Principal Cost Research Articles

Routing design of tree-shaped local public communication networks with high reliability and low cost

This paper discusses reliability problems for local public communication networks such as cable television networks and the subscriber?loops of telecommunication networks. They have tree?shapes and expand continuously as new customers join. By introducing a simple model, it is shown that most principal reliability measures and cost measures for such networks can be described through the networks' graphical characteristic quantities. Extensive simulations show that the prior provision of trunk pipes and a suitable choice of the route selecting rule for new customers are effective in constructing a highly reliable network with low cost.

Medical technology: a solution to the health care cost problem

Examination of U.S. health care problems reveals that the root cause of today's concerns is cost. Unfortunately, technology has been identified by some to be the principal cost escalator. The authors not only believe that this criticism is unjustified, but that medical technology can provide immediate advances in the productivity of health care services, thereby reducing health care costs while increasing the quantity of services. To properly assess whether technology is actually driving the cost of health care services, they advocate that health care service providers be required to report on each patient's bill the cost to that provider of specific technology services. To reduce the cost of medical technology in the short run the authors recommend that the FDA develop a fast-track approval process for medical technology that shows promise for reducing health care costs. To accelerate the discovery of health care cost reducing technology, the authors recommend that the Federal government invest R&D resources in cost-reducing medical devices. In the long run, however, the authors believe that optimization of the U.S. health care system to provide maximum care at minimum cost will require re-engineering of the U.S. health care system. Therefore, development of an engineering systems/economic model of the U.S. health care system is critical to allow the re-engineering process to rapidly converge to the optimum system.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Anti-predator defence by neighbours as a responsive amplifier of parental defence in tree swallows

Abstract. Tree swallows defend their nests against predators with a combination of active and passive defence behaviour. Active defence consists of repeated dives towards the predator accompanied by alarm calling, while passive defence is limited to circling above the predator, with alarm calling at lower rates than during active defence. During 224 presentations of a ferret or rat snake near nests of tree swallows, up to 13 neighbouring tree swallows joined in the defence bouts. With only one exception, these defending neighbours limited their participation to passive defence. In 66 of the predator trials, no neighbouring birds engaged in defence. These trials with no defending neighbours were at nests with significantly lower intensities of parental defence, and there were no other detectable differences between the nests with and without defending neighbours. Of the 158 trials during which defending neighbours were present, the number of neighbours recruited to a defence episode was strongly correlated with male calling behaviour and male and female attendance, with the strongest effect due to the maximal alarm call rate of the defending male parent. Within the limited range of densities provided in the experiments, the numbers of defending neighbours recruited was not significantly affected by the local density of active swallow nests, even though most defending neighbours came from nests within 75 m of the nests being defended. Neighbouring swallows engaged in passive defence at all stages in their nesting cycles, although significantly more had older chicks in their own nests when they defended. An examination of the various costs and benefits of anti-predator behaviour by neighbours suggests that the principal cost is the time taken from other activities, especially foraging for the neighbour's own offspring. The principal benefit appears to be defence of the neighbours' offspring and selves through distraction and 'moving on' of predators, respectively. Thus, self-interest alone appears to explain participation in group defence, although the lower benefits obtained by neighbours probably explains their lack of active defence. The responsiveness of neighbours to variation in the intensity of parental defence suggests that they are interpreting the behaviour of the parents at the nest being threatened as an honest signal of the magnitude of the threat, although it is not clear how such honesty might be maintained. In any event, the participation of neighbours in defence bouts amplifies the sensory impact of the anti-predator display and probably enhances its anti-predator function.

Nutrition: estimating requirements of rainbow trout

The formulation and manufacture of fish feed, the principal cost factor in fish production, must be based on sound information regarding nutritional requirements if the process is to be economical. Assessing nutrient requirements from growth experiments depends on the availability of a suitable model of growth, the analysis used to identify required levels of nutrients, choice of response variables, and the feeding scheme used to deliver the target nutrient to the fish. The review examines specific elements critical in experiments designed to estimate nutrient requirements for vitamins, proteins, amino acids, essential fatty acids, and minerals. Also provided are formulations for semi-purified diets and examples of data interpretation.

Volunteers in the Delivery of Public Services: Hidden Costs... and Benefits

The literature on volunteers in public service tends to focus on efficiency and quality of performance. The case reported here illustrates additional benefits and costs of this approach. In 1988 and 1990 the State of Alabama used biracial teams of volunteer trainers to teach the requirements of a federal court order to poll workers in each of its counties. The benefits were a much larger work force than could have been assembled from paid employees, the speed with which it was recruited and deployed, and the symbolic effects of citizen participation. The principal cost was the extraordinary staff commitment required to coordinate the volunteer effort. The lessons of this experience are useful to scholars and public managers as they evaluate volunteer involvement in public service delivery.

Updated Comparison of Economics of Fusion Reactors With Advanced Fission Reactors

The projected cost of electricity (COE) for fusion is compared with that from current and advanced nuclear fission and coal-fired plants. Fusion cost models were adjusted for consistency with advanced fission plants and the calculational methodology and cost factors follow guidelines recommended for cost comparisons of advanced fission reactors. The results show COEs of about 59--74 mills/kWh for the fusion designs considered. In comparison, COEs for future fission reactors are estimated to be in the 43--54 mills/kWh range with coal-fired plant COEs of about 53--69 mills/kWh ($2--3/GJ coal). The principal cost driver for the fusion plants relative to fission plants is the fusion island cost. Although the estimated COEs for fusion are greater than those for fission or coal, the costs are not so high as to preclude fusion's competitiveness as a safe and environmentally sound alternative.

The Causes and Consequences of Melbourne's Central City Property Boom

This paper argues that political factors interacting with a changing global economic environment generated the property boom in Melbourne's central area which culminated in 1990. Four main factors were involved: a steadily increasing demand for offfice space and only limited supply, the availabilityofan immense poolof global capital, thereduction in the cost of capital in 1987, and the creation of an encouraging climate for property investment by the State government. None of these factors were outside politics or action by the state. Governmental action at federal level wasimplicated in three of the four factors. The principal cost of the boom is an opportunity cost. Billions of dollars borrowedoverseas, on which the nation now pays a massive bill, was not invested either in industry which would have allowed Australia to trade its way out of the recession, or in social and physical onfrastructure which would have added to the general welfare

On a computational method for the second fundamental tensor and its application to bifurcation problems

An algorithm is presented for the computation of the second fundamental tensorV of a Riemannian submanifoldM ofR n . FromV the riemann curvature tensor ofM is easily obtained. Moreover,V has a close relation to the second derivative of certain functionals onM which, in turn, provides a powerful new tool for the computational determination of multiple bifurcation directions. Frequently, in applications, thed-dimensional manifoldM is defined implicitly as the zero set of a submersionF onR n . In this case, the principal cost of the algorithm for computingV(p) at a given pointp?M involves only the decomposition of the JacobianDF(p) ofF atp and the projection ofd(d+1) neighboring points ontoM by means of a local iterative process usingDF(p). Several numerical examples are given which show the efficiency and dependability of the method.

The Economics of Seismic Isolation in Buildings

Seismic isolation is a design technique that offers significant benefits in appropriate applications, and interest in its application continues to grow. The two key issues that must be addressed early in the design phase of a project are the technical and economic feasibility issues. This paper focuses on the economic issues, and discusses the four principal cost factors that should be evaluated. These being construction costs, earthquake insurance premiums, physical damage that must be repaired and disruption costs, loss of market share and potential liability. The paper includes a summary of first cost studies on both new and existing buildings. It also discusses methods of estimating the difference in the cost of earthquake damage using different construction techniques.

CIT gyrotron ECRH system design

The elements of a gyrotron electron cyclotron resonant heating system for the Compact Ignition Tokamak are analyzed. A 10–30 megawatt system design at 11 Tesla is discussed. Major elements (gyrotrons, mode convertors, windows, transmission lines, launch hardware) are examined, and further R&D required for component designs are outlined. The principal cost variables (gyrotron efficiency and availability of TFTR neutral beam power supplies) are discussed briefly.

Metal Machining With High-Pressure Water-Jet Cooling Assistance—A New Possibility

Metal machining is one of the fundamental manufacturing processes. The principal cost of shaping metal parts is generated both in the work involved in shearing metal from the original stock, at the area where the chips are formed, and also in the work required to overcome the high frictional forces that exist between the chip and rake face. Current techniques for the lubrication and cooling of this area are not very effective, resulting in a machining cost which is much higher than need be. A more efficient lubricooling effect can be achieved by the use of a high-pressure water jet directed into the tool/chip interface. The study of this idea was prompted by results achieved in the 1950’s, but now extended to much higher jet injection pressures (up to 280 MPa). The emphasis of this article is on the comparison of the coefficient of friction at the tool/rake interface for conventional and high-pressure jet cooling and also on reporting some practical results. Evaluation of these results indicates both a significant gain in the material removal rate as well as an improvement in the chip shape. The results are for a UNS 1020 steel—a representative of the poorly machinable materials.

Cost Drivers for Solar Thermal Central Receiver Power Plants

Studies completed at the Pacific Northwest Laboratory have allowed an in-depth examination of costs for solar thermal central receiver power plants. Central receiver concepts were evaluated for plant power ratings ranging from 0.5 to 100 MWe, and plant capacity factors ranging from 0.25 to 0.60. The large number of plant configurations considered necessitated the development of cost estimating models. Cost models were developed for concentrator, receiver, transport, storage, energy conversion, balance of plant, and O&amp;M components. This paper presents a detailed discussion of costs for solar thermal central receiver power plants. Principal subcomponents and cost drivers are identified for each component. The impact of alternative design choices on cost and the tradeoffs involved between different working fluids are addressed. Cost uncertainties are examined qualitatively for each component. Finally, equations are presented for making preliminary estimates of direct capital and annual O&amp;M costs for solar thermal central receiver systems.

Costs and Benefits of Legislative Service in the American States

A principal cost to most state legislators is the number of days they must spend in the state capital. A principal benefit is their success rate on legislative proposals. Cost-benefit relationships are examined in a regression analysis of data collected for 99 chambers. The number of legislative workdays and member legislation passage rates are shown to be important factors in the extent to which legislators are satisfied with legislative outcomes. The results have implications for the desirability of recent trends toward longer legislative sessions.

Transaction costs to retailers of different methods of payment: Results of a pilot study

AbstractDo credit card transactions cost the retailer substantially more than other forms of payment? This question was central to a study of the relative costs of cash, cheque, credit card and credit account transactions to retailers in the United Kingdom. The study identifies the principal cost elements and provides quantitative estimates based upon a pilot sample. The costs of accepting credit card and providing credit accounts were found to depend crucially upon the generation of additional sales by these forms of payment.

PDM costs now 12% of industry's revenue

Physical distribution costs now account for at least 12% of industry's total sales revenue; there is also a substantial shift in distribution expenditure among the principal cost elements. For example, freight transport now accounts for some 30% of distribution budgets. This is one of the findings which has emerged from the National Survey of Distribution Costs, launched by the Centre for PDM last year and carried out by PW International. In this feature, Brian McKibbin outlines the major trends now emerging from the Survey and assesses the signifance of the preliminary results in providing a yardstick against which individual companies may measure their own PDM cost performance.

The Common Agricultural Policy

Nearly all food prices in Europe are now determined, not by market forces, but by the operation of the Common Agricultural Policy. The purpose of this paper is first to explain the principal elements of the policy and then to estimate the resource flows which result. Recent discussion has concentrated on the budgetary cost to the UK which is neither a complete nor a meaningful measure of teh economic costs imposed by the policy. The principal cost results from the large difference between the prices paid for food by UK consumers and those which they would have to pay if they were able to buy freely on a world market. This is partly offset by the gains which UK producers derive from these higher prices, but increases by the taxes on non-agricultural commodities which are levied to finance comminity agricultural expenditures such as the purchase and storage of farm produce in excess supply. The net sum of these costs to the UK was, we estimate, £1370m in 1977-8 and will rise to around £2350m in 1980.

“Comparing guideway transit implementation plans, including the impact on road traffic”

A methodology for comparing phased implementation plans for a new fixed guideway transit system in an urban area is presented. Four assumptions are made: (1) the guideway system replaces existing or planned bus service, (2) superior service on the new system results in increased ridership when compared to buses; (3) presence of the guideway facility redirects outward urban growth resulting in additional ridership, and (4) conversely, the absence of any action on the new guideway facility reinforces a diffuse urban growth pattern that creates an irreversible loss of transit ridership. The economic comparision of alternative plans includes total as well as “relative” inflation of principal cost components. A key feature of the proposed methodology is including in the comparisons the costs of private automobile mileage that could have been replaced by transit. These costs are expressed as “fuel” and “all other” automobile costs; favorable transit system implementation schedules can then be identified as a fu...

Commercial and scientific aspects of applied mathematical modelling

This paper is based upon an address given at the Second International Conference on Applied Mathematical Modelling in Madrid, September 1978. The purpose of applied mathematical modelling services is to refine semantic information, making it more accessible and reliable. The problem is first posed of determining the value of applied mathematical modelling services, in terms of their relevance, reliability and cost. The principal cost, that makes up nearly all investment in modelling, is that of research. The uncertainty of outcome of research in refining semantic information and the practical impossibility of patenting the results of such research are shown to pose difficult managerial problems. Some strategies for resolving these managerial problems are discussed.

VENTURE ANALYSES FOR A PROPOSED COMMERCIAL WASTE HEAT AQUACULTURE FACILITY

ABSTRACTData on the development and operating costs for a proposed commercial waste heat aquaculture facility dedicated to culture two species on a diseasonal sequence are presented in this paper. The facility would be located at the Mercer Generating Station, a coal‐fired electric power plant, near Trenton, New Jersey.The concept of reliability indices associated with each of the principal cost and income elements of the proposed aquaculture facility is also introduced. Plots of Return‐on‐Investment vs economic factors and reliability indices are used to depict the venture profitability and confidence of success expected with some of the aquaculture species being studied and the production plans under consideration.Rainbow trout (Salmo gairdneri [Richardson]) is the principal income‐producing species at the present time and channel catfish (Ictalurus punctatus [Rafinesque]) is being tested as the warm weather species. High density culture experiments with freshwater shrimp (Macrobrachium rosenbergii [de Man]) have not met the criteria for profitability to date; however, because of the market potential for this species, additional studies are underway.Return‐on‐investment analyses were run by varying the principal parameters determining the profitability of a commercial venture. These included the culture species, production density, plant size and useful life, processing facilities, sale price of products and type of financing for venture.The project is jointly sponsored by the National Science Foundation (Division of Problem Focused Research Applications) and PSE&amp;G Company. The venture analyses are based on experimental studies being conducted by Trenton State College and Rutgers University.

The Relevance of Expected Persistency Rates When Projecting Pension Costs

The Relevance of Expected Persistency Rates When Projecting Pension Costs