• Safety and Health at Work
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• 제4권2호
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• pp.77-83
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• 2013

There is still a considerable burden of occupational diseases and injuries in the world. It is not well known which interventions can effectively reduce the exposures at work that cause this burden. The objective of this article is to summarize evidence from systematic reviews of interventions to prevent occupational diseases and injuries. We included systematic reviews of interventions to reduce the incidence of work-related cancer, dust-related diseases, occupational asthma, chronic obstructive pulmonary disease, noise induced hearing loss, back pain, and occupational injuries. We searched Medline and Embase with predefined search strategies to locate systematic reviews of these interventions. We found 23 systematic reviews of which the results are also applicable to low- and middle income countries. Effective measures to reduce exposure leading to work-related cancer, dust-related diseases, asthma, chronic obstructive pulmonary disease, noise, and injuries are available. However, better implementation of these measures is needed. Regulation, enforcement of regulation, and incentives for employers are effective interventions to achieve this goal. There is evidence that feedback and rewards for workers help in reducing occupational injuries. There is no evidence in many studies that back pain can be prevented. Personal protective equipment technically has the potential to reduce exposure but this is difficult to put into effect. There is no evidence in the studies regarding the effectiveness of education and training, preventive drugs, or health examinations. There is evidence that the implementation of technical measures enforced by regulation can prevent occupational diseases and injuries. For other interventions such as education or health examinations, there is no evidence that supports their effectiveness. More systematic reviews are needed in the area of injury prevention.

• 한국건설관리학회논문집
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• 제20권2호
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• pp.68-78
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• 2019

최근 주택 가격이 전국적으로 상승하였고 정부는 실수요자 보호를 위해 금융, 세금 등 다양한 규제를 지역에 따라 시행하였다. 정책 시행 이후 전국적인 주택 가격 평균은 안정되었으나 지역 별로 살펴보면 양극화 현상이 발생하였다. 또한 규제로 인해 오히려 실수요자가 피해를 볼 우려에 대한 논의도 지속되고 있다. 따라서 정책 계획 및 분석에 있어 시장 변수 간의 상관관계 뿐 아니라 미시적으로 시장 참여자들에게 어떻게 정책의 효과가 파급되는 지 분석할 필요성이 있다. 이에 본 연구에서는 변수 간 인과관계로 구성되는 시장 구조 분석을 위한 시스템 다이내믹스와 시장 참여자들의 의사 결정 과정 모델링을 위한 행위자 기반 모델을 통합하여 시뮬레이션 모델을 구축하였다. 개발한 모델에 금융 규제와 세금 규제를 적용하여 주택 가격의 변화와 이에 시장 참여자들이 어떻게 행동하는 지에 대한 분석을 통해 정책의 실효성을 평가하였다. 본 연구를 통해 가격 안정화라는 같은 목적을 가진 두 규제에 대해 시장 참여자들이 다른 의사결정을 함에 따라 시장을 지배하는 피드백의 차이를 확인했다. 이에 따라 정책 대상 지역 뿐 아니라 그 이외의 지역에 대해서도 다른 파급효과가 나타났다.

• Archives of Pharmacal Research
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• 제23권6호
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• pp.535-547
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• 2000

Recent findings indicate that mechanical strain (deformation) exerted by the extracellular matrix modulates activation of airway smooth muscle cells. Furthermore, cytoskeletal organization in airway smooth muscle appears to be dynamic, and subject to modulation by receptor activation and mechanical strain. Mechanosensitive modulation of crossbridge activation and cytoskeletal organization may represent intracellular feedback mechanisms that limit the shortening of airway smooth muscle during bronchoconstriction. Recent findings suggest that receptor-mediated signal transduction is the primary target of mechanosensitive modulation. Mechanical strain appears to regulate the number of functional G-proteins and/or phospholipase C enzymes in the cell membrane possibly by membrane trafficking and/or protein translocation. Dense plaques, membrane structures analogous to focal adhesions, appear to be the primary target of cytoskeletal regulation. Mechanical strain and receptor-binding appear to regulate the assembly and phosphorylation of dense plaque proteins in airway smooth muscle cells. Understanding these mechanisms may reveal new pharmacological targets for control1ing airway resistance in airway diseases.

• Journal of Mechanical Science and Technology
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• 제16권8호
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• pp.1079-1088
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• 2002

Motivated by the dynamic output feedback passification results, point-to-point control laws for an elastic joint robot are presented when only the position measurements are available. The proposed method makes a parallel connection of the robot system and an input-dimensional linear system which obtains the effect of the desired differentiators. It is shown that the closed-loop nonlinear robot system can be rendered output strictly passive and the regulation of the system is achieved in the end. Robustness analysis is also given with regard to uncertainties on the robot parameters. Performance of the proposed control law is illustrated in the simulation studies of a manipulator with three revolute elastic joints.

• 제어로봇시스템학회논문지
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• 제10권5호
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• pp.385-394
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• 2004

This paper proposes the generalized structure of a model-based disturbance rejection controller called a Robust Internal-loop Compensator (RIC). The framework consists of the RIC in the internal-loop to eliminate disturbances and a feedback controller in the external-loop to achieve nominal control performance. As the main contribution of this paper, we redefine the design problem of the RIC as a regulation control problem, then show that this new definition with the RIC structure provides more design flexibility and less implementation constraints. This is verified through a comparative structural analysis with Disturbance Observer (DOB) and Adaptive Robust Control (ARC). Two design examples of the RIC are given, along with practical issues that should be considered in the design procedure. The proposed framework is demonstrated by simulations of a rotary-type motor and experiments with a linear-type motor system.

• International Journal of Control, Automation, and Systems
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• 제5권6호
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• pp.718-724
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• 2007

We extend the application of an adaptive controller previously introduced in the literature under the assumption that no actuator dynamics exists to the case when the dynamics of the brushed DC-motors used as actuators is not neglected. Convergence to the desired positions is ensured without requiring any feedback to cope with the additional electric dynamics. The proposed control scheme does not require the exact knowledge of neither robot nor actuator parameters to select controller gains.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.543-550
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• 2002

This work is concerned with the estimation of output derivatives and their use for the design of robust controller for linear systems with systems uncertainties due to modeling errors and disturbance. It is assumed that a nominal transfer function model and Quantitative bounds for system uncertainties are known. The developed control schemes are shown to achieve regulation of the system output and ensures boundedness of the system states without imposing any structural conditions on system uncertainties and disturbances. Output derivative estimation is first conducted trough restructuring of the plant in a specific parameterization. They are utilized for constructing robust nonlinear high-gain feedback controller of a SMC(Sliding Mode Controller) Type. The performances of the developed controller are evaluated and shown to be effective and useful through simulation study.

• 공학교육연구
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• 제18권4호
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• pp.3-12
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• 2015

The purpose of this study was to develop a pre-training program of engineering college students for maximizing the effectiveness of internship or field training. To pursue this goal, literature review was conducted for data collection about college and corporate pre-training program for internship or field training and pre-training program(draft) was proposed. A questionnaire survey was conducted with engineering professors, students and graduates to identify the needs for pre-training program(draft) for internship or field training. Based on the results, the contents of pre-training program for internship or field training were composed of basic liberal arts, basic competency, real information related with corporation or job, and information exchange network. And key consideration for operating the pre-training program for internship or field training were proposed with the management department, regulation for the obligatory participation, meaningful organizing content, feedback of needs.

• Molecules and Cells
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• 제41권4호
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• pp.257-263
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• 2018

Vertebrate organ development is accompanied by demarcation of tissue compartments, which grow coordinately with their neighbors. Hence, perturbing the coordinative growth of neighboring tissue compartments frequently results in organ malformation. The growth of tissue compartments is regulated by multiple intercellular and intracellular signaling pathways, including the Hippo signaling pathway that limits the growth of various organs. In the optic neuroepithelial continuum, which is partitioned into the retina, retinal pigment epithelium (RPE) and ciliary margin (CM) during eye development, the Hippo signaling activity operates differentially, as it does in many tissues. In this review, we summarize recent studies that have explored the relationship between the Hippo signaling pathway and growth of optic neuroepithelial compartments. We will focus particularly on the roles of a tumor suppressor, neurofibromin 2 (NF2), whose expression is not only dependent on compartment-specific transcription factors, but is also subject to regulation by a Hippo-Yap feedback signaling circuit.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.179-187
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• 2001

In this paper, a primary pressure regulating type ratio control system is developed for a metal belt CVT, and the CVT ratio changing characteristics are investigated by simulation and experiment. The hydraulic part of the ratio control system has a simple structure with one 3-way spool valve as a main ratio control valve and one bleed type variable force solenoid as a pilot valve. The mathematical modelling of the CVT hydraulic system is derived by considering the CVT shift dynamics. Simulation results of CVT speed ratio and the primary pressure agree with the experimental results demonstrating the validity of the dynamic models. It is found from the simulation and experimental results that the response time of speed ratio and primary pressure can be shortened by increasing the ratio control valve port area, and the size of feedback orifice of ratio control valve gives a damping effect on the primary pressure oscillation.