• Journal of The Korean Astronomical Society
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• v.37 no.5
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• pp.337-342
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• 2004

The presence of magnetic fields in the intracluster medium in clusters of galaxies has been revealed through several different observational techniques. These fields may be dynamically important in clusters as they will provide additional pressure support to the intracluster medium as well as inhibit transport mechanisms such as thermal conduction. Here, we review the current observational state of Faraday rotation measure studies of the cluster fields. The fields are generally found to be a few to 10 $\mu$G in non-cooling core clusters and ordered on scales of 10 - 20 kpc. Studies of sources at large impact parameters show that the magnetic fields extend from cluster cores to radii of at least 500 kpc. In central regions of cooling core systems the field strengths are often somewhat higher (10 - 40 $\mu$G) and appear to be ordered on smaller scales of a few to 10 kpc. We also review some of the recent work on interpreting Faraday rotation measure observations through theory and numerical simulations. These techniques allow us to build up a much more detailed view of the strength and topology of the fields.

• Transactions of Materials Processing
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• v.19 no.8
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• pp.480-485
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• 2010

In this work, the closing behavior of cylindrical-shaped voids was experimentally investigated according to various parameters such as reduction ratio in height, initial void size and billet rotation during hot open die forging process. The reduction ratio in height, number of path, and billet rotation were chosen as key process parameters which influence the void closing behavior including the change of void shape and size. On the other hand, values of die overlapping and die width ratio were set to be constant. Void closing behavior was estimated by microscopic observation. Based on the observations, it was confirmed that application of billet rotation is more efficient to eliminate the void with less reduction ratio in height. The experimental results obtained from this study could be helpful to establish the optimum path schedule of open die forging process.

• Computers and Concrete
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• v.25 no.5
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• pp.471-478
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• 2020

In this work, the analytical solution for the stresses in piezo-thermo-elastic homogeneous, transversely isotropic material under the effect of the rotation has investigated. The thermoelasticity theory has used to study the problem. The material subjected to boundary conditions. Finally, the numerical solution has carried out piezo - thermo-elastic material under the effect of rotation, to illustrate the analytical development. The corresponding simulated results of various physical quantities such as the displacements and the stresses, the temperature and the electrical displacement have presented graphically.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.8
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• pp.798-804
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• 2006

To overcome the limited relative uncertainty and work range of the existing planar stage and the bulk structure of the contact-less motor for rotation, the novel operating principle to realize the precise rotation is suggested. It uses the two-axial vector forces, normal force and thrust force, of three-induction type of axial motors located $120^{\circ}$ apart, resulting in the contact-free rotation of the mover. Firstly in this paper, the magnetic forces across the air gap are modeled and simulated under the various conditions. It clarifies the feasible range of the derived solution. And the algorithm compensating the strong cross couple between the forces and the control inputs; generally AC magnitude and slip frequency, is given to realize the independent control of six axes. Finally, for the successfully implemented system, the round test and the micro step test results are given.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.3
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• pp.425-444
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• 1999

The purpose of this study is to survey evaluation of the nurse on the current Performance Appraisal System. the need for future performance of the nurse and the opinions about the job rotation, and suggest the direction of improvement by obtaining basic data to improve personnel management of the nurse in a hosipial, the subject of the investigation. The study was conducted self-reporting questionniare survey of 330 nurses working at C hospital located in Chonbuk Province and the data was collected from May 4. 1999 through May 14. The research used measuring instrument developed by researcher for evalution about the present performance appraisal. the need for the future performanc appraisal system and the opinion of job rotaion. The analysis of the collected data was computerized using SPSS/PC+ program, calculated frequency, percentage, the mean and standard deviation and used Pearson, s Correlation Coefficients, t-test, chi- square test. Major findings are as follows. 1) As for the purpose of the current performanc appraisal, the appraiser recognized it as a security of promotion standard, while the employee saw it as a means for control as guidance and supervison of work. 2) With regard to use the result of the present performance appraisal, appraiser picked ambiguous appraisal standard, employees recognized unilateral evaluation of superior eliminated the participation of them as the highest priority. 3) In relation to the current criteria for promotion of the nurse, both appraisers and employees placed more weight on the length of clinical than performance appraisal score. 4) There is much possibility of the appraiser making an error to evaluate considering the length of performance appraisal. 5) Both appraisers and employees indicated that prospective result of performance appraisal should be used for the ability development & motivation of the individual. 6) Concerning employee's participation for performance appraisal both sides wanted by far more participation. 7) Regarding the most ideal appraisal method, both parties favored most the way added up the evaluation of the head nurse and peer review and followed by the manner the revaluation of the head nurse by considering self-evaluation. 8) As to the individual interview after the appraisal, more than 60% of appraisers responded it's not necessary, while above 88.5% of employees answered it is essential so that it is showed significantly difference between the appraisers and the employees. 9) As far as open of the evaluation result is concerned. 75% of the appraiser were against it but 80% of the employee were for it so that it showed significantly between them. The most principal reason that the employee want is that it motivates the individual's ability development and the fairness of the appraisal increases. 10) Whether the periodical rotation is necessary or not, 80% of appraisers and employees answered it's necessary, however, over 70% of them did not want the rotation. 11) Work-group Cohesiveness level within the nursing unit was attentive different from desire of the rotation, that is, the work group cohesiveness level of nurses wanting rotation was significantly lower than that of the group not desiring it.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.3 no.2
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• pp.117-124
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• 1993

It was found that the basic principle of continuous crystal growth method was following as; the powder supplied from the feeding system is molten in the graphite crucible under the ambient gas. After forming the molten zone in the lower part of the crucible, the seed crystal is deeped into the melt and pulled down with the rotation so that the melt crystallized from the seed. When the lowering rate, rotation rate, feeding rate and temperature are correct, the single crystal can grow. The critical melt level, the feeding rate, the growth rate, the change of the shape of molten zone by the graphite susceptor and crucible, the position of work coil, the balance between the gravitational force of melt and the centrifugal force originated from the rotation of seed which are the variables of the crystal growth and the sintering phenomenon of melt surface were researched.

• Safety and Health at Work
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• v.7 no.2
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• pp.124-129
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• 2016

Background: Work-related fatigue has a strong impact on performance and safety but so far, no agreed upon method exists to detect and quantify it. It has been suggested that work-related fatigue cannot be quantified with just one test alone, possibly because fatigue is not a uniform construct. The purpose of this study is therefore to measure work-related fatigue with multiple tests and then to determine the underlying factorial structure. Methods: Twenty-eight employees (mean: 36.11; standard deviation 13.17) participated in five common fatigue tests, namely, posturography, heart rate variability, distributed attention, simple reaction time, and subjective fatigue before and after work. To evaluate changes from morning to afternoon, t tests were conducted. For further data analysis, the differences between afternoon and morning scores for each outcome measure and participant (${\Delta}$ scores) were submitted to factor analysis with varimax rotation and each factor with the highest-loading outcome measure was selected. The ${\Delta}$ scores from tests with single and multiple outcome measures were submitted for a further factor analysis with varimax rotation. Results: The statistical analysis of the multiple tests determine a factorial structure with three factors: The first factor is best represented by center of pressure (COP) path length, COP confidence area, and simple reaction time. The second factor is associated with root mean square of successive difference and useful field of view (UFOV). The third factor is represented by the single ${\Delta}$ score of subjective fatigue. Conclusion: Work-related fatigue is a multidimensional phenomenon that should be assessed by multiple tests. Based on data structure and practicability, we recommend carrying out further studies to assess work-related fatigue with manual reaction time and UFOV Subtest 2.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.64-70
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• 2017

In the commercial building such as huge enterprise building, more accurate operation of the center-controlled roller blind. We design, in this work, the target disc that its shape is nonlinearly changing and the sensor coils that are differentially arranged. The performance shows less than 1% accuracy when it is implemented in the roller blind.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.91-97
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• 2000

Anisotropic work hardening of cold rolled low carbon steel sheets is studied. The experiments consist of two stage tensile prestraining and tensile tests. At the first prestraining, steel sheets are streteched along the rolling direction by 3% and 6% tensile strains. The second prestrains are at 0${\cric}$, 30${\cric}$, 60${\cric}$to the rolling directions by varying degrees. Tensile tests are performed on the specimens cut from the sheets after the two stage prestraining. A theoretical framework on anisotropic hardening is proposed which includes Hill's quadratic yield function, ziegler's kinematic hardening rule, and Kim and Yin's assumption on the rotation of orthotropy axes. The predicted variations of R-values with second stage tensile strain are compared with the experimental data.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.341-344
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• 2006

Finite element analysis and verification experiments were performed in order to find cause of defects such as folding and improper radius around the root area of the thread rolled stud bolts. Thread rolling experiments under several conditions were also carried out to understand the effect of process parameters, such as the rotation speed of the dies and the hardness of the work pieces, on the product quality. Folding defects at the top of thread are attributed to the higher hardness of the work piece and higher rotation speed of the rolling die. It was also found that the radius of screw mainly determined by the radius of the die.