• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.1989-2000
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• 2015

In this paper, digital peak current mode control for single phase H-bridge inverters is developed and implemented. The digital peak current mode control is achieved by directly controlling the PWM signals by cycle-by-cycle current limitation. Unlike the DC-DC converter where the output voltage always remains in the positive region, the output of DC-AC inverter flips from positive to negative region continuously. Therefore, when the inverter operates in negative region, the control should be changed to valley current mode control. Thus, a novel control logic circuit is required for the function and need to be analyzed for the hardware to track the sinusoidal reference in both regions. The problem of sub-harmonic instability which is inherent with peak current mode control is also addressed, and then proposes the digital slope compensation in constant-sloped external ramp to suppress the oscillation. For unipolar PWM switching method, an adaptive slope compensation in digital manner is also proposed. In this paper, the operating principles and design guidelines of the proposed scheme are presented, along with the performance analysis and numerical simulation. Also, a 200W inverter hardware prototype has been implemented for experimental verification of the proposed controller scheme.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.35-40
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• 2012

Since the opening of Korean high-speed rail, KTX in 2004, the use of trains in Korea soared. Improved rail technology, as well as the speed of the train was developed. However, the development of the train speed raised new issues of Doppler effect and this effect compensation. Depending on the speed of communication target, Doppler effect generates frequency shifting and this effect leads to a distortion of the signal. For this reason, the Doppler effect adversely affect the communication performance. Therefore, the Doppler effect problem must be solved for the railway wireless communication. In this paper, we present technique of compensation for the Doppler effect that occurs in high-speed railway communication and simulation result.

• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.1
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• pp.11-19
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• 2007

This paper presents two novel compensation circuits for leakage current and power supply noise (PSN) in phase locked loop (PLL) using a nanometer CMOS technology. The leakage compensation circuit reduces the leakage current of the charge pump circuit which becomes more serious problem due to the thin gate oxide and small threshold voltage in nanometer CMOS technology and the PSN compensation circuit decreases the effect of power supply variation on the output frequency of VCO. The PLL design is based on a 32nm predictive CMOS technology and uses a 0.9V power supply voltage. The simulation results show that the proposed PLL achieves a 88% jitter reduction at 440MHz output frequency compared to the PLL without leakage compensator and its output frequency drift is little to 20% power supply voltage variations. The PLL has an output frequency range of $40M{\sim}725MHz$ with a multiplication range of 11023, and the RMS and peak-to-peak jitter are 5ps and 42.7ps, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1104-1111
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• 2003

The paper presents an algorithm for the compensation of gain and phase imbalances to exist between I-phase and Q-phase signal at direct conversion receiver. We propose a gain and phase imbalances blind equalization compensation algorithm by using variable step-size adaptive loop at direct conversion receiver. The blind equalization schemes have trade-off between convergence speed and jitter effect for the compensation of gain and phase imbalance. We propose the variable step-size adaptive loop method, which varies the loop coefficients according to errors, for recovering these problem. By using variable step-size adaptive loops, we propose to speed up the convergence process and reduce the jitter effect and simulation results show that the algorithm compensates signal loss and speeds up convergence time.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.1
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• pp.9-16
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• 2015

The machining-chatter stands for a sudden relative vibration appeared between a material and a tool while processing with a machine. This chatter is key factor that seriously affects the quality of processed materials as well as being a factor which causes serious damages to the tool and the machine. This study is related to the monitoring and smart control of chatter problem that can compensate machining-chatter faster and produce processed goods with more precision by autonomous compensation. The above-mentioned machining-chatter compensator includes the chatter vibration sensor and the chatter compensator that estimates the compensation value according to the sensor detecting the chatter vibration of machine-tool and the chatter vibration detected from the sensor while having a feature of being organized by interlocking with the machine-tool controller.

• Smart Media Journal
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• v.9 no.1
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• pp.75-83
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• 2020

Compensation services that are indispensable during large-scale public utilities projects have been gradually increasing with the recent increase in construction, but there are no systematic compensation services due to the complicated procedures and manual work. For this reason, various problems such as construction period delays due to various complaints, corruption in compensation work, and impossible to trace the history of compensation data in the past are emerging. In this paper, in order to solve this problem, in-depth interviews and questionnaires were conducted to find out the problems of each compensation status. Based on this, 3 core technologies and 10 technical needs based on ICT were selected to improve the compensation work by deriving STEEP analysis and Issue Tree. The three core technologies are big data-based decision-making and prediction technology, advanced measurement technology, and open cloud-based compensation platform technology. In order to introduce the derived technologies to the institutions in charge of compensation, the possibility of technology diffusion by project operators was suggested based on the results of the current status of informatization by institution. Based on the core technology derived from this paper, it is necessary to make a prototype that can be advanced in compensation work and apply it to each institution and analyze the effect.

• The Journal of Fisheries Business Administration
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• v.37 no.1 s.70
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• pp.25-44
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• 2006

Under the provision of Article 63 of the Enforcement Regulation of the Act on Acquisition and Compensation of Land and Others for Public Project that is recently enacted and implemented (hereinafter referred to as the 'Lend Compensation Act') the compensation is required to make 'When the Actual Damage Amount' is confirmed for the damage in fishery affairs that is outside of the public project area. The compensation for fishery business on the indirect damage area has been excluded from the advance compensation subject to conflict with the existing laws on fishery business compensation with the controversy in method, procedure, time and others to confirm the actual damage amount, and it lacks the standard of calculation for detailed compensation on partial damages outside of business implementation area, which caused the ceaseless conflicts and straggles between the project implementation party and the victimized fishermen regarding the calculation method of damages, standard, compensation period and others. In particular, from the numerous problems in damage compensation in fishery on the indirect damage area, the most recent problem emerged is the issue on application method of damage period in calculating the damage compensation amount that the struggle has been deepened with the differences between the project implementation party and the victimized fishermen without the stipulation on the compensation, that caused the difficulties in carrying out the public project and other serious social problems. In this study, the reasonable application method for the damage period and the calculation plan of the damage amount for calculating the damages on fishery industry outside of the public project implementation zone that is not fully specified under the Land Compensation Act, and the indirect damage area is not influenced for the notification of project recognition, and the compensation to undertake with the damage in the fishery industry in project implementation area to have the nature of damage compensation, the right to engage in fishery industry has the perpetual nature of rights, the fishery damage compensation system of Japan also recognizes the perpetual right on fishery industry to calculate the compensation amount, and the compensation for damage amount has been exercised for the period of actual damage occurrence period regardless of remaining effective period for most of fishery permit and license for fishery compensation outside of the project implementation area following the recent various public projects as well as the development process of theory on fishery loss compensation that the calculation of damage amount on the fishery industry outside of the project implementation zone would be prudent to compensate by calculating the applicable damages during the period of actual damages, and by doing so, the 'just compensation' guaranteed under the Constitution may be materialized. Therefore, the calculation of the damages from the implementation of the public project shall consider the actual period of damages and the degree of damage from the public project to calculate by the income capitalization method, however, considering the equitable consideration with the compensation following the cancellation, it shall not exceed the compensation following the termination of the applicable fishery businesses. Furthermore, the calculation method of partial damage amount on the fishery business following the project implementation shall apply, depending on the period of damage occurrence, by (1) the case of calculating the future damage amount at the present time, and (2) calculating the damage from the past to the present time as well as the damage to be incurred later, by selecting the calculation method for damages following the damage occurrence type.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.199-208
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• 2012

This paper proposes a quasi Z-source DVR(Dynamic Voltage Restorer) system with a series connection of the output terminals, to compensate the voltage variations in the 6.6[kV]/60[Hz] power distribution system. The conventional DVR using one quasi Z-source AC-AC converter has the advantage which it can compensate the voltage variations without the need for the additional energy storage device such as a battery, but it is impossible to compensate for the 50[%] under voltage sags. To solve this problem, a DVR system using two quasi Z-source AC-AC converters with the series connection of the output terminals is proposed. By controlling the duty ratio D in the buck-boost mode, the proposed system can control the compensation voltage. For case verification of the proposed system, PSIM simulation is achieved. As a result, in case that the voltage sags-swells occur 10[%], 20[%], 60[%] in power distribution system, and, in case that the 50[%] under voltage sags-swells continuously occur, all case could compensate by the proposed system. Especially, the compensated voltage THD was examined under the condition of the 10[%]~50[%] voltage sags and the 20[${\Omega}$]~100[${\Omega}$] load changes. The compensated voltage THD was worse for the higher load resistances and more severe voltage sags. Finally, In case of the voltage swells compensation, the compensation factor has approached nearly 1 regardless of the load resistance changes, while the compensation factor of voltage sags was related to the load variations.

• Journal of Society of Preventive Korean Medicine
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• v.1 no.1
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• pp.137-148
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• 1997

The Serial Securities and the Social Welfare, as the national policy aimed at securing generals' lives, are the policies or systems for the stabilization in lift; especially of law-incomers and workers, for which the povernment has to establish the Social Security System. No wonder the Social Insurance System is a part of the Social Security System and the most important. The Social Insurance System, along with Public Assistance, is underlying the Social Security System. Social Security System includes medical insurance, industrial accident Compensation insurance, national pention insurance and employment insurance. The study is on 'The Oriental Medical Insurance and the Industrial Accident Compensation in the Social Security System' . The rate of industrial accident in Korea marks the highest rank in the world. for laborer, industrial accident do not merely mean the loss of health but the question of the right to live in terms of their loss of opportunity of life. The industrial accident compensation system should be established as the es post facto remedy system to guarantee the injured worker and his/her family's life. The oriental medical insurance system which began to operate in 1987 in Korea is based on unionism and divided into 3 parts; one part for the worker, a second part for the community inhabitants, and a third part for the public service personnel and private school personnel. Today the medical problem must be the most important social assignment to be considered. The medical system of contemporary industrial society has began greatly stood out in relief as a part of social welfare not emphasized on gainings of physicians. Accordingly systematization of the oriental medical insurance was strongly Pursued and it was developed to to the extent of entire nation insurance. Though the history of it is very short, most of the people are getting benefit from the insurance system by the social security system method. This study develops the Oriental Medical Insurance, the Workmen's Accident Compensation Insurance, the Pension System in relation to the industrial accident compensation of Employees, along with the ideas and principles of social insurance.

• Korean Journal of Occupational Health Nursing
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• v.10 no.1
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• pp.24-40
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• 2001

This study is to observe the effectiveness of the applied model and to present the improvement plan and directions for development for the case management practical model suitable for the actual condition of Korea Labor Welfare Co. and needs of the industrial injury patients. The concrete purpose of this study is: First, observe the difference of stressor experience and experience degree between the experimental group and the comparative group. Second, observe the difference of stress of the experimental group and the comparative group. Third, find out how the stress affects the support degree and satisfaction degree. Fourth, present the improvement plan of case management model, which can promote the psychosocial rehabilitation of the industrial injury patient based on the research results. The outline of the main research results identified in this study is as follows. The stressors the industrial injury patients perceived are health problems, family matters, the problems concerning hospital recuperation (hospital staff and environmental problems), economical problems, problems of coming back to society, problems with companies, problems with Korea labour Welfare Co. and other problems. And the experience of stressor was prominently lower in experimental group than comparative group in the whole problem, health problem, problems with Korea Labour-Welfare Co. and other problems. The stressor experience degree was conspicuously lower in experimental group in the whole problem experience degree, health problem experience degree, problem with Korea Labour Co. experience degree and other problem experience degree. Besides whether or not the case management is applied is having a prominent affect on the primary factor affecting the stressor experience degree, therefore the patients applied with case management has less stressor than the patient who didn't. The difference of degree of tension experienced by the stressor in both groups, the degree of stress, was not conspicuous in statistics so it shows that the application of case management in this research has not affected the degree of tension. The field which had been the most help was emotional support in help level the experimental group perceived through applying case management about industrial accident patients and recuperation, compensation problem, medical treatment problem, family matters has been helpful in this order. The help level of the whole problem was in higher level than the middle value. The stress factor which affects the case management problem settlement is the whole body of stress. The satisfaction level of help through applying case management was highest in emotional support and family matters, recuperation problem, company problem, compensation problem, and medical treatment problem was the next highest. The satisfaction level of the whole problem was higher than the middle value. The stress factor affecting the satisfaction level of help is the whole body of stress. Therefore to reduce the stress level of industrial accident patients and for them to come back to local societies, we need to reinforce the continuance and responsibility of case management model, increase staff, reinforce the role of counsel and medical treatment, intervene in the patient's plan of leaving the hospital, develop social support system and the need to establish After Care Center.