• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.4 no.1
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• pp.20-27
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• 1993

In this paper, a model of TCM / M-PSK with set partitioning and a model of the combined M-ary PSK system with pragmatic coding for digital radio communication are realized. The equations of error probability for TCM / M-PSK system and the combined M-ary PSK system with pragmatic coding are derived on the conditions of the Rayleigh fading with the AWGN. It is found that the combined M-ary PSK systemwith pragmatic coding in the AWGN channel can not be applied to the fading channel since uncoded bits cause parallel:parallel paths in the trellis diagram to degrade the performance of the system. However, the use of pragmatic coding in the AWGN channel could simplify the given system since single convolutional encoder / decoder is required.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.6
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• pp.1668-1688
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• 2012

Cooperative communications and network coding schemes have been proposed to increase system throughput for ad hoc networks. In this paper, we present throughput and delay analysis of the new network coding-enabled cooperative MAC protocol called NC-MAC, which has been proposed by us in order to significantly enhance system performance. This protocol introduces an approach that can accommodate both cooperative communication and network coding for wireless ad hoc networks by slightly increasing overhead and modifying standards. The protocol's performance is evaluated using mathematical analysis and computer simulation and two performance measures, system throughput and average channel access delay, are used for a performance comparison with previous schemes. It is assumed that all the frames exchanged over a wireless channel are susceptible to transmission errors, which is a new but more reasonable assumption differentiating this research from previous research. Numerical results show this protocol provides significantly enhanced system performance compared with conventional cooperative MAC protocols used in previous research. For instance, system performance is 47% higher using the NC-MAC protocol than when using the rDCF protocol.

• Human Ecology Research
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• v.57 no.1
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• pp.109-125
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• 2019

Few studies have utilized observational methods in the field of couple research even though using self-report questionnaires is prone to the subjective biases of the reporter. This study validates the Marital Interaction Coding System-Global (MICS-G), a global version of the well-established microanalytic observational coding system, Marital Interaction Coding System (MICS). Participants in the study consisted of 30 married couples with varied levels of marital adjustment who visited one of the Healthy Family and Multicultural Family Support Centers in Seoul, either for couple therapy or the "Marriage Checkup"program. Ten-minute problem-solving discussions were rated by two undergraduate student raters who were trained for 10 hours. Interobserver agreement based on percentage agreement and intraclass correlation coefficients showed a high level of agreement between raters in establishing interrater reliability. Convergent validity was established by: correlations among marital adjustment, psychological aggression, mental health, and MICS-G categories of conflicts, validation, invalidation, facilitation, and withdrawal. MICS-G categories also were successful in discriminating between distressed and nondistressed couples, which provides evidence of discriminant validity for MICS-G. This study showed that MICS-G is a promising method for researchers to observe couple interactions in a more cost-effective way. Methodological issues and practical applications are also discussed.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.1
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• pp.57-68
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• 2000

The purpose of this study is to find the most effective method of the coding methods by linking the attribute information with the digital map in Taegu metropolitan city. This study was also a precedent plan for street trees management information system and the coding schemes for street trees management information system could be summarized as follows; First, this study extracted 11 coding factors for expressing the position of street trees. Second, 11 coding schemes were made out of these coding factors and applied to the digital map(1:500). Third, two methods of 11 coding schemes were selected for street trees management information system of Taegu metropolitan city. The one was the method which applied serial numbers according to the block name. The other was the method utilizing the concept of 'dynamic segment'. Finally, this study will be the first step for the computerization and management of the street trees information and this computerized data will do for the management efficiency of the street trees on internet.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.7
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• pp.1-11
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• 1993

The bit error rates of DS/SSMA DPSK system with diversity and FEC channel coding in Rayleigh fading and log-normal shadowing channel are evaluated. Microscopic postdetection diversity and macroscopic selection diversiity are used to mitigate the effects of Rayleigh fading and log-normal shadowing, respectively. The numerical results show that the composite use of diversity and channel coding is very efficient for improving system performance compared to their respective uses.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.31-34
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• 1987

A new efficientcoding system which can transmit video conferenceof viedeophone signals at a 64kbps is proposed. In addition to the interframe and CRC (Conditional Repleni shment Coding) system, BTVQ (Binary Tree searched Vector Quantizer)and RLC (Run Length Coding) methods are incorporated. Couble buffer memory is used for simple comtrol of channel symbol transmission and memory underflow And also buffer memory onerfolw is easily controlled by the thresholds of a MAD (Moving Area Betector)

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.805-815
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• 2003

In this paper, we present the development of document compression codec using segmentation, wavelet lifting and bitplane coding. We use the segmentation to preserve the text appearance. We performed integer-to-integer wavelet lifting and also performed bitplane subblock coding for document compression. We acquired a high compression ratio and an efficient compression by encoding only the significant subblocks in the bitplane subblock coding. We also implemented scalar quantization by subband-oriented bit shifting. The system performs color conversion and downsampling before wavelet lifting and also performs graycode conversion and quantization before subblock coding. In the experiment, we show the performances of the system by presenting the high compression ratios and high PSNR values.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1420-1423
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• 2015

This letter considers a ship-to-ship communication system in which two ships exchange their information with the help of multiple relay ships. For the system, we propose a novel relay scheme that allows relay ships to select a method between analog network coding (ANC) and digital network coding (DNC) adaptively based on channel state information. We also provide a relay selection criterion in supporting the proposed adaptive network coding. The simulation results show that the proposed scheme outperforms the conventional scheme employing only the ANC or only the DNC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.7
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• pp.612-622
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• 2013

In this paper, we propose a coding packet group-based ARQ scheme (rNC) for file delivery in wireless networks. rNC assumes multiple network coding points between the source and the destination. Each network coding point gathers and codes a group of packets according to the queue polling system. A queue polling system makes a few or several packets available for coding in a queue while polling the other queues in the system. Thus, we assuem a queue polling system at each network coding point. We call this group of packets as coded packet group. Each coding point acknowledges the reception of every code packet group to its previous coding point for reliable delivery. Thus, the intermediate coding points including the source can release its buffer before the packet is delivered to the destination. To guarantee the ultimate file delivery to the destination, the destination sends acknowledgement to the sender. We evaluate our proposed scheme using ns-2 and compare the performance with CodeCast. The results show that rNC works better than CodeCast in terms of packet delivery ratio and control overhead in unreliable wireless networks.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.4
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• pp.85-96
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• 2001

In this paper, part features are classified and then its coding system is constructed by the considered characteristics of features in assemble process. Analyzing the characteristics of features, code values about part features are determined. Assembly process is divided into five functions such as transporting, handing, approaching, alignment and joining, and then the detail parameters of each functions such as determined. Code values about assembly process are determined according to detail parameters. The detail parameters are kinds of available working method and assembly tools when each assembly function is going on. By the coding system, available assembly process can be grasped and perceived for the part that it is difficult to assemble.