• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.10 no.1
• /
• pp.47-57
• /
• 2016

In this paper, we measured human body signals in order to verify a active harness system that we developed for gait and balance training. The experimental procedure was validated by tests with 20 healthy male subjects. They conducted motions of Activities of Daily Living(ADL)(Normal Walking, Stand-to-Sit, Sit-to-Stand, Stair Walking Up, and Stair Walking Down) according to body weight support rates (0%, 30%, 50% of subjects' body weight). The effectiveness of the active harness system is verified by using the results of foot pressure distribution. In normal walking, the decrease of fore-foot pressure, lateral soleus muscle and biceps femoris muscle were remarkable. The result of stand-to-sit results motion indicated that the rear-foot pressure and tibialis anterior muscle activities exceptionally decreased according to body weight support. The stair walking down show the marked drop of fore-foot pressure and rectus femoris muscle activities. The sit-to-stand and stair walking up activities were inadequate about the effect of body weight support because the velocity of body weight support system was slower than male's activity.

• Journal of Korean Society of Forest Science
• /
• v.104 no.3
• /
• pp.421-426
• /
• 2015

The objective of this paper is to look into the growth of Cryptomeria japonica stand in South Korea along with the evaluation on their yields, followed by their carbon stocks and removals. A total of 106 sample plots were selected from Jeonnam, Gyeongnam, and Jeju, where the groups of standard are grown. We only used 92 plots data except outlier. As part of the analysis, the Weibull diameter distribution was applied. In order to estimate the diameter distribution, the growth estimation equation for each of the growth factors including the height, the diameter at breast height, and the basal area was drafted out and the verification for each equation was examined. The site index for figuring out the forest productivity of Cryptomeria japonica stand for each district was also developed as a Schumacher model and 30yr was used as a reference age for the estimation of the site index. It was found that the site index for Cryptomeria japonica stand in South Korea ranges from 10 to 16 and this result was used as a standard for developing the stand yield table. According to the site 14 in the stand yield table, the mean annual increment (MAI) of the Cryptomeria japonica reaches $7.6m^3/ha$ on its 25yr and its growing stock is estimated to be at $190.1m^3/ha$. This volume is about $20m^3$ as high as that of the Chamaesyparis obtusa. Furthermore, the annual carbon absorptions for a Cryptomeria japonica stand reached the peak at 25yr, which is 2.14 tC/ha/yr, $7.83tCO_2/ha/yr$. When compared to the other conifers, this rate is slightly higher than that of a Chamaecyparis obtusa ($7.5tCO_2/ha/yr$) but lower than that of the Pinus koraiensis ($10.4tCO_2/ha/yr$) and Larix kaempferi ($11.2tCO_2/ha/yr$). With such research result as a base, it is necessary to come up with the ways to enhance the utilization of Cryptomeria japonica as timbers, besides making use of their growth data.

• The Korean Journal of Ecology
• /
• v.18 no.4
• /
• pp.493-502
• /
• 1995

Nodulation phenology in relation to plant phenology, vertical distribution of nodul and root biomass in different soil, correlation between nodule and root size, and nitrogen mineralization around the rhizosphere by ion-exchange resin bag buried at 10 cm of soil were studied in Elaeagnus nmbellata (autumn-olive) stand, Korea. Nodulation appeared from spring to autumn and nodule phenology was coincided with the timing of root activity rather than that of foliation. Nodul size increased in proportion to the root size. In the sand dune with the lower root biomass, nodule appeared up to 80 cm deep in soil and the nodule biomass was 1,070 kg/ha, which was the highest value reported for several actinorhizal plants in the temperate regions. It is suggested that nodule distribution and production are mainly influenced by soil aeration among environmental factors. The higher ammonification or lower nitrification rate contrasted markedly with the earlier studies that reported lower ammonification or higher nitrification in actinorhizal plant soil. Nitrogen mineralization rate around the rhizosphere with root and nodule was characterized by higher nitrification rate than that in the control soil without root and nodule.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.4
• /
• pp.24-32
• /
• 2012

Of many approaches to reduce motion analysis errors, the compensation method of anatomical landmarks estimates the position of anatomical landmarks during motion. The method models the position of anatomical landmarks with joint angle or skin marker displacement using the data of the so-called dynamic calibration in which anatomical landmark positions are calibrated in ad hoc motions. Then the anatomical landmark positions are calibrated in target motions using the model. This study applies the compensation methods with joint angle and skin marker displacement to three lower extremity motions (walking, sit-to-stand/stand-to-sit, and step up/down) in ten healthy males and compares their performance. To compare the performance of the methods, two sets of kinematic variables were calculated using different two marker clusters, and the difference was obtained. Results showed that the compensation method with skin marker displacement had less differences by 30~60% compared to without compensation. And, it had significantly less difference in some kinematic variables (7 of 18) by 25~40% compared to the compensation method with joint angle. This study supports that compensation with skin marker displacement reduced the motion analysis STA errors more reliably than with joint angle in lower extremity motion analysis.

• Journal of the Korean Society of Physical Medicine
• /
• v.5 no.2
• /
• pp.245-254
• /
• 2010

Purpose : The purpose of this study is to investigate the effects of falls prevention exercise program(center of gravity control training, multiple sensory training, strategic posture training, ambulation training, muscle strengthening training) to balance and muscular strength in the elderly females. Methods : A total of 30 elderly womens participated in this study. All subjects have participated in exercise program on three times a week for eight weeks. Before and after of exercise program, They have measured about Berg Balance Scale (BBS), Performance Oriented Mobility Assessment (POMA), Time Up & Go (TUG), Sit to stand, Fall Efficacy Scale (FES), Quality of Life (QOL). Results : The results of this study were as follows ; 1) There were statistically significant difference in the BBS, POMA, FES, QOL test on within-subject. 2) There were not significant difference in the TUG, Sit to stand test on within-subject. 3) The BBS was correlated with POMA and QOL. The POMA was also correlated with QOL. Conclusion : The result of this study shows that falls prevention exercise program was meaningful increasing of balance ability and quality of life on elderly women

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.3
• /
• pp.825-831
• /
• 1996

Using the two-dimensional hydrocode HI-DYNA2D, a calculation on the explosive selding of dissimilar plates(Steel Titanium) was made for the pressure, temperature, velocity and impact ingles adjacent to the collision point during the welding process. The FEM result indicates that optimal stand-off distance of initially parallel set-up is 3-5mm for various values of the explosive thickness. The calculation shows that when the explosive thickness is around 30mm, the temperature of welding point which is strongly related to the metallic jet formation is 2, 000-3, 500K for the given stand-off distance.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.3 no.3
• /
• pp.189-196
• /
• 1999

The community structure, phytomass, and primary productivity in Thuja orientalis stands on a limestone area located in Maepo-up, Chungbuk province in Korea were estimated quantitatively. Seven species including a small proportion of Quercus dentata were identified in the tree layer, 26 species including Ulmus macrocarpa in the shrub layer, and 79 species including Carex lnceolata in the herb layer of the Thuja stands. The vertical distribution of the fine root phytomass exhibited a power functional decrease relative to the soil depth. The seasonal changes in the fine root phytomass at a soil depth of 5 cm were closely related to the pecipitation in the study area. The productivity of the stand of stems, branches, leaves, and roots were 10.72, 0.82, 0.45 and 6.46 ton DM. $ha^{-1}$ .$yr^{-1}$, respectively. The Thuja stand had a high foliage(25%) and low rate of production per unit of foliage. The annual turnover rate of the fine roots int he Thuja stand was 6.71 $yr^{-1}$. The net primary production of the overstory including the understory was estimated at 19.48 ton DM.$ha^{-1}$.$yr^{-1}$ including an underground section of 6.46 ton DM.$ha^{-1}$.$yr^{-1}$(33%). The allocation ratio of net production to root was lower in the limestone Thuja communities than at the nearby non-limestone ones, whereas the production efficiency to leaf weight was higher in the limestone communities. These results would seem to indicate that the limited production capacity is due to the calcium toxicity and low availability of iron and phosphorus in a limestone soil with a high pH, calcium, and bicarbonate content with a strategy for survival in a hostile habitat.

• PNF and Movement
• /
• v.12 no.1
• /
• pp.19-25
• /
• 2014

Purpose: To investigate the effect of action observation training on the muscle onset time and symmetrical use of rectus femoris(RF) and gastrocnemius medialis(GCM) during sit-to-stand (STS). Methods: Sixteen patients with stroke entered a single-blind trial and were randomly assigned to the experimental(Action) or control(Landscape) groups. Those in the Action observation group watched video clips showing specific movement and strategies to STS, wheas those in the control group watched video clips of static pictures showing differnet landscapes. All patients was measured the EMG data in the STS on the affected side and unaffected side. The EMG data were collected from RF and GCM while performing the STS task. The EMG onset time and onset time ratio for the RF and GCM were calculated by dividing the EMG onset time of RF and GCM action on the affected side by these on the unaffected side. Results: Onset time of affected side RF, GCM was significantly faster action observation training group than control group(p<.05). But interventions before and after the symmetry did not show a significant increase. Conclusion: There findings suggest that action observation training has a positive effect on the muscle onset time shortened during STS tasks.

• Journal of Satellite, Information and Communications
• /
• v.9 no.1
• /
• pp.102-106
• /
• 2014

In this paper, we investigate the realistic environment influence on the Hearing-Aid Compatibility(HAC) of the body-held device mock-up with a dual-band antenna. In detail, first, a dual-band internal antenna is designed considering the neighboring objects essential to a real attachable mobile device. This comes to reality by making its mock-up version. Second, the HAC of this device is simulated and measured for 'stand alone', and 'hand-held' cases. Particularly, the electromagnetic simulation of the designed antenna in the real device is verified by the standard measurement. Finally, the evaluated HAC is analyzed in terms of the relations with the bands, the mock-up environment and the hand effect.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.4
• /
• pp.133-142
• /
• 2021

The purpose of this study was to examine the most suitable exercise for the elderly women by comparing the changes in body composition and physical function fitness after modern dance, aquarobic and combined exercise programs for the elderly women. The subjects of this study were 47 elderly women in J-do, chosen as MDG(n=13), AEG(n=11), CEG(n=11) and CG(n=12) for participated for 60 minutes/day and three times/wk for 12 weeks. The results of grip strength, chair stand, arm curl, 2 minute step, 244cm up and go was significantly than in the control group. Back scratch was decreased significantly after exercise only in the modern dance group and combined exercise group but there was no change in chair sit and reach. These results suggest that various exercises were found to play a positive role in maintaining and improving fitness for the elderly women. In addition, additional exercise programs are needed to improve flexibility and mobility of joints for the elderly. It is thought that it is important to voluntarily participate in a movement that suits your interests to make it sustainable.