WorldWideScience

Sample records for forget real options

  1. Getting real with real options

    OpenAIRE

    M. R Grasselli

    2006-01-01

    We apply a utility-based method to obtain the value of a finite-time investment opportunity when the underlying real asset is not perfectly correlated to a traded financial asset. Using a discrete-time algorithm to calculate the indifference price for this type of real option, we present numerical examples for the corresponding investment thresholds, in particular highlighting their dependence with respect to correlation and risk aversion.

  2. Valuing real options: frequently made errors

    OpenAIRE

    Fernández, Pablo

    2002-01-01

    In this paper we analyze frequently made errors when valuing real options. The best way of doing it is through examples. We start by analyzing Damodaran's proposal to value the option to expand the business of Home Depot. Some of the errors and problems of this and other approaches are: - Assuming that the option is replicable and using Black and Scholes' formula. - The estimation of the option's volatility is arbitrary and has a decisive effect on the option's value. - As there is no riskles...

  3. Franchise ownership redirection: real options perspective

    OpenAIRE

    Nugroho, Lukito Adi

    2016-01-01

    Background: For over 40 years, the franchise ownership redirection hypothesis has attracted the attention of many scholars. This study, differing from previous ones, proposes an alternative approach for this hypothesis using a real options framework with the extension of agency theory. Method: The real options model is built using the least square Monte Carlo method, where the franchisor's decision to franchise is perceived as a deferred investment while maintaining the right of future acquis...

  4. THE REAL OPTIONS OF CAPITAL BUDGET

    Directory of Open Access Journals (Sweden)

    Antonio Lopo Martins

    2008-07-01

    Full Text Available The traditional techniques of capital budget, as the deducted cash flow and the net value present, do not incorporate existing flexibilities in an investment project, they tend to distort the value of certain investments, mainly those that are considered in scenes of uncertainty and risk. Therefore, this study intends to demonstrate that the Real Options Theory (TOR is a useful methodology to evaluate and to indicate the best option for project of expansion investment. To reach the considered objective the procedure method was used a case study, having as unit of case the Resort Praia Hotel do Litoral Norte of Salvador. This study was developed of the following form: first it identified the traditional net value present and later it was incorporated the volatileness of each analyzed uncertainty. Second, as the real options are analogous to the financial options, it was necessary to identify elements that composed the terminologies of the financial options with intention to get the value of the real option. For this model of options pricing of Black & Scholes jointly with a computational simulator was used (SLS to get the expanded net value present. As a result of this study it was possible to evidence that using the traditional tool of capital budget Net Value Present (VPL is negative, therefore the project of expansion of the Hotel would be rejected. While for the application of methodology TOR the project presents positive Expanded Present Value which would represent an excellent chance of investment. Key-word: Capital budget, Real options, Analysis of investments.

  5. Research into real-option evaluation method

    International Nuclear Information System (INIS)

    Shiba, Tsuyoshi; Wakamatsu, Hitoshi

    2002-03-01

    As an evaluational method for valuation of a corporation, an investment project, a research and development, or the evaluation technique of an enterprise strategy, a real option analysis attracts attention instead of conventional Discount Cash Flow method. The reason is that it can divert the technique for the option valuation in financial engineering to the decision-making process performed according to change in investment environment. Related references, the analysis tools, the application examples, etc. were investigated about the decision-making technique using real option analysis, and this investigation considered the application method to decision-making of the research and development at Japan Nuclear Cycle Development Institute. Consequently, since the feature is in real option analysis being the evaluation technique on condition of that business conditions and business itself also change, the real option analysis fits for evaluation of a research and development that business conditions were opaque and it turns out that the businesses are highly flexible. Moreover, it turns out that it fits also for evaluation of a capital concentration type investment issue like power plants. (author)

  6. Euro Membership as a Real Option Trigger

    DEFF Research Database (Denmark)

    Aabo, Tom; Pantzalis, Christos

    2007-01-01

    -adopters (UK, Sweden, and Denmark) to exercise various forms of real options such as to establish alliances / partnerships, to enter new markets / market segments, to switch suppliers, and to generally expand in the Euro-area. The study furthermore shows that small, profitable and financially constrained firms...... are particularly likely to exercise such real options triggered by the introduction of the Euro. The results go beyond the immediate trade effects, which empirical studies have shown to be weak and without trade diversion as to the three non-adopters, and provide important insights about the potential long...

  7. Acquisitions and Real Options : The Greenfield Alternative

    NARCIS (Netherlands)

    Brouthers, Keith D.; Dikova, Desislava

    P>Although acquisitions are a popular way to enter new markets, empirical evidence tends to indicate few benefits accrue to acquiring firms. This might be the case because firms use acquisitions when they should be employing an alternative mode of expansion. Applying real options theory to this

  8. The Fundamental Uncertainty of Business: Real Options

    Science.gov (United States)

    Dyer, James S.

    The purpose of this paper is to discuss the manner in which uncertainty is currently evaluated in business, with an emphasis on economic measures. In recent years, the accepted approach for the valuation of capital investment decisions has become one based on the theory of real options. From the standpoint of this workshop, the interesting aspect of real options is its focus on the flexibility of management to respond to changes in the environment as a feature of an alternative that has unique value, known as "option value." While this may not be surprising to most participants in this workshop, it does represent a radical change in traditional thinking about risk in business, where efforts have primarily been focused on the elimination of risk when possible.

  9. Real Options Analysis of Electricity Investments

    Energy Technology Data Exchange (ETDEWEB)

    Heggedal, Ane Marte

    2012-07-01

    This thesis utilizes real options analysis for evaluating investment opportunities in the electricity sector. It also formally tests how investors in hydropower plants have included uncertainty when considering their investment opportunities. The real options method applies financial options theory to quantify the value of management flexibility and is chosen due to three important characteristics of investments in the electricity sector. First; the investment is completely or partially irreversible, second; the investor can choose when to invest in the facility, and third; there is uncertainty in several factors affecting the cash flows of the investments. Factors of uncertainty include the development of electricity prices, policies, technological advances, and macroeconomics measures.Four papers are included in this thesis. Paper 1, Upgrading hydropower plants with storage: Timing and capacity choice, presents a valuation framework for deciding when to upgrade an existing hydropower plant and which capacity to choose. The second paper, Transmission capacity between Norway and Germany: A real options analysis, sheds light on when two electricity markets, in this case Norway and Germany, should be connected through a sub sea cable. The investor can choose when to invest and the capacity of the cable, and may also choose to invest sequentially. Paper 3, Optimal timing and capacity choice for pumped hydropower storage, investigates when investment in a pumped hydropower plant with storage should be undertaken and what the capacity of the facility should be. Whereas the three first papers investigate investment opportunities, Paper 4, Uncertain climate policy decisions and investment timing: Evidence from small hydropower plants, studies when investors in small hydropower plants chose to invest. The analyses disclose whether the net present value approach or the real options method best describe the investment decisions made by the investors. Viewing investment

  10. Real Options Analysis of Mining Projects

    OpenAIRE

    Rudolf Zdravlje

    2011-01-01

    When long life assets are being evaluated based on constant predictions of future variables and the assumptions of zero management flexibility, is value being missed? In project evaluation today, the most common evaluation methods that calculate a net present value are discounted cash flow (DCF) analysis, decision tree analysis and Monte Carlo simulation. A fourth method, which is beginning to gain ground in terms of its use in the mining industry, is real option analysis (ROA). ROA utilizes ...

  11. Acquisitions Through a Behavioral and Real Options Lens

    NARCIS (Netherlands)

    J.C.M. Kil (Joris)

    2013-01-01

    textabstractThis thesis combines four studies that contribute to our understanding of corporate acquisitions by taking a behavioral and real options perspective. Chapter 2 classifies acquisitions based on real option characteristics and shows option type (single vs. compound) and option nature

  12. Valuing of research project in energy field with real options

    International Nuclear Information System (INIS)

    De Blasio, N.; Marzo, G.; Turatto, R.

    2008-01-01

    This article presents an application of real options theory for valuing a research project in the field of stranded gas valorisation. After a presentation of the theory, the analysis addresses the use of real options evaluation for generating alternative pathways in order to add new value to the R D projects. It also shows how real option approach may be important for selecting among competitive projects, but also for providing a system for valorisation of decision-maker flexibility [it

  13. Nuclear Fuel Cycle Evaluation and Real Options

    Directory of Open Access Journals (Sweden)

    L. Havlíček

    2008-01-01

    Full Text Available The first part of this paper describes the nuclear fuel cycle. It is divided into three parts. The first part, called Front-End, covers all activities connected with fuel procurement and fabrication. The middle part of the cycle includes fuel reload design activities and the operation of the fuel in the reactor. Back-End comprises all activities ensuring safe separation of spent fuel and radioactive waste from the environment. The individual stages of the fuel cycle are strongly interrelated. Overall economic optimization is very difficult. Generally, NPV is used for an economic evaluation in the nuclear fuel cycle. However the high volatility of uranium prices in the Front-End, and the large uncertainty of both economic and technical parameters in the Back-End, make the use of NPV difficult. The real option method is able to evaluate the value added by flexibility of decision making by a company under conditions of uncertainty. The possibility of applying this method to the nuclear fuel cycle evaluation is studied. 

  14. Forgetting to forget

    DEFF Research Database (Denmark)

    Nørby, Simon

    week, which suggests that memory suppression interferes with immediate retrieval but does not lead to long-term forgetting. Furthermore, the amount of training that reduced immediate recall of neutral items did not at all reduce recall of emotional items. This finding is in accordance with the notion......Using Anderson and Green's (2001) ‘‘think/no-think" paradigm with neutral and emotional nouns, we found in agreement with other studies that memory for neutral words was reduced instantly upon repeated attempts at suppression. However, the effect was temporary and vanished after a period of one...

  15. Retrospective insights from real options in R&D

    NARCIS (Netherlands)

    Lint, L.J.O.

    2000-01-01

    Absent empirical validation of real option pricing in R&D, we discuss the evolution of three cases in R&D option valuation. The first case concerns an option on conversion of an existing production process. The other two cases concern R&D to develop new product technology in the consumer electronics

  16. Real option analysis in a replicating portfolio perspective

    NARCIS (Netherlands)

    van Heeswijk, W.J.A.; Joosten, Reinoud A.M.G.; Huisman, Kuno; Bos, Christian

    2013-01-01

    In the last decades, a vast body of literature has arisen on real option analysis (ROA). The use of di¤erent approaches and the often implicit adoption of major assumptions may cause confusion on what ROA precisely entails, or in which situations it may be applied. We assess the �eld of real option

  17. INVESTMENT IN ANTIVIRAL DRUGS : A REAL OPTIONS APPROACH

    NARCIS (Netherlands)

    Attema, Arthur E.; Lugner, Anna K.; Feenstra, Talitha L.

    2010-01-01

    Real options analysis is a promising approach to model investment under uncertainty. We employ this approach to value stockpiling of antiviral drugs as a precautionary measure against a possible influenza pandemic. Modifications of the real options approach to include risk attitude and deviations

  18. Towards phronetic knowledge for strategic planning in corporate real estate management: A real options approach

    NARCIS (Netherlands)

    van Reedt Dortland, Maartje; Voordijk, Johannes T.; Dewulf, Geert P.M.R.

    2014-01-01

    Purpose – The objective of this paper is to provide insights about the potential of real option thinking for corporate real estate management (CREM) from the owner-user perspective. A promising approach to classifying and evaluating flexibility in real estate is the real options approach. Most

  19. Flexibility and Project Value: Interactions and Multiple Real Options

    Science.gov (United States)

    Čulík, Miroslav

    2010-06-01

    This paper is focused on a project valuation with embedded portfolio of real options including their interactions. Valuation is based on the criterion of Net Present Value on the simulation basis. Portfolio includes selected types of European-type real options: option to expand, contract, abandon and temporarily shut down and restart a project. Due to the fact, that in reality most of the managerial flexibility takes the form of portfolio of real options, selected types of options are valued not only individually, but also in combination. The paper is structured as follows: first, diffusion models for forecasting of output prices and variable costs are derived. Second, project value is estimated on the assumption, that no real options are present. Next, project value is calculated with the presence of selected European-type options; these options and their impact on project value are valued first in isolation and consequently in different combinations. Moreover, intrinsic value evolution of given real options with respect to the time of exercising is analysed. In the end, results are presented graphically; selected statistics and risk measures (Value at Risk, Expected Shortfall) of the NPV's distributions are calculated and commented.

  20. The Real Options Attached to an Investment Project

    Directory of Open Access Journals (Sweden)

    Mihai-Cristian DINICĂ

    2011-12-01

    Full Text Available The real options capture the importance of the managerial team’s role in creating value through investment projects. The investments in real assets have a set of options that managers can exercise during the period of the project to increase the value of the assets or to limit the eventual losses. This options have their own value.The traditional methods for investment project evaluatioan, based on discounted cash flows, have some major disadvantages: they assume the irreversibility of a decision, do not take into account the interactions between decisions in several periods and treat the investment as pasive. The evaluation using real options undertake this disadvantage. The paper shows the main types of real options, together with their elements and captures the impact of these options on the value of the investment. The main two models used to evaluate real options, the binomial model and Black-Scholes model, are explained and used to compute the value of real options attached to an investment project.

  1. Capital renewal as a real option

    NARCIS (Netherlands)

    Reindorp, M.J.; Fu, M.C.

    2011-01-01

    We consider the timing of replacement of obsolete subsystems within an extensive, complex infrastructure. Such replacement action, known as capital renewal, must balance uncertainty about future profitability against uncertainty about future renewal costs. Treating renewal investments as real

  2. Real options valuation of fusion energy R and D programme

    International Nuclear Information System (INIS)

    Bednyagin, Denis; Gnansounou, Edgard

    2011-01-01

    This paper aims to perform a real options valuation of fusion energy R and D programme. Strategic value of thermonuclear fusion technology is estimated here based on the expected cash flows from construction and operation of fusion power plants and the real options value arising due to managerial flexibility and the underlying uncertainty. First, a basic investment option model of Black-Scholes type is being considered. Then, a fuzzy compound real R and D option model is elaborated, which reflects in a better way the multi-stage nature of the programme and takes into account the imprecision of information as one of the components of the overall programme uncertainty. Two different strategies are compared: 'Baseline' corresponding to a relatively moderate pace of fusion research, development, demonstration and deployment activities vs. 'Accelerated' strategy, which assumes a rapid demonstration and massive deployment of fusion. The conclusions are drawn from the model calculations regarding the strategic value of fusion energy R and D and the advantages of accelerated development path. - Research highlights: → Real options analysis of fusion R and D, demonstration and deployment (RDDD) programme. → ENPV of fusion RDDD programme is calculated using stochastic probabilistic simulation. → Fusion RDDD programme exhibits substantial positive real options value: Euro 245 billion. → Fuzzy compound real option valuation method provides more robust results.

  3. Corporate investment under uncertainty and competition : A real options approach

    NARCIS (Netherlands)

    Pawlina, G.

    2003-01-01

    Corporate investment opportunities can be represented as a set of (real) options to acquire productive assets. Identification of the optimal exercise strategies for these options plays a crucial role in improving the quality of capital budgeting decisions and, as a consequence, in maximizing

  4. The Implications of Real Options on ERP-Enabled Adoption

    Science.gov (United States)

    Nwankpa, Joseph K.

    2012-01-01

    Current research on Enterprise Resource Planning (ERP) systems and real options focuses on valuation and justification issues that manager's face prior to project approval with existing literature attempting to demonstrate that ERP systems as technology positioning investments have option-like characteristics thus making such ERP systems…

  5. Real Options in Capital Budgeting. Pricing the Option to Delay and the Option to Abandon a Project

    Directory of Open Access Journals (Sweden)

    Nicoleta Vintila

    2007-07-01

    Full Text Available Traditional discounted cash-flows method for assessing projects assumes that investment decision is an irreversible one, which is not correct. Managers can and must reconsider their initial decision as the new information arises during the project life. This is managerial flexibility and it creates strategic value for a project, only if management takes advantage of the opportunities associated with an analyzed project. Real options represent a new approach in capital budgeting, using the theory of pricing financial options for investments in real assets. In this paper, we emphasize the characteristics and valuation methodologies of real options. The objective in the last section is pricing the option to delay and the option to abandon a project in construction materials field.

  6. Real options and volume uncertainty by field development projects

    International Nuclear Information System (INIS)

    Ekern, S.; Stensland, G.

    1993-12-01

    The report concerns a study on the use of option methodology in field development projects. The report shows how the value of flexibility in the different decision processes is to be found by means of real option methodology. Particular attention is laid on the uncertainty concerning the volume of reserves and production capacity. The results from the study were based on the research project dubbed ''Use of real options in field development projects''. The project is partially connected to another project dubbed ''Decisive behaviour and alternative action under uncertainty in the petroleum sector''. Main topics cover as follow: Example with volume uncertainty; real options and volume uncertainty; gradual disclosure of uncertainty in the production; value of flexible production equipment. 33 refs., 19 figs., 17 tabs

  7. Real option valuation of power transmission investments by stochastic simulation

    International Nuclear Information System (INIS)

    Pringles, Rolando; Olsina, Fernando; Garcés, Francisco

    2015-01-01

    Network expansions in power markets usually lead to investment decisions subject to substantial irreversibility and uncertainty. Hence, investors need valuing the flexibility to change decisions as uncertainty unfolds progressively. Real option analysis is an advanced valuation technique that enables planners to take advantage of market opportunities while preventing or mitigating losses if future conditions evolve unfavorably. In the past, many approaches for valuing real options have been developed. However, applying these methods to value transmission projects is often inappropriate as revenue cash flows are path-dependent and affected by a myriad of uncertain variables. In this work, a valuation technique based on stochastic simulation and recursive dynamic programming, called Least-Square Monte Carlo, is applied to properly value the deferral option in a transmission investment. The effect of option's maturity, the initial outlay and the capital cost upon the value of the postponement option is investigated. Finally, sensitivity analysis determines optimal decision regions to execute, postpone or reject the investment projects. - Highlights: • A modern investment appraisal method is applied to value power transmission projects. • The value of the option to postpone decision to invest in transmission projects is assessed. • Simulation methods are best suited for valuing real options in transmission investments

  8. Multinationality as real option facilitator – Illusion or reality?

    DEFF Research Database (Denmark)

    Aabo, Tom; Pantzalis, Christos; Park, Jung Chul

    2016-01-01

    Previous literature provides multiple conflicting arguments on why and when multinationality should enhance or impede the value-relevance of firms’ real options. We address this issue by examining whether the relationship between stock returns and changes in return volatility varies with multinat......Previous literature provides multiple conflicting arguments on why and when multinationality should enhance or impede the value-relevance of firms’ real options. We address this issue by examining whether the relationship between stock returns and changes in return volatility varies...... with multinationality. Our results indicate that multinationality does indeed act as a real option facilitator. Furthermore, we show that, consistent with the notion that there are limits to the operating flexibility associated with multinationality this benefit only accrues fully if the firm is not financially...

  9. Investing in Marine Scrubber under Uncertainty with Real Option Thinking

    DEFF Research Database (Denmark)

    Jiang, Liping; Hansen, Carsten Ørts

    works that examine the economic feasibility of scrubber retrofitting through the net present value rule, this paper applies the Real Option Analysis to find the optimal investment strategies. The proposed decision-making framework addresses the uncertainty and the value of deferral option embedded...... in the scrubber investment. The multiple sources of investment uncertainties are explicitly analyzed and integrated in the modeling by using Rainbow option. The results demonstrate that the value of the scrubber investment has significantly increased for several cases by considering the deferral option....... It is thus important for ship owners to consider the available options before proceeding with abandoning or investing strategy. The proposed framework can be widely applied to other ship retrofitting investment evaluations, which include similar investment alternatives and uncertainties....

  10. Applying real options analysis to assess cleaner energy development strategies

    International Nuclear Information System (INIS)

    Cheng, Ching-Tsung; Lo, Shang-Lien; Lin, Tyrone T.

    2011-01-01

    The energy industry, accounts for the largest portion of CO 2 emissions, is facing the issue of compliance with the national clean energy policy. The methodology for evaluating the energy mix policy is crucial because of the characteristics of lead time embedded with the power generation facilities investment and the uncertainty of future electricity demand. In this paper, a modified binomial model based on sequential compound options, which may account for the lead time and uncertainty as a whole is established, and a numerical example on evaluating the optional strategies and the strategic value of the cleaner energy policy is also presented. It is found that the optimal decision at some nodes in the binomial tree is path dependent, which is different from the standard sequential compound option model with lead time or time lag concept. The proposed modified binomial sequential compound real options model can be generalized and extensively applied to solve the general decision problems that deal with the long lead time of many government policies as well as capital intensive investments. - Highlights: → Introducing a flexible strategic management approach for government policy making. → Developing a modified binomial real options model based on sequential compound options. → Proposing an innovative model for managing the long term policy with lead time. → Applying to evaluate the options of various scenarios of cleaner energy strategies.

  11. How Do Real Options Concepts Fit in Agile Requirements Engineering?

    NARCIS (Netherlands)

    Racheva, Z.; Daneva, Maia

    Agile requirements engineering is driven by creating business value for the client and heavily involves the client in decision-making under uncertainty. Real option thinking seems to be suitable in supporting the client’s decision making process at inter-iteration time. This paper investigates the

  12. A Real Options Perspective On R&D Portfolio Diversification

    NARCIS (Netherlands)

    S. van Bekkum (Sjoerd); H.P.G. Pennings (Enrico); J.T.J. Smit (Han)

    2009-01-01

    textabstractThis paper shows that the conditionality of investment decisions in R&D has a critical impact on portfolio risk, and implies that traditional diversification strategies should be reevaluated when a portfolio is constructed. Real option theory argues that research projects have

  13. New perspective of real options theory for policy analysis

    NARCIS (Netherlands)

    Sadowski, B.M.

    2007-01-01

    In deze Reflectie geeft Sadowski een alternatief, of eigenlijk een aanvulling op de KBA, vanuit de real options theory, zoals die ook in de financiële sector gebruikt wordt. Het idee is dat er in dynamische markten veel ontwikkelingen zijn: technologisch, een markt in beweging of industriële

  14. Capacity choice in (strategic) real options models : A survey

    NARCIS (Netherlands)

    Huberts, Nick; Huisman, Kuno; Kort, Peter; Lavrutich, Maria

    2015-01-01

    The theory of real options determines the optimal time to invest in a project of given size. As a main result, it is found that in a more uncertain environment, it is optimal for a firm to delay its investment. In other words, uncertainty generates a “value of waiting.” Recently, contributions

  15. Pricing real estate index options under stochastic interest rates

    Science.gov (United States)

    Gong, Pu; Dai, Jun

    2017-08-01

    Real estate derivatives as new financial instruments are not merely risk management tools but also provide a novel way to gain exposure to real estate assets without buying or selling the physical assets. Although real estate derivatives market has exhibited a rapid development in recent years, the valuation challenge of real estate derivatives remains a great obstacle for further development in this market. In this paper, we derive a partial differential equation contingent on a real estate index in a stochastic interest rate environment and propose a modified finite difference method that adopts the non-uniform grids to solve this problem. Numerical results confirm the efficiency of the method and indicate that constant interest rate models lead to the mispricing of options and the effects of stochastic interest rates on option prices depend on whether the term structure of interest rates is rising or falling. Finally, we have investigated and compared the different effects of stochastic interest rates on European and American option prices.

  16. Real options methodology in public-private partnership projects valuation

    Directory of Open Access Journals (Sweden)

    Rakić Biljana

    2014-01-01

    Full Text Available PPP offers numerous benefits to both public and private partners in delivery of infrastructure projects. However this partnership also involves great risks which have to be adequately managed and mitigated. Private partners are especially sensitive to revenue risk, since they are mostly interested in the financial viability of the project. Thus they often expect public partners to provide some kind of risk-sharing mechanism in the form of Minimum Revenue Guarantees or abandonment options. The objective of this paper is to investigate whether the real option of abandoning the project increases its value. Therefore the binominal option pricing model and risk-neutral probability approach have been implemented to price the European and American abandonment options for the Build-Operate-Transfer (BOT toll road investment. The obtained results suggest that the project value with the American abandonment option is greater than with the European abandonment option, hence implying that American options offer greater flexibility and are more valuable for private partners. [Projekat Ministarstva nauke Republike Srbije, br. 179066 and III 42006

  17. Development of real options model for nuclear power plants

    International Nuclear Information System (INIS)

    Ono, Kenji

    2004-01-01

    As the Japanese electricity market is deregulated, it becomes more important for electric utilities to recognize their financial risks and to adopt strategic and scientific decision making methodology. We have developed two models for valuation of Japanese nuclear power plants to support utilities' decision making. One is a net present value (NPV) model using discounted cash flow analysis method. Another is a real options model. This model is based on strict financial technology theory and can calculate value of early retirement, life extension and new unit addition options of nuclear units under electricity price uncertainty. This can also derive an optimal period for retirement, life extension and new unit addition. (author)

  18. Costing the EPR Project Using the Real Options Method

    International Nuclear Information System (INIS)

    Epaulard, Anne; Gallon, Stephane

    2001-01-01

    Real options theory makes it possible to cost investments which offer flexibility but whose returns are uncertain, such as the construction in 2000 of an EPR prototype; this prototype will enable the European pressurised-water reactor (EPR) to be used to renew EDF's nuclear power stations in 2020 (flexibility) but its economic worth will then depend on the cost of the competing gas-fired power plants (uncertain return). Options theory shows that investing in EPR technology in 2000 provides sufficient flexibility in 2020 to be considered cost-effective, even though use of EPRs is unlikely by that date. The investment made in 2000 to develop EPR technology therefore actually plays the part of an option or, in other words, insurance (against the risk of high gas prices)

  19. Using real options analysis to support strategic management decisions

    Science.gov (United States)

    Kabaivanov, Stanimir; Markovska, Veneta; Milev, Mariyan

    2013-12-01

    Decision making is a complex process that requires taking into consideration multiple heterogeneous sources of uncertainty. Standard valuation and financial analysis techniques often fail to properly account for all these sources of risk as well as for all sources of additional flexibility. In this paper we explore applications of a modified binomial tree method for real options analysis (ROA) in an effort to improve decision making process. Usual cases of use of real options are analyzed with elaborate study on the applications and advantages that company management can derive from their application. A numeric results based on extending simple binomial tree approach for multiple sources of uncertainty are provided to demonstrate the improvement effects on management decisions.

  20. What is the (Real Option) Value of a College Degree?

    OpenAIRE

    Jeffrey R. Stokes

    2013-01-01

    The value of a college degree is often quantified as the difference in earnings between those with and without a degree. The research presented here operationalizes this idea in two important ways. First, since future income and tuition are uncertain, a contingent claims model is developed and the appropriate discount rate for valuing future earnings is, therefore, endogenized given an economy that does not permit arbitrage. Second, the model is sensitive to the valuation of the real option t...

  1. Real Option Cost Vulnerability Analysis of Electrical Infrastructure

    Science.gov (United States)

    Prime, Thomas; Knight, Phil

    2015-04-01

    Critical infrastructure such as electricity substations are vulnerable to various geo-hazards that arise from climate change. These geo-hazards range from increased vegetation growth to increased temperatures and flood inundation. Of all the identified geo-hazards, coastal flooding has the greatest impact, but to date has had a low probability of occurring. However, in the face of climate change, coastal flooding is likely to occur more often due to extreme water levels being experienced more frequently due to sea-level rise (SLR). Knowing what impact coastal flooding will have now and in the future on critical infrastructure such as electrical substations is important for long-term management. Using a flood inundation model, present day and future flood events have been simulated, from 1 in 1 year events up to 1 in 10,000 year events. The modelling makes an integrated assessment of impact by using sea-level and surge to simulate a storm tide. The geographical area the model covers is part of the Northwest UK coastline with a range of urban and rural areas. The ensemble of flood maps generated allows the identification of critical infrastructure exposed to coastal flooding. Vulnerability has be assessed using an Estimated Annual Damage (EAD) value. Sampling SLR annual probability distributions produces a projected "pathway" for SLR up to 2100. EAD is then calculated using a relationship derived from the flood model. Repeating the sampling process allows a distribution of EAD up to 2100 to be produced. These values are discounted to present day values using an appropriate discount rate. If the cost of building and maintain defences is also removed from this a Net Present Value (NPV) of building the defences can be calculated. This distribution of NPV can be used as part of a cost modelling process involving Real Options, A real option is the right but not obligation to undertake investment decisions. In terms of investment in critical infrastructure resilience this

  2. Applying Real Options for Evaluating Investments in ERP Systems

    Science.gov (United States)

    Nakagane, Jun; Sekozawa, Teruji

    This paper intends to verify effectiveness of real options approach for evaluating investments in Enterprise Resource Planning systems (ERP) and proves how important it is to disclose shadow options potentially embedded in ERP investment. The net present value (NPV) method is principally adopted to evaluate the value of ERP. However, the NPV method assumes no uncertainties exist in the object. It doesn't satisfy the current business circumstances which are filled with dynamic issues. Since the 1990s the effectiveness of option pricing models for Information System (IS) investment to solve issues in the NPV method has been discussed in the IS literature. This paper presents 3 business cases to review the practical advantages of such techniques for IS investments, especially ERP investments. The first case is EDI development. We evaluate the project by a new approach with lighting one of shadow options, EDI implementation. In the second case we reveal an ERP investment has an “expanding option” in a case of eliminating redundancy. The third case describes an option to contract which is deliberately slotted in ERP development to prepare transferring a manufacturing facility.

  3. A Real Options Approach to Nuclear Waste Disposal in Sweden

    International Nuclear Information System (INIS)

    Soederkvist, Jonas; Joensson, Kristian

    2004-04-01

    This report is concerned with an investigation of how the real options approach can be useful for managerial decisions regarding the phase-out of nuclear power generation in Sweden. The problem of interest is the optimal time-schedule for phase-out activities, where the optimal time-schedule is defined in purely economical terms. The approach taken is actual construction and application of three real options models, which capture different aspects of managerial decisions. The first model concerns when investments in deep disposal facilities should optimally be made. Although the model is a rough simplification of reality, the result is clear. It is economically advantageous to postpone deep disposal forever. The second model focuses on how the uncertainty of future costs relates to managerial investment decisions. Construction of this model required some creativity, as the nuclear phase-out turns out to be quite a special project. The result from the second model is that there can be a value associated with deferral of investments due to the uncertainty of future costs, but the result is less clear-cut compared to the first model. In the third model, we extend an approach suggested by Louberge, Villeneuve and Chesney. The risk of a nuclear accident is introduced through this model and we develop its application to investigate the Swedish phase-out in particular, which implies that waste continuously disposed. In the third model, focus is shifted from investment timing to implementation timing. The results from the third model are merely qualitative, as it is considered beyond the scope of this work to quantitatively determine all relevant inputs. It is concluded that the phase-out of nuclear power generation in Sweden is not just another area of application for standard real options techniques. A main reason is that although there are a lot of uncertain issues regarding the phase-out, those uncertainties do not leave a lot of room for managerial flexibility if

  4. Evaluation of Foreign Investment in Power Plants using Real Options

    Science.gov (United States)

    Kato, Moritoshi; Zhou, Yicheng

    This paper proposes new methods for evaluating foreign investment in power plants under market uncertainty using a real options approach. We suppose a thermal power plant project in a deregulated electricity market. One of our proposed methods is that we calculate the cash flow generated by the project in a reference year using actual market data to incorporate periodic characteristics of energy prices into a yearly cash flow model. We make the stochastic yearly cash flow model with the initial value which is the cash flow in the reference year, and certain trend and volatility. Then we calculate the real options value (ROV) of the project which has abandonment options using the yearly cash flow model. Another our proposed method is that we evaluate foreign currency/domestic currency exchange rate risk by representing ROV in foreign currency as yearly pay off and exchanging it to ROV in domestic currency using a stochastic exchange rate model. We analyze the effect of the heat rate and operation and maintenance costs of the power plant on ROV, and evaluate exchange rate risk through numerical examples. Our proposed method will be useful for the risk management of foreign investment in power plants.

  5. Real Silver and Its Investment and Business Options

    Directory of Open Access Journals (Sweden)

    Novotný Josef

    2016-06-01

    Full Text Available The article deals with investment and business opportunities offered by silver. Silver is the metal used in industry and for investing at financial markets. The main problem related to this real commodity is the issue of “the undervaluation” of its investment options, if compared to gold. If considering silver as the investment option, its investment potential is significantly enhanced by its industrial usage. The aim of this paper is to highlight business and investment opportunities for both professionals and non professional investors at the commodity markets. The price growth of this investment and industrial metal can generate profits for the investors. And on the other hand, industries which cannot do without silver in their production may efficiently utilize the knowledge of setting up its price at the markets.

  6. Applying real options in investment decisions relating to environmental pollution

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tyrone T. [Department of International Business, National Dong Hwa University, 1, Sec. 2, Da Hsueh Road, Shou-Feng, Hualien 974, Taiwan (China)]. E-mail: tjlin@mail.ndhu.edu.tw; Ko, C.-C. [Department of International Trade, Jin Wen Institute of Technology, Taiwan (China); Yeh, H.-N. [Graduate School of Management, Ming Chuan University, Taiwan (China)

    2007-04-15

    This study focuses on how to assess the optimal environmental investment decisions under economic and ecological uncertainty, and establishes the continuous time model using the real option approach to optimize environmental pollution policy. Unlike traditional cost benefit analysis, this work extends the model of [Pindyck, R.S., 2002. Optimal timing problems in environmental economics. Journal of Economic Dynamics and Control 26(9-10), 1677-1697], and attempts to identify the storage threshold of pollution stocks and the optimal timing for implementing environmental pollution decisions.

  7. A Real Options Analysis of Coffee Planting in Vietnam

    OpenAIRE

    Luong, Quoc; Tauer, Loren W.

    2004-01-01

    Vietnam grew from an insignificant to the world’s second largest coffee producer during the 1990s. To understand this growth, this paper examines Vietnamese coffee growers’ investment decisions using real options theory. The study finds that producers, with variable costs of 19 cents/lb and total cost of 29.3 cents/lb, would enter coffee production at a coffee price of 47 cents/lb and exit at a coffee price of 14 cents/lb. Most Vietnamese growers appear to be sufficiently efficient to continu...

  8. Applying real options in investment decisions relating to environmental pollution

    International Nuclear Information System (INIS)

    Lin, Tyrone T.; Ko, C.-C.; Yeh, H.-N.

    2007-01-01

    This study focuses on how to assess the optimal environmental investment decisions under economic and ecological uncertainty, and establishes the continuous time model using the real option approach to optimize environmental pollution policy. Unlike traditional cost benefit analysis, this work extends the model of [Pindyck, R.S., 2002. Optimal timing problems in environmental economics. Journal of Economic Dynamics and Control 26(9-10), 1677-1697], and attempts to identify the storage threshold of pollution stocks and the optimal timing for implementing environmental pollution decisions

  9. MODERN OPTIONS FOR THE FINANCING OF THE REAL ESTATE INVESTMENTS

    Directory of Open Access Journals (Sweden)

    Chiriac Silviu-Cornel-Virgil

    2015-07-01

    Full Text Available The investments represent one of the most important elements in the national economy development strategies, as well as in all the business fields and branches. The notion of investment is extremely complex, perceived with different meanings and significates. In a general, wider meaning the investments represent a capital placement which is made with the purpose of obtaining profit bearing incomes in the future. In a narrower meaning, investments mean the totality of expenses made for obtaining capital assets which are future potential factors in the formation of incomes. Investments represent the most important factor in the development strategies of the national economy as well as in all the business fields and branches. The investment strategy represents an important element in the management of the investments and a component of the general strategy of the entity. The use of investment strategies in the management activity implies the application of scientific techniques and methods. The great number of studies carried out shows that there were no certain answers formed, very often the option for a form of financing or the other is influenced only by the “level of accessibility” of the resources available on the financial market and the financing policy of many companies is guided rather by the constraints of the financial market than a coherent company strategy In order to ensure a constant economic growth it is necessary to prepare investment projects. In practice the predominant one is the investment activity based on real investments performed for the modernising of assets, in order to ensure their physical and moral wear and tear. The analysis of real estate investments can be made using a various range of indicators, from the traditional ones to those based on the updated cash flow, using traditional analysis techniques or complex techniques used by specialists with training in the analysis of real estate investment. The

  10. Sequencing Infrastructure Investments under Deep Uncertainty Using Real Options Analysis

    Directory of Open Access Journals (Sweden)

    Nishtha Manocha

    2018-02-01

    Full Text Available The adaptation tipping point and adaptation pathway approach developed to make decisions under deep uncertainty do not shed light on which among the multiple available pathways should be chosen as the preferred pathway. This creates the need to extend these approaches by means of suitable tools that can help sequence actions and subsequently enable the outlining of relevant policies. This paper presents two sequencing approaches, namely, the “Build to Target” and “Build Up” approach, to aid in sub-selecting a set of preferred pathways. Both approaches differ in the levels of flexibility they offer. They are exemplified by means of two case studies wherein the Net Present Valuation and the Real Options Analysis are employed as selection criterions. The results demonstrate the benefit of these two approaches when used in conjunction with the adaptation pathways and show how the pathways selected by means of a Build to Target approach generally have a value greater than, or at least the same as, the pathways selected by the Build Up approach. Further, this paper also demonstrates the capacity of Real Options to quantify and capture the economic value of flexibility, which cannot be done by traditional valuation approaches such as Net Present Valuation.

  11. Application of Real Options Valuation to R&D Investments in Pharmaceutical Companies

    OpenAIRE

    Zhang, Huan Ran

    2006-01-01

    This paper provides an insight into the application of real option valuation method to R&D projects in pharmaceutical companies. As one of the most important corporate finance decision-making methods, real option valuation method has been introduced in the last two decades. By applying option valuation methods, real option valuation is a useful tool to company managers. R&D investments in pharmaceutical companies are subject to considerable uncertainty, which may involve possibilities (i...

  12. Real options and asset valuation in competitive energy markets

    Science.gov (United States)

    Oduntan, Adekunle Richard

    The focus of this work is to develop a robust valuation framework for physical power assets operating in competitive markets such as peaking or mid-merit thermal power plants and baseload power plants. The goal is to develop a modeling framework that can be adapted to different energy assets with different types of operating flexibilities and technical constraints and which can be employed for various purposes such as capital budgeting, business planning, risk management and strategic bidding planning among others. The valuation framework must also be able to capture the reality of power market rules and opportunities, as well as technical constraints of different assets. The modeling framework developed conceptualizes operating flexibilities of power assets as "switching options' whereby the asset operator decides at every decision point whether to switch from one operating mode to another mutually exclusive mode, within the limits of the equipment constraints of the asset. As a current decision to switch operating modes may affect future operating flexibilities of the asset and hence cash flows, a dynamic optimization framework is employed. The developed framework accounts for the uncertain nature of key value drivers by representing them with appropriate stochastic processes. Specifically, the framework developed conceptualizes the operation of a power asset as a multi-stage decision making problem where the operator has to make a decision at every stage to alter operating mode given currently available information about key value drivers. The problem is then solved dynamically by decomposing it into a series of two-stage sub-problems according to Bellman's optimality principle. The solution algorithm employed is the Least Squares Monte Carlo (LSM) method. The developed valuation framework was adapted for a gas-fired thermal power plant, a peaking hydroelectric power plant and a baseload power plant. This work built on previously published real options valuation

  13. Real options valuation and optimization of energy assets

    Science.gov (United States)

    Thompson, Matthew

    In this thesis we present algorithms for the valuation and optimal operation of natural gas storage facilities, hydro-electric power plants and thermal power generators in competitive markets. Real options theory is used to derive nonlinear partial-integro-differential equations (PIDEs) for the valuation and optimal operating strategies of all types of facilities. The equations are designed to incorporate a wide class of spot price models that can exhibit the same time-dependent, mean-reverting dynamics and price spikes as those observed in most energy markets. Particular attention is paid to the operational characteristics of real energy assets. For natural gas storage facilities these characteristics include: working gas capacities, variable deliverability and injection rates and cycling limitations. For thermal power plants relevant operational characteristics include variable start-up times and costs, control response time lags, minimum generating levels, nonlinear output functions, structural limitations on ramp rates, and minimum up/down time restrictions. For hydro-electric units, head effects and environmental constraints are addressed. We illustrate the models with numerical examples of a gas storage facility, a hydro-electric pump storage facility and a thermal power plant. This PIDE framework is the first in the literature to achieve second order accuracy in characterizing the operating states of hydro-electric and hydro-thermal power plants. The continuous state space representation derived in this thesis can therefore achieve far greater realism in terms of operating state specification than any other method in the literature to date. This thesis is also the first and only to allow for any continuous time jump diffusion processes in order to account for price spikes.

  14. Economic Evaluation for Energy Business Using Real Options Pricing Method

    Energy Technology Data Exchange (ETDEWEB)

    Yun, W.C. [Korea Energy Economics Institute, Euiwang (Korea)

    2001-11-01

    Recently, facing the new era of restructuring, privatization, and liberalization the energy industry in the world is changing rapidly, and thus the uncertain factors tend to increase. This would imply that energy-related business is now confronted with new market risks as well as the simple price risks. The traditional investment valuation method using the concept of net present value (NPV) or internal rate of revenue (IRR) might not incorporate the managerial alternatives which enable managers to respond flexibly to the changes in business environment. This study pointed out the problems of the traditional discounted cash flow (DCF) method when evaluating a certain capital investment in energy industry. As an alternative, the real option pricing method (ROPM) was proposed, which is widely adopted in the field of profit projection for the venture business. In addition, when applying to energy sector the feasibility of ROPM was discussed, and the frameworks and major results of previous related studies were described. For those using the ROPM in real business, I explained the detailed procedures and solutions of ROPM, and introduced the log-transformed binomial model which provides a more efficient solution. In order to verify the usefulness of the ROPM, this study performed an empirical analysis for a virtual construction and operation project of power plant. And, the results from the ROPM was compared to those from the traditional DCF method. Based on the empirical results, the values of various investment opportunities were shown to be high. Therefore, the project not justified in terms of traditional DCF would turn into the project with a positive gross project value, properly reflecting managerial flexibilities inherent in the original project. (author). 58 refs., 32 figs., 33 tabs.

  15. Biomass Power Generation Investment in China: A Real Options Evaluation

    Directory of Open Access Journals (Sweden)

    Mingming Zhang

    2016-06-01

    Full Text Available This paper proposes a real options model for evaluating the biomass power generation investment in China. The uncertainties in the market price of electricity, CO2 price and straw price are considered. Meanwhile the dynamic relationship between installed capacity and fuel cost, as well as the long-term reduction of subsidy are described. Two scenarios, i.e., with the carbon emission trading scheme existent and non-existent, respectively, is built to empirically analyze the investment of a 25-MW straw-based power generation project. The results show that investors should undertake the investment in 2030 under two scenarios. Investment values are 14,869,254.8 and 37,608,727 Chinese Yuan (RMB, respectively. The implementation of the carbon emission trading scheme theoretically helps improve investment value and advance the most likely optimal investment time. However, the current CO2 price is not sufficient to advance the most likely optimal investment time. The impacts of several factors, including subsidy policy, CO2 price, straw price, installed capacity, correlation structure and the validity period of investment, on the optimal investment strategy are also examined. It is suggested that governments take some measures, including increasing subsidy, setting the growth pattern of subsidy and establishing and perfecting a nationwide carbon trading market, to improve the investment environment and attract more investments.

  16. Applications of Real Options in the Real Estate Market Focusing the City of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Priscilla Yung Medeiros

    2003-06-01

    Full Text Available An investment opportunity in the real state market can be compared with an option and, because of this analogy, we can make use of the real options theory to determinate not only the best timing to begin a new property development, but also to determine the optimal density to develop in a specific property. To investigate these two main decisions, we are going to base our research on the model developed by Williams (1991 and extend it in a way to include taxes and a discount in the net cash inflow caused by the times spent in the construction process. An empirical analysis of the of the residential real estate market in the city of Rio de Janeiro is going to be developed in a way to verify the compatibility of the theoretical model developed here according to the reality of this market. We found that the extensions proposed to the basic model of Williams (1991 had significant effects in the theoretical model. We could also confirm empirically that the theoretical results are compatible to the reality of this market.

  17. Recursive forgetting algorithms

    DEFF Research Database (Denmark)

    Parkum, Jens; Poulsen, Niels Kjølstad; Holst, Jan

    1992-01-01

    In the first part of the paper, a general forgetting algorithm is formulated and analysed. It contains most existing forgetting schemes as special cases. Conditions are given ensuring that the basic convergence properties will hold. In the second part of the paper, the results are applied...... to a specific algorithm with selective forgetting. Here, the forgetting is non-uniform in time and space. The theoretical analysis is supported by a simulation example demonstrating the practical performance of this algorithm...

  18. The research for flexible product family manufacturing based on real options

    Directory of Open Access Journals (Sweden)

    Maozhu Jin

    2015-01-01

    Full Text Available Purpose: The goal of this paper is to find the best production strategy for product mix, which means the largest value of the options. And finally, give a case and find the solution of the optimal production strategy for product mix. Design/methodology/approach: This article, based on the production with characteristics of a call option and 0-1 integer programming model, build new-products mix strategy, and through case demonstrate that traditional method underestimates the value of the products mix. Finding: According to market being volatility and uncertainty and the production can being delayed, firms can flexibly arrange the best time for products to manufacture. Use real options theory to analyze product decision and the best production timing decision. Find the total options value is higher than the traditional methods. Research limitations/implications: We are not applied to real option pricing theory in modular flexible production system. We just applied real option pricing theory to the product platform. The basic model needs to improve. While the thinking of this paper provides some research ideas for flexible production systems based on real option in further research. Practical Implications: The introduction of the real option make the company can achieve dynamic planning and flexible management for production of products mix and get the better benefit. Originality/value: The central contribution of this paper is to introduce the option mechanism in the production timing for the product mix.

  19. A Real Options Perspective on R&D Portfolio Diversification

    NARCIS (Netherlands)

    S. van Bekkum (Sjoerd); H.P.G. Pennings (Enrico); J.T.J. Smit (Han)

    2008-01-01

    textabstractThis paper shows that the presence of conditional staging in R&D (Research & Development) has a critical impact on portfolio risk, and changes diversification arguments when a portfolio is constructed. When R&D projects exhibit option-like characteristics, correlation between projects

  20. The use of fuzzy real option valuation method to rank Giga ...

    African Journals Online (AJOL)

    The use of fuzzy real option valuation method to rank Giga Investment Projects on Iran's natural gas reserves. ... Journal of Fundamental and Applied Sciences ... methodology – discounted cash flow analysis – in valuation of Giga investments.

  1. DIRECTIONS FOR FUTURE CONSTRUCTION SUPPLY CHAIN MANAGEMENT RESEARCH IN NEW ZEALAND: A REAL OPTIONS PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Tran, Van

    2012-04-01

    Full Text Available Real Options (RO has been a universally accepted concept in a number of major industries. However, its use in the construction supply chain management (CSCM sector has been limited. Some rare supply chain management RO studies have shown a number of limitations. First, there is a lack of a rigorous theoretical RO framework pertaining specifically to CSCM. All such supply chain management RO studies are based off RO theories or models developed for other sectors (engineering, infrastructure, natural resources. And second, attempts to extend real option to wider uses in CSCM seem premature at the present. This paper reviews all recent literature pertaining to real options and real options applied specifically to the construction supply chain management area. The study proposes a research programme pertaining to CSCM in New Zealand in order to enhance the current understanding of RO in this area and in the process develop a comprehensive theory for the RO application in New Zealand CSCM.

  2. REAL OPTIONS ANALYSIS – ASSESSMENT METHOD OF INVESTMENT PROJECTS IN GREEN ENERGY

    Directory of Open Access Journals (Sweden)

    MAFTEI DANIEL

    2014-10-01

    Full Text Available This article highlights the importance of real options as a evaluation method of investment in green energy. Article consider several theoretical and practical approaches, the analysis based on real options by many authors who have theorized and used this method. Each approach provides a operationalisation through a steps series of specific evaluation. This paper highlights the different views: academics, financiers, managers and facilitates the access to an accurate evaluation decisions of projects.

  3. Real Option--A New Approach in the Evaluation of Telecom Investment Projects

    Institute of Scientific and Technical Information of China (English)

    WU Hong

    2005-01-01

    This paper gives a new method into the evaluating system of telecom investment projects, I.e. Real Option. This may overcome the defects resulted from employing Net Present Value (NPV), which is now used in the evaluation of telecom projects. A theoretical analysis of Real Option is provided, followed by an example of telecom investment project to illustrate the differences between the two methods.

  4. Influence of Transaction costs and real options on firms' own-or-rent ...

    African Journals Online (AJOL)

    Based on secondary data on 79 companies in Mekelle, Ethiopia, this paper investigates the influence of transaction cost and real option factors on firms' own or rent decision for building resources. Empirical results suggest that both transaction cost and option factors have significant influence on firms' own or rent decision.

  5. Valuation of Wind Energy Projects: A Real Options Approach

    Directory of Open Access Journals (Sweden)

    Luis M. Abadie

    2014-05-01

    Full Text Available We address the valuation of an operating wind farm and the finite-lived option to invest in it under different reward/support schemes: a constant feed-in tariff, a premium on top of the electricity market price (either a fixed premium or a variable subsidy such as a renewable obligation certificate or ROC, and a transitory subsidy, among others. Futures contracts on electricity with ever longer maturities enable market-based valuations to be undertaken. The model considers up to three sources of uncertainty: the electricity price, the level of wind generation, and the certificate (ROC price where appropriate. When analytical solutions are lacking, we resort to a trinomial lattice combined with Monte Carlo simulation; we also use a two-dimensional binomial lattice when uncertainty in the ROC price is considered. Our data set refers to the UK. The numerical results show the impact of several factors involved in the decision to invest: the subsidy per MWh generated, the initial lump-sum subsidy, the maturity of the investment option, and electricity price volatility. Different combinations of variables can help bring forward investments in wind generation. One-off policies, e.g., a transitory initial subsidy, seem to have a stronger effect than a fixed premium per MWh produced.

  6. Asymmetric Exchange Rate Exposures: A Search for the Effect of Real Options

    DEFF Research Database (Denmark)

    Aabo, Tom

    2001-01-01

    Real options like the ability to reallocate production resources can lead to an asymmetric exchange rate exposure. Using a stock market approach in which the exchange rate exposure is derived from the information content in the stock prices this study examines the extra-market exchange rate...... exposures of a group of blue chip, industrial companies listed on the Copenhagen Stock Exchange. In these companies the existence of real options is an integrated part of the exchange rate exposure management process. The result of the stock market approach is mixed. Statistically significant asymmetric...... exchange rate exposures are identified successfully but the asymmetries can only to a limited extent be explained by the existence of real options. Financial options and pricing to market are competing explanations. Omitted variable bias further blurs the picture. These problems and the concept of path...

  7. STRATEGIC EXERCISE OF REAL OPTIONS:INVESTMENT DECISIONS IN TECHNOLOGICAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Kevin ZHU; John WEYANT

    2003-01-01

    Viewing investment projects in new technologies as real options, this paper studies the effects of endogenous competition and asymmetric information on the strategic exercise of real options. We first develop a multi-period, game-theoretic model and show how competition leads to early exercise and aggressive investment behaviors and how competition erodes option values. We then relax the typical full-information assumption found in the literature and allow information asymmetry to exist across firms. Our model shows, in contrast to the literature that payoff is independent of the ordering of exercise, that the sequential exercise of real options may generate both informational and payoff externalities. We also find some surprising but interesting results such as having more information is not necessarily better.

  8. Mainstreaming Disaster Risk Management for Finance: Application of Real Options Method for Disaster Risk Sensitive Project

    Directory of Open Access Journals (Sweden)

    KUSDHIANTO SETIAWAN

    Full Text Available This paper discusses the application of real options analysis for a project that is in the process of construction and was affected by a natural disaster. The use of the analytical method has become a way of thinking in making decisions that should be taught to business school students. The case in this paper is based on an MBA thesis at the University of Gadjah Mada that was intended as a showcase for application of real options to address real business problems. It shows one of the strategies in mainstreaming disaster risk management in the business school that also answers the needs of businesses in the disaster-prone country.

  9. Growing short rotation coppice on agricultural land in Germany: A Real Options Approach

    International Nuclear Information System (INIS)

    Musshoff, Oliver

    2012-01-01

    In many cases decision-makers apparently do not adapt as fast as expected to changing economic conditions. This is also the case for the conversion of farm land to short rotation coppice. From an economic point of view, short rotation coppice has become more interesting in the last few years. Nevertheless, farm land still is rarely used to grow this quite unknown crop. Several explanatory approaches (e.g., traditionalistic behavior and risk aversion) are currently discussed in order to explain this behavior. A relatively new explanatory approach is the Real Options Approach. The Real Options Approach uses a comprehensive dynamic-stochastic model that combines the uncertainty of investment returns, the sunk costs, and the temporal flexibility of the investment implementation. The quintessence of the Real Options Approach is that—compared to the Classical Investment Theory—the investment triggers will be shifted upwards if investments involve intertemporal opportunity costs. This paper develops a real options model which allows the determination of triggers on the basis of realistic assumptions. We examined when farmers, who only dispose of sandy soils with little water-storing capacity, should convert set-aside land to short rotation coppice. The results show that farmers should not convert until the present value of the investment returns exceeds the investment costs considerably. Thus, they confirm the empirically observed reluctance in conversion. Furthermore, it turned out that the magnitude of the difference between the Classical Investment Theory and the Real Options Approach depends heavily on the type of stochastic process that underlies the investment returns. -- Highlights: ► Frequently observed reluctance of farmers to convert to short rotation coppice. ► Risk neutral farmers should convert if the investment multiple exceeds 1.57. ► The Real Options Approach is an explanatory approach for this observation. ► Results depend very much on the

  10. An Economic Evaluation on Replacement Plan for Aged Thermal Power Plants through a Real Option Approach

    Science.gov (United States)

    Kato, Moritoshi; Zhou, Yicheng

    This paper presents a novel method to evaluate replacement plan for aged thermal power plants under uncertain circumstances through a real option approach. The most economical plan is selected among the three options: an option to operate an existing oil-fired thermal plant, an option to mothball it, and an option to abandon it and to construct an advanced gas combined cycle power plant (ACC) at the same time. Basic ideas of our model are: we use quadranomial approach in order to evaluate an option value consisted by two different uncertain assets; we consider cash flow with a dividend in order to reflect conditions of an aged oil-fired thermal plant and use the sequential compound option approach; we evaluate replacement time using quadranomial decision tree taking into account the options. We also analyze value and time of replacement using numerical examples. Our proposed method will be practically used for generation planning. For example it is possible to make priority quantitatively in replacements of aged thermal power plants by real option values. The target year of replacement may be set as a year when cumulative probability of replacement becomes over certain level.

  11. Identification of the real options in a program of nuclear plants

    International Nuclear Information System (INIS)

    Camacho G, D.; Diaz N, M. J.; Reinking C, A.

    2008-01-01

    The development of our societies and our economies this intimately related to electric power and this as well with the generating sources, due to the projection of world-wide growth should go associate with a strategy of growth of energy generation. Considering to the nuclear power as an option to satisfy the energy needs that a country can provide two main immediate benefits: The stabilization of prices of security of provision of electric power of the nation. The care of the environment, since the gas discharges greenhouse are almost null. At the moment nuclear energy represents economically a viable option for the capital investment, taking into account the development from technology, the policies implemented by the state and the prices of other fuels. Due to the great investment that its require for the nuclear plants are necessary to use financial tools that allow to analyze the future scenes in which ours investment can be seen affected and to value the flexibility of being able to enlarge, to postpone or to stop our project in order to have majors profits or to diminish the lost ones. This valuation of the flexibility can be obtained from the called method Real Options. By analysis of Real Options the process is understood to apply to the methodology of the Financial Options to the valuation of projects or the management of real assets. The Real Options appear in flexible plans, projects, activities or enterprise investments, like for example, to leave or to sell the investment project before concluding it, changing to their use or its technology, to prolong their life, the option to choose, one or the other capacity, among others possibilities. In this work is an example of the application of the method of Real Options in the decision to invest or to defer the investment for the construction of a nuclear plant following the behavior of the tariffs in the market or the costs of generation of other technologies with which a nuclear plant competes. (Author)

  12. Real options analysis for land use management: Methods, application, and implications for policy.

    Science.gov (United States)

    Regan, Courtney M; Bryan, Brett A; Connor, Jeffery D; Meyer, Wayne S; Ostendorf, Bertram; Zhu, Zili; Bao, Chenming

    2015-09-15

    Discounted cash flow analysis, including net present value is an established way to value land use and management investments which accounts for the time-value of money. However, it provides a static view and assumes passive commitment to an investment strategy when real world land use and management investment decisions are characterised by uncertainty, irreversibility, change, and adaptation. Real options analysis has been proposed as a better valuation method under uncertainty and where the opportunity exists to delay investment decisions, pending more information. We briefly review the use of discounted cash flow methods in land use and management and discuss their benefits and limitations. We then provide an overview of real options analysis, describe the main analytical methods, and summarize its application to land use investment decisions. Real options analysis is largely underutilized in evaluating land use decisions, despite uncertainty in policy and economic drivers, the irreversibility and sunk costs involved. New simulation methods offer the potential for overcoming current technical challenges to implementation as demonstrated with a real options simulation model used to evaluate an agricultural land use decision in South Australia. We conclude that considering option values in future policy design will provide a more realistic assessment of landholder investment decision making and provide insights for improved policy performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Optimal Investment Timing and Size of a Logistics Park: A Real Options Perspective

    Directory of Open Access Journals (Sweden)

    Dezhi Zhang

    2017-01-01

    Full Text Available This paper uses a real options approach to address optimal timing and size of a logistics park investment with logistics demand volatility. Two important problems are examined: when should an investment be introduced, and what size should it be? A real option model is proposed to explicitly incorporate the effect of government subsidies on logistics park investment. Logistic demand that triggers the threshold for investment in a logistics park project is explored analytically. Comparative static analyses of logistics park investment are also carried out. Our analytical results show that (1 investors will select smaller sized logistics parks and prepone the investment if government subsidies are considered; (2 the real option will postpone the optimal investment timing of logistics parks compared with net present value approach; and (3 logistic demands can significantly affect the optimal investment size and timing of logistics park investment.

  14. The Optimal Timing of Strategic Action – A Real Options Approach

    Directory of Open Access Journals (Sweden)

    Gordon G. Sollars

    2012-01-01

    Full Text Available he possibility of a first-mover advantage arises in a variety of strategic choices, including product introductions, business start-ups, and mergers and acquisitions. The strategic management literature reflects ambiguity regarding the likelihood that a first mover can or will capture additional value. This paper uses a real options approach to address the optimal timing of strategic moves. Previous studies have modeled real options using either a perpetual or a European financial option. With these models, a strategic choice could only be made either without respect to a time frame (perpetual or at a fixed point in time (European option. Neither case is realistic. Companies typically have strategic options with only a limited time frame due to market factors, but companies may choose to act at any time within that constraint. To reflect this reality, we adapt a method for valuing an American financial option on a dividend paying stock to the real options context. The method presented in this paper proposes a solution for the optimum value for a project that should trigger a strategic choice, and highlights the value lost by not acting optimally. We use simulation results to show that the time frame available to make a strategic choice has an important effect on both the project value for when action should be taken, as well as on the value of waiting to invest at the optimal time. The results presented in this paper help to clarify the ambiguity that is found in the strategic management literature regarding the possibility of obtaining a first-mover advantage. Indeed, a first mover that acts sub-optimally could incur losses or at least not gain any advantage. A first mover that waits to invest at the right time based on the superior information supplied by models based on real options could be better positioned to obtain the benefits that might come from the first move.

  15. Valuation of exploration and production assets. An overview of real options models

    International Nuclear Information System (INIS)

    Dias, Marco Antonio Guimaraes

    2004-01-01

    This paper presents a set of selected real options models to evaluate investments in petroleum exploration and production (E and P) under market and technical uncertainties. First are presented some simple examples to develop the intuition about concepts like option value and optimal option exercise, comparing them with the concepts from the traditional net present value (NPV) criteria. Next, the classical model of Paddock, Siegel and Smith is presented, including a discussion on the practical values for the input parameters. The modeling of oil price uncertainty is presented by comparing some alternative stochastic processes. Other E and P applications discussed here are the selection of mutually exclusive alternatives under uncertainty, the wildcat drilling decision, the appraisal investment decisions, and the analysis of option to expand the production through optional wells

  16. Real options approach to inter-sectoral migration of U.S.farm labor

    Science.gov (United States)

    Gulcan Onel; Barry K. Goodwin

    2014-01-01

    The core of the literature on inter-sectoral labor migration is based on net present value models of investment in which individuals are assumed to migrate to take advantage of positive wage differentials. In this article, we argue that a real options approach, taken together with the adjustment costs associated with sectoral relocation, may provide a basis for...

  17. The Application of the Real Options Method for the Evaluation of High-Rise Construction Projects

    Science.gov (United States)

    Izotov, Aleksandr; Rostova, Olga; Dubgorn, Alissa

    2018-03-01

    The paper is devoted to the problem of evaluation of high-rise construction projects in a rapidly changing environment. The authors proposed an algorithm for constructing and embedding real options in high-rise construction projects, which makes it possible to increase the flexibility of managing multi-stage projects that have the ability to adapt to changing conditions of implementation.

  18. When Do Firms Invest in Corporate Social Responsibility? : A Real Option Framework

    NARCIS (Netherlands)

    Cassimon, D.; Engelen, P.J.; Liedekerke, L.

    2014-01-01

    In this paper, the process for firms to decide whether or not to invest in corporate social responsibility is treated from a real option perspective. We extend the Husted (2005) framework with an important extra parameter that allows us to understand the timing of CSR investment and explain why some

  19. Understanding the advantages of open innovation practices in corporate venturing in terms of real options

    NARCIS (Netherlands)

    Vanhaverbeke, W.P.M.; Vrande, van de V.J.A.; Chesbrough, H.

    2008-01-01

    Part of the advantages of using open innovation (compared to closed innovation) in corporate venturing can be explained by applying the real options approach. Open innovation in risk-laden activities such as corporate venturing has the following advantages: (i) benefits from early involvement in new

  20. Real Options in an Aymmetric Duopoly : Who Benefits from your Competitive Disadvantage

    NARCIS (Netherlands)

    Pawlina, G.; Kort, P.M.

    2001-01-01

    This paper considers the impact of investment cost asymmetry on the value and optimal real option exercise strategies of firms under imperfect competition.Both firms have an opportunity to invest in a project enhancing (ceteris paribus) the profit now.We show that three types of equilibria exist and

  1. The impact of delaying an investment decision on R&D projects in real option game

    International Nuclear Information System (INIS)

    Chang, Shuhua; Li, Yue; Gao, Fanglu

    2016-01-01

    In a research and development (R&D) investment, the cost and the project value of such an investment are usually uncertain, which thus increases its complexity. Correspondingly, the NPV (Net Present Value) rule fails to evaluate the value of this project exactly, because this method does not take into account the market uncertainty, irreversibility of investment and ability of delay entry. In this paper, we employ the real option theory to evaluate the project value of a R&D investment. Since the cost of a R&D investment is very high and the flow of the information is crowded, an investor cannot make an immediate decision every time. So, the proposed real option model is an exchange option. At the same time, combining the real option and the game theory, we can find the Nash equilibrium which is the optimal strategy. Moreover, we also study how the delayed time influences the price of the project investment and how the different delayed times effect the choice of the optimal strategies.

  2. Valuation: From The Discounted Cash Flows (DCF Approach To The Real Options Approach (ROA Valuation: From The Discounted Cash Flows (DCF Approach To The Real Options Approach (ROA

    Directory of Open Access Journals (Sweden)

    Cecilia Maya Ochoa

    2004-12-01

    Full Text Available There exists an abysm between market prices and traditional valuation approaches such as Discounted Cash Flows (DCF, a fact that neither academics nor practitioners could continue ignoring. Recently, a complementary approach has taken a foothold into the valuation world. Building on the DCF approach yet going further in the sense of incorporating flexibility in management investment decisions, and taking advantage of the advances in option pricing theory, the real options approach (ROA has become the alternative to capital budgeting and, lately, to corporate valuation. Empirical evidence shows that ROA explains actual prices better than DCF approaches and nowadays there is no question that from a theoretical point of view, ROA is a much more appealing concept than passive NPV. However, its acceptance by practitioners has been very slow due to the complexity of real options pricing.Existe un abismo entre precios de Mercado y la valoración estimada por métodos tradicionales tales como Flujos de Caja Descontados, un hecho que ni académicos ni practicantes pueden continuar ignorando. Recientemente, una metodología complementaria ha tomado gran fuerza. Partiendo de los Flujos de Caja Descontados, pero incorporando flexibilidad en las decisiones de inversión y aprovechando los avances en la teoría de valoración de opciones, el enfoque de opciones reales (ROA se ha convertido en la alternativa para presupuestación de capital y valoración de empresas. La evidencia empírica muestra que ROA explica los precios de mercado mejor que los enfoques basados en flujos de caja descontados y, hoy en día, no hay discusión de que es más atractivo desde un punto de vista teórico; sin embargo, su utilización en la práctica ha sido muy limitada debido a las dificultades que presenta la valoración de las opciones reales.

  3. A real options approach to biotechnology Investment policy - the case of developing a Campylobacter vaccine to poultry

    DEFF Research Database (Denmark)

    Lund, Mogens; Jensen, Jørgen Dejgård

    2016-01-01

    The aim of the article is to identify and analyse public-private incentives for the development and marketing of new animal vaccines within a real options methodological framework, and to investigate how real options methodology can be utilized to support economic incentives for vaccine developme...

  4. In or Out: The Effect of Euro Membership on the Exercise of Real Business Options

    DEFF Research Database (Denmark)

    Aabo, Tom; Pantzalis, Christos

    2011-01-01

    This empirical study of manufacturing firms (NAICS 33) in the EU15 countries goes beyond the trade statistics that have indicated only a small to negligible effect from the introduction of the Euro and shows that the introduction of the Euro has made Euro firms (firms based in one of the twelve...... Euro countries) more inclined than non-Euro firms (firms based in one of the three non-Euro countries: UK, Sweden and Denmark) to undertake various forms of real actions (exercise real business options) such as to establish alliances / partnerships, to enter new markets / market segments, to switch...

  5. A real option analysis of investments in hydropower-The case of Norway

    International Nuclear Information System (INIS)

    Kjaerland, Frode

    2007-01-01

    This paper presents a valuation study of hydropower investment opportunities in the Norwegian context. According to NVE (Norwegian Water Resources and Energy Directorate, the regulator), there is a potential of 39 TWh not yet developed (generation in a normal year is approximately 120 TWh). By using the conceptual real option framework of Dixit and Pindyck [1994. Investment Under Uncertainty. Princeton University Press, Princeton, NJ] one can estimate the value of investment opportunities to NOK 11 million/GWh (EUR 1.4 million/GWh). Furthermore, the optimal trigger price for initiating an investment based on electricity forward prices is calculated to NOK 0.32/kWh (EUR 0.04/kWh). The analysis shows consistency between real option theory and aggregate investment behaviour in Norwegian hydropower

  6. A real option-based simulation model to evaluate investments in pump storage plants

    International Nuclear Information System (INIS)

    Muche, Thomas

    2009-01-01

    Investments in pump storage plants are expected to grow especially due to their ability to store an excess of supply from wind power plants. In order to evaluate these investments correctly the peculiarities of pump storage plants and the characteristics of liberalized power markets have to be considered. The main characteristics of power markets are the strong power price volatility and the occurrence of prices spikes. In this article a valuation model is developed capturing these aspects using power price simulation, optimization of unit commitment and capital market theory. This valuation model is able to value a future price-based unit commitment planning that corresponds to future scope of actions also called real options. The resulting real option value for the pump storage plant is compared with the traditional net present value approach. Because this approach is not able to evaluate scope of actions correctly it results in strongly smaller investment values and forces wrong investment decisions.

  7. Evaluation of Cloud Computing Hidden Benefits by Using Real Options Analysis

    Directory of Open Access Journals (Sweden)

    Pavel Náplava

    2016-12-01

    Full Text Available Cloud computing technologies have brought new attributes to the IT world. One of them is a flexibility of IT resources. It enables effectively both to downsize and upsize the capacity of IT resources in real time. Requirements for IT size change defines business strategy and actual market state. IT costs are not stable but dynamic in this case. Standard investment valuation methods (both static and dynamic are not able to include the flexibility attribute to the evaluation of IT projects. This article describes the application of the Real Options Analysis method for the valuation of the cloud computing flexibility. The method compares costs of the on-premise and cloud computing solutions by combining put and call option valuation. Cloud computing providers can use the method as an advanced tool that explains hidden benefits of cloud computing. Unexperienced cloud computing customers can simulate the market behavior and better plan necessary IT investments.

  8. Frontal transcranial direct current stimulation (tDCS) abolishes list-method directed forgetting.

    Science.gov (United States)

    Silas, Jonathan; Brandt, Karen R

    2016-03-11

    It is a point of controversy as to whether directed forgetting effects are a result of active inhibition or a change of context initiated by the instruction to forget. In this study we test the causal role of active inhibition in directed forgetting. By applying cathodal transcranial direct current stimulation (tDCS) over the right prefrontal cortex we suppressed cortical activity commonly associated with inhibitory control. Participants who underwent real brain stimulation before completing the directed forgetting paradigm showed no directed forgetting effects. Conversely, those who underwent sham brain stimulation demonstrated classical directed forgetting effects. We argue that these findings suggest that inhibition is the primary mechanism that results in directed forgetting costs and benefits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. When to Wait for More Evidence? Real Options Analysis in Proton Therapy

    Science.gov (United States)

    Abrams, Keith R.; de Ruysscher, Dirk; Pijls-Johannesma, Madelon; Peters, Hans J.M.; Beutner, Eric; Lambin, Philippe; Joore, Manuela A.

    2011-01-01

    Purpose. Trends suggest that cancer spending growth will accelerate. One method for controlling costs is to examine whether the benefits of new technologies are worth the extra costs. However, especially new and emerging technologies are often more costly, while limited clinical evidence of superiority is available. In that situation it is often unclear whether to adopt the new technology now, with the risk of investing in a suboptimal therapy, or to wait for more evidence, with the risk of withholding patients their optimal treatment. This trade-off is especially difficult when it is costly to reverse the decision to adopt a technology, as is the case for proton therapy. Real options analysis, a technique originating from financial economics, assists in making this trade-off. Methods. We examined whether to adopt proton therapy, as compared to stereotactic body radiotherapy, in the treatment of inoperable stage I non-small cell lung cancer. Three options are available: adopt without further research; adopt and undertake a trial; or delay adoption and undertake a trial. The decision depends on the expected net gain of each option, calculated by subtracting its total costs from its expected benefits. Results. In The Netherlands, adopt and trial was found to be the preferred option, with an optimal sample size of 200 patients. Increase of treatment costs abroad and costs of reversal altered the preferred option. Conclusion. We have shown that real options analysis provides a transparent method of weighing the costs and benefits of adopting and/or further researching new and expensive technologies. PMID:22147003

  10. A real-options analysis of wine grape farming in north west Victoria

    OpenAIRE

    Seyoum, Emayenesh; Chan, Chris

    2012-01-01

    This paper reports a use of a real-options valuation methodology to analyse wine grape farm investment under price and yield uncertainty. Revenue levels to incentivise entry and exit were calculated for three different sizes of wine grape farms in North West Victoria. The modelling identified lower exit and higher entry triggers than indicated by conventional net present value calculation. The wide gap of estimated indeterminacy in farm investment highlights the intertwined influence of numer...

  11. Construction strategies and lifetime uncertainties for nuclear projects: A real option analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Shashi, E-mail: s.jain@cwi.nl [TU Delft, Delft Institute of Applied Mathematics, Delft (Netherlands); Nuclear Research Group, Petten (Netherlands); Roelofs, Ferry, E-mail: roelofs@nrg.eu [Nuclear Research Group, Petten (Netherlands); Oosterlee, Cornelis W., E-mail: c.w.oosterlee@cwi.nl [CWI – Centrum Wiskunde and Informatica, Amsterdam (Netherlands); TU Delft, Delft Institute of Applied Mathematics, Delft (Netherlands)

    2013-12-15

    Highlights: • Real options can be used to value flexibility of modular reactors. • Value of NPPs increases with implementation of long term cost reductions. • Levels of uncertainties affect the choice between projects. -- Abstract: Small and medium sized reactors, SMRs (according to IAEA, ‘small’ are reactors with power less than 300 MWe, and ‘medium’ with power less than 700 MWe) are considered as an attractive option for investment in nuclear power plants. SMRs may benefit from flexibility of investment, reduced upfront expenditure, and easy integration with small sized grids. Large reactors on the other hand have been an attractive option due to economy of scale. In this paper we focus on the advantages of flexibility due to modular construction of SMRs. Using real option analysis (ROA) we help a utility determine the value of sequential modular SMRs. Numerical results under different considerations, like possibility of rare events, learning, uncertain lifetimes are reported for a single large unit and modular SMRs.

  12. Construction strategies and lifetime uncertainties for nuclear projects: A real option analysis

    International Nuclear Information System (INIS)

    Jain, Shashi; Roelofs, Ferry; Oosterlee, Cornelis W.

    2013-01-01

    Highlights: • Real options can be used to value flexibility of modular reactors. • Value of NPPs increases with implementation of long term cost reductions. • Levels of uncertainties affect the choice between projects. -- Abstract: Small and medium sized reactors, SMRs (according to IAEA, ‘small’ are reactors with power less than 300 MWe, and ‘medium’ with power less than 700 MWe) are considered as an attractive option for investment in nuclear power plants. SMRs may benefit from flexibility of investment, reduced upfront expenditure, and easy integration with small sized grids. Large reactors on the other hand have been an attractive option due to economy of scale. In this paper we focus on the advantages of flexibility due to modular construction of SMRs. Using real option analysis (ROA) we help a utility determine the value of sequential modular SMRs. Numerical results under different considerations, like possibility of rare events, learning, uncertain lifetimes are reported for a single large unit and modular SMRs

  13. THE THEORY OF REAL OPTIONS in investment ANALYSIS of agroforestry systems

    Directory of Open Access Journals (Sweden)

    Maísa Santos Joaquim

    2015-09-01

    Full Text Available In this study we compared the values generated by traditional economic analysis (Net Present Value - NPV with Real Options Method. The objective was to apply the method proposed by Copeland & Antikarov for rainbow options, due to three stochastic variables selected with decision of abandonment if the project value with flexibility was less than the value of the underlying stock. It enabled the flexibility value generation in order to entrepreneurs to have more confidence in their decision when they are investing in a project with Agroforestry System, with different scenarios visualization in a single analysis. The results evidenced that the economic viability analysis, using Real Options, provided the best view of the possible scenarios, within a range generated by the prices volatility. The Net Present Value adopted as the underlying stock value was R$ 5,684.32, using the discount rate (WACC of 9.95% and risk-free interest rate of 7.5%. To determine the volatility were calculated: the logarithmic return standard deviation (27.06, the average (0.0883, upward movements values (u (1.3107 with 61.34% of probability and downward movements values (d(0.7628 with 38.66%  of probability. The option value in case of abandonment was R$ 2,059.01/ha positive. The results showed that the NPV overestimated the project return and that it would be viable to abandon it.

  14. Combination of real options and game-theoretic approach in investment analysis

    Science.gov (United States)

    Arasteh, Abdollah

    2016-09-01

    Investments in technology create a large amount of capital investments by major companies. Assessing such investment projects is identified as critical to the efficient assignment of resources. Viewing investment projects as real options, this paper expands a method for assessing technology investment decisions in the linkage existence of uncertainty and competition. It combines the game-theoretic models of strategic market interactions with a real options approach. Several key characteristics underlie the model. First, our study shows how investment strategies rely on competitive interactions. Under the force of competition, firms hurry to exercise their options early. The resulting "hurry equilibrium" destroys the option value of waiting and involves violent investment behavior. Second, we get best investment policies and critical investment entrances. This suggests that integrating will be unavoidable in some information product markets. The model creates some new intuitions into the forces that shape market behavior as noticed in the information technology industry. It can be used to specify best investment policies for technology innovations and adoptions, multistage R&D, and investment projects in information technology.

  15. Cost-effective design of ringwall storage hybrid power plants: A real options analysis

    International Nuclear Information System (INIS)

    Weibel, Sebastian; Madlener, Reinhard

    2015-01-01

    Highlights: • Economic viability, optimal size, and siting of a hybrid ringwall hydro power plant. • Real options analysis for optimal investment timing and stochastic storage volumes. • Stochastic PV and solar power production affects optimal size of the storage device. • Monte Carlo simulation is used for wind/solar power, el. price, and investment cost. • Numerical computations for two different hybrid ringwall storage plant scenarios. - Abstract: We study the economic viability and optimal sizing and siting of a hybrid plant that combines a ringwall hydro storage system with wind and solar power plants (ringwall storage hybrid power plant, RSHPP). A real options model is introduced to analyze the economics of an onshore RSHPP, and in particular of the varying storage volume in light of the stochastic character of wind and solar power, as well as the optimal investment timing under uncertainty. In fact, many uncertainties arise in such a project. Energy production is determined by the stochastic character of wind and solar power, and affects the optimal size of the storage device. Monte Carlo simulation is performed to analyze the following sources of uncertainty: (i) wind intensity and solar irradiation; (ii) future electricity price; and (iii) investment costs. The results yield the optimal size of the storage device; the energy market on which the operator should sell the electricity generated; numerical examples for two different RSHPP scenarios; and a real options model for analyzing the opportunity to defer the project investment and thus to exploit the value of waiting

  16. Optimizing the Level of Renewable Electric R&D Expenditures Using Real Options Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Davis, G.; Owens, B.

    2003-02-01

    One of the primary objectives of the United States' federal non-hydro renewable electric R&D program is to promote the development of technologies that have the potential to provide consumers with stable and secure energy supplies. In order to quantify the benefits provided by continued federal renewable electric R&D, this paper uses ''real option'' pricing techniques to estimate the value of renewable electric technologies in the face of uncertain fossil fuel prices. Within the real options analysis framework, the current value of expected future supply from renewable electric technologies, net of federal R&D expenditures, is estimated to be $30.6 billion. Of this value, 86% can be attributed to past federal R&D efforts, and 14% can be attributed to future federal R&D efforts, assuming continued federal R&D funding at $300 million/year. In addition, real options analysis shows that the value of renewable electric technologies increases as current and future R&D funding levels increase. This indicates that the current level of federal renewable electric R&D funding is sub-optimal low.

  17. A real option-based model for promoting sustainable energy projects under the clean development mechanism

    International Nuclear Information System (INIS)

    Lee, Hyounkyu; Park, Taeil; Kim, Byungil; Kim, Kyeongseok; Kim, Hyoungkwan

    2013-01-01

    The clean development mechanism (CDM) provides a way of assisting sustainable development in developing countries for developed countries to reduce greenhouse gas (GHG) emissions. Despite its intended benefits, the primary CDM market decreased from US$5.8 billion in 2006 to US$1.5 billion in 2010. One of the primary reasons for the reduction of market size is that developed countries as investors have a high level of risks caused by the volatility of the market price for certified emission reductions (CERs). Another issue to be resolved is that developing countries as host countries cannot claim any right to the CERs produced on their own land. This paper presents a real option-based model for both parties (developed and developing countries) to have their fair share of profits and risks by controlling the uncertainty associated with the future value of CERs. A case study illustrated that the proposed model can effectively attract investors to CDM projects leading to mitigation of climate change. - Highlights: ► This study focused on the risks associated with the uncertainty of future CER value in CDM projects. ► A real option-based model was developed for both parties in CDM to have fair share of profit and risk. ► Key variables and boundary conditions were identified for application of real option to CDM. ► The model allowed both parties to own options, which have an identical value. ► Hydropower plant projects in Indonesia were used to illustrate the implementation of the model

  18. When Forgetting Becomes Digital

    DEFF Research Database (Denmark)

    Marton, Attila; Kallinikos, Jannis

    The structure of social memory is in a process of significant change as social operations of forgetting and remembering are increasingly written in IT and mediated in digital media. Based on an in-depth case study about the digitalization of memory institutions (libraries, archives, museums......), the paper demonstrates the emergence of a digital social memory structure that stores data as a means of forgetting. Building on such a concept, we explain the shifting structure of social memory from pre-defined, taxonomic order to algorithmic computation of artefacts and ordering. Finally, we draw...... implications from our study with regards to core organizational concepts of institutions and platforms as well as broader categories of information infrastructures and a sociology of digital knowledge....

  19. Designing regulatory frameworks for merchant transmission investments by real options analysis

    International Nuclear Information System (INIS)

    Pringles, Rolando; Olsina, Fernando; Garcés, Francisco

    2014-01-01

    In deregulated electricity markets, the transmission network is a key infrastructure for enabling competition in the generation sector. A deficient expansion of the transmission grid prevents the realization of the benefits in terms of efficiency associated with market mechanisms. Consequently, it is essential to provide clear investment policies and economic signals to attract timely and efficient transmission investments in order to develop the system at minimum cost meeting the requirements of generators and consumers, while keeping adequate levels of service quality and reliability. This paper proposes a modern tool of economic evaluation based on real options analysis that provides the regulator the ability to assess various incentives that would lead transmission investors to make efficient decisions in highly uncertain environments. Real options properly values partially irreversible investment decisions, such as to defer, modify or abandon an investment project in response to the arrival of new information or as uncertainties are resolved. Decisions are evaluated from the point of view of a transmission investor trying to maximize its own profits in the time period set to recover the capital invested. The results allow the study of the behavior of transmission investors regarding their decision making when they have the possibility to manage the option to defer, under different regulatory schemes that encourage the expansion of the transmission system. - Highlights: • Regulatory frameworks for efficient and timely transmission expansions are designed. • Irreversibility and uncertainty of transmission investment is properly accounted for. • Response of network investors to regulatory incentives is quantitatively established

  20. Real Option in Capital Budgeting for SMEs: Insight from Steel Company

    Science.gov (United States)

    Muharam, F. M.; Tarrazon, M. A.

    2017-06-01

    Complex components of investment projects can only be analysed accurately if flexibility and comprehensive consideration of uncertainty are incorporated into valuation. Discounted cash flow (DCF) analysis has failed to cope with strategic future alternatives that affect the right value of investment projects. Real option valuation (ROV) proves to be the right tool for this purpose since it enables to calculate the enlarged or strategic Net Present Value (ENPV). This study attempts to provide an insight of the usage of ROV in capital budgeting and investment decision-making processes of SMEs. Exploring into the first stage processing of steel industry, analysis of alternatives to cancel, to expand, to defer or to abandon is performed. Completed with multiple options interaction and a sensitivity analysis, our findings prove that the application of ROV is beneficial for complex investment projects independently from the size of the company and particularly suitable in scenarios with scarce resources. The application of Real Option Valuation (ROV) is plausible and beneficial for SMEs to be incorporated in the strategic decision making process.

  1. Renewable energy policy evaluation using real option model. The case of Taiwan

    International Nuclear Information System (INIS)

    Lee, Shun-Chung; Shih, Li-Hsing

    2010-01-01

    This study presents a policy benefit evaluation model that integrates cost efficiency curve information on renewable power generation technologies into real options analysis (ROA) methods. The proposed model evaluates quantitatively the policy value provided by developing renewable energy (RE) in the face of uncertain fossil fuel prices and RE policy-related factors. The economic intuition underlying the policy-making process is elucidated, while empirical analysis illustrates the option value embedded in the current development policy in Taiwan for wind power. In addition to revealing the benefits that RE development provides when considering real options, analytical results indicate that ROA is a highly effective means of quantifying how policy planning uncertainty including managerial flexibility influences RE development. In addition to assessing the policy value of current RE development policy, this study also compares policy values in terms of internalized external costs and varying feed-in tariff (FIT). Simulation results demonstrate that the RE development policy with internalized CO 2 emission costs is appropriate policy planning from sustainability point of view. Furthermore, relationship between varying FIT and policy values can be shown quantitatively and appropriate FIT level could be determined accordingly. (author)

  2. The Value of a Biotechnology Start-up: Creative Destruction and Real Options Approach The Value of a Biotechnology Start-up: Creative Destruction and Real Options Approach

    Directory of Open Access Journals (Sweden)

    Cecilia Maya Ochoa

    2006-12-01

    Full Text Available The value of investments in high growth start-up firms is difficult to assess because payments are far in the future and their arrival is uncertain. Some of these firms may seem overvalued according to traditional methods, such as the Net Present Value, which fails to account for three drivers of value for highly innovative industries: intellectual capital as the engine of innovation, market power as the expectation of monopolistic power when innovating, and a growth option which may be exercised in the case of success.This paper presents a case study on a biotechnology start-up and applies the Creative Destruction – Real Options approach (CD-ROA (Maya, 2004 which takes into account all three drivers of value and is able to explain the high prices investors pay for shares of a company in this industry. It proves that such prices are not cases of overpricing but of recognition of the large growth potential of firms which are part of highly innovative industries.La valoración de la inversión en compañías nacientes de alto crecimiento no estarea fácil, pues los ingresos esperados se generan en un futuro lejano y bajo granincertidumbre. De acuerdo con métodos tradicionales de valoración como el ValorPresente Neto, el mercado parece sobrevalorar algunas de estas compañías. Ello sedebe a que estos métodos tradicionales no tienen en cuenta tres elementos esencialesque determinan el valor en estos casos: el capital intelectual como el motor de lainnovación, el poder de mercado por la expectativa de ingresos monopolísticos sise da la innovación y una opción real de crecimiento que puede ser ejercida en casode éxito.Este artículo aplica a una empresa de biotecnología el enfoque de opciones realesy destrucción creativa (Maya, 2004, el cual incluye estos tres determinantes delvalor y logra explicar el alto precio que los inversionistas pagan por una acción deeste tipo de empresas. Se demuestra que éste no es un caso de

  3. A real options approach to biotechnology investment policy-the case of developing a Campylobacter vaccine to poultry.

    Science.gov (United States)

    Lund, Mogens; Jensen, Jørgen Dejgård

    2016-06-01

    The aim of the article is to identify and analyse public-private incentives for the development and marketing of new animal vaccines within a real options methodological framework, and to investigate how real options methodology can be utilized to support economic incentives for vaccine development in a cost-effective way. The development of a vaccine against Campylobacter jejuni in poultry is applied as a case study. Employing the real options methodology, the net present value of the vaccine R&D project becomes larger than a purely probabilistic expected present value throughout the different stages of the project - and the net present value becomes larger, when more types of real options are taken into consideration. The insight from the real options analysis reveals opportunities for new policies to promote the development of animal vaccines. One such approach might be to develop schemes combining stage-by-stage optimized subsidies in the individual development stages, with proper account taken of investors'/developers' economic incentives to proceed, sell or cancel the project in the respective stages. Another way of using the real options approach to support the development of desirable animal vaccines could be to issue put options for the vaccine candidate, enabling vaccine developers to hedge against the economic risk from market volatility. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. What do you do when the binomial cannot value real options? The LSM model

    Directory of Open Access Journals (Sweden)

    S. Alonso

    2014-12-01

    Full Text Available The Least-Squares Monte Carlo model (LSM model has emerged as the derivative valuation technique with the greatest impact in current practice. As with other options valuation models, the LSM algorithm was initially posited in the field of financial derivatives and its extension to the realm of real options requires considering certain questions which might hinder understanding of the algorithm and which the present paper seeks to address. The implementation of the LSM model combines Monte Carlo simulation, dynamic programming and statistical regression in a flexible procedure suitable for application to valuing nearly all types of corporate investments. The goal of this paper is to show how the LSM algorithm is applied in the context of a corporate investment, thus contributing to the understanding of the principles of its operation.

  5. The value of product flexibility in nuclear hydrogen technologies: A real options analysis

    International Nuclear Information System (INIS)

    Botterud, Audun; Yildiz, Bilge; Conzelmann, Guenter; Petri, Mark C.

    2009-01-01

    Previous economic studies of nuclear hydrogen technologies focused on levelized costs without accounting for risks and uncertainties faced by potential investors. To address some of these risks and uncertainties, we used real options theory to assess the profitability of three nuclear hydrogen production technologies in evolving electricity and hydrogen markets. Monte-Carlo simulations are used to represent the uncertainty in hydrogen and electricity prices. The model computes both the expected value and the distribution of discounted profits from the production plant. It also quantifies the value of the option to switch between hydrogen and electricity production. Under these assumptions, we conclude that investors will find significant value in the capability to switch plant output between electricity and hydrogen. (author)

  6. A real options approach to analyse wind energy investments under different support schemes

    International Nuclear Information System (INIS)

    Kitzing, Lena; Juul, Nina; Drud, Michael; Boomsma, Trine Krogh

    2017-01-01

    Highlights: • Real options model for wind projects considering investment timing and sizing. • Introducing a capacity constraint in the optimisation. • Addressing several uncertainty factors while still providing analytical solution. • Comparative policy analysis of investment incentives from different support schemes. • Improved quantification of trade-off between fast deployment and large projects. - Abstract: A real options model is developed to evaluate wind energy investments in a realistic and easily applicable way. Considering optimal investment timing and sizing (capacity choice), the model introduces a capacity constraint as part of the optimisation. Several correlated uncertainty factors are combined into a single stochastic process, which allows for analytical (closed-form) solutions. The approach is well suited for quantitative policy analysis, such as the comparison of different support schemes. A case study for offshore wind in the Baltic Sea quantifies differences in investment incentives under feed-in tariffs, feed-in premiums and tradable green certificates. Investors can under certificate schemes require up to 3% higher profit margins than under tariffs due to higher variance in profits. Feed-in tariffs may lead to 15% smaller project sizes. This trade-off between faster deployment of smaller projects and slower deployment of larger projects is neglected using traditional net present value approaches. In the analysis of such trade-off, previous real options studies did not consider a capacity constraint, which is here shown to decrease the significance of the effect. The impact on investment incentives also depends on correlations between the underlying stochastic factors. The results may help investors to make informed investment decisions and policy makers to strategically design renewable support and develop tailor-made incentive schemes.

  7. Real options and a large producer: the case of electricity markets

    International Nuclear Information System (INIS)

    Keppo, J.

    2003-01-01

    In this paper we extend the real option theory to consider the situation of a large producer and we employ the model to electricity markets. This is important because many producers in these markets affect the market supply and, therefore, also the electricity price. This production price effect influences not only on the assets that the energy company owns but also on its investment opportunities. We show that this production's price effect has to be considered in the investment analysis if the company is not able to hedge the price effect in the financial markets and if there is no competition on the investment opportunity. (author)

  8. Integrated Portfolio Analysis: Return on Investment and Real Options Analysis of Intelligence Information Systems (Cryptologic Carry On Program)

    National Research Council Canada - National Science Library

    Rios, Jr., Cesar G; Housel, Thomas; Mun, Johnathan

    2006-01-01

    ...) on individual projects, programs, and processes within a portfolio of IT investments. Using KVA historical data as a platform, the authors evaluate potential strategic investments with real options analysis...

  9. Real options valuation of US federal renewable energy research, development, demonstration, and deployment

    International Nuclear Information System (INIS)

    Siddiqui, Afzal S.; Marnay, Chris; Wiser, Ryan H.

    2007-01-01

    Benefits analysis of US Federal government research, development, demonstration, and deployment (RD 3 ) programmes for renewable energy (RE) technology improvement typically employs a deterministic forecast of the cost and performance of renewable and non-renewable fuels. The benefits estimate for the programme derives from the difference between two forecasts, with and without the RD 3 programme in place. Three deficiencies of this approach are that it ignores: (1) uncertainty in the cost of non-renewable energy (NRE); (2) the possibility of adjustment to the RD 3 effort commensurate with the evolving state of the world; and (3) the underlying technical risk associated with RD 3 . In this paper, an intuitive approach to determining the option value of RE RD 3 is developed. This approach seeks to tackle the first two deficiencies noted above by providing an estimate via a compound real option of an RE RD 3 programme in a future with uncertain NRE costs. A binomial lattice reveals the economic intuition underlying the decision-making process, while a numerical example illustrates the option components embedded in a simplified representation of current US Federal RE RD 3

  10. Decision-making model of generation technology under uncertainty based on real option theory

    International Nuclear Information System (INIS)

    Ming, Zeng; Ping, Zhang; Shunkun, Yu; Ge, Zhang

    2016-01-01

    Highlights: • A decision-making model of generation technology investment is proposed. • The irreversible investment concept and real option theory is introduced. • Practical data was used to prove the validity of the model. • Impact of electricity and fuel price fluctuation on investment was analyzed. - Abstract: The introduction of market competition and the increased uncertainty factors makes the generators have to decide not only on whether to invest generation capacity or not but also on what kind of generation technology to choose. In this paper, a decision-making model of generation technology investment is proposed. The irreversible investment concept and real option theory is introduced as the fundamental of the model. In order to explain the decision-making process of generator’s investment, the decision-making optimization model was built considering two generation technologies, i.e., the heat-only system and the combined heat and power generation. Also, we discussed the theory deducing process, which explained how to eliminate the overrated economic potential caused by risk hazard, based on economic evaluation of both generation technologies. Finally, practical data from electricity market of Inner Mongolia was used to prove the validity of the model and the impact of uncertainties of electricity and fuel price fluctuation on investment was analyzed according to the simulated results.

  11. Is forgetting caused by inhibition?

    NARCIS (Netherlands)

    Raaijmakers, J.G.W.; Jakab, E.

    2013-01-01

    A well-known finding in memory research is the forgetting effect that occurs because of practicing some Item A on the recall of a related Item B. The traditional explanation for such interference effects is based on the notion of competition. According to the inhibition theory of forgetting,

  12. Corporate social responsibility: a real options approach to the challenge of financial sustainability.

    Science.gov (United States)

    Bosch-Badia, Maria-Teresa; Montllor-Serrats, Joan; Tarrazon-Rodon, Maria-Antonia

    2015-01-01

    In contemporary complex societies, social values like ethics, corporate social responsibility, and being respectful with the environment, among others, are becoming social requirements. Corporations are expected to fulfill them and, according to empirical evidence, an overwhelming majority aspires to good social valuation. At the same time, the maximization of market share value in the long run continues to be the central corporate goal. Making environmental and social expenses compatible with value creation is a central challenge for corporations since it implies the financial sustainability of Corporate Social Responsibility (CSR). The value creation capacity of CSR projects, mainly through innovation, is widely acknowledged in economic literature and corporate practice. This fact arouses the need of having a quantitative framework capable of summarizing the value creation capacity of the variables involved in CSR projects. With this aim we build up a sensitivity analysis of real option ratios that studies and quantifies the value creation capacity of CSR projects connected with innovation. Ratio analysis has the advantage of being scale independent. Hence, it furnishes a homogeneous framework to express the interaction of value creation variables and, thus, supports strategic thinking quantitatively. Often, CSR expenses can be regarded as preliminary projects that create the opportunity to undertake a full future project. For them, we obtain the minimum expectations scenario that makes financially sustainable a preliminary project that can be interpreted as a call option. We propose a classification of CSR projects from the decision analysis perspective following a two-fold approach: Their relationship with value creation and their links with existing corporate activities. This classification of CSR projects aims at contributing to choose the best capital budgeting method to study the financial sustainability of the project and identifying those CSR projects

  13. Corporate social responsibility: a real options approach to the challenge of financial sustainability.

    Directory of Open Access Journals (Sweden)

    Maria-Teresa Bosch-Badia

    Full Text Available In contemporary complex societies, social values like ethics, corporate social responsibility, and being respectful with the environment, among others, are becoming social requirements. Corporations are expected to fulfill them and, according to empirical evidence, an overwhelming majority aspires to good social valuation. At the same time, the maximization of market share value in the long run continues to be the central corporate goal. Making environmental and social expenses compatible with value creation is a central challenge for corporations since it implies the financial sustainability of Corporate Social Responsibility (CSR.The value creation capacity of CSR projects, mainly through innovation, is widely acknowledged in economic literature and corporate practice. This fact arouses the need of having a quantitative framework capable of summarizing the value creation capacity of the variables involved in CSR projects. With this aim we build up a sensitivity analysis of real option ratios that studies and quantifies the value creation capacity of CSR projects connected with innovation. Ratio analysis has the advantage of being scale independent. Hence, it furnishes a homogeneous framework to express the interaction of value creation variables and, thus, supports strategic thinking quantitatively. Often, CSR expenses can be regarded as preliminary projects that create the opportunity to undertake a full future project. For them, we obtain the minimum expectations scenario that makes financially sustainable a preliminary project that can be interpreted as a call option. We propose a classification of CSR projects from the decision analysis perspective following a two-fold approach: Their relationship with value creation and their links with existing corporate activities. This classification of CSR projects aims at contributing to choose the best capital budgeting method to study the financial sustainability of the project and identifying

  14. Forgetting "murder" is not harder than forgetting "circle" : Listwise-directed forgetting of emotional words

    NARCIS (Netherlands)

    Wessel, Ineke; Merckelbach, H.

    The list-method directed forgetting (DF) paradigm has attracted the attention of clinical psychologists because it is widely believed that a retrieval inhibition mechanism underlies its effects. Thus, the idea is that people are capable of intentionally forgetting negative emotional material. On the

  15. Identification of the real options in a program of nuclear plants; Identificacion de las opciones reales en un programa de plantas nucleoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Camacho G, D.; Diaz N, M. J.; Reinking C, A. [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac 8532, Jiutepec, Morelos 62550 (Mexico)]. e-mail: danielkmacho@yahoo.com.mx

    2008-07-01

    The development of our societies and our economies this intimately related to electric power and this as well with the generating sources, due to the projection of world-wide growth should go associate with a strategy of growth of energy generation. Considering to the nuclear power as an option to satisfy the energy needs that a country can provide two main immediate benefits: The stabilization of prices of security of provision of electric power of the nation. The care of the environment, since the gas discharges greenhouse are almost null. At the moment nuclear energy represents economically a viable option for the capital investment, taking into account the development from technology, the policies implemented by the state and the prices of other fuels. Due to the great investment that its require for the nuclear plants are necessary to use financial tools that allow to analyze the future scenes in which ours investment can be seen affected and to value the flexibility of being able to enlarge, to postpone or to stop our project in order to have majors profits or to diminish the lost ones. This valuation of the flexibility can be obtained from the called method Real Options. By analysis of Real Options the process is understood to apply to the methodology of the Financial Options to the valuation of projects or the management of real assets. The Real Options appear in flexible plans, projects, activities or enterprise investments, like for example, to leave or to sell the investment project before concluding it, changing to their use or its technology, to prolong their life, the option to choose, one or the other capacity, among others possibilities. In this work is an example of the application of the method of Real Options in the decision to invest or to defer the investment for the construction of a nuclear plant following the behavior of the tariffs in the market or the costs of generation of other technologies with which a nuclear plant competes. (Author)

  16. The Crucial Role of Postcue Encoding in Directed Forgetting and Context-Dependent Forgetting

    Science.gov (United States)

    Pastotter, Bernhard; Bauml, Karl-Heinz

    2007-01-01

    People can intentionally forget previously studied material if, after study, a forget cue is provided and new material is learned. It has recently been suggested that such list-method directed forgetting arises because the forget cue induces a change in internal context and causes context-dependent forgetting of the studied material (L. Sahakyan &…

  17. Directed Forgetting of Recently Recalled Autobiographical Memories

    Science.gov (United States)

    Barnier, Amanda J.; Conway, Martin A.; Mayoh, Lyndel; Speyer, Joanne; Avizmil, Orit; Harris, Celia B.

    2007-01-01

    In 6 experiments, the authors investigated list-method directed forgetting of recently recalled autobiographical memories. Reliable directed forgetting effects were observed across all experiments. In 4 experiments, the authors examined the impact of memory valence on directed forgetting. The forget instruction impaired recall of negative,…

  18. Evaluating cash benefits as real options for a commodity producer in an emerging market

    Directory of Open Access Journals (Sweden)

    Fernando Antonio Lucena Aiube

    2009-07-01

    Full Text Available The amount of cash a firm should maintain is an old problem tackled by finance literature. The recent advances in finance, mainly in the derivatives area, has opened the opportunity to revisit this subject. Cossin and Hricko (2004 studied the benefits of cash holdings using the Real Options approach. We follow their ideas extending the problem to a specific commodity producer firm in an emerging economy. We evaluate the benefits considering that raising capital takes time (timing benefit and also the benefit of avoiding the issue of securities at unfavorable moments (underpricing benefit. We use numerical procedures to solve the problem. Despite the fact that the results are not totally intuitive, we verify that the timing benefit is much more relevant than that of avoiding the underpricing benefit and that firms in emerging economies have greater advantage holding cash than those in developed economies. There is empirical evidence of this last result in the literature.

  19. REAL OPTIONS ANALYSIS OF RENEWABLE ENERGY INVESTMENT SCENARIOS IN THE PHILIPPINES

    Directory of Open Access Journals (Sweden)

    Casper Agaton

    2017-12-01

    Full Text Available Abstract - With the continuously rising energy demand and much dependence on imported fossil fuels, the Philippines is developing more sustainable sources of energy. Renewable energy seems to be a better alternative solution to meet the country’s energy supply and security concerns. Despite its huge potential, investment in renewable energy sources is challenged with competitive prices of fossil fuels, high start-up cost and lower feed-in tariff rates for renewables. To address these problems, this study aims to analyze energy investment scenarios in the Philippines using real options approach. This compares the attractiveness of investing in renewable energy over continuing to use coal for electricity generation under uncertainties in coal prices, investments cost, electricity prices, growth of investment in renewables, and imposing carbon tax for using fossil fuels.

  20. Renewable energy investments under different support schemes: A real options approach

    DEFF Research Database (Denmark)

    Boomsma, Trine Krogh; Meade, Nigel; Fleten, Stein-Erik

    2012-01-01

    -in tariff encourages earlier investment. Nevertheless, as investment has been undertaken, renewable energy certificate trading creates incentives for larger projects. In our baseline scenario and taking the fixed feed-in tariff as a base, the revenue required to trigger investments is 61% higher......This paper adopts a real options approach to analyze investment timing and capacity choice for renewable energy projects under different support schemes. The main purpose is to examine investment behavior under the most extensively employed support schemes, namely, feed-in tariffs and renewable...... energy certificate trading. We consider both multiple sources of uncertainty under each support scheme and uncertainty with respect to any change of support scheme, and we obtain both analytical (when possible) and numerical solutions. In a Nordic case study based on wind power, we find that the feed...

  1. Real options theory to the pricing of allowances contract to carbon emission

    International Nuclear Information System (INIS)

    Horii, Leticia Takahashi; Parente, Virginia; Goldemberg, Jose

    2010-01-01

    The objective of this work is to develop a pricing model contract for allowances to emit carbon through Real Options. Emissions allowances are equivalent tons of carbon traded between Annex I countries from companies that have the ability to reduce their emissions beyond what is assigned to it. The surplus of emission reductions produced by these companies may be sold in the emissions market. Thus, this work can contribute to improving the management of contractual risk and enable companies estimated the price at which a contract can be signed. Properly evaluate the contracts that the market environment is a challenge for companies. The historic low of information and randomness in the price of carbon allowances in the spot market suggest extreme caution in its use. (author)

  2. A decision model for E and P petroleum projects using real options and preference theory

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Gabriel A.C. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Geociencias. Lab. de Analise Geoconomica (LAGE); Suslick, Saul B. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Geociencias. Centro de Estudo do Petroleo; Nepomuceno Filho, Francisco [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The results from Discounted Cash Flow (DCF) are limited as a tool for decision-making in the petroleum industry because they do not properly take into account three important features of the modern investments: uncertainty, irreversibility, timing and corporation's risk-aversion. Recent developments in real options and preference theories have allowed decision-makers to employ these two approaches separately in the process of valuation and decision-making of risky projects. This paper presents a model for valuation and decision-making integrating discounted cash flow, real options and reference theory. This model seems to be suitable to answer to the following questions: what is the current value of an oil project? what is the optimal working interest in this project venture?; what is criteria to select projects considering investment irreversibility, uncertainty and timing to implement decisions? This model is applied to valuation and decision-making of a project to produce oil from a deep-water reservoir and its results are compared to those of the traditional approach. NPV model suggest that, as the project value is above its investment cost, the corporation should invest immediately and take 100% working interest in the project. Contrarily, the integrated model suggest the corporation should invest as long as project current value is as large as 1.85 times investment cost and should take only 44.38% working interest, whereas partners fund and acquire the remaining 55,62% of the project. In general, results indicate that NPV tend to pay more attention on return and does not account properly for risk. Then, as the uncertainty or volatile of strategic variables increases, the two models give more divergent results. (author)

  3. A real options-based CCS investment evaluation model: Case study of China's power generation sector

    International Nuclear Information System (INIS)

    Zhu, Lei; Fan, Ying

    2011-01-01

    Highlights: → This paper establishes a carbon captures and storage (CCS) investment evaluation model. → The model is based on real options theory and solved by the Least Squares Monte Carlo (LSM) method. → China is taken as a case study to evaluate the effects of regulations on CCS investment. → The findings show that the current investment risk of CCS is high, climate policy having the greatest impact on CCS development. -- Abstract: This paper establishes a carbon capture and storage (CCS) investment evaluation model based on real options theory considering uncertainties from the existing thermal power generating cost, carbon price, thermal power with CCS generating cost, and investment in CCS technology deployment. The model aims to evaluate the value of the cost saving effect and amount of CO 2 emission reduction through investing in newly-built thermal power with CCS technology to replace existing thermal power in a given period from the perspective of power generation enterprises. The model is solved by the Least Squares Monte Carlo (LSM) method. Since the model could be used as a policy analysis tool, China is taken as a case study to evaluate the effects of regulations on CCS investment through scenario analysis. The findings show that the current investment risk of CCS is high, climate policy having the greatest impact on CCS development. Thus, there is an important trade off for policy makers between reducing greenhouse gas emissions and protecting the interests of power generation enterprises. The research presented would be useful for CCS technology evaluation and related policy-making.

  4. Optimal feed-in tariff for solar photovoltaic power generation in China: A real options analysis

    International Nuclear Information System (INIS)

    Zhang, M.M.; Zhou, D.Q.; Zhou, P.; Liu, G.Q.

    2016-01-01

    The feed-in tariff policy is widely used to promote the development of renewable energy. China also adopts feed-in tariff policy to attract greater investment in solar photovoltaic power generation. This study employs real options method to assess the optimal levels of feed-in tariffs in 30 provinces of China. The uncertainties in CO_2 price and investment cost are considered. A method that integrates the backward dynamic programming algorithm and Least-Squares Monte Carlo method is used to solve the model. The results demonstrate that the feed-in tariffs of 30 provinces range from 0.68 RMB/kWh to 1.71 RMB/kWh, and the average level is 1.01 RMB/kWh. On this basis, we find that the levels of sub-regional feed-in tariff announced in 2013 are no longer appropriate and should be adjusted as soon as possible. We have also identified the implications of technological progress and carbon emission trading schemes, as well as the importance of strengthening electricity transmission. It has been suggested that the Chinese government takes diverse measures, including increasing research and development investment, establishing and improving a nationwide carbon emission trading scheme and accelerating the construction of electricity-transmission infrastructure, to reduce the required feed-in tariff and promote the development of solar photovoltaic power generation. - Highlights: • We estimate the optimal levels of feed-in tariffs for 30 provinces in China by using real options method. • The uncertainties in CO_2 price and investment cost are considered. • The feed-in tariffs of 30 provinces range from 0.68 RMB/kWh to 1.71 RMB/kWh, and the average level is 1.01 RMB/kWh.

  5. Hydrogen storage for wind parks: A real options evaluation for an optimal investment in more flexibility

    International Nuclear Information System (INIS)

    Kroniger, Daniel; Madlener, Reinhard

    2014-01-01

    Highlights: • Economic analysis of investing in H 2 storage for excess wind power production. • Use of real options analysis to account for uncertainty and managerial flexibility. • Hourly profits are simulated for profit-maximizing operation of the storage device. • Revenues by load factor increase, offering minute reserve, temporal arbitrage, H 2 sale. • Power-to-power is unprofitable under current techno-political conditions in Germany. - Abstract: In this paper, we investigate the economic viability of hydrogen storage for excess electricity produced in wind power plants. For the analysis, we define two scenarios (50 MW system with and without re-electrification unit) and apply Monte Carlo simulation and real options analysis (ROA) to compute hourly profits under uncertainty regarding wind speed, spot market electricity prices, and call of minute reserve capacity. Hydrogen as a storage medium helps to either (1) increase capacity utilization of the wind park in case of grid disconnection; (2) to offer minute reserve; or (3) to exploit temporal price arbitrage at the electricity spot market; additionally, hydrogen can also be directly sold as a commodity. We find that power-to-power operation is highly uneconomical under current framework conditions in Germany, irrespective of potential energy efficiency gains. Interestingly, due to counterbalancing effects, offshore wind parks are found to have only a modest economic advantage compared to onshore ones. The power-to-fuel plant can be operated profitably (at hydrogen prices of more than 0.36 € m −3 and a 100% utilization of the electrolyzer) if hydrogen is directly marketed instead of used to store and re-generate electrical energy. The ROA recommends investment in a storage device without re-electrification unit beyond an expected project value that is about twice the investment cost of the storage device, a figure which is reduced markedly as conversion efficiency rises, assuming technical change

  6. A real options evaluation model for the diffusion prospects of new renewable power generation technologies

    International Nuclear Information System (INIS)

    Kumbaroglu, Guerkan; Madlener, Reinhard; Demirel, Mustafa

    2008-01-01

    This study presents a policy planning model that integrates learning curve information on renewable power generation technologies into a dynamic programming formulation featuring real options analysis. The model recursively evaluates a set of investment alternatives on a year-by-year basis, thereby taking into account that the flexibility to delay an irreversible investment expenditure can profoundly affect the diffusion prospects of renewable power generation technologies. Price uncertainty is introduced through stochastic processes for the average wholesale price of electricity and for input fuel prices. Demand for electricity is assumed to be increasingly price-sensitive, as the electricity market deregulation proceeds, reflecting new options of consumers to react to electricity price changes (such as time-of-use pricing, unbundled electricity services, and choice of supplier). The empirical analysis is based on data for the Turkish electricity supply industry. Apart from general implications for policy-making, it provides some interesting insights about the impact of uncertainty and technical change on the diffusion of various emerging renewable energy technologies

  7. Water resources planning under climate change: Assessing the robustness of real options for the Blue Nile

    Science.gov (United States)

    Jeuland, Marc; Whittington, Dale

    2014-03-01

    This article presents a methodology for planning new water resources infrastructure investments and operating strategies in a world of climate change uncertainty. It combines a real options (e.g., options to defer, expand, contract, abandon, switch use, or otherwise alter a capital investment) approach with principles drawn from robust decision-making (RDM). RDM comprises a class of methods that are used to identify investment strategies that perform relatively well, compared to the alternatives, across a wide range of plausible future scenarios. Our proposed framework relies on a simulation model that includes linkages between climate change and system hydrology, combined with sensitivity analyses that explore how economic outcomes of investments in new dams vary with forecasts of changing runoff and other uncertainties. To demonstrate the framework, we consider the case of new multipurpose dams along the Blue Nile in Ethiopia. We model flexibility in design and operating decisions—the selection, sizing, and sequencing of new dams, and reservoir operating rules. Results show that there is no single investment plan that performs best across a range of plausible future runoff conditions. The decision-analytic framework is then used to identify dam configurations that are both robust to poor outcomes and sufficiently flexible to capture high upside benefits if favorable future climate and hydrological conditions should arise. The approach could be extended to explore design and operating features of development and adaptation projects other than dams.

  8. Benefits and Limitations of Real Options Analysis for the Practice of River Flood Risk Management

    Science.gov (United States)

    Kind, Jarl M.; Baayen, Jorn H.; Botzen, W. J. Wouter

    2018-04-01

    Decisions on long-lived flood risk management (FRM) investments are complex because the future is uncertain. Flexibility and robustness can be used to deal with future uncertainty. Real options analysis (ROA) provides a welfare-economics framework to design and evaluate robust and flexible FRM strategies under risk or uncertainty. Although its potential benefits are large, ROA is hardly used in todays' FRM practice. In this paper, we investigate benefits and limitations of a ROA, by applying it to a realistic FRM case study for an entire river branch. We illustrate how ROA identifies optimal short-term investments and values future options. We develop robust dike investment strategies and value the flexibility offered by additional room for the river measures. We benchmark the results of ROA against those of a standard cost-benefit analysis and show ROA's potential policy implications. The ROA for a realistic case requires a high level of geographical detail, a large ensemble of scenarios, and the inclusion of stakeholders' preferences. We found several limitations of applying the ROA. It is complex. In particular, relevant sources of uncertainty need to be recognized, quantified, integrated, and discretized in scenarios, requiring subjective choices and expert judgment. Decision trees have to be generated and stakeholders' preferences have to be translated into decision rules. On basis of this study, we give general recommendations to use high discharge scenarios for the design of measures with high fixed costs and few alternatives. Lower scenarios may be used when alternatives offer future flexibility.

  9. Real Options in Defense R and D: A Decision Tree Analysis Approach for Options to Defer, Abandon, and Expand

    Science.gov (United States)

    2016-12-01

    the sale of assets for salvage value. However, for defense R&D projects, since there is no secondhand market for the projects, this option is...Peli, 2001; Panayi & Trigeorgis, 1998; Perlitz et al., 1999). Moreover, there are also very comprehensive books on the theory and practice of

  10. A novel method to value real options in health care: the case of a multicohort human papillomavirus vaccination strategy.

    Science.gov (United States)

    Favato, Giampiero; Baio, Gianluca; Capone, Alessandro; Marcellusi, Andrea; Saverio Mennini, Francesco

    2013-07-01

    A large number of economic evaluations have already confirmed the cost-effectiveness of different human papillomavirus (HPV) vaccination strategies. Standard analyses might not capture the full economic value of novel vaccination programs because the cost-effectiveness paradigm fails to take into account the value of active management. Management decisions can be seen as real options, a term used to refer to the application of option pricing theory to the valuation of investments in nonfinancial assets in which much of the value is attributable to flexibility and learning over time. The aim of this article was to discuss the potential advantages shown by using the payoff method in the valuation of the cost-effectiveness of competing HPV immunization programs. This was the first study, to the best of our knowledge, to use the payoff method to determine the real option values of 4 different HPV vaccination strategies targeting female subjects aged 12, 15, 18, and 25 years. The payoff method derives the real option value from the triangular payoff distribution of the project's net present value, which is treated as a triangular fuzzy number. To inform the real option model, cost-effectiveness data were derived from an empirically calibrated Bayesian model designed to assess the cost-effectiveness of a multicohort HPV vaccination strategy in the context of the current cervical cancer screening program in Italy. A net health benefit approach was used to calculate the expected fuzzy net present value for each of the 4 vaccination strategies evaluated. Costs per quality-adjusted life-year gained seemed to be related to the number of cohorts targeted: a single cohort of girls aged 12 years (€10,955 [95% CI, -1,021 to 28,212]) revealed the lowest cost among the 4 alternative strategies evaluated. The real option valuation challenged the cost-effectiveness dominance of a single cohort of 12-year-old girls. The simultaneous vaccination of 2 cohorts of girls aged 12 and 15

  11. Do not forget tuberculous meningitis

    African Journals Online (AJOL)

    to forget to consider it as an explanation for a patient's presenting problem. ... HIV infected patients (in these patients TBM may ... Papilloedema contraindicates a lumbar puncture. The CSF ... Grading of a clinical status can aid the indication of.

  12. Memory and Forgetfulness: NIH Research

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Memory & Forgetfulness NIH Research Past Issues / Summer 2013 Table ... agency for research on Alzheimer's disease and related memory research. An analysis funded by the NIA finds ...

  13. Use of real options in nuclear power plant valuation in the presence of uncertainty with CO2 emission credit

    International Nuclear Information System (INIS)

    Kiriyama, Eriko; Suzuki, Atsuyuki

    2004-01-01

    The purpose of this study is to analyze the value of an investment in power generation assets that do not emit CO 2 , by using a real option model. This study evaluates the effects of future uncertainty on investment decision-making, by focusing on the uncertainty of CO 2 emission credits [yen/t-CO 2 ] in the fairly near future in Japan. Electric utilities are required to keep plans to prepare for various future uncertainties such as the price of CO 2 emission credits. The real option approach can evaluate the option value of decision-making under uncertainty. This study examined the option value of a power plant [yen/KW] to evaluate the effects of an externality under uncertainty. The results showed that nuclear power would have the most value under the forthcoming CO 2 emission limitations. In order to secure the effectiveness of measures against global warming, we should reconsider the roles of nuclear power plants in Japan. Finally, the real option model is shown to be an effective candidate for a decision-making support tool to deal with problems in energy environmental policy. (author)

  14. A Real Option Analysis applied to the production of Arabica and Robusta Coffee in Ecuador

    Energy Technology Data Exchange (ETDEWEB)

    Jácome, A.R.; Garrido, A.

    2017-09-01

    The coffee market is distinguished for being volatile and uncertain in terms of domestic and international prices. Arabica and Robusta coffee are produced in 23 provinces of Ecuador. A decade-long decline of coffee production prompted the Ecuadorian government to launch a public program for replanting coffee trees towards the end of 2011. A grower’s decision to enter, remain in or exit the coffee sector is based on fluctuating profits from each year’s harvest sale. We analyzed the hypothesis whereby the coffee grower’s decision to leave the sector is explained by volatile and uncertain prices. This paper aimed to evaluate the coffee sector with an application of Real Option Analysis for the period 2002-2012. We also defined entry (H) and exit (L) prices for Arabica and Robusta coffee for the analyzed period. Our findings revealed high H and L prices encourage growers to leave the sector for the most part of the analyzed period. High H and L prices resulted from high variable cost due to increasing wages for farm workers. The Ecuadorian government is developing a policy to help growers make production more efficient, encouraging them to remain in the sector in the long run.

  15. SMR and economics competitiveness in small grids. A real option analysis

    International Nuclear Information System (INIS)

    Locatelli, Giorgio; Mancino, Mauro; Lotti, Giovanni

    2014-01-01

    The optimal investment in power plants depends on many uncertain parameters (price of electricity, construction costs, cost of emissions, fuel cost..). Traditional approaches based on the Discounted Cash Flows methodologies, like the Net Present Value (NPV), do not properly take into account these uncertainties since they depend on the implicit assumption that all the decisions regarding the investment are evaluated in a specific moment (the time now) and cannot be postponed, waiting to acquire more information. An evolution of these methods is the Real Options Analysis (ROA) that considers a further value into the evaluation: the value of flexibility to choose when to invest. In this paper the ROA will be used to test a hypothesis made in literature, that small-medium sized plants (300-400 MWe) can be a suitable choice for small grids (or markets), thanks to their flexibility in the deployment. The assessment of this hypothesis is based on a ROA model that compares the investment in a Large Reactor (LR) vs. a group of Small Modular Reactors (SMR). Montecarlo simulations are used to approximate the probability distributions of the profitability indicators, both with a static approach, implying that investments are made immediately, and with a dynamic approach, letting the model decide when to invest (optimizing the profitability distribution). The result show as SMR, in small grid, can yield similar profitability in lower risky conditions. (orig.)

  16. Investment opportunity in China's overseas oil project: An empirical analysis based on real option approach

    International Nuclear Information System (INIS)

    Tang, Bao-Jun; Zhou, Hui-Ling; Chen, Hao; Wang, Kai; Cao, Hong

    2017-01-01

    China's overseas oil investments uphold national energy security. Located in the complex international economic and political environment, the benefits of overseas oil projects are affected by various uncertainties. Oil companies call for a set of evaluation method dealing with these uncertainties, especially when encountering low-oil-price conditions. It is much more crucial to answer when to optimally invest rather than whether to invest. This paper analyzes the investment opportunity of an oil project in the development and production phase considering uncertainty, irreversibility and management flexibility. The decision-making process combines Discounted Cash Flow (DCF) method and the trinomial tree model of Real Option Approach (ROA). For practical purposes, tools of hurdle price, cumulative probability and decision tree are adopted. In addition, results of the case project show the economic feasibility at present and optimal start-up timing at the end of 2016. Besides, the lower cost parameters generally make it easier to meet the opportunity. The scenario analysis suggests the higher risk contributes to an earlier start-up. Furthermore, the issues of method applicability, investment signals and decision-lag effects are discussed. - Highlights: • Volatility is combined with fluctuations in oil price, exchange rate and political situation. • Hurdle price is adopted as a critical price to measure investment opportunity. • Scenario analysis suggests the higher risk contribute to earlier investment timing.

  17. SMR and economics competitiveness in small grids. A real option analysis

    Energy Technology Data Exchange (ETDEWEB)

    Locatelli, Giorgio [University of Lincoln - School of Engineering, Lincoln (United Kingdom). Faculty of Science; Mancino, Mauro; Lotti, Giovanni [Politecnico di Milano (Italy). Dept. of Management Economics and Industrial Engineering

    2014-03-15

    The optimal investment in power plants depends on many uncertain parameters (price of electricity, construction costs, cost of emissions, fuel cost..). Traditional approaches based on the Discounted Cash Flows methodologies, like the Net Present Value (NPV), do not properly take into account these uncertainties since they depend on the implicit assumption that all the decisions regarding the investment are evaluated in a specific moment (the time now) and cannot be postponed, waiting to acquire more information. An evolution of these methods is the Real Options Analysis (ROA) that considers a further value into the evaluation: the value of flexibility to choose when to invest. In this paper the ROA will be used to test a hypothesis made in literature, that small-medium sized plants (300-400 MWe) can be a suitable choice for small grids (or markets), thanks to their flexibility in the deployment. The assessment of this hypothesis is based on a ROA model that compares the investment in a Large Reactor (LR) vs. a group of Small Modular Reactors (SMR). Montecarlo simulations are used to approximate the probability distributions of the profitability indicators, both with a static approach, implying that investments are made immediately, and with a dynamic approach, letting the model decide when to invest (optimizing the profitability distribution). The result show as SMR, in small grid, can yield similar profitability in lower risky conditions. (orig.)

  18. A Real Option Analysis applied to the production of Arabica and Robusta Coffee in Ecuador

    Directory of Open Access Journals (Sweden)

    Andres R. Jácome

    2017-04-01

    Full Text Available The coffee market is distinguished for being volatile and uncertain in terms of domestic and international prices. Arabica and Robusta coffee are produced in 23 provinces of Ecuador. A decade-long decline of coffee production prompted the Ecuadorian government to launch a public program for replanting coffee trees towards the end of 2011. A grower’s decision to enter, remain in or exit the coffee sector is based on fluctuating profits from each year’s harvest sale. We analyzed the hypothesis whereby the coffee grower’s decision to leave the sector is explained by volatile and uncertain prices. This paper aimed to evaluate the coffee sector with an application of Real Option Analysis for the period 2002-2012. We also defined entry (H and exit (L prices for Arabica and Robusta coffee for the analyzed period. Our findings revealed high H and L prices encourage growers to leave the sector for the most part of the analyzed period. High H and L prices resulted from high variable cost due to increasing wages for farm workers. The Ecuadorian government is developing a policy to help growers make production more efficient, encouraging them to remain in the sector in the long run.

  19. Real option valuation of free destination in long-term liquefied natural gas supplies

    International Nuclear Information System (INIS)

    Yepes Rodriguez, Ramon

    2008-01-01

    This paper presents a real option model for the valuation of destination flexibility in long-term LNG supplies. Stochastic price dynamics in the different markets is modelled through geometric Brownian motion processes. Mean reversion is considered as well as correlation between markets, but instead of the usual correlation in return shocks, a price convergence term is introduced representing the arbitrage streams between markets. Model parameters are estimated from market data on LNG prices by maximum log-likelihood. The goodness of the fit for the proposed model is tested as well as for two alternative models. Confidence intervals for the parameters are given. Results for the model are calculated by Monte Carlo simulation. Frequency distributions for the main results are plotted. The effect of the main parameters of the model is studied (i.e. price volatilities, price convergence, initial prices in the markets, mean reversion, extra transportation costs, number of alternative markets). The value of destination flexibility is found to be an important share of the value of LNG

  20. Flexibility valuation in the Brazilian power system: A real options approach

    International Nuclear Information System (INIS)

    Marreco, Juliana de Moraes; Carpio, Lucio Guido Tapia

    2006-01-01

    This paper presents a valuation study of operational flexibility in the complex Brazilian Power System. Thermopower plants represent operational flexibility for the national system operator provided they can be dispatched in dry periods to supply part of the load when reservoir waters are too low. Deficit costs can be avoided as a result. We have adopted a real options approach to calculate the fair value of a financial subsidy to be paid to thermal generators for their availability to the system. A financial subsidy is mandatory for their economic feasibility and, therefore, for increased thermopower capacity in the Brazilian Power System. This is why this policy is currently being studied by Brazil's federal government. In order to illustrate our modeling we have run the model for the southeast subsystem. We found a flexibility value of US$4.52 billion, which represents US$497/MW per year. This means that a 100 MW thermopower plant should receive US$49,700 for each year of its economic lifetime as a fair premium incentive to investments

  1. Using real options to evaluate the flexibility in the deployment of SMR

    Energy Technology Data Exchange (ETDEWEB)

    Locatelli, G. [Univ. of Lincoln, Lincoln School of Engineering, Brayford Pool, Lincoln LN6 7TS (United Kingdom); Mancini, M. [Politecnico di Milano, Dept. of Management, Economics and Industrial Engineering, Via Lambruschini 4/B, Milano (Italy); Ruiz, F.; Solana, P. [Universidad Politecnica de Madrid, Dep. de Ingenieria de Organizacion, Administracion de Empresas y Estadistica, C/ Jose Gutierrez Abascal, 2, 28006-Madrid (Spain)

    2012-07-01

    According to recent estimations the financial gap between Large Reactors (LR) and Small Medium Reactors (SMRs) seems not as huge as the economy of scale would suggest, so the SMRs are going to be important players of the worldwide nuclear renaissance. POLIMIs INCAS model has been developed to compare the investment in SMR with respect to LR. It provides the value of IRR (Internal Rate of Return), NPV (Net Present Value), LUEC (Levelized Unitary Electricity Cost), up-front investment, etc. The aim of this research is to integrate the actual INCAS model, based on discounted cash flows, with the real option theory to measure flexibility of the investor to expand, defer or abandon a nuclear project, under future uncertainties. The work compares the investment in a large nuclear power plant with a series of smaller, modular nuclear power plants on the same site. As a consequence it compares the benefits of the large power plant, coming from the economy of scale, to the benefit of the modular project (flexibility) concluding that managerial flexibility can be measured and used by an investor to face the investment risks. (authors)

  2. An entry and exit model on the energy-saving investment strategy with real options

    International Nuclear Information System (INIS)

    Lin, Tyrone T.; Huang, S.-L.

    2010-01-01

    This paper presents an improved decision model based on the real options approach presented by for the firms that have not yet established energy-saving equipment under the entry and exit strategies. Furthermore, the proposed model takes account of the inevitable equipment renewal and the occurrence of unexpected events under the Poisson jump process. The timing for terminating an investment when continuous operations of that business are unprofitable is also explored to realize the optimal timing of implementing the energy-saving strategy. The future discounted benefit B follows the geometric Brownian motion with the Poisson jump process and the replacement of investment equipment. A numerical analysis is followed by a sensitivity study of various parameters to better realize their impacts on the entry and exit thresholds. The results show that for the jump case, the higher probability of occurrence of unfavorable events will result in a higher entry threshold and lower exit threshold. Investors are forced to request higher benefit thresholds to cover the higher probability of losses brought by unfavorable events.

  3. Using real options to evaluate the flexibility in the deployment of SMR

    International Nuclear Information System (INIS)

    Locatelli, G.; Mancini, M.; Ruiz, F.; Solana, P.

    2012-01-01

    According to recent estimations the financial gap between Large Reactors (LR) and Small Medium Reactors (SMRs) seems not as huge as the economy of scale would suggest, so the SMRs are going to be important players of the worldwide nuclear renaissance. POLIMIs INCAS model has been developed to compare the investment in SMR with respect to LR. It provides the value of IRR (Internal Rate of Return), NPV (Net Present Value), LUEC (Levelized Unitary Electricity Cost), up-front investment, etc. The aim of this research is to integrate the actual INCAS model, based on discounted cash flows, with the real option theory to measure flexibility of the investor to expand, defer or abandon a nuclear project, under future uncertainties. The work compares the investment in a large nuclear power plant with a series of smaller, modular nuclear power plants on the same site. As a consequence it compares the benefits of the large power plant, coming from the economy of scale, to the benefit of the modular project (flexibility) concluding that managerial flexibility can be measured and used by an investor to face the investment risks. (authors)

  4. A Real Option Analysis applied to the production of Arabica and Robusta Coffee in Ecuador

    International Nuclear Information System (INIS)

    Jácome, A.R.; Garrido, A.

    2017-01-01

    The coffee market is distinguished for being volatile and uncertain in terms of domestic and international prices. Arabica and Robusta coffee are produced in 23 provinces of Ecuador. A decade-long decline of coffee production prompted the Ecuadorian government to launch a public program for replanting coffee trees towards the end of 2011. A grower’s decision to enter, remain in or exit the coffee sector is based on fluctuating profits from each year’s harvest sale. We analyzed the hypothesis whereby the coffee grower’s decision to leave the sector is explained by volatile and uncertain prices. This paper aimed to evaluate the coffee sector with an application of Real Option Analysis for the period 2002-2012. We also defined entry (H) and exit (L) prices for Arabica and Robusta coffee for the analyzed period. Our findings revealed high H and L prices encourage growers to leave the sector for the most part of the analyzed period. High H and L prices resulted from high variable cost due to increasing wages for farm workers. The Ecuadorian government is developing a policy to help growers make production more efficient, encouraging them to remain in the sector in the long run.

  5. What makes and what does not make a real option? A study of equity shares in international joint ventures

    NARCIS (Netherlands)

    Cuypers, I.R.P.; Martin, Xavier

    2010-01-01

    This paper examines the boundaries of real options logic, with an application to joint ventures (JVs). We distinguish between forms of uncertainty that are resolved endogenously and those that are resolved exogenously, and theorize that only exogenous uncertainty will have the impact predicted by

  6. The Interaction between Real Options and Financial Hedging: An Empirical Study of Danish Non-Financial Companies

    DEFF Research Database (Denmark)

    Aabo, Tom

    The interaction between real options and financial hedging is analyzed empirically. A majority of Danish non-financial companies either (1) chooses at times not to hedge an exchange rate operating exposure financially due to the possibility of the company to react to changes in exchange rates...

  7.  Euro Membership as a Real Option Trigger: An Empirical Study of EU15 Manufacturing Firms

    DEFF Research Database (Denmark)

    Aabo, Tom

    ) to exercise real options such as to establish alliances / partnerships, to enter new markets / market segments, to switch suppliers, and to generally expand in the Euro-area. The results are robust after controlling for the size of the firms and their sales in the Euro-area. The results go beyond what...

  8. Fuel price and technological uncertainty in a real options model for electricity planning

    International Nuclear Information System (INIS)

    Fuss, Sabine; Szolgayova, Jana

    2010-01-01

    Electricity generation is an important source of total CO 2 emissions, which in turn have been found to relate to an acceleration of global warming. Given that many OECD countries have to replace substantial portions of their electricity-generating capacity over the next 10-20 years, investment decisions today will determine the CO 2 -intensity of the future energy mix. But by what type of power plants will old (mostly fossil-fuel-fired) capacity be replaced? Given that modern, less carbon-intensive technologies are still expensive but can be expected to undergo improvements due to technical change in the near future, they may become more attractive, especially if fossil fuel price volatility makes traditional technologies more risky. At the same time, technological progress is an inherently uncertain process itself. In this paper, we use a real options model with stochastic technical change and stochastic fossil fuel prices in order to investigate their impact on replacement investment decisions in the electricity sector. We find that the uncertainty associated with the technological progress of renewable energy technologies leads to a postponement of investment. Even the simultaneous inclusion of stochastic fossil fuel prices in the same model does not make renewable energy competitive compared to fossil-fuel-fired technology in the short run based on the data used. This implies that policymakers have to intervene if renewable energy is supposed to get diffused more quickly. Otherwise, old fossil-fuel-fired equipment will be refurbished or replaced by fossil-fuel-fired capacity again, which enforces the lock-in of the current system into unsustainable electricity generation. (author)

  9. What is the best way to enter Florida's real estate market in today's economy? : This may serve as a simple guide which offers options for a startup real estate company to enter any real estate market

    OpenAIRE

    Bryan, Paul

    2011-01-01

    P&I International real estate (PIIRE for short) is a real estate company which left the Florida real estate market in 2006. PIIRE is now seeking the best method to re-enter the Florida’s real estate market within the near future. The owners are seeking the best method to re-establish their real estate business in Florida. At this point the location in Florida has not yet been determined. The determining factors include financing options, business type entry mode, and governmental issues. ...

  10. “Let’s Wait and See!” The Real Option to Switch as a Value Component of Customer Relationships

    NARCIS (Netherlands)

    Henseler, J.; Roemer, E.

    2013-01-01

    We suggest that a customer’s option to switch suppliers, and to wait and see before switching, adds to customer value in uncertain markets, and affects the customer’s switching behavior. We use a real options model to examine the value of this option and conduct sensitivity analyses based on data

  11. “Let’s Wait and See!” – The Real Option to Switch as a New Element of Customer Value

    NARCIS (Netherlands)

    Henseler, Jörg; Roemer, Ellen

    2013-01-01

    We suggest that a customer’s option to switch suppliers, and to wait and see before switching, adds to customer value in uncertain markets, and affects the customer’s switching behavior. We use a real options model to examine the value of this option and conduct sensitivity analyses based on data

  12. A real-life example of choosing an inherently safer process option

    International Nuclear Information System (INIS)

    Study, Karen

    2007-01-01

    While choosing an inherently safer alternative may seem straightforward, sometimes what seems to be the most obvious alternative may not provide the best risk reduction. The process designer must maintain a broad perspective to be able to recognize all potential hazards when evaluating design options. All aspects of operation such as start-up, shut-down, utility failure, as well as normal operation should be considered. Choosing the inherently safer option is best accomplished early in the option selection phase of a project; however, recycle back to the option selection phase may be needed if an option is not thoroughly evaluated early in the process. In this paper, a project to supply ammonia to a catalytic reactor will be reviewed. During the course of the project, an 'inherently safer' alternative was selected and later discarded due to issues uncovered during the detail design phase. The final option chosen will be compared to (1) the original design and (2) the initial 'inherently safer' alternative. The final option was inherently safer than both the original design and the initial 'inherently safer' alternative even though the design team initially believed that it would not be

  13. EFFECT OF REVENUE INSURANCE ON ENTRY AND EXIT DECISIONS IN TABLE GRAPE PRODUCTION: A REAL OPTION APPROACH

    OpenAIRE

    Seo, Sangtaek; Salin, Victoria; Mitchell, Paul D.; Leatham, David J.

    2004-01-01

    This study determines the entry and exit thresholds of table grape farming with irreversible investment under uncertainty. Real option approach is adopted to consider the investment and management flexibility. Also revenue insurance is introduced to consider the effect of the risk management programs on the entry and exit thresholds. Results show that revenue insurance increases the entry and exit thresholds by 1% and 4%, respectively, thus discouraging new investment and current farming, as ...

  14. Integrated Portfolio Analysis: Return on Investment and Real Options Analysis of Intelligence Information Systems (Cryptologic Carry On Program)

    Science.gov (United States)

    2006-09-30

    14 IV. Proof-of-Concept: USS Readiness Case Study 16 A. Background 17 B. Applying KVA Methodology 19 C. KVA Results 20 D. Real Options Analysis 23...technology assets. • Quantifying intangible human capital assets (i.e., training, skills, knowledge). The average large company spends the equivalent of...Portfolios/Motorola, Unilever • IT Infrastructure/Credit Suisse • Electricity/Peaker-Plants • Acquisitions/Seagate • Contracts/Syngenta, GM Although

  15. A Real Options Approach to Bankruptcy Costs: Evidence from Failed Commercial Banks During the 1990s

    OpenAIRE

    Joseph R. Mason

    2005-01-01

    Literature to date has identified three main aspects of liquidation time: firm size, asset specificity, and industry concentration. The present paper unifies the theory behind these three aspects of bankruptcy costs by treating them as components of a broader option valuation problem faced by the liquidating trustee. In the options valuation framework, at time t the trustee may choose to 1) liquidate at current asset values and incur a known loss, or 2) hold until the next period t+1 at a pos...

  16. Forget organisational unlearning

    DEFF Research Database (Denmark)

    Howells, John; Scholderer, Joachim; Mitev, Natalie

    is unnecessary and the topic of unlearning is best forgotten. First, we point out that Klein found the origin of the concept in experimental psychology where he argued that it was not a real empirical process but an experimental artefact. Second, we show that work which claims to provide empirical evidence...

  17. EL MÉTODO DE DIFERENCIAS FINITAS EN EVALUACIÓN DE OPCIONES REALES THE FINITE DIFFERENCE METHOD IN REAL OPTIONS VALUATION

    Directory of Open Access Journals (Sweden)

    Sebastián Otero G

    2008-06-01

    representa su capacidad de incorporar en el análisis el valor de la flexibilidad operativa del proyecto.In the past few years, real options, an extension of financial derivatives, have arisen as an alternative to traditional valuation methods, such as net present value (NPV. The key attribute of real options is that they take into consideration the uncertainty and flexibility involved in investment valuation. This article provides an overview of the finite difference method, by presenting an application to the real options valuation. The empirical section of the article, which makes use of the implicit finite difference method (IFD, analyzes the options of waiting, abandoning, contracting, expanding and switching, by valuing all the options involved and their possible combinations. The results are compared with those of the NPV method and the binomial tree with a logarithmic transformation (BTLT. Both methods (IFD and BTLT yield similar results, being both greater than those provided by the NPV. This difference comes to no surprise as it represents the value of the flexibility associated to an investment opportunity.

  18. Making sense of future uncertainties using real options and scenario planning

    NARCIS (Netherlands)

    van Reedt Dortland, Maartje; Voordijk, Johannes T.; Dewulf, Geert P.M.R.

    2014-01-01

    Healthcare across the world is facing many uncertainties. In Dutch healthcare, a recent policy change is forcing health organizations to deal more efficiently with their real estate, and this increases the need for real estate strategies that are more flexible. In order to support managers in

  19. Real Options Valuation of U.S. Federal Renewable Energy Research,Development, Demonstration, and Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Afzal S.; Marnay, Chris; Wiser, Ryan H.

    2005-03-01

    Benefits analysis of US Federal government funded research, development, demonstration, and deployment (RD3) programs for renewable energy (RE) technology improvement typically employs a deterministic forecast of the cost and performance of renewable and nonrenewable fuels. The benefits estimate for a program derives from the difference between two forecasts, with and without the RD3 in place. The deficiencies of the current approach are threefold: (1) it does not consider uncertainty in the cost of non-renewable energy (NRE), and the option or insurance value of deploying RE if and when NRE costs rise; (2) it does not consider the ability of the RD3 manager to adjust the RD3 effort to suit the evolving state of the world, and the option value of this flexibility; and (3) it does not consider the underlying technical risk associated with RD3, and the impact of that risk on the programs optimal level of RD3 effort. In this paper, a rudimentary approach to determining the option value of publicly funded RE RD3 is developed. The approach seeks to tackle the first deficiency noted above by providing an estimate of the options benefit of an RE RD3 program in a future with uncertain NRE costs.While limited by severe assumptions, a computable lattice of options values reveals the economic intuition underlying the decision-making process. An illustrative example indicates how options expose both the insurance and timing values inherent in a simplified RE RD3 program that coarsely approximates the aggregation of current Federal RE RD3.This paper also discusses the severe limitations of this initial approach, and identifies needed model improvements before the approach can adequately respond to the RE RD3 analysis challenge.

  20. ARC-VM: An architecture real options complexity-based valuation methodology for military systems-of-systems acquisitions

    Science.gov (United States)

    Domercant, Jean Charles

    The combination of today's national security environment and mandated acquisition policies makes it necessary for military systems to interoperate with each other to greater degrees. This growing interdependency results in complex Systems-of-Systems (SoS) that only continue to grow in complexity to meet evolving capability needs. Thus, timely and affordable acquisition becomes more difficult, especially in the face of mounting budgetary pressures. To counter this, architecting principles must be applied to SoS design. The research objective is to develop an Architecture Real Options Complexity-Based Valuation Methodology (ARC-VM) suitable for acquisition-level decision making, where there is a stated desire for more informed tradeoffs between cost, schedule, and performance during the early phases of design. First, a framework is introduced to measure architecture complexity as it directly relates to military SoS. Development of the framework draws upon a diverse set of disciplines, including Complexity Science, software architecting, measurement theory, and utility theory. Next, a Real Options based valuation strategy is developed using techniques established for financial stock options that have recently been adapted for use in business and engineering decisions. The derived complexity measure provides architects with an objective measure of complexity that focuses on relevant complex system attributes. These attributes are related to the organization and distribution of SoS functionality and the sharing and processing of resources. The use of Real Options provides the necessary conceptual and visual framework to quantifiably and traceably combine measured architecture complexity, time-valued performance levels, as well as programmatic risks and uncertainties. An example suppression of enemy air defenses (SEAD) capability demonstrates the development and usefulness of the resulting architecture complexity & Real Options based valuation methodology. Different

  1. Ranking of options of real estate use by expert assessments mathematical processing

    Science.gov (United States)

    Lepikhina, O. Yu; Skachkova, M. E.; Mihaelyan, T. A.

    2018-05-01

    The article is devoted to the development of the real estate assessment concept. In conditions of multivariate using of the real estate method based on calculating, the integral indicator of each variant’s efficiency is proposed. In order to calculate weights of criteria of the efficiency expert method, Analytic hierarchy process and its mathematical support are used. The method allows fulfilling ranking of alternative types of real estate use in dependence of their efficiency. The method was applied for one of the land parcels located on Primorsky district in Saint Petersburg.

  2. Directed forgetting: Comparing pictures and words.

    Science.gov (United States)

    Quinlan, Chelsea K; Taylor, Tracy L; Fawcett, Jonathan M

    2010-03-01

    The authors investigated directed forgetting as a function of the stimulus type (picture, word) presented at study and test. In an item-method directed forgetting task, study items were presented 1 at a time, each followed with equal probability by an instruction to remember or forget. Participants exhibited greater yes-no recognition of remember than forget items for each of the 4 study-test conditions (picture-picture, picture-word, word-word, word-picture). However, this difference was significantly smaller when pictures were studied than when words were studied. This finding demonstrates that the magnitude of the directed forgetting effect can be reduced by high item memorability, such as when the picture superiority effect is operating. This suggests caution in using pictures at study when the goal of an experiment is to examine potential group differences in the magnitude of the directed forgetting effect. 2010 APA, all rights reserved.

  3. Brief wakeful resting can eliminate directed forgetting.

    Science.gov (United States)

    Schlichting, Andreas; Bäuml, Karl-Heinz T

    2017-02-01

    When cued to intentionally forget previously encoded memories, participants typically show reduced recall of the memories on a later recall test. We examined how such directed forgetting is affected by a brief period of wakeful resting between encoding and test. Encoding was followed by a "passive" wakeful resting period in which subjects heard emotionally neutral music or perceived neutral pictures, or it was followed by an "active" distraction period in which subjects were engaged in counting or calculation tasks. Whereas typical directed forgetting was present after active distraction, the forgetting was absent after wakeful resting. The findings indicate that the degree to which people can intentionally forget memories is influenced by the cognitive activity that people engage in shortly after learning takes place. The results provide first evidence on the interplay between wakeful resting and intentional forgetting.

  4. Pricing and simulation for real estate index options: Radial basis point interpolation

    Science.gov (United States)

    Gong, Pu; Zou, Dong; Wang, Jiayue

    2018-06-01

    This study employs the meshfree radial basis point interpolation (RBPI) for pricing real estate derivatives contingent on real estate index. This method combines radial and polynomial basis functions, which can guarantee the interpolation scheme with Kronecker property and effectively improve accuracy. An exponential change of variables, a mesh refinement algorithm and the Richardson extrapolation are employed in this study to implement the RBPI. Numerical results are presented to examine the computational efficiency and accuracy of our method.

  5. Stochastic control and real options valuation of thermal storage-enabled demand response from flexible district energy systems

    International Nuclear Information System (INIS)

    Kitapbayev, Yerkin; Moriarty, John; Mancarella, Pierluigi

    2015-01-01

    Highlights: • We calculate the real option value of flexibility from CHP-thermal storage. • Stochastic optimal feedback control problem is solved under uncertain market prices. • Efficient real-time numerical solutions combine simulation, regression and recursion. • Clear, interpretable feedback control maps are produced for each hour of the day. • We give a realistic UK case study using projected market gas and electricity prices. - Abstract: In district energy systems powered by Combined Heat and Power (CHP) plants, thermal storage can significantly increase CHP flexibility to respond to real time market signals and therefore improve the business case of such demand response schemes in a Smart Grid environment. However, main challenges remain as to what is the optimal way to control inter-temporal storage operation in the presence of uncertain market prices, and then how to value the investment into storage as flexibility enabler. In this outlook, the aim of this paper is to propose a model for optimal and dynamic control and long term valuation of CHP-thermal storage in the presence of uncertain market prices. The proposed model is formulated as a stochastic control problem and numerically solved through Least Squares Monte Carlo regression analysis, with integrated investment and operational timescale analysis equivalent to real options valuation models encountered in finance. Outputs are represented by clear and interpretable feedback control strategy maps for each hour of the day, thus suitable for real time demand response under uncertainty. Numerical applications to a realistic UK case study with projected market gas and electricity prices exemplify the proposed approach and quantify the robustness of the selected storage solutions

  6. Online EM with weight-based forgetting

    OpenAIRE

    Celaya, Enric; Agostini, Alejandro

    2015-01-01

    In the on-line version of the EM algorithm introduced by Sato and Ishii (2000), a time-dependent discount factor is introduced for forgetting the effect of the old posterior values obtained with an earlier, inaccurate estimator. In their approach, forgetting is uniformly applied to the estimators of each mixture component depending exclusively on time, irrespective of the weight attributed to each unit for the observed sample. This causes an excessive forgetting in the less frequently sampled...

  7. Incorporation of Outcome-Based Contract Requirements in a Real Options Approach for Maintenance Planning

    Science.gov (United States)

    2016-04-30

    corrective maintenance (which increases as the RUL is used up), while maximizing the revenue earned during the RUL (which increases as the RUL is used up...running the system to failure, then performing corrective maintenance The value from exercising the option is the sum of the cumulative revenue loss...and the avoided corrective maintenance cost. The cumulative revenue loss is what the system would earn between the predictive maintenance event and

  8. Capacity payment impact on gas-fired generation investments under rising renewable feed-in — A real options analysis

    International Nuclear Information System (INIS)

    Hach, Daniel; Spinler, Stefan

    2016-01-01

    We assess the effect of capacity payments on investments in gas-fired power plants in the presence of different degrees of renewable energy technology (RET) penetration. Low variable cost renewables increasingly make investments in gas-fired generation unprofitable. At the same time, growing feed-in from intermittent RETs amplifies fluctuations in power generation, thus entailing the need for flexible buffer capacity—currently mostly gas-fired power plants. A real options approach is applied to evaluate investment decisions and timing of a single investor in gas-fired power generation. We investigate the necessity and effectiveness of capacity payments. Our model incorporates multiple uncertainties and assesses the effect of capacity payments under different degrees of RET penetration. In a numerical study, we implement stochastic processes for peak-load electricity prices and natural gas prices. We find that capacity payments are an effective measure to promote new gas-fired generation projects. Especially in times of high renewable feed-in, capacity payments are required to incentivize peak-load investments. - Highlights: • We assess capacity payments under the specific focus of the influence of different degrees of renewable feed-in. • We use a real options approach to analyze investment decision and timing. • Our model reflects stochastic gas prices and stochastic electricity prices. • The case study shows the value of capacity payments to investors especially under high renewable feed-in.

  9. The RealGas and RealGasH2O options of the TOUGH+ code for the simulation of coupled fluid and heat flow in tight/shale gas systems

    Science.gov (United States)

    We developed two new EOS additions to the TOUGH+ family of codes, the RealGasH2O and RealGas. The RealGasH2O EOS option describes the non-isothermal two-phase flow of water and a real gas mixture in gas reservoirs, with a particular focus in ultra-tight (such as tight-sand and sh...

  10. The effects of meshed offshore grids on offshore wind investment – a real options analysis

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten; Kitzing, Lena

    2012-01-01

    Offshore wind farms in future meshed offshore grids could be subject to different regulatory regimes. Feed-in tariffs would absorb market risk from wind farm operators, whereas price premium mechanisms leave operators exposed to market price signals. In this case, it plays a decisive role which...... price applies to a node in an offshore grid. The offshore node will either be integrated into any of the neighbouring markets, with access to the respective maximum price, or be subject to separate nodal pricing. We investigate the different regulatory regimes for connections to one to four countries...... based on a stochastic model capturing uncertainties in prices and line failures. The stochastic analysis shows that in case the wind park is granted access to the respective maximum price, there is a significant option value connected to the operational flexibility of accessing several markets: The wind...

  11. The effects of meshed offshore grids on offshore wind investment – a real options analysis

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten; Kitzing, Lena

    2012-01-01

    based on a stochastic model capturing uncertainties in prices and line failures. The stochastic analysis shows that in case the wind park is granted access to the respective maximum price, there is a significant option value connected to the operational flexibility of accessing several markets: The wind......Offshore wind farms in future meshed offshore grids could be subject to different regulatory regimes. Feed-in tariffs would absorb market risk from wind farm operators, whereas price premium mechanisms leave operators exposed to market price signals. In this case, it plays a decisive role which...... price applies to a node in an offshore grid. The offshore node will either be integrated into any of the neighbouring markets, with access to the respective maximum price, or be subject to separate nodal pricing. We investigate the different regulatory regimes for connections to one to four countries...

  12. Supply chain management and economic valuation of real options in the natural gas and liquefied natural gas industry

    Science.gov (United States)

    Wang, Mulan Xiaofeng

    My dissertation concentrates on several aspects of supply chain management and economic valuation of real options in the natural gas and liquefied natural gas (LNG) industry, including gas pipeline transportations, ocean LNG shipping logistics, and downstream storage. Chapter 1 briefly introduces the natural gas and LNG industries, and the topics studied in this thesis. Chapter 2 studies how to value U.S. natural gas pipeline network transport contracts as real options. It is common for natural gas shippers to value and manage contracts by simple adaptations of financial spread option formulas that do not fully account for the implications of the capacity limits and the network structure that distinguish these contracts. In contrast, we show that these operational features can be fully captured and integrated with financial considerations in a fairly easy and managerially significant manner by a model that combines linear programming and simulation. We derive pathwise estimators for the so called deltas and structurally characterize them. We interpret them in a novel fashion as discounted expectations, under a specific weighing distribution, of the amounts of natural gas to be procured/marketed when optimally using pipeline capacity. Based on the actual prices of traded natural gas futures and basis swaps, we show that an enhanced version of the common approach employed in practice can significantly underestimate the true value of natural gas pipeline network capacity. Our model also exhibits promising financial (delta) hedging performance. Thus, this model emerges as an easy to use and useful tool that natural gas shippers can employ to support their valuation and delta hedging decisions concerning natural gas pipeline network transport capacity contracts. Moreover, the insights that follow from our data analysis have broader significance and implications in terms of the management of real options beyond our specific application. Motivated by current developments

  13. Screening options for Down syndrome: how women choose in real clinical setting.

    Science.gov (United States)

    Lo, T K; Lai, F K; Leung, W C; Lau, W L; Ng, L S; Wong, W C; Tam, S S; Yee, Y C; Choi, H; Lam, H S W; Sham, A S Y; Tang, L C H; Chin, R K H

    2009-09-01

    To study pregnant women's preference among various screening options for Down syndrome (DS) in routine clinical setting, and its potential association with women's demographic characteristics. Women aged 35 years and older carrying singleton pregnancy were offered a variety of screening tests for DS before 14 weeks of gestation. Their preference was confirmed by the test they actually underwent. The association between women's choice of test and a number of demographic characteristics was studied using multinomial regression. Among 1967 eligible women, 619 opted for first-trimester screening test (FTS), 924 for partial integrated test (PIT), and 424 for full integrated test (FIT). Nulliparous women and working mothers were more likely to choose FTS and FIT. Women with history of subfertility were more likely to choose FIT. Women with family history of chromosomal abnormalities were more likely to choose FTS. The choice of screening test could be predicted for 49.9% of women using four demographic characteristics. Among older women of predominantly Chinese ethnicity, integrated test is a favorite alternative to FTS. Their choice of DS screening test can be predicted by their obstetric and socioeconomic characteristics. Many women show willingness to pay for a test with a lower false-positive rate.

  14. Using expanded real options analysis to evaluate capacity expansion decisions under uncertainty in the construction material industry

    Directory of Open Access Journals (Sweden)

    Momani, Amer Mohammad

    2016-08-01

    Full Text Available Capacity expansion generally requires large capital expenditure on illiquid assets. Therefore, decisions to enlarge capacity must support the organisation’s strategic objectives and provide valuable input for the budgeting process. This paper applies an expanded form of Real Options Analysis (ROA to generate and evaluate capacity expansion strategies under uncertainty in the construction material industry. ROA is applied to different expansion strategies associated with different demand scenarios. Evaluating a wider variety of strategies can reduce risk and sponsor decisions that maximise the firm’s value. The case study shows that the execution of a lead expansion strategy with 10-year intervals under a 50 per cent demand satisfaction scenario produces superior results.

  15. Amount of Postcue Encoding Predicts Amount of Directed Forgetting

    Science.gov (United States)

    Pastotter, Bernhard; Bauml, Karl-Heinz

    2010-01-01

    In list-method directed forgetting, participants are cued to intentionally forget a previously studied list (List 1) before encoding a subsequently presented list (List 2). Compared with remember-cued participants, forget-cued participants typically show impaired recall of List 1 and improved recall of List 2, referred to as List 1 forgetting and…

  16. Application of the modified Tobin's q to an uncertain energy-saving project with the real options concept

    International Nuclear Information System (INIS)

    Lin, Tyrone T.; Huang, Shio-Ling

    2011-01-01

    This paper is to develop a modified Tobin's q evaluation method which successfully combines the evaluation criteria of the traditional Tobin's q and the real options. This study provides flexible thinking for decision making criteria. That is, it clearly provides decision-makers with a reference in choosing enter or exit strategies, such as quantitative indicators references. The proposed model introduces two variables stochastic process in continuous time and explores the impact of the occurrence of unexpected events on the project value, so that, it can more authentically response to the project value. The studied issue deals with the firms that have not established energy-saving equipment yet. It attempts to figure out the optimal timing to adopt an energy-saving investment project when it is beneficial and the optimal timing to terminate it when the continuous operation of that business is unprofitable. The future discounted benefit-cost ratio, Q, follows the geometric Brownian motion with the Poisson jump process and the replacement of investment equipment. Except for the evaluation of energy-saving equipment investment project, the proposed model can be applied to other related project evaluation issues, such as energy-saving, CO 2 emission reduction, or general investment projects. - Research highlights: → Develops an approach which combines the traditional Tobin's q and the real options. → Applies to general energy-saving project or other investment projects. → Can more authentically response to the project value with strategic entry and exit. → Provides flexible thinking for decision making criteria via modified Tobin's q model. → Reduces the model complexity and increases the flexibility in practice application.

  17. A real option-based model to valuate CDM projects under uncertain energy policies for emission trading

    International Nuclear Information System (INIS)

    Park, Taeil; Kim, Changyoon; Kim, Hyoungkwan

    2014-01-01

    Highlights: • A real option-based model for the valuation of CDM projects is proposed. • This study investigates the impact of energy policies on the value of CDM projects. • Level of target emission and its schedule should be carefully designed. • Government subsidy facilitates the implementation of CDM projects. • Period for free emission allowance prevents promoting CDM projects. - Abstract: Emission trading has been considered a primary policy tool for emission reduction. Governments establish national targets for emission reduction and assign emission reduction goals to private entities to accomplish the targets. To attain the goal, private entities should perform offset projects that can produce emission credits or buy emission credits from the market. However, it is not easy for private entities to decide to implement the projects because energy policies associated with emission trading keep changing; thus, the future benefits of the offset projects are quite uncertain. This study presents a real option-based model to investigate how uncertain energy policies affect the financial viability of an offset project. A case study showed that the establishment of a target emission was attractive to the government because it could make the CDM project financially viable with a small amount of government subsidy. In addition, the level of the government subsidy could determine the investment timing for the CDM project. In this context, governments should be cautious in designing energy policies, because even the same energy policies could have different impacts on private entities. Overall, this study is expected to assist private entities in establishing proper investment strategies for CDM projects under uncertain energy policies

  18. Using real options to determine optimal funding strategies for CO2 capture, transport and storage projects in the European Union

    International Nuclear Information System (INIS)

    Eckhause, Jeremy; Herold, Johannes

    2014-01-01

    Several projects in the European Union (EU) are currently under development to implement the carbon capture, transport and storage (CCS) technology on a large scale and may be subject to public funding under EU support initiatives. These CCS projects may develop any combination of three types of operating levels: pilot, demonstration and full-scale, representing progressing levels of electric power generation capability. Several projects have commenced at the demonstration level, with full-scale commercial levels planned for approximately 2020. Taking the perspective of a funding agency, we employ a real options framework for determining an optimal project selection and funding strategy for the development of full-scale CCS plants. Specifically, we formulate and solve a stochastic dynamic program (SDP) for obtaining optimal funding solutions in order to achieve at least one successfully operating full-scale CCS plant by a target year. The model demonstrates the improved risk reduction by employing such a multi-stage competition. We then extend the model to consider two sensitivities: (1) the flexibility to spend that budget among the time periods and (2) optimizing the budget, but specifying each time period's allocation a priori. State size and runtimes of the SDP model are provided. - Highlights: • Projects implementing three different CCS technology types are described. • We obtain projects’ transition probabilities and costs from expert interviews. • We use a multi-stage real options model to obtain optimal funding strategies. • Using this approach, actual decision-makers could reduce risks in CCS development

  19. Forgetting: availability, accessibility, and intentional control problem

    Directory of Open Access Journals (Sweden)

    Veronika V. Nourkova

    2016-09-01

    Full Text Available The paper focuses on the phenomenon of forgetting as a primal and generally productive memory process. The cases that require a temporary and permanent forgetting of the material stored in the long-term memory are contrasted. The main methodological obstacle in forgetting research is identified as arising from the logical prohibition to argument from the negative, i.e. “the evidence of absence is not the evidence of absence”. Two mechanisms of forgetting are discussed in the paper: transformation of the memory trace and modulation of trace accessibility. The former mechanism of forgetting consists of memory trace destruction (memory trace decay, retroactive and proactive interference, and «catastrophic» interference or its transformation that leads to forming a new memory representation. We speculate that the most promising way to legitimize the trace destruction mechanism is narrowing the further research to episodic memory subsystem. The latter mechanism of forgetting consists of both passive failure in access to appropriate memory content (the tip of the tongue phenomenon, the category size effect, the fan effect and the process of active retrieval inhibition. This phenomenon represents temporary inhibition of competing semantically similar responses in semantic memory, and motivational inhibition of self-deprecating memories in autobiographical memory. Then we put into consideration a variety of experimental paradigms in intentional forgetting research. Contrary to the common claim that forgetting is а universal and homogeneous phenomenon, we propose that forgetting strategies might vary in different memory subsystems, and also depend on activity characteristics during encoding, storage and retrieval.

  20. Sleep can eliminate list-method directed forgetting.

    Science.gov (United States)

    Abel, Magdalena; Bäuml, Karl-Heinz T

    2013-05-01

    Recent work suggests a link between sleep and memory consolidation, indicating that sleep in comparison to wakefulness stabilizes memories. However, relatively little is known about how sleep affects forgetting. Here we examined whether sleep influences directed forgetting, the finding that people can intentionally forget obsolete memories when cued to do so. We applied the list-method directed forgetting task and assessed memory performance after 3 delay intervals. Directed forgetting was present after a short 20-min delay and after a 12-hr delay filled with diurnal wakefulness; in contrast, the forgetting was absent after a 12-hr delay that included regular nocturnal sleep. Successful directed forgetting after a delay thus can depend on whether sleep or wakefulness follows upon encoding: When wakefulness follows upon encoding, the forgetting can be successful; when sleep follows upon encoding, no forgetting may arise. Connections of the results to recent studies on the interplay between forgetting and sleep are discussed.

  1. Real option valuation of a decremental regulation service provided by electricity storage.

    Science.gov (United States)

    Szabó, Dávid Zoltán; Martyr, Randall

    2017-08-13

    This paper is a quantitative study of a reserve contract for real-time balancing of a power system. Under this contract, the owner of a storage device, such as a battery, helps smooth fluctuations in electricity demand and supply by using the device to increase electricity consumption. The battery owner must be able to provide immediate physical cover, and should therefore have sufficient storage available in the battery before entering the contract. Accordingly, the following problem can be formulated for the battery owner: determine the optimal time to enter the contract and, if necessary, the optimal time to discharge electricity before entering the contract. This problem is formulated as one of optimal stopping, and is solved explicitly in terms of the model parameters and instantaneous values of the power system imbalance. The optimal operational strategies thus obtained ensure that the battery owner has positive expected economic profit from the contract. Furthermore, they provide explicit conditions under which the optimal discharge time is consistent with the overall objective of power system balancing. This paper also carries out a preliminary investigation of the 'lifetime value' aggregated from an infinite sequence of these balancing reserve contracts. This lifetime value, which can be viewed as a single project valuation of the battery, is shown to be positive and bounded. Therefore, in the long run such reserve contracts can be beneficial to commercial operators of electricity storage, while reducing some of the financial and operational risks in power system balancing.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'. © 2017 The Author(s).

  2. Feasibility analysis of the development of an oil field: a real options approach in a production sharing agreement

    Directory of Open Access Journals (Sweden)

    Marcelo Nunes Fonseca

    2017-10-01

    Full Text Available Purpose – The aim of this research is to analyze the feasibility of developing a real oil field in Africa under a production sharing agreement, through the application of the real options theory. Design/methodology/approach – The research was conducted according to the principles of modeling and simulation, based on a structure that consists of three phases, in order to facilitate project feasibility analysis. Findings – Initially, according to the traditional method, we suggest that the decision-maker does not invest in the development of the field. However, by incorporating uncertainty into the decision-making process, other results were obtained. Although reduced, we attested that there is a likelihood of feasibility. Next, by using the binomial model to represent the process of oil barrel price diffusion, the asset value is calculated considering the flexibility of delaying the development of the field. Originality/value – The results show that, if a manager has the right to invest in the future and wait for better oil prices, postponing the development of an oil field adds value to his assets. The proposed method is a contribution that offers subsidies to improve decisionmaking processes to evaluate investments.

  3. How quickly they forget:The relationship between forgetting and working memory performance

    OpenAIRE

    Bayliss, Donna M.; Jarrold, Christopher

    2014-01-01

    This study examined the contribution of individual differences in rate of forgetting to variation in working memory performance in children. One hundred and twelve children (mean age 9 years 4 months) completed 2 tasks designed to measure forgetting, as well as measures of working memory, processing efficiency, and short-term storage ability. Individual differences in forgetting rate accounted for unique variance in working memory performance over and above variance explained by measures of p...

  4. Enfoque de opciones reales para la valoración financiera de marcas Real Options Approach to Financial Valuation of Brands

    Directory of Open Access Journals (Sweden)

    Yessica González Londoño

    2012-12-01

    Full Text Available Los activos intangibles, especialmente las marcas, son parte fundamental del valor de mercado de las compañías, pues representan su ventaja competitiva; sin embargo, la Contabilidad y las Finanzas se enfrentan ante un reto difícil al momento de valorarlos. Los métodos de medición de intangibles en la literatura revisada se caracterizan por ser limitados y subjetivos, e incluso presentan algunos errores conceptuales, encontrándose su utilidad principal en el campo de la gestión. Este artículo propone una metodología para la valoración financiera de marcas a partir de una extensión de la aplicación de opciones reales compuestas de las patentes, aprovechando las similitudes en su construcción. Su aplicación se ilustra mediante la valoración de la marca de una compañía aseguradora.Intangible assets are an important component of the market value of a company, particularly in brands which represent the competitive advantage of the company; however, both Accounting and Finance face a great challenge when trying to value them. The methods which have been proposed by the literature appear to be subjective, limited, and based on some theoretical errors. Their use is mainly circumscribed to the management of intangibles. This paper proposes a methodology for the financial valuation of brands based on the application of a compound real option model to a patent valuation, acknowledging the similarities in their construction. Later, an application to an insurance company is presented.

  5. THE VALUATION OF INITIAL SHARE PRICE USING THE FREE CASH FLOW TO FIRM METHOD AND THE REAL OPTION METHOD IN INDONESIA STOCK EXCHANGE

    Directory of Open Access Journals (Sweden)

    Adhy Listya Paramitha

    2014-01-01

    Full Text Available The purposes of this study were to determine fair share value, to analyze the factors that influence undervalue and overvalue, and to determine the best valuation method. This study made valuation using real options method and free cash flow to firm method. The results of partial logistic regression on Free Cash Flow to Firm showed that tenor variable and equity variable had positive and significant effects, while dummy variable had a negative and significant effect. In the real option model, tenor variable and implied volatility variable had positive and significant effects, while sheets of share variable had a negative and significant effect

  6. Active forgetting of olfactory memories in Drosophila.

    Science.gov (United States)

    Berry, Jacob A; Davis, Ronald L

    2014-01-01

    Failure to remember, or forgetting, is a phenomenon familiar to everyone and despite more than a century of scientific inquiry, why we forget what we once knew remains unclear. If the brain marshals significant resources to form and store memories, why is it that these memories become lost? In the last century, psychological studies have divided forgetting into decay theory, in which memory simply dissipates with time, and interference theory, in which additional learning or mental activity hinders memory by reducing its stability or retrieval (for review, Dewar et al., 2007; Wixted, 2004). Importantly, these psychological models of forgetting posit that forgetting is a passive property of the brain and thus a failure of the brain to retain memories. However, recent neuroscience research on olfactory memory in Drosophila has offered evidence for an alternative conclusion that forgetting is an "active" process, with specific, biologically regulated mechanisms that remove existing memories (Berry et al., 2012; Shuai et al., 2010). Similar to the bidirectional regulation of cell number by mitosis and apoptosis, protein concentration by translation and lysosomal or proteomal degradation, and protein phosphate modification by kinases and phosphatases, biologically regulated memory formation and removal would be yet another example in biological systems where distinct and separate pathways regulate the creation and destruction of biological substrates. © 2014 Elsevier B.V. All rights reserved.

  7. Dissecting neural pathways for forgetting in Drosophila olfactory aversive memory.

    Science.gov (United States)

    Shuai, Yichun; Hirokawa, Areekul; Ai, Yulian; Zhang, Min; Li, Wanhe; Zhong, Yi

    2015-12-01

    Recent studies have identified molecular pathways driving forgetting and supported the notion that forgetting is a biologically active process. The circuit mechanisms of forgetting, however, remain largely unknown. Here we report two sets of Drosophila neurons that account for the rapid forgetting of early olfactory aversive memory. We show that inactivating these neurons inhibits memory decay without altering learning, whereas activating them promotes forgetting. These neurons, including a cluster of dopaminergic neurons (PAM-β'1) and a pair of glutamatergic neurons (MBON-γ4>γ1γ2), terminate in distinct subdomains in the mushroom body and represent parallel neural pathways for regulating forgetting. Interestingly, although activity of these neurons is required for memory decay over time, they are not required for acute forgetting during reversal learning. Our results thus not only establish the presence of multiple neural pathways for forgetting in Drosophila but also suggest the existence of diverse circuit mechanisms of forgetting in different contexts.

  8. Trip Travel Time Forecasting Based on Selective Forgetting Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Zhiming Gui

    2014-01-01

    Full Text Available Travel time estimation on road networks is a valuable traffic metric. In this paper, we propose a machine learning based method for trip travel time estimation in road networks. The method uses the historical trip information extracted from taxis trace data as the training data. An optimized online sequential extreme machine, selective forgetting extreme learning machine, is adopted to make the prediction. Its selective forgetting learning ability enables the prediction algorithm to adapt to trip conditions changes well. Experimental results using real-life taxis trace data show that the forecasting model provides an effective and practical way for the travel time forecasting.

  9. Intentional Forgetting Reduces Color-Naming Interference: Evidence from Item-Method Directed Forgetting

    Science.gov (United States)

    Lee, Yuh-shiow; Lee, Huang-mou; Fawcett, Jonathan M.

    2013-01-01

    In an item-method-directed forgetting task, Chinese words were presented individually, each followed by an instruction to remember or forget. Colored probe items were presented following each memory instruction requiring a speeded color-naming response. Half of the probe items were novel and unrelated to the preceding study item, whereas the…

  10. How Quickly They Forget: The Relationship between Forgetting and Working Memory Performance

    Science.gov (United States)

    Bayliss, Donna M.; Jarrold, Christopher

    2015-01-01

    This study examined the contribution of individual differences in rate of forgetting to variation in working memory performance in children. One hundred and twelve children (mean age 9 years 4 months) completed 2 tasks designed to measure forgetting, as well as measures of working memory, processing efficiency, and short-term storage ability.…

  11. Implementation of a real option in a sustainable supply chain: an empirical study of alkaline battery recycling

    Science.gov (United States)

    Cucchiella, Federica; D'Adamo, Idiano; Gastaldi, Massimo; Lenny Koh, S. C.

    2014-06-01

    Green supply chain management (GSCM) has emerged as a key approach for enterprises seeking to become environmentally sustainable. This paper aims to evaluate and describe the advantages of a GSCM approach by analysing practices and performance consequences in the battery recycling sector. It seeks to integrate works in supply chain management (SCM), environmental management, performance management and real option (RO) theory into one framework. In particular, life cycle assessment (LCA) is applied to evaluate the environmental impact of a battery recycling plant project, and life cycle costing (LCC) is applied to evaluate its economic impact. Firms, also understanding the relevance of GSCM, have often avoided applying the green principles because of the elevated costs that such management involved. Such costs could also seem superior to the potential advantages since standard performance measurement systems are internally and business focused; for these reasons, we consider all the possible value deriving also by uncertainty associated to a green project using the RO theory. This work is one of the few and pioneering efforts to investigate GSCM practices in the battery recycling sector.

  12. Energy Recovery from the Organic Fraction of Municipal Solid Waste: A Real Options-Based Facility Assessment

    Directory of Open Access Journals (Sweden)

    Luigi Ranieri

    2018-01-01

    Full Text Available During the last years, due to the strict regulations on waste landfilling, anaerobic digestion (AD of the organic fraction of municipal solid waste (OFMSW is increasingly considered a sustainable alternative for waste stabilization and energy recovery. AD can reduce the volume of OFMSW going to landfill and produce, at the same time, biogas and compost, all at a profit. The uncertainty about the collected quantity of organic fraction, however, may undermine the economic-financial sustainability of such plants. While the flexibility characterizing some AD technologies may prove very valuable in uncertain contexts since it allows adapting plant capacity to changing environments, the investment required for building flexible systems is generally higher than the investment for dedicated equipment. Hence, an adequate justification of investments in these flexible systems is needed. This paper presents the results of a study aimed at investigating how different technologies may perform from technical, economic and financial standpoints, in presence of an uncertain organic fraction quantity to be treated. Focusing on two AD treatment plant configurations characterized by a technological process with different degree of flexibility, a real options-based model is developed and then applied to the case of the urban waste management system of the Metropolitan Area of Bari (Italy. Results show the importance of pricing the flexibility of treatment plants, which becomes a critical factor in presence of an uncertain organic fraction. Hence, it has to be taken into consideration in the design phase of these plants.

  13. Dedicating new real estate transfer taxes for energy efficiency: A revenue option for scaling up Green Retrofit Programs

    International Nuclear Information System (INIS)

    Lester, T. William

    2013-01-01

    As the labor market in the U.S. remains weak, with high unemployment and sluggish job growth, policymakers at various levels of government are looking for new ways to support job growth and investment during an increasingly tight fiscal climate. Policies that promote the “Green Economy” in general and energy efficiency in particular remain politically popular as potential win–win solutions that will create jobs and curb greenhouse gas emissions. Yet, efforts to promote energy efficiency in the residential sector through rebates and incentives alone have yet to reach critical mass. This paper outlines a policy option for state and local governments to use real estate transfer taxes to generate stronger incentives for home buyers to undertake significant retrofit projects at the time of sale. The economic impact of the proposed energy efficiency transfer tax (EETT) is then modeled for the State of North Carolina, using standard input–output techniques. Ultimately, based on housing sales figures from 2010, a new EETT of 2.5 percent on home purchases would generate a net positive increase of approximately 3485 direct construction jobs and 5900 annually total jobs for the state. -- Highlights: •Proposes an Energy Efficiency Transfer Tax (EETT) to catalyze residential retrofits. •Models household behavioral response to an EETT. •Estimates induced energy efficiency investment levels in North Carolina. •Calculates net employment impacts of a hypothetical EETT. •Finds net impact of 5900 jobs and over $350 million in additional investment

  14. Feasibility analysis in the expansion proposal of the nuclear power plant Laguna Verde: application of real options, binomial model

    International Nuclear Information System (INIS)

    Hernandez I, S.; Ortiz C, E.; Chavez M, C.

    2011-11-01

    At the present time, is an unquestionable fact that the nuclear electrical energy is a topic of vital importance, no more because eliminates the dependence of the hydrocarbons and is friendly with the environment, but because is also a sure and reliable energy source, and represents a viable alternative before the claims in the growing demand of electricity in Mexico. Before this panorama, was intended several scenarios to elevate the capacity of electric generation of nuclear origin with a variable participation. One of the contemplated scenarios is represented by the expansion project of the nuclear power plant Laguna Verde through the addition of a third reactor that serves as detonator of an integral program that proposes the installation of more nuclear reactors in the country. Before this possible scenario, the Federal Commission of Electricity like responsible organism of supplying energy to the population should have tools that offer it the flexibility to be adapted to the possible changes that will be presented along the project and also gives a value to the risk to future. The methodology denominated Real Options, Binomial model was proposed as an evaluation tool that allows to quantify the value of the expansion proposal, demonstrating the feasibility of the project through a periodic visualization of their evolution, all with the objective of supplying a financial analysis that serves as base and justification before the evident apogee of the nuclear energy that will be presented in future years. (Author)

  15. A Real Options Method for Estimating the Adoption Potential of Forestry and Agroforestry Systems on Private Lands in the Lower Mississippi Alluvial Valley, USA

    Science.gov (United States)

    Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt

    2010-01-01

    The Lower Mississippi River Alluvial Valley (LMAV), once was the largest forested bottom-land area in the continental United States, but has undergone widespread loss of forest through conversion to farmland. Restoration of forest functions and values has been a key conservation goal in the LMAV since the 1970s. This study utilizes a partial differential real options...

  16. Reducing uncertainty in load forecasts and using real options for improving capacity dispatch management through the utilization of weather and hydrologic forecasts

    International Nuclear Information System (INIS)

    Davis, T.

    2004-01-01

    The effect of weather on electricity markets was discussed with particular focus on reducing weather uncertainty by improving short term weather forecasts. The implications of weather for hydroelectric power dispatch and use were also discussed. Although some errors in weather forecasting can result in economic benefits, most errors are associated with more costs than benefits. This presentation described how a real options analysis can make weather a favorable option. Four case studies were presented for exploratory data analysis of regional weather phenomena. These included: (1) the 2001 California electricity crisis, (2) the delta breeze effects on the California ISO, (3) the summer 2002 weather forecast error for ISO New England, and (4) the hydro plant asset valuation using weather uncertainty. It was concluded that there is a need for more economic methodological studies on the effect of weather on energy markets and costs. It was suggested that the real options theory should be applied to weather planning and utility applications. tabs., figs

  17. Flexibility in using Diesel or biodiesel: an approach via real options; Flexibilidade na utilizacao de Diesel ou biodiesel: uma abordagem via opcoes reais

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Edson Daniel Lopes [Fundacao Getulio Vargas, Rio de Janeiro, RJ (Brazil)]. E-mail: edson@fgvmail.br; Ferreira, Leonardo Leandro [PETROBRAS, Rio de Janeiro, RJ (Brazil)]. E-mail: leonardo.ferreira@petrobras.com.br

    2008-09-15

    This work will approach the bio diesel development as renewable source fuel in the Brazilian energetic matrix. Essentially, the utilization flexibility will be considered between the traditional petroleum origin Diesel and the vegetable origin Biodiesel. So, our target is the evaluation of the flexibility existent between those two fuels. A consideration will be made via real options, where the fuel choice for supplying is modelled as a an european options sequence. Those switch input real options attributes a value to the project and minimizes the risks associated to the energy offer shortage which is another recurrent problem inside our reality. At least, some comments will be made on the potential gain on the aggregate value for the Brazil, as a consequence of Diesel dependent road transportation.

  18. An ill-posed problem for the Black-Scholes equation for a profitable forecast of prices of stock options on real market data

    Science.gov (United States)

    Klibanov, Michael V.; Kuzhuget, Andrey V.; Golubnichiy, Kirill V.

    2016-01-01

    A new empirical mathematical model for the Black-Scholes equation is proposed to forecast option prices. This model includes new interval for the price of the underlying stock, new initial and new boundary conditions. Conventional notions of maturity time and strike prices are not used. The Black-Scholes equation is solved as a parabolic equation with the reversed time, which is an ill-posed problem. Thus, a regularization method is used to solve it. To verify the validity of our model, real market data for 368 randomly selected liquid options are used. A new trading strategy is proposed. Our results indicates that our method is profitable on those options. Furthermore, it is shown that the performance of two simple extrapolation-based techniques is much worse. We conjecture that our method might lead to significant profits of those financial insitutions which trade large amounts of options. We caution, however, that further studies are necessary to verify this conjecture.

  19. Real Time Pricing as a Default or Optional Service for C&ICustomers: A Comparative Analysis of Eight Case Studies

    Energy Technology Data Exchange (ETDEWEB)

    Barbose, Galen; Goldman, Charles; Bharvirkar, Ranjit; Hopper,Nicole; Ting, Michael; Neenan, Bernie

    2005-08-01

    Demand response (DR) has been broadly recognized to be an integral component of well-functioning electricity markets, although currently underdeveloped in most regions. Among the various initiatives undertaken to remedy this deficiency, public utility commissions (PUC) and utilities have considered implementing dynamic pricing tariffs, such as real-time pricing (RTP), and other retail pricing mechanisms that communicate an incentive for electricity consumers to reduce their usage during periods of high generation supply costs or system reliability contingencies. Efforts to introduce DR into retail electricity markets confront a range of basic policy issues. First, a fundamental issue in any market context is how to organize the process for developing and implementing DR mechanisms in a manner that facilitates productive participation by affected stakeholder groups. Second, in regions with retail choice, policymakers and stakeholders face the threshold question of whether it is appropriate for utilities to offer a range of dynamic pricing tariffs and DR programs, or just ''plain vanilla'' default service. Although positions on this issue may be based primarily on principle, two empirical questions may have some bearing--namely, what level of price response can be expected through the competitive retail market, and whether establishing RTP as the default service is likely to result in an appreciable level of DR? Third, if utilities are to have a direct role in developing DR, what types of retail pricing mechanisms are most appropriate and likely to have the desired policy impact (e.g., RTP, other dynamic pricing options, DR programs, or some combination)? Given a decision to develop utility RTP tariffs, three basic implementation issues require attention. First, should it be a default or optional tariff, and for which customer classes? Second, what types of tariff design is most appropriate, given prevailing policy objectives, wholesale market

  20. Cue-independent forgetting by intentional suppression - Evidence for inhibition as the mechanism of intentional forgetting.

    Science.gov (United States)

    Wang, Yingying; Cao, Zhijun; Zhu, Zijian; Cai, Huaqian; Wu, Yanhong

    2015-10-01

    People are able to intentionally forget unwanted memories through voluntary suppression, as revealed by the Think/No-think (TNT) paradigm. However, the nature of intentional forgetting is controversial. Findings that forgetting is independent of retrieval cues suggest that inhibitory control underlies intentional forgetting, but this result is also in line with an interference account. To resolve this controversy, we have directly contrasted the cue-independent characteristic of suppression versus interference. A double-cue paradigm was used, in which two different cues were associated with the same target during initial memory formation. Only one cue-target association received further interference/suppression training. In the test phase, when both cues were used to retrieve the target, we found that interference caused memory impairment that was restricted to the trained cue-target association, while suppression induced forgetting that generalized to the independent cue-target association. Therefore, the effect of suppression differs from that of interference. The cue-independent forgetting by voluntary suppression indicates that the target memory itself is inhibited, providing evidence that the underlying mechanism of suppression-induced forgetting is inhibitory control. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Computational constraints in cognitive theories of forgetting.

    Science.gov (United States)

    Ecker, Ullrich K H; Lewandowsky, Stephan

    2012-01-01

    This article highlights some of the benefits of computational modeling for theorizing in cognition. We demonstrate how computational models have been used recently to argue that (1) forgetting in short-term memory is based on interference not decay, (2) forgetting in list-learning paradigms is more parsimoniously explained by a temporal distinctiveness account than by various forms of consolidation, and (3) intrusion asymmetries that appear when information is learned in different contexts can be explained by temporal context reinstatement rather than labilization and reconsolidation processes.

  2. A synapse memristor model with forgetting effect

    International Nuclear Information System (INIS)

    Chen, Ling; Li, Chuandong; Huang, Tingwen; Chen, Yiran; Wen, Shiping; Qi, Jiangtao

    2013-01-01

    In this Letter we improved the ion diffusion term proposed in literature and redesigned the previous model as a dynamical model with two more internal state variables ‘forgetting rate’ and ‘retention’ besides the original variable ‘conductance’. The new model can not only describe the basic memory ability of memristor but also be able to capture the new finding forgetting behavior in memristor. And different from the previous model, the transition from short term memory to long term memory is also defined by the new model. Besides, the new model is better matched with the physical memristor (Pd/WOx/W) than the previous one.

  3. Computational constraints in cognitive theories of forgetting

    Directory of Open Access Journals (Sweden)

    Ullrich eEcker

    2012-10-01

    Full Text Available This article highlights some of the benefits of computational modeling for theorizing in cognition. We demonstrate how computational models have been used recently to argue that (1 forgetting in short-term memory is based on interference not decay, (2 forgetting in list-learning paradigms is more parsimoniously explained by a temporal distinctiveness account than by various forms of consolidation, and (3 intrusion asymmetries that appear when information is learned in different contexts can be explained by temporal context reinstatement rather than labilization and reconsolidation processes.

  4. Remembering episodic memories is not necessary for forgetting of negative words: Semantic retrieval can cause forgetting of negative words.

    Science.gov (United States)

    Kobayashi, Masanori; Tanno, Yoshihiko

    2015-06-01

    Retrieval of a memory can induce forgetting of other related memories, which is known as retrieval-induced forgetting. Although most studies have investigated retrieval-induced forgetting by remembering episodic memories, this also can occur by remembering semantic memories. The present study shows that retrieval of semantic memories can lead to forgetting of negative words. In two experiments, participants learned words and then engaged in retrieval practice where they were asked to recall words related to the learned words from semantic memory. Finally, participants completed a stem-cued recall test for the learned words. The results showed forgetting of neutral and negative words, which was characteristic of semantic retrieval-induced forgetting. A certain degree of overlapping features, except same learning episode, is sufficient to cause retrieval-induced forgetting of negative words. Given the present results, we conclude that retrieval-induced forgetting of negative words does not require recollection of episodic memories.

  5. Sleep Can Eliminate List-Method Directed Forgetting

    Science.gov (United States)

    Abel, Magdalena; Bäuml, Karl-Heinz T.

    2013-01-01

    Recent work suggests a link between sleep and memory consolidation, indicating that sleep in comparison to wakefulness stabilizes memories. However, relatively little is known about how sleep affects forgetting. Here we examined whether sleep influences directed forgetting, the finding that people can intentionally forget obsolete memories when…

  6. Forget me (not?’ – Remembering forget-items versus un-cued items in directed forgetting

    Directory of Open Access Journals (Sweden)

    Bastian eZwissler

    2015-11-01

    Full Text Available Humans need to be able to selectively control their memories. Here, we investigate the underlying processes in item-method directed forgetting and compare the classic active memory cues in this paradigm with a passive instruction. Typically, individual items are presented and each is followed by either a forget- or remember-instruction. On a surprise test of all items, memory is then worse for to-be-forgotten items (TBF compared to to-be-remembered items (TBR. This is thought to result from selective rehearsal of TBR, or from active inhibition of TBF, or from both. However, evidence suggests that if a forget instruction initiates active processing, paradoxical effects may also arise. To investigate the underlying mechanisms, four experiments were conducted where un-cued items (UI were introduced and recognition performance was compared between TBR, TBF and UI stimuli. Accuracy was encouraged via a performance-dependent monetary bonus. Across all experiments, including perceptually fully matched variants, memory accuracy for TBF was reduced compared to TBR, but better than for UI. Moreover, participants used a more conservative response criterion when responding to TBF stimuli. Thus, ironically, the F cue results in active processing, but this does not have inhibitory effects that would impair recognition memory beyond a un-cued baseline condition. This casts doubts on inhibitory accounts of item-method directed forgetting and is also difficult to reconcile with pure selective rehearsal of TBR. While the F-cue does induce active processing, this does not result in particularly successful forgetting. The pattern seems most consistent with the notion of ironic processing.

  7. Forgetting to forget: On the duration of voluntary suppression of neutral and emotional memories

    DEFF Research Database (Denmark)

    Nørby, Simon; Lange, Martin; Larsen, Axel

    2010-01-01

    retrieval but does not lead to long-term forgetting. Furthermore, the amount of training that clearly reduced immediate recall of neutral items did not at all reduce recall of emotional items. This finding is in accordance with the notion that emotional items have a higher degree of salience and tend......Can we control the content of our memory and forget what we do not want to think about by an act of will? If so, is forgetting temporary or permanent, and is it independent of the nature of what we wish to forget? Using Anderson and Green’s (2001) ‘‘think/no-think” paradigm with neutral...... and emotional nouns, we found in agreement with other studies that memory for neutral words was reduced instantly upon repeated attempts at suppression. However, the effect was temporary and vanished after a period of one week, which strongly suggests that intended memory suppression interferes with immediate...

  8. An Application of the Real Options Method to the Valuation of a License to Operate 3G Mobile Phone Service in Brazil.

    Directory of Open Access Journals (Sweden)

    Rafael Stille

    2010-10-01

    Full Text Available We analyze the contributions of the real option method to the decision making process in the telecommunications industry. We study the case of a public auction purchase of the license to operate a 3G mobile phone system in Brazil. The results indicate that the embedded flexibilities increase the value of the project by 64% in relative to the discounted cash flow method, which could justify the high premiums paid by the winning firms, which are incompatible with the value obtained from traditional methods of analysis. This suggests that the real options approach used, which can be easily replicated and is fairly intuitive, can be a useful tool to support the decision making process of these firms.

  9. Delaying investments in sensor technology: The rationality of dairy farmers' investment decisions illustrated within the framework of real options theory.

    Science.gov (United States)

    Rutten, C J; Steeneveld, W; Oude Lansink, A G J M; Hogeveen, H

    2018-05-02

    The adoption rate of sensors on dairy farms varies widely. Whereas some sensors are hardly adopted, others are adopted by many farmers. A potential rational explanation for the difference in adoption may be the expected future technological progress in the sensor technology and expected future improved decision support possibilities. For some sensors not much progress can be expected because the technology has already made enormous progress in recent years, whereas for sensors that have only recently been introduced on the market, much progress can be expected. The adoption of sensors may thus be partly explained by uncertainty about the investment decision, in which uncertainty lays in the future performance of the sensors and uncertainty about whether improved informed decision support will become available. The overall aim was to offer a plausible example of why a sensor may not be adopted now. To explain this, the role of uncertainty about technological progress in the investment decision was illustrated for highly adopted sensors (automated estrus detection) and hardly adopted sensors (automated body condition score). This theoretical illustration uses the real options theory, which accounts for the role of uncertainty in the timing of investment decisions. A discrete event model, simulating a farm of 100 dairy cows, was developed to estimate the net present value (NPV) of investing now and investing in 5 yr in both sensor systems. The results show that investing now in automated estrus detection resulted in a higher NPV than investing 5 yr from now, whereas for the automated body condition score postponing the investment resulted in a higher NPV compared with investing now. These results are in line with the observation that farmers postpone investments in sensors. Also, the current high adoption of automated estrus detection sensors can be explained because the NPV of investing now is higher than the NPV of investing in 5 yr. The results confirm that

  10. Modelling Dynamic Forgetting in Distributed Information Systems

    NARCIS (Netherlands)

    N.F. Höning (Nicolas); M.C. Schut

    2010-01-01

    htmlabstractWe describe and model a new aspect in the design of distributed information systems. We build upon a previously described problem on the microlevel, which asks how quickly agents should discount (forget) their experience: If they cherish their memories, they can build their reports on

  11. Retrieval-Induced Forgetting: A Developmental Study

    Science.gov (United States)

    Ford, Ruth M.; Keating, Sam; Patel, Rina

    2004-01-01

    Two studies examined the possibility of retrieval-induced forgetting by 7-year-olds. Children heard a story while viewing pictures of events mentioned in the story, each highlighting objects drawn from two distinct semantic categories (e.g. animals and food). Over the next several days, children were asked the same yes/no questions about half the…

  12. A mathematical model of forgetting and amnesia

    NARCIS (Netherlands)

    Murre, J.M.J.; Chessa, A.G.; Meeter, M.

    2013-01-01

    We describe a mathematical model of learning and memory and apply it to the dynamics of forgetting and amnesia. The model is based on the hypothesis that the neural systems involved in memory at different time scales share two fundamental properties: (1) representations in a store decline in

  13. A model for interference and forgetting

    NARCIS (Netherlands)

    Raaijmakers, J.G.W.; Mensink, G.J.M.A

    1988-01-01

    A new model for interference and forgetting is presented. The model is based on the search of associative memory (SAM) theory for retrieval from long-term memory by J. G. Raaijmakers and R. M. Shiffrin, see record 1981-20491-001). It includes a contextual fluctuation process that enables it to

  14. Rate of Forgetting in Dementia and Depression.

    Science.gov (United States)

    Hart, Robert P.; And Others

    1987-01-01

    Examined patients (N=14) with mild Alzheimer's dementia (DAT), patients with major depression (N=10), and normal control subjects (N=14), for rate of forgetting. Suggests that some form of deficient consolidation contributes to memory loss in DAT but not in depression. Implicates the disruption of different psychobiological mechanisms in these…

  15. Real options as an alternative methodology to assess investment projects Las opciones reales como metodología alternativa en la evaluación de proyectos de inversión

    Directory of Open Access Journals (Sweden)

    Raúl Enrique Aristizábal Velásquez

    2012-12-01

    Full Text Available This paper aims to broaden the applicability of the assessment methodology of investment projects through real options as a key element for investment decision making. Traditional project valuation methodologies are described and their gaps, which special characteristic is uncertainty, are presented. A parallel between financial and real options that could be used for valuation is made, using the binomial tree method. Finally, a case study in the construction sector shows a project valuation using expand and waiting options.Este trabajo busca ampliar la aplicabilidad de la metodología de valoración de proyectos de inversión por medio de opciones reales como un elemento fundamental al momento de tomar una decisión de si se debe invertir o no. Se hace un recorrido por las técnicas tradicionales para valorar un proyecto de inversión y se plantean los vacíos que estos dejan, con respecto a proyectos en los que su principal característica es la incertidumbre. Se realiza un paralelo entre las opciones financieras y las opciones reales que per- mita valorar, utilizando la metodología de los árboles binomiales. Por último, se elabora un caso del que se plantea valorar una opción de espera y una opción de expandir de manera conjunta en el sector de la construcción.

  16. Forgetting and emotion regulation in mental health, anxiety and depression.

    Science.gov (United States)

    Nørby, Simon

    2018-03-01

    Does normal forgetting facilitate mental health and is forgetting impaired in affective disorders? This double-sided question may seem counterintuitive given the fact that forgetting is often associated with troubles in everyday life. However, forgetting does not only have destructive consequences, but also fulfils important functions. I consider the possibility that forgetting may function as a beneficial sorting mechanism which helps healthy people discard information that is undesirable and unpleasant. Thus, selective forgetting of negative memories may be part of emotion regulation, that is, people's attempts to control when and how they experience and express emotions. Such forgetting may allow for a focus on positive memories and thereby help form a mnemonic basis for optimism as well as active and explorative approach behaviour. Also, I consider the possibility that anxiety and depression may in part result from and be maintained by a diminished capacity to forget. A reduced ability to selectively forget negative memories may be one reason that such disorders are characterised by painful emotions such as fear and sadness as well as defensive and withdrawn behaviour. Overall, I review and reflect on evidence for and against functional forgetting in mental health and dysfunctional forgetting in affective disorders.

  17. Memory accessibility and medical decision-making for significant others: The role of socially-shared retrieval induced forgetting

    Directory of Open Access Journals (Sweden)

    Dora M Coman

    2013-06-01

    Full Text Available Medical decisions will often entail a broad search for relevant information. No sources alone may offer a complete picture, and many may be selective in their presentation. This selectivity may induce forgetting for previously learned material, thereby adversely affecting medical decision-making. In the study phase of two experiments, participants learned information about a fictitious disease and advantages and disadvantages of four treatment options. In the subsequent practice phase, they read a pamphlet selectively presenting either relevant (Experiment 1 or irrelevant (Experiment 2 advantages or disadvantages. A final cued recall followed and, in Experiment 2, a decision as to the best treatment for a patient. Not only did reading the pamphlet induce forgetting for related and unmentioned information, the induced forgetting adversely affected decision-making. The research provides a cautionary note about the risks of searching through selectively presented information when making a medical decision.

  18. The RealGas and RealGasH2O Options of the TOUGH+ Code for the Simulation of Coupled Fluid and Heat Flow in Tight/Shale Gas Systems

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, George; Freeman, Craig

    2013-09-30

    We developed two new EOS additions to the TOUGH+ family of codes, the RealGasH2O and RealGas . The RealGasH2O EOS option describes the non-isothermal two-phase flow of water and a real gas mixture in gas reservoirs, with a particular focus in ultra-tight (such as tight-sand and shale gas) reservoirs. The gas mixture is treated as either a single-pseudo-component having a fixed composition, or as a multicomponent system composed of up to 9 individual real gases. The RealGas option has the same general capabilities, but does not include water, thus describing a single-phase, dry-gas system. In addition to the standard capabilities of all members of the TOUGH+ family of codes (fully-implicit, compositional simulators using both structured and unstructured grids), the capabilities of the two codes include: coupled flow and thermal effects in porous and/or fractured media, real gas behavior, inertial (Klinkenberg) effects, full micro-flow treatment, Darcy and non-Darcy flow through the matrix and fractures of fractured media, single- and multi-component gas sorption onto the grains of the porous media following several isotherm options, discrete and fracture representation, complex matrix-fracture relationships, and porosity-permeability dependence on pressure changes. The two options allow the study of flow and transport of fluids and heat over a wide range of time frames and spatial scales not only in gas reservoirs, but also in problems of geologic storage of greenhouse gas mixtures, and of geothermal reservoirs with multi-component condensable (H2O and CH4) and non-condensable gas mixtures. The codes are verified against available analytical and semi-analytical solutions. Their capabilities are demonstrated in a series of problems of increasing complexity, ranging from isothermal flow in simpler 1D and 2D conventional gas reservoirs, to non-isothermal gas flow in 3D fractured shale gas reservoirs involving 4 types of fractures, micro-flow, non-Darcy flow and gas

  19. Investment analysis in hydraulic energy generation by using the real options theory; Analise de investimentos em geracao hidraulica utilizando a teoria de opcoes reais

    Energy Technology Data Exchange (ETDEWEB)

    Noronha, J.C. Caminha; Lima, J.W. Marangon [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)]. E-mails: juliaccn@unifei.edu.br; marangon@unifei.edu.br; Ferreira, T.G. Leite [Associacao Brasileira dos Investidores em Autoproducao de Energia Eletrica (ABIAPE), Brasilia, DF (Brazil)]. E-mail: tiago@abiape.com.br

    2006-07-01

    This paper presents a methodology of investment analysis in power plants using the Real Option Theory. Particularly, the investment opportunity of a hydro plant is valued based on the energy that will be traded at the new energy auction using the Brazilian Development Bank - BNDES financing program for the Generation of electric energy (new energy). Since this kind of project involves a multistage investment consisting of design, construction and operation phases, it can be treated as a sequential compound option. A binomial approach was elaborated to model this investment opportunity analysis. This approach models the uncertainties in setting up the cash flow for the investments and incorporates some possible managerial flexibility associated with the decision taken along the investment forecast. The proposed methodology will be described in parallel with an example of a real hydro-plant in which we incorporated the flexibilities regarding the decision to invest in each step of the project and an build phase abandon option, representing the transfer of concession rights after the auction. (author)

  20. The primary assessment tool at Philips electronics : capturing real options and organizational risk in technology portfolio management

    NARCIS (Netherlands)

    Lint, L.J.O.

    2000-01-01

    I develop an extended scoring approach to build a balanced portfolio of new technology projects under uncertainty at early stages of development. My contribution is twofold. First, I show how the tool incorporates the option approach to decision making to create contingent claims on future market

  1. Learning to forget: continual prediction with LSTM.

    Science.gov (United States)

    Gers, F A; Schmidhuber, J; Cummins, F

    2000-10-01

    Long short-term memory (LSTM; Hochreiter & Schmidhuber, 1997) can solve numerous tasks not solvable by previous learning algorithms for recurrent neural networks (RNNs). We identify a weakness of LSTM networks processing continual input streams that are not a priori segmented into subsequences with explicitly marked ends at which the network's internal state could be reset. Without resets, the state may grow indefinitely and eventually cause the network to break down. Our remedy is a novel, adaptive "forget gate" that enables an LSTM cell to learn to reset itself at appropriate times, thus releasing internal resources. We review illustrative benchmark problems on which standard LSTM outperforms other RNN algorithms. All algorithms (including LSTM) fail to solve continual versions of these problems. LSTM with forget gates, however, easily solves them, and in an elegant way.

  2. FORGETFULNESS DURING AGING: AN INTEGRATED BIOLOGY

    Science.gov (United States)

    Gold, Paul E.; Korol, Donna L.

    2014-01-01

    Age-related impairments in memory are often attributed to failures, at either systems or molecular levels, of memory storage processes. A major characteristic of changes in memory with increasing age is the advent of forgetfulness in old vs. young animals. This review examines the contribution of a dysfunction of the mechanisms responsible for modulating the maintenance of memory in aged rats. A memory-modulating system that includes epinephrine, acting through release of glucose from liver glycogen stores, potently enhances memory in young rats. In old rats, epinephrine loses its ability to release glucose and loses its efficacy in enhancing memory. Brain measures of extracellular levels of glucose in the hippocampus during memory testing show decreases in glucose in both young and old rats, but the decreases are markedly greater in extent and duration in old rats. Importantly, the old rats do not have the ability to increase blood glucose levels in response to arousal-related epinephrine release, which is retained and even increased in aged rats. Glucose appears to be able to reverse fully the increased rate of forgetting seen in old rats. This set of findings suggests that physiological mechanisms outside of the brain, i.e. changes in neuroendocrine functions, may contribute substantially to the onset of rapid forgetting in aged animals. PMID:24674745

  3. A mathematical model of forgetting and amnesia

    Directory of Open Access Journals (Sweden)

    Jaap M. J. Murre

    2013-02-01

    Full Text Available We describe a mathematical model of learning and memory and apply it to the dynamics of forgetting and amnesia. The model is based on the hypothesis that the neural systems involved in memory at different time-scales share two fundamental properties: (1 representations in a store decline in strength (2 while trying to induce new representations in higher-level more permanent stores. This paper addresses several types of experimental and clinical phenomena: (i the temporal gradient of retrograde amnesia (Ribot's Law, (ii forgetting curves with and without anterograde amnesia, and (iii learning and forgetting curves with impaired cortical plasticity. Results are in the form of closed-form expressions that are applied to studies with mice, rats, and monkeys. In order to analyze human data in a quantitative manner, we also derive a relative measure of retrograde amnesia that removes the effects of non-equal item difficulty for different time periods commonly found with clinical retrograde amnesia tests. Using these analytical tools, we review studies of temporal gradients in the memory of patients with Korsakoff's Disease, Alzheimer's Dementia, Huntington's Disease, and other disorders.

  4. Estimating spillover benefits of large R and D projects: Application of real options modelling approach to the case of thermonuclear fusion R and D programme

    International Nuclear Information System (INIS)

    Bednyagin, Denis; Gnansounou, Edgard

    2012-01-01

    This paper is focused on the analysis of spillover benefits of the ongoing R and D programme on thermonuclear fusion technology. The spillover effects are understood here as positive externalities of publicly funded R and D, demonstration and deployment (RDDD) activities that may be revealed at the companies' level in the form of newly created knowledge stock; development of innovative products/processes with broader market applications; strengthening of R and D, manufacturing and marketing capabilities; etc. An integrated compound real options model is proposed that allows to estimate the strategic net social present value of fusion RDDD programme taking into account the different types of spillover benefits along with the hidden real options value arising due to uncertainty and managerial flexibility. It was found that the value of spillover effects, modelled as “expansion option”, could represent a significant proportion of the overall socio-economic value of fusion RDDD programme (nearly 20%). This paper clearly demonstrates that, besides a high-level mission to assure sustainable energy supply, fusion RDDD programme may yield substantial net socio-economic benefits that may be at least two times higher compared to the expected RD and D costs, and hence the pursuit of even more ambitious programme is economically justified. - Highlights: ► Evaluate the strategic net social present value of fusion RDDD programme. ► Consider different types of spillover effects. ► Economic value of spillovers is estimated with a compound real options model. ► Spillover benefits could represent up to 20% of the value of fusion RDDD programme.

  5. Should France invest in new nuclear technology? The enhancement of the EPR project using 'real option' method

    International Nuclear Information System (INIS)

    Epaulard, A.; Gallon, St.

    2000-01-01

    The mathematical tools developed to enhance financial options can also be used to calculate the economics value of investment projects which offer flexibility but whose return is uncertain (like options offered on the stock exchange). In this article, an enhancement method of this kind is applied to a construction project (in 2000) for an EPR nuclear prototype. This prototype will make it possible to use EPR to renew the French electrical infrastructure in 2020 (flexibility), but its economic value will depend upon competitiveness vis-a-vis other production methods available at this time (hence an uncertain return). We demonstrate that investing in EPR technology in 2000 will provide sufficient flexibility in 2020 to be considered profitable, even though it is improbable that the EPR technology will be used at the end of this period. The investment agreed in 2000 to expand EPR technology therefore effectively has the role of an option, or of an insurance policy (guaranteeing against the risk that traditional electricity production methods will be expensive in 2020). (authors)

  6. Directed forgetting of complex pictures in an item method paradigm

    OpenAIRE

    Hauswald, Anne; Kissler, Johanna

    2008-01-01

    An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect that is, better recogni...

  7. Economic assessment of R and D with real options in the field of fast reactors taking into account uncertainty on their competitiveness: the case of France

    International Nuclear Information System (INIS)

    Taverdet-Popiolek, Nathalie; Shoai Tehrani, Bianka

    2013-01-01

    In a context of potential worldwide nuclear development, this paper aims at assessing the economic value of pursuing research in Generation IV fast reactors today, given that it would allow industrial deployment around 2040 in case of high uranium prices. Two key variables shall be considered as inputs for the assessment: the price of uranium and the over-cost of Generation IV reactors compared to the previous generation. Our model based on real options theory demonstrates that this value is positive and outweighs the risks associated with the competitiveness of Generation IV. (authors)

  8. Forgetting: the availability, accessibility, and intentional control problem. Part 2

    Directory of Open Access Journals (Sweden)

    Veronika V. Nourkova

    2016-12-01

    Full Text Available The paper focuses on the phenomenon of forgetting as a primal and generally productive memory process. The cases that require temporary and permanent forgetting of the data stored in the long-term memory are contrasted. The main methodological obstacle in forgetting research is identified as arising from the logical prohibition to argument from the negative, i.e. “the evidence of absence is not the evidence of absence”. Two mechanisms of forgetting are discussed in the paper: transformation of the memory trace and modulation of trace accessibility. The former mechanism of forgetting consists of memory trace destruction (memory trace decay, retroactive and proactive interference, and «catastrophic» interference or its transformation that leads to forming a new memory representation. The most promising way to legitimize the trace destruction mechanism is narrowing the further research to episodic memory subsystem. The latter mechanism of forgetting consists of both passive failure in access to appropriate memory content (the tip of the tongue phenomenon, the category size effect, the fan effect and the process of active retrieval inhibition. This phenomenon represents temporary inhibition of competing semantically similar responses in semantic memory, and motivational inhibition of self-deprecating memories in autobiographical memory. Thus, a variety of experimental paradigms in intentional forgetting research are considered. Contrary to the common claim that forgetting is а universal and homogeneous phenomenon, we propose that forgetting strategies might vary in different memory subsystems, and also depend on activity characteristics during encoding, storage and retrieval.

  9. Accelerated forgetting? An evaluation on the use of long-term forgetting rates in patients with memory problems

    Directory of Open Access Journals (Sweden)

    Sofie eGeurts

    2015-06-01

    Full Text Available The main focus of this review was to evaluate whether long-term forgetting rates (delayed tests days to weeks after initial learning are a more sensitive measure to detect memory problems in various patient groups than standard delayed recall measures. It has been suggested that accelerated forgetting might be characteristic for epilepsy patients, but little research has been performed within other populations. Here, we identified ten studies in a wide range of brain injured patient groups, whose long-term forgetting patterns were compared to that of healthy controls. Signs of accelerated forgetting were found within two studies. The results of seven studies showed normal forgetting over time for the patient groups. However, most of the studies used only a recognition procedure, after optimizing initial learning. Based on the results, we discuss recommendations for assessing long-term forgetting and the need for future research to truly evaluate the usefulness for clinical practice.

  10. The Longer We Have to Forget the More We Remember: The Ironic Effect of Postcue Duration in Item-Based Directed Forgetting

    Science.gov (United States)

    Bancroft, Tyler D.; Hockley, William E.; Farquhar, Riley

    2013-01-01

    The effects of the duration of remember and forget cues were examined to test the differential rehearsal account of item-based directed forgetting. In Experiments 1 and 2, cues were shown for 300, 600, or 900 ms, and a directed forgetting effect (better recognition of remember than forget items) was found at each duration. In addition, recognition…

  11. REIT Performance and Option of Financing Real Estate Project in Developing Countries - (A Case of M-REIT and NREIT

    Directory of Open Access Journals (Sweden)

    Olaopin Olanrele Olusegun

    2014-01-01

    Full Text Available Performance of REITs have been largely measured using benchmark from the stock market indices (S&P500, Sharpe ratio, KLCI, etc or correlation studies. The real world of REIT shows that both economic and environmental factors exert influence on REIT performance on a simultaneous nature. Adopting quantitative method, where secondary data were statistically analysed. We proposed the use of multivariate regression where REIT performance (Y is the independent variable to be predicted by predictor variables of internal and external factors (X1–Xn. We equally proposed a possibility of REIT financing real estate project, against the existing regulations which prohibit such, using average return method of portfolio analysis on assumed numerical data. The study finds that economic factors jointly have a significant effect on REIT performance at P =0.044 while none of the factors has significant contribution individually. A benchmark REIT return of 5.3% is predicted. The study recommends a linear regression model analysis for REITs benchmark based on past performance for return measurement. REIT can only finance real estate project in the countries where there is acute shortage of fund and property stock. We suggest a modification of REIT laws to accommodate real estate financing by REITs.

  12. Estimating the influence of U.S. ethanol policy on plant investment decisions: A real options analysis with two stochastic variables

    International Nuclear Information System (INIS)

    Schmit, T.M.; Luo, J.; Conrad, J.M.

    2011-01-01

    U.S. ethanol policies have contributed to changes in the levels and the volatilities of revenues and costs facing ethanol firms. The implications of these policies for optimal investment behavior are investigated through an extension of the real options framework that allows for the consideration of volatility in both revenue and cost components, as well as the correlation between them. The effects of policy affecting plant revenues dominate the effects of those policies affecting production costs. In the absence of these policies, much of the recent expansionary periods would have not existed and market conditions in the late-1990s would have led to some plant closures. We also show that, regardless of plant size, U.S. ethanol policy has narrowed the distance between the optimal entry and exit curves, implying a more narrow range of inactivity and indicative of a more volatile evolution for the industry than would have existed otherwise. - Highlights: ► An extended real options framework with two stochastic variables is developed. ► Ethanol expansion largely induced by the revenue-enhancing effects of policy. ► Removing effects of policy changes optimal entry/exit environment considerably. ► To expand US ethanol industry, size of policy contributions needs to grow. ► US ethanol policy has fostered more volatile industry development.

  13. The pitfalls of capital budgeting : when costs correlate to oil price. Is the real-options approach superior to traditional valuation?

    Energy Technology Data Exchange (ETDEWEB)

    Schiozer, R.F. [Getulio Vargas Foundation, Sao Paolo (Brazil). School of Administration de Empresas; Costa Lima, G.A.; Suslick, S.B. [Unicamp, Campinas (Brazil). Center of Petroleum Studies

    2007-07-01

    Due to increased demand for drilling rigs, specialized labor force and other resources, the costs of exploration, appraisal, development and production have significantly risen over the last five years. The change in costs has mostly been attributed to the increased activity in the oil and gas exploration and production (EP) industry, as a result of the increase in oil prices. It was hypothesized that operating costs in the EP industry were strongly correlated to the price of oil. However, the correlation between prices and costs has traditionally been overlooked in the capital budgeting process. This paper investigated the economic relationship between oil price and the operating costs in the EP industry. It also explored its implications for the capital budgeting process and decision-making. The paper demonstrated the evaluation of projects under traditional net present value (NPV) and real-option approaches. Empirical evidence was also provided on how costs correlated to oil prices. The differences between project valuation when cost-price correlation was taken into account or not was also discussed. Last, findings, conclusions and general implications of the results obtained for the decision-making process were identified. It was concluded that there was a positive correlation between price and operating costs, and that overlooking this relationship would have significant implications on the valuation of investment projects, both using a traditional NPV methodology, which resulted in undervalued projects, and under real option analysis, which resulted in overvaluing projects. 6 refs., 2 tabs., 5 figs.

  14. The pitfalls of capital budgeting : when costs correlate to oil price. Is the real-options approach superior to traditional valuation?

    International Nuclear Information System (INIS)

    Schiozer, R.F.; Costa Lima, G.A.; Suslick, S.B.

    2007-01-01

    Due to increased demand for drilling rigs, specialized labor force and other resources, the costs of exploration, appraisal, development and production have significantly risen over the last five years. The change in costs has mostly been attributed to the increased activity in the oil and gas exploration and production (EP) industry, as a result of the increase in oil prices. It was hypothesized that operating costs in the EP industry were strongly correlated to the price of oil. However, the correlation between prices and costs has traditionally been overlooked in the capital budgeting process. This paper investigated the economic relationship between oil price and the operating costs in the EP industry. It also explored its implications for the capital budgeting process and decision-making. The paper demonstrated the evaluation of projects under traditional net present value (NPV) and real-option approaches. Empirical evidence was also provided on how costs correlated to oil prices. The differences between project valuation when cost-price correlation was taken into account or not was also discussed. Last, findings, conclusions and general implications of the results obtained for the decision-making process were identified. It was concluded that there was a positive correlation between price and operating costs, and that overlooking this relationship would have significant implications on the valuation of investment projects, both using a traditional NPV methodology, which resulted in undervalued projects, and under real option analysis, which resulted in overvaluing projects. 6 refs., 2 tabs., 5 figs

  15. Stochastic control and real options valuation of thermal storage-enabled demand response from flexible district energy systems

    OpenAIRE

    Kitapbayev, Yerkin; Moriarty, John; Mancarella, Pierluigi

    2014-01-01

    In district energy systems powered by Combined Heat and Power (CHP) plants, thermal storage can significantly increase CHP flexibility to respond to real time market signals and therefore improve the business case of such demand response schemes in a Smart Grid environment. However, main challenges remain as to what is the optimal way to control inter-temporal storage operation in the presence of uncertain market prices, and then how to value the investment into storage as flexibility enabler...

  16. Transfer Appropriate Forgetting: The Cue-Dependent Nature of Retrieval-Induced Forgetting

    Science.gov (United States)

    Perfect, Timothy J.; Stark, Louisa-Jayne; Tree, Jeremy J.; Moulin, Christopher J. A.; Ahmed, Lubna; Hutter, Russell

    2004-01-01

    Retrieval-induced forgetting is the failure to recall a previously studied word following repeated retrieval of a related item. It has been argued that this is due to retrieval competition between practiced and unpracticed items, which results in inhibition of the non-recalled item, detectable with an independent cue at final test. Three…

  17. "Forget to whom you have told this proverb": directed forgetting of destination memory in Alzheimer's disease.

    Science.gov (United States)

    El Haj, Mohamad; Gandolphe, Marie-Charlotte; Allain, Philippe; Fasotti, Luciano; Antoine, Pascal

    2015-01-01

    Destination memory is the ability to remember the receiver of transmitted information. By means of a destination memory directed forgetting task, we investigated whether participants with Alzheimer's Disease (AD) were able to suppress irrelevant information in destination memory. Twenty-six AD participants and 30 healthy elderly subjects were asked to tell 10 different proverbs to 10 different celebrities (List 1). Afterwards, half of the participants were instructed to forget the destinations (i.e., the celebrities) whereas the other half were asked to keep them in mind. After telling 10 other proverbs to 10 other celebrities (List 2), participants were asked to read numbers aloud. Subsequently, all the participants were asked to remember the destinations of List 1 and List 2, regardless of the forget or remember instructions. The results show similar destination memory in AD participants who were asked to forget the destinations of List 1 and those who were asked to retain them. These findings are attributed to inhibitory deficits, by which AD participants have difficulties to suppress irrelevant information in destination memory.

  18. "Forget to whom you have told this proverb'': Directed forgetting of destination memory in Alzheimer's disease

    NARCIS (Netherlands)

    El Haj, M.; Gandolphe, M.C.; Allain, P.; Fasotti, L.; Antoine, P.

    2015-01-01

    Destination memory is the ability to remember the receiver of transmitted information. By means of a destination memory directed forgetting task, we investigated whether participants with Alzheimer's Disease (AD) were able to suppress irrelevant information in destination memory. Twenty-six AD

  19. Mentally walking through doorways causes forgetting: The location updating effect and imagination.

    Science.gov (United States)

    Lawrence, Zachary; Peterson, Daniel

    2016-01-01

    Researchers have documented an intriguing phenomenon whereby simply walking through a doorway causes forgetting (the location updating effect). The Event Horizon Model is the most commonly cited theory to explain these data. Importantly, this model explains the effect without invoking the importance or reliance upon perceptual information (i.e., seeing oneself pass through the doorway). This generates the intriguing hypothesis that the effect may be demonstrated in participants who simply imagine walking through a doorway. Across two experiments, we explicitly test this hypothesis. Participants familiarised themselves with both real (Experiment 1) and virtual (Experiment 2) environments which served as the setting for their mental walk. They were then provided with an image to remember and were instructed to imagine themselves walking through the previously presented space. In both experiments, when the mental walk required participants to pass through a doorway, more forgetting occurred, consistent with the predictions laid out in the Event Horizon Model.

  20. Is 'Opt-Out HIV Testing' a real option among pregnant women in rural districts in Kenya?

    Directory of Open Access Journals (Sweden)

    Wamalwa David

    2011-03-01

    Full Text Available Abstract Background An 'opt-out' policy of routine HIV counseling and testing (HCT is being implemented across sub-Saharan Africa to expand prevention of mother-to-child transmission (PMTCT. Although the underlying assumption is that pregnant women in rural Africa are able to voluntarily consent to HIV testing, little is known about the reality and whether 'opt-out' HCT leads to higher completion rates of PMTCT. Factors associated with consent to HIV testing under the 'opt-out' approach were investigated through a large cross-sectional study in Kenya. Methods Observations during HIV pre-test information sessions were followed by a cross-sectional survey of 900 pregnant women in three public district hospitals carrying out PMTCT in the Busia district. Women on their first antenatal care (ANC visit during the current pregnancy were interviewed after giving blood for HIV testing but before learning their test results. Descriptive statistics and multivariate regression analysis were performed. Results Of the 900 women participating, 97% tested for HIV. Lack of testing kits was the only reason for women not being tested, i.e. nobody declined HIV testing. Despite the fact that 96% had more than four earlier pregnancies and 37% had been tested for HIV at ANC previously, only 17% of the women surveyed knew that testing was optional. Only 20% of those surveyed felt they could make an informed decision to decline HIV testing. Making an informed decision to decline HIV testing was associated with knowing that testing was optional (OR = 5.44, 95%CI 3.44-8.59, not having a stable relationship with the child's father (OR = 1.76, 95%CI 1.02-3.03, and not having discussed HIV testing with a partner before the ANC visit (OR = 2.64 95%CI 1.79-3.86. Conclusion High coverage of HIV testing appears to be achieved at the cost of pregnant women not understanding that testing is optional. Good quality HIV pre-test information is central to ensure that pregnant women

  1. Neurogenesis-mediated forgetting minimizes proactive interference.

    Science.gov (United States)

    Epp, Jonathan R; Silva Mera, Rudy; Köhler, Stefan; Josselyn, Sheena A; Frankland, Paul W

    2016-02-26

    Established memories may interfere with the encoding of new memories, particularly when existing and new memories overlap in content. By manipulating levels of hippocampal neurogenesis, here we show that neurogenesis regulates this form of proactive interference. Increasing hippocampal neurogenesis weakens existing memories and, in doing so, facilitates the encoding of new, conflicting (but not non-conflicting) information in mice. Conversely, decreasing neurogenesis stabilizes existing memories, and impedes the encoding of new, conflicting information. These results suggest that reduced proactive interference is an adaptive benefit of neurogenesis-induced forgetting.

  2. On the Matter of Forgetting and 'Memory Returns'

    NARCIS (Netherlands)

    Muzaini, H.B.

    2015-01-01

    Much geographical attention is paid to issues of memory and its relationship to place. Yet, there has been less disciplinary interrogation of what goes on when one forgets. This paper argues that forgetting, as it involves active embodied, material and spatial practices of producing absences, is

  3. How many types of forgetting? Comments on Connerton

    NARCIS (Netherlands)

    Wessel, Ineke; Moulds, Michelle L.

    2008-01-01

    In his Memory Studies article 'Seven Types of Forgetting', Connerton argues that forgetting on a cultural level is not a unitary phenomenon and that at least seven distinct types can be distinguished. In this commentary, we explore the potential utility of an alternative conceptualization from a

  4. Does Organizational Forgetting Matter? Organizational Survival for Life Coaching Companies

    Science.gov (United States)

    Aydin, Erhan; Gormus, Alparslan Sahin

    2015-01-01

    Purpose: The purposes of this paper are to determine the role of organizational forgetting in different type of coaching companies and to determine organizational survival based on both knowledge structure of coaching companies and organizational forgetting with core features of organizations. Design/methodology/approach: Within the context of…

  5. Directed forgetting of complex pictures in an item method paradigm.

    Science.gov (United States)

    Hauswald, Anne; Kissler, Johanna

    2008-11-01

    An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect--that is, better recognition of "to-be-remembered" than of "to-be-forgotten" pictures--was observed, although its size was smaller than previously reported for words or line drawings. The magnitude of the directed forgetting effect correlated negatively with participants' depression and dissociation scores. The results indicate that, at least in an item method, directed forgetting occurs for complex pictures as well as words and simple line drawings. Furthermore, people with higher levels of dissociative or depressive symptoms exhibit altered memory encoding patterns.

  6. Long expansion planning of electrical power availability in Brazil under the real options theoretical approach; Planejamento de longo prazo da expansao da oferta de energia eletrica no Brasil sob uma perspectiva da teoria das opcoes reais

    Energy Technology Data Exchange (ETDEWEB)

    Marreco, Juliana de Moraes

    2007-05-15

    This thesis considers uncertainty on the long term generation expansion planning in the Brazilian Electric System, under a Real Options Approach . First, Real Options Theory is used to demonstrate the importance of thermo power plants insertion in Brazil, through a flexibility valuation on hydrothermal system. This is the first objective of this thesis. In the second part a Real Options Model is proposed to support long term expansion studies, based in a levelized costs analysis. The adequacy of proposed models to real problem is illustrated by a case study of the Brazilian Power System. The results show the importance of the energetic matrix diversification on the Long Term Planning. In the expansion model proposed, results are in favor of higher participation of biomass, nuclear power and coal in Brazilian electricity generation matrix. (author)

  7. Emotion, directed forgetting, and source memory.

    Science.gov (United States)

    Otani, Hajime; Libkuman, Terry M; Goernert, Phillip N; Kato, Koichi; Migita, Mai; Freehafer, Sarah E; Landow, Michael P

    2012-08-01

    We investigated the role of emotion on item and source memory using the item method of directed forgetting (DF) paradigm. We predicted that emotion would produce source memory impairment because emotion would make it more difficult to distinguish between to-be-remembered (R items) and to-be-forgotten items (F items) by making memory strength of R and F items similar to each other. Participants were presented with negatively arousing, positively arousing, and neutral pictures. After each picture, they received an instruction to remember or forget the picture. At retrieval, participants were asked to recall both R and F items and indicate whether each item was an R or F item. Recall was higher for the negatively arousing than for the positively arousing or neutral pictures. Further, DF occurred for the positively arousing and neutral pictures, whereas DF was not significant for the negatively arousing pictures. More importantly, the negatively arousing pictures, particularly the ones with violent content, showed a higher tendency of producing misattribution errors than the other picture types, supporting the notion that negative emotion may produce source memory impairment, even though it is still not clear whether the impairment occurs at encoding or retrieval. ©2011 The British Psychological Society.

  8. Retrieval-induced forgetting in schizophrenia.

    Science.gov (United States)

    Nestor, Paul G; Piech, Richard; Allen, Christopher; Niznikiewicz, Margaret; Shenton, Martha; McCarley, Robert W

    2005-06-15

    Retrieving category associates (e.g., FRUIT-ORANGE) may induce forgetting other category members (e.g., FRUIT-BANANA), a phenomenon known as retrieval-induced forgetting (RIF). We designed 2 experiments to examine the role of RIF in the associative memory impairment of schizophrenia (SZ). Subjects studied 36 category-exemplar pairs, generated from 6 categories composed of 6 members each. For half of the studied category-exemplar pairs, subjects practiced retrieval by completing word stems, followed by a delayed category-cued recall on all of the practiced and unpracticed items. Experiment 1 used unrelated category exemplars-pairs (e.g., FRUIT-ORANGE, METALS-IRON), whereas experiment 2 included related category exemplar pairs (e.g., COTTON-SHIRT, LEATHER-SKIRT). SZ showed reduced associative memory but normal RIF for unrelated categories used in experiment 1. For experiment 2, SZ showed a significant decline in associative memory for related but not unrelated category-exemplars in comparison to controls. Results suggested faulty specificity/distinctiveness for encoding and retrieval, but not abnormal RIF in the associative memory disturbance of SZ.

  9. Suppress to Forget: The Effect of a Mindfulness-Based Strategy during an Emotional Item-Directed Forgetting Paradigm

    Science.gov (United States)

    Gamboa, Olga L.; Garcia-Campayo, Javier; Müller, Teresa; von Wegner, Frederic

    2017-01-01

    Forgetting is a common phenomenon in everyday life. Although it often has negative connotations, forgetting is an important adaptive mechanism to avoid loading the memory storage with irrelevant information. A very important aspect of forgetting is its interaction with emotion. Affective events are often granted special and priority treatment over neutral ones with regards to memory storage. As a consequence, emotional information is more resistant to extinction than neutral information. It has been suggested that intentional forgetting serves as a mechanism to cope with unwanted or disruptive emotional memories and the main goal of this study was to assess forgetting of emotional auditory material using the item-method directed forgetting (DF) paradigm using a forgetting strategy based on mindfulness as a means to enhance DF. Contrary to our prediction, the mindfulness-based strategy not only did not improve DF but reduced it for neutral material. These results suggest that an interaction between processes such as response inhibition and attention is required for intentional forgetting to succeed. PMID:28382015

  10. Memory accessibility and medical decision-making for significant others: The role of socially-shared retrieval induced forgetting

    OpenAIRE

    Dora M Coman; Alin eComan; William eHirst

    2013-01-01

    Medical decisions will often entail a broad search for relevant information. No sources alone may offer a complete picture, and many may be selective in their presentation. This selectivity may induce forgetting for previously learned material, thereby adversely affecting medical decision-making. In the study phase of two experiments, participants learned information about a fictitious disease and advantages and disadvantages of four treatment options. In the subsequent practice phase, the...

  11. Real options theory to the pricing of allowances contract to carbon emission; Teoria de opcoes reais para a precificacao de contrato de permissoes de emissao de carbono

    Energy Technology Data Exchange (ETDEWEB)

    Horii, Leticia Takahashi; Parente, Virginia; Goldemberg, Jose [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia

    2010-07-01

    The objective of this work is to develop a pricing model contract for allowances to emit carbon through Real Options. Emissions allowances are equivalent tons of carbon traded between Annex I countries from companies that have the ability to reduce their emissions beyond what is assigned to it. The surplus of emission reductions produced by these companies may be sold in the emissions market. Thus, this work can contribute to improving the management of contractual risk and enable companies estimated the price at which a contract can be signed. Properly evaluate the contracts that the market environment is a challenge for companies. The historic low of information and randomness in the price of carbon allowances in the spot market suggest extreme caution in its use. (author)

  12. Some new features of Direct Analysis in Real Time mass spectrometry utilizing the desorption at an angle option.

    Science.gov (United States)

    Chernetsova, Elena S; Revelsky, Alexander I; Morlock, Gertrud E

    2011-08-30

    The present study is a first step towards the unexplored capabilities of Direct Analysis in Real Time (DART) mass spectrometry (MS) arising from the possibility of the desorption at an angle: scanning analysis of surfaces, including the coupling of thin-layer chromatography (TLC) with DART-MS, and a more sensitive analysis due to the preliminary concentration of analytes dissolved in large volumes of liquids on glass surfaces. In order to select the most favorable conditions for DART-MS analysis, proper positioning of samples is important. Therefore, a simple and cheap technique for the visualization of the impact region of the DART gas stream onto a substrate was developed. A filter paper or TLC plate, previously loaded with the analyte, was immersed in a derivatization solution. On this substrate, owing to the impact of the hot DART gas, reaction of the analyte to a colored product occurred. An improved capability of detection of DART-MS for the analysis of liquids was demonstrated by applying large volumes of model solutions of coumaphos into small glass vessels and drying these solutions prior to DART-MS analysis under ambient conditions. This allowed the introduction of, by up to more than two orders of magnitude, increased quantities of analyte compared with the conventional DART-MS analysis of liquids. Through this improved detectability, the capabilities of DART-MS in trace analysis could be strengthened. Copyright © 2011 John Wiley & Sons, Ltd.

  13. A normative theory of forgetting: lessons from the fruit fly.

    Directory of Open Access Journals (Sweden)

    Johanni Brea

    2014-06-01

    Full Text Available Recent experiments revealed that the fruit fly Drosophila melanogaster has a dedicated mechanism for forgetting: blocking the G-protein Rac leads to slower and activating Rac to faster forgetting. This active form of forgetting lacks a satisfactory functional explanation. We investigated optimal decision making for an agent adapting to a stochastic environment where a stimulus may switch between being indicative of reward or punishment. Like Drosophila, an optimal agent shows forgetting with a rate that is linked to the time scale of changes in the environment. Moreover, to reduce the odds of missing future reward, an optimal agent may trade the risk of immediate pain for information gain and thus forget faster after aversive conditioning. A simple neuronal network reproduces these features. Our theory shows that forgetting in Drosophila appears as an optimal adaptive behavior in a changing environment. This is in line with the view that forgetting is adaptive rather than a consequence of limitations of the memory system.

  14. Neural, Cellular and Molecular Mechanisms of Active Forgetting

    Science.gov (United States)

    Medina, Jorge H.

    2018-01-01

    The neurobiology of memory formation attracts much attention in the last five decades. Conversely, the rules that govern and the mechanisms underlying forgetting are less understood. In addition to retroactive interference, retrieval-induced forgetting and passive decay of time, it has been recently demonstrated that the nervous system has a diversity of active and inherent processes involved in forgetting. In Drosophila, some operate mainly at an early stage of memory formation and involves dopamine (DA) neurons, specific postsynaptic DA receptor subtypes, Rac1 activation and induces rapid active forgetting. In mammals, others regulate forgetting and persistence of seemingly consolidated memories and implicate the activity of DA receptor subtypes and AMPA receptors in the hippocampus (HP) and related structures to activate parallel signaling pathways controlling active time-dependent forgetting. Most of them may involve plastic changes in synaptic and extrasynaptic receptors including specific removal of GluA2 AMPA receptors. Forgetting at longer timescales might also include changes in adult neurogenesis in the dentate gyrus (DG) of the HP. Therefore, based on relevance or value considerations neuronal circuits may regulate in a time-dependent manner what is formed, stored, and maintained and what is forgotten. PMID:29467630

  15. On the reliability of retrieval-induced forgetting

    Directory of Open Access Journals (Sweden)

    Christopher eRowland

    2014-11-01

    Full Text Available Memory is modified through the act of retrieval. Although retrieving a target piece of information may strengthen the retrieved information itself, it may also serve to weaken retention of related information. This phenomenon, termed retrieval-induced forgetting, has garnered substantial interest for its implications as to why forgetting occurs. The present study attempted to replicate the seminal work by Anderson, Bjork, and Bjork (1994 on retrieval-induced forgetting, given the apparent sensitivity of the effect to certain deviations from the original paradigm developed to study the phenomenon. The study extends the conditions under which retrieval-induced forgetting has been examined by utilizing both a traditional college undergraduate sample (Experiment 1, along with a more diverse internet sample (Experiment 2. In addition, Experiment 3 details a replication attempt of retrieval-induced forgetting using Anderson and Spellman’s (1995 independent cue procedure. Retrieval-induced forgetting was observed when using the traditional retrieval practice paradigm with undergraduate (Experiment 1 and internet (Experiment 2 samples, though the effect was not found when using the independent cue procedure (Experiment 3. Thus, the study can provide an indication as to the robustness of retrieval-induced forgetting to deviations from the traditional college undergraduate samples that have been used in the majority of existing research on the effect.

  16. Measuring forgetting: a critical review of accelerated long-term forgetting studies.

    Science.gov (United States)

    Elliott, Gemma; Isaac, Claire L; Muhlert, Nils

    2014-05-01

    Accelerated long-term forgetting (ALF) refers to abnormal forgetting over hours to weeks despite normal acquisition or initial consolidation. Since standardised assessments of memory typically only test at delays of up to 40-minutes, ALF may go undetected in clinical practice. The memory difficulties associated with ALF can however cause considerable distress to patients. It is important therefore that clinicians are aware that ALF may represent a distinct phenomenon that will require additional and careful assessment to aid patients' understanding of the condition and assist in developing strategies to address its effects. At the same time, ALF may also provide insight into long-term memory processes. Studies of ALF in patients with epilepsy have so far demonstrated mixed results, which may reflect differences in methodology. This review explores the methodological issues that can affect forgetting, such as the effects of age, general cognitive function, test sensitivity and initial learning. It then evaluates the extent to which existing studies have considered these key issues. We outline the points to consider when designing ALF studies that can be used to help improve their validity. These issues can also help to explain some of the mixed findings in studies of ALF and inform the design of standardised tests for assessing ALF in clinical practice. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Directed forgetting between, but not within, dissociative personality states.

    Science.gov (United States)

    Elzinga, Bernet M; Phaf, R Hans; Ardon, Angelique M; van Dyck, Richard

    2003-05-01

    To investigate amnesia between identities in dissociative identity disorder (DID), the authors assessed explicit and implicit memory performance on a directed-forgetting task in 12 DID patients who switched from one state to an "amnesic" state between presentation and memory testing. DID patients were instructed either to remember or to forget neutral and emotional words. Besides an overall decrease in explicit memory, patients demonstrated selective forgetting of to-be-forgotten, but not of to-be-remembered words in the amnesic state. Patients did not exhibit any directed forgetting within the same state. Implicit memory was fully preserved across states. Independent of state, patients recalled more emotional than neutral information. These results may extend the conceptualization of memory processes in DID, suggesting an important role for retrieval inhibition.

  18. Directed forgetting of visual symbols: evidence for nonverbal selective rehearsal.

    Science.gov (United States)

    Hourihan, Kathleen L; Ozubko, Jason D; MacLeod, Colin M

    2009-12-01

    Is selective rehearsal possible for nonverbal information? Two experiments addressed this question using the item method directed forgetting paradigm, where the advantage of remember items over forget items is ascribed to selective rehearsal favoring the remember items. In both experiments, difficult-to-name abstract symbols were presented for study, followed by a recognition test. Directed forgetting effects were evident for these symbols, regardless of whether they were or were not spontaneously named. Critically, a directed forgetting effect was observed for unnamed symbols even when the symbols were studied under verbal suppression to prevent verbal rehearsal. This pattern indicates that a form of nonverbal rehearsal can be used strategically (i.e., selectively) to enhance memory, even when verbal rehearsal is not possible.

  19. The nature of forgetting from short-term memory

    OpenAIRE

    Muter, Paul

    2001-01-01

    Memory and forgetting are inextricably intertwined. Any account of short-term memory (STM) should address the following question: If three, four, or five chunks are being held in STM, what happens after attention is diverted?

  20. Climate change and the economics of biomass energy feedstocks in semi-arid agricultural landscapes: A spatially explicit real options analysis.

    Science.gov (United States)

    Regan, Courtney M; Connor, Jeffery D; Raja Segaran, Ramesh; Meyer, Wayne S; Bryan, Brett A; Ostendorf, Bertram

    2017-05-01

    The economics of establishing perennial species as renewable energy feedstocks has been widely investigated as a climate change adapted diversification option for landholders, primarily using net present value (NPV) analysis. NPV does not account for key uncertainties likely to influence relevant landholder decision making. While real options analysis (ROA) is an alternative method that accounts for the uncertainty over future conditions and the large upfront irreversible investment involved in establishing perennials, there have been limited applications of ROA to evaluating land use change decision economics and even fewer applications considering climate change risks. Further, while the influence of spatially varying climate risk on biomass conversion economic has been widely evaluated using NPV methods, effects of spatial variability and climate on land use change have been scarcely assessed with ROA. In this study we applied a simulation-based ROA model to evaluate a landholder's decision to convert land from agriculture to biomass. This spatially explicit model considers price and yield risks under baseline climate and two climate change scenarios over a geographically diverse farming region. We found that underlying variability in primary productivity across the study area had a substantial effect on conversion thresholds required to trigger land use change when compared to results from NPV analysis. Areas traditionally thought of as being quite similar in average productive capacity can display large differences in response to the inclusion of production and price risks. The effects of climate change, broadly reduced returns required for land use change to biomass in low and medium rainfall zones and increased them in higher rainfall areas. Additionally, the risks posed by climate change can further exacerbate the tendency for NPV methods to underestimate true conversion thresholds. Our results show that even under severe drying and warming where crop yield

  1. Remembering and forgetting: directed forgetting effect in obsessive-compulsive disorder

    Directory of Open Access Journals (Sweden)

    Konishi M

    2011-06-01

    Full Text Available Mika Konishi1, Kurie Shishikura2, Shutaro Nakaaki3, Shin-ichi Komatsu4, Masaru Mimura11Department of Neuropsychiatry, Keio University School of Medicine, Tokyo; 2Department of Neuropsychiatry, Kitasato University School of Medicine, Kanagawa; 3Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Science, Nagoya; 4Faculty of Education, Shinshu University, Nagano, JapanAbstract: It has been reported that episodic memory seems to be impaired in patients with obsessive-compulsive disorder (OCD because the patients repeat a specific checking behavior, but it is still unknown if OCD patients show memory impairments associated with their unique symptoms or not. To study episodic memory in OCD patients, we examined the directed forgetting effect. Patients with OCD and healthy control participants were given a list of 24 emotionally neutral everyday words (12 remember [R]-cued words and 12 forget [F]-cued words under two conditions: List and Item. The results of our study showed that OCD patients recalled a number of F-cued words similar to that for controls and relatively fewer R-cued words than controls under both List and Item conditions. Consequently, the directed forgetting effect was smaller in OCD patients than controls. Our results demonstrated that both selective encoding and retrieval inhibition processes are impaired in OCD, and we suggest that recall of unfavorable items to be forgotten intruded into necessary items to be remembered. This impairment in episodic memory may partially account for some of the unique clinical symptoms of OCD.Keywords: episodic memory, retrieval inhibition, selective encoding

  2. Using life cycle assessment and techno-economic analysis in a real options framework to inform the design of algal biofuel production facilities.

    Science.gov (United States)

    Kern, Jordan D; Hise, Adam M; Characklis, Greg W; Gerlach, Robin; Viamajala, Sridhar; Gardner, Robert D

    2017-02-01

    This study investigates the use of "real options analysis" (ROA) to quantify the value of greater product flexibility at algal biofuel production facilities. A deterministic optimization framework is integrated with a combined life cycle assessment/techno-economic analysis model and subjected to an ensemble of 30-year commodity price trajectories. Profits are maximized for two competing plant configurations: 1) one that sells lipid-extracted algae as animal feed only; and 2) one that can sell lipid-extracted algae as feed or use it to recover nutrients and energy, due to an up-front investment in anaerobic digestion/combined heat and power. Results show that added investment in plant flexibility does not result in an improvement in net present value, because current feed meal prices discourage use of lipid-extracted algae for nutrient and energy recovery. However, this study demonstrates that ROA provides many useful insights regarding plant design that cannot be captured via traditional techno-economic modeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Reward eliminates retrieval-induced forgetting.

    Science.gov (United States)

    Imai, Hisato; Kim, Dongho; Sasaki, Yuka; Watanabe, Takeo

    2014-12-02

    Although it is well known that reward enhances learning and memory, how extensively such enhancement occurs remains unclear. To address this question, we examined how reward influences retrieval-induced forgetting (RIF) in which the retrieval of a nonpracticed item under the same category as a practiced item is worse than the retrieval of a nonpracticed item outside the category. Subjects were asked to try to encode category-exemplar pairs (e.g., FISH-salmon). Then, they were presented with a category name and a two-letter word stem (e.g., FISH-sa) and were asked to complete an encoded word (retrieval practice). For a correct response, apple juice was given as a reward in the reward condition and a beeping sound was presented in the no-reward condition. Finally, subjects were asked to report whether each exemplar had been presented in the first phase. RIF was replicated in the no-reward condition. However, in the reward condition, RIF was eliminated. These results suggest that reward enhances processing of retrieval of unpracticed members by mechanisms such as spreading activation within the same category, irrespective of whether items were practiced or not.

  4. Less we forget: retrieval cues and release from retrieval-induced forgetting.

    Science.gov (United States)

    Jonker, Tanya R; Seli, Paul; Macleod, Colin M

    2012-11-01

    Retrieving some items from memory can impair the subsequent recall of other related but not retrieved items, a phenomenon called retrieval-induced forgetting (RIF). The dominant explanation of RIF-the inhibition account-asserts that forgetting occurs because related items are suppressed during retrieval practice to reduce retrieval competition. This item inhibition persists, making it more difficult to recall the related items on a later test. In our set of experiments, each category was designed such that each exemplar belonged to one of two subcategories (e.g., each BIRD exemplar was either a bird of prey or a pet bird), but this subcategory information was not made explicit during study or retrieval practice. Practicing retrieval of items from only one subcategory led to RIF for items from the other subcategory when cued only with the overall category label (BIRD) at test. However, adapting the technique of Gardiner, Craik, and Birtwistle (Journal of Learning and Verbal Behavior 11:778-783, 1972), providing subcategory cues during the final test eliminated RIF. The results challenge the inhibition account's fundamental assumption of cue independence but are consistent with a cue-based interference account.

  5. Intentional forgetting reduces color-naming interference: evidence from item-method directed forgetting.

    Science.gov (United States)

    Lee, Yuh-Shiow; Lee, Huang-Mou; Fawcett, Jonathan M

    2013-01-01

    In an item-method-directed forgetting task, Chinese words were presented individually, each followed by an instruction to remember or forget. Colored probe items were presented following each memory instruction requiring a speeded color-naming response. Half of the probe items were novel and unrelated to the preceding study item, whereas the remaining half of the probe items were a repetition of the preceding study item. Repeated probe items were either identical to the preceding study item (E1, E2), a phonetic reproduction of the preceding study item (E3), or perceptually matched to the preceding study item (E4). Color-naming interference was calculated by subtracting color-naming reaction times made in response to a string of meaningless symbols from that of the novel and repeated conditions. Across all experiments, participants recalled more to-be-remembered (TBR) than to-be-forgotten (TBF) study words. More importantly, Experiments 1 and 2 found that color-naming interference was reduced for repeated TBF words relative to repeated TBR words. Experiments 3 and 4 further found that this effect occurred at the perceptual rather than semantic level. These findings suggest that participants may bias processing resources away from the perceptual representation of to-be-forgotten information.

  6. Energy options

    International Nuclear Information System (INIS)

    Hampton, Michael

    1999-01-01

    This chapter focuses on energy options as a means of managing exposure to energy prices. An intuitive approach to energy options is presented, and traditional definitions of call and put options are given. The relationship between options and swaps, option value and option exercises, commodity options, and option pricing are described. An end-user's guide to energy option strategy is outlined, and straight options, collars, participating swaps and collars, bull and bear spreads, and swaption are examined. Panels explaining the defining of basis risk, and discussing option pricing and the Greeks, delta hedging, managing oil options using the Black-Scholes model, caps, floors and collars, and guidelines on hedging versus speculation with options are included in the paper

  7. Feasibility analysis in the expansion proposal of the nuclear power plant Laguna Verde: application of real options, binomial model; Analisis de viabilidad en la propuesta de expansion de la central nucleoelectrica Laguna Verde: aplicacion de opciones reales, modelo binomial

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez I, S.; Ortiz C, E.; Chavez M, C., E-mail: lunitza@gmail.com [UNAM, Facultad de Ingenieria, Circuito Interior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2011-11-15

    At the present time, is an unquestionable fact that the nuclear electrical energy is a topic of vital importance, no more because eliminates the dependence of the hydrocarbons and is friendly with the environment, but because is also a sure and reliable energy source, and represents a viable alternative before the claims in the growing demand of electricity in Mexico. Before this panorama, was intended several scenarios to elevate the capacity of electric generation of nuclear origin with a variable participation. One of the contemplated scenarios is represented by the expansion project of the nuclear power plant Laguna Verde through the addition of a third reactor that serves as detonator of an integral program that proposes the installation of more nuclear reactors in the country. Before this possible scenario, the Federal Commission of Electricity like responsible organism of supplying energy to the population should have tools that offer it the flexibility to be adapted to the possible changes that will be presented along the project and also gives a value to the risk to future. The methodology denominated Real Options, Binomial model was proposed as an evaluation tool that allows to quantify the value of the expansion proposal, demonstrating the feasibility of the project through a periodic visualization of their evolution, all with the objective of supplying a financial analysis that serves as base and justification before the evident apogee of the nuclear energy that will be presented in future years. (Author)

  8. Forgetting emotional and neutral words: an ERP study.

    Science.gov (United States)

    Brandt, Karen R; Nielsen, Maria Kragh; Holmes, Amanda

    2013-03-21

    Previous research has demonstrated that emotional material is more likely to be remembered than neutral material (Hamann, 2001). The present study employed the item-method of directed forgetting in order to examine whether emotionally negative words are not only easier to remember, but also harder to forget. Event-related potentials (ERPs) were additionally measured in order to investigate the processes of selective rehearsal and active inhibition in directed forgetting. The results demonstrated directed forgetting effects for both neutral and negative words, with a stronger effect for negative items. Late positive potentials (LPPs) for 'to-be-remembered' (TBR) relative to 'to-be-forgotten' (TBF) cues were enhanced when the cues followed negative in comparison to neutral words, indicating the greater selective rehearsal of TBR negative items. Frontal positivities to TBF relative to TBR cues were not modulated by word valence, indicating that inhibitory processes were unaffected by emotion. Taken together, the present research demonstrates for the first time that, not only are emotionally negative words prone to the same directed forgetting effects as neutral words, but that these effects are in fact enhanced for negative words and due to increased selective rehearsal of TBR negative items. The discrepancies between the present findings and those of previous studies are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Assessment of alternative fuel and powertrain transit bus options using real-world operations data: Life-cycle fuel and emissions modeling

    International Nuclear Information System (INIS)

    Xu, Yanzhi; Gbologah, Franklin E.; Lee, Dong-Yeon; Liu, Haobing; Rodgers, Michael O.; Guensler, Randall L.

    2015-01-01

    Highlights: • We present a practical fuel and emissions modeling tool for alternative fuel buses. • The model assesses well-to-wheels emissions impacts of bus fleet decisions. • Mode-based approach is used to account for duty cycles and local conditions. • A case study using real-world operations data from Atlanta, GA is presented. • Impacts of alternative bus options depend on operating and geographic features. - Abstract: Hybrid and electric powertrains and alternative fuels (e.g., compressed natural gas (CNG), biodiesel, or hydrogen) can often reduce energy consumption and emissions from transit bus operations relative to conventional diesel. However, the magnitude of these energy and emissions savings can vary significantly, due to local conditions and transit operating characteristics. This paper introduces the transit Fuel and Emissions Calculator (FEC), a mode-based life-cycle emissions modeling tool for transit bus and rail technologies that compares the performance of multiple alternative fuels and powertrains across a range of operational characteristics and conditions. The purpose of the FEC is to provide a practical, yet technically sophisticated tool for regulatory agencies and policy analysts in assessing transit fleet options. The FEC’s modal modeling approach estimates emissions as a function of engine load, which in turn is a function of transit service parameters, including duty cycle (idling and speed-acceleration profile), road grade, and passenger loading. This approach allows for customized assessments that account for local conditions. Direct emissions estimates are derived from the scaled tractive power (STP) operating mode bins and emissions factors employed in the U.S. EPA’s MOVES (MOtor Vehicle Emissions Simulator) model. Life-cycle emissions estimates are calculated using emissions factors from the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model. The case study presented in this paper

  10. Quantifying the value of investing in distributed natural gas and renewable electricity systems as complements: Applications of discounted cash flow and real options analysis with stochastic inputs

    International Nuclear Information System (INIS)

    Pless, Jacquelyn; Arent, Douglas J.; Logan, Jeffrey; Cochran, Jaquelin; Zinaman, Owen

    2016-01-01

    One energy policy objective in the United States is to promote the adoption of technologies that provide consumers with stable, secure, and clean energy. Recent work provides anecdotal evidence of natural gas (NG) and renewable electricity (RE) synergies in the power sector, however few studies quantify the value of investing in NG and RE systems together as complements. This paper uses discounted cash flow analysis and real options analysis to value hybrid NG-RE systems in distributed applications, focusing on residential and commercial projects assumed to be located in the states of New York and Texas. Technology performance and operational risk profiles are modeled at the hourly level to capture variable RE output and NG prices are modeled stochastically as geometric Ornstein-Uhlenbeck (OU) stochastic processes to capture NG price uncertainty. The findings consistently suggest that NG-RE hybrid distributed systems are more favorable investments in the applications studied relative to their single-technology alternatives when incentives for renewables are available. In some cases, NG-only systems are the favorable investments. Understanding the value of investing in NG-RE hybrid systems provides insights into one avenue towards reducing greenhouse gas emissions, given the important role of NG and RE in the power sector. - Highlights: • Natural gas and renewable electricity can be viewed as complements. • We model hybrid natural gas and renewable electricity systems at the hourly level. • We incorporate variable renewable power output and uncertain natural gas prices. • Hybrid natural gas and renewable electricity systems can be valuable investments.

  11. Valuing and timing R and D using a real options pricing framework; including an application to the development of Lunar Helium-3 fusion

    International Nuclear Information System (INIS)

    Ott, S.H.

    1992-01-01

    This dissertation uses the real options framework to study the valuation and optimal investment policies for R and D projects. The models developed integrate and extend the literature by taking into account the unique characteristics of such projects including uncertain investment in R and D, time-to-build, and multiple investment opportunities. The models were developed to examine the optimal R and D investment policy for the Lunar Helium-3 fusion project but have general applicability. Models are development which model R and D investment as an information gathering process where R and D investment remaining changes as investment is expended. The value of the project increased as the variance of required investment increases. An extension of this model combines a stochastic benefit with stochastic investment. Both the value of the R and D project and the region prescribing continued investment increased. The policy implications are significant: When uncertainty of R and D investment is ignored, the value of the project is underestimated and a tendency toward underinvestment in R and D will result; the existence of uncertainty in R and D investment will cause R and D projects to experience larger declines in value before discontinuation of investment. The model combining stochastic investment with the stochastic benefit is applied to the Lunar Helium-3 fusion project. Investment in fusion should continue at the maximum level of $1 billion annually given current levels of costs of alternative fuels and the perceived uncertainty of R and D investment in the project. A model is developed to examine the valuation and optimal split of funding between R and D projects when there are two competing new technologies. Without interaction between research expenditures and benefits across technologies, the optimal investment strategy is to invest in one or the other technology or neither. The multiple technology model is applied to analyze competing R and D projects, namely

  12. AEGIS and Ship Self-Defense System (SSDS) Platforms: Using KVA Analysis, Risk Simulation and Strategic Real Options to Assess Operational Effectiveness

    National Research Council Canada - National Science Library

    Uchytil, Joseph; Housel, Thomas; Hom, Sandra; Mun, Johnathan; Tarantino, Eric

    2006-01-01

    .... The results of the research demonstrated that the leave and layer approach for incrementally replacing AEGIS system modules was the most valuable strategic option, providing the highest return...

  13. Digital Forgetting And The Future of The Past

    DEFF Research Database (Denmark)

    Marton, Attila

    2015-01-01

    to be an overstatement considering the fact that digital media are based on the most radical classification possible – the classification of everything and anything into only two classes of 0 and 1. Digital memory is the dis-membrance of singular events into binary digits leading to the counter-intuitive conclusion...... that the storing of binary-based data itself is a way of forgetting. Re-membrance, in turn, is the computational reconstruction of artefacts composed out of binary digits. Thus conceived, binary-based digital media are very ill-fitted for mnemonic purposes, since, for the first time, the conservation...... of filtering singular details of events in order to make them comparable with other events according to gradually emerging categories. Forgetting means dis-membering singularities into categories; re-membering, by contrast, is the construction of an event out of these categories. Thus conceived, forgetting...

  14. Frontal Control Process in Intentional Forgetting: Electrophysiological Evidence

    Directory of Open Access Journals (Sweden)

    Heming Gao

    2018-01-01

    Full Text Available In this study, we aimed to seek for the neural evidence of the inhibition control process in directed forgetting (DF. We adopted a modified item-method DF paradigm, in which four kinds of cues were involved. In some trials, the words were followed by only a forgetting (F cue. In the other trials, after a word was presented, a maintenance (M cue was presented, followed by an explicit remembering (M-R cue or an forgetting (M-F cue. Data from 19 healthy adult participants showed that, (1 compared with the remembering cue (i.e., M-R cue, forgetting cues (i.e., M-F cue and F cue evoked enhanced frontal N2 and reduced parietal P3 and late positive complex (LPC components, indicating that the forgetting cues might trigger a more intensive cognitive control process and that fewer amounts of cognitive resources were recruited for the further rehearsal process. (2 Both the M cue and the F cue evoked enhanced N2 and decreased P3 and LPC components than the M-R or M-F cue. These results might indicate that compared with the M-R and M-F cues, both the M and F cues evoked a more intensive cognitive control process and decreased attentional resource allocation process. (3 The F cue evoked a decreased P2 component and an enhanced N2 component relative to the other cues (i.e., M-R, M-F, M, indicating that the F cue received fewer amounts of attentional resources and evoked a more intensive cognitive control process. Taken together, forgetting cues were associated with enhanced N2 activity relative to the maintenance rehearsal process or the remembering process, suggesting an enhanced cognitive control process under DF. This cognitive control process might reflect the role of inhibition in DF as attempting to suppress the ongoing encoding.

  15. Weak evidence for increased motivated forgetting of trauma-related words in dissociated or traumatised individuals in a directed forgetting experiment.

    Science.gov (United States)

    Patihis, Lawrence; Place, Patricia J

    2018-05-01

    Motivated forgetting is the idea that people can block out, or forget, upsetting or traumatic memories, because there is a motivation to do so. Some researchers have cited directed forgetting studies using trauma-related words as evidence for the theory of motivated forgetting of trauma. In the current article subjects used the list method directed forgetting paradigm with both trauma-related words and positive words. After one list of words was presented subjects were directed to forget the words previously learned, and they then received another list of words. Each list was a mix of positive and trauma-related words, and the lists were counterbalanced. Later, subjects recalled as many of the words as they could, including the ones they were told to forget. Based on the theory that motivated forgetting would lead to recall deficits of trauma-related material, we created eight hypotheses. High dissociators, trauma-exposed, sexual trauma-exposed, and high dissociators with trauma-exposure participants were hypothesised to show enhanced forgetting of trauma words. Results indicated only one of eight hypotheses was supported: those higher on dissociation and trauma recalled fewer trauma words in the to-be-forgotten condition, compared to those low on dissociation and trauma. These results provide weak support for differential motivated forgetting.

  16. Exordio to the collective memory and the social forgetfulness

    Directory of Open Access Journals (Sweden)

    Jorge Mendoza García

    2005-11-01

    Full Text Available This article argues that memory and forgetting, far from being the individual matters they were taken to be in the 20th century, are social phenomena: that they are collective, or social, products, and form two sides of the same coin. Collective memory has its own resources:it is guided by societal forces and sustained by language. Social forgetting, on the other hand, is sustained by silence, oppression and censorship. The two together furnish society with its presences and its absences. There is a conflict between memory and oblivion. Where one flourishes, the other withers, and vice versa. Societies are built on just such problematic relationships.

  17. Organizational memory and forgetfulness generating vulnerabilities in complex environments

    Directory of Open Access Journals (Sweden)

    Robson Quinello

    2006-01-01

    Full Text Available This article analyzes the relationship between organizational memory and forgetfulness in the generation of operational vulnerabilities, based on a case study carried out with a highly specialized technical team from a multinational company of the automotive sector. The article starts with the presentation of the complexitycontext of the Brazilian automotive sector in the last decades. It then goes on to discuss the theoretical referential on learning organizations, organizational memory and forgetfulness and organizations with high operational reliability characteristics. Finally, a case study is presented, carried out based on the theoretical concepts described in the body of the article, showing the contradictions and evidence of this relationship.

  18. An Estimation of Profitability of Investment Projects in The Oil and Gas Industry Using Real Options Theory / Ocena Opłacalności Projektów Inwestycyjnych W Przemyśle Naftowym Z Wykorzystaniem Teorii Opcji Realnych

    Science.gov (United States)

    Kosowski, Piotr; Stopa, Jerzy

    2012-11-01

    Paper discusses issues relating to the valuation of investment efficiency in the oil and gas industry using a real options theory. The example of investment pricing using real options was depicted and it was confronted with the analysis executed with the use of traditional methods. Indicators commonly used to evaluate profitability of investment projects, based on a discounted cash flow method, have a few significant drawbacks, the most meaningful of which is staticity which means that any changes resulting from a decision process during the time of investment cannot be taken into consideration. In accordance with a methodology that is currently used, investment projects are analysed in a way that all the key decisions are made at the beginning and are irreversible. This approach assumes, that all the cash flows are specified and does not let the fact that during the time of investment there may appear new information, which could change its original form. What is also not analysed is the possibility of readjustment, due to staff managment's decisions, to the current market conditions, by expanding, speeding up/slowing down, abandoning or changing an outline of the undertaking. In result, traditional methods of investment projects valuation may lead to taking wrong decisions, e.g. giving up an owned exploitation licence or untimely liquidation of boreholes, which seem to be unprofitable. Due to all the above-mentioned there appears the necessity of finding some other methods which would let one make real and adequate estimations about investments in a petroleum industry especially when it comes to unconventional resources extraction. One of the methods which has been recently getting more and more approval in a world petroleum economics, is a real options pricing method. A real option is a right (but not an obligation) to make a decision connected with an investment in a specified time or time interval. According to the method a static model of pricing using DCF is

  19. The benefits of forgetting in relation to emotion, cognition and behavior

    DEFF Research Database (Denmark)

    Nørby, Simon

    Forgetting is frequently associated with frustration in everyday life. However, forgetting does not have exclusively negative consequences, and I suggest that it serves at least three constructive functions. First, forgetting is part of emotion regulation, and facilitates subjective well-being by...

  20. Competitive retrieval is not a prerequisite for forgetting in the retrieval practice paradigm.

    NARCIS (Netherlands)

    Camp, Gino; Dalm, Sander

    2018-01-01

    Retrieving information from memory can lead to forgetting of other, related information. The inhibition account of this retrieval-induced forgetting effect predicts that this form of forgetting occurs when competition arises between the practiced information and the related information, leading to

  1. GASIFICACIÓN DE CARBÓN PARA GENERACIÓN DE ENERGÍA ELÉCTRICA: ANÁLISIS CON VALORACIÓN DE OPCIONES REALES COAL GASIFICATION FOR POWER GENERATION: ANALYSIS WITH REAL OPTIONS VALUATION

    Directory of Open Access Journals (Sweden)

    Alejandro Concha A

    2009-12-01

    Full Text Available Se evalúa económicamente la utilización de la tecnología de gasificación de carbón en la generación de energía eléctrica, utilizando información secundaria y el enfoque de valoración de opciones reales mediante árboles binomiales de 2 variables. Se analiza el caso de adaptar una central existente de gas natural de ciclo combinado (NGCC para la utilización de syngas a partir de carbón; en un segundo caso, se evalúa la instalación de una nueva central termoeléctrica de carbón pulverizado (PC o alternativamente una central de gasificación de carbón integrada a ciclo combinado (IGCC. En este último caso, se evalúa la opción de "switching" de combustible. Para los precios de los combustibles se emplean modelos de Movimiento Browniano Geométrico No Homogéneo (IGBM y en ambos casos estudiados se analiza en 2 escenarios de precios, incluyendo análisis de sensibilidad. Respecto al primer caso, la adaptación a syngas de una planta NGCC es conveniente económicamente, teniendo el proyecto una alta sensibilidad respecto a la eficiencia. La sensibilidad a la inversión no es significativa, como tampoco a los gastos de operación. Respecto al segundo caso, la conveniencia económica de la planta IGCC frente a la planta PC no es clara en los escenarios de precios considerados. Pero analizada en diversas combinaciones de precios, la planta IGCC de operación flexible alternando dos combustibles puede lograr ventajas económicas. Respecto a la sensibilidad, se repiten las conclusiones mencionadas para el primer caso.The use of coal gasification technology in the generation of electric power is evaluated economically. Secondary information and valuation of real options approach is used, with two variables binomial lattices. First, the retrofit of an existing natural gas combined cycle plant (NGCC for the utilization of syngas from coal is analyzed; on the second case, an economical evaluation is realized for to compare a new Pulverized

  2. Imagining Another Context during Encoding Offsets Context-Dependent Forgetting

    Science.gov (United States)

    Masicampo, E. J.; Sahakyan, Lili

    2014-01-01

    We tested whether imagining another context during encoding would offset context-dependent forgetting. All participants studied a list of words in Context A. Participants who remained in Context A during the test recalled more than participants who were tested in another context (Context B), demonstrating the standard context-dependent forgetting…

  3. Retrieval and sleep both counteract the forgetting of spatial information.

    Science.gov (United States)

    Antony, James W; Paller, Ken A

    2018-06-01

    Repeatedly studying information is a good way to strengthen memory storage. Nevertheless, testing recall often produces superior long-term retention. Demonstrations of this testing effect, typically with verbal stimuli, have shown that repeated retrieval through testing reduces forgetting. Sleep also benefits memory storage, perhaps through repeated retrieval as well. That is, memories may generally be subject to forgetting that can be counteracted when memories become reactivated, and there are several types of reactivation: (i) via intentional restudying, (ii) via testing, (iii) without provocation during wake, or (iv) during sleep. We thus measured forgetting for spatial material subjected to repeated study or repeated testing followed by retention intervals with sleep versus wake. Four groups of subjects learned a set of visual object-location associations and either restudied the associations or recalled locations given the objects as cues. We found the advantage for restudied over retested information was greater in the PM than AM group. Additional groups tested at 5-min and 1-wk retention intervals confirmed previous findings of greater relative benefits for restudying in the short-term and for retesting in the long-term. Results overall support the conclusion that repeated reactivation through testing or sleeping stabilizes information against forgetting. © 2018 Antony and Paller; Published by Cold Spring Harbor Laboratory Press.

  4. Theoretical Implications of Extralist Probes for Directed Forgetting

    Science.gov (United States)

    Sahakyan, Lili; Goodmon, Leilani B.

    2010-01-01

    In 5 experiments, the authors examined the influence of associative information in list-method directed forgetting, using the extralist cuing procedure (Nelson & McEvoy, 2005). Targets were studied in the absence of cues, but during retrieval, related cues were used to test their memory. Experiment 1 manipulated the degree of resonant…

  5. Electrophysiological correlates of competitor activation predict retrieval-induced forgetting.

    Science.gov (United States)

    Hellerstedt, Robin; Johansson, Mikael

    2014-06-01

    The very act of retrieval modifies the accessibility of memory for knowledge and past events and can also cause forgetting. A prominent theory of such retrieval-induced forgetting (RIF) holds that retrieval recruits inhibition to overcome interference from competing memories, rendering these memories inaccessible. The present study tested a fundamental tenet of the inhibitory-control account: The competition-dependence assumption. Event-related potentials (ERPs) were recorded while participants engaged in a competitive retrieval task. Competition levels were manipulated within the retrieval task by varying the cue-item associative strength of competing items. In order to temporally separate ERP correlates of competitor activation and target retrieval, memory was probed with the sequential presentation of 2 cues: A category cue, to reactivate competitors, and a target cue. As predicted by the inhibitory-control account, competitors with strong compared with weak cue-competitor association were more susceptible to forgetting. Furthermore, competition-sensitive ERP modulations, elicited by the category cue, were observed over anterior regions and reflected individual differences in ensuing forgetting. The present study demonstrates ERP correlates of the reactivation of tightly bound associated memories (the competitors) and provides support for the inhibitory-control account of RIF.

  6. Do not forget tuberculous meningitis | Tibbutt | South Sudan Medical ...

    African Journals Online (AJOL)

    South Sudan Medical Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 8, No 2 (2015) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Do not forget tuberculous meningitis. David Tibbutt. Abstract.

  7. Distributed patterns of brain activity that lead to forgetting

    Directory of Open Access Journals (Sweden)

    Ilke eOztekin

    2011-08-01

    Full Text Available Proactive interference (PI, in which irrelevant information from prior learning disrupts memory performance, is widely viewed as a major cause of forgetting. However, the hypothesized spontaneous recovery (i.e. automatic retrieval of interfering information presumed to be at the base of PI remains to be demonstrated directly. Moreover, it remains unclear at what point during learning and/or retrieval interference impacts memory performance. In order to resolve these open questions, we employed a machine-learning algorithm to identify distributed patterns of brain activity associated with retrieval of interfering information that engenders PI and causes forgetting. Participants were scanned using functional magnetic resonance imaging during an item recognition task. We induced PI by constructing sets of three consecutive study lists from the same semantic category. The classifier quantified the magnitude of category-related activity at encoding and retrieval. Category-specific activity during retrieval increased across lists, consistent with the category information becoming increasingly available and producing interference. Critically, this increase was correlated with individual differences in forgetting and the deployment of frontal lobe mechanisms that resolve interference. Collectively, these findings suggest that distributed patterns of brain activity pertaining to the interfering information during retrieval contribute to forgetting. The prefrontal cortex mediates the relationship between the spontaneous recovery of interfering information at retrieval and individual differences in memory performance.

  8. High Working Memory Capacity Predicts Less Retrieval Induced Forgetting

    NARCIS (Netherlands)

    Mall, Jonathan T.; Morey, Candice C.

    2013-01-01

    Background : Working Memory Capacity (WMC) is thought to be related to executive control and focused memory search abilities. These two hypotheses make contrasting predictions regarding the effects of retrieval on forgetting. Executive control during memory retrieval is believed to lead to retrieval

  9. Effects of Forgetting Phenomenon on Surveillance Test Interval

    International Nuclear Information System (INIS)

    Lee, Ho-Joong; Jang, Seung-Cheol

    2007-01-01

    Technical Specifications (TS) requirements for nuclear power plants (NPPs) define Surveillance Requirements (SRs) to assure safety during operation. SRs include surveillance test intervals (STIs) and the optimization of the STIs is one of the main issues in risk-informed applications. Surveillance tests are required in NPPs to detect failures in standby equipment to assure their availability in an accident. However, operating experience of the plants suggests that, in addition to the beneficial effects of detecting latent faults, the tests also may have adverse effects on plant operation or equipment; e.g., plant transient caused by the test and wear-out of safety system equipment due to repeated testing. Recent studies have quantitatively evaluated both the beneficial and adverse effects of testing to decide on an acceptable test interval. The purpose of this research is to investigate the effects of forgetting phenomenon on STI. It is a fundamental human characteristic that a person engaged in a repetitive task will improve his performance over time. The learning phenomenon is observed by the decrease in operation time per unit as operators gain experience by performing additional tasks. However, once there is a break of sufficient length, forgetting starts to take place. In surveillance tests, the most common factor to determine the amount of forgetting is the length of STI, where the longer the STI, the greater the amount of forgetting

  10. Implementation Learning and Forgetting Curve to Scheduling in Garment Industry

    Science.gov (United States)

    Muhamad Badri, Huda; Deros, Baba Md; Syahri, M.; Saleh, Chairul; Fitria, Aninda

    2016-02-01

    The learning curve shows the relationship between time and the cumulative number of units produced which using the mathematical description on the performance of workers in performing repetitive works. The problems of this study is level differences in the labors performance before and after the break which affects the company's production scheduling. The study was conducted in the garment industry, which the aims is to predict the company production scheduling using the learning curve and forgetting curve. By implementing the learning curve and forgetting curve, this paper contributes in improving the labors performance that is in line with the increase in maximum output 3 hours productive before the break are 15 unit product with learning curve percentage in the company is 93.24%. Meanwhile, the forgetting curve improving maximum output 3 hours productive after the break are 11 unit product with the percentage of forgetting curve in the company is 92.96%. Then, the obtained 26 units product on the productive hours one working day is used as the basic for production scheduling.

  11. Memorable objects are more susceptible to forgetting: Evidence for the inhibitory account of retrieval-induced forgetting.

    Science.gov (United States)

    Reppa, I; Williams, K E; Worth, E R; Greville, W J; Saunders, J

    2017-11-01

    Retrieval of target information can cause forgetting for related, but non-retrieved, information - retrieval-induced forgetting (RIF). The aim of the current studies was to examine a key prediction of the inhibitory account of RIF - interference dependence - whereby 'strong' non-retrieved items are more likely to interfere during retrieval and therefore, are more susceptible to RIF. Using visual objects allowed us to examine and contrast one index of item strength -object typicality, that is, how typical of its category an object is. Experiment 1 provided proof of concept for our variant of the recognition practice paradigm. Experiment 2 tested the prediction of the inhibitory account that the magnitude of RIF for natural visual objects would be dependent on item strength. Non-typical objects were more memorable overall than typical objects. We found that object memorability (as determined by typicality) influenced RIF with significant forgetting occurring for the memorable (non-typical), but not non-memorable (typical), objects. The current findings strongly support an inhibitory account of retrieval-induced forgetting. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Forget to Whom You Have Told This Proverb”: Directed Forgetting of Destination Memory in Alzheimer's Disease

    Science.gov (United States)

    El Haj, Mohamad; Gandolphe, Marie-Charlotte; Allain, Philippe; Fasotti, Luciano; Antoine, Pascal

    2015-01-01

    Destination memory is the ability to remember the receiver of transmitted information. By means of a destination memory directed forgetting task, we investigated whether participants with Alzheimer's Disease (AD) were able to suppress irrelevant information in destination memory. Twenty-six AD participants and 30 healthy elderly subjects were asked to tell 10 different proverbs to 10 different celebrities (List 1). Afterwards, half of the participants were instructed to forget the destinations (i.e., the celebrities) whereas the other half were asked to keep them in mind. After telling 10 other proverbs to 10 other celebrities (List 2), participants were asked to read numbers aloud. Subsequently, all the participants were asked to remember the destinations of List 1 and List 2, regardless of the forget or remember instructions. The results show similar destination memory in AD participants who were asked to forget the destinations of List 1 and those who were asked to retain them. These findings are attributed to inhibitory deficits, by which AD participants have difficulties to suppress irrelevant information in destination memory. PMID:25918456

  13. Rehabilitation Options

    Science.gov (United States)

    ... Speech Pathology Occupational Therapy Art Therapy Recreational therapy Neuropsychology Home Care Options Advanced Care Planning Palliative Care ... Speech Pathology Occupational Therapy Art Therapy Recreational therapy Neuropsychology Home Care Options Advanced Care Planning Palliative Care ...

  14. A real options model to assess the role of flexibility in forestry and agroforestry adoption and disadoption in the Lower Mississippi Alluvial Valley

    Science.gov (United States)

    Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt

    2013-01-01

    Efforts to restore the Lower Mississippi Alluvial Valley’s forests have not achieved desired levels of ecosystem services production.We examined how the variability of returns and the flexibility to change or postpone decisions (option value) affects the economic potential of forestry and agroforestry systems to keep private land in production while still providing...

  15. 32 CFR 644.168 - Exercise of options.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Exercise of options. 644.168 Section 644.168... ESTATE HANDBOOK Acquisition Procurement of Options Prior to Real Estate Directives (military) § 644.168 Exercise of options. Upon issuance of a real estate directive for acquisition of the optioned real property...

  16. An investigation of response competition in retrieval-induced forgetting

    Directory of Open Access Journals (Sweden)

    Gina A. Glanc

    2015-12-01

    Full Text Available It has been demonstrated that retrieval practice on a subset of studied items can cause forgetting of different related studied items. This retrieval-induced forgetting (the RIF effect has been demonstrated in a variety of recall studies and has been attributed to an inhibitory mechanism activated during retrieval practice by competition for a shared retrieval cue. The current study generalizes the RIF effect to recognition memory and investigates this competition assumption. Experiment 1 demonstrated an effect of RIF effect in item recognition with incidental encoding of category-exemplar association during the study phase. Experiment 2 demonstrated evidence of RIF with use of an independent retrieval cue during retrieval practice. Results from this study indicate that response competition may occur outside of the retrieval-practice phase, or may not be limited to situations where there is an overt link to a shared category cue.

  17. Effect of cognitive load on working memory forgetting in aging.

    Science.gov (United States)

    Baumans, Christine; Adam, Stephane; Seron, Xavier

    2012-01-01

    Functional approaches to working memory (WM) have been proposed recently to better investigate "maintenance" and "processing" mechanisms. The cognitive load (CL) hypothesis presented in the "Time-Based Resource-Sharing" model (Barrouillet & Camos, 2007) suggests that forgetting from WM (maintenance) can be investigated by varying the presentation rate and processing speed (processing). In this study, young and elderly participants were compared on WM tasks in which the difference in processing speed was controlled by CL manipulations. Two main results were found. First, when time constraints (CL) were matched for the two groups, no aging effect was observed. Second, whereas a large variation in CL affected WM performance, a small CL manipulation had no effect on the elderly. This suggests that WM forgetting cannot be completely accounted for by the CL hypothesis. Rather, it highlights the need to explore restoration times in particular, and the nature of the refreshment mechanisms within maintenance.

  18. Intentional forgetting: note-taking as a naturalistic example.

    Science.gov (United States)

    Eskritt, Michelle; Ma, Sierra

    2014-02-01

    In the present study, we examined whether note-taking as a memory aid may provide a naturalistic example of intentional forgetting. In the first experiment, participants played Concentration, a memory card game in which the identity and location of pairs of cards need to be remembered. Before the game started, half of the participants were allowed to study the cards, and the other half made notes that were then unexpectedly taken away. No significant differences emerged between the two groups for remembering identity information, but the study group remembered significantly more location information than did the note-taking group. In a second experiment, we examined whether note-takers would show signs of proactive interference while playing Concentration repeatedly. The results indicated that they did not. The findings suggest that participants adopted an intentional-forgetting strategy when using notes to store certain types of information.

  19. Forget about the future - let's get on with the past!

    DEFF Research Database (Denmark)

    McQuaid, Sara Dybris

    'Forget about the Future - Let's get on with the Past! Trails of truth recovery and provisional justice in Northern Ireland' Abstract: In Northern Ireland an agreed and comprehensive framework for ‘dealing with the past’ has yet to be worked out. In this policy vacuum a bricolage of different met...... demonstrate how initiatives conceived to serve a particular function can often transmute to serve other or additional functions with severe consequences for both the peace process and future policies for the past....

  20. Declassification, an actual operating materials management option in Cofrentes; La descalsificacion, una opcion operativa real de gestion de materiales en C. N. Cofrentes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Bermejo, R.; Diego compadre, J. L. de; Lopez Alvarez, L.; Analya Lazaro, M.

    2014-07-01

    Methods and procedures developed for declassification feature a series of methodological options and innovative technology, including the systematic use of the spatial random variable named index of Residual activity, level specific factors for declassification determined empirically for each unit of characterization and contrasts of hypothesis not parametric which are used in the demonstration of compliance of the levels of declassification Decision rules authorized by the CSN. (Author)

  1. Forgetting in immediate serial recall: decay, temporal distinctiveness, or interference?

    Science.gov (United States)

    Oberauer, Klaus; Lewandowsky, Stephan

    2008-07-01

    Three hypotheses of forgetting from immediate memory were tested: time-based decay, decreasing temporal distinctiveness, and interference. The hypotheses were represented by 3 models of serial recall: the primacy model, the SIMPLE (scale-independent memory, perception, and learning) model, and the SOB (serial order in a box) model, respectively. The models were fit to 2 experiments investigating the effect of filled delays between items at encoding or at recall. Short delays between items, filled with articulatory suppression, led to massive impairment of memory relative to a no-delay baseline. Extending the delays had little additional effect, suggesting that the passage of time alone does not cause forgetting. Adding a choice reaction task in the delay periods to block attention-based rehearsal did not change these results. The interference-based SOB fit the data best; the primacy model overpredicted the effect of lengthening delays, and SIMPLE was unable to explain the effect of delays at encoding. The authors conclude that purely temporal views of forgetting are inadequate. Copyright (c) 2008 APA, all rights reserved.

  2. The option to expand a project: its assessment with the binomial options pricing model

    Directory of Open Access Journals (Sweden)

    Salvador Cruz Rambaud

    Full Text Available Traditional methods of investment appraisal, like the Net Present Value, are not able to include the value of the operational flexibility of the project. In this paper, real options, and more specifically the option to expand, are assumed to be included in the project information in addition to the expected cash flows. Thus, to calculate the total value of the project, we are going to apply the methodology of the Net Present Value to the different scenarios derived from the existence of the real option to expand. Taking into account the analogy between real and financial options, the value of including an option to expand is explored by using the binomial options pricing model. In this way, estimating the value of the option to expand is a tool which facilitates the control of the uncertainty element implicit in the project. Keywords: Real options, Option to expand, Binomial options pricing model, Investment project appraisal

  3. The processing of inter-item relations as a moderating factor of retrieval-induced forgetting

    OpenAIRE

    Tempel, Tobias; Wippich, Werner

    2012-01-01

    We investigated influences of item generation and emotional valence on retrieval-induced forgetting. Drawing on postulates of the three-factor theory of generation effects, generation tasks differentially affecting the processing of inter-item relations were applied. Whereas retrieval-induced forgetting of freely generated items was moderated by the emotional valence as well as retrieval-induced forgetting of read items, even though in the reverse direction (Experiment 1), fragment completion...

  4. The short- and long-term consequences of directed forgetting in a working memory task.

    Science.gov (United States)

    Festini, Sara B; Reuter-Lorenz, Patricia A

    2013-01-01

    Directed forgetting requires the voluntary control of memory. Whereas many studies have examined directed forgetting in long-term memory (LTM), the mechanisms and effects of directed forgetting within working memory (WM) are less well understood. The current study tests how directed forgetting instructions delivered in a WM task influence veridical memory, as well as false memory, over the short and long term. In a modified item recognition task Experiment 1 tested WM only and demonstrated that directed forgetting reduces false recognition errors and semantic interference. Experiment 2 replicated these WM effects and used a surprise LTM recognition test to assess the long-term effects of directed forgetting in WM. Long-term veridical memory for to-be-remembered lists was better than memory for to-be-forgotten lists-the directed forgetting effect. Moreover, fewer false memories emerged for to-be-forgotten information than for to-be-remembered information in LTM as well. These results indicate that directed forgetting during WM reduces semantic processing of to-be-forgotten lists over the short and long term. Implications for theories of false memory and the mechanisms of directed forgetting within working memory are discussed.

  5. IMITATING MODEL OF ASSIMILATION AND FORGETTING OF THE LOGICALLY CONNECTED INFORMATION

    Directory of Open Access Journals (Sweden)

    Robert Valerievich Mayer

    2017-09-01

    Full Text Available The educational material we present as a set of a number of information blocks consisting of learning material elements (LMEs; therefore its assimilation and forgetting occurs differently, than in the Ebbinghaus’s experiments. The purpose of the article is constructing of a computer model of assimilation and forgetting of the logically connected information allowing: 1 to prove the fast rise of understanding while training; 2 to receive the forgetting curve for the comprehended information. The modeling methods help to receive the graphs of the knowledge level dependence on time. It is shown, that the processes of assimilation and forgetting occurs according to the logistic law.

  6. Erasing and blurring memories: The differential impact of interference on separate aspects of forgetting.

    Science.gov (United States)

    Sun, Sol Z; Fidalgo, Celia; Barense, Morgan D; Lee, Andy C H; Cant, Jonathan S; Ferber, Susanne

    2017-11-01

    Interference disrupts information processing across many timescales, from immediate perception to memory over short and long durations. The widely held similarity assumption states that as similarity between interfering information and memory contents increases, so too does the degree of impairment. However, information is lost from memory in different ways. For instance, studied content might be erased in an all-or-nothing manner. Alternatively, information may be retained but the precision might be degraded or blurred. Here, we asked whether the similarity of interfering information to memory contents might differentially impact these 2 aspects of forgetting. Observers studied colored images of real-world objects, each followed by a stream of interfering objects. Across 4 experiments, we manipulated the similarity between the studied object and the interfering objects in circular color space. After interference, memory for object color was tested continuously on a color wheel, which in combination with mixture modeling, allowed for estimation of how erasing and blurring differentially contribute to forgetting. In contrast to the similarity assumption, we show that highly dissimilar interfering items caused the greatest increase in random guess responses, suggesting a greater frequency of memory erasure (Experiments 1-3). Moreover, we found that observers were generally able to resist interference from highly similar items, perhaps through surround suppression (Experiments 1 and 4). Finally, we report that interference from items of intermediate similarity tended to blur or decrease memory precision (Experiments 3 and 4). These results reveal that the nature of visual similarity can differentially alter how information is lost from memory. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Expensing options solves nothing.

    Science.gov (United States)

    Sahlman, William A

    2002-12-01

    The use of stock options for executive compensation has become a lightning rod for public anger, and it's easy to see why. Many top executives grew hugely rich on the back of the gains they made on their options, profits they've been able to keep even as the value they were supposed to create disappeared. The supposed scam works like this: Current accounting regulations let companies ignore the cost of option grants on their income statements, so they can award valuable option packages without affecting reported earnings. Not charging the cost of the grants supposedly leads to overstated earnings, which purportedly translate into unrealistically high share prices, permitting top executives to realize big gains when they exercise their options. If an accounting anomaly is the problem, then the solution seems obvious: Write off executive share options against the current year's revenues. The trouble is, Sahlman writes, expensing option grants won't give us a more accurate view of earnings, won't add any information not already included in the financial statements, and won't even lead to equal treatment of different forms of executive pay. Far worse, expensing evades the real issue, which is whether compensation (options and other-wise) does what it's supposed to do--namely, help a company recruit, retain, and provide the right people with appropriate performance incentives. Any performance-based compensation system has the potential to encourage cheating. Only ethical management, sensible governance, adequate internal control systems, and comprehensive disclosure will save the investor from disaster. If, Sahlman warns, we pass laws that require the expensing of options, thinking that's fixed the fundamental flaws in corporate America's accounting, we will have missed a golden opportunity to focus on the much more extensive defects in the present system.

  8. Sex, age, and sex hormones affect recall of words in a directed forgetting paradigm.

    Science.gov (United States)

    Kerschbaum, Hubert H; Hofbauer, Ildiko; Gföllner, Anna; Ebner, Birgit; Bresgen, Nikolaus; Bäuml, Karl-Heinz T

    2017-01-02

    During the course of serious discussion, an unexpected interruption may induce forgetting of the original topic of a conversation. Sex, age, and sex hormone levels may affect frequency and extension of forgetting. In a list-method directed forgetting paradigm, subjects have to learn two word lists. After learning list 1, subjects receive either a forget or a remember list 1 cue. When the participants had learned list 2 and completed a distraction task, they were asked to write down as many recalled items as possible, starting either with list 1 or list 2 items. In the present study, 96 naturally cycling women, 60 oral contraceptive users, 56 postmenopausal women, and 41 young men were assigned to one of these different experimental conditions. Forget-cued young subjects recall fewer list 1 items (list 1 forgetting) but more list 2 items (list 2 enhancement) compared with remember-cued subjects. However, forget-cued postmenopausal women showed reduced list 1 forgetting but enhanced list 2 retention. Remember-cued naturally cycling women recalled more list 1 items than oral contraceptive users, young men, and postmenopausal women. In forget-cued follicular women, salivary progesterone correlated positively with recalled list 2 items. Salivary 17β-estradiol did not correlate with recalled list 1 or list 2 items in either remember- or forget-cued young women. However, salivary 17β-estradiol correlated with item recall in remember-cued postmenopausal women. Our findings suggest that sex hormones do not globally modulate verbal memory or forgetting, but selectively affect cue-specific processing. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Intentional Forgetting in Organizations: The Importance of Eliminating Retrieval Cues for Implementing New Routines

    Directory of Open Access Journals (Sweden)

    Annette Kluge

    2018-02-01

    Full Text Available To cope with the already large, and ever increasing, amount of information stored in organizational memory, “forgetting,” as an important human memory process, might be transferred to the organizational context. Especially in intentionally planned change processes (e.g., change management, forgetting is an important precondition to impede the recall of obsolete routines and adapt to new strategic objectives accompanied by new organizational routines. We first comprehensively review the literature on the need for organizational forgetting and particularly on accidental vs. intentional forgetting. We discuss the current state of the art of theory and empirical evidence on forgetting from cognitive psychology in order to infer mechanisms applicable to the organizational context. In this respect, we emphasize retrieval theories and the relevance of retrieval cues important for forgetting. Subsequently, we transfer the empirical evidence that the elimination of retrieval cues leads to faster forgetting to the forgetting of organizational routines, as routines are part of organizational memory. We then propose a classification of cues (context, sensory, business process-related cues that are relevant in the forgetting of routines, and discuss a meta-cue called the “situational strength” cue, which is relevant if cues of an old and a new routine are present simultaneously. Based on the classification as business process-related cues (information, team, task, object cues, we propose mechanisms to accelerate forgetting by eliminating specific cues based on the empirical and theoretical state of the art. We conclude that in intentional organizational change processes, the elimination of cues to accelerate forgetting should be used in change management practices.

  10. Intentional Forgetting in Organizations: The Importance of Eliminating Retrieval Cues for Implementing New Routines.

    Science.gov (United States)

    Kluge, Annette; Gronau, Norbert

    2018-01-01

    To cope with the already large, and ever increasing, amount of information stored in organizational memory, "forgetting," as an important human memory process, might be transferred to the organizational context. Especially in intentionally planned change processes (e.g., change management), forgetting is an important precondition to impede the recall of obsolete routines and adapt to new strategic objectives accompanied by new organizational routines. We first comprehensively review the literature on the need for organizational forgetting and particularly on accidental vs. intentional forgetting. We discuss the current state of the art of theory and empirical evidence on forgetting from cognitive psychology in order to infer mechanisms applicable to the organizational context. In this respect, we emphasize retrieval theories and the relevance of retrieval cues important for forgetting. Subsequently, we transfer the empirical evidence that the elimination of retrieval cues leads to faster forgetting to the forgetting of organizational routines, as routines are part of organizational memory. We then propose a classification of cues (context, sensory, business process-related cues) that are relevant in the forgetting of routines, and discuss a meta-cue called the "situational strength" cue, which is relevant if cues of an old and a new routine are present simultaneously. Based on the classification as business process-related cues (information, team, task, object cues), we propose mechanisms to accelerate forgetting by eliminating specific cues based on the empirical and theoretical state of the art. We conclude that in intentional organizational change processes, the elimination of cues to accelerate forgetting should be used in change management practices.

  11. Budget Options

    National Research Council Canada - National Science Library

    2000-01-01

    This volume-part of the Congressional Budget Office's (CBO's) annual report to the House and Senate Committees on the Budget-is intended to help inform policymakers about options for the federal budget...

  12. The Forgetful Professor and the Space Biology Adventure

    Science.gov (United States)

    Massa, Gioia D.; Jones, Wanda; Munoz, Angela; Santora, Joshua

    2014-01-01

    This video was created as one of the products of the 2013 ISS Faculty Fellows Summer Program. Our High School science teacher faculty fellows developed this video as an elementary/middle school education component. The video shows a forgetful professor who is trying to remember something, and along the journey she learns more about the space station, space station related plant science, and the Kennedy Space Center. She learns about the Veggie hardware, LED lighting for plant growth, the rotating garden concept, and generally about space exploration and the space station. Lastly she learns about the space shuttle Atlantis.

  13. Diffusion-based neuromodulation can eliminate catastrophic forgetting in simple neural networks.

    Directory of Open Access Journals (Sweden)

    Roby Velez

    Full Text Available A long-term goal of AI is to produce agents that can learn a diversity of skills throughout their lifetimes and continuously improve those skills via experience. A longstanding obstacle towards that goal is catastrophic forgetting, which is when learning new information erases previously learned information. Catastrophic forgetting occurs in artificial neural networks (ANNs, which have fueled most recent advances in AI. A recent paper proposed that catastrophic forgetting in ANNs can be reduced by promoting modularity, which can limit forgetting by isolating task information to specific clusters of nodes and connections (functional modules. While the prior work did show that modular ANNs suffered less from catastrophic forgetting, it was not able to produce ANNs that possessed task-specific functional modules, thereby leaving the main theory regarding modularity and forgetting untested. We introduce diffusion-based neuromodulation, which simulates the release of diffusing, neuromodulatory chemicals within an ANN that can modulate (i.e. up or down regulate learning in a spatial region. On the simple diagnostic problem from the prior work, diffusion-based neuromodulation 1 induces task-specific learning in groups of nodes and connections (task-specific localized learning, which 2 produces functional modules for each subtask, and 3 yields higher performance by eliminating catastrophic forgetting. Overall, our results suggest that diffusion-based neuromodulation promotes task-specific localized learning and functional modularity, which can help solve the challenging, but important problem of catastrophic forgetting.

  14. Diffusion-based neuromodulation can eliminate catastrophic forgetting in simple neural networks

    Science.gov (United States)

    Clune, Jeff

    2017-01-01

    A long-term goal of AI is to produce agents that can learn a diversity of skills throughout their lifetimes and continuously improve those skills via experience. A longstanding obstacle towards that goal is catastrophic forgetting, which is when learning new information erases previously learned information. Catastrophic forgetting occurs in artificial neural networks (ANNs), which have fueled most recent advances in AI. A recent paper proposed that catastrophic forgetting in ANNs can be reduced by promoting modularity, which can limit forgetting by isolating task information to specific clusters of nodes and connections (functional modules). While the prior work did show that modular ANNs suffered less from catastrophic forgetting, it was not able to produce ANNs that possessed task-specific functional modules, thereby leaving the main theory regarding modularity and forgetting untested. We introduce diffusion-based neuromodulation, which simulates the release of diffusing, neuromodulatory chemicals within an ANN that can modulate (i.e. up or down regulate) learning in a spatial region. On the simple diagnostic problem from the prior work, diffusion-based neuromodulation 1) induces task-specific learning in groups of nodes and connections (task-specific localized learning), which 2) produces functional modules for each subtask, and 3) yields higher performance by eliminating catastrophic forgetting. Overall, our results suggest that diffusion-based neuromodulation promotes task-specific localized learning and functional modularity, which can help solve the challenging, but important problem of catastrophic forgetting. PMID:29145413

  15. Individual Differences in Working Memory Capacity Predict Retrieval-Induced Forgetting

    Science.gov (United States)

    Aslan, Alp; Bauml, Karl-Heinz T.

    2011-01-01

    Selectively retrieving a subset of previously studied information enhances memory for the retrieved information but causes forgetting of related, nonretrieved information. Such retrieval-induced forgetting (RIF) has often been attributed to inhibitory executive-control processes that supposedly suppress the nonretrieved items' memory…

  16. Working memory capacity predicts listwise directed forgetting in adults and children.

    Science.gov (United States)

    Aslan, Alp; Zellner, Martina; Bäuml, Karl-Heinz T

    2010-05-01

    In listwise directed forgetting, participants are cued to forget previously studied material and to learn new material instead. Such cueing typically leads to forgetting of the first set of material and to memory enhancement of the second. The present study examined the role of working memory capacity in adults' and children's listwise directed forgetting. Working memory capacity was assessed with complex span tasks. In Experiment 1 working memory capacity predicted young adults' directed-forgetting performance, demonstrating a positive relationship between working memory capacity and each of the two directed-forgetting effects. In Experiment 2 we replicated the finding with a sample of first and a sample of fourth-grade children, and additionally showed that working memory capacity can account for age-related increases in directed-forgetting efficiency between the two age groups. Following the view that directed forgetting is mediated by inhibition of the first encoded list, the results support the proposal of a close link between working memory capacity and inhibitory function.

  17. Rethinking inhibition theory: On the problematic status of the inhibition theory for forgetting

    NARCIS (Netherlands)

    Raaijmakers, J.G.W.; Jakab, E.

    2013-01-01

    The standard textbook account of interference and forgetting is based on the assumption that retrieval of a memory trace is affected by competition by other memory traces. In recent years, a number of researchers have questioned this view and have proposed an alternative account of forgetting based

  18. Rethinking Inhibition Theory: On the Problematic Status of the Inhibition Theory for Forgetting

    Science.gov (United States)

    Raaijmakers, Jeroen G. W.; Jakab, Emoke

    2013-01-01

    The standard textbook account of interference and forgetting is based on the assumption that retrieval of a memory trace is affected by competition by other memory traces. In recent years, a number of researchers have questioned this view and have proposed an alternative account of forgetting based on a mechanism of suppression. In this inhibition…

  19. Evidence for age-related equivalence in the directed forgetting paradigm.

    Science.gov (United States)

    Gamboz, Nadia; Russo, Riccardo

    2002-01-01

    The directed forgetting paradigm involves, under particular experimental circumstances, inhibitory mechanisms, which operate to the successful forgetting of irrelevant words. The item-by-item cueing method (e.g., Basden & Basden, 1996) was used to investigate the directed forgetting effect in young and old adults. Processing of the experimental words was manipulated between subjects by asking participants to perform either a deep or a shallow orienting task on each word of the study list before the occurrence of the cue (to remember of to forget). Results indicated that the instruction to process deeply both to-be-remembered and to-be-forgotten words led to equivalent directed forgetting effects in young and old adults. These results are discussed with respect to the implications they have for the Inhibitory Deficit theory (e.g., Hasher & Zacks, 1988), which suggests that cognitive aging is mainly characterized by a reduction in the efficiency of inhibitory processes.

  20. Recognition-induced forgetting of faces in visual long-term memory.

    Science.gov (United States)

    Rugo, Kelsi F; Tamler, Kendall N; Woodman, Geoffrey F; Maxcey, Ashleigh M

    2017-10-01

    Despite more than a century of evidence that long-term memory for pictures and words are different, much of what we know about memory comes from studies using words. Recent research examining visual long-term memory has demonstrated that recognizing an object induces the forgetting of objects from the same category. This recognition-induced forgetting has been shown with a variety of everyday objects. However, unlike everyday objects, faces are objects of expertise. As a result, faces may be immune to recognition-induced forgetting. However, despite excellent memory for such stimuli, we found that faces were susceptible to recognition-induced forgetting. Our findings have implications for how models of human memory account for recognition-induced forgetting as well as represent objects of expertise and consequences for eyewitness testimony and the justice system.

  1. Hippocampal Activation of Rac1 Regulates the Forgetting of Object Recognition Memory.

    Science.gov (United States)

    Liu, Yunlong; Du, Shuwen; Lv, Li; Lei, Bo; Shi, Wei; Tang, Yikai; Wang, Lianzhang; Zhong, Yi

    2016-09-12

    Forgetting is a universal feature for most types of memories. The best-defined and extensively characterized behaviors that depict forgetting are natural memory decay and interference-based forgetting [1, 2]. Molecular mechanisms underlying the active forgetting remain to be determined for memories in vertebrates. Recent progress has begun to unravel such mechanisms underlying the active forgetting [3-11] that is induced through the behavior-dependent activation of intracellular signaling pathways. In Drosophila, training-induced activation of the small G protein Rac1 mediates natural memory decay and interference-based forgetting of aversive conditioning memory [3]. In mice, the activation of photoactivable-Rac1 in recently potentiated spines in a motor learning task erases the motor memory [12]. These lines of evidence prompted us to investigate a role for Rac1 in time-based natural memory decay and interference-based forgetting in mice. The inhibition of Rac1 activity in hippocampal neurons through targeted expression of a dominant-negative Rac1 form extended object recognition memory from less than 72 hr to over 72 hr, whereas Rac1 activation accelerated memory decay within 24 hr. Interference-induced forgetting of this memory was correlated with Rac1 activation and was completely blocked by inhibition of Rac1 activity. Electrophysiological recordings of long-term potentiation provided independent evidence that further supported a role for Rac1 activation in forgetting. Thus, Rac1-dependent forgetting is evolutionarily conserved from invertebrates to vertebrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Forgetting motor programmes: retrieval dynamics in procedural memory.

    Science.gov (United States)

    Tempel, Tobias; Frings, Christian

    2014-01-01

    When motor sequences are stored in memory in a categorised manner, selective retrieval of some sequences can induce forgetting of the non-retrieved sequences. We show that such retrieval-induced forgetting (RIF) occurs not only in cued recall but also in a test assessing memory indirectly by providing novel test cues without involving recall of items. Participants learned several sequential finger movements (SFMs), each consisting of the movement of two fingers of either the left or the right hand. Subsequently, they performed retrieval practice on half of the sequences of one hand. A final task then required participants to enter letter dyads. A subset of these dyads corresponded to the previously learned sequences. RIF was present in the response times during the entering of the dyads. The finding of RIF in the slowed-down execution of motor programmes overlapping with initially trained motor sequences suggests that inhibition resolved interference between procedural representations of the acquired motor sequences of one hand during retrieval practice.

  3. Vulvar and vaginal atrophy in postmenopausal women: findings from the REVIVE (REal Women's VIews of Treatment Options for Menopausal Vaginal ChangEs) survey.

    Science.gov (United States)

    Kingsberg, Sheryl A; Wysocki, Susan; Magnus, Leslie; Krychman, Michael L

    2013-07-01

    Vulvar and vaginal atrophy (VVA) is a chronic medical condition experienced by many postmenopausal women. Symptoms include dyspareunia (pain with intercourse), vaginal dryness, and irritation and may affect sexual activities, relationships, and activities of daily life. The aim of this study is to characterize postmenopausal women's experience with and perception of VVA symptoms, interactions with healthcare professionals (HCPs), and available treatment options. An online survey was conducted in the United States in women from KnowledgePanel(®) , a 56,000-member probability-selected Internet panel projectable to the overall US population. Altogether, 3,046 postmenopausal women with VVA symptoms (the largest US cohort of recent surveys) responded to questions about their knowledge of VVA, impact of symptoms on their activities, communication with HCPs, and use of available treatments. Percent is calculated as the ratio of response over total responding for each question for all and stratified participants. The most common VVA symptoms were dryness (55% of participants), dyspareunia (44%), and irritation (37%). VVA symptoms affected enjoyment of sex in 59% of participants. Additionally, interference with sleep, general enjoyment of life, and temperament were reported by 24%, 23%, and 23% of participants, respectively. Few women attributed symptoms to menopause (24%) or hormonal changes (12%). Of all participants, 56% had ever discussed VVA symptoms with an HCP and 40% currently used VVA-specific topical treatments (vaginal over-the-counter [OTC] products [29%] and vaginal prescription therapies [11%]). Of those who had discussed symptoms with an HCP, 62% used OTC products. Insufficient symptom relief and inconvenience were cited as major limitations of OTC products and concerns about side effects and cancer risk limited use of topical vaginal prescription therapies. VVA symptoms are common in postmenopausal women. Significant barriers to treatment include lack of

  4. The role of outcome inhibition in interference between outcomes: a contingency-learning analogue of retrieval-induced forgetting.

    Science.gov (United States)

    Vadillo, Miguel A; Orgaz, Cristina; Luque, David; Cobos, Pedro L; López, Francisco J; Matute, Helena

    2013-05-01

    Current associative theories of contingency learning assume that inhibitory learning plays a part in the interference between outcomes. However, it is unclear whether this inhibitory learning results in the inhibition of the outcome representation or whether it simply counteracts previous excitatory learning so that the outcome representation is neither activated nor inhibited. Additionally, these models tend to conceptualize inhibition as a relatively transient and cue-dependent state. However, research on retrieval-induced forgetting suggests that the inhibition of representations is a real process that can be relatively independent of the retrieval cue used to access the inhibited information. Consistent with this alternative view, we found that interference between outcomes reduces the retrievability of the target outcome even when the outcome is associated with a novel (non-inhibitory) cue. This result has important theoretical implications for associative models of interference and shows that the empirical facts and theories developed in studies of retrieval-induced forgetting might be relevant in contingency learning and vice versa. © 2012 The British Psychological Society.

  5. Una aplicación de opciones reales a la valoración de contratos de leasing An application of real options to the assessment of leasing contracts

    Directory of Open Access Journals (Sweden)

    Mónica Andrea Arango Arango

    2009-07-01

    Full Text Available Este artículo es el resultado de una investigación que desarrolla un modelo para la determinación del canon de arrendamiento en un contrato de leasing sobre vehículos, incluyendo la valoración de la opción de compra implícita en éste. Para realizar esta valoración se utilizaron como base los modelos propuestos por Giaccotto et al. [1] y Gamba y Rigon [2] (en tres marcas de vehículos en Colombia para el período comprendido entre Enero de 2004 y Diciembre de 2007. Se identificó el proceso ARMA de las series de los retornos de los precios de los vehículos. Se realizaron pruebas para identificar posibles efectos ARCH en las series de los retornos de los precios de los vehículos analizados. La estimación del valor de la opción de compra del vehículo al finalizar el contrato de leasing se realiza mediante la implementación del modelo de black-scholes y de simulación Monte Carlo.This article is the result of a research that develops a model related to the determination of the rent on a leasing vehicle contract and the valuation of the call option that gives the lessee the right but not the obligation to buy the used car at the end of the contract at a specified price. We used models proposed by [1] and by [2] in three brands of vehicles in Colombia for the period between January of 2004 and December of 2007. The analysis of the time series of returns of the prices vehicles displayed an ARMA process. We also developed further tests to identify possible ARCH effects in the series of returns of prices of the vehicles analyzed. The estimation of the value of the option to purchase the vehicle at the end of the leasing contract is done by the implementation of the model of Black Scholes and Montecarlo Simulation.

  6. Rehearsal of To-Be-Remembered Items Is Unnecessary to Perform Directed Forgetting within Working Memory: Support for an Active Control Mechanism

    Science.gov (United States)

    Festini, Sara B.; Reuter-Lorenz, Patricia A.

    2017-01-01

    Directed forgetting tasks instruct people to forget targeted memoranda. In the context of working memory, people attempt to forget representations that are currently held in mind. Here, we evaluated candidate mechanisms of directed forgetting within working memory, by (a) testing the influence of articulatory suppression, a rehearsal-reducing and…

  7. Forgetting in Reinforcement Learning Links Sustained Dopamine Signals to Motivation.

    Science.gov (United States)

    Kato, Ayaka; Morita, Kenji

    2016-10-01

    It has been suggested that dopamine (DA) represents reward-prediction-error (RPE) defined in reinforcement learning and therefore DA responds to unpredicted but not predicted reward. However, recent studies have found DA response sustained towards predictable reward in tasks involving self-paced behavior, and suggested that this response represents a motivational signal. We have previously shown that RPE can sustain if there is decay/forgetting of learned-values, which can be implemented as decay of synaptic strengths storing learned-values. This account, however, did not explain the suggested link between tonic/sustained DA and motivation. In the present work, we explored the motivational effects of the value-decay in self-paced approach behavior, modeled as a series of 'Go' or 'No-Go' selections towards a goal. Through simulations, we found that the value-decay can enhance motivation, specifically, facilitate fast goal-reaching, albeit counterintuitively. Mathematical analyses revealed that underlying potential mechanisms are twofold: (1) decay-induced sustained RPE creates a gradient of 'Go' values towards a goal, and (2) value-contrasts between 'Go' and 'No-Go' are generated because while chosen values are continually updated, unchosen values simply decay. Our model provides potential explanations for the key experimental findings that suggest DA's roles in motivation: (i) slowdown of behavior by post-training blockade of DA signaling, (ii) observations that DA blockade severely impairs effortful actions to obtain rewards while largely sparing seeking of easily obtainable rewards, and (iii) relationships between the reward amount, the level of motivation reflected in the speed of behavior, and the average level of DA. These results indicate that reinforcement learning with value-decay, or forgetting, provides a parsimonious mechanistic account for the DA's roles in value-learning and motivation. Our results also suggest that when biological systems for value

  8. Forgetting in Reinforcement Learning Links Sustained Dopamine Signals to Motivation.

    Directory of Open Access Journals (Sweden)

    Ayaka Kato

    2016-10-01

    Full Text Available It has been suggested that dopamine (DA represents reward-prediction-error (RPE defined in reinforcement learning and therefore DA responds to unpredicted but not predicted reward. However, recent studies have found DA response sustained towards predictable reward in tasks involving self-paced behavior, and suggested that this response represents a motivational signal. We have previously shown that RPE can sustain if there is decay/forgetting of learned-values, which can be implemented as decay of synaptic strengths storing learned-values. This account, however, did not explain the suggested link between tonic/sustained DA and motivation. In the present work, we explored the motivational effects of the value-decay in self-paced approach behavior, modeled as a series of 'Go' or 'No-Go' selections towards a goal. Through simulations, we found that the value-decay can enhance motivation, specifically, facilitate fast goal-reaching, albeit counterintuitively. Mathematical analyses revealed that underlying potential mechanisms are twofold: (1 decay-induced sustained RPE creates a gradient of 'Go' values towards a goal, and (2 value-contrasts between 'Go' and 'No-Go' are generated because while chosen values are continually updated, unchosen values simply decay. Our model provides potential explanations for the key experimental findings that suggest DA's roles in motivation: (i slowdown of behavior by post-training blockade of DA signaling, (ii observations that DA blockade severely impairs effortful actions to obtain rewards while largely sparing seeking of easily obtainable rewards, and (iii relationships between the reward amount, the level of motivation reflected in the speed of behavior, and the average level of DA. These results indicate that reinforcement learning with value-decay, or forgetting, provides a parsimonious mechanistic account for the DA's roles in value-learning and motivation. Our results also suggest that when biological systems

  9. Predicting remembering and forgetting of autobiographical memories in children and adults: a 4-year prospective study.

    Science.gov (United States)

    Bauer, Patricia J; Larkina, Marina

    2016-11-01

    Preservation and loss to forgetting of autobiographical memories is a focus in both the adult and developmental literatures. In both, there are comparative arguments regarding rates of forgetting. Children are assumed to forget autobiographical memories more rapidly than adults, and younger children are assumed to forget more rapidly than older children. Yet few studies can directly inform these comparisons: few feature children and adults, and few prospectively track the survival of specific autobiographical memories over time. In a 4-year prospective study, we obtained autobiographical memories from children 4, 6, and 8 years, and adults. We tested recall of different subsets of the events after 1, 2, and 3 years. Accelerated rates of forgetting were apparent among all child groups relative to adults; within the child groups, 4- and 6-year-olds had accelerated forgetting relative to 8-year-olds. The differences were especially pronounced in open-ended recall. The thematic coherence of initial memory reports also was a significant predictor of the survival of specific memories. The pattern of findings is consistent with suggestions that the adult distribution of autobiographical memories is achieved as the quality of memory traces increases (here measured by thematic coherence) and the rate of forgetting decreases.

  10. Context-dependent impairment of recollection in list-method directed forgetting.

    Science.gov (United States)

    Hanczakowski, Maciej; Pasek, Tomasz; Zawadzka, Katarzyna

    2012-01-01

    In list-method directed forgetting, people's ability to forget one of the sets of learned material is examined. Research shows that memory for to-be-forgotten items is impaired when assessed by a recall test and by recognition tests reliant on recollective processes. Retrieval inhibition and context-change mechanisms have been proposed to account for the directed forgetting effects and both of them account for the results obtained with recognition tests. However, the context change account makes a specific prediction that recollection is impaired by directed forgetting only if it makes use of contextual associations. In the present study, directed forgetting was examined with two types of recollection-based tasks making use of different types of associations, namely a list discrimination task utilising contextual associations and an associative recognition task utilising interitem associations. Consistent with the context change account, the costs of directed forgetting were observed in a list discrimination task and were not observed in an associative recognition task. The results indicate that impairment in recollection due to directed forgetting is not general and provide converging evidence to support the context-change account.

  11. Predicting remembering and forgetting of autobiographical memories in children and adults: A 4-year prospective study

    Science.gov (United States)

    Bauer, Patricia J.; Larkina, Marina

    2015-01-01

    Preservation and loss to forgetting of autobiographical memories is a focus in both the adult and developmental literatures. In both, there are comparative arguments regarding rates of forgetting. Children are assumed to forget autobiographical memories more rapidly than adults, and younger children are assumed to forget more rapidly than older children. Yet few studies can directly inform these comparisons: few feature children and adults, and few prospectively track the survival of specific autobiographical memories over time. In a 4-year prospective study, we obtained autobiographical memories from children 4, 6, and 8 years, and adults. We tested recall of different subsets of the events after 1, 2, and 3 years. Accelerated rates of forgetting were apparent among all child groups relative to adults; within the child groups, 4- and 6-year-olds had accelerated forgetting relative to 8-year-olds. The differences were especially pronounced in open-ended recall. The thematic coherence of initial memory reports also was a significant predictor of the survival of specific memories. The pattern of findings is consistent with suggestions that the adult distribution of autobiographical memories is achieved as the quality of memory traces increases (here measured by thematic coherence) and the rate of forgetting decreases. PMID:26566236

  12. ADHD and retrieval-induced forgetting: evidence for a deficit in the inhibitory control of memory.

    Science.gov (United States)

    Storm, Benjamin C; White, Holly A

    2010-04-01

    Research on retrieval-induced forgetting has shown that the selective retrieval of some information can cause the forgetting of other information. Such forgetting is believed to result from inhibitory processes that function to resolve interference during retrieval. The current study examined whether individuals with ADHD demonstrate normal levels of retrieval-induced forgetting. A total of 40 adults with ADHD and 40 adults without ADHD participated in a standard retrieval-induced forgetting experiment. Critically, half of the items were tested using category cues and the other half of the items were tested using category-plus-one-letter-stem cues. Whereas both ADHD and non-ADHD participants demonstrated retrieval-induced forgetting on the final category-cued recall test, only non-ADHD participants demonstrated retrieval-induced forgetting on the final category-plus-stem-cued recall test. These results suggest that individuals with ADHD do have a deficit in the inhibitory control of memory, but that this deficit may only be apparent when output interference is adequately controlled on the final test.

  13. Competition between items in working memory leads to forgetting.

    Science.gov (United States)

    Lewis-Peacock, Jarrod A; Norman, Kenneth A

    2014-12-18

    Switching attention from one thought to the next propels our mental lives forward. However, it is unclear how this thought-juggling affects our ability to remember these thoughts. Here we show that competition between the neural representations of pictures in working memory can impair subsequent recognition of those pictures. We use pattern classifiers to decode functional magnetic resonance imaging (fMRI) data from a retro-cueing task where participants juggle two pictures in working memory. Trial-by-trial fluctuations in neural dynamics are predictive of performance on a surprise recognition memory test: trials that elicit similar levels of classifier evidence for both pictures (indicating close competition) are associated with worse memory performance than trials where participants switch decisively from thinking about one picture to the other. This result is consistent with the non-monotonic plasticity hypothesis, which predicts that close competition can trigger weakening of memories that lose the competition, leading to subsequent forgetting.

  14. To remember in order to be able to forget

    DEFF Research Database (Denmark)

    Jørholt, Eva

    2016-01-01

    At its screening in Cannes, Rachid Bouchareb's film on the Algerian war of independence, Hors la loi (Outside the Law, 2010), was met with vehement protests from veterans and French right-wing politicians who accused it of presenting an ‘anti-French’ account of this traumatic war which is still...... affecting many Frenchmen's attitude towards North African immigrants and their descendants. Rather than addressing the war along Manichean national allegiance lines, however, the film emphasises similarities between the Algerian fight for freedom and the French Resistance during the Second World War. Its...... of Ernest Renan's claim that the establishment and consolidation of a nation requires its individual members to forget past controversies, Outside the Law can thus be said to contribute to the construction of a new and more inclusive understanding of the French nation....

  15. VALORACIÓN DEL RIESGO FINANCIERO (CFAR EN LAS EPS A TRAVÉS DE OPCIONES REALES: UNA APLICACIÓN AL NIVEL DE ATENCIÓN IV Financial Risk Valuation (CFARin EPS's through Real Options: An Application at the IV Assistance Level

    Directory of Open Access Journals (Sweden)

    Mónica A. Arango Arango

    2011-12-01

    Full Text Available El número de pacientes tratados por insuficiencia renal en Colombia es cada vez mayor; por esta razón conocer los costos asociados a esta enfermedad es una necesidad manifiesta de las Entidades Promotoras de Salud con el fin de garantizar la estabilidad del Sistema de Seguridad Social en Salud. Este trabajo evalúa financieramente, mediante opciones reales, la posibilidad de hacer un trasplante de riñón en un paciente bajo tratamiento de insuficiencia renal y el Flujo de Caja en Riesgo al tener en cuenta esta opción. Se encontró que al hacer un análisis periódico de los costos asociados a continuar con el tratamiento, existen casos en los que es más eficiente hacer el trasplante, disminuyendo el valor presente de las erogaciones del paciente, mejorando el flujo de caja en riesgo y controlando los gastos futuros de la entidad que lo atiende.Number of patients treated for renal failure in Colombia is increasingly high; for this reason, knowing the costs associated to this disease is a clear need for Health Promoting Entities with the purpose of assuring stability of the Health Social Security System. Through real options, this article is a financial evaluation of the possibility of conducting a kidney transplant in a patient being under a renal failure treatment and the cash flow at risk when having this as an option. It was found that when a periodical analysis of costs associated to continuation of treatment is made, there are cases where transplant is a more efficient option to be executed since the present value of the patient's expenses is decreased, thus improving the cash flow at risk and controlling future expenses of the entity treating the patient.

  16. Energy exotic options

    International Nuclear Information System (INIS)

    Kaminski, V.; Gibner, S.; Pinnamaneni, K.

    1999-01-01

    This chapter with 88 references focuses on the use of exotic options to control exposure to energy prices. Exotic options are defined, and the conversion of a standard option into an exotic option and pricing models are examined. Pricing and hedging exotic options, path-dependent options, multi-commodity options, options on the minimum-or-maximum of two commodities, compound options, digital options, hybrid and complex structures, and natural gas daily options are described. Formulas for option pricing for vanilla, barrier, compound, options on minimum or maximum of two assets, and look back options are given in an appendix

  17. Infectious Cognition: Risk Perception Affects Socially Shared Retrieval-Induced Forgetting of Medical Information.

    Science.gov (United States)

    Coman, Alin; Berry, Jessica N

    2015-12-01

    When speakers selectively retrieve previously learned information, listeners often concurrently, and covertly, retrieve their memories of that information. This concurrent retrieval typically enhances memory for mentioned information (the rehearsal effect) and impairs memory for unmentioned but related information (socially shared retrieval-induced forgetting, SSRIF), relative to memory for unmentioned and unrelated information. Building on research showing that anxiety leads to increased attention to threat-relevant information, we explored whether concurrent retrieval is facilitated in high-anxiety real-world contexts. Participants first learned category-exemplar facts about meningococcal disease. Following a manipulation of perceived risk of infection (low vs. high risk), they listened to a mock radio show in which some of the facts were selectively practiced. Final recall tests showed that the rehearsal effect was equivalent between the two risk conditions, but SSRIF was significantly larger in the high-risk than in the low-risk condition. Thus, the tendency to exaggerate consequences of news events was found to have deleterious consequences. © The Author(s) 2015.

  18. Options theory

    International Nuclear Information System (INIS)

    Markland, J.T.

    1992-01-01

    Techniques used in conventional project appraisal are mathematically very simple in comparison to those used in reservoir modelling, and in the geosciences. Clearly it would be possible to value assets in mathematically more sophisticated ways if it were meaningful and worthwhile so to do. The DCf approach in common use has recognized limitations; the inability to select a meaningful discount rate being particularly significant. Financial Theory has advanced enormously over the last few years, along with computational techniques, and methods are beginning to appear which may change the way we do project evaluations in practice. The starting point for all of this was a paper by Black and Scholes, which asserts that almost all corporate liabilities can be viewed as options of varying degrees of complexity. Although the financial presentation may be unfamiliar to engineers and geoscientists, some of the concepts used will not be. This paper outlines, in plain English, the basis of option pricing theory for assessing the market value of a project. it also attempts to assess the future role of this type of approach in practical Petroleum Exploration and Engineering economics. Reference is made to relevant published Natural Resource literature

  19. Directed forgetting and aging: the role of retrieval processes, processing speed, and proactive interference.

    Science.gov (United States)

    Hogge, Michaël; Adam, Stéphane; Collette, Fabienne

    2008-07-01

    The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items.

  20. Proactive Interference and Directed Forgetting in Short-Term Motor Memory

    Science.gov (United States)

    Burwitz, Leslie

    1974-01-01

    The present study was designed to test the effect of instructions to forget prior motor learning and the results were relevant to the understanding of short-term motor memory (STMM) proactive interference (PI). (Author/RK)

  1. Time-based forgetting in visual working memory reflects temporal distinctiveness, not decay

    OpenAIRE

    Souza Alessandra S.; Oberauer Klaus

    2015-01-01

    Is forgetting from working memory (WM) better explained by decay or interference? The answer to this question is the topic of an ongoing debate. Recently a number of studies showed that performance in tests of visual WM declines with an increasing unfilled retention interval. This finding was interpreted as revealing decay. Alternatively it can be explained by interference theories as an effect of temporal distinctiveness. According to decay theories forgetting depends on the absolute time el...

  2. Intentional Forgetting in Organizations: The Importance of Eliminating Retrieval Cues for Implementing New Routines

    OpenAIRE

    Kluge, Annette; Gronau, Norbert

    2018-01-01

    To cope with the already large, and ever increasing, amount of information stored in organizational memory, “forgetting,” as an important human memory process, might be transferred to the organizational context. Especially in intentionally planned change processes (e.g., change management), forgetting is an important precondition to impede the recall of obsolete routines and adapt to new strategic objectives accompanied by new organizational routines. We first comprehensively review the liter...

  3. The neural substrates of memory suppression: a FMRI exploration of directed forgetting.

    Science.gov (United States)

    Bastin, Christine; Feyers, Dorothée; Majerus, Steve; Balteau, Evelyne; Degueldre, Christian; Luxen, André; Maquet, Pierre; Salmon, Eric; Collette, Fabienne

    2012-01-01

    The directed forgetting paradigm is frequently used to determine the ability to voluntarily suppress information. However, little is known about brain areas associated with information to forget. The present study used functional magnetic resonance imaging to determine brain activity during the encoding and retrieval phases of an item-method directed forgetting recognition task with neutral verbal material in order to apprehend all processing stages that information to forget and to remember undergoes. We hypothesized that regions supporting few selective processes, namely recollection and familiarity memory processes, working memory, inhibitory and selection processes should be differentially activated during the processing of to-be-remembered and to-be-forgotten items. Successful encoding and retrieval of items to remember engaged the entorhinal cortex, the hippocampus, the anterior medial prefrontal cortex, the left inferior parietal cortex, the posterior cingulate cortex and the precuneus; this set of regions is well known to support deep and associative encoding and retrieval processes in episodic memory. For items to forget, encoding was associated with higher activation in the right middle frontal and posterior parietal cortex, regions known to intervene in attentional control. Items to forget but nevertheless correctly recognized at retrieval yielded activation in the dorsomedial thalamus, associated with familiarity-based memory processes and in the posterior intraparietal sulcus and the anterior cingulate cortex, involved in attentional processes.

  4. The neural substrates of memory suppression: a FMRI exploration of directed forgetting.

    Directory of Open Access Journals (Sweden)

    Christine Bastin

    Full Text Available The directed forgetting paradigm is frequently used to determine the ability to voluntarily suppress information. However, little is known about brain areas associated with information to forget. The present study used functional magnetic resonance imaging to determine brain activity during the encoding and retrieval phases of an item-method directed forgetting recognition task with neutral verbal material in order to apprehend all processing stages that information to forget and to remember undergoes. We hypothesized that regions supporting few selective processes, namely recollection and familiarity memory processes, working memory, inhibitory and selection processes should be differentially activated during the processing of to-be-remembered and to-be-forgotten items. Successful encoding and retrieval of items to remember engaged the entorhinal cortex, the hippocampus, the anterior medial prefrontal cortex, the left inferior parietal cortex, the posterior cingulate cortex and the precuneus; this set of regions is well known to support deep and associative encoding and retrieval processes in episodic memory. For items to forget, encoding was associated with higher activation in the right middle frontal and posterior parietal cortex, regions known to intervene in attentional control. Items to forget but nevertheless correctly recognized at retrieval yielded activation in the dorsomedial thalamus, associated with familiarity-based memory processes and in the posterior intraparietal sulcus and the anterior cingulate cortex, involved in attentional processes.

  5. Strategic Investment: Real Options and Games

    NARCIS (Netherlands)

    J.T.J. Smit (Han); L. Trigeorgis (Lenos)

    2004-01-01

    textabstractCorporate finance and corporate strategy have long been seen as different sides of the same coin. Though both focus on the same broad problem, investment decision-making, the gap between the two sides--and between theory and practice--remains embarrassingly large. This book synthesizes

  6. Evaluation of capital investment in thermoelectric generation projects in the Brazilian electric sector using the real options theory; Avaliacao de investimento de capital em projetos de geracao termoeletrica no setor eletrico brasileiro usando teoria das opcoes reais

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Alessandro de Lima

    2000-04-01

    In the Brazilian Electric System about 92% of the generated electricity is of hydraulic origin. Today the system is operating practically in the limit of your capacity. Solutions of short time to make possible the expansion of the offer of electricity generation go by the installation of cycle combining thermal using natural gas as fuel. In this dissertation, it was used the real options theory to evaluate generation assets in the Brazilian electricity sector. In Brazil, central operator dispatches a flexible thermal when the electricity spot price is larger than the operation costs. The operation decision is like an European call, where underlying asset is the electricity and the strike price is the operation cost. The value of the capacity is the sum of all decisions to operate the thermal unit, in the remaining life of unit. It was used Monte Carlo Simulation and Dynamic Programming to evaluate this model. The problem is divided in two parts. In the first part, the base case is fixed and evaluated and the expected NPV and project risk are calculated in function of contract level. In the second part, many sensibilities are done in relation to base case. At the end, the value of flexibility is calculated for each contract level. (author)

  7. Item-cued directed forgetting of related words and pictures in children and adults: selective rehearsal versus cognitive inhibition.

    Science.gov (United States)

    Lehman, E B; McKinley-Pace, M; Leonard, A M; Thompson, D; Johns, K

    2001-01-01

    The main purpose of this study was to compare the relative importance of selective rehearsal and cognitive inhibition in accounting for developmental changes in the directed-forgetting paradigm developed by R. A. Bjork (1972). In two experiments, children in Grades 2 and 5 and college students were asked to remember some words or pictures and to forget others when items were categorically related. Their memory for both items and the associated remember or forget cues was then tested with recall and recognition. Fifth graders recognized more of the forget-cued words than college students did. The pattern of results suggested that age differences in rehearsal and source monitoring (i.e., remembering whether a word had been cued remember or forget) were better explanatory mechanisms for children's forgetting inefficiencies than retrieval inhibition was. The results are discussed in terms of a multiple process view of inhibition.

  8. American options under stochastic volatility

    NARCIS (Netherlands)

    Chockalingam, A.; Muthuraman, K.

    2011-01-01

    The problem of pricing an American option written on an underlying asset with constant price volatility has been studied extensively in literature. Real-world data, however, demonstrate that volatility is not constant, and stochastic volatility models are used to account for dynamic volatility

  9. Indian Jute in Australian Collections: Forgetting and Recollecting Transnational Networks

    Directory of Open Access Journals (Sweden)

    Andrew Hassam

    2011-12-01

    Full Text Available Indian jute sacking played an essential role in Australian life for over 150 years, yet its contribution to Australian development and its Indian origins have been barely recognised in Australian public collections. What has Australian history gained by this erasing of jute from public memory? Wool, sugar and hop sacks are displayed in public collections as evidence of an Australian national story, but their national dimension depends on the cultural invisibility of jute and jute’s connections to the stories of other communities in other places. Developing an awareness of the contribution of Indian jute to the development of Australia requires an awareness not simply that jute comes from India but that the construction of national identity by collecting institutions relies on forgetting those transnational connections evident in their own collections. Where jute sacks have been preserved, it is because they are invested with memories of a collective way of life, yet in attempting to speak on behalf of the nation, the public museum denies more multidimensional models of cultural identity that are less linear and less place-based. If Indian jute is to be acknowledged as part of ‘the Australian story’, the concept of an Australian story must change and exhibitions need to explore, rather than ignore, transnational networks.

  10. Power-law forgetting in synapses with metaplasticity

    International Nuclear Information System (INIS)

    Mehta, A; Luck, J M

    2011-01-01

    The idea of using metaplastic synapses to incorporate the separate storage of long- and short-term memories via an array of hidden states was put forward in the cascade model of Fusi et al. In this paper, we devise and investigate two models of a metaplastic synapse based on these general principles. The main difference between the two models lies in their available mechanisms of decay, when a contrarian event occurs after the build-up of a long-term memory. In one case, this leads to the conversion of the long-term memory to a short-term memory of the opposite kind, while in the other, a long-term memory of the opposite kind may be generated as a result. Appropriately enough, the response of both models to short-term events is not affected by this difference in architecture. On the contrary, the transient response of both models, after long-term memories have been created by the passage of sustained signals, is rather different. The asymptotic behaviour of both models is, however, characterised by power-law forgetting with the same universal exponent

  11. Walking through doorways causes forgetting: Younger and older adults.

    Science.gov (United States)

    Radvansky, Gabriel A; Pettijohn, Kyle A; Kim, Joonsung

    2015-06-01

    Previous research on event cognition has found that walking through doorways can cause forgetting. The explanation for this finding is that there is a competition between event models, producing interference, and depressing performance. The current study explored the degree to which this might be affected by the natural aging process. This is of interest because there is some evidence that older adults have trouble coordinating sources of interference, which is what is thought to underlie this effect. This would suggest that older adults should do worse on this task. Alternatively, there is also evidence that older adults are typically not disrupted at the event level of processing per se. This would suggest that older adults should perform similarly to younger adults on this task. In the study reported here, younger and older participants navigated through a virtual environment, and memory was tested with probes either before or after a shift and for objects that were associated with the participant (i.e., just picked up). In general, both younger and older adults had memory disrupted after walking through a doorway. Importantly, the magnitude of this disruption was similar in the 2 age groups. This is consistent with the idea that processing at the event level is relatively unaffected by the natural aging process. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  12. Big spleens and hypersplenism: fix it or forget it?

    Science.gov (United States)

    Boyer, Thomas D; Habib, Shahid

    2015-05-01

    Hypersplenism is a common manifestation of portal hypertension in the cirrhotic. More than half of cirrhotics will have low platelet counts, but neutropenia is much less common. Despite being common in the cirrhotic population, the presence of hypersplenism is of little clinical consequence. The presence of hypersplenism suggests more advanced liver disease and an increase in risk of complications, but there is no data showing that correcting the hypersplenism improves patient survival. In most series, the most common indications for treating the hypersplenism is to increase platelet and white blood cell counts to allow for use of drugs that suppress the bone marrow such as interferon alpha and chemotherapeutic agents. There are several approaches used to treat hypersplenism. Portosystemic shunts are of questionable benefit. Splenectomy, either open or laparoscopically, is the most effective but is associated with a significant risk of portal vein thrombosis. Partial splenic artery embolization and radiofrequency ablation are effective methods for treating hypersplenism, but counts tend to fall back to baseline long-term. Pharmacological agents are also effective in increasing platelet counts. Development of direct acting antivirals against hepatitis C will eliminate the most common indication for treatment. We lack controlled trials designed to determine if treating the hypersplenism has benefits other than raising the platelet and white blood cell counts. In the absence of such studies, hypersplenism in most patients should be considered a laboratory abnormality and not treated, in other words forget it. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Real Islamic Logic

    NARCIS (Netherlands)

    Bergstra, J.A.

    2011-01-01

    Four options for assigning a meaning to Islamic Logic are surveyed including a new proposal for an option named "Real Islamic Logic" (RIL). That approach to Islamic Logic should serve modern Islamic objectives in a way comparable to the functionality of Islamic Finance. The prospective role of RIL

  14. Pricing and Applications of Digital Installment Options

    Directory of Open Access Journals (Sweden)

    Pierangelo Ciurlia

    2012-01-01

    Full Text Available For its theoretical interest and strong impact on financial markets, option valuation is considered one of the cornerstones of contemporary mathematical finance. This paper specifically studies the valuation of exotic options with digital payoff and flexible payment plan. By means of the Incomplete Fourier Transform, the pricing problem is solved in order to find integral representations of the upfront price for European call and put options. Several applications in the areas of corporate finance, insurance, and real options are discussed. Finally, a new type of digital derivative named supercash option is introduced and some payment schemes are also presented.

  15. Explanation can cause Forgetting: Memory Dynamics in the Generation of New Arguments.

    Science.gov (United States)

    Soares, Julia S; Storm, Benjamin C

    2017-10-01

    Retrieval-induced forgetting is observed when the retrieval of target information causes the forgetting of nontarget information. The present study investigated whether similar dynamics occur in the context of generating arguments in the process of explanation. Participants studied arguments associated with several issues before attempting to think of new arguments pertaining to a subset of those issues. When given a later memory test, participants were less likely to recall the studied arguments if they had attempted to think of new arguments than if they had not. This argument-induced forgetting effect was observed regardless of whether participants attempted to generate arguments that either agreed or disagreed with the position of the arguments they studied. The effect was significantly reduced, however, and even numerically reversed, when participants generated arguments that were highly related to the studied arguments. This finding fits well with previous research on retrieval-induced forgetting, which has shown that the retrieval or generation of new information fails to cause the forgetting of old information when the two types of information are well integrated or semantically associated.

  16. Directed Forgetting in Post-Traumatic-Stress-Disorder: A study of refugee immigrants in Germany

    Directory of Open Access Journals (Sweden)

    Michaela eBaumann

    2013-08-01

    Full Text Available People with post-traumatic stress disorder (PTSD often suffer from memory disturbances. In particular, previous studies suggest that PTSD patients perform atypically on tests of directed forgetting, which may be mediated by an altered emotional appraisal of the presented material. Also, a special role of dissociative symptoms in traumatized individuals’ memory performance has been suggested. Here, we investigate these issues in traumatized immigrants in Germany. In an item-method directed forgetting task, pictures were presented individually, each followed by an instruction to either remember or forget it. Later, recognition memory was tested for all pictures, regardless of initial instruction. Overall, the PTSD group’s discrimination accuracy was lower than the control group’s, as PTSD participants produced fewer hits and more false alarms, but the groups did not differ in directed forgetting itself. Moreover, the more negatively participants evaluated the stimuli, the less they were able to discriminate old from new items. Participants with higher dissociation scores were particularly poor at recognizing to-be-forgotten items. Results confirm PTSD patients’ general discrimination deficits, but provide no evidence for a distinct directed forgetting pattern in PTSD. Furthermore, data indicate that, in general, more negatively perceived items are discriminated with less accuracy than more positively appraised ones. Results are discussed in the larger context of emotion and stress-related modulations of episodic memory, with particular focus on the role of dissociative symptoms.

  17. Motivated Forgetting in Early Mathematics: A Proof-of-Concept Study

    Directory of Open Access Journals (Sweden)

    Gerardo Ramirez

    2017-12-01

    Full Text Available Educators assume that students are motivated to retain what they are taught. Yet, students commonly report that they forget most of what they learn, especially in mathematics. In the current study I ask whether students may be motivated to forget mathematics because of academic experiences threaten the self-perceptions they are committed to maintaining. Using a large dataset of 1st and 2nd grade children (N = 812, I hypothesize that math anxiety creates negative experiences in the classroom that threaten children’s positive math self-perceptions, which in turn spurs a motivation to forget mathematics. I argue that this motivation to forget is activated during the winter break, which in turn reduces the extent to which children grow in achievement across the school year. Children were assessed for math self-perceptions, math anxiety and math achievement in the fall before going into winter break. During the spring, children’s math achievement was measured once again. A math achievement growth score was devised from a regression model of fall math achievement predicting spring achievement. Results show that children with higher math self-perceptions showed reduced growth in math achievement across the school year as a function of math anxiety. Children with lower math interest self-perceptions did not show this relationship. Results serve as a proof-of-concept for a scientific account of motivated forgetting within the context of education.

  18. Two stages of directed forgetting: Electrophysiological evidence from a short-term memory task.

    Science.gov (United States)

    Gao, Heming; Cao, Bihua; Qi, Mingming; Wang, Jing; Zhang, Qi; Li, Fuhong

    2016-06-01

    In this study, a short-term memory test was used to investigate the temporal course and neural mechanism of directed forgetting under different memory loads. Within each trial, two memory items with high or low load were presented sequentially, followed by a cue indicating whether the presented items should be remembered. After an interval, subjects were asked to respond to the probe stimuli. The ERPs locked to the cues showed that (a) the effect of cue type was initially observed during the P2 (160-240 ms) time window, with more positive ERPs for remembering relative to forgetting cues; (b) load effects were observed during the N2-P3 (250-500 ms) time window, with more positive ERPs for the high-load than low-load condition; (c) the cue effect was also observed during the N2-P3 time window, with more negative ERPs for forgetting versus remembering cues. These results demonstrated that directed forgetting involves two stages: task-relevance identification and information discarding. The cue effects during the N2 epoch supported the view that directed forgetting is an active process. © 2016 Society for Psychophysiological Research.

  19. Organizational trauma – Types of organizational forgetting in the case of Belgrade theaters

    Directory of Open Access Journals (Sweden)

    Milena Dragićević-Šešić

    2017-08-01

    Full Text Available Organizational memory studies (OMS frame memory in a managerial mode, treating it as a data storage, limiting the scope from wider field of social memory studies. There is a lack of understanding about how the process of institutional forgetting works and how some memories stay a part of oral narratives and communicative social memory while they are omitted from the official memory represented by the official documents and events of remembering. Inspired by Paul Connerton’s article on the typology of forgetting we explore his typology in selected case studies of three public theaters located in Belgrade, focusing on remembering policy and practices investigating if a type of forgetting typical for a state/society/nation level is possible to be applied in the context of a cultural organization. We agree with Wessel and Moulds that developing common language and terminology would be important and beneficial for cross disciplinary dialogue. In this sense, the study shows how the typology of forgetting in societies can be applied and developed in the organizational memory studies and cultural management. The focus of the research is the dynamics of remembering and forgetting explored through analysis of the interaction between changing context, official institutional memories, and social communicative memories. 

  20. Multiple Signaling Pathways Coordinately Regulate Forgetting of Olfactory Adaptation through Control of Sensory Responses in Caenorhabditis elegans.

    Science.gov (United States)

    Kitazono, Tomohiro; Hara-Kuge, Sayuri; Matsuda, Osamu; Inoue, Akitoshi; Fujiwara, Manabi; Ishihara, Takeshi

    2017-10-18

    Forgetting memories is important for animals to properly respond to continuously changing environments. To elucidate the mechanisms of forgetting, we used one of the behavioral plasticities of Caenorhabditis elegans hermaphrodite, olfactory adaptation to an attractive odorant, diacetyl, as a simple model of learning. In C. elegans, the TIR-1/JNK-1 pathway accelerates forgetting of olfactory adaptation by facilitating neural secretion from AWC sensory neurons. In this study, to identify the downstream effectors of the TIR-1/JNK-1 pathway, we conducted a genetic screen for suppressors of the gain-of-function mutant of tir-1 ( ok1052 ), which shows excessive forgetting. Our screening showed that three proteins-a membrane protein, MACO-1; a receptor tyrosine kinase, SCD-2; and its putative ligand, HEN-1-regulated forgetting downstream of the TIR-1/JNK-1 pathway. We further demonstrated that MACO-1 and SCD-2/HEN-1 functioned in parallel genetic pathways, and only MACO-1 regulated forgetting of olfactory adaptation to isoamyl alcohol, which is an attractive odorant sensed by different types of sensory neurons. In olfactory adaptation, odor-evoked Ca 2+ responses in olfactory neurons are attenuated by conditioning and recovered thereafter. A Ca 2+ imaging study revealed that this attenuation is sustained longer in maco-1 and scd-2 mutant animals than in wild-type animals like the TIR-1/JNK-1 pathway mutants. Furthermore, temporal silencing by histamine-gated chloride channels revealed that the neuronal activity of AWC neurons after conditioning is important for proper forgetting. We propose that distinct signaling pathways, each of which has a specific function, may coordinately and temporally regulate forgetting by controlling sensory responses. SIGNIFICANCE STATEMENT Active forgetting is an important process to understand the whole mechanisms of memories. Recent papers have reported that the noncell autonomous regulations are required for proper forgetting in

  1. Buridan's Ass and a Menu of Options.

    OpenAIRE

    Svetlana Boyarchenko

    2005-01-01

    The goal of the paper is to study how a menu of options affects decisions of a rational agent facing uncertainty over future payoff streams. Using the real options approach, we demonstrate that multiple options not only increase the barrier which the underlying stochastic variable has to reach in order investment became optimal, but cause the investor to be inactive even when the cost of investment is vanishing. As a technical contribution, the paper suggests a robust method of solution of a ...

  2. Was it a mistake to abandon the revision clause? Assessment of entrepreneurial flexibility in the German coal mining industry on the basis of real options; War die Aufgabe der Revisionsklausel ein Fehler? Beurteilung unternehmerischer Flexibilitaet im deutschen Steinkohlebergbau auf Basis von Realoptionen

    Energy Technology Data Exchange (ETDEWEB)

    Bendiek, Ansgar

    2012-07-15

    The author analyzes the decision to abandon the revision clause, i.e. to abandon entrepreneurial flexibility on the basis of the option price theory and the use of derivatives in coal trading. The focus is on subventionless continuation of coal mining. It is found that the abandoning of the revision clause will involve a loss of value of the real option of about 819 million Euros. Politicians and the coal industry are advised to revise the subventionless continuation of coal mining by the end of 2015.

  3. Efficient option valuation of single and double barrier options

    Science.gov (United States)

    Kabaivanov, Stanimir; Milev, Mariyan; Koleva-Petkova, Dessislava; Vladev, Veselin

    2017-12-01

    In this paper we present an implementation of pricing algorithm for single and double barrier options using Mellin transformation with Maximum Entropy Inversion and its suitability for real-world applications. A detailed analysis of the applied algorithm is accompanied by implementation in C++ that is then compared to existing solutions in terms of efficiency and computational power. We then compare the applied method with existing closed-form solutions and well known methods of pricing barrier options that are based on finite differences.

  4. Effects of memory instruction on attention and information processing: Further investigation of inhibition of return in item-method directed forgetting.

    Science.gov (United States)

    Thompson, Kate M; Hamm, Jeff P; Taylor, Tracy L

    2014-02-01

    In the item-method directed-forgetting paradigm, the magnitude of inhibition of return (IOR) is larger after an instruction to forget (F) than after an instruction to remember (R). In the present experiments, we further investigated this increased magnitude of IOR after F as compared to R memory instructions (dubbed the F > R IOR difference), in order to understand both the consequences for information processing and the purpose of the differential withdrawal of attention that results in this difference. Words were presented in one of four peripheral locations, followed by either an F or an R memory instruction. Then, a target appeared in either the same location as the previous word or one of the other locations. The results showed that the F > R IOR difference cannot be explained by attentional momentum (Exp. 1), that the spatial compatibility of the response options with target locations is not necessary for the F > R IOR difference to emerge (Exp. 2), and that the F > R IOR difference is location-specific rather than response-specific (Exp. 3). These results are consistent with the view that F > R IOR represents a bias against responding to information emanating from an unreliable source (Taylor & Fawcett, 2011).

  5. Assessing the Option to Abandon an Investment Project by the Binomial Options Pricing Model

    Directory of Open Access Journals (Sweden)

    Salvador Cruz Rambaud

    2016-01-01

    Full Text Available Usually, traditional methods for investment project appraisal such as the net present value (hereinafter NPV do not incorporate in their values the operational flexibility offered by including a real option included in the project. In this paper, real options, and more specifically the option to abandon, are analysed as a complement to cash flow sequence which quantifies the project. In this way, by considering the existing analogy with financial options, a mathematical expression is derived by using the binomial options pricing model. This methodology provides the value of the option to abandon the project within one, two, and in general n periods. Therefore, this paper aims to be a useful tool in determining the value of the option to abandon according to its residual value, thus making easier the control of the uncertainty element within the project.

  6. The control of working memory resources in intentional forgetting: evidence from incidental probe word recognition.

    Science.gov (United States)

    Fawcett, Jonathan M; Taylor, Tracy L

    2012-01-01

    We combined an item-method directed forgetting paradigm with a secondary task requiring a response to discriminate the color of probe words presented 1400 ms, 1800 ms or 2600 ms following each study phase memory instruction. The speed to make the color discrimination was used to assess the cognitive demands associated with instantiating Remember (R) and Forget (F) instructions; incidental memory for probe words was used to assess whether instantiating an F instruction also affects items presented in close temporal proximity. Discrimination responses were slower following F than R instructions at the two longest intervals. Critically, at the 1800 ms interval, incidental probe word recognition was worse following F than R instructions, particularly when the study word was successfully forgotten (as opposed to unintentionally remembered). We suggest that intentional forgetting is an active cognitive process associated with establishing control over the contents of working memory. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Ensemble learning in fixed expansion layer networks for mitigating catastrophic forgetting.

    Science.gov (United States)

    Coop, Robert; Mishtal, Aaron; Arel, Itamar

    2013-10-01

    Catastrophic forgetting is a well-studied attribute of most parameterized supervised learning systems. A variation of this phenomenon, in the context of feedforward neural networks, arises when nonstationary inputs lead to loss of previously learned mappings. The majority of the schemes proposed in the literature for mitigating catastrophic forgetting were not data driven and did not scale well. We introduce the fixed expansion layer (FEL) feedforward neural network, which embeds a sparsely encoding hidden layer to help mitigate forgetting of prior learned representations. In addition, we investigate a novel framework for training ensembles of FEL networks, based on exploiting an information-theoretic measure of diversity between FEL learners, to further control undesired plasticity. The proposed methodology is demonstrated on a basic classification task, clearly emphasizing its advantages over existing techniques. The architecture proposed can be enhanced to address a range of computational intelligence tasks, such as regression problems and system control.

  8. The nature and position of processing determines why forgetting occurs in working memory tasks.

    Science.gov (United States)

    Jarrold, Christopher; Tam, Helen; Baddeley, Alan D; Harvey, Caroline E

    2010-12-01

    The effect of potentially distracting processing within working memory was examined by varying the nature and position of processing across conditions of a Brown-Peterson-like task. Separate groups of participants carried out verbal or visuospatial processing operations on identical stimuli, while retaining lists of to-be-remembered words. The number of words presented either before or after the processing interval was varied systematically. Results showed that although verbal processing was no more demanding than visuospatial processing, it led to greater forgetting. However, forgetting was confined to items presented prior to processing, and the difference in degree of forgetting shown by the two groups was maximal when four items occurred before processing. Temporal isolation effects were more marked in the verbal processing group. These findings indicate that individuals can keep active a limited number of items in primary memory during processing, unless processing blocks rehearsal, in which case retrieval occurs from secondary memory.

  9. Retrieval-practice task affects relationship between working memory capacity and retrieval-induced forgetting.

    Science.gov (United States)

    Storm, Benjamin C; Bui, Dung C

    2016-11-01

    Retrieving a subset of items from memory can cause forgetting of other items in memory, a phenomenon referred to as retrieval-induced forgetting (RIF). Individuals who exhibit greater amounts of RIF have been shown to also exhibit superior working memory capacity (WMC) and faster stop-signal reaction times (SSRTs), results which have been interpreted as suggesting that RIF reflects an inhibitory process that is mediated by the processes of executive control. Across four experiments, we sought to further elucidate this issue by manipulating the way in which participants retrieved items during retrieval practice and examining how the resulting effects of forgetting correlated with WMC (Experiments 1-3) and SSRT (Experiment 4). Significant correlations were observed when participants retrieved items from an earlier study phase (within-list retrieval practice), but not when participants generated items from semantic memory (extra-list retrieval practice). These results provide important new insight into the role of executive-control processes in RIF.

  10. Variable forgetting factor mechanisms for diffusion recursive least squares algorithm in sensor networks

    Science.gov (United States)

    Zhang, Ling; Cai, Yunlong; Li, Chunguang; de Lamare, Rodrigo C.

    2017-12-01

    In this work, we present low-complexity variable forgetting factor (VFF) techniques for diffusion recursive least squares (DRLS) algorithms. Particularly, we propose low-complexity VFF-DRLS algorithms for distributed parameter and spectrum estimation in sensor networks. For the proposed algorithms, they can adjust the forgetting factor automatically according to the posteriori error signal. We develop detailed analyses in terms of mean and mean square performance for the proposed algorithms and derive mathematical expressions for the mean square deviation (MSD) and the excess mean square error (EMSE). The simulation results show that the proposed low-complexity VFF-DRLS algorithms achieve superior performance to the existing DRLS algorithm with fixed forgetting factor when applied to scenarios of distributed parameter and spectrum estimation. Besides, the simulation results also demonstrate a good match for our proposed analytical expressions.

  11. No Retrieval-Induced Forgetting Using Item-Specific Independent Cues: Evidence against a General Inhibitory Account

    Science.gov (United States)

    Camp, Gino; Pecher, Diane; Schmidt, Henk G.

    2007-01-01

    Retrieval practice with particular items from memory can impair the recall of related items on a later memory test. This retrieval-induced forgetting effect has been ascribed to inhibitory processes (M. C. Anderson & B. A. Spellman, 1995). A critical finding that distinguishes inhibitory from interference explanations is that forgetting is found…

  12. When Does Retrieval Induce Forgetting and when Does It Induce Facilitation? Implications for Retrieval Inhibition, Testing Effect, and Text Processing

    Science.gov (United States)

    Chan, Jason C. K.

    2009-01-01

    Retrieval practice can enhance long-term retention of the tested material (the testing effect), but it can also impair later recall of the nontested material--a phenomenon known as retrieval-induced forgetting (Anderson, M. C., Bjork, R. A., & Bjork, E. L. (1994). "Remembering can cause forgetting: retrieval dynamics in long-term memory." "Journal…

  13. Between-Trial Forgetting Due to Interference and Time in Motor Adaptation.

    Directory of Open Access Journals (Sweden)

    Sungshin Kim

    Full Text Available Learning a motor task with temporally spaced presentations or with other tasks intermixed between presentations reduces performance during training, but can enhance retention post training. These two effects are known as the spacing and contextual interference effect, respectively. Here, we aimed at testing a unifying hypothesis of the spacing and contextual interference effects in visuomotor adaptation, according to which forgetting between trials due to either spaced presentations or interference by another task will promote between-trial forgetting, which will depress performance during acquisition, but will promote retention. We first performed an experiment with three visuomotor adaptation conditions: a short inter-trial-interval (ITI condition (SHORT-ITI; a long ITI condition (LONG-ITI; and an alternating condition with two alternated opposite tasks (ALT, with the same single-task ITI as in LONG-ITI. In the SHORT-ITI condition, there was fastest increase in performance during training and largest immediate forgetting in the retention tests. In contrast, in the ALT condition, there was slowest increase in performance during training and little immediate forgetting in the retention tests. Compared to these two conditions, in the LONG-ITI, we found intermediate increase in performance during training and intermediate immediate forgetting. To account for these results, we fitted to the data six possible adaptation models with one or two time scales, and with interference in the fast, or in the slow, or in both time scales. Model comparison confirmed that two time scales and some degree of interferences in either time scale are needed to account for our experimental results. In summary, our results suggest that retention following adaptation is modulated by the degree of between-trial forgetting, which is due to time-based decay in single adaptation task and interferences in multiple adaptation tasks.

  14. Forgetting in C. elegans Is Accelerated by Neuronal Communication via the TIR-1/JNK-1 Pathway

    Directory of Open Access Journals (Sweden)

    Akitoshi Inoue

    2013-03-01

    Full Text Available The control of memory retention is important for proper responses to constantly changing environments, but the regulatory mechanisms underlying forgetting have not been fully elucidated. Our genetic analyses in C. elegans revealed that mutants of the TIR-1/JNK-1 pathway exhibited prolonged retention of olfactory adaptation and salt chemotaxis learning. In olfactory adaptation, conditioning induces attenuation of odor-evoked Ca2+ responses in olfactory neurons, and this attenuation is prolonged in the TIR-1/JNK-1-pathway mutant animals. We also found that a pair of neurons in which the pathway functions is required for the acceleration of forgetting, but not for sensation or adaptation, in wild-type animals. In addition, the neurosecretion from these cells is important for the acceleration of forgetting. Therefore, we propose that these neurons accelerate forgetting through the TIR-1/JNK-1 pathway by sending signals that directly or indirectly stimulate forgetting.

  15. Treatment Options for Retinoblastoma

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other places in the body. Treatment Option Overview Key Points There are different types of ...

  16. Rumor spreading model with consideration of forgetting mechanism: A case of online blogging LiveJournal

    Science.gov (United States)

    Zhao, Laijun; Wang, Qin; Cheng, Jingjing; Chen, Yucheng; Wang, Jiajia; Huang, Wei

    2011-07-01

    Rumor is an important form of social interaction, and its spreading has a significant impact on people’s lives. In the age of Web, people are using electronic media more frequently than ever before, and blog has become one of the main online social interactions. Therefore, it is essential to learn the evolution mechanism of rumor spreading on homogeneous network in consideration of the forgetting mechanism of spreaders. Here we study a rumor spreading model on an online social blogging platform called LiveJournal. In comparison with the Susceptible-Infected-Removed (SIR) model, we provide a more detailed and realistic description of rumor spreading process with combination of forgetting mechanism and the SIR model of epidemics. A mathematical model has been presented and numerical solutions of the model were used to analyze the impact factors of rumor spreading, such as the average degree, forgetting rate and stifling rate. Our results show that there exist a threshold of the average degree of LiveJournal and above which the influence of rumor reaches saturation. Forgetting mechanism and stifling rate exert great influence on rumor spreading on online social network. The analysis results can guide people’s behaviors in view of the theoretical and practical aspects.

  17. Anxiety as Related to Thinking and Forgetting. What Research Says to the Teacher Series, Number 30.

    Science.gov (United States)

    Lighthall, Frederick F.

    The purpose of this pamphlet is to increase teachers' comprehension of anxiety and its relation to children's thinking and forgetting, to their problem solving ability and their sense of competence. The pamphlet describes four parts of the anxiety experience: 1) the anxiety cue, the particular thought, memory, or sensation which precipitates the…

  18. Rapid Forgetting Results from Competition over Time between Items in Visual Working Memory

    Science.gov (United States)

    Pertzov, Yoni; Manohar, Sanjay; Husain, Masud

    2017-01-01

    Working memory is now established as a fundamental cognitive process across a range of species. Loss of information held in working memory has the potential to disrupt many aspects of cognitive function. However, despite its significance, the mechanisms underlying rapid forgetting remain unclear, with intense recent debate as to whether it is…

  19. Accelerated long-term forgetting in aging and intra-sleep awakenings

    Directory of Open Access Journals (Sweden)

    Alison eMary

    2013-10-01

    Full Text Available The architecture of sleep and the functional neuroanatomical networks subtending memory consolidation processes are both modified with aging, possibly leading to accelerated forgetting in long-term memory. We investigated associative learning and declarative memory consolidation processes in 16 young (18–30 years and 16 older (65–75 years healthy adults. Performance was tested using a cued recall procedure at the end of learning (immediate recall, and 30 minutes and 7 days later. A delayed recognition test was also administered on day 7. Daily sleep diaries were completed during the entire experiment. Results revealed a similar percentage of correct responses at immediate and 30-minute recall in young and older participants. However, recall was significantly decreased 7 days later, with an increased forgetting in older participants. Additionally, intra-sleep awakenings were more frequent in older participants than young adults during the 7 nights, and were negatively correlated with delayed recall performance on day 7 in the older group. Altogether, our results suggest a decline in verbal declarative memory consolidation processes with aging, eventually leading to accelerated long-term forgetting indicating that increased sleep fragmentation due to more frequent intra-sleep awakenings in older participants contribute to the reported age-related decline in long-term memory retrieval. Our results highlight the sensitivity of long-term forgetting measures to evidence consolidation deficits in healthy aging.

  20. Effects of Learning Experience on Forgetting Rates of Item and Associative Memories

    Science.gov (United States)

    Yang, Jiongjiong; Zhan, Lexia; Wang, Yingying; Du, Xiaoya; Zhou, Wenxi; Ning, Xueling; Sun, Qing; Moscovitch, Morris

    2016-01-01

    Are associative memories forgotten more quickly than item memories, and does the level of original learning differentially influence forgetting rates? In this study, we addressed these questions by having participants learn single words and word pairs once (Experiment 1), three times (Experiment 2), and six times (Experiment 3) in a massed…

  1. Cognitive control of familiarity: directed forgetting reduces proactive interference in working memory.

    Science.gov (United States)

    Festini, Sara B; Reuter-Lorenz, Patricia A

    2014-03-01

    Proactive interference (PI) occurs when previously learned information interferes with new learning. In a working memory task, PI induces longer response times and more errors to recent negative probes than to new probes, presumably because the recent probe's familiarity invites a "yes" response. Warnings, longer intertrial intervals, and the increased contextual salience of the probes can reduce but not eliminate PI, suggesting that cognitive control over PI is limited. Here we tested whether control exerted in the form of intentional forgetting performed during working memory can reduce the magnitude of PI. In two experiments, participants performed a working memory task with directed-forgetting instructions and the occasional presentation of recent probes. Surprise long-term memory testing indicated better memory for to-be-remembered than for to-be-forgotten items, documenting the classic directed-forgetting effect. Critically, in working memory, PI was virtually eliminated for recent probes from prior to-be-forgotten lists, as compared to recent probes from prior to-be-remembered lists. Thus cognitive control, when executed via directed forgetting, can reduce the adverse and otherwise persistent interference from familiarity, an effect that we attribute to attenuated memory representations of the to-be-forgotten items.

  2. Subjective Memory Ability and Long-Term Forgetting in Patients Referred for Neuropsychological Assessment

    NARCIS (Netherlands)

    van der Werf, S.P.; Geurts, S.; de Werd, M.M.E.

    2016-01-01

    It has been suggested that the memory complaints of patients who are not impaired on formal memory tests may reflect accelerated forgetting. We examined this hypothesis by comparing the 1-week delayed recall and recognition test performance of outpatients who were referred for neuropsychological

  3. Remembering in a Context of Forgetting: Hauntings and the Old Durham Road Black Pioneer Settlement

    Science.gov (United States)

    Norquay, Naomi

    2014-01-01

    This paper explores the data produced from an oral history project about a Black pioneer settlement in Grey County, Ontario. Twelve area residents were interviewed and the data produced points to various community practices of both remembering and forgetting. I employ Avery Gordon's (2008) theorization of ghosts and hauntings to make sense of the…

  4. Failing to Forget: Prospective Memory Commission Errors Can Result from Spontaneous Retrieval and Impaired Executive Control

    Science.gov (United States)

    Scullin, Michael K.; Bugg, Julie M.

    2013-01-01

    Prospective memory (PM) research typically examines the ability to remember to execute delayed intentions but often ignores the ability to forget finished intentions. We had participants perform (or not perform; control group) a PM task and then instructed them that the PM task was finished. We later (re)presented the PM cue. Approximately 25% of…

  5. History, Language Planners, and Strategies of Forgetting: The Problem of Consciousness in the Philippines.

    Science.gov (United States)

    Tupas, T. Ruanni F.

    2003-01-01

    Examines why language planners in the Philippines argue the way they do concerning critical language issues in the country. Suggests discursive "strategies of forgetting" are employed across complex structures of relations shaped by decades of colonialization, Filipino elite collaboration, and current neocolonial and global conditions.…

  6. Australian Asian Options

    OpenAIRE

    Manuel Moreno; Javier F. Navas

    2003-01-01

    We study European options on the ratio of the stock price to its average and viceversa. Some of these options are traded in the Australian Stock Exchange since 1992, thus we call them Australian Asian options. For geometric averages, we obtain closed-form expressions for option prices. For arithmetic means, we use different approximations that produce very similar results.

  7. Options with Extreme Strikes

    Directory of Open Access Journals (Sweden)

    Lingjiong Zhu

    2015-07-01

    Full Text Available In this short paper, we study the asymptotics for the price of call options for very large strikes and put options for very small strikes. The stock price is assumed to follow the Black–Scholes models. We analyze European, Asian, American, Parisian and perpetual options and conclude that the tail asymptotics for these option types fall into four scenarios.

  8. Individual differences and predictors of forgetting in old age: the role of processing speed and working memory.

    Science.gov (United States)

    Zimprich, Daniel; Kurtz, Tanja

    2013-01-01

    The goal of the present study was to examine whether individual differences in basic cognitive abilities, processing speed, and working memory, are reliable predictors of individual differences in forgetting rates in old age. The sample for the present study comprised 364 participants aged between 65 and 80 years from the Zurich Longitudinal Study on Cognitive Aging. The impact of basic cognitive abilities on forgetting was analyzed by modeling working memory and processing speed as predictors of the amount of forgetting of 27 words, which had been learned across five trials. Forgetting was measured over a 30-minute interval by using parceling and a latent change model, in which the latent difference between recall performance after five learning trials and a delayed recall was modeled. Results implied reliable individual differences in forgetting. These individual differences in forgetting were strongly related to processing speed and working memory. Moreover, an age-related effect, which was significantly stronger for forgetting than for learning, emerged even after controlling effects of processing speed and working memory.

  9. Cognitive and functional correlates of accelerated long-term forgetting in temporal lobe epilepsy.

    Science.gov (United States)

    Audrain, Samantha; McAndrews, Mary P

    2018-03-30

    While we know that hippocampal dysfunction is responsible for the memory deficits that patients with temporal lobe epilepsy exhibit at relatively short study-test delays, the role of this region in accelerated long-term forgetting (ALF) is not yet clear. In the present study, we probed the role of the hippocampus in ALF by directly comparing memory for associations to memory that could be supported by item recognition during a forced choice recognition task over delays ranging from 15-min to 72-h. We additionally examined resting-state functional connectivity between the hippocampus and cortical regions known to be involved in processing these types of stimuli, as well as the relationship between ALF and various clinical variables including structural abnormality in the hippocampus, lateralization of epileptic focus, presence of seizures across the retention period, and standardized composite memory scores. We found evidence of accelerated forgetting for item stimuli (but not associative stimuli) by 6 h post-learning, which became statistically reliable by 72-h. This finding suggests that unlike controls, patients were unable to utilize novelty to reject the incorrect object-scene pair. While none of the examined clinical variables were related to long-term forgetting, reduced resting-state functional connectivity between the affected anterior hippocampus and unaffected lateral temporal cortex predicted forgetting of item stimuli over the 72-h delay. Implications for the role of the hippocampus in accelerated long-term forgetting, and existing theories of systems consolidation in this context are discussed. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  10. Evidence against associative blocking as a cause of cue-independent retrieval-induced forgetting.

    Science.gov (United States)

    Hulbert, Justin C; Shivde, Geeta; Anderson, Michael C

    2012-01-01

    Selectively retrieving an item from long-term memory reduces the accessibility of competing traces, a phenomenon known as retrieval-induced forgetting (RIF). RIF exhibits cue independence, or the tendency for forgetting to generalize to novel test cues, suggesting an inhibitory basis for this phenomenon. An alternative view (Camp, Pecher, & Schmidt, 2007; Camp et al., 2009; Perfect et al., 2004) suggests that using novel test cues to measure cue independence actually engenders associative interference when participants covertly supplement retrieval with practiced cues that then associatively block retrieval. Accordingly, the covert-cueing hypothesis assumes that the relative strength of the practiced items at final test – and not the inhibition levied on the unpracticed items during retrieval practice – underlies cue-independent forgetting. As such, this perspective predicts that strengthening practiced items by any means, even if not via retrieval practice, should induce forgetting. Contrary to these predictions, however, we present clear evidence that cue-independent forgetting is induced by retrieval practice and not by repeated study exposures. This dissociation occurred despite significant, comparable levels of strengthening of practiced items in each case, and despite the use of Anderson and Spellman's original (1995) independent probe method criticized by covert-cueing theorists as being especially conducive to associative blocking. These results demonstrate that cue-independent RIF is unrelated to the strengthening of practiced items, and thereby fail to support a key prediction of the covert-cueing hypothesis. The results, instead, favor a role of inhibition in resolving retrieval interference. © 2011 Hogrefe Publishing

  11. Irregular grid methods for pricing high-dimensional American options

    NARCIS (Netherlands)

    Berridge, S.J.

    2004-01-01

    This thesis proposes and studies numerical methods for pricing high-dimensional American options; important examples being basket options, Bermudan swaptions and real options. Four new methods are presented and analysed, both in terms of their application to various test problems, and in terms of

  12. Prospective memory in adults with traumatic brain injury: an analysis of perceived reasons for remembering and forgetting.

    Science.gov (United States)

    Roche, Nadine L; Moody, Anna; Szabo, Krisztina; Fleming, Jennifer M; Shum, David H K

    2007-06-01

    Reasons for prospective remembering and forgetting after traumatic brain injury (TBI) were investigated using Ellis' (1996) five phases of prospective memory as a framework. Participants were 38 individuals with severe TBI and 34 controls. Participants self-rated their perceived reasons for prospective remembering and forgetting using section C of the Comprehensive Assessment of Prospective Memory (CAPM). Significant others also rated participants using the same scale. Analyses were conducted to examine the effect of group membership (TBI or control) on reported reasons for prospective remembering and forgetting. Findings highlighted the TBI group's difficulties with encoding, performance interval, and execution phases of prospective remembering.

  13. Traditional preventive treatment options

    DEFF Research Database (Denmark)

    Longbottom, C; Ekstrand, K; Zero, D

    2009-01-01

    Preventive treatment options can be divided into primary, secondary and tertiary prevention techniques, which can involve patient- or professionally applied methods. These include: oral hygiene (instruction), pit and fissure sealants ('temporary' or 'permanent'), fluoride applications (patient...... options....

  14. Breast Cancer: Treatment Options

    Science.gov (United States)

    ... Breast Cancer > Breast Cancer: Treatment Options Request Permissions Breast Cancer: Treatment Options Approved by the Cancer.Net Editorial ... can be addressed as quickly as possible. Recurrent breast cancer If the cancer does return after treatment for ...

  15. Distributed Energy Implementation Options

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Chandralata N [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-13

    This presentation covers the options for implementing distributed energy projects. It distinguishes between options available for distributed energy that is government owned versus privately owned, with a focus on the privately owned options including Energy Savings Performance Contract Energy Sales Agreements (ESPC ESAs). The presentation covers the new ESPC ESA Toolkit and other Federal Energy Management Program resources.

  16. Acute psycho-social stress does not disrupt item-method directed forgetting, emotional stimulus content does.

    Science.gov (United States)

    Zwissler, Bastian; Koessler, Susanne; Engler, Harald; Schedlowski, Manfred; Kissler, Johanna

    2011-03-01

    It has been shown that stress affects episodic memory in general, but knowledge about stress effects on memory control processes such as directed forgetting is sparse. Whereas in previous studies item-method directed forgetting was found to be altered in post-traumatic stress disorder patients and abolished for highly arousing negative pictorial stimuli in students, no study so far has investigated the effects of experimentally induced psycho-social stress on this task or examined the role of positive picture stimuli. In the present study, 41 participants performed an item-method directed forgetting experiment while being exposed either to a psychosocial laboratory stressor, the Trier Social Stress Test (TSST), or a cognitively challenging but non-stressful control condition. Neutral and positive pictures were presented as stimuli. As predicted, salivary cortisol level as a biological marker of the human stress response increased only in the TSST group. Still, both groups showed directed forgetting. However, emotional content of the employed stimuli affected memory control: Directed forgetting was intact for neutral pictures whereas it was attenuated for positive ones. This attenuation was primarily due to selective rehearsal improving discrimination accuracy for neutral, but not positive, to-be-remembered items. Results suggest that acute experimentally induced stress does not alter item-method directed forgetting while emotional stimulus content does. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Implementation of the Least-Squares Lattice with Order and Forgetting Factor Estimation for FPGA

    Czech Academy of Sciences Publication Activity Database

    Pohl, Zdeněk; Tichý, Milan; Kadlec, Jiří

    2008-01-01

    Roč. 2008, č. 2008 (2008), s. 1-11 ISSN 1687-6172 R&D Projects: GA MŠk(CZ) 1M0567 EU Projects: European Commission(XE) 027611 - AETHER Program:FP6 Institutional research plan: CEZ:AV0Z10750506 Keywords : DSP * Least-squares lattice * order estimation * exponential forgetting factor estimation * FPGA implementation * scheduling * dynamic reconfiguration * microblaze Subject RIV: IN - Informatics, Computer Science Impact factor: 1.055, year: 2008 http://library.utia.cas.cz/separaty/2008/ZS/pohl-tichy-kadlec-implementation%20of%20the%20least-squares%20lattice%20with%20order%20and%20forgetting%20factor%20estimation%20for%20fpga.pdf

  18. RLS Channel Estimation with Adaptive Forgetting Factor for DS-CDMA Frequency-Domain Equalization

    Science.gov (United States)

    Kojima, Yohei; Tomeba, Hiromichi; Takeda, Kazuaki; Adachi, Fumiyuki

    Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can increase the downlink bit error rate (BER) performance of DS-CDMA beyond that possible with conventional rake combining in a frequency-selective fading channel. FDE requires accurate channel estimation. Recently, we proposed a pilot-assisted channel estimation (CE) based on the MMSE criterion. Using MMSE-CE, the channel estimation accuracy is almost insensitive to the pilot chip sequence, and a good BER performance is achieved. In this paper, we propose a channel estimation scheme using one-tap recursive least square (RLS) algorithm, where the forgetting factor is adapted to the changing channel condition by the least mean square (LMS)algorithm, for DS-CDMA with FDE. We evaluate the BER performance using RLS-CE with adaptive forgetting factor in a frequency-selective fast Rayleigh fading channel by computer simulation.

  19. Inhibition of Rac1 Activity in the Hippocampus Impairs the Forgetting of Contextual Fear Memory.

    Science.gov (United States)

    Jiang, Lizhu; Mao, Rongrong; Zhou, Qixin; Yang, Yuexiong; Cao, Jun; Ding, Yuqiang; Yang, Yuan; Zhang, Xia; Li, Lingjiang; Xu, Lin

    2016-03-01

    Fear is crucial for survival, whereas hypermnesia of fear can be detrimental. Inhibition of the Rac GTPase is recently reported to impair the forgetting of initially acquired memory in Drosophila. Here, we investigated whether inhibition of Rac1 activity in rat hippocampus could contribute to the hypermnesia of contextual fear. We found that spaced but not massed training of contextual fear conditioning caused inhibition of Rac1 activity in the hippocampus and heightened contextual fear. Furthermore, intrahippocampal injection of the Rac1 inhibitor NSC23766 heightened contextual fear in massed training, while Rac1 activator CN04-A weakened contextual fear in spaced training rats. Our study firstly demonstrates that contextual fear memory in rats is actively regulated by Rac1 activity in the hippocampus, which suggests that the forgetting impairment of traumatic events in posttraumatic stress disorder may be contributed to the pathological inhibition of Rac1 activity in the hippocampus.

  20. On the form of the forgetting function: the effects of arithmetic and logarithmic distributions of delays.

    Science.gov (United States)

    Sargisson, Rebecca J; White, K Geoffrey

    2003-11-01

    Forgetting functions with 18 delay intervals were generated for delayed matching-to-sample performance in pigeons. Delay interval variation was achieved by arranging five different sets of five delays across daily sessions. In different conditions, the delays were distributed in arithmetic or logarithmic series. There was no convincing evidence for different effects on discriminability of the distributions of different delays. The mean data were better fitted by some mathematical functions than by others, but the best-fitting functions depended on the distribution of delays. In further conditions with a fixed set of five delays, discriminability was higher with a logarithmic distribution of delays than with an arithmetic distribution. This result is consistent with the treatment of the forgetting function in terms of generalization decrement.

  1. Research on Open-Closed-Loop Iterative Learning Control with Variable Forgetting Factor of Mobile Robots

    Directory of Open Access Journals (Sweden)

    Hongbin Wang

    2016-01-01

    Full Text Available We propose an iterative learning control algorithm (ILC that is developed using a variable forgetting factor to control a mobile robot. The proposed algorithm can be categorized as an open-closed-loop iterative learning control, which produces control instructions by using both previous and current data. However, introducing a variable forgetting factor can weaken the former control output and its variance in the control law while strengthening the robustness of the iterative learning control. If it is applied to the mobile robot, this will reduce position errors in robot trajectory tracking control effectively. In this work, we show that the proposed algorithm guarantees tracking error bound convergence to a small neighborhood of the origin under the condition of state disturbances, output measurement noises, and fluctuation of system dynamics. By using simulation, we demonstrate that the controller is effective in realizing the prefect tracking.

  2. Age and excuses for forgetting: self-handicapping versus damage-control strategies.

    Science.gov (United States)

    Erber, J T; Prager, I G

    2000-01-01

    Either before or after being interviewed for a volunteer position, a young or old protagonist (i.e., target) gave an excuse for forgetting. Study participants (i.e., perceivers) had a higher opinion of the target's memory, were more confident in the target's capability of performing memory-related tasks, and attributed the target's memory failures more to bad luck when the excuse was given after (damage-control strategy) rather than before (self-handicapping strategy) the interview. Moreover, the excuse given before the interview had no significant effect on perceivers' judgments when compared with data from an earlier study in which the target gave no excuse for forgetting. The present findings suggest that a damage-control strategy can ameliorate negative capability impressions.

  3. Neural modularity helps organisms evolve to learn new skills without forgetting old skills.

    Science.gov (United States)

    Ellefsen, Kai Olav; Mouret, Jean-Baptiste; Clune, Jeff

    2015-04-01

    A long-standing goal in artificial intelligence is creating agents that can learn a variety of different skills for different problems. In the artificial intelligence subfield of neural networks, a barrier to that goal is that when agents learn a new skill they typically do so by losing previously acquired skills, a problem called catastrophic forgetting. That occurs because, to learn the new task, neural learning algorithms change connections that encode previously acquired skills. How networks are organized critically affects their learning dynamics. In this paper, we test whether catastrophic forgetting can be reduced by evolving modular neural networks. Modularity intuitively should reduce learning interference between tasks by separating functionality into physically distinct modules in which learning can be selectively turned on or off. Modularity can further improve learning by having a reinforcement learning module separate from sensory processing modules, allowing learning to happen only in response to a positive or negative reward. In this paper, learning takes place via neuromodulation, which allows agents to selectively change the rate of learning for each neural connection based on environmental stimuli (e.g. to alter learning in specific locations based on the task at hand). To produce modularity, we evolve neural networks with a cost for neural connections. We show that this connection cost technique causes modularity, confirming a previous result, and that such sparsely connected, modular networks have higher overall performance because they learn new skills faster while retaining old skills more and because they have a separate reinforcement learning module. Our results suggest (1) that encouraging modularity in neural networks may help us overcome the long-standing barrier of networks that cannot learn new skills without forgetting old ones, and (2) that one benefit of the modularity ubiquitous in the brains of natural animals might be to

  4. Neural modularity helps organisms evolve to learn new skills without forgetting old skills.

    Directory of Open Access Journals (Sweden)

    Kai Olav Ellefsen

    2015-04-01

    Full Text Available A long-standing goal in artificial intelligence is creating agents that can learn a variety of different skills for different problems. In the artificial intelligence subfield of neural networks, a barrier to that goal is that when agents learn a new skill they typically do so by losing previously acquired skills, a problem called catastrophic forgetting. That occurs because, to learn the new task, neural learning algorithms change connections that encode previously acquired skills. How networks are organized critically affects their learning dynamics. In this paper, we test whether catastrophic forgetting can be reduced by evolving modular neural networks. Modularity intuitively should reduce learning interference between tasks by separating functionality into physically distinct modules in which learning can be selectively turned on or off. Modularity can further improve learning by having a reinforcement learning module separate from sensory processing modules, allowing learning to happen only in response to a positive or negative reward. In this paper, learning takes place via neuromodulation, which allows agents to selectively change the rate of learning for each neural connection based on environmental stimuli (e.g. to alter learning in specific locations based on the task at hand. To produce modularity, we evolve neural networks with a cost for neural connections. We show that this connection cost technique causes modularity, confirming a previous result, and that such sparsely connected, modular networks have higher overall performance because they learn new skills faster while retaining old skills more and because they have a separate reinforcement learning module. Our results suggest (1 that encouraging modularity in neural networks may help us overcome the long-standing barrier of networks that cannot learn new skills without forgetting old ones, and (2 that one benefit of the modularity ubiquitous in the brains of natural animals

  5. Effect of Direction Type, Emotional Valence of Words And Gender on Directed Forgetting

    OpenAIRE

    Sayar, Filiz

    2018-01-01

    In the present study, the effects of emotional valence of words and gender on directed forgettingwere investigated. The directed forgetting effect was investigated by requiring from participants toforget the words that they have to recall and at the same time, to recall the words that they have toforget. The study was composed of two experiments. In the first experiment, the participants werepresented with a list of words consisting of neutral and emotional words once, while the participantsw...

  6. Noncompetitive retrieval practice causes retrieval-induced forgetting in cued recall but not in recognition.

    Science.gov (United States)

    Grundgeiger, Tobias

    2014-04-01

    Retrieving a subset of learned items can lead to the forgetting of related items. Such retrieval-induced forgetting (RIF) can be explained by the inhibition of irrelevant items in order to overcome retrieval competition when the target item is retrieved. According to the retrieval inhibition account, such retrieval competition is a necessary condition for RIF. However, research has indicated that noncompetitive retrieval practice can also cause RIF by strengthening cue-item associations. According to the strength-dependent competition account, the strengthened items interfere with the retrieval of weaker items, resulting in impaired recall of weaker items in the final memory test. The aim of this study was to replicate RIF caused by noncompetitive retrieval practice and to determine whether this forgetting is also observed in recognition tests. In the context of RIF, it has been assumed that recognition tests circumvent interference and, therefore, should not be sensitive to forgetting due to strength-dependent competition. However, this has not been empirically tested, and it has been suggested that participants may reinstate learned cues as retrieval aids during the final test. In the present experiments, competitive practice or noncompetitive practice was followed by either final cued-recall tests or recognition tests. In cued-recall tests, RIF was observed in both competitive and noncompetitive conditions. However, in recognition tests, RIF was observed only in the competitive condition and was absent in the noncompetitive condition. The result underscores the contribution of strength-dependent competition to RIF. However, recognition tests seem to be a reliable way of distinguishing between RIF due to retrieval inhibition or strength-dependent competition.

  7. Neural Modularity Helps Organisms Evolve to Learn New Skills without Forgetting Old Skills

    Science.gov (United States)

    Ellefsen, Kai Olav; Mouret, Jean-Baptiste; Clune, Jeff

    2015-01-01

    A long-standing goal in artificial intelligence is creating agents that can learn a variety of different skills for different problems. In the artificial intelligence subfield of neural networks, a barrier to that goal is that when agents learn a new skill they typically do so by losing previously acquired skills, a problem called catastrophic forgetting. That occurs because, to learn the new task, neural learning algorithms change connections that encode previously acquired skills. How networks are organized critically affects their learning dynamics. In this paper, we test whether catastrophic forgetting can be reduced by evolving modular neural networks. Modularity intuitively should reduce learning interference between tasks by separating functionality into physically distinct modules in which learning can be selectively turned on or off. Modularity can further improve learning by having a reinforcement learning module separate from sensory processing modules, allowing learning to happen only in response to a positive or negative reward. In this paper, learning takes place via neuromodulation, which allows agents to selectively change the rate of learning for each neural connection based on environmental stimuli (e.g. to alter learning in specific locations based on the task at hand). To produce modularity, we evolve neural networks with a cost for neural connections. We show that this connection cost technique causes modularity, confirming a previous result, and that such sparsely connected, modular networks have higher overall performance because they learn new skills faster while retaining old skills more and because they have a separate reinforcement learning module. Our results suggest (1) that encouraging modularity in neural networks may help us overcome the long-standing barrier of networks that cannot learn new skills without forgetting old ones, and (2) that one benefit of the modularity ubiquitous in the brains of natural animals might be to

  8. TANK SPACE OPTIONS REPORT

    International Nuclear Information System (INIS)

    Willis, W.L.; Ahrendt, M.R.

    2009-01-01

    Since this report was originally issued in 2001, several options proposed for increasing double-shell tank (DST) storage space were implemented or are in the process of implementation. Changes to the single-shell tank (SST) waste retrieval schedule, completion of DST space saving options, and the DST space saving options in progress have delayed the projected shortfall of DST storage space from the 2007-2011 to the 2018-2025 timeframe (ORP-11242, River Protection Project System Plan). This report reevaluates options from Rev. 0 and includes evaluations of new options for alleviating projected restrictions on SST waste retrieval beginning in 2018 because of the lack of DST storage space.

  9. Development of Dual-Retrieval Processes in Recall: Learning, Forgetting, and Reminiscence

    Science.gov (United States)

    Brainerd, C. J.; Aydin, C.; Reyna, V. F.

    2012-01-01

    We investigated the development of dual-retrieval processes with a low-burden paradigm that is suitable for research with children and neurocognitively impaired populations (e.g., older adults with mild cognitive impairment or dementia). Rich quantitative information can be obtained about recollection, reconstruction, and familiarity judgment by defining a Markov model over simple recall tasks like those that are used in clinical neuropsychology batteries. The model measures these processes separately for learning, forgetting, and reminiscence. We implemented this procedure in some developmental experiments, whose aims were (a) to measure age changes in recollective and nonrecollective retrieval during learning, forgetting, and reminiscence and (b) to measure age changes in content dimensions (e.g., taxonomic relatedness) that affect the two forms of retrieval. The model provided excellent fits in all three domains. Concerning (a), recollection, reconstruction, and familiarity judgment all improved during the child-to-adolescent age range in the learning domain, whereas only recollection improved in the forgetting domain, and the processes were age-invariant in the reminiscence domain. Concerning (b), although some elements of the adult pattern of taxonomic relatedness effects were detected by early adolescence, the adult pattern differs qualitatively from corresponding patterns in children and adolescents. PMID:22778491

  10. Forgetting of Foreign-Language Skills: A Corpus-Based Analysis of Online Tutoring Software.

    Science.gov (United States)

    Ridgeway, Karl; Mozer, Michael C; Bowles, Anita R

    2017-05-01

    We explore the nature of forgetting in a corpus of 125,000 students learning Spanish using the Rosetta Stone ® foreign-language instruction software across 48 lessons. Students are tested on a lesson after its initial study and are then retested after a variable time lag. We observe forgetting consistent with power function decay at a rate that varies across lessons but not across students. We find that lessons which are better learned initially are forgotten more slowly, a correlation which likely reflects a latent cause such as the quality or difficulty of the lesson. We obtain improved predictive accuracy of the forgetting model by augmenting it with features that encode characteristics of a student's initial study of the lesson and the activities the student engaged in between the initial and delayed tests. The augmented model can predict 23.9% of the variance in an individual's score on the delayed test. We analyze which features best explain individual performance. Copyright © 2016 Cognitive Science Society, Inc.

  11. It's in the details: The role of selective discussion in forgetting of children's autobiographical memories.

    Science.gov (United States)

    Glynn, Ruth; Salmon, Karen; Low, Jason

    2018-03-01

    This experiment investigated whether retrieval-induced forgetting (RIF) would be found in children's self-generated autobiographical memory recall. An adapted version of the RIF paradigm for adults' autobiographical memories was administered to 8- and 9-year-old children (N = 65). We hypothesized that RIF would be found in terms of both number of memories recalled and amount of memory detail reported. The relationship between memory detail at the retrieval practice phase and RIF magnitude was also investigated. Consistent with hypotheses, RIF was found for both the number of memories recalled and the amount of memory detail reported. In addition, memory detail at retrieval practice was associated with increased RIF magnitude. Findings extend the current literature in three ways. First, they indicate that selective discussion of autobiographical events with children can cause forgetting of similar non-discussed events. Second, even when these non-discussed events are recalled, they contain sparser memory detail. Finally, when events are selectively discussed in greater detail, forgetting of similar non-discussed events occurs to a greater extent. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Intentional forgetting of emotional words after trauma: a study with victims of sexual assault.

    Science.gov (United States)

    Blix, Ines; Brennen, Tim

    2011-01-01

    Following exposure to a trauma, people tend to experience intrusive thoughts and memories about the event. In order to investigate whether intrusive memories in the aftermath of trauma might be accounted for by an impaired ability to intentionally forget disturbing material, the present study used a modified Directed Forgetting task to examine intentional forgetting and intrusive recall of words in sexual assault victims and controls. By including words related to the trauma in addition to neutral, positive, and threat-related stimuli it was possible to test for trauma-specific effects. No difference between the Trauma and the Control group was found for correct recall of to-be-forgotten (F) words or to-be-remembered (R) words. However, when recalling words from R-list, the Trauma group mistakenly recalled significantly more trauma-specific words from F-list. "Intrusive" recall of F-trauma words when asked to recall R-words was related to symptoms of post-traumatic stress disorder reported on the Impact of Event Scale and the Post-traumatic Diagnostic Scale. The results are discussed in term of a source-monitoring account.

  13. If you negate, you may forget: negated repetitions impair memory compared with affirmative repetitions.

    Science.gov (United States)

    Mayo, Ruth; Schul, Yaacov; Rosenthal, Meytal

    2014-08-01

    One of the most robust laws of memory is that repeated activation improves memory. Our study shows that the nature of repetition matters. Specifically, although both negated repetition and affirmative repetition improve memory compared with no repetition, negated repetition hinders memory compared with affirmative repetition. After showing participants different entities, we asked them about features of these entities, leading to either "yes" or "no" responses. Our findings show that correctly negating an incorrect feature of an entity elicits an active forgetting effect compared with correctly affirming its true features. For example, after seeing someone drink a glass of white wine, answering "no" to "was it red wine?" may lead one to greater memory loss of the individual drinking wine at all compared with answering "yes" to "was it white wine?" We find this negation-induced forgetting effect in 4 experiments that differ in (a) the meaning given for the negation, (b) the type of stimuli (visual or verbal), and (c) the memory measure (recognition or free recall). We discuss possible underlying mechanisms and offer theoretical and applied implications of the negation-induced forgetting effect in relation to other known inhibition effects. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  14. The Role of Cognitive Load in Intentional Forgetting Using the Think/No-Think Task.

    Science.gov (United States)

    Noreen, Saima; de Fockert, Jan W

    2017-01-01

    We investigated the role of cognitive control in intentional forgetting by manipulating working memory load during the think/no-think task. In two experiments, participants learned a series of cue-target word pairs and were asked to recall the target words associated with some cues or to avoid thinking about the target associated with other cues. In addition to this, participants also performed a modified version of the n-back task which required them to respond to the identity of a single target letter present in the currently presented cue word (n = 0 condition, low working memory load), and in either the previous cue word (n = 1 condition, high working memory load, Experiment 1) or the cue word presented two trials previously (n = 2 condition, high working memory load, Experiment 2). Participants' memory for the target words was subsequently tested using same and novel independent probes. In both experiments it was found that although participants were successful at forgetting on both the same and independent-probe tests in the low working memory load condition, they were only successful at forgetting on the same-probe test in the high working memory load condition. We argue that our findings suggest that the high load working memory task diverted attention from direct suppression and acted as an interference-based strategy. Thus, when cognitive resources are limited participants can switch between the strategies they use to prevent unwanted memories from coming to mind.

  15. A Study of Memory and Forgetting in The Sound of One Hand Clapping

    Institute of Scientific and Technical Information of China (English)

    杨炤宇

    2011-01-01

    The Sound of One Hand Clapping is a 1997 novel by Australian author Richard Flanagan. Richard Flanagan was born in 1961 in Tasmania. He left school at 16, later winning a Rhodes scholarship to Oxford, where he took a Master of Letters degree. He later worked as a labourer and river guide. The Sound of One Hand Clapping (1998) is his second novel which tells the story of Slovenian immigrants; Richard Flanagan also wrote and directed the film version of The Sound of One Hand Clapping, which was re- leased in 1998, and world premiered at the 1998 Berlin Film Festival, where it was nominated for Golden Bear for Best film. The novel, The Sound of One Hand Clapping (1998), examines the Tasmanian immigrant experience. It asks us not to ignore the existence of the soul and the spirit, not to sublimate all to a blind rationality, Flanagan also suggests that healing is not only possible but that it should be looked for. Original, poetic and compelling, this novel comes highly recommended,?As the novel is formed largely by means of memory and forgetting. So the author of this paper intends to give a tentative study of memory as well as forgetting, Wing to figure out the reasons and influences that memory and forgetting brings on different characters.

  16. [Treatment options for patellar tendinopathy].

    Science.gov (United States)

    Duthon, V B; Borloz, S; Ziltener, J-L

    2012-07-25

    Patellar tendinopathy is also called jumper's knee because of its high incidence in athletes with jumping or cutting activities as soccer, basketball, volleyball. Many different treatment methods have been described. However, no consensus exists regarding the optimal treatment for this condition. According to the literature, eccentric exercise-based physical therapy should be proposed first because of its strong scientific evidence. Shockwave therapy and injections may be useful but their real efficacy still has to be proven by randomized controlled study. For patients recalcitrant to more conservative options, operative management may be indicated.

  17. Effects of 5-HT5A receptor blockade on amnesia or forgetting.

    Science.gov (United States)

    Aparicio-Nava, L; Márquez-García, L A; Meneses, A

    2018-01-09

    Previously the effects (0.01-3.0 mg/kg) of post-training SB-699551 (a 5-HT 5A receptor antagonist) were reported in the associative learning task of autoshaping, showing that SB-699551 (0.1 mg/kg) decreased lever-press conditioned responses (CR) during short-term (STM; 1.5-h) or (3.0 mg/kg) long-term memory (LTM; 24-h); relative to the vehicle animals. Moreover, as pro-cognitive efficacy of SB-699551 was reported in the ketamine-model of schizophrenia. Hence, firstly aiming improving performance (conditioned response, CR), in this work autoshaping lever-press vs. nose-poke response was compared; secondly, new set of animals were randomly assigned to SB-699551 plus forgetting or amnesia protocols. Results show that the nose-poke operandum reduced inter-individual variance, increased CR and produced a progressive CR until 48-h. After one week of no training/testing sessions (i.e., interruption of 216 h), the forgetting was observed; i.e., the CR% of control-saline group significantly decreased. In contrast, SB-699551 at 0.3 and 3.0 mg/kg prevents forgetting. Additionally, as previously reported the non-competitive NMDA receptor antagonist dizocilpine (0.2 mg/kg) or the non-selective cholinergic antagonist scopolamine (0.3 mg/kg) decreased CR in STM. SB-699551 (0.3 mg/kg) alone also produced amnesia-like effect. Co-administration of SB-699551-dizocilpine or SB-699551-scopolamine reversed the SB-699551 induced-amnesic effects in LTM (24-h). Nose-poke seems to be a reliable operandum. The anti-amnesic and anti-forgetting mechanisms of amnesic SB-699551-dose remain unclear. The present findings are consistent with the notion that low doses of 5-HT 5A receptor antagonists might be useful for reversing memory deficits associated to forgetting and amnesia. Of course, further experiments are necessary. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. The importance of Real Options Theory in the analysis of investment: what is the added value to a GTL (Gas to Liquid) plant considering managerial flexibility; Qual o valor agregado a uma planta 'Gas to Liquid' considerando-se a flexibilidade gerencial: a importancia da teoria das opcoes reais na analise de investimentos

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Marcela Lobo [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2008-07-01

    The goal of this article is to do an investment analysis applying Real Options Theory in the plant Gas to Liquid (GTL). This analysis is the most indicated, because there are several flexibilities in this plant, related to the inputs (many products can be applied) as well the outputs (there are many possible combinations to use). In order to make the analysis as close as possible of reality and the most accurate it became fundamental to calculate the value that those flexibilities add to final value of the plant. It is going to be calculated the value of switch use of inputs (possibility to each semester to choose different resources) and the value of switch use of outputs (the possibility of the plant to produce more than one combination of outputs). Although in order to be feasible the implementation of the real option of switch use it is necessary to know if the added value is bigger or lesser from the cost of implementation. In the research it is achieve the conclusion that the value of switch use of inputs is lower than the cost of its implementation. (author)

  19. Can We Retrieve the Information Which Was Intentionally Forgotten? Electrophysiological Correlates of Strategic Retrieval in Directed Forgetting

    Directory of Open Access Journals (Sweden)

    Xinrui Mao

    2017-08-01

    Full Text Available Retrieval inhibition hypothesis of directed forgetting effects assumed TBF (to-be-forgotten items were not retrieved intentionally, while selective rehearsal hypothesis assumed the memory representation of retrieved TBF (to-be-forgotten items was weaker than TBR (to-be-remembered items. Previous studies indicated that directed forgetting effects of item-cueing method resulted from selective rehearsal at encoding, but the mechanism of retrieval inhibition that affected directed forgetting of TBF (to-be-forgotten items was not clear. Strategic retrieval is a control process allowing the selective retrieval of target information, which includes retrieval orientation and strategic recollection. Retrieval orientation via the comparison of tasks refers to the specific form of processing resulted by retrieval efforts. Strategic recollection is the type of strategies to recollect studied items for the retrieval success of targets. Using a “directed forgetting” paradigm combined with a memory exclusion task, our investigation of strategic retrieval in directed forgetting assisted to explore how retrieval inhibition played a role on directed forgetting effects. When TBF items were targeted, retrieval orientation showed more positive ERPs to new items, indicating that TBF items demanded more retrieval efforts. The results of strategic recollection indicated that: (a when TBR items were retrieval targets, late parietal old/new effects were only evoked by TBR items but not TBF items, indicating the retrieval inhibition of TBF items; (b when TBF items were retrieval targets, the late parietal old/new effect were evoked by both TBR items and TBF items, indicating that strategic retrieval could overcome retrieval inhibition of TBF items. These findings suggested the modulation of strategic retrieval on retrieval inhibition of directed forgetting, supporting that directed forgetting effects were not only caused by selective rehearsal, but also retrieval

  20. Rare disasters, credit, and option market puzzles

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Du, Du; Elkamhi, Redouane

    2017-01-01

    calibrated to the real economy can simultaneously explain several key empirical regularities in equity, credit, and options markets. Our model captures the empirical level and volatility of credit spreads, generates a flexible credit risk term structure, and provides a good fit to a century of observed...

  1. To forget or not to forget: mnemonic “renunciation” effect and the subjective evaluation of the truth of autobiographical memories

    Directory of Open Access Journals (Sweden)

    Nourkova V. V.

    2015-08-01

    Full Text Available Identifying patterns of influence deliberate lie on deferred confidence of reliability of autobiographical memories is current problem for legal psychology. We reviewed the variability of autobiographical memories in the context of legal practice. In addition, we conducted the experimental field study of the dynamics of subjective assessments of the reliability of memories. It was found that truthful confirmation and false refutation of reliable last episodes, as well as after a truthful refutation and false confirmation of unreliable last episodes lead to regular changes in the subjective assessment of the reliability. The mnemonic "renunciation effect" is that a false refutation of a reliable episode leads to its forgetting and a truthful refutation of an unreliable episode leads to its erroneous inclusion in autobiographical memory.

  2. The origins of options.

    Science.gov (United States)

    Smaldino, Paul E; Richerson, Peter J

    2012-01-01

    Most research on decision making has focused on how human or animal decision makers choose between two or more options, posed in advance by the researchers. The mechanisms by which options are generated for most decisions, however, are not well understood. Models of sequential search have examined the trade-off between continued exploration and choosing one's current best option, but still cannot explain the processes by which new options are generated. We argue that understanding the origins of options is a crucial but untapped area for decision making research. We explore a number of factors which influence the generation of options, which fall broadly into two categories: psycho-biological and socio-cultural. The former category includes factors such as perceptual biases and associative memory networks. The latter category relies on the incredible human capacity for culture and social learning, which doubtless shape not only our choices but the options available for choice. Our intention is to start a discussion that brings us closer toward understanding the origins of options.

  3. Americal options analyzed differently

    NARCIS (Netherlands)

    Nieuwenhuis, J.W.

    2003-01-01

    In this note we analyze in a discrete-time context and with a finite outcome space American options starting with the idea that every tradable should be a martingale under a certain measure. We believe that in this way American options become more understandable to people with a good working

  4. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... 2006, and supervisory authorities in many other European countries have implemented similar regulation. Traffic light options are therefore likely to attract the attention of a wider audience of pension fund managers in the future. Focusing on the valuation of the traffic light option we set up a Black...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  5. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    2007-01-01

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... 2006, and supervisory authorities in many other European countries have implemented similar regulation. Traffic light options are therefore likely to attract the attention of a wider audience of pension fund managers in the future. Focusing on the valuation of the traffic light option we set up a Black...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  6. 7 CFR 1781.14 - Planning, options, and appraisals.

    Science.gov (United States)

    2010-01-01

    ... designated agent when a WS loan, WS advance or RCD loan is made. (d) Options and appraisals related to the purchase of real estate for which a WS loan, WS advance, or RCD loan is made must be developed in...

  7. Application of forgetful analgesia induction in induction period in patients with obstructive jaundice

    Directory of Open Access Journals (Sweden)

    Wei DU

    2014-03-01

    Full Text Available Objective To observe the effect of forgetful analgesia induction and tracheal intubation on the hemodynamic changes in induction period in patients with obstructive jaundice, and explore a safe method for anesthesia induction and tracheal intubation. Methods Sixty patients with obstructive jaundice undergoing elective abdominal operation in General Hospital of PLA from February, 2013 to August, 2013 were involved in the present study. Participants included 36 male and 24 female patients, aging 19-65 years (mean 42±5 years, weighing 47-73 kg (mean 54±6 kg, with ASA Ⅰ-Ⅱ. These 60 patients were randomly divided into forgetful analgesia induction-tracheal intubation group (group A, n=30 and rapid induction-tracheal intubation group (group B, n=30. The heart rate (HR, mean arterial pressure (MAP, pulse oxygen saturation (SpO2 at the time point of before induction (T0, before intubation (T1, at the moment of intubation (T2 and 3 min after intubation (T3 were determined in both groups. Administration times of ephedrine hydrochloride and atropine was recorded in both groups. Results There was no significant difference in HR, MAP, SpO2 before and after induction in group A. In the patients of group B, the HR increased and MAP decreased after induction compared with those before induction (P<0.05, and the change of SpO2 was not significant. Ephedrine hydrochloride and atropine were administrated in both groups, and the cases and times of ephedrine hydrochloride administration were more in group B than in group A (P<0.05. Conclusion The forgetful analgesia induction-tracheal intubation could effectively control the stress response and reduce the fluctuation in hemodynamics during induction of anesthesia in patients with obstructive jaundice. DOI: 10.11855/j.issn.0577-7402.2014.02.15

  8. Towards solving the riddle of forgetting in functional amnesia: recent advances and current opinions.

    Science.gov (United States)

    Staniloiu, Angelica; Markowitsch, Hans J

    2012-01-01

    Remembering the past is a core feature of human beings, enabling them to maintain a sense of wholeness and identity and preparing them for the demands of the future. Forgetting operates in a dynamic neural connection with remembering, allowing the elimination of unnecessary or irrelevant information overload and decreasing interference. Stress and traumatic experiences could affect this connection, resulting in memory disturbances, such as functional amnesia. An overview of clinical, epidemiological, neuropsychological, and neurobiological aspects of functional amnesia is presented, by preponderantly resorting to own data from patients with functional amnesia. Patients were investigated medically, neuropsychologically, and neuroradiologically. A detailed report of a new case is included to illustrate the challenges posed by making an accurate differential diagnosis of functional amnesia, a condition that may encroach on the boundaries between psychiatry and neurology. Several mechanisms may play a role in "forgetting" in functional amnesia, such as retrieval impairments, consolidating defects, motivated forgetting, deficits in binding and reassembling details of the past, deficits in establishing a first person autonoetic connection with personal events, and loss of information. In a substantial number of patients, we observed a synchronization abnormality between a frontal lobe system, important for autonoetic consciousness, and a temporo-amygdalar system, important for evaluation and emotions, which provides empirical support for an underlying mechanism of dissociation (a failure of integration between cognition and emotion). This observation suggests a mnestic blockade in functional amnesia that is triggered by psychological or environmental stress and is underpinned by a stress hormone mediated synchronization abnormality during retrieval between processing of affect-laden events and fact-processing.

  9. Towards Solving the Riddle of Forgetting in Functional Amnesia: Recent Advances and Current Opinions

    Directory of Open Access Journals (Sweden)

    Angelica eStaniloiu

    2012-11-01

    Full Text Available Remembering the past is a core feature of human beings, enabling them to maintain a sense of wholeness and identity and preparing them for the demands of the future. Forgetting operates in a dynamic neural connection with remembering, allowing the elimination of unnecessary or irrelevant information overload and decreasing interference. Stress and traumatic experiences could affect this connection, resulting in memory disturbances, such as functional amnesia. An overview of clinical, epidemiological, neuropsychological and neurobiological aspects of functional amnesia is presented, by preponderantly resorting to own data from patients with functional amnesia. Patients were investigated medically, neuropsychologically and neuroradiologically. A detailed report of a new case is included to illustrate the challenges posed by making an accurate differential diagnosis of functional amnesia, a condition that may encroach on the boundaries between psychiatry and neurology. Several mechanisms may play a role in forgetting in functional amnesia, such as retrieval impairments, consolidating defects, motivated forgetting, deficits in binding and reassembling details of the past, deficits in establishing a first person autonoetic connection with personal events and loss of information. In a substantial number of patients, we observed a synchronization abnormality between a frontal lobe system, important for autonoetic consciousness, and a temporo-amygdalar system, important for evaluation and emotions, which provides empirical support for an underlying mechanism of dissociation (a failure of integration between cognition and emotion. This observation suggests a mnestic blockade in functional amnesia that is triggered by psychological or environmental stress and is underpinned by a stress hormone mediated synchronization abnormality during retrieval between processing of affect-laden events and fact-processing.

  10. Autoregressive Model with Partial Forgetting within Rao-Blackwellized Particle Filter

    Czech Academy of Sciences Publication Activity Database

    Dedecius, Kamil; Hofman, Radek

    2012-01-01

    Roč. 41, č. 5 (2012), s. 582-589 ISSN 0361-0918 R&D Projects: GA MV VG20102013018; GA ČR GA102/08/0567 Grant - others:ČVUT(CZ) SGS 10/099/OHK3/1T/16 Institutional research plan: CEZ:AV0Z10750506 Keywords : Bayesian methods * Particle filters * Recursive estimation Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.295, year: 2012 http://library.utia.cas.cz/separaty/2012/AS/dedecius-autoregressive model with partial forgetting within rao-blackwellized particle filter.pdf

  11. Performance and stochastic stability of the adaptive fading extended Kalman filter with the matrix forgetting factor

    Directory of Open Access Journals (Sweden)

    Biçer Cenker

    2016-01-01

    Full Text Available In this paper, the stability of the adaptive fading extended Kalman filter with the matrix forgetting factor when applied to the state estimation problem with noise terms in the non–linear discrete–time stochastic systems has been analysed. The analysis is conducted in a similar manner to the standard extended Kalman filter’s stability analysis based on stochastic framework. The theoretical results show that under certain conditions on the initial estimation error and the noise terms, the estimation error remains bounded and the state estimation is stable.

  12. Pooling and Dynamic Forgetting Effects in Multitheme Advertising: Tracking the Advertising Sales Relationship with Particle Filters

    OpenAIRE

    Norris I. Bruce

    2008-01-01

    Firms often use a pool or series of advertising themes in their campaigns. Thus, for example, a firm may employ some of its advertising to promote price-related themes or messages and other of its advertising to promote product-related themes. This study examines the interdependence that can occur between pairs of themes in a pool (i.e., ), the impact of these pooling effects on the allocation of advertising expenditures, and the factors that can affect forgetting rates (or, conversely, carry...

  13. Polish Toxic Currency Options

    Directory of Open Access Journals (Sweden)

    Waldemar Gontarski

    2009-06-01

    Full Text Available Toxic currency options are defined on the basis of the opposition to the nature (essence of an option contract, which is justified in terms of norms founded on the general law clause of characteristics (nature of a relation (which represents an independent premise for imposing restrictions on the freedom of contracts. So-understood toxic currency options are unlawful. Indeed they contravene iuris cogentis regulations. These include for instance option contracts, which are concluded with a bank, if the bank has not informed about option risk before concluding the contract; or the barrier options, which focus only on the protection of bank’s interests. Therefore, such options may appear to be invalid. Therefore, performing contracts for toxic currency options may be qualified as a criminal mismanagement. For the sake of security, the manager should then take into consideration filing a claim for stating invalidity (which can be made in a court verdict. At the same time, if the supervisory board member in a commercial company, who can also be a subject to mismanagement offences, commits an omission involving lack of reaction (for example, if he/she fails to notify of the suspected offence committed by the management board members acting to the company’s detriment when the management board makes the company conclude option contracts which are charged with absolute invalidity the supervisory board member so acting may be considered to act to the company’s detriment. In the most recent Polish jurisprudence and judicature the standard of a “good host” is treated to be the last resort for determining whether the manager’s powers resulting from criminal regulations were performed. The manager of the exporter should not, as a rule, issue any options. Issuing options always means assuming an obligation. In the case of currency put options it is an absolute obligation to purchase a given amount in euro at exchange rate set in advance. On the

  14. 2005 resource options report

    International Nuclear Information System (INIS)

    Morris, T.

    2005-01-01

    This resource options report (ROR) fulfils regulatory requirements in British Columbia's two-year resource planning process. It identifies a wide range of resources and technologies that could be used to meet BC Hydro's future electricity demand. As such, it facilitates a transparent public review of resource options which include both supply-side and demand-side options. The resource options that will be used in the 2005 integrated electricity plan (IEP) were characterized. This ROR also documents where there is a general agreement or disagreement on the resource type characterization, based on the First Nations and Stakeholder engagement. BC Hydro used current information to provide realistic ranges on volume and cost to characterize environmental and social attributes. The BC Hydro system was modelled to assess the benefit and cost of various resource options. The information resulting from this ROR and IEP will help in making decisions on how to structure competitive acquisition calls and to determine the level of transmission services needed to advance certain BC Hydro projects. The IEP forecasts the nature and quantity of domestic resources required over the next 20 years. A strategic direction on how those needs will be met has been created to guide the management of BC Hydro's energy resources. Supply-side options include near-commercial technologies such as energy storage, ocean waves, tidal, fuel cells and integrated coal gasification combined cycle technology. Supply-side options also include natural gas, coal, biomass, geothermal, wind, and hydro. 120 refs., 39 tabs., 21 figs., 6 appendices

  15. Early Option Exercise

    DEFF Research Database (Denmark)

    Heje Pedersen, Lasse; Jensen, Mads Vestergaard

    A classic result by Merton (1973) is that, except just before expiration or dividend payments, one should never exercise a call option and never convert a convertible bond. We show theoretically that this result is overturned when investors face frictions. Early option exercise can be optimal when...... it reduces short-sale costs, transaction costs, or funding costs. We provide consistent empirical evidence, documenting billions of dollars of early exercise for options and convertible bonds using unique data on actual exercise decisions and frictions. Our model can explain as much as 98% of early exercises...

  16. Early Option Exercise

    DEFF Research Database (Denmark)

    Jensen, Mads Vestergaard; Heje Pedersen, Lasse

    2016-01-01

    A classic result by Merton (1973) is that, except just before expiration or dividend payments, one should never exercise a call option and never convert a convertible bond. We show theoretically that this result is overturned when investors face frictions. Early option exercise can be optimal when...... it reduces short-sale costs, transaction costs, or funding costs. We provide consistent empirical evidence, documenting billions of dollars of early exercise for options and convertible bonds using unique data on actual exercise decisions and frictions. Our model can explain as much as 98% of early exercises...

  17. Blocking Synaptic Removal of GluA2-Containing AMPA Receptors Prevents the Natural Forgetting of Long-Term Memories.

    Science.gov (United States)

    Migues, Paola Virginia; Liu, Lidong; Archbold, Georgina E B; Einarsson, Einar Ö; Wong, Jacinda; Bonasia, Kyra; Ko, Seung Hyun; Wang, Yu Tian; Hardt, Oliver

    2016-03-23

    The neurobiological processes underpinning the natural forgetting of long-term memories are poorly understood. Based on the critical role of GluA2-containing AMPA receptors (GluA2/AMPARs) in long-term memory persistence, we tested in rats whether their synaptic removal underpins time-dependent memory loss. We found that blocking GluA2/AMPAR removal with the interference peptides GluA23Y or G2CT in the dorsal hippocampus during a memory retention interval prevented the normal forgetting of established, long-term object location memories, but did not affect their acquisition. The same intervention also preserved associative memories of food-reward conditioned place preference that would otherwise be lost over time. We then explored whether this forgetting process could play a part in behavioral phenomena involving time-dependent memory change. We found that infusing GluA23Y into the dorsal hippocampus during a 2 week retention interval blocked generalization of contextual fear expression, whereas infusing it into the infralimbic cortex after extinction of auditory fear prevented spontaneous recovery of the conditioned response. Exploring possible physiological mechanisms that could be involved in this form of memory decay, we found that bath application of GluA23Y prevented depotentiation, but not induction of long-term potentiation, in a hippocampal slice preparation. Together, these findings suggest that a decay-like forgetting process that involves the synaptic removal of GluA2/AMPARs erases consolidated long-term memories in the hippocampus and other brain structures over time. This well regulated forgetting process may critically contribute to establishing adaptive behavior, whereas its dysregulation could promote the decline of memory and cognition in neuropathological disorders. The neurobiological mechanisms involved in the natural forgetting of long-term memory and its possible functions are not fully understood. Based on our previous work describing the

  18. Thermometers: Understand the Options

    Science.gov (United States)

    ... the options Thermometers come in a variety of styles. Understand the different types of thermometers and how ... MA. Fever in infants and children: Pathophysiology and management. http://www.uptodate.com/home. Accessed July 23, ...

  19. How to choose the right capitalization option.

    Science.gov (United States)

    Vaughan, J; Wise, J

    1996-12-01

    Physician group practices and networks must have ready access to capital to finance their working capital needs, capital equipment acquisitions, and real estate purchases, as well as to fund the acquisition of additional practices. At least three options for capitalization are available to group practices and networks: debt financing, equity financing, or a combination of the two. The best option for physician group practices and networks depends on the costs of capital and the impact the strategy will have on decision making and governance.

  20. Was abandonment of the review clause a mistake? Evaluation of management flexibility in the German coal mining industry on the basis of real options; War die Aufgabe der Revisionsklausel ein Fehler? Beurteilung unternehmerischer Flexibilitaet im deutschen Steinkohlenbergbau auf Basis von Realoptionen

    Energy Technology Data Exchange (ETDEWEB)

    Bendiek, Ansgar [Hochtief Concessions AG, Essen (Germany)

    2012-07-01

    The author analyses the decision to abandon the co called ''review clause'' (which was the right to revisit the decision to close German hard coal mines in 2012), and thus management flexibility on the basis of the option price theory and use of hedging instruments (derivatives) in coal trading. Only the case of coal production without any subsidies will be taken into account. The original intention of the review clause to subsidise coal production for further years will be left aside. Abandonment of the review clause destroyed a value of the real option of approx. 819 Mio. EUR. It should be agreed with the politicians that the decision concerning potential extension of coal production without subsidies should be made at the end of 2015. At this point in time the coal price for 2019 to 2021 can be locked in by forward contracts. A prerequisite for coal mining without subsidies would be an increase in the coal price of 3.1% p.a., which is only slightly above the inflation rate and seems to be realistic against the background of rising oil prices and increased scarcity of natural resources. (orig.)

  1. Options for human intrusion

    International Nuclear Information System (INIS)

    Bauser, M.; Williams, R.

    1993-01-01

    This paper addresses options for dealing with human intrusion in terms of performance requirements and repository siting and design requirements. Options are presented, along with the advantages and disadvantages of certain approaches. At the conclusion, a conceptual approach is offered emphasizing both the minimization of subjective judgements concerning future human activity, and specification of repository requirements to minimize the likelihood of human intrusion and any resulting, harmful effects should intrusion occur

  2. Accelerated long-term forgetting and behavioural difficulties in children with epilepsy.

    Science.gov (United States)

    Gascoigne, Michael B; Smith, Mary Lou; Barton, Belinda; Webster, Richard; Gill, Deepak; Lah, Suncica

    2018-03-30

    Patients with epilepsy have been shown to exhibit a range of memory deficits, including the rapid forgetting of newly-learned material over long, but not short, delays (termed accelerated long-term forgetting; ALF). Behavioural problems, such as mood disorders and social difficulties, are also overrepresented among children with epilepsy, when compared to patients with other chronic diseases and the general population. We investigated whether ALF was associated with behavioural or psychosocial deficits in children with epilepsy. Patients with either idiopathic generalised epilepsy (IGE; n = 20) or temporal lobe epilepsy (TLE; n = 23) and healthy controls (n = 53) of comparable age, sex, and socioeconomic status completed a battery of neuropsychological tests, including a list-learning task that required recall after short (30-min) and long (7-day) delays. Parents or guardians of all participants also completed the Child Behavior Checklist (CBCL). Compared to control participants, patients with IGE and TLE had higher scores on all but one of the indices of behavioural problems. When patients with IGE and TLE were merged into a single group, they were found to have negative correlations between 7-day recall and internalising, social and total problem behaviour domains, where poorer 7-day recall was associated with behavioural problems of greater severity. These findings suggest that impaired episodic recall is associated with behavioural deficits, including social problems, which are routinely observed in patients with epilepsy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Accelerated long-term forgetting in children with idiopathic generalized epilepsy.

    Science.gov (United States)

    Gascoigne, Michael B; Barton, Belinda; Webster, Richard; Gill, Deepak; Antony, Jayne; Lah, Suncica Sunny

    2012-12-01

    The rapid forgetting of information over long (but not short) delays (accelerated long-term forgetting [ALF]) has been associated with temporal lobe epilepsy but not idiopathic generalized epilepsy (IGE). Long-term memory formation (consolidation) is thought to demand an interaction between medial temporal and neocortical networks, which could be disrupted by epilepsy/seizures themselves. The present study investigates whether ALF is present in children with IGE and whether it relates to epilepsy severity. Sixty-one children (20 with IGE and 41 healthy controls [HC]) of comparable age, sex, and parental socioeconomic status completed neuropsychological tests, including a measure of verbal learning and recall after, short (30-min) and long (7-day) delays, and recognition. Epilepsy severity was rated by treating neurologists. A two-way repeated measures analysis of covariance (ANCOVA) found a significant Group x Delay interaction; the children with IGE recalled (and recognized) significantly fewer words after a long, but not short (2- and 30-min) delay relative to the HC children. Moreover, greater epilepsy severity was associated with poorer recognition. This study demonstrates, to our knowledge for the first time, that children with IGE present with ALF, which is related to epilepsy severity. These findings support the notion that epilepsy/seizures themselves may disrupt long-term memory consolidation, which interferes with day-to-day functioning of children with IGE. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

  4. Memory, forgetting, and economic crisis: drug use and social fragmentation in an Argentine shantytown.

    Science.gov (United States)

    Epele, Maria E

    2010-03-01

    Closely linked to the increase in psychotropic pill consumption, forgetting and remembering emerged from devastated social scenarios as a new local idiom among poor youth in the late 1990s and the new millennium. Drawing on ethnographic fieldwork carried out during the years of the deepest economic crisis in Argentina (2001-03), I argue that psychotropic pill consumption is associated with not only deteriorating economic conditions but also changes in the quality and price of cocaine, and in the scarcity and subsequent change of status of medications during the economic breakdown. Taking into account developments in the field of memory studies, I examine the relationship among political economy, social memory work, and changing drug-use practices. Regarding memory as a social practice, I argue that the growth of psychotropic pill consumption in the late 1990s can be understood through the interplay of Paul Ricoeur's notions regarding different kinds and levels of forgetting. By analyzing changing survival strategies, social network dismantlement, changing mortality patterns, and abusive police repression, I discuss how social fragmentation engendered by structural reforms has modified social memory work.

  5. "I just forget to take it": asthma self-management needs and preferences in adolescents.

    Science.gov (United States)

    Koster, Ellen S; Philbert, Daphne; de Vries, Tjalling W; van Dijk, Liset; Bouvy, Marcel L

    2015-10-01

    Medication adherence rates often decline as children become teenagers. Effective adherence-enhancing interventions for adolescents are lacking. The objective of this study was to assess adolescent asthmatics needs and preferences regarding medication counseling and support, with focus on new media. Three focus groups including 21 asthmatic adolescents recruited from both primary and secondary care were held to explore needs and preferences regarding asthma-self management. Questions concerned adherence behavior and needs and preferences in adherence support with focus on new media (mobile technology, social media, health games). Forgetting was mentioned as major reason for not using medication as prescribed. Adolescents also mentioned lack of perceived need or beneficial effects. Parents mainly play a role in reminding to take medication and collecting refills. The suggested strategies to support self-management included smartphone applications with a reminder function and easy access to online information. Participants were positive about sharing of experiences with other teenagers. Forgetfulness is a major reason for non-adherence in adolescents. Furthermore, our results suggest use of peer support may be helpful in promoting good medication use. Future interventions should be aimed at providing practical reminders and should be modifiable to individual preferences.

  6. Differential Involvement of the Dentate Gyrus in Adaptive Forgetting in the Rat.

    Directory of Open Access Journals (Sweden)

    Mickaël Antoine Joseph

    Full Text Available How does the brain discriminate essential information aimed to be stored permanently from information required only temporarily, and that needs to be cleared away for not saturating our precious memory space? Reference Memory (RM refers to the long-term storage of invariable information whereas Working Memory (WM depends on the short-term storage of trial-unique information. Previous work has revealed that WM tasks are very sensitive to proactive interference. In order to prevent such interference, irrelevant old memories must be forgotten to give new ones the opportunity to be stabilized. However, unlike memory, physiological processes underlying this adaptive form of forgetting are still poorly understood. Here, we precisely ask what specific brain structure(s could be responsible for such process to occur. To answer this question, we trained rats in a radial maze using three paradigms, a RM task and two WM tasks involving or not the processing of interference but strictly identical in terms of locomotion or motivation. We showed that an inhibition of the expression of Zif268 and c-Fos, two indirect markers of neuronal activity and synaptic plasticity, was observed in the dentate gyrus of the dorsal hippocampus when processing such interfering previously stored information. Conversely, we showed that inactivating the dentate gyrus impairs both RM and WM, but improves the processing of interference. Altogether, these results strongly suggest for the first time that the dentate gyrus could be a key structure involved in adaptive forgetting.

  7. Temporal dynamics of categorization: Forgetting as the basis of abstraction and generalization

    Directory of Open Access Journals (Sweden)

    Haley eVlach

    2014-09-01

    Full Text Available Historically, models of categorization have focused on how learners track frequencies and co-occurrence information to abstract relevant category features for generalization. The current study takes a different approach by examining how the temporal dynamics of categorization affect abstraction and generalization. In the learning phase of the experiment, all relevant category features were presented an equal number of times across category exemplars. However, the relevant features were presented on one of two learning schedules: massed or interleaved. At a series of immediate and delayed tests, learners were asked to generalize to novel exemplars that contained massed features, interleaved features, or all novel features. The results of this experiment revealed that, at an immediate test, learners more readily generalized based upon features presented on a massed schedule. Conversely, at a delayed test, learners more readily generalized based upon features presented on an interleaved schedule, until information was no longer readily retrievable from memory. These findings suggest that forgetting and retrieval processes engendered by the temporal dynamics of learning are used as a basis of abstraction, implicating forgetting as a central mechanism of generalization.

  8. Remembering and Forgetting: The History of Sheikh Yusuf Struggle for Human Right

    Directory of Open Access Journals (Sweden)

    Erwiza Erman

    2016-01-01

    Full Text Available For 300 years,. the name of Sheikh Yusuf, son of Macassar was missing from the government's attention and public intellectual as well. But when Nelson Mandela, President of South Africa,. commemorated 300 years of the arrival of Sheikh Yusuf in Cape Town in 1994, since that time government institution civil society and academics from Indonesia and South Africa have been paying to attention to remember, understand and study him from various perspectives. By using concept of remembering and forgetting, this article shows that the process of remembering by the two countries did not take place in the empty space, but rely on psychological consideration of the individuals, communities and socio-political condition from the two countries. The process of forgetting constructed by the Dutch colonial state in 17th century became inversely proportional to the action of remembering the Sheikh Yusuf by African and Indonesian officials in 20th century. The proces of remembering shows its own dynamics ranging from individuals communities to public memory. When remembering Syekh Yusuf reached state memory or public memory it became a power that can define and plan a socio-political and economic agenda for the future by the countries.

  9. Putting retrieval-induced forgetting in context: an inhibition-free, context-based account.

    Science.gov (United States)

    Jonker, Tanya R; Seli, Paul; MacLeod, Colin M

    2013-10-01

    We present a new theoretical account of retrieval-induced forgetting (RIF) together with new experimental evidence that fits this account and challenges the dominant inhibition account. RIF occurs when the retrieval of some material from memory produces later forgetting of related material. The inhibition account asserts that RIF is the result of an inhibition mechanism that acts during retrieval to suppress the representations of interfering competitors. This inhibition is enduring, such that the suppressed material is difficult to access on a later test and is, therefore, recalled more poorly than baseline material. Although the inhibition account is widely accepted, a growing body of research challenges its fundamental assumptions. Our alternative account of RIF instead emphasizes the role of context in remembering. According to this context account, both of 2 tenets must be met for RIF to occur: (a) A context change must occur between study and subsequent retrieval practice, and (b) the retrieval practice context must be the active context during the final test when testing practiced categories. The results of 3 experiments, which directly test the divergent predictions of the 2 accounts, support the context account but cannot be explained by the inhibition account. In an extensive discussion, we survey the literature on RIF and apply our context account to the key findings, demonstrating the explanatory power of context. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  10. Nevada Transportation Options Study

    International Nuclear Information System (INIS)

    P. GEHNER; E.M. WEAVER; L. FOSSUM

    2006-01-01

    This study performs a cost and schedule analysis of three Nevada Transportation options that support waste receipt at the repository. Based on the U.S. Department of Energy preference for rail transportation in Nevada (given in the Final Environmental Impact Statement), it has been assumed that a branch rail line would be constructed to support waste receipt at the repository. However, due to potential funding constraints, it is uncertain when rail will be available. The three Nevada Transportation options have been developed to meet a varying degree of requirements for transportation and to provide cost variations used in meeting the funding constraints given in the Technical Direction Letter guidelines for this study. The options include combinations of legal-weight truck, heavy-haul truck, and rail. Option 1 uses a branch rail line that would support initial waste receipt at the repository in 2010. Rail transportation would be the primary mode, supplemented by legal weight trucks. This option provides the highest level of confidence in cost and schedule, lowest public visibility, greatest public acceptability, lowest public dose, and is the recommended option for support of waste receipt. The completion of rail by 2010 will require spending approximately $800 million prior to 2010. Option 2 uses a phased rail approach to address a constrained funding scenario. To meet funding constraints, Option 2 uses a phased approach to delay high cost activities (final design and construction) until after initial waste receipt in 2010. By doing this, approximately 95 percent of the cost associated with completion of a branch rail line is deferred until after 2010. To support waste receipt until a branch rail line is constructed in Nevada, additional legal-weight truck shipments and heavy-haul truck shipments (on a limited basis for naval spent nuclear fuel) would be used to meet the same initial waste receipt rates as in Option 1. Use of heavy-haul shipments in the absence

  11. Options Study - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    R. Wigeland; T. Taiwo; M. Todosow; W. Halsey; J. Gehin

    2010-09-01

    The Options Study has been conducted for the purpose of evaluating the potential of alternative integrated nuclear fuel cycle options to favorably address the issues associated with a continuing or expanding use of nuclear power in the United States. The study produced information that can be used to inform decisions identifying potential directions for research and development on such fuel cycle options. An integrated nuclear fuel cycle option is defined in this study as including all aspects of the entire nuclear fuel cycle, from obtaining natural resources for fuel to the ultimate disposal of used nuclear fuel (UNF) or radioactive wastes. Issues such as nuclear waste management, especially the increasing inventory of used nuclear fuel, the current uncertainty about used fuel disposal, and the risk of nuclear weapons proliferation have contributed to the reluctance to expand the use of nuclear power, even though it is recognized that nuclear power is a safe and reliable method of producing electricity. In this Options Study, current, evolutionary, and revolutionary nuclear energy options were all considered, including the use of uranium and thorium, and both once-through and recycle approaches. Available information has been collected and reviewed in order to evaluate the ability of an option to clearly address the challenges associated with the current implementation and potential expansion of commercial nuclear power in the United States. This Options Study is a comprehensive consideration and review of fuel cycle and technology options, including those for disposal, and is not constrained by any limitations that may be imposed by economics, technical maturity, past policy, or speculated future conditions. This Phase II report is intended to be used in conjunction with the Phase I report, and much information in that report is not repeated here, although some information has been updated to reflect recent developments. The focus in this Options Study was to

  12. Are biofuels a feasible option?

    International Nuclear Information System (INIS)

    Goldemberg, Jose; Guardabassi, Patricia

    2009-01-01

    Recently a number of objections have been raised against the use of ethanol produced from agricultural products such as maize, sugarcane, wheat or sugar beets as a replacement for gasoline, despite some of their advantages such as being cleaner and to some extent renewable. We address these objections in this paper. Topics discussed include the 'corn connection' (which was theorized to be a cause of deforestation in the Amazonia), the rise of food prices due to ethanol production and the real possibilities of ethanol in reducing greenhouse gas emissions. It has been shown that such concerns are grossly exaggerated and that ethanol from sugarcane, as produced in Brazil, is the preferred option for the production of fuel not only in terms of cost but also as a favourable energy balance. Finally, the possibility of expanding ethanol production to other sugar-producing countries is also discussed

  13. Treatment Options for Wilms Tumor

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... come back) after it has been treated. Treatment Option Overview Key Points There are different types of ...

  14. Treatment Options for Myelodysplastic Syndromes

    Science.gov (United States)

    ... special light. Certain factors affect prognosis and treatment options. The prognosis (chance of recovery) and treatment options ... age and general health of the patient. Treatment Option Overview Key Points There are different types of ...

  15. Treatment Option Overview (Prostate Cancer)

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  16. Treatment Option Overview (Myelodysplastic Syndromes)

    Science.gov (United States)

    ... special light. Certain factors affect prognosis and treatment options. The prognosis (chance of recovery) and treatment options ... age and general health of the patient. Treatment Option Overview Key Points There are different types of ...

  17. Treatment Option Overview (Esophageal Cancer)

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  18. Treatment Option Overview (Childhood Rhabdomyosarcoma)

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  19. Treatment Option Overview (Penile Cancer)

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  20. Treatment Option Overview (Vulvar Cancer)

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  1. Treatment Option Overview (Pancreatic Cancer)

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  2. Treatment Option Overview (Adrenocortical Carcinoma)

    Science.gov (United States)

    ... affect the prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  3. Treatment Options for Childhood Rhabdomyosarcoma

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  4. Treatment Options for Kaposi Sarcoma

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... or in other parts of the body. Treatment Option Overview Key Points There are different types of ...

  5. Treatment Options for Childhood Craniopharyngioma

    Science.gov (United States)

    ... factors affect prognosis (chance of recovery) and treatment options. The prognosis (chance of recovery ) and treatment options ... the brain where it was first found. Treatment Option Overview Key Points There are different types of ...

  6. Forget Unlearning?

    DEFF Research Database (Denmark)

    Howells, John; Scholderer, Joachim

    2016-01-01

    provide evidence of its existence. Typically, under the label ‘unlearning’ evidence is provided of a conventional process of theory-change; the setting aside (not deletion) of an established understanding in favour of new understanding when presented with perceived new facts. In all cases we examine...... of its adherents believe it to be. We recommend that for concepts allegedly imported from other disciplines more frequent commissioning of cross-disciplinary reviews may encourage the critical works so obviously lacking in the ‘unlearning literature’....

  7. Global Factors that Affect the Real Estate Markets in the EU

    Directory of Open Access Journals (Sweden)

    Povilas Švogžlys

    2016-06-01

    Full Text Available The place, neighbourhood, infrastructure, and apartment plan are the main factors which have an influence on price for the buyers, sellers, investors, or brokers participating in the buying and selling processes of real estate. Participants of the process forget frequently that there are more crucial factors which can affect not only the prices of property, but the prices of real estate in the whole region as well in the future. The article uses benchmarking and discuss the main external factors which affect the real estate market in the European Union, the current events and the proposals are presented and the specific conclusions are identified.

  8. The List-Strength Effect in Recall: Relative-Strength Competition and Retrieval Inhibition May both Contribute to Forgetting

    Science.gov (United States)

    Verde, Michael F.

    2009-01-01

    According to the principle of relative-strength competition, stronger items in memory block the retrieval of weaker items. This principle, integral to many theories of forgetting over the years, derives much of its support from the list-strength effect (LSE), in which strengthening some items in a study list makes it more difficult to recall other…

  9. Four-hour delayed memory recall for stories: Theoretical and clinical implications of measuring accelerated long-term forgetting.

    Science.gov (United States)

    Ladowsky-Brooks, Ricki L

    2016-01-01

    It has been noted that clinical neuropsychological assessment is "blind" to certain abnormalities of consolidation that occur beyond standard 30-min delay intervals. For example, normal forgetting at 30-min delays has been followed by enhanced forgetting at longer delays in temporal-lobe epilepsy, termed accelerated long-term forgetting (ALF). To evaluate whether ALF could be identified in the neuropsychological assessment of a small sample of examinees with head injuries or other neurological diagnoses (n = 42), a 4-hr delayed recall condition was added to the Logical Memory subtest of the Wechsler Memory Scale-Third Edition. A small percentage of examinees (5/42 or 11%), despite exhibiting unimpaired story recall immediately and after 30-min delays, showed increased forgetting when compared with the average retention of stories (M = 0.83, SD = 0.17) after a 4-hr delay. Three of these 5 examinees also had impaired scores on 20-min delayed recall of the California Verbal Learning Test-Second Edition (CVLT-II) and would have been identified as having memory impairment without an extended, 4-hr delayed recall. In fact, the highest correlation among memory indexes was between 4-hr delayed recall of stories and delayed recall of the CVLT-II word list (r = .59, p < .0001), suggesting different consolidation rates for relational and nonrelational material.

  10. Facilitative Effects of Forgetting from Short-Term Memory on Growth of Long-Term Memory in Retardates

    Science.gov (United States)

    Sperber, Richard D.

    1976-01-01

    Competing explanations of the beneficial effect of spacing in retardate discrimination learning were tested. Results are inconsistent with consolidation and rehearsal theories but support the prediction of the Geber, Greenfield, and House spacing model that forgetting from short-term memory facilities retardate learning. (Author/SB)

  11. Directed Forgetting in Direct and Indirect Tests of Memory: Seeking Evidence of Retrieval Inhibition Using Electrophysiological Measures

    Science.gov (United States)

    Van Hooff, Johanna C.; Whitaker, T. Aisling; Ford, Ruth M.

    2009-01-01

    We investigated whether directed forgetting as elicited by the item-cueing method results solely from "differential rehearsal" of to-be-remembered vs. to-be-forgotten words or, additionally, from "inhibitory" processes that actively impair retrieval of to-be-forgotten words. During study, participants (N = 24) were instructed to remember half of a…

  12. A Novel Method for Lithium-Ion Battery Online Parameter Identification Based on Variable Forgetting Factor Recursive Least Squares

    Directory of Open Access Journals (Sweden)

    Zizhou Lao

    2018-05-01

    Full Text Available For model-based state of charge (SOC estimation methods, the battery model parameters change with temperature, SOC, and so forth, causing the estimation error to increase. Constantly updating model parameters during battery operation, also known as online parameter identification, can effectively solve this problem. In this paper, a lithium-ion battery is modeled using the Thevenin model. A variable forgetting factor (VFF strategy is introduced to improve forgetting factor recursive least squares (FFRLS to variable forgetting factor recursive least squares (VFF-RLS. A novel method based on VFF-RLS for the online identification of the Thevenin model is proposed. Experiments verified that VFF-RLS gives more stable online parameter identification results than FFRLS. Combined with an unscented Kalman filter (UKF algorithm, a joint algorithm named VFF-RLS-UKF is proposed for SOC estimation. In a variable-temperature environment, a battery SOC estimation experiment was performed using the joint algorithm. The average error of the SOC estimation was as low as 0.595% in some experiments. Experiments showed that VFF-RLS can effectively track the changes in model parameters. The joint algorithm improved the SOC estimation accuracy compared to the method with the fixed forgetting factor.

  13. Designing Pareto-superior demand-response rate options

    International Nuclear Information System (INIS)

    Horowitz, I.; Woo, C.K.

    2006-01-01

    We explore three voluntary service options-real-time pricing, time-of-use pricing, and curtailable/interruptible service-that a local distribution company might offer its customers in order to encourage them to alter their electricity usage in response to changes in the electricity-spot-market price. These options are simple and practical, and make minimal information demands. We show that each of the options is Pareto-superior ex ante, in that it benefits both the participants and the company offering it, while not affecting the non-participants. The options are shown to be Pareto-superior ex post as well, except under certain exceptional circumstances. (author)

  14. Time course of scopolamine effect on memory consolidation and forgetting in rats.

    Science.gov (United States)

    Popović, Miroljub; Giménez de Béjar, Verónica; Popović, Natalija; Caballero-Bleda, María

    2015-02-01

    The effect of scopolamine on the consolidation and forgetting of emotional memory has not been completely elucidated yet. The aim of the present study was to investigate the time course of scopolamine effect on consolidation and forgetting of passive avoidance response. In a first experiment of the present study, we tested the effect of scopolamine (1mg/kg, i.p., immediately after acquisition), on 24h and 48h retention performance of the step-through passive avoidance task, in adult male Wistar rats. On the 24h retested trial, the latency of the passive avoidance response was significantly lower, while on the 48h retested trial it was significantly higher in scopolamine than in the saline-treated group. In a second experiment, we assessed the 24h time course of scopolamine (1mg/kg) effect on memory consolidation in passive avoidance task. We found that scopolamine administration only within the first six and half hours after acquisition improved memory consolidation in 48h retention performance. Finally, a third experiment was performed on the saline- and scopolamine-treated rats (given immediately after acquisition) that on the 48h retention test did not step through into the dark compartment during the cut-off time. These animals were retested weekly for up to first three months, and after that, every three months until the end of experiment (i.e., 15 months after acquisition). The passive avoidance response in the saline treated group lasted up to 6 weeks after acquisition, while in the scopolamine treated group 50% of animals conserved the initial level of passive avoidance response until the experiment end point. In conclusion, the present data suggest that (1) improving or impairment effect of scopolamine given in post-training periods depends on delay of retention trial, (2) memory consolidation process could be modify by scopolamine within first six and half hours after training and (3) scopolamine could delay forgetting of emotional memory. Copyright

  15. Accelerated long-term forgetting in children with temporal lobe epilepsy.

    Science.gov (United States)

    Gascoigne, Michael B; Smith, Mary Lou; Barton, Belinda; Webster, Richard; Gill, Deepak; Lah, Suncica

    2014-07-01

    Adults with temporal lobe epilepsy (TLE) have been found to have accelerated long-term forgetting, but this phenomenon has not yet been investigated in children. Although deficits in recall of materials after short (20- to 30-minute) delays have been shown to slowly emerge from childhood to adolescence in patients with TLE, it is unknown whether such a trend will also be found in recall of materials after long delays. This study examined the presence of accelerated long-term forgetting in children with TLE and how it relates to chronological age. Twenty-three children with TLE and 58 healthy controls of similar age, sex distribution and socioeconomic status completed a battery of neuropsychological tests, including standardised tests of story recall and design location, as well as two experimental tests requiring the learning of words and design locations to a criterion, both of which assessed recall after short (30-min) and long (7-day) delays. Word recall at the 7-day delay (relative to the 30-min recall) was significantly poorer in the TLE group, compared to the control group. The TLE group also exhibited worse 30-min recall performance on a standardised test of story recall. Individual patient analyses revealed dissociation between performance on the experimental and standardised verbal memory tests; children who were impaired on the experimental test (7-day delay) were not impaired on the standardised test (30-min delay). Compared to controls, patients with a left-hemisphere seizure focus recalled fewer words at short and long delays while patients with an abnormal hippocampus recalled fewer words at the long delay. No between-group differences were found with respect to the design location task. Age negatively correlated with the recall of words after short- and long-term delays within the TLE group, where older age was associated with worse memory. This association was not present in the control group. To our knowledge, this is the first study to show

  16. 20 CFR 416.2035 - Optional supplementation: Additional State options.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Optional supplementation: Additional State options. 416.2035 Section 416.2035 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL... § 416.2035 Optional supplementation: Additional State options. (a) Residency requirement. A State or...

  17. Novel preventive treatment options

    DEFF Research Database (Denmark)

    Longbottom, C; Ekstrand, K; Zero, D

    2009-01-01

    A number of novel preventive treatment options which, as with traditional methods, can be differentiated into 3 categories of prevention (primary, secondary and tertiary), have been and are being currently investigated. Those reviewed are either commercially available or appear relatively close...... of these techniques show considerable promise and dentists should be aware of these developments and follow their progress, the evidence for each of these novel preventive treatment options is currently insufficient to make widespread recommendations. Changes in dental practice should be explored to see how oral...

  18. Tank Space Options Report

    International Nuclear Information System (INIS)

    BOYLES, V.C.

    2001-01-01

    A risk-based priority for the retrieval of Hanford Site waste from the 149 single-shell tanks (SSTs) has been adopted as a result of changes to the Hanford Federal Facility Agreement and Consent Order (HFFACO) (Ecology et al. 1997) negotiated in 2000. Retrieval of the first three tanks in the retrieval sequence fills available capacity in the double-shell tanks (DSTs) by 2007. As a result, the HFFACO change established a milestone (M-45-12-TO1) requiring the determination of options that could increase waste storage capacity for single-shell tank waste retrieval. The information will be considered in future negotiations. This document fulfills the milestone requirement. This study presents options that were reviewed for the purpose of increasing waste storage capacity. Eight options are identified that have the potential for increasing capacity from 5 to 10 million gallons, thus allowing uninterrupted single-shell tank retrieval until the planned Waste Treatment Plant begins processing substantial volumes of waste from the double-shell tanks in 2009. The cost of implementing these options is estimated to range from less than $1 per gallon to more than $14 per gallon. Construction of new double-shell tanks is estimated to cost about $63 per gallon. Providing 5 to 10 million gallons of available double-shell tank space could enable early retrieval of 5 to 9 high-risk single-shell tanks beyond those identified for retrieval by 2007. These tanks are A-101, AX-101, AX-103, BY-102, C-107, S-105, S-106, S-108, and S-109 (Garfield et al. 2000). This represents a potential to retrieve approximately 14 million total curies, including 3,200 curies of long-lived mobile radionuclides. The results of the study reflect qualitative analyses conducted to identify promising options. The estimated costs are rough-order-of magnitude and, therefore, subject to change. Implementing some of the options would represent a departure from the current baseline and may adversely impact the

  19. Alternative energy options

    International Nuclear Information System (INIS)

    Bennett, K.F.

    1983-01-01

    It is accepted that coal will continue to play the major role in the supply of energy to the country for the remainder of the century. In this paper, however, emphasis has been directed to those options which could supplement coal in an economic and technically sound manner. The general conclusion is that certain forms of solar energy hold the most promise and it is in this direction that research, development and implementation programmes should be directed. Tidal energy, fusion energy, geothermal energy, hydrogen energy and fuel cells are also discussed as alternative energy options

  20. Thermal test options

    International Nuclear Information System (INIS)

    Koski, J.A.; Keltner, N.R.; Sobolik, K.B.

    1993-02-01

    Shipping containers for radioactive materials must be qualified to meet a thermal accident environment specified in regulations, such at Title 10, Code of Federal Regulations, Part 71. Aimed primarily at the shipping container design, this report discusses the thermal testing options available for meeting the regulatory requirements, and states the advantages and disadvantages of each approach. The principal options considered are testing with radiant heat, furnaces, and open pool fires. The report also identifies some of the facilities available and current contacts. Finally, the report makes some recommendations on the appropriate use of these different testing methods

  1. Lighting Options for Homes.

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W.S.

    1991-04-01

    This report covers many aspects of various lighting options for homes. Types of light sources described include natural light, artificial light, incandescent lamps, fluorescent lamps, and high intensity discharge lamps. A light source selection guide gives the physical characteristics of these, design considerations, and common applications. Color, strategies for efficient lighting, and types of lighting are discussed. There is one section giving tips for various situations in specific rooms. Rooms and types of fixtures are shown on a matrix with watts saved by using the recommended type lighting for that room and room location. A major emphasis of this report is saving energy by utilizing the most suitable, recommended lighting option. (BN)

  2. Accelerated forgetting of contextual details due to focal medio-dorsal thalamic lesion

    Directory of Open Access Journals (Sweden)

    Sicong eTu

    2014-09-01

    Full Text Available Effects of thalamic nuclei damage and related white matter tracts on memory performance are still debated. This is particularly evident for the medio-dorsal thalamus which has been less clear in predicting amnesia than anterior thalamus changes. The current study addresses this issue by assessing 7 thalamic stroke patients with consistent unilateral lesions focal to the left medio-dorsal nuclei for immediate and delayed memory performance on standard visual and verbal tests of anterograde memory, and over the long-term (> 24 hrs on an object-location associative memory task. Thalamic patients showed selective impairment to delayed recall, but intact recognition memory. Patients also showed accelerated forgetting of contextual information after a 24 hour delay, compared to controls. Importantly, the mammillothalamic tract was intact in all patients, which suggests a role for the medio-dorsal nuclei in recall and early consolidation memory processes.

  3. Stimulus attributes of reactivated memory: alleviation of ontogenetic forgetting in rats is context specific.

    Science.gov (United States)

    Richardson, R; Riccio, D C; McKenney, M

    1988-03-01

    Numerous studies have shown that ontogenetic forgetting (infantile amensia) can be alleviated by a number of different types of reminder treatment. The present study extends the information about the alleviation of infantile amnesia by examining the "content" of the reactivated memory. Toward this purpose, one attribute of memory (environmental context) was examined in rats tested either shortly after training (preamnesic) or after 1-week retention interval. For the latter, a reactivation treatment was used to reverse infantile amnesia. At both intervals, a context shift resulted in impaired performance of a conditioned fear response. These findings demonstrate that environment context is an important component of the originally encoded memory as well as the reactivated amnestic memory. The implications of these results for both the reactivation of memory and general memory processes are discussed.

  4. On-Line Identification of Simulation Examples for Forgetting Methods to Track Time Varying Parameters Using the Alternative Covariance Matrix in Matlab

    Science.gov (United States)

    Vachálek, Ján

    2011-12-01

    The paper compares the abilities of forgetting methods to track time varying parameters of two different simulated models with different types of excitation. The observed parameters in the simulations are the integral sum of the Euclidean norm, deviation of the parameter estimates from their true values and a selected band prediction error count. As supplementary information, we observe the eigenvalues of the covariance matrix. In the paper we used a modified method of Regularized Exponential Forgetting with Alternative Covariance Matrix (REFACM) along with Directional Forgetting (DF) and three standard regularized methods.

  5. Mixed waste management options

    International Nuclear Information System (INIS)

    Owens, C.B.; Kirner, N.P.

    1992-01-01

    Currently, limited storage and treatment capacity exists for commercial mixed waste streams. No commercial mixed waste disposal is available, and it has been estimated that if and when commercial mixed waste disposal becomes available, the costs will be high. If high disposal fees are imposed, generators may be willing to apply extraordinary treatment or regulatory approaches to properly dispose of their mixed waste. This paper explores the feasibility of several waste management scenarios and management options. Existing data on commercially generated mixed waste streams are used to identify the realm of mixed waste known to be generated. Each waste stream is evaluated from both a regulatory and technical perspective in order to convert the waste into a strictly low-level radioactive or a hazardous waste. Alternative regulatory approaches evaluated in this paper include a delisting petition) no migration petition) and a treatability variance. For each waste stream, potentially available treatment options are identified that could lead to these variances. Waste minimization methodology and storage for decay are also considered. Economic feasibility of each option is discussed broadly. Another option for mixed waste management that is being explored is the feasibility of Department of Energy (DOE) accepting commercial mixed waste for treatment, storage, and disposal. A study has been completed that analyzes DOE treatment capacity in comparison with commercial mixed waste streams. (author)

  6. Strategic growth options

    NARCIS (Netherlands)

    Kulatilaka, N.; Perotti, E.C.

    1998-01-01

    We provide a strategic rationale for growth options under uncertainty and imperfect corn-petition. In a market with strategic competition, investment confers a greater capability to take advantage of future growth opportunities. This strategic advantage leads to the capture of a greater share of the

  7. New Options, Old Concerns.

    Science.gov (United States)

    O'Neil, John

    1996-01-01

    Will greater school choice result in more responsive, higher quality schools and happier parents? Or will proliferating options further sort students and families by race, social class, and special interest? Increasingly, education is viewed as a private good. If parents become autonomous, self-interested consumers, erosion of common purposes and…

  8. Heterogeneity and option pricing

    NARCIS (Netherlands)

    Benninga, Simon; Mayshar, Joram

    2000-01-01

    An economy with agents having constant yet heterogeneous degrees of relative risk aversion prices assets as though there were a single decreasing relative risk aversion pricing representative agent. The pricing kernel has fat tails and option prices do not conform to the Black-Scholes formula.

  9. Option Pricing and Momentum

    NARCIS (Netherlands)

    Rodriguez, J.C.

    2007-01-01

    If managers are reluctant to fully adjust dividends to changes in earnings, stock returns and changes in the dividend yield will tend to be negatively correlated. When this is the case, stock returns will exhibit positive autocorrelation, or mo- mentum. This paper studies the pricing of options in

  10. Idaho's Energy Options

    Energy Technology Data Exchange (ETDEWEB)

    Robert M. Neilson

    2006-03-01

    This report, developed by the Idaho National Laboratory, is provided as an introduction to and an update of the status of technologies for the generation and use of energy. Its purpose is to provide information useful for identifying and evaluating Idaho’s energy options, and for developing and implementing Idaho’s energy direction and policies.

  11. Fuzzy Optimization of Option Pricing Model and Its Application in Land Expropriation

    Directory of Open Access Journals (Sweden)

    Aimin Heng

    2014-01-01

    Full Text Available Option pricing is irreversible, fuzzy, and flexible. The fuzzy measure which is used for real option pricing is a useful supplement to the traditional real option pricing method. Based on the review of the concepts of the mean and variance of trapezoidal fuzzy number and the combination with the Carlsson-Fuller model, the trapezoidal fuzzy variable can be used to represent the current price of land expropriation and the sale price of land on the option day. Fuzzy Black-Scholes option pricing model can be constructed under fuzzy environment and problems also can be solved and discussed through numerical examples.

  12. Real Language Meets Real Business

    Science.gov (United States)

    Muirhead, Muirhead; Schechter, Sarah

    2016-01-01

    The Real Business Language Challenge was a collaborative pilot project between Coca-Cola Enterprises (CCE) and Routes into Languages East for Year 9 and 10 pupils. It was based on CCE's award-winning Real Business Challenge, part of its highly acclaimed education programme. The Real Business Language Challenge transformed the project into a…

  13. Management options of varicoceles

    Directory of Open Access Journals (Sweden)

    Peter Chan

    2011-01-01

    Full Text Available Varicocele is one of the most common causes of male infertility. Treatment options for varicoceles includes open varicocelectomy performed at various anatomical levels. Laparoscopic varicocelectomy has been established to be a safe and effective treatment for varicoceles. Robotic surgery has been introduced recently as an alternative surgical option for varicocelectomy. Microsurgical varicocelectomy has gained increasing popularity among experts in male reproductive medicine as the treatment of choice for varicocele because of its superior surgical outcomes. There is a growing volume of literature in the recent years on minimal invasive varicocele treatment with percutaneous retrograde and anterograde venous embolization/sclerotherapy. In this review, we will discuss the advantages and limitations associated with each treatment modality for varicoceles. Employment of these advanced techniques of varicocelectomy can provide a safe and effective approach aiming to eliminate varicocele, preserve testicular function and, in a substantial number of men, increase semen quality and the likelihood of pregnancy.

  14. Energy options?; Energie opties?

    Energy Technology Data Exchange (ETDEWEB)

    Van Sark, W. (ed.)

    2006-05-15

    March 2006 the so-called Options Document was published by the Energy research Centre of the Netherlands (ECN) and the Netherlands Environmental Assessment Agency (MNP). The document is an overview of technical options to reduce energy consumption and emission of greenhouse gases up to 2020. Next to a brief summary of the document a few reactions and comments on the contents of the document are given. [Dutch] Maart 2006 publiceerde het Energieonderzoek Centrum Nederland (ECN) en het Milieu- en Natuurplanbureau (MNP) het zogenaamde Optiedocument energie en emissies 2010-2020. Daarin wordt een overzicht gegeven van de technische mogelijkheden voor vermindering van het energieverbruik en de uitstoot van broeikasgassen en luchtverontreinigende stoffen tot 2020. Naast een korte samenvatting van het document worden enkele reacties gegeven op de inhoud.

  15. Evaluating technology service options.

    Science.gov (United States)

    Blumberg, D F

    1997-05-01

    Four service and support options are available to healthcare organizations for maintaining their growth arsenals of medical and information technology. These options include maintaining and servicing all equipment using a facility-based biomedical engineering and MIS service department; using a combination of facility-based service and subcontracted service; expanding facility-based biomedical and MIS service departments to provide service to other healthcare organizations to achieve economies of scale; and outsourcing all maintenance, repair, and technical support services. Independent service companies and original equipment manufacturers (OEMs) are offering healthcare organizations a wider array of service and support capabilities than ever before. However, some health systems have successfully developed their own independent service organizations to take care of their own--and other healthcare organizations'--service and support needs.

  16. The Effect of Organizational Agility on Employees\\' Empowerment Characteristics Regarding the Role of Forgetting and Organizational Silence (Case Study: Shafa Hospital Personnel of Khorramabad

    Directory of Open Access Journals (Sweden)

    Mahmood Reza Esmaeili

    2017-12-01

    Conclusion: The results showed that organizational agility can be considered as an important factor in organizational forgetting management and enhancement of staff empowerment which is a necessary requirement for managers to adapt to today's dynamic environment.

  17. Optioner eller betingede aktier?

    DEFF Research Database (Denmark)

    Bechmann, Ken L.; Thorsell, Christopher

    2016-01-01

    Incitamentsaflønning – og herunder især aktieaflønning – fortsætter med at tiltrække sig stor opmærksomhed fra en lang række sider. Et spørgsmål, der ofte diskuteres, er selskabernes anvendelse af aktieaflønning, dvs. aflønning med optioner, betingede aktier o. lign. Diskussionerne har blandt andet...

  18. Shungnak Energy Configuration Options.

    Energy Technology Data Exchange (ETDEWEB)

    Rosewater, David Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Eddy, John P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    Power systems in rural Alaska villages face a unique combination of challenges that can increase the cost of energy and lowers energy supply reliability. In the case of the remote village of Shungnak, diesel and heating fuel is either shipped in by barge or flown in by aircraft. This report presents a technical analysis of several energy infrastructure upgrade and modification options to reduce the amount of fuel consumed by the community of Shungnak. Reducing fuel usage saves money and makes the village more resilient to disruptions in fuel supply. The analysis considers demand side options, such as energy efficiency, alongside the installation of wind and solar power generation options. Some novel approaches are also considered including battery energy storage and the use of electrical home heating stoves powered by renewable generation that would otherwise be spilled and wasted. This report concludes with specific recommendations for Shungnak based on economic factors, and fuel price sensitivity. General conclusions are also included to support future work analyzing similar energy challenges in remote arctic regions.

  19. The safeguards options study

    Energy Technology Data Exchange (ETDEWEB)

    Hakkila, E.A.; Mullen, M.F.; Olinger, C.T.; Stanbro, W.D. [Los Alamos National Lab., NM (United States); Olsen, A.P.; Roche, C.T.; Rudolph, R.R. [Argonne National Lab., IL (United States); Bieber, A.M.; Lemley, J. [Brookhaven National Lab., Upton, NY (United States); Filby, E. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others

    1995-04-01

    The Safeguards Options Study was initiated to aid the International Safeguards Division (ISD) of the DOE Office of Arms Control and Nonproliferation in developing its programs in enhanced international safeguards. The goal was to provide a technical basis for the ISD program in this area. The Safeguards Options Study has been a cooperative effort among ten organizations. These are Argonne National Laboratory, Brookhaven National Laboratory, Idaho National Engineering Laboratory, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Mound Laboratory, Oak Ridge National Laboratory, Pacific Northwest Laboratories, Sandia National Laboratories, and Special Technologies Laboratory. Much of the Motivation for the Safeguards Options Study is the recognition after the Iraq experience that there are deficiencies in the present approach to international safeguards. While under International Atomic Energy Agency (IAEA) safeguards at their declared facilities, Iraq was able to develop a significant weapons program without being noticed. This is because negotiated safeguards only applied at declared sites. Even so, their nuclear weapons program clearly conflicted with Iraq`s obligations under the Nuclear Nonproliferation Treaty (NPT) as a nonnuclear weapon state.

  20. The safeguards options study

    International Nuclear Information System (INIS)

    Hakkila, E.A.; Mullen, M.F.; Olinger, C.T.; Stanbro, W.D.; Olsen, A.P.; Roche, C.T.; Rudolph, R.R.; Bieber, A.M.; Lemley, J.; Filby, E.

    1995-04-01

    The Safeguards Options Study was initiated to aid the International Safeguards Division (ISD) of the DOE Office of Arms Control and Nonproliferation in developing its programs in enhanced international safeguards. The goal was to provide a technical basis for the ISD program in this area. The Safeguards Options Study has been a cooperative effort among ten organizations. These are Argonne National Laboratory, Brookhaven National Laboratory, Idaho National Engineering Laboratory, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Mound Laboratory, Oak Ridge National Laboratory, Pacific Northwest Laboratories, Sandia National Laboratories, and Special Technologies Laboratory. Much of the Motivation for the Safeguards Options Study is the recognition after the Iraq experience that there are deficiencies in the present approach to international safeguards. While under International Atomic Energy Agency (IAEA) safeguards at their declared facilities, Iraq was able to develop a significant weapons program without being noticed. This is because negotiated safeguards only applied at declared sites. Even so, their nuclear weapons program clearly conflicted with Iraq's obligations under the Nuclear Nonproliferation Treaty (NPT) as a nonnuclear weapon state