• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.829-832
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• 2002

Deformation of the specimens was investigated on hydrogen absorption-desorption cycling. In order to study this problem, the cold rolled and the annealed palladium thin plate as specimens had been used. By using the electrochemical method, the palladium plate specimens were cyclically hydrogenated in the 0.1mol $H_2SO_4$ electrolyte. As results, it is noted that the thickness of the plate specimens gradually increased in increasing hydrogenation cycles whereas the width and the length decreased. Also, Deformation of the cold rolled palladium specimen was lager than the annealed palladium specimen. And grains in the plate specimen were greatly deformed after hydrogenation cycling. But hydrogen absorption rate scarcely changed.

• 한국해양공학회지
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• 제29권2호
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• pp.163-168
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• 2015

This paper presents the results of experimental work on the wedge slamming impact problem. An experiment was done with a wedge model. The deadrise angle of the wedge was $4^{\circ}$. The model was made in two parts: the outside part was made of a 5-mm-thick steel plate that could be assumed to be a rigid body, and the inside part was made of a thin SUS plate that could be assumed to be an elastic body. Thin SUS plate thicknesses of 2 mm and 3 mm were used to determine the effect of plate rigidity. The drop height was varied from 0.25 m to 1 m to determine the effect of a large deformation.

• Structural Engineering and Mechanics
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• 제22권2호
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• pp.151-167
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• 2006

A p-version of the finite element method in conjunction with the modeling dynamic method using the arc-length stretch deformation is considered to determine the bending natural frequencies of a cantilever flexible plate mounted on the periphery of a rotating hub. The plate Fourier p-element is used to set up the linear equations of motion. The transverse displacements are formulated in terms of cubic polynomials functions used generally in FEM plus a variable number of trigonometric shapes functions representing the internals DOF for the plate element. Trigonometric enriched stiffness, mass and centrifugal stiffness matrices are derived using symbolic computation. The convergence properties of the rotating plate Fourier p-element proposed and the results are in good agreement with the work of other investigators. From the results of the computation, the influences of rotating speed, aspect ratio, Poisson's ratio and the hub radius on the natural frequencies are investigated.

• Structural Engineering and Mechanics
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• 제49권6호
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• pp.793-810
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• 2014

This research work deals with the development of a new Triangular finite element for the linear analysis of plate bending with transverse shear effect. It is developed in perspective to building shell elements. The displacements field of the element has been developed by the use of the strain-based approach and it is based on the assumed independent functions for the various components of strain insofar as it is allowed by the compatibility equations. Its formulation uses also concepts related to the fourth fictitious node, the static condensation and analytic integration. It is based on the assumptions of tick plate.s theory (Reissner-Mindlin theory). The element possesses three essential external degrees of freedom at each of the four nodes and satisfies the exact representation of the rigid body modes of displacements. As a result of this approach, a new bending plate finite element (Pep43) which is competitive, robust and efficient.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제24권3호
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• pp.293-303
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• 2020

The present work aims to analyzed the transient thermoelastic stress analysis of a thin circular plate with uniform internal heat generation. Initially, the plate is characterized by a parabolic temperature distribution along the z-direction given by T = T₀(r, z) and perfectly insulated at the ends z = 0 and z = h. For times t > 0, the surface r = a is subjected to convection heat transfer with convection coefficient h_c and fluid temperature T_∞. The integral transform method used to obtain the analytical solution for temperature, displacement, and thermal stresses. The associated thermoelastic field is analyzed by making use of the temperature and thermoelastic displacement potential function. Numerical results are carried out with the help of computational software PTC Mathcad Prime-3.1 and shown in figures.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.699-706
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• 2021

Existing license plate recognition system is used as an optical character recognition method, but a method of using deep learning has been proposed in recent studies because it has problems with image quality and Korean misrecognition. This requires a lot of data collection, but the collection of license plates is not easy to collect due to the problem of the Personal Information Protection Act, and labeling work to designate the location of individual license plates is required, but it also requires a lot of time. Therefore, in this paper, to solve this problem, five types of license plates were created using a virtual Korean license plate generation program according to the notice of the Ministry of Land, Infrastructure and Transport. And the generated license plate is synthesized in the license plate part of collectable vehicle images to construct 10,147 learning data to be used in deep learning. The learning data classifies license plates, Korean, and numbers into individual classes and learn using YOLOv5. Since the proposed method recognizes letters and numbers individually, if the font does not change, it can be recognized even if the license plate standard changes or the number of characters increases. As a result of the experiment, an accuracy of 96.82% was obtained, and it can be applied not only to the learned license plate but also to new types of license plates such as new license plates and eco-friendly license plates.

• Steel and Composite Structures
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• 제23권5호
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• pp.493-499
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• 2017

The behaviour of steel frames is highly influenced by the beam-column connections. Traditionally, Steel frames were usually designed assuming that connections are ideally pinned or fully rigid. A semi-rigid connection, however, creates a balance between the two extreme approaches mentioned above. In this research, two full scales of Extended End Plate Connections (EEPCs) were tested. Mathematical and numerical models were used to analyse the connections, and close correlations were found between these models and the corresponding tested specimens, which confirmed the confidence in the experimental results. The experimental results obtained enrich the available test data about behaviour of EEPC. In addition, the purpose of studying EEPC experimentally is to compare the stiffness and moment-rotation curve of EEPCs with that of Cap Plate Connections (CPCs), which were tested in a previous work. CPCs have not been studied sufficiently in the literature. The results obtained show that the typical CPC reduces the connection stiffness and these results will make a valuable contribution to the available test data in the research area of CPC.

• Journal of Trauma and Injury
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• 제29권1호
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• pp.22-27
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• 2016

Purpose: The optimal method of fixation of symphysis pubis (SP) diastasis in pelvic ring injuries is still controversial. In this study, we investigated the radiological and the clinical results of a precontoured 4.5-mm symphysis pubis (SP) plate with tension band wiring (TBW) after an anterior pelvic injury in pelvic fractures. Methods: We treated 25 patients with traumatic SP diastasis by open reduction and internal fixation with plates and wires. We used a four-hole 4.5-mm precontoured SP plate with a tension band wiring. Results: Patients with a SP with TBW fixation achieved excellent or good results at final follow-up. Post-operative complications included two (8%) patients with metal work movement. The mean symphyseal width was smaller in 4.5 mm SP plate with TBW during 1-year follow up period. Conclusion: A precontoured symphysis pubis plate (4.5 mm) with figure-of-eight fashion tension band wiring shows favorable radiological results, excellent or good clinical outcome, and a lower complication (hardware failure and revision surgery).

• Journal of Welding and Joining
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• 제27권3호
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• pp.60-66
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• 2009

The structures distorted by welding have to be corrected. Since the correcting work needs a lot of costs and time, it is very important to minimize the buckling distortion due to welding of thin plate structure. Therefore the aim of this study is to investigate the effect of single bead on plate welding and fillet welding on the buckling distortion. In the single bead on plate welding, it was found that the welding speed and welding sequence were the most dominant factors on distortion. In the fillet welding, there were four typical buckling modes observed, and the welding sequence was the most influential factor on the buckling distortion. However typical distortion measuring method is not considered for the distortion correcting process costs of each buckling modes, therefore, in this study, the measuring method is developed to classify the buckling modes for torsion of specimen and buckling distortion depend on nodal point for the bead on plate welding specimen and fillet welds.

• 소성∙가공
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• 제15권4호
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• pp.311-318
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• 2006

One of the most important quality problems in flat plate leveled from hot rolled coils in cut-to-Iength lines is bowing and cambering when they are cut in small width parts. It is verified analytically and experimentally that residual stress remained in plate is th ε source of the problem. In order to produce low residual stress flat plate from hot rolled coils, the proper conditions of leveling are studied and two things are implemented. One is proper plastic deformation area ratio to reduce residual stress within customer requirement by applying suitable plastic deformation and maintain leveling load within structural strength limit of leveler. The other is maintaining uniform plastic deformation along the width of the plate during leveling. Customer requirement for residual stress is met by applying above 70% of plastic deformation area ratio and uniform deformation along width of coil by adjusting back up rolls according to deformation analysis of work roll and back up roll assembly and leveling tests.