An Exhaustive Solution of Power System Unit Commitment Problem Using Enhanced Binary Salp Swarm Optimization Algorithm

Venkatesh Kumar C.,Ramesh Babu M. 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.1

The Unit Commitment (UC) problem is a combinatorial optimization problem in power system operation with the key focus on achieving optimum commitment schedule of the generators for forecasted demand and spinning reserve. The computational complexity to determine a solution for the UC problem grows exponentially with the number of generators and system constraints. In this paper, the UC problem is formulated as a mixed-integer optimization problem and solved using novel Adaptive Binary Salp Swarm Algorithm by considering minimum up/down time limits, prohibited operating zones, spinning reserve, valve-point eff ect, and ramp rate limits. The proposed algorithm is tested for effi ciency on the standard 10-unit system, 26-unit RTS system, 54-unit IEEE 118-bus system, 20, 40, 60, 80, and 100-unit systems. Additionally, an Adaptive Multi-Objective Binary Salp Swarm Optimization Algorithm is proposed for resolving the bi-objective emission constrained UC problem and tested using a 10-unit system. The obtained results are analyzed for positive diff erences against other algorithms from the literature. The statistical analysis exhibits the effi ciency of the proposed method for large scale real-time systems.

Modelling and Performance Analysis of UPQC with Digital Kalman Control Algorithm under Unbalanced Distorted Source Voltage conditions

Venkatesh Kumar,Rajeswari Ramachandran 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.6

In this paper, the generation of a reference current and voltage signal based on a Kalman filter is offered for a 3-phase 4wire UPQC (Unified Power Quality Conditioner). The performance of the UPQC is improved with source voltages that are distorted due to harmonic components. Despite harmonic and frequency variations, the Kalman filter is capable enough to determine the amplitude and the phase angle of load currents and source voltages. The calculation of the first state is sufficient to identify the fundamental components of the current, voltage and angle. Therefore, the Kalman state estimator is fast and simple. A Kalman based control strategy is proposed and implemented for a UPQC in a distribution system. The performance of the proposed control strategy is assessed for all possible source conditions with varying nonlinear and linear loads. The functioning of the proposed control algorithm with a UPQC is scrutinized and validated through simulations employing MATLAB/Simulink software. Using a FPGA SPATRAN 3A DSP board, the proposed algorithm is developed and implemented. A small-scale laboratory prototype is built to verify the simulation results. The stated control scheme for the UPQC reduces the following issues, voltage sags, voltage swells, harmonic distortions (voltage and current), unbalanced supply voltage and unbalanced power factor under dynamic and steady-state operating conditions.

Interactive Motivational Concept: A Study of Motivation among Corporate of Bhopal Region in India

Bharti Venkatesh,Amit Kumar Sharma 한국유통과학회 2015 The Journal of Asian Finance, Economics and Busine Vol.2 No.2

Managers, supervisors, executives and others whose office is to get work done by staff in organizations would desire a motivated workforce. Despite the advances in technology, any system has tot have motivated people to achieve its goals and at some time or other, no one in charge of a unit has failed to wonder, ‘How best do I get individuals and groups motivated’? What is motivation, how can employees be motivated to direct their energies towards execution of the job and how is this achieved on a sustained on-going basis? Is a highly motivated employee necessarily an ace performer? These are the issues which the author would address in the present paper. The authors has conducted an empirical study by administering motivational test and collected data from 100 corporate of Bhopal region.

Comparative Analysis of Effect of Density, Insertion Angle and Reinsertion on Pull-Out Strength of Single and Two Pedicle Screw Constructs Using Synthetic Bone Model

Venkatesh Krishnan,Vicky Varghese,Gurunathan Saravana Kumar 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.3

Study Design: Biomechanical study. Purpose: To determine the effect of density, insertion angle and reinsertion on pull-out strength of pedicle screw in single and two screw-rod configurations. Overview of Literature: Pedicle screw pull-out studies have involved single screw construct, whereas two screws and rod constructs are always used in spine fusions. Extrapolation of results using the single screw construct may lead to using expensive implants or increasing the fusion levels specifically in osteoporotic bones. Methods: Single screw and two screw pull-out strength tests were carried out according to American Society for Testing and Materials F 543-07 on foam models to test the effect of density, insertion angle and reinsertion using poly axial pedicle screws. Results: Bone density was the most significant factor deciding the pull-out strength in both single and two screw constructs. The difference in pull-out strength between single screw and two screw configurations in extremely osteoporotic bone model (80 kg/m3) was 78%, whereas in the normal bone model it was 48%. Axial pull-out value was highest for the single screw configuration; in the two screw configuration the highest pull-out strength was at 10°–15°. There was an 18% reduction in pull-out strength due to reinsertion in single screw configuration. The reinsertion effect was insignificant in the two screw configuration. Conclusions: A significant difference in response of various factors on holding power of pedicle screw between single and two-screw configurations is evident. The percentage increase in pull-out strength between single and two screw constructs is higher for osteoporotic bone when compared to normal bone. Reinsertion has no significant effect on pull-out strength in the two screw rod configuration.

Novel chemical scaffolds of the tumor marker AKR1B10 inhibitors discovered by 3D QSAR pharmacophore modeling

Kumar, Raj,Son, Minky,Bavi, Rohit,Lee, Yuno,Park, Chanin,Arulalapperumal, Venkatesh,Cao, Guang Ping,Kim, Hyong-ha,Suh, Jung-keun,Kim, Yong-seong,Kwon, Yong Jung,Lee, Keun Woo Springer Science and Business Media LLC 2015 Acta pharmacologica Sinica. Vol.36 No.8

<P>Recent evidence suggests that aldo-keto reductase family 1 B10 (AKR1B10) may be a potential diagnostic or prognostic marker of human tumors, and that AKR1B10 inhibitors offer a promising choice for treatment of many types of human cancers. The aim of this study was to identify novel chemical scaffolds of AKR1B10 inhibitors using in silico approaches.</P>

Identification of Pedicle Screw Pullout Load Paths for Osteoporotic Vertebrae

Krishnan Venkatesh,Varghese Vicky,Kumar Gurunathan Saravana,Yoganandan Narayan 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.3

Study Design: A biomechanical study.Purpose: To determine the actual load path and compare pullout strengths as a function of screw size used in revision surgeries using postmortem human subject specimens.Overview of Literature: Pedicle screw fixation has become the standard of care in the surgical management of spinal instability. However, pullout failures are widely observed in osteoporotic spines and treated by revision surgeries using a higher diameter screw, performing cement augmentation, or increasing the levels of fixation. While the peak forces to final pullout are reported, the actual load path to achieve the final force level is not available. Methods: Six osteoporotic lumbar spines (L2–L5) were instrumented with 5.5×40 mm polyaxial screws and loaded along the axis of the screw using a material testing machine according to American Society for Testing of Materials 543-07 test protocol. Tests were again conducted by replacing them with 6.5×40 mm (group A) or 7.5×40 mm (group B) screws. Force-displacement data were grouped and load paths (mean±1 standard deviation) were compared.Results: Pullout strength decreased by 36% when the size of the revision screw was increased by 1 mm, while it increased by 35% when the size of the revision screw was increased by 2 mm compared to the index screw value. While the morphologies of the load paths were similar in all cases, they differ between the two groups: the larger screw responded with generally elevated stiffer path than the smaller screw, suggesting that revision surgery using a larger screw has more purchase along the inserted body-pedicle axis.Conclusions: A larger screw enhances strength and increases biomechanical stability in revision surgeries, although the final surgical decision is made by the clinician, which includes the patient’s anatomy and associated characteristics.

Predictors of Mortality after Surgery for Empyema Thoracis in Chronic Kidney Disease Patients

Mohan Venkatesh Pulle,Harsh Vardhan Puri,Belal Bin Asaf,Sukhram Bishnoi,Manish Malik,Arvind Kumar 대한흉부외과학회 2020 Journal of Chest Surgery (J Chest Surg) Vol.53 No.6

Background: Surgical treatment of empyema thoracis in patients with chronic kidney disease is challenging, and few studies in the literature have evaluated this issue. In this study, we aim to report the surgical outcomes of empyema and to analyze factors predict- ing perioperative mortality in patients with chronic kidney disease. Methods: This retrospective study included data from 34 patients with chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m2 for 3 or more months) who underwent surgery for empyema between 2012 and 2020. An analysis of demo- graphic characteristics and perioperative variables, including complications, was carried out. Postoperative mortality was the primary outcome measure. Results: Patients’ age ranged from 20 to 74 years with a 29-to-5 male-female ratio. The majority (n=19, 55.9%) of patients were in end-stage renal disease (ESRD) requiring main- tenance hemodialysis. The mean operative time was 304 minutes and the mean intraop- erative blood loss was 562 mL. Postoperative morbidity was observed in 70.5% of patients (n=24). In the subgroup analysis, higher values for operative time, blood loss, intensive care unit stay, and complications were found in ESRD patients. The mortality rate was 38.2% (n=13). In the univariate and multivariate analyses, poor performance status (East- ern Cooperative Oncology Group >2) (p=0.03), ESRD (p=0.02), and late referral (>8 weeks) (p<0.001) significantly affected mortality. Conclusion: ESRD, late referral, and poor functional status were poor prognostic factors predicting postoperative mortality. The decision of surgery should be cautiously assessed given the very high risk of perioperative morbidity and mortality in these patients.

An Optimized Methodical Energy Management System for Residential Consumers Considering Price‑Driven Demand Response Using Satin Bowerbird Optimization

Ganesh Kumar Chellamani,Premanand Venkatesh Chandramani 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.2

Home energy management system (HEMS) is a section of demand response (DR), that plays an imperative role in the residential areas towards appliance management for the enhancement of energy efciency and grid stability. In this article, a methodical home energy management system (Methodical-HEMS) was proposed based upon K-means, a machine learning algorithm and satin bowerbird optimization (SBO) algorithm to optimize the scheduling of appliances within a 24-h period. The K-means algorithm is used for defning the discrete comfort window (DCW) for schedulable appliance, while SBO algorithm is used for defning the suitable time slots for the schedulable appliance to operate within the DCW. MethodicalHEMS is considered for a single home with the day ahead time of use pricing, to minimize the overall electricity bill (EB) and to satisfy the consumer’s comfort. The performance of Methodical-HEMS is evaluated with other heuristic algorithms, including a particle swarm optimization algorithm, grey wolf optimization algorithm, artifcial bee colony algorithm and genetic algorithm. The simulation outcomes demonstrate that, the SBO based HEMS algorithm efectually reduces the overall EB from ₹ 29.14/day to ₹ 22.84/day, minimizes the peak-to-average ratio by 10.28% and remains uncompromising on the consumer’s comfort.

Meta-Analysis of Limited Thymectomy versus Total Thymectomy for Masaoka Stage I and II Thymoma

Pulle Mohan Venkatesh,Asaf Belal Bin,Puri Harsh Vardhan,Bishnoi Sukhram,Arvind Kumar 대한흉부외과학회 2021 Journal of Chest Surgery (J Chest Surg) Vol.54 No.2

Background: This meta-analysis aimed to evaluate the incidence of tumor recurrence, postoperative myasthenia gravis, postoperative complications, and overall survival after limited versus total thymectomy for Masaoka stage I and II thymoma. Methods: A systematic search of the literature was conducted using the PubMed, Em- base, MEDLINE, and Cochrane databases to identify relevant studies that compared limited and total thymectomy in Masaoka stage I–II patients. The quality of the included obser- vational studies was assessed using the Newcastle-Ottawa Scale. The results of the me- ta-analysis were expressed as log-transformed odds ratios (log ORs), with 95% confidence intervals (CIs). Results: Seven observational studies with a total of 2,310 patients were included in the meta-analysis. There was an overall non-significant difference in favor of total thymectomy in terms of tumor recurrence (pooled log OR, 0.40; 95% CI, -0.07 to 0.87; p=0.10; I2=0%) and postoperative myasthenia gravis (pooled log OR, 0.12; 95% CI, -1.08 to 1.32; p=0.85; I2=22.6%). However, an overall non-significant difference was found in favor of limited thymectomy with respect to postoperative complications (pooled log OR, -0.21; 95% CI, -1.08 to 0.66; p=0.64; I2=36.1%) and overall survival (pooled log OR, -0.01; 95% CI, -0.68 to 0.66; p=0.98; I2=47.8%). Conclusion: Based on the results of this systematic review and meta-analysis, limited thymectomy as a treatment for stage I and II thymoma shows similar oncologic outcomes to total thymectomy.

Evaluating Pedicle-Screw Instrumentation Using Decision-Tree Analysis Based on Pullout Strength

Vicky Varghese,Venkatesh Krishnan,Gurunathan Saravana Kumar 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.4

Study Design: A biomechanical study of pedicle-screw pullout strength. Purpose: To develop a decision tree based on pullout strength for evaluating pedicle-screw instrumentation. Overview of Literature: Clinically, a surgeon’s understanding of the holding power of a pedicle screw is based on perioperative intuition (which is like insertion torque) while inserting the screw. This is a subjective feeling that depends on the skill and experience of the surgeon. With the advent of robotic surgery, there is an urgent need for the creation of a patient-specific surgical planning system. A learning-based predictive model is needed to understand the sensitivity of pedicle-screw holding power to various factors. Methods: Pullout studies were carried out on rigid polyurethane foam, representing extremely osteoporotic to normal bone for different insertion depths and angles of a pedicle screw. The results of these experimental studies were used to build a pullout-strength predictor and a decision tree using a machine-learning approach. Results: Based on analysis of variance, it was found that all the factors under study had a significant effect (p <0.05) on the holding power of a pedicle screw. Of the various machine-learning techniques, the random forest regression model performed well in predicting the pullout strength and in creating a decision tree. Performance was evaluated, and a correlation coefficient of 0.99 was obtained between the observed and predicted values. The mean and standard deviation of the normalized predicted pullout strength for the confirmation experiment using the current model was 1.01±0.04. Conclusions: The random forest regression model was used to build a pullout-strength predictor and decision tree. The model was able to predict the holding power of a pedicle screw for any combination of density, insertion depth, and insertion angle for the chosen range. The decision-tree model can be applied in patient-specific surgical planning and a decision-support system for spine-fusion surgery.