• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.319-322
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• 2002

Distance relay is operated in calculating line impedance. It can be worked accurately in overhead line. However, power cables or combined transmission lines need compensation for calculated impedance because cable systems have sheaths, grounding wires and sheath voltage limiters(SVLs) Neuro-fuzzy can be viewed either as a fuzay system, a neural network or fuzzy neural network and it can estimate the location of the fault accurately. In this paper, fault section and fault location can be classified and estimated in neuro- fuzzy inference system and neural network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1587-1605
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• 2015

Mobile cloud computing (MCC) combines mobile Internet and cloud computing to improve the performance of applications. In MCC, the data processing and storage for mobile devices (MDs) is provided on the remote cloud. However, MCC faces the problem of energy efficiency caused by randomly varying channels. In this paper, by introducing the Lyapunov optimization method, we propose a combined service subscription and delivery (CSSD) algorithm that can guide the users to subscribe to services reasonably. This algorithm can also determine whether to deliver the data and to whom data is sent in the current time unit based on the queue backlog and the channel state. Numerical results validate the correctness and effectiveness of our proposed CSSD algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.7
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• pp.1477-1486
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• 1997

Conventioally the decoding methods and the design of coset codes for burst synchronization and error detection have been based on the concept that slips occuring to the right or to the left with respect to a reference timing are corrected. In this paper we newly approach to the design of coset codes relying on the condition that only a single code word can exists in an observation interval, which provides an extentended view on the conventional approach. A theorem concerning the condition is presented. A combined burst synchronization and error detection system with maximum slip correction capability have been devised based on the theorem and a detection method is falsely accepted in the presented of channel errors. The false acceptance probabilities of the system are derived and its performance is analyzed through computer computation using the derived results.

• Journal of electromagnetic engineering and science
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• v.4 no.1
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• pp.1-7
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• 2004

In this paper the Individual tap - Least Mean Square(IT-LMS) algorithm is applied to the adaptive multipath channel equalization using hybrid-type Genetic Algorithm(GA) for achieving lower minimum Mean Squared Error(MSE). Owing to the global search performance of GA, LMS-type equalizers combined with it have shown preferable performance in both global and local search but those still have unsatisfying minimum MSE performance. In order to lower the minimum MSE we investigated excess MSE of IT-LMS algorithm and applied it to the hybrid GA equalizer. The high convergence rate and lower minimum MSE of the proposed system give us reason to expect that it will perform well in practical multi-path channel equalization systems.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.12
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• pp.713-721
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• 2003

This paper analyzes the switching overvoltage occurred on 345kV underground power cable system as well as combined transmission system using EMTP. Cable length and closing time, preinsertion resistance have effect on switching overvoltage. Therefore, this paper analyzes the switching overvoltage occurred on conductor and sheath with change of those parameters. Specially, the cross bonding position becomes discontinuity point because of the difference between surge impedance of metal sheath and that of lead cable. Thus, the transmission and the reflection of traveling wave complexly occur at this connection point. According to these influences, voltage between sheath and earth as well as voltage between joint boxes rise. Time to crest point of switching overvoltage is longer than lightning overvoltage. Even though the voltage induced by switching surge is smaller than lightning surge, that voltage may have serious effect on the metal sheath. Therefore, this paper also analyses the reduction effect of switching overvoltage when the preinsertion resistance of circuit breaker is considered.

• Proceedings of the Korea Society for Simulation Conference
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• 2000.11a
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• pp.142-149
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• 2000

Most of supply chain simulation models have been developed on the basis of discrete-event simulation. Since supply chain systems are neither completely discrete nor continuous, the need of constructing a model with aspects of both discrete-event simulation and continuous is provoked, resulting in a combined discrete-continuous simulation. Continuous simulation concerns the modeling over time of a system by a representation in which the state variables change continuously with respect to time. In this paper, an architecture of combined modeling for supply chain simulation is proposed, which presents the equation of continuous part in supply chain and how these equations are used supply chain simulation models. A simple supply chain model is demonstrated the possibility and the capability of this approach.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.2
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• pp.236-243
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• 1999

Aluminum/Freon-22 heat pipes were manufactured and tested which have a special wick geometry combining axial groove and screen mesh. There were 14 axial grooves in a cross-section and these were covered by two layers of 350 mesh screens to enhance the thermal performance. The performance test was conducted by varying the thermal load and tilt angle. Furthermore, the operation limits and overall heat transfer coefficient were investigated. The experimental results will be useful in a variety of applications, especially in design and manufacturing of a high-efficiency heat exchanger and energy recovery systems.

• Animal cells and systems
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• v.3 no.1
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• pp.69-72
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• 1999

A tandemly repeated DNA sequence was identified and characterized y the combined RAPD and FISH data from a total genomic DNA of Welsh onion (Allium fistulosum). A clone containing this repeating sequence was selected and sequenced. This repeating unit of 314 bp inserted into pAf 072 contained 54.1% adenine and thymine residues, and showed the primer sequence used, 5'-GAAACGGGTG-3', in both terminals of the sequence. Fluorescence in situ hybridization using this tandemly repeated sequence as a probe indicated that the detected sites were coincident with the major C-banded constitutive heterochromatin in the terminal regions of both arms of all 6 chromosomes.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.1
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• pp.1-7
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• 2008

In this paper, a MSS-NOVO method that combines the HMM composition method with a noise reduction method is proposed for speech recognition in noisy environments. This combined method starts with noise reduction with modified spectral subtraction (MSS) to enhance the input noisy speech, then the noise and voice composition (NOVO) method is applied for making noise adapted models by using the noise in the non-utterance regions of the enhanced noisy speech. In order to evaluate the effectiveness of our proposed method, we compare MSS-NOVO method with other methods, i.e., SS-NOVO, MWF-NOVO. To set up the noisy speech for test, we add White noise to KLE 452 database with different SNRs range from 0dB to 15dB, at 5dB intervals. From the tests, MSS-NOVO method shows average improvement of 66.5% and 13.6% compared with the existing SS-NOVO method and MWF-NOVO method, respectively. Especially our proposed MSS-NOVO method shows a big improvement at low SNRs.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.62
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• pp.1-10
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• 2001

The electronics industry is fast growing segment of manufacturing and service industries. It is important that the manufacturer develops a product with adequate life cycle, high quality, and low failure rate in the specified time period. Environmental Stress Screening(ESS) and burn-in are widely used in the electronic industry to assist in the elimination of early failure. In this research, we construct optimal cost model of combined ESS and burn-in under various warranty policy and establish optimal testing times for given environments. Also we conduct sensitivity analysis on various parameter. The results of this study are summarized as follows. Comparing free warranty policy to rebate warranty policy, optimal ESS time is longer under free warranty policy, and optimal burn-in time is longer under rebate warranty policy. Free warranty policy higher than rebate warranty policy in total cost.