1,763 research outputs found

    Hybrid branch prediction for pipelined MIPS processor

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    In the modern microprocessors that designed with pipeline stages, the performance of these types of processors will be affected when executing branch instructions, because in this case there will be stalls in the pipeline. In turn this causes in reducing the Cycle Per Instruction (CPI) of the processor. In the case of executing a branch instruction, the processor needs an extra clocks to know if that branch will happen (Taken) or not (Not Taken) and also it requires calculating the new address in the case of the branch is Taken. The prediction that the branch is T / NT is an important stage in enhancing the processor performance. In this research more than one method of branch prediction (hybrid) is used and the designed circuit will choose different types of prediction algoritms depending on the type of the branch. Some of these methods were used are static while the other are dynamic. All circuits were built practically and examined by applying different programs on the designed predictor algorithm to compute the performance of the processor

    Using Fuzzy Rules in Identifying Cybercrime in Iranian Banking System

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    Similar growth of security and information technology and non-slot between these two subjects are factors of comfort in human societies. Therefore, base on evidences, with popularity and prevalence of using internet, cybercrime increases everyday because of failure of achieving balanced growth points, so that methods of attacks and fraud have become more complex. Therefore, security of cyberspace is major concern of banks, corporations and insurance companies. The main goal of this paper is using fuzzy algorithm and recommending effective systemrsquos cybercrime identification. Proposed frameworks, identifies and reports suspected cases in two levels. First level is analysis of user information and second one is detecting wrong warnings

    Cache coherency controller for MESI protocol based on FPGA

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    In modern techniques of building processors, manufactures using more than one processor in the integrated circuit (chip) and each processor called a core. The new chips of processors called a multi-core processor. This new design makes the processors to work simultanously for more than one job or all the cores working in parallel for the same job. All cores are similar in their design, and each core has its own cache memory, while all cores shares the same main memory. So if one core requestes a block of data from main memory to its cache, there should be a protocol to declare the situation of this block in the main memory and other cores.This is called the cache coherency or cache consistency of multi-core. In this paper a special circuit is designed using very high speed integrated circuit hardware description language (VHDL) coding and implemented using ISE Xilinx software. The protocol used in this design is the modified, exclusive, shared and invalid (MESI) protocol. Test results were taken by using test bench, and showed all the states of the protocol are working correctly

    Design and implementation of dual-core MIPS processor for LU decomposition based on FPGA

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    Many systems like the control systems and in communication systems, there is usually a demand for matrix inversion solution. This solution requires many operations, which makes it not possible or very hard to meet the needs for real-time constraints. Methods were exists to solve this kind of problems, one of these methods by using the LU decomposition of matrix which is a good alternative to matrix inversion. The LU matrices are two matrices, the L matrix, which is a lower triangular matrix, and the U matrix, which is an upper triangular matrix. In this paper, a design of dual-core processor is used as the hardware of the work and certain software was written to enable the two cores of the dual-core processor to work simultaneously in computing the value of the L matrix and U matrix. The result of this work are compared with other works that using single-core processor, and the results found that the time required in the cores of the dual-core is more less than using single-core. The designed dual-core processor is invoked using the VHDL language

    Complications After Laparoscopic and Conventional Cholecystectomy: A Comparative Study

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    The growing popularity of laparoscopic cholecystectomy (LC) has made extensive series comparing laparoscopic and conventional cholecystectomy in a prospective, randomized way nearly impossible. To evaluate LC we compared retrospectively 800 laparoscopic with 748 conventional cholecystectomies (CC). Of the 800 LC, 10 (1.2%) were converted to laparotomy. 6 conversions were related to aberrant anatomical features or features making dissection very difficult, 4 conversions were due to complications. There were 5 (0, 6%) intraoperative complications during LC and 4 (0.5%) during CC. Postoperative morbidity was 2.1% (n = 17) after LC and 3.7% (n = 28) after CC. Particularly the incidence of wound problems was only 0.5% (n = 4) after LC while it was 1.3% (n = 10) after CC. Overall morbidity was 2.7% (n = 22) for LC and 4.2% (n = 32) for CC. Mortality rate after CC was 0.4% (n = 3), there were no deaths after LC. Common bile duct-injury rate was 0.2% (n = 2) for both groups. Complication rates after LC have been rapidly decreasing with growing experience. Laparoscopic cholecystectomy can safely be performed by appropriately trained surgeons in more than 90% of patients suffering from gallbladder disease. The low morbidity and mortality together with the significant advantages to patient recovery makes laparoscopic cholecystectomy the treatment of choice for symptomatic cholecystolithiasis

    Self-Excited Dynamics of Discrete-Time Lur'e Models with Affinely Constrained, Piecewise-C1 Feedback Nonlinearities

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    Self-excited systems (SES) arise in numerous applications, such as fluid-structure interaction, combustion, and biochemical systems. In support of system identification and digital control of SES, this paper analyzes discrete-time Lur'e models with affinely constrained, piecewise-C1 feedback nonlinearities. The main result provides sufficient conditions under which a discrete-time Lur'e model is self-excited in the sense that its response is 1) bounded for all initial conditions, and 2) nonconvergent for almost all initial conditions.Comment: 12 pages, 12 figures, under revie

    Melody contour identification and instrument recognition using semitone mapping in Nucleus Cochlear Implant recipients

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    Cochlear implants (CIs) were originally aimed at restoring speech perception for patients with profound hearing loss. Many postlingually deafened CI patients report that music is not well perceived while others enjoy it. Music consists of complex sounds composed of tones with harmonic structure of overtones and temporal fine structure. The harmonic structure is not preserved by the current standard (Std) ACE (advanced combination encoders) mapping and the temporal fine structure is not well encoded. The mapping is believed to produce distortion due to compression oin the low frequency range. In 2008 we proposed two new semitone (Smt) mappings (Smt-LF and Smt-MF) in two frequency ranges (130-1502 Hz and 440-5040 Hz) respectively (Omran et al. 2008). Smt mapping is expected to preserve the harmonic structure representation of overtones and this may improve melody recognition with CIs. In this paper two psychoacoustic experiments (melody contour identification (MCI) (Galvin et al. 2007) and instrument recognition (IR)) were conducted with three different conditions (Std, Smt-MF and Smt-LF mappings) with CI recipients by streaming processed stimuli directly to the implant. The MCI test included five patterns (rising - rising falling - flat - falling rising – falling). Each pattern consisted of five tones; each tone had a fundamental frequency and four overtones. The lowest fundamental frequency of each pattern is called “root”. Signals had two different roots A3 (220 Hz) and A4 (440 Hz). Proposed nine patterns with three roots (A3, A4 and A5) by Galvin et al. (2007) were examined in a pilot test. This test took a long time and the preliminary results showed a possibility to reduce the number of patterns to five and eliminate the fifth octave root (A5). In the IR test, four pairs of instruments (Trumpet and Trombone, Flute and Clarinet, Violin and Cello, Guitar and Piano) from four groups (Brass, Woodwind, Struck and String instruments) respectively were used. MCI and IR tests were conducted with 8 CI recipients. Results from MCI tests showed an improvement with Smt mapping in respect to Std mapping or at least similar results. However, wrong identification occurred with notes having filtered out partials. CI recipients showed an increase in identifying melody contour patterns with Smt mappings. Instrument identification performance decreased with semitone mappings

    MEASURING STRATEGIES FOR KNOWLEDGE MANAGEMENT AND ORGANIZATIONAL PERFORMANCE IN LIBYAN TRANSPORTATION INDUSTRY: STRUCTURAL EQUATION MODELLING

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    The purpose of this research is to measure the strategies for knowledge management and organisational performance in Libya using an approach to structural equation modelling (SEM). The research method of this analysis is a quantitative method only, where the total sample size is assumed to be 453 using simple random sampling. The structural model for this analysis showed the relationships between the variables. The results show that the framework of knowledge management is significantly related to the strategy of knowledge management, while knowledge management practise is significantly related to the strategy of knowledge management. However, the framework of knowledge management was found not to be very positively linked to organisational performance. Unexpectedly, in terms of significantly related to organisational performance, knowledge management activity has also not been considered relevant. Knowledge management approach, on the other hand, is positively linked to organisational performance and to the reciprocal relationship between the system of knowledge management and the practise of knowledge management. By offering an empirically validated model that could be used to forecast organisational performance as a whole, this study has added to established knowledge. JEL: L10; L25; L91 Article visualizations

    A CONCEPTUALIZATION OF KNOWLEDGE MANAGEMENT STRATEGY TOWARD ORGANIZATION PERFORMANCE IN THE LIBYAN TRANSPORTATION INDUSTRY

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    This conceptual paper aims to examine the relationship between the knowledge management strategy and organizational performance in Libya transportation industry. Libya’s government policy proposals for public organisation reform have largely failed to encourage the development of information. The transport industry is suffering from a shortage of backward-integrated equipment. Most Arab nations have inherited their transparent authoritative practises from their previous founder legacies. This is despite the way in which the region needs knowledge management as never before due to the evolving way of global aggression. Also, the introduction and use of different information technologies in an enterprise will be the key to conducting knowledge management activities in the transport industry. The promotion of trust among members of intra- and inter-organizational teams is of primary concern for the establishment of a strong and sound knowledge base. It takes some time to establish a desired knowledge culture for the sharing of knowledge and exchange of knowledge. However, only a small section of the public would appreciate gains and any aspect of it could be overlooked by the rest. It should strive to develop the academic resources of the general public and involve people in basic leadership in general. JEL: L10; L25; L91 Article visualizations
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