• Preventive Nutrition and Food Science
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• 제3권1호
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• pp.48-55
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• 1998

An acute ethanol load(50mmol/kg , i.p) resulted in an increase in peroxidation and a decrease in the levels of $\alpha$-tocopherol and ascorbate in rat cerebellum. Pretreatement with allopurinol(146$\mu$mol/kg, i.p) prevented the ethnol-induced increment in lipid peroxidation and decrease in $\alpha$-tocopherol content. However, the decrease of ascorbate was of greater magnitude when allopurinol was associated with ethanol. These results suggested that allopurinol. besides its action as a radical scavenger and xanthine oxidase inhibitor, might favor the regeneration of $\alpha$-tocopherol antioxidant acitviity was studied using ${\gamma}$-radiolysis in aerated ethanolic solutions. Even though allopurinol did not react by itself with $\alpha$-hydroxyethyl-peroxyl radicals [H3C-CH(OH)OO] , it enhance the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$tocopherol. The regeneration of $\alpha$-tocopherol from the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$-tocophero. The regeneration of $\alpha$-tocopherol from the $\alpha$-tocopherol radical by ascorbate remained as efficient in the presence of allopurinol as in its absence. The effects of allopurinol on the Vitamin E oxidation-reduction mechanism could be involoved in the beneficial effectof allopurinol on the biological cellular damages linked to free radical reactions.

• 센서학회지
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• 제20권1호
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• pp.25-29
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• 2011

This paper describes the design and analyses of vibration driven electromagnetic energy harvester with high power generation which is suitable for supplying power generator from human body motion. The proposed harvester consists of magnet, coil, and SM (Soft magnetic Material). In order to generate more induced voltage, the SM to concentrate flux lines from end of magnetic poles was arranged into insert moving magnet. Each model was designed and analyzed by using ANSYS software to simulation. The maximum power is generated when load resistance of $1303\;{\Omega}$ is equal to coil resistance. The generated maximum power of for harvesters with SM is $677.85\;{\mu}W$ and 5.46 times higher than without SM at 6 Hz vibration frequency.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.414-421
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• 2001

Recently, the damping effect of building structures are greatly reduced because the use of non-structures members as like curtain wall are decreased and large open space are in need for the service of buildings. Assembly and office buildings with a lower natural frequency have a higher possibility of experiencing excessive vibration induced by human activities as like jumping, running and walking. These excessive vibration make the occupants uncomfortable and the serviceability deterioration. The common method of application of walking loads for the vibration analysis of structures subjected to walking loads is to inflict a series unit walking load and a periodic function at a node. But this method could not consider the moving effect of walking. In this study, natural frequency and damping ratio of plate structure are evaluated by heel drop tests. And new application of equivalent walking loads are introduced for vibration analysis of real slab system subjected to walking loads. The response obtained from the numerical analysis are compared well to the results measured by experimental tests. It is possible to efficiently analyze the vibration of floor which is subjected to walking loads by applying equivalent walking loads.

• 센서학회지
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• 제20권4호
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• pp.249-253
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• 2011

This paper describes the fabrication and characteristics of vibration-driven electromagnetic energy harvester without spring to use at low frequency like a human body motion. The implemented energy harvester consists of NdFeB magnets, copper coil. The optimization of induced voltage was done by the various widths of coil, number of the turns, size of fixed and moving magnets and thicknesses of the cylinder. The fabricated energy harvester is capable of producing up to 15.0 $V_{pp}$ for basic model and 28.80 $V_{pp}$ for improved model at 5.0 Hz resonance frequency and 0.75 g acceleration level. The basic model and improved model are provided a maximum power of 6.375 mWand 25.831 mW at 1 KHz of load resistance in rectifier circuit.

• 대한의용생체공학회:의공학회지
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• 제32권3호
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• pp.230-236
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• 2011

The aim of this study was to investigate the alteration of lumbar spine and trunk postures on different load-carrying types and amounts under static loading. Two load-carrying types(unilateral carrying: UC vs. bilateral carrying: BC) and four different loads(0, 5, 10, and 15 kg) were randomly tested in this study. Carrying a heavy bag would affect human body posture, specifically lumbar spine curvature, which is considered as one of sources of back problems. Previous studies have not paid attention to the approach of the multisegment model of the lumbar spine and trunk. This study separated two compartments of trunk segment(the lumbar and thorax) in the analysis. The multisegment model of the lumbar spine in addition to Helen-Hayes marker set was used. Eight motion analysis cameras and a force plate were utilized. Ten male subjects(mean mass, $70.6{\pm}3.97$ kg; mean height, $178{\pm}4.18$ m) having no musculoskeletal disease participated in this study. We analyzed trunk angles in three anatomical planes and the spinal curvature in sagittal and frontal planes. Increased loading in both UC and BC significantly resulted in increases in trunk forward lean but only UC induced increases in trunk lateral lean. In addition, increased loading in BC produced flatten lumbar curvature in sagittal plane. As far as coupling motion, subjects tended to use axial rotation of the lumbar spine in transverse plane in response to increased UC loading. Finally, it is concluded that the increased static loading in UC rather than in BC tends to causes combined alterations of the spinal postures(sagittal and transverse planes together), which would be vulnerable to improper mechanical stresses on the spine.

• International Journal of Human Ecology
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• 제16권2호
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• pp.1-9
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• 2015

This study investigated the effects of persimmon-dyed clothing materials upon thermophysiological responses and subjective comfort sensations during exercise and rest in a warm environment. Six healthy, untrained women participated in two separate testing sessions, with cotton materials dyed with astringent persimmon extract (DC) and undyed cotton materials (UDC). The physical characteristics associated with heat and moisture transfer were improved in DC; also, stiffness, anti-drapery stiffness and crispness in the primary hand values were higher in DC. The experimental protocol consisted of a 10-min rest, 15-min exercise on a treadmill (at ${7km{\cdot}h^{-1}}$) and 25-min recovery at $28{\pm}0.2^{\circ}C$ and $50{\pm}3%\;RH$. The results were as follows: When wearing DC rather than UDC, mean body temperature, heart rate, heat storage and body mass loss were significantly lower during the whole experimental period. Clothing microclimate temperature showed different profiles between the two clothing materials, being lower with DC than UDC during the first half of exercise and the second half of recovery. Clothing microclimate humidity was significantly lower with DC than UDC during the whole experimental period. When wearing UDC, subjects felt significantly warmer and less comfortable during exercise, and sensed greater humidity during exercise and recovery. These results suggest that eco-friendly clothing materials dyed with astringent persimmon extract can reduce exercise-induced heat load and improve subjective sensations when exercising and resting in a warm environment, due to greater heat dissipation from the body to the outside environment compared with undyed clothing materials.

• 한국전산구조공학회논문집
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• 제30권6호
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• pp.469-477
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• 2017

본 논문에서는 실제 공연장을 예제 건물로 하여 공연장에 발생한 진동을 측정한 결과를 바탕으로 공연장 구조물의 안전성에 대해 해석적으로 평가하였다. 수치해석 프로그램은 MIDAS GEN을 사용하였으며, 바닥판은 합성효과를 고려하여 모델링하였다. 해석결과 진동계측실험을 통해 구한 바닥판 고유진동수와 유사한 결과를 보였다. 또한 군중의 율동에 의한 동적하중을 시간이력해석으로 해석하여 진동계측 실험과 유사한 수준의 바닥판 가속도 응답을 확인하였다. 이 모델을 사용하여 예제 공연장의 최대관람인원인 400명의 집단율동 시 발생하는 상황에 대하여 분석하였다. 그 결과 기둥과 보의 가해지는 외력은 설계 내력을 하회하여 안전성에 문제없음을 확인하였다. 또한 공연 시 발생하는 수평방향 진동수준은 지진하중의 2% 수준으로 수직수평 모두 안전성에 문제가 없는 것을 확인하였다.

• 터널과지하공간
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• 제27권6호
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• pp.387-392
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• 2017

최근 도심지 도로 하부 지반함몰 사고는 상수관로, 하수관거, 통신관로, 가스관로, 배전지중관로, 지하철 등의 다양한 공익시설 및 지하구조물이 시공되고 있으며 이러한 시설물의 부적절한 시공, 노후로 인한 시설물 손상, 유지관리 소홀이 그 원인으로 추정되고 있다. 도로함몰은 도로하부에서 매설관 파손 등의 원인으로 공동이 발생한 후 공동이 성장 확대되어 포장면 하부까지 도달하고 도로를 통행하는 차량의 하중을 도로포장 부분이 지탱할 수 없을 정도의 소성변형이 발생하여 갑자기 함몰이 발생할 경우 인명피해 및 교통장애를 초래하는 등 사회전반적인 안전과 경제 발전에 위협이 될 수 있다. 서울시에서는 도로 하부의 공동이 함몰되기 이전 단계에서 3D GPR 탐사를 통해 발견하여 복구함으로써 지반함몰에 따른 피해를 사전에 차단하는 노력이 우선적으로 진행되고 있으며 그 사례를 소개하였다.

• 조명전기설비학회논문지
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• 제24권6호
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• pp.138-146
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• 2010

본 논문은 직류 전기철도 급전시스템에서 레일전위와 누설전류의 분석 기법을 제시하였다. 일반적으로 직류 전기철도 급전시스템에서는 운행용 레일을 귀로 전류(부극성)의 도체로 사용하고 있으므로 레일전위가 발생하고, 특히 차량 운행용 레일과 대지사이의 저항이 작은 경우에는 대지로 흐르는 누설전류가 문제가 된다. 이 레일전위 및 누설전류는 레일 주변에 설치된 지하 매설물에 영향을 미치며, 인체의 안전과도 관련이 있다. 이에 따라 직류 전기철도 급전시스템에서 레일전위와 누설전류를 억제하는 것은 전기철도 주변 환경 및 안전 측면에서 중요한 문제이다. 이상과 같은 관점에서, 직류 전기철도 급전시스템에 대하여 단독급전 및 병렬급전 상황에서 레일전위와 누설전류를 계산할 수 있는 알고리즘을 제안하였으며, 또한 열차주행시뮬레이션(TPS)과 연동하여 열차주행에 따라 부하전류가 변동되는 상황에서 레일전위와 누설전류를 정량적으로 분석할 수 있도록 하였다. 제안한 알고리즘을 이용하여 시뮬레이션 프로그램을 개발하였고, 직류전기철도 급전시스템에 대하여 사례 연구를 수행하였다.

• Biomolecules & Therapeutics
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• 제5권4호
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• pp.364-368
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• 1997

Onion (Allium cepa Linn) has been reported to have hypoglycemic activity in human and several animal models. In the present study, we performed intraperitoneal glucose tolerance test (IPGTT) in young (1.5mo) and aged (5 mo) rats treated with onion in order to determine whether aging can influence on the anti-hy-perglycemic effect of onion. In addition, we investigated the hypoglycemic effect of onion in streptozotocin- induced diabetic rats treated with aqueous extracts of onion (500 mg/kg, i.p., daily) for 4 weeks. Blood glucose level was determined in fasted and fed rats by using a glucometer (Johnson & Johnson). In glucose tolerance test, blood glucose level was maximally increased 15 min after glucose load (2 g/kg, i.p.), and recovered to the basal level 3 hr after glucose challenge in young and old rats. The maximum blood glucose levels of young and aged rat were 184$\pm$7.49 and 225.2$\pm$ 12.55 mg/dl, respectively. A single i.p. injection of aqueous extract of onion (1 g/kg) 30 min before glucose challenge significantly decreased blood glucose levels at 15, 30, 60, 90 min after glucose load in aged rats, while the administration of onion did not show any significant effect in young rats. In onion-treated diabetic rats, significant hypoglycemic effect (p<0.05) was observed, and the effect was greater in fasted rats than in fed. In conclusion, these results suggest that anti-hyperlycemic effect of onion can be changed by age and fasting.