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21.
Mosfata Khattab Ph.D.
F. Choobineh P.E.
Ph.D. 《Computers & Industrial Engineering》1991,21(1-4):291-295Two important characteristics of a project network are the network's topology and the amount of resources available. Most published project scheduling procedures take one or both of these two characteristics into account. Project scheduling procedures that are robust over variations of network characteristics are desirable. The degree of robustness is generally gauged by one or more measures of performance.
The objective of this paper is to compare a set of priority rules that are useful for a single resource project scheduling problem. The set of networks suggested by Patterson (1973) is used along with the set of performance measures proposed by Khattab and Choobineh 1991. The result of this comparison allows one to design a multiattribute heuristic for a single resource project scheduling problem. 相似文献
22.
23.
Measurement of Inlet Drop Size Distribution of Secondary Dispersions by Laser Particle Size Analyzer
Knowledge of the Oil drop size distribution, in addition to the mean drop size, is necessary in order to characterize secondary dispersions. Furthermore, the capture efficiency for any drop flowing through a packed bed depends upon its Oil inlet drop diameter. The Oil/Water secondary dispersions produced by the centrifugal pump were analyzed at regular intervals during an experiment to ascertain the drop size distribution and to check that the feed to the coalescence bed was consistent. New techniques that were developed for measurement of drop size distribution of secondary dispersions using Laser Particle Size Analyzer, which consisted of (He/Ne) laser emitter and laser receiver and lenses. The Laser Particle Size Analyzer was fixed directly to the experimental equipment by using the special designed circular cell. The measurement of drop size distribution was done by computer system with application software package. The new mean drop diameter (i.e., d21) equation has been derived theoretically and the results that predicted from this equation exhibited a maximum error of ±15% from the experimental data. 相似文献
24.
AW Ibrahim 《Canadian Metallurgical Quarterly》1998,21(2-3):194-197
Shunting systems widely used for the treatment of hydrocephalus have been connected with certain risks and potential complications which stem from implanting a non-biological material into the human body. Several complications have been reported to arise from the insertion of ventriculo-peritoneal shunts. This short report highlights the observation that when anaerobic meningitis together with gram negative E. Coli in the CSF of a V-P shunted patient is found, bowel perforation should be assumed. Four cases developed such a complication among 643 hydrocephalic patients of various etiology over a period of ten years. 相似文献
25.
Asim Muhammad Nabeel Ghani Muhammad Usman Ibrahim Muhammad Ali Mahmood Waqar Dengel Andreas Ahmed Sheraz 《Neural computing & applications》2021,33(11):5437-5469
Neural Computing and Applications - In order to provide benchmark performance for Urdu text document classification, the contribution of this paper is manifold. First, it provides a publicly... 相似文献
26.
Pradeep K. Atrey Hicham Ibrahim M. Anwar Hossain Sheela Ramanna Abdulmotaleb El Saddik 《Multimedia Tools and Applications》2012,60(1):69-96
Significant growth of multimedia content on the World Wide Web (or simply ??Web??) has made it an essential part of peoples lives. The web provides enormous amount of information, however, it is very important for the users to be able to gauge the trustworthiness of web information. Users normally access content from the first few links provided to them by search engines such as Google or Yahoo!. This is assuming that these search engines provide factual information, which may be popular due to criteria such as page rank but may not always be trustworthy from the factual aspects. This paper presents a mechanism to determine trust of websites based on the semantic similarity of their multimedia content with already established and trusted websites. The proposed method allows for dynamic computation of the trust level of websites of different domains and hence overcomes the dependency on traditional user feedback methods for determining trust. In fact, our method attempts to emulate the evolving process of trust that takes place in a user??s mind. The experimental results have been provided to demonstrate the utility and practicality of the proposed method. 相似文献
27.
Ibrahim M. Alarifi 《乙烯基与添加剂工艺杂志》2021,27(1):77-88
This study aims to examine the morphology and mechanical properties (tensile, flexural, and compressive) of epoxy composites reinforced with epoxy date palm leaves (EDPL), epoxy date palm branch (EDPB), and epoxy/hardener date palm core shell (EDPC) fibers (particle size <1 μm depend on the date palm fibers). A three-step technique was used to obtain the composites. The EDPL composites showed a maximum tensile strength of 3.45 MPa, while the EDPB composites showed maximum compressive and flexural rigidity of 9.46 and 5.55 MPa, respectively, owing to the good compatibility of fiber-matrix bonding. In this work, epoxy composites reinforced with date palm fibers (DPF) leaves, branches, and core shell were recycled using a cost-effective and easily reproducible three-step technique. EDPC fibers fabricated with 64.65% weight carbon fibers content demonstrated improved tensile strengths and stiffness properties. The three samples of palm date composites revealed mechanical properties that could be used to trial these fibers for manufacturing purposes, and to exploit their extraordinary mechanical properties shown in current results. 相似文献
28.
To impart easy‐care properties to cellulose‐containing fabrics along with avoiding any harmful effects of formaldehyde on both the health and the environment, attempts have been made to use citric acid (CA) as an ester crosslinking agent along with different catalytic systems in the absence and presence of certain additives. Further, fixation conditions, type of crosslinking agent, as well as type of substrate have been studied. Results revealed that the enhancement in carboxyl content, performance properties, and the decrease in tear strength (TS) as well as in whiteness indices (WI) of the finished fabric samples were increased by increasing CA concentration up to 80 g/L and by raising thermofixation temperature from 140 up to 180°C for 90 s. Inclusion of triethanolamine hydrochloride (TEA. HCl), decreased the carboxyl content, TS, color strength K/S, as well as oily stain release rating (SRR) of the finished fabric samples along with an increase in bound nitrogen (%N), wrinkle recovery angle WRA, and an improvement in WI without affecting the durable press rating (DP). Within the range examined (0–30 g/L), increasing PEG‐600 concentration improved the wet resiliency, TS, as well as WI properties of the finished samples. Increasing DMDHEU ratio in the CA/DMDHEU crosslinking system gave rise to an increase in %N, WRA (dry and wet), DP, as well as in free CH2O of finished fabrics, along with a slight improvement in WI values. On the other hand, the TS, carboxyl content, K/S, SRR values of the finished fabric samples were lower at a higher DMDHEU ratio. Increase in carboxyl content, %N, WRA (dry and wet), DP and SRR, as well as extent of post dyeing (K/S) of the treated fabric samples upon using different ester crosslinking agents followed the descending order: citric acid > pyromellitic dianhydride. The opposite holds true for the TS, and WI values. Among the esterifying catalysts used, and for a given set of finishing conditions, NaH2PO2 · H2O proved to be the most effective one, and the following order of effectiveness may be drawn: NaH2PO2 · H2O > K2HPO4 > Na3–citrate > Na2–tartrate. Inclusion of silicone softener in the finishing formulation brought about an improvement in softeness degree, WRA, %N, DP, TS as well as K/S values along with a decrease in carboxyl content, SRR, and WI values of the treated fabric samples, regardless of the used silicone softener.The performance properties of the finished fabric samples were determined by the type and nature of the substrate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2243–2253, 2002 相似文献
29.
Yasser H El Hamaky Somaia Tawfeek Dalia F Ibrahim Dalia Maamoun Said Gaber 《Coloration Technology》2007,123(6):365-373
The behaviour of reactive dyes of high reactivity during the printing process of 100% cotton fabrics from an alkaline and acidic printing paste was studied in detail. The printing pastes were stored for different periods of time and then the fabrics were printed. The samples were subjected to two methods of fixation, the first by steaming and the second by thermofixation. The effects of different factors such as alkali and acid concentration, storage time of the printing pastes and method of fixation on the K/S values of the prints were investigated. The fastness properties of the printed areas were also measured to determine the improvement obtained by acidic printing with high-reactivity reactive dyes on cotton fabrics. 相似文献
30.
Ugur Ozdemir Yucel Orkut Aktas Aslihan Vuruskan Yasin Dereli Ahmed Farabi Tarhan Karaca Demirbag Ahmet Erdem Ganime Duygu Kalaycioglu Ibrahim Ozkol Gokhan Inalhan 《Journal of Intelligent and Robotic Systems》2014,74(1-2):371-393
For the last four decades Unmanned Air Vehicles (UAVs) have been extensively used for military operations that include tracking, surveillance, active engagement with weapons and airborne data acquisition. UAVs are also in demand commercially due to their advantages in comparison to manned vehicles. These advantages include lower manufacturing and operating costs, flexibility in configuration depending on customer request and not risking the pilot on demanding missions. Even though civilian UAVs currently constitute 3 % of the UAV market, it is estimated that their numbers will reach up to 10 % of the UAV market within the next 5 years. Most of the civilian UAV applications require UAVs that are capable of doing a wide range of different and complementary operations within a composite mission. These operations include taking off and landing from limited runway space, while traversing the operation region in considerable cruise speed for mobile tracking applications. This is in addition to being able traverse in low cruise speeds or being able to hover for stationary measurement and tracking. All of these complementary and but different operational capabilities point to a hybrid unmanned vehicle concept, namely the Vertical Take-Off and Landing (VTOL) UAVs. In addition, the desired UAV system needs to be cost-efficient while providing easy payload conversion for different civilian applications. In this paper, we review the preliminary design process of such a capable civilian UAV system, namely the TURAC VTOL UAV. TURAC UAV is aimed to have both vertical take-off and landing and Conventional Take-off and Landing (CTOL) capability. TURAC interchangeable payload pod and detachable wing (with potential different size variants) provides capability to perform different mission types, including long endurance and high cruise speed operations. In addition, the TURAC concept is to have two different variants. The TURAC A variant is an eco-friendly and low-noise fully electrical platform which includes 2 tilt electric motors in the front, and a fixed electric motor and ducted fan in the rear, where as the TURAC B variant is envisioned to use high energy density fuel cells for extended hovering time. In this paper, we provide the TURAC UAV’s iterative design and trade-off studies which also include detailed aerodynamic and structural configuration analysis. For the aerodynamic analysis, an in-house software including graphical user interface has been developed to calculate the aerodynamic forces and moments by using the Vortex Lattice Method (VLM). Computational Fluid Dynamics (CFD) studies are performed to determine the aerodynamic effects for various configurations For structural analysis, a Finite Element Model (FEM) of the TURAC has been prepared and its modal analysis is carried out. Maximum displacements and maximal principal stresses are calculated and used for streamlining a weight efficient fuselage design. Prototypes have been built to show success of the design at both hover and forward flight regime. In this paper, we also provide the flight management and autopilot architecture of the TURAC. The testing of the controller performance has been initiated with the prototype of TURAC. Current work focuses on the building of the full fight test prototype of the TURAC UAV and aerodynamic modeling of the transition flight. 相似文献