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REAL COdEd GENETIC ALGORITHM FOR STOCHASTIC HYdROTHERMAL GENERATION SCHEdULING

Journal of Systems Science and Systems Engineering 2011年第1期20卷 87-109页

作者： Jarnail S.dHILLON J.S.dHILLON d.p.kothari G.Z.S.College of Engineering and Technology Sant Longowal Institute of Engineering and Technology Vindhya Institute of Technology and Science

The intent of this paper is to schedule short-term hydrothermal system probabilistically considering stochastic operating cost curves for thermal power generation units and uncertainties in load demand and reservoir water inflows. Therefore, the stochastic multi-objective hydrothermal generation scheduling problem is formulated with explicit recognition of uncertainties in the system production cost coefficients and system load, which are treated as random variable. Fuzzy methodology has been exploited for solving a decision making problem involving multiplicity of objectives and selection criterion for best compromised solution. A real-coded genetic algorithm with arithmetic-average-bound-blend crossover and wavelet mutation operator is applied to solve short-term variable-head hydrothermal scheduling problem. Initial feasible solution has been obtained by implementing the random heuristic search. The search is performed within the operating generation limits. Equality constraints that satisfy the demand during each time interval are considered by introducing a slack thermal generating unit for each time interval. Whereas the equality constraint which satisfies the consumption of available water to its full extent for the whole scheduling period is considered by introducing slack hydro generating unit for a particular time interval. Operating limit violation by slack hydro and slack thermal generating unit is taken care using exterior penalty method. The effectiveness of the proposed method is demonstrated on two sample systems.

关键词： Stochastic multi-objective optimization real-coded genetic algorithm fuzzy set economicload dispatch

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IoT Based Approach in a power System Network for Optimizing distributed Generation parameters

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Computer Modeling in Engineering & Sciences 2019年第6期119卷 541-558页

作者： p.Shanmugapriya J.Baskaran C.Nayanatara d.p.kothari Sri SaiRam Engineering College Chennai-600044Tamil Nadu.India Adhiparasakthi Engineering College Melmaruvathur.Kanchipuram DistrictTamil Nadu dean-Research&development J.D.College of Engineering and ManagementNagpur

The objective of this paper is to provide a robust Virtual power plant(Vpp)network collaborated with Internet of Things(IoT)which uses a conceptual model to integrate each device in the *** on the functionality all the devices which are purely distributed within the grid are networked initially from residential units to substations and up to service data and demand *** ensure the trapping of the available power and the efficient transfer of distributed Generation(dG)power to the grid distribution Active Control(dAC)strategy is *** optimization of dG parameter which includes dG size,location and type are adopted using dispatch *** case studies are optimized by rescheduling the generation and with load *** Customer Benefit(MCB)is taken as an objective function and a straight forward solution is given by heuristic search *** method was vindicated in a practical Indian Utility *** control proposes better performances,ensures reliability and efficiency even under parameter variations along with disturbances which is justified using IEEE 118 bus system and real time Indian utility 63 bus *** reveal that the proposed technique proves advantages of low computational intricacy.

关键词： Customer benefit distributed generation internet of things virtual power plant distribution active control

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A solution to the unit commitment problem a review

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Frontiers in Energy 2013年第2期7卷 223-236页

作者： B. SARAVANAN Siddharth dAS Surbhi SIKRI d. p. kothari School of Electrical Engineering VIT University Vellore 632014 TamilNadu India Raisoni Group of Institutions Nagpur 400016 India

Unit commitment （UC） is an optimization problem used to determine the operation schedule of the generating units at every hour interval with varying loads under different constraints and environments. Many algorithms have been invented in the past five decades for optimization of the UC problem, but still researchers are working in this field to find new hybrid algorithms to make the problem more realistic. The importance of UC is increasing with the constantly varying demands. There- fore, there is an urgent need in the power sector to keep track of the latest methodologies to further optimize the working criterions of the generating units. This paper focuses on providing a clear review of the latest techniques employed in optimizing UC problems for both stochastic and deterministic loads, which has been acquired from many peer reviewed published papers. It has been divided into many sections which include various constraints based on profit, security, emission and time. It emphasizes not only on deregulated and regulated environments but also on renewable energy and distributed generating systems. In terms of contributions, the detailed analysis of all the UC algorithms has been discussed for the benefit of new researchers interested in working in this field.

关键词： unit commitment (UC) optimization deter-ministic load stochastic load evolutionary programming(Ep) hybrid

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Impact of FACTS devices on exercising market power in deregulated electricity market

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Frontiers in Energy 2013年第4期7卷 448-455页

作者： Shanmugam pRABHAKAR KARTHIKEYAN I. JACOB RAGLENd d. p. kothari School of Electrical Engineering V1T University Vellore 632014 India School of Electrical Sciences Nooml Islam University Thakkalai Nagercoil 629180 India Raisoni Group of Institutions Nagpur 440001 India

In power system studies, congestion in trans- mission lines and utilization of flexible alternating current transmission system （FACTS） devices are closely associated. These devices are very important due to their role in power delivery system enhancement. It is to be noted that the generation companies can exercise their market power which depends on the line flows, line constraints, generators＇ location and its share to the individual loads. This issue cannot be overlooked as it creates monopoliness which is against the deregulated market policy. The objective of this paper is to study the impact of market power when FACTS devices like thyristor controlled switching capacitor （TCSC） and thyristor controlled phase angle regulator （TCpAR） are used under steady state operation. The market power is determined using nodal must-run share （NMRS） index for the standard IEEE 14- bus system with and without the above FACTS devices and the results obtained are compared. All the above simula- tions are conducted in a MATLAB 7.9-R2009b environment.

关键词： flexible alternating current transmission system (FACTS) thyristor controlled switching capacitor (TCSC) thyristor controlled phase angle regulator (TCpAR) market power must-run generation (MRG) nodal must-run share (NMRS)

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A solution to unit commitment problem using invasive weed optimization algorithm

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Frontiers in Energy 2013年第4期7卷 487-494页

作者： B. SARAVANAN E. R. VASUdEVAN d. p. kothari School of Electrical Engineering Vellore Institute of Technology University Vellore 632014 India JB Group of Educational Institutions Hyderabad 500 034 India

Unit commitment （UC） is one of the most important aspect of power generation in the world today. Though, there is no method to find the exact optimized solution, there exists several meta-heuristic algorithms to determine the close to exact solution. This paper proposes a novel solution to effectively determine UC and generation cost using the technique of invasive weed optimization （IWO）. The existing technique distributes the load demand among all the generating units. The method proposed here utilizes the output of UC obtained by using the Lagrangian relaxation （LR） method and calculates the required generation from only the plants that are ON discarding the OFF generator units and thereby giving a faster and more accurate response. Moreover, the results show the comparison between the LR-particle swarm optimization （pSO） and LR-IWO, and prove that the cost of generation for a 4 unit, 8 hour schedule is much less in the case of IWO when compared to pSO.

关键词： Lagrangian relaxation (LR) invasive weed optimization (IWO) economic dispatch optimization fuel cost seed fitness

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Unit commitment using dynamic programming-an exhaustive working of both classical and stochastic approac

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Frontiers in Energy 2013年第3期7卷 333-341页

作者： Balasubramaniyan SARAVANAN Surbhi SIKRI K. S. SWARUp d. p. kothari School of Electrical Engineering VIT University Vellore 632014 India department of Electrical Science IIT Madras Chennai 600036 India JB Group of Institutions Hyderabad 500075 India

In the present electricity market, where renewable energy power plants have been included in the power systems, there is a lot of unpredictability in the demand and generation. There are many conventional and evolutionary programming techniques used for solving the unit commitment （UC） problem. dynamic programming （dp） is a conventional algorithm used to solve the deterministic problem. In this paper dp is used to solve the stochastic model of UC problem. The stochastic modeling for load and generation side has been formulated using an approximate state decision approach. The programs were developed in a MATLAB environment and were exten- sively tested for a four-unit eight-hour system. The results obtained from these techniques were validated with the available literature and outcome was good. The commitment is in such a way that the total cost is minimal. The novelty of this paper lies in the fact that dp is used for solving the stochastic UC problem.

关键词： unit commitment chastic dynamic programming diagram (UC) deterministic sto- (dp) optimization state

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Natural history,clinical characteristics,outcomes,and long-term follow-up of pain-free chronic pancreatitis

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Gastroenterology Report 2023年第1期11卷 309-315页

作者： Awais Ahmed Ishani Shah Rachel Bocchino Steven d.Freedman darshan J.kothari Sunil G.Sheth department of Medicine Division of GastroenterologyBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA department of Medicine Division of Internal MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA department of Medicine Division of GastroenterologyDuke UniversityDurhamNCUSA

Background:Chronic pancreatitis(Cp)is characterized by chronic abdominal pain and functional ***,a small subset of patients with prior acute pancreatitis(Ap)and/or underlying risk factors for developing Cp may be pain-free at diagnosis and may have a different clinical *** aimed to compare the clinical characteristics,outcomes,and healthcare utilization between Cp patients with and without ***:Reviewed patients with established Cp were followed in our pancreas Center between January 2016 and April *** without risk factors for developing Cp and/or without Ap prior to their diagnosis and only with incidental radiologic features of Cp were excluded,so as tominimize confounding factors of pancreatopathy unrelated to *** were divided into painful and pain-free groups to analyze differences in demographics,outcomes,and healthcare ***:Of 368 Cp patients,49(13.3%)were pain-free at diagnosis and had remained so for>9 *** were no significant differences in body mass index,race,sex,or co-morbidities between the two ***-free patients were older at diagnosis(53.9 vs 45.7,p=0.004)and had less recurrent Ap(RAp)(43.8%vs 72.5%,pd less exocrine pancreatic insufficiency(EpI)(34.7%vs 65.7%,ppain-free patients had less disability(2.2%vs 22.0%,p=0.003),mental illness(20.4%vs 61.0%,pp=0.059),and therapeutic interventions(0.0%vs 16.4%,p=0.005)for ***:We described a unique subset of patients with underlying risk factors for Cp and/or prior Ap who were painfree at *** were older at diagnosis,had less EpI and RAp,and overall favorable outcomes with minimal resource utilization.

关键词： chronic pancreatitis pain-free pancreatic insufficiency diabetes

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An open-access endoscopy screen correctly and safely identifies patients for conscious sedation

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Gastroenterology Report 2016年第4期4卷 281-286,I0001页

作者： darshan kothari Joseph d.Feuerstein Laureen Moss Julie d’Souza Kerri Montanaro daniel A.Leffler Sunil G.Sheth department of Medicine and division of Gastroenterology Beth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA department of Nursing Beth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA

Background and aims:Open-access scheduling is highly utilized for facilitating generally low-risk *** screening addresses sedation requirements;however,procedural safety may be compromised if screening is *** sought to determine the reliability of our open-access scheduling system for appropriate use of conscious ***:We prospectively and consecutively enrolled outpatient procedures booked at an academic center by open-access using screening after in-office gastroenterology(GI)*** collected the cases inappropriately booked for conscious sedation and compared the characteristics for significant ***:A total of 8063 outpatients were scheduled for procedures with conscious sedation,and 5959 were booked with *** 78 patients(0.97%,78/8063)were identified as subsequently needing anesthesiologist-assisted sedation;44(56.4%,44/78)were booked through open-access,of which chronic opioid(47.7%,21/44)or benzodiazepine use(34.1%,15/44)were the most common reasons for needing anesthesiologist-assisted *** on chronic benzodiazepines required more midazolam than those not on chronic benzodiazepines(p=0.03)of those patients who underwent conscious ***,patients with chronic opioid use required more fentanyl than those without chronic opioid use(p=0.04).Advanced liver disease and alcohol use were common reasons for patients being booked after in-office consultation and were significantly higher than those booked with open-access(both pd that the majority of patients can be triaged for conscious sedation using a multi-tiered screening ***,few patients(ppropriately booked for conscious *** most common reasons for considering anesthesiologist-assisted sedation were chronic opioid,benzodiazepine and/or alcohol use and advanced liver *** suggests that these entities could be included in screening proces

关键词： open-access endoscopy sedation screen

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Extra-pancreatic complications,especially hemodialysis predict mortality and length of stay,in ICU patients admitted with acute pancreatitis

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Gastroenterology Report 2018年第3期6卷 202-209,I0001页

作者： darshan kothari Maarten R.Struyvenberg Michael C.perillo Ghideon Ezaz Steven d.Freedman Sunil G.Sheth department of Medicine Beth Israel Deaconess Medical CenterHarvard Medical School330 Brookline AveBostonMA 02215USA

Background and aims:patients in the intensive care unit(ICU)with acute pancreatitis(Ap)are at risk for extra-pancreatic complications given their severe illness and prolonged length of *** sought to determine the rate of extra-pancreatic complications and its effect on length of stay(LOS)and mortality in ICU patients with ***:We performed a retrospective cohort study of ICU patients admitted to a tertiary-care center with a diagnosis of Ap.A total of 287 ICU patients had a discharge diagnosis of Ap,of which 163 met inclusion *** calculated incidence rates of extra-pancreatic complications and performed a univariate and multi-variable analysis to determine predictors of LOS and ***:There were a total of 158 extra-pancreatic complications(0.97 extra-pancreatic complications per patient).Ninetyfive patients had at least one extra-pancreatic complication,whereas 68 patients had no extra-pancreatic *** with extra-pancreatic complications had a significantly longer LOS(14.7 vs 8.8 days,ppancreatic *** with non-infectious extra-pancreatic complications had a higher rate of mortality(24.0%vs 16.2%,p=0.04).patients requiring dialysis was an independent predictor for LOS and mortality(incidence risk ratio[IRR]1.73,95%confidence interval[CI]:1.263–2.378 and IRR 1.50,95%CI 1.623–6.843,ppredictor for mortality(p=0.05).Other extra-pancreatic complications were not ***:Extra-pancreatic complications occur frequently in ICU patients with Ap and impact *** with noninfectious extra-pancreatic complications have a higher mortality *** controlling for local pancreatic complications,patients requiring dialysis remained an independent predictor for LOS and mortality.

关键词： Severe acute pancreatitis extra-pancreatic complications intensive care unit length of stay in-hospital mortality infections

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Escalating complexity of endoscopic retrograde cholangiopancreatography over the last decade with increasing reliance on advanced cannulation techniques

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World Journal of Gastroenterology 2020年第41期26卷 6391-6401页

作者： Monique T Barakat Mohit Girotra Nirav Thosani Shivangi kothari Subhas Banerjee divisions of Adult and pediatric Gastroenterology and Hepatology Stanford University Medical CenterCupertinoCA 95014United States division of Gastroenterology and Hepatology University of Miami Miller School of MedicineMiamiFL 33136United States department of Internal Medicine Division of GastroenterologyHepatology&NutritionUniversity of Texas Health Science Center HoustonHoustonTX 77030United States division of Gastroenterology and Hepatology University of Rochester Medical CenterRochesterNY 14627United States division of Gastroenterology and Hepatology Stanford University Medical CenterStanfordCA 94304United States

BACKGROUNd At our academic tertiary care medical center, we have noted patients referred for endoscopic retrograde cholangiopancreatography(ERCp) who increasingly require advanced cannulation techniques. This trend is noted despite increased endoscopist experience and annual ERCp volume over the same *** To evaluate this phenomenon of perceived escalation in complexity of cannulation at ERCp and assessed potential underlying *** demographic/clinical variables and records of ERCp patients at the beginning(2008), middle(2013) and end(2018) of the last decade were reviewed retrospectively. Cannulation approaches were classified as "standard" or "advanced" and duodenoscope position was labeled as "standard"(short position) or "non-standard"(e.g., long, semi-long).RESULTS patients undergoing ERCp were older in 2018 compared to 2008(69.7 ± 15.2 years vs 55.1 ± 14.7, p d ampullary distortion and peri-ampullary diverticula were noted in 2018(p ps were increasingly performed with a non-standard duodenoscope position, from 2.2%(2008) to 5.6%(2013) and 16.1%(2018)(p dvanced cannulation technique for a given ERCp increased from 0.7%(2008) to 0.9%(2013) to 6.6%(2018)(p primary mass size > 4 cm, pancreatic uncinate mass, and bilirubin > 10 mg/d L predicted use of advanced cannulation techniques(p plexity of cannulation at ERCp has sharply increased over the past 5 years, with an increased proportion of elderly patients and those with malignancy requiring advanced cannulation approaches. These data suggest that complexity of cannulation at ERCp may be predicted based on patient/ampulla characteristics. This may inform selection of experienced, high-volume endoscopists to perform these complex procedures.

关键词： Endoscopic retrograde cholangiopancreatography Biliary cannulation Goff trans-pancreatic septotomy Needle knife precut sphincterotomy Endoscopy Complexity

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