• The Journal of Korean Academy of Prosthodontics
• /
• v.29 no.3
• /
• pp.1-32
• /
• 1991

Tho osseointegrated dental prosthetic treatment has develped for the edentulous patient with severely resorbed alveolar ridge, and has given us a successful clinical results to date. Nowadays the partially edentulism is included among the indications of the osseointegrated prosthetic treatment. The purpose of this study was to analyze the stress distribution at supporting bone according to the types of connection modality between implant and tooth in the superstructure. Two dimensional finite element stress analysis was applied for this study. FEM models were created using software Super SAP for MBM 16bit personal computer. Three modalities of connection were modeled and analyzed under load condition. The results were as follws: 1. The stress develped at tooth and implant in the cancellous bone was lower in the case of rigid connection than in the case of norigid connection, but higher between the two implants in the case of rigid connection than in the case of nonrigid connection. 2. The stress developed at the cortical bone and at the supporting bone interface was lower in the case of rigid connection than in the case of nonrigid connection 3. The stress developed at the supporting tissue interface of the implant nearby the tooth, was lower in the case of rigid connection than in the case of nonrigid connection. 4. The stress developed at the supporting tissue interface of posteriormost implant, was same between the cases of rigid and nonrigid connection. 5. The stress distribution related to the freestanding case was generally similar to the stress distribution pattern of nonrigid connection case. 6. The magnitude of applied load which produces deformation within elastic limit, had influence on the absolute value of stress, but had no influence on the pattern of stress distribution of the same case.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.9
• /
• pp.2882-2903
• /
• 2022

Image super-resolution (SR) processing is of great value in the fields of digital image processing, intelligent security, film and television production and so on. This paper proposed a densely connected deep learning network based on cascade architecture, which can be used to solve the problem of super-resolution in the field of image quality enhancement. We proposed a more efficient residual scaling dense block (RSDB) and the multi-channel cascade architecture to realize more efficient feature reuse. Also we proposed a hybrid loss function based on L₁ error and L_∞ error to achieve better L_∞ error performance. The experimental results show that the overall performance of the network is effectively improved on cascade architecture and residual scaling. Compared with the residual dense net (RDN), the PSNR / SSIM of the new method is improved by 2.24% / 1.44% respectively, and the L_∞ performance is improved by 3.64%. It shows that the cascade connection and residual scaling method can effectively realize feature reuse, improving the residual convergence speed and learning efficiency of our network. The L_∞ performance is improved by 11.09% with only a minimal loses of 1.14% / 0.60% on PSNR / SSIM performance after adopting the new loss function. That is to say, the L_∞ performance can be improved greatly on the new loss function with a minor loss of PSNR / SSIM performance, which is of great value in L_∞ error sensitive tasks.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.23 no.1
• /
• pp.1-8
• /
• 2018

A problem exists in the conventional transportation cart applications, in which an external power supply with mechanical contact connection (bus bar connection) is required to drive the motor. Therefore, continuous effort for maintenance is required, aside from the expensive bus bar connector. To solve this problem, a self-electricity-generated transportation cart system without bus bar has recently been introduced. In this system, a battery needs to store the power of the generated wheel, and a boost converter, which converts the low battery voltage to high bus voltage to drive the motor inverter, is necessary. However, since the instantaneous large current required for starting the motor is supplied from the battery, a battery with large size and volume should be adopted to withstand this large current. In this study, a boost converter that can supply a large instantaneous current by using super Capacitor string is proposed. The proposed converter can be realized with a small size and volume compared with the conventional battery-fed boost converter. Operational principles, analysis, and design of the proposed converter are presented, and experimental results are provided to validate the proposed converter.

• Journal of Digital Policy
• /
• v.2 no.3
• /
• pp.1-7
• /
• 2023

In this paper, I proposes a method for performing single image super resolution by separating texture-spatial domains and then classifying features based on detailed information. In CNN (Convolutional Neural Network) based super resolution, the complex procedures and generation of redundant feature information in feature estimation process for enhancing details can lead to quality degradation in super resolution. The proposed method reduced procedural complexity and minimizes generation of redundant feature information by splitting input image into two channels: texture and spatial. In texture channel, a feature refinement process with step-wise skip connections is applied for detail restoration, while in spatial channel, a method is introduced to preserve the structural features of the image. Experimental results using proposed method demonstrate improved performance in terms of PSNR and SSIM evaluations compared to existing super resolution methods, confirmed the enhancement in quality.

• Journal of Digital Policy
• /
• v.3 no.1
• /
• pp.27-32
• /
• 2024

In this paper, proposes a super resolution method that enhances the quality of results by refining texture features, contrasting each, and utilizing the results as weights. For the improvement of quality, a precise and clear restoration result in details such as boundary areas is crucial in super resolution, along with minimizing unnecessary artifacts like noise. The proposed method constructs a residual block structure with multiple paths and skip-connections for feature estimation in conventional Convolutional Neural Network (CNN)-based super resolution methods to enhance quality. Additional learning is performed for sharpened and blurred image results for further texture analysis. By contrasting each super resolution result and allocating weights through this process, the proposed method achieves improved quality in detailed and smoothed areas of the image. The experimental results of the proposed method, evaluated using the PSNR and SSIM values as quality metrics, show higher results compared to existing algorithms, confirming the enhancement in quality.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.3
• /
• pp.276-283
• /
• 2005

The cooperative production system was proposed as an efficient production system to reduce the ship construction cost and to enhance the competitiveness for small/medium sized shipbuilder in the previous paper. In viewpoint of cooperative production system, the specialization of the FRP ship sizes has already been accomplished to reduce the number of the hull molds by FRP shipbuilders of the Sapjin industrial complex located in Mokpo area in 2003. There also exist lots of effective methods, as a cooperative production system, to cut down the construction cost. In this study, an effective production system in connection with the super structure and outfitting members is proposed such as the standardization of those items and specialized company which intensively produces the super structure and outfitting members at the collectivization area for cooperative work.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2007.04a
• /
• pp.271-274
• /
• 2007

The finite element linear buckling analysis of folded plate structures using adaptive h-refinement methods is presented in this paper. The variable-node flat shell element used in this study possesses the drilling D.O.F. which, in addition to improvement of the element behavior, permits an easy connection to other elements with six degrees of freedom per node. The Box-typed structures can be analyzed using these developed flat shell elements. By introducing the variable node elements some difficulties associated with connecting the different layer patterns, which are common in the adaptive h-refinement on quadrilateral mesh, can be overcome. To obtain better stress field for the error estimation, the super-convergent patch recovery is used. The convergent buckling modes and the critical loads associated with these modes can be obtained.

• Journal of Power Electronics
• /
• v.9 no.4
• /
• pp.575-581
• /
• 2009

In this paper two modes of operating a wound rotor induction machine as a generator at sub-and super-synchronous speeds in wind energy conversion systems are investigated. In the first mode, known as double fed induction generator (DFIG), the rotor circuit is fed from the ac mains via a controlled rectifier and a forced commutated inverter. Adjusting the applied rotor voltage magnitude and phase leads to machine operation as a generator at sub-synchronous speeds. In the second mode, the machine is operated in a slip recovery scheme where the slip energy is fed back to the ac mains via a rectifier and line commutated inverter. This mode is described as double output induction generator (DOIG) leading to increase the efficiency of the wind-to electrical energy conversion system. Simulated results of both modes are presented. Experimental verification of the simulated results are presented for the DOIG mode of operation, showing larger amount of power captured and better power factor when compared to conventional induction generators.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• fall
• /
• pp.106-109
• /
• 2021

본 논문에서는 입력에 따라 합성곱 레이어 간의 잔차 연결을 변화시키는 동적 잔차 연결을 활용해 고해상도 복원 (Super-resolution) 작업을 위한 경량 네트워크를 설계하는 방법을 제안한다. 먼저, 동적 잔차 연결을 입력에 따라 변화시킬 수 있도록 경량화된 (Lightweight) 모듈을 설계하는 방법을 제안한다. 또한 이렇게 설계한 모듈로부터 얻은 잔차 연결에 대한 정보를 토대로 네트워크를 설계하는 방법을 제시한다. 제안된 방법을 통해 설계된 고해상도 복원 작업을 위한 네트워크는 적은 파라미터로도 입력에 따라 적응적으로 네트워크의 구조를 변화시킬 수 있어 효울적으로 다양한 입력 영상을 처리할 수 있다.

• International Journal of High-Rise Buildings
• /
• v.11 no.3
• /
• pp.189-196
• /
• 2022

The practical difficulties of construction will impose many restrictions on the structural design, and the construction method can also provide unexpected ideas for solving design problems. Through the discussion of three issues closely related to construction in the structural design of Wuhan Center, this paper illustrates the importance of in-depth consideration of the construction situations in the structural design stage. The topics of "Connection between Embedded Steel Plates in Steel Plate Composite Shear Wall" and "Connection Joint between Outrigger Truss and Core Wall" are about how to facilitate on-site construction by simplifying and optimizing detail design. The topic of "Adjusting Internal Force Distribution by Optimizing Construction Sequence" is about how to make the construction process a tool for structural design.