• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.10
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• pp.21-31
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• 1994

This paper describes the multichannel combined R2MFC/DTMF/CCT reciver which provides a signaling service functions for call processing control in digital switching system. Using the TMS320C25 DSP chip, we have implemented multi-function receriver shich processes 8 channels of R2MFC, DTMF, and CCT signals simultaneously. In order to increase the channel multiplicity of the combined receiver. R2MFC and CCT receiver were employed by discrete Fourier transform(DFT) method using Goertzel algorithm, and DTMFreceiver was employ by infinite impulse reponse(IIR) filtering method using 4KHz subsampling technique. The combined receiver has 4 function modes for each channel such as R2MFC, DTMF, CCT, and Idle modes. The function mode of each channel may be selected at any time by single-chip micro-controller(.mu.C). Hence, the number of channels assigned for each function mode can be adjusted dynamically according to the signaling traffic variations. From the experimental test results using the test-bed, it has been proved that the combined receiver statisfies all receiver satisfies all receiver specifications, and provides good channel multiplicity and performance, Therefore, it may give a great improvement than existing receiver in cost, reliability, availability, and serviceability.

• Journal of Korea Port Economic Association
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• v.24 no.3
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• pp.125-146
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• 2008

Port marketing using websites in the e-business environment is essential in response to the competition to become hub ports, especially since shipping companies, ports' major customers, are being pressed by shippers to reduce logistics costs and introduce large ships to realize economies of scale, thereby reducing the number of ports of call. In this sense, this study intends to approach the port industry from the perspective of e-business and suggest vitalization methods using Gwangyang Port websites(6C; contents, community, communication, connection, commerce, customization) as one of the ways to turn it into Northeast Asia's hub port of logistics.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.1-10
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• 1995

We have analyzed the reliability of failure models in circuit-switched networks. These models are grid topology circuit-switched networks, and each node transmits a packet to a destination node using a Flooding routing method. We have assumed that the failure of each link and node is independent. We have considered two method to analyze reliability in these models : The Karnaugh Map method and joint probability method. In this two method, we have analyzed the reliability in a small grid topology circuit switched network by a joint probability method, and comared analytic results with simulated ones. For a large grid enormous. So, we have evaluated the reliability of the network by computer simulation techniques. As results, we have found that the analytic results are very close to simulated ones in a small grid topology circuit switched network. And, we have found that network reliability decreases exponentially, according to increment of link or node failure, and network reliability is almost linearly decreased according to increment of the number of links, by which call has passed. Finally, we have found an interesting result that nodes in a center of the network are superior to the other nodes from the reliability point of view.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.7
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• pp.17-28
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• 2000

A novel and efficient approach for the numerical solution of time-dependent coupled-wave equations, which are frequently used for the modeling of DFB(Distributed Feedback), DBR(Distributed Bragg Reflector), and FP(Fabry Perot) laser diodes, is proposed. In this approach, the coupled wave equations are split into two sets of equations. One of two sets of equations contains only the phase factors and the other contains only the coupling terms. The separate equations are solved exactly in their split form successively. This new numerical scheme, which we call the SS-TDM(Split-Step Time Domain Model), is found to require an order of magnitude smaller number of subsections to get accurate results than the previous methods while the computation time for each time step is comparable to the previous methods.

• Journal of Korean Library and Information Science Society
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• v.23
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• pp.109-145
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• 1995

This study is to find out general problems a n.0, ppeared in the management and utilization of these and dissertation and to suggest some recommendations, through the survey and analysis on the Korean university libraries. Questionnaires were sent to 109 university libraries which offer master's and doctoral degrees, during the period between March 7 and March 27, 1995. Responded questionnaires of 91 libraries (about 83%) were processed using SAS. The results of this survey can be summarized as follows: 1. Most of Korean university libraries have the collections of theses and dissertations ranging from less than 10,000 volumes (27 libraries ; 32.1%) ; 10,000 to 30,000 volumes (20 libraries ; 25.0%) ; to more than 80,000 volumes (16 libraries ; 19.0%). The largest collection was around 200,000 volumes. 2. In the management of them, 35 libraries (38.5%) were active in collecting them, but 56 libraries (61.5%) were not active, mainly for the shortage of manpower and the space problems. In 62.6% of libraries, they are arranged with the books. And 51.3% of libraries process them in less than one month. 46 libraries (52.9%) computerize their system, and among them 40 libraries (87%) establish their own databases. 3. The collections of theses and dissertations are called by various name, including periodical room, theses room, reference reading room etc. reaching to 15 kinds. 71 libraries (78.0%) adopt open system, and 17 libraries closed system ; and 2 libraries (3.2%) partial open system. 62 libraries (68.1%) arrange them in the order of call number, while 20 libraries (31.9%) by other criteria.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.8
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• pp.1578-1586
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• 1994

In this paper, a new overload control scheme is proposed for a stored program control system. The proposed control scheme is fit for a distributed architecture. In a distributed architecture, most of the call control functions are distributed to many subscriber control processors(SP) and some functions as number translation and routing control are centralized to central processors(CP). Therefore the performance of the CP is critical to the switching system. We needed a control scheme that ensures the proper operation of the CP in overload condition. We conducted lots of simulation experiments to evaluate the performance of the proposed overload control scheme and concluded that the proposed overload control scheme is very effective for a distributed architecture.

• The Journal of Korea Robotics Society
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• v.6 no.2
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• pp.147-155
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• 2011

This paper presents an edutainment robot for young children. The edutainment robot called 'Mon-e' has developed by the Central R&D Laboratory at KT. The main services of the Mon-E robot are autonomous moving service, object card and story book telling service and videophone service. The RFID technology was introduced for easy interface to young children. The face of Mon-E robot is mounted with an RFID reader. The RFID tag is pasted on story book and object card. If you approach a book or an object card to the face of Mon-E, the Mon-E robot recognizes the identified code and plays its service. In autonomous moving, if the Mon-E robot meets obstacles, it moves back and turns left or right or half rotation. In videophone service, if young children approach an RFID card to the Mon-E, the Mon-E can make a call to the specific number, which is contained in the RFID card. The developed Mon-E robot has tested in real world environment and is evaluated young children and their parents. In the result of evaluation, the feeling of satisfaction was high to main services of Mon-E robot.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.20 no.2
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• pp.163-174
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• 2016

In this paper, we propose an optimal choice scheme to determine the best option among comparable options whose current expectations are all the same under the condition that an investor has a confidence in the future value realization of underlying assets. For this purpose, we use a path-averaged option as our base instrument in which we calculate the time discounted value along the path and divide it by the number of time steps for a given expected path. First, we consider three European call options such as vanilla, cash-or-nothing, and asset-or-nothing as our comparable set of choice schemes. Next, we perform the experiments using historical data to prove the usefulness of our proposed scheme. The test suggests that the path-averaged option value is a good guideline to choose an optimal option.

• Journal of the Korean Society for Library and Information Science
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• v.29
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• pp.141-172
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• 1995

The main objective of this study is to analyse the information flows and representations which is shown at the displays of the user-OPACs interfaces in the 5 academic library automation systems. The findings made in the study are summarized as follows: 1) The interactive styles of that displays are based on the menu selection style. 2) The structures of information flow on that displays are the compound structure which is basically made of the network, the binary, and the pop-up structures. 3) The elements of the displays are consisted with the fields concerning the database name, the current working area, the indicator, the menu, the exit, the prompt and the system message. 4) The essential entries of the main menus are Book, Periodical. and Thesis. 5) The important languages of the command language styles are Search, Display, Print, Help, and End. 6) The elements of the display structures for the retrieval are the retrieving key, the Boolean operators, and the exit. 7) The major retrieving keys are Title, Author, Subject name, Call Number, and Publisher. 8) The marks of Boolean operators on the retrieval displays is different among the systems each other.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4A
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• pp.393-401
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• 2006

Energy consumption is an important design parameter for battery-operated embedded systems. Dynamic power management is one of the most well-known low-power design techniques. This paper proposes an online realtime scheduling algorithm, which we call energy-aware realtime scheduling using slack stealing (EARSS). The proposed algorithm gives the highest priority to the task with the largest degree of device overlap when the slack time exists. Scheduling result enables an efficient power management by reducing the number of state transitions. Experimental results show that the proposed algorithm can save the energy by 23% on average compared to the DPM-enabled system scheduled by the EDF algorithm.