• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.346-349
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• 1994

This paper is concerned with a motion control of a manipulator under parametric uncertainties and external disturbances. The parametric uncertainties are regarded as internally generated disturbances in the manipulator. Based on this idea, we formulate a model reference control problem with desired disturbance attenuation. The solution of this control problem not only reduces the worst-case effect on tracking error due to internal and external disturbances (combined disturbances) as much as possible, but also achieve optimal tracking when perturbations are absent. In order to solve the control problem which is formulated in this paper we reduce it to a constrained minmax cost control problem. A differential game theory is used to treat this constrained minmax cost control problem. The differential game theory leads to a sufficient condition for the global solvability of the model reference control problem with desired disturbance attenuation.

• 정보저장시스템학회논문집
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• 제8권2호
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• pp.72-77
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• 2012

The demand for the laptop computer has been increased day by day and most of users ask quiet computer and devices to work in comfortable environment. One of the devices which generate acoustic noise is an external ODD. Unlike the internal ODD, the external ODD is easy to emit noise because it runs outside of the computer and also it is packed with a thin plastic covers. As the disk rotates, vortex flow is generated inside of the cavity due to various and complicated mold parts of the cover. In addition, there is a gap between the disk tray and the upper/lower cases, through which the air flows as well as the noise leaks. In this study, we have proposed how to reduce the acoustic noise of an external ODD using numerical and experimental analysis. The pressure fluctuations and turbulent kinetic energy distributions are calculated for the developed model. The results show that the sound pressure level is reduced by 2.3dB through simple modifications of ribs of the top cover, which remove or suppress flow instabilities inside of the cavity.

• 복식
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• 제25권
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• pp.215-231
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• 1995

Semiotics is an external expression for show-ing internal meaning, and the signs express the internal meaning. The architects and the designers are very similar each other in using semiotics for expressing their desires. Histori-cally, the design similarity exists between the architecture and the fashion. In this study, the fashion designs are interpreted by using semiotics of architectural design, especially emphasizing external expression methods for representing internal desires. To express the human body's character-istics, the volume, weight support, structural simplicity, controllability and beauty of fashion were used for the fashion designs, and those characters could be found at the architec-tural patterns. Balenciaga's fashion emphasized the volume, the weigh support, the structural simplicity and the controllability, while Roberto Capucci rejected the approach of using women's body curves, but used the volume and simplicity of natures in addition to Balenciaga's heavy weight design patterns. The control and the modern dedication were used to make the simple patterns by Courreges, and then brought the Modernism to the fashion. Courreges used the cutting characters to func-tional design for expressing the structural sim-plicity.

• 혜화의학회지
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• 제11권1호
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• pp.91-101
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• 2002

According to the literature on the, the results were as follows. 1. The mechanism of External therapy for prostatitis is some medicicne to come into prostate have anti-inframation and the other medicine to come into nerve system control pain. 2. For the method are uesed hip bath, enema and sticking the pacth to the umbilicus etc. 3. For the medicine are used safflower(紅花), patrinia(敗醫草), chrysanthemum flower(菊花) and Cortex Phellodendri(黃栢). nature and flavor of the medicine is almost cold, bitter in taste and hot in taste. 4. For the classification of medicine are used drug to induce diuresis to elominate stranguria(利尿通淋藥) and drug to induce diuresis to dispersing swelling(利水退腫藥). sometimes they are used to Heat-clearing and detoxifying drug(淸熱解毒藥) and blood-quickening aget(活血祛瘀藥).

• International Journal of Aeronautical and Space Sciences
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• 제3권2호
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• pp.13-23
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• 2002

In this paper, we present a sliding mode control strategy for the re-orientation maneuver of rigid spacecraft containing rotating wheels. The wheels are considered as internal devices, and external inputs are employed for generation of control commands. The formulation is developed for a general case while particular example is applied to pitch bias momentum spacecraft with a single momentum wheel. The resultant control commands are used to take the gyroscopic effects into account which are caused by the rotating wheels. The controller designed demonstrates that the nutational motion of the pitch bias momentum spacecraft is effectively controlled. It is also assumed that the external control torque device is of on-off nature, and pulse width modulation technique is applied to construct proper control torque history.

• International Journal of Computer Science & Network Security
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• 제21권1호
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• pp.64-69
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• 2021

In this paper, we have proposed a new internal model control structure (IMC). It is aimed at unstable overactuated multivariable systems whose transfer matrices are singular and unstable. The model inversion problem is essential to understand this structure. Indeed, the precision between the output of the process and the setpoint is linked to the quality of the inversion. This property is preserved in the presence of an additive disturbance at the output. This inversion approach proposed in this article can be applied to multivariable systems with no minimum phase or minimum phase shift with or without delays in their transfer matrices. It is proven by an example of simulation through which we have shown its good performance as a guarantee of stability, precision as well as rapidity of system responses despite the presence of external disturbances and we have tested this control structure in the frequency domain hence the robustness of the IMC.

• 드라이브 ㆍ 컨트롤
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• 제13권3호
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• pp.32-38
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• 2016

For this paper, the position-control performances of dual EHA(electro-hydrostatic actuator) systems were investigated according to two cases wherein the double-rod- and single-rod-type hydraulic cylinders were combined. Since the control performance is significantly dependent on the load conditions including external forces such as the inertia load, it is proposed here that the two sub-EHAs are driven by separate position and force controllers, instead of two identical position controllers. According to the simulation results, the best performance was achieved by the position-controlled single-rod-type EHA that was combined with a force-controlled double-rod-type EHA. As the force-controlled double-rod-type EHA compensated for the external loads on the position-controlled single-rod-type EHA, the position-control performance was not influenced by external forces including the inertia load. In addition, the position-controlled single-rod-type EHA contributed to the enhancement of the damping ratio by absorbing the pressure peaks through its internal accumulator. Due to the symmetrical piston areas, the double-rod-type EHA is more suitable for force control than the single-rod- type EHA.

• Journal of Nutrition and Health
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• 제34권2호
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• pp.222-229
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• 2001

This study describes the application of the stages of change construct to fat intake by examining the associations of the stages of change with nutritional status and beliefs on health behavior. Data were obtained from apparently healthy 596 adults(326 females and 270 males) residing in large cities. Stages of change assessed by an algorithms based on 6 items were designed each subject into one of the 5 stages: precontemplation(PC), contemplation(CO), preparation(PR), action(AC) and maintenance(MA). Beliefs on health behavior were assessed by self efficacy as well as 4 belief scales from the Locus of Illness Control(LIC) developed using factor analysis such as internal disease cure and prevention and external disease cure and prevention. Energy and fat intakes were measured by a 39 item short form food frequency questionnaire. Regarding the 5 stages of change, MA stage comprised the largest group(37.9%), followed by Ac(30.7%), PC(11.4%), CO(10.4%) and PR(9.6%). Subjects who were females, older or healthier were more likely to belong to either AC or MA. Stage assignment of individuals was corroborated by their nutritional variables. Those in PC had the most energy and fat and those in MA ate the least for females. BMI was higher in PR than any other stages for both males and females. Those in PC were distinctive in that they were more externally oriented in terms of health control showing higher scores on external disease prevention(for males) and external disease cure(for females), and lower score on internal disease cure. On the other hand, those in MA received the highest scores on internal disease prevention and self efficacy, which suggested that they were more internally oriented. Canonical discriminant function analysis indicated that the 5 stages were importantly discriminated by BMI, self efficacy, internal disease prevention and external disease prevention for males and by fat intake, self efficacy and external disease cure variables for females. The results of our study confirm differences in stages of change in fat intake in terms of nutritional status and beliefs on heath behavior and indicate the need for taking these phases of change into account in nutrition advice. (Korean J Nutrition 34(2) : 222-229, 2001)

• Safety and Health at Work
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• 제11권1호
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• pp.10-18
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• 2020

Background: The elevated risk of occupational infection such as tuberculosis among health workers in many countries raises the question of whether the quality of occupational health and safety (OHS) and infection prevention and control (IPC) can be improved by auditing. The objectives of this study were to measure (1) audited compliance of primary health-care facilities in South Africa with national standards for OHS and IPC, (2) change in compliance at reaudit three years after baseline, and (3) the inter-rater reliability of the audit. Methods: The study analyzed audits of 60 primary health-care facilities in the Western Cape Province of South Africa. Baseline external audits in the time period 2011-2012 were compared with follow-up internal audits in 2014-2015. Audits at 25 facilities that had both internal and external audits conducted in 2014/2015 were used to measure reliability. Results: At baseline, 25% of 60 facilities were "noncompliant" (audit score<50%), 48% "conditionally compliant" (score >50 < 80%), and only 27% "compliant" (score >80%). Overall, there was no significant improvement in compliance three years after baseline. Percentage agreement on specific items between internal and external audits ranged from 28% to 92% and kappa from -0.8 to 0.41 (poor to moderate). Conclusion: Low baseline compliance with OHS-IPC measures and lack of improvement over three years reflect the difficulties of quality improvement in these domains. Low inter-rater reliability of the audit instrument undermines the audit process. Evidence-based investment of effort is required if repeat auditing is to contribute to occupational risk reduction for health workers.

• Journal of Advanced Marine Engineering and Technology
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• 제40권6호
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• pp.527-534
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• 2016

무궤도 이동랙은 물류센터에서 보관공간효율화를 위해 이용되고 있으며, 궤도가 없이 움직일 수 있는 특징으로 인하여 종래 물류센터에서 레일을 추가하는 등의 바닥공사 없이 용이하게 설치할 수 있다는 장점을 지니고 있다. 그러나 본 이동랙은 왼쪽과 오른쪽 구동부가 별도로 설치되어 있어 독립적으로 동기화 제어를 해야 하는 어려움이 있다. 특히, 화물의 불균형성이 제어 성능에 크게 영향을 미치므로, 강인한 제어기를 기반으로 한 동기화제어가 필요하다. 본 연구에서는 파라미터 변동에 대하여 강인한 강인서보계를 구성하였으며, 내부 및 외부의 동기화제어를 위하여 반복제어기법을 이용한 동기화 제어알고리즘을 제안하였다. 시뮬레이션을 통하여 강인서보계 및 반복제어계의 유효성을 보였으며, 실험에서는 동기화제어기법을 통한 제어의 유효성을 고찰하였다.