Search results for: optimal portfolio

Authors: Mohammad Azam

Abstract:

This work is an endeavor to empirically investigate the Gross Domestic Product-Growth as mediating variable between various factors and portfolio returns using a broad sample of 522 financial and non-financial firms enlisted on Pakistan Stock Exchange between January-1993 and June-2022. The study employs the Structural Equation modeling and Ordinary Least Square regression to determine the findings before and during the Covid-19 epidemiological situation, which has not received due attention by researchers. The analysis reveals that market and investment factors are redundant, whereas size and value show significant results, whereas Gross Domestic Product-Growth performs significant mediating impact for the whole time frame. Using before Covid-19 period, the results reveal that market, value, and investment are redundant, but size, profitability, and Gross Domestic Product-Growth are significant. During the Covid-19, the statistics indicate that market and investment are redundant, though size and Gross Domestic Product-Growth are highly significant, but value and profitability are moderately significant. The Ordinary Least Square regression shows that market and investment are statistically insignificant, whereas size is highly significant but value and profitability are marginally significant. Using the Gross Domestic Product-Growth augmented model, a slight growth in R-square is observed. The size, value and profitability factors are recommended to the investors for Pakistan Stock Exchange. Conclusively, in the Pakistani market, the Gross Domestic Product-Growth indicates a feeble moderating effect between risk-premia and portfolio returns.

Keywords: asset pricing puzzle, mediating role of GDP-growth, structural equation modeling, COVID-19 pandemic, Pakistan stock exchange

Procedia PDF Downloads 71

Authors: Yuanhao Gao, Pin Lin, Kees Weijer

Abstract:

In this paper, we will determine the external body force distribution with analysis of stokes fluid motion using mathematical modelling and numerical approaching. The body force distribution is regarded as the unknown variable and could be determined by the idea of optimal control theory. The Stokes flow motion and its velocity are generated by given forces in a unit square domain. A regularized objective functional is built to match the numerical result of flow velocity with the generated velocity data. So that the force distribution could be determined by minimizing the value of objective functional, which is also the difference between the numerical and experimental velocity. Then after utilizing the Lagrange multiplier method, some partial differential equations are formulated consisting the optimal control system to solve. Finite element method and conjugate gradient method are used to discretize equations and deduce the iterative expression of target body force to compute the velocity numerically and body force distribution. Programming environment FreeFEM++ supports the implementation of this model.

Keywords: optimal control model, Stokes equation, finite element method, conjugate gradient method

Procedia PDF Downloads 404

Authors: M. F. F. Ab Rashid, A. N. Mohd Rose, N. M. Z. Nik Mohamed, W. S. Wan Harun, S. A. Che Ghani

Abstract:

Traveling salesman problem with precedence constraint (TSPPC) is one of the most complex problems in combinatorial optimization. The existing algorithms to solve TSPPC cost large computational time to find the optimal solution. The purpose of this paper is to present an efficient genetic algorithm that guarantees optimal solution with less number of generations and iterations time. Unlike the existing algorithm that generates priority factor as chromosome, the proposed algorithm directly generates sequence of solution as chromosome. As a result, the proposed algorithm is capable of generating optimal solution with smaller number of generations and iteration time compare to existing algorithm.

Keywords: traveling salesman problem, sequencing, genetic algorithm, precedence constraint

Procedia PDF Downloads 557

Authors: D. De-León-Escobedo, D. J. Delgado-Hernández, S. Pérez

Abstract:

A probabilistic formulation to assess the slopes safety under the hazard of strong storms is presented and illustrated through a slope in Mexico. The formulation is based on the classical safety factor (SF) used in practice to appraise the slope stability, but it is introduced the treatment of uncertainties, and the slope failure probability is calculated as the probability that SF<1. As the main hazard is the rainfall on the area, statistics of rainfall intensity and duration are considered and modeled with an exponential distribution. The expected life-cycle cost is assessed by considering a monetary value on the slope failure consequences. Alternative mitigation measures are simulated, and the formulation is used to get the measures driving to the optimal one (minimum life-cycle costs). For the example, the optimal mitigation measure is the reduction on the slope inclination angle.

Keywords: expected life-cycle cost, failure probability, slopes failure, storms

Procedia PDF Downloads 158

Authors: Kevin Spencer G. Anglim, Zhenyu Zhang, Qingbin Gao

Abstract:

Reusable launch vehicles (RLVs) present a more environmentally-friendly approach to accessing space when compared to traditional launch vehicles that are discarded after each flight. This paper studies the recyclable nature of RLVs by presenting a solution method for determining minimum-fuel optimal trajectories using principles from optimal control theory and particle swarm optimization (PSO). This problem is formulated as a minimum-landing error powered descent problem where it is desired to move the RLV from a fixed set of initial conditions to three different sets of terminal conditions. However, unlike other powered descent studies, this paper considers the highly nonlinear effects caused by atmospheric drag, which are often ignored for studies on the Moon or on Mars. Rather than optimizing the controls directly, the throttle control is assumed to be bang-off-bang with a predetermined thrust direction for each phase of flight. The PSO method is verified in a one-dimensional comparison study, and it is then applied to the two-dimensional cases, the results of which are illustrated.

Keywords: minimum-fuel optimal trajectory, particle swarm optimization, reusable rocket, SpaceX

Procedia PDF Downloads 277

Authors: Asma Ben Yaghlane, Mohamed Naceur Azaiez

Abstract:

In this paper, we treat a model that falls in the area of protecting targeted systems from intelligent threats including terrorism. We introduce the concept of system survivability, in the context of continuous attacks, as the probability that a system under attack will continue operation up to some fixed time t. We define a constant attack rate (CAR) process as an attack on a targeted system that follows an exponential distribution. We consider the superposition of several CAR processes. From the attacker side, we determine the optimal attack strategy that minimizes the system survivability. We also determine the optimal strengthening strategy that maximizes the system survivability under limited defensive resources. We use operations research techniques to identify optimal strategies of each antagonist. Our results may be used as interesting starting points to develop realistic protection strategies against intentional attacks.

Keywords: CAR processes, defense/attack strategies, exponential failure, survivability

Procedia PDF Downloads 392

Authors: H. Tai Pham, Bae Wisup, Sungmin Jung, Ivan Efriza, Ratna Widyaningsih, Byung Un Min

Abstract:

The middle-phase-microemulsion in Alkaline-Surfactant-Polymer (ASP) solution and oil play important roles in the success of an ASP flooding process. The high quality microemulsion phase has ultralow interfacial tensions and it can increase oil recovery. The research used optimal experimental design and response-surface-methodology to predict the optimum concentration of chemicals in ASP solution for maximum microemulsion quality. Secondly, this optimal ASP formulation was implemented in core flooding test to investigate the effective injection volume. As the results, the optimum concentration of surfactants in the ASP solution is 0.57 wt.% and the highest effective injection volume is 19.33% pore volume.

Keywords: optimize, ASP, response surface methodology, solubilization ratio

Procedia PDF Downloads 346

Authors: Pratheeba Subramanian, Anjula Gurtoo, Mary Mathew

Abstract:

Transaction of patents in emerging patent markets is gaining momentum. Pricing patents for a transaction say patent sale remains a challenge. Patents vary in their pricing with some patents fetching higher prices than others. Sale of patents in portfolios further complicates pricing with multiple patents playing a role in pricing a bundle. In this paper, a set of 138 US patents sold individually as single invention lots and 462 US patents sold in bundles of 120 portfolios are investigated to understand the dynamics of selling prices of singletons and portfolios and their determinants. Firstly, price variations when patents are sold individually as singletons and portfolios are studied. Multivariate statistical techniques are used for analysis both at the lot level as well as at the individual patent level. The results show portfolios fetching higher prices than singletons at the lot level. However, at the individual patent level singletons show higher prices than per patent price of individual patent members within the portfolio. Secondly, to understand the price determinants, the effect of patent, seller, and bundling related characteristics on selling prices is studied separately for singletons and portfolios. The results show differences in the set of characteristics determining prices of singletons and portfolios. Selling prices of singletons are found to be dependent on the patent related characteristics, unlike portfolios whose prices are found to be dependent on all three aspects – patent, seller, and bundling. The specific patent, seller and bundling characteristics influencing selling price are discussed along with the implications.

Keywords: auction, patents, portfolio bundling, seller type, selling price, singleton

Procedia PDF Downloads 327

Authors: Wen Liang Chang

Abstract:

In this study, the optimal replacement time and number of preventive maintenance (PM) actions were investigated for a second-hand device. Suppose that a user intends to use a second-hand device for manufacturing products, and that the device is replaced with a new one. Any device failure is rectified through minimal repair, thereby incurring a fixed repair cost to the user. If the new device fails within the FRW period, minimal repair is performed at no cost to the user. After the FRW expires, a failed device is repaired and the cost of repair is incurred by the user. In this study, two profit models were developed, and the optimal replacement time and number of PM actions were determined to maximize profits. Finally, the influence of the optimal replacement time and number of PM actions were elaborated on, using numerical examples.

Keywords: second-hand device, preventive maintenance, replacement time, device failure

Procedia PDF Downloads 466

Authors: Virgil Miranda, Gissele Mosqueda, Pablo Delgado, Yimesker Yihun

Abstract:

Muscular fatigue affects the muscle activation that is needed for producing the desired clinical outcome. Integrating optimal muscle relaxation periods into a variety of health care rehabilitation protocols is important to maximize the efficiency of the therapy. In this study, four muscle relaxation periods (30, 60, 90, and 120 seconds) and their effectiveness in producing consistent muscle activation of the muscle biceps brachii between sets of elbow flexion and extension task was investigated among a sample of 10 subjects with no disabilities. The same resting periods were then utilized in a controlled exoskeleton-based exercise for a sample size of 5 subjects and have shown similar results. On average, the muscle activity of the biceps brachii decreased by 0.3% when rested for 30 seconds, and it increased by 1.25%, 0.76%, and 0.82% when using muscle relaxation periods of 60, 90, and 120 seconds, respectively. The preliminary results suggest that a muscle relaxation period of about 60 seconds is needed for optimal continuous muscle activation within rehabilitation regimens. Robot-based rehabilitation is good to produce repetitive tasks with the right intensity, and knowing the optimal resting period will make the automation more effective.

Keywords: rest intervals, muscle biceps brachii, robot rehabilitation, muscle fatigue

Procedia PDF Downloads 189

Authors: Ghazaleh Monazami Tehrani, Zhamak Monazami Tehrani, Raziyeh Hadavand

Abstract:

Optimal site selection for temporary housing is one of the most important issues in crisis management. In this research, district six of Tehran city with high frequency and geographical distribution of earthquakes has been selected as a case study for positioning temporary housing after a probable earthquake. For achieving this goal this study tries to identify and evaluate distribution of location according to some standards such as compatible and incompatible urban land uses with utility of GIS and AHP. The results of this study show the most susceptible parts of this region in the center. According to the maps, north eastern part of Kordestan, Shaheed Gomnam intersection possesses the highest pixels value in terms of areal extent, therefore these places are recommended as an optimum site location for construction of emergency evacuation base.

Keywords: optimal site selection, temporary housing , crisis management, AHP, GIS

Procedia PDF Downloads 253

Authors: Eugene C. Lim

Abstract:

This paper seeks to examine the extent to which ‘forum shopping’ is available to patent filers seeking protection of GMO (genetically modified organisms)-based inventions in Hong Kong. Under Hong Kong’s current re-registration system for standard patents, an inventor must first seek patent protection from one of three Designated Patent Offices (DPO) – those of the People’s Republic of China (PRC), the Europe Union (EU) (designating the UK), or the United Kingdom (UK). The ‘designated patent’ can then be re-registered by the successful patentee in Hong Kong. Interestingly, however, the EU and the PRC do not adopt a harmonized approach toward the patenting of GMOs, and there are discrepancies in their interpretation of the phrase ‘animal or plant variety’. In view of these divergences, the ability to effectively manage ‘conflict of law’ issues is an important priority for multinational biotechnology firms with a patent portfolio in the Greater China region. Generally speaking, both the EU and the PRC exclude ‘animal and plant varieties’ from the scope of patentable subject matter. However, in the EU, Article 4(2) of the Biotechnology Directive allows a genetically modified plant or animal to be patented if its ‘technical feasibility is not limited to a specific variety’. This principle has allowed for certain ‘transgenic’ mammals, such as the ‘Harvard Oncomouse’, to be the subject of a successful patent grant in the EU. There is no corresponding provision on ‘technical feasibility’ in the patent legislation of the PRC. Although the PRC has a sui generis system for protecting plant varieties, its patent legislation allows the patenting of non-biological methods for producing transgenic organisms, not the ‘organisms’ themselves. This might lead to a situation where an inventor can obtain patent protection in Hong Kong over transgenic life forms through the re-registration of a patent from a more ‘biotech-friendly’ DPO, even though the subject matter in question might not be patentable per se in the PRC. Through a comparative doctrinal analysis of legislative provisions, cases and court interpretations, this paper argues that differences in the protection afforded to GMOs do not generally prejudice the ability of global MNCs to obtain patent protection in Hong Kong. Corporations which are able to first obtain patents for GMO-based inventions in Europe can generally use their European patent as the basis for re-registration in Hong Kong, even if such protection might not be available in the PRC itself. However, the more restrictive approach to GMO-based patents adopted in the PRC would be more acutely felt by enterprises and inventors based in mainland China. The broader scope of protection offered to GMO-based patents in Europe might not be available in Hong Kong to mainland Chinese patentees under the current re-registration model for standard patents, unless they have the resources to apply for patent protection as well from another (European) DPO as the basis for re-registration.

Keywords: biotechnology, forum shopping, genetically modified organisms (GMOs), greater China region, patent portfolio

Procedia PDF Downloads 326

Authors: Tomoaki Hashimoto

Abstract:

In recent decades, probabilistic constrained optimal control problems have attracted much attention in many research field. Although probabilistic constraints are generally intractable in an optimization problem, several tractable methods haven been proposed to handle probabilistic constraints. In most methods, probabilistic constraints are reduced to deterministic constraints that are tractable in an optimization problem. However, there is a gap between the transformed deterministic constraints in case of known and unknown probability distribution. This paper examines the conservativeness of probabilistic constrained optimization method with the unknown probability distribution. The objective of this paper is to provide a quantitative assessment of the conservatism for tractable constraints in probabilistic constrained optimization with the unknown probability distribution.

Keywords: optimal control, stochastic systems, discrete time systems, probabilistic constraints

Procedia PDF Downloads 578

Authors: Muhammad Danish Khan, Imran Naeem, Mudassar Imran

Abstract:

In this article, we study time-space Fractional Advection-Dispersion (FADE) equation and time-space Fractional Whitham-Broer-Kaup (FWBK) equation that have a significant role in hydrology. We introduce suitable transformations to convert fractional order derivatives to integer order derivatives and as a result these equations transform into Partial Differential Equations (PDEs). Then the Lie symmetries and corresponding optimal systems of the resulting PDEs are derived. The symmetry reductions and exact independent solutions based on optimal system are investigated which constitute the exact solutions of original fractional differential equations.

Keywords: modified Riemann-Liouville fractional derivative, lie-symmetries, optimal system, invariant solutions

Procedia PDF Downloads 429

Authors: Wafa' Alsharafat, Suhila Farhan Abu-Owida

Abstract:

Genetic algorithm (GA) is a powerful evolutionary searching technique that is used successfully to solve and optimize problems in different research areas. Genetic Algorithm (GA) considered as one of optimization methods used to solve Travel salesman Problem (TSP). The feasibility of GA in finding a TSP solution is dependent on GA operators; encoding method, population size, termination criteria, in general. In specific, crossover and its probability play a significant role in finding possible solutions for Symmetric TSP (STSP). In addition, the crossover should be determined and enhanced in term reaching optimal or at least near optimal. In this paper, we spot the light on using a modified crossover method called modified sequential constructive crossover and its impact on reaching optimal solution. To justify the relevance of a parameter value in solving the TSP, a set comparative analysis conducted on different crossover methods values.

Keywords: genetic algorithm, crossover, mutation, TSP

Procedia PDF Downloads 226

Authors: Mitchell Gohnert

Abstract:

This paper reviews some fundamental concepts of structural optimization, which is focused on the shape of the structure. Bending stresses produce high peak stresses at each face of the member, and therefore, substantially more material is required to resist bending. The shape of the structure has a profound effect on stress levels. Stress may be reduced dramatically by simply changing the shape to accommodate natural stress flow. The main objective of structural optimization is to direct the thrust line along the axis of the member. Optimal shapes include the catenary arch or dome, triangular shapes, and columns. If the natural flow of stress matches the shape of the structures, the most optimal shape is determined. Structures, however, must resist multiple load patterns. An optimal shape is still possible by ensuring that the thrust lines fall within the middle third of the member.

Keywords: optimization, natural structures, shells, catenary, domes, arches

Procedia PDF Downloads 39

Authors: Slim Amami

Abstract:

A model is developed to prevent the risks related to climate conditions in the agricultural sector. It will determine the yearly optimum premium to be paid by a farmer in order to reach his required turnover. The model is mainly based on both climatic stability and 'soft' responses of usually grown species to average climate variations at the same place and inside a safety ball which can be determined from past meteorological data. This allows the use of linear regression expression for dependence of production result in terms of driving meteorological parameters, main ones of which are daily average sunlight, rainfall and temperature. By a simple best parameter fit from the expert table drawn with professionals, optimal representation of yearly production is deduced from records of previous years, and yearly payback is evaluated from minimum yearly produced turnover. Optimal premium is then deduced, and gives the producer a useful bound for negotiating an offer by insurance companies to effectively protect their harvest. The application to wheat production in the French Oise department illustrates the reliability of the present model with as low as 6% difference between predicted and real data. The model can be adapted to almost every agricultural field by changing state parameters and calibrating their associated coefficients.

Keywords: agriculture, database, meteorological factors, production model, optimal price

Procedia PDF Downloads 221

Authors: Engy Adel Mohamed, Yasser Gamal-Eldin Hegazy

Abstract:

This paper presents a firefly based algorithm for optimal sizing and allocation of distributed generators for profit maximization. Distributed generators in the proposed algorithm are of photovoltaic and combined heat and power technologies. Combined heat and power distributed generators are modeled as voltage controlled nodes while photovoltaic distributed generators are modeled as constant power nodes. The proposed algorithm is implemented in MATLAB environment and tested the unbalanced IEEE 37-node feeder. The results show the effectiveness of the proposed algorithm in optimal selection of distributed generators size and site in order to maximize the total system profit.

Keywords: distributed generators, firefly algorithm, IEEE 37-node feeder, profit maximization

Procedia PDF Downloads 439

Authors: Sunsoo Kim, Niladri Das, Raktim Bhattacharya

Abstract:

This paper addresses modeling and control of a six-degree-of-freedom unmanned aerial vehicle capable of vertical take-off and landing in the presence of wind disturbances. We design a hybrid vehicle that combines the benefits of both the fixed-wing and the rotary-wing UAVs. A non-linear model for the hybrid vehicle is rapidly built, combining rigid body dynamics, aerodynamics of wing, and dynamics of the motor and propeller. Further, we design a H₂ optimal controller to make the UAV robust to wind disturbances. We compare its results against that of proportional-integral-derivative and linear-quadratic regulator based control. Our proposed controller results in better performance in terms of root mean squared errors and time responses during two scenarios: hover and level- flight.

Keywords: hybrid UAVs, VTOL, aircraft modeling, H2 optimal control, wind disturbances

Procedia PDF Downloads 151

Authors: Yingyi Zhou, Tohru Kawabe

Abstract:

With the spread of EVs (electric Vehicles), the ride comfort has been gaining a lot of attention. The influence of the lateral acceleration is important for the improvement of ride comfort of EVs as well as the longitudinal acceleration, especially upon turning of the vehicle. Therefore, this paper proposes a practical optimal speed control method to greatly improve the ride comfort in the vehicle turning situation. For consturcting this method, effective criteria that can appropriately evaluate deterioration of ride comfort is derived. The method can reduce the influence of both the longitudinal and the lateral speed changes for providing a confortable ride. From several simulation results, we can see the fact that the method can prevent aggravation of the ride comfort by suppressing the influence of longitudinal speed change in the turning situation. Hence, the effectiveness of the method is recognized.

Keywords: electric vehicle, speed control, ride comfort, optimal control theory, driving support system

Procedia PDF Downloads 214

Authors: I. Goual, M. S. Goual, M. K. Gueddouda, Taïbi Saïd, Abou-Bekr Nabil, A. Ferhat

Abstract:

The aim of the paper is to study the hydro-mechanical behavior of a tuff and calcareous sand mixture. A first experimental phase was carried out in order to find the optimal mixture. This showed that the material composed of 80% tuff and 20% calcareous sand provides the maximum mechanical strength. The second experimental phase concerns the study of the drying-wetting behavior of the optimal mixture was carried out on slurry samples and compacted samples at the MPO. Experimental results let to deduce the parameters necessary for the prediction of the hydro-mechanical behavior of pavement formulated from tuff and calcareous sand mixtures, related to moisture. This optimal mixture satisfies the regulation rules and hence constitutes a good local eco-material, abundantly available, for the conception of pavements.

Keywords: tuff, sandy calcareous, road engineering, hydro mechanical behaviour, suction

Procedia PDF Downloads 438

Authors: Qasim M. Kriri

Abstract:

Few Saudi Arabia production companies face financial profit issues until this moment. This work presents a linear integer programming model that solves a production problem of a Saudi Food Company in Saudi Arabia. An optimal solution to the above-mentioned problem is a Linear Programming solution. In this regard, the main purpose of this project is to maximize profit. Linear Programming Technique has been used to derive the maximum profit from production of natural juice at Saudi Food Co. The operations of production of the company were formulated and optimal results are found out by using Lindo Software that employed Sensitivity Analysis and Parametric linear programming in order develop Linear Programming. In addition, the parameter values are increased, then the values of the objective function will be increased.

Keywords: parameter linear programming, objective function, sensitivity analysis, optimize profit

Procedia PDF Downloads 203

Authors: Satyendra Pratap Singh, S. P. Singh

Abstract:

This paper presents a methodology using Gravitational Search Algorithm for optimal placement of Phasor Measurement Units (PMUs) in order to achieve complete observability of the power system. The objective of proposed algorithm is to minimize the total number of PMUs at the power system buses, which in turn minimize installation cost of the PMUs. In this algorithm, the searcher agents are collection of masses which interact with each other using Newton’s laws of gravity and motion. This new Gravitational Search Algorithm based method has been applied to the IEEE 14-bus, IEEE 30-bus and IEEE 118-bus test systems. Case studies reveal optimal number of PMUs with better observability by proposed method.

Keywords: gravitational search algorithm (GSA), law of motion, law of gravity, observability, phasor measurement unit

Procedia PDF Downloads 502

Authors: Mohammad Amin Hamedirad, Seyed Javad Vaziri Kang Olyaei

Abstract:

Project planning and control are one of the most critical issues in the management of construction projects. Traditional methods of project planning and control, such as the critical path method or Gantt chart, are not widely used for planning projects with discrete and repetitive activities, and one of the problems of project managers is planning the implementation process and optimal allocation of its resources. Massive concreting projects is also a project with discrete and repetitive activities. This study uses the concept of simulating discrete events to manage resources, which includes finding the optimal number of resources considering various limitations such as limitations of machinery, equipment, human resources and even technical, time and implementation limitations using analysis of resource consumption rate, project completion time and critical points analysis of the implementation process. For this purpose, the concept of discrete-event simulation has been used to model different stages of implementation. After reviewing the various scenarios, the optimal number of allocations for each resource is finally determined to reach the maximum utilization rate and also to reduce the project completion time or reduce its cost according to the existing constraints. The results showed that with the optimal allocation of resources, the project completion time could be reduced by 90%, and the resulting costs can be reduced by up to 49%. Thus, allocating the optimal number of project resources using this method will reduce its time and cost.

Keywords: simulation, massive concreting, discrete event simulation, resource management

Procedia PDF Downloads 147

Authors: Svetlana Bialkova, Marnix van Gisbergen

Abstract:

Advanced Virtual Reality (VR) technologies offer compelling multisensory and interactive experiences applicable in various fields from education to entertainment. However, serious VR applications within the financial sector are scarce, and managing ‘real’ business services with(in) VR is a challenge inviting further investigation. The current research addresses this challenge, by exploring the key parameters influencing the VR business power and the development of appropriate VR applications in real financial business. We conducted profound investigation of both B2B and B2C needs, and how these could be met. In three studies, we have approached experts from leading international banks (finance to computer specialists), and their (potential) customers. Study 1 included focus group discussions with experts. First, participants could experience different VR devices such as Samsung Gear VR, then a structured discussion was held. The outcomes are analyzed and summarized in a portfolio. Study 2 further used the portfolio analyzer to profile the management of real business services with(in) VR. Again experts participated, where first being introduced with Samsung Gear, then experiencing it and being interviewed. Based on the outcomes, a survey was developed to interview (potential) customers and test ideas created (Study 3). The results suggest that developing proper system architectures to connect people and to connect devices is crucial for building up powerful business with(in) VR. From one side, connecting devices, e.g., pairing mobile Head Mounted Displays for VR with smart-phones and/or wearable technologies would be appropriate way “to have” customers anywhere, anytime with a brand and/or business. Developing VR Apps, providing detailed real time visualization of performance and infrastructure types could enable 3D VR navigation, 3D contents viewing, but also being opportunity for connecting people in collaborative platforms. The outcomes of the current research are summarized in a model which could be applied to unlock the real business power of VR.

Keywords: business power, B2B, B2C, VR applications

Procedia PDF Downloads 289

Authors: Jason Sheng-Hong Tsai, Faezeh Ebrahimzadeh, Min-Ching Chung, Shu-Mei Guo, Leang-San Shieh, Tzong-Jiy Tsai, Li Wang

Abstract:

In this paper, we first construct a new state and disturbance estimator using discrete-time proportional plus integral observer to estimate the system state and the unknown external disturbance for the discrete-time system with an input-to-output direct-feedthrough term. Then, the generalized optimal linear quadratic digital tracker design is applied to construct a proportional plus integral observer-based tracker for the system with an unknown external disturbance to have a desired tracking performance. Finally, a numerical simulation is given to demonstrate the effectiveness of the new application of our proposed approach.

Keywords: non-minimum phase system, optimal linear quadratic tracker, proportional plus integral observer, state and disturbance estimator

Procedia PDF Downloads 501

Authors: Piyush V. Surjagade, Jiamei Deng, Paul Doney, S. R. Shimjith, A. John Arul

Abstract:

In sophisticated and complex systems such as nuclear power plants, maintaining the system's stability in the presence of uncertainties and disturbances and obtaining a fast dynamic response are the most challenging problems. Thus, to ensure the satisfactory and safe operation of nuclear power plants, this work proposes a new fast, robust optimal switching control strategy for pressurized water reactor-type nuclear power plants. The proposed control strategy guarantees a substantial degree of robustness, fast dynamic response over the entire operational envelope, and optimal performance during the nominal operation of the plant. To improve the robustness, obtain a fast dynamic response, and make the system optimal, a bank of controllers is designed. Various controllers, like a baseline proportional-integral-derivative controller, an optimal linear quadratic Gaussian controller, and a robust adaptive L1 controller, are designed to perform distinct tasks in a specific situation. At any instant of time, the most suitable controller from the bank of controllers is selected using the switching logic unit that designates the controller by monitoring the health of the nuclear power plant or transients. The proposed switching control strategy optimizes the overall performance and increases operational safety and efficiency. Simulation studies have been performed considering various uncertainties and disturbances that demonstrate the applicability and effectiveness of the proposed switching control strategy over some conventional control techniques.

Keywords: switching control, robust control, optimal control, nuclear power control

Procedia PDF Downloads 132

Authors: Rita SahaRay, Ganesh Dutta

Abstract:

In this article, experimental situations are considered where a main effects plan is to be used to study m two-level factors using n runs which are partitioned into b blocks, not necessarily of same size. Assuming the block sizes to be even for all blocks, for the case n ≡ 2 (mod 4), optimal designs are obtained with respect to type 1 and type 2 optimality criteria in the class of designs providing estimation of all main effects orthogonal to the block effects. In practice, such orthogonal estimation of main effects is often a desirable condition. In the wider class of all available m two level even sized blocked main effects plans, where the factors do not occur at high and low levels equally often in each block, E-optimal designs are also characterized. Simple construction methods based on Hadamard matrices and Kronecker product for these optimal designs are presented.

Keywords: design matrix, Hadamard matrix, Kronecker product, type 1 criteria, type 2 criteria

Procedia PDF Downloads 365

Authors: Umar Salisu

Abstract:

This research presents the development of a hot air tomatoes drying system. To provide a more efficient and continuous temperature control, microcontroller-based optimal controller was developed. The system is based on a power control principle to achieve smooth power variations depending on a feedback temperature signal of the process. An LM35 temperature sensor and LM399 differential comparator were used to measure the temperature. The mathematical model of the system was developed and the optimal controller was designed and simulated and compared with the PID controller transient response. A controlled environment suitable for fruit drying is developed within a closed chamber and is a three step process. First, the infrared light is used internally to preheated the fruit to speedily remove the water content inside the fruit for fast drying. Second, hot air of a specified temperature is blown inside the chamber to maintain the humidity below a specified level and exhaust the humid air of the chamber. Third, the microcontroller disconnects the power to the chamber after the moisture content of the fruits is removed to minimal. Experiments were conducted with 1kg of fresh tomatoes at three different temperatures (40, 50 and 60 °C) at constant relative humidity of 30%RH. The results obtained indicate that the system is significantly reducing the drying time without affecting the quality of the fruits. In the context of temperature control, the results obtained showed that the response of the optimal controller has zero overshoot whereas the PID controller response overshoots to about 30% of the set-point. Another performance metric used is the rising time; the optimal controller rose without any delay while the PID controller delayed for more than 50s. It can be argued that the optimal controller performance is preferable than that of the PID controller since it does not overshoot and it starts in good time.

Keywords: drying, microcontroller, optimum controller, PID controller

Procedia PDF Downloads 299

Authors: Shilan Rahmani Azr, Siavash Emtiyaz

Abstract:

Recent development in computing and communicative technologies leads to much easier mobile accessibility to the information. Users can access to the information in different places using various deceives in which the care variety of abilities. Meanwhile, the format and details of electronic documents are changing each day. In these cases, a mismatch is created between content and client’s abilities. Recently the service-oriented content adaption has been developed which the adapting tasks are dedicated to some extended services. In this method, the main problem is to choose the best appropriate service among accessible and distributed services. In this paper, a method for determining the optimal path to the best services, based on the quality control parameters and user preferences, is proposed using max heap tree. The efficiency of this method in contrast to the other previous methods of the content adaptation is related to the determining the optimal path of the best services which are measured. The results show the advantages and progresses of this method in compare of the others.

Keywords: service-oriented content adaption, QoS, max heap tree, web services

Procedia PDF Downloads 256