• PNF and Movement
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• v.19 no.2
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• pp.233-242
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• 2021

Purpose: The purpose of this study was to determine the changes in foot contact area and pressure when walking with a functional insole that emphasizes the Hallux point as compared to a general insole. Methods: In this study, an experiment was conducted to investigate changes in plantar pressure and contact area for a functional insole that emphasized the Hallux point as compared to a general insole. A lower extremity robot was used for walking reproduction. First, the gait sequence according to the two insoles was determined through a randomized controlled trial comparison. According to the sequence procedure, the insole was attached to the shoe and then worn on the right side of the lower extremity robot for gait reproduction at a normal gait speed of 20 steps per minute. After programming the robot to walk, the experiment was carried out. The result value was determined by averaging the pressure and area data of the fore and rear foot measures after walking at 20 steps per minute. Results: The functional insole that emphasized the hallux point significantly increased the forefoot and rearfoot contact area (p < 0.05) and significantly decreased the forefoot and rearfoot contact pressure (p < 0.05) compared to the general insole. Conclusion: A functional insole that emphasizes the hallux point does not collapse the medial longitudinal arch during gait, increasing foot stability and reducing fatigue. Thus, this functional insole needs to be widely used clinically.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.51-51
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• 2017

정식기는 주로 노외에서 사용되므로 사용자에 따라 극심한 작업환경 하에 놓일 수 있다. 사용 중 정식기 호퍼에 토양이나 자갈, 돌 등에 의해 반복적인 하중이 가해지거나 순간적인 충격하중이 가해져 취약부가 파손될 가능성이 있으므로, 토양과 직접 맞닿는 삽날부의 경우 내구성을 고려한 설계/제작이 필수적이다. 본 연구에서는 보행형 반자동 정식기 개발에서 고추묘와 같은 초장이 긴 작물의 묘를 효과적으로 이식할 수 있도록 개선된 삽날에 대해 기존 삽날과 강도 및 강성을 비교하고, 그 결과가 삽날의 내구성에 미칠 영향에 대하여 고찰하였다. 실험에는 양날 개폐 방식의 기존 및 개선삽날 2종이 사용되었으며, 각각 3회씩 정적 강도를 평가하였다. 실제 정식기 사용시 하중이 가해지는 방향은 삽날에 수직한 방향의 압축하중으로 이를 모사하여 일정변위 속도로 삽날에 하중을 가하였으며, 시험 진행시 DAQ 시스템을 통해 실시간으로 하중 및 변위 데이터를 저장하여 시험 종료 후 해당 데이터를 이용하여 $P-{\delta}$ 선도를 도출하였다. 시험 결과 기존삽날의 평균 최대하중이 개선삽날에 비해 높은 것으로 나타났으며, 최대 하중이 나타나는 지점의 변위의 경우, 기존삽날이 개선삽날에 비해 짧게 나타났다. 정적 강도측면에서 개선삽날이 기존삽날에 비해 최대 강도가 낮은 것으로 판단할 수 있으나, 실제 호퍼의 내구성에 영향을 줄 수 있는 주요 인자는 반복적으로 가해지는 비교적 낮은 수준의 충격하중으로 볼 수 있다. 이러한 관점에서 볼 때 일정 수준 이상의 강도를 가지면서, 기존삽날에 비해 낮은 강성을 가지는 개선삽날이 변형을 통한 충격에너지 흡수로 오히려 삽날 조립체(호퍼)의 내구성 측면에서 유리할 수 있다. 따라서 향후에는 기존 및 개선삽날을 적용한 호퍼에 대해 피로시험을 수행하여 관련 내용을 실험적으로 검증하고자 한다.

• Journal of Environmental Impact Assessment
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• v.18 no.6
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• pp.461-467
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• 2009

This paper provides two case studies of environmental impacts with socio-economic values. The first case is on flood protection levees conducted from 2003 to 2004 in Phu Tan district, An Giang province. The impacts were found by comparing full flood protection levees area (FFPL) to non-full flood protection levees area (NFFPL). Participatory Rural Appraisal (PRA) tools per each group of rich, middle, and poor people were used to list the impacts. Then, major impacts were selected by ranking and interviewing 60 households per site, and assessed by Cost Benefit Analysis (CBA) in rice production from 1996 to 2002 between two areas. The tested research indicated moving system of NFFPL to that of FFPL lost about 11 million VND/ha/year. The second case is on impacts of Penaeid shrimp farming conducted in Duyen Hai District, Tra Vinh Province in 2004-2005. Ninety households and 12 local officials were interviewed. Four PRAs were conducted and 36 water samples were taken inside and outside shrimp pond to measure values of DO, COD, Fe total, TSS, N-$NO_3{^-}$, N-$NH_4{^+}$, P-$PO{_4}^{3-}$, and Chlorophyll-a. Research results showed only 36.7% of the households got profit from shrimp farming. Highest financial efficiency was 0.72 for the semi-intensive system. Tested water indicators showed surface water quality did not match Vietnamese standard for surface water in coastal area (TCVN 5943-1995) and in rain. The water was very muddy and contaminated by organic aluminum. Summarily, the impacts were clarified more obviously via adding socio-economic values to assessment. Importantly, the values were transformed to household's income which is an indicator for policy-makers to consider the impacts obviously. Besides, data of different group of people impacted are cases contributing to consideration of the impacts in an appropriate social level.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.629-639
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• 2004

A steel frame is one of the most commonly used structural systems due to its resistance to various types of applied loads. Many studies have been conducted to investigate the effects of several parameters, such as connection flexibility, the boundary condition of each support, and beam-to-column stiffness ratio, on the characteristic behavior of a frame. Based on the results of these studies, several design methods have been proposed. This research focused on the number of bolts on the rotational stiffness of a double-angle connection, and its effect on the story drift of a frame. To achieve these purposes, a simplified analytical model was proposed. Several experimental tests were also conducted to obtain the rotational connection stiffness of each double-angle connection.

• Journal of the Korean Geotechnical Society
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• v.23 no.6
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• pp.85-95
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• 2007

In this study, in order to propose the prediction method of the residual settlement of clayey ground improved by vertical drains, a series of numerical analyses for a model ground were carried out using the elasto-viscous consolidation model. And the effects of ground improvement conditions of the ratio of effective radii $(r_e/r_w)$, consolidation pressure $({\Delta}p)$ on normally consolidated state, and the OCR (overconsolidation ratio) on overconsolidated state to reduce the residual settlement in three-dimensional consolidation by vertical drains were investigated by performing a series of numerical analyses. Furthermore, based on the results of a series of numerical analyses for the model ground, the predicting method of the residual settlement of clayey ground with vertical drains and the determination method of the value of OCR required to control the residual settlement within an acceptable value are proposed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6C
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• pp.277-285
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• 2009

A series of undrained cyclic triaxial tests were carried out to investigate the cyclic shear stress strength characteristics of sands with respect to the silt content. Silty sand was collected around the basin of Nak-Dong River and remolded in laboratory with the range of silt content 0~50% in sand located. As results, with the change of silt content cyclic shear stress ratio (CSR) at N=10 showed the maximum value at 5% and the minimum at 20% in all relative density. The development tendency of the pore water pressure analyzed by the relationship cyclic ratio and pore water pressure ratio is unrelated the change of CSR varying silt content. Comparing the results of the void ratio and skeleton void ratio after consolidation, CSR varying silt content was much affected by skeleton void ratio which is known to affect shear behavior of silty sand.

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.226-235
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• 2017

Roselle (Hibiscus sabdariffa L.) is a shrub which grows well in a tropical climate. There are large amounts of anthocyanins, organic acids and other compounds in roselle. Mostly, roselle is cultivated to use its red calyx. Its calyx is used as a natural food colorant and commonly consumed as a tea. This quality study was conducted to investigate the characteristics and antioxidant activities of Sulgidduck with roselle calyx powder. Four samples and a control were made with different ratios of added roselle calyx powder (0.5%, 1%, 1.5%, 2%). The moisture content of the 0.5%-sample was the highest as 40.60%, and that of the 2%-sample was the lowest as 37.37%. The pH of samples significantly decreased from 6.26 to 3.65 as the amount of roselle calyx powder increased (p<0.05). The L-value of samples also significantly decreased (p<0.05). In contrast, a-value and ${\Delta}E$ of samples significantly increased with elevated amounts of roselle calyx powder (p<0.05). The b-value of roselle calyx added Sulgidduck samples significantly increased compared to the control (p<0.05). Hardness and chewiness of Sulgidduck samples with added roselle calyx also significantly increased compared to the control (p<0.05). Cohesiveness of Sulgidduck samples with roselle calyx significantly decreased compared to control (p<0.05), with the exception of the 1% sample. There were no significant differences in springiness among samples. Total phenolic contents significantly increased when roselle calyx powder was added above a level of 1.5% (p<0.05). The flavonoid content of the control was the lowest as 0.73. ABTS radical scavenging activity significantly increased with increasing amounts roselle calyx powder (p<0.05). The 2%-sample got the lowest sensory preference scores in sweetness and overall acceptability. In contrast, the control and 1%-sample got the highest sensory preference scores. Based on these study findings, addition of 1% roselle calyx powder optimized the preparation of Sulgidduck and roselle calyx is therefore a useful natural colorant and antioxidant.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.74-81
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• 2000

Purpose: The purpose of this study was to develop in vivo dosimetries using both chromosomal aberrations and micronuclei in mice to assess biological effects of radiations. Materials and Methods: Five each mice were irradiated with 0, 1, 2, 3, 4, 5, 10 Gy of Cs-137 gamma-rays. We scored numbers of chromosomal aberrations in metaphase spreads and numbers of micronuclei in bone marrow smears under light microscope, and obtained the dose-response relationships. We also examined the relationship between the two dose-response curves. Results: The frequency of both chromosomal aberrations and micronuclei increased with dose, in a linear-quadratic manner The delta, beta, and alpha coefficients were 0.0176, 0.0324, and 0.0567 for metaphase analysis (r=1.0, p<0.001) and 0.0019, 0.0073, and 0.0506 for micronuclei assay (r=1.0, p<0.001). The frequency of chromosomal aberrations and micronuclei in different radiation doses was significantly correlated (r=0.99, p<0.01). Conclusion: In vivo dosimetry using either metaphase analysis or micronucleus assay was feasible in mice. These methods could be useful to evaluate biological effects of radiation.

• Journal of Ginseng Research
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• v.28 no.4
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• pp.191-195
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• 2004

An investigation was conducted to ascertain the basic information on characteristics of embryonic tissue development among Korean Ginseng, American ginseng, $F_{1}$ hybrids and $BC_{1}F_{1}(F_{1}$ pollen back cross to $BC_{1}=Korean\;Ginseng)seeds$. The specific activities of lipoxygenase (LOX) and the protein assays were made during the above embry­onic growth period at 5 or 25 degree C. The results are summarized as follows: The fresh weights(mg) of germinating seeds were significantly different among species. Ginseng seeds were stratified at $5^{\circ}C\;for\;60\;days$ the ratios of embryo/endosperms in $P.g.,\;P.q\;or\;F_{1}\;were\;about\;90{\%}$. The ratio was in $BC_{1}F_{1},\;79.2{\%}$ during the same period. The ratios of embryo/endosperms of seeds of P.g. or P.q. germinated at $5^{\circ}C$ showed rather higher values as compared to that at $25^{\circ}C$ LOX specific activity the highest in the $F_{1}$ and decreased in the order of P.g., P.q., and $BC_{1}F_{1}$. The highest LOX specific activity was shown at 80 days after sowing, followed by 70 days sowing, the least LOX activity was shown at 60 days.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.295-300
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• 2010

The aim of this study were to elucidate effects of fluoridated bleaching agents and post-treatment fluoride application on the color and microhardness of enamel surface. Twenty freshly extracted human adult molar were each sectioned into halves, the specimens divided and treated according to four experimental groups: 1, untreated controls: 2, treatment with 10% carbamide peroxide (CP) bleaching agent; 3, treatment with 10% CP containing 0.11% fluoride; 4, treatment with 10% CP followed by a 0.9% sodium fluoride gel application. Group 2-4 were compared with the baseline data. treated 8 h per day for 14 days then immersed in distilled water for 2 weeks. Changes in enamel color and microhardness were evaluated on Days 7 and 14. All the bleached enamel specimens revealed increased whiteness and overall color value. Groups 2 and 4 showed significantly decreased enamel microhardness compared to their baseline. The specimens treated with fluoridated bleaching agents showed relatively less reduction in enamel microhardness than those treated with nonfluoridated agents during the bleaching treatment. The addition of fluoride did not impede the tooth whitening. The fluoridated bleaching agents reduced the microhardness loss of enamel.