• Korean Journal of Applied Biomechanics
• /
• v.17 no.1
• /
• pp.175-184
• /
• 2007

The first purpose of this study was to compare kinematic variables during spinning motion with or without upper extremity and identify the most effective spinning method. The second purpose of this study was to compare functional difference between novice and elite dancers with the term of training. Ten experienced female dancers and ten novices were recruited as subjects for this study. Elite group was asked to perform turn motion with three types of upper extremity. Novice group has taken training of spotting technique for five weeks. Four Falcon HiRES cameras were used to analyze kinematic variables including head angular velocity and CG displacement during spinning. These data were sampled before training, after 3-week, and 5-week of training. Eight different events in two consecutive turns were defined for statistical comparison. One-way ANOVA was performed to compare among the kinematics of turning motion with three types of upper extremity. Independent t-test also used to compare kinematics between elite and novice at three different length of training. As results, spinning with both arm increased angular velocity and stability compared to the turning motion with one arm or with arm strapped and found out that the turn with both arm was the most effective way of spin. Also, for novice dancers, three weeks of training were needed to complete spinning motion.

• Journal of the Korean School Mathematics Society
• /
• v.16 no.4
• /
• pp.883-898
• /
• 2013

The purpose of this study is to examine that high school students recognize mathematical situation when they are requested for changing identical mathematics situations into different situations. The results of the study are followings. First, percentage of correct answers to the questions of turning equal mathematical situation into function is higher than the one of turning equal mathematical situation into equation and inequality. As a result of individual interview for comprehensibility of the students on these relations, it is found that if degree goes up and there is different expressions of questionaries although mathematical situation is identical, it affects comprehensibility of the subjects. Second, we found that they cannot understand identical mathematics situations because they have trouble in drawing graph or applying to get the answer while many students understand a point of intersection on the graph as a correct answer. Third, As a result of individual interview for comprehensibility of the students on relation between equation, inequality and function, we found that students manage to get correct answer even without perfect comprehensibility on this relation.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.49 no.10
• /
• pp.637-645
• /
• 2000

This study was represented the improvement of the flexible position control for linear motion of hybrid type linear pulse motor(HLPM). The driving method used a minute 125 microstep drive instead of full step drive method. The digital control method was applied to the PI control for more stable position control, at this time the PI control parameters have gained by a Ziegler-Nichols turning method. The loop transfer function of control system was combined with both motor transfer function and digital PI control equation. Such, the proper for digital PI control system is verified to through the simulation and experimental result of the stability step response and bode plot with proper gain and phase margin.

• Korean Journal of Adult Nursing
• /
• v.13 no.3
• /
• pp.451-462
• /
• 2001

This study was conducted to examine and compare the characteristics in the cognitive functions of peritoneal dialysis, hemodialysis and normal kidney function groups as basic data for effectively educating dialysis patients. The data were collected from May 10 to October 30. 2000, collected from each of 20 patients with peritoneal dialysis, hemodialysis and normal Kidney function and who registered for the dialysis room at a general hospital affiliated to a university in Seoul and sampled by age and educational level through personal interviews with the researchers of this study. As a measuring tool, MMSE developed by Folstein et al.(1975) to measure cognitive function disorder was used, slightly revised for hemodialysis patients. Collected data were processed into frequency, percentage, mean, and standard deviation by the use of SAS. The results of this study are as follows : 1. With a maximum of 30 points for cognitive function, the mean of the peritoneal dialysis patients was $27.06{\pm}2.06$, while that of the hemodialysis patients was $27.25{\pm}2.76$; that of the normal Kidney function patients was $27.85{\pm}2.00$, indicating no significant difference among those three groups. 2. As for the subjects who scored 23 points, the turning point of confirming the cognitive disorder, the percentage was 5% in the case of the peritoneal dialysis, 10% in the case of the hemodialysis and 5% in the case of the normal Kidney function group. 3. Differences between the peritoneal dialysis and hemodialysis patients by gender, occupation, spouse, diabetes, hypertension, the period of dialysis, number of hospitalizations, and the use of erythropoietin were not significant in the scoring of cognitive function. 4. There was no significant correlation between the level of Hb, Hct, albumin, aluminium, PTH, BUN, Cr, dialysis adequacy and the cognitive function. Considering such results, it is clear that there is no significant difference in the cognitive functions of the sampled subjects. Therefore, the nurse in the dialysis room should continually carry out assessment and intervention against elements degrading the effect of patients' education to improve self- care.

• The Journal of Korean Physical Therapy
• /
• v.21 no.2
• /
• pp.1-8
• /
• 2009

Purpose: This study examined the effect of EMG-stim related to the functional recovery of the upper extremity in chronic stroke patients with an intensive massed practice protocol. Methods: The subjects were assigned randomly to either the EMG-stim group (n=10) or sham treatment group (n=10). Both groups received conventional physical therapy, occupational therapy and FES, five times per week over a four week period. In the EMG-stim group, EMG-stim was applied to the hemiplegic wrist and finger extensors for 2 sessions for 30 minutes per day, 5 times per week over a 4 week period. As the pre- and the post-test, the following four motor tests were assessed as the function of the upper extremity clinical functional test: extensor digitorum strength test, Box and Block test, Fugl-Mayer Assessment, and Jebson-Taylor Hand Function Test. Results: In the Box and Block test and Fugl-Mayer Assessment, there were statistically significant differences between both groups as well as between pre- and post-test. The extensor digitorum and wrist extensor strength were similar in both groups. In the Jebson-Taylor Hand Function Test, there was a significant difference in simulated page turning but not in the other subtests. Conclusion: Intensive massed practice with EMG-stim intervention applied to the hemiplegic upper extremity is an effective therapeutic method for chronic stroke patients. However, a variety of intervention methods designed for stroke patients in clinical settings are needed.

• The Journal of Korean Physical Therapy
• /
• v.29 no.2
• /
• pp.55-61
• /
• 2017

Purpose: The purpose of this study was to investigate the effects of a task-oriented upper arm exercise performed in a sitting position on either an unstable support surface or a stable support surface for children with cerebral palsy. Methods: We prospectively evaluated 18 children with cerebral palsy. Eight subjects were randomly assigned to each of the stable and unstable support surface groups. We performed the upper arm exercise three times a week for 6 weeks. To confirm the effects of the intervention, the berg balance scale test, modified functional reaching test (MFRT), timed up and go test (TUG), and Jebsen-Taylor hand function test were conducted before and after the study. Results: Significant differences were observed in MFRT and TUG between the experimental and control groups (p<0.05). In the Jebsen-Taylor hand function test, there were significant differences between the groups for the items picking up small objects, stacking checkers, lifting large light objects, and lifting large heavy objects (p<0.05), but not for writing and stimulation of feeding. Significant differences were observed between the groups in items of card turning, lifting large light objects, and lifting heavy objects. Conclusion: The purpose of this study was to evaluate the effectiveness of a task-oriented upper extremity exercise program for dynamic balance and hand function performed in a sitting position with either stable or unstable support by cerebral palsy patients. There were improvements in the two groups, but performing the exercise while sitting on an unstable support surface had a greater effect on dynamic balance and hand function than exercise while sitting on a stable supporting surface. The results of this study can be used to improve the daily lives of cerebral palsy patients.

• Korean Journal of Optics and Photonics
• /
• v.23 no.4
• /
• pp.154-158
• /
• 2012

In this paper, for low cost infrared optical equipment, we design and fabricate an infrared optical system for an uncooled detector using PGM(Precision Glass Molding) lenses. The designed infrared optical system has a good athermalization, and the material of all of its lenses is a chalcogenide glass suitable for the PGM method. In addition, we also fabricate the same infrared optical system using SPDT(Single Point Diamond Turning) lenses in order to measure the optical performance of PGM lenses. We measure the MTF(Modulation Transfer Function) of the two infrared optical systems which use the PGM lenses and the SPDT lenses. And then we compare and analyze the images of them both. As a result, we find that they have only a very small difference in optical performance. If the use of PGM lenses increases, we expect to reduce the cost of infrared optical equipment.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.17 no.5
• /
• pp.27-36
• /
• 2013

Linear stability analysis for combustion instability within a cylindrical port of solid rocket motor has been conducted. The analysis of acoustic energy has been performed by a commercial COMSOL code to obtain the mode function associated to each acoustic mode prior to the calculation of stability alpha. An instability diagnosis based on the linear stability analysis of Culick is performed where special interests have been focused on 5 stability factors(alpha) such as pressure coupling, nozzle damping, particle damping and additionally, flow turning effect and viscous damping to take into account the flow and viscosity effect near the fuel surface. The instability decay characteristics depending on the particle size is also analyzed.

• Journal of Korean Society for Quality Management
• /
• v.25 no.3
• /
• pp.11-21
• /
• 1997

The mean residual life(MRL) function gives the expected remaining life of a item at age t. In particular F is said to be an increasing intially then decreasing MRL(IDMRL) distribution if there exists a turing point $t^*\ge0$ such that m(s)$\le$ m(t) for 0$$\le s$\le$ t $t^*$, m(s)$\ge$ m(t) for $t^*\le$ s$\le$ t. If the preceding inequality is reversed, F is said to be a decreasing initially then increasing MRL(DIMRL) distribution. Hawkins, et al.(1992) proposed test of H0 : F is exponential versus$H_1$: F is IDMRL, and $H_0$ versus $H_1$' : F is DIMRL when turning point is unknown. Their test is based on a complete random sample $X_1$, …, $X_n$ from F. In this paper, we generalized Hawkins-Kochar-Loader test to random censored data.

• Journal of Power System Engineering
• /
• v.3 no.4
• /
• pp.63-68
• /
• 1999

The determination of the optimal machining parameters in metal cutting, such as cutting speed, feed rate, and depth of cut, is an important aspect in an economic manufacturing process. The main objective in general is either to minimize the production cost or to maximize the production rate. Also there are constraints on all the machining operations which put restrictions on the choice of the machining parameters. In this paper as an objective function the production cost is considered with two constraints, surface finish and cutting power. Genetic Algorithm is applied to determine the optimum machining parameters, and the effectiveness of the applied algorithm is demonstrated by means of an example, turning operation.