• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.515-523
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• 2015

This study reviewed 612 DP LOP(Loss of Position) incident reports which submitted to IMCA from 2001~2010 and identified 103 human error caused incidents and classified it through HFACS. And, this study analysis of conditional probability of human error on DP LOP incidents through application of bayesian network. As a result, all 103 human error related DP LOP incidents were caused by unsafe acts, and among unsafe acts 70 incidents(68.0 %) were related to skill based error which are the largest proportion of human error causes. Among skill based error, 60(58.3%) incidents were involved inadvertent use of controls and 8(7.8%) incidents were involved omitted step in procedure. Also, 21(20.8%) incidents were involved improper maneuver because of decision error. Also this study identified that unsafe supervision(68%) is effected as the largest latent causes of unsafe acts through application to bayesian network. As a results, it is identified that combined analysis of HFACS and bayesian network are useful tool for human error analysis. Based on these results, this study suggest 9 recommendations such as polices, interpersonal interaction, training etc. to prevent and mitigate human errors during DP operations.

• Journal of Convergence Society for SMB
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• v.3 no.2
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• pp.51-56
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• 2013

Real-time processing of sensor data network, is one of the important factors. Each node in the detected data are required to be transmitted within a certain time since the accurate processing is possible. Thus, the data nodes are successfully delivered within a specified time, it is very important to check whether the. Recently more and more accurate real-time embedded systems are reliable and haejyeoseo been able to provide sophisticated services. Because of the inherent complexity of embedded systems in the physical world and the difficulty of predicting the difficulty of a safe design constraints on the runtime violation of system as to cause unexpected causes. Each node data in time detected by the time required to be passed in the appropriate processing is possible because the data transfer time in this paper, the monitoring of the sensor network through a node are allowed to exist within the time range and transmits data to the server Analysis of the data transfer time for checking whether the system was implemented. Implementation of the data transmission time to the process for analyzing and presenting, according to the procedure suggested by the transit time required for analysis a time difference analysis method, a data collection method and a data transmission time and transmission time calculating method presented.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.77-85
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• 2013

Recently, location information based routing protocol has been studied to estimate end-to-end path in wireless ad-hoc network. This protocol assumes all nodes can get heir location information via GPS devices and floods only limited area with routing message through acquired location information. Therefore, this protocol has advantage that can reduce the number of routing message than the existing IP-based routing protocols. In addition, all nodes enabling this protocol must acquire their own location information to participate in the location-based routing. However, recent because of the miniaturization of sensor node, sensor node without GPS function has been launched. Therefore in case of the sensor node that does not know location information, it is impossible to participate in the ad hoc network configuration and location information based routing. In this paper, a virtual location information based routing scheme is proposed for wireless nodes without GPS function to be able to participate in location information based routing within ad hoc network environments consisting of wireless nodes with GPS function and wireless nodes without GPS function. Therefore, the proposed protocol has the advantage that a wireless node without a GPS function is able to participate in ad hoc network configuration and the location information based routing.

• Journal of IKEEE
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• v.15 no.4
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• pp.354-362
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• 2011

One of the unsolved problems in Artificial Neural Networks is related to the capacity of a neural network. This paper presents a CoreNet which has a multi-leveled input and a multi-leveled output as a 2-layered artificial neural network. I have suggested an equation for calculating the capacity of the CoreNet, which has a p-leveled input and a q-leveled output, as $a_{p,q}=\frac{1}{2}p(p-1)q^2-\frac{1}{2}(p-2)(3p-1)q+(p-1)(p-2)$. With an odd value of p and an even value of q, (p-1)(p-2)(q-2)/2 needs to be subtracted further from the above equation. The simulation model 1(3)-1(6) has 3 levels of an input and 6 levels of an output with no hidden layer. The simulation result of this model gives, out of 216 possible functions, 80 convergences for the number of implementable function using the cot(x) input leveling method. I have also shown that, from the simulation result, the two diverged functions become implementable by precalculating the weight values. The simulation result and the precalculation of the weight values give the same result as the above equation in the total number of implementable functions.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.559-563
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• 2015

Monitor of All-sky X-ray Image (MAXI) is a Japanese X-ray all-sky surveyer mounted on the International Space Station (ISS). It has been scanning the whole sky since 2009 during every 92-minute ISS rotation. X-ray transients are quickly found by the real-time nova-search program. As a result, MAXI has issued 133 Astronomer's Telegrams and 44 Gamma-ray burst Coordinated Networks so far. MAXI has discovered six new black holes (BH) in 4.5 years. Long-term behaviors of the MAXI BHs can be classified into two types by their outbursts; a fast-rise exponential-decay type and a fast-rise flat-top one. The slit camera is suitable for accumulating data over a long time. MAXI issued a 37-month catalog containing 500 sources above a ~0.6 mCrab detection limit at 4-10 keV in the region ${\mid}{b}{\mid}$ > $10^{\circ}$. The SSC instrument utilizing an X-ray CCD has detected diffuse soft X-rays extending over a large solid angle, such as the Cygnus super bubble. MAXI/SSC has also detcted a Ne emission line from the rapid soft X-ray nova MAXI J0158-744. The overall shapes of outbursts in Be X-ray binaries (BeXRB) are precisely observed with MAXI/GSC. BeXRB have two kinds of outbursts, a normal outburst and a giant one. The peak dates of the subsequent giant outbursts of A0535+26 repeated with a different period than the orbital one. The Be stellar disk is considered to either have a precession motion or a distorted shape. The long-term behaviors of low-mass X-ray binaries (LMXB) containing weakly magnetized neutron stars are investigated. Transient LMXBs (Aql X-1 and 4U 1608-52) repeated outbursts every 200-1000 days, which is understood by the limit-cycle of hydrogen ionization states in the outer accretion disk. A third state (very dim state) in Aql X-1 and 4U 1608-52 was interpreted as the propeller effect in the unified picture of LMXB. Cir X-1 is a peculiar source in the sense that its long-term behavior is not like typical LMXBs. The luminosity sometimes decreases suddenly at periastron. It might be explained by the stripping of the outer accretion disk by a clumpy stellar wind. MAXI observed 64 large flares from 22 active stars (RS CVns, dMe stars, Argol types, young stellar objects) over 4 years. The total energies are $10^{34}-10^{36}$ erg $s^{-1}$. Since MAXI can measure the spectrum (temperature and emission measure), we can estimate the size of the plasma and the magnetic fields. The size sometimes exceeds the size of the star. The magnetic field is in the range of 10-100 gauss, which is a typical value for solar flares.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.319-343
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• 2009

This paper considers some kinds of socio-spatial constraints and strategies for overcoming them which immigrant workers in Korea have experienced in their work-place and life-space, with an analysis of questionnaire data and of direct interview materials on them. Though they appear somewhat satisfactory or positive with their work-place, this can be seen as a hypocritical or false attitude rather than a real one: they are forced to work with long hours (more than 70 hours per week) and rigid controls in the other' territory. Their daily life-spaces also are severe: they can be hardly embedded in an existing community with a sense of place due to serious institutional and interaction constraints, even though they seem to have a basic mobility to survive in life-spaces. In order to escape or alleviate such local constraints, they try to constitute multi-scalar (local, trans-regional, and transnational) networks, and to find informations and means to resolve or cope with them. However, this kind of endeavors of immigrant workers to make a trans-national network and social space has a limitation for them to be free entirely from constraints, which might be strengthened with a lack of geographical knowledge of them. Then immigrant workers in Korea live ineluctably with not only hybrid national identity but also with disturbed local identity in an aliened workplace and life-spaces.

• KDI Journal of Economic Policy
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• v.36 no.2
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• pp.175-196
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• 2014

This paper is a theoretical attempt to analyze and understand Yeonjulmang and Yeongyeolmang, which are terms for social networks with negative and positive connotation respectively in Korean Sociology. To do that, we analyze a social network where unilateral help are reciprocated. A social network in this context is a network where the past behaviors of its members are transmitted. With the information how the members behaved before, a social norm can emerge in the network, which facilitate the indirect reciprocation of unilateral help. In this norm, an agent's helping now will be rewarded by his being helped in the future. Since the reward happens in the future, this norm may not be sustained even if it is efficient. To sustain the reciprocation of the help, a norm can evolve to punish the violation of the norm more severely. If the punishment becomes too severe, the reciprocation of the help can be sustained even if it is not efficient any more in that the cost of help exceeds the benefit. If we allow the exit of the network, members have incentive to do it as belonging to the network is not beneficial any more. Then the social network may collapse. To avoid the collapse of the network, the exclusive norm, which exclude even mutually beneficial relationship with outsiders, may emerge. This can explain the emergence of Yeonjulmang, or a closed network, which is inefficient in double senses; 1) it may sustain inefficient reciprocation of help, and 2) the mutually beneficial relationship is excluded between an insider and an outsider of the network.

• Journal of the Korean Society for Library and Information Science
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• v.17
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• pp.161-201
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• 1989

1. Introduction Korean society is moving toward an information society in 2000. At present a few Korean libraries are computerized and networks between libraries have yet to be formed. And there is no study done on the computerization of the Korean libraries. Therefore, this study will attempt to find elements that influence the computerization of Korean libraries. This research is composed of the following three parts. 1) Survey on the present status of computerized Korean libraries. 2) The influencing factors for Korean library computerization on the level of organization. 3) The relationship between professionalism and the access to the computer information on the level of librarians. 2. Hypothesis The basic hypothesis of this research is from the theory of the innovation of organization by Moch. He found that the size of the organization, specialization of the staffs, the task differentiation, and decentralization of decision making were the underlying influence for the organizational innovation. From this theory, hypothesis were formulated as follows. 1) The size of the library influences the library computerization. 2) Specialization of the librarians influences the library computerization. 3) Differentiation of the library services influences the library computerization. 4) The decision making process influences the library computerization. 3. Collection of the data Questionnaires were sent to 21 computerized libraries among which were 8 experimental group and 7 other controlled group libraries. Data were collected from April to July 1988. 4. Findings 1) The present status of Korean library computerization. -Korean libraries are computerized mostly in cataloguing. -The computer technology gate-keepers are mainly librarians. -The computerization budgets are not specifically allocated or funded by the organization but librarians made decisions to allocate library budget for the computer application. Gradually, more libraries are being funded specially for library computerization. 2) Factors that influence library computerization. -The size of the western books and the number of western periodical subscription influence the library computerization. -The number of annual book increase influences library computerization. -The number of annual book use influences library computerization. -The number of annual library users does not influences library computerization. - The size of the library budget influences the library computerization. -Librarian's specialization influences the library computerization. -Differentiation of library service influences the library computerization. Information service is positively related to the library computerization while data service is not related to the library computerization. -Decentralization of decision making in library service influences the library computerization.

• Journal of the Korean association of regional geographers
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• v.17 no.5
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• pp.617-637
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• 2011

This study employs qualitative approaches to examining geographical characteristics and patients' determinants of online referrals in terms of regionalization. In this light, I conducted interviews with 20 patients receiving online referrals in Choongbook, Korea, and investigated their behaviors regarding these referrals between July and August 2009. I found that many patients who suffered from various levels of illness preferred tertiary care centers outside of Choongbook and did not enjoy their experience with the local medical institutions as the online referral service sites. This result might be because patients choose online referrals for psychological considerations such as quality and level of health care services, personal stakes in online referral service sites, acceptability and credibility of good tertiary care centers, and easy access to and use of medical institutions. Meanwhile, immediate benefits with regard to the technological value of online referrals, such as convenience, utility, and original purpose associated with regionalization, did not influence patients' decision-making. Therefore, the social and public networks affiliated with online referrals plus the effect of Korean medical laws play hostage to private decisions made by citizens, who prefer high-level medical institutions. Accordingly, the technological contribution of online referrals does not halt the outflow of patients from local, tertiary care centers. Especially, the existing health care system and patients' behaviors are deeply related to referrals in the online system. To protect regionalization, the improvement of health care services from the present state of affairs is required.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.2
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• pp.86-100
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• 2015

Cloud computing is a computing term that evolved in the late 2000s, based on utility and consumption of computer resources. Google say that "Cloud computing involves deploying groups of remote servers and software networks that allow different kinds of data sources be uploaded for real time processing to generate computing results without the need to store processed data on the cloud. Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over a network. At the foundation of cloud computing is the broader concept of converged infrastructure and shared services. Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the effectiveness of the shared resources." The cloud service is a smart and/or intelligent service to save private files in any device, anytime, anywhere. Dropbox, OAuth, PAClous are required that the accumulated user's data are archives with cloud service. Currently we suggest an implementation technique to process many tasks to the cloud server with a thread pooling. Thread pooling is one of efficient implementating technique for client and service environment. In this paper, to present the implementation technique we suggest three diagrams in the consideration of software engineering.