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Wireless mesh networks are designed as an economical solution to provide high quality service for last-mile broadband Internet access. The paramount priority of these networks is the throughput maximization which is in conflict with a scarce bandwidth. Multicast is a technology that provides a good trade-off between maximizing the throughput and minimizing the bandwidth usage. This paper quantifies the reliability gain of combining classes for reliable multicast in the wireless mesh network. We define the delay as the performance metric for reliability. We then provide an analytical analysis to study the impact of group size, packet loss rate and depth of the multicast tree on the performance improvement achieved by combining classes. Our numerical results show that combining classes significantly reduces distribution delays, compared to the receiver-initiated class alone. The performance gains increase as the group size, the packet loss rate and the depth of the multicast tree increase, making the classes combination approach more scalable with respect to these parameters. [ABSTRACT FROM AUTHOR]

Horse riding machine is a typical fitness equipment, and widely used in various fitness places, which can make people feel more comfortable when using a riding machine, a 3D modeling of the riding machine based on ergonomics is established by using SolidWorks software. Then the position, velocity and acceleration equations of the saddle, pedal and armrest are established by the kinematic analysis of mechanism, then analytical analysis are conducted to determine the optimal length of each component, i.e., the length of AB pole is L 1=95mm, the length of BC pole is L 2=255mm, the length of BE pole is L 3=310mm, the length of DE pole is L 4=270mm, the length of EF pole is L 5=100mm, and the length of FG pole is L 6=400mm. [ABSTRACT FROM AUTHOR]

Shell foundations, or geometrically shaped footings, were first used as a substitute for the conventional flat shallow foundations in the nineteen fifties in Mexico, West Germany, India, China and the Soviet Union. It is not known whether their use was developed independently or was incorporated after observing their use elsewhere. However, it is certain that their use was not based on any research data that has been reported at that time. Since then, the use of shell foundations has drawn considerable interest around the world. Experimental and theoretical investigations by the author on 'shell type' foundations have shown significant increases in bearing capacity, better settlement characteristics, and ability to resist higher lateral forces which might be induced due to wind loads or earthquakes as compared to the conventional flat foundations. This is primarily due to partial absorption of the vertical load through lateral compression of the soil particles under the shell. Given these attributes, the practical implications could make shell foundations ideally suited for foundations subjected to lateral loadings. It is also known that shell foundations require less construction materials, which could benefit its use in developing countries where materials are scarce and expensive while labor is abundant and inexpensive. This paper presents analytical analysis of shell and flat foundations subjected to lateral loading. The results of this study will be presented in the form of a comparative study and numerical example, which will demonstrate that shell foundations are superior to resist lateral loading. [ABSTRACT FROM AUTHOR]

Various areas related to fixture are already described by renowned authors, but still there is an urgent need to apply all these research works to an industrial application. This paper presents design and development of rotary fixture for machining real industrial component - Flow TEE body of petroleum refinery. Actually HMC is the best solution for performing the required operations, but HMC costs around 12.5 million rupees whereas CNC turning centre costs only about 2.5 million rupees. Here the research work of this paper is proved. A fixture is designed & manufactured, which helps to accomplish required machining operations on CNC turning centre and hence 10 million rupees are saved in installation cost. Methodology for mass balance of rotary fixture developed by investigators mostly act as post-mortem tool; calculating unbalanced mass after fixture is manufactured. In the present work, a pre-mortem tool is developed to predict unbalanced mass well before manufacturing. The present research work also proposes three alternate methods for mass balancing of rotary fixture using Pro/Mechanism. Analytical analysis under dynamic machining is also covered. Fixture not only being designed and mass balanced, but manufactured also; this paper sets the classical example of design for manufacturing. [ABSTRACT FROM AUTHOR]

The optimum position of parallel underground cables will be calculated numerically. The criterion is how much joule losses should be dissipated in each cable so that the temperature increases of all cables are equal. A simple analytical formula is also given. [ABSTRACT FROM AUTHOR]

A new direction of crashworthiness improvement using a smart extendable front-end structure is introduced in this paper to support the function of the existing vehicle structure. The smart front-end structure consists of two extendable, independently controlled hydraulic cylinders (dampers) integrated with the front-end longitudinal members. The main objectives of the smart front-end structure are to find solutions of the trade-off problem faced by the designer for offset collision events and to mitigate full frontal collisions. The work carried out in this paper includes developing and analysing mathematical models of different vehicle crash scenarios, including vehicle-to-vehicle frontal collision in both full and offset events. In these models, vehicle components are modelled by lumped masses and cubic non-linear springs. The hydraulic cylinders are represented by cubic non-linear damper elements. In this paper, the dynamic responses of the crash events are obtained with the aid of an analytical approach using the incremental harmonic balance method. The intrusion injury as the maximum deformation of the front-end structure and the occupant deceleration injury are used for interpreting the results. It is demonstrated from simulation results that significant improvements to both intrusion and deceleration injuries are obtained using the smart front-end structures. [ABSTRACT FROM AUTHOR]