• Fibers and Polymers
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• 제5권3호
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• pp.225-229
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• 2004

The effect of UV and $^60{Co}$ gamma radiations on the physical and mechanical properties of nylon 6 mono-filaments with different draw ratios has been studied. Specimens were exposed to either up to 25 Mrad of gamma or up to 168 hrs of intense UV irradiation. The results show that nylon mono-filaments exposed to gamma rays, with much higher quantum energy than UV, undergo a larger extent of molecular chain scission. Higher irradiation dose also results in the production of insoluble, macroscopic three-dimensional cross-linked network structure. The amorphous regions with a lower density of cohesive energy (lower molecular orientation) show a higher extent of cross linking reaction whereas amorphous regions with a higher density of cohesive energy (higher orientation) show higher extent of chain scission reaction, irrespective of UV ray or gamma ray irradiation.

• 대한기계학회논문집A
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• 제24권8호
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• pp.1968-1799
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• 2000

A warpage analysis program has been developed for fiber-reinforced injection molded parts. The warpage is predicted from the residual stress and anisotropic thermo-mechanical properties coupled with fiber orientation in the integrated injection molding simulation. A simple elastic model is used for the calculation of thermally and pressure-induced residual stresses which are employed as the initial conditions in the structural analysis. To improve the reliability of warpage analysis, a new triangular flat shell element superimposing well-known efficient plate bending and membrane element is presented. The numerical examples address the necessity to use anisotropic models for fiber-reinforced materials and show that predicted warpage is in good agreement with experimentally measured one.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.402-405
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• 1997

Based on the relative velocity method and the inverse kinematics theory, this paper presents an automated system for designing and manufacturing of an open type cylindrical cam with a rotating follower(OCRF). In the first part, this paper defines the relative velocity method for OCRF and calculates the contact point by using the coordinate transformation technique. In the second part, it generates NC Code of a CNC machine center for inverse kinematics by using the cutter location and the cutter orientation of OCRF. Finally, the automated CADICAM program developed in the paper shows an example on the desip and manufacture process of OCRF.

• 대한기계학회논문집A
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• 제24권9호
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• pp.2266-2273
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• 2000

Equations of motion of a multi-beam system undergoing overall rigid body motion are derived by employing finite element method. An orientation angle is employed to allow the arbitrary orientation o f the beam element. Modal coordinate reduction technique, which has been successfully utilized in the conventional linear modeling method, is employed for the present modeling method to reduce the computational effort. Different from the conventional linear modeling method, the present modeling method captures the motion-induced stiffness variations which are important for the dynamic analysis of structures undergoing overall rigid body motion. The numerical results are compared to those of a commercial program to verify the reliability of the present method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.745-750
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• 2000

A warpage analysis program has been developed for fiber-reinforced injection molded parts. The warpage is Predicted from the residual stress and anisotropic thermo-mechanical properties coupled with fiber orientation in the integrated injection molding simulation. A simple elastic model is used for the calculation of thermally and pressure-induced residual stresses which are employed as the initial conditions in the structural analysis. To improve the reliability of warpage analysis, a new triangular flat shell element superimposing well-known efficient plate bending and membrane element is presented. The numerical examples address the neccesity to use anisotropic models for fiber-reinforced materials and show that predicted warpage is in good agreement with experimentally measured one.

• 가정과삶의질연구
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• 제21권3호
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• pp.1-13
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• 2003

The purpose of this study is to understand the importance of exterior environments and to identify the design guidelines for the therapeutic garden for cognitively impaired seniors with Alzheimer's disease and related dementias. The data was collected from 4 Adult Day Care Centers, 2 Nursing Homes, & 1 Assisted living in the U.S.A. from 2001 to 2002 by interview and the floor plan about the outdoor space. Although some may believe that patients with Alzheimer's disease and related disorders are unresponsive to environment, evidence shows that environments especially designed for cognitively impaired seniors can maintain or increase their level of functioning. The use of specially designed exterior environments nay have in reducing incidents of aggressive behavior, and contributing significantly to a wanderer management program. The checklist includes 6 dimensions： safety environment, various sensual stimulations, social interactions, wandering, privacy, and support orientation and reality. The results indicated that the exterior environment have to support wandering behavior, orientation and reality.

• 한국태양에너지학회 논문집
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• 제25권4호
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• pp.119-123
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• 2005

The main purpose of this study is to define an optimum slope of the roof that demands minimum cooling load of the building, when the roof is affected by the solar and wind energy. Two different roof shapes were chosen: hip, gabled. The cooling load of building having those roof shapes was calculated through the computer simulation, using DOE program. For the simulation, the angle of the roof and angle of the orientation was changed. In the conclusion of this paper, an optimum slope of the roof which causes minimize cooling load is presented according to the roof shape and orientation. The result of this study could provide a practical design guideline for determining the roof angle for various climatic conditions.

• 한국IT서비스학회지
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• 제12권4호
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• pp.307-318
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• 2013

This study developed the prevention education program of smartphone overuse for adolescents in middle school and testified its outcome. Finally the 4-session prevention education program for smartphone overuse was developed. 1st session was composed of psychoeducation about smartphone overuse and its side effect by quiz question. 2nd session smartphone addiction and brain change, 3rd session motivational enhancement program for smartphone overuse, 4th session cognitive behavioral program for it. The outcome was testified by internet addiction scale, smartphone addiction scale, and school adaptation scale for 2 classes of middle school students(experimental and control class). 2 Main results were as follows; First, the smartphone addiction total score and cyberworld orientation of the students participating in it were statistically significantly reduced. The difficulty of daily living and abstinence symptom due to smartphone overuse of them tended to reduce. Second, internet addiction total and all subscores of them were not changed. Third, class adaptation of them was statistically significantly increased and school adaptation total score and teacher adaptation of them tended to increase. Its meaning, implication and limitation were discussed.

• 한국초등과학교육학회지:초등과학교육
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• 제25권spc5호
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• pp.522-531
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• 2007

A Science Camp Program was developed and applied as an intensified course for gifted students. The implications for the development and implementation of out-of-school science activities were also deduced through the analysis of the preliminary application results. The key point of the science camp program is to boost students' science inquiry skills through self-directed activities. Several positive effects in terms of interest and participation in the program were observed and some implications were derived as follows; (1) The program should provide the students with more opportunities for discussion and debate in group activities. (2) The tasks need be divided into two parts; basic tasks and optional tasks in order to ensure that the students engage in fewer tasks more intensively. (3) Each activity needs sufficient orientation taking consideration of the possibility that not all students may be ready for the inquiry. (4) The use of real examples of scientific research processes can help the students develop open inquiry skills and problem posing skills.

• 한국간호교육학회지
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• 제24권4호
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• pp.443-452
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• 2018

Purpose: This purpose of this study was to examine the effects of a rational emotive behavior therapy (REBT) counseling program on self-efficacy and adjustment to college life for nursing freshmen. Methods: This study used a nonequivalent control pretest-posttest quasi-experimental design. Thirty-eight new nursing students were randomly assigned to either an experimental group (n=18) or a control group (n=20) recruited from a four-year nursing college. An REBT counseling program was composed of 8 group sessions of orientation, understanding the theory of REBT, finding irrational beliefs, internalizing rational beliefs, and closing over a duration of 5 weeks. The duration of each session was 90 minutes. Self-efficacy and adjustment to school life were measured by the Sherer's Self-Efficacy Scale and Baker & Siryk's Student Adjustment to College before and after the REBT counseling program. Data were analyzed using t-tests and paired t-tests. Results: The experimental group showed a significant improvement in self-efficacy compared to the control group. There was no significant change in college life adjustment between the experimental and control groups. Conclusion: An REBT counseling program could be applied as an effective program in enhancing self-efficacy resulting in positive and goal-oriented behavior for new nursing students in college.