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AbstractIn this paper we study the scheduling problem that considers both production and job delivery at the same time with machine availability considerations. Only one vehicle is available to deliver jobs in a fixed transportation time to a distribution center. The vehicle can load at most K jobs as a delivery batch in one shipment due to the vehicle capacity constraint. The objective is to minimize the arrival time of the last delivery batch to the distribution center. Since machines may not always be available over the production period in real life due to preventive maintenance, we incorporate machine availability into the models. Three scenarios of the problem are studied. For the problem in which the jobs are processed on a single machine and the jobs interrupted by the unavailable machine interval are resumable, we provide a polynomial algorithm to solve the problem optimally. For the problem in which the jobs are processed on a single machine and the interrupted jobs are nonresumable, we first show that the problem is NP‐hard. We then propose a heuristic with a worst‐case error bound of 1/2 and show that the bound is tight. For the problem in which the jobs are processed on either one of two parallel machines, where only one machine has an unavailable interval and the interrupted jobs are resumable, we propose a heuristic with a worst‐case error bound of 2/3. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007

Results of past research suggest that affect plays an important role in risk perception. Because affect may also increase the availability of risks, affect and availability are closely related concepts. Three studies tested the hypothesis that evoking negative affect (fear), either through past experience or through experimental manipulation, results in greater perceived risk. The present research focused on perception of flooding risk. Study 1 and Study 2 showed that participants who received risk information concerning a longer time period (e.g., 30 years) perceived more danger compared with participants who received risk information for one year. Study 2 showed that the interpretation of risk information was influenced by participants' own experiences with flooding. In Study 3, affect was experimentally manipulated. After looking at photographs depicting houses in a flooded region, participants perceived greater risk compared with participants in a control group. Taken together, the results of these three studies suggest that affect is important for successful risk communication. Results of the present research are in line with the affect heuristic proposed by Slovic and colleagues.

This paper presents experimental evidence that non-experts do not distinguish between macroeconomically relevant and irrelevant events in the way economic theory would suggest. Students were asked to predict the likely consequences of several events in fictitious newspaper reports on GDP, inflation, unemployment, and aggregate sales. They overestimate the effects of irrelevant events, especially if those events are easy to imagine. The magnitudes of the predicted effects are clearly related to the concreteness of the events. The results are compatible with the use of the availability heuristic in the process of forming economic expectations. [Copyright 2008 Elsevier B.V.]

By combining a theory of herding behavior with the phenomenon of availability heuristic, this paper shows that non-informative advertisements can affect people's choices by influencing their perception of product quality. We present a model in which people can learn about product quality by observing the choices of others. Consumers are, however, not able to fully distinguish between the observations of real people and fictitious characters in advertisements. Even if a person is aware of this limitation and updates his beliefs accordingly, it is still rational for him to choose the product he has observed most often. In equilibrium the most observed product is always most likely to be of the highest quality. The analysis has important policy implications.

In most Western economies, the flourishing of the Welfare State has coincided with a decline of the role of the family: divorce has been introduced, and the number of marriages has decreased. We suggest that a taboo against divorce was part of the informal safety net in a period when social protection was provided by the family. Once the State started offering suitable alternatives, the taboo was no longer expedient, and was dropped. For the same reasons, marriage has become less popular. We further notice that divorce is an extremely costly process, and once allowed it may act as an independent reason for the reduction of the number of marriages. This latter result is especially evident under the assumption that agents subjectively evaluate the probability of facing a divorce using an availability heuristic.

Travel demand models focus on explaining how much individuals actually travel but offer no insight into how much individuals think they travel. The authors propose that the latter is an important determinant of traveler behavior, and that actual mobility is refracted through a variety of filters that magnify or diminish those subjective evaluations of travel amounts. Linear regression models of subjective mobility measures provided by 1,358 San Francisco Bay Area commuters were estimated earlier; the focus of this article is on identifying the potential cognitive and affective mechanisms that influence subjective mobility upward or downward, after controlling for objective mobility. The authors find three major types of mechanisms: awareness-heightening, affective, and comparison-inducing. Recurring patterns of effects in these three categories are analyzed in the light of psychological and marketing research concepts including the availability heuristic, social comparison, relative deprivation, autobiographical memory, and motivation theory.

Experts on the risk of flooding have developed very detailed maps for different parts of Switzerland that indicate the types of damage possible and the probabilities of adverse events. Four categories of risk severity are defined on the maps, ranging from high risk to no risk. Based on these existing maps, we selected respondents for a mail survey, some from areas high in risk and others from low‐risk regions. Respondents answered several questions related to flood risk perception and preparedness. Survey results showed that respondents' risk perceptions were correlated with the experts' risk assessments. Respondents who lived in areas designated "no risk" by the experts had lower perceptions of risk than respondents who lived in areas with higher levels of designated risk. With regard to concrete prevention behavior, no differences between people living in different risk areas were observed. Survey results further suggest that many inhabitants do not know that flooding maps exist for their region. Results suggest that in some regions people overestimate the risks associated with flooding. Consequently, some people are more afraid of flooding than is justified by the facts. Some people show prevention behavior that most likely is superfluous. However, in other regions people underestimate the risks associated with flooding. These people do not show prevention behavior, and they are not well prepared for an adverse event. Furthermore, results suggest that respondents' experiences with flooding are positively related to their perceptions of flood risk. Findings of the present study are in line with the availability heuristic.

"We investigate whether the theory of strategic voting can explain voting behavior in a fairly common type of political system, multi-party systems with proportional representation, minimum vote thresholds, and coalition governments. In this paper, we develop a formal (computational) strategic voting game and show in a simulation that the model produces election scenarios and outcomes with desirable characteristics as well as different opportunities for strategic voting. We then test the decision-theoretic model in a laboratory experiment, taking into account both sophisticated and heuristic decision strategies. Participants with a purely instrumental (financial) motivation voted in a series of 25 independent elections. The availability of polls and coalition signals by parties was manipulated. The results show that voters are frequently able to make optimal or strategic vote decisions, but that voters also rely on simple decision heuristics and are highly susceptible to coalition signals by parties." (author's abstract)

Availability: Free download from the isoFinder project site: http://isofinder.sourceforge.net/ Web server: http://bioinfo2.ugr.es/IsoFinder ; Isochores are long genome segments relatively homogeneous in G+C. A heuristic algorithm based on entropic segmentation has been developed by our group, and a web server implementing all the required components is available. However, a researcher may want to perform batch processing of many sequences simultaneously in its local machine, instead of analyzing them on one by one basis through the web. To this end, standalone versions are required. We report here the implementation of two standalone programs, able to predict isochores at the sequence level: 1) a command-line version (IsoFinder) for Windows and Linux systems; and 2) a user-friendly version (IsoFinderWin) running under Windows. ; The IsoFinder project was supported by the Spanish Government (Grant No. BIO2005-09116-C03-01) and the Spanish Junta de Andalucía (Grants No. P06-FQM-01858, P07-FQM3163 and CVI-162).

We consider modeling and operational analysis of a generic asymmetric service-system situation in which (a) Red agents, potentially threatening, but possibly requiring assistance, arrive according to some partially known and possibly changing pattern in time and space; and (b) Reds are impatient: have effectively limited unknown deadlines or times of availability for Blue service, i.e., detection, classification, and attack in a military setting, or emergency assistance in other settings, such as medical care. We discuss various service options by Blue service agents and devise several approximations allowing one to compute efficiently proportions of tasks of different types that are successfully served or, more generally, if different rewards are associated with different types of tasks, the percentage of the possible reward gained. We suggest a heuristic policy for a Blue server to select the next task to perform and to decide how much time to allocate to that service. We discuss this and related policies for a number of specific examples.

Wireless communication is used in many different situations such as mobile telephony, radio and TV broadcasting, satellite communication, wireless LANs, and military operations. In each of these situations a frequency assignment problem arises with application specific characteristics. Researchers have developed different modeling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion. This survey gives an overview of the models and methods that the literature provides on the topic. We present a broad description of the practical settings in which frequency assignment is applied. We also present a classification of the different models and formulations described in the literature, such that the common features of the models are emphasized. The solution methods are divided in two parts. Optimization and lower bounding techniques on the one hand, and heuristic search techniques on the other hand. The literature is classified according to the used methods. Again, we emphasize the common features, used in the different papers. The quality of the solution methods is compared, whenever possible, on publicly available benchmark instances.

Wireless communication is used in many different situations such as mobile telephony, radio and tv broadcasting, satellite communication, wireless lans, and military operations. In each of these situations a frequency assignment problem arises with application specific characteristics. Researchers have developed different modeling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion.,this survey gives an overview of the models and methods that the literature provides on the topic. We present a broad description of the practical settings in which frequency assignment is applied. We also present a classification of the different models and formulations described in the literature, such that the common features of the models are emphasized. The solution methods are divided in two parts. Optimization and lower bounding techniques on the one hand, and heuristic search techniques on the other hand. The literature is classified according to the used methods. Again, we emphasize the common features, used in the different papers. The quality of the solution methods is compared, whenever possible, on publicly available benchmark instances.,.