• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1290-1294
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• 2004

In this study, new stochastic point rainfall models which can consider the correlation structure between rainfall intensity and duration are developed. In order to consider the negative and positive correlation simultaneously, the Gumbels type-II bivariate distribution is applied, and for the cluster structure of rainfall events, the Neyman-Scott cluster point process is selected. In the theoretical point of view, it is shown that the models considering the dependent structure between rainfall intensity and duration have slightly heavier tail autocorrelation functions than the corresponding independent mode]s. Results from generating long time rainfall events show that the dependent models better reproduce historical rainfall time series than the corresponding independent models in the sense of autocorrelation structures, zero rainfall probabilities and extreme rainfall events.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.1
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• pp.31-37
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• 1985

An interesting area of application which makes use of the unique features of the walsh series is that on non-linear stochastic problems. In particular, some success has been obtained in improving the efficiency of signal detection for those transducers which are essentially non-linear in operation. The set of harmonically-related nonorthogonal triangle waves is shown to form a basis apanning the same function space representable by fourier(trigonometric) series. A method for generating nonorthogonal bases for signal representation is presented tailor-made basis function can be used for specific purposes. Fundamental proofs of the basis properties of the representation are examined along with examples illustrating the techniques and computer simulation.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.7
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• pp.525-530
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• 2004

A classifier was constructed by using a generalized regression neural network (GRU) and random generator (RG), which was applied to classify DNA sequences. Three data sets evaluated are eukaryotic and prokaryotic sequences (Data-I), eukaryotic sequences (Data-II), and prokaryotic sequences (Data-III). For each data set, the classifier performance was examined in terms of the total classification sensitivity (TCS), individual classification sensitivity (ICS), total prediction accuracy (TPA), and individual prediction accuracy (IPA). For a given spread, the RG played a role of generating a number of sets of spreads for gaussian functions in the pattern layer Compared to the GRNN, the RG-GRNN significantly improved the TCS by more than 50%, 60%, and 40% for Data-I, Data-II, and Data-III, respectively. The RG-GRNN also demonstrated improved TPA for all data types. In conclusion, the proposed RG-GRNN can effectively be used to classify a large, multivariable promoter sequences.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.100-102
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• 2001

This paper resents digital controller of emergency power generator system. The controller offers an integrated alternative for Genset control, metering and remote monitoring. Proposed controller used 80c196kc one chip microprocessor for digital control, it measures parameters of generator and provides output signals to control starting and stopping of generator. Additionally protection and alarm functions are considered to system stability. As almost parts of controller are embedded by digital microprocessor and FPGA techniques, the controller has a more flexible feature and an improvement of precision. The developed system has a big merit economically and is suitable for any kW size generator.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2322-2324
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• 2002

Korea Water Resources Corporation (KOWACO) operates nine hydroelectric power stations on the Han River, Nakdong River, Geum River & Seomjin River Areas. KOWACO will take the lead in improving the efficiency of water resources supply in this parer, KOWACO Generation Intergrated Operating System(GIOS) project will improve the generating plant, hydraulic structures, switchgear, and station controls, alarms and services for unmanned remote controlled operation by modern intergraed SCADA system. Mordern SCADA is used to cover all computer systems designed to perform the following main functions: - to collect data from industrial plant devices. - to process and perform calculations on the collected. - to present collected and derived data on displays on. - to accept commands entered by human operators and act on them such as sending control commands to plant devices.

• Journal of the Korean Ceramic Society
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• v.36 no.12
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• pp.1374-1380
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• 1999

The cause of Scond Harmonic Generation (SHG) in thermally poled silica glass is suggested basedon the electrical and dielectric relaxation measurements. The absorption currents as functions of time were measured for various types of silica glasses and analyzed by the theory of Space Charge Polarization. Space charge polarization occurs when an ionic conducting material is subjected to dc electric field with blocking electrode. Thermal poling performed to induce SHG in silica glass is basically identical to the process generating space charge polarization. Hence it was found that gene-ration removal reproduction and temperature dependence of SHG in poled silica is directly related to those of space charge polarization. It turned out that the fundamental parameters governing the SHG in poled silica are charge carrier concentration and mobility. Based on the theory of space charge polarization and experimental results of electrical rela-xation the method to increase the intensity of SHG is proposed.

• Nuclear Engineering and Technology
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• v.39 no.6
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• pp.717-724
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• 2007

A measurement-based time-domain noise simulation of radiation detector-preamplifier (front-end) noise in nuclear spectroscopy is described. The time-domain noise simulation was performed by generating "noise random numbers" using Monte Carlo's inverse method. The probability of unpredictable noise was derived from the empirical cumulative distribution function via the sampled noise, which was measured from a preamplifier output. Results of the simulated noise were investigated as functions of time, frequency, and statistical domains. Noise behavior was evaluated using the signal wave-shaping function, and was compared with the actual noise. Similarities between the response characteristics of the simulated and the actual preamplifier output noises were found. The simulated noise and the computed nuclear pulse signal were also combined to generate a simulated preamplifier output signal. Such simulated output signals could be used in nuclear spectroscopy to determine energy resolution degradation from front-end noise effect.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.859-862
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• 2002

In this paper, we consider a discrete-time two-phase queueing system. We derive the PCF of the system size and show that it is decomposed into two probabilty generating functions (PCFs), one of which is the PGF of the system size in the standard Ceo/G/1 queue. Based on this PGF, we present the performance measure of interest such as the mean number of customers In the system.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.142-148
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• 2011

Because currently available wireless technologies are not appropriate for wireless body area networks (WBANs), the IEEE 802.15.6 standard was introduced by the IEEE 802.15.6 Task Group to satisfy all the requirements for a monitoring system that operates on, in, or around the human body. In this work, we develop an analytical model for evaluating the performance of an IEEE 802.15.6-based WBAN under saturation condition and a noisy channel. We employ a three-dimensional Markov chain to model the backoff procedure as specified in the standard. Probability generating functions (PGFs) are used to compute the performance descriptors of the network. The results obtained from the analytical model are validated by simulation results. Our results indicate that under saturation condition, the medium is accessed by the highest user priority nodes at the vast majority of time while the other nodes are starving.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.1
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• pp.43-50
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• 1990

Using the trace mapping, we suggest the generating algorithm of non-binary GMW code sequences, to expand the ground field GF(2) into GF(p), p>2. And constructing non-binary GMW code sequences over GF(3) and GF(5), respectively, it is shown that they have the Hamming autocorrelation functions identical to m-sequences, non-linearity to improve the disadvantages of linearity, and balance properties.