VLC Enabled Hybrid Wireless Network for B5G/6G Communications

Wireless Personal Communications - In the present scenario, there is a boom in the demand of the users to achieve increased capacity, high data, low latency, and high-performance rates. 5G New...     

Fuzzy set based cost model of additive manufacturing with specific example of selective laser sintering

A fuzzy set based cost model for additive manufacturing is proposed. The model is illustrated through an example of selective laser sintering (SLS), a commonly used additive manufacturing (AM) process. Initially, a deterministic cost model is developed. It is then converted to a fuzzy set based model by considering uncertainty in build time estimation and cost components. For the specific case of SLS, a build time estimation procedure is developed as a part of the cost model. A method to evaluate the reliability of the cost estimate in AM and its significance is also introduced. The cost model is illustrated through two examples of products manufactured by SLS.

     

A study of the energy consumption characteristics of cryptographic algorithms and security protocols

Security is becoming an everyday concern for a wide range of electronic systems that manipulate, communicate, and store sensitive data. An important and emerging category of such electronic systems are battery-powered mobile appliances, such as personal digital assistants (PDAs) and cell phones, which are severely constrained in the resources they possess, namely, processor, battery, and memory. This work focuses on one important constraint of such devices-battery life-and examines how it is impacted by the use of various security mechanisms. In this paper, we first present a comprehensive analysis of the energy requirements of a wide range of cryptographic algorithms that form the building blocks of security mechanisms such as security protocols. We then study the energy consumption requirements of the most popular transport-layer security protocol: Secure Sockets Layer (SSL). We investigate the impact of various parameters at the protocol level (such as cipher suites, authentication mechanisms, and transaction sizes, etc.) and the cryptographic algorithm level (cipher modes, strength) on the overall energy consumption for secure data transactions. To our knowledge, this is the first comprehensive analysis of the energy requirements of SSL. For our studies, we have developed a measurement-based experimental testbed that consists of an iPAQ PDA connected to a wireless local area network (LAN) and running Linux, a PC-based data acquisition system for real-time current measurement, the OpenSSL implementation of the SSL protocol, and parameterizable SSL client and server test programs. Based on our results, we also discuss various opportunities for realizing energy-efficient implementations of security protocols. We believe such investigations to be an important first step toward addressing the challenges of energy-efficient security for battery-constrained systems.     

Partitioned encoding schemes for algorithm-based fault tolerance inmassively parallel systems

Considers the applicability of algorithm based fault tolerance (ABET) to massively parallel scientific computation. Existing ABET schemes can provide effective fault tolerance at a low cost For computation on matrices of moderate size; however, the methods do not scale well to floating-point operations on large systems. This short note proposes the use of a partitioned linear encoding scheme to provide scalability. Matrix algorithms employing this scheme are presented and compared to current ABET schemes. It is shown that the partitioned scheme provides scalable linear codes with improved numerical properties with only a small increase in hardware and time overhead     

Prevalence of hepatitis B and C virus infections among haemodialysis patients in Pune (western India)

Vascular injuries may occur as complications of elbow dislocation and usually involve the brachial artery. A case report is presented in which only the radial artery was compromised as a result of the dislocation.     

Ceramic Composites Fabricated by Selective Laser Sintering

Selective laser sintering (SLS) uses a computer controlled laser beam to create objects directly from the CAD data without part-specific tooling. In this paper, the effect of material and processing parameters on the microstructure and mechanical properties of an alumina/aluminum phosphate composite fabricated by SLS is described. The precursor material is a blend of alumina and ammonium phosphate powder. This paper deals primarily with the effect of alumina particle size and material composition on the strength of the composite. A constitutive equation is also proposed to relate the mechanical properties of the composite to its microstructural characteristics.     

DESP: a distributed economics-based subcontracting protocol for computation distribution in power-aware mobile ad hoc networks

In this paper, we present a new economics-based power-aware protocol, called the distributed economic subcontracting protocol (DESP) that dynamically distributes task computation among mobile devices in an ad hoc wireless network. Mobile computation devices may be energy buyers, contractors, or subcontractors. Tasks are transferred between devices via distributed bargaining and transactions. When additional energy is required, buyers and contractors negotiate energy prices within their local markets. Contractors and subcontractors spend communication and computation energy to relay or execute buyers' tasks. Buyers pay the negotiated price for this energy. Decision-making algorithms are proposed for buyers, contractors, and subcontractors, each of which has a different optimization goal. We have built a wireless network simulator, called ESIM, to assist in the design and analysis of these algorithms. When the average communication energy required transferring a task is less than the average energy required to execute a task, our experimental results indicate that markets based on our protocol and decision-making algorithms fairly and effectively allocate energy resources among different tasks in both cooperative and competitive scenarios.