Fuzzy reasoning in the investigation of seismic behavior

In this paper, we propose a fuzzy logic–based mathematical model of a sequence of earthquakes using fuzzy reasoning tools. We formed a set of fuzzy implications in order to study them, and we computed their deviation, so that we could compare them and conclude about the most accurate one. The compositional rule of inference was considered, which is based on the generalized modus ponens scheme. The new fuzzy methodology was used for each implication. The data required for the implications were obtained from the aftershocks of an earthquake with significant effects in a specific area. The magnitude of the aftershocks and their time difference from the main incident provided the values for the new fuzzy algorithm application. Two samples were selected relative with the seismic activity, which occurred the following days. The one sample consisted of 30 values, and the other sample from all the values found in the data archives of the National Observatory of Athens. Results were shown for both samples. So a mathematical technique, which reproduces the incidents using basic information and based on only two parameters, is developed for the simulation of a seismic sequence, which follows a strong earthquake.     

Truncated Distributive Lattices: Conceptual Structures of Simple-Implicational Theories

Logical relationships in everyday human thought are predominantly inferences with one-element premises. This becomes apparent in the practice of Formal Concept Analysis by the frequent occurrence of truncated distributive lattices as concept lattices. This paper gives a mathematization of the underlying everyday theories of logical relationships and elaborates useful mathematical results, in particular about algorithmically drawing concept lattices which correspond to the everyday logical theories. This revised version was published online in June 2006 with corrections to the Cover Date.     

Expert opinion on nanotechnology: risks,benefits, and regulation

A survey of American (US) nanotechnology researchers (N = 177) suggests a diversity of views about what areas are most important to the burgeoning field, as well as perceptions about the overall benefits and risks of such research. On average, respondents saw a range of technologies as key and viewed public health and environmental issues as areas where both risks and the need for regulation are greatest. These areas were also where respondents said current regulations were least adequate. Factor analyses of the survey questions suggest that, when considering both risks and regulations, respondents make a distinction between health and environmental risks, and what might be termed “social risks” (e.g., invasion of privacy, use of nanotechnology in weapons, and economic impacts).

Public perceptions about nanotechnology: Risks,benefits and trust

We report data from the first representative national phone survey of Americans' perceptions about nanotechnology (N =1536). Public opinion about nanotechnology is in its infancy, and knowledge about it is quite limited. Yet, Americans' initial reaction to nanotechnology is thus far generally positive, probably rooted in a generally positive view of science overall. Survey respondents expected benefits of nanotechnology to be more prevalent than risks, and they reported feeling hopeful about nanotechnology rather than worried. Their most preferred potential benefit of nanotechnology is new and better ways to detect and treat human diseases, and they identified losing personal privacy to tiny new surveillance devices as the most important potential risk to avoid. The most discouraging aspect to the data is respondents' lack of trust in business leaders to minimize nanotechnology risks to human health. Overall, these data indicate that while Americans do not necessarily presume benefits and the absence of risks, their outlook is much more positive than not.     

Cytotoxic and radiosensitizing effects of nano-C<Subscript>60 </Subscript>on tumor cells in vitro

There is growing evidence in recent years that the pristine fullerene may be endowed with strong pro-oxidant capacity to biological samples. In this investigation we tested the hypothesis that water-soluble fullerene-C₆₀ (nano-C₆₀) may interact with ionizing radiation enhancing its antiproliferative effects. The two tumor cell lines with different radiosensitivity B16 and SMMU-7721 were treated by a combination of pristine fullerene and ⁶⁰Co γ irradiation. We measured cell survival rates, apoptotic characteristics, reactive oxygen species (ROS) production and alteration of cell diameter with or without γ-irradiation. There was reduced survival with B16 and SMMU-7721 cells exposed to nano-C₆₀, with the inhibitory concentrations reducing the viability by 50% to 65 part per billion (ppb) and 150 ppb respectively. For cells exposed to nano-C₆₀ prior to γ-irradiation, damage to cell membranes and increased numbers of apoptotic cells were detected by morphologic Hoechst-staining analysis and Annexin V/propidium iodide double-staining. In cells exposed to nano-C₆₀, there were increased levels of ROS, as measured by fluorescence detection under laser confocal microscopy. Preincubation with non-toxic pristine C₆₀ before γ-ray caused enlargement of cells with increased diameter. The results show that nano-C₆₀ inhibits the growth of tumor cells at certain concentrations and increases the effects of ⁶⁰Co γ-irradiation, possibly through the elevated production of cellular ROS and the membrane disruption. Data in this study indicates a possible consideration of using C₆₀ as a candidate of sensitization modifier in tumor radiation biology.     

Protecting workers and the environment: An environmental NGO’s perspective on nanotechnology

Nanotechnology, the design and manipulation of materials at the atomic scale, may well revolutionize many of the ways our society manufactures products, produces energy, and treats diseases. New materials based on nanotechnology are already reaching the market in a wide variety of consumer products. Some of the observed properties of nanomaterials call into question the adequacy of current methods for determining hazard and exposure and for controlling resulting risks. Given the limitations of existing regulatory tools and policies, we believe two distinct kinds of initiatives are needed: first, a major increase in the federal investment in nanomaterial risk research; second, rapid development and implementation of voluntary standards of care pending development of adequate regulatory safeguards in the longer term. Several voluntary programs are currently at various stages of evolution, though the eventual outputs of each of these are still far from clear. Ultimately, effective regulatory safeguards are necessary to provide a level playing field for industry while adequately protecting human health and the environment. This paper reviews the existing toxicological literature on nanomaterials, outlines and analyzes the current regulatory framework, and provides our recommendations, as an environmental non-profit organization, for safe nanotechnology development.     

Triple I method of approximate reasoning on Atanassov's intuitionistic fuzzy sets

Two basic inference models of fuzzy reasoning are fuzzy modus ponens (FMP) and fuzzy modus tollens (FMT). The Triple I method is a very important method to solve the problems of FMP and FMT. The aim of this paper is to extend the Triple I method of approximate reasoning on Atanassov's intuitionistic fuzzy sets. In the paper, we first investigate the algebra operators' properties on the lattice structure of intuitionistic fuzzy information and provide the unified form of residual implications which indicates the relationship between intuitionistic fuzzy implications and fuzzy implications. Then we present the intuitionistic fuzzy reasoning version of the Triple I principles based on the models of intuitionistic fuzzy modus ponens (IFMP) and intuitionistic fuzzy modus tollens (IFMT) and give the Triple I method of intuitionistic fuzzy reasoning for residual implications. Moreover, we discuss the reductivity of the Triple I methods for IFMP and IFMT. Finally, we propose α-Triple I method of intuitionistic fuzzy reasoning.     

Systemic cost-effectiveness analysis of food hazard reduction – Campylobacter in Danish broiler supply

An integrated microbiological–economic framework for policy support is developed to determine the cost-effectiveness of alternative intervention methods and strategies to reduce the risk of Campylobacter in broilers. Four interventions at the farm level and four interventions at the processing stage are considered. Cost analyses are conducted for different risk reduction targets and for three alternative scenarios concerning the acceptable range of interventions. Results demonstrate that using a system-wide policy approach to risk reduction can be more cost-effective than a policy focusing purely on farm-level interventions. Allowing for chemical decontamination methods may enhance cost-effectiveness of intervention strategies further.     

Ethics in OR/MS: past,present and future

The pervasiveness and impact on society and on every day human life of technology has led to a growing awareness that science and technology cannot be considered above or beyond the realm of value judgements and hence of ethics. This is especially true for Operations Research/Management Science (OR/MS), that particular science which is concerned with methodologies for scientifically deciding how to design and operate man-machine systems in an optimal way, usually under conditions requiring the allocation of scarce resources. Here we try to give a historical account of the growing interest for ethics within the OR/MS community from its birth to present days. Starting from attempts to define models and codes of ethical behaviour in our profession, the OR/MS community has arrived at more fundamental questions about the ethical responsibility it faces in a world of growing inequalities and in which the ever greater stress that human activities impose on the environment puts at risk the very survival of human kind. This paper appeared in 4OR 2, 95–110, 2004.     

Equitable birthdate categorization systems for organized minor sports competition

In some organized minor sports programs where there is early competitive streaming, players born early in the year are more likely to reach elite levels than those born late in the year. This is generally attributed to the calendar year system most minor sports programs use to group players for the purposes of competition. In this paper I show how to devise more equitable systems based only on player ages. These systems rotate the relative age advantage so that those players born late in the calendar year are not always the youngest players in their age division.