A Method of Evaluating Trust and Reputation for Online Transaction

The widespread use of the Internet and evaluater-based technologies has transformed the way business is conducted. Traditional offline businesses have increasingly become online, and there are new kinds of businesses that solely exist online. Unlike offline business environments, interpersonal trust is generally lacking in online business settings. Trading partners might feel insecure about the exchange of products and services over the net as they have limited information about each other's reliability or about the product quality. Considering that enough trust needs to be created to get the online buyer and seller to take actions, trust is a precious asset in online transactions. In order to address the issue of evaluating trust and reputation in online transaction environments, this paper makes use of a social network that graphically represents interpersonal relationships. This paper proposes computational models that systematically evaluate the quantitative level of trust and reputation based on the social network. A method that combines the evaluated trust and reputation levels is also proposed to increase the reliability of online transactions

Control-theoretic dynamic thermal management of automotive electronics control units

There has been a large body of research on dynamic thermal management (DTM) to manage the die temperature of integrated circuits against their high power density. Control-theoreticDTMis one of the most effectiveDTMschemes that guarantee stability criteria while meeting several performance requirements such as response time, steady-state error, overshoot, undershoot, phase margin, margin, and so forth. Conventional control-theoretic DTM schemes show reasonable stability and performance for general-purpose processors, but they may not fulfill those requirements for vehicle electronics control units (ECUs) primarily because the ambient temperature of an ECU is dependent on the associated unit temperature that often exceeds 100 degrees C. This results in a high steady-state die temperature and a very narrow temperature headroom. Furthermore, the unit temperature dynamically changes according to the driving condition that acts as a major disturbance to the DTM system. This paper introduces an advanced control-theretic DTM mechanism for high-performance vehicle ECUs. We model such ambient temperature variation as a disturbance, and adopt a disturbance predictor and compensator that effectively mitigates the effects of ambient temperature variations. We demonstrate that the proposed method is superior to the previous control-theoretic DTM in terms of RMS errors, peak temperature, and thermal violation.X110sciescopu

Optimization of Parameters Affecting Horizontal Cracking in Continuously Reinforced Concrete Pavement (CRCP)

Field evaluation of distresses in continuously reinforced concrete pavement (CRCP) indicated punch-out distress associated with horizontal cracking at the depth of the longitudinal steel is the most severe performance problem in CRCP. The developed 3-D model was used to perform a parametric analysis to determine the effects of critical loading location, concrete properties, and longitudinal steel design on horizontal cracking potential. The maximum vertical tensile stresses in the concrete were slightly affected by the coefficient of thermal expansion of the concrete. The critical tensile stresses in the concrete were observed to decrease as the base modulus, slab-base friction, slab thickness, and transverse crack spacing increase. The vertical tensile stresses significantly decreased when the longitudinal steel spacing decreased. The use of varying longitudinal steel spacing and reducing the depth of steel may be one of the ways to reduce the horizontal cracking potential without changing the steel ratio of the slab.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Effect of Dowel Bar Arrangements on Performance of Jointed Plain Concrete Pavement (JPCP)

Abstract A full-scale jointed plain concrete pavement (JPCP) with two different dowel bar arrangements, namely, standard and special method, was constructed and evaluated under actual traffic-environmental condition in Florida. For standard dowel bar arrangement, dowel bars spaced at 304.8 mm (12 in), while three dowel bars spaced at 304.8 mm (12 in) only within the wheel paths were installed for special dowel bar arrangement. Field performance evaluation was conducted in terms of longitudinal crack, transverse crack, corner crack, spalling, and load transfer efficiency (LTE). Also, a three-dimensional (3-D) finite element (FE) model was developed to evaluate change in structural response characteristics due to different dowel bar arrangements under the critical loading condition. The developed FE model was used to perform a parametric analysis to determine the effects of different dowel bar arrangements. Results indicated that no significant changes in pavement structural responses, including the slab stresses and deflections, were predicted between two dowel bar arrangements that may result in no significant difference in expected performance for the test slabs evaluated, and this matched well with results of field performance evaluation. Also, it was indicated that the base modulus plays an important role on the dowel-joint behavior and stiffer base condition could significantly improve the dowel-joint performance. Therefore, when the base layer is stiff enough to support the slab deflection and resist erosion (e.g., AC layer), special dowel bar arrangement could provide similar performance as compared to standard dowel bar arrangement that result in significant cost savings without any negative effects on expected pavement performance

Development of Mix Designs for Minimally Refined Reclaimed Asphalt Pavement (RAP) Concrete for Florida Concrete Test Road

The main objective was to develop mix designs for concrete incorporating minimally processed reclaimed asphalt pavement (RAP) materials to be used in the Florida Concrete Test Road. The laboratory program was conducted in two phases. Phase I involved testing of twelve (12) trial mixes to identify feasible mixes which could meet the Florida Department of Transportation (FDOT) specification requirements for pavement concrete. Based on the preliminary test results from the trial mixes, ten (10) production mixes were identified and evaluated more extensively in Phase II to establish the optimum concrete mixes incorporating RAP to be recommended. Concrete mixtures, with 0% to 40% RAP as aggregate replacement and using 20% fly ash and 50% slag as cement replacement, were designed using the optimized aggregate gradation (OAG) technique instead of the American Concrete Institute (ACI) method. Among the RAP concrete evaluated, the 20% RAP concrete mixes with 0%, 20% fly ash, and 50% slag as cement replacement were able to meet Florida Department of Transportation’s (FDOT) over-design compressive strength of 29 MPa (4200 psi) at 28 days. Using 20% and 40% RAP in concrete could result in saving in the total cost of aggregate by 9% and 17%, respectively. When the RAP is not refined (e.g., no washing of RAP, and no separating of coarse and fine portions), it is recommended that 20% of RAP can be used as aggregate replacement in pavement concrete

Brief Communication: The reliability of gas extraction techniques for analysing CH4 and N2O compositions in gas trapped in permafrost ice wedges

International audienceMethane (CH 4) and nitrous oxide (N 2 O) compositions in ground ice may provide information on their production mechanisms in permafrost. However, existing gas extraction methods have not been well tested. We tested conventional wet and dry gas extraction methods using ice wedges from Alaska and Siberia, finding that both methods can extract gas from the easily extractable parts of the ice (e.g. gas bubbles) and yield similar results for CH 4 and N 2 O mixing ratios. We also found insignificant effects of microbial activity during wet extraction. However, both techniques were unable to fully extract gas from the ground ice, presumably because gas molecules adsorbed onto or enclosed in soil aggregates are not easily extractable. Estimation of gas production in a subfreezing environment of permafrost should consider such incomplete gas extraction

A multimodal screening system for elderly neurological diseases based on deep learning

Abstract In this paper, we propose a deep-learning-based algorithm for screening neurological diseases. We proposed various examination protocols for screening neurological diseases and collected data by video-recording persons performing these protocols. We converted video data into human landmarks that capture action information with a much smaller data dimension. We also used voice data which are also effective indicators of neurological disorders. We designed a subnetwork for each protocol to extract features from landmarks or voice and a feature aggregator that combines all the information extracted from the protocols to make a final decision. Multitask learning was applied to screen two neurological diseases. To capture meaningful information about these human landmarks and voices, we applied various pre-trained models to extract preliminary features. The spatiotemporal characteristics of landmarks are extracted using a pre-trained graph neural network, and voice features are extracted using a pre-trained time-delay neural network. These extracted high-level features are then passed onto the subnetworks and an additional feature aggregator that are simultaneously trained. We also used various data augmentation techniques to overcome the shortage of data. Using a frame-length staticizer that considers the characteristics of the data, we can capture momentary tremors without wasting information. Finally, we examine the effectiveness of different protocols and different modalities (different body parts and voice) through extensive experiments. The proposed method achieves AUC scores of 0.802 for stroke and 0.780 for Parkinson’s disease, which is effective for a screening system

Origin of CO2_2, CH4_4, and N2_2O trapped in ice wedges in central Yakutia and their relationship

International audiencePermafrost thawing as a result of global warming is expected to foster the biological remineralization of intact organic carbon and nitrogen and release greenhouse gas (GHG) into the atmosphere, which will have positive feedback for future global warming. However, GHG budgets and their controls in permafrost ground ice are not yet fully understood. This study aims to better understand the control mechanisms of GHG in ground ice by using new gas and chemistry data. In this study, we present new data on carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) mixing ratios in three different ice wedges, Churapcha, Syrdakh, and Cyuie, located in central Yakutia, Siberia. The GHG mixing ratios in the studied ice wedges range from 0.0% to 13.8% CO2, 1.3–91.2 ppm CH4, and 0% and 0–1414 N2O. In particular, all three ice wedges demonstrate that ice-wedge samples enriched in CH4 were depleted in N2O mixing ratios and vice versa. N2–O2–Ar compositions indicate that the studied ice wedges were most likely formed by dry snow or hoarfrost, not by freezing of snow meltwater, and the O2-consuming biological metabolism was active. Most of the observed GHG mixing ratios cannot be explained without microbial metabolism. The inhibitory impact of denitrification products of nitrate (including N2O) could be an important control of the ice-wedge CH4 mixing ratio

Structural basis for the enantioselectivity of esterase Est-Y29 toward (S)-ketoprofen

The thermostable esterase Est-Y29, belonging to the family VIII lipolytic esterases isolated from metagenomes extracted from the topsoil in Republic of Korea, was identified as a promising catalyst for the production of (S)-ketoprofen, an important nonsteroidal anti-inflammatory drug (NSAID). For industrial applications, the enantioselectivity of the enzyme toward the S-enantiomer of the racemic ketoprofen ester substrate needs to be improved. To understand the structural basis of Est-Y29 enantioselectivity, which is necessary for the rational design of an enzyme with enhanced enantioselectivity, we solved the crystal structures of Est-Y29 bound to (S)-ketoprofen at 1.69 Å resolution. Structural analyses revealed that the S-enantiomer can be stabilized by a π-interaction between the methyl substituent at the chiral carbon of the ligand and the aromatic pocket formed by Tyr123, Phe125, and Tyr170. This finding is further supported by the highly improved enantioselectivity of the mutant Est-Y29 (F125W) toward (S)-ketoprofen due to the enhanced π-interaction. Our results provide the molecular basis of the enantioselectivity of Est-Y29 against (S)-ketoprofen and further offer the opportunity for the rational design of enzyme enantioselectivity as well as potential applications of the mutant Est-Y29 to industrial biocatalysts