Mehran University Research Journal of Engineering and Technology

6

Authors: Memon N.A., Laghari M.A., Memon F.A.

Generation of construction waste is a worldwide issue that concerns not only governments but also the building actors involved in construction industry. For developing countries like Pakistan, rising levels of waste generation, due to the rapid growth of towns and cities have become critical issue. Therefore this study is aimed to detect the factors, which are the main causes of construction waste generation. Questionnaire survey has been conducted to achieve this task and RIW (Relative Importance Weight) method has been used to analyze the results of this study. The important factors contributing to the generation of construction as identified in this study are: frequent changes/ revision in design during construction process; poor scheduling; unavailability of storage; poor workmanship; poor layout; inefficient planning and scheduling of resources and lack of coordination among supervision staff deployed at site. Based on the identified factors, the study also has presented some suggestions for the reduction of construction waste in building construction projects of Pakistan

8

Authors: Ibrar-Ul-Haque M., Hassan H.,Anisi M.I.

This paper proposed a new technique to compressed image blockiness/blurriness in frequency domain through edge detection method by applying Fourier transform. In image processing, boundaries are characterized by edges and thus, edges are the problems of fundamental importance. The edges have to be identified and computed thoroughly in order to retrieve the complete illustration of the image. Our novel edge detection scheme for blockiness and blurriness shows improvement of 60 and 100 blocks for high frequency components respectively than any other detection technique.

8

Authors: Amanullah, Rashad M. Ahmed I.

The binary operation of usual addition is associative in all matrices over R. However, a binary operation of addition in matrices over Z n of a nonassociative structures of AG-groupoids and AG-groups are defined and investigated here. It is shown that both these structures exist for every integer n > 3. Various properties of these structures are explored like: (i) Every AG-groupoid of matrices over Z n is transitively commutative AG-groupoid and is a cancellative AG-groupoid ifn is prime. (ii) Every AG-groupoid of matrices over Z n of Type-II is a T3-AG-groupoid. (iii) An AG-groupoid of matrices over Z n ; G nAG(t,u), is an AG-band, ift+ u=1(mod n).

10

Authors: Fizza G., Hussain A., Jokhio S.H.

Nonlinearities implanted by refractive index and scattering degrade the performance of optical networks. In this paper, FWM (Four Wave Mixing) has been analyzed for four different channels with 10 nm spacing. Due to the presence of resonant frequency, FWM interface of different channels in WDM (Wavelength Division Multiplexing) hinders the performance of the system. The system is affected by nonlinear cross talk. A system with the bandwidth of 10 Gbps has been investigated using External Modulation and an optical rectangle filter as a key parameter to improve the system performance with respect to FWM effect

10

Authors: Jan I., Pervez S.

Effective institutional arrangements at local and national levels are important for promotion of renewable energy in a country. The present study attempts to examine the institutional arrangements for development of domestic clean energy in rural northwest Pakistan. The survey data were collected from 100 randomly selected households in District Swat in northwest Pakistan. The data were analyzed using descriptive statistics and Chi-Square test was applied wherever needed. The study describes that very limited number of public and private organizations were working on CD (Clean Development) in the area. Surprisingly, no institutional arrangements exclusively meant for domestic clean energy promotion were observed in the area. The study concludes that the objectives of Kyoto Protocol in Pakistan can be achieved only if the government and NGOs (Non-Governmental Organizations) work together to initiate cost-effective renewable energy interventions, particularly in rural areas. This will not only improve the socioeconomic and environmental conditions in the local context, but will play a key role in achieving the SDGs (Sustainable Development Goals) of the United Nation?s post-2015 development agenda.

10

Authors: Sahito A.A., Tunio S.M., Khizer A.N.

Fast dynamic response, high efficiency, low cost and small size of power electronic converters have exponentially increased their use in modern power system which resulted in harmonically distorted voltage and currents. Voltage harmonics mainly caused by current harmonics are more dangerous as performance and expected operating life of other power system equipment are affected by harmonically distorted supply voltage. Electronic filter circuits are used to improve system power quality by mitigating adverse effects of harmonics. Hybrid filters having advantages of both passive and active filters are preferred to resolve the problem of harmonics efficiently and avoiding any chance of resonance. In this paper, a three phase three wire network is considered to supply an adjustable speed drive represented by a resistive load connected across a three phase bridge rectifier. Simulation of the considered system shows THD (Total Harmonic Distortion) of 18.91 and 7.61% in supply current and voltage respectively. A HAPF (Hybrid Active Power Filter) is proposed to reduce these THD values below 5% as recommended by IEEE Standard-519. P-Q theorem is used to calculate required parameters for proposed filter, which is implemented through hysteresis control. Simulation results confirm the effectiveness of the designed filter as THD for both current and voltage have reduced below allowable limit of 5%.

12

Authors: Hayat U., Khan M.U.G.

Uncertain data can be categorized as imprecise data and probabilistic data. In each of these categories, the uncertainty can be found at different granularity levels. Conventional data models are developed for the purpose of storing, manipulating and retrieving certain data. These data models do not extend their support for the management of uncertain data. Thus, a standalone data model is required aimed at storing, manipulating and retrieving certain as well as uncertain data. In this paper we introduce UDMrelations, an uncertain data model for the management of uncertain data along with certain data. Vertical partitioning approach is used to translate an uncertain relation into UDM-relations. Our data model supports ALU (Attribute-Level Uncertainty) as well as TLU (Tuple-Level Uncertainty) for the finite sets of possible worlds. It follows the concept of standard relational database technology. With slight modifications to standard relational algebra operators, we have introduced four relational operators that are used to evaluate a query on UDM-relations.

14

Authors: Draz U., Jahanzeb M., Asghar G.

SMEs (Small and Medium Sized Enterprises) sector is facing problems relating to implementation of international quality standards. These SMEs need to identify factors affecting business success abroad for intelligent allocation of resources to the process of internationalization. In this paper, MLP NN (Multi-Layer Perceptron Neural Network) has been used for identifying relative importance of key variables related to firm basics, manufacturing, quality inspection labs and level of education in determining the exporting status of Pakistani SMEs. A survey has been conducted for scoring out the pertinent variables in SMEs and coded in MLP NNs. It is found that ?firm registered with OEM (Original Equipment Manufacturer) and ?size of firm? are the most important in determining exporting status of SMEs followed by other variables. For internationalization, the results aid policy makers in formulating strategies