• 대한기계학회논문집B
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• 제34권5호
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• pp.515-522
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• 2010

본 연구의 목적은 무착상 조건에서 나선형 원형핀-튜브 열교환기의 형상변수에 따른 열전달특성을 고찰하고 평판 사각핀-튜브 열교환기와 열전달성능을 비교하는 것이다. 나선형 원형핀-튜브 열교환기는 Lfoot 길이 2.7 mm 에서 열전달계수가 최대로 나타났으며, 공기측 열전달계수는 튜브열수가 2 열에서 5 열로 증가하면서 평균 10% 감소하였고 핀피치가 5 mm 에서 10 mm 로 증가하면서 평균 17.5% 증가하였다. 모든 풍량조건에서 나선형 원형핀-튜브 열교환기의 튜브피치 30 mm 가 35 mm 보다 열전달량이 평균 5.1% 높게 나타났고 튜브두께 0.5 mm 가 0.7 mm 보다 열전달량이 평균 4.1% 높게 나타났다. 나선형 원형핀-튜브 열교환기의 열전달계수가 평판 사각핀-튜브 열교환기에 비하여 평균 24.3% 정도 높게 나타났다.

• Archives of Plastic Surgery
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• 제36권6호
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• pp.679-684
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• 2009

Purpose: Human lipoaspirate cells are relatively easy to obtain in large quantities without cell culture. The aim of this in vitro pilot study was to determine the effect of cell therapy using uncultured lipoaspirate cells on cell proliferation and collagen synthesis of diabetic fibroblasts, which are the major contributing factors in wound healing. Methods: In order to get diabetic fibroblasts, dermis tissues were obtained from foot skin of diabetic patients who underwent debridements or toe amputations(n = 4). In order to isolate lipoaspirate cells, the same diabetic patients' abdominal adipose tissues were obtained by liposuction. The diabetic fibroblasts were co - cultured with or without autogenous lipoaspirate cells using porous culture plate insert. Initial numbers of the lipoaspirate cells and diabetic fibroblasts seeded were 15,000 cells/well, respectively. For cell proliferation assay, two treatment groups were included. In group I, diabetic fibroblasts were cultured with the insert having no cells, which serves as a control. In group II, the lipoaspirate cells were added in the culture plate insert. For collagen synthesis assay, one additional group(group III), in which diabetic fibroblasts were not seeded in the well and only lipoaspirate cells inside the insert were incubated without diabetic fibroblasts, was included for a reference. Results: One hundred to one hundred sixty thousand lipoaspirate cells were isolated per ml of aspirated adipose tissue. After 3 - day incubation, the mean cell numbers in group I and II were 17,294/well and 22,163/well. The mean collagen level in group I, II, and III were 29, 41, and 2 ng/ml, respectively. These results imply that both cell proliferation and collagen synthesis in the lipoaspirate cell treatment group were 28 and 44 percents higher than in the control group, respectively(p < 0.05). Conclusion: Uncultured lipoaspirate cell autografts may stimulate the wound healing activity of diabetic fibroblasts.

• The Korean Journal of Pain
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• 제37권2호
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• pp.151-163
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• 2024

Background: Galangin, commonly employed in traditional Chinese medicine for its diverse medicinal properties, exhibits potential in treating inflammatory pain. Nevertheless, its mechanism of action remains unclear. Methods: Mice were randomly divided into 4 groups for 7 days: a normal control group, a galangin-treated (25 and 50 mg/kg), and a positive control celecoxib (20 mg/kg). Analgesic and anti-inflammatory effects were evaluated using a hot plate test, acetic acid-induced writhing test, acetic acid-induced vascular permeability test, formalin-induced paw licking test, and carrageenan-induced paw swelling test. The interplay between galangin, transient receptor potential vanilloid 1 (TRPV1), NF-κB, COX-2, and TNF-α proteins was evaluated via molecular docking. COX-2, PGE2, IL-1β, IL-6, and TNF-α levels in serum were measured using ELISA after capsaicin administration (200 nmol/L). TRPV1 expression in the dorsal root ganglion was analyzed by Western blot. The quantities of substance P (SP) and calcitonin gene-related peptide (CGRP) were assessed using qPCR. Results: Galangin reduced hot plate-induced licking latency, acetic acid-induced contortions, carrageenan-triggered foot inflammation, and capillary permeability in mice. It exhibited favorable affinity towards TRPV1, NF-κB, COX-2, and TNF-α, resulting in decreased levels of COX-2, PGE2, IL-1β, IL-6, and TNF-α in serum following capsaicin stimulation. Galangin effectively suppressed the upregulation of TRPV1 protein and associated receptor neuropeptides CGRP and SP mRNA, while concurrently inhibiting the expression of NF-κB, TNF-α, COX-2, and PGE2 mRNA. Conclusions: Galangin exerts its anti-inflammatory pain effects by inhibiting TRPV1 activation and regulating COX-2, NF-κB/TNF-α expression, providing evidence for the use of galangin in the management of inflammatory pain.

• Structural Engineering and Mechanics
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• 제48권4호
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• pp.455-466
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• 2013

In recent years, many countries have added railway noise to the issues covered by noise regulations. It is known that the rail is the dominant source of rolling noise at frequency range of 500Hz-2000Hz for the conventional speeds (<160km/h). One of the effective ways to reduce noise from railway track is using a rail vibration absorber. To study the acoustic performance of rail absorber, the decay rates of vibration have long been used by researcher. In this paper, A FE model of a periodic supported rail with infinite element in ABAQUS is developed to study the acoustic performance of the rail absorber. To compute the decay rates, acceleration responses along the rail transferred to MATLAB to obtain response levels in frequency domain and then by processing the response levels, the decay rates obtained for each1/3octav band. Continous rail absorber is represented by a steel layer and an elastomer layer. The decay rates for conventional rail and rail with one-side absorber and also, the rail with two side absorber are obtained and compared. Then, to improve the system of rail absorber, a steel plate with elastomer layer is added to bottom of the rail foot. The vertical decay rate results show that the decay rate of rail vibration along the track is significantly increased around the tuned frequency of the absorber and thus the rail vibration energy is substantially reduced in the corresponding frequency region and also effective in rail noise reduction.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.383-386
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• 2005

Low frequency heavy-weight impact noise is the most irritating noise in Korean high-rise reinforced concrete apartment buildings. This low frequency noise is generated by foot traffic due to the fact that Koreans do not wear shoes at home. The transmission of the noise is facilitated by a load bearing wall structural system without beams and columns which is used in these buildings. In order to control low frequency heavy-weight impact noise, floating floors using isolation materials such as glass-wool mat and poly-urethane mat are used. However, it was difficult to control low frequency heavy-weight impact sound using isolation material. In this study, reinforcement of concrete slab using beams and plate was conducted. Using the FEM analysis, the effect of concrete slab reinforcement using FRP(fiber-glass reinforced plastic) on the bang machine impact vibration acceleration level and sound were conducted at the standard floor impact sound test building. The $3{\sim}4dB$ floor impact vibration acceleration level and impact sound pressure level were reduced and the natural frequency of slabs were changed.

• 한국정밀공학회지
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• 제32권3호
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• pp.285-292
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• 2015

This paper presents a wireless ground reaction force (GRF) sensing system for ambulatory GRF recording. The system is largely divided into three parts: force sensing modules based on optical sensor, outsole type frame, and embedded system for wireless communication. The force sensing module has advantages of the low height, robustness to the moment interference, and stable response in long term use. In simulation study, the strain and stress properties were examined to satisfy the requirements of the GRF sensing system. Four sensing modules were mounted on the toe, ball, and heel of foot shaped frame, respectively. The GRF signals were extracted using Micrpcontroller unit and transferred to the smart phone via Bluetooth communication. We measured the GRF during the normal walking for the validation of the continuous recording capability. The recorded GRF was comparable to the off the shelf stationary force plate.

• Archives of Plastic Surgery
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• 제35권4호
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• pp.400-406
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• 2008

Purpose: Since ancient times, larval therapy has been applied to help wound healing. Its use has recently been rediscovered, and the interest in this therapy has been increased in clinical practice, as well as in research. The objective of this study is to assess the efficacy of maggot therapy for the treatment of intractable, chronic wounds. Methods: Twenty patients, suffering mostly from chronic wounds were treated using maggots of greenfly (Phaenicia sericata). Sterile maggots were administered to the wound twice a week. The causes of the development of wounds were diabetic foot(14), trauma(3), plate exposure(1), and unknown origin(2). Results: Complete debridement was achieved in 10 wounds; in 8 wounds, the debridement was partially achieved; 2 patients escaped. Four patients were healed without any additional surgical procedures but fourteen patients were treated with skin graft. Pain, reported by six patients, was relatively well controlled with oral analgesics. Conclusion: We found larval therapy to be effective for chronic wounds. Maggot therapy is a relatively rapid and effective treatment, particularly in necrotic wounds or the wounds resistant to conventional treatment.

• 한국운동역학회지
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• 제23권1호
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• pp.19-24
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• 2013

The aim of the study was a quantitative analysis of elite athlete's $540^{\circ}$ Dwihuryeochagi and effects of ground movements to the jumping height and kicking velocity. Eleven elite players(Taekwondo demonstration team) participated in this study. In order to get the kinetic and kinematic variables, ten Vicon cameras and a force plate were used. Foot segment velocity(FSV), vertical ground reaction force(GRF), impulse, ground time(GT) in phase 1, trunk angular velocity(TAV), vertical center of gravity(COG), flight time(FT) in phase 2 and kicking leg segment velocity(KSV) in phase 3 were measured and analyzed. Results indicated that there were similar patterns of variables among phases between subjects. Non-significant correlation(r=.145) between flight time(FT) and impulse was found. Also non-significant correlation(r=.119) between center of gravity(COG) and impulse was found. In conclusions, there were similar strategies in phase 1, phase 2, and phase 3 between subjects.

• 대한물리치료과학회지
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• 제11권2호
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• pp.5-17
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• 2004

The purpose of this study was to investigate the relationship between normal adults' resting calcaneal stance position(RCSP) and postural sway. Subjects were 70 normal adults(34 men and 36 women) in their twenties who attend S. University. Postural sway during a single limb stance was measured using the CMS 10 Measuring System when subjects positioned on the balance trainer in their bare foot. RCSP while subjects were standing on the glass plate was measured using the angle tinder after subjects were positioned in prone to divide equally lower leg and calcaneus using the goniometer. The result was as follows. There were significant weak positive correlations between RCSP and postural sway(r=0.362, p<0.01), the leg of the small RCSP within a subject has the small postural sway index($X^2=43.758$, p<0.001). There was no significant difference between groups of rearfoot valgus(RCSp<$2^{\circ}$) and those of rearfoot varus (RCSp>$2^{\circ}$) in the postural sway. In conclusion, there is a weak relationship between increasing the absolute value of RCSP and increasing postural sway.

• The Journal of Korean Physical Therapy
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• 제33권3호
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• pp.162-167
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• 2021

Purpose: A hyperextended knee is described as knee pain associated with an impaired knee extensor mechanism. Additionally, a hyperextended knee may involve reduced position sense of the knee joint that decreases the individual's ability to control end-range knee extension movement. The purpose of this study was to investigate the effects of visual biofeedback information for plantar pressure distribution on knee joint angle and lower extremity muscle activities in participants with hyperextended knees. Methods: Twenty-three participants with hyperextended knees were recruited for the study. Surface electromyography signals were recorded for the biceps femoris, rectus femoris, gastrocnemius, and tibialis anterior muscle activities. The plantar pressure distribution was displayed and measured using a pressure distribution measuring plate. Knee joint angle kinematic parameters were recorded using a motion analysis system. The visual biofeedback condition was the point at which the difference between the forefoot and backfoot plantar foot pressure on the monitor was minimized. The Wilcoxon signed-rank test was used to determine the significance between the visual biofeedback condition and the preferred condition. Results: The knee joint angle was significantly decreased in the visual biofeedback condition compared to that in the preferred condition (p<0.05). The rectus femoris and gastrocnemius muscle activities were significantly different between the visual biofeedback and preferred conditions (p<0.05). Conclusion: The results of this study showed that visual biofeedback of information about plantar pressure distribution is effective for correcting hyperextended knees.