• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.327-335
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• 2009

In the seismic region, non-ductile structures often form soft story and exhibit brittle collapse. However, structure demolition and new structure construction strategies have serious problems, as construction waste, environmental pollution and popular complain. And these methods can be uneconomical. Therefore, to satisfy seismic performance, so many seismic retrofit methods have been investigated. There are some retrofit methods as infill walls, steel brace, continuous walls, buttress, wing walls, jacketing of column or beam. Among them, the infilled frames exhibit complex behavior as follows: flexible frames experiment large deflection and rotations at the joints, and infilled shear walls fail mainly in shear at relatively small displacements. Therefore, the combined action of the composite system differs significantly from that of the frame or wall alone. Purpose of research is evaluation on the seismic performance of infill walls, and improvement concept of this paper is use of SHCCs (strain-hardening cementitious composites) to absorb damage energy effectively. The experimental investigation consisted of cyclic loading tests on 1/3-scale models of infill walls. The experimental results, as expected, show that the multiple crack pattern, strength, and energy dissipation capacity are superior for SHCC infill wall due to bridging of fibers and stress redistribution in cement matrix.

• The KIPS Transactions:PartD
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• v.18D no.1
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• pp.9-22
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• 2011

In this paper we present an efficient solution to rotation?invariant boundary image matching. Computing the rotation-invariant distance between image time-series is a time-consuming process since it requires a lot of Euclidean distance computations for all possible rotations. In this paper we propose a novel solution that significantly reduces the number of distance computations using the envelope-based lower bound. To this end, we first present how to construct a single envelope from a query sequence and how to obtain a lower bound of the rotation-invariant distance using the envelope. We then show that the single envelope-based lower bound can reduce a number of distance computations. This approach, however, may cause bad performance since it may incur a larger lower bound by considering all possible rotated sequences in a single envelope. To solve this problem, we present a concept of rotation interval, and using the rotation interval we generalize the envelope-based lower bound by exploiting multiple envelopes rather than a single envelope. We also propose equi-width and envelope minimization divisions as the method of determining rotation intervals in the multiple envelope approach. Experimental results show that our envelope-based solutions outperform existing solutions by one or two orders of magnitude.

• Journal of Korean Academy of Nursing Administration
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• v.7 no.1
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• pp.127-144
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• 2001

The purpose of this study is to provided a basic administrative data for effective personnel management of nurses' by investigation their assessment and satisfaction with the job rotation and by analyzing the relation between their satisfaction and organizational commitment. Data were collected from Nov. 20 to Nov. 25, 2000 through self-reporting questionnaires taken by 280 nurses working at a university hospitals The 3 structured instruments were used for collecting the data; Questionnaires for measuring the utility and the problem of job rotation, Questionaires for measuring the satisfaction with the job rotation, and Mowday's Organizational Commitment Questionnaires. The data obtained were analyzed using frequency, percentage, average, standard deviation, range, Cronbach's alpha coefficients, Peason's correlation coefficients, t-test, one-way ANOVA, and chi-square test, multiple regression. The Results were as follows : 1. The supporters for regular job rotation account for 67% while the opponents to it account for 33%. The chief reason for endorsing the regular job rotation is quoted ${\lceil}$to attain more diverse job experiences${\rfloor}$, followed in order by ${\lceil}$to improve the job motivation and morale through the realization of personal needs${\rfloor}$, ${\lceil}$to place the right man in the right position${\rfloor}$. The reasons for opposing to the regular job rotation were listed in order ${\lceil}$difficulties to secure the expertise of nursing${\rfloor}$, ${\lceil}$personal needs not fully reflected in the job rotation${\rfloor}$, ${\lceil}$job rotations prompted rather by the administrative needs than by personal aptitude and ability${\rfloor}$. 2. In the assessment of job rotation, the points affirming the utility of the job rotation are $2.60({\pm}.66)$ out of possible 5 points and those admitting the problems the job rotation are $3.58({\pm}.59)$. The satisfaction with the job rotation is rated at $2.98({\pm}.55)$. 3. In the analysis into the relation between the assessment of job rotation and satisfaction with the job rotation, fairly high positive correlation is revealed between the satisfaction and utility of job rotation, whereas, considerably high negative correlation is seen between the satisfaction and problems with the job rotation(p=.000). 4. There is relatively high positive correlation between the satisfaction with the job rotation and organizational commitment(p=.000). In conclusion, the utility of on the job rotation and their satisfaction with the job rotation have positive correlation and the satisfaction with the job rotation and organizational commitment showed the positive correlation, too. Therefore, it is thought desirable to take administrative strategies well as education to improve the recognition of the job rotation's utility and to reduce the recognition of the problems with the job rotation to remain in the direction toward contributing to enhancement of the organizational commitment.

• Progress in Medical Physics
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• v.24 no.4
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• pp.290-294
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• 2013

Stereotactic Radiosurgery require high accuracy and precision of patient positioning and target localization. We evaluate the real time positioning accuracy of isocenter using optic guided patient positioning system, ExacTrac (BrainLab, Germany), during spinal radiosurgery procedure. The system is based on real time detect multiple body markers attached on the selected patient skin landmarks. And a custom designed patient positioning verification tool (PPVT) was used to check the patient alignment and correct the patient repositioning before radiosurgery. In this study, We investigate the selected 8 metastatic spinal tumor cases. All type of tumors commonly closed to thoracic spinal code. To evaluate the isocenter positioning, real time patient alignment and positioning monitoring was carried out for comparing the current 3-dimensional position of markers with those of an initial reference positions. For a selected patient case, we have check the isocenter positioning per every 20 millisecond for 45 seconds during spinal radiosurgery. In this study, real time average isocenter positioning translation were $0.07{\pm}0.17$ mm, $0.11{\pm}0.18$ mm, $0.13{\pm}0.26$ mm, and $0.20{\pm}0.37$ mm in the x (lateral), y (longitudinal), z (vertical) directions and mean spatial error, respectively. And body rotations were $0.14{\pm}0.07^{\circ}$, $0.11{\pm}0.07^{\circ}$, $0.03{\pm}0.04^{\circ}$ in longitudinal, lateral, table directions and mean body rotation $0.20{\pm}0.11^{\circ}$, respectively. In this study, the maximum mean deviation of real time isocenter positioning translation during spinal radiosurgery was acceptable accuracy clinically.