• International Journal of Computer Science & Network Security
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• v.23 no.6
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• pp.127-139
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• 2023

Numerous genuine issues, for example, financial exchange expectation, climate determining and so forth has inalienable arbitrariness related with them. Receiving a probabilistic system for forecast can oblige this dubious connection among past and future. Commonly the interest is in the contingent likelihood thickness of the arbitrary variable included. One methodology for expectation is with time arrangement and auto relapse models. In this work, liner expectation technique and approach for computation of forecast coefficient are given and likelihood of blunder for various assessors is determined. The current methods all need in some regard assessing a boundary of some accepted arrangement. In this way, an elective methodology is proposed. The elective methodology is to gauge the restrictive thickness of the irregular variable included. The methodology proposed in this theory includes assessing the (discretized) restrictive thickness utilizing a Markovian definition when two arbitrary factors are genuinely needy, knowing the estimation of one of them allows us to improve gauge of the estimation of the other one. The restrictive thickness is assessed as the proportion of the two dimensional joint thickness to the one-dimensional thickness of irregular variable at whatever point the later is positive. Markov models are utilized in the issues of settling on an arrangement of choices and issue that have an innate transience that comprises of an interaction that unfurls on schedule on schedule. In the nonstop time Markov chain models the time stretches between two successive changes may likewise be a ceaseless irregular variable. The Markovian methodology is especially basic and quick for practically all classes of classes of issues requiring the assessment of contingent densities.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.115-124
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• 2002

The optimum design of auto-catalyst needs a good compromise between the pressure drop and flow distribution in the monolith. One of the effective methods to achieve this goal is to use the concept of radially variable cell density. However, there has been no study of evaluating the usefulness of this method on light-off catalyst. We have computationally investigated the effectiveness of variable cell density technique applied to the light-off catalyst using a three-dimensional integrated CFD model. in which transient chemical reacting calculations are involved. Computed results show that variable cell density technique can reduce the accumulated emissions of CO and HC during the early 100sec of FTP cycle by 86.78 and 80.87%, respectively, The effect of air-gap between the monoliths has been also examined. It is found that air-gap has a beneficial effect on reducing pressure drop and cold-start emissions.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.8
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• pp.677-682
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• 2014

One of the most important element technologies for achieving high-precision in machine tool spindle systems is preload technology for the bearing of spindle systems. Fixed position preload, constant pressure preload, conversion preload and variable preload methods have been applied for the spindle systems. In this study, a new variable preload method using centrifugal force and rubber pressure is used for reducing installation costs through simplifying its structure. The main objective of the work is the verification of the operability in a preload device using the rubber pressure by the finite element analysis. It is shown that the variable preload device proposed in this study is applicable to high speed machine tool spindles.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.261-266
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• 2003

The growth behavior of the transverse crack, which was one of the most dangerous damages of rail defects, was investigated under mode I and mixed mode loading in rail steel. In the case of variable amplitude loading, the fatigue crack growth behavior was discussed using characteristic stress intensity factor ranges ${\Delta}_{rms}$. In addition, characteristic comparative stress intensity factor ranges ${\Delta}_{V,rms}$ was proposed to evaluate the quantitative effects of the variable amplitude under mixed mode loading. As a result, crack growth rate under variable amplitude loading was faster than that under constant amplitude loading.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.3
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• pp.28-36
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• 2002

The continuously variable transmission (CVT) mechanism considered here is the output coupled type which combines the functions of a 2K-H I type differential gear unit and a V-belt type continuously variable unit (CVU). One shaft of the CVU is connected directly to the output shaft and another shaft of it is linked to the differential gear unit. It is shown that some fundamental relations (speed ratios, power flows and efficiencies) for twelve mechanisms previously described are valid by various experimental studies, six of them produce a power circulation and the others produce a power split. Parametric analysis is carried out in relation to the efficiency, speed ratio and power ratios in order to assist in the design of an optimum configuration. Some useful properties associated with power flow modes also are discussed in the output coupled type continuously variable transmission.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1633-1637
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• 2008

In this study, we developed 3D MLS-based variable-node elements for easy meshing. These elements should be derived from 2D MLS-based variable-node elements and would be utilized as key elements of easy meshing technique we proposed. Using developed 3D MLS-based variable-node elements, we demonstrated several examples having complex configuration compared with conventional meshing technique. Moreover, we compared with the stress results of our model and conventional one.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.8
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• pp.698-707
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• 1990

As proved in many studies, LZW algorithm, one of the widely used compression schemes, itself contains some types of redundancy, In this paper, VV-LZW coompression algorithm is presented which encodes variable length source string into variable size codewords and reduces such redundancies that the original LZW scheme has. Experiment shows that this scheme especially has good initial compression efficiency and produces more complex output strings than the original LZW. This scheme is very useful to the data compression with small size, and the applications such as crytography.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.4
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• pp.277-281
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• 2006

Cyber counseling, one of the most compatible type of consultation for the information society, enables people to reveal their mental agonies and private problems anonymously, since it does not require face-to-face interview between a counsellor and a client. However, there are few cyber counseling centers which provide high quality and trustworthy service, although the number of cyber counseling center has highly increased. Therefore, this paper is intended to enable an appropriate consultation for each client by analyzing client propensity using Bayesian variable selection. Bayesian variable selection is superior to stepwise regression analysis method in finding out a regression model. Stepwise regression analysis method, which has been generally used to analyze individual propensity in linear regression model, is not efficient since it is hard to select a proper model for its own defects. In this paper, based on the case database of current cyber counseling centers in the web, we will analyze clients' propensities using Bayesian variable selection to enable individually target counseling and to activate cyber counseling programs.

• Communications for Statistical Applications and Methods
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• v.29 no.6
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• pp.629-640
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• 2022

Variable selection is one of the most crucial tasks in supervised learning, such as regression and classification. The best subset selection is straightforward and optimal but not practically applicable unless the number of predictors is small. In this article, we propose directly solving the best subset selection via the genetic algorithm (GA), a popular stochastic optimization algorithm based on the principle of Darwinian evolution. To further improve the variable selection performance, we propose to run multiple GA to solve the best subset selection and then synthesize the results, which we call ensemble GA (EGA). The EGA significantly improves variable selection performance. In addition, the proposed method is essentially the best subset selection and hence applicable to a variety of models with different selection criteria. We compare the proposed EGA to existing variable selection methods under various models, including linear regression, Poisson regression, and Cox regression for survival data. Both simulation and real data analysis demonstrate the promising performance of the proposed method.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.166-175
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• 1998

When we make a speaker adapted model using MAPE (maximum a posteriori estimation), the adapted model has one mixture in each state. This is because we cannot estimate a number of a priori distribution from a speaker-independent model in each state. If the model is represented by one mixture in each state, it is not well adadpted to specific speaker because it is difficult to represent various speech informationof the speaker with one mixture. In this paper, we suggest the method using several mixtures to well represent various speech information of the speaker in each state. But, because speaker-specific training dat is not sufficient, this method can't be used in every state. So, we make the number of mixtures in each state variable in proportion to the number of frames and to the determinant ofthe variance matrix in the state. Using the proposed method, we reduced the error rate than methods using one branch in each state.