• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.364-366
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• 2004

WDR(Wide Dynamic Range) camera has been recently introduced to provide good detailed information for the extremely dark or white area. The double shuttering camera acquires two pictures with different exposure time for the same scenes so that each image has its unique information as for the bright/dark area. Those images are combined internally to produce an image with enough details. This paper proposes a NN based method to control the exposure time of the WDR camera. Our goal is to develop a method to automatically control the exposure time like human decision. A neural model is trained to determine to increase/decrease shutter time for the given situation. The ability to adapt to unknown situation is shown for the sample cases.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.4
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• pp.336-339
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• 2001

The ozone forecasting systems have many problems because the mechanism of the ozone concentration is highly complex, nonlinear, and nonstationary. Especially, the performance of the prediction results in the high-level ozone concentration are not good. This paper describes the modeling method of the ozone prediction system using neuro-fuzzy approaches and fuzzy clustering methods. The dynamic polynomial neural network (DPNN) based upon a typical algorithm of GMDH (group method of data handling) is a useful method for data analysis, the identification of nonlinear complex systems, and prediction of dynamical systems.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.3
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• pp.67-80
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• 2005

This paper deals with a container terminal where containers are discharged by quay cranes from a ship and transported by a fleet of vehicles to the terminal yard. Since container terminals are fully utilized in general, It is important to increase terminal throughput by discharging the containers out of the ship without any delay, At the operational level, it should be decided which vehicle transports which container. The vehicle dispatching decision should be carefully made since the container discharging time increases when the quay cranes wait idle for the vehicles. This paper presents vehicle dispatching heuristics with the objective of minimizing the total container discharging time. The heuristics are based on a network flow model and a look-ahead concept. Through some experiments, the performance of the dispatching methods is evaluated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3C
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• pp.257-267
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• 2009

This paper presents a training method for neural networks and the employment of MSE (mean scare error) values as the basis of a decision regarding the identity claim of a speaker in a recurrent neural networks based speaker verification system. Recurrent neural networks (RNNs) are employed to capture temporally dynamic characteristics of speech signal. In the process of supervised learning for RNNs, target outputs are automatically generated and the generated target outputs are made to represent the temporal variation of input speech sounds. To increase the capability of discriminating between the true speaker and an impostor, a discriminative training method for RNNs is presented. This paper shows the use and the effectiveness of the MSE value, which is obtained from the Euclidean distance between the target outputs and the outputs of networks for test speech sounds of a speaker, as the basis of speaker verification. In terms of equal error rates, results of experiments, which have been performed using the Korean speech database, show that the proposed speaker verification system exhibits better performance than a conventional hidden Markov model based speaker verification system.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1039-1042
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• 2008

Wireless sensor networks enable pervasive, ubiquitous, and seamless communication with the physical world. In this paper, we are concerned for clustering sensors into groups, so that sensors communicate information only to cluster heads and then the cluster heads communicate the aggregated information to the sink node, that the network can save energy. In this paper, we propose the algorithm for electing the cluster head and fuzzy registration of cluster head in a dynamic cluster wireless sensor networks. For making decision for clustering we will use fuzzy logic system. In simulation, we could achieve power regulation of total consumption and also the stabilization of the networks energy efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1146-1165
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• 2013

Collaborative awareness between persons with various smart multimedia devices is a new trend in the Internet of Things (IoT). Because of the mobility, randomness, and complexity of persons, it is difficult to achieve complete data awareness and data transmission in IoT. Therefore, research must be conducted on mobile-aware service models. In this work, we first discuss and quantify the social relationships of mobile nodes from multiple perspectives based on a summary of social characteristics. We then define various decision factors (DFs). Next, we construct a directed and weighted community by analyzing the activity patterns of mobile nodes. Finally, a mobile-aware service routing algorithm (MSRA) is proposed to determine appropriate service nodes through a trusted chain and optimal path tree. The simulation results indicate that the model has superior dynamic adaptability and service discovery efficiency compared to the existing models. The mobile-aware service model could be used to improve date acquisition techniques and the quality of mobile-aware service in the IoT.

• The Journal of Information Systems
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• v.6 no.1
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• pp.223-256
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• 1997

Since the business scales of retailing companies become to be very large and the number of items dealt increases explosively, automation of inventory management becomes one of the most important issues to solve in retailing industry. In order to accomplish this automation of inventory management, there must be a great need to a method which can perform real-time decision making on inventory control in an automatic fashion, while communicating with inventory information systems like POS system and automatic warehousing system. But even in this circumstance, there are also many obstructions to such automation like varying demands, limited capacity of warehouse and exhibition room, need for strategic consideration on inventory control, etc., in a real sense. Due to these reasons, it seems very difficult that most large-scaled retailing companies get fully automated inventory management system. To overcome those difficulties and reflect them into inventory control, we propose a automated inventory control methodology for retailing industry based on neural network and policy model. Especially, policy model is devised to deal with dynamic varying demands and using this model, strategic goals on inventory can be considered into inventory control mechanism. Our proposed approach is implemented in workstation and its performance is also empirically verified also against to real case of one of the major retailing firm in Korea.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.6
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• pp.2095-2110
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• 2015

This paper presents a design for a throughput-efficient online relay selection scheme for dual-hop multi-relay cooperative networks. Problems arise with these networks due to unpredictability of the relaying link quality and high time-consumption to probe the dual-hop link. In this paper, we firstly propose a novel probing and relaying protocol, which greatly reduces the overhead of the dual-hop link estimation by leveraging the wireless broadcasting nature of the network. We then formulate an opportunistic relay selection process for the online decision-making, which uses a tradeoff between obtaining more link information to establish better cooperative relaying and minimizing the time cost for dual-hop link estimation to achieve higher throughput. Dynamic programming is used to construct the throughput-optimal control policy for a typically heterogeneous Rayleigh fading environment, and determines which relay to probe and when to transmit the data. Additionally, we extend the main results to mixed Rayleigh/Rician link scenarios, i.e., where one side of the relaying link experiences Rayleigh fading while the other has Rician distribution. Numerical results validate the effectiveness and superiority of our proposed relaying scheme, e.g., it achieves at least 107% throughput gain compared with the state of the art solution.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2335-2341
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• 2009

High technique growth of modem times and high industrial facility in consequence of buildings demand for electric power of an extensive scale with stability supply and maintenance of high quality. But, power system always have risk of network contingency. When power system break out disturbance, it circumstantially happen like uncontrolled loss of load developing from of cascading. Severely which would be raised wide area blackout, plan to prevent, which make stability through a little of load shedding and multi-level UnderVoltageLoadShdding should work. This paper presents target, sensitivity of bus voltage have choose appropriating load shedding location and load shedding decision making logic with considering rate of change of voltage have studied multi-level under voltage load shedding scheme. Calculation of rate of change of voltage applied method of least square. As a result, we are studied an dynamic analysis of 2008 summer peak data. We have been known that network analysis is a little development and developing UnderVoltageLoadShedding scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4543-4552
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• 2010

A leader is a special process who roles as the coordinator within multiple processes of a group. In a distributed system, leader election is the procedure of electing a coordinator. This is a very important issue for building fault-tolerant distributed systems. When two normal mobile ad hoc networks are merged, there are two leaders. This violates the safety property, so a mechanism to detect and handle are required. In mobile ad hoc distributed computing system, we propose a leader competition protocol and to prove the temporal logic to it. This solution is based on the group membership detection algorithm.