• Journal of Chest Surgery
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• v.23 no.6
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• pp.1280-1287
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• 1990

A seven month old female infant with isolated ventricular inversion and anatomically corrected malposition of the great arteries in situs solitus, associated with ventricular septal defect, patent ductus arteriosus, right-sided juxtaposition of left atrial appendage, is reported. The patient showed usual atrial arrangement with somewhat superoinferior relation, a discordant atrioventricular connection, and a concordant ventriculoarterial connection with aorta in the right-sided position. A normal sized left atrium was connected to the left superiorly positioned morphologic right ventricle through a tricuspid valve, which crossed the left ventricular outflow tract anteriorly. Well developed bilateral[subaortic and sub-pulmonary]conus was documented at operative field. successful surgical repair was done by performing the Senning procedure and by closing the ventricular sepal defect with a patch through the right ventriculotomy. The infant’s postoperative course was uneventful with normal sinus rhythm. Postoperative cardiac catheterization revealed no hemodynamic obstruction or residual shunt.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.469-472
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• 2008

In general, structures in service gradually lose original performance according to time due to initial defects in design and construction, or exposure to unfavorable external conditions such as repeated loading or deteriorating environment, and in extreme cases, may collapse in large disaster. Therefore, in order to maintain the serviceability of structures at optimal level, advanced structure measuring system which can inform optimal time point and method of maintenance is required in addition to accurate prediction of residual life the structure by periodic inspection. To guarantee the safety level of bridge structure and to prevent from disaster, the integration of safety network for bridge structures are needed. Therefore in this study, to enhance the effectiveness of safety network for bridge, the connection methodologies between safety network and pre-installed bridge monitoring system are investigated.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.540-543
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• 2020

기존의 초해상도 딥러닝 기법은 모델의 깊이가 깊어지면서, 좋은 성능을 내지만 점점 더 복잡해지고 있고, 실제로 사용하는데 있어 많은 시간을 요구한다. 이를 해결하기 위해, 우리는 딥러닝 모델의 가중치를 양자화 하여 추론시간을 줄이고자 한다. 초해상도 모델은 feature extraction, non-linear mapping, reconstruction 세 부분으로 나누어져 있으며, 레이어 사이에 많은 skip-connection 이 존재하는 특징이 있다. 따라서 양자화 시 최종 성능 하락에 미치는 영향력이 레이어 별로 다르며, 이를 감안하여 강화학습으로 레이어 별 최적 bit 를 찾아 성능 하락을 최소화한다. 본 논문에서는 Skip-connection 이 많이 존재하는 MSRN 을 사용하였으며, 결과에서 feature extraction, reconstruction 부분과 블록 내 특정 위치의 레이어가 항상 높은 bit 를 가짐을 알 수 있다. 기존에 영상 분류에 한정되어 사용되었던 혼합 bit 양자화를 사용하여 초해상도 딥러닝 기법의 모델 사이즈를 줄인 최초의 논문이며, 제안 방법은 모바일 등 제한된 환경에 적용 가능할 것으로 생각된다.

• Steel and Composite Structures
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• v.18 no.4
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• pp.1045-1062
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• 2015

Concrete-filled circular t steel tubular joints (CFSTJs) in practice are frequently subjected to fluctuated loadings caused by wind, earthquake and so on. As fatigue crack is sensitive to such cyclic loadings, assessment on performance of CFSTJs with crack-like defect attracts more concerns because both high stress concentration at the brace/chord intersection and welding residual stresses along weld toe cause the materials in the region around the intersection to be more brittle. Once crack initiates and propagates along the weld toe, tri-axial stresses in high gradient around the crack front exist, which may bring brittle fracture failure. Additionally, the stiffness and the load carrying capacity of the CFSTJs with crack may decrease due to the weakened connection at the intersection. To study the behaviour of CFSTJs with initial crack, experimental tests have been carried out on three full-scale CFCST T-joints with same configuration. The three specimens include one uncracked joint and two corresponding cracked joints. Load-displacement and load-deformation curves, failure mode and crack propagation are obtained from the experiment measurement. According to the experimental results, it can be found that he load carrying capacity of the cracked joints is decreased by more than 10% compared with the uncracked joint. The effect of crack depth on the load carrying capacity of CFCST T-joints seems to be slight. The failure mode of the cracked CFCST T-joints represents as plastic yielding rather than brittle fracture through experimental observation.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.12
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• pp.11-20
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• 2018

The purpose of this study is to investigate the seismic performance of exposed column-base plate strong-axis connections for small-sized steel buildings. Even though the seismic design for small-sized buildings became mandatory since Dec.2017, the arbitrary connection details in steel structure have been applied at the construction site, which is considered to be very insufficient to secure structural safety and stability considering the increased seismic risk. Therefore, a series of experimental test programs had been carried out to develop enhanced connection details in order to ensue the adequate seismic safety of small buildings. The hysteretic behavior of the exposed column-base plate connections commonly used in Korea seem to be very pure poor due to the "Rocking" phenomena between anchor plate and concrete by the residual plastic deformation of anchor bolts. A series of hysteretic tests were conducted to find the solution to overcome the "Rocking" phenomena of the exposed column-base plate connections, finally the stable seismic behavior was obtained by uisng at least 8 anchor bolts with good bonding strength to the protptype specimen.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5A
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• pp.873-880
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• 2006

PSC composite bridge with precast decks which was designed by the proposed horizontal shear equation was fabricated. Fatigue test was performed to evaluate the endurance of shear connection and the behavior of PSC composite bridge. After all the fatigue loading were applied, no crack and no residual slip were occurred. The flexural stiffness of PSC composite bridge was maintained the initial value, and demage of shear connection was not occurred. To verify the applicability of horizontal shear equation and shear connection detail and to evaluate the strength of PSC composite bridges, static test was also executed. PSC composite bridges with precast decks had 2.08 safety factor which was the ratio of crack to serviceability load and showed ductile behavior after ultimate load. Test results showed that the proposed design equation of the shear connection gave reasonable horizontal shear connection design. Fast and easy construction would be achieved using the suggested precast system.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.110-119
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• 2016

Purpose: This study is aimed to assess changes of stress distribution dependent on different connection lengths and placement of the fixture top relative to the ridge crest. Materials and methods: The internal-conical connection implant which has a hexagonal anti-rotation index was used for FEM analysis on stress distribution in accordance with connection length of fixture-abutment. Different connection lengths of 2.5 mm, 3.5 mm, and 4.5 mm were designed respectively with the top of the fixture flush with residual ridge crest level, or 2 mm above. Therefore, a total of 6 models were made for the FEM analysis. The load was 170 N and 30-degree tilted. Results: In all cases, the maximum von Mises stress was located adjacent to the top portion of the fixture and ridge crest in the bone. The longer the connection length was, the lower the maximum von Mises stress was in the fixture, abutment, screw and bone. The reduction rate of the maximum von Mises stress depending on increased connection length was greater in the case of the fixture top at 2 mm above the ridge crest versus flush with the ridge crest. Conclusion: It was found that the longer the connection length, the lower the maximum von Mises stress appears. Furthermore, it will help prevent mechanical or biological complications of implants.

• Journal of KIISE
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• v.45 no.1
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• pp.94-98
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• 2018

We propose Wide Inception ResNet (WIR Net) an optimized neural network architecture as a real-time semantic segmentation method for autonomous driving. The neural network architecture consists of an encoder that extracts features by applying a residual connection and inception module, and a decoder that increases the resolution by using transposed convolution and a low layer feature map. We also improved the performance by applying an ELU activation function and optimized the neural network by reducing the number of layers and increasing the number of filters. The performance evaluations used an NVIDIA Geforce GTX 1080 and TX1 boards to assess the class and category IoU for cityscapes data in the driving environment. The experimental results show that the accuracy of class IoU 53.4, category IoU 81.8 and the execution speed of $640{\times}360$, $720{\times}480$ resolution image processing 17.8fps and 13.0fps on TX1 board.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.6
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• pp.679-687
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• 2008

The fatigue life of ship structure under cyclic loading condition is made up of crack initiation and propagation stages. For a welding member in ship structure, the fatigue crack propagation life is more important than the fatigue crack initiation life. To calculate precisely the fatigue crack propagation life at the critical welding location, the knowledge of the residual stress sensitivity on the fatigue strength is necessary. In this study, thermo elastic-plastic analysis was conducted in order to examine the effect of residual stress on the fatigue crack propagation life. Also the fatigue crack propagation lives considering residual stress were calculated using fatigue crack growth code, AFGROW, on the basis of fracture mechanics. AFGROW is widely used for fatigue crack growth predictions under constant and variable amplitude loading. The reliability of AFGROW on the fatigue of ship structure was confirmed by the comparison of the estimated results with the fatigue propagation test results.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.06a
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• pp.35-46
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• 1996

The powder forging process offers beneficial material utilization as well as the minimization of finishing operations over that of conventionally forged rods. In the present work, the sintering behavior of Fe-2Cu-0.6C-0.35MnS, optimum preform design and forgeability of various forging conditions were investigated. This data were generated using a newly proposed sub-scaled con-rod specimen developed specifically to simulate the powder forging process. The results of present work, powder perform is so difficult to flow material into die cavity and mass flow has no effect on improving the strength. And, applied force to increase density of the specimen flowed material is greater than that of all repessing mode. On the contrary, the specimen flowed material became increased hardness of inside in contrast with all repressing mode, but the tensile strength were decreased with residual porosity in surface. Due to material flow characteristic of powder preform, the section of lower density in powder preform became also lower density in forged con-rod. So, preform design is very important in manufacturing powder forged connecting rod.