Circuits

In today's Internet, demand is increasing for guarantees of speed and efficiency. Current routers are very limited in the type and quantity of observed data they can provide, making it difficult for providers to maximize utilization without the risk of degraded throughput. This research uses statistical data currents provided by router vendors to estimate the impact of changes in network

The telecommunications industry has undergone major paradigm shifts in previous years. One of these is the shift from circuit-switched networks towards packet-switched networks. There is hardly any doubt that IP will be the ubiquitous transport protocol for multimedia of the future. At present, the work towards Internet telephony has attracted a lot of attention. Two standards have been developed: SIP (session initiation protocol) by the Internet Engineering Task Force (IETF) and H.323 by the International Telecommunications Union (ITU). The rapid deployment of services on top of SIP is hindered by a well known problem, feature interactions, also well known in traditional telephony networks. In this paper, the technological changes in SIP compared to the traditional telephony network are highlighted as well as the impact of the changed business environment. In a multi-service provider environment (as encouraged by a SIP environment), the feature interaction problem is regarded to be an even more pressing issue. Services of different providers from a multitude of service creators are likely to interwork. This in turn leads to the fact that the ad-hoc approaches to service interaction handling, commonly applied in the industry today, will not be sufficient any more. In this paper, a new approach addressing these changes is introduced and the results of a case study are presented

This paper presents new, fast hardware for computing the exponential function, sine, and cosine. The main new idea is to use low-precision arithmetic components to approximate high precision computations, and then to correct very quickly the approximation error periodically so that the effect is to get high precision computation at near low-precision speed. The algorithm used in the paper is a nontrivial modification of the well-known CORDIC algorithm, and might be applicable to the computation of other functions than the ...

Abstract Summary form only given. In a broadcasting problem, a message is sent from a source to all the other nodes in the network. Blind flooding is a classical mechanism for broadcasting, where each node retransmits received message to all its neighbors. We ...

The highly nonuniform transient power densities in modern semiconductor devices present difficult performance and reliability challenges for circuit components, multiple levels of interconnections and packaging, and adversely impact overall power efficiencies. Runtime temperature calculations would be beneficial to architectures with dynamic thermal management, which control hotspots by effectively optimizing regional power densities. Unfortunately, existing algorithms remain computationally prohibitive for integration within such systems. This work addresses these shortcomings by formulating an efficient method for fast calculations of temperature response in semiconductor devices under a time-dependent dissipation power. A device temperature is represented as output of an infinite-impulse response (IIR) multistage digital filter, processing a stream of sampled power data; this method effectively calculates temperatures by a fast numerical convolution of the sampled power with the ...

The dentate gyrus is a simple cortical region that is an integral portion of the larger functional brain system called the hippocampal formation. In this review, the fundamental neuroanatomical organization of the dentate gyrus is described, including principal cell types and their connectivity, and a summary of the major extrinsic inputs of the dentate gyrus is provided. Together, this information

A microcomputer, the Altair 8800, was used to generate the gating signals for a single-phase-to-single-phase cycloconverter, keeping the same firing angle on all thyristors for a particular output voltage and frequency. The power circuit and the required interface circuits were built. Output waveforms for different firing angles and output frequencies were obtained.

Light-emitting diode (LED) nonlinear differential gain (DG) and differential phase (DP) were measured, since they are important performance factors in video signal transmission. Typical, experimentally measured temperature dependence of DG and DP is also presented. A linearizing method for minimizing LED DG and DP distortions, using predistortion, is proposed and experimentally examined. With this technique, and with precise adjustment of the predistortion circuits, the DG of a typical LED was improved from 12.5 percent to less than 1 percent, and the DP from 2.8° to 1°. This corresponds to an improvement in second and third-order harmonic distortions of 19 dB and 21 dB, respectively. DG and DP were measured with respect to the 3.58-MHz color subcarrier frequency superimposed on the 15.75-kHz horizontal scanning sawtooth wave. The linearization stability with regard to temperature variation was lowered to be less than 1-percent DG and 1° DP in the temperature range from 15 to 45°C.

In this paper, a high efficiency C-band GaN HEMT high power amplifier with internal harmonic manipulation circuits is presented. We employed a new circuit topology for simultaneous high efficiency matching at both fundamental and 2nd-harmonic frequencies. The developed GaN HEMT amplifier has achieved over 57% drain efficiency (50% power-added-efficiency) with 100 W output power at C-band. This is the state-of-the-art efficiency of GaN HEMT high power amplifier at C-band to the best of our knowledge.

In this paper we propose a design using both a microprocessor and light sensors for automatic room light detection and control. Our design, the HLCM (Home Light Control Module) which will be installed in every light fixture of a family, is made up of four blocks: the pyroelectric infrared (PIR) sensor circuit, the light sensor circuit, the microprocessor and the RF module. By using the PIR sensor circuit, the HLCM detects if a human body enters the detection area or not. If there is no human body present, all controlled lights are turned off. If there is, the HLCM detects the light intensity under the environment and maintains sufficient light by controlling the number of lights. We have also integrated an RF module to transmit and receive the data from each HLCM so we can control different lights in different regions. The result of using the HLCM shows that the total power consumption can be reduced.

Decimal data processing applications have grown exponentially in recent years thereby increasing the need to have hardware support for decimal arithmetic. In this paper, an improved architecture for efficient Binary Coded Decimal (BCD) addition/subtraction is presented that performs binary addition/subtraction without any extra hardware. The architecture works for both signed and unsigned numbers. The design is runtime reconfigurable and maximum utilization of the hardware is a feature of the architecture. Simulation results show that the proposed architecture is at least 32% better in terms of power-delay product than the existing designs.

A VLSI implementation of a data acquisition system processor for failure detection and location inside oil pipelines is presented. The DAQP02 prototype is capable of reading and storing information inside pipelines. With support for two analog signals and a 22 bits address bus, the DAQP02 is an efficient solution for in-line inspection tools known as Smart Pig. The main goal for this implementation is to minimize the physical dimension and power consumption of these equipments. The DAQP02 was manufactured in CMOS 0.8 μm double poly, double metal, n-well technology. The experimental results agree with simulations