Showing papers in "International journal of engineering and technology in 2016"

Extraction of Texture Features using GLCM and Shape Features using Connected Regions

Abstract: Feature extraction is an important step in Computer Assisted Diagnosis of brain abnormalities using Magnetic Resonance Images (MRI).Feature Extraction is the process of reducing the size of image data by obtaining necessary information from the segmented image. The visual content of a segmented image can be captured using this process. From the extracted features it is possible to demarcate between normal and abnormal brain MRI. The reliability of the classification algorithm depends on segmentation method and extracted features. In this work texture features are extracted using Gray Level Co-occurrence Matrix (GLCM) and shape features are extracted using connected regions. Images with malignant tumor, benign tumor and normal brain have different features. This variation in feature values is useful in classification of MR images. The features thus obtained will be given to a classifier for training and testing.

Predictive Models for Equipment Fault Detection in the Semiconductor Manufacturing Process

Abstract: Semiconductor manufacturing is one of the most technologically and highly complicated manufacturing processes. Traditional machine learning algorithms such as uni-variate and multivariate analyses have long been deployed as a tool for creating predictive model to detect faults. In the past decade major collaborative research projects have been undertaken between fab industries and academia in the areas of predictive modeling. In this paper we review some of these research areas and thus propose machine learning techniques to automatically generate an accurate predictive model to predict equipment faults during the wafer fabrication process of the semiconductor industries. This research paper aims at constructing a decision model to help detecting as quickly as possible any equipment faults in order to maintain high process yields in manufacturing. In this research, we use WEKA tool and R languages for implementing our proposed method and other five machine learning discovery techniques.

Soil Engineering Properties Improvement By Utilization of Cut Waste Plastic and Crushed Waste Glass as Additive

Abstract: In general, clayey soil was used as soil material or embankment material for increasing road way level before road structure being constructed. Some types of clay are expansive soil, its have been contributing to pavement failures and subsequently causing increased annual maintenance expenditure of the road. The pavements design/redesign methods are found to be the primary cause of these failures. Thus, it is quite important to propose the utilization of waste plastic and waste glass on soil subgrade improvement and then contributing decreased of pavement failures. This paper was evaluated the engineering properties on utilizing waste plastic High Density Polyethylene (HDPE) and waste crushed glass as additive on subgrade improvement. The research were conducted soil engineering properties, standard compaction, four days soaked California Bearing Ratio (CBR) and Triaxial test to some clayey soil samples from various sites in Kuantan. The 4 days soaked CBR of clayey soil samples were prepared at optimum water content. The variation of additive content on stabilized soil: 4%, 8%, 12% by dry total weight of soil sample respectively. The chemical element was investigated by Integrated Electron Microscope and Energy-Dispersive X-Ray Spectroscopy (SEM-EDS). Test result were shown that engineering properties and CBR on stabilized clayey samples were increased when the content of waste HDPE and Glass were increased.

OpenCV Based Disease Identification of Mango Leaves

Abstract: This paper aims in classifying and identifying the diseases of mango leaves for Indian agriculture. K-means algorithm is chosen for the disease segmentation, and the disease classification and identification is carried out using the SVM classifier. Disease identification based on analysis of patches or discoloring of leaf will hold good for some of the plant diseases, but some other diseases which will deform the leaf shape cannot be identified based on the same method. In this case leaf shape based disease identification has to be performed. Based on this analysis two topics are addressed in this research paper. (1) Disease identification using the OpenCV libraries (2) Leaf shape based disease identification. Keywordk-means,Principal Component Analysis (PCA), feature extraction, shape detection, disease identification, Elliptic fourier analysis, Support Vector Machine(SVM), Artificial Neural Network (ANN)

Fuzzy Gain Scheduling of PID (FGS-PID) for Speed Control Three Phase Induction Motor Based on Indirect Field Oriented Control (IFOC)

Abstract: This paper propose about using PID control system based on Kp, Ki, and Kd parameter determination with scheduling process from fuzzy logic. Control system is used to arrange speed of three phase induction motor using IFOC method. This method can be minimized the main problem from speed control of induction motor which is a transient condition. The robustness validation from this system use testing process of dynamic speed which is compared with the other control system to know the system performance in transient condition such as (rise time, overshoot, undershoot and settling time). The result shows using the proposed system has better performance responses which is requiring 0.001 seconds time in transient condition up to steady state condition without overshoot and undershoot problem.

Determination of Acceleration for Belt Conveyor Speed Control in Transient Operation

Abstract: Speed control has been found a feasible mean to reduce the energy consumption of belt conveyors. However, the current research has not taken the determination of the acceleration in transient operation into account sufficiently. With respect to the belt tension rating, demanded safety factor and the ratio between belt tension before and after drive pulley, this paper presents an approach to estimate the acceleration time. Case with specific horizontal belt conveyor is studied. The simulations with finite element model are carried out to analyze the belt dynamic behaviors in transient operation. Further simulations are carried out to get the optimum acceleration time.

Credit Risk Analysis and Prediction Modelling of Bank Loans Using R

Abstract: Nowadays there are many risks related to bank loans, especially for the banks so as to reduce their capital loss. The analysis of risks and assessment of default becomes crucial thereafter. Banks hold huge volumes of customer behaviour related data from which they are unable to arrive at a judgement if an applicant can be defaulter or not. Data Mining is a promising area of data analysis which aims to extract useful knowledge from tremendous amount of complex data sets. In this paper we aim to design a model and prototype the same using a data set available in the UCI repository. The model is a decision tree based classification model that uses the functions available in the R Package. Prior to building the model, the dataset is pre-processed, reduced and made ready to provide efficient predictions. The final model is used for prediction with the test dataset and the experimental results prove the efficiency of the built model. Keyword-Credit Risk, Data Mining, Decision Tree, Prediction, R

Reuse of Ground Granulated Blast Furnace Slag (GGBFS) in Lime Stabilized Embankment Materials

Abstract: Abstrac t—This paper presents an effective way of utilizing the ground granulated blast furnace slag (GGBFS), which is a by-product of the steel manufacturing process with lime for stabilization of road materials. In the study Ankara clay was used for stabilization. Although slag–lime and clay mixtures do not affect optimum water contents of clay significantly, they decrease dry density and smoothes Proctor curve. Then, the soil transforms into a rapid structure and the modulus of elasticity increases. When the results of the experiments were evaluated, unconfined compressive strength (UCS) and soaked California Bearing Ratio (CBR) values of the soils have shown significant increases. These increases reach to 46 times in CBR values for Ankara clay compared to natural case in 28 day-cured samples. This stabilization technique is more effective than the lime alone and also the slag will prevent the ettringite formation that occurs in lime stabilization with sulfate rich soils that leads swelling behaviour. And finally the slag may turn from a waste material into a valuable product for road construction works with huge volumes even at far away from the steel factories.

Nine States HCI using Electrooculogram and Neural Networks

Abstract: Human Computer Interface (HCI) translate biosignals to control external devices like computers wheelchairs, mouse and keyboard. This paper presents the feasibility of creating one such HCI using Electroooculography. Electrooculography is a technique of measuring the potential difference between the cornea and retina of the eye. Most of the EOG based HCI have focused on two to four and six states, this study focuses on increasing the possible states of the HCI to nine states. Two new eye movements were proposed. The proposed reference power technique was applied to extract the features from twenty subjects. Layered recurrent neural networks were used to classify the different EOG eye movement task signals. Experimental results validate the feasibility of using eleven different eye movements EOG signals for designing nine states HCI. From the result it was proved that feasibility of designing a nine states HCI is possible using reference power features with Layered Recurrent Neural Network. Keyword-Electrooculography, Human Computer Interaction, Layered Recurrent Network

An intrusion detection system against UDP flood attack and ping of death attack (DDOS) in MANET

Abstract: DDoS is one of the serious attacks in the ad hoc network. Among lot many DDoS attacks, UDP flood attack and Ping of death attack are considered to be important as these two attacks may cause severe damage to the network. To provide better security to the network, efficient intrusion detection (IDS) system is required to monitor the network continuously, keeping track of malicious activities and policy violations and produce report to the network administrator. UDP flood attack and ping of death attack are given importance in this paper as they are not well addressed in the existing research works. Packet capture and packet decoder is used to identify the packets and retrieve the packet details. A threshold is set for each node that is connected to the network. If the packet flow into the node exceeds the threshold that is set then the administrator is notified about the same. Keyword MANETmobile ad-hoc network, DDoS-distributed denial of service, Intrusion detection system, UDP flood attack, Ping of death attack.

Analysing the Behaviour and Performance of Opportunistic Routing Protocols in Highly Mobile Wireless Ad Hoc Networks

Abstract: Recent advances in wireless networks have enabled us to deploy and use mobile ad hoc networks for communication between the rescue officers in disaster recovery and reconstruction operations. This highly dynamic network does not require any infrastructure or centralized control. As the topology of the network remain dynamic, severe performance limitations incur with traditional routing strategies. Recently a new routing paradigm known as opportunistic routing protocols have been proposed to overcome these limitations and to provide efficient delivery of data in these highly dynamic ad hoc networks. Using the broadcasting nature of the wireless medium, this latest routing technique tries to address two major issues of varying link quality and unpredictable node mobility in ad hoc networks. Unlike conventional IP forwarding, where an intermediate node looks up a forwarding table for a suitable next hop, opportunistic routing brings in opportunistic data forwarding that allows multiple candidate nodes in the forwarding area to act on the broadcasted data packet. This increases the reliability of data delivery in the network with reduced delay. One of the most important issues that have not been studied so far is the varying performance of opportunistic routing protocols in wireless networks with highly mobile nodes. This research paper analyses and compares the various advantages, disadvantages and the performance of the latest opportunistic routing protocols in wireless ad hoc networks with highly mobile nodes. Keyword-Ad hoc networks, Network Mobility, Opportunistic Routing, Performance Analysis, Reliability

Improving of the wear resistance of working parts agricultural machinery by the implementation of the effect of self-sharpening

Abstract: The failure of the cutting elements of farm machinery is due to the blunting of cutting edges (increase of their radius) till the limit values. The most effective method for increasing the wear resistance of farm machinery is the realization of self-sharpening effect of the cutting elements. The testings took place in laboratory and field at the State Technical University of Kirovograd (Ukraine) in 2015. The technical equipment consists of the consolidated farmer plowshares by different methods as well as their samples, devices for measuring the wear resistance and thumbprint plowshares. It was determined the resistance to wear, the radius of curvature and the changing coefficient of the blades shape. The self-sharpening process was examined throughout the experiment. The results showed that the consolidated plowshares by the proposed technology (laser welding of the mixture (PS-14-60 + 6% В4С) compared to the traditional technology (volumetric heat treatment) have a blade radius 2.5 times lower, a wear 2.2 to 2.78 times lower and the self-sharpening process of the plowshares has been observed since the beginning of the wear until the time limit operation. The changing shape coefficient was respectively of 0.98 for the consolidated plowshares with alloy PS-14-60 + 6% B4C and 0.82 for those consolidated by volumetric heat treatment.

Review of A* (A Star) Navigation Mesh Pathfinding as the Alternative of Artificial Intelligent for Ghosts Agent on the Pacman Game

Abstract: Shortest pathfinding problem has become a populer issue in Game’s Artificial Intelligent (AI). This paper discussed the effective way to optimize the shortest pathfinding problem, namely Navigation Mesh (NavMesh). This method is very interesting because it has a large area of implementation, especially in games world. In this paper, NavMesh was implemented by using A* (A star) algorithm and examined in Unity 3D game engine. A* was an effective algorithm in shortest pathfinding problem because its optimization was made with effective tracing using segmentation line. Pac-Man game was chosen as the example of the shortest pathfinding by using NavMesh in Unity 3D. A* algorithm was implemented on the enemies of Pac-Man (three ghosts), which path was designed by using NavMesh concept. Thus, the movement of ghosts in catching Pac-Man was the result of this review of the effectiveness of this concept. In further research, this method could be implemented on several optimization programmes, such as Geographic Information System (GIS), robotics, and statistics.

An Enhanced Method for Data Hiding using 2-Bit XOR in Image Steganography

Abstract: As we all know security is needed when we want to send data over any medium so this requires a secure medium to send data. That’s why steganography comes in mind whose aim is to send data securely without knowing of any hacker. In this paper, a new technique is projected whose aim is to keep secrete communication intact. The proposed method blends the advantage of 2 bit LSB and XOR operation. In this, first we are XORing the 8th, 1st bit of data and 7th, 2nd bit of data after this two bit are obtained. These obtained bits are replaced at the LSB position. However, with some way, any person get know about hidden message and it takes the LSB position bit then there are no chances of getting message as it is not the actual message. An experiment was performed with different dataset of images. Furthermore, it was observed that the proposed method promises good result as the PSNR and MSE are good. When the method was compared with other existing methods, it shows enhancement in the imperceptibility and message capacity. Keyword Steganography, XOR, Information Hiding, LSB

Effects of Selective Laser Melting Parameters on Relative Density of AlSi10Mg

Abstract: Selective Laser Melting (SLM) is an advance Additive Manufacturing (AM) technique in which a component is manufacturing in a layer by layer manner by melting the top surface of a powder bed with a high intensity laser according to sliced 3D CAD data. AlSi10Mg alloy is a traditional cast alloy that is often used for die-casting. Because of its good mechanical and other properties, this alloy has been widely used in the automotive industry. In this work, the effects on the relative density is investigated for SLM-produced AlSi10Mg parts on one factor at a time (OFAT) basis by keeping constant various parameters such as laser power, scanning speed and hatching distance. It is shown that AlSi10Mg parts produced by SLM having best relative density values are at 350 watt laser power, 1650 mm/s of scanning speed and hatching distance of 0.13mm.

Adaptive Sleep Scheduling for Health Monitoring System Based on the IEEE 802.15.4 Standard

Abstract: In the recent years, Wireless Sensor Networks (WSNs) have become a very popular technology for research in various fields. One of the technologies which is developed using WSN is environmental health monitoring. However, there is a problem when we want to optimize the performance of the environmental health monitoring such as the limitation of the energy. In this paper, we proposed a method for the environmental health monitoring using the fuzzy logic approach according to the environmental health conditions. We use that condition to determine the sleep time in the system based on IEEE 802.15.4 standard protocol. The main purpose of this method is to extend the life and minimize the energy consumption of the battery. We implemented this system in the real hardware test-bed using temperature, humidity, CO and CO2 sensors. We compared the performance without sleep scheduling, with sleep scheduling and adaptive sleep scheduling. The power consumption spent during the process of testing without sleep scheduling is 52%, for the sleep scheduling is 13%, while using the adaptive sleep scheduling is around 7%. The users also can monitor the health condition via mobile phone or web-based application, in real-time anywhere and anytime.

Feature Selection of Network Intrusion Data using Genetic Algorithm and Particle Swarm Optimization

Abstract: This paper describes the advantages of using Evolutionary Algorithms (EA) for feature selection on network intrusion dataset. Most current Network Intrusion Detection Systems (NIDS) are unable to detect intrusions in real time because of high dimensional data produced during daily operation. Extracting knowledge from huge data such as intrusion data requires new approach. The more complex the datasets, the higher computation time and the harder they are to be interpreted and analyzed. This paper investigates the performance of feature selection algoritms in network intrusiona data. We used Genetic Algorithms (GA) and Particle Swarm Optimizations (PSO) as feature selection algorithms. When applied to network intrusion datasets, both GA and PSO have significantly reduces the number of features. Our experiments show that GA successfully reduces the number of attributes from 41 to 15 while PSO reduces the number of attributes from 41 to 9. Using k Nearest Neighbour (k-NN) as a classifier,the GA-reduced dataset which consists of 37% of original attributes, has accuracy improvement from 99.28% to 99.70% and its execution time is also 4.8 faster than the execution time of original dataset. Using the same classifier, PSO-reduced dataset which consists of 22% of original attributes, has the fastest execution time (7.2 times faster than the execution time of original datasets). However, its accuracy is slightly reduced 0.02% from 99.28% to 99.26%. Overall, both GA and PSO are good solution as feature selection techniques because theyhave shown very good performance in reducing the number of features significantly while still maintaining and sometimes improving the classification accuracy as well as reducing the computation time.

Wavelet Based Color Video Steganography

Abstract: This paper describes the algorithm developed with the aim to hide a "secret" color video sequence within another color video sequence. An approach to apply a wavelet transform in order to decompose the cover video sequence and then replace the less significant wavelet band with "secret" video frames has been implemented and tested. On the receiver side, process is reversed and the hidden color video recovered from stego color video. Proposed algorithm has been implemented using Mat lab and PSNR and MSE error metrics employed to evaluate the quality of both video sequences.

Mechanical and Physical Properties of AlSi10Mg Processed through Selective Laser Melting

Abstract: In the past few decade, Additive Manufacturing (AM) has become popular and substantial to manufacture direct functional parts in varieties industrial applications even in very challenging like aerospace, medical and manufacturing sectors. Selective Laser Melting (SLM) is one of the most efficient technique in the additive Manufacturing (AM) which able to manufacture metal component directly from Computer Aided Design (CAD) file data. Accuracy, mechanical and physical properties are essentials requirement in order to meet the demand of those engineering components. In this paper, the mechanical properties of SLM manufactured AlSi10Mg samples such as hardness, tensile strength, and impact toughness are investigated andcompared to conventionallyhigh pressure die cast A360 alloy. The results exposed that the hardness and the yield strength of AlSi10Mg samples by SLM were increased by 42% and 31% respectively to those of conventionally high pressure die cast A360 alloy even though without comprehensive post processing methods. It is also discovered that AlSi10Mg parts fabricated by SLM achieved the highest density of 99.13% at the best setting parameters from a previous studyof 350 watts laser power, 1650 mm/s scanning speed and hatching distance 0.13 mm. Keywords-Additive Manufacturing; AlSi10Mg; Mechanical Properties; Selective Laser Melting

A New Multiple-Pattern Matching Algorithm for the Network Intrusion Detection System

Abstract: String matching algorithms are essential for network application devices that filter packets and flows based on their payload. Applications like intrusion detection/ prevention, web filtering, anti-virus, and anti-spam all raise the demand for efficient algorithms dealing with string matching. In this paper, we present a new algorithm for multiple-pattern exact matching. Our approach reduces character comparisons and memory space based on graph transition structure and search technique using dynamic linked list. Theoretical analysis and experimental results, when compared with previously known pattern-matching algorithms, show that our algorithm is highly efficient in both space and time.

Application on One-at-a-T ime Sensitivity Analysis of Semi-Distributed Hydrological Model in Tropical Watershed

Abstract: Abstrac t—A soil and water assessment tool (SWAT) model has been employed for the Langat River basin, Malaysia to predict stream flows. The basin was divided into 27 sub basins comprising 193 hydrological response units. Monthly calibration and validation were performed using the measured discharge data of the Kajang station. One-at-a-time sensitivity analysis using Sequential Uncertainty Fitting (SUFI-2) algorithms was performed to examine the critical input variables of the study area. It was found that the SWAT model can be successfully applied for hydrological evaluation of the basin and the SCS runoff curve number, base flow alpha factor and groundwater delay were found to be the most sensitive parameters. The next step should be conducting a 30 years continuous hydrological modeling. It is needed to analyze the water balance and the hydrological trends of the basin due to the basin experienced major land used changes since 1980 for urbanization activities.

Gradient Based Image Edge Detection

Abstract: —Due to the importance of image edge detection in image analysis, object recognition and many applications, many edge detection algorithms are used to detect edges of objects in the image. Edges typically occur on the boundary between two different regions in the image. There are a number of algorithms for this, but these may be classified as derivative based where the algorithm takes first or second derivative on each pixel, or gradient based where a gradient of consecutive pixels is taken in x and y direction. In our paper we address the problem of gradient based image edge detection, several algorithms are tested, as a result of these algorithms binary images are produced, which represent objects and their background which then helps interpreting the content of the considered images, several medical(for different and the same organ) as well as natural images are used to evaluate the performance of the algorithms and their suitability for both kinds of images.

Review on experimental study of Nd:YAG laser beam welding, with a focus on aluminium metal matrix composites

Abstract: The demand for high performance materials particularly in aviation and automobile industries gradually increases, CO 2 and Nd: YAG lasers are becoming most popular in processing these advanced materials. In this context, one of the most important process is joining by welding. It has been a constant endeavour by researchers to explore various methods and techniques to enhance the process efficiency of autogenous Nd: YAG laser welding of various materials i.e. without any filler materials. In this work, we present a comprehensive review of major research findings for the last decades or so, obtained by researchers about the effect of process parameters on autogenous laser beam welding (LBW) process performance. Main objective of such experimental research was to improve laser weld quality such as tensile strength, weld micro structure, heat affected zone (HAZ), weld penetration etc. In this paper, discussions are also made about different parameter optimisation techniques, design of experiments (DOE), modelling and simulation techniques, adopted by different researchers to achieve optimum weld quality. This review tries to bring out a foresight for direction of further research needed in this field.

A Method for Shellcode Extractionfrom Malicious Document Files Using Entropy and Emulation

Abstract: We propose a method for the dynamic analysis of malicious documents that can exploit various types of vulnerability in applications. Static analysis of a document can be used to identify the type of vulnerability involved. However, it can be difficult to identify unknown vulnerabilities, and the application may not be available even if we could identify the vulnerability. In fact, malicious code that is executed after the exploitation may not have a relationship with the type of vulnerability in many cases. In this paper, we propose a method that extracts and executes "shellcode" to analyze malicious documents without requiring identification of the vulnerability or the application. Our system extracts shellcode by executing byte sequences to observe the features of a document file in a priority order decided on the basis of entropy.Our system was used to analyze 88 malware samples and was able to extract shellcode from 74 samples. of these, 51 extracted shellcodes behaved as malicious software according to dynamic analysis. Index Terms—Malware, shellcode, entropy, dynamic analysis, vulnerability.

Service Models for Cloud Computing: Search as a Service (SaaS)

Abstract: Search as a Service (SaaS) is a cloud service model whose main focus is on enterprise search or site-specific web search. Modern companies require fast and accurate information from their internal databases, internal document stores, or through the content of a website. Having a reliable searching mechanism is essential for both internal company staff and for external customers. In this paper the overview of current state and technological advances of Search as a Service (SaaS) cloud service is given, as well as its security issues on current internet service platforms. Keyword Cloud computing, Search as a Service (SaaS), internet technologies.

Medical Image Analysis of Image Segmentation and Registration Techniques

Abstract: ---Medical Image Analysis is essential in order to detect and diagnose the various types of Cancers. In recent years there is a rise in the death rate of patients suffering from brain cancer and lung cancer. The chances of survival among people can increase if the detection is done in the earlier stage. The widely used diagnose technique is Magnetic Resonance Imaging (MRI), Computed Tomography (CT) Images which are used to present the cancer location in the brain and lungs. In this work the brain tumour and lung cancer is detected and registered through the medical images in three stages. First is the pre -processing stage, a set of medical images is filtered for removing noise by Gaussian filter, Secondly the image is segmented automatically using Otsu and KNN clustering. Edge Detection method is done by using canny detection method. Third stage is the feature extraction stage, in this stage the segmented MRI and CT images are registered to obtain the tumour. The feature detection methods used are the SIFT and SURF algorithm for both brain and lung images to obtain effective results. The SIFT and Affine Transform registration technique used increases the speed and reduces the complexity of geometrical alignments of two images that is the reference and sensed images. It also displays the minute difference between two identical images rapidly and accurately which is essential for medical diagnoses.

A Comparison between Genetic Algorithms and Simulated Annealing for Minimizing Transfer Waiting Time in Transit Systems

Abstract: —Reducing the waiting time imposed on thepassengerstransferring between transit lines has always been a concern for public transport schedulers, as it is a complicated problem by nature. Typically, network-wide minimization of transfer waiting time is a highly complex optimization problem, particularly in the case of dealing with huge transit networks. This problem is unlikely to be solved by exact optimization techniques. This study aims to investigate the capability of two powerful metaheuristic algorithms, genetic algorithms and simulate annealing, in coping with the transfer optimization problem. Amathematical model is presented in this study for minimizing the total transfer waiting time in transit systems. Based on this model, a genetic algorithm and a simulated annealing algorithm are developed and applied to a transit network comprising numerous transfer points. The comparative analysis of the results revealed the ability of the both algorithms in reducing the transfer waiting time although the genetic algorithm could return better results in relatively shorter computation times.

An Overview of Semi-Supervised Fuzzy Clustering Algorithms

Abstract: Fuzzy clustering plays an important role in data-mining, especially in decision making, pattern recognition, etc. There have been many approaches to improve fuzzy clustering performance and quality when it was first introduced by Bezdek. Recently, an approach related to data with sub-information has been most concerned. The idea of this approach combines the advantages of fuzzy C-means method with the benefits of additional information so-called the semi-supervised fuzzy clustering algorithms (SSFC). Through this report, a series of typical SSFC algorithms are presented in brief to give an overview of this approach.

Effect of Ultraviolet Radiations on Medium and High Voltage Cables Insulation Properties

Abstract: Under operating conditions effect, insulated power cables can undergo critical degradations. Ultraviolet (UV) radiations are one of the most destructive constraints which affect the properties of the material used for insulation. Because of its good properties, crosslinked polyethylene (XLPE) is widely used in medium voltage (MV) and high voltage (HV) cables insulation. Regardless of its excellent performances, XLPE can degrade when exposed to UV. The objective of this work is to report experimental results concerning the effect of accelerated UV ageing on the properties of XLPE insulation. For this purpose, dielectric characterization, visual observations and scanning electron microscopy (SEM) analysis are performed to assess the extent of ageing. Obtained results show that UV ageing affects greatly the XLPE insulation. So, an evolution in the dielectric properties (dielectric constant, dissipation factor, dielectric loss index and AC volume resistivity), color change and deterioration of surface morphology with ageing time are noticed. Keywords—Ultraviolet (UV) Radiations, Insulation, Crosslinked Polyethylene, UV Ageing, Dielectric Chracterisation.

Developing Satellite Towns: A Solution to Housing Problem or Creation of New Problems

Abstract: Dhaka, the capital of Bangladesh is the 20th megacity is now the home for over 15 million people. Housing problem for this vast population has become one of the major concerns for this fastest growing mostly unplanned (73% fully unplanned) megacity of the world. To reduce the pressure of population of Dhaka to a great extent by developing the surrounding area of Dhaka city in a planned way and establishing permanent residence for these vast population two projects were commenced. Purbachal New Town, the biggest planned township of the country and Uttara 3rd phase. Planning of these satellite towns lacks the provisions of introducing modern, futuristic amenities and misses out the concept of sustainable city. In this paper the present major drawbacks of the Dhaka city as it faces due to an unplanned densely populated urban area are pointed out. And along with that the provisions that the new satellite town missed out in their planning are identified. Also modern similar developments around the world are considered and in that regard position of the ongoing new towns are scrutinized. A set of recommendations is provided to make the best use of the available resources, and use our learning from the mistakes that have been made by our progenitor in planning the Dhaka city.