• Structural Engineering and Mechanics
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• 제7권2호
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• pp.225-240
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• 1999

This paper presents a mechanistic approach to uniaxial viscoelastic constitutive modeling of asphalt concrete that accounts for damage evolution under cyclic loading conditions. An elasticviscoelastic correspondence principle in terms of pseudo variables is applied to separately evaluate viscoelasticity and time-dependent damage growth in asphalt concrete. The time-dependent damage growth in asphalt concrete is modeled by using a damage parameter based on a generalization of microcrack growth law. Internal state variables that describe the hysteretic behavior of asphalt concrete are determined. A constitutive equation in terms of stress and pseudo strain is first established for controlled-strain mode and then transformed to a controlled-stress constitutive equation by simply replacing physical stress and pseudo strain with pseudo stress and physical strain. Tensile uniaxial fatigue tests are performed under the controlled-strain mode to determine model parameters. The constitutive equations in terms of pseudo strain and pseudo stress satisfactorily predict the constitutive behavior of asphalt concrete all the way up to failure under controlled-strain and -stress modes, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제23권5호
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• pp.1282-1290
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• 1998

In this paper, the physical layer design of IMT-2000 system being developed by SK Telecom is introuduced. The outband signaling scheme and the two-pilot scheme are adopted for multimedia service and inter-cell asynchronous mode respectively. In addition, the synchronous transmission scheme is proposed to reduce the interference in the reverse link. The algorithm and simulation results of 'two-pilot scheme' for inter-cell asynchronous mode and 'reverse synchronous control' for synchronous transmission are presented.

• Proceedings of the KSME Conference
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.578-583
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• 2007

Many papers have studied computer-aided simulations of elastic bodies undergoing large deflections and large deformations. But there have been few attempts to validate their numerical formulations used in these studies. The main aim of this paper is to validate the absolute nodal coordinate formulation (ANCF) by comparing the results to experimental measurements on beams. Physical experiments with a high-speed camera were carried out to capture the large displacement of the beam and to verify the results of computer simulations. To consider the damping forces, the Rayleigh's damping and quadratic damping are employed and compared to the experimental results, respectively. Numerical results obtained from computer simulations were compared with the results from the physical experiments according to the $1^{st}$ mode and the $2^{nd}$ mode of the beam, respectively.

• Journal of the Korea Safety Management & Science
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• 제8권1호
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• pp.17-26
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• 2006

Basis frame-work's base in a semiconductor industry have gas, chemical, electricity and various facilities in bring to it. That it is a foundation by fire, power failure, blast, spill of toxicant huge by large size accident human and physical loss and damage because it can bring this efficient, connect with each kind mechanical, physical thing to prevent usefully need that control finding achievement factor of human factor of human action. Large size accident in a semiconductor industry to machine and human and it is involved that present, in system by safety interlock defect of machine is conclusion for error of behaviour. What is not construing in this study, do safety in a semiconductor industry to do improvement. Control human error analyzes in human control with and considers mechanical element and several elements. Also, apply achievement factor using O'conner Model by control method of human error. In analyze by failure mode effect using actuality example.

• Geomechanics and Engineering
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• 제32권5호
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• pp.475-482
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• 2023

This paper studies the effect of the relaxation time on a two-dimensional thermoelastic medium which has a doubly porous structure in the presence of diffusion and gravity. The normal mode analysis is used to obtain the analytic expressions of the physical quantities, which we take the solution form in the exponential image. We have discussed a homogeneous thermoelastic half-space with double porosity with the effect of diffusion and gravity. The equations of generalized thermoelastic material with double porosity structure with one relaxation time have been developed. Moreover, the expressions of many physical quantities are explained. The general solutions, under specific boundary conditions of the problem, were found in some detail. In addition, numerical results are computed.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• 제11권2호
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• pp.26-39
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• 2005

The purpose of this descriptive study is to investigate the general knowledge and attitude about HIV/AIDS among gender in physical therapists and physical therapy students. AIDS a clinical syndrome that involves progressive immune deficiency and consequent development of opportunistic infection, tumors, neurologic disease and systemic wasting with chronic trends. Many medical specialists are afraid of AIDS patients because they have a little information of AIDS and fear of HIV infection from AIDS patients at work site. This study surveyed 649 physical therapists and physical therapy students by means of a self-administered questionnaire. This study was carried out from April, 2003 to October, 2003 for collecting data. The findings of this study can be summarized as follows. 1) The male and female physical therapist and physical therapy students who have an experience of educational program for HIV/AIDS show higher general knowledge about HIV/AIDS. 2) The male physical therapist and physical therapy students were conscious of the need for physical therapeutic intervention for the complication of HIV/AIDS. 3) The male who has higher general knowledge about HIV/AIDS are conscious of the need for educational program about HIV/AIDS. 4) The male and female want to have the choice to accept or reject the HIV/AIDS patients for treatment. 5) The knowledge of transmission mode in sexual intercourse of HIV/AIDS influence the attitude of male and female to patients with HIV/AIDS. 6) The knowledge of prevention of HIV/AIDS influence the attitude of male and female to patients with HIV/AIDS. 7) The knowledge of regarding symptom of HIV/AIDS influence the attitude of female to patients with HIV/AIDS. 8) The knowledge of general transmission mode of HIV/AIDS influence the attitude of male and female to patients with HIV/AIDS. 9) The knowledge of transmission risk factors in work site of HIV/AIDS influence the attitude of male and female to patients with HIV/AIDS. 10) The knowledge of needs for prevention in work site of HIV/AIDS influence the attitude of male and female to patients with HIV/AIDS. In conclusion, male and female with more knowledge of HIV/AIDS could positively treat HIV/AIDS patients.

• SUVANNABHUMI
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• 제15권1호
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• pp.35-59
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• 2023

This study examined adolescent male and female students' attitudes toward physical education (PE) from the Philippines and South Korea. Participants were 451 middle school students from the Philippines and South Korea. The Physical Education Attitude Scale (PEAS) was used to measure students' PE attitudes. Overall, students had moderately positive attitudes toward PE. PE attitudes of Korean boys were more positive compared with Filipino boys, while the reverse was found for Korean females and their Filipino counterparts. Based on the different aspects of PE, Filipino girls were more motivated to participate in PE activities and more satisfied with their PE class than Korean girls. Korean boys were highly satisfied, more comfortable, and less anxious during PE compared with Filipino boys. Finally, Filipino boys had less positive view towards their PE teacher than Korean boys. This study shows adolescent students' attitudes toward PE were generally positive, complex, and affected by sex and nationality. It also provides additional knowledge on comparative international research on cross-cultural PE attitudes.

• Journal of Korean Society for Atmospheric Environment
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• 제15권2호
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• pp.175-182
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• 1999

Scanning electron microscopy (SEM) has played an important role in receptor modeling area because it is a powerful tool for characterizing individual particles. The purpose of the study was to classify individual diesel particles base on statistical analysis and image analysis by SEM/EDX (energy dispersive x-ray analyser). The diesel particles were sampled by both a modified CVS 75 mode and a high speed mode with a chassis dynamometer. The SEM/EDX system provides various physical parameters including particle's particle diameter and chemical information. Thus density and mass of the diesel particle were estimated cased on its chemical composition and further fractal dimensions of the diesel particle were obtained by the Hurst exponent method. The fractal dimension in the sample of modified CVS 75 mode was higher than the high speed mode. Finally, mass fractions for a diesel vehicle as a source profile were estimated cased on a particle class concept.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.103.1-103
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• 2002

In variable structure control algorithms, The control law used to realized the desired sliding mode dynamics is discontinuous on the switching manifold. However, due to imperfections in switching, such as time delays, the system trajectory chatters instead of sliding along the switching manifold. This chattering is undesirable because it may excite unmodeled high frequency dynamics in the physical system. In this paper, to overcome this drawback a self-organizing fuzzy sliding mode control algorithm using gradient descent method is proposed. The proposed method has the characteristics which are viewed in conventional VSC, e.g. insensitivity to a class of disturbance, parameter variations and uncertainties ill the sliding mode. To demonstrate its performance, the proposed control algorithm is applied to an inverted pendulum system. The results show that both alleviation of chattering and performance are achieved.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제26권1호
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• pp.113-120
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• 2002

Experimental procedure to measure fracture toughness (J$_{c}$) under mixed mode loading using CTS(Compact Tension-Shear) specimens is described. It\`s loading angle ranges from 0$^{\circ}$ to 45$^{\circ}$ with interval of 157. The general outline of experimental procedure is similar to that of ASTM E8l3-89 fur mode I fracture. Equations fur determining J-integral is quoted from the authors' previous works. The relation between unloading compliance and physical crack size was calibrated. As an example, fracture toughness of aluminum alloy 2024p-7361 was measured and some reasonable results of J$_{c}$ with various loading angles were obtained.