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High-rate low-density parity-check (LDPC) codes are the focus of intense research in magnetic recording because, when decoded by the iterative sum-product algorithm, they show decoding performance close to the Shannon capacity. However, cycles, especially short cycles, are harmful to LDPC codes. The paper describes the partition-and-shift LDPC (PS-LDPC) codes, a new class of regular, structured LDPC codes that can be designed with large girth and arbitrary large minimum distance. Large girth leads to more efficient iterative decoding and codes with better error-floor properties than random LDPC codes. PS-LDPC codes can be designed for any desired column weight and with flexible code rates. The paper details the girth and distance properties of the codes and their systematic construction and presents analytical and simulation performance results that show that, in the high signal-to-noise ratio region, PS-LDPC codes out- perform random codes, alleviating the error floor phenomenon. [ABSTRACT FROM AUTHOR]

In this paper a new RC - active polyphase filter section is presented. The section uses three conventional current conveyor (CCII). With a cascade of these sections, any higher order polyphase filter function can be realized. Frequency transfer functions, gain and phase errors of the proposed section are derived for ideal and nonideal CCIIs. In the case of using nonideal CCIIs filter characteristics are investigated by performing computer simulations. Also the paper deals with the leakage caused by the effects of a limited gains of a current conveyors. [ABSTRACT FROM AUTHOR]

The basic task of the transportation fleets is to carry personnel and cargo from one point to another according to the daily planned flight schedule. Mission-ready flight crews and aircrafts are needed to accomplish the task. The goal of this paper is to determine which factors affect the success of the daily planned flight schedule and how, and also to define a prediction model to estimate the success of the daily planned flight schedule in order to help making more precise flight schedule. In this study, the simulation model is designed by ARENA software; the inputs defined by the NOLH experiment design, and the outputs are transferred to Design-Expert software. The effects of the factors are analyzed by Design-Expert and the prediction model is defined by using Response Surface. [ABSTRACT FROM AUTHOR]

Many classification algorithms and econometric models require that training examples contain only discrete values. In order to use these algorithms when some variables have continuous values, the numeric variables must be converted into discrete ones. This paper describes a new way of discretizing numeric values using multiple structural changes. [ABSTRACT FROM AUTHOR]

In this paper, a sliding mode controller is designed for active shaping of the input current in the boost converter. Robustness of the designed controller is tested with variable output voltage references, different loads and network voltage variations. For the simulations, MATLAB/Simulink programme is used. From simulation results, the same phase was provided between input current and input voltage and nearly unity power factor was obtained. [ABSTRACT FROM AUTHOR]

A parity code and a distance enhancing constrained code are often concatenated with a Reed-Solomon code to form a coding system for magnetic recording. The tensor-product parity coding scheme helps to improve efficiency of the parity code while retaining the same level of performance. In this paper, we present two methods for combining a tensor-product parity code with a distance-enhancing constrained code. The first method incorporates a constrained code with unconstrained positions. The second method uses a new technique, which we call word-set partitioning, to achieve a higher code rate relative to the first method. We simulate the performance of several coding systems based upon the two combination methods on a perpendicular recording channel, and we compare their symbol error rates and sector error rates with those of a system that uses only a Reed-Solomon code. [ABSTRACT FROM AUTHOR]