• Journal of Navigation and Port Research
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• v.36 no.3
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• pp.169-173
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• 2012

In this paper, we propose an equalizer to minimize the inter-symbol interference when PSSK(Phase Silence Shift Keying) technique is applied to the low power underwater acoustic communication. PSSK is a QPSK(Quadrature Phase Shift Keying) modulation combined with PPM(Pulse Position Modulation), and it was proposed for low power communication. However, it has poor performance due to delay spread of underwater channel. In this paper, we propose a decision feedback equalizer to minimize the error in PSSK receiver. The sea trial was performed to evaluate the performance of the proposed method. In the result, the BER of PSSK was $4.36{\times}10^{-2}$ before the equalizer was applied, but the BER of PSSK was $3.95{\times}10^{-4}$ after the proposed equalizer was applied.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5C
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• pp.452-460
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• 2003

In this paper, an equalizer(RNE) using nonlinear multilayer combining techniques in Bayesian equalizer with a structure of radial basis function network is proposed in order to simplify the structure and enhance the performance of the equalizer(RE) using a radial basis function network. The conventional RE Produces its output using linear combining the outputs of the basis functions in the hidden layer while the proposed RNE produces its output using nonlinear combining the outputs of the basis function in the first hidden layer. The nonlinear combiner is implemented by multilayer perceptrons(MLPs). In addition, as an infinite impulse response structure, the RNE with decision feedback equalizer (RNDFE) is proposed. The proposed equalizer has simpler structure and shows better performance than the conventional RE in terms of bit error probability and mean square error.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.560-569
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• 2005

This paper proposes an algorithm for transmit antenna selection in a multi-input multi-output(MIMO) spatial multiplexing system with per antenna rate control(PARC) and an ordered successive interference cancellation (OSIC) receiver. The active antenna subset is determined at the receiver and conveyed to the transmitter using feedback information on transmission rate per antenna. We propose a serial decision procedure consisting of a successive process that tests whether antenna selection gain exists when the antenna with the lowest pre-processing signal to interference and noise ratio(SINR) is discarded at each stage. Furthermore, we show that 'reverse detection ordering', whereby the signal with the lowest SINR is decoded at each stage of successive decoding, widens the disparities among fractions of the whole capacity allocated to each individual antenna and thus maximizes a gain of antenna selection. Numerical results show that the proposed reverse detection ordering based serial antenna selection approaches the closed-loop MIMO capacity and that it induces a negligible capacity loss compared with the heuristic selection strategy even with considerably reduced complexity.

• Management & Information Systems Review
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• v.32 no.3
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• pp.43-59
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• 2013

The most important thing in training of organization is that how effectively it can be made most of the performance among the staff. It will be useless if the knowledge which gaining after training can not be applied. Therefore the transfer of learning is studied since it is important for decision of training. We studied the factors of transfer of learning and carried out a survey targeting the public officials of Gangwon province with the factors we made a study. We define the factor of both promoted and interrupted in training and suggest the way of improving it. The first, the modeling of competency can stimulate the desire of achievement and complete a course of training among staff of organizations. The second, the construction of training program and organizational culture just for Gangwon province can increase the satisfaction of training among the learners. The third, the establishment of management system after training can reinforce the capability making use of train. The sharing of each information with boss at the office can help to stimulate the function of feedback after training as well.

• Journal of The Korean Association of Information Education
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• v.14 no.3
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• pp.319-328
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• 2010

Computer programming education gives students a chance to use computers independently and actively. This plays a very positive role in acquiring higher cognitive skills such as mathematical skills and creative logical thinking. Thus the purpose of this study is to measure the degrees of students' problem-solving abilities using MCU programming kits based on the ICT Education Guide. The experiment confirms that programming classes using MCU kits have a more positive effect on the students problem-solving abilities than do those using the existing computer textbooks. The sub-constituents of problem-solving abilities - problem recognition, information gathering, analysis, diffuse thinking, decision-making, planning, execution, evaluation and feedback - also show significant statistical differences. Therefore, we can conclude that programming classes using MCU kits are very effective in advancing problem-solving abilities.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.115-120
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• 2017

Online reputation systems for social network services(SNS) aggregate users' feedback and estimate the reputation of contents or providers. The aim of this research is to enhance credibility of the online reputation system on the SNS based e-Commerce(we called it as social commerce). SNS users usually refer to evaluations from other users who bought the products before. Most social commerce sites provide reputation system to help their customer make a decision, but sometimes we can't believe the reputation because the reputation is too subjective and the seller can deceive the customer for sales promotion. Threrefore, we usually use just the average value to show the general customer's evaluation result. We applied collaborative filtering method to give more weighting to the users who have evaluated correctly in the past. As a result, we could get more accurate evaluation results by considering each customers' credibility value that was computed by collaborative filtering.

• Journal of the military operations research society of Korea
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• v.34 no.1
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• pp.61-77
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• 2008

Data Envelopment Analysis(DEA) is a promising methodology to evaluate the relative efficiency of the decision-making units. We have compared the efficiency of six electric power generation companies in Korea using DEA. The analysis results by input-oriented CCR and BCC models are summarized as follows: first, different results were acquired between using input factors as total capacity of generators and as sub-totals of generator capacity based on primary energy sources. It is the result influenced by input factors which are characterized by the proportion of fixed costs(generating facilities) and variable costs(generation costs for primary energy), Second, the efficiency will be increased if the input factors selected, according to primary energy sources discussed in this research, are used during long-term expansion of electric power capacity plans. It is expected that this approach can give a feedback for management of electric power generation companies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2094-2100
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• 2014

The performance of underwater acoustic communication system is sensitive to the inter-symbol interference due to delay spread develop of multipath signal propagation. Thus, it is necessary technique of equalizer and channel code to eliminate inter-symbol interference. In this paper, underwater acoustic communication system were analyzed by experiment using these techniques on the Kyeong-chun lake, Munkyeong City. Based on the results of experiment, we confirmed that the performance of the proposed iterative BCJR equalization method is improved by increasing the number of iterations.

• Proceedings of the Korean System Dynamics Society
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• 2001.10a
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• pp.3-14
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• 2001

Since 1998, government-led Korean venture business boom now proceeds into the stage of market-oriented venture business growth. At such a moment, this research is to clarify the relations between the success factors of Korean venture businesses, based on domestic and foreign documentary surveys and inquiry surveys over domestic venture businesses. This research starts from the necessity to overcome the limits of the existing researches by uni-dimensional probing research into success factors of Korean venture businesses and to manifest the multi-dimensional relations between the success factors from the various viewpoints. And this research adopts System-Dynamics methodology to manifest and utilize relations among those factors, avoiding the existing metrical approaches. This research can be called a new approach to the current ecosystems of Korean venture in which whether venture businesses success in Korea is considered to depend on the list on the stock market. For this, this research implemented verification analysis through the simulations of each factor at various levels to build causality map which clarifies the causality of success factors of venture businesses through the System-Dynamics methodology and to utilize it as a way of supporting tool for decision-making of venture businesses. This research will be able to suggest the reactions depending on various internal and external situations. This research tried to manifest the causality map of each factor on the basis of inquiry surveys and documentary surveys to verify feedback among each factor by the SD methodology. This research will be a basis bolster up the still fragile substructure of venture businesses through an efficient analysis framework using the verification of SD methodology and resulting outcomes from this research.

• The Korean Journal of Franchise Management
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• v.11 no.4
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• pp.45-57
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• 2020

Purpose: The purpose of this study is to determine the importance and priority arising from the relationship between MRO-office supplies franchisor ("franchisor") and franchisees through an in-depth investigation. In particular, with respect to the MRO-Office franchise industry, we would like to make meaningful contributions in the decision-making process by comparing and contrasting factors that affect the importance and priority of communication, conflict, support and satisfaction through AHP analysis. Research design, data, and methodology: After completion of AHP analysis, the study will also identify factors in order of priority and factors of importance between the franchisor and franchisees. Another purpose of this study is to evaluate and propose business relationship strategies between the franchisor and franchisees. Through AHP analysis, this study will facilitate the relationship between the franchisor and franchise, and determine the factors of importance and factors in order of priority. Result: This study evaluates the differences and priorities of the two groups arising from the relationship between the franchisor and the franchisees through AHP analysis after separately analyzing the franchisor. In this study, the franchisees find that communication is the most important factor, then support as the second most important factor between the two groups. In contrast, the franchisor finds that support is the most important factor followed by communication between the two groups. Conclusions: This analysis demonstrates the discrepancy in evaluating important factors from the perspectives of the franchisor and the franchisees. The largest discrepancy between the franchisor and franchisees comes from an information system related to communication factors. This effectively means that the franchisor has an understanding of this inadequate information system on the part of franchisees but this understanding is not deemed an important factor. The franchisees recognize and focus on the need to obtain feedback from the franchisor regarding management improvement as the most important factor rather than the ability of the franchisor to guide them through the franchisees' operations. To this end, the franchisor should be more flexible in dealing with the problem of improving the work required by the franchisees. For this study, a survey was conducted on employees of MRO-office supplies franchisor, franchisees, and employees and completed based on AHP analysis.