• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.976-986
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• 2014

In this paper, the problem of reliable control of linear systems with time-varying delays, randomly occurring disturbances, and actuator failures is investigated. It is assumed that actuator failures occur when disturbances affect to the systems. Firstly, by using a suitable Lyapunov-Krasovskii functional and some recent techniques such as Wirtinger-based integral inequality and reciprocally convex approach, stabilization criterion for nominal systems with time-varying delays is derived. Secondly, the proposed method is extended to the reliable $H_{\infty}$ controller design for linear dynamic systems with time-varying delays, randomly occurring disturbances, and actuator failures. Since nonlinear matrix inequalities (NLMIs) are involved in proposed results, the cone complementarity algorithm will be introduced. Finally, two numerical examples are included to show the effectiveness of the proposed criteria.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.12
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• pp.1330-1337
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• 2004

In this study, the equations of motion of a rigid rotor supported by magnetic bearings are derived via Hamilton's principle, and transformed to a state-space form for control purpose. The optimal motion control of rotor magnetic bearing system based on the LQR(linear quadratic regulator) theory is addressed. New schemes related to the selection of the state weighting matrix Q and the control weighting matrix R involved in the quadratic functional to be minimized are proposed. And the robust control of the system with an LMI(linear matrix inequality) based H$_{\infty}$ theory is dealt with in this paper. Loop shapings of TFM (transfer function matrix) are used to increase the performance of control capability of the system. The control abilities of LQR and H$_{\infty}$ controller are compared by simulation and experimental tests and show that the capability of H$_{\infty}$ controller is superior to that of LQR.

• Journal of Preventive Medicine and Public Health
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• v.26 no.1 s.41
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• pp.1-19
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• 1993

Mail questionnaire was administrated to 370 practising physicians and 388 pharmacists in Taegu city selected by systematic sampling to examine utilization states and opinion of pharmacy under medical care insurance programme and the attitude to the functional division between physicians and pharmacists from April to May 1992. Regarding the opinion on the outcome of drug-store under medical insurance, 71.2 percent of practicing physician answered faliure but 13.4 percent of practicing pharmacists answered failure in contrast. Fifty percent of practicing physician asserted introducing functional division between physician and pharmacist while 66.9 percent of practicing pharmacist answered drug-store under medical insurance itself is sucessful programme. Average daily numbers of preparation of medicine was 32.2 case. Percentage of utilization of drug-store under medical issurance to average daily cases of preparing of medicine was 20 percent, percentage of utilization with physician's prescription was 0.7 percent. And 58.7 percent of practicing physician experienced outside the institute prescription. Regarding the opinion on the pros and cons of enforcing functional division between physician and pharmacist, 59.2 percent of practicing physician prefered pros and 17.7 percent cons, but 38 percent of practicing pharmacist prefered pros and 45.5 percent cons. And pharmacist knew better the content of functional division between physician and pharmacist than physician. As a reason for pros of enforcing functional division between physician and pharmacist, practicing physician emphasized to prevent misuse or abuse of medicine but practicing pharmacist emphasized to display physician and pharmacist's professional ability. And as an opinion on implementation style of functional division between physician and pharmacist in pros respondents, practicing physician favored mandatory enforcement (52.3%), while practicing pharmacist favored partial incomplete functional division (81.7%). As the method of prescription if functional division between physician and pharmacist will be enforced, both practicing physician and pharmacist prefered generic name (44.0%, 89%) mostly, but physician prefered brand name (35.3%) secondly. Regarding the reason for not implementing functional division between physician and pharmacist up to date, both physician and pharmacist answered problem of business right between physician and pharmacist, followed by lack of recognition, and interest of people and lack of the govermental willness. Regarding the opinion on prior decision of condition for enforcing functional division between physician and pharmacist, practicing physician and pharmacist named uneven distribution of medical facilities and drug-store between rural and urban, inequality of physician and pharmacist manpower and the problem of manpower demand and supply mostly, and practicing physician pointed out establishing attitude of acceptance on the part of pharmacist and practicing pharmacist favored establishing attitude of acceptance on the part of physician, which was different attitudes between physician and pharmacist. Following conclusion was reached ; 1. Current drug-store under medical insurance program yield insufficient outcome, so we should consider program conversion from drug-store under medical insurance program to functional division between physician and pharmacist. 2. There were problem of business right and conflicts between physician and pharmacist at enforcing functional division between physician and pharmacist, so the goverment should search for formulating plan to resolve the problem and have neutral willness for the protection of the national health.

• The Korean Journal of Applied Statistics
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• v.28 no.4
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• pp.827-845
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• 2015

This study evaluates and suggests a new reform plan that overcomes the limitations of the Government Employees Pension Scheme (GEPS) reforms in 2015. Research results indicate that the reforms were insufficient in terms of financial sustainability, functional transparency, and equity. Debates on the GEPS reforms will continue until an equitable solution is found. The priority of the next reform plans should lie in the unification of public pension schemes. In contrast to previous reform proposals, this study suggests a reforms plan, which should result in not the parametric change but the structural change in GEPS. The distinctive point of the new reform plan lies in translating a single-tire into a multi-tire pension system. Accordingly, the new GEPS should consist of a 'National Pension Scheme (NPS)', occupational pension (additional pension), and retirement allowance. Newly appointed government employee officials should be enrolled in the NPS. This study stresses that inequality between the public pension systems will be alleviated and a pension system of social solidarity will be established when the NPS develops in to a basic old age income security system for all citizens including civil servants.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.1
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• pp.10-16
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• 2008

With the advent of effective chemotherapy and the realization of high economic cost associated with amputation, limb salvage surgery has become the standard of treatment in children with primary malignant bone tumors. Reconstruction after resection of malignant bone tumors of children has to address the leg length inequality and also has to be durable to cope with high functional demands of young patients. Expandable endoprostheses have been used in children for achieving limb length equality with substantial risk of complications. Recently, significant advances in prosthetic designs have reduced the morbidities associated with these prostheses. The purpose of this study was to review the indications, characteristics, complications and recent developments of expandable endoprostheses used for malignant bone tumors in children.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.3
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• pp.337-342
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• 2009

This paper concerns delay-range-dependent robust stability and stabilization for time-delay nonliner system via T-S fuzzy model approach. The time delay is assumed to be a time-varying continuous function belonging to a given range. On the basis of a novel Lyapunov-Krasovskii functional, which includes the information of the range, delay-range-dependent stability criteria are established in terms of linear matrix inequality. It is shown that the new criteria can provide less conservative results than some existing ones. Moreover, the stability criteria are also used to design the stabilizing state-feedback controllers. Numerical examples are given to demonstrate the applicability of the proposed approach.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.3
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• pp.323-328
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• 2009

In this paper, a decentralized fuzzy output feedback controller for the nonlinear networked control system is proposed for wireless sensor network. Especially, it is assumed that the networked control system has the output packet loss and the input transmission failure. For the fuzzy control of the nonlinear subsystem, it presents Takagi-Sugeno (T-S) fuzzy model of each subsystem and it designs the decentralized fuzzy output feedback controller. The stability condition of the closed-loop system with the proposed controller is obtained by Lyapunov functional. The obtained stability condition is represented to the linear matrix inequality (LMI) form, and the control gain is obtained by LMI. An example is given to show the verification discussed throughout the paper.

• Korean Journal of Social Welfare
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• v.61 no.2
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• pp.61-84
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• 2009

There has been a continuous debate on decentralization of welfare. The proponents of decentralization argue that it will enhance the autonomy of local governments and the efficiency in the provision of service. However, the opponents argue that it will lead to the welfare reduction and the increased inequality among localities. This study attempts to deal with the question, focusing on the evaluation of decentralization reform of Roh Government. The main results are as follows: After the decentralization, local governments has undergone hardships in financing the welfare service, while there is no clear evidence that the local autonomy has enhanced. In respect of fiscal role-sharing, local duties has significantly increased because of the insufficient grants-in-aid for decentralization and inappropriate formula in assessing the grants. In respect of functional role-sharing, the decreased role of central government made it difficult for local governments to provide enough residential institution for the elderly and the disabled. To improve the decentralization reform, deliberate reclassification is needed to decide which item should be transferred to localities. Regarding the characteristic of the projects, social services could be transferred in the long run, while central government should take more responsibilities for the income guarantee and protection for the disadvantaged.

• Korean Journal of Oriental Medicine
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• v.13 no.1 s.19
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• pp.129-138
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• 2007

Background : Recently a discussion about Qi including a study about the effect or the theory of acupuncture is getting prevailing in various angles. In most of studies about acupuncture stimulus, 'Filiform acupuncture'(毫鍼) is used. A study about Nine kinds of acupuncture(九鍼), except 'Filiform acupuncture'(毫鍼) has not been reported yet, and there is no study about using a special acupuncture made for controling Qi either. Objectives : 'DONG CHU CHIM' can be used for patients who are scared of a pain because it is a medical Qikong tool and non-invasive stimulus one. To assess a effect of Qikong operation using 'DONG CHU CHIM' objectively, we stimulated non-invasive to Sobu point of 30 normal adults using 'DONG CHU CHIM' and examined the result in the basis of high confirmed and repetitive HRV which is a functional assessment method of the autonomic nervous system. Method : This study has been proceeded in three periods. Total was 35min : 10min for the former and latter period of acupuncture stimulus, l5min for the acupuncture stimulus period. For each period, we measured 5min of 3 times(Stage I, II, III). Result : Comparing the changes of HRV during pre-stimulation and post-stimulation, HRT was significantly reduced, LOGTP, LOGVLF, LOGLF, LF/HF were significantly increased and SDNN, LOGHF were generally increased but did not show any significant changes. So we think that the stimulus of 'DONG CHU CHIM' affects on the sympathetic system and parasympathetic system, it activates the autonomic nervous system, and it makes the inequality of the sympathetic and parasympathetic nerve to be equal status. Conclusions : We can conclude that the non-invasive stimulus of 'DONG CHU CHIM' can affect significantly to the autonomic nervous system. So it can be used in clinic as a tool of Qikong operation, and it can be also used to weak patients or children because it doesn't give a lot of pain like 'Filiform acupuncture'(毫鍼) compared to invasive stimulus. By the basis of this study, more studies about the effect of 'DONG CHE CHIM' should be done in the future.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.149-158
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• 2002

For the purpose of preciously describing real time traffic pattern in urban road network, dynamic network loading(DNL) models able to simulate traffic behavior are required. A number of different methods are available, including macroscopic, microscopic dynamic network models, as well as analytical model. Equivalency minimization problem and Variation inequality problem are the analytical models, which include explicit mathematical travel cost function for describing traffic behaviors on the network. While microscopic simulation models move vehicles according to behavioral car-following and cell-transmission. However, DNL models embedding such travel time function have some limitations ; analytical model has lacking of describing traffic characteristics such as relations between flow and speed, between speed and density Microscopic simulation models are the most detailed and realistic, but they are difficult to calibrate and may not be the most practical tools for large-scale networks. To cope with such problems, this paper develops a new DNL model appropriate for dynamic traffic assignment(DTA), The model is combined with vertical queue model representing vehicles as vertical queues at the end of links. In order to compare and to assess the model, we use a contrived example network. From the numerical results, we found that the DNL model presented in the paper were able to describe traffic characteristics with reasonable amount of computing time. The model also showed good relationship between travel time and traffic flow and expressed the feature of backward turn at near capacity.