• 전기학회논문지
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• 제65권9호
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• pp.1551-1556
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• 2016

A combined CPG (Central Pattern Generator) based foot trajectory and GP (Genetic Programming) based joint compensation method is presented for the adaptive humanoid walking. The CPG based foot trajectory methods have been successfully applied to basic slops and variable slops with slow rates, but have a limitation for the steep slop terrains. In order to increase an adaptability of humanoid walking for the rough terrains, a GP based joint compensation method is proposed and combined to the CPG (Central Pattern Generator) based foot trajectory method. The experiments using humanoid robot Nao are conducted in an ODE based Webots simulation environmemt to verify a stability of walking for the various aslope terrains. The proposed method is compared to the previous CPG foot trajectory technique and shows better performances especially for the steep varied slopes.

• 한국통신학회논문지
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• 제29권2C호
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• pp.298-305
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• 2004

본 논문은 워드길이가 W 비트인 입력으로부터 W 비트를 출력하는 고정길이 modified Booth 곱셈기에 대한 오차보상 방법을 설명한다. 효율적으로 양자화 오차를 보상하기 위해 Booth 인코더의 출력정보를 이용하여 오차보상 바이어스를 생성한다. 절단된 부분이 양자화 오차에 미치는 영향에 따라 두 그룹(major or minor group)으로 나누고, 각 그룹에 서로 다른 오차보상 방법을 적용한다. 기존 방법과 비교하여 제안한 방법이 오차보상 바이어스를 생성하는 회로의 하드웨어 오버헤드는 비슷하면서 약 50％ 정도 양자화 오차가 적음을 시뮬레이션을 통해 보인다. 또한, 면적과 전력소모 면에서 제안한 고정길이 곱셈기가 이상적인 곱셈기 보다 약 40％ 정도 적게 나타났다.

• Safety and Health at Work
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• 제5권2호
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• pp.66-72
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• 2014

Background: The purpose of this study was to enumerate the annual morbidity and mortality incidence and estimate the direct and indirect costs associated with occupational injuries and illnesses in Bangkok in 2008. In this study, data on workmen compensation claims and costs from the Thai Workmen Compensation Fund, Social Security Office of Ministry of Labor, were aggregated and analyzed. Methods: To assess costs, this study focuses on direct costs associated with the payment of workmen compensation claims for medical care and health services. Results: A total of 52,074 nonfatal cases of occupational injury were reported, with an overall incidence rate of 16.9 per 1,000. The incidence rate for male workers was four times higher than that for female workers. Out of a total direct cost of $13.87 million, $9.88 million were for medical services and related expenses and $3.98 million for compensable reimbursement. The estimated amount of noncompensated lost earnings was an additional $2.66 million. Conclusion: Occupational injuries and illnesses contributed to the total cost; it has been estimated that workers' compensation covers less than one-half to one-tenth of this cost.

• Journal of Mechanical Science and Technology
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• 제15권11호
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• pp.1472-1481
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• 2001

In this paper, an advanced shift controller that supervises the shift transients with adaptive compensation is presented. Modern shift control systems for vehicle automatic transmission are designe d to provide smooth transients for passengers' comfort and better component durability. In the conventional methods, lots of testing and calibration works have been done to tune gains of the controller, but it does not assure optimum shift quality at all times owing to system variations often caused by uncertainties in shifting hydraulic systems and external disturbances. In the proposed control scheme, an adaptive compensation controller with intelligent supervisor is implemented to achieve improved shift quality over the system variations. The control input pattern which generates clutch pressure commands in hydraulic actuating systems, is updated through a learning process to adjust for each subsequent shift based on continuous monitoring of shifting performance and environmental changes. The proposed algorithm is implemented and evaluated on the experimental test setup. Results from the experimental studies for several operation modes show both improved performance and adaptability of the proposed shift controller to uncertain changes of the shifting environment in vehicle power transmission systems.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.278-285
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• 1999

This paper utilizes the method of Q-parameterization control to design a controller which solves the problem of imbalance in magnetic bearing systems. There are two methods to solve this problem using feedback controal. The first method is to compensate for the imbalance forces by generating opposing forces on the bearing surface (imbalance compensation). The second method is to make the rotor rotate around its axis of inertia (automatic balancing);in this case no imbalance forces will be generated. In this paper we deal with only imbalance compensation. The free parameter of the Q-parameterization controller is chosen such that these goals are achieved. After the introduction of a model of the magnetic bearing system, we explain the Q-parameterization controller design of the magnetic bearing system with emphasis on the rejection of sinusoidal disturbance for imbalance compensation design. The design objectives are formulated as a linear equations in the controller free paramete Q. Finally, simulation and experimental results are presented and showed the robustness and effectiveness of the proposed controllers.

• Journal of health informatics and statistics
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• 제43권4호
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• pp.267-273
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• 2018

Objectives: An increase in the number of caregivers is necessary to provide services to the elderly, but more importantly, it is qualitative management for them. The purpose of this study was to identify occupational stress, job satisfaction, and organizational commitment and to explore the impact of occupational stress on job satisfaction and organizational commitment among caregivers employed in health service centers for the elderly. Methods: This descriptive survey was a cross-sectional correlational design of 118 caregivers. The questionnaire included occupational stress, job satisfaction, and organizational commitment. Stepwise multiple regression was applied. Results: Job satisfaction and organization commitment of caregivers were found to be above the average. There was a high level of job stress due to lack of job autonomy, job demands, and inadequate compensation. It has been found that the inappropriate compensation, organization system, work culture, and lack of job autonomy affected job satisfaction of caregivers. The factors affecting organizational commitment were inadequate compensation, job insecurity, and work culture. Conclusions: Efforts should be made to assess and complement the appropriateness of compensation and work culture that are taken to relieve job stress to enhance the job satisfaction and organizational commitment of caregivers.

• 한국산업보건학회지
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• 제29권3호
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• pp.278-288
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• 2019

Objectives: The objectives of this study are to summary controversy over health risks among semiconductor workers, to review major cancer risk results conducted in semiconductor operation and to evaluate occupational health activities in Korea for controlling hazardous agents generated in semiconductor operations Methods: Major occupational health issues that has been social controversies among semiconductor workers since 2007 were reviewed through an extensive literature, report and article review. Results: Since a female semiconductor worker aged 22 died from leukemia in 2007, job-association of a number of former semiconductor workers with various types of cancer and rare diseases have been denied by the Korea Workers' Compensation and Welfare Service (KWCWS), but some of them were later awarded compensation as an occupational disease by the administrative court. Two epidemiologic cancer risk studies conducted in Korea found increased risks in leukemia and non-Hodgkin's lymphoma among semiconductor workers. Various legal occupational health activities taken in semiconductor industry were found to fail to assess a complex characteristics of semiconductor operations, such as drastic changes in chemical use, processes, and technology, multiple exposure. National compensation regulation also showed the limitation to evaluate job-association of semiconductor workers who had worked in semiconductor operation. Conclusions: National legal measures should be taken to improve several occupational health activities and duties for protecting workers. In addition, the KWCWS program should be revised so that all workers who meet minimal job or environment associations can be compensated.

• Journal of Power Electronics
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• 제19권1호
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• pp.89-98
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• 2019

This paper analyzes the input side performance of a conventional three-phase to single-phase matrix converter (3-1MC). It also presents the input-side waveform quality under this topology. The suppression of low-frequency input current harmonics is studied using the 3-1MC plus capacitance compensation unit. The constraint between the modulation function of the output and compensation sides is analyzed, and the relations among the voltage utilization ratio and the output compensation capacitance, filter capacitors and other system parameters are deduced. For a 3-1MC without large-capacity energy storage, the system performance is susceptible to input voltage imbalance. This paper decouples the inner current of the 3-1MC using a Lyapunov function in the input positive and negative sequence bi-coordinate axes. Meanwhile, the outer loop adopts a voltage-weighted synthesis of the output and compensation sides as a cascade of control objects. Experiments show that this strategy suppresses the low-frequency input current harmonics caused by input voltage imbalance, and ensures that the system maintains good static and dynamic performances under input-unbalanced conditions. At the same time, the parameter selection and debugging methods are simple.

• 지역사회간호학회지
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• 제32권1호
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• pp.64-72
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• 2021

Purpose: The purpose of this study is to analyze occupational accident compensation insurance coverage and occupational accidents incidence for special-type delivery workers. Methods: The data for occupational accident compensation insurance coverage and occupational accidents from 2012 to 2017 were analyzed through descriptive statistics. Results: Rates of occupational accident compensation insurance coverage of special-type delivery workers decreased gradually from 43.4% in 2012 to 28.5% in 2016, and 29.0% in 2017. Rates of occupational illnesses death per ten thousand workers increased gradually from 2.1‱ in 2013 to 3.1‱ in 2016, and 8.6‱ in 2017. All occupational illness deaths were due to cerebro-cardiovascular diseases. Road traffic accidents and slips accounted for the largest proportion of occupational accidents. Conclusion: Special-type delivery workers have a high risk of industrial accidents, so it is necessary to raise industrial accident insurance coverage and provide professional and systematic occupational safety and health services.

• 한국정보통신학회논문지
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• 제17권10호
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• pp.2466-2472
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• 2013

40 채널의 파장 다중화된 광신호를 3000 km 까지 전송하면서 후치분산 보상 방법의 차이에 따른 성능 변화를 조사하였다. 개별 광신호는 10 Gbps 대역폭의 RZ 신호포맷을 사용하였고 40 채널들의 파장은 1533.5 nm에서 1564.7 nm 사이에 100 GHz 의 주파수 간격을 가졌다. 후치분산 보상을 위해 40개의 개별채널 별로 후치분산을 최적화하는 경우, 전 40 채널들을 하나의 분산값으로 후치분산 보상하는 경우, 그리고 제안된 방법으로 8개씩 묶은 채널 그룹별로 최적화하는 경우의 세가지 경우가 비교되었다. 최저 성능 채널과 그 성능 값은 세가지 방식에서 차이가 없었다. 최고 성능값은 전 채널을 하나의 후치분산 값으로 사용하는 경우가 다른 두 가지 방식에 비해 성능에 떨어졌지만 그룹별 방식이나 개별 채널별 방식은 차이가 없었다. 따라서 채널 그룹별로 후치분산을 통해 신호 성능의 희생 없이 전송시스템을 단순화시킬 수 있음을 확인하였다.