Motivated by the recent advances in light-emitting diode (LED) technology and the scarcity of spectrum resources, visible light communication (VLC) has gained great interest over the past few years. One of the key challenges in VLC is the limited modulation bandwidth (BW) of the light sources, which typically spans a few MHz. Recently, multiple-input multipleoutput (MIMO) techniques have demonstrated great potentials in VLC, as they overcome the modulation BW limitation and offer significant improvement in link reliability. However, in such scenarios, multiple LEDs (i.e., transmitters) and multiple photo detectors (i.e., receivers) share the same communication medium, thus resulting in mutual interference among different data transmission channels. This paper proposes a new dynamic precoding scheme that makes use of the constructive interference and eliminate the unwanted interference
Construction site layout planning process is controlled by allocating site facilities to minimize the movement of laborers and equipment. Due to the complexity of modern construction projects, dynamic allocation was proposed as a solution for site layout planning problems. In this study, a safety based dynamic optimization model is used to account for the planning changes throughout the construction process. A comprehensive survey is done to investigate other qualitative aspects that may affect site layout process in large construction projects in UAE, while Fuzzy TOPSIS will be used as a multi criteria decision making approach to quantify and order those aspects. Safety relationship approach will be used in the site layout model which will be prepared in a grid layout system. The facilities will be allocated using a Binary Linear Optimization Model considering availability, overlapping and safety constraints. This model is then validated through a real-life case study in UAE.
A Firm can accomplish competitiveness by reducing total logistics costs through integration of its various activities of procurement process. The objective of this research is to develop a mathematical model that integrates a joint decision of supplier selection; order allocation; carrier selection and warehouse selection which result in maximum attainment of cost and quality goals. The total cost would include procurement related costs, transportation costs and warehousing costs. The model will be formulated by a joint AHP-Fuzzy Goal Programming approach under conditions of multiple products being procured from multiple suppliers in multiple periods under discount environments and where target goal values are fuzzy. In the multi-objective formulation, net rejected items, net costs and net late delivered items are some of the considered objectives that have to be minimized over the decision horizon. An illustration would be provided in a fourth party logistics provider context to show the model's effectiveness.
natural gas with high nitrogen content will lower the gas heating value, and increase the gathering and transportation power consumption. In regard to this problem, a nitrogen removal from natural gas process using single-column cryogenic distillation method is established based on Aspen Plus. An expanding refrigeration process using N2-CH4 is selected to provide the needed cold energy for this plant. The effect of feedstock natural gas properties, the nitrogen content of the refrigerant, and the operation pressure of distillation column on the plant evaluation indicators such as energy consumption, nitrogen removal efficiency, and methane recovery ratio, are conducted. Moreover, at the optimization condition of the above variables, the exergy analysis method is employed to evaluate the exergy loss distribution of each unit in the plant.
Individuals data collected from various sources are stored in data sets which can be vulnerable to some attacks resulting in violating the privacy of those individuals. Also, due to the fact that connected devices are increasing which lead more data to be generated, big data privacy has become one of the major concerns in the Internet of Things (IoT). This paper gives an overview about the issue of privacy in big data including data collected from IoT. Then one of the most common privacy solutions is studied which is the technique known as Anonymization. However, vulnerabilities of anonymization are listed and studied which mainly focus around Re-Identification attacks. Finally, a fast encryption technique is suggested to be used on the data which found to be non-critical in order to prevent from the re-identification attacks.
Throughout the years, hackers' intentions' varied from curiosity, to financial gains, to political statements. Armed with their botnets, bot masters could crash a server or website. Statistics show that botnet activity accounts for 29% of the Internet traffic. But how can bot masters establish undetected communication with their botnets? The answer lies in the Domain Name System (DNS), using which hackers host their own domain and assign to it changing IP addresses to avoid being detected. In this paper, we propose a multi-factor cyber-threat detection system that relies on DNS traffic analysis for the detection of malicious domains. The proposed system was implemented, and tested, and the results yielded are very promising.
Cyber-attacks are becoming more prevalent across the globe, and organizations need to stay abreast of the latest threats and risks that are occurring. Several studies have been conducted to demonstrate how to counterintelligence cyber-threats (CT), in specific Advanced Persistent Threats. However, none of these studies have proposed a comprehensive Cyber Threat Intelligence (CTI) program, beginning with the initial threat, creating an attack profile based on the threat's behavior, and ending in a forensic investigation. This proposal is aimed to mitigate the security breaches to ascertain how these attacks are carried out. The researcher believes that such a CTI program is needed for the following reasons: 1. To demonstrate the CTI issues and challenges; 2. To implement guidelines for CT analysts and therefore, enhance it's features, and 3. To establish the advantages of a CTI program over traditional solutions. Furthermore, we have identified and recommended the most effective CTI sub-types.
Visual cryptography is based on dividing a binary image (the secret) into shares and distributing these shares among n participants. The original image can be recovered by stacking together the shares. This paper provides a survey for different Visual Cryptography Schemes (VCS) techniques.
This paper designs and implements a three-stage more secure authentication system. In the first stage, the user's username coupled with the device serial number are required to complete the registration process. In the second stage, the user must select m squares out of a grid with n squares. In the final stage, the user must select s out of i images in the same exact order. This paper discusses the advantages and disadvantages of the proposed system and we intend to experimentally prove that the proposed system is very secure and immune to most of today's common attacks.
We present an FPGA hardware platform for the prototyping and analysis of ultra-low power IoT sensor networks using single-channel communication protocols. This FPGAbased IoT network platform is based on three fundamental ingredients: a full HDL implementation of ultra-low power TI MSP430 microcontroller; a novel ultra-low power single-wire communication protocol that does not require any clock and data recovery, the protocol is called pulsed-index communication (PIC); embedded C implementation of the PIC transceivers within the TI MSP430. In one of our bus network analysis, we have used the Virtex-7 FPGA environment to instantiate the TI MSP430 a number of times equal to the number of IoT sensors to implement highthroughput, ultra-low power network communication between the IoT sensors. The platform is also scalable in that the resources used for a two-sensor, point-to-point communication link is less than 1% of the Virtex-7 available hardware.
