• Title/Summary/Keyword: Bridge foundation

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Addressing Mobile Agent Security through Agent Collaboration

  • Jean, Evens;Jiao, Yu;Hurson, Ali-R.
    • Journal of Information Processing Systems
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    • v.3 no.2
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    • pp.43-53
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    • 2007
  • The use of agent paradigm in today's applications is hampered by the security concerns of agents and hosts alike. The agents require the presence of a secure and trusted execution environment; while hosts aim at preventing the execution of potentially malicious code. In general, hosts support the migration of agents through the provision of an agent server and managing the activities of arriving agents on the host. Numerous studies have been conducted to address the security concerns present in the mobile agent paradigm with a strong focus on the theoretical aspect of the problem. Various proposals in Intrusion Detection Systems aim at securing hosts in traditional client-server execution environments. The use of such proposals to address the security of agent hosts is not desirable since migrating agents typically execute on hosts as a separate thread of the agent server process. Agent servers are open to the execution of virtually any migrating agent; thus the intent or tasks of such agents cannot be known a priori. It is also conceivable that migrating agents may wish to hide their intentions from agent servers. In light of these observations, this work attempts to bridge the gap from theory to practice by analyzing the security mechanisms available in Aglet. We lay the foundation for implementation of application specific protocols dotted with access control, secured communication and ability to detect tampering of agent data. As agents exists in a distributed environment, our proposal also introduces a novel security framework to address the security concerns of hosts through collaboration and pattern matching even in the presence of differing views of the system. The introduced framework has been implemented on the Aglet platform and evaluated in terms of accuracy, false positive, and false negative rates along with its performance strain on the system.

Seismic Analysis for Multi-pile Concrete Foundation in 5MW Class Offshore Wind Turbine (5MW 해상풍력타워를 위한 콘크리트 지지구조물의 내진해석)

  • Kim, Woo Seok;Jeong, Yuseok;Kim, Kidu;Kim, Kyeong Jin;Lee, Jae Ha
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.3
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    • pp.209-218
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    • 2016
  • Recently, Wind-turbine electronic generator become popular. Wind-Turbine is free to cost for purchase and noise problem. For this reason, trend is shifting from Wind-turbine on land to offshore. Research and Development for offshore Wind-turbine has been conducted by various research institution. However, There is no solid design code for offshore Wind-turbine even in domestic as well as foreign. In this paper, conduct seismic analysis and compare results using design codes Korea Bridge Design Codes, Korea Harbor and Marina Design Codes, and DNV OS. Time-History analysis conducted for checking time dependent effect. The Added-Mass Method applied to consider water-structure effects and compared for w/ water and w/o water condition.

3D imaging of fracture aperture density distribution for the design and assessment of grouting works (절리 암반내 그라우팅 설계 및 성과 판단을 위한 절리틈새 밀도 분포의 3차원 영상화 연구)

  • Kim, Jung-Yul;Kim, Yoo-Sung;Nam, Ji-Yeon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.113-120
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    • 2004
  • Grouting works in fractured rocks have been performed to reinforce the underground and/or to block ground water flow at the foundation site of dam, bridge and so on. For the efficient grouting design, a prior knowledge of the fracture pattern of underground area to be grouted in very important. For the practical use, aperture sizes of open fractures that will be filled up with grouting materials will be kind of valuable information. Thus, the main purpose of this study is to develop a new technique (so called "GenFT") enable to form a three dimensional image of fracture aperture density distribution from Televiewer data. For this, the study is to focus on dealing with (1) estimating aperture size of each fracture automatically from Televiewer time image, (2) mapping extension of fracture planes on a given section, (3) evaluating aperture density distribution on the section by using both aperture size and fracture face mapping result of each fracture, (4) developing an algorithm that can transfer the previous results to any arbitrary(vertical and/or horizontal) section around the borehole. Since 3D imaging means "a strategy used to form an image of arbitrarily subdivided 2D sections with aperture density distribution", it will help avoid ambiguities of fracture pattern interpretation and hence will be of practical use not only for the design and assessment of grouting works but also for various engineering works. Examples of fields experiments are illustrated. It would seem that this technique might lead to reflecting future trend in underground survey.

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Experimental Evaluation of Reserve Capacities for Connection Details between Steel Pipe Pile and Concrete Footing of Type-B (Type-B방식의 강관말뚝과 확대기초 연결부 상세에 따른 보유내력의 실험적 평가)

  • Han, Sang-Hoon;Hong, Ki-Nam;Kwon, Yong-Kil
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.1
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    • pp.183-192
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    • 2008
  • Generally, application of steel pipe pile as deep foundation member needs special requirement for the connection method between steel pipe pile and concrete footing. Even though two types of connection method are suggested in the korea highway bridge code, type-B method is prevalent. In this study, vertical, lateral, and tension loading test are done for two types of type B connection to review stress concentration, formation and behavior of imaginary RC column in the footing. Welding type and hook type as the connection method are considered in this study. Test results show that welding type have the more reserve capacity than hook type and the specimens connected by the welding type behave as the imaginary RC column in the footing. However, the specimens connected by the hook type did not behave as the imaginary RC column in the footing but behave as the hinge.

Development of IFC Converter Prototype for Applying BIM in the Road Field (도로분야 BIM 적용을 위한 IFC 변환기 프로토타입 시스템 개발)

  • Seo, MyoungBae;Ju, KiBeom
    • Korean Journal of Computational Design and Engineering
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    • v.19 no.4
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    • pp.347-355
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    • 2014
  • IFC converters and viewers, applicable in the construction field, are being actively developed while, in the civil engineering field, IFC schemata are being developed. To prove the IFC schema grammatically, the existing ISO 10303 30s' pre-processors and post-processors may be used. However, to visually prove the IFC model, the existing commercial 3D modeling software should be converted into the IFC schema of civil engineering field, and a viewer is needed to view it. Thus, this study developed a IFC converter and viewer prototype system to apply BIM in the road field. To express the road line, LandXML was analyzed, and IFC suitable for expressing shapes in the road field was designed. Also, an IFC suitable for bridges with focus on representative bridge structures such as abuts, piers and decks was designed. Further, a converter was developed using AutoCAD's Civil3D and Revit's 3rdp party tools, and software was also developed designed to combine each converted IFC model into one IFC. In addition, a viewer designed to view IFC in the road field was developed to prove the converted IFC. Eight major verification and examination items were selected and used in testing the converted model, and it was confirmed that the viewer normally viewed the IFC schema in the road field. The proposed IFC converter is expected to be used as a visual IFC verification tool in the road field.

Seismic Performance of Fabricated Internally Confined Hollow CFT Column (조립식 내부 구속 중공 CFT 기둥의 내진 성능)

  • Won, Deok Hee;Han, Taek Hee;Kim, Seungjun;Kang, Young Jong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.397-407
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    • 2013
  • Recently, a great progress has been made in bridge construction technology through the development of high performance materials and new structural types. However, most of attention has been paid to the cast-in-place technologies and material cost saving. The cast-in-place method is always subject to some environmental damages in construction sites, which frequently causes conflicts with residents. To overcome the disadvantages, a lot of fabrication construction method was developed. Most fabrication construction methods developed up to now have been applied for superstructure of bridges. In contrast, such fabricable methods developed for substructures are extremely rare. A fabricated column using ICH CFT(Internally Confined Hollow CFT) column was developed in a series of previous researches. Included in the previous studies are design and construction methods for the precast segmental coping, the column-coping connection, the column-segment connection, column-foundation connection. In this paper, seismic performance of the fabricated ICH CFT columns was extensively investigated experimentally. Two test specimens were prepared depending on the connection methods of segments; one by mortar-grouting method and the other by reinforcement method using stiffeners.

S&T Collaboration in Developing Countries: Lessons from Brazilian Collaboration Activities with South Korea

  • Fink, Daniel;Hameed, Tahir;So, Minho;Kwon, Youngsun;Rho, Jae Jeung
    • STI Policy Review
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    • v.3 no.2
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    • pp.92-110
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    • 2012
  • An active policy role is suggested for collaboration that will enhance national level Science and Technology (S&T) capabilities. In contrast, some studies see a limited role of policy support for collaborative S&T research at the individual level (including research groups or institutional levels) due to their self-organizing nature. Two views on S&T collaboration look at different levels but existing research largely ignores the context of developing countries. This paper shows how S&T collaborations between Brazil and Korea have developed over the past two decades. The paper indicates the gaps between initiation and the actual establishment of collaborative research at national and individual levels, differences in the focus areas of research, differences in resources and project planning, and the nature of collaborations. Collaborative research activities at the national level were initiated before the individual level but activated later than the individual level; in addition, the focus areas of research were laid down earlier at the national level with individual collaborations focused on different areas. Project types remained different at each level (i.e. top-down and bottom-up) or with a slightly changing mix. This study suggests appropriate policy measures (such as the timely and effective information collection of activities at different levels and proactive coordination) that could reduce the gaps in the timing and alignment of research areas. This paper also alludes to an evolutionary model to develop S&T collaboration among developing countries.

Flattening Class Hierarchy for Reorganization of Object-Oriented Software (객체지향 소프트웨어의 재구성을 위한 클래스계층 구조의 평탄화)

  • Hwang, Seok-Hyeong;Yang, Hae-Sul;Park, Jeong-Ho
    • The KIPS Transactions:PartD
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    • v.8D no.6
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    • pp.853-860
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    • 2001
  • In the object-oriented software development, redesigning of classes and reorganizing of class hierarchy structures should be necessary to reduce many of the headaches of object-oriented software design and maintenance. To support this task, in this paper, we propose a theoretical foundation for class hierarchy reorganizations that is relatively complete, correct, formal and easy to understand and use. We introduce the flattened class hierarchy that characterizes the class hierarchy structures in object-oriented software evolution. And we also present an algorithm which transforms a given class hierarchy into the normalized form. The flattened class hierarchy helps us map the inheritance and aggregation paths in a class hierarchy to paths in an object hierarchy that is an instance of the class hierarchy. By applying the algorithm into a given class hierarchy, we can make a new, object-preserved, and flattened class hierarchy that is the cornerstone for reorganization of class hierarchy structure and plays an important role as a bridge on the incremental evolutionary changes and reuse of object-oriented software to reorganize class hierarchies.

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A Multi-Perspective Benchmarking Framework for Estimating Usable-Security of Hospital Management System Software Based on Fuzzy Logic, ANP and TOPSIS Methods

  • Kumar, Rajeev;Ansari, Md Tarique Jamal;Baz, Abdullah;Alhakami, Hosam;Agrawal, Alka;Khan, Raees Ahmad
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.1
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    • pp.240-263
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    • 2021
  • One of the biggest challenges that the software industry is facing today is to create highly efficient applications without affecting the quality of healthcare system software. The demand for the provision of software with high quality protection has seen a rapid increase in the software business market. Moreover, it is worthless to offer extremely user-friendly software applications with no ideal security. Therefore a need to find optimal solutions and bridge the difference between accessibility and protection by offering accessible software services for defense has become an imminent prerequisite. Several research endeavours on usable security assessments have been performed to fill the gap between functionality and security. In this context, several Multi-Criteria Decision Making (MCDM) approaches have been implemented on different usability and security attributes so as to assess the usable-security of software systems. However, only a few specific studies are based on using the integrated approach of fuzzy Analytic Network Process (FANP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) technique for assessing the significant usable-security of hospital management software. Therefore, in this research study, the authors have employed an integrated methodology of fuzzy logic, ANP and TOPSIS to estimate the usable - security of Hospital Management System Software. For the intended objective, the study has taken into account 5 usable-security factors at first tier and 16 sub-factors at second tier with 6 hospital management system softwares as alternative solutions. To measure the weights of parameters and their relation with each other, Fuzzy ANP is implemented. Thereafter, Fuzzy TOPSIS methodology was employed and the rating of alternatives was calculated on the foundation of the proximity to the positive ideal solution.

Strength of Improved Soil on the Work-conditions of Deep Mixing Method (시공조건에 따른 심층혼합처리 개량체의 강도에 관한 연구)

  • Lee, Kwang-Yeol;Yoon, Sung-Tai;Kim, Sung-Moo;Han, Woo-Sun
    • Journal of the Korean Geotechnical Society
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    • v.23 no.7
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    • pp.99-104
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    • 2007
  • The deep soil mixing, on ground modification technique, has been used for many diverse applications including building and bridge foundations, port and harbor foundations, retaining structures, liquefaction mitigation, temporary support of excavation and water control. This method has the basic objective of finding the most efficient and economical method for mixing cement with soil to secure settlements through improvement of stability on soft ground. In this research, the experiments were conducted on a laboratory scale with the various test conditions of mixing method; the angle of mixing wing, mixing speed. Strength and shapes of improved soil of these test conditions of deep mixing method were analysed. From the study, it was found that the mixing conditions affect remarkably to the strength and shapes of improved soils.