• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.93-102
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• 2021

In this research, we present a natural lighting system with transmission distance of 30m and lighting efficiency of 35% (30m standard) for operating hours of 7h/day (based on clear sky). The system is composed of parabolic reflective mirror and modified light pipe that can secure more than 88% of light concentration efficiency. The light loss rate of newly designed light pipe transmission system is demonstrated to 0.8 %/m in the straight-line part and 2%/m in the curved part. Modified light pipe daylighting system shows better performance over fiber optic daylighting system in terms of transmission distance (1.5 times longer) and illuminance (3.05 times higher).

• International Journal of Internet, Broadcasting and Communication
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• 제15권4호
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• pp.191-198
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• 2023

In recent years, we have witnessed a growing popularity of virtual reality (VR) technology. Understanding the factors that contribute to a comfortable VR viewing experience is crucial for its successful implementation. This study specifically explored the role of gender in determining the ideal viewing distance for VR animation. To do so, we enlisted 100 participants, comprising 41 males and 59 females, and had them engage in a VR animation viewing task, during which we recorded their preferred viewing distances. Our findings revealed that there was no significant distinction between males and females regarding their favored VR animation viewing distances. These results suggest that when creating VR content, gender may not be a noteworthy factor to take into account when determining the optimal viewing distances for a comfortable experience.

• 조명전기설비학회논문지
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• 제29권1호
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• pp.31-36
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• 2015

In this paper, an LED lighting system that is capable of automatic or maunal dimming control using a ultrasonic sensor and Bluetooth wireless communication technology is presented. The LED lighting system consists of a ultrasonic sensor, microcontroller unit, Bluetooth wireless communication, LED driver, and LED light source. By using the implemented LED lighting system sample, it is shown that the automatic and manual dimming control is realized. By using the ultrasonic sensor, the LED lighting is automatically brighter or dimmer depending on the distance between the sensor and an object. When using a smartphone that includes Bluetooth wireless communication function, one can not only manually control the brightness of the LED lighting from level 1 to 10, but also monitor the distance between the sensor and object on the smartphone.

• Transactions on Electrical and Electronic Materials
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• 제11권5호
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• pp.238-241
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• 2010

The purpose of this study is to solve the problems of radio frequency bandwidth frequency depletion, confusion possibilities, and security that are in current wireless communications systems, and to confirm the possibility of applying those solutions for the next generation network. To solve the problems of the current wireless communications system, a visible light communications system for power line communication (PLC) via 8-bit microcontroller is created and the capacity is analyzed. The exclusive PLC chip APLC-485MA, an 8-bit ATmega16 microcontroller, high brightness 5pi light emitting diodes (LEDs), and the LLS08-A1 visible light-receiving sensor were used for the transmitter and receiver. The performance was analyzed using a designed program and an oscilloscope. The voltage change was measured as a function of distance from 10-50 cm. Blue LEDs showed the best performance among the measured LED types, with 0.47 V of voltage loss, but for a distance over 50 cm, precise data was not easy to obtain due to the weak light. To overcome these types of problems, specific values such as the changing conditions and efficiency value relevant to the light emitting parts and the visible light-receiving sensor should be calculated, and continuous study and improvements should also be realized for better communication conditions.

• Journal of the Korean Data and Information Science Society
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• 제22권1호
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• pp.9-18
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• 2011

PCS 3사의 동시 서비스가 제공되면서 유무선 통화 수요는 초기의 보완관계에서 대체관계로 전환되었고, 이후 유선 시외전화 시장은 이동전화에 의해 잠식되어 매출액이 매년 감소해 왔다. 본 연구에서는 통화시장의 변환기 동안 유선 시외전화 시장과 이동전화 시장 간 상호 역학관계를 분석하고, 이동통화의 확산이 과연 시외통화 매출 감소의 직접적인 요인이었나를 통계적으로 검정하였다. 검정결과는 이동전화 이용과 시외전화 매출 간 직접적 대체관계의 증거를 발견하기는 어려우며 일반적 인식과는 달리 초기의 보완관계가 상당기간 유지되었음을 입증해준다.

• 한국군사과학기술학회지
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• 제11권1호
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• pp.15-24
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• 2008

The data delivery confirmation method of MIL-STD-188-220C, which is a tactical wireless mobile Ad-Hoc communication protocol, is that a source node requires the end-to-end ack from all destination nodes and the data-link ack from 1-hop neighboring destination nodes and relaying nodes, regardless of the hop distance from a source node to destination nodes. This method has the problem to degrade the whole communication network performance because of excessive data traffic due to the duplicate use of end-to-end ack and data-link ack, and the collision among end-to-end acks on the wireless network in the case of confirming a data delivery within an 1-hop distance. In order to solve this problem, this paper has proposed the method to perform the data delivery confirmation with the improvement of communication network performance through the data traffic reduction by achieving the reliable data delivery confirmation requiring the only data-link ack within an 1-hop distance. The effects of the proposed method are analyzed in the two aspects of the data delivery confirmation delay time and the data delivery confirmation success ratio.

• 한국전자통신학회논문지
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• 제3권3호
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• pp.170-176
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• 2008

인터넷의 발달로 인해 국제간 대용량의 광신호를 장거리 전송하기 위해서는 DWDM 시스템의 성능향상이 필수적으로 요구된다. 전송 용량을 높이기 위해서는 전송 속도를 높이거나, 채널수를 늘려야 하며 이런 요구 조건을 충족시키기 위하여 라인 코딩, 변조기술, 최적화된 광섬유, 광대역 광증폭 기술, 분산보상 기술, 순방향 에러정정기술 등이 적용되고 있다. 특히, 순방향 에러정정기술은 고속 대용량 트래픽을 장거리 전송하기 위한 혁신적인 기술로 각광 받고 있다. 본 논문에서는 순방향 에러정정기술의 세대별 발전 현황과 코딩이득을 분석하여 상용 시스템에 구현하는 방법을 제시하였다.

• Asia pacific journal of information systems
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• 제10권4호
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• pp.57-75
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• 2000

Most current literature on knowledge and technology transfer(Appropriability Model, Dissemination Model, and Knowledge Utilization Model), describe the process of transfer in details, but has limitation in terms of their application in contemporary high-tech industries since most studies have not provided plausible explanation on levels and factors affecting transfer of knowledge and/or technology. To overcome these limitations, the four levels of knowledge and technology transfer are suggested: Knowledge and Technology Creation(Level I), Sharing(Level II), Implementation(Level III), and Commercialization(Level IV). Comprehensive literature identifies sixteen variables affecting the process and results of knowledge and technology transfer. The survey results show four key factors in knowledge and technology transfer: Communication, Distance, Equivocality, and Motivation, Communication refers to the degree to which a medium is able to efficiently and accurately conveys task-relevant information and media while distance involves both physical and cultural proximity. Equivocality refers to the degree of concreteness of knowledge and technology to be transferred while motivation involves incentives for and the recognition of the importance of knowledge and technology transfer activities. Further analysis shows that there are four distinctive clusters and they show very contrasting characteristics in terms of four key factors. The careful mapping of the four clusters on the four key factors show very informative knowledge and technology transfer patterns, the Knowledge and Technology Transfer Grid. Finally, actions to increase communication interactivity and motivation, and to reduce cultural distance and equivocality are suggested.

• International Journal of Computer Science & Network Security
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• 제22권12호
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• pp.116-124
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• 2022

Information and communication technologies used in the social sphere are born due to the development of computer technologies. The main task of the distance learning process in higher education institutions is not to provide information, but to teach how to obtain and use it. The purpose of the article: to identify innovative approaches in the training of specialists in higher education institutions in the context of distance learning. Various innovative approaches to organizing the work of students of higher educational institutions in the context of distance learning are considered. Based on the conducted research, it is concluded that each of the approaches described by us outlines the study of the phenomenon of professional training of a specialist in the condition of distance learning. All the described approaches significantly contribute to the improvement of professional training of specialists, encourage students to self-improvement, professional development and enrich their professional competence in modern conditions. The emergence and spread of innovative technologies means not only a change in the activity itself and its inherent means and mechanisms of its implementation, but also a significant restructuring of goals, value orientations, specific knowledge, skills and abilities. Therefore, the current stage of the development of civilization, scientific and technological progress requires the emergence of such specialists who would have broad humanitarian thinking, would have good psychological training, would be able to build professional activities according to laws that take into account the relationship between economic productivity and creativity, as well as the desire of the individual for constant renewal, self-realization. Only such qualities will help you master the specifics of innovative technologies well. We see the prospects in the study of innovative approaches to training specialists in higher education institutions in the condition of distance learning in foreign countries.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.41.6-41
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• 2002

In this paper, we present a remote control strategy for vehicles moving in an intelligent Vehicle Highway System(IVHS). We study a method for optimal off-line scheduling of a limited communication channel that is used for lead vehicle control in a platoon. The deviated distance from the desired trajectory is used for defining a cost functional that measures the performance of the system with communication constraints in relation to the desired system without communication constraints. The optimal communication sequence is obtained by simulations.