• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.165-173
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• 2012

In this paper, we propose a random backoff scheme for Emergency Warning Messages (EWMs) in the vehicle-to-vehicle environment. The EWMs are disseminated from a vehicle that detects an emergency situation to other vehicles in a multi-hop fashion. Since the vehicle-to-vehicle communication based on IEEE 802.11 adapts CSMA/CA, the density of vehicles increase the probability of collisions between transmissions. Moreover, in the presence of background traffic, the EWM should have a higher priority than that of other messages in neighboring vehicles. To that end, we propose the Distant-Dependent Adaptive Backoff (DDAB) scheme, which set a different contention window for random backoff depending on the distance from the sender to the receiver. In the case when a vehicle is expected to located in the outskirts of the communication boundary, the proposed scheme makes the contention window size small in order to compete the background traffic transmission. Otherwise the contention window is set to a large number to reduce the collision possibility among the EWM transmissions. Via simulations, we show that the proposed scheme performs better than the previous schemes for EWM.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3307-3314
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• 2012

The annual energy demand of the standard rural house models was analyzed using the DesignBuilder. Indoor temperature set-point, U-value of outer wall, type of window, and degree of ventilation were selected as simulation parameters. In all the simulation cases, heating energy demand was higher than cooling energy demand regardless of the building size. When the lower U-value of the outer wall was applied to account for the thicker insulation layer, heating energy demand was decreased while cooling energy demand was increased. However, it is better to reduce the area of outer wall which is directly exposed to outdoor air because reducing the U-value of the outer wall is not effective in decreasing heating energy demand. Among the four different window types, the double skin window is most favorable because heating energy demand is the lowest. For a fixed infiltration rate, higher ventilation rate resulted in an increased heating energy demand and had minor impact on cooling energy demand. As long as the indoor air quality is acceptable, lower ventilation rate is favorable to reduce the annual energy demand.

• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.217-223
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• 2012

This study describes an experimental investigation about the impact damage characteristics of various types of high speed train window glass. Kinds of impact test standards for glass were studied and impact test considering scattering ballast were developed. Windows with external impact side made with annealed, heat strengthened and tempered glasses are likely to be broken by sharp tipped falling object. Broken shape of annealed glass is like line in part and that of heat strengthened glass is line on the whole. Tempered glass is destroyed to pieces. The change of tip type from sharp to blunt makes the higher destroyed level. Tempered glass has higher strength than annealed glass with blunt tip. When the protective films are attached to glasses, strength against destruction increases. In case of real ballast test, glasses without protective films were destroyed, but those with protective films are hard to be broken.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1734-1740
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• 2012

Voltammetric characterization of hydrophilic anion transfer processes across a 66 microhole array interface between the water and polyvinylchloride-2-nitrophenyloctylether gel layer is demonstrated. Since the transfer of hydrophilic anions including $Br^-$, $NO_3{^-}$, $I^-$, $SCN^-$ and $ClO_4{^-}$ across the liquid/gel interface usually sets the potential window within a negative potential region, a highly hydrophobic organic electrolyte, tetraoctylammonium tetrakis(pentafluorophenyl)borate, providing a wider potential window was incorporated into the gel phase. The transfer reaction of perchlorate anions across the microhole-water/gel interface was first studied using cyclic voltammetry and differential pulse voltammetry. The full voltammetric response of perchlorate anion transfer was then used as a reference for evaluating the half-wave transfer potentials, the formal transfer potentials and the formal Gibbs transfer energies of more hydrophilic anions such as $Br^-$, $NO_3{^-}$, $I^-$, and $SCN^-$. The current response associated with the perchlorate anion transfer across the micro-water/gel interface versus the perchlorate concentration was also demonstrated for sensing applications.

• Journal of Power System Engineering
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• v.16 no.1
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• pp.98-105
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• 2012

안티핀치 시스템은 파워 윈도우 상승 시에 인체의 특정 부위가 창문 틈 사이에 끼여 발생하는 치명적인 사고를 방지하기 위한 안전 시스템이다. 이러한 안티핀치 시스템은 물체의 끼임을 검출하는 센서 방식에 따라 접촉식과 비접촉식 두 가지로 크게 구분된다. 본 논문에서는 접촉식의 한 방법으로 전류 정보에 의해 강화된 미국의 안전 규정 FMVSS 118-S5를 만족하는 안티핀치 시스템을 제안한다. 안티핀치 시스템에 사용된 전류 정보는 추가적인 장치의 부착 없이도 기존의 파워 윈도우용 모터 드라이브에 내장된 과전류 검출용 전류 센서를 이용하여 쉽게 얻을 수 있다. 또한 전류 정보는 물체의 끼임을 신속히 검출, 반영함으로써 안티핀치 시스템에 요구되는 반전력 저감에 기여한다. 특히, 본 논문에서는 전류의 임계값이 모터 경년 변화나 운전 조건에 따라 변동하는 문제점을 개선하기 위해 핀치 상태를 효과적으로 판정할 수 있는 자동 임계값 설정 방법을 제안한다. 마지막으로 다양한 실험 및 시험을 통해 제안된 안티핀치 시스템이 FMVSS 118-S5를 만족함을 보인다.

• The Journal of the Korea Contents Association
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• v.12 no.1
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• pp.154-165
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• 2012

In this paper, I examine the history of split screens, primarily seek to explain types of them, and explore the narrative meaning of each type in feature films. In short, I try to categorize the types of split screens and present a figure of them according to events and characters, focusing the relations between/among simultaneous images and narrative meanings. In addition, I assert that split screen have altered some methods of filmic storytelling and the ontology of screen. Story lines no longer have to be linear and the screen need not to remain a window through which we can see another world. The screen has come to be a canvas upon which several images can be arranged for narrative purposes.

• Journal of Korea Multimedia Society
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• v.15 no.8
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• pp.986-995
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• 2012

In this paper we propose a real-time moving object tracking method on a smart phone camera. By considering the limit of non-learning approach on low-performance platforms, we use the sliding-window detection technique based on histogram features. We solve the problem of the time-consuming histogram computation on each sub-window by adapting the integral histogram. For additional speed and tracking performance, we propose a new adaptive bin method. From the experiments on our dataset, we achieved high speed performance demonstrating 34~63 frames per second.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2323-2340
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• 2012

Recent advances in cognitive radio technology have drawn immense attention to higher layer protocols above medium access control, such as transmission control protocol (TCP). Most proposals to improve the TCP performance in cognitive radio (CR) networks have assumed that either all nodes are in CR networks or the TCP sender side is in CR links. In those proposals, lower layer information such as the CR link status could be easily exploited to adjust the congestion window and improve throughput. In this paper, we consider a TCP network in which the TCP sender is located remotely over the Internet while the TCP receiver is connected by a CR link. This topology is more realistic than the earlier proposals, but the lower layer information cannot be exploited. Under this assumption, we propose an enhanced TCP protocol for CR networks called TCP for cognitive radio (TCP-CR) to improve the existing TCP by (1) detection of primary user (PU) interference by a remote sender without support from lower layers, (2) delayed congestion control (DCC) based on PU detection when the retransmission timeout (RTO) expires, and (3) exploitation of two separate scales of the congestion window adapted for PU activity. Performance evaluation demonstrated that the proposed TCP-CR achieves up to 255% improvement of the end-to-end throughput. Furthermore, we verified that the proposed TCP does not deteriorate the fairness of existing TCP flows and does not cause congestions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.15-20
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• 2012

In this paper, an algorithm that enhances the conventional directional CSMA/CA protocol in IEEE 802.15.3c is proposed under saturation environments. For the algorithm, a Markov chain model is presented and analyzed in no-ACK mode. The effects of directional antennas and the features of IEEE 802.15.3c MAC are considered in the model. The optimal sizes of contention window are derived from the numerical results. The numerical results show that the proposed directional CSMA/CA algorithm outperforms conventional one. The overall analysis is verified by simulation. The obtained results provide the criterion for selecting the optimal parameters and developing a MAC protocol that enhances the performance of mmWave WPANs.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.171-176
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• 2012

This research on building Integrated Photovoltaic System replacing windows and doors with amorphous silicon thin film PV windows and doors installing same exact mount on Mock-up. The windows and doors should be installed in different angle and bearing so that we can analyse the amount of electricity from them. The objective of the research is to evaluate and investigate the relationship between factors(intensity of solar radiation, PV window surface temporature, incidence angle, and sky conditions) that affects performance of PV window and performance. The range and method of this research is to establish mornitoring system and analysis the date from the mornitoring system to evaluate the performance of PV windows that has thin film of solar battery. We should evaluate the insolation according to the position of PV window, output, and surface temperature according to months and seasons so that we can figure out the relationship between these. And we should investigate the relationship between performance and efficiency according to incidence angle and sky condition so that we can figure out the correlation between factors and performance.