A PC-Based Simulator/Controller/Monitor Software for a Generic 6-DOF Manipulator

General form application is a very important issue in industrial design. Prototyping a design helps in determining system parameters, ranges and in structuring better systems. Robotics is one of the industrial design fields in which prototyping is crucial for improved functionality. Developing an environment that enables optimal and flexible design using reconfigurable links, joints, actuators and sensors is essential for using robots in the education and industrial fields. We propose a PC-based software package to control, monitor, and simulate a generic 6-DOF (six degrees of freedom) robot including a spherical wrist. This package may be used as a black box for the design implementations or as a white (detailed) box for learning about the basics of robotics and simulation technology.     

Statistical synchronization among participants in real-time multimedia conferencing

In this paper, an algorithm to determine the set of packets generated continuously and periodically from different participants that are arriving at a node either for mixing at the master of a conference, or for simply playing back at a regular participant of a conference, is proposed. The essence of the algorithm is to estimate the expected packet arrival time (or reference time) for each participant. With the reference time at hand, the maximum jitter and the optimum waiting time for a mixer to wait packets from all participants can be determined. An enhancement to improve synchronization which deals with the estimation of the time offsets between the individual periods of the sources and the period of the receiver is also presented. The error of the proposed algorithm is enumerated by the Chernoff bound and demonstrated by simulation and is shown to be acceptable in practical application. The algorithm can also be employed when traffic sources operate with different periods.     

A modified flow enforcement technique for ATM networks

In ATM networks the requirement of providing the negotiated Quality of Service (QOS) needs an efficient flow enforcement technique that will result in preventive congestion control. A very effective technique is the Exponentially Weighted Moving Average (EWMA) method. In this paper, we have suggested improvements to the EWMA and call it the Enhanced EWMA (EEWMA). Simulation results show that the EEWMA is consistently better than the EWMA in most of the situations. We present comparisons of cell loss under various conditions. No theoretical analysis is presented.     

Adaptive multimedia synchronization in a teleconference system

In this paper, we present an adaptive buffering scheme for implementing intra-stream and inter-stream synchronization in real-time multimedia applications. The essence of the proposed scheme is to dynamically enforce equalized delays to incoming media streams, in order to piece-wise smooth the network delay variations and to synchronize the streams at the sink. An adaptive control mechanism based on an event-counting algorithm is employed to calibrate the PlayOut Clocks (POCs), which manages the presentations of multimedia data. The algorithm does not rely on globally synchronized clock and makes minimal assumption on underlying network delay distribution. Also, the user defined quality of service (QoS) specifications can be directly incorporated into the design parameters of the synchronization algorithm. The proposed synchronization scheme has been experimentally implemented in a teleconference system which consists of separately controllable audio, video, and data channels. The modular structure of the synchronization control provides the flexibility to maintain an arbitrary synchronization group in conjunction with a distributed conference management scheme. This paper also shows the experimental results of the test implementation and the suitability of the proposed scheme with respect to the multimedia traffic across an FDDI/Ethernet network.     

The design and implementation of a modular and extensible Java Virtual Machine

This paper describes the design, implementation, and experimental evaluation of a modular and extensible Java? Virtual Machine (JVM) infrastructure, called Jupiter. The infrastructure is intended to serve as a vehicle for our research on scalable JVM architectures for a cluster of PC workstations, with support for shared memory in software. Jupiter is constructed, using a building block architecture, out of many modules with small, simple interfaces. This flexible structure, similar to UNIX® shells that build complex command pipelines out of discrete programs, allows the rapid prototyping of our research ideas by confining changes in JVM design to a small number of modules. In spite of this flexibility, Jupiter delivers good performance. Experimental evaluation of the current implementation of Jupiter using the SPECjvm98 and the EPCC Java Grande single‐threaded and multithreaded benchmarks reflects competitive performance. Jupiter is on average about 2.5 times faster than Kaffe and about 2 times slower than the Sun Microsystems JDK (interpreter versions only). By providing a flexible JVM infrastructure that delivers competitive performance, we believe we have developed a framework that supports further research into JVM scalability. Copyright © 2003 John Wiley & Sons, Ltd.     

Multilayered substrate integrated waveguide 4 × 4 butler matrix

In this article, a multilayered substrate integrated waveguide (SIW) Butler matrix beam‐forming network is proposed, designed, and demonstrated at 24 GHz for automotive radar system applications. The proposed low‐cost SIW structure can be used to develop a highly integrated multibeam antenna platform in automotive radar systems and other applications. In this structure, an SIW H‐plane coupler is optimized with an H‐plane slit to provide the required phase shift. A class of SIW E‐plane 3‐dB couplers in doubled layer substrate are studied and designed as the fundamental building blocks to avoid crossovers usually required in the construction of a Butler matrix. A 4 × 4 matrix is investigated and designed, which shows excellent performance over 22–26 GHz frequency band. Two types of antenna are tested with the proposed matrix scheme. First, an antipodal linearly tapered slot antenna (ALTSA) is incorporated into the Butler matrix to verify the broadband performances. Second, a longitudinal slotted waveguide antenna array is examined to generate radiation patterns in the broadside direction. Measured results agree well with simulated counterparts, thus validating the proposed multilayer SIW design concepts. In the next sections, the use as feeding networks for providing the reconfigurability operation of an antenna will be illustrated. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE , 2012.     

Improved adaptive neuro-fuzzy inference system

This paper introduces a new type of Adaptive Neuro-fuzzy System, denoted as IANFIS (Improved Adaptive Neuro-fuszzy Inference System). The new structure is realized by the insertion of the error of training of ANFIS in the third layer of this system. The recurrence of the error of training will increase the capability of convergence and the robustness of ANFIS. The proposed IANFIS system is applied to make the identification of nonlinear functions, and the obtained results are compared with these obtained by usual ANFIS to verify the effectiveness of the proposed adaptive neuro-fuzzy system.     

Oil thermal annealed nano‐structured indium tin oxide thin films for display applications

Indium tin oxide‐coated thin films (200 nm) are deposited on glass substrates by using R.f. sputtering technique. Here, we investigate the influence of new technique of treatment, which is called as “oil thermal annealing” on the nano‐structured indium tin oxide thin films at fixed temperature (150 °C) which improves adhesion strength, electrical conductivity and optical properties (transmittance) of the films. Oil thermal annealing is used to reduce inherent defects that may be introduced during the prepared thin film and cooling processes. Proposed technique is highly suitable for liquid crystal displays, solar cells and organic light emitting diodes, and many other display‐related applications.     

A synchronization algorithm for distributed multimedia environments

Network synchronization plays a significant role in transmitting multimedia objects over computer networks. Even packets from a single channel must be synchronized due to the problems in a packet switching environment, such as network jitter, frequency, and time offsets. We present an algorithm that determines the set of packets generated periodically by various participants arriving at a node. The basic advantage of the proposed algorithm is that the receiver estimates the reference times (expected arrival times of the packets) and achieves synchronization, without knowledge of the packet delays. The accuracy is improved and the complexity is reduced by predicting the time/frequency offsets between the clocks at the source and the mixer. The error is calculated by the Chernoff bound, demonstrated by simulation, and shown to be acceptable in practical applications.     

Load-Balanced Sparse Matrix–Vector Multiplication on Parallel Computers

We considered the load-balanced multiplication of a large sparse matrix with a large sequence of vectors on parallel computers. We propose a method that combines fast load-balancing with efficient message-passing techniques to alleviate computational and inter-node communications challenges. The performance of the proposed method was evaluated on benchmark as well as on synthetically generated matrices and compared with the current work. It is shown that, by using our approach, a tangible improvement over prior work can be obtained, particularly for very sparse and skewed matrices. Moreover, it is also shown that I/O overhead for this problem can be efficiently amortized through I/O latency hiding and overall load-balancing.