• The Journal of the Korea Contents Association
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• v.8 no.4
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• pp.183-196
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• 2008

This research will mainly focus on security issues in a university campus and delve into the risk factors and its characteristics due to the extreme polarization growth, and ultimately conduct research on legislative issues regarding safety & security management. A university campus is a miniature of the society, concentrated with human resources, material resources and knowledge information resources. It is also a region in which various underlying risk factors threaten these resources. However, due to the insensibility of danger and carefree indolence, these risk factors have been ignoring, leaving university campus amidst a "dead zone." Currently, a systematic and synthetic measures not only for safety inside the laboratory but also for the new type of crimes such as cyber crimes and motiveless crime due to extreme polarization, stress, uneasiness about the future, increase of mental illnesses, and drug abuse are urgently required. Therefore, I would like to introduce a legislative program in a crisis management perspective that can prevent universities from danger and protect the resources which would ultimately create a new security system.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.1
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• pp.1-8
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• 2008

The object of this study is to develop the examination technique for measuring the O-ring deformation behavior under the pressure and the squeezed condition simultaneously. The O-ring deformation measuring device in which two grooves were dug to insert the two O-rings was manufactured to be not deformed under the high pressure and the 1 mm and 0.1 mm gap were designed to measure the extrusion lengths under the internal pressure. The beam hardening correction, the histogram analysis and the dead zone correction were executed to exactly measure the shape of O-ring deformation and the lengths of the O-ring deformation were measured by the LSF and the ERF. The computed tomography applied the pressure of 0, 1.378, 4.902, 9.804, 15.692 MPa at 22.3% squeezed condition and the expanded diameter, contact length and extrusion depth were measured in each pressure. The shape of O-ring deformation was evaluated by the FEM to verify the results of measuring by the computed tomography and the area of O-ring was mutually compared to the area measured by the computed tomography.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.3
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• pp.85-92
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• 2005

Due to the friction characteristic of pump, cylinder, and between passenger car and the rail, there exist dead zone in the hydraulic system actuated with inverter, which can not be controlled by a PID controller. In this paper, the friction characteristic of a cylinder is considered first, which may cause the uncontrolled speed in the zero-crossing speed region. And then, the zooming fuzzy logic controller is designed to overcome the drawback by the existing PID speed controller. Finally, The proposed hybrid fuzzy controller is applied to the PID controller in the normal speed region and to the fuzzy controller in the zero-crossing speed region. The reason is that the problem of the uncontrolled speed in the zero-crossing speed region caused by the friction characteristic of the cylinder in hydraulic elevator can be solved, and the effectiveness of the controlling system not only in the zero-crossing speed region but also the overall controlling region including steady-state can be simulated and performed.

• Korean Journal of Environment and Ecology
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• v.23 no.4
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• pp.302-308
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• 2009

For the proper tree management of Taxus cuspidata, distributed in the High 1 Ski Slope construction area in Baekwoonsan, Jeungsun-gun, Kangwon-do, the growing states of 323 trees(including transplanted 57trees) are investigated. Tree height, rootcollar diameter, D.B.H., stem condition, apical shoot, dead branch, needle growth condition, 2-year-old needle loss, root condition, tree form are investigated. Taxus cuspidata are mainly growing at the sites, high elevated mountain ridge or slopes facing north. Growing states of Taxus cuspidata, distributed in Baekwoonsan are relatively better than those of Taxus cuspidata and Abies koreana at other subalpine zone in Korea. Damaged trees are mainly due to root-removal through transplanting, root-damages by raising the ground level and digging. Several methods of Taxus cuspidata conservation were suggested.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.55-64
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• 2007

In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it and other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.116-127
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• 2013

Korea, like most of other countries, is enforcing the national pension as social insurance which is a kind of the income policy. Despite the fundamental limitation on public pension or the imperfect policy, the guarantee of the minimum living standard for maintaining dignity of human being is not being reached for the standard. Poverty rate of the elderly in Korea is the first among the OECD countries and public pension dead zone is very large. The elderly low income class could become a serious social problem if low fertility and aging keep getting worse. In this study, I will analyze the present condition of the retirement security for the elderly in South Korea. Also, I will look into the present situation of old-age income security and determine problems, and propose the improvement devices for related laws.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1660-1670
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• 2015

Many robust controllers have been studied but most are considered in the theoretical point of view and can be used for only specific systems. So, in this paper, a more practical robust controller is proposed based on SMC(sliding mode control) and disturbance observer. The integral sliding mode is used to eliminate the reaching phase and minimizes the steady-state error, and the disturbance observer reduces the chattering due to the switching input for the bounded disturbances. The inevitable chattering of SMC is also removed by replacing the sign function with dead-zone function. The proposed controller has the improved steady-state error and robustness compared to PID controller.

• Journal of Legislation Research
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• no.41
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• pp.171-200
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• 2011

Protection of vulnerable people in our country today, "the National Basic Livelihood Security Act," is primarily responsible. But current law income and wealth, and by a person responsible for supporting consider only the absolute protection of the poor, and because it is insufficient for the protection of vulnerable people. Specifically, current law does not mean the relative poverty of vulnerable people is limited to the protection of economic demand. It also incorporates the payment of salaries paid individual because the people most vulnerable to social protection is insufficient demand. Dependent regulation is too strict and a person responsible for supporting do not receive legal protection by forming a dead zone is a major cause. In this study, the development direction for the protection of vulnerable people suggests. The first, "National Basic Livelihood Security Act" award in determining the minimum cost of living is relatively proposed to introduce the concept of poverty. Second, payment of the consolidation benefit and the individual benefit to adopt a intermix approach, the social needs of vulnerable people to adapt to that proposed. Third, a person responsible for supporting dependent criteria and whether according to the actual supporting to be judged.

• Journal of Biomedical Engineering Research
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• v.43 no.6
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• pp.390-398
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• 2022

Ultrasound examination using ultrasound equipment is an ultrasound device that images human organs using sound waves and is used in various areas such as diagnosis, follow-up, and treatment of diseases. However, if the quality of ultrasound equipment is not guaranteed, the possibility of misdiagnosis increases, and the diagnosis rate decreases. Accordingly, The Korean Society of Radiology and Korea society of Ultrasound in Medicine presented guidelines for quality management of ultrasound equipment using ATS-539 phantom. The DenseNet201 classification algorithm shows 99.25% accuracy and 5.17% loss in the Dead Zone, 97.52% loss in Axial/Lateral Resolution, 96.98% accuracy and 20.64% loss in Sensitivity, 93.44% accuracy and 22.07% loss in the Gray scale and Dynamic Range. As a result, it is the best and is judged to be an algorithm that can be used for quantitative evaluation. Through this study, it can be seen that if quantitative evaluation using artificial intelligence is conducted in the qualitative evaluation item of ultrasonic equipment, the reliability of ultrasonic equipment can be increased with high accuracy.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.275-280
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• 2022

Suspended solids play an important role in the growth and survival of aquatic organisms. The marine zooplankton species tested in this study were Tigriopus west (Copepoda) and Haustorioides koreanus (Amphipoda) sampled from the intertidal zone, including Artemia nauplii(Branchiopoda) hatched from cysts. The study design included six concentrations (0, 50, 100, 250, 500, and 1,000mg L^-1) of the suspended test particles assayed in triplicate. Experimental cultures in 500 mL-round polycarbonate bottles were subsampled after 96 h to count dead zooplankton. The culture bottles were agitated at 4 RPM on a rotating wheel at 23℃ and 30 PSU. The survival rates of Artemia nauplii and T. west were not affected by suspended solid concentrations higher than 50.0 mg L^-1, whereas the survival rate of H. koreanus decreased with increasing concentrations (p<0.05). In conclusion, H. koreanus and T. west, which were continuously exposed to suspended solid concentrations higher than 50.0 mg L^-1, were affected by low-intensity ecological stress. However, in the case of H. koreanus, a concentration of 50.0 mg L^-1 may be considered to be the limit of tolerance to suspended solids, suggesting that the number of individuals who eventually die will increase if continuously exposed.