• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.132-141
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• 1995

This study is intended to propose practical but systematic and rational approaches for proof load test and integrity assessment of segmental PC box-girder bridges. The proposed models cover the whole range of field tests and assessment of such as inspections, nondestructive tests, static and dynamic load tests, structural analysis, and integrity assessment for the evaluation of load carrying capacity, serviceability, and durability of PC box-girder bridges. They are applied to a newly constructed precast segmental PC box-girder bridge which is a part of the Seoul interior circuit elevated expressway.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.1-11
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• 1993

Precast/Prestressed concrete segmental bridges with moderate range of span length normally have a constant section height for economic segment manufacturing. Inside sectional dimension is often controlled for design of non-prismatic section between supports when variable stiffness is required. It is usual, in the preliminary design stage, to adopt trial bridge sections by past experience or by approximately estimated member forces. Three bridge models of different member stiffness have been selected to investigate flexural stiffness effects on member forces for preliminary design stage. The selected bridge stiffness has been determined by the flexibility index from review of the practically usable sections.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.35-42
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• 1995

One of the main objectives of this study is to propose a realistic limit state model for reliability-based safety assessment of precast segmental prestressed concrete box girder bridges, considering 1) combined effects of bending, shear and torsional forces, and 2) the difference between transverse reinforcments of box girder. A improved limit state model is derived from a modified interaction equation compared with the Bruno's equation. A Drectional sampling algorithm is used for reliability analysis of the proposed model.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.42-46
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• 1994

본 연구에서는 프리캐스트 PC 세그멘탈 교량 접합부의 전단거동을 파악하기 위하여 전단키 접합부의 전단거동과 전단강도 특성을 실험적으로 연구하였다. 본 연구를 통하여 접합부 형상에 따른 하중-변위 관계, 균열거동, 파괴모드, 전단강도 등을 규명하고, 접합부의 역학적 거동에 영향을 미치는 여러인자들에 대해 분석한다. 또한 이로부터 최적의 접합부 형상을 도출하고, 이에 따른 최적의 접합방식을 검토함으로써 접합부 설계의 지침과 해석의 근거를 제시한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.1-13
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• 1993

In design of prestressed concrete structures, structural analysis is performed normally several times for selection of adequate sectional dimension and tendon amount. Especially for precast segmental multi-span bridges. time consuming structural analysis process due to time dependent material properties and structural system change could be effectively reduced by use of a reduced-span bridge model. 5-span and 3-span bridges are selected as reduced-span models for the 10-span full bridge to investigate the acceptability in practical design. The analytical results of deflection, total moment, statical moment, and ultimate moment of the reduced span-models are compared with those of the 10-span full bridge. Application of the load factors to structural analysis for ultimate moment calculation in prestressed concrete is reviewed and a rational method is proposed.

• Molecules and Cells
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• v.21 no.3
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• pp.436-442
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• 2006

Different proliferation of neuroblast 6-4 (NB6-4) in the thorax and abdomen produces segmental specific expression pattern of several neuroblast marker genes. NB6-4 is divided to form four medialmost cell body glia (MM-CBG) per segment in thorax and two MM-CBG per segment in abdomen. As homeotic genes determine the identities of embryonic segments along the A/P axis, we investigated if temporal and specific expression of homeotic genes affects MM-CBG patterns in thorax and abdomen. A Ubx loss-of-function mutation was found to hardly affect MM-CBG formation, whereas abd-A and Abd-B caused the transformation of abdominal MM-CBG to their thoracic counterparts. On the other hand, gain-of-function mutants of Ubx, abd-A and Abd-B genes reduced the number of thoracic MM-CBG, indicating that thoracic MM-CBG resembled abdominal MM-CBG. However, mutations in Polycomb group (PcG) genes, which are negative transregulators of homeotic genes, did not cause the thoracic to abdominal MM-CBG pattern transformation although the number of MM-CBG in a few percent of embryos were partially reduced or abnormally patterned. Our results indicate that temporal and spatial expression of the homeotic genes is important to determine segmental-specificity of NB6-4 daughter cells along the anterior-posterior (A/P) axis.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.235-244
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• 2011

Failures of segmental bridges have been attributed to the inadequate joint connection techniques, which led to corrosion of the post-tensioned tendons connecting the segmental joints. The principal objective of this study is to evaluate the performances of the in-situ cast joint and epoxy applied shear key joints as a function of shear and ultimate strengths. Furthermore, shear behavior and strength of shear key joints in ultra high performance precasted concrete segmental bridges are experimentally evaluated to understand its shear failure behavior. The test parameters of shear key shape and type, load-displacement relations, cracking behavior, concrete strength, and fracture modes are considered in the study. Also, several parameters which influence the mechanical behavior of the shear key joint are analyzed. Based on the study results, the optimal shear key shape and joint type are proposed for the joint design and analysis guidelines.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1462-1469
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• 2008

The purpose of the study was to confirm what effect HRHDT treatment had on cell extinction by damage of endoplasmic reticulum induced to PC-12 cell damage by glucose deprivation. The study confirmed what effect it had on forming the condition of glucose deprivation within a culture fluid of PC-12 cell and on a nerve cell's survival rates and tested whether HRHDT could prevent extinction of PC-12 cell by glucose deprivation. Also, the study confirmed what effect HRHDT treatment had on the emitted quantity of LDH by glucose deprivation. To examine PC-12 cell's behavioral change under the condition of glucose deprivation and a protective effect of HRHDT on the change, the study observed PC-12 cell's behavioral change with a microscope. Also, the study confirmed density of calcium ion within cells followed by a culture time in the condition of glucose deprivation with FACS and confirmed what effect HRHDT treatment had on the above density of calcium ion within cells. Finally, the study carried out the western blot and confirmed what effect HRHDT treatment had on revelation of GRP 78 and CHOP protein and a segmental type of aspase 12. In this study, HRHDT rescued PC-12 cells from glucose deprivation-induced cell death. HRHDT also prevents the LDH release, Ca++ accumulation, and morphological change, which was associated with the ER stress. Furthermore, HRHDT reduced the expression of ER chaperone (Grp78 and CHOP) proteins by glucose deprivation in PC-12 cells. These results suggest that HRHDT might provide a useful therapeutic strategy in treatment of the neurodegenerative diseases caused by glucose deprivation injuries.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.49-62
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• 1994

An analysis method for the time-dependent nonlinear analysis of segmentally erected planar prestressed concrete cable-stayed bridges was described. To account for the time-dependent effects, load history, creep, shrinkage. aging of concrete and relaxation of prestress were considered. Changes in boundary conditions and loads, installing and removing frame elements, stressing, restressing and removing cables and prestressing tendons were incorporated for modeling segmental erection operations. One typical example on segmentally erected prestressed concrete cable-stayed bridge was presented to illustrate the analysis method. Results of this example show that it is important to follow the development of stresses and deformations at all stages of construction to predict the true response of the bridge through its various load history.

• The Journal of the Acoustical Society of Korea
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• v.14 no.5
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• pp.74-82
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• 1995

This paper is study on the voice dialing using HMM and post processing of the connected digits. HMM algorithm is widely used in the speech recognition with a good result. But, the maximum likelihood estimation of HMM(Hidden Markov Model) training in the speech recognition does not lead to values which maximize recognition rate. To solve the problem, we applied the post processing to segmental K-means procedure are in the recognition experiment. Korea connected digits are influenced by the prolongation more than English connected digits. To decrease the segmentation error in the level building algorithm some word models which can be produced by the prolongation are added. Some rules for the added models are applied to the recognition result and it is updated. The recognition system was implemented with DSP board having a TMS320C30 processor and IBM PC. The reference patterns were made by 3 male speakers in the noisy laboratory. The recognition experiment was performed for 21 sort of telephone number, 252 data. The recognition rate was $6\%$ in the speaker dependent, and $80.5\%$ in the speaker independent recognition test.