124 research outputs found
Machine Learning Ensembles for Grid Congestion Price Forecasting
Title from PDF of title page, viewed June 21, 2023Thesis advisor: Reza DerakhshahniVitaIncludes bibliographical references (pages 54-56)Thesis (M.S.)--Department of Computer Science and Electrical Engineering. University of Missouri--Kansas City, 2023In this thesis, we embarked on a comprehensive study to develop a cutting-edge model for forecasting real-time electricity prices across 35 nodes within the PJM zone. The task at hand was particularly challenging, given the volatility of the day-ahead electricity market and the numerous factors that influence prices, such as load variations, weather conditions, and historical prices. Our objective was to devise a model that could provide more accurate day-ahead price forecasts than existing methods. To achieve this goal, we proposed an ensemble-based approach that leveraged the strengths of low-bias and high-variance machine learning models. To handle missing values, we employed K-Nearest Neighbors (KNN) imputation. To enhance the performance of the models, we employed Principal Component Analysis (PCA) and correlation feature selection techniques. We then employed a direct multi-output strategy to forecast real-time prices. Our ensemble incorporated a variety of models such as Support Vector Regression (SVR), Huber Regression, and deep neural networks such as Convolutional Neural Network (CNN), Long-Short Term Memory (LSTM), Bidirectional LSTM (BiLSTM), and Temporal Convolutional Network (TCN). Our results on test data from the first half of 2021 demonstrate that our proposed strategy outperforms any single model by 8.75% over all 35 nodes and beats the day-ahead prices. However, we noticed a decrease in testing accuracy in the latter half of 2021, indicating a need for a more dynamic ensemble fusion.
In conclusion, our research provides valuable insights into electricity price forecasting and illustrates the effectiveness of ensemble learning techniques, incremental learning, and deep neural networks for time series forecasting. Our proposed method can be utilized by energy traders, independent system operators, and policymakers to make more informed decisions in the uncertain and volatile energy market.Introduction -- Literature review -- Data collection and preprocessing -- Data modellin
Long-Term Outcomes of Drug-Coated Balloon Angioplasty in The Treatment of Small Vessel Coronary Artery Disease
Long-Term Outcomes of Drug-Coated Balloon Angioplasty in The Treatment of Small Vessel Coronary Artery Disease
Objectives: To determine the outcomes in patients with small-vessel disease (SVD) who underwent percutaneous coronary intervention (PCI) with a drug-coated balloon (DCB) and correlate these adverse outcomes with various risk factors.
Methodology: The prospective cohort study was conducted at the Rawalpindi Institute of Cardiology (RIC) from January 2020 to December 2022. After being approved by the Hospital Ethics Committee, fifty-four patients who presented with SVD were enrolled using non-probability consecutive sampling. Written informed consent was obtained from the patients. They were treated with DCB and observed clinically on follow-ups at 15, 30, 60, and 90 days, & later after every 6 months for up to 2 years. Only those patients who presented with symptoms underwent repeat angiography. The outcomes assessed were cardiovascular mortality, myocardial infarction (MI), and target lesion revascularization (TLR).
Results: Cardiovascular mortality occurred in 2(3.7%), MI in 3(5.6%) and TLR in 2(3.7%) patients. There was a significant association between cardiovascular mortality, MI, and TLR with diabetes mellitus and BMI. Age was only significantly related to cardiovascular mortality.
Conclusion: A drug-coated balloon is an effective and feasible treatment modality for small vessel disease. The incidence of outcomes of cardiovascular mortality, MI, and TLR after DCB is low, making it a safe modality. Advanced age, obesity, and diabetes mellitus alone or with hypertension are the predicting factors of adverse outcomes after DCB in patients with SVD.
Keywords: Drug-coated balloon, DCB, Small vessel coronary artery disease, SV
Thyroid disorders in Hepatitis C virus infected untreated patients
Background: To determine the association of thyroid disorders with chronic hepatitis C virus infection in patients who are not getting any antiviral treatment. Methods: Fifty patients without pre-existing thyroid abnormality having positive Hepatitis C Virus (HCV) infection (confirmed on PCR) and not willing for getting anti-viral treatment (interferon) were included in the study. Blood samples from 50 patients were collected at base line, 03 months, 06 months, 09 months and at 12 months. The level of thyroid stimulating hormone (TSH) and thyroid antibodies was measured in these samples. Results: Eleven patients (22%) developed thyroid disorder during the study period. Majority of the patients (73%) developed thyroid disorder on the basis of change in TSH level whereas 18% developed thyroid disorder on the basis of alteration in thyroid antibodies levels and 9% patients abnormality both in TSH levels and change in thyroid antibody titre. Conclusion: A close association of thyroid disorder and chronic HCV infection is noted in the study population
Online Education and Internet Connectivity Problems: A Perspective of the Teachers and Undergraduate Dental Students
OBJECTIVES
Assessment of difficulties and glitches regarding internet connectivity faced by undergraduates and teachers during online learning.Â
METHODOLOGY
This study was conducted using an online questionnaire. 186 undergraduate students and teachers were included from CMH, Lahore. The duration of this study was 3 months. .
RESULTS
There was found to be no statistical difference in reluctance to use online platforms (p=0.17), frequent loss of internet (p=0.181), difficulty in dealing with the loss of connection (p=0.181), disturbance in planned schedule due to loss of connection (p=0.213), lagging behind in schedule (p=0.630), inability to convey the message (p=0.093), lack of internet in remote areas (p=0.302), lack of training to deal with connection problems (p=0.766), poor connection due to technical problems in devices (p=0.089) and poor quality internet (p=0.740) among faculty and students.
CONCLUSION
The problems due to internet connectivity issues in online education were faced more by students as compared to faculty
Entamoeba species associated with chronic diarrhoea in Pakistan
We determined the prevalence of Entamoeba (E.) histolytica, E. dispar and E. moshkovskii in patients with chronic diarrhoea associated with abdominal pain or discomfort mimicking irritable bowel syndrome. Stool samples were collected from 161 patients with chronic diarrhoea and from 157 healthy controls. Stool microscopy with modified trichrome stain, culture and polymerase chain reaction (PCR) for Entamoeba spp. differentiation was performed. Microscopy demonstrated Entamoeba cysts in 44% (57/129) of patients with diarrhoea compared to 29% (44/151) of controls (P=0·009). In patients with diarrhoea, PCR for E. histolytica was positive in 9% (11/129) (P=0·008), E. dispar in 19% (24/129) (P=0·117) and E. moshkovskii in 19% (24/129) (P\u3c0·001). E. histolytica and E. moshkovskii were significantly associated with diarrhoea while E. dispar was found equally in both groups
Clinical study on the use of nozovent in a tertiary care setting
Objective: To assess the effectiveness of the Nozovent device in Pakistani subjects at Aga Khan University Hospital, Karachi and Sir Ganga Ram Hospital, Lahore from 15 January 2001 to 15 January 2002.Methods: Sixty males and 40 females were selected by non probability purposive sampling, from OPD of ENT Department, complaining of nasal obstruction due to various reasons, e.g. vasomotor rhinitis, allergic rhinitis, congestion during pregnancy and menstruation, common cold, traumatic nose and nasal valve problem.Results: All patients benefited subjectively but the degree of relief varied in individuals.CONCLUSION: The Nozovent provides a unique method to relieve nasal obstruction with no side effects
Prevalences of giardia lamblia and cryptosporidium parvum infection in adults presenting with chronic diarrhoea
iardia lamblia and Cryptosporidium parvum are both waterborne pathogens associated with diarrhoea in developing countries. In a recent study based at the Aga Khan University in Karachi, 334 adults aged 16–83 years (178 patients with chronic diarrhoea and 156 diarrhoea-free volunteers who acted as controls) were checked for infection with these parasites, using stool microscopy and/or PCR. Overall, 21 (6.3%) and 29 (8.7%) of the subjects were found positive for G. lamblia by microscopy and PCR, respectively, while the corresponding values for C. parvum were 13 (3.9%) and 14 (4.2%). Although, compared with the diarrhoea-free controls, the patients with diarrhoea were not significantly more likely to be found infected with Giardia, either by microscopy [15 (8.4%) v. six (3.8%); P=0.085] or PCR [19 (10.7%) v. 10 (6.4%); P=0.167], they were significantly more likely to be found infected with C. parvum, both by microscopy [11 (6.2%) v. two (1.3%); P=0.024] and by PCR [12 (6.7%) v. two (1.3%); P=0.014].
The 19 patients found PCR-positive for Giardia comprised 10 (67%) of the 15 found smear-positive for the same parasite but only nine (5%) of the 163 found smear-negative (k=0.545; PCryptosporidium comprised all 11 (100%) patients found smear-positive for the same parasite but only one (0.6%) of the 167 found smear-negative (k=0.954; P\u3c0.001).
Although C. parvum was associated with chronic diarrhoea in the present study, the carriage of G. lamblia often appeared asymptomatic
Irritable bowel syndrome: is it associated with genotypes of Blastocystis hominis.
Blastocystis hominis is the most common intestinal parasite in humans. An extensive genetic variability has been described recently in B. hominis isolates. The aim of this study was to analyze genotypes of B. hominis isolates obtained from the healthy individuals and patients with irritable bowel syndrome-diarrhea (IBS-D). The patients with IBS-D were enrolled from gastroenterology outpatient department at the Aga Khan University Hospital. History and physical examination was done. Stool microscopy, culture, and polymerase chain reaction for B. hominis genotyping were carried out. The study included 158 patients with IBS-D, mean age 41 +/- 15, age range 16-83 years, and male/female ratio of 109:49. One hundred fifty-seven (49.8%) were taken as healthy control. The dominant B. hominis genotypes were genotype 1 in 87 (65%) and type 3 in 49 (37%). In IBS-D, genotype 1 was present in 75 (86%; P \u3c 0.001) compared to 12 (14%) in controls while type 3 was present in 23 (47%) compared to 26 (53%) in controls (P \u3c 0.001), respectively. Infection with single genotype of B. hominis was present in 70 (73%) with IBS-D and in 26 (27%) in control group while with multiple genotypes in 25 (64%) in IBS-D and 14 (36%) in control group (P = 0.30), respectively. Majority of our patients had typeable B. hominis infection. The genotype of B. hominis in IBS-D was type 1 while in control genotype 3 was predominant
Irritable bowel syndrome: in search of an etiology: role of Blastocystis hominis.
This study was designed to examine stool specimens of irritable bowel syndrome (IBS) patients for Blastocystis hominis, a common intestinal parasite. One hundred fifty patients were enrolled, 95 IBS cases and 55 controls. These patients provided a medical history, and underwent physical and laboratory evaluations that included stool microscopy and culture for B. hominis and colonoscopy. The 95 cases (51 males and 44 females) had a mean +/- SD age of 37.8 +/- 13.2 years. Stool microscopy was positive for B. hominis in 32% (30 of 95) of the cases and 7% (4 of 55) of the controls (P = 0.001). Stool culture was positive in 46% (44 of 95) of the cases and 7% (4 of 55) of the controls (P \u3c 0.001). Stool culture for B. hominis in IBS was more sensitive than microscopy (P \u3c 0.001). Blastocystis hominis was frequently demonstrated in the stool samples of IBS patients; however, its significance in IBS still needs to be investigated. Stool culture has a higher positive yield for B. hominis than stool microscopy
Efficacy of exogenous application of 2, 4-Dichlorophenoxyacetic acid (2, 4-D) on growth and yield of mungbean (Vigna radiata L.)
The growth and yield promotion of mungbean in response to the use of 2, 4-Dichlorophenoxy acetic acid (2, 4-D) was investigated through a pot study which was arranged in the wire house of Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad. The study was comprised of five treatments and three replications (control, 0.2 ppm 2, 4-D, 0.5 ppm 2, 4-D, 0.8 ppm 2, 4-D, and 1 ppm 2, 4-D). The suggested dose of Nitrogen, Phosphorus and Potassium (NPK) was applied at the amount of 20, 60 and 25 kg ha-1 added as Urea, DAP and SOP, respectively at sowing time. The data regarding growth (plant height, root and shoot length, root and shoot fresh and dry weight, and total biomass), yield (grain weight, number of grains plant-1) and NPK analysis in plants and soil was recorded and statistically analyzed. The response of exogenous application of 2, 4-D was significant at all levels in improving the performance of all the growth parameters and yield as compared to untreated control treatment. Maximum performance of all the parameters was recorded at 0.8 ppm application of 2, 4-D. As the concentration of 2, 4-D increased the development of plants also showed positive effect but up to 0.8 ppm application after that it started to decrease which showed that at higher concentrations 2, 4-D acts as growth retardant
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