• Tunnel and Underground Space
• /
• v.12 no.4
• /
• pp.312-320
• /
• 2002

It is well-known that when single rock fractures undergo shear displacement, they are influenced by the boundary conditions and fracture roughness. In this case, aperture geometry will change by means of dilation due to the shear displacement. As fractures become the flow paths, fluid flow through rock fractures is affected by the void geometry. In this study, therefore, the influence of roughness on shear behavior of fractures has been investigated, and the resulting hydraulic behavior has been analyzed. In order for this study, a statistical method has been used to generate rough fractures, and they have been adopted into new conceptual models fur fracture shearing and flow calculations. The main contributions of this study are as follows: firstly, fracture shear behavior becomes less brittle with decreasing fracture roughness and increasing normal stress. Then, the characteristics of aperture distribution becomes those of roughness of fractures indicating its hydraulic significance. Finally, it is observed that with decreasing fracture roughness the breakdown of channel flow occurs more slowly.

• Tunnel and Underground Space
• /
• v.16 no.6 s.65
• /
• pp.495-505
• /
• 2006

Calculating the distribution of stresses and displacements around a circular tunnel excavated in infinite isotropic rock mass subjected to hydrostatic stress condition is one of the basic problems in rock engineering. While closed-form solutions for the distribution are known if rock masses are considered as elastic, perfectly plastic, or brittle-plastic media, a few numerically approximated solutions based on various simplifying assumptions have been reported for strain-softening rock mass. In this study, a simple numerical method is introduced for the analysis of strain-softening behavior of the circular tunnel in Mohr-Coulomb rock mass. The method can also applied to the analysis of the tunnel in brittle-plastic or perfectly plastic media. For the brittle-plastic case where closed-formsolution exists, the performance of the present method is verified by showing an excellent agreement between two solutions. In order to demonstrate the strain-softening behaviors predicted by the proposed method. a parameter study for a softening index is given and the construction of ground reaction curves is carried out. The importance of defining the characteristics of dilation in plastic analysis is discussed through analyzing the displacements near the surface of tunnel.

• Tunnel and Underground Space
• /
• v.14 no.5
• /
• pp.318-326
• /
• 2004

In this study, a new direct shear apparatus was developed to investigate the shear characteristics of the rock joints at various conditions. Using the developed apparatus, various experiments on filled rock joints were carried out considering the asperity angle, the normal stress, the type and thickness of filling material and to investigated the basic shear characteristics of filled rock joints were analyzed. According to the experiments performed under the constant normal stress condition by varying the asperity angle, the type and thickness of filling material, it was shown that the behavior and strength of filled rock joint could be defined by the type and thickness of the filling material. The dilation angle of the filled joints was found to be smaller than that of unfilled rock joint, and thereby, the effect of roughness was also reduced due to the filling material. And critical thickness ratio varied according to stress level and roughness as well as the type of filing materials.

• Journal of the Korea Society for Simulation
• /
• v.27 no.2
• /
• pp.1-10
• /
• 2018

This paper presents an autonomous detection and aiming point computation of a battle tank by using RGB images. Maximally stable extremal regions algorithm was implemented to find features of the tank, which are matched with images extracted from streaming video to figure out the region of interest where the tank is present. The median filter was applied to remove noises in the region of interest and decrease camouflage effects of the tank. For the tank segmentation, k-mean clustering was used to autonomously distinguish the tank from its background. Also, both erosion and dilation algorithms of morphology techniques were applied to extract the tank shape without noises and generate the binary image with 1 for the tank and 0 for the background. After that, Sobel's edge detection was used to measure the outline of the tank by which the aiming point at the center of the tank was calculated. For performance measurement, accuracy, precision, recall, and F-measure were analyzed by confusion matrix, resulting in 91.6%, 90.4%, 85.8%, and 88.1%, respectively.

• Journal of Veterinary Clinics
• /
• v.28 no.1
• /
• pp.144-148
• /
• 2011

A Shihtzu (6-year-old, intact female) was referred to Konkuk University Teaching Animal Hospital for cystic calculus and hydronephrosis of right kiney. The dog was suspected to have ureteral rupture and peritonitis. Radiographic findings included cyctic calculi and right kidney enlargement. On ultrasonographic examination hyperechoic mass with severe acoustic shadowing was located in the right proximal ureter which was dilated. Hydronephrosis of the right kidney, right ureteral caculus and cytic calculus were confirmed by radiography and ultrasonography. Cystotomy for removal of calculus in the bladder and ureterotomy for removal of calculus in the right ureter were performed. Excretory urography (EU) performed one month after surgery revealed that the right ureter was homogeneously opacified and decreased to 3 to 6 mm in diameter. Surgical removal of ureteroliths was appropriate treatment for the ureteral and cystic calculi. The result suggests that ureterotomy is effective treament for the dilation and calculi of ureter.

• Journal of Veterinary Clinics
• /
• v.31 no.4
• /
• pp.325-328
• /
• 2014

A 8-month-old female Maltese dog was presented with a history of heart murmur. In physical examination, grade 4/6 systolic murmur heard at the left heart base. Electrocardiography showed sinus arrhythmia, right axis deviation, deep S wave and splintered QRS complex. Thoracic radiography revealed enlarged right side heart and bulging of the main pulmonary artery. Echocardiography showed mild hypertrophy of right ventricle, a supravalvular stenosis, marked post-stenotic dilation of the main pulmonary artery and a moderately increased pulmonary arterial velocity through the stenotic area (4.4 m/s, pressure gradient of 78.7 mmHg). The dog was diagnosed with supravalvular pulmonic stenosis based on the diagnostic imaging findings. Medical management using ${\beta}1$-blocker and ACE inhibitor was started in this dog and this is first case report described diagnostic characteristic features of supravalvular pulmonic stenosis in korea.

• Korean Journal of Veterinary Research
• /
• v.11 no.2
• /
• pp.105-116
• /
• 1971

The effects of aconite root in rats and rabbits were studied following oral administration of the powder which was prepared by lyophilization of the decoction of the salted aconite roots. The $LD_{50}$ of the powder, the blood picture, total blood volume, uptake rate of ${42}^K$ and ${24}^Na$ in various organs, oxygen consumption, thyroid activity, and histopathological changes in various organs, were observed. The results obtained were as follows: 1. The $LD_{50}$ of the powder of decoction of the aconite root was 4.07g/kg of body weight in mice which is equivalent to approximately 40g/kg of the salted aconite roots. 2. The number of erythrocytes and leukocytes, hematocrit value, and the amount of hemoglobin in blood were increased in the rats administered daily dosages of 0.1, 0.5, and 1.0g/kg respectively. No significant differences were observed in the differential count of leukocytes. A slight tendency of hemoconcentration was recognized. 3. No changes in the erythrocyte volume, plasma volume and total blood volume were observed in the rats after administration of the powder for one, three, and six days. However, those were decreased in rats treated for ten days. 4. Generally, in various organs of rats the uptake rate of ${24}^Na$ showed a tendency of increasing but that of ${42}^K$ slowed a decreasing tendency. 5. The oxygen consumption was markedly decreased in rats administered the powder. 6. Iodine-131 uptake of thyroid gland was markedly decreased in the rabbits following administration of the powder. 7. In rabbits administered 0.5g/kg for 20 days, fatty changes of hepatic cells, cloudy swelling of the epithelial cells of proximal convoluted tubules of the kidney and the dilation of splenic sinuses were observed, however, milder changes were found in rabbits treated with 0.1g/kg for the same period.

• The Journal of Internal Korean Medicine
• /
• v.16 no.1
• /
• pp.197-213
• /
• 1995

The present experiment was desinged to investigate the effects of Sopungtang water extracts on the Cardiovascular System in the Experimental Animals. Thus, the changes of blood pressure and heart rate were measured after oral administration. Measurments of Mortality rate were observed for measuring the effect of Sopungtang water extract. Sopungtang water extract against pulmonary thromboembolism induced by collagen the mixture(0.1ml/10g, 2mg/kg B.W) plus serotonin(5mg/kg B.W) in mouse. The effects of Sopungtang water extract were examined by observing the change of collagen-induced platelet aggregation, coagulation activity, ex vivo and in vitro fibrinolytic activity of euglobulin fraction in rats. The results were summarized as followings. 1. Sopungtang dropped the blood pressure in spontaneous hypertensive rat. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 4. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The drug increased the antithrombin activity in rat and the fibrinogen lyses time was reduced and lyses area was increased. 8. Sopungtang reduced fibrinogen lyses time of rat in vitro assay. According to the above mentioned results, Sopungtang increased the blood flow and dropped the blood pressure by the dilation of blood vessel. And the drug presented the antithrombin acivity, inhibited the platelet aggregation.

• Transactions on Control, Automation and Systems Engineering
• /
• v.3 no.4
• /
• pp.283-288
• /
• 2001

In this paper, we proposed a method for extracting facial characteristics of human being in an image. Given a pair of gray level sample images taken with and without human being, the face of human being is segmented from the image. Noise in the input images is removed with the help of Gaussian filters. Edge maps are found of the two input images. The binary edge differential image is obtained from the difference of the two input edge maps. A mask for face detection is made from the process of erosion followed by dilation on the resulting binary edge differential image. This mask is used to extract the human being from the two input image sequences. Features of face are extracted from the segmented image. An effective recognition system using the discrete wave let transform (DWT) is used for recognition. For extracting the facial features, such as eyebrows, eyes, nose and mouth, edge detector is applied on the segmented face image. The area of eye and the center of face are found from horizontal and vertical components of the edge map of the segmented image. other facial features are obtained from edge information of the image. The characteristic vectors are extrated from DWT of the segmented face image. These characteristic vectors are normalized between +1 and -1, and are used as input vectors for the neural network. Simulation results show recognition rate of 100% on the learned system, and about 92% on the test images.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.39 no.3
• /
• pp.32-43
• /
• 2002

In this paper, we propose a pattern classification system for digital signal which is based on neural networks. The proposed system consists of two models of neural network. The first part is a wavelet neural network whose role is a feature extraction. For this part, we compare existing models of wavelet networks and propose a new model for feature extraction. The other part is a wavelet network for pattern classification. We modify the structure of previous wavelet network for pattern classification and propose a learning method. The inputs of the pattern classification wavelet network is connection weights, dilation and translation parameters in hidden nodes of feature extraction network. And the output is a class of the signal which is input of feature extraction network. The proposed system is, applied to classification of EEG signal based on frequency.