• Journal of Korean Neurosurgical Society
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• v.38 no.4
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• pp.255-258
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• 2005

Objective : Lumbar lordotic curve on L4 to S1 level is important in maintaining spinal sagittal alignment. Although there has been no definite report in lordotic value, loss of lumbar lordotic curve may lead to pathologic change especially in degenerative lumbar disease. This study examines the changes of lumbar lordotic curve after posterior lumbar interbody fusion with wedge shape cage. Methods : We studied 45patients who had undergone posterior lumbar interbody fusion with wedge shape cage and screw fixation due to degenerative lumbar disease. Preoperative and postoperative lateral radiographs were taken and one independent observer measured the change of lordotic curve and height of intervertebral space where cages were placed. Segmental lordotic curve angle was measured by Cobb method. Height of intervertebral space was measured by averaging the sum of anterior, posterior, and midpoint interbody distance. Clinical outcome was assessed on Prolo scale at 1month of postoperative period. Results : Nineteen paired wedge shape cages were placed on L4-5 level and 6 paired same cages were inserted on L5-S1 level. Among them, 18patients showed increased segmental lordotic curve angle. Mean increased segmental lordotic curve angle after placing the wedge shape cages was $1.96^{\circ}$. Mean increased disc height was 3.21mm. No cases showed retropulsion of cage. The clinical success rate on Prolo's scale was 92.0%. Conclusion : Posterior lumbar interbody fusion with wedge shape cage provides increased lordotic curve, increased height of intervertebral space, and satisfactory clinical outcome in a short-term period.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3165-3168
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• 1999

When a input image is extensively magnified on the computer system, it is almost impossible to replicate the original shape because of mismatched coordinates system. In order to resolve the problem, the shape of the magnified image has been reconfigured using the bilinear interpolation method, low pass special filtering interpolation method and B-spline interpolation method. Ferguson curve interpolation method based on the CAD/CAM curve interpolation algorithm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05e
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• pp.15-18
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• 2003

In this paper, We explained the best shape design of electrode for discharge on the water. Electrode with rounding was reduced maximum electric field of over 40% to electrode without rounding for discharge on the water and the best shape of electrode for discharge on the water designed when shape of electrode had a curve radius of over $60^{\circ}$ at electrode's face to electrode's face with minimum distance and a curve radius of under $120^{\circ}$ at electrode's side face to electrode's front face. And When dielectric beads are used between electrodes, the life of electrodes is improved by lower stress of electric field on surface of electrodes.

• Journal of computational fluids engineering
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• v.10 no.3 s.30
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• pp.27-35
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• 2005

A design optimization of hypersonic flight vehicle has been studied by using upwind Navier-Stokes method and numerical optimization method. CFD method is linked to numerical optimization method by using a Bezier curve and a design optimization of blunt nose hypersonic flight vehicle has been studied. Heat transfer coefficient and drag coefficient are selected as objective functions or design constraints. The Bezier curve-based shape function was applied to blunt body shape.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.920-924
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• 2002

This paper presents the reverse design of a cam mechanism using NURBS(Nonuniform Rational B-spline curve). Cam is very difficult to make the accurate shape on the design and the manufacture. Because the cam shape is commonly made in order to move in special functions. The reverse design can be used to check accuracy between the designed data and the manufactured data of the cam shape and also reproduce the cam without the design data. The reverse design procedures consist of motion analysis and curve fitting. The motion analysis is used the central difference method and the relative velocity method to find the displacement and velocity. The curve fitting is used NURBS to develope the whole curve. The central difference method is derived in the 3 dimensional space.

• Journal of Biomedical Engineering Research
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• v.28 no.5
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• pp.665-675
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• 2007

The morphological change of ECG is the important diagnostic parameter to finding the malfunction of a heart. Generally ST segment deviation is concerned with myocardial abnormality. The aim of this study is to detect the change of ST in shape using a polynomial approximation method and the reference ST type. The developed algorithm consists of feature point detection, ST level detection and ST shape classification. The detection of QRS complex is accomplished using it's the morphological characteristics such as the steep slope and high amplitude. The developed algorithm detects the ST level change, and then classifies the ST shape type using the polynomial approximation. The algorithm finds the least squares curve for the data between S wave and T wave in ECG. This curve is used for the classification of the ST shapes. ST type is classified by comparing the slopes of the specified points between the reference ST set and the least square curve. Through the result from the developed algorithm, we can know when the ST level change occurs and what the ST shape type is.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.243-244
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• 2006

• Fashion & Textile Research Journal
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• v.20 no.4
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• pp.429-438
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• 2018

This study analyzed the fit-zone of the neck for females in their 60s. We considered the standard body types of females in their 60s and the four body types from the sixth Size Korea. The results of the study were as follows. We could not determine a pattern formula for the neck based on the changes in the body type of females in their 60s. However, the position of the lateral neck point generally showed a significant difference from that of females in their 20s. In the case of the shoulder angle, the point of the shoulder was angled slightly towards the back in all body types. It was also found that the curve of the neck circumference for both the collar and the bodice should have been smoother than what was shown on the 3D shape. The larger the height difference between the point of the back of the neck and the lateral neck point in the 3D shape, the smoother the design should be at the curve of the circumference at the front of the neck. A larger curvature in the front radius of the 3D shape increased the difference in the shape of the curve between the collar and the basic pattern of the bodice. Hence, a more careful design is required for these parts of the pattern. In addition, the more the front neck is bent, the smoother the circumference curve should be in the pattern design at the front of the neck and the collar.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.123-130
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• 2010

The aim of this paper is a seismic performance evaluation of metallic damper devices which are efficient in workability and installation process. For this V shape and S shape dampers is considered. The strut figures of dampers are V shape and S shape and, the research parameters are strut height and angle of the dampers. ABAQUS program is used for nonlinear finite element analysis. The analysis is performed with the hysteretic curve that has maximum displacement with 50mm and has increased progressive. As a results of evaluating the yield strength, maximum strength and energy dissipation capacity of each device, V and S shape have a good strength capacity and the devices with strut angle $60^{\circ}$ and strut height 140 and 200mm are evaluated stable in seismic behaviors. The response of S shape is more efficient than that of V shape. In the yield strength estimation process, proposed formula can not estimate the yield strength of V and S shape dampers. Even though, the formula can not consider the variation of strut heights and strut angles. Finally the S shape damper is recommended in seismic performance than V shape damper.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.2
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• pp.86-95
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• 2003

During this study, constant stress ratio tests with previous compression anisotropic stress history are performed on compacted decomposed granite soil sampled at Iksan, Jeonbuk. Yielding points are determined from stress-strain curves. The shape and characteristics of compression anisotropic yield curves is examined. In addition, the measured value of yielding curve and stress-strain behavior is predicted by Yasufuku's anisotropic constitutive model based on non-associated flow rule. The main results are summarized as follows : 1) Shape of yielding curves shows almost ellipse but asymmetry with respect to stress path during previous consolidation stress. 2) Yasufuku's anisotropic constitutive model is suitable in evaluation of yielding curves on anisotropic consolidated decomposed granite soil. 3) The predicted stress-strain curve shows reasonable agreement to measured behaviours.