• The Journal of Korean Physical Therapy
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• v.26 no.3
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• pp.216-219
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• 2014

Purpose: We presented with a patient with traumatic brain injury who showed a transcallosal ipsilateral motor pathway from unaffected motor cortex to affected extremities, as evaluated by diffusion tensor tractography (DTT). Methods: One patient and six age-matched normal subjects were enrolled. A 42-year-old left hemiparetic male who suffered from brain injury by motor vehicle accident 9 years ago showed a leukomalactic lesion in the right corona radiata and parieto-temporal lobe. His left extremities were completely paralyzed initially, but recovered slowly over 2 years. At the time of the evaluation, he was able to grasp and release an object, and to walk with spastic gait pattern. DTT was performed using 1.5 T with a Synergy-L Sensitivity Encoding head coil. DTT was obtained with termination criteria of FA <0.2 and an angle change > $45^{\circ}c$. Results: The motor tracts of the unaffected (left) hemisphere of the patient and control subjects originated from the motor cortex and descended along the known corticospinal tract without any transcallosal tract. By contrast, the tract of the affected (right) hemisphere originated from the left premotor cortex, descended through the left corona radiata, and then crossed the mid-portion of the corpus callosum. The tract then descended through the known corticospinal tract pathway to the right medulla. Conclusion: We conclude that the transcallosal ipsilateral motor pathway from the unaffected hemisphere appeared to contribute to the motor recovery in this patient.

• Membrane and Water Treatment
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• v.1 no.1
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• pp.83-92
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• 2010

To improve the antifouling characteristics of polypropylene hollow fiber microporous membranes in a submerged membrane-bioreactor for wastewater treatment, the surface-modification was conducted by Ar plasma treatment. Surface hydrophilicity was assessed by water contact angle measurements. The advancing and receding water contact angles reduced after the surface modification, and hysteresis between the advancing and receding water contact angles was enlarged after Ar plasma treatment due to the increased surface roughness after surface plasma treatment. After continuous operation in a submerged membrane-bioreactor for about 55 h, the flux recovery after water cleaning and the flux ratio after fouling were improved by 20.0 and 143.0%, while the reduction of flux was reduced by 28.6% for the surface modified membrane after 1 min Ar plasma treatment, compared to those of the unmodified membrane. Morphological observations showed that the mean membrane pore size after Ar plasma treatment reduced as a result of the deposition of the etched species; after it was used in the submerged membrane-bioreactor, the further decline of the mean membrane pore size was caused by the deposition of foulants. X-ray photoelectron spectroscopy and infrared spectroscopy confirmed that proteins and polysaccharide-like substances were the main foulants in the precipitate.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.47-54
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• 2013

In this paper, we present an inertial sensor-based motion capturing system to measure and analyze whole body movements. This system implements a wireless AHRS(attitude heading reference system) we developed using a combination of rate gyroscope, accelerometer and magnetometer sensor signals. Several AHRS modules mounted on segments of the patient's body provide the quaternions representing the patient segments's orientation in space. We performed 3D motion capture using the quaternion data calculated. And a method is also proposed for calculating three-dimensional inter-segment joint angle which is an important bio-mechanical measure for a variety of applications related to rehabilitation. To evaluate the performance of our AHRS module, the Vicon motion capture system, which offers millimeter resolution of 3D spatial displacements and orientations, is used as a reference. The evaluation resulted in a RMSE of 2.56 degree. The results suggest that our system will provide an in-depth insight into the effectiveness, appropriate level of care, and feedback of the rehabilitation process by performing real-time limbs or gait analysis during the post-stroke recovery process.

• Journal of Power Electronics
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• v.15 no.3
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• pp.621-633
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• 2015

This paper proposes the analysis and design of a DC-side symmetrical zero-current-switching (ZCS) Class-D current-source driven resonant rectifier to improve the low power-factor and high line current harmonic distortion of lighting applications. An analysis of the junction capacitance effect of Class-D ZCS rectifier diodes, which has a significant impact on line current harmonic distortion, is discussed in this paper. The design procedure is based on the principle of the symmetrical Class-D ZCS rectifier, which ensures more accurate results and provides a more systematic and feasible analysis methodology. Improvement in the power quality is achieved by using the output characteristics of the DC-side Class-D ZCS rectifier, which is inserted between the front-end bridge-rectifier and the bulk-filter capacitor. By using this symmetrical topology, the conduction angle of the bridge-rectifier diode current is increased and the low line harmonic distortion and power-factor near unity were naturally achieved. The peak and ripple values of the line current are also reduced, which allows for a reduced filter-inductor volume of the electromagnetic interference (EMI) filter. In addition, low-cost standard-recovery diodes can be employed as a bridge-rectifier. The validity of the theoretical analysis is confirmed by simulation and experimental results.

• Fashion & Textile Research Journal
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• v.20 no.3
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• pp.343-352
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• 2018

The objective of this study is to investigate the market of fitness compression wear as well as to design an optimal fitness compression wear by analyzing the muscle and movement characteristics of the elderly women in Korea. In this regard, research for functional garments is needed to increase muscle activity of elderly people during physical exercise. Firstly, we investigated the brand, design, size, material, and pattern of fitness wear based on the market survey. Secondly, we identified preference, evaluation items, evaluation method, and pattern design method based on the literature review. Finally, in addition, the motion type, range, angle to improve the muscle strength of the elderly were investigated and the maximum muscle strengths of each motion were analyzed by using 2007 Size Korea data (n = 386). It is also designed for muscle fatigue through exercise and rapid fatigue recovery after exercise. The evaluation methods for fitness compression wear were classified as motor functionality, physiological comfort, pattern and material suitability evaluations. The muscle strength at leg (pushing force) and waist (lifting force) of the ages of 60 to 69 years old showed 239.3 N and 274.5 N, respectively, which were the lowest forces compared to younger age groups. By applying these results to the design process of fitness wear, it is anticipated that the fitness wear will have a proper fit to the body shape of elderly people in South Korea as well as it can increase muscle efficiency to promote physical capability and healthy life for senior people.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.12
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• pp.1061-1068
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• 2013

This study predicts distillate productions according to design variables by numerical analysis when the waste heat from a diesel generator is added to the solar-assisted still proposed in a previous study. Mathematical models were set up in reference to previous studies, and the amount of heat exchange from the waste heat recovery pipe was considered. To ensure the reliability of numerical analysis, the result was compared with that of a previous study and then, the distillate productions according to design variables were obtained by the analysis model. The results were found to generally be in agreement, and the increasing amount of distillate production of the still with the added waste heat was confirmed. In addition, the optimal value of the tilt angle of glass cover and the number of cells were determined by numerical analysis.

• Fashion & Textile Research Journal
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• v.15 no.6
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• pp.985-992
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• 2013

Polytrimethylene terephthalate(PTT) offers several advantageous properties such as good tensile strength, uniformity, stiffness, toughness, UV stability, resilience, stain resistance, outstanding elastic recovery, and dyeability. The effects of annealing temperature on physical properties and the structure of PTT filaments and yarn were investigated by measuring wide-angle X-ray diffraction (WAXD), density, optical birefringence, dynamic visco elasticity, and tensile testing. The intensity of maximum tan ${\delta}$ decreased and the temperature of maximum tan ${\delta}$ shifted to a higher temperature as the annealing temperature of filaments increased; however, it shifted to a lower temperature when the annealing temperature exceeded $130^{\circ}C$. In addition, crystallinity, density and D-spacing of (010) crystal face increased as the annealing temperature increased. Optical birefringence and specific stress were almost constant up to $100^{\circ}C$ and then decreased above $130^{\circ}C$. The shrinkage of PTT filament is 0 in boiling water when annealed above $130^{\circ}C$; consequently, the use of annealed fiber above $130^{\circ}C$ can remove thermal instability when dyeing PTT fiber. In the case of yarns, the thermal stability and physical properties of yarns showed the best effect when the ply number is less than 5, twist number is less than 400tpm, and the annealing time is 20minutes.

• Earthquakes and Structures
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• v.2 no.3
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• pp.233-256
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• 2011

This paper investigates the applicability of newly developed Cu-Al-Mn shape memory alloy (SMA) bars to retrofitting of historical masonry constructions by performing quasi-static tests of half-scale brick walls subjected to cyclic out-of-plane flexure. Problems associated with conventional steel reinforcing bars lie in pinching, or degradation of stiffness and strength under cyclic loading, and in their inability to restrain residual deformations in structures during and after intense earthquakes. This paper attempts to resolve the problems by applying newly developed Cu-Al-Mn SMA bars, characterized by large recovery strain, low material cost, and high machinability, as partial replacements for steel bars. Three types of brick wall specimens, unreinforced, steel reinforced, and SMA reinforced specimens are prepared. The specimens are subjected to quasi-static cyclic loading up to rotation angle enough to cause yielding of reinforcing bars. Corresponding nonlinear finite element models are developed to simulate the experimental observations. It was found from the experimental and numerical results that both the steel reinforced and SMA reinforced specimens showed substantial increment in strength and ductility as compared to the unreinforced specimen. The steel reinforced specimen showed pinching and significant residual elongation in reinforcing bars while the SMA reinforced specimen did not. Both the experimental and numerical observations demonstrate the superiority of Cu-Al-Mn SMA bars to conventional steel reinforcing bars in retrofitting historical masonry constructions.

• Journal of Conservation Science
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• v.28 no.3
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• pp.229-233
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• 2012

This research was to evaluate conservational stability of cleaning treatment and color recovery by weak acid treatment on ivory. Before this experiment, had an ivory identification such as black light and schreger angle to find whether it is authentic or not. In wet cleaning treatment on ivory, used polar solvents such as distilled water, acetone, ethyl alcohol and acetic acid which usually used for cleaning ivory and bones. After cleaning took a experiment to evaluate conservational stability in surface observation, calculate weight and color difference. Following these results, these polar solvents were stable on the ivory samples. On the other hand, in weak acid treatment, used samples that were exposed by UV-A, UV-B, UV-C for 1 weeks, to restore its color from changed to original color. After treatment, found tiny cracks and exfoliation on the surface. Moreover, the color changed when it is treated by lemon juice, so, it is impossible to adapt.

• Journal of Korean Neurosurgical Society
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• v.57 no.1
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• pp.36-41
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• 2015

Objective : To investigate the causes for failed anterior cervical surgery and the outcomes of secondary laminoplasty. Methods : Seventeen patients failed anterior multilevel cervical surgery and the following conservative treatments between Feb 2003 and May 2011 underwent secondary laminoplasty. Outcomes were evaluated by the Japanese Orthopaedic Association (JOA) Scale and visual analogue scale (VAS) before the secondary surgery, at 1 week, 2 months, 6 months, and the final visit. Cervical alignment, causes for revision and complications were also assessed. Results : With a mean follow-up of $29.7{\pm}12.1$ months, JOA score, recovery rate and excellent to good rate improved significantly at 2 months (p< 0.05) and maintained thereafter (p>0.05). Mean VAS score decreased postoperatively (p<0.05). Lordotic angle maintained during the entire follow up (p>0.05). The causes for secondary surgery were inappropriate approach in 3 patients, insufficient decompression in 4 patients, adjacent degeneration in 2 patients, and disease progression in 8 patients. Complications included one case of C5 palsy, axial pain and cerebrospinal fluid leakage, respectively. Conclusion : Laminoplasty has satisfactory results in failed multilevel anterior surgery, with a low incidence of complications.