• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.239-248
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• 2003

This paper was conducted as an attempt in order to construct the data bank of target strength for acoustic estimation of fish length in the coastal waters of Korea. The fish length dependence of acoustic target strength for 13 large yellow croakers (Pseudosciaena crocea) at 75 kHz was investigated and the prediction of the target strength by using the Kirchhoff-Ray Mode model (KRM model) was compared with target strength measurements. The results obtained are summarized as follows; 1. In the averaged target strength pattern for 13 large yellow croakers the maximum target strength was -35.13 dB at $-13.35^{\circ}$ on a tilted angle. 2. The relationship between fork length(L, cm) and averaged target strength(TS, dB) was expressed as follows; TS=23. 76log (L) -73.45 (r=0.47) TS=20log(L) -67.35 From this result, the conversion coefficient was -73.45 dB and 6.1 dB lower than the coefficient -67.35 dB where the value of the slope of the regression equation is forced to be 20. 3. Averaged target strength and a length conversion coefficient derived from a target strength histogram for 13 large yellow croakers of mean length 25.59 cm were -41.23 dB, -69.72 dB, respectively. 4. In the range of $$2;{\ll} L (fish length /{\lambda}(wave length);{\ll}40$$, the prediction of the averaged target strength by the KRM model increased gradually with the increasing of $L/{\lambda}$ and was lower than the measured target strength.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.543-552
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• 1994

A series of drained plane strain compression tests was performed on dried samples of dense Toyoura sand and Silver Leighton Buzzard sand prepared by air-pluviation method to find out the deformation and strength characteristics on the value of confining pressure ${\sigma}{_3}^{\prime}({\sigma}{_3}^{\prime}=0.05{\sim}4.0kgf/cm^2)$. The axial and lateral strains measured in this apparatus ranged from $10^{-6}$ up to the failure of the specimen. So the stress-strain characteristics would be investigated from very small to very large strain levels. It was found that the change of the angle of internal friction ${\phi}^{\prime}{_{max}}=arcsin\{({\sigma}{_1}^{\prime}-{\sigma}{_3}^{\prime})/({\sigma}{_1}^{\prime}+{\sigma}{_3}^{\prime})\}_{max}$ with the change of ${\sigma}{_3}^{\prime}$ is very small when ${\sigma}{_3}^{\prime}$ is lower than higher. Furthermore, the effect of confining pressure on stiffness of sands was evaluated. It was also found that for the range of shear strain ${\gamma}$ from $10^{-6}$ to those at peak, the Rowe's stress-dilatancy relation seems to be a good approximation for air-dried Toyoura sand and Silver Leighton Buzzard sand, irrespective of the change of ${\sigma}{_3}^{\prime}$.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.109-111
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• 2006

본 논문은 애니메이터로 하여금 얼굴 표정들의 공간으로부터 일련의 표정을 선택하게 함으로써 3차원 아바타의 표정을 실시간적으로 제어할 수 있도록 하기 위한 표정공간의 생성방법에 관하여 기술한다. 본 시스템에서는 약 2400여개의 얼굴 표정 프레임을 이용하여 표정공간을 구성하였다. 본 기법에서는 한 표정을 표시하는 상태표현으로 얼굴특징 점들 간의 상호거리를 표시하는 거리행렬을 사용한다. 이 거리행렬의 집합을 표정공간으로 한다. 그러나 이 표정공간은 한 표정이 다른 표정까지 이동할 때 두 표정간의 직선경로를 통해 이동할 수 있는 그런 공간이 아니다. 본 기법에서는 한 표정에서 다른 표정까지 거쳐 갈 수 있는 경로를 캡쳐된 표정 데이터로부터 근사적으로 유추한다. 우선, 각 표정상태를 표현하는 거리행렬간의 거리가 일정 값 이하인 경우 두 표정을 인접해 있다고 간주한다. 임의의 두 표정 상태가 일련의 인접표정들의 집합으로 연결되어 있으면 두 표정간에 경로가 존재한다고 간주한다. 한 표정에서 다른 표정으로 변화할 때 두 표정간의 최단경로를 통해 이동한다고 가정한다. 두 표정간의 최단거리를 구하기 위해 다이내믹 프로그래밍 기법을 이용한다. 이 거리행렬의 집합인 표정공간은 다차원 공간이다. 3차원 아바타의 얼굴 표정 제어는 애니메이터들이 표정공간을 항해할 때 실시간적으로 수행된다. 이를 도와주기 위해 표정공간을 차원 스케일링 기법을 이용하여 2차원 공간으로 가시화하였고, 애니메이터들로 하여금 본 시스템을 사용하여 실시간 표정 제어를 수행하게 했는데, 본 논문은 그 결과를 평가한다.참여하는 빈들 간의 관계를 분석하여 워크플로우에 대한 성능 측정이 가능하도록 한다. 또한 제안된 메트릭을 통하여 EJB 어플리케이션의 성능 향상을 도모할 수 있도록 한다.로 표면 위로 자라났고, 부종은 창상 밑 조직까지 감소하였으며, 육아조직은 교원질 섬유로 대체되었다. 창상 유발 21일 후, 다른 창상에 비해, HG 처치창은 유의적으로 창상 표면이 거의 재생성 상피로 덮였으며, 육아조직은 창상 유발 14일 후와 비교해서 유의적으로 교원질 섬유로 대체되었다. 위의 모든 결과에서 보듯이, 개에서 전층피부 창상의 처치 시 HG의 사용은 HC와 생리 식염수에 비해 창상치유 복구기의 치유 속도를 촉진하는 것으로 사료된다.시범학교의 자녀를 들 부모들은 환경관련문제에 대한 의식 및 환경관련 제품에 대한 구매행동의 변화가 두드러지게 나타났다.EX>$d^{2+}$ + SA처리구는 두 화합물의 이중 효과에 의해 전반적인 생리 활성을 억제하여, 결국에는 식물의 고사를 유도하는 것으로 사료된다.목에 대한 보안'이 가장 중요한 것으로 나타났다. 본 연구에서는 솔루션 선정요인에 관한 중요도를 e-마켓플레이스의 유형과 산업 별로 평가해보았는데, 여기에서 밝혀진 중요도를 통해 e 마켓플레이스를 구축하고 자 하는 기업은 솔루션을 자체 개발하거나 구입할 때 올바른 의사결정을 할 수 있다. 그리고 솔루션을 제공하려는 기업측면에서는 e-마켓플레이스를 구축하고자 하는 기업에게 유형과 산업별로 적절한 솔루션을 제공할 수 있다.순환이 뇌대사 및 수술 후 신경학적 결과에 보다 유익한 효과를 제공해 줄 수 있음

• Analytical Science and Technology
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• v.8 no.1
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• pp.63-68
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• 1995

For the preparation of pH-selectrode, tribenzylamine, polyvinylchloride, dioctylphthalate, sodium tetraphenylborate and tetrahydrofuran were mixed with 0.02, 0.62, 1.34, 0.02g and 10ml respectively, and added 1g of acetylene black, graphite, silicon carbide or tungsten carbide respectively to improve electric conductivity. The selectrodes of seven kinds were shown linear to hydrogen ion in the range of pH 2 and 9. The best electric conductor for preparation of pH-selectrode based on tribenzylamine as neutral carrier was acetylene black and responded potential of the selectrode to hydrogen ion was shown the values near to theoretical Nernstian slope at $20^{\circ}C$. The interfering effects of the selectrode on hydrogen ion in the presence of alkali and alkaline earth metal ions were shown the better results with less error than glass electrode. The reproducibility and stability were good for use as a selectrode, especially in the presence of fluoride ion.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.342-347
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• 1983

The effects of barley tea concentration and atomizing air pressure on the size, homogeneity and distribution of the sprayed droplets were investigated. An equation relating mean diameter (${\overline{D}}$) with the concentration where the coefficient a and b were determined empirically. As the operating air pressure was increased, the mean diameter of the droplets decreased and finally reached the limiting mean diameter, $36{\mu}m$ at 15.7% barley tea concentration. The homogeneity of the droplets increased with the operating air pressure, increase and it was decreased steadily as the soluble solid concentration increased up to 20% and markedly over 20% at every operating air pressure. The distribution ($P_D$) of sprayed droplets related with the droplet size as the following exponential equation; $P_D$ = e 1nD + f where e and f are empirical constants.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.411-417
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• 2012

Purpose: To investigate changes of contrast sensitivity with decreasing luminance in photopic conditions. Methods: Contrast sensitivities for 63 university students were investigated at 5 different luminance levels using FACT chart. Results: All contrast sensitivities measured were in the normal range. The peak of contrast sensitivity function was observed to move from 6 to 3 cpd between 40 and $10cd/m^2$. From an intersection point of two hypothetical lines related with contrast sensitivity for 6 and 3 cpd, we could evaluated that the peak moved from 6 to 3 cpd at about $25cd/m^2$. When luminance decreases from 120 to $10cd/m^2$, contrast sensitivity loss at 6 cpd was most, while contrast sensitivity at 1.5 cpd changed little. We could evaluate that at luminance of more than $25cd/m^2$ evaluated approximately, contrast sensitivity was high in the following order of spatial frequency: 18< 12<1.5<3<6 cpd, while at luminance of less than about $25cd/m^2$ as follows: 18<12<1.5<6<3 cpd. Contrast sensitivity losses with decreasing luminance were also evaluated using the decrements and decrement rates of contrast sensitivity. The decrement of contrast sensitivity was the greatest at 6 cpd, while the decrement rate was the greatest at 8 cpd. Conclusions: We propose that evaluation methods used in this research may be available as another methods to evaluate the changes of contrast sensitivity.

• Journal of the Korean Wood Science and Technology
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• v.28 no.2
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• pp.10-18
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• 2000

Nondestructive testing(NDT) by using ultrasonic sound is widely applied to wood for grading, moisture and defect detecting, estimating degree of decay, etc. Before practicing such application, basic relationships between ultrasonic transmission and wood properties shall be studied first. In this study, ultrasonic NDT was applied to larch and red pine to investigate the effects of moisture content and slope of grain on ultrasonic transmission speed. Specimens for testing about moisture content were prepared to have moisture content of green state, 30%, 20%, 10% and oven-dry state. Specimens for testing about slope of grain were prepared to have grain angle of 0, 15, 30, 45, 60, 75 and 90 degree in the tangential direction. Ultrasonic transmission speed was inversely proportional to moisture content in low range of moisture content under around 30% that was considered to be close to fiber saturation point. In high moisture content range above 30%, the ultrasonic transmission speed was almost constant. The same trend was observed in the relationships between compressive strength and moisture content. Slope of grain also had inversely proportional relationship with ultrasonic transmission speed and compressive strength. The relationship between compressive strength and ultrasonic transmission speed could be expressed by a linear equation.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.339-350
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• 2018

The rail wear measurements in urban underground railway have been analyzed to predict the particulate matter emission caused by rail wear which is one of the major sources of particulate matter emission for underground railway systems. From the rail profile variations measured in the interval of one and half year by dedicated rail wear measuring instrument over the commercial urban underground railway line, 'line-s' which is about 45km long, the characteristics as well as the amount of rail wear have been analyzed after dividing the whole line into about 170 section with radius of curve(R). It has been concluded that the vertical wear parameter V0 and corner wear parameter C0 have been selected to represent the wear amount of straight and curved rail respectively. The amount of rail wear as well as the particulate matter emission by rail wear over the whole line normalized by the rail length as well as the number of train has also been deduced from the relationship between the rail wear parameters and the amount of rail cross-section area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.389-394
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• 2023

In recent years, use of machine automation is rising in the industry. Ships also obtain machine condition information from sensor as digital information. However, on ships, crew members regularly surveil the engine room to check the condition of equipment and their information through analog gauges. This is a time-consuming and tedious process and poses safety risks to the crew while on surveillance. To address this, engine room surveillance using an autonomous mobile robot is being actively explored as a solution because it can reduce time, costs, and the safety risks for crew. Analog gauge reading using an autonomous mobile robot requires digitization for the robot to recognize the gauge value. In this study, image processing techniques were applied to achieve this. Analog gauge images were subjected to image preprocessing to remove noise and highlight their features. The center point, indicator point, minimum value and maximum value of the analog gauge were detected through image processing. Through the straight line connecting these points, the angle from the minimum value to the maximum value and the angle from the minimum value to indicator point were obtained. The obtained angle is digitized as the value currently indicated by the analog gauge through a formula. It was confirmed from the experiments that the digitization of the analog gauge using image processing was successful, indicating the equivalent current value shown by the gauge. When applied to surveillance robots, this algorithm can minimize safety risks and time and opportunity costs of crew members for engine room surveillance.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.1
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• pp.21-30
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• 1991

The estimation of the fish biomass density or the size of fish by means of the acoustic equipment is an important part in the quantitative assessment of fisheries resources. The precision of such estimates depend upon the target strength of fish and the accuracy to which the acoustic equipment has been calibrated. This paper examine the accuracy of the digital measurement system which is manufactured by way of trial in order to masure the target strength of fish, and calibrations of that system carry out with an ogive and a ellipsoid made of the aluminum and the epoxy, respectively. Furthermore, measurements of target strength for eight species of fish are made at 25, 50, 100 kHz. The accuracy of the digital measurement system is compared the theory with measurements on ogive and ellipsoid, and the agreement is reasonable. Result of establishments on the target strength to fish length and to fish weight regression obtained from the measurements are available to provide the methods of design for use in interpreting acoustic measurements of fish abundance on the experimented eight species.