• 한국축산시설환경학회지
• /
• 제7권3호
• /
• pp.177-182
• /
• 2001

본 연구는 가축분뇨의 오염물질의 농도와 영상처리를 통해 얻어 낸 영상정보값과의 상관관계를 구하기 위해 수행하였다. CCD-카메라와 개인용 컴퓨터를 사용하여 축 분뇨의 영상을 받은 후 각 활성 영역에서의 영상정보와 공정시험 법으로 구한 오염물질과의 관계를 회귀분석법을 이용하여 다음과 같은 결론을 얻을 수 있었다. 1. 영상정보 R값은 CDD값과 결정계수가 0.9213으로 가장 높았으며, G값은 BOD값과 결정계수가 0.9019로 가장 높게 나타났으며, B값의 경우 오염물질 농도와의 상관관계는 매우 적은 것을 알 수 있었다. 2. H값은 BOD와의 결정계수($R^2$)가 0.9496으로 매우 높게 나타났다. 이는 BOD추정에 이용가능할 것으로 판단되었다. 3. BOD농도 추종을 위해서 G값,GRAY, H값, S값, 1값 등이 결정계수가 0.8이상을 나타냈으며, 그 중 H값이 가장 높은 결정계수를 나타냈으며, 이러한 정보를 이용하여 농도 추정이 가능할 것으로 판단되었다. 4. COD농도 추정을 위해서 R값, GRAY값, S값이 0.8이상의 결정계수를 나타냈으며, 그 중에서 R값과의 관계가 가장 높게 나타났으며, 이를 이용하여 간접적으로 농도 추정이 가능할 것으로 판단되었다. 5. SS농도와 영상정보값과 결정계수가 모두 0.8이하로 나타났으며, $NH_4$-N와 $NO_3$-N의 농도와 영상정보와의 결정계수는 모두 0.2이하로 매우 낮게 나타났으며, 가시광선영역의 CCD-카메라를 이용한 농도추정은 불가능할 것으로 판단되었다.

• 한국항공운항학회지
• /
• 제14권3호
• /
• pp.30-39
• /
• 2006

The purpose of this study is to analyze how much Air Transportation Industry contribute to national economy by measuring economic spreading effects of Air Transportation Industry on national economy. To achieve the purpose of the study, the study uses an Air Transportation Input-Output Table of year 2000 of korea. The results shows that Air Transportation Industry induce 274,530.8 billion won of national production, import inducement 13,7073.7 billion won, value-added 110,994.9 billion won, especially Air Transportation Industry shows that production inducement coefficient is 1.36803, import inducement coefficient is 0.60581, value-added coefficient is 0.45189, income inducement coefficient is 0.18599 and employment inducement coefficient is 0.00841.

• Journal of the Korean Data and Information Science Society
• /
• 제21권4호
• /
• pp.803-811
• /
• 2010

This study analyzes the characteristics of preference ratings by dividing estimated values into four groups according to rank correlation coefficient after obtaining preference estimated value to user's ratings by using collaborative filtering algorithm. It is known that the value of standard error of skewness and standard error of kurtosis lower in the group of higher rank correlation coefficient This explains that the preference of higher rank correlation coefficient has lower extreme values and the differences of preference rating values. In addition, top n recommendation lists are made after obtaining rank fitting by using the result ranks of prediction value and the ranks of real rated values, and this top n is applied to the four groups. The value of top n recommendation is calculated higher in the group of higher rank correlation coefficient, and the recommendation accuracy in the group of higher rank correlation coefficient is higher than that in the group of lower rank correlation coefficient Thus, when using standard error of skewness and standard error of kurtosis in recommender system, rank correlation coefficient can be higher, and so the accuracy of recommendation prediction can be increased.

• 한국군사과학기술학회지
• /
• 제14권2호
• /
• pp.281-288
• /
• 2011

In this paper, a variable quantization coefficient scanning for macroblock considering the histogram value of previous macroblock's quantization coefficient is proposed. In order to scan a quantization coefficient, the proposed method makes $4{\times}4$ histograms for various prediction modes($16{\times}16$, $16{\times}8$, $8{\times}16$, $8{\times}8$) by adding 1 if the value of quantization coefficient is not 0. After a final mode decision procedure, the $4{\times}4$ histogram of the final mode will be sorted. Then, quantization coefficients in corresponding macroblock of the next frame are scanned using the sorted order. The experimental results show that the proposed scheme reduces the total bits by approximately 0.01~2.25% with similar PSNR performance compared with the previous method.

• 대한전기학회논문지
• /
• 제34권7호
• /
• pp.289-296
• /
• 1985

The Townsend primary ionization coefficient a was measured by the luminous-flux method using the fact that the intensity of radiant light is proportional to electron density in the townsend discharge domain. The ranges of measurements were 15for He gas and 10

• Journal of Advanced Marine Engineering and Technology
• /
• 제24권1호
• /
• pp.67-74
• /
• 2000

Recently, PTFE-polymide composites are being used self-lubricating parts for industrial field. Thus, this study is mainly concerned with friction and wear properties for the piston ring of non-lubricating air compressor which made of PTFE-polymide composites. The friction and wear test was carried out for the different composition ratio under the atomsphere room temperature and constant load of 7.69N and their friction and wear properties were compared with each other at various sliding speed. notable results are summarized as follows. PTFE 100% showed that friction coefficient was almost same values at 0.94 and 1.88m/s but the value was decreased at 2.83m/s because the friction temperature is higher than low speed. PTFE 80%-PI 20% showed the lowest mean friction coefficient at 2.83m/s. PTFE 20-PI 80% showed the highest friction coefficient at 0.94m/s and the value was decreased at high speed but the value is higher than other materials except PTFE 100 %. PI 100% showed the highest friction coefficient at 0.94 and 1.88m/s becuase adhesive wear mainly occurred that speed. PTFE 100% showed highest specific wear rate on the whole. Specific wear rate of PTFE 80%-PI 20% was almost the same value with PTFE 20%-PI80%. PI 100%showed the lowest value at high sliding speed because the friction surface was thicken and carbonated by high friction temperature.

• 한국포장학회지
• /
• 제10권1호
• /
• pp.7-14
• /
• 2004

Migration behavior of selected solvents and food samples showed differences of the chemical structures and polarities, the food samples which have similar polar expresses more higher affinity than different polar degrees. Water which is polar has a highest partitioning coefficient values on polar isopropanol, and oil which is nonpolar has highest partitioning value on non-polar toluene. The increasing order of partitioning values was accord with increasing water contents in food samples. It is showed that the wheat flour with 13.2% moisture content has the highest partitioning coefficient values on the isopropanol with -OH. Kp value of sugar showed remarkable lower partitioning coefficient values than other food samples due to high degree crystallinity. This phenomenon can be predictable with ${\delta}$ values, because order of partitioning coefficient values which comes out through the experiment and the sequence of Hildebrand solubility parameter value difference between food sample and printing ink solvent correspond almost. This Hildebrand solubility parameter value can be easily applied to the food package industry because the effect of food-safety can be considered without passing through complicated steps by using this method.

• 한국유체기계학회 논문집
• /
• 제10권5호
• /
• pp.46-53
• /
• 2007

Stem friction coefficient and valve factor are very important parameters for the evaluation of valve performance. In this study, the characteristics of stem friction coefficient and valve factor are analyzed, and thor bounding value is determined. The hydraulic testing is performed for many flexible wedge gate valves in the plant and statistical method is applied to the determination of bounding value. According to the results of this study, stem friction coefficient does not change much with differential pressure, and the bounding value of closing stroke is higher than that of opening stroke. The valve factor of valves with high differential pressure is higher than that of valves with medium differential pressure. It means valve factor is more sensitive to the differential pressure than the stem friction coefficient. Valve factor of the closing stroke is higher than that of opening stroke due to piston effect.

• 한국염색가공학회지
• /
• 제9권5호
• /
• pp.1-9
• /
• 1997

In the single yarn spinning process by the ring spinning system, the finer the fineness of yarn and the lower the twist coefficient, the lower the breaking strength and breaking elongation. The change of yarn specific volume to yarn number agreed with Peirce's formula in the range of Ne 50 to 70, but above that range the values of the experiment are higher than that of the formula. The change of diameter of yarn to the reciprocal of the square root of yarn number agreed with Peirce's formula in the range of under 0.14, but above that value the values of the experiment are higher than that of the formula. In breaking strength variation according to twist constant of single yarn, as the twist coefficient increased, breaking strength increased. At 5.8∼6.0 of twist coefficient the maximum breaking strength was shown, but above that value breaking strength decreased. Breaking elongation also showed a similar tendency. But at 6.0∼6.5 of twist coefficient the maximum breaking elongation was shown. Also spinning tension increased as twist coefficient increased. Twist coefficient, breaking strength and breaking elongation according to the number of coils stayed almost the same. Yarn spinning tension according to the number of coils at the maximum of diameter was the lowest value. The speed of the traveller at the maximum of diameter was the highest value.

• 한국방사선학회논문지
• /
• 제9권6호
• /
• pp.375-379
• /
• 2015

이 연구의 목적은 다종에너지 X선 빔의 유효에너지를 결정하는데 있다. 80 kVp X선 빔에 대한 알루미늄의 반가층은 광자극형광나노닷선량계들(OSLnDs)을 사용하여 측정하였다. 선감쇠계수(${\mu}$)는 측정된 반가층을 사용하여 계산하였다. 그리고 질량감쇠계수(${\mu}/{\rho}$)는 알루미늄의 밀도로 선감쇠계수를 나누어 얻었다. 얻어진 질량감쇠계수의 유효에너지($E_{eff}$)는 미국표준기술연구소(NIST)에서 주어진 알루미늄의 광자에너지들에 대한 X선질량감쇠계수들의 자료를 사용하여 결정하였다. 결과로서, 반가층, 선감쇠계수 및 질량감쇠계수는 각각 2.262 mmAl, $3.06cm^{-1}$, $1.114cm^2/g$이다. 그리고 유효에너지는 29.79 keV에서 결정되었다.