two-step optimization technique

Top PDF two-step optimization technique:

A Retrospective Filter Trust Region Algorithm for Unconstrained Optimization

A Retrospective Filter Trust Region Algorithm for Unconstrained Optimization

In the algorithm RFTR, the retrospective idea and the filter technique are two important characteristics. The retrospective ratio uses the information at the current iterate and the last iterate to adjust the trust-region radius, which can give the more effective estimation of trust region radius. The filter technique relaxes the condition of accepting a trial step comparing with the usual trust region method, which improves the effectiveness of the algorithm in some sense. From the algorithm RFTR, if the trial point is not accepted (Case 3 in Step 5 occurs), then the algorithm is similar to the basic trust-region al- gorithm, whose difference is just that we use the retro- spective idea in the algorithm RFTR. However, if the trial point is accepted by the algorithm (Case 1 or Case 2 in Step 5 occurs), the retrospective idea and the filter technique all play the roles.
Show more

10 Read more

A Two-Step Method for Damage Identification and Quantification in Large Trusses via Wavelet Transform and Optimization Algorithm

A Two-Step Method for Damage Identification and Quantification in Large Trusses via Wavelet Transform and Optimization Algorithm

quantified as well. A rather thorough review on new and traditional damage detection methods is discussed in [1, 2]. As a result to high capability of wavelet transform, henceforth referred to as WT, in revealing singular points in a given signal, either stationary or non-stationary, it has been extensively employed in damage detection literature. One of the first scholars utilizing WT for damage detection purposes is [3] in which not only have the authors authenticated that damages will emerge as singular points in the deflection curve, however they have carried out experiments to validate their method as well. This vibrational technique and its applications are comprehensively reviewed in [4]. In most WT literature, researchers utilized WT only to pinpoint damage locations and the damage severities were not quantified by this method. An illustration of this can be found in [5] where WT is applied for locating damage in truss structures. An identical approach is adapted in [6] for spotting impairments in plate structures. A new damage index based on wavelet residual force is introduced in [7] in order to compute where damages took place in shear, plane frames in time-domain. Moreover, a complex mother wavelet is utilized in [8] for multiple damage detection in Euler beams. On that account, one of the major demerits of WT is its incapability in directly identifying damage severities especially in the displacement-domain. In order to address this issue, researchers have put forth a number of indirect methods for finding damage severities. For instance, [9] discrete wavelet transform (DWT) is applied to localize structural defects, and a statistical approach is suggested to predict the extent of defects based on wavelet coefficients. Moreover, in a number of recent studies, two-step approaches are opted to overcome
Show more

20 Read more

Optimization of Radial Distribution Networks Using Path Search Algorithm

Optimization of Radial Distribution Networks Using Path Search Algorithm

Optimization technique to select the optimal radial connection or feeder lines for given distribution network (all possible connection between nodes) have basically two problems. First problem is to calculate all possible paths for each load nodes, starting from a substation node. There may be many possible radial paths to reach a load node. The proposed path search algorithm is used to calculate all possible paths for energizing each load node. The second problem is related to total cost calculation for each path and to select the optimum path for each nodes. Applying the forward/backward sweep algorithm load flow technique in each radial path to calculate the energy losses costs and adding the fixed investment cost of connected feeders and substation. The minimum cost path among all the radial paths for feeding a particular node will be the optimum path for the node. Step by step algorithm proposed for searching the optimal radial distribution network is shown below.
Show more

6 Read more

Two-Step Rate Distortion Optimization Algorithm for High Efficiency Video Coding

Two-Step Rate Distortion Optimization Algorithm for High Efficiency Video Coding

cost value is a linear combination of rate and distortion, most of time due to little improvement in the RD cost value, highly distorted blocks are selected. In this paper, we have explored the RD cost calculation of HEVC encoder and come up with a novel two-step RD cost calculation technique. In the proposed method, along with the conventional RD cost calculation method, the structural similarity index (SSIM) is also used. Moreover, we propose an approximated version of SSIM, FSSIM, which has less computational complexity compared to SSIM.
Show more

6 Read more

Optimization of A Two-Step Method to Synthesize Azelaic Acid from Oleic Acid

Optimization of A Two-Step Method to Synthesize Azelaic Acid from Oleic Acid

In this paper, the oxidative cleavage of unsaturated oleic acid by the H 2 O 2 -H 2 WO 4 - NaOCl system is presented. The RSM associated with CCD is utilized to study the effect of adding co-oxidant and other changing variable process of the azelaic acid resulted, and to get a mathematical model that accurately describes the process. RSM is a mathematical technique and empirical statistics which are used to build a significant relationship between a set of experimental factors that are controlled with one or more variables by conducting a number of experiments 16,17 . The RSM has been
Show more

8 Read more

Advanced Optimization Technique

Advanced Optimization Technique

Scientists, engineers, economists, and managers always have to take many technological and managerial decisions at several times for construction and maintenance of any system. Day by day the world becomes more and more complex and competitive so the decision making must be taken in an optimal way. Therefore optimization is the main act of obtaining the best result under given situations. Optimization originated in the 1940s, when the British military faced the problem of allocating limited resources (for example fighter airplanes, submarines and so on) to several activities [1]. Over the decades, several researchers have generated different solutions to linear and non-liner optimization problems. Mathematically an optimization problem has a fitness function, describing the problem under a set of constraints which represents the solution space for the problem. However, most of the traditional optimization techniques have calculated the first derivatives to locate the optima on a given constrained surface. Due to the difficulties in evaluation the first derivative for many rough and discontinuous optimization spaces, several derivatives free optimization methods have been constructed in recent time.
Show more

8 Read more

Optimized method to harvest both kidneys from one donor rat for transplantation

Optimized method to harvest both kidneys from one donor rat for transplantation

The distal end of the ureter was ligated. At this moment, the whole left kidney, including the RA, RV, and ureter, was dissected free. Two vascular clips were used to block the AO and IVC together at the lower and upper levels of the left renal vessels. The left RV root proximal to the IVC was tied and transected (Fig. 1). A needle was inserted in the middle of the blocked AO (Fig. 2). After the graft was per- fused with 10 ml of heparin physiological saline (25 U/ml, 4 °C), the RA root proximal to the AO was tied and cut (Fig. 3). The ureter was then cut, and the left graft was placed in ice physiological saline in preparation for trans- plantation. A cross suture was made on the side of needle insertion into the AO. Vascular clips were loosed. After left kidney removal, the donor rat was slowly injected with 3 ml physiological saline via the penile vein. The abdom- inal viscera were replaced in their original position, and the abdominal wound was sutured continuously in layers. The donor rat survived the operation and was prepared for right donor nephrectomy.
Show more

6 Read more

A COMPARATIVE STUDY OF ECONOMIC LOAD DISPATCH BY USING GA AND PSO

A COMPARATIVE STUDY OF ECONOMIC LOAD DISPATCH BY USING GA AND PSO

The economic load dispatch plays an important role in the operation of power system. The main objective of this paper is to determine the optimal combination of power outputs of all generating units so as to meet the required demand at minimum cost while satisfying all types of constraints. In this paper the lambda iteration method and the two main types evolutionary optimization technique genetic algorithm and particle swarm optimization which are generic population based probabilistic search optimization algorithms and can be applied to real world problem are respectively applied to solve an ELD problem and at last the comparison between all three method has been presented. The PSO provides the generation level such that the generation level is coming out to be lower than the cost resulted with genetic algorithm method.
Show more

14 Read more

An Ant Inspired Bacterial Foraging Methodology Proposed to Solve Open Shop Scheduling Problems

An Ant Inspired Bacterial Foraging Methodology Proposed to Solve Open Shop Scheduling Problems

The Ant Colony Optimization algorithm is well known for its shortest path finding technique first proposed by M.Dorigo in 1992. The ACO algorithm is based on food searching behavior of ant colony. Real ants or Ants are capable of finding the shortest path from their nest to food source. Ant deposits pheromone on their path while travelling and information exchanged through environment by particular type of communication. In every ant cycle the pheromone values updated at the end of its tour. Pheromone get evaporated after certain time and calculated based on their density. Ant probably chooses the path that previously chosen by ant based on their density to find the shortest path. Pheromones get updated by the ant if it chooses the same path and improves the pheromone density. The ACO algorithm is a multi-agent approach for solving Combinatorial Optimization problems, searching problem and decision problem to find optimal solution [9].
Show more

8 Read more

Multi-Objective Two-Dimensional Truss Optimization by using Genetic Algorithm

Multi-Objective Two-Dimensional Truss Optimization by using Genetic Algorithm

The optimization of truss structures can be classified into three categories depending on what component of the structure is used as design variable : sizing configuration and topological optimization. In sizing optimization of trusses the cross-sectional areas of the members are the design variables and the coordinates of the nodes and the connectivity between various members are fixed. This can be made more practically useful by restricting the member areas to pre-specified discrete values. In configuration optimization the design variables are the nodal coordinates, and in topological optimization the number of nodes and the connectivity between nodes are the design variables. These optimization problems have been discussed separately however the most efficient design will be obtained by considering all three simultaneously. In general, multilevel optimization methods are used in which topological optimization is first performed keeping the configuration and member sizes fixed. When an optimal topology is found, configuration and/or sizing optimization is performed on the topology found in the previous step. As mentioned earlier this method will not provide the most optimal solution as all the three problems are not linearly separable. As a result, traditional methods of optimization have failed and the use of other tools such GAs is gaining popularity in the field of structural optimization.
Show more

5 Read more

St.Gallen consensus on safe implementation of transanal total mesorectal excision

St.Gallen consensus on safe implementation of transanal total mesorectal excision

The consensus statements were developed using a Del- phi methodology [7] incorporating three successive rounds. The first two consecutive rounds were web-based with anonymous voting, and explicitly asked for feedback and suggestions from the international experts. The comments recorded were included into the iterative development of the consensus statements. The third round was a dedicated expert meeting during the European Colorectal Congress in St.Gallen on November 30th, 2016 with face-to-face open discussion and finalisation of the consensus document. Con- sensus was defined as agreement by 80% or more of the experts. The final manuscript was then drafted by the four convenors of the consensus with only minor editing of the consensus statements if required. The discussion further developed practical advice, including perspectives from the expert radiologist and oncologist. The final consensus docu- ment was reviewed and approved by all involved experts.
Show more

13 Read more

Data Throughput Assessment of 4T4R MIMO Technique on LTE Wireless Cellular Networks

Data Throughput Assessment of 4T4R MIMO Technique on LTE Wireless Cellular Networks

Long Term Evolution (LTE) known as 4G technology is developed to solve exponential demand for higher data rate by the users. This research work carried out measurement on a captured LTE wireless network of a 4- way Transmit, 4-way Receive (4T4R) multiple-input multiple-output (MIMO) optimization technique and existing 2x2 MIMO to assess the throughput. The assessment was conducted on a mobile network set up of four sites and unit inter connection on LTE continuous coverage with inter-site distance of 500m using two terminals user equipment to download and upload data by drive test. Monitoring and results collection were carried out using Local monitoring Terminal (LMT) and Test mobile system (TEMs) Drive Test (DT) kit as well as analysis of data using TEMs DT kit and NetPerSec. The results showed that Terminal 1 recorded a maximum achievable downlink and uplink throughput of 47.5 Mbps and 14.2 Mbps respectively against the system baseline 2x2 MIMO of 33.6Mbps and 10.7Mbps respectively. Terminal2, on the other hand, achieved maximum downlink and uplink throughput of 44.0 Mbps and 14.1 Mbps respectively higher than the same baseline 2x2 MIMO. This improvement indicates that increasing the number of transmit and receive antennas expands the network capacity thereby yielding more throughput.
Show more

7 Read more

6012.pdf

6012.pdf

Besides humanoid robots, some other robots may work in a non-stationary environment, such as a singe spherical wheeled mobile robot (Nagarajan et al., 2009, 2013) and multi- wheeled robots balancing on and driving a ball (Endo and Nakamura, 2005; Lauwers et al., 2006; Kumagai and Ochiai, 2009). In that case, the wheels always make three or four symmetric contacts with the ball, which greatly benefits the balance control of the robot. In my case, however, the feet of a biped robot can only make one or two contacts with a cylinder, which are usually asymmetrical about the top of the cylinder. Furthermore, because of the limited foot size and support region, the ideal COP, which is continuously changing on a rolling cylinder, may go beyond the support region. Hence, I have to not only design controllers to maintain system’s balance but also combine them with a stepping motion generator to provide the robot with timely support on the rolling cylinder during walking, which will be discussed in the next chapter.
Show more

121 Read more

Optimization of Cost and Emissions of a KRW-Gasifier based IGCC System under Variability and Uncertainty

Optimization of Cost and Emissions of a KRW-Gasifier based IGCC System under Variability and Uncertainty

environmental pollutant inventory (Frey and Bammi, 2002, Frey and Zheng, 2002). Distinction between variability and uncertainty has rarely been done in probabilistic analysis or optimization of process technologies only until recently by Frey and Zhang (2003), Rooney and Biegler (2003). Rooney and Biegler consider two types of unknown input parameters, uncertainty model parameters, and variable process parameters. In the former case, a process is designed that is feasible over the entire domain of uncertain parameters, while in the later case, control variables can be adjusted during process operation to compensate for variable process parameters. However, their work does not address uncertainty in parameters that characterize variability in an input.
Show more

130 Read more

Ciprofloxacin: A Two Step Process

Ciprofloxacin: A Two Step Process

Ciprofloxacin (1) is used to treat a wide variety of infections. Ciprofloxacin is broad based antibiotic of the fluoroquinoline class. It is active against both Gram-positive and Gram-negative bacteria (Figure 1). It functions by inhibiting DNA gyrase and a type-II and type-IV topoisomerases necessary to separate bacterial DNA, there by inhibiting cell division. The drug was invented by Bayer in 1983 and introduced in 1987. It became a blockbuster drug and sales reached two billion Euros in 2001. Now generics are introduced (after 2014). It is included in the essential medicinal list of WHO (2015).
Show more

5 Read more

Two-Step Authentication FAQ

Two-Step Authentication FAQ

authentication, it is much more difficult for someone to impersonate you online. This step will help to protect direct deposit information, research, intellectual property and faculty, staff and student personal information. Stanford will likely require additional measures in the near future, including password strength requirements, upgrades/replacements of old operating systems such as Windows XP and encryption of laptops and mobile devices.

5 Read more

Development of a modularized two-step (M2S) chromosome integration technique for integration of multiple transcription units in Saccharomyces cerevisiae

Development of a modularized two-step (M2S) chromosome integration technique for integration of multiple transcription units in Saccharomyces cerevisiae

are shown in Additional file  1: Table S3. Since different chromosome regions showed diversity of transcription levels, Jens Nielsen’s group characterized 20 different integration sites of the S. cerevisiae genome by insert- ing lacZ as a reporter gene under the control of two different promoters and determined expression levels through enzyme activity measurement. Seventeen of these sites are solo long terminal repeats (solo LTRs), none of them was located in close proximity to an open reading frame. Higherβ-Galactosidase activity (The lacZ expression levels) of S. cerevisiae strains with integration sites of YORWΔ17, YORWΔ22, YPRCΔ15, and YPRCτ3 was observed. Thus, we selected three sites YORWΔ17, YORWΔ22, and YPRCΔ15 as our integration targets [26]. As common yeast chromosomal integration method, these modular parts were co-transformed into S. cer- evisiae by electroporation. PCR analysis was used to verify correctly integrated strains with designed universal primers.
Show more

11 Read more

One step and Two step Classification for Abusive Language Detection on Twitter

One step and Two step Classification for Abusive Language Detection on Twitter

We explored a two-step approach of combin- ing two classifiers - one to classify abusive lan- guage and another to classify a specific type of sexist and racist comments given that the lan- guage is abusive. With many different machine learning classifiers including our proposed Hy- bridCNN, which takes both character and word features as input, we showed the potential in the two-step approach compared to the one-step ap- proach which is simply a multi-class classifica- tion. In this way, we can boost the performance of simpler models like logistic regression, which is faster and easier to train, and combine different types of classifiers like convolutional neural net- work and logistic regression together depending on each of its performance on different datasets.
Show more

5 Read more

Existence and convergence theorems for the new system of generalized mixed variational inequalities in Banach spaces

Existence and convergence theorems for the new system of generalized mixed variational inequalities in Banach spaces

In 2011, Zhang and Deng [1] introduced and considered the system of mixed varia- tional inequalities in Banach spaces. Using the generalized f-projection operator techni- que, they introduced two-step iterative methods for solving the system of mixed variational inequalities and proved the convergence of the proposed iterative methods under suitable conditions in Banach spaces.

13 Read more

A Two-Step Synthesis of 2-Spiropiperidines

A Two-Step Synthesis of 2-Spiropiperidines

selection of cyclic (4-6 membered ring) ketones containing O, S or N-heteroatoms all reacted smoothly with the -amino-- ketoester to give the desired piperidines 4a-s. The two-step procedure is easy to carry out and robust as is demonstrated by the synthesis of 2-spiropiperidine 4h on a 1.5 g scale. The piperidines existed as a mixture of diastereomeric methyl esters, with the relative stereochemistry shown predominating, and there was no evidence of the diastereomers interconverting during chromatographic purification. Interestingly, in the major [a] Mr. S. D. Griggs, Mr. N. Thompson, Miss M. Fabre, Dr. P. A. Clarke,
Show more

5 Read more

Show all 10000 documents...