Numerical Evaluation of Steel Columns Buckling under Cyclic Loading

This paper aims to exhibit the use of finite element analysis as a numerical method to validate the experimental results of steel column stability under cyclic loading. Finite element package ANSYS was utilized for this purpose. The structural behavior of hollow box steel columns under the merged action of a constant axial load and cyclic lateral loads was investigated. Hot rolled unstiffened steel box column sections were simulated as cantilever-type columns as in common usage in the bridge piers. A nonlinear buckling finite element analysis was carried out in which both material and geometric nonlinearities were taken into account. The results show a reasonable agreement with Load and Resistance Factor Design (LRFD) formula. In addition, transient dynamic analysis was executed to determine the dynamic response of the specimens under the action of two loading tests: monotonic test and three cycle test. Isotropic strain-hardening and kinematic strain-hardening were included in simulating plastic deformation. It is shown that the non-linear finite element analysis shows good capabilities in simulating the buckling behavior of a steel column under cyclic loading

A Horizontal Fragmentation Algorithm for the Fact Relation in a Distributed Data Warehouse

Data warehousing is one of the major research topics of appliedside database investigators. Most of the work to date has focused on building large centralized systems that are integrated repositories founded on pre-existing systems upon which all corporate-wide data are based. Unfortunately, this approach is very expensive and tends to ignore the advantages realized during the past decade in the area of distribution and support for data localization in a geographically dispersed corporate structure. This research investigates building distributed data warehouses with particular emphasis placed on distribution design for the data warehouse environment. The article provides an architectural model for a distributed data warehouse, the formal definition of the relational data model for data warehouse and a methodology for distributed data warehouse design along with a "horizontal" fragmentation algorithm for the fact relation. Most of the work to date has focused on building large centralized systems that are integrated repositories founded on pre-existing systems upon which all corporate-wide data is based. The centralized data warehouse is very expensive and tends to ignore the advantages realized during the past decade in the areas of distribution and support for data localization in a geographically dispersed corporate structure. Further, it would be unwise to enforce a centralized data warehouse when the operational systems exist over a widely distributed geographical area. The distributed data warehouse supports the decision makers by providing a single view of data even though that data are physically distributed across multiple data warehouses in multiple systems at different branches. Currently, the field of distributed data warehouse in terms of architecture and design is considered an important research problem that needs investigation. This research contributes to the problem of distributed data warehouse architecture and design by: Keywords distributed data warehouse architecture, distributed data warehouse design, horizontal fragmentation. Extending the preliminary architecture model that has been presented in [8] by proposing a distributed data warehouse system architecture and describing the functionality of its components

Encryption Quality Analysis of the RCBC Block Cipher Compared with RC6 and RC5 Algorithms

In this paper, we investigate the encryption quality of the robust chaotic block cipher (RCBC) algorithm; which is based on chaotic map. In addition to visual inspection of images encryption testing, five analytical metrics are developed for analyzing the encryption quality. These metrics are used to evaluate several encrypted images factors include: maximum deviation, irregular deviation, information entropy, correlation coefficients, and avalanche effect. Comparison of the encryption quality for RCBC, RC6 and RC5 implantations to digital images are performed. In the experimental results, we have made our tests using color images Lena, Cman, and Peppers, each of size 512x512 pixels, as the original images (plain-images). Results show better quality of the RCBC

A Nonlinear Goal Programming Model for University Admission Capacity Planning with Modified Differential Evolution Algorithm

This paper proposes a nonlinear Goal Programming Model (GPM) for solving the problem of admission capacity planning in academic universities. Many factors of university admission capacity planning have been taken into consideration among which are number of admitted students in the past years, total population in the country, number of graduates from secondary schools, desired ratios of specific specialties, faculty-to-students ratio, and the past number of graduates. The proposed model is general and has been tested at King Abdulaziz University (KAU) in the Kingdom of Saudi Arabia, where the work aims to achieve the key objectives of a five-year development plan in addition to a 25-year future plan (AAFAQ) for universities education in the Kingdom. Based on the results of this test, the proposed GPM with a modified differential evolution algorithm has approved an ability to solve general admission capacity planning problem in terms of high quality, rapid convergence speed, efficiency, and robustness

Saudi-KAU Coupled Global Climate Model: Description and Performance

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Reconciling formal and informal documentation in business modelling

Business modelling, the modelling of architectures and processes of organizations, should have a broad scope. It should not exclusively capture the basic information of the processes, but also address the various kinds of documentation related to the processes under consideration. In this combination, organizational models will be more expressive and useful.The research reported here describes and demonstrates a new approach for reconciling formal and informal documentation in business modelling. It is based on the integration of an underlying formal modelling approach with hypertext concepts that provide mechanisms for capturing, manipulating and viewing informal model documentation.We have developed the Hypertec tool which complements the Macrotec environment. Macrotec is a business modelling environment that is based on the formalism of extended colored Petri nets. Hypertec is a hypertext-based component supporting authoring, display and navigation of all the process documentation that cannot be captured by Macrotec. Our experience with Macrotec/Hypertec shows that their combined functionality substantially facilitates the understanding of business processes and clearly reduces problems such as miscommunication, misinterpretation, and misunderstandings about entire processes or some of their components

Flood Hazard Assessment and Mapping in Semi-arid Urban Areas: A Case Study in the Wadi Al-Sayelah, Sana'a, Yemen

The Second International Symposium on Flash Floods in Wadi Systems: 25-27 October 2016. Technische Universität Berlin, Campus El Gouna, Egypt