• Asia Marketing Journal
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• 제13권3호
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• pp.79-102
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• 2011

본 연구는 지금까지 유통분야에서 제조업자와 판매업자간에 관계를 연구해오던 상호의존성의 개념을 판매업자간의 공동마케팅 제휴관계에 적용하였다. 제휴관계에 있는 양자 간의 의존성과 상호의존성이 갈등에 미치는 영향을 사회학 분야에서 상호의존성과 갈등 간의 관계에 대해 상반된 견해를 제시하는 이론인 갈등 나선형 이론과 쌍무적 억제이론으로 설명해보고자 하였다. 기존의 연구들이 설문을 통해 변수간의 관계를 파악하였다면, 본 연구에서는 이동통신사와 공동마케팅 제휴관계에 있는 181개 기업의 거래데이터 및 설문을 동시에 이용하였으며 상호의존성의 선행요인으로 거래기간, 거래빈도, 거래선의 수, 거래특유자산 등의 변수를 도출하여 상호의존성과의 관계를 파악하였다. 실증분석결과, 이통통신사의 제휴서비스 환경에서는 상호의존성의 총합이 증가할수록 갈등수준 역시 증가함을 알 수 있었으며 따라서, 상호의존성과 갈등간의 관계를 설명하기 위해서는 쌍무적 억제 이론 보다는 갈등 나선형 이론이 더 적합함을 알 수 있었다. 아울러, 이동통신사의 관점에서는 거래기간, 거래빈도, 거래특유자산이, 제휴파트너 관점에서는 거래빈도, 거래특유자산, 거래선의 수가 각각 상대방에 대한 의존성에 영향을 미치는 요소로 도출되었다. 이를 통해 이통통신사 및 제휴파트너 관점에서 효율적인 갈등관리 전략을 제시하였으며 학문적 시사점들과 연구의 한계점에 대해 제시하였다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.283-287
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• 2007

Pine Wilt Disease (Bursaphelenchus Xylophilus) has been attacked since 1988, then it becomes very serious problem of the all over the country. Government has been invested a lot of money to prevent but it is hard to survey the damaged area and ineffectively control the process of prevention. Therefore, this study is focused on development of Pine Wilt Disease (Bursaphelenchus Xylophilus) Prevention System using GIS and GPS through constructiong database of digital map, satellite imagery and attribute data and development component for desktop PC, internet and mobile system to realtime data transmission between project manager and field worker. Especially, we developed the mobile system that can transmit field conditions in realtime using GPS, GIS and CCD camera, the telecommunication control server that transmit received field condition data to web connecting module and system manager, the web system for end user to notify prevention details, the control system lot manager to recognize filed conditions and to control field workers and the wireless telecommunication module to connect in realtime between field and control center.

• ETRI Journal
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• 제30권1호
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• pp.21-32
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• 2008

Cognitive radio (CR) has been proposed as an effective technology for flexible use of the radio spectrum. The interference between primary users and CR users, however, becomes a critical problem when they are using adjacent frequency channels with different transmission power levels. In this paper, a robust CR orthogonal frequency division multiplexing (OFDM) architecture, which can effectively suppress interference to nearby primary users and overcome adjacent channel interference (ACI) to the CR user, is proposed. This new approach is characterized by adaptive data repetition for subcarriers under heavy ACI, and adaptive time spreading for subcarriers near the borders of the CR user's spectrum. The data repetition scheme provides extra power gain against the ACI coming from primary users. Time spreading guarantees an acceptable interference level to nearby primary users. By computer simulation, we demonstrate that, under a CR environment, the proposed CR OFDM architecture outperforms conventional OFDM systems in terms of throughput and BER performance.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
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• pp.179-182
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• 2001

This paper has been studied a wavelet based still image transmission over the wireless channel. EZW(Embedded Zerotree Wavelet) is an efficient and scalable wavelet based image coding technique, which provides progressive transfer of signal resulted in multi-resolution representation. It reduces therefore the reduce cost of storage media. Although EZW has many advantages, it is very sensitive on error. Because coding are performed in subband by subband, and it uses arithmetic coding which is a kind of variable length coding. Therefore only 1∼2bit error may degrade quality of the entire image. So study of error localization and recovery are required. This paper investigates the use of reversible variable length codes(RVLC) and data partitioning. RVLC are known to have a superior error recovery property due to their two-way decoding capability and data partitioning is essential to applying RVLC. In this work, we show that appropriate data partitioning length for each SNR(Signal-to-Noise Power Ratio) and error localization in wireless channel.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권4호
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• pp.613-631
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• 2013

Cognitive radio (CR) is proposed as a key solution to improve spectral efficiency and overcome the spectrum scarcity. Spectrum sensing is an important task in each CR system with the aim of identifying the spectrum holes and using them for secondary user's (SU) communications. Several conventional methods for spectrum sensing have been proposed such as energy detection, matched filter detection, etc. However, the main limitation of these classical methods is that the CR network is not able to communicate with its own base station during the spectrum sensing period and thus a fraction of the available primary frame cannot be exploited for data transmission. The other limitation in conventional methods is that the SU data frames should be synchronized with the primary network data frames. To overcome the above limitations, here, we propose a spectrum sensing technique based on blind source separation (BSS) that does not need time synchronization between the primary network and the CR. Moreover, by using the proposed technique, the SU can maintain its transmission with the base station even during spectrum sensing and thus higher rates are achieved by the CR network. Simulation results indicate that the proposed method outperforms the accuracy of conventional BSS-based spectrum sensing techniques.

• The Journal of the Acoustical Society of Korea
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• 제19권2E호
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• pp.8-13
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• 2000

In this paper, we present an adaptive formant tracking algorithm for speech using closed phase WRLS-VFF-VT method. The pitch synchronous closed phase methods is known to give more accurate estimates of the vocal tract parameters than the pitch asynchronous method. However the use of a pitch-synchronous closed phase analysis method has been limited due to difficulties associated with the task of accurately isolating the closed phase region in successive periods of speech. Therefore we have implemented the pitch synchronous closed phase WRLS-VFF-VT algorithm for speech analysis, especially for formant tracking. The proposed algorithm with the variable threshold(VT) can provide a superior performance in the boundary of phone and voiced/unvoiced sound. The proposed method is experimentally compared with the other method such as two channel CPC method by using synthetic waveform and real speech data. From the experimental results, we found that the block data processing techniques, such as the two-channel CPC, gave reasonable estimates of the formant/antiformant. However, the data windows used by these methods included the effects of the periodic excitation pulses, which affected the accuracy of the estimated formants. On the other hand the proposed WRLS-VFF-VT method, which eliminated the influence of the pulse excitation by using an input estimation as part of the algorithm, gave very accurate formant/bandwidth estimates and good spectral matching.

• 전자공학회논문지S
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• 제35S권3호
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• pp.29-38
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• 1998

This ppaer suggests a congestion control scheme for CL(ConnectionLess) overlay network using the feedback loops getween CL werver, between CL servers, and the header translation table of CL server. The CL overlay network for CBDS(Connectionless Broadband Data Service) defined by ITU0T(International Telecommunication Union-Telecommunication) consists of CL servers which route frames and links which connect between CL user and CL server or between CL servers. In this CL overlay network, two kinds of congestions, link congestion and CL server congestion, may occur. We suggest a scheme that can solve the congestion using ABR(Available Bit Rate) feedback control loop, the traffic control mechanism. This scheme is the link-by-link method suing the ABR feedback control loops between CL user and CL server or between CL servers, and the header translation table of CL server. As CL servers are always endpoints of ABR connections, the congestion staturs of the CL server can be informed to the traffic sources using RM(Resource Management) cell of the ABR feedback loops. Also CL server knows the trafffic sources making congestion by inspecting the source address field of CLNAP-PDUs(ConnectionLess Network Access Protocol - Protocol Data Units). Therefore this scheme can be implemeted easily using only both ABR feedback control loop of ATM layer and the congestion state table using the header translation table of CL server because it does not require separate feedback links for congestion control of CL servers.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1345-1360
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• 2016

In this paper, we propose a new real-time human detection under omni-directional cameras for visual surveillance purpose, based on CNN with unified detection and AGMM. Compared to CNN-based state-of-the-art object detection methods. YOLO model-based object detection method boasts of very fast object detection, but with less accuracy. The proposed method adapts the unified detecting CNN of YOLO model so as to be intensified by the additional foreground contextual information obtained from pre-stage AGMM. Increased computational time incurred by additional AGMM processing is compensated by speed-up gain obtained from utilizing 2-D input data consisting of grey-level image data and foreground context information instead of 3-D color input data. Through various experiments, it is shown that the proposed method performs better with respect to accuracy and more robust to environment changes than YOLO model-based human detection method, but with the similar processing speeds to that of YOLO model-based one. Thus, it can be successfully employed for embedded surveillance application.

• 한국컴퓨터정보학회논문지
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• 제23권11호
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• pp.85-93
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• 2018

In recent years, there has been an increasing number of ways to distribute document-based malicious code using vulnerabilities in document files. Because document type malware is not an executable file itself, it is easy to bypass existing security programs, so research on a model to detect it is necessary. In this study, we extract main features from the document structure and the JavaScript contained in the stream object In addition, when JavaScript is inserted, keywords with high occurrence frequency in malicious code such as function name, reserved word and the readable string in the script are extracted. Then, we generate a machine learning model that can distinguish between normal and malicious. In order to make it difficult to bypass, we try to achieve good performance in a black box type algorithm. For an experiment, a large amount of documents compared to previous studies is analyzed. Experimental results show 98.9% detection rate from three different type algorithms. SVM, which is a black box type algorithm and makes obfuscation difficult, shows much higher performance than in previous studies.

• 한국전자파학회논문지
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• 제18권11호
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• pp.1309-1317
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• 2007

본 논문은 낙뢰에 의해 전송 선로에 유기되는 유도뢰 전압을 해석하고 낙뢰 위치 및 선로 길이에 따른 유도뢰 전압의 크기, 파두장, 파미장 등에 대한 낙뢰 파라미터 변화를 분석하였다. 분석한 결과를 확인하기 위해 실제 통신 선로를 대상으로 유도뢰 전압을 측정하였다. 선로 길이가 길어짐에 따라 그리고 낙뢰 위치가 선로와 멀어짐에 따라 파두장, 파미장이 증가하는 경향을 확인하였다. 전체 선로 길이보다는 가공 선로 길이가 상대적으로 유도 전압 크기에 영향을 끼침을 확인하였다.