• Annals of Clinical Neurophysiology
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• v.19 no.1
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• pp.34-39
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• 2017

Background: Automated nerve excitability testing is used to assess various peripheral neuropathies and motor neuron diseases. Comparing these excitability parameters with normal data provides information regarding the axonal excitability properties and ion biophysics in diseased axons. This study measured and compared normal values of axonal excitability parameters in both the distal motor and sensory axons of normal Koreans. Methods: The axonal excitability properties of 50 distal median motor axons and 30 distal median sensory axons were measured. An automated nerve excitability test was performed using the QTRACW threshold-tracking software (Institute of Neurology, University College London, London, UK) with the TRONDF multiple excitability recording protocol. Each parameter of stimulus-response curves, threshold electrotonus, current-voltage relationship, and recovery cycle was measured and calculated. Results: Our Korean normal data on axonal excitability showed ranges of values and characteristics similar to previous reports from other countries. We also reaffirmed that there exist characteristic differences in excitability properties between motor and sensory axons: compared to motor axons, sensory axons showed an increased strength-duration time constant, more prominent changes in threshold to hyperpolarizing threshold electrotonus (TE) and less prominent changes in threshold to depolarizing TE, and more prominent refractoriness and less prominent subexcitability and superexcitability. Conclusions: We report normal data on axonal excitability in Koreans. These data can be used to compare various pathological conditions in peripheral nerve axons such as peripheral neuropathies and motor neuron disease.

• Journal of the Korean Wood Science and Technology
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• v.16 no.4
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• pp.70-78
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• 1988

To separate and utilize the main components of hardwood (Quercus mongolica) by organosov pulping (ester pulping), chips were cooked at various conditions such as; the solvent ratio (acetic acid: ethylacetate: water, 50:25:25; 33:33:34; 25:50:25), maximum temperature (165, 170, $175^{\circ}C$), and cooking times (2, 2.5, 3 hr). The pulps were bleached by the sequences of CEDED, C/DEDED, PEDED. Lignin, sugars, and acetic acid were separated from black liquor and washing liquors. 1. The selective delignification at optimal pulp yield (43-45%) was obtained by cooking at acetic acid: ethylace tate: water ratio of 33:34:34 for 3 hr at $170^{\circ}C$. But in this case, kappa no. of the pulp was not reduced under 60 points. 2. Kappa no. of the pulp could be dropped by an acetone wash to remove reprecipitated lignin a t cooked pulp. 3. The unbleached pulps had a brightness of 45-50%, whereas the bleached pulps gave at 88-93% brightness. Tensile, burst, and tear strengths of the bleached pulps were lower than those of kraft pulp, especially in tear strength. The pulps which were bleached with CEDED sequence were higher in strengths than another bleaching sequences. 4. Lignin of 90-95%(lignin base on wood)was separated from black liquor and washing liquors, while the purified sugars and recovery of acetic acid were a low. An organic phase composed of acetic acid, ethylacetate, and water was separated to a two-phase system by proper adjustment of the solvent ratios.

• Journal of the Korean Wood Science and Technology
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• v.21 no.4
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• pp.45-54
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• 1993

This study examines the differences in structures, physical and mechanical properties between domestic(Quercus variabilis Blume) and foreign(Quercus suber L.) corks. The results obtained are as follows: 1. The cork tissue consists of cork cells, lenticels, sclereids and dark-brown zone. There was a significant difference in ratio of cork cells between foreign cork(93 %) and domestic cork(87 %). The ring width and width of late cork of the foreign cork were wider than those of domestic cork. But the percentage of late cork of domestic cork was richer than that of foreign cork. The size of cork cell of foreign cork was larger by about two times than that of domestic cork. 2. The density was slightly higher in domestic cork(0.22 g/$cm^3$) than in foreign cork(0.19 g/$cm^3$). During first 24 hours, the amount of water absorption of the foreign cork was greater than that of domestic cork. However, after 24 hours, the tendency was reversed. The level of EMC was higher in domestic cork than in foreign cork. Total shrinkage in the radial and tangential directions was larger in domestic cork than tn foreign cork. In the longitudinal direction, the tendency was reversed. There was no difference in total swelling in three woody directions between the two corks. 3. The modulus of elasticity in compression in the logitudinal and tangential direction was higher in domestic cork than in foreign cork, but the tendency was reversed in the radial direction. Both corks showed 95% of recovery rate after 24 hours when they were compressed by 0.5. There were no differences in tension strength and Brinell,s hardness bet ween domestic and foreign corks.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.271-277
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• 2012

The aim of this study was to evaluate the effects of mental practice to improve on gait and quality of life in stroke patients. Participants were randomly allocated to two groups: experimental(n=10) and control (n=10). Both groups received neural development treatment training for 6 sessions 1 hour per week during 6 weeks. Experimental group practiced additional mental practice for 3 session 10 minutes per week 6 weeks. Results were evaluated by spatial-temporal parameter, 10m walk test, and quality of life. There were significantly increased by mental practice in outcomes of the gait performance from the gait velocity, cadence, double support, single support, 10m walk test. There were significantly increased by mental practice in outcomes of stroke impact scale from the strength, social participants, and stroke recovery. In conclusion, the mental practice improves gait performance and quality of life in stroke patients. The results suggest that mental practice training is feasible and suitable to stroke patients.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.495-500
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• 1994

Mackerel water-soluble protein solution Mackerel meat washing water were concentrated by isoelectric point shifting precipitation process, and the concentrates were utilized as a material for processing of an elastic gel food such as kamaboko. The water-soluble proteins were partly polymerized during the isoelectric point shifting precipitation process. Then, the water soluble protein concentrates were partly substituted for frozen minced Alaska pollack meat in processing of a good quality kamaboko. The maximum substitution percentage for good quality kamaboko manufacturing was concluded to be below $30\%$, according to the criteria of color difference, jelly strength and folding tests using the substituted recovered protein concentrates.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.62-67
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• 2004

Many ships in voyage experience weight and buoyancy distribution change by various reasons such as change of sea water density and waves, weather condition, and consumption of fuel, provisions, etc . The weight and buoyancy distribution change can bring the ships out of allowable trim, heeling angle. In these case, the ships should adjust trim and heeling angle by shifting of liquid cargo or ballasting, deballasting of ballast tanks for recovery of initial state or for a stable voyage. But, if the adjustment is performed incorrectly, ship's safety such as longitudinal strength, intact stability, propeller immersion, wide visibility, minimum forward draft cannot be secured correctly. So it is required that the adjustment of trim and heeling angle should be planned not by human operators but by optimization computer algorithm. To make an optimized plan to adjust trim and heeling angle guaranteeing the ship's safety and quickness of process, Uk! combined mechanical analysis and optimization algorithm. The candidate algorithms for the study were heuristic algorithm, meta-heuristic algorithm and uninformed searching algorithm. These are widely used in various kinds of optimization problems. Among them, heuristic algorithm $A^\ast$ was chosen for its optimality. The $A^\ast$ algorithm is then applied for the study. Three core elements of $A^\ast$ Algorithm consists of node, operator, evaluation function were modified and redefined. And we analyzed the $A^\ast$ algorithm by considering cooperation with loading instrument installed in most ships. Finally, the algorithm has been applied to tanker ship's various conditions such as Normal Ballast Condition, Homo Design Condition, Alternate Loading Condition, Also the test results are compared and discussed to confirm the efficiency and the usefulness of the methodology developed the system.

• Annals of Clinical Neurophysiology
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• v.14 no.2
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• pp.64-71
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• 2012

Background: It is generally accepted that upper motor neuron (UMN) lesion can alter lower motor neuron (LMN) function by the plasticity of neural circuit. However there have been only few researches regarding the axonal excitability of LMN after UMN injury especially during the acute stage. The aim of this study was to investigate the nerve excitability properties of the LMNs following an acute to subacute supratentorial corticospinal tract lesion. Methods: An automated nerve excitability test (NET) using the threshold tracking technique was utilized to measure multiple excitability indices in median motor axons of 15 stroke patients and 20 controls. Testing of both paretic and non-paretic side was repeated twice, during the acute stage and subacute stage. The protocols calculated the strength-duration time constant from the duration-charge curve, parameters of threshold electrotonus (TE), the current-threshold relationship from sequential sub-threshold current, and the recovery cycle from sequential supra-threshold stimulation. Results: On the paretic side, compared with the control group, significant decline of superexcitablity and increase in the relative refractory period were observed during the subacute stage of stroke. Additionally, despite the absence of statistical significance, a mildly collapsing in ('fanning in') of the TE was found. Conclusions: Our results suggest that supratentorial brain lesions can affect peripheral axonal excitability even during the early stage. The NET pattern probably suggests background membrane depolarization of LMNs. These features could be associated with trans-synaptic regulation of UMNs to LMNs as one of the "neural plasticity" mechanisms in acute brain injury.

• Korean Journal of Food Science and Technology
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• v.11 no.3
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• pp.192-199
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• 1979

With cells of Streptomyces spp K-45 isolated from soil, the immobilization of glucose isomerase by a series of treatments ; heat, carefully manipulated drying, extrusion with a thickening agent, and glutaraldehyde-induced crosslinking, was presented. This was aimed to obtain a mechanically stable form of whole cell containing glucose isomerase. The resulted pellet form had a good mechanical strength, compared with a commercial product, and showed 26 % of the activity recovery. The specific activity was 48.1 units per g of the dry material. The immobilized glucose isomerase generally showed properties similar to those of the soluble enzyme ; optimal pH at $7.5{\sim}9.0$, optimal temperature at $80{\sim}85^{\circ}C$, activation energy of 10.9 kcal/mole, and $K_m$ for glucose of 10.9M. The immobilized enzyme was very thermostable and pH stable.

• Journal of KIISE:Information Networking
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• v.30 no.6
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• pp.755-763
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• 2003

To improve performance over noisy wireless channels, mobile wireless networks employ forward error correction(FEC) techniques. The performance of static FEC algorithms, however, degrades by poorly matching the overhead of their correction code to the degree of the fluctuating underlying channel error. This paper proposes an adaptive FEC technique called FECA(FEC-level Adaptation), which dynamically tunes FEC strength to the currently estimated channel error rate at the data link layer. FECA is suitable for wireless networks whose error rate is high and slowly changing compared to the round-trip time between two communicating nodes. One such example network would be a sensor network in which the average bit error rate is higher than $10^{-6}$ and the detected error rate at one time lasts a few hundred milliseconds on average. Our experiments show that FECA performs 15% in simulations with theoretically modeled wireless channels and in trace-driven simulations based on the data collected from real sensor networks better than any other static FEC algorithms.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.123-134
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• 2007

This study was carried out for evaluating correlation of aging level and deformation resistance of asphalt mixtures conditioned by artificial aging treatment. The specimens were made of the short-term aged loose asphalt mixture which was kept in a convection oven at $154^{\circ}C$ for 2 hours, and then were artificially aged at $110^{\circ}C$ for 24, 48, 72 and 96 hours for long-term aging. Deformation strength ($S_D$) and large molecular size ratio (LMS(%)) were measured after short-term and each long-term aging treatment to evaluate aging extents of each mixture with aging time using GPC(Gel-permeation chromatograph) test. It is shown that the $S_D$ and LMS(%) were increased with aging time increment, and that LMS(%) quantity and $S_D$ have relatively good correlation each other. This study found that the aged asphalt mixture had better resistance against rutting and it was possible to estimate rutting characteristics of asphalt mixtures by using LMS(%) without a binder recovery.