Usman Muhammad - Academia.edu (original) (raw)

Papers by Usman Muhammad

2014 12th International Conference on Frontiers of Information Technology, 2014

In a cognitive radio network (CRN), cognitive radio users (CUs) should be powered by a small batt... more In a cognitive radio network (CRN), cognitive radio users (CUs) should be powered by a small battery for their operations. The operations of the CU often include spectrum sensing and data transmission. The spectrum sensing process may help the CU avoid a collision with the primary user (PU) and may save the energy that is wasted in transmitting data when the PU is present. However, in a time-slotted manner, the sensing process consumes energy and reduces the time for transmitting data, which degrades the achieved throughput of the CRN. Subsequently, the sensing process does not always offer an advantage in regards to throughput to the CRN. In this paper, we propose a scheme to find an optimal policy (i.e., perform spectrum sensing before transmitting data or transmit data without the sensing process) for maximizing the achieved throughput of the CRN. In the proposed scheme, the data collection period is considered as the main factor effecting on the optimal policy. Simulation results show the advantages of the optimal policy.

African journal of microbiology research

Enterobacter cloacae is not a primary human pathogen but has obtained an important role as a noso... more Enterobacter cloacae is not a primary human pathogen but has obtained an important role as a nosocomial pathogen. Acquiring this property of metallo-â-lactamases (MBL) producers, the pathogen becomes very virulent for the susceptible neonates and leaves little choice of antibiotics for its management. Blood samples (n=103) were collected in peadriatic blood culture bottles from suspected neonates aseptically. The samples were processed in BACTEC 9120. Antimicrobial susceptibility testing was performed using Kirby-Bauer disc diffusion method according to CLSI 2009. Carbapenems resistant E. cloacae were further analyzed for the detection of carbapenamase as per CLSI guidelines and MBL production by double disc potentiation method. Of 103 blood cultures specimens, 71 were declared positive by BACTEC 9120 and 91 isolates were recovered. Among these isolates, E. cloacae (n=12) were found to be carbapenems resistant and 10 out of these were carbapenamase and MBL producers. All MBL produci...

American Journal of Plant Sciences, 2012

Sunflower (Helianthus annuus L.) has emerged as an economically important crop in Pakistan due to... more Sunflower (Helianthus annuus L.) has emerged as an economically important crop in Pakistan due to its significant share in vegetable oil production. The plant metabolic processes require protein to increase the vegetative, reproductive growth and yield of the crop. The protein is wholly dependent upon the amount of nitrogen fertilization available for plant use. A two-year field study was conducted in 2008 and 2009. The objective was to determine the effect of different nitrogen (N) levels (N 1 = 0 kg•ha-1 , N 2 = 60 kg•ha-1 , N 3 = 120 kg•ha-1 , N 4 = 180 kg•ha-1 and N 5 = 240 kg•ha-1) on three sunflower hybrids (Hysun-33, Hysun-38 and Poineer-64A93) in agro-climatic conditions of Gujranwala, a sub-humid region in the centre of the Punjab province of Pakistan. A randomized complete block design split plot experiment was setup with cultivars in the main plots and N levels in the subplots. Results showed that Hysun-38 gave maximum TDM (15815 kg•ha-1) and maximum grain yield (3389 kg•ha-1), while minimum TDM (14640 kg•ha-1) and grain yield (3125 kg•ha-1) was observed in Hysun-33. Among different N rates evaluated, N 4 gave maximum TDM (17890 kg•ha-1) and grain yield (3809 kg•ha-1) compared to the other N rates. The maximum oil content (46.2%) was observed in Hysun-38 without application of N fertilizer (N 1), while the minimum oil content (40.6%) was observed from N 5 treatment. In conclusion, the application of 180 kg•ha-1 N to Hysun-38 provided the best combination for good yield in sunflower crop under the prevailing sub-humid conditions of Pakistan.

International Journal of Applied Information Systems, 2012

Cooperation and network coding are two such powerful techniques that heightened the proficiency o... more Cooperation and network coding are two such powerful techniques that heightened the proficiency of wireless Networks. This paper mainly focuses on Physical-layer Network Coding (PNC) and Analog Network Coding (ANC), as they are the most studied variants of network coding in literature and represent radically different strategies between themselves, thus shedding light into which problems may hinder the scalability of network coding to more better wireless network topologies. Also, performance of cooperative networks can be enhanced with optimum relay selection. In this paper, we present the simulation results for both Analog Network Coding and Physical-layer Network Coding. We have evaluated the bit error rate (BER) over Rician fading channelsfor ANC and PNC with relay optimization by taking path loss in our system model. BPSK modulation is used for simulation results.

TheScientificWorldJournal, 2014

Both reliable detection of the primary signal in a noisy and fading environment and nullifying th... more Both reliable detection of the primary signal in a noisy and fading environment and nullifying the effect of unauthorized users are important tasks in cognitive radio networks. To address these issues, we consider a cooperative spectrum sensing approach where each user is assigned nonuniform reliability based on the sensing performance. Users with poor channel or faulty sensor are assigned low reliability. The nonuniform reliabilities serve as identification tags and are used to isolate users with malicious behavior. We consider a link layer attack similar to the Byzantine attack, which falsifies the spectrum sensing data. Three different strategies are presented in this paper to ignore unreliable and malicious users in the network. Considering only reliable users for global decision improves sensing time and decreases collisions in the control channel. The fusion center uses the degree of reliability as a weighting factor to determine the global decision in scheme I. Schemes II and...

2012 International Conference on Emerging Technologies, 2012

ABSTRACT Hybrid Time division multiple access-Frequency division multiple access (TDMA-FDMA) base... more ABSTRACT Hybrid Time division multiple access-Frequency division multiple access (TDMA-FDMA) based three time slots transmission protocol is proposed with inter-relay communication. In this paper an in-depth analysis of two protocols has been assessed for Nakagami-m fading channel. The system is also simulated at various relay locations to estimate the performance for optimization. Performance is analyzed in terms of Bit Error Rate (BER), Outage probability and Gain.

2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013

ABSTRACT Network simulators have gained an increased importance in the research community to an e... more ABSTRACT Network simulators have gained an increased importance in the research community to an extent that approximately 11% of the research papers that appeared in the proceedings of leading international conferences used network simulators to test their claims. It is anticipated that due to the several advantages network simulators will become more prevalent in the research community in future. However, with the growing popularity of the network simulators, challenges in the form of consistent revelations about their inaccuracies have started to seriously question the use of such simulators and simulation based research. This paper attempts to answer the questions (1) How can assumptions/simplifications in modeling affect realism of simulations? (2) How credibility of simulation based research be improved?, and (3) What necessary steps must be taken to make network simulators credible? The paper provides deliberated recommendations for improving the authenticity of simulation based experiments. The authors believe that the discussion in this paper will greatly facilitate the repeatability of simulation based research and will help researchers to select the most suitable (credible) simulator.

International Journal of Marketing Studies, 2010

The objective of this research is to examine cultural influence on the general attitude of Pakist... more The objective of this research is to examine cultural influence on the general attitude of Pakistani people towards advertising. The study aims to analyze the cultural impact on attitude of people towards advertisements of brands according to product information, social integration and hedonism/pleasure, whereas power distance and masculinity as culture dimensions. Sample size includes 250 respondents which are involved directly in purchasing. It includes adults from all disciplines, house wives within the vicinity of Islamabad/ Rawalpindi and the people from different age groups and educational backgrounds. Regression is used to check the impact of product information, social integration and hedonism over public general attitude towards advertisement. And apply moderation analysis to check the impact of culture as moderating variable. Social integration, product information and hedonism have a significant impact on attitude towards advertisement. But product information has weak impact on attitude towards advertisement; whereas culture has a significant moderating effect which strengthen the relationship between dependent and independent variables. The most important limitation was the time constraint. The time was limited due to which a huge sample size was impossible to manage. The responses were taken only from Islamabad and Rawalpindi cities which restrict the generalizability of the study. This study will help marketers to advertise there products according to the culture values and attitude of the people which reflects their personality. It will also help companies to segment their customers according to their behavior/attitude towards advertisement, which in turn will help companies to gain competitive advantage and increase profitability.

Water productivity need to be enhanced in view of diminishing water supplies. A study was conduct... more Water productivity need to be enhanced in view of diminishing water supplies. A study was conducted to assess the existing water productivity status in cotton-wheat cropping zone in Punjab Province of Pakistan and identifying factors for its improvement. Six watercourses on four distributaries taking off from Lower Bari Doab Canal (LBDC) of river Ravi were selected in tehsil Kabirwala, district Khanewal. The data regarding crop yield, irrigation water, fertilizer and pesticides was recorded from farmers and cross checked with information collected from Patwaris. The results indicated that mean yield, apparent water productivity (yield/irrigation water) and real water productivity (yield/water evapotranspired) for wheat was 3210 kg ha-1 , 0.43 kg m-3 and 1.12 kg m-3 , respectively. The corresponding values for cotton were 2675 kg ha-1 , 0.22 kg m-3 and 0.26 kg m-3 , respectively. It was concluded that all the three considered factors (irrigation water, fertilizer and pesticide) improved real water productivity (yield/water evapotranspired). Further pesticide in wheat and fertilizer in cotton was the most effective. However, water productivity studies on the larger scale and inclusion of factors (irrigation method, soil fertility, crop variety, irrigation scheduling etc.) influencing water productivity are recommended for future to improve water productivity.

ABSTRACT The growing number of ontologies on the web has emerged new research issues in the field... more ABSTRACT The growing number of ontologies on the web has emerged new research issues in the field of semantic web. It is now common to have more than one ontologies on the web for a specific domain. These ontologies may have various types of heterogeneities and therefore it is a challenging task for information retrieval systems to utilize the knowledge of all available ontologies. A number of ontology alignment systems have proposed by researchers in the last decade to bridge this semantic gap. During an alignment process, the entities from different ontologies are compared to find the semantically similar entities. For this purpose, various similarity measures are discussed according to the type of ontological heterogeneities. This paper investigates most common types of heterogeneities exist in ontologies and matchers which can deal with such heterogeneities. Furthermore, the role of aggregation methods in alignment systems have also been analyzed and discussed.

Journal of the Croatian Association of Civil Engineers, 2020

1st National Conference on Security, Computing, & Communication, May 23, 2008

Abstract—In this paper we propose the architecture of a neural co-processor for on-board learning... more Abstract—In this paper we propose the architecture of a neural co-processor for on-board learning. The co-processor is based on backprop-agation network and acts as a dedicated hardware connected to a PC. It consists of several sub-modules ie sub-processors rep-resenting a column of the backpropagation neural network. The architecture allows the co-processor to form any structure de-pending on the specific application. We have built a communi-cation network for the sub-modules to communicate with each other and within ...