• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.441-447
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• 2014

Background: Multi-state models are appropriate for cancer studies such as gastrectomy which have high mortality statistics. These models can be used to better describe the natural disease process. But reaching that goal requires making assumptions like Markov and homogeneity with time. The present study aims to investigate these hypotheses. Materials and Methods: Data from 330 patients with gastric cancer undergoing surgery at Iran Cancer Institute from 1995 to 1999 were analyzed. To assess Markov assumption and time homogeneity in modeling transition rates among states of multi-state model, Cox-Snell residuals, Akaikie information criteria and Schoenfeld residuals were used, respectively. Results: The assessment of Markov assumption based on Cox-Snell residuals and Akaikie information criterion showed that Markov assumption was not held just for transition rate of relapse (state 1 ${\rightarrow}$ state 2) and for other transition rates - death hazard without relapse (state 1 ${\rightarrow}$ state 3) and death hazard with relapse (state 2 ${\rightarrow}$ state 3) - this assumption could also be made. Moreover, the assessment of time homogeneity assumption based on Schoenfeld residuals revealed that this assumption - regarding the general test and each of the variables in the model- was held just for relapse (state 1 ${\rightarrow}$ state 2) and death hazard with a relapse (state 2 ${\rightarrow}$ state 3). Conclusions: Most researchers take account of assumptions such as Markov and time homogeneity in modeling transition rates. These assumptions can make the multi-state model simpler but if these assumptions are not made, they will lead to incorrect inferences and improper fitting.

• 복합신소재구조학회 논문집
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• 제1권4호
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• pp.1-5
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• 2010

In this study, it is presented analysis results of bending problems in the anisotropic cantilever thick plates and the anisotropic laminated cantilever thin plates bending problems. Finite element method in this analysis was used. Both Kirchoff's assumptions and Mindlin assumptions are used as the basic governing equations of bending problems in the anisotropic laminated plates. The analysis results are compared between the anisotropic laminated cantilever thick plates and the anisotropic laminated cantilever thin plates for the variations of thickness-width ratios.

• 설비공학논문집
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• 제16권9호
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• pp.811-819
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• 2004

A silica gel desiccant dehumidifier is studied theoretically in this paper adopting several linearization assumptions. The governing equations are linearized with the assumptions, and the exact solutions to the temperature and the humidity ratio are obtained. In spite of the assumptions, the theoretical results are found to agree well with those from the numerical analysis without any assumption. In typical operation ranges of the desiccant dehumidifier, the time-averaged errors in the process air temperature and humidity ratio are less than 4% and 7%, respectively, and the corresponding root-mean-square values are less than 5% and 15%, respectively The analytical solutions are expected to contribute to the fundamental understanding of the dehumidification and regeneration processes and the correlation analysis of the numerous parameters influencing the dehumidifier operation.

• 가족자원경영과 정책
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• 제5권1호
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• pp.141-150
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• 2001

This study applicates one of the five elaborated functional analyses of Piotr Stztompka to the housewives’study. The four general assumptions of plurality, wholeness, integration and boundary of the simple system issue the eight specific solutions; reciprocity, exploitation, consensus, conflict, dependence, autonomy, isolation and structural context of the relationships among the various elements of the system. From the eight specific assumptions of the housewives’studies, we have found that many managerial subsystem studies see the housewives’relationships to other elements in their reciprocity, concensus, dependence and isolation characteristics. If the assumptions of autonomy and structual context are used to this kind of study, we can understand the housewives’problem and potential but as an active subject of their humanlives, not as a simply passive primary manager of the family, and we can find a new concept of the development to change the housewives’quality of life.

• 인터넷정보학회논문지
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• 제5권2호
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• pp.17-31
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• 2004

본 논문에서는 PP내의 보안환경 부분 중 환경에 대한 가정문장을 작성하는 방법을 제시한다. CC에서 가정에 관련된 요구 사항을 살피고, 기존 PP들에서 실제 사용한 가정문장과 NIST의 PKB내의 가정문장을 토대로 하여 새로운 "일반 가정문장 목록"과 이를 이용한 가정문장 생성 방법을 제시하였다.방법을 제시하였다.

• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.139-149
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• 2002

This paper presents an approach to derive probability models for use in structural reliability studies. Two main points are made. First, that it is possible to translate engineering and physics knowledge into a requirement on the form of a probability model. And second, that making assumptions about a probability model for structural failure implies either explicit or hidden assumptions about material and structural properties. The work is foundational in nature, but is developed with explicit examples taken from planar and general stress problems, the von Mises failure criterion, and a modified Weibull distribution.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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• pp.187-190
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• 1994

During the initial design phases for prestressed concrete structures, the mecessary information concerning the physical properties of the hardened concrete such as creep, drying shrinkage, modulus of elasticity, and Poisson's ratio are obtained from design assumptions or accepted standards. But these assumptions may not totally reflect the actual long-term behavior of the concrete. So they may be of limited use in predicting the actual behavior. The purpose of this paper is to describe the test procedures and methods of evaluation which were used during the long-term study.

• Communications for Statistical Applications and Methods
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• 제4권2호
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• pp.581-588
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• 1997

Univariate F test is based on the multisample sphericity assumption. Robustness for tests of a main effect of the within-subjects factor was investigated when the assumptions of the onmibus F tests are violated in a split-plot design with one between-subjects factor using untrimmed data and trimmed data. The results indicate that when sample sizes are unbalanced and dispersion matrices are heterogeneous, the CIGA and the $CIGA_T$ tests better control Type I error rates than do the $F_T$test and the$\widetilde{\xi_T}$test.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.788-790
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• 2006

The algorithm of calculating NUC table, based on Image data collection, is based on two basic assumptions. These basic assumptions are as follow: one is the NUC is of a linear nature. The other is all pixel see the same statistical distribution for large number of lines. We generated NUC tables for a radiometric calibration & validation of KOMPSAT-2 using a dark cal. Data.

• 호남수학학술지
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• 제31권2호
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• pp.247-258
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• 2009

This paper introduces new mixed vector FQ-implicit variational inequality problems and corresponding mixed vector FQ-implicit complementarity problems for set-valued mappings, and studies the equivalence between them under certain assumptions in Banach spaces. It also derives some new existence theorems of solutions for them with examples under suitable assumptions without monotonicity. This paper generalizes and extends many results in [8, 10, 19-22].