Papers by Ayesha Omer Abbasi
Energies
Demand response (DR) strategies are recieving much attention recently for their applications in t... more Demand response (DR) strategies are recieving much attention recently for their applications in the residential sector. Electric vehicles (EVs), which are considered to be a fairly new consumer load in the power sector, have opened up new opportunities by providing the active utilization of EVs as a storage unit. Considering their storage capacities, they can be used in vehicle-to-grid (V2G) or vehicle-to-community (V2C) options instead of taking power in peak times from the grid itself. This paper suggests a community-based home energy management system for microgrids to achieve flatter power demand and peak demand shaving using particle swarm optimization (PSO) and user-defined constraints. A dynamic clustered load scheduling scheme is proposed, including a method for managing peak shaving using rules specifically designed for PV systems that are grid-connected alongside battery energy storage systems and electric vehicles. The technique being proposed involves determining the lim...
Background: Pneumothorax is a potentially fatal condition that requires early diagnosis and promp... more Background: Pneumothorax is a potentially fatal condition that requires early diagnosis and prompt management upon arrival at the Emergency Department(ED). The purpose of this study is to validate a Pneumothorax Machine learning (PneumoDetect) model designed on both an online and in-hospital dataset, and to compare its accuracy to that of radiologist and emergency physician Method: We conducted a cross-sectional study using an online available open access tool. We obtained a hospital dataset from January 1, 2010 to December 31, 2020, and extracted 4,788 DICOM X-ray images. A machine learning team manually labelled the images from hospital records. We performed internal validation using a supervised learning machine learning model with a Convolutional Neural Network architecture implemented in Python and Medcalc. We calculated Kappa statistics were calculated using STATA v14.2 to assess the model’s performance. Additionally, we generated AUROC curves using sensitivity, specificity, p...
IEEE Access
Load scheduling and peak demand shaving are two critical aspects of the utility grid operation th... more Load scheduling and peak demand shaving are two critical aspects of the utility grid operation that help both the grid operators as well as end-users. This paper proposes a two-stage community home energy management system for microgrids. The first stage deals with the dynamic clustered community load scheduling scheme. Comparatively flatter power demand was attained using particle swarm optimization (PSO) incorporating user-defined constraints. The new arising or remaining peaks as a consequence of consumer constraints are catered to in the second stage. The second stage proposes a rule-based peak shaving management method for the photovoltaic (PV) systems that are connected to the grid and the battery energy storage systems. The proposed technique determines the dynamic demand and feed-in limits based on the estimations of the upcoming day's load demand and PV power profiles. Also, the study presents an optimal rule-based management technique for peak shaving of utility grid power that sets the charge/discharge day ahead schedules of the battery. For peak energy minimization, PSO is used to calculate the optimal inputs needed for implementing the appropriate rule-based management strategy. MATLAB is used to test the proposed method for different PV power and load demand patterns, thus, achieving an average improvement of 8.5%. INDEX TERMS Microgrid, home energy management system, dynamic clustering, peak shaving, optimization, smart devices, battery energy storage. NOMENCLATURE ABBREVIATIONS AMI Advanced metering infrastructure. ATS Activation time slot. BES Battery Energy Storage. CRP Cost reduction percentage. DHEMS Dynamic clustered home energy management system. DSM Demand side management. DTE Device operation time end. The associate editor coordinating the review of this manuscript and approving it for publication was Elizete Maria Lourenco .
Circulation, Nov 16, 2021
Introduction: Seizures are one of the most common presentations in children requiring urgent care... more Introduction: Seizures are one of the most common presentations in children requiring urgent care in Emergency Departments. This study was conducted to determine the clinical profile, management and spectrum of patients presenting to Emergency department in a low middle income country. Methods: This was an observational cross-sectional study carried out in Aga Khan University Hospital, Karachi, Pakistan. Data was collected on a predesigned questionnaire from June 2018- May 2019. Qualitative variables like gender and type of seizure were expressed as percentages and frequencies. Quantitative variables like age, levels of sodium, potassium and calcium were expressed as median, interquartile ranges and Wilcoxin Rank Sum test was used. Conclusion: Seizure was one of the commonest neurological condition occurring predominantly in males. Febrile seizures usually donot require hospitalization. Emergency Department care was needed in majority of children and 45.7% were discharged directly f...
IEEE Access, 2021
Power scheduling of domestic appliances is a vital preference for bridging the gap between demand... more Power scheduling of domestic appliances is a vital preference for bridging the gap between demand and generation of electricity in a microgrid. For a stable microgrid, an acceptable mechanism must reduce the peak to average ratio (PAR) of power demand with supplementary benefits for consumers as reduced electricity charges. Recent studies have focused on PAR and cost reduction for a small consumer population. Furthermore, researchers have mainly considered homogeneous consumer loads. This study focuses on residential power scheduling for electricity cost reduction for consumers and load profile PAR curtailment for a relatively large consumer population with non-homogeneous loads. A sample population of 1000 consumers from various classes of society is considered. The proposed dynamic clustered community home energy management system (DCCHEMS) allows the clustering of appliances based on time overlap criteria. Comparatively flatter power demand is attained by utilizing the clustered appliances in conjunction with particle swarm optimization under the influence of user-defined constraints. Modified inclined block rates with real-time electricity pricing strategies are deployed to minimize the electricity costs. DCCHEMS achieved higher efficiency rates in contrast to the traditional non-clustering and static clustering optimization schemes. An improvement of 21% in peak to average ratio, 4% in cost reduction, and 19% in variance to mean ratio is obtained. INDEX TERMS Smart grid, dynamic clustering, home energy management system, demand response, optimization, controllable appliances, microgrid.
International Journal of Surgery Open, 2020
Abstract Introduction: Seizures are one of the most common presentation in children requiring urg... more Abstract Introduction: Seizures are one of the most common presentation in children requiring urgent care in Emergency Departments. This study was conducted to determine the clinical profile, management and spectrum of patients presenting to Emergency department in a low middle income country. Methods: This was an observational cross-sectional study carried out in tertiary care hospital. Data was collected on a predesigned questionnaire from June 2018- May 2019. Qualitative variables like gender and type of seizure were expressed as percentages and frequencies. Quantitative variables like age, levels of sodium, potassium and calcium were expressed as median, interquartile ranges and Wilcoxon Rank Sum test was used. Results: The prevalence of seizures amongst children presenting to pediatric emergency room was found to be 9.36 per 1000 children. A total of 186 patients presented to pediatric emergency department with seizures. There were 58.1% boys and 41.9% females. The median age of children presented with seizure was 26 months. The most common type of seizure noticed by eye witness were grandmal 95 (51.1%), simple partial 6(3.3%), complex 1 (0.5%).Hyponatremia was the most commonly reported abnormality 54.2%. Febrile Convulsion were reported in 46.8%, 24.7% were known epileptic, 9.1% had an infective source, 5.4% metabolic & 2.7% had afebrile seizures. Conclusion: Seizure was one of the commonest neurological condition occurring predominantly in males. Febrile seizures usually do not require hospitalization. Emergency Department care was needed in majority of children and 45.7% were discharged directly from Emergency Room.
JPMA. The Journal of the Pakistan Medical Association, 2018
OBJECTIVE To assess the time in therapeutic range in patients on warfarin anti-coagulation therap... more OBJECTIVE To assess the time in therapeutic range in patients on warfarin anti-coagulation therapy. METHODS The retrospective chart review was conducted at Aga Khan University Hospital, Karachi, and comprised data of patients having undergone anti-coagulation with warfarin from January 2013 to April 2015. To determine the mean time in therapeutic range, Rosendaal method was used. Association of time in therapeutic range with the composite outcome, bleeding and thromboembolic events was also assessed. Percentage of patients with time in therapeutic range <60% was calculated. RESULTS There were 92 patients whose median time in therapeutic range was 34.9% (interquartile range: 20.0- 55.7). Overall, 71(77.2%) patients had time in therapeutic range below 60% which had statistically significant correlation with the composite outcome (p<0.05). Number of comorbids was significant in predicting time in therapeutic range and patients with time in therapeutic range< 60% (p<0.05). C...
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Papers by Ayesha Omer Abbasi