• Journal of the Ergonomics Society of Korea
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• v.21 no.2
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• pp.25-33
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• 2002

The purpose of study is to investigate the relationship between the trunk muscle fatigue and recovery time during repetitive extension by using a surface electromyogram(EMG). Ten healthy subjects particioated in a simulated lifting task with five levels of recovery time and three levels of sub-maximal contraction. EMG signals of the L1(Lumbar 1st Vertebrae) and L3(Lumbar 3rd Vertebrae) level of the erector spinae muscle were recorded. and analyzed in terms of MPF(mean power frequency) parameter to quantify the level of muscle fatigue. It was found that MPF significantly (p<0.05) decreased during repetitive extension task at 50% and 75% sub-maximal contractions. Then it took minutes for the trunk muscle to recover from fatigue during 50% sub-maximal contraction. and it took five minutes during 75% sub-maximal contraction. and it took five minutes during 75% sub-maximal contraction. The recovery time estimated by the maximum force needs to be re-evaluated for the trunk muscle to fully recover from fatigue. In conclusion. the work/rest cycle needs to be studied based upon the information of muscle fatigue in order to prevent workers from musculoskeletal injuries during repetitive lifting task.

• Microbiology and Biotechnology Letters
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• v.27 no.4
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• pp.320-326
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• 1999

The effects of operating pressure, lactate concentration, impurities, and pH on solution flux and lactate rejection in nanofiltration were investigated with model sodium lactate solutions (lactate 10~200g/L) as a model system. In the tested range of pressure(80~140 psig), the solution flux was observed to be proportional to the operating pressure and the rejection of lactate increased only slightly with the pressure. Both of the flux and the rejection decreased with lactate concentration, while the recovery rate of lactate increased. The effects of glucose and yeast extract as impurities on lactate rejection were negligible, but the flux decreased significantly with the addition of yeast extract. At low lactate concentrations, the rejection of lactate increased with pH due to the increased repulsion (Donnan exclusion effect) between lactate ions and membrane surface. But, at high lactate concentrations, the donnan effect was observed to be overwhelmed by the effect of sodium ions added to adjust the pH, and the rejection of lactate decreased with pH. When fermentation broth containing about 89g/L of lactate was nanofiltered, the flux and the rejection of lactate were 2.8L/$m^2$h and 5%, respectively at 120psig. Both of them were slightly lower than those with model solutions. The recovery rate was 2.6mol/$m^2$h.

• Physical Therapy Korea
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• v.16 no.2
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• pp.41-49
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• 2009

This study was designed to investigate the effects of treadmill exercise of low-intensity and moderate- intensity on the functional recovery and histological change in spinal cord injury (SCI) rats. SCI was induced by the spinal cord impactor dropped after laminectomy. Experimental groups were divided into the Group I (normal control), Group II (non-treatment after SCI induction), Group III (low-intensity treadmill exercise after SCI induction), Group IV (moderate-intensity treadmill exercise after SCI induction). After operation, rats were tested at modified Tarlov scale at 2 days with divided into 4 groups, and motor behavior test (BBB locomotor rating scale, Grid walk test) was examined at 3, 7, 14, and 21 days. For the observation of damage change and size of the organized surface in spinal cord, histopathological studies were performed at 21 days by H & E, and BDNF(brain-derived neutrophic factor) & Trk-b immunohistochemistry studies were performed at 1, 3, 7, 14, 21 days. According to the results, treadmill exercise can play a role in facilitating recovery of locomotion following spinal cord injury. Specially, moderate-intensity treadmill exercise after SCI induction was most improvement in functional recovery and histological change.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.419-425
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• 2001

A dense pellicular solid matrix has been fabricated by coating 4% agarose gel on to dense zironia-silica(ZS) spheres by watr-in-oil emulsification . The agarose evenly laminated the ZS bead to a depth of 30㎛, and the resultin gpellicular assembly was characterised by densities up to 2.39g/mL and a mean particle dimeter of 136 ㎛. In comparative fluidisation tests, the pellicular solid phase exhibited a two-fold greater flow velocity than commercial benchmark ad-sorbents necessary to achieve common values of bed expansion. Furthermore, the perlicular parti-cles were characterised by improved qualities of chromatographic behaviour, particularly with re-spect to a three-fold increase in the apparent effective diffusivity of lysozyme within a pellicular assembly modified with Cibacron Blue 3GA. The properties of rapid protein adsorption/desorp-tion were attributed to the physical design and pellicular deployment of the reactive surface in the solid phase. When combined with enhanced feedstock throughput, such practical advantages recommend the pellicular assembly as a base matrix for the selective recovery of protein products from complex, particulate feedstocks(whole fermentation broths, cell disruptates and biological extracts).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9C
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• pp.840-848
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• 2007

A multiple description coding (MDC) scheme for 3-D Data is presented. First, a plane-based 3-D data is split into two descriptions, each of which has identical contribution in 3-D surface reconstruction. In order to maximize the visual quality of reconstructed 3-D data, then, plane parameters are modified according to channel error condition. Finally, these descriptions are compressed and transmitted over distinct channels. In decoder, if two descriptions are available, we reconstruct a high quality 3-D data. If only one description is transmitted, however, 3-D surface recovery scheme reduces artifacts on erroneous 3-D surface, yielding a smooth 3-D surface. Therefore, the proposed algorithm guarantees acceptable quality reconstruction of 3-D data even though one channel is totally lost.

• Journal of the Korean Vacuum Society
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• v.13 no.3
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• pp.120-126
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• 2004

A damage-reduced trench was investigated in view of the defect distribution along trench sidewall and bottom using high resolution transmission electron microscopy, which was formed by HBr plasma and additive gases in magnetically enhanced reactive ion etching system. Adding $O_2$ and other additive gases into HBr plasma makes it possible to eliminate sidewall undercut and lower surface roughness by forming the passivation layer of lateral etching. To reduce the RIE induced damage and obtain the fine shape trench corner rounding, we investigated the hydrogen annealing effect after trench formation. Silicon atomic migration on trench surfaces using high temperature hydrogen annealing was observed with atomic scale view. Migrated atoms on crystal surfaces formed specific crystal planes such as (111), (113) low index planes, instead of fully rounded comers to reduce the overall surface energy. We could observe the buildup of migrated atoms against the oxide mask, which originated from the surface migration of silicon atoms. Using this hydrogen annealing, more uniform thermal oxide could be grown on trench surfaces, suitable for the improvement of oxide breakdown.

• Archives of Reconstructive Microsurgery
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• v.19 no.2
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• pp.108-111
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• 2010

Purpose: In reconstructing a defect on the dorsum of the hand, there are many cases of extensor tendons exposed or even missing. The repaired or reconstructed tendons need relevant gliding environment for good functional recovery. The anterolateral thigh flap offers a vascular fascial component with large amounts that can be used for covering exposed tendons and we report a unique case of single-stage hand dorsum and gliding surface reconstruction. Methods: A 35-year-old man had severe post-traumatic scarring in his left dorsal hand and coverage of the flap with split-thickness skin graft has been done before. After scarred skin excision and extensor tendon graft for missed part, a free anterolateral thigh adipofascial flap was used to resurface the hand dorsum and to reconstruct a two-layer gliding surface of the extensor tendons. The extensor tendons were wrapped in the fascial component with the fat layer inside. Results: He had an uneventful postoperative course without infection, dehiscence and flap necrosis. Good overall functional recovery and tendon excursion were observed. He was also satisfied with postoperative appearance. Conclusion: A free anterolateral thigh adipofascial flap was used successfully for reconstruction of a two-layer tendon gliding surface to treat a patient with severe scarring in the dorsal hand.

• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.107-113
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• 2003

This study was carried out to improve the performance of pre-developed heat recovery devices attached to exhaust-gas flue connected to combustion chamber of greenhouse heating system. Four different units were compared in the aspect of heat recovery performance; A-, B-, and C-types are exactly the same with the old ones reported in previous studies. D-type newly developed in this experiment is mainly different with the old ones in its heat exchange area and tube thickness. But airflow direction(U-turn) and pipe arrangement are similar with previous three types. The results are summarized as follows; 1. System performances in the aspect of heat recovery efficiency were estimated as 42.2% for A-type, 40.6% for B-type, 54.4% for C-type, and 69.2% for D-type. 2. There was not significant improvement of heat recovering efficiency between two different airflow directions inside the heat exchange system. But considering current technical conditions, straight air flow pattern has more advantage than hair-pin How pattern (U-turn f1ow). 3. The main factors influencing on heat recovery efficiency were presumably verified to be the total area of heat exchange surface, the thickness of ail-flow pipes, and the convective heat transfer coefficient influenced by airflow velocity under the conditions of allowable pipe durability and safety. 4. Desirable blower capacity for each type of heat recovery units were significantly different to each other. Therefore, the optimum airflow capacity should be determined by considering in economic aspect of electricity required together with the optimum heat recovery performance of given heat recovery systems.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.1
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• pp.17-26
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• 1973

A survey on nutrient recovery by rice plant was carried out countrywide in 1967 and 1968. The relationships between percent recovery of fertilizer nutrient and climatic zone or deposition mode, drainage grade, and texture of paddy soil profile, or chemical characteristics of surface soil were as follows. 1. The percent recovery of fertilizer nitrogen was highest in south and least in north, and that of potassium was highest in south and least in middle climatic zone. 2. Since the percent recovery of Phosphorus variates yearly with climatic zone, mode of deposition drainage grade or soil texture, it seemed to depend greatly on soil-weather interaction. 3. Nitrogen recovery was highest in alluvial colluvial (AC) and it was followed by alluvial (A), fluvomarine (FM) and old alluvial in decreasing order while potassium recovery was OA>AC>A>FM. 4. The greater the drainage was, the higher the nitrogen recovery. The recovery of potassium and phosphorus tended to show high in moderately well drain, and low in poorly and well drain. 5. Nitrogen recovery was highest in fine silty and gradually decreased with coarseness. That of potassium or phosphorus was greater in those below fine loamy than in those above coarse silty. 6. Nitrogen recovery was high in Jisan, Geugrag, and Sindab series, and low in Hwadong, Gyuam, Yongji and Hwabong series. 7. Nitrogen recovery showed significant positive correlation with the content of organic matter (OM), Ca, CEC of surface soil and only in the year of high phosphorus recovery it had significant negative correlation with soil phosphorus. Phosphorus recovery had significant posititive correlation with CEC, Mg or Ca. 8. Potassium recovery showed negative correlation with K/(Ca+Mg), P, OM or K while positive correlation with Ca, Mg, CEC but significant only with K/(Ca+Mg) in the year of low potassium recovery. In the year of high K recovery it showed positive correlation with P, OM, K/(Ca+Mg) or K while negative with CEC, Mg or Ca but significant only with P, OM or CEC. Soil potassium has significant positive correlation with soil OM and P only in the year of low potassium recovery. 9. The percent recovery of N, P or K showed negative correlation coefficient with pH without significant. 10. There was significant positive correlation between OM and P, K or K/(Ca+Mg), P and K or K/(Ca+Mg), K and K/(Ca+Mg), Mg or CEC, Ca and K/(Ca+Mg), Mg, CEC or pH, Mg and CEC while significant negative correlation between Mg and OM, P or K/(Ca+Mg), P and CEC, Ca and K/(Ca+Mg). 11. From the percent rcovery of fertilizer and soil chemical characteristics it was known that soil organic matter increase nitrogen uptake, that K uptake has closer relation to K/(Ca+Mg) than K, that Mg affects P ugtake, and that the annual difference of P and K recovery was partly explainable.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.332-338
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• 2017

Launch and recovery system(LARS) is required to perform an USV-based underwater exploration. Through the analysis of the requirements according to the scenario of underwater exploration, the mechanism of LARS and the conceptual design of the mechanical parts of LARS are carried out. In addition, a USV motion can be induced due to environmental disturbances such as waves, so the detailed design of LARS for recovering the underwater tow-fish stably in consideration of the USV motion is performed. To verify the performance of launch and recovery operations, LARS and test bed were developed. The results show that the proposed LARS can stably launch and recovery an underwater tow-fish.