• Journal of Korean Public Health Nursing
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• v.8 no.2
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• pp.35-56
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• 1994

This article was intended to survey whether Roy' Adapation model ('Roy Model') can be applied to family health assessment and to study whether application of the Roy Model to a Korean family is feasible. under the Roy Model, a family is viewed as an adaptation system having a series of process of input. process, feedback, and output. Further, the Roy Model indicates that a family contains Physiolosical, self-concept. role function and interdependent mode in respect of internal or external stimuli. In the event where the family health assessed, the adaptation mode of that family must be assess at the first stage. Then, the focal, contextual, residual stimuli affecting the family must be assessed. In 1984 Hanson suggested four types of family adaptation mode based upon the Roy Model and thereby enhanced the possibility for family health assessment. In order survey whether the Roy Model can be applied to the Korean family, the author of this article contracted adults of 169 who live in 'A' city to make open questions regarding family and then analyzed responses from them by utilizing Roy model. This study categorized family Adaptation mode based upon the' four types of family adaptation mode developed by Hanson. As a result of this study, family adaptation mode was categorized into 117 concepts. Those 117 concepts are consisted or Physiolosical mode of 47. self­concept mode of 56, role function mode of 9 and interdependent mode of 5. Further. stimuli affecting family were classified based upon Roy's definition as to three types of stimuli. Stimuli on a family are comprised focal stimuli concept of 19, contextual stimuli concepts of 19, one residual stimuli concept. this result implies that the Roy's Model can be applied to Korean family. Physiological mode shows meaning of survival. while self-concept mode reflects meaning of growth and emphasizes harmony among the family based on the familism. The role function mode shows continuity rather control of family member. By contrast, interdependent mode shows interaction with community to which the family belongs. but the degree of interaction does not appear too high. The analysis of family stimuli led this study to conclude that troubles within a family. changes in family structure and diease of family member generate stimuli. However, an application of the Roy Model contains the following problems: First, Roy argued that the family adaptation mode should be assessed at the first level family health assessment and then stimuli affecting family adaptation should be adaptation assessed at the second stage. To the belief of the author of this article. however, for checking family adaptation level. focal, contextual, residual stimuli should be confirmed by assessing stimuli at first stage. Then, the family adaptation mode in respect of such stimuli should be assessed. The rationale for this is that the family adaptation level is determined depending on degree of strength of focal. contextual. residual stimuli. Second. Whall (1991) raised a question 'Does one assess family adaptation mode and intervene in the stimuli?' 'Likewise, assessment of the family adaptation should be made in the following manner in order for family health to be enhanced. Third. Roy believes that additional stimuli (such as contextual and residual) are same as internal process (including nurturance. support, and socialization). However, the basis for this Roy's belief is not too clear. In spite of these problems which the author indicated above, it can be concluded that the Roy Model can serve as a good device for an assessment of family health and that the Roy Model can be applied to a Korean family. Finally, further research of family adaptation theory and family nursing theory is required for a development of these theories.

• Journal of Korean Society of Transportation
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• v.13 no.4
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• pp.47-59
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• 1995

The main purpose of this study is identifying the factors which affect the mode choice behavior of work trips. Disaggregate behavioral approach is used for the analysis . The data were collected using the questionnaire survey method in Taegu. Two models were developed in this study which are multinomial logit model(MODEL-1) for auto, taxi and bus and multinomial logit model (MODEL-2) for auto, taxi, bus and subway. The stated preference (SP) data were used for the analysis of the subway mode choice behavior. MODEL-1 provide reasonable results for the future application. A multinomial model (MODEL-2) developed using the stated preference(SP) data was tested for the use of future transportation mode. It is four that the those models provides reasonable results in terms of behavioral and statistical consideration.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.87-96
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• 2016

The multinomial logit model, based on random utility maximization (RUM) theory, has been the predominant model used in travel mode choice contexts. In this paper, the travel mode choice model based on random regret minimization (RRM) theory is proposed as an alternative to the RUM model, and the applicability of the RRM model is examined. The presented model is applied to the case of inter-city travel mode choice in Korea. The empirical results show that the RUM model and RRM model have parameters that are consistent with the intuition. The goodness of fit statistics in the RRM model improved compared with the results of the RUM model. Consequently, these results show the possibility of using the RRM model in the context of travel mode choice.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.12
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• pp.1133-1145
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• 2000

In this paper a model following flight control system design using the discrete time quasi-sliding mode control method is described. The quasi-sliding mode is represented as the sliding mode band, not as the sliding surface. The quasi-sliding mode control is composed of the equivalent control for the nominal system without uncertainties and disturbances and the additive control compensating the uncertainties and disturbances. The linearized plant on the equilibrium point is used in designing a flight control system and the stability conditions are proposed for the model uncertainties. Pseudo-state feedback control which uses the model variables for the unmeasured states is proposed. The proposed method is applied to the design of the roll attitude and pitch load factor control of a bank-to-turn missile. The performance is verified through the nonlinear six degrees of freedom flight simulation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.195-203
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• 2007

In this paper, an analytic model of sleep model operation in the IEEE 802.16e is investigated. A mobile subscribe. station (MSS) goes to sleep mode after negotiations with the base station (BS) and wakes up periodically for a short interval to check whether there is downlink traffic to it. If the arrival of traffic is notified, an MSS returns to wake mode. Otherwise, it again enters increased sleep interval which is double as the previous one. In order to consider the situation more practically, we propose the sleep mode starting threshold, during which MSS should await packets before it enters the sleep mode. By modifying the M/G/1 with multiple vacations model, energy consumption ratio(ECR) and average packet response time are calculated. Our analytic model provides potential guidance in determining the optimal parameters values such as sleep mode starting threshold, minimal sleep and maximal sleep window.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.296-304
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• 2002

A position tracking control schemes on the precise mechanical system in presence of nonlinear dynamic friction is proposed. A nonlinear dynamic friction is regarded as the bristle friction model to compensate effects of friction. The conventional sliding mode controller often has been used as a non-model-based friction controller, but it has a poor tracking performance in high-precision position tracking application since it completely cannot compensate the friction effect below a certain precision level. Thus to improve the precise position tracking performance, we propose the sliding mode control method combined with the friction-model-based observer having tunable structure of the transient response. Then this control scheme has a good transient response as well as the high precise tracking performance compared with the conventional sliding mode control without observer and the control system with similar type of observer. The experiments on the bali-screw drive table with the nonlinear dynamic friction show the feasibility of the proposed control scheme.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1366-1371
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• 2006

A structural coupling method is developed for the dynamic analysis of a nonlinear structure with concentrated nonlinear hinge joints or sliding lines. Component mode synthesis method is extended to couple substructures and the nonlinear models. In order to verify the improved coupling method, a numerical plate model consisting of two substructures and torsional springs, is synthesized by using the proposed method and its model parameters are compared with analysis data. Then the coupling method is applied to a three-substructure-model with the nonlinearity of sliding lines between the substructures. The coupled structural model is verified from its dynamic analysis. The analysis results show that the improved coupling method is adequate for the structural nonlinear analyses with the nonlinear hinge and sliding mode condition.

• Ocean Systems Engineering
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• v.5 no.4
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• pp.279-299
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• 2015

Suction anchors are widely adopted and play an important role in mooring systems. However, how to reliably predict the failure mode and ultimate pullout capacity of the anchor in sand, especially by an easy-to-use theoretical method, is still a great challenge. Existing methods for predicting the inclined pullout capacity of suction anchors in sand are mainly based on experiments or finite element analysis. In the present work, based on a rational mechanical model for suction anchors and the failure mechanism of the anchor in the seabed, an analytical model is developed which can predict the failure mode and ultimate pullout capacity of suction anchors in sand under inclined loading. Detailed parametric analysis is performed to explore the effects of different parameters on the failure mode and ultimate pullout capacity of the anchor. To examine the present model, the results from experiments and finite element analysis are employed to compare with the theoretical predictions, and a general agreement is obtained. An analytical method that can evaluate the optimal position of the attachment point is also proposed in the present study. The present work demonstrates that the failure mode and pullout capacity of suction anchors in sand can be easily and reasonably predicted by the theoretical model, which might be a useful supplement to the experimental and numerical methods in analyzing the behavior of suction anchors.

• Journal of the Korean Society for Railway
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• v.12 no.5
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• pp.656-662
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• 2009

In general, the analysis of travelers' mode choice behavior is accomplished by developing the utility functions which reflect individual's preference of mode choice according to their demographic and travel characteristics. In this paper, we propose a methodology that takes the spatial effects of individuals' departure locations into account in the mode choice model. The statistical models considered here are spatial logistic regression model and conditional autoregressive model taking a spatial association parameter into account. We employed the Bayesian approach in order to obtain more reliable parameter estimates. The proposed methodology allows us to estimate mode shares by departure places even though the survey does not cover all areas.

• Coupled systems mechanics
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• v.9 no.2
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• pp.125-145
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• 2020

In this paper, we present a 3D thermo-hydro-mechanical coupled discrete beam lattice model of structure built of the nonisothermal saturated poro-plastic medium subjected to mechanical loads and nonstationary heat transfer conditions. The proposed model is based on Voronoi cell representation of the domain with cohesive links represented as inelastic Timoshenko beam finite elements enhanced with additional kinematics in terms of embedded strong discontinuities in axial and both transverse directions. The enhanced Timoshenko beam finite element is capable of modeling crack formation in mode I, mode II and mode III. Mode I relates to crack opening, mode II relates to in-plane crack sliding, and mode III relates to the out-of-plane shear sliding. The pore fluid flow and heat flow in the proposed model are governed by Darcy's law and Fourier's law for heat conduction, respectively. The pore pressure field and temperature field are approximated with linear tetrahedral finite elements. By exploiting nodal point quadrature rule for numerical integration on tetrahedral finite elements and duality property between Voronoi diagram and Delaunay tetrahedralization, the numerical implementation of the coupling results with additional pore pressure and temperature degrees of freedom placed at each node of a Timoshenko beam finite element. The results of several numerical simulations are presented and discussed.