Optimal Technology Choice Research Articles

Morphologic Versions of Postoperative Opacities of the Lens Capsule in Contemporary Cataract Surgery (Working Classification)

Purpose: creation of working classification of morphologic variations of postoperative lens capsule opacity after Micro-Invasive cataract surgery. Material and methods. Morphologic study of the lens capsule (LC) has been conducted on 4 artiphakic cadaveric eyes. A specimen of an isolated anterior lens capsule, obtained during the repeated operation with changes characteristic for anterior capsular contraction syndrome has been studied too. The obtained specimens have been researched with the method of semithin sections. Results. The analysis of the morphologic cadaveric LC specimens revealed the polymorphism of secondary cataract (SC). Besides well known “classic” SC forms, which were caused by fibroplasias processes or pseudo-regeneration a new type of postoperative LC opacity not represented in the available literature before has been revealed. The given variant of opacities was called “pseudo-hyaloid” form and characterized by the absence of clear LC borders, changes of its normal structure, the appearance of loose fibrillar structure with microslit spaces and exfoliations, that possibly was the consequence of acustic cavitation, arising in the result of ultrasonic effect. As a result the LC lost characteristic for it the role of the dense bed and made impossible adhesion and migration on its changed surface the proliferative fibrocellular elements characteristic for “classic” SC forms. The microscopy results of the isolated anterior LC specimen in the area of capsulotomic aperture showed the presence of altered abundant loose fibrillar tissue with microporous structure and expressed forming of folds. Making layers of fibrous tissue exceeded the thickness of the normal anterior LC in 10 and more times and considerably reduced the diameter of capsulotomic aperture. Conclusion. The variety of postoperative LC opacities confirmed by the results of morphologic studies afforded to suggest a new working classification in which all possible morphologic variants and the stages of the secondary pathologic changes forming of anterior LC. The suggested classification is convenient for the understanding and must promote to make a right algorithm in the choice of optimal and safe technology of laser reconstructive interventions.

Substantiation of Mineral Extraction from Man-Made Deposits

Analysis of scientific publications of recent years has shown the need to further study the development of man-made mineral deposits in Ukraine. The main reasons for development of man-made deposits were considered, and the basic requirements for mining man-made deposits were formed, including: efficiency increase of mining operations; reduction of negative environmental impact on the region and restoration of land after industrial activity. Technology that made it possible to group dumps based on their formation is analyzed, which allowed to form clusters. They allow to determine the optimal technology for the development of man-made deposits based on the type of minerals to be extracted and the method of its formation. As a result of the study, the algorithm of making decision on the choice of optimal technology for the development of man-made deposits based on graphical data was developed, taking into account the type of minerals to be extracted, depending on the structure of the deposit and the specific features of its formation.

FEATURES OF MANUFACTURE OF COMPOSITE MATERIAL WITH MACROHETEROGENEOUS STRUCTURE WITH THE APPLICATION OF MAGNETIC FIELDS

Casted composite materials have found application in various branches of industrial production. However, there are still a number of problems related to the choice of optimal technology for their synthesis and the solution of which will help to achieve in practice high level of properties predicted by the theory and provide the control of interfacial interactions to enhance the stability of the structure and properties of composites. There is s need in additional research related to the development of new types of reinforcing elements, which will provide the raise in the level of performance of the composite. It is established that an important role plays not only the type of the matrix but also the chemical composition and microstructure of the reinforcing material. This would require research on optimization of technology for production of composite materials during the solid-liquid synthesis. The paper presents generalized results of experimental studies of peculiarities during the formation of composite materials on the basis of bronze and iron granules with the use of high-speed induction melting. As reinforcing phase iron granules DCHL with a diameter of about 1 mm were used.

Strategic facility location, capacity acquisition, and technology choice decisions under demand uncertainty: Robust vs. non-robust optimization approaches

This paper presents a robust optimization (RO) modeling approach to develop insights into strategic capacity planning and resource acquisition decisions, including the facility location problem and the technology choice problem. The main purpose of the proposed model and numerical experiments is to examine the effects of economies of scale, economies of scope, and the combined effects of scale and scope under uncertain demand realizations using robust optimization. The type of capacities, or technology alternatives, that a firm can acquire can be classified on two basic dimensions. The first dimension relates to the effects of scale via distinction between labor-intensive technologies and capital-intensive technologies. The second dimension relates to the effects of scope via distinction between product-dedicated and flexible technologies. Moreover, each product-dedicated and flexible technology can have different levels of labor or capital-intensity, leading to the joint effects of economies of scale and economies of scope. Extensive computational results document how the optimal technology choice patterns depend on the cost structures and levels of model robustness specified to accommodate uncertain demand realizations. The results obtained by the two-stage robust optimization approach are compared to the results obtained by a non-robust approach.

Land use influence on raw surface water quality and treatment costs for drinking supply in São Paulo State (Brazil)

Anthropogenic disturbances to the environment can compromise valuable ecosystem services, including the provision of potable water. These disturbances decrease water quality, potentially increasing treatment costs for producing drinking water. We investigated the land use influence on raw surface water quality for drinking supply in the most populous state in Brazil (São Paulo). We analyzed a long-term dataset (2000–2014) to assess the raw water quality for drinking purposes in more than 50 river/stream sites located in predominantly industrial/urban, agriculture or forested watersheds. Temporal, seasonal and land cover influences were assessed through Analysis of Covariance (ANCOVA). Infrastructure and operating costs of the Water Treatment Plants (WTPs) were estimated. We found significantly better water quality (p<0.01, ANCOVA) in forested watersheds (e.g., mean turbidity and true color: 10 NTU and 14mgPt/L versus 48–56 NTU and 38–49mgPt/L in industrial/urban and agriculture areas). THMPF and TOC were greater in altered basins (304μg/L and 5.8mg/L, respectively), especially in the rainy season. Drinking water outputs varied across WTPs located in industrial/urban (average: 525L/s), agriculture (392L/s) and forest (167L/s) watersheds. Infrastructure and operating costs, shown as cost per unit of capacity, were greater for plants located in forested areas (US$ 98,208 per L/s), as compared to industrial/urban (US$ 78,230 per L/s) and agriculture (US$ 75,332 per L/s) basins. This was probably because treatment costs in these locations were greater in spite of plants starting with higher quality water. We recommend upgrades in the existing WTPs and the construction of new water utilities consider treatment costs related to predicted changes in land use in supply watersheds. Watershed conservation practices, water demand management, remediation and adaptation actions could also lower treatment costs and alter optimal treatment technology choice.

The Impact of Budget Constraints on Flexible vs. Dedicated Technology Choice

This paper studies the flexible versus dedicated technology choice and capacity investment decisions of a multiproduct firm under demand uncertainty in the presence of budget constraints. The firm operates under a capital budget for financing the capacity investment, and an operating budget, which is uncertain in the capacity investment stage, for financing the production. We investigate how the tightening of the capital budget and a lower financial flexibility in the production stage (the likelihood of having a sufficient operating budget) shape the optimal technology choice. We find that the dominant regime is one where dedicated technology should be adopted for a larger investment cost range, and thus, is the best response to the tighter capital budget, whereas flexible technology is the best response to lower financial flexibility. We identify the key roles that the capacity intensity (the ratio of unit capacity cost to total unit capacity and production cost) of each technology and the pooling value of operating budget with dedicated technology, which brings this technology closer to flexible technology in terms of the resource network’s flexibility, play in a budget-constrained environment. Managerially, our results underline that in the presence of financial constraints, firms should manage technology adoption together with plant location, which shapes capacity intensity, or product portfolio, which shapes financial flexibility. This paper was accepted by Serguei Netessine, operations management.

Factor-augmenting technology choice and monopolistic competition

We put forward a tractable, interpretable, and easily generalizable framework for modeling endogeneous factor-augmenting technology choice by monopolistically competitive firms. The setup is framed within the standard Dixit and Stiglitz (1977) model of monopolistic competition. Optimal technology choice is made here either by final goods producers or the representative household which holds the shares of (differentiated) intermediate goods producers. These two cases have different implications for the distribution of output but they yield the same aggregate level of output, the same aggregate production function and equivalent macroeconomic dynamics. Thanks to this property, the proposed framework can be used as a building block in a variety of embedding structures, including those which require to be solved recursively (separately for the dynamics of aggregate variables and for the distribution in each time period).

Optimal Production Planning with Emissions Trading

Emissions trading is a market-based mechanism for curbing emissions, and it has been implemented in Europe, North America, and several other parts of the world. To study its impact on production planning, we develop a dynamic production model, where a manufacturer produces a single product to satisfy random market demands. The manufacturer has access to both a green and a regular production technology, of which the former is more costly but yields fewer emissions. To comply with the emissions regulations, the manufacturer can buy or sell the allowances in each period via forward contracts in an outside market with stochastic trading prices while needing to keep a nonnegative allowance account balance at the end of the planning horizon. We first derive several important structural properties of the model, and based upon them, we characterize the optimal emissions trading and production policies that minimize the manufacturer's expected total discounted cost. In particular, the optimal emissions trading policy is a target interval policy with two thresholds that decrease with the starting inventory level. The optimal production policy is established by first determining the optimal technology choice and then showing the optimality of a base-stock type of production policy. We show that the optimal base-stock level is independent of the starting inventory level and the allowance level when the manufacturer trades the allowance or uses both technologies simultaneously. A numerical study using representative data from the cement industry is conducted to illustrate the analytical results and to examine the value of green technology for the manufacturer.

Выбор и обоснование оптимальной технологии изготовления лопасти вертолета из композиционных материалов

Выбор и обоснование оптимальной технологии изготовления лопасти вертолета из композиционных материалов

Comparing the Cost-Effectiveness of Water Conservation Policies in a Depleting Aquifer: A Dynamic Analysis of the Kansas High Plains

This research analyzes two groundwater conservation policies in the Kansas High Plains located within the Ogallala aquifer: 1) cost-share assistance to increase irrigation efficiency; and 2) incentive payments to convert irrigated crop production to dryland crop production. To compare the cost-effectiveness of these two policies, a dynamic model simulated a representative irrigator's optimal technology choice, crop selection, and irrigation water use over time. The results suggest that the overall water-saving effectiveness can be improved when different policy tools are considered under different conditions. High prevailing crop prices greatly reduce irrigators' incentive to give up irrigation and therefore cause low enrollment and ineffectiveness of the incentive payment program. In areas with low aquifer-saturated thickness, the incentive payment program is more effective, whereas in areas with relatively higher water availability, the cost-share program could be a better choice.

Applying the fuzzy analytic network process to the selection of an advanced integrated circuit (IC) packaging process development project

In the modern business environment, process technology evaluation and selection (PTES) is a crucial component of innovation in new product development (NPD). The most difficult task for project managers in PTES is to make the optimal technology choice for a Research and Development (R&D) project, and there are many attendant uncertainties and risks in process technology R&D projects for NPD. Recently, Integrated Circuit (IC) Packaging has become an equal part of the cost-performance equation in the silicon world, and packaging foundries have responded quicker than many other semiconductor companies to the rapidly changing requirements of chip-scale packaging. This facilitates the transfer of new technology from the assemblers to the chip suppliers. This study applies the fuzzy analytic network process (FANP) model to evaluate the strategic impact of new IC manufacturing technologies in firms within Taiwan’s IC packaging industry. Our study will determine the key decision-making factors affecting R&D project selection using FANP, and additionally we develop an optimal manufacturing process. As a case study, the ongoing “Controller IC packaging R&D project A” was chosen to minimize warpage of controller IC.

Factor-Augmenting Technology Choice and Monopolistic Competition

We put forward a tractable, interpretable, and easily generalizable framework for modeling endogeneous factor-augmenting technology choice by monopolistically competitive firms. The setup is framed within the standard Dixit and Stiglitz (1977) model of monopolistic competition. Optimal technology choice is made here either by final goods producers or (differentiated) intermediate goods producers. These two cases have different implications for the distribution of output but they yield the same aggregate level of output, the same aggregate production function, and equivalent macroeconomic dynamics. Thanks to this property, the proposed framework can be used as a building block in a variety of embedding structures, including those which require to be solved recursively (separately for the dynamics of aggregate variables and for the distribution in each time period).

Market-Based Instruments and Technology Choices: A Synthesis

Market-based instruments are widely used to encourage innovation and investment in cleaner technologies. Using a simple analytical framework and graphical representations, this paper provides a theoretical synthesis of the relationship between emissions prices/taxes and the firm’s optimal technology choice. This unified treatment incorporates the insights of a wide theoretical literature, as well as providing several new findings. Most surprisingly, perhaps, we identify circumstances in which a higher price of emissions actually reduces the incentive for investment in abatement technologies. We discuss the implications for environmental policy. The main conclusion is that a price on emissions invariably affects the type of abatement technologies firms invest in, so that the technological side of emissions abatement must always be considered in tandem with the design of the market-based instrument itself.

Optimal technology choice and investment timing: A stochastic model of industrial cogeneration vs. heat-only production

In this paper we develop an economic model that explains the decision-making problem under uncertainty of an industrial firm that wants to invest in a process technology. More specifically, the decision is between making an irreversible investment in a combined heat-and-power production (cogeneration) system, or to invest in a conventional heat-only generation system (steam boiler) and to purchase all electricity from the grid. In our model we include the main economic and technical variables of the investment decision process. We also account for the risk and uncertainty inherent in volatile energy prices that can greatly affect the valuation of the investment project. The dynamic stochastic model presented allows us to simultaneously determine the optimal technology choice and investment timing. We apply the theoretical model and illustrate our main findings with a numerical example that is based on realistic cost values for industrial oil- or gas-fired cogeneration and heat-only generation in Switzerland. We also briefly discuss expected effects of a CO 2 tax on the investment decision.

A Compact Physical Model for Yield Under Gate Length and Body Thickness Variations in Nanoscale Double-Gate CMOS

Double-gate (DG) CMOS is projected to replace classical bulk and silicon-on-insulator technologies around the 32-nm node. Predicting the impact of process variations on yield for these devices is necessary at an early stage of the design cycle to enable optimal technology and circuit design choices. This paper presents a compact physical model for DG leakage and threshold voltage distribution due to gate length L and body thickness tsi variations, both for single devices and multiple-device stacks. The model is derived directly from the solution of Poisson and Schrodinger equations and thus captures the effect of unique DG phenomena such as volume inversion and quantum confinement. The model is verified for devices at the end of the scaling roadmap (L=13nm, tsi=3nm), with the yield estimation error less than 3% compared to the Monte Carlo simulation for a 3sigma variation of as much as 20% of the nominal process parameters

Future carbon regulations and current investments in alternative coal-fired power plant technologies

We analyze how uncertain future US carbon regulations shape the current choice of the type of power plant to build. Our focus is on two coal-fired technologies, pulverized coal (PC) and integrated coal gasification combined cycle technology (IGCC). The PC technology is cheapest—assuming there is no need to control carbon emissions. The IGCC technology may be cheaper if carbon must be captured. Since power plants last many years and future regulations are uncertain, a US electric utility faces a standard decision under uncertainty. A company will confront the range of possible outcomes, assigning its best estimate of the probability of each scenario, averaging the results and determining the power plant technology with the lowest possible cost inclusive of expected future carbon related costs, whether those costs be in the form of emissions charges paid or capital expenditures for retrofitting to capture carbon. If the company assigns high probability to no regulation or to less stringent regulation of carbon, then it makes sense for it to build the PC plant. But if it assigns sufficient probability to scenarios with more stringent regulation, then the IGCC technology is warranted. We provide some useful benchmarks for possible future regulation and show how these relate back to the relative costs of the two technologies and the optimal technology choice. Few of the policy proposals widely referenced in the public discussion warrant the choice of the IGCC technology. Instead, the PC technology remains the least costly. However, recent carbon prices in the European Emissions Trading System are higher than these benchmarks. If it is any guide to possible future penalties for emissions in the US, then current investment in the IGCC technology is warranted. Of course, other factors need to be factored into the decision as well.

The trade-off between environmental care and long-term growth—Pollution in three prototype growth models

The effects of increased environmental care on optimal technology choice and long-term growth are studied for an economy in which pollution is a side-product of physical capital used in production. First, it is shown that in case of a standard neoclassical production structure, the result is a less capital-intensive production process whereas the long-run growth rate is not affected. Next, we introduce assumptions of the endogenous growth literature. When there are constant returns to physical capital, an increase in abatement activities crowds out investment and lowers the endogenous growth rate. When human capital accumulation is the engine of growth, physical capital intensity declines and the endogenous optimal growth rate is unaffected by increased environmental care or is even higher, depending on whether or not pollution influences agents' ability to learn.

INVESTING IN GRAIN STORAGE FACILITIES UNDER FLUCTUATING PRODUCTION*

Fluctuating annual harvest volumes create a peak load problem in the provision of grain storage capacity. There are a number of technologies for handling and storing grain, ranging from capital intensive to labour intensive methods. Optimal provision of grain storage capacity can therefore be analysed in the framework of the conventional peak load pricing model. An investment model of grain storage is outlined and the optimal technology choices are determined according to simple investment roles. Capacity of the more capital intensive storage types should be only provided if the extra capital cost is justified by the saving in operating costs, which depends on the expected utilisation of storage. Some level of supply failure is justifiable. An examination of grain storage costs in Western Australia revealed that horizontal storage was the best technology for dealing with most grain storage demand at sites where turnover is limited In the receival period. This concurs with the general investment choices in Western Australia. However, there appears to be a high level of overcapacity at many sites, implying that the cost of supply failure is perceived to be greater than the marketable value of the grain.

Optimal technology choice in a dynamic‐stochastic environment

AbstractThe issue of technology management has become particularly relevant to operations planners as a result of the introduction of new, computer‐aided process technologies in recent years. At the same time, the fields of economics and management science have developed a number of models and paradigms for technology management and equipment replacement. In this article we present a model structure that builds on this theory and that is directed toward providing insights into the particular issues associated with fixed versus variable cost trade‐offs.A fairly general, dynamic, stochastic model is presented. This model links production planning with technology selection in a direct manner. The model computes optimal production plans in the face of uncertain demand in the course of evaluating the costs and benefits of each technology alternative. The key result of the article concerns conditions for the optimality of moves to lower variable cost technologies.

Technology and employment in the production of cotton cloth

This paper makes use of two well-known UN studies of the integrated spinning and weaving of cotton cloth in order to examine the relationship between technology and employment in developing countries. In particular the paper: (a) considers the choice of technology in the production of a given volume of cotton cloth in Western Europe, Latin America and Africa; (b) estimates and discusses the elasticity of capital-labour substitution in such production: and (c) examines some aspects of job creation, factor prices and economic efficiency. The variation in ‘optimal’ technology choice across wage areas is found to be rather narrow and to lie in the upper part of the capital-labour spectrum. The variation in profitability across technologies, however, is found to be much less than that of employment in all three areas. The limited range of ‘optimal’ technologies is partly explained by the elasticity of substitution which lies between 0.2 and 0.25 for Europe; 0.25 and 0.33 for Latin America; and 0.33 and 0.50 for Africa. A certain prodigality in the use of both men and machines in the developing regions is also part of the explanation of the relative similarity in optimal technology choice in the three wage areas considered. In the light of this prodigality and the low elasticity, consideration is given to the question of increasing developing country employment in a state enterprise and a private firm respectively. Not surprisingly, it is found that it would pay to exploit the scope for substitution in the state factory if more employment were sought, although the difference in total costs by ignoring such scope could be relatively small. It is further found that the magnitude of factor price changes required to induce a profit-maximizing businessman to provide the required volume of employment could be dauntingly large. It is noted that increased efficiency in the developing textile industry could result in increased unemployment.