4,659 research outputs found
Robust active heave compensated winch-driven overhead crane system for load transfer in marine operation
Active heave compensation (AHC) is important for load transfer in marine operation using the overhead crane system (OCS). The control of marine OCS aims to continuously regulate the displacement of the cart and the payload sway angle, whilst at the same time, maintaining the gap between the payload and the vessel main deck at a desirable and safe distance. As the marine OHC system is to be operated in a continuously changing environment, with plenty inevitable disturbances and undesirable loads, a robust controller, i.e., active force control (AFC) is thus greatly needed to promote accuracy and robustness features into the controllability of OCS in rough working environment. This paper highlights a novel method for controlling the payload in an OCS based on the combination of both AFC and AHC. Results from the simulation study clearly indicate that the performance of OCS can be greatly improved by the proposed robust AFC controller, as compared with the classical PID controller scheme
Building a Multimodal, Trust-Based E-Voting System
This paper addresses the issue of voter identification and authentication, voter participation and trust in the electoral system. A multimodal/hybrid identification and authentication scheme is proposed which captures what a voter knows – PIN, what he has – smartcard and what he is – biometrics. Massive participation of voters in and out of the country of origin was enhanced through an integrated channel (kiosk and internet voting). A multi-trust voting system is built based on service oriented architecture. Microsoft Visual C#.Net, ASP.Net and Microsoft SQL Server 2005 Express Edition components of Microsoft Visual Studio 2008 was used to realize the Windows and Web-based solutions for the electronic voting system
Knowledge Discovery in Online Repositories: A Text Mining Approach
Before the advent of the Internet, the newspapers were the prominent instrument of
mobilization for independence and political struggles. Since independence in Nigeria, the
political class has adopted newspapers as a medium of Political Competition and
Communication. Consequently, most political information exists in unstructured form and
hence the need to tap into it using text mining algorithm.
This paper implements a text mining algorithm on some unstructured data format in some newspapers. The algorithm involves the following natural language processing techniques: tokenization, text filtering and refinement. As a follow-up to the natural language techniques, association rule mining technique of data mining is used to extract knowledge using the Modified Generating Association Rules based on Weighting scheme (GARW).
The main contributions of the technique are that it integrates information retrieval scheme (Term Frequency Inverse Document Frequency) (for keyword/feature selection that automatically selects the most discriminative keywords for use in association rules generation) with Data Mining technique for association rules discovery. The program is applied to Pre-Election information gotten from the website of the Nigerian Guardian newspaper. The extracted association rules contained important features and described the informative news included in the documents collection when related to the concluded 2007 presidential election. The system presented useful information that could help sanitize the polity as well as protect the nascent democracy
A comparison between Asian and Australasia backpackers using cultural consensus analysis
This study tests the differences in the shared understanding of the backpacker cultural domain between two groups: backpackers from Australasia and backpackers from Asian countries. A total of 256 backpackers responded to a questionnaire administered in Kuala Lumpur, Bangkok and Krabi Province (Thailand). Cultural consensus analysis (CCA) guided the data analysis, to identify the shared values and the differences in the backpacker culture of the two groups. The findings revealed that while the two groups share some of the backpacker cultural values, some other values are distinctively different from one another. The study provides the first empirical evidence of the differences in backpacking culture between the two groups using CCA. Based on the study findings, we propose some marketing and managerial implications
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Where lean construction and value management meet
The lean construction (LC) community’s key vision and goal is to provide value, yet they are increasingly challenged with understanding and dealing with the concept of value, with reports that value is one of the weakest points. Regardless of the previous studies and contributions already made on the concept of value in LC, the absence of a consistent understanding of value has resulted in misperceptions and indistinct boundaries with other construction value-related disciplines. Without a consistent understanding of value, the full potential of applying value-established concepts will not occur. Thus, the study of different concepts in construction will open new opportunities to deliver value in the future. Literature reviewed only revealed a small number of interdisciplinary comparisons of Lean manufacturing and LC with value management (VM)/value engineering (VE) on value. Secondary data was used to present an in-depth comparison of the principal points of the current practice and theories of LC and VM, which are seen as ways to improve the delivery of value to clients and building users. The study revealed a range of similarities at a high level, which could easily point to an early conclusion that LC and VM are interchangeable, leading to the same goal of value delivery and shared misapplication of cost reduction techniques. However, a more detailed examination indicates significant differences in the philosophy and scope in different areas, including project timing, practitioner duties, and areas of practice which could complement each other. Also the study identified that LC is a broader philosophy which covers more aspects than VM, it is evident that LC has advanced over the years towards discussions on the concept of value. The current work in LC on value relies less on other construction value-related disciplines such as VM, VE and partnering. Furthermore, LC literature still views value as a confusing concept associated with different interpretations, forming the basisof its understanding. The study established that value plays a central role in both LC and VM. Their combination could offer great synergy regarding the concept of value
Spatial Analysis of Groundwater Potential: A first hand Approach towards Groundwater Development in Moroto District, Uganda
Groundwater is a vital resource that helps mankind and development. However, in Moroto District challenges of groundwater development has increased arising from changes in rainfall patterns coupled with high abstraction from population increase. In this study, the spatial variability of groundwater potential was assessed to develop a tool that will aid decision on groundwater potential sites selection for groundwater development/exploration. The study utilized an integrated technique and tools such as Remote Sensing (RS), Geographic Information System (GIS) and Multi Criteria Decision Analysis (MCDA) in analysis and delineation of potential areas for successful groundwater development. The generated map through weighted overlay of thematic layers (slope, soil, lithology, rainfall, land use and land cover) produced five categories of potential zones indicating 90% (i.e., 35% very high, 40% high and 15% moderate) of the study area to be suitable for groundwater development and only 10% (i.e., 2% poor and 8% very poor) exists as poor groundwater potential zones. Maps produced from this study can hence be used to identify appropriate sites for groundwater development, and therefore minimizing unsuccessful boreholes development.
Keywords: GIS; Groundwater Development; Groundwater Potential; MCDA; Spatial Analysis
Fabrication of Fully Dense UHTC by Combining SHS and SPS
The combination of the Self-propagating High-temperature Synthesis (SHS) technique and the Spark Plasma Sintering (SPS) technology is adopted in this work for the fabrication of fully dense MB2-SiC and MB2-MC-SiC (M = Zr, Hf, Ta) Ultra High Temperature Ceramics (UHTCs). Specifically, Zr, Hf or Ta, B4C, Si, and graphite reactants are first converted to the desired composites by SHS. For the case of the lowexothermic Ta-based compositions, a preliminary 20 min ball milling treatment of the starting reactants is required to activate the corresponding synthesis reactions. When the resulting powders are then subjected to consolidation by SPS, it is found that products with relative densities greater than 96% can be obtained for all systems investigated within 30 min of total processing time, when setting the dwell temperature to 1800 °C and the mechanical pressure to 20 MPa. Hardness, fracture toughness, and oxidation resistance characteristics of the resulting dense UHTCs are comparable to, or superior than, those relative to similar products synthesized by alternative, less rapid, processing routes. Moreover, it is found that the ternary composites display relatively low resistance to oxidation as a consequence of the lower SiC content in the composite, in comparison with the binary systems, as well as to the presence of transition metal carbides. Indeed, although the latter ones are potentially able to increase mechanical and resistance to ablation properties, they tend to oxidize rapidly to form MO2 and COx, so that the resulting porosity make the material bulk more sensitive to oxidation.</p
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