Miracle-dz/UniFAR-FTUs huggingface dataset:
Dealing with misbehavior in distributed systems: a game-theoretic approach

Most distributed systems comprise autonomous entities interacting with each other to achieve their objectives. These entities behave selfishly when making decisions. This behavior may result in strategical manipulation of the protocols thus jeopardizing the system wide goals. Micro-economics and game theory provides suitable tools to model such interactions. We use game theory to model and study three specific problems in distributed systems. We study the problem of sharing the cost of multicast transmissions and develop mechanisms to prevent cheating in such settings. We study the problem of antisocial behavior in a scheduling mechanism based on the second price sealed bid auction. We also build models using extensive form games to analyze the interactions of the attackers and the defender in a security game involving honeypots. Multicast cost sharing is an important problem and very few distributed strategyproof mechanisms exist to calculate the costs shares of the users. These mechanisms are susceptible to manipulation by rational nodes. We propose a faithful mechanism which uses digital signatures and auditing to catch and punish the cheating nodes. Such mechanism will incur some overhead. We deployed the proposed and existing mechanisms on planet-lab to experimentally analyze the overhead and other relevant economic properties of the proposed and existing mechanisms. In a second price sealed bid auction, even though the bids are sealed, an agent can infer the private values of the winning bidders, if the auction is repeated for related items. We study this problem from the perspective of a scheduling mechanism and develop an antisocial strategy which can be used by an agent to inflict losses on the other agents. In a security system attackers and defender(s) interact with each other. Examples of such systems are the honeynets which are used to map the activities of the attackers to gain valuable insight about their behavior. The attackers want to evade the honeypots while the defenders want them to attack the honeypots. These interesting interactions form the basis of our research where we develop a model used to analyze the interactions of an attacker and a honeynet system.
FEHMN 1.0: Finite element heat and mass transfer code; Revision 1

A computer code is described which can simulate non-isothermal multi-phase multicomponent flow in porous media. It is applicable to natural-state studies of geothermal systems and groundwater flow. The equations of heat and mass transfer for multiphase flow in porous and permeable media are solved sing the finite element method. The permeability and porosity of the medium are allowed to depend on pressure and temperature. The code also has provisions for movable air and water phases and noncoupled tracers; that is, tracer solutions that do not affect the heat and mass transfer solutions. The tracers can be passive or reactive. The code can simulate two-dimensional, two-dimensional radial, or three-dimensional geometries. A summary of the equations in the model and the numerical solution procedure are provided in this report. A user`s guide and sample problems are also included. The FEHMN (Finite Element Heat and Mass Nuclear) code, described in this report, is a version of FEHM (Finite Element Heat and Mass, Zyvoloski et al., 1988) developed for the Yucca Mountain Site Characterization Project (YMP). The main use of FEHMN will be to assist in the understanding of flow fields in the saturated zone below the potential Yucca Mountain repository.
Multi SLMs holographic display with inclined plane wave illumination

Holography can store full wide angle information about a registered object, since during registration process information about amplitude and phase of an optical wave scattered from an object is captured. Because of this unique feature people put hope in holography as the method which can be utilized in a 3D imaging display. In the paper we present the design of a wide viewing angle display system utilizing multiple Spatial Light Modulators (SLMs). The system is capable of displaying objects from both virtual and real worlds. In our system we are using phase only reflective SLMs based on liquid crystal on silicon (LCoS). There are designed to work with normal illumination. However in order to simplify an optomechanical system of the display here the SLMs are used with an inclined plane wave illumination. Therefore in the paper at first we focus on determination of a tilt depended SLM calibration, so thus SLM even with highly off axis inclined illumination is capable of an accurate wave reproduction. Then we focus on obtaining high quality reconstruction of objects from virtual world. We present an algorithm based on Gerchberg-Saxton scheme and diffraction computing between tilted and parallel planes. All of the paper discussions are accompanied with experimental results obtained in the multi SLMs display.
DEMONSTRATION OF SIMULATED WASTE TRANSFERS FROM TANK AY-102 TO THE HANFORD WASTE TREATMENT FACILITY

In support of Hanford's AY-102 Tank waste certification and delivery of the waste to the Waste Treatment and Immobilization Plant (WTP), Savannah River National Laboratory (SRNL) was tasked by the Washington River Protection Solutions (WRPS) to evaluate the effectiveness of mixing and transferring the waste in the Double Shell Tank (DST) to the WTP Receipt Tank. This work is a follow-on to the previous 'Demonstration of Internal Structures Impacts on Double Shell Tank Mixing Effectiveness' task conducted at SRNL 1. The objective of these transfers was to qualitatively demonstrate how well waste can be transferred out of a mixed DST tank and to provide insights into the consistency between the batches being transferred. Twelve (12) different transfer demonstrations were performed, varying one parameter at a time, in the Batch Transfer Demonstration System. The work focused on visual comparisons of the results from transferring six batches of slurry from a 1/22nd scale (geometric by diameter) Mixing Demonstration Tank (MDT) to six Receipt Tanks, where the consistency of solids in each batch could be compared. The simulant used in this demonstration was composed of simulated Hanford Tank AZ-101 supernate, gibbsite particles, and silicon carbide particles, the same simulant/solid particles used in themore » previous mixing demonstration. Changing a test parameter may have had a small impact on total solids transferred from the MDT on a given test, but the data indicates that there is essentially no impact on the consistency of solids transferred batch to batch. Of the multiple parameters varied during testing, it was found that changing the nozzle velocity of the Mixer Jet Pumps (MJPs) had the biggest impact on the amount of solids transferred. When the MJPs were operating at 8.0 gpm (22.4 ft/s nozzle velocity, U{sub o}D=0.504 ft{sup 2}/s), the solid particles were more effectively suspended, thus producing a higher volume of solids transferred. When the MJP flow rate was reduced to 5 gpm (14 ft/s nozzle velocity, U{sub o}D = 0.315 ft{sup 2}/s) to each pump, dead zones formed in the tank, resulting in fewer solids being transferred in each batch to the Receipt Tanks. The larger, denser particles were displaced (preferentially to the smaller particles) to one of the two dead zones and not re-suspended for the duration of the test. As the liquid level dropped in the MDT, re-suspending the particles became less effective (6th batch). The poor consistency of the solids transferred in the 6th batch was due to low liquid level in the MDT, thus poor mixing by the MJPs. Of the twelve tests conducted the best transfer of solids occurred during Test 6 and 8 where the MJP rotation was reduced to 1.0 rpm. « less
Phase distortion due to airflow over a hemispherical laser turret

Abstract : Compressible flow over a laser turret creates a phase distortion. To gain insight to this problem a model of a hemispherical turret is developed. The flow field is obtained using a second order solution based on Janzen-Rayleigh expansion for the compressible potential flow equation. Contours of constant phase distortion were calculated; results at the critical Mach number are presented and discussed. It was found that the distortion at 0 degree elevation angle was equivalent to a positive lens whereas at 90 degrees the distortion is similar to a negative lens. At 45 degrees the main effect is beam tilting into the wind. For a ratio of beam radius to turret radius equal to 0.5, the focal length at beam elevation angle of 0 degrees is 16.5km. At beam elevation of 54 degrees the beam tilt was found to be 26.5 microradians. Cruise missiles with intercontinental ranges may use celestial navigation which requires precise measurement of angular location of stars. A distorted lens created by the ambient flow field causes an error in measurement. Knowledge of the external aerodynamics is important.
Developing a numerical model for the design of sheet pilewalls

This project involves the investigation, development and validation of cantilevered and anchored sheet pile wall models. The effect of sheet pile construction penetrating a sandy soil are investigated by analysing numerical outputs such as the wall deformation, ground settlement and maximum bending moment. The numerical analysis is completed using an industrially known computer software program: Fast Lagrangian Analysis of Continua (FLAC). The quality of the FLAC models used to obtain the numerical solutions was validated for accuracy against available analytical solutions. The aims of this project were to gain sufficient knowledge on sheet pile wall design methods, better known as the limit equilibrium methods; develop an automatic Excel spreadsheet as a design tool for solving any sheet pile wall design problem; and be able to easily validate the accuracy of the obtained numerical solutions by comparing the numerical and analytical solutions. The main focus of the investigation was to develop new cantilever and anchored sheet pile wall models for a specific geotechnical problem of a sheet pile penetrating a sandy soil in the presence of a water table. This was done by validating the numerical models and undertaking parametric studies varying specific parameters to investigate thoroughly the behaviour of the sheet pile wall system. This research concludes that the analytical methods provide a basic understanding of the soil-wall system behaviour; however, the hypothesis on which these methods are based makes them necessarily conservative, due to the number of assumptions required to simplify the design procedure. Numerical modelling in FLAC produces more accurate results and, by undertaking advanced parametric studies, indicates the actual behaviour of the soil-wall system in the real world. The development of numerical models, undertaking of parametric studies and validation of solutions by comparing against analytical method solutions are areas deserving of further research, as this will lead to more effective sheet pile wall designs in the engineering industry.
The future of mobile learning in the Nigerian education system

Mobile phones have the potential to improve educati on for the millions of underprivileged users in the developing world. Howe ver, the subjects of mobile learning in the developing countries have not been largely studied. This article presents a perfect vehicle for making educational opportunit ies accessible to students in places and times that are more convenient than formal scho oling, focusing on the Nigerian context. We conducted a study to investigate the ex tent to which students in the developing countries make use of mobile phones to access educational content. Our study shows a reasonable level of learning and moti vation. We also report on the social context surrounding the results. The objective of t his study is to examine the feasibility of mobile learning in in and out-of-school settings in the developing countries with Nigeria as the context of our study.
Needle Sharing and HIV Transmission: A Model with Markets and Purposive Behavior

Without well designed empirical studies, mathematical models are an important way to use data on needle infection for inferences about human infection. We develop a model with explicit behavioral foundations to explore an array of policy interventions related to HIV transmission among IDU. In our model, needle exchanges affect the spread of HIV in three ways: more HIV-negative IDUs use new needles instead of old ones; needles are retired after fewer uses; and the proportion of HIV-positive IDUs among users of both old and new needles rises owing to sorting effects. The first and second effects reduce the long-run incidence of HIV, while the third effect works in the opposite direction. We compare the results of our model with those of Kaplan and O'Keefe (1993) that is the foundation of many later models of HIV transmission among IDU.
Design of Theme Crawler for Web Forum

Network crawler as web information extraction tools, it can download web pages from internet for the engine. The implementation strategy and operating efficiency of crawling program have a direct influence on results of subsequent work. The paper aimed at the shortcomings of ordinary crawler, puts forward a practical and efficient precise crawler theme method for the BBS, the method for the BBS characteristics, attempts in the web page parsing, theme correlation analysis and the crawling strategy, using the template configuration, analyze and crawl on the article. The method is better than the general crawler in the performance, accuracy and comprehensive rate.
Implanted Antennas and Intra-Body Propagation Channel for Wireless Body Area Network

Implanted Devices are important components of the Wireless Body Area Network (WBAN) as a promising technology in biotelemetry, e-health care and hyperthermia applications. The design of WBAN faces many challenges, such as frequency band selection, channel modeling, antenna design, physical layer (PHY) protocol design, medium access control (MAC) protocol design and power source. This research focuses on the design of implanted antennas, channel modeling between implanted devices and Wireless Power Transfer (WPT) for implanted devices. An implanted antenna needs to be small while it maintains Specific Absorption Rate (SAR) and is able to cope with the detuning effect due to the electrical properties of human body tissues. Most of the proposed antennas for implanted applications are electric field antennas, which have a high near-zone electric field and, therefore, a high SAR and are sensitive to the detuning effect. This work is devoted to designing a miniaturized magnetic field antenna to overcome the above limitations. The proposed Electrically Coupled Loop Antenna (ECLA) has a low electric field in the near-zone and, therefore, has a small SAR and is less sensitive to the detuning effect. The performance of ECLA, channel model between implanted devices using Path Loss (PL) and WPT for implanted devices are studied inside different human body models using simulation software and validated using experimental work. The study is done at different frequency bands: Medical Implanted Communication Services (MICS) band, Industrial Scientific and Medical (ISM) band and 3.5 GHz band using ECLA. It was found that the proposed ECLA has a better performance compared to the previous designs of implanted antennas. Based on our study, the MICS band has the best propagation channel inside the human body model among the allowed frequency bands. The maximum PL inside the human body between an implanted antenna and a base station on the surface is about 90 dB. WPT for implanted devices has been investigated as well, and it has been shown that for a device located at 2 cm inside the human body with an antenna radius of 1 cm an efficiency of 63% can be achieved using the proposed ECLA.
Catalysis of Metallic and Ceramic TPS-Materials

A facility for the determination of total and spectral emission coefficients is described. Values of measured total emission coefficients of the different high temperature ceramics such as HfO2, Al2O3, Yt2O3 and the metals/alloys Tungsten, TZM and PM1000 in the temperature regime of 750 - 1800 K are given. The drastic influence of the oxidation state of PM1000 on the emissivity is discussed. Additionally, results of an investigation of the influence of surface roughness and surface topology on emissivity are presented. Therefore, three SSiC samples with root-mean-squared roughness surface roughness from Rq = 0.05 to Rq = 0.66 have been prepared using common finishing operations. The tests showed that the emissivity increased about 10 % with an increase of the surface roughness even in the regime where Rq values are in the same magnitude or much smaller than the maximum emitting wavelength. Knowledge on emissivity is a basis for the analysis of thermo-chemical behavior and related properties (i.e. recombination coefficients) as the two properties influence each other. In a second step a high enthalpy inductively heated plasma wind tunnel (PWK3) is described and a methodology to derive recombination coefficients is explained. Recombination coefficients for the above mentioned materials have been determined in pure oxygen plasma. The methodology for the determination of recombination coefficients of ceramic and metallic Thermal Protection System (TPS) materials in single species gases used at IRS and its latest improvements are presented. Test results for the recombination coefficients in oxygen plasma are shown between 1469 and 2072 K.
Issues in Assessing the Contribution of Research and Development to Productivity Growth

This article outlines the production function approach to the estimation of the returns to R&D and then proceeds to discuss in turn two very difficult problems: the measurement of output in R&D intensive industries and the definition and measurement of the stock R&D "capital. " The latter concept leads to a discussion of modeling of the spillover effects of R&D and to suggestions for possible measurement of such effects via the concept of technological distance between firms and industries. Somewhat more familiar econometric problems (multicollinearity and simultaneity) are taken up in the next section and another section is devoted to estimation and inference problems arising more specifically in the R&D context. Several recent studies of returns to R&D are then surveyed, and the paper concludes with a plea for a lowering of expectations as to what the available data can tell us and with suggestions for ways of expanding the current data base in this field. (This abstract was borrowed from another version of this item.)
BiomechanicalModellingofColorectal CryptFormationandIn-VitroReplication

The colon's epithelial lining exhibits a number of invaginations into the underlying tissue, called the crypts of Lieberkuhn. Housing stem cells at their bases, these crypts play an essential role in the maintenance of the epithelium; however, the processes by which crypts form are not conclusively understood. This study deploys mathematical and experimental modelling to validate one potential mechanism: that cellular growth in the developing epithelium causes a build up of compressive stresses, resulting in buckling instabilities which initiate crypt formation. We begin with an extension to the model of Edwards & Chapman (2007), modelling the epithelium as a beam tethered to underlying tissue by a series of springs. Modelling growth parametrically as a sequence of equilibrium configurations attained by beams of increasing length, we demonstrate that competition between lateral supports and stromal adhesion determines buckling wavelength. We show how non-equilibrium relaxation of tethering forces affects post-buckled shapes, and illustrate that growth inhomogeneity has a much weaker influence upon buckled configurations than do variations of mechanical properties. An in-vitro study, in which we culture intestinal epithelial cells upon a flexible substrate, demonstrates that the cells can exert sufficient force to induce buckling upon reaching confluence. A corresponding one-dimensional model is presented, in which a growing, confluent cell monolayer adheres to a thin compressible elastic beam. The model exhibits buckling via parametric growth. Cell-substrate adhesion and growth inhomogeneity have minimal influence upon configurations. Compressibility is important only in separating bifurcation points; large-amplitude shapes are accurately approximated by incompressible solutions. A two-dimensional analogue of this model, which extends von Karman plate theory, is then given. Axisymmetric configurations are compared with an alternative shell theory model, highlighting discrepancies arising from constitutive assumptions. Examining configurations of an inhomogeneous plate reveals that generation of multiple crypts by targeted softening alone is difficult; however, attachment to an elastic foundation can bias high frequency configurations.
A Near Input-Output Linearizing Force Tracking Controller for an Electrohydraulic Actuatorn

Under simple practical assumptions, the theory of feedback linearization can be applied to a physical model of an electrohydraulic rectilinear actuator. This paper presents the derivation of a near input-output (IO) linearizing force tracking controller and its experimental implementation on a fatigue testing electrohydraulic actuator. Comparisons are conducted against a linear state feedback with integral controller and a standard PID controller. It is shown that, within the limits of investigated system bandwidth and smoothness restrictions of the desired force trajectory, the near IO linearizing controller has better tracking properties. It is also noted that a sliding mode controller can be interpreted as a robust version of the near IO linearizing controller. Experiments are conducted to investigate the robustness of the controlled system to the parameters of the near IO linearizing controller.Copyright © 2005 by ASME
Evaluation of Recruiter Performance Measures and Policy

Abstract : Effective selection of recruiters is essential to the success of recruitment. To meet this objective, the Recruiter Selection Battery- Experimental (RSB-X) was developed. The RSB-X was administered to over 400 recruiters who entered the Army Recruiting Course during May and June 1985. This report documents the results of the first stages of an attempt to examine the ability of the RSB-X and other characteristics to predict recruiter success. On the basis of interviews with key U.S. Army Recruiting Command personnel and examination of performance records for the sample of recruiters, a definition of recruiter success was developed was developed, multiple measures of recruiter performance documented, and data elements of the RSB-X described. These preliminary activities indicate that an assessment of the ability of the RSB-X and other characteristics gathered at the same time to predict recruiter success can proceed efficiently. (KR)
On determining the power of a test after data collection

The term retrospective power describes methods for estimating the true power of a test after data have been collected. These methods have been recommended by some authors when null hypothesis of a test cannot be rejected. This report uses simulations to study power as a construct of an observed effect, variance, sample size, and set level of significance under the balanced one-way analysis of variance model for normally distributed populations with constant variance. Retrospective power, as a construct of sample data, is not recommended when the null hypothesis of a test cannot be rejected. When the p-value of the test is large, estimates for true power tend to fall below the 0.80 level and width-minimized confidence limits for true power tend to be wide. TABLE OF CONTENTS List of Figures . v List of Tables . vii Acknowledgements . viii