• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.73-81
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• 2006

In order to evaluate the thrust of a propulsion system, generally the captive thrust stand is used Based on the applied propulsion system, the various captive ways between thrust stand and the propulsion system are considered. In this paper, the effect of motor deformation generated during firing in horizontal thrust stand on the measured thrust is theoretically derived from classical beam theory. New flexure performance index is defined and estimated on the basis of the thrust measurement error. Its result is good agreement with numerical result of ABAQUS. This study showed that measurement reliability and safety of test can be highly upgraded, in case of two flexure-type captive thrust stand.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.11
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• pp.1305-1310
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• 2014

In this paper, the new integrated crane monitoring system that complemented the point at issue for existing crane monitoring system is implemented. The Implementing monitoring system based on wireless communication system, consist of a measuring system of total load currents of main circuit breaker, a temperature and vibration measuring system with temperature sensors and vibration sensors for monitoring an oil and bearing of a main decelerator, a temperature measuring system with temperature sensors of a main motor bearing, and sensors for fire monitoring of an entire electrical space. The measured data from these sensors transmit main controller which is located in external location. Then the Integrating monitoring system is implemented and is performed the performance test to performing diagnosis of motors of a crane.

• Journal of Biosystems Engineering
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• v.25 no.5
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• pp.385-390
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• 2000

The heat pump is one of heating and cooling systems driven by electricity using natural energy as a heat source. The heat pump system was mainly adopted to a cooling system or a refrigeration system. In regions with a large amount of electricity, it is used as a heating system or a heating and cooling system of houses, buildings and agricultural facilities. During cold weather, air source heat pumps do not work well because of some technical problems, such as frosting on evaporator coil when outside air temperature is below -5$^{\circ}C$. In this research, the heat regenerative technology was employed to eliminate the frosting on evaporator coil and improve the COP of the heat pump system. This fiber belt heat regeneration system(FBHRS) has very simple structure consisting of a geared motor and a porous fiber belt passing through alternatively between cold and warm air duct. The laboratory test showed that the heat pump system with a FBHRS yielded an impressive COP higher than 3.5 at the outside air temperature of -7$^{\circ}C$ in heating mode.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.386-390
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• 2014

Purpose: We aimed to investigate whether visuomotor function would be modulated, when healthy subjects performed tracking task after tDCS application over the primary sensorimotor cortex (SM1) in the non-dominant hemisphere. Methods: Thirty four right-handed healthy participants were enrolled, who randomly and evenly divided into two groups, real tDCS group and sham control group. Direct current with intensity of 1 mA was delivered over SM1 for 15 minutes. After tDCS, tracking task was measured, and their performance was calculated by an accuracy index (AI). Results: No significant difference in AI at the baseline between the two groups was observed. The AI of the real tDCS group was significantly increased after electrical stimulation, compared to the sham control group. Two way ANOVA with repeated measurement showed a significant finding in a large main effects of time and group-by-repeated test interaction. Conclusion: This study indicated that application of the anodal tDCS over the SM1 could facilitate higher visuomotor coordination, compared to sham tDCS group. These findings suggest possibility that tDCS can be used as adjuvant brain modulator for improvement of motor accuracy in healthy individuals as well as patients with brain injury.

• Journal of Mechanical Science and Technology
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• v.19 no.6
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• pp.1321-1328
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• 2005

The characteristics of the diesel spray have affected certain aspects of engine performance, such as the power, fuel consumption, and emissions. Therefore, this study was performed to investigate the effects of various injection parameters. In order to obtain the effect of injection parameters on diesel spray characteristics, the experiment is performed by using a high temperature and pressure chamber. The behaviors of the spray are visualized by using a high speed video camera, spray angle, penetration, and various other things. The results of the experiment are summarized as follows. (1) The correlation of the spray penetration can be expressed as follows. $$0< t $$t_{b} (2) The correlation of the spray angle can be expressed as follows $$T_a=293K\;tan({\theta}/2)=0.59({\rho}a/{\rho}f)^{0.437}$$ $$T_a=473K\;tan({\theta}/2)=0.588({\rho}a/{\rho}f)^{0.404}$$ (3) The measured macro characteristics that include the spray tip penetration and spray angle corresponded with the established correlations.

• Journal of Drive and Control
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• v.12 no.3
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• pp.25-35
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• 2015

The hydraulic power-take-off mechanism (HPTO) is one of the most popular methods in wave energy converters (WECs). However, the conventional HPTO with only one direction motion has a number of drawbacks that limit its power capture capability. This paper proposes an adjustable moving angle wave energy converter (AMAWEC) and investigates the effect of the moving angle on the performance of the wave energy converter to find the optimal moving angle in order to increase the power capture capability as well as energy efficiency. A mathematical model of components from a floating buoy to a hydraulic motor was modeled. A small scale WEC test rig was fabricated to verify the power capture capability and efficiency of the proposed system through experiments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.269-272
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• 2008

Internal flow field of supersonic nozzle with pintle, which control thrust of solid rocket motor, is very complicated by pintle tip shape and contour of nozzle. For studying of pintle nozzle performance by effects of internal flow field variation with pintle position, cold flow test and numerical analysis about needle type pintle shape were performed and results were presented in this paper. As the results of this study, three types of internal shocks exists in the pintle nozzle and oblique shock is oscillated by pintle position

• The Journal of Korean Academy of Sensory Integration
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• v.8 no.1
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• pp.27-40
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• 2010

Objective : This study is designed to identify effect of a sensory integration(SI) program provided to elementary school students as an after-school activity. The study is looking at both occupational performance components and school-task performance which is an area of occupational performance. Methods : SI program specially designed as an after-school activity was provided to three boys who are first- or second grade students of Y elementary school in Dae-Jeon city. The SI intervention was organized with 25 sessions and carried out for two months. One group pretest-posttest design was used to evaluate the effectiveness of the SI program. Measurements used are Short Sensory Profile(SSP), K-DTVP-2, and BOTMP for occupational performance components, and School Function Assessment for functional schooltask performance. Results : It is found that posttest scores were enhanced in all assessments SSP; BOTMP; K-DTVP-2; and SFA. Conclusion : Results of this study simply propose that sensory integration program designed as after-school activity may have positive effects on not only occupational performance components but also on school-task performance of elementary school student. Since sample size is too small, however, there is limitation to find statistical significance. Further researches testing large number of subjects are required to boost the finding of this study.

• Korean Journal of Biological Psychiatry
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• v.8 no.2
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• pp.258-265
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• 2001

Objectives : Chronic alcohol consumption has been known to result in various neurocognitive deficits. Many neuropsychological studies revealed that the major disturbances occurred in the executive function, learning and short-term memory, visuospatial performance function, perceptuo-motor skills, and abstraction and problem solving abilities. This study was done to identify which cognitive areas might be mainly affected. Methods : The cognitive disturbance was evaluated using the Korean Version of the Mini Mental State Examination(MMSEK) and the 7 Minute Screen(7MS) in male inpatients with alcohol dependence(N=3 : as well as in age and education level matched healthy male controls(N=30). Four individual tests of the 7MS were consisted of the Benton Temporal Orientation Test, the Enhanced Cued Recall, the Clock Drawing and the Category Fluency. Results : 1) The average scores of four individual test of the 7MS for the alcoholics were $2.77{\pm}4.38$ for the Benton Temporal Orientation Test, $13.90{\pm}2.02$ for the Memory Test(the Cued Recall $6.77{\pm}1.94$, the Uncued Recall $7.10{\pm}2.45$), $5.84{\pm}1.86$ for the Clock Drawing, and $12.58{\pm}3.29$ for the Category Fluency. Except the Benton Temporal Orientation Test, there were statistically significant differences between test scores of alcoholics and those of controls(p<0.01). 2) The alcoholics who had MMSE-K score <24 were 9.68%. The average(${\pm}S.D.$) score of the MMSE-K for the patient group($27.23{\pm}2.62$) was significantly(p<0.001) lower than that of the healthy controls($29.20{\pm}1.24$). There were no statistically significant differences between four individual test scores of the 7MS of alcoholics with the MMSE-K score <24(N=3) and those of alcoholics with the MMSE-K score ${\geq}24$(N=28). 3) Four individual test scores of the 7MS seemed to have statistically significant association with such variables as MMSE-K, duration of alcohol drinking, blood magnesium concentration, liver function and thyroid function. Conclusion : Mild deficits of cognitive areas such as orientation, memory, visuospatial abilities and verbal fluency could be found in alcohol dependence.

• The Journal of Korean Academy of Sensory Integration
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• v.9 no.2
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• pp.1-13
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• 2011

Objective : Purpose of this study is to discuss benefits and implications of the clinical reasoning process and re-evaluation in the OTIPM by introducing a single case that occupational therapy intervention is provided based on the OTIPM. Methods : The case subject is a boy aged 5 years and 10 month who had diagnosed as attachment disorder and anxiety disorder from a pediatric psychiatrist before. The boy is referred to sensory integration therapy clinic and underwent occupational therapy intervention service twice a week for four month. Therapeutic activities for the intervention were consisted of sensory integration activities for restorative model, care-giver education for educational model, and performance skill training for acquisitional model. Measurements used in the initial evaluation are JSI-R, DDST-2, Social Maturity Test, KPPS-R, and observation-based performance task analysis. For the performance task analysis, performance skill items were constructed based on the Occupational Therapy Process Framework (OTPF), and those were assessed by the evaluation system of Assessment of Motor and Process Skill (AMPS) and Evaluation of Social Participation (ESI). Results : The detail process of implementing of the OTIPM in this study is reported by following four phases; 1) establish client-centered performance context; 2) establish baseline and interpret cause (initial evaluation); 3) intervention planning and implementing; and 4) recognize intervention outcome (reevaluation). Conclusion : In this case, occupational therapist could provide the client an occupation-based intervention within comprehensive performance context based on the OTIPM. Therapist could clearly identify the cause of problematic performance skills and behaviors and so provide effective intervention to improve client's occupational performance. Additionally, it was found that client's satisfaction of the intervention can be raised when the concept of 'who is the client' is expanded based on the OTIPM. From this study, it is proposed that OTIPM may be a model educible 'comprehensive' enhancement of 'specific' occupational engagement, as it considers both improvement of occupational performance and satisfaction.