• The Korean Journal of Applied Statistics
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• v.24 no.6
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• pp.1095-1102
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• 2011

The classical two-period, two-sequence crossover design is no longer sufficient to assess various demands in a bioequivalence study. For instance, to estimate the within-subject and between-subject variances of test and reference formulations separately, it is necessary to use a replicate design in which each subject receives at least the reference formulation in two periods. Several designs were studied to satisfy the demands. It is provided a unified Bayesian approach applicable to those study designs. The benefit of the method in the bioequivalence study is discussed.

• Journal of Oral Medicine and Pain
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• v.33 no.2
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• pp.167-176
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• 2008

We analyzed 121 age estimation clients who had visited oral medicine clinic, Chonbuk National University Hospital, from January 2000 to December 2007 to evaluate its characters in Jeonllabuk-do. The obtained results were as follows : 1. There was distinct difference in sex distribution(Male : 58.7%, Female : 41.3%) and more than half percent(55.4%) was over 50's. 2. The difference between registered and alleged age was the most in more than 5 years, and most of them were over 50's. 3. There were more clients who wanted to increase their age than to decrease and was no prominent difference in sex. Age estimation clients who wanted to decrease their age were predominant under 10 years old and in 20's, and those wanted to increase were predominant in 10's and over 30's. 4. The most reasons to correct age were related to welfare benefit. The purpose of age estimation was different according to each age groups; welfare benefit was the most over 50's, occupation in 40's and 50's, friendship in 30's and 40's, sibling-related in 50's, employment in 10's and 20's. 5. Age was estimated by the attrition of permanent tooth and pulp/tooth ratio from 20 years, root apex closure for 10's and calcification of permanent tooth under 10 years old. In cases that were difficult to estimate by use of the attrition of permanent tooth and pulp/tooth ratio, age was estimated by missing time of permanent tooth and the change of mandibular angle with age. 6. The estimated ages were close to alleged age in 77.7% of clients but the rest(22.3%) was close to registered age.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.12
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• pp.4099-4113
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• 2022

In this paper, we propose improved maximum access delay time, noise variance, and power delay profile (PDP) estimation schemes for orthogonal frequency division multiplexing (OFDM) system in multipath fading channels. To this end, we adopt the approximate maximum likelihood (ML) estimation strategy. For the first step, the log-likelihood function (LLF) of the received OFDM symbols is derived by utilizing only the cyclic redundancy induced by cyclic prefix (CP) without additional information. Then, the set of the initial path powers is sub-optimally obtained to maximize the derived LLF. In the second step, we can select a subset of the initial path power set, i.e. the maximum access delay time, so as to maximize the modified LLF. Through numerical simulations, the benefit of the proposed method is verified by comparison with the existing methods in terms of normalized mean square error, erroneous detection, and good detection probabilities.

• Journal of Information Technology Applications and Management
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• v.21 no.4_spc
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• pp.345-359
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• 2014

Technological, policy and economic factors are both important variables in maximizing the results of a national R&D program and key indicators in evaluating an R&D program's eligibility for financial support. Economic analysis, in particular, is used when selecting R&D programs, setting priorities, and estimating economic effects. This paper examines a series of methodological issues related to the economic analysis of national R&D programs within the framework of the current preliminary feasibility evaluation system, and proposes alternative approaches to each of the issues discussed. The issues include the definition of R&D valuation and establishment of valuation factors; estimation of sales attributable to R&D investment; assessment of the total economic value of R&D as intellectual assets; estimation of R&D benefits and assumption of related to sales; and the application of discount rates based on the weighted average cost of capital. Finally, this study presents directions for future research on analytical procedures and methods of improving the reliability of the results of economic analysis within the national technology planning system.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.164-169
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• 2009

An RFID system consists of radio frequency tags attached to objects that need to be identified and one or more electromagnetic readers. Unlike the traditional bar code system, the great benefit of RFID technology is that it allows information to be read without requiring contact between the tag and the reader. For this contact-less feature, RFID technology in the near future will become an attractive alternative to bar code in many application fields. In almost all the 13.56MHz RFID systems, FSA (Framed Slot ALOHA) algorithm is used for identifying multiple tags in the reader's identification range. In FSA algorithm, the tag identification time and system efficiency depend mainly on the number of tags and frame size. In this paper, we propose a tag number estimation scheme and a dynamic frame size allocation scheme based on the estimated number of tags.

• Smart Structures and Systems
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• v.15 no.3
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• pp.735-749
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• 2015

The major difficulty of using Bayesian probabilistic inference for system identification is to obtain the posterior probability density of parameters conditioned by the measured response. The posterior density of structural parameters indicates how plausible each model is when considering the uncertainty of prediction errors. The Markov chain Monte Carlo (MCMC) method is a widespread medium for posterior inference but its convergence is often slow. The differential evolution adaptive Metropolis-Hasting (DREAM) algorithm boasts a population-based mechanism, which nms multiple different Markov chains simultaneously, and a global optimum exploration ability. This paper proposes an improved differential evolution adaptive Metropolis-Hasting algorithm (IDREAM) strategy to estimate the posterior density of structural parameters. The main benefit of IDREAM is its efficient MCMC simulation through its use of the adaptive Metropolis (AM) method with a mutation strategy for ensuring quick convergence and robust solutions. Its effectiveness was demonstrated in simulations on identifying the structural parameters with limited output data and noise polluted measurements.

• Korean Journal of Hydrosciences
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• v.5
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• pp.57-70
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• 1994

For the system benefit optimization by considering risk or reliability from a multiple reservoir system using the Monte Carlo Technique, Many stochastically generated inflow series have to be used for the system analysis. In this study, the stochastically generated inflow series for the multiple reservoir system operation are preprocessed according to the considering system objectives and operating time periods. Through this procedure, several representative inflow series which have discrate probability levels and operation horizons are selected among the thousands of generated inflows. Then a deterministic optimization technique is applied to the hydropower energy estimation from the Han River Reservoir System which considers five reservoirs in this study. It took much less computational requirements than using the original Morite Carlo Technique, even though estimated result was almost similar.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.405-406
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• 2002

서울시 대기오염물질의 배출량 중 맡은 부분이 자동차 배출물질에 의한 것임은 잘 알려진 사실이다. 특히 이 중 디이젤 연료를 사용하는 자동차 배출량의 기여도가 가장 큰 것으로 알려져 있다 따라서 환경부에서는 디이젤의 대체 연료인 천연 가스를 시내 버스에 적용하여 점차적인 보급을 계획 중에 있다. 청정연료로 알려진 천연가스는 특히 입자상 물질이나 오존 등의 감소에 큰 역할을 하는 것으로 알려져 있다. (중략)

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1749-1752
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• 2005

For online high accurate reconstruction of an object from an visual information, a linear reconstruction method for multiple images is popular. Basically this method needs many cameras or many different screen shots from different view points. This method, however, has the benefit of less calculation and is adequate for a real time application by comparing other popular method. In this paper, online reconstruction system using more than three cameras is treated. An evaluation method of cameras' position, and of the number is derived for the linear reconstruction method. To decrease errors that are caused from skew of lens, positional error between corresponding points is taken into consideration on the evaluation. The proposed evaluation method enables estimation of the adequate number of cameras and then of feasible view locations. Additionally, repeating search of epipolar lines enables estimation of the hidden point. Comparing with result of an average error analysis, it was confirmed that the proposed methods works effectively.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.49-57
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• 2001

Since the value of travel time savings is found to be the most important benefit of transportation projects, considerable work has been done on the estimation of the value of travel time in many countries, including U. S. A. England, Australia, and Korea. And majority of them was mode choice model. This paper estimated the VTTS for commuters using traffic regulation obedience market model, which had not been applied in any previous studies, and survey data, which was obtained using Contingent Valuation Method. The result meets our expectations.