• Asia pacific journal of information systems
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• 제17권3호
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• pp.79-103
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• 2007

The main purpose of this study is to define antecedents that influence e-SCM synchronization and to investigate how it affects e-SCM performance. We, therefore, investigate (1) the impact of firms' internal IT planning capabilities on e-SCM synchronization and on SCM process management capability, (2) the impact of firms' internal IT infrastructure on e-SCM synchronization and on SCM process management capability, (3) the impact of firms' internal SCM process management capabilities on e-SCM synchronization, and finally (4) the impact of e-SCM synchronization on SCM performance. A survey has been administrated to the firms' SCM and marketing staffs and 171 returns analyzed. The results show that (1) IT plan has not direct impacts on e-SCM synchronization, but has direct impacts on organizational support, purchasing, and operations processes except logistics process. IT plan, however, has indirect impacts on e-SCM synchronization through purchasing and operations of SCM process management capability. (2) IT infrastructure has both direct and indirect effects on e-SCM synchronization, and also has direct impacts on organizational support, purchasing, and operations processes except logistics process. (3) SCM process management capabilities have direct impacts on e-SCM synchronization. Among these SCM core processes purchasing positively influences operations, which in turn positively influences logistics process management capability. (4) e-SCM synchronization has positive impacts on SCM performance indicator (SCOR), such as delivery reliability, responsiveness & flexibility, and cost. These results indicate that e-SCM synchronization can be critical to achieve better internal performance like cost and external performance like delivery reliability, responsiveness & flexibility of firms' SCM. In sum, this study demonstrates that the intervening role of e-SCM synchronization between e-SCM performance and IT management capability and between e-SCM performance and SCM core process management capability has been significant in achieving better e-SCM performance. Therefore, it can be suggested that e-SCM performance should be accomplished in consequence of the acceleration of e-SCM synchronization through the enhancement of preceding factors for the e-SCM synchronization.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.217-220
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• 2009

모바일 환경에서 기존의 양방향 동기화 시스템은 다수 클라이언트의 동기화를 순서대로 처리하였다. 이런 경우 처리시간이 긴 동기화 작업으로 인해 다른 클라이언트들의 동기화 작업이 오랜 시간 대기하는 문제가 있다. 이 논문에서 변경충돌이 없는 다수 클라이언트들간 동기화 작업을 다중 큐를 이용하여 동시에 수행하는 시스템을 설계 구현하였다. 또한, 동기화 작업 처리기간의 비율과 작업처리 패턴에 따른 순차적 동기화와 동시 동기화의 성능을 비교하였다.

• Journal of information and communication convergence engineering
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• 제16권2호
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• pp.84-92
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• 2018

For large wireless sensor networks running on battery power, the time synchronization of all sensor nodes is becoming a crucial task for waking up sensor nodes with exact timing and controlling transmission and reception timing. However, as network size increases, this synchronization process tends to require long processing time consume significant power. Furthermore, a naïve synchronization scheduler may leave some nodes unsynchronized. This paper proposes a power-efficient scheduling algorithm for time synchronization utilizing the notion of density, which is defined by the number of neighboring nodes within wireless range. The proposed scheduling algorithm elects a sequence of minimal reference nodes that can complete the synchronization with the smallest possible number of hops and lowest possible power consumption. Additionally, it ensures coverage of all sensor nodes utilizing a two-pass synchronization scheduling process. We implemented the proposed synchronization algorithm in a network simulator. Extensive simulation results demonstrate that the proposed algorithm can reduce the power consumption required for the periodic synchronization process by up to 40% for large sensor networks compared to a simplistic multi-hop synchronization method.

• Journal of Electrical Engineering and information Science
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• 제2권3호
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• pp.41-50
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• 1997

In this paper, we describe the design, implementation and evaluation for a multimedia conferencing system with intramedia and intermedia synchronization support between audio and video. The synchronization mechanism proposed here is capable of dynamically adapting to various network conditions thus providing an optimized QoS. In realizing the system based on this mechanism, NeVoT on Mbone is used for audio and VIC for video. Furthermore a synchromization controller is designed and realized with a unique process in supporting intermedia synchronization. Each media agents handling its media stream are modified with intramedia synchronization function. And a communicative function between media agents and synchronization controller is added as well for intermedia synchronization function. Each media agents function reports its buffering status to the synchronization control process which in turn send out optimized buffering delay value thus supporting intermedia synchronization. The realized system is configured and tested on Ethernet and ATM network where performance measurements were performed and its effective synchronization support has been assured.

• Journal of Communications and Networks
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• 제2권1호
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• pp.58-68
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• 2000

In this paper we introduce the correlation-aided distributed sample acquisition (CDSA) scheme for fast cell search in IMT-2000 W-CDMA cellular system. The proposed scheme incorporates the state symbol correlation process into the comparison-correction based synchronization process of the original DSA scheme to enable fast acquisition even under very poor channel environment. for its realization, each mobile station (MS) has to store in its memory a set of state sample sequences. which are determined by the long-period scrambling sequences used in the system and the sampling interval of the state samples. CDSA based cell search is carried out in two stages : First, the MS first acquires the slot timing by using the primary synch code (PSC) and then identifies the igniter code which conveys the state samples of the current cell . Secondly. the MS identifies the scrambling code and frame timing by taking the comparison-correction based synchronization approach and, if the identification is not done satisfactorily within preset time. it initiates the state symbol correlation process which correlates the received symbol sequence with the pre-stored state sample sequences for a successful identification. As the state symbol SNR is relatively high. the state symbol correlation process enables reliable synchronization even in very low chip-SNR environment. Simulation results show that the proposed CDSA scheme outperforms the 3GPP 3-step approach, requiring the signal power of about 7 dB less for achieving the same acquisition time performance in low-SNR environments. Furthermore, it turns out very robust in the typical synchronization environment where large frequency offset exists.

• 한국컴퓨터정보학회논문지
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• 제19권12호
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• pp.359-368
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• 2014

프로세스 동기화는 학생들이 운영체제 과목에서 가장 어려워하는 주제 중 하나이다. 한 번에 한 가지만을 생각하는 인간의 특성 상 여러 사건이 동시에 일어나는 병행 프로세스 환경을 이해하기 어렵기 때문이다. 유한버퍼 문제나 식사하는 철학자 문제 등 고전적 동기화 예제는 그 내용이 너무 기술적이거나 비현실적이기 때문에 운영체제를 처음 접하는 저학년 학생들의 관심과 이해를 이끌기 어려웠다. 본 논문에서는 이러한 고전적 동기화 예제의 대안으로 은행계좌 문제의 사용을 제안한다. 은행계좌 문제는 쉽고 현실적이며 일상생활에서 누구나 경험해 본 문제이기 때문에 학생들의 높은 이해와 흥미를 이끌 수 있었다. 프로세스 실행 순서의 제어, 경쟁조건으로 인한 잘못된 결과의 발생, 세마포어 사용, 교착상태, 모니터 등 다양한 동기화 주제에 대한 은행계좌 문제의 적용에 대해 연구하였다.

• ETRI Journal
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• 제30권3호
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• pp.441-450
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• 2008

The scalable extension of H.264, known as scalable video coding (SVC) has been the main focus of the Joint Video Team's work and was finalized at the end of 2007. Synchronization between media is an important aspect in the design of a scalable video streaming system. This paper proposes an efficient media synchronization mechanism for SVC video transport over IP networks. To support synchronization between video and audio bitstreams transported over IP networks, a real-time transport protocol/RTP control protocol (RTP/RTCP) suite is usually employed. To provide an efficient mechanism for media synchronization between SVC video and audio, we suggest an efficient RTP packetization mode for inter-layer synchronization within SVC video and propose a computationally efficient RTCP packet processing method for inter-media synchronization. By adopting the computationally simple RTCP packet processing, we do not need to process every RTCP sender report packet for inter-media synchronization. We demonstrate the effectiveness of the proposed mechanism by comparing its performance with that of the conventional method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1817-1822
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• 1991

A method of reducing overhead caused by the processor synchronization process and common memory accesses in finely grained tasks is described. We propose a scheduler which considers the preparation time during searching to minimize the redundant accesses to shared memory. Since the suggested hardware (synchronizer) determines the access order of processors and bus arbitration simultaneously by including the synchronization process into the bus arbitration process, the synchronization time vanishes. Therefore this synchronizer has no overhead caused by the processor synchronization[l]. The proposed scheduler algorithm is processed in parallel. The processes share the upper bound derived by each searching and the lower bound function is built considering the preparation time in order to eliminate as many searches as possible. An application of the proposed method to a multi-DSP system to calculate inverse dynamics for robot arms, showed that the sampling time can be twice shorter than that of the conventional one.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.89-95
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• 2003

We consider a problem of application of analytical redundancy to engine synchronization process of spark ignition engines, which is critical to timing for every ECU process including ignition and injection. The engine synchronization process we consider here is performed using the pulse signal obtained by the revolution of crankshaft trigger wheel (CTW) coupled to crank shaft. We propose a discrete-time linear model for the signal, for which we construct FDI (Fault Detection & Isolation) system consisting residual generator and threshold based on linear observer.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.49-54
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• 2009

Synchronization between media is an important aspect in the design of multimedia streaming system. This paper proposes a precise media synchronization mechanism for digital video and audio transport over IP networks. To support synchronization between video and audio bitstreams transported over IP networks, RTP/RTCP protocol suite is usually employed. To provide a precise mechanism for media synchronization between video and audio, we suggest an efficient media synchronization algorithm based on NPT (Normal Play Time) which can be derivable from the timestamp information in the header part of RTP packet generated for the transport of video and audio streams. With the proposed method, we do not need to send and process any RTCP SR (sender report) packet which is required for conventional media synchronization scheme, and accordingly could reduce the number of required UDP ports and the amount of control traffic injected into the network.