• Journal of Educational Research in Mathematics
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• v.25 no.3
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• pp.303-321
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• 2015

This research purposes to find out the mathematical cognitive characteristics of Korean students and compare it with that of TIMSS 2011 high-achieving countries based on the Cognitive Diagnostic Theory. Based on framework and questions of TIMSS 2011, we select cognitive attributes. Using the data of 8th grade students' mathematical achievement in TIMSS 2011, we compare and analyze the top 15-countries students' cognitive traits. As a result, cognition domain of TIMSS 2011 is reclassified as 9 cognitive attributes. we could distinguish between easy attributes and difficult attributes that students in each country relatively think. Especially, Students of Korea relatively think Recall/Recognize, Compute, Classify/Measure and Represent are easy. On the other hand, relatively they have difficulties in Retrieve, Implement, and Generalize. Based on this research result, It is necessary to establish an educational measures for each attributes which students have difficulties.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.5
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• pp.471-478
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• 2011

High resolution Pan-sharpening technique is becoming increasingly important in the field of remote sensing image analysis as an essential image processing to improve the spatial resolution of original multispectral image. The general scheme of pan-sharpening technique consists of upsampling process of multispectral image and high-pass detail injection process using the panchromatic image. The upsampling process, however, brings about image blurring, and this lead to spectral distortion in the pan-sharpening process. In order to solve this problem, this paper presents a new method that adopts image restoration techniques based on optimization theory in the pan-sharpening process, and evaluates its efficiency and application possibility. In order to evaluate the effect of image restoration techniques on the pansharpening process, the result obtained using the existing method that used bicubic interpolation were compared visually and quantitatively with the results obtained using image restoration techniques. The quantitative comparison was done using some spectral distortion measures for use to evaluate the quality of pan-sharpened image.

• Journal of Korean Physical Therapy Science
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• v.20 no.1
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• pp.43-49
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• 2013

Background and purpose : The shoulder joints permit the greatest mobility of any joint area carries out the important function of stabilization for hand use. Research has now shown that grip strength has proven to be a reliable indicator for quality of life at an older age. The purpose of this study was to investigate the effects of testing posture and shoulder position on grip strength for repetitive gripping task. Methods : Forty(20male, 20female) college adult volunteers with no known shoulder dysfunction participated subject in two testing posture(sitting and standing) and three positions with shoulder flexion: (1) shoulder $0^{\circ}$ flexion (2) shoulder $90^{\circ}$ flexion (3) shoulder $180^{\circ}$ flexion. The paired t-test was used to determine any significant difference in grip strength between the testing posture and shoulder position. Results : The higher grip strength gained in the sitting with the shoulder $180^{\circ}$ flexion and the higher grip strength gained in the standing with the shoulder $180^{\circ}$ flexion. The second experiment showed that the grip strength was significant for sitting, standing position of shoulder $0^{\circ}$ flexion( p<0.05). Grip strength goes up as increase height and weight. Conclusion : These findings demonstrate that the theory does not fit with, because of the influence of gravity, a measure from the shoulder joint is the most high, $0^{\circ}$. And sitting posture and stance in the grip of a difference when compared SIT $0^{\circ}$ and standing position $0^{\circ}$ significant difference in indicated but, $90^{\circ}$ and $180^{\circ}$ in the sitting position and stance in the grip of the difference was not significant difference. To demonstrate the universality of this study's results, future studies should have a larger and more subject as well as a more even distribution of male and female subject. Therefore future research is needed to refine the definition and identify optimal methods of measuring this grip strength.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.4
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• pp.291-303
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• 2009

Round robin based proportional share scheduling(RRPS) defines weight which determines share for each task and allocates CPU resource to each task in proportional to its respective weight. RRPS uses fairness as the measure of performance and aims at high fairness of scheduling. However, researches for scheduling fairness problem due to synchronization among tasks have been rarely investigated. In this paper, we discuss that scheduling delay due to synchronization may result high unfairness in RRPS. We explain such a situation as weight inversion. We then propose weight inheritance protocol(WIP), a synchronization mechanism, that prevents weight inversion. We also show that WIP can reduce unfairness using fairness analysis and simulation.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.4
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• pp.387-401
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• 2007

Recently, because of the restriction of land for construction and interference of adjacent structure, parallel tunnels with small clearance have been planned and constructed in many sites. In this case, the stability of pillar at center part is very important factor to satisfy the stability of tunnel structure under the construction. In this paper, numerical analyses for the asymmetry parallel tunnels with a narrow width of pillar have been carried out to search for the optimum reinforcement measure for rock pillar and verify the stability of tunnel. Rock pillar between each single tunnel is supposed to be under heavy load by rock mass. The analysis of stress state at rock pillar at various cases for construction conditions is required to investigate the structural behaviour of tunnels and stability of the pillar. Strength-stress ratio is calculated based on the failure theory of rock and the safety factor of tunnel is computed with strength reduction technique. Through these numerical results, reasonable reinforcement measures for rock pillar at parallel tunnel were established and recommended.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.9_10
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• pp.417-420
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• 2008

We consider the problem of optimizing the performance of a system shared by selfish non-cooperative users. In this problem, small jobs which the users request should be scheduled on a set of shared machines with their speed functions, each of which dependson the amount of jobs allocated on a machine. The performance of the system is measured by the maximum of the completion times when the machines complete the jobs allocated on them. The selfish users can choose a machine on which their jobs are executed, and they choose the fastest machine. But it typically results in suboptimal system performance. The Price of Anarchy(PoA) was introduced as a measure of the performance degradation due to the user's selfish behavior. The PoA is the worst-case ratio of the cost of a Nash equilibrium to the optimal cost. In this paper, we estimate the PoA for the above scheduling problem.

• Journal of Distribution Science
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• v.15 no.1
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• pp.115-121
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• 2017

Purpose - Although ensuring that all the organizational members know their roles exactly is an important part of managerial work, few studies address the role clarity in food manufacturing and distribution firms. Role clarity refers to the extent to which individuals clearly understand the tasks, duties, responsibilities, and expectations of their work roles (Hinkin & Schriesheim, 2008). The purpose of this study is to examine the effect of the role clarity on organizational commitment and the mediating role of creativity in the role clarity-organizational commitment relationship. Research design, data, and methodology - Data were collected from 297 employees in food manufacturing and distribution firms of Korea by self-evaluations questionnaires. The unit of the analysis for testing is an individual. We proposed four hypotheses: (1) is about the relationship between role clarity and organizational commitment, (2) is about the relationship between role clarity and creativity, (3) is about the relationship between creativity and organizational commitment, and (4) is about the mediating role of creativity. We conducted the hierarchical regression analysis for testing the main and mediating effects. Results - The results of the study indicated that the role clarity was positively associated with organizational commitment and creativity. Results also indicated that the creativity was positively associated with organizational commitment. Especially, the impact of the role clarity on organizational commitment was mediated by creativity. Conclusions - An important contribution of this study is extending prior theory on the relationship between role clarity and organizational commitment by shedding new light on assumptions regarding the mediating effect of creativity. The results demonstrate that the role clarity has an indirect effect as well as a direct effects on organizational commitment. Our research suggests important implications for organizations that pursue to stimulate their employees' creativity, emphasizing the importance of the role clarity. This study has several potential limitations. Maybe the most serious limitation is its cross-sectional study design. Another limitation is the use of employees' self-reports to measure the variables. In the future, researchers should employ a longitudinal study design and use diverse sources of data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.185-191
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• 1999

Mathematical morphology based on set theory has been applied to various areas in image processing. Pitas proposed a object recognition algorithm using Morphological Shape Decomposition(MSD), and a new representation scheme called Morphological Shape Representation(MSR). The Pitas's algorithm is a simple and adequate approach to recognize objects that are rotated 45 degree-units with respect to the model object. However, this recognition scheme fails in case of random rotation. This disadvantage may be compensated by defining small angle increments. However, this solution may greatly increase computational complexity because the smaller the step makes more number of rotations to be necessary. In this paper, we propose a new method for object recognition based on MSD. The first step of our method decomposes a binary shape into a union of simple binary shapes, and then a new tree structure is constructed which ran represent the relations of binary shapes in an object. finally, we obtain the feature informations invariant to the rotation, translation, and scaling from the tree and calculate matching scores using efficient matching measure. Because our method does not need to rotate the object to be tested, it could be more efficient than Pitas's one. MSR has an intricate structure so that it might be difficult to calculate matching scores even for a little complex object. But our tree has simpler structure than MSR, and easier to calculated the matchng score. We experimented 20 test images scaled, rotated, and translated versions of five kinds of automobile images. The simulation result using octagonal structure elements shows 95% correct recognition rate. The experimental results using approximated circular structure elements are examined. Also, the effect of noise on MSR scheme is considered.

• Korean Journal of Oriental Medicine
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• v.6 no.1
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• pp.69-80
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• 2000

Objectives : Assuming that the characteristic of meridian system has been similar to this of electric potentials in human body and that measurements of electric potential at well(井穴) and sea(合穴) points in branches of the twelves meridians will be representative of measurements of the twelve meridians, to measure the electric potentials in twenty healthy volunteers when they were sleeping or waking respectively, to do significance test for electric potential of meridian system between hand and foot meridian, yin and yang meridian, exterior and interior of the body, and among the five elements. Methods : When twenty healthy volunteers were sleeping, their electric potentials of well and sea points in branches of the twelve meridians were simultaneously measured by physiograph. After a minute we measured them again, totally 5 times. And then when they were waking, their electric potentials were measured 5 times by the above method. Results : Measurements were analyzed by statistical t-test, we obtained that the left side electric potential of hand or yin meridian was significantly different from that of foot or yang meridian both sleeping and waking. The right side of electric potential was the same result as the left side's. Most of the t-test was significant between exterior and interior of the body, and among the five elements. That meaned that it was partly possible to apply the ancient theory of meridians to the study of electric potential at well and sea points in branches of the twelves meridians.

• Journal of Power Electronics
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• v.3 no.2
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• pp.99-114
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• 2003

This paper presents a feasible development on a highly accurate quick response adjustable speed drive implementation fur general purpose induction motor which operates on the basis of sensorless slip frequency type vector controlled sine-wave PWM inverter with an automatic tuning machine parameter estimation schemes. In the first place, the sensorless vector control theory on the three-phase voltage source-fed inverter induction motor drive system is developed in slip frequency based vector control principle. In particular, the essential procedure and considerations to measure and estimate the exact stator and rotor circuit parameters of general purpose induction motor are discussed under its operating conditions. The speed regulation characteristics of induction motor operated by the three-phase voltage-fed type current controlled PWM inverter using IGBT's is illustrated and evaluated fur machine parameter variations under the actual conditions of low frequency and high frequency operations for the load torque. In the second place, the variable speed induction motor drive system, employing sensorless vector control scheme which is based on three -phase high frequency carrier PWM inverter with automatic toning estimation schemes of the temperature -dependent and -independent machine circuit parameters, is practically implemented using DSP-based controller. Finally, the dynamic speed response performances for largely changed load torque disturbances as well as steady state speed vs. torque characteristics of this induction motor control implementation are illustrated and discussed from an experimental point of view.