the communication systems depends on many factors such as climate, radio frequency, time percentage of interest, distance and path topography. Interference due to rain scattering is the most important factorin Ghz frequencies. ITU-R offers the model related to interference due to rain scattering. In this paper the transmission loss due to rain scattering is predicted and compared with the measured results.

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Modeling of Propagation Interference and Channel Application Solution Suggestion In the UHF Band RFID Propagation Path (UHF 대역 RFID 전파경로에서의 전파간섭 모델링 및 채널 운용 방안 제안)

  • Moon, Young-Joo;Yeo, Seon-Mi;Jeon, Bu-Won;Roh, Hyoung-Hwan;Joung, Myoung-Sub;Oh, Ha-Ryoung;Seong, Yeong-Rak;Park, Jun-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.11
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    • pp.2047-2053
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    • 2008
  • Auto-ID industries and their services have been improved since decades ago, and radio frequency identification (RFID) has been contributing in many applications. Product management can be the foremost example. In our industrial experiences, RFID in ultra high frequency (UHF) band provides much longer interrogation ranges than that of 13.56MHz; many more applications exist thereby. There should be several interesting and useful ideas on UHF RFID; however, those ideas can be limited due to the inevitable environmental circumstances that restrict the interrogation range in shorten value. This paper discusses the propagation interference among different types of readers (e.g, mobile RFID readers in stationary reader zone) in dense-reader environment. In most cases, UHF RFIDs in Korea will be dependent on the UHF mobile RFIDs. In this sense, the UHF mobile users accidently move into the stationary reader's interrogation zone. This is serious problem. In this paper, we analyze propagation loss and propose the effective channel allocation scheme that can contribute developing less-invasive UHF RFID networks. The simulation and practical measurement process using the commercial CAD tools and measurement equipments are presented.

A Study on the Noise and Vibration Path of Hermetic Rotary Compressor by SEA (통계적 에너지 해석 기법에 의한 밀폐형 회전 압축기의 소음진동 전달경로 해석)

  • Hwang, Seon-Woong;Ahn, Byung-Ha;Jeong, Hyeon-Chul;Jeong, Weui-Bong;Kim, Kyu-Hwan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.869-874
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    • 2002
  • Hermetic rotary compressor is one of the most important components for air conditioning system since it has a great effect on both the performance and the noise and vibration of the system. Noise and vibration of rotary compressor is occurred due to gas pulsation during compression process and unbalanced dynamic force. In order to reduce noise and vibration, It is necessary to identify sources of noise and vibration and effectively control them. Many approaches have been tried to identify noise sources of compressor. However, compressor noise source identification has proven to be difficult since the characteristics of compressor noise are complicated due to the interaction of the compressor parts and gas pulsation. In this work, Statistical Energy Analysis has been used to trace the energy flow in the compressor and identify transmission paths from the noise source to the sound field.

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Multicast Extension to Proxy Mobile IPv6 for Mobile Multicast Services

  • Kim, Dae-Hyeok;Lim, Wan-Seon;Suh, Young-Joo
    • Journal of Computing Science and Engineering
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    • v.5 no.4
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    • pp.316-323
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    • 2011
  • Recently, Proxy Mobile IPv6 (PMIPv6) has received much attention as a mobility management protocol in next-generation all-IP mobile networks. While the current research related to PMIPv6 mainly focuses on providing efficient handovers for unicast-based applications, there has been relatively little interest in supporting multicast services with PMIPv6. To provide support for multicast services with PMIPv6, there are two alternative approaches called Mobile Access Gateway (MAG)-based subscription and Local Mobility Anchor (LMA)-based subscription. However, MAG-based subscription causes a large overhead for multicast joining and LMA-based subscription provides non-optimal multicast routing paths. The two approaches may also cause a high packet loss rate. In this paper, we propose an efficient PMIPv6-based multicast protocol that aims to provide an optimal delivery path for multicast data and to reduce handover delay and packet loss rate. Through simulation studies, we found that the proposed protocol outperforms existing multicast solutions for PMIPv6 in terms of end-to-end delay, service disruption period, and the number of lost packets during handovers.

Fast Spectrum Sensing in Radar-Interfered Airborne Cognitive Radio Systems (레이다 신호의 간섭 환경에서 항공 인지무선 시스템의 빠른 스펙트럼 센싱)

  • Kim, Soon-Seob;Choi, Young-June
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.8C
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    • pp.655-662
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    • 2012
  • In this work, we propose an airborne cognitive radio system that searches a new spectrum band to avoid a communication interruption due to the interference from many radar signals. We develop a method of fast spectrum sensing based on an effective frequency by recognizing the interfering radar as well as geographical information. This effective frequency is calculated by the free-space path loss between a base station and a fighter with the speed parameter. From our analysis, it is verified that the maximum frequency searching time is reduced by half by using our method.

MANAGEMENT OF ANKYLOSED PRIMARY MOLARS ; CASE REPORT (유착 유구치의 처치에 관한 증례보고)

  • Jang, Mi-Ra;Choi, Byung-Jai;Lee, Jong-Gap;Lee, Jae-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.24 no.3
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    • pp.590-596
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    • 1997
  • Ankylosis is defined as a fusion of alveolar bone with dentin and/or cementum and may occur at any time during or following active eruption. Ankylosed teeth maintain existing occlusal levels while adjacent teeth continue to erupt via deposition of alveolar bone. This may result in the clinical appearance of depression or submergence of ankylosed teeth below the occlusal plane. It is found more frequently in children of late mixed dentition and in mandibular primary molars. The problems arising from ankylosed teeth, due to their submerged positions, are elongation of the antagonist, tipping of the adjacent teeth, loss of arch length, food impaction and subsequent destruction of periodontal tissue, disturbance of succedaneous tooth eruption. The author observed several cases of ankylosed primary molars and properly managed. Following results were obtained. 1. Severe infraoccluded ankylosis results in loss of arch length and undesirable effect on eruption path of succedaneous tooth, therefore early diagnosis and management are important. 2. The teeth without problems may be examined periodically and restored in order to maintain the normal occlusal function.

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Effects of the Leakage Tangential Velocity on the Leakage Flow Path in Shrouded Axial Compressor Cascades (축류압축기 슈라우드 캐비티내의 누수유동 경로에 대한 연구)

  • Sohn, Dae-Woong;Kim, Tong-Beum;Song, Seung-Jin
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.311-317
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    • 2005
  • Measurements of the leakage flow in the shrouded cavity were performed in axial compressor cascades at $Re=2.6{\times}10^5$. This paper describes the effects of the leakage flow tangential velocity on kinematics of the leakage flow in the shrouded cavity and consequent overall loss and exit flow turning at stator blade row downstream. Flow data and flow visualization images consistently indicate that leakage flow circumferentially migrates 2, 4 and 5 blade passages in the direction of rotation for ${\upsilon}_y/c=0.09$, 0.35 and 0.45, respectively where ${\upsilon}_y$ is the leakage tangential velocity and c is the mainstream velocity. The leakage flow contracts to a jet across the seal-tooth resulting in an increase in the leakage axial velocity-doubling the leakage axial velocity in upstream cavity compared to that in the downstream cavity. Consequently, two flow regions are distinguished before and after the seal-tooth. As increasing the leakage tangential velocity, the overall loss downstream of stator blade row decreases and the exit flow turning in the range of span. from the hub endwall to 15% increases while the decreases in the flow turning from 15% to 30% span is observed.

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Study on a Hedging Volatility Depending on Path Type of Underlying Asset Prices (기초자산의 추세 여부에 따른 헤지변동성의 결정에 관한 연구)

  • Koo, Jeongbon;Song, Junmo
    • The Korean Journal of Applied Statistics
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    • v.26 no.1
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    • pp.187-200
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    • 2013
  • In this paper, we deal with the problem of deciding a hedging volatility for ATM plain options when we hedge those options based on geometric Brownian motion. For this, we study the relation between hedging volatility and hedge profit&loss(P&L) as well as perform Monte Carlo simulations and real data analysis to examine how differently hedge P&L is affected by the selection of hedging volatility. In conclusion, using a relatively low hedging volatility is found to be more favorable for hedge P&L when underlying asset prices are expected to be range bound; however, a relatively high volatility is found to be favorable when underlying asset prices are expected to move on a trend.

Evaluation of design variables to improve noise radiation and insulation performances of a dash panel component of an automotive vehicle (방사소음 및 투과소음에 대한 승용차량 대시패널의 설계인자별 영향도분석)

  • Yoo, Ji-Woo;Chae, Ki-Sang;Park, Chul-Min;Suh, Jin-Kwan;Lee, Ki-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.04a
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    • pp.526-531
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    • 2011
  • A dash panel component, close to passengers, plays a very important role to protect heat and noise from a power train. Meanwhile, it is also a main path that transfers vibration energy and eventually radiates acoustic noise into the cavity. Therefore, it seems important to provide an optimal design scheme incorporating sound packages such as dash isolation pad and carpet, as well as structures. The present study is the extension of the previous investigation how design variables affect sound radiation, which was carried out using the simple plate and framed system. The system taken into account in this paper is a dash panel component of a sedan, which includes A pillar, front side member, dash panel and the corresponding sound packages. Design variables such as panel thickness and sound package layers are investigated how they are related for the better radiation performance (i.e. structure-borne) and sound transmission loss (i.e. air borne).

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