• 대한음성학회지:말소리
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• 제60호
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• pp.67-84
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• 2006

The purpose of this study is to find some acoustic parameters on frequency domain to distinguish the Korean nasals, $/m,\;n,\;{\eta}/$ from each other. The new parameters are devised on the basis of LTAS (Long Term Average Spectrum). The maximum peak amplitude and the relevant formant frequency are measured in low and high frequency range, respectively. The frequency of spectral valley and its energy level are also obtained in the specific frequency range of the spectrum. Spectral slope, total energy value in specific frequency range, statistical distribution of spectral energy like centroid, skewness, and kurtosis are suggested as new parameters as well. The parameters that show statistically significant differences across nasals are summerized as follows. 1) in syllable initial positions: the total energy value from 1,500 to 2,200 Hz(zeroENG); 2) in syllable final positions: the peak amplitude of the first formant(peak1_a), the formant frequency with maximum peak amplitude from 4,000 to 8,000 Hz(peak2_f), the maximum peak amplitude of the formant frequency from 4,000 to 8,000 Hz(peak2_a), and the total energy value from 1,500 to 2,200 Hz(zeroENG).

• 한국지형학회지
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• 제28권2호
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• pp.15-30
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• 2021

This study tried to reveal distribution of incision rate and the factors from fluvial terrace deposits on the western and eastern slopes in the Middle Sobaek Mountain Range, using OSL age dating and topographical analysis. An average incision rate of 0.220 m/ka was estimated in the western slope streams, while the streams on the eastern slope showed a lower average incision rate of 0.121 m/ka. These results seem to indicate that the study area experienced an asymmetric uplift. Patterns of incision rate in the study area were different from those in the Northern Sobaek Mountain Range, probably suggesting that the Sobaek Mountain Range experienced spatially different uplift patterns. Among the factors, which were considered to influence on distribution of incision rate in the study area (e.g., altitude of sampling point, distance from divide, distance from axis, channel width, and bedrock type), distance from axis showed the strongest relationship with incision rate. Therefore, uplift is thought to be the most significant factor in distribution of incision rate in the Middle Sobaek Mountain Range.

• 한국환경보건학회지
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• 제32권5호
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• pp.485-491
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• 2006

It is widely known that Environmental Tobacco Smoke(ETS) is not good for health. ETS is composed of a lot of chemicals. So indicators are needed to evaluate the risk of ETS in air. One of the indicators is Nicotine. Active sampler has been used to measure nicotine concentration in air. The experiments were conducted to compare the active sampler method with diffusive sampler in exposure chamber and smoking areas, respectively. Sampling rate was 40.5 ml/min in exposure chamber. Experimental sampling rate (40.5 ml/min) was more than theoretical sampling rate (33.52 ml/min). And the higher was the concentration in air, the higher was experimental sampling rate. The average desorption, rate was 113.6%. The overall precision was 7.31 %. The overall accuracy was 18.96%, which were under NIOSH criteria. The average(GM) concentrations of nicotine by two sampling methods were $8.29{\mu}g/m^{3}$ (active sampler), $7.54{\mu}/m^{3}$ (diffusive sampler) in smoking area and smoking room. There was no regression between active sampler and diffusive sampler ($R^{2}=0.2397$). But slope, coefficient of determination was 1.017, 0.9292, respectively after removing outliers. And the slope (1.017) was close to the theoretical slope (1). In conclusion, this study indicated that diffusive sampler can be used to evaluate concentration of nicotine in air instead of active sampler.

• 전기전자학회논문지
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• 제23권2호
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• pp.704-709
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• 2019

본 논문에서는 다양한 열처리(annealing) 조건에서 tunneling field effect transistor(TFET)의 전기적 특성을 연구 하였다. TFET 샘플은 수소 혼합 가스(4 %) 및 중수소($D_2$) 혼합 가스 (4 %)를 사용하여 열처리를 진행하였으며 측정은 노이즈 차폐실에서 진행되었다. 실험 결과, 열처리 전과 비교하여 열처리 공정 후에 subthreshold slope(SS)이 33 mV / dec만큼 감소함을 확인할 수 있었다. 그리고 측정 온도 범위에서 온도가 증가할수록 $V_G=3V$ 조건에서 10 기압의 중수소 혼합 가스에 대해 평균 31.2 %의 노이즈가 개선됨을 확인할 수 있었다. $D_2$ 혼합 가스로 메탈 증착 후 열처리 공정(post metal annealing)을 실시한 결과, $I_D=100nA$ 조건에서 평균 30.7 %의 노이즈가 감소되었음을 확인할 수 있다.

• 한국운동역학회지
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• 제16권1호
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• pp.43-53
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• 2006

Among several movements that occurred upon a slope, golf swing is the most typical one because environmental conditions dynamically vary with many kinds of slopes. Some studies on the golf swing were performed about a weight transfer on flatland, however, there couldn't be seen any study about the weight transfer on slope elsewhere. Therefore, the purpose of this study was to provide quantified data to objectively test the coaching words and keys about the weight transfer at sidehill slope during goal impact EspeciaIly sidehill Slopes with ball above the feet. Four highschool golfer, who have average handy 5, were recruited for this study. Plantar pressure distribution and cinematographic data were collected during golf swing in the conditions of flatland, $5^{\circ}$, $10^{\circ}$ and $15^{\circ}$sidehill slope simultaneously. The two data were used to synchronize the two data later. The plantar regions under the foot were divided into 8 regions according to the directly applied pressure pattern of the subject to insole sensor. The 8 foot regions were hullux, medial forefoot, central forefoot, lateral forefoot, medial midfoot, lateral midfoot, medial heel, and lateral heel. And the plantar pressure data was also divided into four movement address, phases-backswing. downswing, and follow-through phases according to the percentage shown to the visual information of film data. Based on the investigations on public golf books and experiences of golfers, it was hypothesized by the authors in the early of this study that the steeper slopes are, the more weight loads on left foot that positions at the higher place. When observing the results of plantar pressure and vertical force curves according to the sidehill slope conditions, the hypothesis could be accepted.

• 농업과학연구
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• 제45권4호
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• pp.749-760
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• 2018

In Korea, the largest agricultural lands are paddy fields which have poor infiltration and drainage properties. Recently, the Korean government has pursued cultivating upland crops in paddy fields to reduce overproduced rice in Korea. For this policy to succeed, it is critical to understand the topographic information of paddy fields and its effects on upland crops cultivated in the soils of paddy fields. The objective of this study was to characterize the growth properties of sesame and perilla from paddy fields with three soil topographic features and soil water effects which were induced by the topographic features of the sesame and perilla. The crops were planted in paddy fields located in Miryang, Gyeongnam with different topographies: mountain foot slope, local valley and alluvial plain. Soil water contents and groundwater levels were measured every hour during the growing season. The paddy field of the mountain foot slope was significantly effective in alleviating wet injury for the sesame and perilla in the paddy fields. The paddy field of the mountain foot slope had a decreased average soil water content and groundwater level during cultivation. Stress day index (SDI) from the alluvial plain paddy field had the greatest values from both crops and the smallest from the ones from the paddy field of the mountain foot slope. This result means that sesame and perilla had the smallest stress from the soil water content of the paddy field on the mountain foot slope and the greatest stress from the soil water content of the alluvial plain. It is important to consider the topography of paddy fields to reduce wet injury and to increase crop yields.

• 한국산학기술학회논문지
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• 제21권10호
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• pp.509-516
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• 2020

1960년대 이후 경제발전을 위한 하천 개수사업, 도시화에 따른 소하천의 복개 등으로 많은 하천이 오염되고 파괴되었다. 지금까지의 연구는 측량된 하천 지형인자를 이용해 하천을 분석한 연구가 많았으나, 홍수 시와 같이 유량이 급격히 변하는 경우에는 측량이 쉽지 않다. 또한, 이전까지의 연구는 주로 하천의 횡단면에 대한 연구가 많아 하천 종단면에 대한 정보가 부족한 실정이다. 본 연구에서는 정보엔트로피 이론을 이용하여 하천 유역에 대한 평균 하천 경사, 하천 경사, 하천 종단고도를 실시간으로 산정할 수 있는 식을 제시하였으며, 충청북도 지방하천 기본계획에서 얻은 달천 유역과 부산 온천천, 동천 기본계획에서 얻은 하천 특성인자 실측 자료와 비교를 통해 적용성을 분석하였다. 이를 위해 정보엔트로피 이론에 실측 자료를 이용하여 비선형 회귀분석을 이용해 매개변수를 산정한 후 하천별 종단고도 엔트로피식을 산정하였으며, 평균 하천 경사를 산정하였다. 본 연구에서 제시한 식의 적용성을 R²로 분석한 결과, R²가 모두 0.96이상의 값으로 나타나 하천 특성인자를 산정하는데 신뢰도 높은 결과를 얻을 수 있을 것으로 보인다.

• 환경영향평가
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• 제15권1호
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• pp.53-65
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• 2006

Topographic condition is one of the most important things in farming activities. The topographic condition didn't matter for farming in the past because agricultural products had competitive power in the market. So farmers tried to extend their farms without any concern of topographic condition. We need less labor-consuming farming as industrial structure has been changed and the competitive power of the farming has been getting weak. This study analyzed the fallow potential in agricultural area by topographic condition so that we have got results as follows. Maps of elevation, slope, distance from roads and water resources were made for getting a fallow probability model in farms, and these 4 factors were used as independent variables while a variable on whether it is fallow or not is a dependent variable in logistic regression model. In an analysis of the fallow potential depending on farm land types, the fallow probability in fallow orchard showed the highest value of farm lands, 0.973. Cultivated orchard had 0.730 and upland had 0.616 of the fallow probability. The fields having high fallow potential had high elevation, steep slope, and long distance from water resources and roads. Especially, fields having a probability over 0.99 appeared in orchards, fallow uplands and single cropping uplands, which were recognized to have several disadvantages related to the fallow like as high elevation, steep slope, and long distance from water resources and roads. With the logistic analysis, the suitable farm lands appeared at 16.45m of the mean elevation, 1.89 degree of the mean slope, 39.91m of the average distance from water resources, and 32.39m of the average distance from roads. On the contrary, non-suitable land appeared at 114.7m of the mean elevation, 24.9 degree of the mean slope. The distance from roads was more important variable than the distance from water resources for analyzing suitable farm land.

• 한국초지조사료학회지
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• 제7권2호
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• pp.92-96
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• 1987

남북향 사면에 대한 목장의 생산성을 구명코자 orchardgrass, tall fescue, timothy, redtop, ladino clover 등 5 초종을 남사면과 북사면에 각각 난괴법 4반복으로 보양배치하여 1983년 9월부터 1986년 10월까지 본 실험을 실시하였던바 그 결과를 요약하면 다음과 같다. 1. 생육기 동안의 3년 평균 지표온도는 남사면이 북사면보다 2.0^{\circ}C$ 높았으며, 토양 10cm 깊이의 지중온도는 남향지가 북향지보다 0.8^{\circ}C$ 높았으나 이절에 따라서는 서로 대차없었다. 2. 토양 목장의 초기생육 상태는 북사면이 남사면보다 준수하였다. 3. 화본과 목장의 건물생산량은 남향지보다 북향지가 많았으나 이에 반하여 ladino clover는 남사면이 월등히 많았다. 4. 화본과 목장중에서 orchardgrass와 tall fescue의 건물수량은 북사면이 남사면보다 다소 많았으나 대차없었으며, timothy와 red top은 북사면에서 현저히 많은 수량을 생산하였다.

• 한국습지학회지
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• 제24권2호
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• pp.93-101
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• 2022

본 연구는 지형 및 토지피복에 따른 묵논습지의 분포 특성을 분석하기 위해 수행되었다. 충남도 서산시, 당진시, 보령시, 태안군을 대상으로 GIS와 현장답사를 통해 묵논습지를 찾아내어 경사도와 고도 및 토지피복유형에 따른 분포현황을 분석하였다. 연구결과, 4개시군의 묵논습지는 총106개로 확인되었고, 각 묵논습지가 위치한 지점의 평균 고도는 38.85m(S.D. 32.76)이고 평균 경사도는 6.27˚(S.D. 5.39), 총면적은 24,200km²로 나타났다. 경사도 5˚ 미만의 평지에 63개(12,121.07km²), 5~10˚ 27개(9,524.15km²) 등 10˚ 미만의 평지 또는 완경사지에 90개(84.9%)의 묵논습지가 분포하고 있었다. 면적은 21,645.22km²로서 전체 묵논습지 면적의 89.5%에 이른다. 고도 25m 미만의 저지대에 48개(12,326km²), 50m미만 29개(4,909.4km²) 등으로서, 모두 77개(72.7%)의 묵논습지가 고도 50m 이내의 저지대에 분포하고 있으며, 면적으로는 17,235.8km²로서 전체 묵논습지 면적의 71.2%에 이른다. 묵논습지 환경요인 중 경사도와 고도 사이에 통계적으로 상관관계는 없는 것으로 나타났다. 토지피복 분류에 따라서는 인공초지(38), 논(33), 밭(22) 등에 많이 분포하였다.