Digital Filters

The recent advances in miniaturization and the creation of low-power circuits, combined with small-sized batteries have made the development of wireless sensor networks a working reality. Lately, the production of cheap complementary metal-oxide semiconductor cameras and microphones, which are able to capture rich multimedia content, gave birth to what is called Wireless Multimedia Sensor Networks (WMSNs). WMSNs will boost the capabilities of current wireless sensor networks, and will fuel several novel applications, like multimedia surveillance sensor networks. WMSNs introduce several new research challenges, mainly related to mechanisms to deliver application-level Quality-of-Service (e.g., latency minimization). To address this goal in an environment with extreme resource constraints, with variable channel capacity and with requirements for multimedia in-network processing, the caching of multimedia data, exploiting the cooperation among sensor nodes is vital. This article presents a cooperative caching solution particularly suitable for WMSNs. The proposed caching solution exploits sensor nodes which reside in “positions” of the network that allow them to forward packets or communicate decisions within short latency. These so-called “mediator” nodes are selected dynamically, so as to avoid the creation of hot-spots in the communication and the depletion of their energy. The mediators are not more powerful than the rest of the nodes, but they have some special role in implementing the cooperation among the sensors. The proposed cooperative caching protocol includes components for locating cached data as well as for implementing data purging out of the sensor caches. The proposed solution is evaluated extensively in an advanced simulation environment, and it is compared to the state-of-the-art cooperative caching algorithm for mobile ad hoc networks. The results confirm that the proposed caching mechanism prevails over its competitor.

A coding theory approach to error control in redundant residue number systems (RRNSs) is presented. The concepts of Hamming weight, minimum distance, weight distribution, and error detection and correction capabilities in redundant residue number systems are introduced. The necessary and sufficient conditions for the desired error control capability are derived from the minimum distance point of view. Closed-form expressions are

Users of modern digital libraries (DLs) can keep themselves up-to-date by searching and browsing their favorite collections, or more conveniently by resorting to an alerting service. The alerting service notifies its clients about new or changed documents. Proprietary and mediating alerting services fail to fluidly integrate information from differing collections. So far, no sophisticated service has been proposed that is integrated with the digital library software and covers heterogeneous and distributed collections. This paper ...

چکیده
در این کتاب ما در تلاش هستیم تا با استفاده از یک روش جدید فیلتر دیجیتال IIR را طراحی کنیم، چرا که فیلترهای IIR در بسیاری از زمینه‌های فنی وکاربردهای دیجیتال در سیستم‌های پردازش سیگنال دیجیتال (DSP) قابل استفاده¬اند ومی‌توانند در مقایسه با فیلتر FIR عملکرد بهتری از خود نشان دهند. در این کتاب یک الگوریتم ترکیبی PSO با DS ارائه شده است تا برخی از مشکلاتی را که نمی‌توانیم به تنهایی توسط PSO حل کنیم پوشش دهند. وقتی از DSPSO برای طراحی فیلتر دیجیتال IIR استفاده می‌شود بایستی مجموعه‌ای از مشکلات پیش رو مورد بحث وبررسی قرار گیرد. اولین مساله محاسبه¬ی تقریبی پاسخ اندازه-فرکانس فیلترهای دیجیتال IIR در شرایطی است که حداکثر شعاع قطب نزدیک به 1.0 باشد. مشکل دوم حداقل ساختن غیرخطی خطای میانگین مربعات بین پاسخ‌های مربوط به فیلتر طراحی شده وفیلتر مطلوب در باند عبور، باند توقف وباند انتقال به صورت همزمان است که این مساله اجازه ی وجود ریپل‌های مجاز در باند عبور وباند مجاز را ایجاد می‌کند، مشکله سوم حداقل مقدار خطا برای فیلرهای IIR پایین‌گذر وفیلتر بالا گذر است. ومشکل چهارم تعریف یک تابع برازندگی مناسب است که به ریپل در باند عبور، ریپل در باند توقف ومقادیر باند انتقال وابستگی دارد. پس از به دست آوردن نتایج ومقایسه آنها با نتایج دیگر تحقیقات قبلی برای طراحی فیلتر دیجیتال IIR با روش‌های مختلف، می‌بینیم که نتایج ما بهترین عملکرد را ارائه می‌کنند.

  IIR، PSO.،واژگان کلیدی: فیلتر دیجیتال، بهینه‌سازی ذره ای، پاسخ ضربه بی نهایت

Abstract
In this book, we are striving to design an infinite impulse response (IIR) digital filter using a "Novel" method. Because of IIR filters have become used in digital signal processing systems (DSP) for many technical fields and digital applications. Due to the IIR filter can perform well compared to the FIR filter. We have proposed a hybrid particle swarm optimization (PSO) algorithm with Dynamic-Static DS, which solves some problems that we cannot solve by the independent PSO. When we used DSPSO to design a digital IIR filter, we discussed four of the problems. The first problem is the approximation magnitude-frequency response of the IIR digital filter when the maximum pole radius is close to 1.0. The second problem is a nonlinear minimization of mean square error between the designed and desired filter responses in the passband, stopband, and transition band simultaneously, allowing permissible ripples in passband and stopband. The third problem is the minimum error for the lowpass and highpass IIR filters. As for the fourth problem is defining a suitable error fitness function that depends on passband ripple, stopband ripple, and transition band values. Also, we compared our results with many previous results of designing the IIR filter using smart algorithms. Results of simulation and analysis have proven that the proposed method DSPSO is the best for designing an IIR digital filter while ensuring optimum stability and a high convergence ratio.
Keywords: IIR, PSO, Infinite Impulse Response, Particle Swarm Optimization, Digital filter .

Virtual Reality (VR) is on the edge of becoming the next major delivery plat- form for digital content. Technological progress has made accessible a variety of new tools, allowing development of the necessary hardware and software for VR interaction. The importance of audio in this process is increasing. Audio can intensify the three dimensional experience and immersion of game players and users in other applications.
This research focuses on determining and implementing the necessary ele- ments for a system able to deliver Virtual Auditory Display (VAD). The system structure is adapted to fit a new emerging gaming platform: smart- phones. Developing for mobile platforms requires consideration of many con- straints such as memory, processor load and development components.
The result is a real-time dynamic VAD, manageable by mobile devices, and able to trigger spatial auditory perception across the azimuthal plane. In this study it is also shown how the VAD developed following custom imple- mentation of selected Head Related Transfer Function (HRTF), is able to generate azimuthal localization of sound events in VR scenarios.

Salt water intrusions of marine origin are a major cause of contamination for coastal fresh water aquifers. They are generated mainly by the uncontrolled exploitation of fresh water in pumping stations from coastal areas. In Romania, such marine intrusions have occurred in the southern part of Black Sea's coastline, in the area of Vama Veche and Costineşti resorts, contaminating the main aquifers which are hosted within Sarmatian (late Middle Miocene) lumachelic and oolitic limestones. Fresh water exploitation management requires the identification, mapping and monitoring of marine intrusions. These are achievable by means of an adequate application of geoelectrical methods, because sea water intrusions lead to major variations of the aquifers resistivity. Apparent resistivity surveys such as electrical profiling and vertical electrical sounding (VES) are able to delineate the areal extent of these intrusions and to identify the approximate depth of the fresh water/salt water interface. Assuming the subsurface geology consists of horizontal and homogeneous layers, the VES apparent resistivity data can be interpreted in terms of layer thicknesses and true resistivities, i.e. a one-dimensional (1-D) geoelectrical model with a stepwise variation of true resistivity with depth. The optimal model is obtained by repeated forward modeling trials or through the inversion of measured apparent resistivities.
This paper presents an algorithm and a set of software applications for the forward modeling of VES apparent resistivity curves, by using digital linear filtering. The codes were elaborated in MATLAB programming environment and allow the calculation of the theoretical VES response for horizontally-layered geological media with virtually unlimited number of layers, including layers with a quasi-continuous resistivity variation. The latter option can be used to simulate particular hydrogeological situations regarding the sea water intrusions in fresh water aquifers, which often show a mixing/transition zone of variable salinity and resistivity. The interpretation of VES curves recorded in Vama Veche area by using the elaborated software indicates that the sea water intrusion occurs at more than 50 m depth. This agrees with water wells tests which confirm the presence of salt water at 40–60 m depth in that area.

In this paper, we discuss how asynchronous design techniques can be used in the implementation of continuous-time signal processors. Such processors are presented by signals developed by continuous-time analog-to-digital converters which involve no sampling, and thus do not exhibit aliasing; in addition, the resulting in-band quantization error is lower than in conventional techniques. Several design considerations are given, and preliminary experimental results are presented.

The research on optimal design of Finite impulse response (FIR) filter based on various optimization techniques, including evolutionary algorithm (EAs) have gained much attention in recent years. Genetic algorithm is a particular class of evolutionary algorithms that use techniques inspired by evolutionary biology such as inheritance, mutation, selection, and crossover. The New Differential evolution algorithm based on reserve genes (Eclectic Differential Evolution) have been used here for the design of finite impulse response filters. This algorithm is applied in order to obtain the actual filter response as close as possible to the ideal response. In this method, the new vectors can be produced by the combination of genes of selected chromosomes. These new vectors as the individuals are evolved with other individuals in the population and also increase the diversity of population.

Abstract: This paper examines the design and simulation of a 12-bit Sigma-Delta Modulator that operates from a single 3-V power supply. The proposed modulator has been designed with fully-differential switched-capacitor integrators implemented with folded-cascode operational amplifiers. The main feature of the designed modulator is its simplicity. It shows that it is possible to design a precise modulator of moderated Signal-to-Noise