• 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.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2005년도 춘계학술발표회
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• pp.195-208
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• 2005

선박은 전통적으로 국제법상 기국주의 원칙이 적용되어 기국정부가 선박의 통제 및 관할권을 행사하여 왔으나 국제적으로 기준미달선이 자주 출현하여 부당한 해운서비스를 제공하고 특히, 외국연안에서 해양오염사고를 일으킴에 따라 항만국들이 자국의 이익보호를 위해 외국적의 기준미달선에 대한 통제를 강화하고 있다. 따라서 항만국통제제도는 기국에 대해서는 책임의 문제이고 항만국으로서는 권한이라고도 할 수 있는데 보다 더 큰 의미로 한다면 기준미달선을 제거함으로써 해상안전과 해양오염방지를 보장하려는 항만국과 기국의 협력체제라고 할 수 있다. 그런데 해상안전과 해양환경보호를 위하여 기항지국에 의한 항만국통제 행위가 아무리 정당한 행위라 할지라도 국제규칙을 잘못 적용하거나 항만만국통제관의 권한을 일탈한 통제행위를 한 경우 국제적 분쟁을 야기시킬 수 있다. 따라서 본 연구에서는 항만국통제의 법적근거를 국제협약과 국내해사법에서 알아보고, 이를 기초로 항만국통제관이 통제제도를 국내적으로 실시함에 있어서 제기될 수 있는 국제법과 국내법과의 충돌문제를 다룬다.

• Progress in Superconductivity
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• 제11권2호
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• pp.135-140
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• 2010

We propose a variational wave function for the ground state of the magnetic heavy fermion (HF) systems, in which both the Kondo and the RKKY interactions are variationally incorporated and the local f-orbital state exists as a linear combination of a full local moment state and a fully compensated state (mixed wave state). We describe the mechanism for the mixed wave ground state based on the large-N treatment of the Kondo lattice Hamiltonian added with RKKY interaction. With the mixed wave ground state we can explain several puzzling experiments in magnetic HF compounds such as a small value of local moment, coexistence of the antiferromagnetic (AFM) and the paramagnetic (PM) phases, local quantum criticality, etc.

• 전자공학회논문지A
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• 제29A권4호
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• pp.83-90
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• 1992

The state machine synthesizer is widely used to FSM synthesis. In this paper, we developed the state machine description language "state CHDL" such as IF, THEN, ELSE, SWITCH, CASE statements. Also, an algorithm for efficient state minimization and two level minimizer of FSM and graphical user interface-pin map window, supporting the designer with input-ouput effency, are presented.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.680.1-680.1
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• 2006

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.10.1-10.1
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• 2008

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.119-121
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• 2005

The sliding-mode control technique could make a system unstable which external disturbance and uncertainty exists in. This paper suggests a robust sliding-mode control algorithm which can be applied to a linear system with parameter uncertainties. To reduce the chattering effect, the whole system is comprised of using a state variable in which the state's estimated value is added. The condition of estimated state results from state observer. The proposed control algorithm uses the optimal feedback controller following the dynamic system equation which consists of a state variable resulting from its own state variable, controller input, estimated state variable. Through comparison with the time optimal control algorithm using simulation, the suggested algorithm shows the improved stability and robustness while it manifests the fast tracking characteristics.

• 전자공학회논문지S
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• 제35S권3호
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• pp.166-175
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• 1998

When we make a speaker adapted model using MAPE (maximum a posteriori estimation), the adapted model has one mixture in each state. This is because we cannot estimate a number of a priori distribution from a speaker-independent model in each state. If the model is represented by one mixture in each state, it is not well adadpted to specific speaker because it is difficult to represent various speech informationof the speaker with one mixture. In this paper, we suggest the method using several mixtures to well represent various speech information of the speaker in each state. But, because speaker-specific training dat is not sufficient, this method can't be used in every state. So, we make the number of mixtures in each state variable in proportion to the number of frames and to the determinant ofthe variance matrix in the state. Using the proposed method, we reduced the error rate than methods using one branch in each state.

• Journal of Communications and Networks
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• 제9권4호
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• pp.356-367
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• 2007

In large networks, maintaining precise global network state information is impossible. The imprecise network state information has significant impacts on Quality-of-Service(QoS) routing and path establishment. In this paper, we develop analytical models for investigating the QoS routing schemes that are designed to tolerate imprecise network state information, and study the performance of various QoS routing schemes, including randomized routing, multi-path routing, and probability based routing, using both the models and simulations. We further propose a new mechanism, called local rerouting, that improves the effectiveness of QoS path establishment in the presence of imprecise global network state information. Local rerouting is orthogonal to existing schemes for dealing with imprecise state information and can be used in conjunction with them to alleviate the impacts of the imprecise information. The results of our performance study indicate that local rerouting is robust and effective.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.178-180
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• 2001

State estimation in power system is to estimate state variable value which minimizes the error from the real state measured by the gauge and connection state of the circuit breaker. In the past, it was difficult to determine measure function considering the correlation of the measured values. In this paper, an extended state estimation is proposed to process easily various kinds of estimation variable. The proposed algorithm is developed by expanding state variable concept based on many measured values and treating correlation between estimation variable and state variable, it is considered that the state variable satisfy some limitations named "Equality Limitation conditions".