Welcome to Journal of Theoretical and Applied Information Technology

Author:

Source:

Abstract

Frequent pattern mining is one of the active research themes in data mining. It plays an important role in all data mining tasks such as clustering, classification, prediction, and association analysis. Identifying all frequent patterns is the most time consuming process due to a massive number of patterns generated. A reasonable solution is identifying maximal frequent patterns which form the smallest representative set of patterns to generate all frequent patterns. In this paper, an efficient numerical method for mining frequent patterns is proposed. This method is based on prime number characteristics to generate all frequent patterns by using maximal frequent ones. There are two new properties introduced in this method; a novel tree structure called PC_Tree and PC_Miner algorithm. The PC_Tree is a simple tree structure but yet capable to capture the whole of transactions information with an efficient data transformation technique that utilizes the prime number theory. The PC_Miner algorithm traverses the PC_Tree by using an efficient pruning technique. The experimental results verify the compactness and the efficiency of mining shown by the proposed method.

Author:

Source:

Abstract

Power transmission and distribution lines are the vital links that achieve the essential continuity of service of electrical power to the end users. Transmission lines connect the generating stations and load centers. As the generating stations are far away from the load centers they run over hundreds of kilometers. Hence, the chances of fault occurring in transmission lines are very high. Since faults can destabilize the power system they must be isolated immediately. Fault analysis is very important issue in power system engineering in order that to clear faults quickly and restore power supply as soon as possible with minimum interruption. Signal processing is one of the most important parts of the digital distance protection schemes. The faulted phases identification is done by analyzing the detail coefficients of the phase currents. To distinguish ground faults from phase to phase ones, the analysis of the smooth coefficients of the neutral current can be used. The proposed model is based upon a combination of the impedance calculation and the Continuous Wavelet Transformation (CWT) method to detect the disturbance along with distance of Fault occurrence. MATLAB/Simulink is used to generate fault signals and verify the correctness of the algorithm. Simulation results reveal that the performance of the proposed fault detection indicator is promising.

Author:

Source:

Abstract

Power Quality is a major concern of our modern industries and other consumers. Poor quality of supply will affect the performance of customer equipment such as computers, microprocessors adjustable speed drives, power electronic devices, life saving equipment in hospitals, etc. and result in heavy financial losses to customers due to loss of production or breakdown in industries or loss of life in a hospital. The two major power quality disturbances are voltage sag and harmonic distortion. In the event of voltage sag, due to insufficient energy, equipments may malfunction or trip. Harmonics introduced by nonlinear loads can pollute the input supply to the sensitive equipments and cause the connected equipments to malfunction. In this work, a Power Quality Provider (QPP) is proposed and modeled by simulation.. The QPP has a novel feature of performing dual functions of mitigation of sag and suppression of harmonics quickly, dynamically and simultaneously using a simple unique and novel control scheme. The QPP will be connected close the sensitive loads which are to be protected in the distribution network. For a case study the hospital distribution network which supplies many life saving equipments such as MRI, CTSCAN, computerized surgery equipment, etc. at Ipoh, Malaysia was chosen to conduct experiments. Experimental results prove the credibility of QPP in mitigating power quality disturbances effectively, such that the voltage at the sensitive loads are at the rated value and sinusoidal. The design, modeling and simulation are done using PSS/ADEPT and PSCAD software.

Author:

Source:

Abstract

Mobile Ad hoc Networks are highly dynamic networks. Quality of Service (QoS) routing in such networks is usually limited by the network breakage due to either node mobility or energy depletion of the mobile nodes. Also, to fulfill certain quality parameters, presence of multiple node-disjoint paths becomes essential. Such paths aid in the optimal traffic distribution and reliability in case of path breakages. Thus, to cater such problem, we present a node-disjoint multipath protocol. The metric used to select the paths taking into account both the link stability and energy levels of the nodes.

Author:

Mahdi Shafieezadeh, Abbas Hajfataliha

Source:

Abstract

Supply chain management is concerned with the coordination of material, information and financial flows within and across often legally separated organizational units. With the recent advances in information technology, real time data exchange has become feasible and affordable. As a result, an equally (if not more) important issue for supply chain coordination is to incorporate information into a coordination policy. In this paper, we have studied a vast literature on coordination problem for supply chains with suppliers, manufacturers, retailers, and customers. In this research we have developed a framework for: (1) information sharing within supply chain members, (2) improving decision making process, and finally (3) strategic management of the whole supply chain. The information sharing within supply chain members is considered in two dimensions. First dimension is the quantitative information on demand, inventory, and backlog, which will decrease bullwhip effect, and improve efficiency of production planning and inventory control. Second dimension is the qualitative information on customer preference which can be used in decision making and planning that will lead to customer satisfaction. In this model the decision making process is based on four prominent aspects of customer satisfaction namely: price, lead time, quality, and service level. This framework can be used by strategic decision makers who need comprehensive models to guide them in efficient decision making that increases the profitability of the entire chain.

Author:

Source:

Abstract

There are so many important results toward finding the association rules. But, when we consider the sale of seasonal items then no algorithm existed till now that can able to mine the interesting pattern on time–variant seasonal database. In view of this, we propose an Effective Miner (abbreviatedly as EM) algorithm to perform the mining for this problem as well as I conduct the corresponding performance studies.
Furthermore, without fully considering the time-changing characteristics of items and transactions, it is noted that some discovered rules may be expired from user’s interest i.e rules generated in one season can not give the useful information in other season. Under EM we first partition the database on the bases of season i.e Yearly, Half Yearly or Quarterly etc according to user’s requirements and then we apply weighted mining on each partition. In EM (Effective Miner) the cumulative information of mining previous partitions is selectively carried over toward the generation of candidate itemsets for the subsequent partitions I have also applied scan reduction technique in EM due to that only two scan of database are required, means saving lots of time.

Author:

Source:

Abstract

Negotiation is being known as a main form of communication in contexts including multiple autonomous agents. One of these fundamental contexts would be autonomous e-commerce contexts in which human traders will be substituted by trader agents. In spite of ignorance of its role in previous researches, a prominent factor that can affect negotiation’s features in such multi-agent contexts may be issues’ kinds; by considering each issue (e.g. price, quality, guarantee, timing, …) as a beneficial issue for both sides of a negotiation or as a beneficial issue for one side, this paper introduces two kinds of issues- common and peripheral issues. To analyze the effect of this factor (issues’ kinds) on negotiation’s features, without being influenced by other factors, we will categorize negotiation methods based on kinds of issues. After investigating each method’s features, next great deal would be selection of best method and the best opponent to negotiate with. Hence, this paper offers an architectural design to conduct this work properly.

Author:

Source:

Abstract

Because of providing services to the users in the heterogeneous distributed environments, service oriented systems are very important. Most of the time, the individual services do not have the sufficient conditions to provide any services to the users. In order to resolve the aforementioned problem, one may compose several individual services together.
In this paper, we propose a dynamic approach to select the best composition. This composition is selected based on the quality and the compose-ability of participated services.
In the real life situation, we are facing with different servers, in which they present the same services with the different interfaces. This proposed method considers these varieties. Another advantage of the proposed approach in the paper is to recognize the feasibility of the composition process at any point of execution.
We introduce an algorithm with a better speedup and a less consumption of memory to select composition of services dynamically. Needless to say, that this algorithm considers matching of interfaces of services.

Author:

Source:

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) has become a popular modulation method in high speed wireless communications. By partitioning a wideband fading channel into flat narrowband channels, OFDM is able to mitigate the detrimental effects of multipath fading using a simple one-tap equalizer. There is a growing need to quickly transmit information wirelessly and accurately. OFDM is a suitable candidate for high data rate transmission with forward error correction (FEC) methods over wireless channels. In this research paper, the system throughput of a working OFDM system has been enhanced by adding turbo coding. The use of turbo coding and power allocation in OFDM is useful to the desired performance at higher data rates. Simulation is done over additive white Gaussian noise (AWGN) and impulsive noise (which is produced in broadband transmission) channels. The wideband system has 48 data sub-channels; each is individually modulated according to channel state information acquired during the previous burst. This research paper is to increase the system throughput while maintaining system performance under a desired bit error rate (BER). To improve the performance of the uncoded OFDM signal by convolution coding.

Author:

Source:

Abstract

Maintenance of good quality of power supply is essential for reliability and stability of power system. The effects due to power transformer switching and the transient effects are investigated in this paper. The DWT based techniques are suggested in the past to analyze the transient effects and to respond at a faster rate to improve the quality of power system and protection. These measures were though efficient in providing better solution but found to be high resource consuming under remote applications. This high resource consumption results in slower response and reduces the reliability issue in power system. A FPGA based DWT architecture is suggested to improve the efficiency of estimation and response in the power system. The Field Programmable Gate Arrays (FPGA) based DWT architecture is evaluated with theoretical results from MATLB and were observed to be meeting the accuracy of estimation.

Author:

Source:

Abstract

Choice of rating, setting, and co-ordination of protective devices is very vital for improving the power quality in power systems. This necessitates detection and classification of the faults quickly and accurately. In this paper Wavelet Transforms have been used to obtain the detailed and approximate coefficients of the fault signal. An algorithm is developed based on the histogram representation of these detailed and approximate coefficients to classify the faults. The effectiveness of this new method is compared with that of the fuzzy logic.

Author:

Source:

Abstract

Document categorization is a widely researched area of information retrieval. A research on Malay natural language processing has been done up to the level of retrieving documents but not to the extent of automatic semantic categorization. Thus, an approach for the clustering of Malay documents based on semantic relations between words is proposed in this paper. The method described in this paper uses Singular Value Decomposition (SVD) technique for the vector representation of each document where familiar clustering techniques can be applied in this space. The experimental results we obtained taking into account the semantics of the document that performed good document clustering by obtaining relevant subjects appearing in a cluster.

Author:

Source:

Abstract

This paper analyses the reliability of computer network system consists of a server and two subsystems connected in parallel. In this way whole system will down only when both the subsystems are down or server fails. By supplementary variable technique it is concluded that Steady state transition probability is around 99.55%, system will degrade slowly with time shown in fig-4. It is also shown that availability and reliability also decreases with time as shown in fig-5. This study also describes that how MTTF will effect with respect to failure rate as shown in fig-6.