• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.495-501
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• 2014

The objective of this study was to evaluate the differences and reproducibility of Hounsfield unit (HU) value and volume measurements on different computed tomography (CT) scanner types and different collimations by using a gelatin phantom. The phantom consisting of five synthetic simulated calculus spanning diameters from 3.0 mm to 12.0 mm with 100 HU was scanned using a two-channel multi-detector row CT (MDCT) scanner, a four-channel MDCT scanner, and two 64-channel MDCT scanners. For all different scanner types, the thinnest possible collimation and the second thinnest collimation was used. The HU values and volumes of the synthetic simulated calculus were independently measured three times with minimum intervals of 2 weeks and by three experienced veterinary radiologists. ANOVA and Scheff$\acute{e}$ test for the multiple comparison were performed for statistical comparison of the HU values and volumes of the synthetic simulated calculus according to different CT scanner types and different collimations. The reproducibility of the HU value and volume measurements was determined by calculating Cohen's k. The reproducibility of HU value and volume measurements was very good. HU value varied between different CT scanner types, among different beam collimations. However, there was not statistically significant difference. The percent error (PE) decreased as the collimation thickness decreased, but the decrease was statistically insignificant. In addition, no statistically significant difference in the PEs of the different CT scanner types was found. It can be concluded that the CT scanner type insignificantly affects HU value and the volumetric measurement, but that a thinner collimation tends to be more useful for accurate volumetric measurement.

• Journal of the Korea Computer Industry Society
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• v.3 no.7
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• pp.901-914
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• 2002

In this paper, We propose an efficient automatic caption detection and location method, caption recognition using FE-MCBP(Feature Extraction based Multichained BackPropagation) neural network for content based retrieval of video. Frames are selected at fixed time interval from video and key frames are selected by gray scale histogram method. for each key frames, segmentation is performed and caption lines are detected using line scan method. lastly each characters are separated. This research improves speed and efficiency by color segmentation using local maximum analysis method before line scanning. Caption detection is a first stage of multimedia database organization and detected captions are used as input of text recognition system. Recognized captions can be searched by content based retrieval method.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.1061-1071
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• 2018

A subsea tunnel, being a super-sized underground structure must ensure safety at the time of earthquake, as well as at ordinary times. At the time of earthquake, in particular, of a subsea tunnel, a variety of response behaviors are induced owing to relative rigidity to the surrounding ground, or difference of displacement, so that the behavior characteristics can be hardly anticipated. The investigation aims to understand the behavior characteristics switched by earthquake of an imaginary subsea tunnel which passes through a fault zone having different physical properties from those of the surrounding ground. In order to achieve the aim, dynamic response behaviors of a subsea tunnel which passes through a fault zone were observed by means of indoor experiments. For the sake of improved earthquake resistance, a shape of subsea tunnel to which flexible segments have been applied was considered. Afterward, it is believed that a D/B can be established through 3-dimensional earthquake resistance interpretation of various grounds, on the basis of verified results from the experiments and interpretations under various conditions. The present investigation performed 1 g shaking table test in order to verify the result of 3-dimensional earthquake resistance interpretation. A model considering the similitude (1:100) of a scale-down model test was manufactured, and tests for three (3) Cases were carried out. Incident seismic wave was introduced by artificial seismic wave having both long-period and short-period earthquake properties in the horizontal direction which is rectangular to the processing direction of the tunnel, so that a fault zone was modeled. For numerical analysis, elastic modulus of the fault zone was assumed 1/5 value of the modulus of individual grounds surround the tunnel, in order to simulate a fault zone. Resultantly, reduced acceleration was confirmed with increase of physical properties of the fault zone, and the result from the shaking table test showed the same tendency as the result from 3-dimensional interpretation.

• The Journal of Engineering Geology
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• v.13 no.2
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• pp.207-225
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• 2003

According to the data analysis of the regional fracture systems in southern Korea, the fracture orientations show three dominant sets : NNE, NW and WNW. A NNE set is the most abundant and includes most of the largest fractures. The highest fracture density is shown in the Taebaegsan mineralized area corresponding to Ogchon nonmetamorphic belt and the lowest one in the southwestern area of southern Korea. In addition, the density is higher in nonmetamorphic sedimentary rocks such as Choseon Supergroup. Pyeongan Supergroup, Daedong Supergroup and Kyeongsang Supergroup than in Precambrian basements and Jurassic granites. The regional fractures in southern Korea can be classified into four orders designated $F_1,{\;}F_2,{\;}F_3{\;}and{\;}F_4${\;}and{\;}F_4$ on the basis of their trace length. It is quite significant that fractures of each order are self-similar with respect to orientation and the combined fracture length distribution indicates a power-law distribution with an exponent of -2.04. As fractures were analyzed based on the tectonic provinces, Gyeonggj Massif and Kyeongsang Basin have all orders of fractures from $F_1$ to $F_4$. Most of the large scale faults may be ascribed to the products of slip accumulation through multiple deformation. Others besides $F_1$ fractures are thought to be evenly distributed through the whole area of southern Korea.

• Clinics in Shoulder and Elbow
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• v.15 no.2
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• pp.73-78
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• 2012

Purpose: Understanding exactly detailed anatomy and morphology of scapula is very important for further surgical procedures. This study was intended to provide accurate anatomic and morphologic information of scapula by exactly measuring scapular thickness using computed tomography and reconstructing its geometric model. Materials and Methods: Eight average lengths and two angles of 102 scapular structures obtained from 51 cadavers were generally measured by computed tomography. Also, to measure the scapular thickness, sagittal planes of each scapula were divided almost equally and the thicknesses of each sagittal plane was measured by computed tomography. After measuring every thickness, average results were calculated and the gender difference was compared by Student t-test. Results: Average results of the thickness of glenoid fossa, lateral border, medial border, and the middle 1/3 portion of the scapular body were 22.4 mm, 13.83 mm, 4.44 mm and 2.06 mm, respectively. Also, male scapulars were found to be significantly thicker than female. Based on these measured thicknesses, we reconstructed the 3-dimensional geometric model of scapula. Conclusion: From these results, glenoid fossa and lateral border were the thickest part of scapula, while the middle 1/3 portion of the scapular was the thinnest.

• Journal of the Korean Society of Radiology
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• v.10 no.1
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• pp.45-51
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• 2016

The purpose of this study was tried to remove the noise and improve the spatial resolution in the computed tomography (CT) by using anisotropic 2-dimensional (2D) diffusion based filter. We used 4-channel multi-detector CT and american association of physicists in medicine (AAPM) phantom was used for CT performance evaluation to evaluate the image quality. X-ray irradiation conditions for image acquisition was fixed at 120 kVp, 100 mAs and scanned 10 mm axis with ultra-high resolution. The improvement of anisotropic 2D diffusion filtering that we suggested firstly, increase the contrast of the image by using histogram stretching to the original image for 0.4%, and multiplying the individual pixels by 1.2 weight value, and applying the anisotropic diffusion filtering. As a result, we could distinguished five holes until 0.75 mm in the original image but, five holes until 0.40 mm in the image with improved anisotropic diffusion filter. The noise of the original image was 46.0, the noise of the image with improved anisotropic 2D diffusion filter was decreased to 33.5(27.2%). In conclusion improved anisotropic 2D diffusion filter that we proposed could remove the noise of the CT image and improve the spatial resolution.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.508-510
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• 2015

A 7-year-old castrated male Boston terrier dog was referred due to dyspnea and unilateral cervical mass. On physical examination, mass on left submandibular region was palpated. CT findings revealed this case could be the tumor originated from left lingual vein. The client refused further treatment and the patient expired because of respiratory failure 10 days after presentation. On necropsy, a well-defined firm mass which located in the left side of larynx was detected. Histopathological findings for the mass indicated polygonal tumor cells arranged in nest and separated by fibrovascular septa. We performed immunohistochemisry to evaluate of chromogranin A and tumor cells showed positive immunoreactivity for chromogranin A. Based on computed tomography (CT), histopathological and immunohistochemical findings, this case was definitely diagnosed to paraganglioma of the body on the lingual vein. This report describes the clinical findings, CT imaging characteristics, histopathologic and immunohistochemical features of paraganglioma arised from lingual vein in a dog.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.20-27
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• 2006

중국 Three Gorges Project의 대수로사면 안정성은 설계와 시공측면에 있어 주요 관심사가 되었다. 사면 굴착으로 인한 제하과정에서 암반은 역학적으로 불안정한 상태에 놓인다. 본 논문은 FEM(2D-3D)를 이용하여 단층 암반 굴착으로 인한 암반사면의 안정성을 평가하였다. 해석결과 굴착 후 수로사면의 양측 수직벽과 분리울타리의 중간 상부에서 인장응력과 전단손상영역이 주로 발생하였다. 해석결과를 토대로 대규모 사면활동에 대한 안정성을 확인하였으나 시공단계에서 국부적 사면활동을 방지하기 위한 록볼트와 록앵커 등의 보강이 필요한 것으로 검토되었다.

• Tuberculosis and Respiratory Diseases
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• v.64 no.2
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• pp.133-137
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• 2008

Pulmonary paragonimiasis continues to be a diagnostically challenging parasitic disease, despite a drastically decreased prevalence in South Korea during the past decade. Pulmonary paragonimiasis is characterized by fever, chest pain, and chronic cough with hemoptysis. Numerous radiographic and computed tomographic findings including the presence of pneumothorax, pleural effusion, and parenchymal lesions such as nodular or infiltrative opacities have been reported. The clinical and radiological manifestations of paragonimiasis can resemble those of lung cancer, tuberculosis or a metastatic malignancy. Furthermore, this disease can mimic lung cancer as seen on $^{18}F$-fluorodeoxyglucose positron emission tomography (FDG-PET). We report a case of pulmonary paragonimiasis in a 48-year old man that presented with a solitary pulmonary nodule and was suspected as a lung cancer based on FDG-PET imaging.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4276-4283
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• 2015

The purpose of this research is to identify the effectiveness of injection with soil conditions by injecting CaCO3(created by microorganism reaction), which was recreated with equipment in similar situ condition. To analyze our research, we made 2 cases of single-layer (SP, SW) in D 150mm ${\times}$ H 300mm. Layers were made by RC 70, 80, 85, 90, 95% of soil condition. We measured uniaxial compression strength with cone penetrometer and watched injection range by checking a bulb formation around the injection nozzle. As a result, the relative compaction(RC) in more 85% were not injected in SW, we could identify the effect of bio-grouting technology on ground in relative compaction(RC) of injection ratio and cementation range.