• 한국컴퓨터정보학회논문지
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• 제27권8호
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• pp.161-168
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• 2022

본 연구에서는 20대 경도비만 남성을 대상으로 시판 남성용 상체 보정속옷에 대한 착용만족도를 알아보고 개선점을 파악하고자 하였다. 피험자는 20대 남성이면서 BMI지수가 25~30인 (경도비만)인 사람으로 15명을 선정했다. 연구 결과, 남성들의 보정속옷에 대한 인지도와 관심도는 낮은 편이었다. 착용 만족도 조사에서는 입고 벗을 때 불편하다고 부정적으로 답한 사람이 많았다. 압박감면에서는 초반에는 압박감이 강하다고 느끼지만 시간이 지날수록 익숙진다고 하였다. 답답함과 더위와 관련하여 부정적으로 응답한 사람이 과반을 넘었고 땀 흡수 및 배출과 관련해서도 부정적인 의견이 많았다. 시각적인 부문에서는 가슴 보정, 허리 옆부분 보정, 허리 앞부분에서 모두 긍정적인 반응을 보였다. 결론적으로, 남성용 상체 보정속옷의 개선점은 과한 압박감이 가져다주는 답답함과 소화불량, 여름철을 고려하여 더위와 땀과 관련한 기능성 부분인 것으로 나타났다.

• Corrosion Science and Technology
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• 제15권3호
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• pp.120-124
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• 2016

The effect of alloying element Ca (0, 1, and 2 wt%) on corrosion resistance and bioactivity of the as-received and anodized surface of rolled plate AM60 alloys was investigated. A plasma electrolytic oxidation (PEO) was carried out to form anodic oxide film in $0.5mol\;dm^{-3}\;Na_3PO_4$ solution. The corrosion behavior was studied by polarization measurements while the in vitro bioactivity was tested by soaking the specimens in Simulated Body Fluid (1.5xSBF). Optical micrograph and elemental analysis of the substrate surfaces indicated that the number of intermetallic particles increased with Ca content in the alloys owing to the formation of a new phase $Al_2Ca$. The corrosion resistance of AM60 specimens improved only slightly by alloying with 2 wt% Ca which was attributed to the reticular distribution of $Al_2Ca$ phase existed in the alloy that might became barrier for corrosion propagation across grain boundaries. Corrosion resistance of the three alloys was significantly improved by coating the substrates with anodic oxide film formed by PEO. The film mainly composed of magnesium phosphate with thickness in the range $30-40{\mu}m$. The heat resistant phase of $Al_2Ca$ was believed to retard the plasma discharge during anodization and, hence, decreased the film thickness of Ca-containing alloys. The highest apatite forming ability in 1.5xSBF was observed for AM60-1Ca specimens (both substrate and anodized) that exhibited more degradation than the other two alloys as indicated by surface observation. The increase of surface roughness and the degree of supersaturation of 1.5xSBF due to dissolution of Mg ions from the substrate surface or the release of film compounds from the anodized surface are important factors to enhance deposition of Ca-P compound on the specimen surfaces.

• Restorative Dentistry and Endodontics
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• 제27권6호
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• pp.587-599
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• 2002

Extracellular single unit recordings were made from the ventral posteromedial thalamic (VPM) nociceptive neurons to determine mechanoreceptive field (RF) and response properties. A total of 44 VPM thalamic nociceptive neurons were isolated from rats anesthetized with urethane-chloralose. Based on responses to various mechanical stimuli including touch, pressure and pinch applied to the RF, 32 of 44 neurons were classified as nociceptive specific (NS) neuron. The other 12 neurons, classified as wide dynamic range (WDR), showed a graded response to increasingly intense stimuli, with a maximum discharge to noxious pinch. The VPM nociceptive neurons showed various spontaneous activity ranged from 0-6 Hz. They were located throughout the VPM, and had an contralateral RF including mainly intraoral (and perioral) regions. The RF size was relatively small, and very few neurons had a receptive field involving 3 trigeminal divisions. The NS neurons activated only by pressure and pinch stimuli had high mechanical thresholds compared to WDR neurons activated also by touch stimuli. The VPM nociceptive neurons were tested with suprathershold graded mechanical stimuli. Most of 21 NS and 8 WDR neurons showed a progressive increase in number of spikes as mechanical stimulus intensity was increased. In some neurons, the responses reached a peak before the highest intensity was given. Application of 5 mM $CoCl_2{\;}(10{\;}{\mu}\ell)$ solution to the trigeminal subnucleus caudalis did not produce any significant changes in the spontaneous activity, RF size, mechanical threshold, and response to suprathreshold mechanical stimuli of 9 VPM nociceptive neurons tested. 17 of 33 VPM nociceptive neurons responded to noxious heat as well as noxious mechanical stimuli applied to their RF. Application of the mustard oil, a small-fiber excitant and inflammatory irritant, to the right maxillary first molar tooth pulp induced an immediate but short-lasting neuronal discharges upto approximately 4 min in 16 of 42 VPM nociceptive neurons. These results suggest that VPM thalamic nucleus may contribute to the sensory discriminative aspect of orofacial nociception.

• 한국세라믹학회지
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• 제42권9호
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• pp.624-630
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• 2005

To investigate the possibility of the $ZrO_2$ buffer layer as the insulator for the Metal-Ferroelectric-Insulator-semiconductor (MFIS) structure, $ZrO_2$ and $SrBi_2Ta_2O_9$ (SBT) thin films were deposited on the P-type Si(111) wafer by the R.F. magnetron-sputtering method. According to the process with and without the post-annealing of the $ZrO_2$ buffer layer and SBT thin film, the diffusion amount of Sr, Bi, Ta elements show slight difference through the Glow Discharge Spectrometer (GDS) analysis. From X-ray Photoelectron Spectroscopy (XPS) results, we could confirm that the post-annealing process affects the chemical binding condition of the interface between the $ZrO_2$ thin film and the Si substrate. Compared to the MFIS structure without the post-annealing of the $ZrO_2$ buffer layer, memory window value of MFlS structure with post-annealing of the $ZrO_2$ buffer layer were considerably improved. The window memory of the Pt/SBT (260 nm, $800^{\circ}C)/ZrO_2$ (20 nm) structure increases from 0.75 to 2.2 V under the applied voltage of 9 V after post-annealing.

• 한국해양환경ㆍ에너지학회지
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• 제11권2호
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• pp.92-97
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• 2008

일반적으로 해수가 강으로 침입하거나 담수가 해양으로 유입을 하면 두 유체간의 밀도차에 의한 밀도류의 성질을 가진다. 하지만, 염분과 온도가 동시에 밀도의 차를 결정하는 경우, 특히 이 중 하나가 중력과 불안정한 수직 분포를 갖게되면 이중확산이 혼합을 결정하는 중요한 요인이 된다. 본 연구에서는 고온, 고염의 수괴가 저온, 저염의 수괴로 진입할 때 기계적 혼합과 이중확산에 의한 대류가 혼합에 미치는 상대적 영향을 비교 연구하였다. 실험실에서 차갑고 염도가 없는 주 흐름에 온도가 높고 염분이 높은 밀도류를 조심스럽게 방류시켜 정상상태의 염수침입 형태를 유지하였다. 수평방향으로 따라 밀도율(Turner 1979)이 15정도 되면 온도와 염분의 유출입량비율이 가파르게 변화하였고, 전체적으로 방출구 부분에서 이중확산의 영향이 강하게 나타나게 되며 이 경우에는 총 방출량도 함께 증가하였다. 아울러 밀도율이 낮은 경우 밀도율이 높은 경우에 비해서 약 $6{\times}10$배의 높은 혼합율을 보였다.

• 물과 미래
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• 제15권3호
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• pp.23-36
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• 1982

The stochastic variations and structures of time series data on water quality were examined by employing the techniques of autocorrelation function, variance spectrum, Fourier series, autoregressive model and ARIMA model. These time series included hourly and daily observation on DO, turbidity, conductivity pH and water temperature. The measurement was made by automatic recording instrument at Noryangjin and Dook-do located in the downstream part of Han River during 1975 and 1976. Hourly water quality time series varied with the dominant 24-hour periodicity, and the 12-hour periodicity was also observed. An important factor affecting 24-hour periodic variation of DO is believed to be photosynthesis by algae. These phenomena might be attributable to periodic discharges of municipal sewage. Noryangjin site showed the more distinct 12-hour periodicity than Dook-do site did, and tidal effect might be responsible for the difference. The water quality, as measured by DO and turbidity, was better in the afternoon compared with the quality in the morning. This change can be explained by the periodic variation of DO, temperature and the amount of municipal wewage discharge. It was also observed that the water temperature at Noryangjin was higher than the temperature at Dook-do. This difference might have been caused by the pollutants that were added to the section between two sites. The correlation coefficients between some of the variables were fairly high. For example, the coefficient was -0.88 between DO and water temperature, 0.75 between turbidity and river flow, and 0.957 between water temperature and air temperature. The lag time of heat transfer from the air to the water was estimated as 24 days. The first order auto-regressive model was appropriate for explaning standardized hourly DO time series. The ARIMA model of (1, 0, 0) type provided relatively satisfactory results for daily DO time series after the removal of significant harmonic value.

• 한국재료학회지
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• 제26권4호
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• pp.187-193
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• 2016

Fabrication of iron oxide/carbon nanotube composite structures for detection of ammonia gas at room temperature is reported. The iron oxide/carbon nanotube composite structures are fabricated by in situ co-arc-discharge method using a graphite source with varying numbers of iron wires inserted. The composite structures reveal higher response signals at room temperature than at high temperatures. As the number of iron wires inserted increased, the volume of carbon nanotubes and iron nanoparticles produced increased. The oxidation condition of the composite structures varied the carbon nanotube/iron oxide ratio in the structure and, consequently, the resistance of the structures and, finally, the ammonia gas sensing performance. The highest sensor performance was realized with $500^{\circ}C/2h$ oxidation heat-treatment condition, in which most of the carbon nanotubes were removed from the composite and iron oxide played the main role of ammonia sensing. The response signal level was 62% at room temperature. We also found that UV irradiation enhances the sensing response with reduced recovery time.

• 한국수정란이식학회지
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• 제29권2호
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• pp.157-161
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• 2014

The study aimed to determine the physical characteristics of estrus mucus and conception rates in dairy cattle. Samples of estrus mucus from the cervix were collected from 108 dairy cattle during heat and were examined for color and consistency. Samples were taken from bred animals at starting from day of breeding to the completion of one estrus cycle. The color of the cervical mucus was studied based on its transparency while the consistency was based on the thinness and thickness of the cervical mucus. The dairy cattle were bred and the pregnancy diagnosis was performed at the $60^{th}$ day post breeding. Findings showed that the estrus mucus of the dairy cattle was transparent in 58.3%, turbid in 31.5% and dirty in 10.2%. It was further observed that the mucus consistency of the dairy cattle was thin in 74.1% and thick in 25.9%. In the pregnant group, 67.3% mucus samples were found transparent, turbid in 23.6% and dirty in 9.1%. However, the corresponding figures for the non-pregnant group had 49.1%, 39.6% and 11.3%. The consistency of cervical mucus was found to be thin in 74.1% and thick in 25.9% of dairy cattle. The conception rates of dairy cattle with thin and thick consistency of cervical mucus were 81.8% and 18.2%, respectively. Pregnant was associated with consistency of cervical mucus (p<0.10). Findings indicated that dairy cattle with thin consistency of cervical mucus and had clear discharge were pregnant cows.

• Korean Chemical Engineering Research
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• 제54권3호
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• pp.350-359
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• 2016

본 연구는 vessel blowdown 시 발생하는 온도와 압력 변화를 보다 정확히 예측하기 위하여 기존에 개발된 dynamic model을 기반으로 새로운 모델을 개발하고, 개발한 모델의 정확도를 높이기 위하여 vessel 내부의 흐름이 층류일 때와 난류일 때를 모두 고려하여 vessel 벽면으로부터 기체로의 열 전달량을 계산하였다. 효율적인 열역학 계산을 위해 일체의 계산식은 압력이 감소하는 단계 별로 나누어 진행하였으며 계산의 부담을 덜어주면서 계산의 정확도를 유지하기 위한 압력변화 size를 결정하였다. 개발한 모델에 Peng-Robinson equation과 Soave-Redlich-Kwong equation을 적용하여 각각의 경우에 따른 결과의 차이를 비교하였다. 마지막으로 모델의 검증을 위해 Haque et al.의 실험조건을 동일하게 적용하여 실험 결과와 시뮬레이션 결과를 비교 하였으며, 이를 통해 모델의 정확도를 입증하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.176-180
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• 2002

During the last two decades the laser beam has progressed from a sophisticated laboratory apparatus to an adaptable and viable industrial tool. Especially, in its welding mode, the laser offers high travel speed, low distortion, and narrow fusion and heat-affected zones (HAZ). The principal obstacle to selection of a laser processing method in production is its relatively high equipment cost and the natural unwillingness of production supervision to try something new until it is thoroughly proven. The major objective of this work is focused on the combined features of gas tungsten arc and a low-power cold laser beam. Although high-power laser beams have been combined with the plasma from a gas tungsten arc (GTA) torch for use in welding as early as 1980, recent work at the Ohio State University has employed a low power laser beam to initiate, direct, and concentrate a gas tungsten arcs. In this work, the laser beam from a 7 watts carbon monoxide laser was combined with electrical discharges from a short-pulsed capacitive discharge GTA welding power supply. When the low power CO laser beam passes through a special composition shielding gas, the CO molecules in the gas absorbs the radiation, and ionizes through a process known as non-equilibrium, vibration-vibration pumping. The resulting laser-induced plasma (LIP) was positioned between various configurations of electrodes. The high-voltage impulse applied to the electrodes forced rapid electrical breakdown between the electrodes. Electrical discharges between tungsten electrodes and aluminum sheet specimens followed the ionized path provided by LIP. The result was well focused melted spots.