• Proceedings of the Korea Association of Information Systems Conference
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• 2001.12a
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• pp.413-426
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• 2001

본 연구는 첫째, 정보통신기술의 발달이 시각장애인 복지 증진에 미칠 수 있는 가능성에 대한 이론적인 부분을 고찰하였다. 둘째, 우리나라 시각장애인 정보화의 문제점과 해결책을 도출하였고 셋째, 시각장애 사용자를 위한 전자상거래 인터페이스 디자인의 분석 및 설계를 통해 전자상거래에서 시각장애 사용자들이 큰 제약없이 사용할 수 있는 방안을 제시하고자 한다. 현재 시각장애인들의 웹 사용을 보면 시각장애 전용 S/W의 보조 하에 사용을 하고 있다. 그러한 보조 도구의 실정에 맞도록 텍스트 버전 및 Non-Frame버전, Alt-Text 옵션, 캡션 등을 넣어 접근성을 확보하고 인터넷을 큰 제약을 받지않고 이용할 수 있도록 웹 페이지의 설계가 필요한 실정이다. 이를 위하여 먼저 시각장애에 대한 개념과 원인 및 종류 그리고 특성을 통해 시각장애인에 대한 이론적 배경을 파악하였다. 그리고 시각장애인의 정보화 환경과 이용 현황과 시각장애인의 정보 접근을 제도적, 기기 및 소프트웨어 개발 측면에서 분석을 하였고, 장애인을 위한 정보통신기술 중 대표적인 사례를 검토해 보았다. 다음으로 국내외의 대표적인 전자상거래 사이트에서의 인터페이스를 화면구성(Layout), 텍스트(Text), 그래픽(Graphic), 멀티미디어(MultiMedia) 측면에서 분석을 하였다. 분석한 내용을 바탕으로 시각장애 사용자의 입력(User Input) 부분을 고려한 인터페이스 방향을 제시하고 프로토타입을 개발하여 시험 대상 사이트와의 만족도를 시각장애 사용자를 통해 비교 ·분석하였다. 결론부분에서는 정보불평등을 해소하고, 정보통신기술이 장애인의 복지향상에 기여하도록 하기 위해 전자상거래 싸이트에서의 시각 장애인들을 위한 방향을 제시하고자 한다.박의 표현, 등록 및 색인방법 (c) 공급 선박의 분류와 표현 방법 (d) 에이전트의 정보 수집을 위한 메시지 표현 방법 (e) 수집된 선박정보의 데이터베이스 저장 표현방법 (f) 요구 선박을 찾아주는 정보제공 서비스가 요구된다.동을 보여 조사대상 5호분, 6호분, 7호분, 중 가장 심한 거동을 보이고 있다. 이는 고분 벽돌의 깨짐이 6호분이 가장 심하다는 사실과 무관하지 않은 것으로 판단된다. 봉분내부의 토양층구조에 대한 지오레이다 영상단면을 분석한 결과 무령왕릉 연도상부의 누수지방지층이 심하게 균열되어 있음을 발견하였다. 이 곳은 고분내부로 직접누수가 발생하는 곳이다. 직접누수와 지하수 형태로 유입된 침투수는 고분군 주위의 지반의 함수비를 증가시켜 지반의 지지력을 약화시키고 또한 고분내로 서서히 유입되어 고분내부의 습도를 100%로 유지시키는 주된 원인이다. 이러한 높은 습도는 고분내의 남조류의 번식을 가져왔으며 남조류의 번식은 현재 6호분이 가장 심각하고 7호분이 우려되는 수준이며 5호분은 문제가 없는 것으로 판단된다. 이와 같이 고분군의 발굴후 인위적인 환경변화와 지속적인 강우침투 및 배수 불량의 영향은 고분군의 안정성에 상당한 위험을 초래하였으며, 현 상태는 각 고분에 대한 보강이 불가피한 것으로 판단된다. 고분 벽돌의 깨짐, 고분 벽체의 거동, 조류의 서식등을 포함하여 송산리 고분군에서 발생되고 있는 보존상의 제반 문제점들을 일차적으로 누수 및 침투수에 의한 결과이다. 그러므로 무엇보다도 고분군 내부 및 고분 주변으로의 강우 및 지하수 침투를 막는 차수 대책이 시급한 것으로 판단된다. 또한 이미 발생한 변위가 더 이상 진행되지 않도록 하중을 경감하고 토압의 균형을 이루는 보강대책이 시급한 실정이다. 고분군

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.3
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• pp.75-84
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• 1991

When we construct the earth structures such as embankments, on soft ground which are consisted of thick marine silty clay, the foundations deform due to consolidation and creep. For the stabilization of the earth structures constructed on soft foundations, we usually uses the mattress and they play an important role in increasing an ultimate bearing capacity by the dispersion of load of embankment. The purpose of this paper was to predict rationally a long term deformation of earth structures and to contribute to embankment design and maintenance. We determined a rheological model of marine clay from experimental data, and developed a computer program using the chosen model and found out the long term behavior of embankment. The results of this paper are as follows: 1. The developed program can analyze simultaneously consolidation and creep. 2. From the results of creep test, the rheological model of marine silty clay can be represented by the Vyalov model. 3. The displacement of embankment on reinforced foundation were smaller than those of the unreinforced foundation in showing the effects of geotextiles on foundation deformations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1161-1167
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• 2016

In this study, an attempt was made to conduct a case study on the development of ground expansive displacement due to lack of bearing capacity of original ground in spite of applying reinforcement treatments that intended to enhance the stability of big size high-speed rail tunnel in large fault zone. For the purpose of this, in-situ measurements made in the middle of excavation stage were analyzed in order to characterize ground responses and numerical analysis was performed to evaluate the effectiveness of reinforcement technique such as elephant foot method applied for this site via comparing with field monitoring measurements. In addition, further numerical studies were carried out to investigate the influence of leg pile installation angle and length, which is one of types of elephant foot method. The results revealed that the optimum condition for the leg pile installation is to maintain 45 degree of installation angle along with 6 meter of embedment depth.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.67-73
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• 2017

Recently, the demand for large diameter piles has been rapidly increased in order to secure the allowable bearing capacity of pile foundation due to the increase of large structures such as high rise buildings. In this study, to improve the shear capacity of a conventional PHC pile, a large diameter composite PHC pile strengthened by in-filled concrete and shear reinforcement was manufactured. All the piles were tested according to the shear strength test method of Korean Standard. As a result of the shear test, the F-type piles which are produced without shear reinforcement occurred abrupt horizontal cracks after flexural and inclined shear cracks occurred. On the contrary, the FT-type piles which are produced with shear reinforcement exhibited stable flexural and inclined shear cracks uniformly over the entire pile without abrupt horizontal cracks. Furthermore, the maximum load of the large diameter composite PHC pile improved to 2.9 times in the F series, and more than 3.3 times in the FT series compared to the conventional PHC pile. This result indicated that FT-type piles had excellent composite behavior due to the shear reinforcement and effectively prevented the unstable growth of inclined shear cracks.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.260-270
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• 1998

The field tests were performed to suggest the rational method for stability evaluation of soft clay. The behavior of settlement-displacement obtained by field monitoring system was to compare and analyze the results of the observationed method, and to investigate the complex behavior of soft clay with filling height. The results of this study are summarized as follows. 1. The horizontal displacement was suddenly increased when physical properties of soft clay showed maximum values and the part of the turning point. The values of these properties were available to the fundamental data for stability evaluation. The shear deformation appeared that difference of the horizontal displacement was maximum values. 2. Although the stability of embankment by step filling showed the unstable part over the failure standard line, the embankment was confirmed stable. So the evaluation of the stability of embankment is reasonable to use the inclination of curve than failure standard line. 3. The horizontal displacement and relative settlement were increased as same ratio at improvement ground. Estimation of shear deformation using Terzaghi's modified bearing capacity should consider the relations of embankment load and undrained shear strength at nonimprovement ground, and minimum safety factor is recommended to use larger than 1.2. 4. Excess pore water pressure was increased with increasing of filling height and decreased with maintain the filling height. The embankment was unstable when filling height was exceed the evaluation standard line, and the behavior of excess pore water pressure and horizontal displacement could use as a standard of judgement of the filling velocity control because their behavior were agree with each other.

• Journal of the Korean Geosynthetics Society
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• v.16 no.2
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• pp.35-45
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• 2017

Gravel compaction pile (GCP) is widely used as it increases the bearing capacity of soft ground and reduces the consolidation settlement. Stress concentration ratio for design is dependent on the area replacement, surcharge pressure, depth and penetration rate. However, a range of stress concentration ratio obtained through field, laboratory experiments and numerical analysis is large. But since the main objective of the study is to evaluate the stress concentration ratio and settlement for both area replacement ratio and penetration rate through numerical analysis. Numerical analysis using the finite element program ABAQUS 6.12-4 has been performed for the composite ground with GCP. As a result, the stress concentration ratio at the points except for the point of top is in the range of 1.21-5.36, 1.19-5.45, 2.16-5.60 for 60%, 80% and 100% penetration, respectively. In general, as the penetration rate and area replacement ratio increases, the stress concentration ratio tends to increase.

• Journal of the Korean Geotechnical Society
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• v.32 no.9
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• pp.37-50
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• 2016

Gravel compaction pile (GCP) is widely used as it increases the bearing capacity of soft ground and reduces the consolidation settlement. Stress concentration ratio for GCP design is dependent on the area replacement, surcharge pressure and depth. However, a range of stress concentration ratio obtained through field, laboratory experiments and numerical analysis is large. Little study has been done on the stress concentration ratio for the mixing ratio of gravel and sand. The main objective of the study is to evaluate the stress concentration ratio for both area replacement ratio and mixing ratio through literature review and numerical analysis. Numerical analysis using the finite element program ABAQUS 6.12-4 has been performed for the composite ground with GCP. The excess pore water pressure and stress concentration ratio of composite ground have been analyzed for both the area replacement ratio and the mixing ratio. Based on the previous research results, a range of stress concentration ratio obtained from the field tests, laboratory tests, numerical analysis on the GCP studies is found to be 1.7-3.2, 2.0-7.5 and 2.0-6.5, respectively. Based on the numerical analysis results, as the area replacement ratio increases, the stress concentration ratio increases up to 30% and then decreases at 40%. Also, the stress concentration ratio tends to increase up to 70:30 and then to decrease after 60:40.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.391-400
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• 2019

In the case of fire, a structure loses its original stiffness due to the temperature rise, and the load bearing capacity decreases. The loss of structural strength increases with increasing fire time of the structure. To prevent the collapse of buildings, it is very important to understand whether or not the members are damaged. On the other hand, there is insufficient data to be a guideline for diagnosing and evaluating the residual strength of the members in Korea. Therefore, this study examined the resistance performance by Finite-Element-Analysis of composite beams, which are composite structures among structural members. Composite beam modeling was carried out based on the model used in the Electrical Penetration Room (EPR) in cooperation with KEPCO. The heat transfer analysis and structural analysis of the critical phase were performed using ANSYS, a finite element analysis program. ANSYS was used to perform heat transfer analysis and structural analysis at the static analysis. To analyze the residual performance, the temperature distribution of the composite beam and the maximum displacement result of the heat-affected structure analysis were derived and the experimental data and the structural analysis result data were compared and analyzed.

• Journal of the Korean Geotechnical Society
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• v.22 no.9
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• pp.61-68
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• 2006

Recently the large scale civil engineering projects are being implemented by reclaiming the sea or utilizing seashore and river embankment areas. The reclaimed land and utilized seashore are mostly soft ground that doesn't have sufficient bearing capacity. This soft ground consists of fine-grained soil such as clayey and silty soils or large void soil like peat or loose sand. It has high ground water table and it may cause the failure and crock of building foundation by uplift pressure and ground water leakage. In this study, the permittivity and the transmissivity were evaluated with the applied normal pressure in the laboratory. The laboratory model tests were conducted by utilizing geocomposite drainage system for draining the water out to release the uplift pressure. The soil used in the laboratory drainage test was dredged soil from the reclaimed land where uplift pressure problems can arise in soil condition. Geocomposite drainage system was installed at the bottom of apparatus and dredged soil was layered with compaction. Subsequently the water pressure was supplied from the top of specimen and the quantities of drainage and the pore water pressure were measured at each step water pressure. The results of laboratory measurements were compared with theoretical values. For the evaluation of propriety of laboratory drainage test, 2-D finite elements analysis that can analyze the distribution and the transferring of pore water pressure was conducted and compared with laboratory test results.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.6
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• pp.128-137
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• 2023

In this study, the bearing pressure on the rubble mound of a gravity-based harbor structure with an arbitrarily shaped bottom was targeted. Assuming that the bottom of the structure is a rigid body, the rubble mound was modeled as a linear spring uniformly distributed on the bottom that resists compression only, and the bearing pressure evaluation formula was derived. It was confirmed that there were no errors in the derivation process by showing that when the bottom was square, the derived equation was converted to the equation used in the design. In addition, the validity of the derived equation was proven by examining the behavior and convergence value of the bearing pressure when an arbitrarily shaped bottom converges into a square one. In order to examine the adequacy of the method used in the current design, the end bearing pressure for the pre-designed breakwater cross-section was calculated and compared with the values in the design document. As a result, it was shown that the method used for design was not appropriate as it gave unsafe results. In particular, the difference was larger when the eccentricity of the vertical load was large, such as in the case of extreme design conditions.