• Proceedings of the KSME Conference
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• 2001.06a
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• pp.889-894
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• 2001

A three dimensional transient thermo-elastic frictional contact analysis of airplane brakes is performed. The velocity history of the airplane during braking is calculated from energy conservation law. ABAQUS code is used in the analysis, and user subroutines supported in the ABAQUS are coded to calculate the frictional heat generation between pads and linings attached to back/pressure plate and rotor, respectively. Numerical results are compared with experimental ones.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1093-1098
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• 2002

Dynamic behaviors of the Korean High-speed Train(KHST) have been analyzed to investigate the performance on the stability, the safety and the ride comfort. Multi-body dynamics analysis program using Recursive method, called RecurDyn, have been employed in the numerical simulation. To model the wheel-rail contact, the RecurDyn uses its built-in module which uses the square root creep law. The accuracy of the rail module in RecurDyn. however, decreases in the analysis of flange contact because it linearizes the shape of the wheel and rail. To solve this problem, a nonlinear contact theory have been developed that considers the profiles of the wheel and rail. The results show that the KHST still needs more stability. The problem should be solved by the examinations of module and modeling.

• The Journal of Korean Medical History
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• v.36 no.2
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• pp.27-48
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• 2023

This study identifies 164 Korean medicine practitioners among the independence activists and describes the types and characteristics of their independence movements. Their occupations included apothecary pharmacist, herbalist, and medicine dealer. They originated from Gyeongbuk, Hamnam, Pyeongnam, and Gyeongnam, with a higher proportion of Hamnams compared to independence fighters. Their ages are concentrated in the 30s and 40s. Their movements are similar to those of independence heroes, in the order of domestic resistance, the March 1 Movement, and Manchurian resistance. The crimes are Security Law, Exorcism No. 7 of the 8th Reign of Daejeong, Public Order Maintenance Law, and attempted murder. In terms of sentences, the proportion of those sentenced to five years or more in prison is higher, and the proportion of those sentenced to less is lower. The above independence movements in Korean medicine practitioners are characterized by (1) the use of direct force, (2) long-term and planned struggle, (3) the provision of contact points and funding sources, (4) a nationalist line, and (5) low socialist-communist share.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.12
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• pp.4062-4080
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• 2022

COVID-19, a highly infectious disease, has affected the globe tremendously since its outbreak during late 2019 in Wuhan, China. In order to respond to the pandemic, governments around the world introduced a variety of public health measures including contact-tracing, a method to identify individuals who may have come into contact with a confirmed COVID-19 patient, which usually leads to quarantine of certain individuals. Like many other governments, the South Korean health authorities adopted public health measures using latest data technologies. Key data technology-based quarantine measures include:(1) Electronic Entry Log; (2) Self-check App; and (3) COVID-19 Wristband, and heavily relied on individual's personal information for contact-tracing and self-isolation. In fact, during the early stages of the pandemic, South Korea's strategy proved to be highly effective in containing the spread of coronavirus while other countries suffered significantly from the surge of COVID-19 patients. However, while the South Korean COVID-19 policy was hailed as a success, it must be noted that the government achieved this by collecting and processing a wide range of personal information. In collecting and processing personal information, the data minimum principle - one of the widely recognized common data principles between different data protection laws - should be applied. Public health measures have no exceptions, and it is even more crucial when government activities are involved. In this study, we provide an analysis of how the governments around the world reacted to the COVID-19 pandemic and evaluate whether the South Korean government's digital quarantine measures ensured the protection of its citizen's right to privacy.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.1-11
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• 2003

A mathematical model was proposed to analyze the oxygen diffusion reaching the cornea through the tear layers and contact lens based on Fick's law and the principle of continuity of the diffusion flux through the each layers. The model predicts how the parameters such as the thickness of tear layer on the cornea, both the Dk and thickness of contact lenses etc., affect the oxygen tension at cornea and oxygen flux entering the cornea. It is found that either too flat or too tightly fitted contact lenses can cause the oxygen deficiency inside the periphery of the cornea because of the reduction of oxygen flux resulted from too thickened tear layer.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.1
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• pp.18-34
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• 2018

Objectives: This study aims to identify and solve problems in the consistency, procedural justification, effectiveness, and other matters concerning approaches to occupational safety and health legislation, administrative rules, and administrative guidelines. Methods: In this study of policy on the industrial safety and health law of Korea, problems were raised based on important information on the approach to occupational safety and health legislation and administrative guidelines such as notices, ordinances, and instructions, as well as on their interpretation and operation standards. Secondly, based on the identified problems in the occupational safety and health law policy, core practical methods to present improvement directions for occupational safety health policy in Korea were sought. Results: It is absolutely necessary to actively promote the infrastructure for occupational safety and health by developing and disseminating notices, guidelines, and manuals that act as contact points between laws and the field in various ways at the administrative institution level. In addition to sanctions, efforts to systematically guide and promote complex professional matters must be supported. Efforts should be made to strengthen administrative expertise so that administrative authorities can secure professional authority and fully enforce legal policies according to the purpose of legislation. In order to ensure the effectiveness of occupational safety and health law policies, it is necessary to shift the focus of the legal policy toward confirming and guiding substantial compliance with legal standards. Conclusions: As a result of the above efforts, when reliable occupational safety and health law policy is implemented, the understanding and acceptance of the legal policy for the administrative object will be increased, and the safety and health management of the enterprise will be maximized to its full extent.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.175-182
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• 2020

The non-contact eye tracking is a nonintrusive human-computer interface providing hands-free communications for people with severe disabilities. Recently. it is expected to do an important role in non-contact systems due to the recent coronavirus COVID-19, etc. This paper proposes a novel approach for an eye mouse using an eye tracking method based on a context-aware based AdaBoost multi-region classifier and ASSL algorithm. The conventional AdaBoost algorithm, however, cannot provide sufficiently reliable performance in face tracking for eye cursor pointing estimation, because it cannot take advantage of the spatial context relations among facial features. Therefore, we propose the eye-region context based AdaBoost multiple classifier for the efficient non-contact gaze tracking and mouse implementation. The proposed method detects, tracks, and aggregates various eye features to evaluate the gaze and adjusts active and semi-supervised learning based on the on-screen cursor. The proposed system has been successfully employed in eye location, and it can also be used to detect and track eye features. This system controls the computer cursor along the user's gaze and it was postprocessing by applying Gaussian modeling to prevent shaking during the real-time tracking using Kalman filter. In this system, target objects were randomly generated and the eye tracking performance was analyzed according to the Fits law in real time. It is expected that the utilization of non-contact interfaces.

• Structural Engineering and Mechanics
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• v.56 no.1
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• pp.85-106
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• 2015

Postbuckling of thick plates made of functionally graded material (FGM) subjected to in-plane compressive, thermal and thermomechanical loads is investigated in this work. It is assumed that the plate is in contact with a Pasternak-type elastic foundation during deformation. Thermomechanical non-homogeneous properties are considered to be temperature independent, and graded smoothly by the distribution of power law across the thickness in the thickness in terms of the volume fractions of constituents. By employing the higher order shear deformation plate theory together the non-linear von-Karman strain-displacement relations, the equilibrium and compatibility equations of imperfect FGM plates are derived. The Galerkin technique is used to determine the buckling loads and postbuckling equilibrium paths for simply supported plates. Numerical examples are presented to show the influences of power law index, foundation stiffness and imperfection on the buckling and postbuckling loading capacity of the plates.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.399-402
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• 1999

In this paper, a new method for calculating capacitance in arbitrarily shape structure is Presented. This new approach based on divergence theorem of Gauss\`s law is acheive by Surface-Contacted Element(SCE) for Gaussian surface. To evaluate accurate capacitance value in nonuniform electric field. in two dimensional analysis the interpolation using the elements which contact one nod (PE: Point-Element) or two nod (FE: Face-Element) is employed. Because the elements contacted with surface are very small compared with total elements in analytic model, SCE method has shorter computing time to calculate capacitance. This proposed method is verified by comparing the simulated results with value obtained by analytic method.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.80-93
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• 1996

A 2-dimensional FEM/GEM program was developed under the plane strain assumption using linear line elements for analyzing stretch/draw forming operations of an arbitrarily shaped draw-die. FEM formulation adopted a new algorithm for solving force equilibrium as well as non-penetration condition simultaneously. Also, a rigid-viscoplastic material model with Hill's normal anisotropic yield condition and rate-sensitive hardening law is assumed, along with the Coulomb friction law in the contact regions. For the case of numerical divergence at nearly final forming stages, geometric force equilibrium method(GEM) is also introduced. The developed program was tested by simulating the forming processes of cylindrical punch/open die, and the drawing processes of automotive oilpan and hood inner panel in order to verify the usefulness and validity of FEM/GEM formulation. The numerical simulation verified the validity and robustness of developed program.