• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.300-307
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• 2005

Steel Reinforced Concrete (SRC) composite column has several advantage such as excellent durability, rapid construction, reduction of column section. Due to these aspect, applications of SRC columns to bridge piers are continuously increasing. For the design of relatively large SRC columns for bridge piers, it is necessary to check the current design provisions which were based on small section having higher steel ratio. In this study, seven concrete encased composite columns were fabricated and static tests were performed. Embedded steel members were a H-shape rolled beam and a partially filled steel tube. Based on the test results, the ultimate strength according to section details and local behavior were estimated. For the analysis of inelastic behavior of the SRC column, the cracked section stiffness of the columns was evaluated and compared with calculations. The stiffness of the cracked section showed that 25% of the initial value and this stiffness reduction occurred at 85% of the ultimate load in the experiments.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.485-488
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• 2004

Steel encased composite columns have been used for buildings and piers of bridges. Since column section for pier is relatively larger than that of building columns, economical steel ratio need to be investigated for the required performance. Composite action between concrete and embedded steel sections can be obtained by bonding and friction. However, the behavior. of the column depends on the load introduction mechanism. Compression can be applied to concrete section, steel section and composite section. In this paper, experiments on shear strength of the steel encased composite column were performed to study the effect of confinement by transverse reinforcements, mechanical interlock by holes, and shear connectors. Shear strength obtained from the tests showed considerably higher than the design value. Confinement, mechanical interlock and stud connectors increased the shear strength and these values can be used effectively to obtain composite action of SRC columns.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1132-1143
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• 2008

A single Column/Shaft which extended the pile to the column of the bridge with same diameter has better safety and economical profit, but it usually has larger lateral displacement due to lateral loads such as wind, earthquake, wave, etc. A series of horizontal pile load testing were performed to study the lateral behavior of single column/shaft with varying different free lengths and embedded pile lengths. Eight instrumented test piles were cast-in-placed by bonding strain gauges at certain locations on both faces of the pile to measure bending moment, from two-way loadings. Linear variable differential transformers(LVDTs) were installed to measure the lateral pile displacement. Based on this, it is found that the test single column/shaft with different free lengths shows different failure modes. If the test pile has a longer free length, the failure occurs at the near the ground surface, but the shorter one's failure occurs at the below the ground surface.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.204-206
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• 2005

In this paper, we have designed a Fingerprint Recognition System based on the Embedded LINUX. The fingerprint is captured using the AS-S2 semiconductor sensor. To extract a feature vector we transform the image of t10he fingerprint into a column vector. The image is row-wise filtered with the low-pass filter of the Haar wavelet. The feature vectors of the different fingerprints are compared by computing with the probabilistic neural network the distance between the target feature vector and the stored feature vectors in advance. The system implemented consists of a server PC based on the LINUX and a client based on the Embedded LINUX. The client is a Tynux box-x board using a PXA-255 CPU. The algorithm is simple and fast in computing and comparing the fingerprints.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.12
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• pp.73-79
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• 2009

With the advance of VLSI technology, the capacity and density of memories are rapidly growing. In this paper we proposed MRI (Memory built-in self Repair Imagination zone) as reallocation algorithm. All faulty cells of embedded memory are reallocated into the row and column spare memory. This work implements reallocation algorithm and BISR to verify its design.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.2
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• pp.113-120
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• 2007

With the advance of VLSI technology, the capacity and density of memories is rapidly growing. In this paper we proposed reallocation algorithm. All faulty cell of embedded memory is reallocated into the row and column spare memory. This work implements reallocation algorithm and BISR to verify its design.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.96-97
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• 2014

Green Frame is a column-beam structure built by steel frame joints embedded in the columns and beams. Here, the steel frame embedded in the columns and beams is not a standardized product, instead it needs to be order-produced. The quantity for each steel frame size should be calculated to estimate the quantity of steel frames to be manufactured. However, it is highly time-consuming and requires a lot of effort in calculating the quantity of steel frames, for there are a wide range of steel frame types that are embedded in the columns and beams. To solve this problem, the study proposes an algorithm for calculation of the amount of steel frames with ease and promptness. When a program is developed using the algorithm proposed in the study in connection to the information on precast concrete members prepared in the design phase, it is anticipated that the manpower required as well as the manufacturing time will be decreased.

• International Journal of Concrete Structures and Materials
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• v.18 no.3E
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• pp.151-159
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• 2006

A total of 32 pullout tests were performed for the multiple headed bars relatively deeply embedded in reinforced concrete column-like members. The objective was to determine the minimum embedment depth that was necessary to safely design exterior beam-column joints using headed bars. The variables for the experiment were embedment depth of headed bar, center-to-center distance between adjacent heads, and amount of supplementary reinforcement. Regular strength concrete and grade SD420 reinforcing steel were used. The results of the test the indicated that a headed bar embedment depth of $10d_b$ was not sufficient to have relatively closely installed headed bars develop the pullout strength corresponding to the yield strength. All the experimental variables, influenced the pullout strength. The pullout strength increased with increasing embedment depth and head-to-head distance. It also increased with increasing amount of supplementary reinforcement. For a group of closely-spaced headed bars installed in a beam-column joint, it is recommended to use column ties at least 0.6% by volume, 1% or greater amount of column main bars, and an embedment depth of $13d_b$ or greater simultaneously, to guarantee the pullout strength of individual headed bars over 125% of $f_y$ and ductile load-displacement behavior.

• Steel and Composite Structures
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• v.23 no.4
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• pp.445-452
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• 2017

This study intends to improve the structural details of the anchors in the conventional CFT column-to-foundation connection. To that goal, finite element analysis is conducted with various design variables (number and embedded length of deformed bars, number, aspect ratio, height ratio and thickness ratio of ribs) selected based upon the results of loading test and strength evaluation. The finite element analysis is performed using ABAQUS and the analytical results are validated by comparison with the load-displacement curves obtained through loading test applying axial and transverse loads. The behavioral characteristics of the numerical model according to the selected design variables are verified and the corresponding results are evaluated.

• Steel and Composite Structures
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• v.15 no.3
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• pp.343-355
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• 2013

Shear failure and core concrete crushing at plastic hinge region are the two main failure modes of bridge piers, which can make repair impossible and cause the collapse of bridge. To avoid the two types of failure of pier, a composite pier was proposed, which was formed by embedding high strength concrete filled steel tubular (CFT) column in reinforced concrete (RC) pier. Through cyclic loading tests, the seismic performances of the composite pier were studied. The experimental results show that the CFT column embedded in composite pier can increase the flexural strength, displacement ductility and energy dissipation capacity, and decrease the residual displacement after undergoing large deformation. The analytical analysis is performed to simulate the hysteretic behavior of the composite pier subjected to cyclic loading, and the numerical results agree well with the experimental results. Using the analytical model and time-history analysis method, seismic responses of a continuous girder bridge using composite piers is investigated, and the results show that the bridge using composite piers can resist much stronger earthquake than the bridge using RC piers.