255 research outputs found
Design of cyclic prefix characteristic-based OFDM system for WiMAX technology
Worldwide interoperability for microwave access (WiMAX) offers the wireless connectivity using orthogonal frequency division multiplexing (OFDM) modulation is a proficient wireless technology that capacities high-speed data transmission facilities. The existing WiMAX techniques have the problem of increase in inter-symbol interference (ISI) and bit error rate (BER) at reduced power spectrum that degrades the performance of WiMAX system due to high data rate transmission. The utilization of different adaptive modulation techniques seen as a potential solution to reduce the ISI and BER for high data rate transmission. In this paper, OFDM is adapted using advanced modulation technique for WiMAX system. The technique proposes the cyclic prefix (CP) is utilized that include supplementary bits at the stage of the transmitter. The proposed technique offers minimization of ISI and improvement in BER. It is defined that performance of the existing CP system is equated with the designed single cyclic prefix (SCP) and double cyclic prefix (DCP) and non-cyclic prefix (NCP). BER, probability of error, and power spectral density are utilized to analyse the performance of the designed system. The OFDM based SCP and DCP and NCP for WiMAX are demonstrated for modulation techniques such as; QPSK, BPSK, and QAM. It is determined that BPSK has the smallest BER when compared to QPSK, 16-QAM, and 64-QAM modulations. It is also demonstrated that QPSK is also very competent, however, it has a higher BER as compared to BPSK modulation. It is also observed that 16-QAM and 64-QAM are less efficient in terms of BER compared to QPSK and BPKS modulations. 64-QAM offers the high data rates, and due to high SNR ratio. The designed system is tested for under AWGN and Rayleigh fading channel, and effect power spectral density of signal to noise ratio on OFDM for rayleigh fading channel are demonstrated for SCP and DCP and NCP. It is determined that the OFDM transmitter with proposed DCP for random signals is efficiently reducing the BER and ISI for WiMAX system
Physio-Chemical Characterization of Biochar, Compost and Co-Composted Biochar Derived from Green Waste
Organic wastes are naturally biodegradable, but they contribute to environmental pollution and management issues. Composting and pyrolysis are widely used technologies for recycling these wastes into valuable organic products for soil health and crop production. In the current study, fruits vegetables waste (FVW) was converted to biochar, compost, and co-composted biochar. The microcrystal structure, functional groups, surface morphology, and nutrient contents of organic materials were investigated by XRD, FTIR, SEM-EDS, AAS, multi C-N analyzer, and ICP-OES techniques. Heavy metals contamination was not detected in the biomass used for pyrolysis and compost preparation. FVW had an acidic pH (5.92), while biochar, compost, and co-composted biochar had an alkaline pH. Total macronutrient (K, Na, S) and micronutrient (Cu, Fe) concentrations were higher in compost and co-composted biochar, with the exception of K, which was higher in biochar. Biochar had the highest surface area (4.99 m(2)g), followed by FVW, compost, and co-composted biochar. Co-composted biochar had a porous structure. Si, Ca, and Al contents were common in all organic materials, while P, K, Mg, and S were found with lower concentrations in both biochar and compost. Iron was only found in compost and co-composted biochar. Quartz, sylvite, and calcite were common minerals found in all organic treatments. Biochar contained more aromatic carbon ring structure C=C/C=O and aromatic C-H bending as compared to FVW and compost, thus, making biochar a stable carbon rich material suitable for soil carbon sequestration
Factors Impacting the Buying Behavior of Housewives towards Hypermarkets in Karachi
The objective of this research is an effort to understand what are the factors that impact the choice of hypermarkets made by housewives and what do they think about the factors like Convenience level, Store atmosphere, Price and Variety of products, which influence the buying behavior. This research is qualitative in nature and in-depth interview technique is used for the collection of data through respondents and then thematic analyses have been constructed. The results of the study concluded that Convenience level is the most important factor that affects the choice of hypermarkets for the housewives. It is considered as a positive factor for their shopping experience. Some factors within convenience level include parking space available, a well-stated store in terms of prices and category placement so that it saves time and the most important convenience factor due to which housewives are not willing to shift permanently to other store is the location/nearness of the hypermarket to their homes. It is further concluded that the Store atmosphere must be friendly that doesn’t make the customer confuse every time they visit the store. Proper placement of the goods on the aisle, space between them, lightening and the music it is being played all affects the shopping experience of the customer. Prices do affect the way the customer shops but it is not considered a factor that makes the customer shifts their store permanently if it’s not convenient for them. Variety is the least impacting factor that would make the customer shifts their outlet. The housewives generally like hypermarkets as it serves as a one-stop shop for them for all their required items Keywords: Hyperstar, Buying behavior, Housewives, Convenience Level, Store Atmosphere, Variety of Product
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Estimation of Dulling Rate and Bit Tooth Wear Using Drilling Parameters and Rock Abrasiveness
NoOptimisation of the drilling operations is becoming increasingly important as it can significantly reduce the oil well development cost. One of the major objectives in oil well drilling is to increase the penetration rate by selecting the optimum drilling bit based on offset wells data, and adjust the drilling factors to keep the bit in good condition during the operation. At the same time, it is important to predict the bit wear and the time to pull out the bit out of hole to prevent fishing jobs. Numerous models have been suggested in the literature for predicting the time to pull the bit out to surface rather than predict or estimate the bit wear rate. Majority of the available models are largely empirical and can be applied for limited conditions, and do not include all the drilling parameters such as the formation abrasiveness and bit hydraulic. In this paper, a new approach is presented to improve the drill bit wear estimation that consists of a combination of both Bourgoyne and Young (BY) drilling rate model and theory of empirical relation for the effects of rotary speed (RPM), and weight on bit (WOB) on drilling arte (ROP) and rate of tooth wear. In addition to the drilling parameters, the formation abrasiveness and the effect of the jet impact force of the mud have also been accounted to estimate the bit wear. The proposed model enables estimation of the rock abrasiveness, and that lead to calculate the dynamic dulling rate of the bit while drilling that used in more accurate to assess the bit tooth wear compared with the mechanical specific energy (MSE). Then the estimated dulling rate at the depth of pulling out is used to determine the dull grade of the bit. The technique is validated in five wells located in two different oil fields in Libya. All studied wells in this showed a good agreement between the actual bit tooth wear and the estimated bit tooth wear
Diagnostic accuracy of serum albumin for diagnosis of esophageal varices in patients of chronic liver disease
Objective: To determine the diagnostic accuracy of serum albumin for detection of esophageal varices (EVs) in patients of chronic liver disease (CLD) taking Esophagogastroduodenoscopy (EGD)as a gold standard.Methodology: The cross sectional study was accomplished at the department of gastroenterology, Isra University Hospital Hyderabad in collaboration with department of Gastroenterology, AIMS Hospital, Hyderabad, during six months from February 2017 to July 2017. All the Patients of age 20-60 years of either gender presenting with CLD were included. Blood samples from each patient submitted to laboratory to assess serum albumin level. Serum albumin level <3.4 g/dl was assessed as positive. Then patients were referred to department of gastroenterology for EGD. The data recording process was carried out by a proforma.
Results: mean age of the patients was 53.63±14.61 years with male to female ratio was 2.3:1. Esophageal varices on serum albumin were found positive in 39 (41.1%) cases and EGD was found positive in 38.95% cases. The sensitivity of esophageal varices on serum albumin was 81.08% with specificity of 84.48%. The PPV value was 76.92%, NPV value was 87.5% and diagnostic accuracy of esophageal varices on serum albumin was 83.16% taking esophageal varices on EGD as gold standard.Conclusion: Serum albumin is a useful forecaster of esophageal varices among patients of chronic hepatic disorder with 81.08% sensitivity and of 84.48% specificity
Problems Faced and Difference in Quality of Life Among The Elderly Population of Suburban Areas of Twin Cities
Objective: To evaluate the problems faced and the difference in the quality of life among the elderly population of three suburban areas of twin cities of Pakistan.Setting and duration: This study was conducted in three suburban setting around Islamabad and Rawalpindi in a duration of six months from February to August 2017.Methodology: A total of 110 participants consisting on 55 males and 55 female were selected for the study. This cross sectional survey was conducted on a geriatric population of age more than 60 years. The elders having any disease, psychological or physical disorder were excluded from the study. In this study, we used the Quality of life Instruments developed by WHO (WHOQOL-BREF) which is a validated and one of the most widely used tools in QoL research. Informed consent was taken from all the participants prior to the study. The data form all the participants was collected through face to face interviews and entry with analysis was done through SPSS v. 21.Results: Majority 58 (52.73%) of the participants were of age interval of 60-64 years followed by 39 (35.45%) in the age group of 65-69 years. A large number 41 (37.27%) of elderly participants were uneducated. Most 63 (57.27%) of the participants of the study were living in the extended family system. Main bulk 49 (44.55%) of the study sample belonged to families having a monthly income of 16000-25000 rupees, followed by 25 (22.73%) families having an income of 26000-35000 rupees. The main source of income was a dependency on children. The most common 24 (21.82%) problem faced was related to financial issues, followed by loneliness 22 (20%). Majority 68 (61.82%) of the study sample replied that the bahaviour of family members is friendly and politely with them. The QoL score for physical health, psychological health, social relationship and environment were significantly higher in male participants as compared to female counterparts. The overall quality of life on the basis of the quality of life score QoL was significantly better in male participants as compared to female participants. Conclusions: The overall quality of life on the basis of quality of life score QoL was significantly better in male participants as compared to female participants. Their busy children or family conflicts and misapprehensions instigate their miserable moments of older life
Diagnosing isolated hepatosplenic tuberculosis in an immunocompetent patient: A case report
For many years, tuberculosis (TB) has been endemic in Pakistan; many rare and unusual presentations have been reported. There is a myriad of non-specific symptoms which always requires a high index of clinical suspicion for TB. World Health Organization data suggest that Pakistan ranks as the fifth highest country burdened with TB and has the fourth highest prevalence of multi-drug resistant TB globally. With an annual incidence of 277 cases per 100,000, the importance of early diagnosis and treatment is self-evident. We present a case where a strong suspicion of isolated hepatosplenic TB in an immunocompetent patient justified a directed approach
Perforated appendix! An experience of a Public teaching hospital
Introduction
 The most common cause of non-traumatic acute abdominal pain as well as the most common acute abdominal condition presenting to Surgical Emergency is none other than Acute Appendicitis hence it becomes the most common entity undergoing surgery in Emergencies all over the world. The lifetime risk for someone to develop acute appendicitis is 8.6% and 6.7% for males and females respectively, with 90% found in children and young adults and 10% in patients over 60 years of age.1
Increasing age or in other words decreasing immunity does affect the incidence of perforated appendix as we see the the perforation rate in acute appendicitis is approximately 20~30% but as the age goes beyond 60 years it inclines to 32-72%.2 Delay in the diagnosis caused by indefinite history and physical examination tends to contribute to higher incidence of perforated appendix as reported by Siripong et al.
In another study the risk factors that were found to be associated with perforated appendicitis were male sex, fever ≥ 38°C, anorexia, and duration of pain in the pre-admission period.3 In one of the the study pre-hospital delays were exceeding related to perforation as compared to in-hospital delays which was explainable because of a linear relationship present among the pathological grade to hospital interval ratio , thus leading to increased risk of perforation.4 As far as the blood work was concerned , an increase in Total Leucocyte count with majority being polymorphonuclear leukocytes (PMN), and raised C-reactive protein (CRP) levels were found to be responsible for substantial increment in the risk and gravity of complications in appendicitis. Presence of comorbid diseases didn't show any significant affect on perforation rate.5
Promotion of Hinduism in Children through Cartoons in Pakistan
This study is an effort to explore the promotion of Hinduism in children through cartoons in Pakistan which are based on Hindu religious topics and dub in Hindi language. Objective of the study is to probe the planned agenda of Indian media and to aware parents about the harmful effects of such productions. Social Cognitive theory is used, the methodology is survey method and questionnaire is used as tool of data collection. Sample drawn for the study is 200 of which 100 are children and 100 are parents. The results of the study reveal that children are quick learner and they copy the same which they observe in cartoons such as words of Hindi language hence, Indian cultural and religious values have started to evolve rapidly in Pakistani culture.Key words: Indian & Pakistani culture, Cartoon effects, Hindi Religion & language, Social learning behavior.Résumé Cette étude est un effort pour explorer la promotion de l’hindouisme chez les enfants à travers le dessin au Pakistan, qui sont fondés sur des thèmes religieux hindous et dub dans la langue hindi. Objectif de l’étude est de sonder l’ordre du jour prévu de médias indiens et à sensibiliser les parents sur les effets nocifs de ces productions. La théorie sociale cognitive est utilisée, la méthode est la méthode d’enquête et le questionnaire est utilisé comme outil de collecte de données. Echantillon tiré de l’étude est de 200 dont 100 sont des enfants et 100 sont des parents. Les résultats de l’étude révèlent que les enfants sont apprend vite et ils copient les mêmes qu’ils observent dans les dessins animés tels que les mots de la langue hindi par conséquent, les valeurs culturelles et religieuses indiennes ont commencé à évoluer rapidement dans la culture pakistanaise.Mots clés: Culture indienne et pakistanaise, Effets de bande dessinée, La religion Hindi et la langue, Le comportement de l’apprentissage social
Self-Navigation Car using Reinforcement Learning
In this paper, a project is described which is a 2-D modelled version of a car that will learn how to drive itself. It will have to figure everything out on its own. In addition, to achieve that the simulator contains a car running simultaneously &can be controlled by different control algorithms - heuristic, reinforcement learning-based, etc. For each dynamic input, the Reinforcement- Learning modifies new patterns. Ultimately, Reinforcement Learning helps in maximizing the reward from every state. In this first Part, we will implement a Reinforcement-Learning model to build an AI for Self Driving Car. Project will be focusing on the brain of the car not any graphics. The car will detect obstacles and take basic actions. To make autonomous car or self-driving car a reality, some of the factors to be considered are human safety and quality of life
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