Karachi Institute of Economics & Technology

Karachi, Pakistan

Karachi Institute of Economics and Technology was established in 1997 with the aim of providing quality of education at affordable cost. Its academic programs are designed to prepare the students to meet the challenges of the nation and industry. KIET received the recognition by the Higher Education Commission vide letter no. 15-2297IT category.KIET was awarded a degree-granting status through a charter from the Government of Sindh on 24 May 2000. Wikipedia.

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Ishaque K.,Karachi Institute of Economics & Technology | Salam Z.,University of Technology Malaysia | Lauss G.,AIT Austrian Institute of Technology
Applied Energy | Year: 2014

With the rapid growth of photovoltaic (PV) systems, stringent standards are envisaged to ensure the safe and efficient generation of power. Therefore, the performance of maximum power point tracking (MPPT) element in PV system under dynamic environmental conditions is very crucial. Hence, this paper evaluates the performance of perturb and observe (P&O) and incremental conductance (IC) MPPT technique on the basis of European Efficiency Test, EN 50530, which is specifically devised for the dynamic performance of PV system. Both techniques are implemented in direct control structure and buck-boost converter is used as MPPT converter. Experiments are conducted using a custom designed PV array simulator. Results reveal that both methods yield almost equivalent dynamic MPPT efficiency. However, in average, the performance of IC method is found to be slightly better that gives 98.5% efficiency compare to 98.3% in P&O. It is also seen that the performance of IC method is very sensitive to its perturbation size, especially at low insolation levels. © 2014 Elsevier Ltd.

Ducruet C.,CITES | Zaidi F.,Karachi Institute of Economics & Technology | Zaidi F.,French Institute for Research in Computer Science and Automation
Maritime Policy and Management | Year: 2012

The analysis of community structures is one major research field in the science of networks. This exercise is often biased by strong hierarchical configurations as it is the case in container shipping. After reviewing the multiple definitions of port systems, this paper applies a topological decomposition method to worldwide inter-port maritime links. Isolating ports of comparable size reveals hidden substructures with the help of graph visualization. While geographic proximity is one main explanatory factor in the emergence of port systems, other logics also appear, such as specialized and long-distance trading links. This research provides interesting evidence about the role of geography, technology and trade in the architecture of maritime networks. © 2012 Copyright Taylor and Francis Group, LLC.

Ishaque K.,University of Technology Malaysia | Ishaque K.,Karachi Institute of Economics & Technology | Salam Z.,University of Technology Malaysia
IEEE Transactions on Industrial Electronics | Year: 2013

This paper proposes a deterministic particle swarm optimization to improve the maximum power point tracking (MPPT) capability for photovoltaic system under partial shading condition. The main idea is to remove the random number in the accelerations factor of the conventional PSO velocity equation. Additionally, the maximum change in velocity is restricted to a particular value, which is determined based on the critical study of $P$-$V$ characteristics during partial shading. Advantages of the method include: 1) consistent solution is achieved despite a small number of particles, 2) only one parameter, i.e., the inertia weight, needs to be tuned, and 3) the MPPT structure is much simpler compared to the conventional PSO. To evaluate the idea, the algorithm is implemented on a buck-boost converter and compared to the conventional hill climbing (HC) MPPT method. Simulation results indicate that the proposed method outperforms the HC method in terms of global peak tracking speed and accuracy under various partial shading conditions. Furthermore, it is tested using the measured data of a tropical cloudy day, which includes rapid movement of the passing clouds and partial shading. Despite the wide fluctuations in array power, the average efficiency for the 10-h test profile reaches 99.5%. © 1982-2012 IEEE.

Iqbal R.,Karachi Institute of Economics & Technology
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

Domain ontology is a descriptive representation of any particular domain which in detail describes the concepts in a domain, the relationships among those concepts and organizes them in a hierarchal manner. It is also defined as a structure of knowledge, used as a means of knowledge sharing to the community. An Important aspect of using ontologies is to make information retrieval more accurate and efficient. Thousands of domain ontologies from all around the world are available online on ontology repositories. Ontology repositories like SWOOGLE currently have over 1000 ontologies covering a wide range of domains. It was found that up to date there was no ontology available covering the domain of "Sufism". This unavailability of "Sufism" domain ontology became a motivation factor for this research. This research came up with a working "Sufism" domain ontology as well a framework, design of the proposed framework focuses on the resolution to problems which were experienced while creating the "Sufism" ontology. The development and working of the "Sufism" domain ontology are covered in detail in this research. The word "Sufism" is a term which refers to Islamic mysticism. One of the reasons to choose "Sufism" for ontology creation is its global curiosity. This research has also managed to create some individuals which inherit the concepts from the "Sufism" ontology. The creation of individuals helps to demonstrate the efficient and precise retrieval of data from the "Sufism" domain ontology. The experiment of creating the "Sufism" domain ontology was carried out on a tool called Protégé. Protégé is a tool which is used for ontology creation, editing and it is open source. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Naseem I.,Karachi Institute of Economics & Technology | Naseem I.,University of Western Australia | Togneri R.,University of Western Australia | Bennamoun M.,University of Western Australia
Pattern Recognition | Year: 2012

In this paper we address the problem of robust face recognition by formulating the pattern recognition task as a problem of robust estimation. Using a fundamental concept that in general, patterns from a single object class lie on a linear subspace (Barsi and Jacobs, 2003 [1]), we develop a linear model representing a probe image as a linear combination of class specific galleries. In the presence of noise, the well-conditioned inverse problem is solved using the robust Huber estimation and the decision is ruled in favor of the class with the minimum reconstruction error. The proposed Robust Linear Regression Classification (RLRC) algorithm is extensively evaluated for two important cases of robustness i.e. illumination variations and random pixel corruption. Illumination invariant face recognition is demonstrated on three standard databases under exemplary evaluation protocols reported in the literature. Comprehensive comparative analysis with the state-of-art illumination tolerant approaches indicates a comparable performance index for the proposed RLRC algorithm. The efficiency of the proposed approach in the presence of severe random noise is validated under several exemplary noise models such as dead-pixel problem, salt and pepper noise, speckle noise and Additive White Gaussian Noise (AWGN). The RLRC algorithm is found to be favorable compared with the benchmark generative approaches. © 2011 Elsevier Ltd. All rights reserved.

Ishaque K.,Karachi Institute of Economics & Technology | Ishaque K.,University of Technology Malaysia | Salam Z.,University of Technology Malaysia
Renewable and Sustainable Energy Reviews | Year: 2013

This paper presents a review on the state-of-the-art maximum power point tracking (MPPT) techniques for PV power system applications. The main techniques that will be deliberated are the Perturb and Observe, Incremental Conductance and Hill Climbing. The coverage will also encompass their variations and adaptive forms. In addition, the more recent MPPT approaches using soft computing methods such as Fuzzy Logic Control, Artificial Neural Network and Evolutionary Algorithms are included. Whilst the paper provides as thorough treatment of MPPT at normal (uniform) insolation, its focus will be on the applications of the abovementioned techniques during partial shading conditions. It is envisaged that this review work will be a source of valuable information for PV professionals to keep abreast with the latest progress in this area, as well as for new researchers to get started on MPPT. © 2012 Elsevier Ltd.

Chin V.J.,University of Technology Malaysia | Salam Z.,University of Technology Malaysia | Ishaque K.,Karachi Institute of Economics & Technology
Applied Energy | Year: 2015

This review paper deliberates the important works on the modelling and parameters estimation of photovoltaic (PV) cells for PV simulation. It provides the concepts, features, and highlights the advantages and drawbacks of three main PV cell models, namely the single diode RS-, RP- and the two-diode. For the parameter estimation techniques, both the analytical and the soft computing approach are covered. A critical evaluation is carried out to summarize the performance of the models, while at the end, a summary of the future trend and direction of research is given. Since the literature on this subject is very large and dispersed, the availability a single cohesive and comprehensive document on the subject matter is crucial in order to piece the information together and understand the bigger picture. Therefore it is envisaged that this work will be convenient for new entrants as well as experienced researchers and practitioners to update their knowledge in the latest development in the area of PV modelling and simulation. © 2015 Elsevier Ltd.

Ishaque K.,University of Technology Malaysia | Ishaque K.,Karachi Institute of Economics & Technology | Salam Z.,University of Technology Malaysia | Amjad M.,University of Technology Malaysia | Mekhilef S.,University of Malaya
IEEE Transactions on Power Electronics | Year: 2012

This paper proposes an improved maximum power point tracking (MPPT) method for the photovoltaic (PV) system using a modified particle swarm optimization (PSO) algorithm. The main advantage of the method is the reduction of the steady-state oscillation (to practically zero) once the maximum power point (MPP) is located. Furthermore, the proposed method has the ability to track the MPP for the extreme environmental condition, e.g., large fluctuations of insolation and partial shading condition. The algorithm is simple and can be computed very rapidly; thus, its implementation using a low-cost microcontroller is possible. To evaluate the effectiveness of the proposed method, MATLAB simulations are carried out under very challenging conditions, namely step changes in irradiance, step changes in load, and partial shading of the PV array. Its performance is compared with the conventional Hill Climbing (HC) method. Finally, an experimental rig that comprises of a buck-boost converter fed by a custom-designed solar array simulator is set up to emulate the simulation. The software development is carried out in the Dspace 1104 environment using a TMS320F240 digital signal processor. The superiority of the proposed method over the HC in terms of tracking speed and steady-state oscillations is highlighted by simulation and experimental results. © 2012 IEEE.

Ishaque K.,University of Technology Malaysia | Ishaque K.,Karachi Institute of Economics & Technology | Salam Z.,University of Technology Malaysia | Shamsudin A.,University of Technology Malaysia | Amjad M.,University of Technology Malaysia
Applied Energy | Year: 2012

This paper presents maximum power point tracking (MPPT) of photovoltaic (PV) system using particle swarm optimization (PSO) algorithm. The key advantage of the proposed technique is the elimination of PI control loops using direct duty cycle control method. Furthermore, since the PSO is based on optimized search method, it overcomes the common drawback of the conventional MPPT, i.e. the inability to track the global maximum point (GP) of PV array under partial shading conditions. The algorithm is employed on a buck-boost converter and tested experimentally using a PV array simulator. Ten irradiance patterns are imposed on the array, the majority of which include various partial shading patterns. Compared to the conventional direct duty cycle method, the proposed method performs excellently under all shading conditions. Finally, the performance of the proposed method is tested using the measured data of a tropical country (Malaysia) from 8.00 am to 6.00. pm. For the 10. h (daytime) irradiance and temperature profile, it yields an average MPPT efficiency of 99.5%. © 2012 Elsevier Ltd.

Ishaque K.,University of Technology Malaysia | Ishaque K.,Karachi Institute of Economics & Technology | Salam Z.,University of Technology Malaysia | Mekhilef S.,University of Malaya | Shamsudin A.,University of Technology Malaysia
Applied Energy | Year: 2012

This paper proposes a penalty based differential evolution (P-DE) for extracting the parameters of solar photovoltaic (PV) modules at different environmental conditions. The two diode model of a solar cell is used as the basis for the extraction problem. The analyses carried out using synthetic current-voltage (I-V) data set showed that the proposed P-DE outperforms other Evolutionary Algorithm methods, namely the simulated annealing (SA), genetic algorithm (GA), and particle swarm optimization (PSO). P-DE consistently converges to the global optimum values very rapidly. The performances are evaluated using the well known quality test and student T-tests. Furthermore, the P-DE extraction method is practically validated by six solar modules of different types (multi-crystalline, mono-crystalline, and thin-film). The results were found to be in close agreement with the experimental I-V data set, especially at very low irradiance values. The latter can be very useful in predicting the performance of the solar system under partial shading conditions. The main application of the proposed work is the possibility of developing a highly accurate simulator for solar PV system designer. © 2012 Elsevier Ltd.

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