Average Interest Rate Caps

There exist a number of approximation methods for the price of average rate options, when the underlying asset is a currency or equity. Realistic pricing models for average interest rate caps based on interbank offered rates have not yet been published. In this paper we propose to adapt the methods of Levy (1992), Vorst (1992) and Rogers and Shi (1995) for average rate options to price average interest rate caps, and we compare their computational efficiencies. All three methods are very fast, compared to the Monte Carlo simulation. Two of them are fast enough for on-the-fly calculations. The underlying interest rate model we use is consistent with the observed term structure of the interest rate. Hence, the models developed here are suitable for practical implementation.     

Registering Landsat images by point matching

Image registration of Landsat Thematic Mapper scenes with translational and rotational differences is studied. Two major steps of image registration, control-point selection and control-point matching, are emphasized. In control-point selection, the properties that a good control point should satisfy are defined. Several potential control-point candidates are suggested, and methods are discussed for extracting them from the input image. In control-point matching, a relaxation algorithm proposed in the literature is improved by reducing its time complexity from O(n⁴) to O(n³ ), where n is the number of control points. The matching algorithm also uses a two-way matching concept which utilizes the inherent symmetry property of the point-matching problem. The robustness of the proposed algorithm was demonstrated through simulation experiments by evaluating a matching index. Experimental results on Landsat images show that the proposed method produces results comparable to those obtained by an experienced photointerpreter     

Comparison of manual control methods for space manipulator positioning tasks

The Russian Segment of the International Space Station will be equipped with a 10 m long anthropomorphic space manipulator with six degrees of freedom. The robot is called the European Robot Arm, or ERA. Its hand, or end-effector, contains a camera which will be used for fine positioning of the end-effector, in order to grasp an object. At the Delft University of Technology, a human-machine interface for manual control of the ERA is being developed. The control device is a Spaceball controller, which is used to control the spatial end-effector velocity. This article describes four control methods that transform the Spaceball movements into movements in the end-effector camera picture. The control methods are compared by means of human-machine experiments. The results are also useful in many other areas of spatial manipulation, like undersea robots, robots in the nuclear industry, and minimally invasive surgery.     

An experimental study to evaluate the effectiveness of different methods and intensities of law enforcement on driving speed on motorways

Two field experiments were conducted to establish the most effective method of enforcement in reducing driving speed and to establish the most efficient strategy in terms of police force personnel required. In the first experiment, the effect of three variables on driving speed on motorways was studied. The first variable, intensity of enforcement, was manipulated by creating three different objective levels of apprehension for detected speeding drivers. The second variable was method of enforcement. On-view stopping and ticketing of offenders was compared to mailing of fines on the basis of the car's licence plate number. The third variable manipulated was the time delay in the mailing of fines. Time delay between detection of the offence and feedback to the driver was shortened in one condition. In a second experiment, police enforcement effort was optimized by relating intensity level of enforcement to the proportion of speeding vehicles. In the first experiment, police enforcement was applied for four weeks; in the second experiment, enforcement activities were continued for 12 consecutive weeks. In both cases the main dependent variable was driving speed. Before, during, and after the application of enforcement, speed was registered using induction loops. In addition, driver opinion about speeding and speed enforcement was studied using postal questionnaire surveys. The results show the largest and longest lasting reduction in driving speed in the highest intensity level-condition, giving support for a relation between objective chance of apprehension and speed choice. On-view stopping of offenders was shown to be a more effective method to reduce driving speed than mailing of fines. Some of these results are discussed in the light of game theory. The questionnaire surveys indicated that most drivers did not notice the recurrence in enforcement activities due to infrequent passing of the sections of motorways studied. The preventive effect of police enforcement appeared to be far more substantial than its repressive effect. Enforcement primarily deters the current nonoffender from speeding.     

Human and simian T-cell leukemia viruses type 2 (HTLV-2 and STLV-2(pan-p)) transform T cells independently of Jak/STAT activation

Human T-lymphotropic virus type 1 (HTLV-1) and HTLV-2 differ in pathogenicity in vivo. HTLV-1 causes leukemia and neurologic and inflammatory diseases, whereas HTLV-2 is less clearly associated with human disease. Both retroviruses transform human T cells in vitro, and transformation by HTLV-1 was found to be associated with the constitutive activation of the Jak/STAT pathway. To assess whether HTLV-2 transformation may also result in constitutive activation of the Jak/STAT pathway, six interleukin-2-independent, HTLV-2-transformed T-cell lines were analyzed for the presence of activated Jak and STAT proteins by electrophoretic mobility shift assay. In addition, the phosphorylation status of Jak and STAT proteins was assessed directly by immunoprecipitation and immunoblotting with an antiphosphotyrosine antibody. Jak/STAT proteins were not found to be constitutively activated in any of the T-cell lines infected by the type 2 human and nonhuman primate viruses, suggesting that HTLV-2 and the cognate virus simian T-lymphotropic virus type 2 from Pan paniscus transform T cells in vitro by mechanisms at least partially different from those used by HTLV-1.     

Lexical effects in phonemic processing: Facilitatory or inhibitory?

This article addresses the questions of how and when lexical information influences phoneme identification in a series of phoneme-monitoring experiments in which conflicting predictions of autonomous and interactive models were evaluated. Strong facilitatory lexical effects (reflected by large differences in detection latencies to targets in words and matched nonwords) were found only when targets came after the uniqueness point of the target-bearing word. Furthermore, no evidence was obtained for lexically mediated inhibition on phoneme identification as predicted by the interactive activation model TRACE. These results taken together point to strong limitations in the way in which lexical information can affect the perception of unambiguous speech. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oral tissue response to ovine grafting biomaterial: Morphological and morphometric study using scanning electron and light microscopy tissue response to ovine grafting biomaterial

OBJECTIVE: To evaluate the oral tissue response to an experimental particle ovine biomaterial by scanning electron microscopy (SEM) and light microscopy (LM). MATERIAL AND METHODS: Forty‐eight rats had surgical periodontal defects treated with either blood clotting (control), bovine biomaterial? (B), or an experimental ovine biomaterial (O). Data from SEM analysis (defect exposure, root surface exposure, diameter of matrix fibers and bundles, and globuli areas; n = 5) were applied to Shapiro–Wilk, Kruskal–Wallis, and Dunn's test, whereas LM analysis (tissue cicatrization characteristics and diameter defect; n = 3) had data applied to two‐way analysis of variance. Animals were monitored for 1 and 3 weeks. RESULTS: By SEM, the O samples showed significant differences from B and C in the area of defect exposure (H_2,15 = 8.66; P < 0.05). In both periods, O and B samples showed similar results for matrix fiber diameters, differently than C samples (H_2,15 = 14.0; P < 0.05). All other SEM variables were considered equivalent among the groups (P > 0.05). Under LM, an acute and chronic granulomatous inflammation was seen in the presence of both biomaterials (B and O, 1 week); both the control and the ovine grafting samples showed mature bone in the repair site (3 weeks); the defect diameter showed similar values among groups, at both monitoring periods (F_2,12 = 1.0401; P > 0.05). CONCLUSION: The ovine particles of this study showed a favorable response to oral tissue repair, demonstrating to be a potential source for the development of bone grafting biomaterials. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

Preserving architectural decisions through architectural patterns

Architectural decisions have emerged as a means to maintain the quality of the architecture during its evolution. One of the most important decisions made by architects are those about the design approach such as the use of patterns or styles in the architecture. The structural nature of this type of decisions give them the potential to be controlled systematically. In the literature, there are some works on the automation of architectural decision violation checking. In this paper we show that these works do not allow to detect all possible architectural decision violations. To solve this problem we propose an approach which: (i) describes architectural patterns that hold the architectural decision definition, (ii) integrates architectural decisions into an architectural model and, (iii) automates the architectural decision conformance checking. The approach is implemented using Eclipse modeling framework and its accompanying technologies. Starting from well-known architectural patterns, we show that we can formalize all those related to the structural aspect. Through two evaluations, we show that our approach can be adapted to different architecture paradigms and allows to detect more violations comparing to the existing approaches.