• Communications for Statistical Applications and Methods
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• v.16 no.2
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• pp.363-372
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• 2009

The difference of two independent binomial proportions is frequently of interest in biomedical research. The interval estimation may be an important tool for the inferential problem. Many confidence intervals have been proposed. They can be classified into the class of exact confidence intervals or the class of approximate confidence intervals. Ore may prefer exact confidence interval s in that they guarantee the minimum coverage probability greater than the nominal confidence level. However, someone, for example Agresti and Coull (1998) claims that "approximation is better than exact." It seems that when sample size is large, the approximate interval is more preferable to the exact interval. However, the choice is not clear when sample, size is small. In this note, an exact confidence and an approximate confidence interval, which were recommended by Santner et al. (2007) and Lee (2006b), respectively, are compared in terms of the coverage probability and the expected length.

• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.1147-1157
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• 2005

Bonus-Malus system is generally constructed based on claim frequency and Bayesian credibility model is used to represent claim frequency distribution. However, there is a problem with traditionally used credibility model for the purpose of constructing bonus-malus system. In traditional Bonus-Malus system adopted credibility model, individual estimates of premium rates for insureds are determined based solely on the total number of claim frequency without considering when those claims occurred. In this paper, a new model which is a modification of structural time series model applicable to counting time series data are suggested. Based on the suggested model relatively higher premium rates are charged to insured with more claim records.

• Health Policy and Management
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• v.5 no.1
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• pp.106-131
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• 1995

Nowadays there are a lot of medical accidents and medical disputes in Korea. Our government has made efforts to legislate The Medical Disputes Conciliation Law for several years. But this law has many problems. These problems are followings. 1. the problem of going certainly through compulsory screening panels before coming to court. 2. the possibility in making the impartial screening panels for malpractice claims 3. the utilization of a mutual aid association to have low efficiency in paying for damages by medical malpractice and so on. To resolve medical disputes rapidly, we must legislate The Medical Disputes Conciliation Law in a short time. However, all medical disputes are not rationally dissolved by only this law, The Medical Lsw(Arztrecht) is needed to improve the solubility of medical disputes through setting up the decision criteria.

• Structural Engineering and Mechanics
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• v.4 no.5
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• pp.541-552
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• 1996

This paper is concerned with the structural optimization problem of maximizing the compressive buckling load of orthotropic rectangular plates for a given volume of material. The optimality condition is first derived via variational calculus. It states that the thickness distribution is proportional to the strain energy density contrary to popular claims of constant strain energy density at the optimum. An engineers physical meaning of the optimality condition would be to make the average strain energy density with respect to the depth a constant. A double cosine thickness varying plate and a double sine thickness varying plate are then fine tuned in a one parameter optimization using the Rayleigh-Ritz method of analysis. Results for simply supported square plates indicate an increase of 89% in capacity for an orthotropic plate having 100% of its fibers in $0^{\circ}$ direction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.409-415
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• 2017

This paper addresses on an linear matrix inequality (LMI) formulation of the robust waypoint tracking problem of large diameter unmanned underwater vehicles (LDUUVs) in the horizontal plane. The interested design issue can be reformed as the robust asymptotic stabilization of the provided error dynamics with respect to the desired yaw angle, surge speed and attitude. Sufficient conditions for its robust asymptotic stabilizability against the hydrodynamic uncertainties are derived in the format of LMI. An example is provided to testify the validity of the proposed theoretical claims.

• Advances in aircraft and spacecraft science
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• v.4 no.3
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• pp.335-351
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• 2017

Kalman filter based spacecraft attitude estimation has been used in many space missions and has been widely discussed in literature. While some models in spacecraft attitude estimation include spacecraft dynamics, most do not. To our best knowledge, there is no comparison on which model is a better choice. In this paper, we discuss the reasons why spacecraft dynamics should be considered in the Kalman filter based spacecraft attitude estimation problem. We also propose a reduced quaternion spacecraft dynamics model which admits additive noise. Geometry of the reduced quaternion model and the additive noise are discussed. This treatment is easier in computation than the one with full quaternion. Simulations are conducted to verify our claims.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.622-624
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• 2015

As uncertain factors are latent in a construction project by nature, a change order occurs frequently. The occurrence of change orders in construction projects conducted during construction phase is known to cause unexpected negative impacts such as cost overrun, schedule delay, quality problem, and claims in the post-process. Thus, an efficient management method is necessary to prevent and minimize change orders during construction phase when they occur frequently. This paper analyzed the causes of change orders and the impact factors that occur during the construction phase of a construction project and suggested a direction for change order database building.

• Korean Journal of Logic
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• v.13 no.1
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• pp.21-52
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• 2010

What van Fraassen calls 'Reflection Principle' is claimed to meet several counterexamples, one of which stands out in the form of the Sleeping Beauty problem. Adam Elga argues that what he believes is the correct answer to the Sleeping Beauty problem shows that Reflection is subject to counterexamples. David Lewis proposes a different answer which preserves Reflection intact. Recently, Nick Bostrom presents a hybrid view which is supposed to allow us to keep Reflection. In proposing his hybrid view Bostrom criticizes both Elga and Lewis while taking some 'good' parts from each. He claims that Elga's view is not entirely acceptable because it presupposes the 'Self-Indication Assumption'. I shall claim, however, that Elga could avoid Bostrom's criticisms by introducing Bostrom's notion of agent-part. I believe that several probability-related puzzles including the Sleeping Beauty problem indicate a promising view concerning the way we should regard our future selves' opinions. According to this view, whether one takes the outsider stance or insider stance makes a difference in an important way that one and the same proposition is associated with different degrees of belief by one agent.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.31-41
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• 2011

Since the cases of time extension have continuously transpired in the public construction project, the potential of economical loss and claims is increasing because the concerned parties such as an owner or a contractor have not properly performed their own responsibility for time extension. One of the main reasons is that the present planning and scheduling do not support the method to apportion the proper responsibility to the right party. This problem has repeatedly led to time extension and made it difficult for the concerned parties to perform the responsibility for time extension. In order to overcome this problem, a framework of delay administration is required as the method to apportion the proper responsibility to the right party. To solve this problem, this paper aimed to develop the conceptual model and prototype system as the practical method to administrate delay causation. Furthermore, the verification result for the reliability and applicability throughout the case studies on real construction projects shows that the conceptual model and prototype system developed would help efficiently to administrate the delay causation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.1 no.1
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• pp.11-26
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• 1978

Economic development is usually identified with the increased of G.N.P and capital formation connected directly wi:11 the net increase of land, structure, commodity, stocks and foreign claims, etc. The increase of G.N.P. is driving at capital formation. The usual concept of capital formation for economic development misses the important productivity factor of human capital. Because it is now increasingly realized that a massive injection of material into production will 11 not necessarily explain a successful productivity unless that country already possesses 1 suitable human capital. Human capital is built of educational investment which is related to the physical capital. Many statistical investigations identified this reality. Of late years, a great crowd of economists studying an the problem of economic development have turned their attention towards human capital. Thereupon, this paper has dealt with the fact that educational investment affects physical capital and employment. The qualitative increment of human capital will increase the productivity but excessive expenditure on human capital will squander a physical capital. In designing a strategy of human capital for economic development, one needs to consider tile level of educational investment because educational investment of developing countries will be accasionaly made or marred by investment level and direction.