• ETRI Journal
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• 제42권3호
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• pp.351-365
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• 2020

Directional sensor networks (DSNs) can significantly improve the performance of a network by employing energy efficient communication protocols. Neighbor discovery is a vital part of medium access control (MAC) and routing protocol, which influences the establishment of communication between neighboring nodes. Neighbor discovery is a challenging task in DSNs due to the limited coverage provided by directional antennas. Furthermore, in these networks, communication can only take place when the beams of the directional antennas are pointed toward each other. In this article, we propose a novel multiple token-based neighbor discovery (MuND) protocol, in which multiple tokens are transmitted based on an area exploration algorithm. The performance of the protocol is evaluated using the Cooja simulator. The simulation results reveal that the proposed MuND protocol achieves lower neighbor discovery latency, with a 100% neighbor discovery ratio, and has a relatively low communication overhead and low energy consumption.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2326-2345
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• 2016

For the compression of color images, a common bitmap usually is generated to replace the three individual bitmaps that originate from block truncation coding (BTC) of the R, G and B channels. However, common bitmaps generated by some traditional schemes are not the best possible because they do not consider the minimized distortion of the entire color image. In this paper, we propose a near-optimized common bitmap scheme for BTC using Binary Ant Colony Optimization (BACO), producing a BACO-BTC scheme. First, the color image is compressed by the BTC algorithm to get three individual bitmaps, and three pairs of quantization values for the R, G, and B channels. Second, a near-optimized common bitmap is generated with minimized distortion of the entire color image based on the idea of BACO. Finally, the color image is reconstructed easily by the corresponding quantization values according to the common bitmap. The experimental results confirmed that reconstructed image of the proposed scheme has better visual quality and less computational complexity than the referenced schemes.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2003년도 추계학술발표논문집 (하)
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• pp.1437-1440
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• 2003

의사결정지원시스템으로서의 DW는 기업정보시스템에서 두뇌역할을 담당하는 만큼 전략적 중요도에 있어서 매우 중요한 역할을 차지하고 있다. 이러한 추세와 더불어 많은 기업들이 DW구축에 엄청난 예산을 투입하여 시스템을 구축하지만 프로젝트의 실패 역시 흔하게 찾아 볼 수 있는 사실이다. 이러한 실패의 주요인은 기술적인 문제에서 발생하기 보다는 낮은 시스템 활용도와 명확하지 않은 분석요구사항에서 주요원인을 찾아 볼 수 있는데 이는 구축단계에서 이용자와 이해관계자들이 DW의 시스템적 목적을 제대로 이해하지 못하여 사용자 관점의 요구사항을 제대로 제시하지 못하고 이에 따라 시스템의 활용도 역시 낮아지는 데에서 본질적인 원인을 찾을 수 있다. 본 논문에서는 시스템의 사용자가 요구사항을 적극적으로 제시하고 시스템에 끊임없는 관심을 같도록 유도하여 이용자의 요구사항을 충족시킨 수 있는 정확한 주제분야와 분석관점을 발굴함과 통시에 시스템의 활용도를 높이기 위한 방안으로 정형화되고 주기적인 분석정보를 제시하기 위하여 정적 Reporting을 위한 Web Reporting Tool과 함께 시스템의 이용자와 주기적으로 Communication을 유지하여 시스템에 지속적으로 관심을 갖도록 하기 위한 상호 Communication기능을 통한 문제의 해결방안을 제시하고자 한다.

• 한국군사과학기술학회지
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• 제21권5호
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• pp.640-648
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• 2018

Time division wireless communication in tactical MANET is attractive to deliver both high data rates and long-range coverage, and to provide scheduled QoS to mission participants. This paper is about the time synchronization issue of multi-mission USV in tactical MANET. As USV communication coverage becomes longer, the synchronization error also becomes higher; therefore, which results in link disconnection, and consequent failures of reconnection because base station cannot configure necessary parameters over long-distant terminal. We propose a range adaptive time synchronization method to compensate for synchronization errors. The issue of long-range time synchronization problem was identified during maritime communication tests, and we verified the proposed method through analyses of both indoor and outdoor test results.

• 한국간호교육학회지
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• 제19권4호
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• pp.571-579
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• 2013

Purpose: This study was done to identify the influences of ego resilience and communication ability on problem-solving ability in nursing students. Methods: The subjects consisted of 448 first and second year nursing students. The data were collected from June 10 to 21, 2013. The data were analyzed using t-test, ANOVA, Scheffe's test, Pearson's correlation coefficients and multiple linear regression with IBM SPSS Statistics version 19.0. Results: The Ego resilience score of subjects was 2.84 out of a perfect score of 4, the communication ability score of subjects was 3.51, and the problem-solving ability score of subjects was 3.44 out of a perfect score of 5. A positive correlation was found for problem-solving ability with ego resilience and communication ability. The strongest predictor of problem-solving ability was a communication ability. Conclusion: These findings indicate that there is a need to increase communication ability to improve the problem-solving ability of nursing students. The results should be reflected in the development of effective curricula.

• 한국지역사회생활과학회지
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• 제19권4호
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• pp.641-658
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• 2008

The purpose of this study was to analyze the effects of parent-child communication, and the self-efficacy of middle school students on school adjustment. The data was collected from 285 middle school students living in Kwangju. For statistical analysis, Cronbach' $\alpha$, t-test, one-way ANOVA, Scheffe's multiple Comparison Analysis, LSD and hierarchical regression analysis were used. The results were summarized as follows : concerning connections between demographic variables and parent-child communication, the education of the father made the most significant difference, followed by living standard, free time for communication with the father, and free time for communication with the mother. The level of communication with parent made a significant difference to each sub-factor of school adjustment. As a result of making a hierarchical regression analysis to find out the relative impact of the demographic variables on school adjustment, self-efficacy was identified as the most important variable and predictor of school adjustment. The independent variables exercised a different influence on the sub-factors of school adjustment. These results indicated that adolescent's self-efficacy is the most important variable to improve the school adjustment of students.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.285-292
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• 2002

A cluster tool for semiconductor manufacturing is an integrated device that consists of several single wafer processing modules and a wafer transport module based on a robot. The distributed module controllers are integrated by an inter-module communication network and coordinated by a centralized controller, called a cluster tool controller (CTC). Since the CTC monitors and coordinates the distributed complex module controllers for advanced process control, complex commuication messaging and services between the CTC and the module controllers are required. A SEMI standard, CTMC(Cluster Tool Module Communication), specifies application-level communication service requirements for inter-module communication. We propose the use of high-level fieldbuses, for instance. PROFIBUS-FMS, for implementing CTMC since the high-level fieldbuses are well suited for complex real-time distributed manufacturing control applications. We present a way of implementing CTMC using PROFIBUS-FMS as the communication enabler. We first propose improvements of a key object of CTMC for material transfer and the part transfer protocol to meet the functional requirements of modem advanced cluster tools. We also discuss mapping objects and services of CTMC to PROFIBUS-FMS communication objects and services. Finally, we explain how to implement the mappings.

• 한국군사과학기술학회지
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• 제24권2호
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• pp.204-210
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• 2021

In this paper, we studied a method of wirelessly checking up the POD for captive flight tests which is performed during the development of guided weapons systems. The wireless power transfer module, the power distribution device, and the battery pack were designed to wirelessly power the captive flight test POD, and the communication device was designed to enable wireless communication between the POD and the check-up device. The communication device was designed to enable WiFi, IR communication, and laser diode communication, so that various communication methods could be tested. Through the performance test, it was confirmed that power was stably supplied to the captive flight test POD, and the wireless communication performance was verified by measuring the delay time and error rate. As a result, by using our system the POD check-up for the captive flight test was performed wirelessly and the data of the captive equipment could be obtained effectively.

• 한국군사과학기술학회지
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• 제27권5호
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• pp.611-618
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• 2024

5G New Radio(NR) technology, with its focus on high speed, low latency, and connectivity, introduces crucial advancements like MIMO for enhanced reliability and transmission rates, edge computing for reduced latency, and IAB for extended coverage. However, military communication networks face challenges such as limited capacity, unpredictable mobility and communication dead zones. This paper delves into the trends of the above 5G NR technologies outlined by the 3GPP standard, exploring their potential applications within military infrastructure networks. Our aim is to underscore the benefits of harnessing these technologies in military settings. Additionally, through simulation, we forecast the advantages associated with integrating these core 5G NR technologies, thereby paving the way for enhanced military communication capabilities.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2556-2558
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• 2002

In this paper, the design guideline of communication interrace module for home-appliances is proposed. The requirements of the interface between white-goods and communication module are analyzed. Finally, the proposed interface structure is implemented using PLC technology.