Strict Coherence Research Articles

Adapting an XCT-scanner to enable edge illumination X-ray phase contrast imaging

Conventional X-ray computed tomography (XCT) is a non-destructive imaging technique to visualize and inspect the internal structure of materials in 3D, where materials are distinguished solely on the basis of their attenuation coefficient. However, with more specialized X-ray phase contrast imaging methods, sensitivity to complementary contrasts can be achieved, namely phase contrast and dark field contrast. Edge illumination X-ray phase contrast imaging (EI-XPCI) is a technique that is especially suited for laboratory application, because it has no strict coherence requirements for the source. While there is a wide variety of XCTscanners available on the market, a commercial EI-XPCI scanner does not yet exist. In this work, we present the procedure of outfitting an existing XCT-scanner with components to enable EI-XPCI scans and discuss the alignment procedure of these added components. Finally, phase contrast images are shown demonstrating the successful upgrade of a conventional XCT system with edge illumination based phase contrast possibilities.

Biographische Real-Fiktion als Paradigma narrativer Erklärung

Biographische Real-Fiktion als Paradigma narrativer Erklärung

THREE CHARACTERIZATIONS OF STRICT COHERENCE ON INFINITE-VALUED EVENTS

AbstractThis article builds on a recent paper coauthored by the present author, H. Hosni and F. Montagna. It is meant to contribute to the logical foundations of probability theory on many-valued events and, specifically, to a deeper understanding of the notion of strict coherence. In particular, we will make use of geometrical, measure-theoretical and logical methods to provide three characterizations of strict coherence on formulas of infinite-valued Łukasiewicz logic.

STRICT COHERENCE ON MANY-VALUED EVENTS

AbstractWe investigate the property of strict coherence in the setting of many-valued logics. Our main results read as follows: (i) a map from an MV-algebra to [0,1] is strictly coherent if and only if it satisfies Carnap’s regularity condition, and (ii) a [0,1]-valued book on a finite set of many-valued events is strictly coherent if and only if it extends to a faithful state of an MV-algebra that contains them. Remarkably this latter result allows us to relax the rather demanding conditions for the Shimony-Kemeny characterisation of strict coherence put forward in the mid 1950s in this Journal.

Weak Dutch Books with imprecise previsions

Uncertainty assessments for imprecise previsions based on coherence and related concepts require that the suprema of certain random numbers (interpreted as gains) are non-negative. The extreme situation that a supremum is zero represents what is called a Weak Dutch Book (WDB) in a betting interpretation language. While most of the previous dedicated literature focused on WDBs for de Finetti's coherence with precise probabilities, in this paper we analyse the properties of WDBs with imprecise previsions, notably for conditional (Williams') coherent lower previsions. We show that WDB assessments ensure a certain ‘local precision’ property and imply, in the agent's evaluation, some kind of ‘protection’ against real losses. Further, these properties vary with the consistency notion we adopt, tending to vanish with weaker ones. A generalisation of the classical strict coherence and other alternative approaches to WDBs are also discussed.

Strict coherence of conditional rewriting modulo axioms

Conditional rewriting modulo axioms with rich types makes specifications and declarative programs very expressive and succinct and is used in all well-known rule-based languages. However, the current foundations of rewriting modulo axioms have focused for the most part on the unconditional and untyped case. The main purpose of this work is to generalize the foundations of rewriting modulo axioms to the conditional order-sorted case. A related goal is to simplify such foundations. In particular, even in the unconditional case, the notion of strict coherence proposed here makes rewriting modulo axioms simpler and easier to understand. Properties of strictly coherent conditional theories, like operational equi-termination of the →R/B and →R,B relations and general conditions for the conditional Church–Rosser property modulo B are also studied.

A highly sensitive chemosensor for solution based on organic semiconductor laser gain media

Laser has been widely applied in the scientific and engineering areas including communications, medical treatment, industry, and military due to its extremely strict monochromaticity, high coherence and high energy density. Organic laser based on solution processable polymer gain media has attracted considerable attention in various applications due to its easy fabrication, compact system and flexibility. At present, the chemosensors based on organic semiconductor laser have been widely developed. It has been reported to achieve solution monitoring by organic DFB (distributed feedback) laser. Although the method has its own advantages, there are still many operability and craftsmanship problems to be resolved. In this paper we introduce a new type of the real-time monitoring for various solution. The monitor is realized by using amplified spontaneous emission (ASE) from optically pumped organic semiconductor gain media. The gain media comprising blends of poly(9, 9-dioctylfluorene-co-benzothiadiazole) (F8BT) and poly(3-hexylthiophene) (P3HT) at a ratio of 15:85 wt.% is dissolved into toluene (25 mg/mL). Thin films (90 nm thickness) of P3HT/F8BT are obtained by spin coating (2000 rpm) from solution onto pre-cleaned quartz substrates. The P3HT/F8BT film demonstrates the absorption peak at 471 nm, the PL peak at 622 nm, and the ASE peak at 661 nm with FWHM (full-width-at-half-maximum) linewidth of ～ 10 nm under the stripe laser pumping. The thin films are, then, covered by droplet of solution to form planar waveguide structure with variable effective refractive index. Upon analyte binding, a change in refractive index at the P3HT/F8BT film surface results in a change in the effective refractive index of the planar waveguide and in turn induces shift of the ASE mode wavelength and variation of ASE threshold of the organic gain media. The changes in ASE wavelength and threshold can be monitored for sensing. The red shift of 4.5 nm in the ASE spectrum is from 661 to 665.5 nm and the threshold increases from 0.579 J/pulse to 1.447 J/pulse which can be detected with the concentration of sodium chloride increasing from 0 to 25 wt.% in pure water. Our experimental results show that this method is easy to detect the concentration grads of 1 wt.% sodium chloride solution. The measurement sensitivity of solution reaches 97.8 nm/RIU (refractive index unit), and accuracy reaches 141.9 nm/RIU. Furthermore, we demonstrate that the chemosensor could be used for detecting different kinds of solution in the same concentration. The ASE peak position and threshold display clearly different when the droplet 10 wt.% sodium, chloride solution and hydromel solution onto P3HT/F8BT film. Our study suggests that the organic gain media films have potentiality to be developed as a high sensitivity and high accuracy chemosensor to detect solution due to the high sensitivity of the ASE peak position and threshold to the refractive index of the solution.

Strict Identity, Coherence, and Parallelism in VP Ellipsis

No abstract.

Is Strict Coherence Coherent?

Bayesians have a seemingly attractive account of rational credal states in terms of coherence. An agent's set of credences (degrees of belief) are synchronically coherent just in case they conform to the probability calculus. Some Bayesians impose a further putative coherence constraint called regularity: roughly, if X is possible, then it is assigned positive probability. I look at two versions of regularity – logical and metaphysical – and I canvass various defences of it as a rationality norm. Combining regularity with synchronic coherence, we have a set of constraints known as strict coherence. I argue that strict coherence is untenable. In particular, I attack regularity as a rationality norm. First, I rebut each of the various defences of regularity. Then I argue directly against regularity: it conflicts with the Bayesian decision-theoretic treatment of rational action. Thus, seemingly plausible theoretical and pragmatic norms turn out to be inconsistent.

E. Nesbit, Pathfinder

E. Nesbit, Pathfinder Rod McGillis (bio) E. Nesbit's Psammead Trilogy: A Children's Classic at 100, edited by Raymond E. Jones. Lanham, MD: Children's Literature Association and Scarecrow P, 2007. This collection of essays on E. Nesbit's Psammead novels is the third of four volumes in the Children's Literature Association's Centennial Studies series, published in association with Scarecrow Press, to celebrate well-known works for children. The other volumes are on Peter Rabbit, Baum's Oz books, and Peter Pan. In the future the series may feature less well-known works, which promises to complicate and enrich the making of a children's literature canon, something ChLA has been interested in for a long time. The choice of E. Nesbit's Psammead trilogy is especially suitable, then, for its role in inaugurating the modernist template for children's books. The first decade of the twentieth century in Britain sees other justly famous children's books—Burnett's A Little Princess (1905), and Grahame's The Wind in the Willows (1908)—but Nesbit's Psammead trilogy arguably constitutes the most influential of the books published in that decade in Britain. As writers in this volume point out, these books begin the time slip conventions so prevalent in recent children's books; they also combine fantasy and realism with social awareness and self-conscious narrative positioning. Even Nesbit's willingness to release her narratives from strict coherence and causality looks forward to a kind of plotting we might associate with more recent fiction than with the familiar kind of thing we see in the traditional bildungsroman. First, I note this volume's form. On the whole, the contents are free of typos and slips in grammar, the font is easy to read, and the page setup is serviceable. The margins might be somewhat larger than they are, but the book is certainly readable. What does strike me as an oversight is the absence of an index. The various chapters make reference to a great range of primary and secondary material, and an index would assist readers in locating, for example, discussions of Nesbit and C. S. Lewis or Nesbit and Fabianism, and so on. Scanning an index can prove useful in judging the thoroughness of a book, or it can bring surprises. We might not consider Nesbit a writer particularly receptive to psychoanalytic readings, but an index here would flag Freud and [End Page 228] Lacan for readers who might not read the book in its entirety. But I cavil; what matters is the strength of the various discussions, and these are uniformly impressive. The volume contains thirteen chapters plus the editor's introduction, in which Raymond Jones reviews Nesbit's critical reputation among her biographers and critics of children's literature. He also summarizes her life, and in doing so he raises pertinent issues relating to her work: her role as a woman writer, her formal innovations, and her socialist interests. With regard to the last of this list, Jones suggests: "If she was not always a penetrating or consistent social critic in her fiction, her concern with issues of class and poverty did add thematic depth to her stories, and this concern did pave the way for later writers to introduce serious social problems in books for children" (xiii). The comment that her work "did pave the way" for later writers to discuss weighty social matters implies that Nesbit was a pathfinder in her concern with "serious social problems." However, what we do not sufficiently see in the Nesbit presented in this book is her debt to earlier writers whose work confronts social issues such as poverty, class, economic exploitation, and race relations. We might argue that Nesbit is part of a tradition of socially conscious writing dating back to Mary Wollstonecraft and Anna Laetitia Barbauld, a tradition that includes such writers as John Ruskin, Frances Browne, Charles Dickens, George MacDonald, Charles Kingsley, Jean Ingelow, Augusta Webster, and Oscar Wilde. Many of the contributors to E. Nesbit's Psammead Trilogy focus on the influence of Fabianism on Nesbit's work without noticing the trail of writers behind her. Indeed, the Nesbit who emerges from this...

The Oxford Guide to Arthurian Literature and Legend by Alan Lupack (review)

ALAN LUPACK, The Oxford Guide to Arthurian Literature and Legend. Oxford: Oxford University Press, 2005. ISBN: 0-19-180287-9. $90. Alan Lupack's Guide to Arthurian Literature is a remarkably scrupulous attempt to document every surviving Arthurian textual monument from the earliest records to contemporary literary and musical compositions. He even acknowledges the contributions to the Arthurian corpus from such popular sources as pornography, painting, comic books, and Barbie dolls (see the complete list on p. 9). Even without an investigation of these intriguingly frivolous areas, the book is an impressive display of learning, compression, organization, and completeness. Lupack's Table of Contents provides the outline and guide to the organization of his book and if it appears to impose more coherence on his material than the notoriously unwieldy Arthurian corpus would seem to accommodate, it is nevertheless a necessary and functional heuristic that helps to guide the reader as well as the author through the masses of texts covered in this work. Chapter I, titled 'Early Accounts of Arthur, Chronicles and Historical Literature' is in itself a masterful achievement. In a mere 82 pages (including a Bibliography), Lupack surveys the remaining accounts (mostly enigmatic, dubious, or both) of the life and afterlife (the quondam et fitturus) of the historical Arthur and subsequent treatments of that history in verse, drama, and the novel from the Renaissance to the twentieth century. If, for most medievalists, there may be little new in the review of the ancient documents, there are bound to be revelations and surprises in at least some of the later treatments. The well-known is treated with admirable compression and efficiency, while the thoroughness of his investigation of the post-medieval treatments will undoubtedly lead most readers to texts previously unknown to them. The following section covers the traditional companion to the chronicles, the romances, and is similarly structured with a review of the medieval texts and an excursion into post-medieval materials. The strict coherence of Lupack's organizational structure breaks down at this point, however. The post-Chretien romances are subdivided into 'Lancelot and Guinevere,' 'Romances with Non-traditional Heroes, 'Lanval and Launfal,' 'Chastity Tests,' and 'Ballads.' While not quite as fanciful as Borges's description of the Chinese encyclopedia, there is a certain randomness to this division. Nevertheless, it serves the purpose of providing rubrics that allow Lupack to cover a vast array of romances and to defer the mass of material on Tristan, the Grail, etc., to fuller treatments in subsequent chapters. The following chapter, 'Malory, His Influence, and the Continuing Romance Tradition,' is the only one to concentrate on a single author (and his literary descendants). …

Reference-beam storage for long-range low-coherence pulsed Doppler lidar

We present a laser Doppler velocimeter that stores and delays the reference beam to preserve coherence with a long-path-length measurement beam. Our storage and delay technique relaxes the strict coherence requirements associated with lidar laser sources, permitting the use of low-coherence lasers. This technique potentially could reduce the cost and size of lidar systems for commercial applications. Experiments that use fiber-optic ring resonators to store the reference beams and generate reference pulse trains validated the concept. We obtained results at several simulated distances by beating each usable reference pulse with a delayed Doppler-shifted measurement beam reflected off a rotating mirror.

Strict coherence, sigma coherence and the metaphysics of quantity

In 1955 Abner Shimony introduced a strong notion of coherence which has become known as strict coherence. It is a variation on a theme by Ramsey and de Finetti: that of testing the coherence of your system of beliefs by seeing how much damage can be done by a cunning bettor with a finite number of bets, each of which you take to be fair. The bettor makes a Dutch Book against you if his bets taken together guarantee that you must suffer a loss; that is to say that no matter what the outcomes of the events upon which bets are placed you suffer a net loss. Let us say that a bettor makes a Weak Dutch Book against you if you can suffer a loss but cannot enjoy a gain: that is to say that there are possible outcomes of the events on which bets are made such that you suffer a net loss and no such outcomes which yield a net gain. If no Dutch book can be made against you, your beliefs are coherent; if- in addition no weak Dutch book can be made against you, your beliefs are strictly coherent. Betting quotients are coherent if and only if they are finitely additive probabilities. They satisfy the stronger requirement of strict coherence if and only if they are finitely additive probabilities which assign a positive probability to every possible event (Kemeny 1955). Coherence is a pragmatic consistency condition. Strict coherence adds to this a requirement of open-mindedness. The strictly coherent agent does not assign probability zero to anything unless it is must be judged impossible by virtue of the underlying Boolean logic. Strict coherence is epistemologically attractive and was easily implementable in the context of finite Carnapian inductive logic in which it was introduced. But

Possibility and probability

De Finetti was a strong proponent of allowing 0 credal probabilities to be assigned to serious possibilities. I have sought to show that (pace Shimony) strict coherence can be obeyed provided that its scope of applicability is restricted to partitions into states generated by finitely many ultimate payoffs. When countable additivity is obeyed, a restricted version of ISC can be applied to partitions generated by countably many ultimate payoffs. Once this is appreciated, perhaps the compelling character of the Shimony argument will be less overwhelming and the attractiveness of de Finetti's more permissive attitude will become more apparent. I want to push the permissive tendency in de Finetti still further. It seems doubtful that RUIWC should be required as de Finetti apparently suggested. It is also excessively dogmatic and restrictive to require that the credal states of ideally situated rational agents be numerically definite (Levi 1974, 1980). And de Finetti's rejection of objectivism in statistics overreached itself when he dismissed objective probabilities as meaningless metaphysical artefacts (Levi 1986). In this respect, the philosophically most important lessons de Finetti has to teach us are to be found not in his celebrated representation theorem but in his discussions of the relations between 0-probability and possibility, conditional probability and countable additivity. Perhaps, the technical issues involved are remote and pedantic. But the attitude de Finetti sought to inculcate is of profound importance.

From Aristotle to Darwin and Bach Again: A Journey in Final Causality, Species, and Evolution by Etienne Gilson

318 BOOK REVIEWS relativism is false, then there is a very real sense in which the ethical relativist is a moral skeptic and would not be able to believe any moral truths, that is, have any moral beliefs of his own. Whatever practical difficulties an ethical relativist would face when confronted with the fact that he cannot believe that any course of action is better than any other need not be considered here, but it certainly does not seem to be a comfortable situation. Jack W. Meiland and Michael Krausz's Relativism is an excellent book. Besides the essays discussed here, there are essays by Davidson, Doppelt, Lyons, and Harrison. There is also a useful bibliography and helpful index. The importance of the articles, together with the well-written introductions that the editors provide, makes this a book that evry philosopher should have at hand. DOUGLAS B. RASMUSSEN St. John's University New York City, New York From Aristotle to Darwin and Back Again: A Journey in Final Causality, Species, and Evolution. By ETIENNE GILSON. Translated by J. Lyon. Notre Dame, Ind.: University of Notre Dame Press, 1984. Pp. xx + 203 + Index. $23.00 (cloth). This work is a translation of Gilson's D'Aristote aDarwin et Retour: Essai sur Quelques Constantes de la Biophilosophie (Paris: J. Vrin, 1971). The work has been rendered into very readable English by John Lyon, who has also done yeoman service in his completions, augmentations, and corrections of Gilson's original set of notes, tasks which sorely needed doing. There is also an Introduction by S.L. Jaki, providing a brief uverview of Gilson's career, philosophical interests and methods, and the contents and purpose of the work. Why the long delay in making this work available to English-speaking readers f I can see several reasons that might be offered for not bothering to translate the work at all. It lacks the strict coherence and integrity of intellectual development we are so used to finding in Gilson's written material. The central and longest (58 pages) chapter, Chapter Three, " Finality and Evolution," for instance, could easily stand as a separate rssay, as is true of some of the others. Also, Gilson is not as cautious in this work, when it comes to giving evaluations of the intentions of various authors, as he has been in the past. The harsh judgment he passes on Malthus, for example, does not seem fully justified, something noted by Lyon (p. 181). In addition, soon after its appearance in French, the work was outdated in certain ways. By the middle 1970s, Darwinian BOOK REVIEWS 319 scholarship was witnessing a new outburst of activity, such as the publication of Darwin's early notebooks, the re-evaluation of Darwin's supposed atheism, and the debate (which still continues) over punctuated equilibriumism and gradualism in which Gilson's work does not participate. However, in my opinion, these reasons for not publishing the work in English are by and large irrelevant. Its main strength, after all, is its powerful x-ray vision approach to certain constant problems in the philosophy of animate nature. I see two main themes in the book. One is the emphasis upon the fact of teleology in nature, a fact to which those who verbally denounce teleo~ogy (usually because they misunderstand it in the first place) are forced to return over and over again. The other is the role of anthropomorphism in the rational evaluation of the relationship between art and nature. In an earlier work, God and Philosophy, Gilson had pointed out that anthropomorphism in natural theology was really not such a bad thing, because it is quite unavoidable, and in fact serves the very fundamental purpose of preserving a minimal personalism (the essential presence of intellect and will) in our understanding of superhuman beings. Chapter Four of God and Philosophy is very much concerned with anthropomorphism and teleology in contemporary thought, and the present work can be viewed as an expansion, up-dating, ru1d development of that chapter in reference to the history of modern (1750-1970) biology. Roughly speaking, the work under review pictures Aristotle's four causes as being divided up, so to...

Source encoding, signal sampling and spectral band filtering for partially coherent optical signal processing

Relations between coherence requirement, spectral filtering, signal sampling, and source encoding are discussed. Since the spatial coherence requirement is determined by the signal processing operation, a strict spatial coherence is usually not required. The advantage of the source encoding is to relax the constraints of a physical light source so that the signal processing can be carried out with an extended incoherent source. The effect of signal sampling is to improve the temporal coherence requirement at the Fourier plane so that the spatial filtering can be carried out with a partially coherence mode. The objective of broad spectral band filtering is to carry out the signal processing over the entire spectral band of the light source so that the coherent noise can be eliminated. Since the partially coherent optical processor utilizes a broad spectral band white-light source, it is particularly suitable for color signal processing. Experimental demonstrations for the source encoding, signal sampling and spectral band filtering are included.

Source encoding for partially coherent optical processing

A relation between spatial coherence function and source encoding intensity transmittance function is presented. Since the spatial coherence is depending upon the information processing operation, a strictly broad spatial coherence function may not be required for the processing. The advantage of the source encoding is to relax the constraints of strict coherence requirement, so that the processing operation can be carried out with an extended incoherent source. Emphasis of the source encodings and experimental demonstrations are given. The constraint of temperal coherence requirement is also discussed.

Modifying a coherent optical processing system to achieve a measure of redundancy

A coherent optical processing system is usually nonredundant because any attempt to secure redundancy by band-limiting the input leads to a corresponding underuse of the Fourier plane. Methods are suggested for putting additional copies of the signal into the unused region. This results in a certain departure from strict coherence but is in no case as extreme as using noncoherent methods.

Discussion: On Falling Short of Strict Coherence

Abner Shimony called it coherence; John Kemeny called it strict fairness; today many people speak of strict coherence. According to Shimony's definition, a set of betting rates on a series of propositions hi and ei is strictly incoherent, when “there exists a choice of stakes Si such that, if X accepts the series of bets at these stakes, then no matter what the actual truth values of hi, and ei may be, X can at best lose nothing, and in at least one possible eventuality he will suffer a positive loss” ([3], p. 9).