• 한국초전도학회:학술대회논문집
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• v.9
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• pp.83-86
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• 1999

We have fabricated $_2Cu_3O_7$ step-edge junctions with different step orientations and studied their transition properties. Steps with different orientations were prepared on the substrate. Josephson junctions were made on a single substrate with step orientations ranging from 0$^{\circ}$ to 165$^{\circ}$ at 15$^{\circ}$ interval. We measured current-voltage characteristics, the critical current, and the superconducting transition temperature as a function of the angle. The critical current showed a modulation that has a maximum near 0$^{\circ}$ or 90$^{\circ}$ and a minimum near 45$^{\circ}$ and 135$^{\circ}$. We believe that the critical current modulation with the step orientation could be associated with the symmetry of high T$_c$ superconductor.

• Tunnel and Underground Space
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• v.5 no.1
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• pp.1-10
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• 1995

The behavior of a jointed rock mass depends mainly on the geometrical and mechanical properties of joints. The failure mode of a rock mass and kinematics of rock blocks are governed by the orientation, spacing, and persistence of joints. The mechanical properties such as dilation angle, shear strength, maximum closure, strength of asperities and friction coeffiient play important roles on the stability and deformation of the rock mass. The normal and shear behaviour of a joint are coupled due to dilation, and the joint deformation depends also on the boundary conditions such as stiffness conditons. In this paper, the joint constitutive law including the dilatant behaviour of a joint is numerically modelled using the edge-to-edge contact logic in distinct element method. Also, presented is the method to quantify the input parameters used in the joint law. The results from uniaxial compression and direct shear tests using the numeical model of the single joint were compared to the analytic results from them. The boundary effect on the behaviour of a joint is verified by comparing the results of direct shear test under constant stress boundary condition with those under constant stiffness boundary condition. The numerical model developed is applied to a complex jointed rock mass to examine its performance and to evaluate the effect of joint dilation on tunnel stability.

• Korean Journal of Crystallography
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• v.13 no.2
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• pp.69-72
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• 2002

The interlaminar problems near the free edge of composite laminates are analyzed in this paper. CFRP specimen (［+40/-40］s) and interleaved specimen (［+40//-40］s) with non-woven carbon tissue (NWCT) are discussed under tensile loading condition. The symbol “//”means that the NWCT is located between the CFRP interfaces. The NWCT has carbon short fibers which are discretely distributed with the in-plane random orientation. It was reported/sup 3)/ that the Mode Ⅱ interlaminar fracture toughness of CFRP laminates with NWCT is increased largely and the Mode I interlaminar fracture toughness is not changed significantly. Mode Ⅲ interlaminar fracture toughness is also an important factor in composite structures. But it is not easy to experimentally investigate the Mode Ⅲ interlaminar fracture toughness. The objective of this work is to study the effect of the NWCT and to fundamentally understand the Mode Ⅲ interlaminar shear characteristics of laminated composites with NWCT in the vicinity of a free edge by using finite element method analysis.

• The KIPS Transactions:PartB
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• v.9B no.3
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• pp.327-336
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• 2002

Texture analysis is an important technique in many image understanding areas, such as perception of surface, object, shape and depth. But the previous works are intend to the issue of only texture segment, that is not capable of acquiring recognition information. No unsupervised method is basased on the recognition of texture in image. we propose a novel approach for efficient texture image analysis that uses unsupervised learning schemes for the texture recognition. The self-organization neural network for multiple texture image identification is based on block-based clustering and merging. The texture features used are the angle and magnitude in orientation-field that might be different from the sample textures. In order to show the performance of the proposed system, After we have attempted to build a various texture images. The final segmentation is achieved by using efficient edge detection algorithm applying to block-based dilation. The experimental results show that the performance of the system Is very successful.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.80-85
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• 2010

BGA 409 chip currently the most as a visual inspection of the exterior inspection is conducted. Human depending on visual inspection of the exterior inspection of the current state of testers, depending on how the test results because the change is difficult to expect reliable results. Therefore, the challenges of visual inspection of BGA solder balls to improve the visual inspection technique was developed. However, BGA solder ball size of the microstructure and the characteristics of the distinction between hard test the accuracy of the fall orientation error has a problem. In this paper BGA solder balls exterior inspection of the accuracy to improve the edge detection algorithm, the complement of features and only the comparison proposed a pattern-matching techniques, based on the characteristics of spatial configuration of the area by improving the standard error of the orientation proposed improvements.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.3
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• pp.197-203
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• 2007

Statement of problem: It is very important to establish the suitable position for artificial maxillary anterior teeth and the orientation of occlusal plane in fabrication of the complete dentures. Incisive papilla has been considered the most useful anatomic landmark in the arranging of a maxillary anterior artificial teeth. Purpose: To determine correct position of upper anterior artificial teeth in complete denture patients, relationship of incisive papilla, intercanine line, occlusal plane were evaluated in Korean adults. Materials and Method: Maxillary casts were made in 60 Korean dentate subjects. Each cast was mounted in Hanau modular articulator using Hanau spring bow. Then, anatomic landmarks were determined in each cast. Distance from central incisor to incisive papilla, distance from incisive papilla to intercanine line and discrepancies between frankfurt plane and occlusal plane were measured and analysed. Results: 1. The mean distance between the posterior point of incisive papilla and the incisal edge of central incisor was 11.20 mm (in male 11.77 mm, in female 10.55 mm) and there was no significant difference in measured values between male and female 2. The mean distance between the posterior point of incisive papilla and intercanine line was 2.52 mm (Male 2.57 mm, Female 2.35 mm) and there were no significant differencies in measured values between male and female 3. The mean discripancy between the Frankfurt plane and the occlusal plane were 9. 75 degree (Male 9.81 degree, Female 9.55 degree), and there was no significant difference in measured values between left and right sides.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.262-270
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• 2008

We propose a technique to protect digital images using the magnitude and orientation of their edges. The proposed technique uses the content-associated copyright message generated by combining the original copyright message with the magnitude and orientation of some edges of a digital image. It enables the distribution of the original copyright message without any distortion of original digital images by avoiding embedment of the original copyright message into images. In addition to the advantage in the image quality, it also has a relatively low computational complexity by using simple operations to generate the content-associated copyright message. To verify the proposed technique, we performed experiments on its robustness to the external attacks such as histogram equalization, median filtering, rotation, and cropping. Experimental results on restoring the copyright message from images distorted by attacks show that more than 90%, on the average, can be recovered.

• Design & Manufacturing
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• v.12 no.2
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• pp.27-33
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• 2018

Korea's automobile industry, which has grown rapidly to become the world's fifth-largest automobile producer, To cope with environmental pollution and energy problems in order to prevail competitive edge in global market We are investing a lot of research personnel and costs. Among them, for realizing alternative light weight It is a part of the automobile module system that has achieved the technological development before the breakthrough in the injection molding process in the press process. Door module PNL was the subject of research. The door module PNL is expected to cause warpage before the mold production due to the thin and flat product characteristics and fiber orientation characteristic of the material. In this paper, CAE analysis and reverse correction tool Design. CAE analysis to obtain the results of weld line position, bending position and deformation value Through the correction tool, think3, the original product was modified before the mold production to improve the completeness of the parts. In fiber orientation, the position and size of the cooling channel in the mold, the position and size of the gate, Temperature, pressure, time, and work environment. Compared with the result of CAE analysis, the product that was reverse-corrected by Think3 was manufactured, and injection molding was performed. Injection molding products were tested 24 hours later. 3.5 mm to 7.0 mm, and under the fixed condition, the deviation was from 1.1 mm to 1.5 mm. Unlike the CAE analysis, the deviation of the actual injection pressure and the cooling temperature, the fiber orientation of the material, In order to solve this problem, it is necessary to compare the injection conditions with the database, I knew I had to catch the standard.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2840-2848
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• 1997

Recognition of 3D objects using computer vision is complicated by the fact that geometric features vary with view orientation. An important factor in designing recognition algorithms in such situations is understanding the variation of certain critical features. The features selected in this paper are the angles between landmarks in a scene. In a class of polyhedral objects the angles at certain vertices may form a distinct and characteristic alignment of faces. For many other classes of objects it may be possible to identify distinctive spacial arrangements of some readily identifiable landmarks. In this paper given an isotropic view orientation and an orthographic projection the two dimensional joint density function of two angles in a scene is derived. Also the joint density of all defining angles of a polygon in an image is derived. The analytic expressions for the densities are useful in determining statistical decision rules to recognize surfaces and objects. Experiments to evaluate the usefulness of the proposed methods are reported. Results indicate that the method is useful and powerful.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2143-2149
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• 2007

Visual Cortex Stimulator is among artificial retina prosthesis for blind man, is the method that stimulate the brain cell directly without processing the information from retina to visual cortex. In this paper, we propose image construction and recognition model that is similar to human visual processing by recognizing the feature data with orientation information, that is, the characteristics of visual cortex. Back propagation algorithm based on Delta-bar delta is used to recognize after extracting image feature by Kirsh edge detector. Various numerical patterns are used to analyze the performance of proposed method. In experiment, the proposed recognition model to extract image characteristics with the orientation of information from retinal cells to visual cortex makes a little difference in a recognition rate but shows that it is not sensitive in a variety of learning rates similar to human vision system.