• International Journal of Precision Engineering and Manufacturing
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• v.2 no.4
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• pp.40-46
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• 2001

Bulging is a forming method to shape die cavity by using hydraulic pressure in tube or vessel. Bulging machine and die were developed in order to produce vessel for keeping warm. Bulging machine is a double type with two horizontal cylinders for bulging of two pieces at the same time. The developed die system has one bulging die and two drawing dies for necking at both ends of the tube. The diameter of tube expands by hydraulic pressure in tube. At the same time, thrust at both ends of the tube pushes tube in the direction of expansion to obtain high expansion rate with no crack. In this study, the bulging properties were investigated to solve tube crack and necking in manufacturing vessel by combining bulging and drawing. As a result, high expanding rate of tube radius without crack, precision necking and high productivity were obtained.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.438-446
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• 1999

Crop minimization of the top and bottom ends of hot rolled plate, in a plate, in a plate mill, has been investigated. The existing model to determine the edging pattern at the finishing rolling pass was not reasonable to get high width accuracy and rolling yields. New models including width prediction have been formulated by using neural network model of back propagation learning algorithm and statistical analysis based on the actual production rolling data to give the optimal pattern for minimizing trimming loss. Using these models, at a given rolling condition of broadside pass and finishing pass and the permissible condition of width variation, it was possible to minimize crip at the top and bottom ends according to optimum procedure in plate mill. An application to improve the plan view pattern reduced width variation by 23% and crop length by 30% on average with an effective fishtail crop shape.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.48-51
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• 2000

In plate mill studies on crop decrease of the top and bottom ends of hot rolled plate have been performed. The plane view shape for the thin plate after broadside rolling was controlled by roll gap difference with AGC in broadside rolling process. New models for thin slab after broadside rolling have been formulated based on the actual production rolling data to give optimal rolling condition A new plate rolling method called by dog bone rolling has been applied making it is possible to prevent non-uniform plastic deformation at top and bottom ends. By new rolling method crop losses of rolled plate have been improved by 10% on average with an effective fishtail crop shape.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.429-437
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• 1999

Width variation of the top and bottom ends of steel at finishing rolling in a plate, has been investigated. It was found that width variation after finishing rolling is affected by edging, broadside rolling ratio, longitudinal rolling ratio, width shape after broadside rolling, temperature, width-to-thickness ratio, and so on. A neural network modelling of back propagation has been conducted on the width variation during rolling. Based on these prediction models, a width control system, by which the roll opening and closing of the hydraulic AWC edger can be adjusted during edge rolling in finishing rolling passes, has been developed. Compared to conventional width model, the neural network model is much accurate in a model. The width control system is applied to a newly built production mill.

• Journal of Chest Surgery
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• v.28 no.2
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• pp.218-220
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• 1995

This 51 years old male patient was admitted to the department of thoracic and cardiovascular surgery via OPD because of anterior chest pain. 7days before admission, He got the chest trauma after traffic accidents,the lateral chest roentgenogram showed complete transverse sternal fracture. He also complained of mild dyspnea. We also noticed that he had depressed anterior chest wall. It looks like funnel chest. The operative findings revealed dislocated & callus formations at the both 4th and 5th costochondral junction and transverse fracture of sternal body between 4th and 5th costochondral junction, the upper end of sternal fracture was situated below the lower end of sternal fracture. The two ends of sternal fracture were situated at the same level and reapproximated the two ends by two-interrupted wire sutures. The patient is well on the road to recovery after the operation.

• Fibers and Polymers
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• v.6 no.4
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• pp.332-335
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• 2005

The fibrogram theory is newly derived from the superposition principle of the conventional staple diagram, in which the left-hand ends of the fibers have to share a common starting point in order for the fiber length distribution to be measured, and the right-hand ends of the fibers form points. It is shown that the fibrogram is the staple diagram of the fiber sample having different random starting points, as well as the double cumulative distribution function of the frequency length function in the length biased sample. Also, the various means, viz. the numerical mean length, numerical mean length in median, length biased mean length, and length biased mean length in median, and the various upper half means, viz. the numerical upper half mean length, numerical upper half mean length in median, length biased upper half mean length, and length biased upper half mean length in median, are discussed in relation to the cotton blending process.

• Communications of the Korean Mathematical Society
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• v.22 no.2
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• pp.277-287
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• 2007

We prove that if a graph G of bounded degree has finitely many p-hyperbolic ends($1) in which every bounded energy finite p-harmonic function is asymptotically constant for almost every path, then the set $\mathcal{HBD}_p(G)$ of all bounded energy finite p-harmonic functions on G is in one to one corresponding to $\mathbf{R}^l$, where $l$ is the number of p-hyperbolic ends of G. Furthermore, we prove that if a graph G' is roughly isometric to G, then $\mathcal{HBD}_p(G')$ is also in an one to one correspondence with $\mathbf{R}^l$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.389-391
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• 2013

본 논문에서는 초음파 검사자가 효율적으로 충수염을 진단할 수 있도록 하기 위하여 초음파 영상에서 충수를 추출하는 방법을 제안한다. 충수를 추출하는 과정은 초음파 영상에서 Ends_in Search Stretching 기법을 적용하여 명암 대비를 강조하고, Max-Min 이진화, 영역 레이블링, 잡음 제거, Cubic Spline 보간법을 적용하여 복부 근육의 하단 근막 부분을 추출한다. 초음파 영상에서 추출된 근막 영역을 제거한 후, K-Means 클러스터링과 영역 레이블링을 적용하여 충수 영역을 추출한다. 제안된 방법을 초음파 영상을 대상으로 실험한 결과, 충수염을 진단하기에 적합한 충수 영역이 추출되는 것을 영상의학과 전문의를 통하여 확인하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.2
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• pp.215-223
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• 2008

The differential equations governing free vibrations of the elastic arches with hollow section are derived in polar coordinates, in which the effect of rotatory inertia is included. Natural frequencies is computed numerically for parabolic arches with both clamped ends and both hinged ends. Comparisons of natural frequencies between this study and reference are made to validate theories and numerical methods developed herein. The lowest four natural frequency parameters are reported, with the rotatory inertia, as functions of three non-dimensional system parameters: the breadth ratio, the thickness ratio and the rise to span length ratio.

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.1
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• pp.68-74
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• 1986

The governing differential equations and the boundary conditions for the free vibra- tion of the unsymmetric parabolic arch with fixed ends are derived on the basis of the equilibrium equations and the D'Alembert principle. The effect of the rotary inertia as well as the extensional and the flexural deformations is considered in the governing differential equations. A trial eigenvalue method is used for determining the natural frequencies. The Ru- uge-Kutta method is used in this method to perform the integration of the differential equations. The detailed studies are made of the lowest three vibration frequencies for the par- abolic chord length equal to 10m. The effect of the rotary inertia is analyzed and it's numerical data are presented in table. And as the numerical results the frequency versus the rise of arch and the radius of gyration are presented in figures.