• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1840-1848
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• 2017

Linear wireless sensor networks typically construct a network topology with a high reliability through sequential 1:1 mapping among sensor nodes, so that they are used in various surveillance applications of major national infrastructures. Most existing techniques for identifying sensor nodes in those networks are using GPS, AOA, and RSSI mechanisms. However, GPS or AOA based node identification techniques affect the size or production cost of the nodes so that it is not easy to construct practical sensor networks. RSSI based techniques may have a high deviation regrading location identification according to propagation environments and equipment quality so that complexity of error correction algorithm may increase. We propose a timestamps based sequential localization algorithm that uses transmit and receive timestamps in a message between sensor nodes without using GPS, AOA, and RSSI techniques. The algorithms for distance measurement between each node are expected to measure distance within up to 1 meter in case of an crystal oscillator of 300MHz or more.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.333-340
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• 2011

KJJVC(Korea-Japan Joint VLBI Correlator) was installed at the KJCC(Korea-Japan Correlation Center) and has been operated by KASI(Korea Astronomy and Space Science Institute) from 2009. KJNC is able to correlate the VLBI observed data through KVN(Korean VLBI Network), VERA(VLBI Exploration of Radio Astrometry), and JVN(Japanese VLBI Network) and its joint network array. And it is used exclusively as computer in order to process the observed data for the scientific purpose KJJVC used the VSI(VLBI Standard Interface) as the VLBI international standard at the data input-output specification between each component. Especially, for correlating the observed data, the data is transmitted with 1024Mbps speed between Mark5B high-speed playback and RVDB(Raw VLBI Data Buffer). The EMI(Electromagnetic lnterference), which is occurred by data transmission with high-speed, cause the data loss and the loss occurrence is frequently often for long transmission cable. Finally it will be caused the data recognition error by decreasing the voltage level of digital data signal. In this paper, in order to minimize the data loss by measuring the EMI noise level in transmission of the VSI specification, the 3 methods such as 1) RC filtering method, 2) lmpedance matching using Microstrip line, and 3) Signal buffering method using Differential line driver, were proposed. To verify the effectiveness of each proposed method, the performance evaluation was conducted by implementing and simulations for each method. Each proposed method was effectively confirmed as the high-speed data transmission of the VSI specification.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.468-476
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• 2011

A lack of basic academic skills of junior college students has negatively impacted on the quality of vacational education and student dropout prevention, and yet it is true that there still are unclear alternatives or solutions to come up with that concern. As a way to find out the actual levels of basic academic skills of junior college students and educational efforts to improve these skills, the study investigated prior studies and benchmarked strengths and weaknesses of the related educational programs and supporting systems operated by ten junior colleges around the nation. Further, the study addressed emerging issues and challenges related to basic academic skills, based on the case study of D college. Major research methodologies included literature review, surveys for students and faculty members and focus-group interviews of faculty members in order to examine the states of students' basic academic skills in the area of language, in particular. Accordingly, the study proposed several suggestions with which educational practitioners could assist in supporting students to acquire improved basic academic skills(such as the development of a competence-based curriculum, implementation of reliable diagnosis tools and supporting educational systems for evaluating students' basic academic skills and upgrading of diverse teaching and learning resources and methods).

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.255-260
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• 2007

The construction industry has been recognized as lagging behind other industries in the area of research and development (R&D) due primarily to the lack of R&D funds. To overcome this situation, the Korea Ministry of Construction and Transportation has a plan to expand its investments on the construction R&D up to 1.72 billion US dollars over the next 3 years. Despite this effort, it is still challenging to conduct the quantitative measurement on the efficiency of construction R&D projects, which can be utilized as the objective basis in the reasonable selection of a promising R&D team or in the consequential evaluation of a R&D performance. This study aims to conduct the efficiency analysis on the construction R&D projects to provide the basis for evaluating the performance of research and development. Toward this end, this study performs an efficiency analysis, which reflects all of the input and output data into/from the construction R&D by utilizing the Data Envelopment Analysis (DEA). The proposed methodology can be utilized to make a better decision on the priority of the R&D investments and present a sound basis to suggest the areas to be improved so as to reduce the inefficiency of R&D projects.

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.495-520
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• 2018

Because of structural changes in the international oil market and the economy, it is widely recognized that the impact of oil shocks on the economy has weaken since the mid-1980s. This study tries to examine the validity of the recent perception about the relationship between oils shocks and the economy, estimating the time-varying effects of oil shocks on the Korean economy. The results show that the dynamic effects of oil shocks normalized to a one standard deviation has been relatively constant, in contrast to the recent perception and a number of existing studies. In addition, because the shape of impulse response functions at each point in time spanning from 1984:II to 2017:IV has not been changed significantly, it seems that the propagation mechanism of oil shocks also has not been substantially altered. These findings indicate that even though structural changes of the economy, such as the reduction in the share of oil consumption and the spread of high-efficiency energy technologies, have been rapidly progressed, it is not still enough to offset the negative effects of oil shocks. Rather, it seems that the recent perception about the shrinking effects of oil shocks is mainly due to the assumptions that do not reflect changes in the size of oil shocks. In particular, this problem appears more pronounced in the case of the typical a one standard deviation increase oil shock under homoskedasticity assumption, which is widely adopted in the most VAR analyses. Therefore, in estimating the effects of oil shocks on the economy, it is important to specify the correct model and normalization method, to reflect changes in the size of oil shocks.

• Journal of the Society of Disaster Information
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• v.10 no.2
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• pp.288-293
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• 2014

The purpose of this study was to provide response plans against acts of suicide bomb using utilize unmanned aircrafts to prevent large losses of lives such as the terrorist attacks of September 11. As the result, First, this research suggests revising the definition and categorization of utilizing unmanned aircrafts and legislating the Anti-terrorism law. Second, it is needed to establish the proper social safety network through terrorism response management integrated system against the terror of related organization. Third, suicide bomb using utilizing unmanned aircrafts can be occurred because it is possible to make bomb and open web site for terrorism without connection with terrorist organization because of universal use of Internet. In response to this, it is needed to make a law which can block the use and open of illegal site and contents. Forth, the increasing number of foreigners and immigrants can make conflicts, and cause the foreigner's anti-korea feeling and the citizen's anti-cultural diffusion. Therefore, it is needed for the citizen to change and improve the awareness of them, and the change of social politics.

• Journal of the Korean Wood Science and Technology
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• v.33 no.1 s.129
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• pp.63-76
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• 2005

Wood-culture is new paradigm which is substituted for the cement culture, and the study of wood-culture should keep pace with not only the study of a engineering science but also a sociological study to form a theory system. The purpose of this study is to suggest the method of sociological approach of the wood culture which have not yet tried at home and abroad; in view of structural-functionalism, systemical-functionalism, conflict theory, social-change theory by analyzing cases in Korea. In view of structural-functionalism, social system consists of cognition system, institution system, life system and technology system. These sub-systems fulfill the function of what-should-be, reasonability, reality and development. In view of systemical-functionalism, according to the acknowledgment and spreading proccess of the wood usefulness, wood culture system consists of the individual system, organizational system and the social system. In view of conflict theory, the society which has the wood culture can be classified into three types. The one is society which the traditional wood culture is declining and the cement culture is spreading. The other one is society which the cement culture is declining and the traditional wood culture is spreading. Another is Finally the society which the two type balance with. In view of social-change theory, the society can be classified into three types. The one is society which the wood culture is proceeding to the cement culture. The other is society which the cement culture is proceeding to the wood culture. Another is society which the wood culture changes itself. Finally, from a view of changing level, the society can be classified into three types: the micro-change, the middle-level-change, and the macro-change. It's need to study wood culture systemically in view of engineering and sociological science. And then it will be possible to make 'wood culture theory system'.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.3
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• pp.94-110
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• 2000

While most of the previous information technology adoption and diffusion researches focus the critical factors not on the organizational perspective but on the individual perspective based on the various reasons such as informational characteristics. This paper will try to analysis the adoption and diffusion factors of the Internet related technologies based on the organizational perspective. Nowadays, in especially, the evolving and fast diffusing Internet related technologies and the flourishing e-commerce applications pressure retail banks that prepare the new types of online payment systems to maintain their existing and new customer relationship and compete with their potential competitors in the coming market environments. In addition, while most previous researches only focus on the adoption of new information technologies, this paper not only analysis the adoption of innovational technology but also analysis the diffusion process in an organization, which encourage practitioners and researchers to reveal more detail and practical analysis of the innovational technology adoption and diffusion process in ann organizational setting. Based on the previous researches, there are several factor-category will be selected for this research: 1) organizational factor, 2) within banking industry factor, 3) non-banking industry factor, 4) customer acceptance factor, 5) government factor, and 6) the functionality of e-commerce systems factor. Finally, in this study, we assumed that the more sophisticated e-commerce adopting banks provide the more broad range of banking services in general. Thus, we develop the extended integrated technology diffusion model to provide empirical evidences to distinguish between adopters and non-adopters and explain the diffusion levels of e-commerce using the level of services provided via Internet to the customer in retail bank industry.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.149-156
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• 2019

In the field of maintenance of power transmission lines, drones have been used for their patrol and inspection by KEPCO since 2017. This drone technology was originally developed by KEPCO Research Institute, and now workers from four regional offices of KEPCO have directly applied this technology to the drone patrol and inspection tasks. In the drone inspection system, a drone with an optical zooming camera and a thermal camera can fly automatically along the transmission lines by the ground control system developed by KEPCO Research Institute, but its camera gimbal has been remotely controlled by a field worker. Especially the drone patrol and inspection has been mainly applied for the transmission lines in the inaccessible areas such as regions with river-crossings, sea-crossings and mountains. There are often communication disruptions between the drone and its remote controller in such extreme fields of mountain areas with many barriers. This problem may cause the camera gimbal be out of control, even though the inspection drone flies along the flight path well. In addition, interference with the reception of real-time transmitted videos makes the field worker unable to operate it. To solve these problems, we have developed the auto-tracking camera gimbal system with deep learning method. The camera gimbal can track the transmission line automatically, even when the transmitted video on a remote controller is intermittently unavailable. To show the effectiveness of our camera gimbal system, its field test results will be presented in this paper.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.539-546
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• 2016

It is over 12 years since the launch of Korea Train eXpress (KTX) services. Demand for the KTX has been on the increase continuously but few studies have been produced related to this phenomenon. KTX passenger demand has been constantly increasing due to influencing factors such as the expansion of network, rise of oil prices, etc. In this study, our main focus is to verify that there are other types of elements that are causing an increase in KTX demand; our approach looks at changes in social and psychological aspect that have occurred due to the reduction of travel time and cost, as well as the imposition of a five-day workweek. In other words, we considered diffusion theory in the marketing area, which affects product selection and purchasing attitudes, as a key factor that is causing passenger demand to increase. That is to say that it is hypothesized that the demand for travel on the KTX has increased due to the train's utility, which is spread by the diffusion effect Therefore, the Bass diffusion model was applied to explain the dramatic increase in KTX passenger demand. Based on this foundation, it was also discussed how certain marketing strategies that incorporate the diffusion effect should be considered variously for sustainable management of rail transportation, while considering a steady passenger demand.