Weighting Factor Method Research Articles

Aquaculture species selection method applied to marine fish in the Caribbean

A five-phase method for the evaluation and selection of tropical marine fish for intensive culture is proposed and the application of the first four phases is presented for the Caribbean region. In phase-1, an initial list of 50 species was prepared from 2175 present in the Western Central Atlantic, based on their commercial importance, and certain relevant biological features. Phase 2 includes economic and technological development considerations. Eleven preselected, four non-preselected, and six traditionally cultivated species (controls) were evaluated in phase-3 using a score and weighting factor method with four categories, established according to the point score. Species preselection by environment and culture system (phase-4) was carried out according to estimated performance at the site and culture system under Caribbean conditions, as well as the species' tolerance to environmental factors and the total score obtained as final criteria. To be finally selected, species must be subject to practical pilot-scale (phase 5) trials with technical, financial and ecological feasibility analyses. Yellowtail amberjacks, Seriola spp., and cobia, Rachycentron canadum, ranked first for open water cage and supra-littoral tank culture. Ranking in the second category were Florida pompano, Trachinotus carolinus, pompano, Trachinotus falcatus, and common snook, Centropomus undecimalis, which were selected for ponds and floating cages on estuarine and coastal waters, and Nassau grouper, Epinephelus striatus and mutton snapper, Lutjanus analis, which were selected for cages on coastal or offshore clear waters. Two of the exotic tropical species: barramundi, Lates calcarifer and mangrove red snapper, Lutjanus argentimaculatus, as well as one of the subtropical control species: red drum, Sciaenops ocellatus, were highly scored and ranked in the first two priority categories, thereby confirming the effectiveness of the selection method applied.

Application of SLP Method in Rubber Powder Workshop

In this article, system layout planning (SLP) method analyzes the relationship between the refined rubber workshop logistics and the mutual relationship between logistic, draw up the position related figure of operating unit and relevant figure of operating unit area. According to the actual situation of the rubber factory, it determines three sets of optimizing distribution schemes, and uses the weighted factor method to evaluate the schemes, so as to determine the optimal arrangement scheme, each operating unit facilities layout planning unit has its guiding significance.

Study on Facility Layout of a Manufacturing Shop Based on SLP Method

Aimed at the production technological process, analysis has been carried out on the current situation of workshop layout, and find out the existed problems; Systematic Layout Planning (SLP) method is exerted to analyze the workshop concerning relationship between logistics and non-logistics, draw out correlation diagram of location of working unit and correlation diagram of area of working unit. Two optimum proposals are determined according to the realistic of workshop, and weighting factor method is adopted for evaluation, thus obtain the optimal layout proposal. So that aims are achieved for workshop like shorter logistics route, effectively usage of space and resource, improvement of working environment and improvement of production efficiency of enterprises.

Calculation of the deterministic optimum loading pattern of the BUSHEHR VVER-1000 reactor using the weighting factor method

In the calculation of the optimum loading pattern for a nuclear reactor, several parameters, including the multiplication factor maximization, the raising of the desired safety threshold during the cycle length and the flattening of the radial power peaking factor should be taken into account.Our evaluation of numerous probable arrangements within the VVER-1000 reactor core (approx. 6×1014cases) indicated that a direct search of the optimum loading pattern is not feasible. Hence, in this study, the weighting factor method and some constraints on the arrangement of the fuel assemblies were applied so that the above cases were reduced to only 244 possible arrangements.Then, using a thermo-neutronic computational cycle based on the in-tandem application of WIMSD5-B, CITATION-LDI2 and COBRA-EN codes, the thermo-neutronic parameters of all 244 probable arrangements were calculated. Finally, the optimum loading pattern of the VVER-1000 reactor core was evolved through a screening of the mentioned cases.

A nondominated sorting genetic algorithm solution for shortest path routing problem in computer networks

The shortest path routing problem is a multiobjective nonlinear optimization problem with a set of constraints. This problem has been addressed by considering delay and cost objectives simultaneously and as a weighted sum of both objectives for comparison. Multiobjective evolutionary algorithms can find multiple pareto-optimal solutions in one single run and this ability makes them attractive for solving problems with multiple and conflicting objectives. This paper uses an elitist multiobjective evolutionary algorithm based on the nondominated sorting genetic algorithm (NSGA), for solving the dynamic shortest path routing problem in computer networks. A priority-based encoding scheme is proposed for population initialization. Elitism ensures that the best solution does not deteriorate in the succeeding generations. Results for a sample test network have been presented to demonstrate the capabilities of the proposed approach to generate well-distributed pareto-optimal solutions of dynamic routing problem in one single run. The results obtained by NSGA are compared with single objective weighting factor method for which genetic algorithm (GA) is applied.

Comparative dose in pediatric radiology: uncertainty, estimates and ballparks

There is an increasing need for all radiologists, particularly pediatric radiologists, to have a good working knowledge of the relative radiation dose of the examinations we perform or supervise. We must be capable of providing such information to our referring physicians, patients and their families, for internal quality-assurance purposes and in the future, perhaps to outside regulatory or advisory bodies. In an ideal world, there would be a universally accepted common dose parameter applicable to all medical examinations involving ionizing radiation. That parameter would be derived with a user-friendly standard methodology that accounted for age and developmental variability and involved minimal extrapolations and assumptions. We do not have such a parameter. Currently, the most practicable common dose assessor is effective dose (ED). Defined by the ICRP and measured in miliSieverts (mSv), ED is the sum of the absorbed doses in all tissues and organs in the radiation field, each multiplied by a tissue-specific weighting factor. It provides an assessment of overall radiation detriment from a non-uniform dose distribution in terms of a uniform or whole-body exposure. The merits of ED are that it allows us to compare the relative dose impact of common radiographic, fluoroscopic, CT and nuclear medicine examinations, enables comparison to annual background radiation, and can be used together with risk models to provide a broad estimate of future excess malignancy risk. However, there are reservations associated with its use in medical imaging, certainly when applied to an individual patient. Calculation involves multiple levels of intrinsic uncertainties, extrapolations and error bars, generating an ED value that is a broader estimate than often appreciated. Expert assessment suggests that we should expect an uncertainty of +/−40%, whether using organ dose and weighting-factor methods; Monte Carlo simulations; or age-, regionand modality-specific conversion factor methods. Systematic and random components to error exist at each stage in calculation, and for all modalities. A few of the many potential contributors include dosimeter thresholds, accuracy, and placement; inter-observer variability in field of view specification with implication on partially included organs; whole-population based (not pediatric) weighting factors that are periodically updated with new epidemiological evidence; console-displayed CT dose parameters based on previously calculated standardized cylindrical phantom doses, the use of Monte Carlo or conversion factor data derived from older CT scanners, and uncertainties in models of radionuclide uptake, distribution and retention. A decade ago, there was a paucity of available ED data for the practicing pediatric radiologist. Isolated publications addressed individual examinations, mostly radiographic and fluoroscopic studies, and there was some dose data from national surveys but rarely providing ED values. Although conversion coefficients were available, they were not widely appreciated beyond physics circles. There was almost no dose data for pediatric CT. Some ED values, when investigated, did not relate to children but to the more extensive, although still not comprehensive or collated, adult-based data. In the years since, publications involving organ dose measurement and ED estimation in pediatric imaging have escalated. The information available to all of us has significantly increased, although there is ongoing debate as to the merits of various approaches and a need to improve the methodology and inconsistencies that especially plague pediatric CT dosimetry. Disclaimer Dr. Thomas has no financial interests, investigational or off-label uses to disclose.

A novel multi-objective evolutionary algorithm for shortest path routing problem

This paper presents an application of non-dominated sorting genetic algorithm-II (NSGA-II) technique for solving shortest path routing problems in computer networks. The problem is formulated as a non-linear constrained multi-objective optimisation problem. NSGA-II is applied to handle shortest path routing problem as a true multi-objective optimisation problem (MOOP) with competing and non-commensurable objectives. A priority-based encoding scheme is employed for population initialisation. Priorities are assigned to all the edges and NSGA-II is implemented to find the optimal solution. It is noted that this approach can find a diverse set of solutions and is converging near the true Pareto-optimal set. Results for a sample test network have been presented to demonstrate the capabilities of the NSGA-II algorithm to generate well-distributed Pareto-optimal solutions of shortest path routing problem in one single run. The results obtained by NSGA-II are compared with single objective weighting factor method for which genetic algorithm (GA) is applied.

End User Perceptual Distorted Scenes Enhancement Algorithm Using Partition-Based Local Color Values for QoE-Guaranteed IPTV

In this letter, we propose distorted scenes enhancement algorithm in order to provide end user perceptual QoE-guaranteed IPTV service. The block edge detection with weight factor and partition-based local color values method can be applied for the degraded video frames which are affected by network transmission errors such as out of order, jitter, and packet loss to improve QoE efficiently. Based on the result of quality metric after using the distorted scenes enhancement algorithm, the distorted scenes have been restored better than others.

The mass and luminosity functions and the formation rate of DA white dwarfs in the Sloan Digital Sky Survey

Aims. The SDSS Data Release 1 includes 1833 DA white dwarfs (WDs) and forms the largest homogeneous sample of WDs. This sample provides the best opportunity to study the statistical properties of WDs. Methods. We adopt a recently established theoretical model to calculate the mass and distance of each WD using the observational data. Then we adopt a bin-correction method to correct for selection effects and use the 1/V weight-factor method to calculate the luminosity function, the continuous mass function and the formation rate of these WDs. Results. The SDSS DA WD sample is incomplete and suffers seriously from selection effects. After corrections for the selection effects, only 531 WDs remain. From this final sample we derive the most up-to-date luminosity function and mass function, in which we find a broad peak of WD masses centered around 0.58 M ⊙ . The DA WD space density is calculated as 8.81 x 10 -5 pc -3 and the formation rate is 2.579 × 10 -13 pc -3 yr -1 . Conclusions. The statistical properties of the SDSS DA WD sample are generally in good agreement with previous observational and theoretical studies, and provide us information on the formation and evolution of WDs. However, a larger and more complete all-sky WD sample is still needed to explain some subtle disagreements and unresolved issues.

Assessment of degradation and stability of a cut slope in limestone, Ankara-Turkey

Due to the rapidly growing population of the city of Ankara (Turkey) and increased traffic congestion, it becomes necessary to widen the Ankara-Eskişehir (E-90) highway, connecting the newly built areas west of the city to the city center. During widening, several cut slopes were formed along the highway route. As a result, some instability problems (small-sized rock falls/sliding, sloughing, raveling) produced detachment zones along a cut slope in highly jointed, folded and sheared limestone, causing local degradation of the cut slope. Identification of the areas that are likely to detach from the cut slope in the future is considered to be very important for the application of remedial measures. For this purpose, the relationships between the existing detachment zones and various parameters (e.g. point load strength index, weathering, block size, daylighting, shear zone) were investigated using GIS-based statistical detachment susceptibility analyses in order to predict the further aerial extension of the detachment zones with time. During the overlay analyses, statistical index and weighting factor methods were used. Limit equilibrium analyses were also carried out for the determination of the possible large scale mass failures. The detachment susceptibility map using W i method without the block size layer gives the best result and indicates some hazardous zones where detachments are likely to occur in the future. On the other hand, the limit equilibrium analysis of the rock mass using Bishop simplified method shows that except one section no mass failure is expected in the cut slope. Suitable remediation measures which include the use of wire mesh, shotcrete, toe support, and concrete barrier blocks or catch/barrier fences are recommended for these zones.

Reduction in post forging errors for aerofoil forging using finite element simulation and optimization

This paper reports on recent work in the development of a finite element (FE) based forging optimization methodology. It utilizes the commercial FE package ABAQUS and the optimization code VisualDOC. Taking into account the effect of die and press elastic deflections and thermal distortion in cooling, a direct compensation approach and optimized weighting factor method are used to achieve the optimized die shape for improved dimensional accuracy of forged aerofoil blades. The significant predicted reduction in aerofoil shape errors using a single 2D section from a forged nickel-based blade demonstrates the efficiency and potential for applying this approach to more complex, realistic and industrially relevant 3D forging problems.

GIS-based detachment susceptibility analyses of a cut slope in limestone, Ankara—Turkey

Due to the rapidly growing population of the city of Ankara (Turkey) and increased traffic congestion, it has become necessary to widen the Ankara-Eskisehir (E-90) highway connecting the newly built areas west of the city to the city center. During widening, several cut slopes were formed along the highway route. As a result, some instability problems (small-sized rock falls/sliding, sloughing, raveling) produced detachment zones along a cut slope in highly jointed, folded and sheared limestone, causing local degradation of the cut slope. Identification of the areas that are likely to detach from the cut slope in the future is considered to be very important for the application of remedial measures. For this purpose, the relationships between the existing detachment zones and various parameters (e.g., point load strength index, weathering, block size, daylighting, shear zone) were investigated using GIS-based statistical detachment susceptibility analyses in order to predict the further aerial extension of the detachment zones with time. During the overlay analyses, statistical index and weighting factor methods were used. The outcomes of the analyses were compared and evaluated with the field observations to check the reliability of the methods and to assess the detachment zones that may develop in the future. The detachment susceptibility map without the block-size layer gives the best result and indicates some risky zones where detachments are likely to occur in the future. Recommendations on remedial measures of the cut slope should consider these risky zones.

エンジンの一次元性能解析における多目的最適設計の適用(解析コンテストIII)

The automation, optimization and robust design have been widely used in the engine performance design using one-dimensional simulation. In this paper, application examples of VVT (variable valve timing) engine design problem are reported by using multi-objective optimization approach such as weight factor method and multi-objective GA. In addition, a new approach on multi-objective optimization is proposed for series engine design problem with multi ending speed by using mluti-task system. This system has a main task and 6 subtasks regarding to 6 kinds of engine speed, where each subtask has a set of independent design variables on VVT optimization problem.

NEW FAMILY OF ADAPTIVE VERY HIGH RESOLUTION SCHEMES

The family of skew very high resolution (VHR) schemes is adoptively combined with the family of high-resolution (HR) schemes to yield a new family of adaptive very high resolution (AVHR) schemes. A new simple adaptive switching criterion is devised. For convection-diffusion type problems the adaptive schemes are accelerated by using in tandem the normalized weighting factor method to implement the HR scheme and the deferred-correction (DC) procedure to implement the skew scheme. For flow problems the DC procedure is used to implement both types of schemes. Numerical results for the new family of AVHR schemes are compared in terms of accuracy and computation cost against those generated using the VHR base family of schemes by solving four problems: (1) pure convection of a step profile in an oblique velocity field, (2) driven flow in a skew cavity, (3) laminar sudden expansion of an oblique velocity field in a rectangular cavity, (4) and turbulent sudden expansion of an oblique velocity field in a rectangular cavity. For the same accuracy, the AVHR schemes are found to decrease the computation cost, on average, by 48.74% as compared to the VHR schemes.

Dynamical Complex System. Multi-Objective Nonlinear Control System by Fuzzy Weighting Factor Method based on Universal Learning Network.

Control probrems on the large-scale complicated systems such as optimal distributed control and optimal hierarchical control have been extensively studied in the 1960's. On the other hand, recently, multi-objective optimization problems have been studied in the field of Linear Programming and Non Linear Programming problems. In this paper, a new control methodology called fuzzy weighting factor method is presented that automatically determines the weighting factors of the criterion function of the large-scale multi-objective non linear systems which are made up of plural subsystems with their own criterion functions. Hitherto, weighting factor method, e constraint method and fuzzy Min Max method etc. have been presented as the method of optimizing the multiobjective systems. Most of them are applied to static optimization probrems, and they have the problem to be solved such that as the methods are converted to linear programming problems, the membership functions of the plural criterion functions should be approximated linearly and the methods need a fairly amount of computations. In this paper, the controller's parameter variables in the dynamic multi-objective non-linear control systems are determined by using Universal Learning Network (ULN) and a new fuzzy weighting factor method. And the new method can solve the above mentioned problems and is also different from the usual fuzzy Min Max method in the point that the new fuzzy weighting factor method can arbitrarily adopt the membership functions. The Universal Learning Network is a super set of all kinds of neural network paradigms with supervised learning capability and in this paper both control objects and its controllers of the large-scale complicated systems are represented by ULN. Finally, characteristics of the fuzzy weighting factor method are studied by simulations on a nonlinear tank network.

Building Energy Performance Using Sheap

This paper describes a Simplified Hourly Energy Analysis Package (SHEAP) for the computation of annual energy consumption in non-residential buildings. The package, developed at the Mechanical Engineering Faculty, uses the transmission matrix method in calculating conduction heat gains through opaque building sections, and adopts the weighting factor method for the calculations of cooling loads, heat extraction rates and actual space air dry bulb temperatures. Typical daily profiles of measured hourly weather data are used to approximate the external climatic conditions over a one-year period. A preliminary validation study indicates that SHEAP produces, reasonably good estimates when compared to the predictions by BUNYIP, a commercial building energy analysis package.

学習型ファジィ制御システムによるｐＨ制御

This paper proposes a new self-organizing fuzzy control system for a nonlinear system accompanied by Gaussian noise and its application to pH control. This system permits to change a scaling factor for the membership function in accordance with the command signal, and also to estimate automatically a weighting factor for improving the fuzzy production rule. The pH control is carried out by simulation considered a two-stage stirred tank system.The conclusions are as follows:(1) The self-organizing fuzzy controller is sufficiently available in pH control without a strict control rule.(2) The automatic estimation method of the weighting factor for improving the control matrix is better than the fixed weighting factor method.

The set of efficient solutions for multiple objective shortest path problems

This paper considers an extension of the usual scalar valued shortest path problem to one in which there are m objective functions and for which we wish to find the efficient set of policies and paths. The paper discusses some of the deficiencies involved in the use of weighting factor methods to determine the efficient sets with respect to the original pure paths and policies. The main result is that if we wish to find which original paths are efficient with respect to the convex extensions of such sets, then they may be obtained exactly by the weighting factor method with minimisation restricted to the original pure policies, and such optimising policies will be jointly efficient in the convex extension, and hence in the original pure set. The paper also discusses linear programming and dynamic programming computational aspects.

Catalyst particle effectiveness with unsymmetrical boundary conditions

In trickle-bed reactors part of the surface of the catalyst particles may be covered by liquid and part by gas. Under such conditions conventional expressions for effectiveness factors are not applicable because the surface concentration is not uniform. In this paper more general equations for both particle and overall effectiveness factors are derived. The first development is for slab geometry where the two plane surfaces of equal areas have different reactant concentrations. This is followed by treatment of a cubic particle where one or more faces are covered by liquid. Approximate methods are then presented for evaluating the effectiveness factor for any fractional liquid coverage, f. Comparison of the results at permissible values of f indicates that a simple weighting-factor method gives good results. The method is illustrated by comparing predicted and experimental reaction rates for a case where experimental results are available—the hydrogenation of α-methyl styrene.

Absolute determination of spins of neutron resonances in terbium-159 by a weighting factor method using polarized neutrons and a polarized Tb-target

Abstract The spins of the lowest three neutron resonances in 159 Tb have been determined by transmission of polarized monochromatic neutrons through a sample containing polarized terbium nuclei. The spins were found to be I + 1 2 = 2 , I − 1 2 = 1 , and I + 1 2 = 2 respectively for the 3.35-eV, 4.99-eV, and 11.14-eV resonances. Ordinarily these assignments depend on two assumptions: 1) that the nuclear moment of 159 Tb is positive, and 2) that the effective field at the nucleus, due to the 4f electrons of Tb 3+ , is parallel to the external polarizing field. However, the correctness of the combination of the given assignments is verified in an independent way, which uses the ratio of transmission effects measured at the three resonances. Approximate formulae for the transmission and the transmission effect are presented, which are of practical use for many resonances observed with neutron crystal spectrometers.