• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.18 no.2
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• pp.67-75
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• 2012

Background: Hemiplegic patients have the problems of the balance and weight shifting to the affected leg in walking. The aim of this study was to investigate the effect of unilateral stepping exercise combined with auditory feedback on balance and walking ability of the hemiplegic patients. Methods: Thirty hemiplegic patients were allocated in study group (n=15) or control group (n=15). General exercise and weight supporting exercise were conducted for the control group, and general exercises and unilateral stepping exercise combined with auditory feedback were conducted for the study group. Exercise were conducted three times a week for six weeks. Balance ability was measured by Berg Balance Scale (BBS), postural assessment scale for stroke (PASS), and performance-oriented mobility assessment (POMA). Walking ability was measured by time up and go test (TUG), 10m walk test (10mWT), and six minutes walk test (6MWT). Results: Balance and walking ability were significant increased in both group (p<.05). Balance and walking ability of the study group were more increased than that of the control group (p<.05). Conclusions: Unilateral stepping exercise combined with auditory feedback is more effective than weight supporting exercise to increase on balance and walking ability for the hemiplegic patients.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.229-239
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• 2010

Performing a series of in-situ thermal response tests, the effective thermal conductivity of six vertical closed-loop ground heat exchangers was experimentally evaluated and compared each other, which were constructed in a test bed in Wonju. To compare thermal efficiency of the ground heat exchangers in field, the six boreholes were constructed with different construction conditions: grouting materials (cement vs. bentonite), different additives (silica sand vs. graphite) and the shape of pipe-sections (general U-loop type vs. 3 pipe-type). From the test results, it can be concluded that cement grouting has a higher effective thermal conductivity than that of bentonite grouting, and the efficiency of graphite better performs over silica sand as a thermally-enhancing addictive. In addition, a new 3 pipe-type heat exchanger provides less thermal interference between the inlet and outlet pipe than the conventional U-loop type heat exchanger, which results in superior thermal performance.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.321-324
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• 2002

Hydraulic valve control the pressure and the How of fluid by the hydraulic oil transfered from pump but the ER fluid consists of solid particles of micrometer in size and insulating oil so in the general hydraulic valve. We invented ER-Valve using ER fluid as working fluid. The ER fluid, working fluid of ER-Valve is a functional fluid to represent the feature of fluid according to strength of electric field. In this research we made our own 4 types of plate type ER-Valve which has same surface but different width and length and then we conducted performance test. We measured flow rate and pressure drop of fluid which is flowing in the ER-Valve according to the electric field strength to conduct this test. We modeling ER-Valve relating to ER-Valve system and yield shear stress according to the strength of electric field. We used the pressure drop according to the strength of electric field by differential pressure gauge in the our own made ER-Valve. This test reviewed experimental the special changes of ER-Fluid in the steady flow condition.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.55.2-55.2
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• 2011

This research aims to study the effects of the incidence angle and surface temperature on the power generation performance of a thin-film CIGS solar cell for solar powered unmanned aerial vehicles (UAVs). The test rig consists of a unit CIGS solar cell is installed on a table whose angle is controlled manually. A K-type thermocouple is attached to the solar cell surface for temperature measurements. A solar module analyzer measures the voltage and current generated from the test solar cell. The solar module analyzer also calculates the maximum solar power and efficiency of the solar cell. All test data are acquired in a PC. Test results show that the solar cell efficiency decreases significantly with increasing incidence angle and increasing surface temperature in general. As the incidence angle increases from 0 degree to 90 degree, the solar cell efficiency decreases by 60%. The solar cell efficiency decreases by 10% with increasing solar cell surface temperature from $20^{\circ}C$ to $30^{\circ}C$, for exmaple. The direct cooling method of the solar cell using dry ice decreases dramatically the solar cell surface temperature, thus increasing the solar cell efficiency by 15%.

• The KSFM Journal of Fluid Machinery
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• v.20 no.2
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• pp.63-68
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• 2017

This paper predicts the rotordynamic force coefficients of tilting pad journal bearings (TPJBs) with ball-socket pivot and compares the predictions to the published test data obtained under load-between-pad (LBP) configuration. The present TPJB model considers the pivot stiffness calculated based on the Hertzian contact stress theory. Due to the compliance of the pivot, the predicted journal eccentricity agree well with the measured journal center trajectory for increasing static loads, while the early prediction without pivot model consideration underestimates it largely. The predicted pressure profile shows the significant pressure development even on the unloaded pads along the direction opposite to the loading direction. The predicted stiffness coefficients increase as the static load and the rotor speed increase. They agree excellently with test data from open literature. The predicted damping coefficients increase as the static load increases and the rotor speed decreases. The prediction underestimates the test data slightly. In general, the current predictive model including the pivot stiffness improves the accuracy of the rotordynamic performance predictions when compared to the previously published predictions.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.2
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• pp.31-38
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• 2008

A column test was performed far a new-type column with a quasi static test. An internally confined hollow reinforced concrete column with a corrugated steel tube (ICH RC-CT column) was tested to evaluate its seismic performance. And also, a general solid RC column was tested fur the comparison. The test was performed as planned drift levels. The lateral displacements and the lateral loads of column specimens were measured during tests. From the test results, the ICH RC-CT column showed smaller energy absorbing capacity than a solid RC column but showed the almost equal energy ductility and equivalent viscous damping ratio to those of the solid RC column.

• Journal of Positioning, Navigation, and Timing
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• v.2 no.2
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• pp.115-121
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• 2013

For the auto-landing operation of an air vehicle, the possibility of auto-landing operation should be first evaluated by testing the navigation performance through a flight test. In general, navigation performance is tested by analyzing north/east/down (NED) errors relative to reference equipment whose precision is about 8~10 times higher than that of a navigation system. However, to evaluate the auto-landing operation of an air vehicle, whether the air vehicle approaches a glide path aligned with the runway, within a specific error, needs to be examined rather than examining the north/east errors of the navigation system. Therefore, the longitudinal/lateral errors of air vehicle heading need to be analyzed. In this study, a method for analyzing the longitudinal/lateral errors of a navigation system was proposed as the navigation performance test method for evaluating the safety during the auto-landing of an air vehicle. Also, flight tests were performed six times, and the safety of auto-landing was examined by analyzing the performance using the proposed method.

• Journal of Korean Academy of Nursing
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• v.35 no.1
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• pp.95-103
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• 2005

Purpose: The purpose of this study was to develop an instrument of task performance evaluation for clinical nurses, thus testing the validity and the reliability of the scale. Method: Data was collected from 84 Head Nurses and 255 General Nurses. A conceptual framework, composed of 4 factors of meaning in task performance evaluation, was identified through review of the relevant literature. A total of 78 items were developed and were used on a five-point likert scale. Through factor analysis, items whose factor loading was below 0.50 were deleted, thus 35 items remained. To test the validity and reliability of the instrument, the SPSS 11.0 windows program was used. Result: The results of the factor analysis indicated that 4 factors were classified and the cumulative percent of variance was 67.54%. The results of the reliability test indicated that Cronbach's coefficient of the total 35 items was over 0.9176. The results of the factor analysis indicated that factor loadings of all items was over 0.50. Conclusively, the validity and the reliability of the scale were proven. Conclusion: This study was identified as a tool with a high degree of reliability and validity.

• Korean Journal of Occupational Health Nursing
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• v.25 no.1
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• pp.29-40
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• 2016

Purpose: The purposes of this study were to examine the differences in need, necessity, performance, barriers, and effectiveness of workers' health promotion program and to determine the influencing factors in effectiveness of workers' health promotion program by business types. Methods: Subjects were participants of an education held by Korean association of occupational health nurses and a survey was self-reported. Survey items were developed by researchers through literature review. It included general characteristics of occupational health providers and worksites, need, necessity, performance, barriers and effectiveness of workers' health promotion (WHP) program. The total number of worksites was 168, manufacturing/construction was 76 (45.2%), other services were 52 (31.0%), and healthcare services were 40 (23.8%). We used ${\chi}^2test$, ANOVA test, correlation analysis, and multiple regression analysis. Results: There were differences in need, necessity and performance of WHP by business types. In healthcare services, WHP had statistically significant effectiveness to reduce turnover rates. And the influencing factors of WHP's effectiveness were workers' need in manufacturing/construction, health provider's career in other services, and perceived necessity in healthcare services. Conclusion: Based on this result, we propose differentiated strategies depending on the business types for effective workers' health promotion program.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.39-43
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• 2010

The main objective of this research is to develop a mechanistic performance predictive model for fatigue cracking of asphalt-aggregate mixtures. Controlled-stress diametral fatigue tests were performed to characterize fatigue cracking of asphalt-aggregate mixtures. Performance prediction model for fatigue cracking was developed using the internal damage ratio (IDR) growth method. In the IDR growth method, the general concepts of the dissipated energy, the reference tensile strain, the threshold tensile strain, and the strain shift factor were introduced. The source of the dissipated energy in the fatigue test is from the intrinsic viscoelastic material property of an asphalt concrete mixture and the damage growth within the asphalt concrete specimen. In controlled-stress mode test, the dissipated energy is gradually increased with an increasing number of load applications.