459 research outputs found
Energy Commitment for a Power System Supplied by Multiple Energy Carriers System using Following Optimization Algorithm
In today’s world, the development and continuation of life require energy. Supplying this energy demand requires careful and scientific planning of the energy provided by a variety of products, such as oil, gas, coal, electricity, etc. A new study on the operation of energy carriers called Energy Commitment (EC) is proposed. The purpose of the EC is to set a pattern for the use of energy carriers to supply energy demand, considering technical and economic constraints. EC is a constrained optimization problem that can be solved by using optimization methods. This study suggests the Following Optimization Algorithm (FOA) to solve the EC problem to achieve technical and economic benefits. Minimizing energy supply costs for the total study period is considered as an objective function. The FOA simulates social relationships among the community members who try to improve their community by following each other. Simulation is carried out on a 10-unit energy system supplied by various types of energy carriers that includes transportation, agriculture, industrial, residential, commercial, and public sectors. The results show that the optimal energy supply for a grid with 0.15447 Millions of Barrels of Oil Equivalent (MBOE) of energy demand costs 9.0922 millions dollar for a 24-h study period. However, if the energy supply is not optimal, the costs of operating energy carriers will increase and move away from the optimal economic situation. The economic distribution of electrical demand between 10 power plants and the amount of production units per hour of the study period is determined. The EC outputs are presented, which include an appropriate pattern of energy carrier utilization, energy demand supply costs, appropriate combination of units, and power plant production. The behavior and process of achieving the answer in the convergence curve for the implementation of FOA on EC indicates the exploration and exploitation capacity of FOA. Based on the simulated results, EC provides more information than Unit Commitment (UC) and analyzes the network more efficiently and deeply.Peer ReviewedPostprint (published version
Genetic algorithm for energy commitment in a power system supplied by multiple energy carriers
Prediction of Face-Lift Outcomes Using the Preoperative Supine Test
Patients considering a facelift (facial rhytidectomy) need some means of predicting their surgical outcomes. This will help them decide whether to proceed with the operation.
A total of 50 consecutive patients were asked to examine themselves with a hand-held mirror while lying supine on an examining table to give them a reasonable approximation of their postoperative result.
The tissues of the face redrape in a very aesthetic manner when lying completely supine. The appearance that the patient sees of himself or herself during the “supine test” correlated very well with the actual postop result after rhytidectomy consisting of subcutaneous undermining, SMAS plication, and platysmaplasty.
This supine test may be useful in helping patients preoperatively predict their facelift outcomes and may serve as a good adjunct to imaging
Components Separation Technique Combined with a Double-Mesh Repair for Large Midline Incisional Hernia Repair
Background The surgical treatment of large midline incisional hernias remains a challenge. The aim of this report is to present the results of a new technique for large midline incisional hernia repair which combines the components- separation technique with a double-prostheticmesh repair. Methods The records of all consecutive patients who received a double-mesh combined with the componentsseparation technique for ventral hernia repair were reviewed. The clinical, surgical, and follow-up data were analyzed. Results Nine patients [3 women, 6 men; median age = 62 years (range = 26-77)] were included in the study. Median transverse defect size was 20 cm (range = 15-25). The median duration of hospital stay was 8 days (range = 5-17). Postoperative complications occurred in 66% (6/9). Follow-up [median = 13 months (range = 3-49)] showed no recurrent hernias, but one patient had a small hernia after a relaparotomy for colon carcinoma recurrence. The overall occurrence of wound infections was 44% (4/9). There was no mortality. Conclusion The components-separation technique in combination with a double-mesh has shown a low recurrence rate in the short-term follow-up. However, there is a considerable occurrence of postoperative wound infections. Long-term results of the hernia recurrence rate have to be awaited
Fail-safe optimization of viscous dampers for seismic retrofitting
This paper presents a new optimization approach for designing minimum-cost
fail-safe distributions of fluid viscous dampers for seismic retrofitting.
Failure is modeled as either complete damage of the dampers or partial
degradation of the dampers' properties. In general, this leads to optimization
problems with large number of constraints. Thus, the use of a working-set
optimization algorithm is proposed. The main idea is to solve a sequence of
relaxed optimization sub-problems with a small sub-set of all constraints. The
algorithm terminates once a solution of a sub-problem is found that satisfies
all the constraints of the problem. The retrofitting cost is minimized with
constraints on the inter-story drifts at the peripheries of frame structures.
The structures considered are subjected to a realistic ensemble of ground
motions, and their response is evaluated with time-history analyses. The
transient optimization problem is efficiently solved with a gradient-based
sequential linear programming algorithm. The gradients of the response
functions are calculated with a consistent adjoint sensitivity analysis
procedure. Promising results attained for 3-D irregular frames are presented
and discussed. The numerical results highlight the fact that the optimized
layout and size of the dampers can change significantly even for moderate
levels of damage
New technical approach for the repair of an abdominal wall defect after a transverse rectus abdominis myocutaneous flap: a case report
<p>Abstract</p> <p>Introduction</p> <p>Breast reconstruction with autologous tissue transfer is now a standard operation, but abnormalities of the abdominal wall contour represent a complication which has led surgeons to invent techniques to minimize the morbidity of the donor site.</p> <p>Case presentation</p> <p>We report the case of a woman who had bilateral transverse rectus abdominis myocutaneous flap (TRAM-flap) breast reconstruction. The surgery led to the patient developing an enormous abdominal bulge that caused her disability in terms of abdominal wall and bowel function, pain and contour. In the absence of rectus muscle, the large defect was repaired using a combination of the abdominal wall component separation technique of Ramirez et al and additional mesh augmentation with a lightweight, large-pore polypropylene mesh (Ultrapro<sup>®</sup>).</p> <p>Conclusion</p> <p>The procedure of Ramirez et al is helpful in achieving a tension-free closure of large defects in the anterior abdominal wall. The additional mesh augmentation allows reinforcement of the thinned lateral abdominal wall.</p
Combined Use of Ultrasound-Assisted Liposuction and Limited-Incision Platysmaplasty for Treatment of the Aging Neck
Australian Gay Men’s Satisfaction with Sexual Agreements: The Roles of Relationship Quality, Jealousy, and Monogamy Attitudes
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