• 제목/요약/키워드: electronic communications

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Implementation of Estimation and Inference on the Web

  • Kang, Heemo;Sim, Songyong
    • Communications for Statistical Applications and Methods
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    • 제7권3호
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    • pp.913-926
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    • 2000
  • An electronic statistics text on the web is implemented. The introduced text provide interactive instructions on the statistical estimation and inference. As a by-product, we also provide a calculation of quantiles and p-value of t-distribution and standard normal distribution. This program was written in JAVA programming language.

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청약과 관련한 CISG규정하에서 이루어지는 전자통신에 유엔전자협약 적용시 유의사항 (A Study on Notable Points in Mind for the Use of Electronic Convention to be Made under CISG in Connections with Offer)

  • 오세창
    • 무역상무연구
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    • 제38권
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    • pp.3-45
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    • 2008
  • A motive and aim of enactment of UN Convention on the Use of Electronic Communication in Int'l Contracts is based on need to eliminate legal obstacles that might arise under existing int'l trade law instruments and promote int'l electronic commercial transaction. But when it is used with related articles, 14, 15, 16, 17 for offer under CISG, one of the most successful conventions which produces substantive law for the unification of int'l trade, questions of practical importance, for example possibilities of withdrawal, revocation, rejection of offer, the extent of its criteria arise from therewith. In conclusion, a effective electronic offer has to assure easily access and confirmation of trade terms besides criteria of offer under CISG. An offer can be withdrawal, if electronic message of withdrawal has entered the offeree's server before or at the same time when the offer has reached the offeree but agreement expressly or impliedly, between the parties about type, format, email address is a prerequisited. Implied consent could be presumed through prior conduct or trade usages between the parties under CISG articles 8, 9. The term "have reached" correspond to the time which is able to retrieve the electronic message of withdrawal. But without express or implied agreement between them about electronic communication of type, format, email address, an offer can be withdrawal before or at the same time when it has entered offeree's other e-mail address and confirmed by his retrieval. In case of the revocation, electronic message of the revocation is effective before the offeree's dispatching an acceptance. A prerequisite for the revocation by electronic communication is came as the above mentioned withdrawal except for concept of a time difference for reach. In case of a rejection of offer, when a rejection by electronic communication has entered the offeror's server, an offer is ended. But a prerequisite for the rejection by electronic message is same as the above mentioned withdrawal and revocation.

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Real-Time Eye Detection and Tracking Under Various Light Conditions

  • Park Ho Sik;Nam Kee Hwan;Seol Jeung Bo;Cho Hyeon Seob;Ra Sang Dong;Bae Cheol Soo
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 학술대회지
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    • pp.862-866
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    • 2004
  • Non-intrusive methods based on active remote IR illumination for eye tracking is important for many applications of vision-based man-machine interaction. One problem that has plagued those methods is their sensitivity to lighting condition change. This tends to significantly limit their scope of application. In this paper, we present a new real-time eye detection and tracking methodology that works under variable and realistic lighting conditions. Based on combining the bright-pupil effect resulted from IR light and the conventional appearance-based object recognition technique, our method can robustly track eyes when the pupils are not very bright due to significant external illumination interferences. The appearance model is incorporated in both eyes detection and tracking via the use of support vector machine and the mean shift tracking. Additional improvement is achieved from modifying the image acquisition apparatus including the illuminator and the camera.

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EPC Sensor Network-based Product and Process Traceability System in the Food Supply Chain

  • Chun, Jung-Woo;Oh, Ji-Sung;Rho, Jae-Jueng;Lee, Jung-Wook
    • 한국경영정보학회:학술대회논문집
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    • 한국경영정보학회 2007년도 International Conference
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    • pp.184-189
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    • 2007
  • Concerns about food safety continue to rise and under this situation, governments of some countries have reinforced their regulations more strictly for food safety. In order to prevent food safety incidents or, at least to minimize the impact, the preparedness is very important. As a consequence of this, traceability system has become an essential tool for food safety. Recently, it requires more prevention-based food safety control system. One of the most generally used systems for food safety control is Hazard Analysis and Critical Control Point (HACCP). Both traceability and HACCP systems can be integrated through Electronic Product Code (EPC) Sensor Network technologies which have four value propositions. In this paper, we will introduce the concept of product and process traceability system (P2TS) through the integration of three systems to improve food safety management. The final aim is to find out the added values of the P2TS.

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Nonbinary Convolutional Codes and Modified M-FSK Detectors for Power-Line Communications Channel

  • Ouahada, Khmaies
    • Journal of Communications and Networks
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    • 제16권3호
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    • pp.270-279
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    • 2014
  • The Viterbi decoding algorithm, which provides maximum - likelihood decoding, is currently considered the most widely used technique for the decoding of codes having a state description, including the class of linear error-correcting convolutional codes. Two classes of nonbinary convolutional codes are presented. Distance preserving mapping convolutional codes and M-ary convolutional codes are designed, respectively, from the distance-preserving mappings technique and the implementation of the conventional convolutional codes in Galois fields of order higher than two. We also investigated the performance of these codes when combined with a multiple frequency-shift keying (M-FSK) modulation scheme to correct narrowband interference (NBI) in power-line communications channel. Themodification of certain detectors of the M-FSK demodulator to refine the selection and the detection at the decoder is also presented. M-FSK detectors used in our simulations are discussed, and their chosen values are justified. Interesting and promising obtained results have shown a very strong link between the designed codes and the selected detector for M-FSK modulation. An important improvement in gain for certain values of the modified detectors was also observed. The paper also shows that the newly designed codes outperform the conventional convolutional codes in a NBI environment.

음향 통신 및 위치측정 시스템에서의 비가청 음향 신호 설계에 관한 연구 (A Study on the Design of Inaudible Acoustic Signal in Acoustic Communications and Positioning System)

  • 오종택
    • 한국인터넷방송통신학회논문지
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    • 제17권2호
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    • pp.191-197
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    • 2017
  • 스마트폰의 사용이 보편화됨에 따라 스마트폰을 이용한 다양한 응용서비스가 개발되고 있으며, 추가적인 장치없이 음향 신호를 이용하여 데이터를 송수신하거나 위치를 측정하는 기술이 활발하게 개발되고 있다. 그러나 스마트폰 장치의 한계로 음향 주파수의 선택에 한계가 있고, 음향신호 발생 장치의 전자회로의 비선형성으로 인해 인간이 감지할 수 있는 음향신호 잡음이 발생하는 문제가 있다. 따라서 시끄러운 소리가 나므로 실용화에 어려움이 있다. 본 논문에서는 인간이 감지하는 음향 신호의 크기 측정 방법을 제안하고, 이에 따라 여러 가지 음향 신호를 비교 분석함으로써 음향 통신 및 위치측정 시스템 개발시에 비가청 음향 신호 설계에 활용하도록 한다.

A Multithreaded Implementation of HEVC Intra Prediction Algorithm for a Photovoltaic Monitoring System

  • Choi, Yung-Ho;Ahn, Hyung-Keun
    • Transactions on Electrical and Electronic Materials
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    • 제13권5호
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    • pp.256-261
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    • 2012
  • Recently, many photovoltaic systems (PV systems) including solar parks and PV farms have been built to prepare for the post fossil fuel era. To investigate the degradation process of the PV systems and thus, efficiently operate PV systems, there is a need to visually monitor PV systems in the range of infrared ray through the Internet. For efficient visual monitoring, this paper explores a multithreaded implementation of a recently developed HEVC standard whose compression efficiency is almost two times higher than H.264. For an efficient parallel implementation under a meshbased 64 multicore system, this work takes into account various design choices which can solve potential problems of a two-dimensional interconnects-based 64 multicore system. These problems may have not occurred in a small-scale multicore system based on a simple bus network. Through extensive evaluation, this paper shows that, for an efficient multithreaded implementation of HEVC intra prediction in a mesh-based multicore system, much effort needs to be made to optimize communications among processing cores. Thus, this work provides three design choices regarding communications, i.e., main thread core location, cache home policy, and maximum coding unit size. These design choices are shown to improve the overall parallel performance of the HEVC intra prediction algorithm by up to 42%, achieving a 7 times higher speed-up.

An Efficient and Stable Congestion Control Scheme with Neighbor Feedback for Cluster Wireless Sensor Networks

  • Hu, Xi;Guo, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권9호
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    • pp.4342-4366
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    • 2016
  • Congestion control in Cluster Wireless Sensor Networks (CWSNs) has drawn widespread attention and research interests. The increasing number of nodes and scale of networks cause more complex congestion control and management. Active Queue Management (AQM) is one of the major congestion control approaches in CWSNs, and Random Early Detection (RED) algorithm is commonly used to achieve high utilization in AQM. However, traditional RED algorithm depends exclusively on source-side control, which is insufficient to maintain efficiency and state stability. Specifically, when congestion occurs, deficiency of feedback will hinder the instability of the system. In this paper, we adopt the Additive-Increase Multiplicative-Decrease (AIMD) adjustment scheme and propose an improved RED algorithm by using neighbor feedback and scheduling scheme. The congestion control model is presented, which is a linear system with a non-linear feedback, and modeled by Lur'e type system. In the context of delayed Lur'e dynamical network, we adopt the concept of cluster synchronization and show that the congestion controlled system is able to achieve cluster synchronization. Sufficient conditions are derived by applying Lyapunov-Krasovskii functionals. Numerical examples are investigated to validate the effectiveness of the congestion control algorithm and the stability of the network.