• International Journal of Highway Engineering
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• v.14 no.2
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• pp.45-53
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• 2012

Hollows are easily made and bearing capacity is lowered near underground structures of concrete pavement because of poor compaction and long term settlement of the ground. Distresses occur and lifespan is shortened because of larger stress induced by external loadings expected than that in the design. In this paper, the distresses of the concrete pavement slab over box culverts were investigated at the Korea Expressway Corporation(KEC) test road. The transverse cracking of the slabs over the culverts was compared between up and down lines with different soil cover depth. The box culvert without soil cover and concrete pavement were modeled and analyzed by the finite element method(FEM) to verify the transverse cracking at the test road. Wheel loading was applied after self weight of the pavement and temperature gradient of the concrete slab at Yeojoo, Gyeonggi where the test road is located were considered. Positions of maximum tensile stress and corresponding positions of the wheel loading were found for each loading combination. Joint position minimizing the maximum tensile stress was found and optimal slab length over the culverts with diverse size were suggested.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1B
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• pp.71-76
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• 2000

On multimedia teleconferencing system existing a number of participants, face of the participants can beperceived by visual image. However, differentiation of each participant's voice and spaciousness sense are very hard since voice of all participants is processed with one dimensional data. In this paper, we implemented three dimensional audio rendering system using the HRTF(Head Related Transfer Function) and distance sense reproduction method and determined the optimal location of the participants for teleconferencing system. In the results of the listening test using elevation and azimuth angle, we showed that directional perception of the azimuth angles were better than that of the elevation angles. Specially, we showed that participant location using the HRTFS of the azimuth angle 10" , 90" , 270" and350" was efficient in teleconferencing system existing four participants. We also proposed that distance cue was used for enhancement of the reality and location of many participants more than five.ipants more than five.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.477-493
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• 2016

A single process using hot water (0% green liquor) and green liquor (GL) was investigated for pre-pulping extraction on two types of raw material. The GL was applied at different alkali charges of 0-5% on a dry wood weight basis. The extractions were performed at an H-factor 900 at $180^{\circ}C$. The 0% and 3% GL extraction detected acetic acid (AA) at 10.02 and $9.94g/{\ell}$, extracts derived from hardwood, 2.46 and $3.76g/{\ell}$, extracts derived from softwood, respectively. The single liquid-liquid extraction (LLE) was studied using tri-n-alkylphosphine oxide (TAPO). Response surface methodology (RSM) was employed as an efficient approach for predictive model building and optimization of AA recovery conditions. The extraction of AA was evaluated with a three-level factorial design. Three independent variables, pH (0.5-3.5), temperature ($25-65^{\circ}C$), and residence time (24-48 min) were investigated. Applying the RSM models obtained, the optimal conditions selected of extracts derived from hard- and softwood with a 3% GL were approximately pH 1.4, $26.6^{\circ}C$, 43.8 min and approximately pH 0.7, $25.2^{\circ}C$, 24.6 min, respectively. The predicted and experimental values of AA recovery yield were similar whilst sugar retention was 100%.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1110-1116
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• 2003

The effects of packaging methods on the storage quality of minimally processed (prepeeled) onions were investigated to determine the optimal packing design. Various packaging treatments used for modifying headspace atmospheres included two passive MAP using LDPE and PP films, two active MAP using a gas mixture of 20% $O_2/10%\;CO_2/balance\;N_2$ and an ethylene scavenging sachet, and moderate vacuum packaging (MVP). The quality attributes of onion samples were evaluated periodically in terms of flesh weight loss, color of cut surface, decay ratio, microbial counts, and sensory properties during storage at $10^{\circ}C$ for 28 days. Packaging methods did not significantly influence surface color, weight loss, and microbiological populations of mesophiles, psychrotrophs, and lactic acid bacteria. They did, however, affect sensory characteristics as well as decay occurrence. Results indicated that seal-packaging with a gas-permeable plastic film under a mild vacuum condition could retain better onion quality in terms of microbial decay and visual sensory aspects as compared with the other packages.

• Korean journal of food and cookery science
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• v.32 no.6
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• pp.704-715
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• 2016

Purpose: This study was conducted to optimize the conditions of manufacturing the wet noodle added with Aloe powder. Methods: The I-optimal design of response surface methodology (RSM) was used for the optimization of added amount of Aloe powder, water content, and kneading time as the independent variables. The quality characteristics (color, texture, water absorption ratio, volume, turbidity) and sensory characteristics (color, flavor, taste, mouth feel, overall acceptance) were analyzed as dependent variables. Results: The lightness, redness, and yellowness of the Aloe noodle were all lowered with the addition of Aloe powder. All texture characteristics such as hardness, elasticity and chewiness of Aloe noodle showed the tendency to increase with increasing amount of Aloe added and kneading time. The water uptake and the volume expansion tended to increase with increasing aloe addition and water addition. As the kneading time increased, the dissolution of solids decreased and the turbidity tended to decrease. Aloe powder content influenced the color, flavor and taste of the noodles most among independent variables, and the mouthfeel of the noodle influenced by the water addition and the kneading time. Conclusion: Aloe noodle showed the best desirability with 3.03% of Aloe powder, 43.56% of water content and 13.06 min of kneading time by RSM analysis. Aloe noodles prepared under these optimized conditions are expected to be able to manufacture and utilize functional Aloe noodles by meeting the content of isobarbaloin, which helps the intestinal functional activity.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.4
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• pp.299-307
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• 2011

The offshore plants such as FPSO are subjected to combination loading of environmental conditions (swell, wave, wind and current). Therefore the fatigue damage is occurred in the operation time because the units encounter the environmental phenomena and the structural configurations are complicated. This paper is a research for frequency domain fatigue analysis of wide-band random loading focused on accuracy of fatigue damage estimation regarding the proposed methods. We selected ideal bi-modal spectrum. And comparison between time-domain fatigue analysis and frequency-domain fatigue analyses are conducted through the fatigue damage ratio. Fatigue damage ratios according to Vanmarcke's bandwidth parameter are founded for wide-band. Considering safety, we recommend that Jiao-Moan and Tovo-Benasciutti methods are optimal way at the fatigue design for wide-band response. But, it is important that these methods based on frequency-domain unstably change the accuracy according to the material parameter of S-N curve. This study will be background and guidance for the new frequency-domain fatigue analysis development in the future.

• Physical Therapy Rehabilitation Science
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• v.9 no.3
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• pp.178-183
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• 2020

Objective: This study conducted in order to investigate the correlations between fall experience, balance, mobility, and confidence. We examined the difference between fall experience, and Berg Balance Scale (BBS), Timed-Up-and-Go test (TUG), Tinetti balance assessment (Tinetti balance [TiB], Tinetti gait [TiG]), and Activities-specific Balance Confidence (ABC) scale scores to see how fall experience, balance, mobility, and confidence of the persons with stroke affects their balance. Design: Cross-sectional study. Methods: Forty-one subjects participated in this study. The BBS includes 14 items, consisting of a 5-point scale from 0 to 4, totaling up to 56 points. The Timed Up and Go-Alone (TUGA) was used to measure the average time to take a 3 m round-trip by getting up and down from a 46-cm high chair with an armrest on a flat floor. The Timed-Up-and-Go-Cognitive (TUGC) was performed by counting backwards and the Timed Up and Go-Manual (TUGM) is performed by holding a cup full of water. The total score for the TiB is 16 points, and the TiG is 12 points, making a total of 28 points. There are 16 items total for the ABC scale. Results: According to the fall experience, BBS, the TUGA and TUGC values were significantly higher in the inexperienced group compared to the experienced group (p<0.05). The number of falls was significantly correlated with BBS, TUGA, TUGC, TUGM, TiB, TiG, TiB+TiG (p<0.05). Conclusions: This study supports that falls experience is strongly related to balance, mobility, and confidence. Optimal balance training programs for fall prevention is still insufficient and must be developed.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.99-104
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• 2013

To detect five plant viruses (Beet black scorch virus, Beet necrotic yellow vein virus, Eggplant mottled dwarf virus, Pelargonium zonate spot virus, and Rice yellow mottle virus) for quarantine purposes, we designed 15 RT-PCR primer sets. Primer design was based on the nucleotide sequence of the coat protein gene, which is highly conserved within species. All but one primer set successfully amplified the targets, and gradient PCRs indicated that the optimal temperature for the 14 useful primer sets was $51.9^{\circ}C$. Some primer sets worked well regardless of annealing temperature while others required a very specific annealing temperature. A primer specificity test using plant total RNAs and cDNAs of other plant virus-infected samples demonstrated that the designed primer sets were highly specific and generated reproducible results. The newly developed RT-PCR primer sets would be useful for quarantine inspections aimed at preventing the entry of exotic plant viruses into Korea.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.117-125
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• 2008

Recently, users of bicycles as a green mode are rising sharply, but there are few efforts to increase bicycle safety and to decrease the number of accidents between vehicles and bicycle users. Therefore, this research seeks to improve bicycle safety at intersections by analysing causation factors of bicycle accidents pattern and providing optimal intersection design guidelines. For this study, real bicycle accident data of fifty six occurred in the Incheon metropolitan area in the year of 2005 were collected and field surveys were conducted. In addition, this research developed a bicycle accident pattern model with using multinomial logit model. The model results showed that presence of fatality, presence of traffic islands on the minor road, highway_type, weather, presence of traffic bus_stop on the major road, minor road lane width, victim induce factor are significant for bicycle safety.

• Progress in Superconductivity
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• v.7 no.2
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• pp.114-119
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• 2006

High critical current density, high n value, multiple faults endurances, and fast recovery characteristics of YBCO thin films are very attractive characteristics for developing resistive type superconducting fault current limiters. But due to the limited current and voltage ratings of one YBCO module, it is needed to construct series and parallel module connections for high capacity electric networks. Especially for distribution network, more than 30 units should be connected in series to meet voltage level. So in order to construct distribution-level superconducting fault current limiter, simultaneous quench in one YBCO thin films should be realized, and furthermore, quench should be occurred in all fault current limiting units equally to avoid local heating and failures. In this paper, we proposed optimum design of YBCO thin films for fault current limiting module and technical method using shunt resistor to achieve simultaneous quench between multi current limiting units. From the analytical and the experimental results, optimal current path and thickness of shunt material was determined for YBCO thin films and shunt resistor between modules was developed. Finally, 14 kV one phase resistive fault current limiter using multi YBCO thin films was constructed and it was possible to get satisfactory test results.