• 대한통합의학회지
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• 제6권4호
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• pp.1-13
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• 2018

Purpose : The purpose of this study has been performed to find the relationship between seafarers' cumulative fatigue and stress by evaluating autonomic nervous functions and the results of surveys conducted using questionnaires. Methods : The subjects were seafarers working on various ships (home trade ships) of South Korea, who were healthy adults without any diseases, as confirmed through preliminary surveys were recruited through simple random sampling. A device that measures autonomic nervous functions by analyzing heart rate variability, which is also used often in clinical diagnoses and studies at universities, university hospitals, and general hospitals was used to measure the seafarers' cumulative fatigue and stress. Pearson's correlation analyses were also conducted to test the relationship between cumulative fatigue and stress measured by evaluating autonomic nervous functions and the results of surveys conducted with questionnaires. Results : There was no correlation between mean cumulative fatigue measured for each ship type and seafarers position through autonomic nervous functions evaluation and fatigue severity scale (FSS). There also was no correlation between the mean levels of stress measured for each ship type and seafarers position through autonomic nervous functions evaluation and survey scores of Korean occupational stress scale (KOSS). Conclusion : Therefore, in order to prevent man-made accidents in the sea among seafarers working with irregular port entry/departure schedules and under environments involving continued vibration, noises, and shaking, it is necessary to analyzed cumulative fatigue and stress scientifically and objectively, such as through autonomic nervous functions evaluation rather than through surveys.

• East Asian mathematical journal
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• 제18권2호
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• pp.219-224
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• 2002

Recently the theory of the multiple Gamma functions, which were studied by Barnes and others a century ago, has been revived in the study of determinants of Laplacians. Here we are aiming at evaluating the values of the multiple Gamma functions ${\Gamma}_n(\frac{1}{2})$ in terms of the Hurwitz or Riemann Zeta functions.

• ETRI Journal
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• 제32권6호
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• pp.965-968
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• 2010

In this letter, we derive the distribution functions of five ratios involving two correlated Gaussian random variables by using the rotation of Cartesian coordinates. The results can be used in evaluating the various probability performances of wireless communications systems.

• 대한수학회보
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• 제36권3호
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• pp.419-439
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• 1999

In this paper, we first develop a general formula for evaluating conditional abstract Wiener integrals of cylinder functions. we next use our formula to evaluate the conditional abstract wiener integral of various cylinder functions and then specialize our results to conditional Yeh-Wiener integrals to show that we can obtain the corresponding results by Park and Skoug. We finally obtain a Cameron-Martin translation theorem for conditional abstract Wiener integrals.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.157.6-157
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• 2001

We estimated various neuron functions to construct of engineering neurons, which are the combination of sigmoid, linear, sine, quadric, double/single bended, soft max/minimum functions. These combinations are estimated by the property on the potential surface between the learning points, calculation speed, and learning convergence; because the surface depends on the inference ability of a neuron system; and speed and convergence are depend on the efficiency on the points of engineering applications. After the evaluating discussions, we can select more appropriate combination than original sigmoid function´s, which is single bended function and linear one. The combination ...

• 산업경영시스템학회지
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• 제19권37호
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• pp.95-101
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• 1996

AHP is a competent methodology for multicriteria decision-making such as selection of technology in research laboratory, which requires the consideration of both quantitative and qualitative factors. This paper considers prioritization of technology alternatives using value functions for evaluating quantitative factors in AHP. Value functions are useful for the reducing questionars in this paper.

• 한국산림과학회지
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• 제97권1호
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• pp.71-76
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• 2008

본 연구에서는 공유림의 기능평가를 수행하기 위한 효율적인 평가단위를 결정하고자 하였다. 이러한 기능평가 단위로써 대유역, 중유역 그리고 소유역 단위의 평가방법을 고려하였다. 공유림의 경우 소유주체가 일원화 되지 않고 각 시 군의 행정권이 분산화 되어있으며, 산림의 규모가 영세한 특징이 있어 지번 단위의 평가방법은 공유림의 기능평가 단위로 적합하지 않다. 이에 따라 공유림 기능평가에 적합한 평가단위를 결정하기 위하여 집수량 기준에 따라 소 중 대유역으로 구분하고 각각에 대하여 산림기능평가를 수행하고 타당성을 검토하였다. 각 평가단위에 따른 기능평가 결과에서는 유역단위 기능 구분 시 공유림의 소규모 산지들을 일정 규모 이상의 산지로 집단화할 수 있는 장점이 있었다. 각 평단단위 별로는 소유역 단위에서 중 대유역 단위로 갈수록 산림의 기능이 지나치게 단순화 되는 경향이 나타나 소유역 단위의 기능구분이 공유림의 산림기능평가에 적합한 것으로 나타났다.

• 경영과학
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• 제17권3호
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• pp.161-180
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• 2000

The purpose of this paper is to propose an analytical model for evaluating Internet Web sites, that is comprehensive and flexible enough to accomodate different categories of Internet Web sites. This paper is intended to identify critical success factors of Internet Web sites to determine criteria for evaluating the Web sites, and use the criteria to develop a framework for comprehensive evaluation of Internet Web sites. The framework consists of eight categories, including design, business functions, trustworthiness, interface, technology, community, contents, and others. An empirical study designed to validated the framework has been conducted for each of the three Web site categories, including (1) information provision, (2) product sale, and (3) customer service. The results show that ‘content ’ is the most important for information provision Web sites, ‘trustworthiness’for product sale Web sites, and ‘design’ for customer service Web sites. The framework may be used not only as a tool to evaluate Internet Web sites, but also as a checklist to improve the quality of a Web site that is under development.

• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.439-450
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• 2010

In this paper, we propose a new idea to evaluate the prediction accuracy of user's preference generated by memory-based collaborative filtering algorithm before prediction process in the recommender system. Our analysis results show the possibility of a pre-evaluation before the prediction process of users' preference of item's transaction on the web. Classification functions proposed in this study generate a user's rating pattern under certain conditions. In this research, we test whether classification functions select users who have lower prediction or higher prediction performance under collaborative filtering recommendation approach. The statistical test results will be based on the differences of the prediction accuracy of each user group which are classified by classification functions using the generative probability of specific rating. The characteristics of rating patterns of classified users will also be presented.

• 대한수학회지
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• 제58권3호
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• pp.609-631
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• 2021

Let C[0, T] denote a generalized analogue of Wiener space, the space of real-valued continuous functions on the interval [0, T]. Define $Z_{\vec{e},n}$ : C[0, T] → ℝⁿ⁺¹ by $$Z_{\vec{e},n}(x)=\(x(0),\;{\int}_0^T\;e_1(t)dx(t),{\cdots},\;{\int}_0^T\;e_n(t)dx(t)\)$$, where e₁,…, e_n are of bounded variations on [0, T]. In this paper we derive a simple evaluation formula for Radon-Nikodym derivatives similar to the conditional expectations of functions on C[0, T] with the conditioning function $Z_{\vec{e},n}$ which has an initial weight and a kind of drift. As applications of the formula, we evaluate the Radon-Nikodym derivatives of various functions on C[0, T] which are of interested in Feynman integration theory and quantum mechanics. This work generalizes and simplifies the existing results, that is, the simple formulas with the conditioning functions related to the partitions of time interval [0, T].