Efficient and Privacy-Preserving Ride Sharing Organization for Transferable and Non-Transferable Services

Ride-sharing allows multiple persons to share their trips together in one vehicle instead of using multiple vehicles. This can reduce the number of vehicles in the street, which consequently can reduce air pollution, traffic congestion and transportation cost. However, a ride-sharing organization requires passengers to report sensitive location information about their trips to a trip organizing server (TOS) which creates a serious privacy issue. In addition, existing ride-sharing schemes are non-flexible, i.e., they require a driver and a rider to have exactly the same trip to share a ride. Moreover, they are non-scalable, i.e., inefficient if applied to large geographic areas. In this paper, we propose two efficient privacy-preserving ride-sharing organization schemes for Non-transferable Ride-sharing Services (NRS) and Transferable Ride-sharing Services (TRS). In the NRS scheme, a rider can share a ride from its source to destination with only one driver whereas, in TRS scheme, a rider can transfer between multiple drivers while en route until he reaches his destination. In both schemes, the ride-sharing area is divided into a number of small geographic areas, called cells, and each cell has a unique identifier. Each driver/rider should encrypt his trip's data and send an encrypted ride-sharing offer/request to the TOS. In NRS scheme, Bloom filters are used to compactly represent the trip information before encryption. Then, the TOS can measure the similarity between the encrypted trips data to organize shared rides without revealing either the users' identities or the location information. In TRS scheme, drivers report their encrypted routes, an then the TOS builds an encrypted directed graph that is passed to a modified version of Dijkstra's shortest path algorithm to search for an optimal path of rides that can achieve a set of preferences defined by the riders

Securing routing protocols in mobile ad hoc networks

A Mobile Ad Hoc Network (MANET) is more prone to security threats than other wired and wireless networks because of the distributed nature of the network. Conventional MANET routing protocols assume that all nodes cooperate without maliciously disrupting the operation of the protocol and do not provide defence against attackers. Blackhole and flooding attacks have a dramatic negative impact while grayhole and selfish attacks have a little negative impact on the performance of MANET routing protocols. Malicious nodes or misbehaviour actions detection in the network is an important task to maintain the proper routing protocol operation. Current solutions cannot guarantee the true classification of nodes because the cooperative nature of the MANETs which leads to false exclusions of innocent nodes and/or good classification of malicious nodes. The thesis introduces a new concept of Self- Protocol Trustiness (SPT) to discover malicious nodes with a very high trustiness ratio of a node classification. Designing and implementing new mechanisms that can resist flooding and blackhole attacks which have high negative impacts on the performance of these reactive protocols is the main objective of the thesis. The design of these mechanisms is based on SPT concept to ensure the high trustiness ratio of node classification. In addition, they neither incorporate the use of cryptographic algorithms nor depend on routing packet formats which make these solutions robust and reliable, and simplify their implementations in different MANET reactive protocols. Anti-Flooding (AF) mechanism is designed to resist flooding attacks which relies on locally applied timers and thresholds to classify nodes as malicious. Although AF mechanism succeeded in discovering malicious nodes within a small time, it has a number of thresholds that enable attacker to subvert the algorithm and cannot guarantee that the excluded nodes are genuine malicious nodes which was the motivation to develop this algorithm. On the other hand, Flooding Attack Resisting Mechanism (FARM) is designed to close the security gaps and overcome the drawbacks of AF mechanism. It succeeded in detecting and excluding more than 80% of flooding nodes within the simulation time with a very high trustiness ratio. Anti-Blackhole (AB) mechanism is designed to resist blackhole attacks and relies on a single threshold. The algorithm guarantees 100% exclusion of blackhole nodes and does not exclude any innocent node that may forward a reply packet. Although AB mechanism succeeded in discovering malicious nodes within a small time, the only suggested threshold enables an attacker to subvert the algorithm which was the motivation to develop it. On the other hand, Blackhole Resisting Mechanism (BRM) has the main advantages of AB mechanism while it is designed to close the security gaps and overcome the drawbacks of AB mechanism. It succeeded in detecting and excluding the vast majority of blackhole nodes within the simulation time

Effect of diaphragm wall construction on adjacent deep foundation

The need of using the underground space was limited in the human history, but in the last century and due to the increase of world population, the use of the underground space has become essential. Underground metro stations, deep garages, tunnels and basements, etc... are examples of using the underground space inside the cities. The use of underground space is conducted through deep excavation or tunneling. Several techniques are used to conduct the deep excavation and one of the most popular and well known techniques used for deep excavation is the diaphragm walling technique which is widely used specially inside the cities to safe space because it requires a very small space to conduct a deep reinforced concreted wall under the ground. However, the construction of such walls causes deformation of the surrounding ground and it could also affect the nearby existing structures. In some recorded cases the slurry trench failed and causes a great deformation which effect the nearby structures. However, Minor damages and cracks were observed in buildings near stable slurry trenches, because the soil deformation was high. The existing structures inside the cities have been constructed on shallow or deep foundations and this research was oriented to study the effect of diaphragm wall installation on the existing adjacent piled foundation. Very limited studies were made to investigate such an effect. At Cambridge university centrifuge model tests were conducted to investigate the effect of slurry reduction on single piles. Field observation was conducted in several projects and showed the settlement and deformation of buildings located on deep foundation during the diaphragm wall trenching. Numerical analysis was conducted using FLAC 3D to simulate the laboratory and the available field works. FLAC 3D is a commercial software and it depend in its analysis on finite difference method. The purpose of the simulation was to verify the used numerical analysis method. The results from the numerical analysis were in a good agreement with the available field data results, and they were also in good agreement with the laboratory test results regarding soil settlement but it was not in such good agreement when they were compared regarding the pile. Generally, from the verification the numerical analysis method is considered to be reliable. A parametric study was performed using the verified numerical analysis method. The flexible nature of the numerical analysis allows to simulate different cases and to study a variety of parameters. The output of the parametric study was the pile deflection, the bending moment and the shaft friction. The study was divided into three main parts while each part contains several parameter combinations. The first part studied the effect of the single and double panel(s) on the single pile group that has different piles numbers and formations. The second and third parts studied the effect of multiple panels on connected pile groups and piled raft foundation, respectively. Generally, the studied parameters can be divided into three main groups. The first is related to the trench which includes the panel dimension, the number of panels and the slurry level inside the panel. The effect of slurry pressure reduction at some levels inside the trench was also studied. The second group concerned the soil type and ground water level. The third group is related to the deep foundation which includes pile characteristics, location, and formation within the group. The results from the parametric study showed that the pile behavior was greatly affected by panel length, groundwater level, slurry level inside the trench and steadiness of the slurry pressure. The piles were also affected by the different stages of construction related to the pile location from the constructed panel. The piles within the group act together so they behave different from each other according to their position. The effect of the pile on the trench stability is presented through a simple analytical approach which is based on the wedge analysis. The analytical approach provided equations that calculate the factor of safety in two and three dimensions. The pile location was governing the equation that calculate the factor of safety because the pile could be fully inside the failure wedge or intersect with the failure surface. A comparative study was conducted to find out the effect of the different pile location and other parameters on the safety factor. Generally, this comparative study showed that the pile located within the failure wedge reduces the factor of safety, while the pile that intersects the failure surface could increase it. The pile row near a trench that contains piles inside the failure wedge and others intersects the failure surface act together to balance the failure wedge. The factor of safety results of some cases from the analytical approach were also compared with those calculated from the numerical analysis. In general, the factor of safety from the numerical analysis was higher than that calculated from the proposed analytical approach. This research helped to understand the trenching effect on the ground surface and on the nearby piled foundations. It provided charts that could help to predict the soil deformation and earth pressure coefficient which could be used in the design. It showed through the parametric study the precautions that should be taken into consideration during trenching process near piled foundation. This research provided a design method for the slurry trench panel near piled foundation

آليات ومتطلبات تطبيق فكر الزراعة المستدامة المبتكرة، في إطار تحقيق أهداف التنمية المستدامة بالتطبيق على نطاق الدلتا المصرية

The agricultural sector faces several challenges that are working to exploit it to solve the issue of the rise in world population, which requires an increase in food production, which leads to increased pressure on constantly depleting resources, as agriculture is a source of employment and foreign exchange, a supplier of raw materials for industry, and has important potential for economic development. On the other hand, the sector’s capabilities are weak compared to other economic sectors, as the sector has not succeeded in ensuring income for farmers, achieving food security, or supporting integrated sectors. The reasons behind this include using agricultural technologies that have been transferred without any development, as well as storage and transportation difficulties and problems. Marketing. Therefore, the world has turned to innovative agricultural systems that depend on the sustainability of food production and support the sector to become more resilient in the face of challenges since global food production relies heavily on farmers who often lack access to adequate production technology at reasonable prices. As well as sources of funding to invest in their work, the agricultural sectors characterized by technology and innovation that are targeted by urban clusters shortly have provided solutions to these problems, which have a significant impact on regional development within the scope of those clusters and are also working to achieve the basic principles of the sustainable development goals. Which aims to make the communities economically and physically sustainable

Improvement Optical and Electrical Characteristics of Thin Film Solar Cells Using Nanotechnology Techniques

This work presents a theoretical study for the distribution of nanocomposite structure of plasmonic thin-film solar cells through the absorber layers. It can be reduced the material consumption and the cost of solar cell. Adding nanometallic fillers in the absorber layer has been improved optical, electrical characteristics and efficiency of traditional thin film solar cells (ITO /CdS/PbS/Al and SnO2/CdS/CdTe/Cu) models that using sub micro absorber layer.  Also, this paper explains analysis of J-V, P-V and external quantum efficiency characteristics for nanocomposites thin film solar cell performance. Also, this paper presents the effect of increasing the concentration of nanofillers on the absorption, energy band gap and electron-hole generation rate of absorber layers and the effect of volume fraction on the energy conversion efficiency, fill factor, space charge region of the nanocomposites solar cells.

Improvement Optical and Electrical Characteristics of Thin Film Solar Cells Using Nanotechnology Techniques

This work presents a theoretical study for the distribution of nanocomposite structure of plasmonic thin-film solar cells through the absorber layers. It can be reduced the material consumption and the cost of solar cell. Adding nanometallic fillers in the absorber layer has been improved optical, electrical characteristics and efficiency of traditional thin film solar cells (ITO /CdS/PbS/Al and SnO2/CdS/CdTe/Cu) models that using sub micro absorber layer.  Also, this paper explains analysis of J-V, P-V and external quantum efficiency characteristics for nanocomposites thin film solar cell performance. Also, this paper presents the effect of increasing the concentration of nanofillers on the absorption, energy band gap and electron-hole generation rate of absorber layers and the effect of volume fraction on the energy conversion efficiency, fill factor, space charge region of the nanocomposites solar cells.

Elective Division Versus Preservation of The Ilioinguinal Nerve to Reduce Postoperative Pain in Hernioplasty for Inguinal Hernia

Background: Lichtenstein tension-free mesh hernioplasty is the gold standard and the method of choice for the repair of inguinal hernia in developed countries. Chronic post-operative inguinal pain (CPIP), which is defined as pain lasting at least 2–3 months after surgery, is a major problem that affects about 8-16 % of inguinal hernia patients and affects their daily lives. Pain can be caused by perioperative injury to nerves or nerves that are being trapped and impaired by sutures or perforated by fixation devices such as tacks. Ilioinguinal nerve trauma throughout dissection, inflammation or fibrosis, and nerve entrapment by the mesh have all been involved in the pathogenesis of inguinodynia. Objective: To evaluate the effect of ilioinguinal neurectomy versus nerve preservation on the incidence and severity of chronic groin pain following Lichtenstein tension-free mesh hernioplasty for inguinal hernia. Patients and Methods: This prospective study was conducted on 100 patients with inguinal hernias who underwent Lichtenstein tension-free mesh hernioplasty. They were divided randomly into 2 equal groups; ilioinguinal neurectomy group (A) and nerve preservation group (B). There was no significant difference in patients of both groups regarding age, type of the hernia, precipitating factors, or type of anesthesia. Follow-up of postoperative groin pain was done at1st and 7th POD and after 1, 3, and 6 months during rest as well as after minor exercises using NRS. Results: The Incidence of postoperative groin pain was significantly lower in the neurectomy group than the preservation group in all follow-up periods. Conclusion: Resection of ilioinguinal nerve during inguinal hernia repair reduces significantly the incidence of postoperative chronic pain

Physiological impacts of groundwater and surface water application on desert graminoids of different geographic origin

Desert plant communities are among the most sensitive to changes in soil water conditions. In areas with shallow aquifers, it is important to understand both the effects of groundwater alterations on vegetation and how changes in surface-soil water affect plant water uptake. Studies in arid environments have evaluated the effect of groundwater variation and simulated precipitation on plant production and vegetation condition but it is not clear if plants respond equally to the availability of surface water or groundwater. This study was conducted in a greenhouse to evaluate growth and physiology of three desert graminoids (Distichlis spicata, Leymus triticoides, and Juncus arcticus) as affected by surface water availability (mimicking precipitation) or subsurface water availability (mimicking groundwater). The species of study are amply distributed in wetlands and open rangelands of western USA and were collected from two sources of ecological distribution: an area near Bishop, California, and an area near Burns, Oregon. The Bishop, California area has a characteristic shallow aquifer and plants in this area are considered somewhat dependent on groundwater. The Burns, Oregon, area sustains the same species but in a variety of soil moisture conditions. We had two general hypotheses for this study: 1) that the use of surface water is favored over groundwater and 2) that there are ecotypic differences in the response of the species to water availability. The first hypothesis was partially supported by the results of the study, but variability existed among species. However, when all species had equal access to both surface soil water and groundwater plants tended to preferentially use surface water. The second hypothesis was clearly supported by our results. Although the mechanism is not clear, it is possible that an area with periodic and predictable shallow groundwater underlying a dry or saline soil layer, such as the California site, might favor plant ecotypes with high proficiency in water acquisition by deeper roots. Knowledge of water use characteristics of vegetation is essential to provide management guidelines for areas where plants depend on both surface-soil water and groundwater. This study contributed to that knowledge. Further studies on ecotypic variation and an expansion to different species that inhabit areas with shallow aquifers are recommended

Evaluation of new scoring system predicting the occurrence of deep infection in open fractures patients

Background: Open fractures of long bones incidence is 11.5 per 100,000 person per year. The management of open fractures had been improved by early adequate surgical debridement and various types of fracture fixation. The Gustilo classification is commonly used for treatment decisions and comparison. Although it had a good prediction power for deep infection but the variability among the inter observer was a problem. Yokoyama et al., 2009 he had advised a new scoring system based on three items of HFS-98 to predicting significant deep infections in open upper and lower extremity fractures.Methods: This study was conducted at Emergency Department Suez Canal University Hospital on 233 Patients with open fractures of long bones from April 2014 till November 2015. The patients were classified according to the criteria proposed by Gustilo classification & Yokoyama’s new scoring system. The relationship between the new score three items were investigated by categorical regression multivariate analysis.Results: In this study, we had 233 Patients with open fractures of long bones. Road traffic accidents were the mechanism of injury in (44.6%). Deep infection was positive in 70/233 patients with Gustilo GI. The cut-off point of application of Yokoyama’s new scoring system was 30, Sensitivity; 63.3%, Specificity; 89%, significant P-value <0.001.Conclusions:The cut-off point of the new Yokoyama’s new scoring application in this study was slit different from the reported applicable values before. This revised scoring system was thought to be useful for predicting deep. Further prospective trial is needed for advising new scoring system.