Cost Optimization Approach Research Articles

Proposal for a Modified Cost-optimal Approach by Introducing Benefits Evaluation

The recast of the Energy Performance of Buildings Directive introduced the concept of nearly-zero energy building and encouraged setting the nearly-zero energy target with a view to cost-optimal level - the energy performance that leads to the lowest cost during the building estimated economic lifecycle. To searching this regard, the cost-optimal methodology based on the global cost was defined providing a tool to assess different nearly-zero energy scenarios. Nowadays, the cost-optimal analysis is used as a decision-making tool between different energy design alternatives mostly on a theoretical level; but it has spread little among the professional field. The aim of this paper is to give a more holistic and all-comprehensive approach to the cost-optimal methodology. This paper proposes and applies a modified approach of the cost-optimal evaluation, which will lead to the achievement of more interesting results for all the actors involved, including investors and final users. This study highlights the usefulness of including not only costs but also benefits that can derive from each energy design scenario. Choosing different energy efficiency solutions, the related benefits evaluation could turn the tables. Different kinds of benefits could be considered as the increase of the real estate market value, the enhancement of the indoor comfort, the reduction of CO2 emissions and others. Thus, a proposal of how quantifying these qualitative benefits in monetary terms is shown to introduce them in the global cost formula. Actually, benefits conversion into monetary values is the most challenging issue. Precisely, this paper shows a list of benefits that can affect the choice of different envelope and HVAC system solutions, pointing out their influence on the global cost evaluation. Certainly, introducing benefits in the global cost formula means using a more holistic and complete approach, while the already complex degree of the cost-optimal methodology – due to the numerous input data –increases. To validate the reviewed global cost formula, it will be necessary to apply it to various case studies.

Preparation of iron/zinc bound whey protein concentrate complexes and their stability

Food fortification is the most cost effective, sustainable and optimal approach in the battle against iron and zinc deficiencies. Iron/zinc, being members of the transition metal series, are highly reactive and poses numerous challenges with respect to physicochemical stability of fortified foods. Whey proteins concentrate (WPC) produced as the principal byproduct of cheese or casein manufacturing is widely used as food ingredient. Among the various technologies explored, iron/zinc binding to milk proteins has long been understood and applied. Therefore, method for the preparation of WPC – mineral (iron/zinc) complex was standardized on the basis of maximum mineral binding ability of proteins. Method involving ultrafiltration and diafiltration (repeated washing to remove free mineral from retentate) has been standardized. Structural modification upon mineral binding was confirmed by RP-HPLC chromatograms. Both iron and zinc bound WPC complexes possessed good stability (resistance towards release of bound mineral) under different processing conditions. However, zinc bound WPC showed better heat stability and lower pH and ionic stability compared to iron bound WPC. The final protein – mineral complexes could be used as a suitable organic fortificants for various food applications with better solubility.

Modelling corn silage harvest logistics for a cost optimization approach

Harvesting corn silage requires balancing the capacities for harvest, transport, and storage operations to eliminate bottlenecks.The overall goal of this paper is to simulate the silage harvest system in order to provide the technicians with a decision support tool. This tool will be useful when performing both the strategic planning at the beginning of the harvest season, and in daily decision making, in order to determine the right combination of resources according to fields to harvest. A model was constructed to evaluate the handling system comprising the harvest, transport and packing of forage intended for corn silage.In order to provide a real example of the usefulness for strategic planning by the tool developed, the harvesting of 590 fields of corn silage in a region of NW Spain was simulated. The model obtained provided a value of 27 trucks to obtain lower harvesting costs if 6-row SPFH were used and 33 trucks with 8-row SPFH. The proper packer capacity at the silo was 3.35tmin−1. The impact that the matching of equipment has on the costs and on the length of the harvest season for each of the harvesters analyzed was more significant with 8-row SPFH. If the number of trucks is less than 30, a 6-row SPFH is more cost efficient than an 8-row SPFH. On the other hand if the number is greater, then the use of the 8-row SPFH would incur lower costs. The harvesting process is more sensitive to changes in the packing capacity than to the number of trucks used relative to the optimum value determined.

OPTIMIZATION OF PRESTRESSED CONCRETE GIRDER

Bridge construction today has achieved a worldwide level of importance. Bridges are the key elements in any road network Use of prestressed concrete I girder bridge is gaining popularity in bridge engineering fraternity because of its better stability, serviceability, economy, aesthetic appearance and structural efficiency. This paper concerned idea about prestressed concrete.In the method of prestressing two types are consider that pre tensioning and post tensioning .At the time of prestressing different losses are consider. These are the losses due to elastic shortening, friction losses, relaxation losses, losses due to creep and shrinkage. In this way total amount of losses in pretensioning and post tensioning calculate and detailed information has given in this report. The objective is to minimize the total cost in the design process of the bridge system considering the cost of materials like steel, concrete, tendons etc. For a particular problem the design variables considered for the cost minimization of the bridge system, are depth of girder, various cross sectional dimensions of the girder, number of tendons, A programme is developed for analysis and designing an low cost prestressed girder in MATLAB R2010a software. The optimtool is used to find out minimum cost of structure Illustrative case of prestressed girder presented and discuss by using active set method from optimtool. Optimization problem is characterized by considering design variables and bound constraints are according to AASHTOO Standards ,IRC 212000 bridge specifications .The proposed cost optimization approach is compared with an existing project which leads to a considerable cost saving while resulting in feasible design.

Multi-objectives optimization of Energy Efficiency Measures in existing buildings

The enhancement of the energy performance of the existing buildings stock is nowadays a priority. To promote buildings energy renovation, the European Committee (2010) [1] asks Member States to define retrofit strategies finding cost-effective solutions. This so-called cost-optimal approach, described by the Commission Delegated Regulation EU (European Commission, 2012) [2], pursues a balance of energy and economic targets, but currently neglects some important aspects, such as indoor thermal comfort. This research investigates the relationship between the initial characteristics of residential buildings and the definition of optimal retrofit solutions in terms of either maximum economic performance, or energy consumption minimization towards nZEBs behaviour for the lowest achievable thermal discomfort. A multi-objective optimization has been carried out using a genetic algorithm (NSGA-II) coupled with a dynamic simulation tool. The results demonstrate that (i) with conventional Energy Efficiency Measures, it is possible to approach the zero energy target maintaining the economical convenience but worsening the indoor thermal comfort and that (ii) there is the necessity to introduce incentives to foster solutions not economically profitable, but more efficient in terms of energy savings and indoor thermal comfort.

Vulnerabilities and mitigation techniques toning in the cloud: A cost and vulnerabilities coverage optimization approach using Cuckoo search algorithm with Lévy flights

Information and Communication Technology (ICT) security issues have been a major concern for decades. Today's ICT infrastructure faces sophisticated attacks using combinations of multiple vulnerabilities to penetrate networks with devastating impact. With the recent rise of cloud computing as a new utility computing paradigm, organizations have been considering it as a viable option to outsource major IT services in order to cut costs. Some organizations have opted for a private or hybrid cloud to take advantage of the emerging technologies and services. However, ICT security issues have to be appropriately mitigated. This research proposes a cloud security framework and an approach for vulnerabilities coverage and cost optimization using Cuckoo search algorithm with Lévy flights as random walks. The objective is to mitigate an identified set of vulnerabilities using a selected set of techniques when minimizing cost and maximizing coverage. The results show that Cloud Computing providers and organizations implementing cloud technology within their premises can effectively balance IT security coverage and cost using the proposed approach.

Transforming the electricity generation of the Berlin–Brandenburg region, Germany

We present possible steps for Germany's capital region for a pathway towards high-level renewable energy contributions. To this end, we give an overview of the current energy policy and status of electricity generation and demand of two federal states: the capital city Berlin and the surrounding state of Brandenburg. In a second step we present alternative, feasible scenarios with focus on the years 2020 and 2030. All scenarios were numerically evaluated in hourly time steps using a cost optimisation approach. The required installed capacities in an 80% renewables scenario in the year 2020 consist of 8.8 GW wind energy, 4.8 GW photovoltaics, 0.4 GWel bioenergy, 0.6 GWel methanation and a gas storage capacity of 180 GWhth. In order to meet a renewable electricity share of 100% in 2030, approximately 9.5 GW wind energy, 10.2 GW photovoltaics and 0.4 GWel bioenergy will be needed, complemented by a methanation capacity of about 1.5 GWel and gas storage of about 530 GWhth. In 2030, an additional 11 GWhel of battery storage capacity will be required. Approximately 3 GW of thermal gas power plants will be necessary to cover the residual load in both scenarios. Furthermore, we studied the transmission capacities of extra-high voltage transmission lines in a second simulation and found them to be sufficient for the energy distribution within the investigated region.

APPLICATIONS OF MATLAB IN OPTIMIZATION OF BRIDGE SUPERSTRUCTURES

Optimization is an act of obtaining the best results under given circumstances. In design, construction and maintenance of any engineering system engineers have to take many technological and managerial decisions at several stages. The ultimate aim of all such decisions is either to minimize the efforts required or to maximize the desired benefit. Optimization is a process of finding the conditions that give the maximum or minimum value of any function. Any engineering system or problem is defined by set of quantities and these quantities can be classified as design variables, constraints, and objective function. All these quantities collectively form a optimization problem and this problem can be solved with the help of MATLAB programming language. The optimization problem is characterized by having a combination of continuous, discrete and integer sets of design variables. MATLAB is a high-level language and interactive environment for numerical computation, visualization, and programming. Using MATLAB we can analyse data, develop algorithms, and create models and applications. The language contains tools, and built-in math functions which enable us to explore multiple approaches and reach a solution faster than with spread sheets or traditional programming languages such as C, C++, java, Fortran etc. In this present study, cost optimization approach for various bridge superstructures is presented. The main objective function is to minimize the total cost in the design process of the bridge system considering the cost of materials. The cost of structural element covers cost of material and labor for reinforcement, concrete and formwork. Design constraints for the optimization are considered according to Standard Specifications for road bridges. The optimization process is done for different grades of concrete and steel. The comparative results for different grades of concrete and steel are presented in tabulated form.

An integrated guaranteed- and stochastic-service approach to inventory optimization in supply chains

Multi-echelon inventory optimization literature distinguishes stochastic- (SS) and guaranteed-service (GS) approaches as mutually exclusive frameworks. While the GS approach considers flexibility measures at the stages to deal with stockouts, the SS approach only relies on safety stock. Within a supply chain, flexibility levels might differ between stages rendering them appropriate candidates for one approach or the other. The existing approaches, however, require the selection of a single framework for the entire supply chain instead of a stage-wise choice. We develop an integrated hybrid-service (HS) approach which endogenously determines the overall cost-optimal approach for each stage and computes the required inventory levels. We present a dynamic programming optimization algorithm for serial supply chains that partitions the entire system into subchains of different types. From a numerical study we find that, besides implicitly choosing the better of the two pure frameworks, whose cost differences can be considerable, the HS approach enables additional pipeline and on-hand stock cost savings. We further identify drivers for the preferability of the HS approach.

Stochastic cost optimization of DNAPL remediation – Field application

A stochastic remediation design optimization methodology implemented in the program Stochastic Cost Optimization Toolkit (SCOToolkit) was successfully applied to evaluate remediation options at the East Gate Disposal Yard (EGDY) at the former Fort Lewis, now Joint Base Lewis-McChord (JBLM), Washington. Non-optimized forward simulations based on calibrated parameters and their uncertainty inferred from data prior to actual thermal source remediation system implementation at the site indicated a low probability of the actual thermal system design meeting remediation criteria in a reasonable time frame. Calibration using additional data collected during thermal treatment reduced prediction uncertainty, but still predicted a high probability of taking more than 100 years to reach compliance criteria using the actual thermal treatment design with no additional remedial action. Stochastic optimization of the thermal treatment design indicated larger treatment areas were needed to capture source mass due to uncertainty in source delineation. The expected cost for the enlarged thermal treatment system was estimated to be $22M, which is nearly twice that of the actual system, suggesting that additional characterization to reduce source delineation uncertainty or consideration of an alternative strategy that is less sensitive to delineation uncertainty may be warranted. Stochastic optimization of whey injection was investigated to accelerate source zone dense nonaqueous phase liquid (DNAPL) dissolution and enhance dissolved plume biodecay. The optimized design indicated a 93% probability of meeting compliance criteria by 2100 with an expected net present value cost of $4.7M. Whey injection substantially shortened the remediation time compared to no whey injection. The results indicate that the proposed stochastic cost optimization approach is able to reduce expected remediation costs, increase the probability of achieving remediation objectives, and identify data characterization needs.

Probabilistic Approach for Cost Optimization of Structural Materials Using Plastic Hinge Mechanism

In the seismic design, it is important to consider higher risks of damage under seismic design forces than under other general loads, such as live load, dead load, or wind load. Although the full strength of the structure can be developed to resist various types of earthquake forces with respect to increased safety factor, this design concept may be not appropriate when we consider the economic benefit since the design under the seismic force is normally 15 to 25 % more expensive than the design of elastic response. As a one of the seismic design approaches, plastic hinge mechanism has drawn an interest to ensure the economic design performance under the earthquake. In this paper, forecasted seismic motion was simulated using a Monte Carlo simulation to determine the seismic design load applied to the structure system. Then for each seismic load, the economical set of plastic hinge mechanisms was optimized using linear programming.

Assessing the impact of cost optimization based on infrastructure modelling on CO 2 emissions

Traditionally, logistics design is driven by a need to reduce costs and improve customer service. Recently, the environmental concerns from transport have been increasingly discussed. The traffic levels and associated energy consumption are influenced by supply chain structure, modal split and vehicle utilization. This paper aims to assess the impact of the traditional cost optimization approach to strategic modelling on overall logistics costs and CO 2 emissions by taking into account the supply chain structure (number of depots) and different freight vehicle utilization ratios (90%, 75% and 60%). The simulation model, based on a European case study from the automotive industry, considers strategic and operational level decisions simultaneously. The analysis shows that the optimum design based on costs does not necessary equate to an optimum solution for CO 2 emissions, therefore there is a need to address economical and environmental objectives explicitly as part of the logistics design.

Optimizing product support (spare parts procurement) strategy by considering system operating environment – A case study

Existing industrial system / machinery availability depends highly on the form and the level of product support. Product support, which is also referred to as after sale service to the product, is important for the customer as well, because it assures the expected function of the product in its operational phase. Product support is affected by different factors, such as reliability and maintainability characteristics and the operating environment of the product. The forecasting of required product support and spare parts based on these factors is one approach for product life cycle cost optimization along with system availability maximization. This paper describes a method to estimate the spare part requirements based on an estimation of reliability of the existing product under the influence of the product-operating environment. Subsequently, in a case study, the management of the spare parts inventory based on the geographical location and required performance of the product will be addressed.

Basic design considerations for a medium-size superconducting magnetic energy storage system (SMES)

In a feasibility study, a 2 MWh magnet system suitable for electric utility application (primary control reserve) is analyzed. Basic choices for a realistic SMES design are considered taking into account practical industrial feasibility. Compared to a large solenoid, advantages are seen for a modular, toroidal configuration with circular coils. To achieve a robust coil pack, internal cooling with supercritical helium for an impregnated winding is selected. System parameters are derived from a cost optimization approach. Possible conductor concepts, a thin-walled coil casing, and a corresponding refrigeration system based on a cryogenic loss estimate are presented.

The multicriteria approach for cost and specification optimization in space operations

The multicriteria approach, by its formalised and operational character, is a methodology well adapted to take into account simultaneously costs and other criteria (time scales, political criteria) from the beginning of the design phase.