• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.919-922
• /
• 2006

Comparing with the conventional transformer without the air gap, a contact-less transformer with the large air-gap (4.8cm) between the long primary winding and the secondary winding has the increased leakage inductance and the reduced magnetizing inductance. By the increased leakage inductance and the reduced magnetizing inductance on the primary of the contact-less transformer, a good deal of the primary current circulates through magnetizing inductance, which results in a massive loss in contact-less power supply (CPS). In this paper, the efficiency characteristics of the contact-less power supply using a series resonant converter is analyzed and simulated. The results are verified on the simulation based on the theoretical analysis and the 1.8kW experimental prototype.

• PNF and Movement
• /
• v.17 no.3
• /
• pp.353-368
• /
• 2019

Purpose: This study investigated the effects of trunk exercise using less-affected extremities on gait and balance in chronic stroke patients. Methods: Thirty subjects with chronic stroke disease were divided into two groups: a trunk exercise group that used less-affected extremities (n=15) and a general trunk exercise group (n=15). All interventions were conducted 30 min a day, 6 times per week, for 3 weeks. Gait parameters were measured before and after the intervention using Zebris FDM-1.5. In addition, all subjects were evaluated using the Trunk Impairment Scale, the Berg Balance Scale, and the Functional Gait Assessment before and after the intervention. Results: Both groups showed improvements on all outcome measured pre- to post-intervention (p<0.05). The groups exhibited significant differences for TIS, BBS, FGA, gait speed, step length, and cadence at post-intervention (p<0.05). Conclusion: This study showed that trunk exercise using less-affected extremities has therapeutic benefits on gait and balance in individuals with chronic stroke disease.

• Journal of Sensor Science and Technology
• /
• v.22 no.6
• /
• pp.415-420
• /
• 2013

Calibration capabilities for thermometer calibration by comparison method were assessed using high-precision industrial platinum resistance thermometers (IPRT). It was found in the performance assessment that out of 31 laboratories who participated, 28 laboratories resulted magnitude of En number less than 1 at every calibration points they submitted results in the range from 50 to $500^{\circ}C$. The results of about 75% of the laboratories showed the difference from the assigned values less than 1/10 of the tolerance level of the class B IPRT. This indicates that the participating calibration laboratories performed with satisfactory level that was enough to calibrate IPRTs to significant precision. The sensors used in this work were manufactured and chosen by the criteria of long-term instability less than 4 mK and hysteresis less than 8 mK in the temperature range used in this work. Furthermore, the change in the resistance of the sensors in the calibration temperature range were less than the uncertainty of the calibration, 25 mK (k=2).

• Korean Journal of Applied Biomechanics
• /
• v.28 no.2
• /
• pp.109-117
• /
• 2018

Objective: To compare head and hand movement patterns during squash forehand motions between experts and less-skilled squash players. Method: Four experts and four less-skilled squash players participated in this study. They performed squash forehand swings and a VICON motion analysis system was used to obtain displacement and velocity data of the head and right hand during the movement. Mann-Whitney U-tests were performed to compare head and hand range of motion and peak velocity, and cross-correlation was performed to analyze the head-hand coordination pattern between groups in three movement directions. Results: In terms of head and hand kinematic data, experts had greater head range of motion during down swings than less-skilled squash players. Experts seemed to reach peak hand velocity at impact by reaching peak head velocity followed by hand peak velocity within a given temporal sequence. In terms of head-hand coordination patterns, both groups revealed high positive correlations in the medial-lateral direction, indicating a dominant allocentric coordination pattern. However, experts had uncoupled coordination patterns in the vertical direction and less-skilled squash players had high positive correlations. These results indicate that the head-hand movement pattern likely an important factor squash forehand movement. Conclusion: Analysis of head and hand movement patterns could be a key variable in squash training to reach expert-level performance.

• Journal of the Korean Society of Physical Medicine
• /
• v.4 no.2
• /
• pp.87-92
• /
• 2009

Objects：The purpose of this study is to investigate the values of foot pressure of the stance phase during a gait cycle in hemiplegic gait. Method：42 patients who had a stroke and 42 healthy adults were evaluated by the RSscan system to analyze the stance phase of hemiplegic gait. The stance phase was evaluated as plantar foor pressure. Results：1) Foot plantar pressure of toe area, affected side and less affected side showed low distribution of the plantar foot pressure which is lower than plantar foot pressure of normal adults(p<0.05). 2) Foot plantar pressure of metatarsal area, showed significantly differences among hemiplesic patient's affected side and less affected side and distribution of plantar foot pressure of normal adults(p<0.05). 3) Foot plantar pressure of heel area, hemiplesic patients' affected side and less affected side showed lower distribution of the plantar foot pressure than plantar foot pressure of normal adults(p<0.05). Conclusion：The results of this study suggest that not only affected side but also less affected side in hemiplegic patients showed significantly differences in distribution of the plantar foot pressure of normal adults.

• Psychiatry investigation
• /
• v.15 no.12
• /
• pp.1181-1187
• /
• 2018

Objective In Korea, online board games, such as "flower cards," are played using virtual money. In contrast, Internet-based gambling (ibGambling) concerns the use of real money to gamble online. We hypothesized that online board gamers using virtual money show less risky behaviors than do gamblers who use real money, and that, in regard to psychological aspects, online board gamers are less depressed and more introverted than online gamblers are. Methods For this study, 100 online board gamers, 100 ibGamblers, 100 offline gamblers (offGamblers), and 100 age- and sex-matched healthy controls were recruited by an online research company. Gambling behavior and self-efficacy were assessed using the Korean Gambling Behavior Scale-high/low factors (KGBS-H/L) and the Gambling Abstinence Self-efficacy Scale (GASS). Additionally, introversion, depression, and mania tendency were assessed. Results Online board gamers had good intentions gaming, as evidenced by their higher KGBS-L scores than ibGamblers and offGamblers, and they showed less risky behaviors, as evidenced by their lower KGBS-H scores than offGamblers. Additionally, online board gamers were less introverted than ibGamblers and less depressed than offGamblers. Conclusion Online board gaming could be a gateway to the world of gambling (ibGambling or OffGambling). However, the higher tendency of online board gamers to engage in good intentioned gaming could help prevent online board gaming from progressing to online or offline gambling.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.55 no.3
• /
• pp.190-197
• /
• 2019

This study investigated the luring effect of the sardine bait, which is used to catch octopus with pot, as the preliminary study for the development of alternative bait for octopus pot. The soaking time for bait was divided into "5 days or less" and "11 days or longer" The number of times octopus entered the pot with bait and the empty pot was investigated under dark adaptation and light adaptation processes and the distribution of tank section was investigated under light adaptation process. The case of "11 days or longer" sardine soaking time showed higher rate of distribution in the section of pot with bait compared to the case of "5 days or less" In the case of "5 days or less" soaking time, the number of times the octopus entered the pot with bait was similar to that it entered the pot without it even during dark adaptation and light adaptation. However, in the case of "11 days or longer", the octopus entered the pot with bait more quickly than the pot without bait and more frequently during dark adaptation hours. There were cases where the octopus did not enter any pot. In the case of "5 days or less", with less decomposition of baits, the octopus entered the empty pot more during light adaptation process, and it appeared that the pot was used as a hideout.

• Physical Therapy Rehabilitation Science
• /
• v.8 no.3
• /
• pp.141-145
• /
• 2019

Objective: The purpose of this study was to compare walking conditions (straight line and curved path) on walking patterns in persons who had experienced hemiplegic stroke and to determine whether if they adapt their walking pattern and performances according to changes in environmental conditions. Design: Cross-sectional study. Methods: Forty-four hemiplegic stroke survivors participated in this study. This study measured walking performance in three different walking conditions, such as straight walking, the more-affected leg in the inner curve walking, and less-affected leg in the inner curve walking conditions, and a 2-dimentional gait analysis system was used as a primary measurement. This study also measured secondary clinical factors including the Timed Up-and-Go Test, the Trunk Impairment Scale, and the Dynamic Gait Index. Results: After analyzing, cadence and step length of the less-affected side, stride length in the more-affected side, and stride length in less-affected side were significantly different among the three different walking conditions in this study (p<0.05), but other temporospatial parameters were not significant. Cadence was the largest in the straight walking condition. Step length in the less-affected side, stride length in the more-affected side, and stride length in less-affected side were also the longest in the straight walking condition. Conclusions: The results of the study suggest that hemiplegic stroke survivors show walking adaptability according to changes in walking demands and conditions, and moreover, cadence and step and stride lengths were significantly different between straight and curved walking conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1097-1098
• /
• 2013

• Resources Recycling
• /
• v.11 no.5
• /
• pp.21-23
• /
• 2002

A new process based on the co-precipitation method was developed fer removing harmful impurities during Mn-Zn ferrite production such as $SiO_2$ and P from waste pickle liquor. By this process a final result of less than 100 ppm of $SiO_2$ and less than 10 ppm of P content in the ferric oxide is easily attained. Though Ca cannot be removed by this process, water rinsing of the ferric oxide is effective fer reducing Ca content to less than 100 pm. For further purification, the origins of each impurity must be investigated and then taken away.