• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.194-199
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• 2001

Lap splice in plastic hinge region is inevitable because of due to constructional joint between footing and column. R/C Circular columns with lap-splice in plastic hinge region are widely used in Korean highway bridges. In addition, these columns which constructed before the seismic design code have a number of structural deficiencies. It is, however, believed that there are not many experimental research works for nonlinear behavior of these columns subjected to earthquake motions. The object of this research is to evaluate the seismic performance of existing circular reinforced concrete bridge piers by the Quasi-static test. Existing reinforced concrete bridge piers were moderate seismically designed in accordance with the conventional provisions of Korea Highway Design Specification. This study has been performed to verify the effect of lap spliced longitudinal steel, confinement steel type and confinement steel ratio far the seismic behavior of reinforced concrete bridge piers. Quasi-static test has been done to investigate the physical seismic performance of RC bridge piers, such as displacement ductility, energy absorption, strength degradation etc.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.119-124
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• 2003

An effective grafting method for jujube nursery trees was developed to shorten the operation time, improve the percentage of "takes" and shoot emergence, and form the better graft union. Out of 7 grafting methods the splice, modified scion Ono graft and the bark graft showed relatively short operation time during the grafting operation comparing to the modified rootstock Ono graft or the chip budding. Among these methods, the bark graft demonstrated 100% "takes", but the modified scion Ono graft or the standard Ono graft showed 58.3% of "takes". The percentages of the vegetative shoot emergence were 100% fir the bark graft, 70% f3r the modified scion Ono graft and lower emergence percent for the rest grafting methods. The union tissue formation for the modified scion Ono graft, the bark graft, or the whip-and-tongue graft was significantly larger than the standard Ono graft or the splice graft. In a close examination of the cross sectional areas of the graft union formation through the microscope, the bark graft was superior, the standard Ono graft was inferior and rest of the grafting methods were intermediate.ing methods were intermediate.

• Structural Monitoring and Maintenance
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• v.1 no.3
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• pp.273-292
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• 2014

The effectiveness of a retrofitting method for concrete columns with particular weaknesses is experimentally evaluated and presented in this paper. Structural deficiencies namely the inadequacy of transverse reinforcement and short length of lap splices are very common in columns found in structures built prior to the 1960s and 1970s. Recent earthquakes worldwide have caused severe damages and collapses of these structures. Nevertheless, the importance of improving the load transfer capacity between the deficiently lap-spliced bars is usually underestimated during the strengthening procedures applied in old buildings, though critical for the safety of the residents' lives. Thus, the seismic performance of the enhanced columns is frequently overestimated. The retrofitting approach presented herein involves reinforced concrete jacketing of the column sub-assemblages and welding of the lap-spliced bars to prevent the splice failure and conform to the provisions of modern design Codes. The cyclic lateral loading response of poorly confined original column specimens with insufficient lap splices and the seismic behavior of the retrofitted columns are compared. Test results clearly demonstrate that the retrofitting procedure followed is an effective way of significantly improving the seismic performance of substandard columns found in old buildings.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.123-126
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• 2011

최근 전투체계는 동시에 다수의 장비들 사이에 실시간으로 데이터를 전달해야 하는데, 이러한 특성을 만족하는 통신 미들웨어로서 OMG (Object Management Group)에서 정의한 데이터 분배 서비스 (DDS ; Data Distribution Service)가 적합하다. 이를 구현한 DDS 시스템에는 RTI의 NDDS, PrismTech의 OpenSplice, 충남대학교의 ReTicom 등이 있다. 이 중 NDDS와 OpenSplice는 데이터의 영속성을 지원하지만 ReTicom에서는 영속성을 아직 지원하지 못한다. 이를 해결함과 동시에 실시간성을 보장하기 위해서 ReTicom은 메인 메모리 기반의 객체 관계형 데이터베이스를 사용하여 구현중이다. 이를 위해서는 DDS의 객체 모델 데이터를 정의하는 IDL과 객체 관계형 데이터베이스의 데이터 타입 및 구조 등이 동일하지 않기 때문에 IDL과 객체 관계형 데이터베이스간의 데이터 타입 및 구조를 변환하는 메타 모델 변환 방법이 제공되어야 한다. 본 논문에서는 이러한 메타 모델 변환 방법을 해결하고자 IDL을 구조파악이 쉬운 XML 스키마로 변환 후 이를 객체 관계형 데이터베이스의 데이터 타입 및 구조 형태로 변환 해주는 방법을 제안한다.

• Korean Journal of Optics and Photonics
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• v.12 no.4
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• pp.289-293
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• 2001

A metal capillary splice fiber-optic sensor was fabricated for use as an intensity-based macro-bending sensor. As the radius of curvature due to the macro-bending decreases, the angular misalignment of the fiber ends inside the metal capillary increases, i.e., the coupling efficiency of the fiber splice is reduced. Thus, macro-bending can be detected by the measurement of the reduction of transmitted power. The detectable range of macro-bending. was measured approximately from 20 mm to 85 mm. The center wavelengths of the fiber Bragg gratings are 1543.3 nm and 1549.5 nm, respectively. The maximum bending loss of this sensor was measured about -11.92 dB. Using this metal capillary spliced fiber sensor and fiber Bragg gratings, macro-bending detection has been demonstrated, and it is shown to have potential for multi-point macro-bending sensors. nsors.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.79-88
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• 2012

The purpose of this study is to evaluate the stiffness of the mechanical sleeve reinforcement splices filling high-strength mortar under monotonic loading. For this objective, we analyzed and compared the previous test data of 189 actual-sized mortar-filled sleeve bar splices specimens, including the reinforcing bar splices prepared and tested by the author. The paper results indicated that the minimum values of compressive strength of mortar($f_g$) multiplied by the ratio of reinforcement development length to bar diameter(L/d) were suggested for holding the stiffness of the mortar-filled sleeve reinforcement splices required in AIJ code.

• Structural Engineering and Mechanics
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• v.17 no.1
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• pp.99-112
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• 2004

It is known that lap splices in the longitudinal reinforcement of reinforced concrete (RC) bridge columns are not desirable for seismic performance, but it is sometimes unavoidable. Lap splices were practically located in the potential plastic hinge region of most bridge columns that were constructed before the 1992 seismic design provisions of the Korea Bridge Design Specification. The objective of this research is to evaluate the seismic performance of reinforced concrete (RC) bridge piers with lap splicing of longitudinal reinforcement in the plastic hinge region, to develop an enhancement scheme for their seismic capacity by retrofitting with glassfiber sheets, and to assess a damage of bridge columns subjected to seismic loadings for the development of rational seismic design provisions in low or moderate seismicity region. Nine (9) test specimens with an aspect ratio of 4 were made with three confinement ratios and three types of lap splice. Quasi-static tests were conducted in a displacement-controlled way under three different axial loads. A significant reduction of displacement ductility was observed for test columns with lap splices of longitudinal reinforcements, whose displacement ductility could be greatly improved by externally wrapping with glassfiber sheets in the plastic hinge region. A damage of the limited ductile specimen was assessed to be relatively small.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.113-119
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• 2008

The World Wide Web is a dynamic collection of pages that includes a huge number of hyperlinks and huge volumes of usage informations. The resulting growth in online information combined with the almost unstructured web data necessitates the development of powerful web data mining tools. Recently, a number of approaches have been developed for dealing with specific aspects of web usage mining for the purpose of automatically discovering user profiles. We analyze sequence data, such as web-logs, protein sequences, and retail transactions. In our approach, we propose the clustering algorithm for sequence data using rough set theory. We present a simple example and experimental results using a splice dataset and synthetic datasets.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.180-188
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• 2011

Recently a number of researches about mechanical splice have been studied to apply on a large diameter reinforcing steel bars of spliced sleeves. In this study the structural performance of large diameter reinforcing bars with spliced sleeves was evaluated. For the application of nuclear power plant structures, two different types of existing splices with #11, 14, 18 rebars were fabricated and static and dynamic test were performed on the basis of ASME SEC III DIV.2CC-4330.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.263-270
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• 2003

Before the implementation of the 1992 seismic design provisions in Korea, longitudinal steels of RC bridge piers were practically lap-spliced in the plastic hinge region. Experimental investigation was made to evaluate the seismic performance of RC bridge pier specimens in a flexure/shear mode. Six circular test specimens in an aspect ratio of 2.5 (600mm in diameter) were made with test parameters confinement ratio, lap splices, and retrofit FRP materials. They were damaged under a series of artificial earthquakes with 0.22g PGA, being compatible in Korean peninsula, through the pseudo-dynamic test. Probable damages were assessed by the Park and Ang damage index. Approximate 0.1 and 0.3 damage indices were obtained for RC specimens without lap splice and with lap splice, respectively. Directly after the pseudo-dynamic test, damaged test columns were laterally actuated under inelastic reversal cyclic loadings simultaneously under a constant axial load. Through curvature measurements, residual seismic performance was evaluated for test specimens. Test results show that RC pier specimens with lap-spliced appeared to fail at low ductility, but significant improvement was obtained for the ductility of these specimens if externally wrapped with FRP.