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The occurrence of fault fracture zones is a frequently encountered geological impediment while carrying out shield-driven twin tunnels, which presents significant hazards to the construction process. To examine the impact of these zones on shield-driven twin tunnels, an improved three-dimensional numerical model is utilized, based on the three-dimensional discrete fracture network (DFN) approach. This model assesses the surrounding rock’s deformation, the lining response, and the excavation plastic zone (EPZ). The joint orientation, joint density, and lagging distance are systematically analyzed. The research findings indicate that the surrounding rock response occurs mainly during the passage of the shield machine, with twin-tunnel excavation leading to the increased response of the surrounding rock and lining. Joint orientation poses complexities for twin-tunneling excavation, as discontinuities intersect the tunnel axis obliquely, leading to elevated construction risk. Large joint density weakens the overall strength of the surrounding rock, rendering it more akin to a soft equivalent homogeneous medium. Lagging distance primarily influences the surrounding rock’s deformation and lining response, emphasizing the need for a larger lagging distance in twin-tunnel construction. These results establish a solid theoretical basis for shield-driven twin tunnels crossing fault fracture zones construction. [ABSTRACT FROM AUTHOR]

With the development of Location-Based Social Networks, successive Point Of Interest (POI) recommendation systems have become a hot spot in the field of recommendation systems. Successive POI recommendation systems suggest to users new and interesting places to visit. However, in real-life POI recommendation, there are often a small number of users facing a huge number of POIs. Traditional successive POI recommendation methods are not capable to deal with the large sparse datasets, as they only consider the simple relationship between users and POIs. They do not use the context information of users and POIs, which can enable better recommendation results. To utilize the context information, this paper proposes a novel successive POI recommendation method, SQPMF, which integrates user personal preferences, user social relationships and POI transition relationships into the system for accurate recommendation of the next POI. Our experimental evaluation using three real-life datasets, Gowalla, Foursquare and Brightkite, shows that our method SQPMF consistently outperforms all state-of-the-art methods in recommendation of successive POIs. Compared with other methods, SQPMF improves Precision, Recall and F1-score by an average of at least 6.1 % , 5.8 % and 5.7 % respectively on three publicly available datasets. [ABSTRACT FROM AUTHOR]

Multi-layer perceptron (MLP) is a class of Artificial Neural Networks widely used in regression, classification, and prediction. To accelerate the training of MLP, more cores can be used for parallel computing on many-core systems. However, with the increasing number of cores integrated into the chip, the communication bottleneck in the training of MLP on electrical network-on-chip (ENoC) becomes severe, degrading MLP training performance. Replacing ENoC with optical network-on-chip (ONoC) can break the communication bottleneck in MLP training. To facilitate the development of ONoC for MLP training, it is necessary to compare and model the MLP training performance of ONoC and ENoC in advance. This paper first analyzes and compares the differences between ONoC and ENoC. Then, we formulate the performance and energy model of MLP training on ONoC and ENoC by analyzing the communication and computation time, static energy, and dynamic energy consumption, respectively. Furthermore, we conduct extensive simulations to compare their MLP training performance and energy consumption with our simulation infrastructure. The experimental results show the MLP training time of ONoC has been reduced by 65.16% and 52.51% on average in different numbers of cores and batch sizes compared with ENoC. The results also exhibit that ONoC overall has 54.86% and 43.13% on average energy reduction in different numbers of cores and batch sizes compared with ENoC. However, with a small number of cores (e.g., less than 50) in MLP training, ENoC consumes less energy than ONoC. These experiments confirm that generally ONoC is a good replacement for ENoC when using a large number of cores in terms of performance and energy consumption for MLP training. [ABSTRACT FROM AUTHOR]

The backcalculated modulus of subgrade reaction (k-value), elastic modulus of concrete (E), and effective thickness (heff) given the deflection basin from the Falling Weight Deflectometer (FWD) testing has been extensively used in evaluating the response and performance of in situ concrete pavements. Traditional backcalculation assumption of an interior-loaded infinite slab can lead to large errors in backcalculated parameters for edge-loaded continuously reinforced concrete pavement (CRCP) because of the load position and closely-spaced transverse cracks. In this paper, the backcalculaion formulas for edge-loaded CRCP with various crack spacing was proposed based on 2-D finite element analysis. According to the backcalculated results, both positive and negative temperature differentials of less than 16 °F had limited impact. As expected, the larger the lateral offset of the plate, the greater the impact on backcalculated results given the minimum error in heff reaching 5.0% with a 4 in. lateral offset. In order to verify the proposed backcalculation method, a field CRCP test section with different base types and reinforcement ratio were evaluated. The impact of edge support provided by base layer was also shown to be significant, given the support of a 2 ft overwidth base showing the same impact of approximately 1 in. extra thick base. [ABSTRACT FROM AUTHOR]

Sparse bundle adjustment (SBA) is a key but time- and memory-consuming step in three-dimensional (3D) reconstruction. In this paper, we propose a 3D point-based distributed SBA algorithm (DSBA) to improve the speed and scalability of SBA. The algorithm uses an asynchronously distributed sparse bundle adjustment (A-DSBA) to overlap data communication with equation computation. Compared with the synchronous DSBA mechanism (SDSBA), A-DSBA reduces the running time by 46%. The experimental results on several 3D reconstruction datasets reveal that our distributed algorithm running on eight nodes is up to five times faster than that of the stand-alone parallel SBA. Furthermore, the speedup of the proposed algorithm (running on eight nodes with 48 cores) is up to 41 times that of the serial SBA (running on a single node). [ABSTRACT FROM AUTHOR]

In this paper, an adaptive critic design (ACD) based control algorithm is proposed for road tunnel ventilation systems with jet fans. Firstly, a comprehensive dynamic model is established for control purpose, which considers both the static and dynamic nonlinearities between the pollutant concentration and the jet speed or the air flow inside the tunnel. Vehicle speed and density are also integrated into the model as system external disturbances. To cope with the time-varying model parameters and unknown system uncertainties, one artificial neural network (NN) unit is employed in controlling the jet fans to regulate the pollutant concentration to a desired level, even in the presence of varying working conditions. An additional NN is utilized to approximate the cost-to-go function required for the performance optimization. The proposed scheme is also verified and compared with traditional control design in simulation environment. The simulation results substantiate the conclusion that the adaptive controller can achieve a better regulation performance along with less energy consumption. [ABSTRACT FROM AUTHOR]

Effect of chitosan (CS) enriched with salicylic acid (SA) treatment on physicochemical quality enhancement of Chinese kiwi fruit ( Actinidia chinensis Planch) was evaluated during storage at room temperature for 14 days. Preservative treatment samples were dipped by CS, SA, and their combination (CS + SA), compared with the control treated by distilled water. Changes in texture, weight loss, surface colour, pH, vitamin C, soluble solids content (SSC), and microbiology were synchronously examined. Results demonstrated that chitosan with salicylic acid presented more effective preservative effect than sole chitosan or salicylic acid treatment. This optimal treatment significantly maintained texture and colour, inhibited moisture loss and acidity change, and delayed the decomposition of vitamin C and soluble solids. The optimal treatment efficiently maintained texture and surface colour, inhibited weight loss percentage (2.60 %) and acidity change, and delayed the decomposition of vitamin C (maximal content 97.93 mg/kg) and soluble solids. Therefore, CS enriched with SA coating provides an efficient alternative for physicochemical quality enhancement of Chinese kiwi fruits. [ABSTRACT FROM AUTHOR]

In this paper, a sucrose sensor by means of functional Cu foam material was investigated. Cu foam material was prepared and utilized as working electrode in a three-electrode electrochemical system. Scanning electron microscopy (SEM) results displayed stable and uniform multi-layered three-dimensional (3-D) mesh structure of Cu foam. Cyclic voltammetry (CV) explained sucrose electro-oxidation procedure on Cu foam electrode. Amperometric i-t scanning results demonstrated that the sensor selectively and sensitively responded to sucrose in mixtures. Interference experiment results indicated that this sensor had no responses to NaCl and citric acid (CA). Mixtures containing different tastants could be discriminated by non-linear double-layered cascaded series stochastic resonance (DCSSR) output signal-to-noise ratio (SNR) feature peak parameters. The proposed method provides a rapid way for sucrose quantitative analysis in real samples. [ABSTRACT FROM AUTHOR]

The isotope labeled graphene was synthesized in the concentration of C carbon atom in 1%, 25%, 50%, 75% and 99%. The isotope effect on the phonon behavior in graphene was investigated based on the micro-Raman analysis of C isotope labeled graphene samples. We found that the phonon scattering is affected by the isotopic carbon atom as a point defect. Based on the experiment results, the Klemens-Callaway model and uncertainty principle were used to obtain the mean free path of the G and D phonons. The results agree with the thermal conductivity measurement by non-contact optical method and with other theoretical calculations. [ABSTRACT FROM AUTHOR]

This paper proposes a Restricted Admission Control (RAC) scheme for View-Oriented Transactional Memory. The scheme can control the number of threads concurrently accessing a view in order to reduce the number of aborts of transactions. The RAC scheme has the merits of both the locking mechanism and the transactional memory. A theoretical model is proposed to analyze the performance of the RAC scheme and to provide guidance for dynamic adjustment of the number of concurrent threads accessing the same view. Experimental results demonstrate that theoretical RAC model can mostly provide correct guidance to transactional concurrency control. Our RAC implementation shows that RAC can optimize concurrency control of transactions and performs much better than conventional transactional memory systems such as TinySTM that have no dynamic admission control. [ABSTRACT FROM AUTHOR]

A fast multipole boundary element method (FMBEM) is developed for the analysis of 2D linear viscoelastic composites with imperfect viscoelastic interfaces. The transformed fast multipole formulations are established using the time domain method. To simulate the viscoelastic behavior of imperfect interfaces that are frequently encountered in practice, the Kelvin type model is introduced. The FMBEM is further improved by incorporating naturally the interaction among inclusions as well as eliminating the phenomenon of material penetration. Since all the integrals are evaluated analytically, high accuracy and fast convergence of the numerical scheme are obtained. Several numerical examples, including planar viscoelastic composites with a single inclusion or randomly distributed multi-inclusions are presented. The numerical results are compared with the developed analytical solutions, which illustrates that the proposed FMBEM is very efficient in determining the macroscopic viscoelastic behavior of the particle-reinforced composites with the presence of imperfect interfaces. The laboratory measurements of the mixture creep compliance of asphalt concrete are also compared with the prediction by the developed model. [ABSTRACT FROM AUTHOR]

A micromechanical approach based on a two-layer built-in model and a numerical simulation based on boundary element method are proposed to predict the effective properties of the multi-inclusion composite with imperfect interfaces. The spring model is introduced to simulate the interface imperfection. These two methods are compared with each other, and good agreement is achieved. The effects of interface spring stiffness, volume ratio and stiffness of inclusions on the micro- and macro-mechanical behaviors of fiber-reinforced composites are investigated. It is shown that the developed micromechanical method is very comprehensive and efficient for fast prediction of effective properties of composites, while the numerical method is very accurate in detailed modeling of the mechanical behavior of composites with multiple inclusions. [ABSTRACT FROM AUTHOR]

The effect of Ag nanoislands on the Raman of graphene was investigated in this work. Compared with that on the bare silicon wafer, Raman enhancement was observed in the graphene film that covered on Ag/Si surface with nanoscale Ag islands, which would be induced by the localized plasmon resonance in Ag nanostructures. The interaction between the graphene sheet and Ag/Si substrate was further studied. The peak shift and line shape of Raman spectroscopy indicated a nonuniform strain distribution in the Ag/Si supported graphene film. [ABSTRACT FROM AUTHOR]

Logic programs offer many opportunities for the exploitation of parallelism. But the parallel execution of a task incurs various overheads. This paper focuses on the issues relevant to parallelizing Prolog on shared-memory multiprocessors efficiently. [ABSTRACT FROM AUTHOR]

In this paper, we present a detection technique of and-parallelism in logic programs. The detection consists of three phases: analysis of entry modes, derivation of exit modes and determination of execution graph expressions. Compared with other techniques, our approach, with the compile- time program- level data- dependence analysis of logic programs, can efficiently exploit and- parallelism in logic programs. Two precompilers, based on our technique and DeGroot's approach respectively, have been implemented in SES- PIM system. Through compiling and running some typical benchmarks in SES- PIM, we conclude that our technique can, in most cases, exploit as much and- parallelism as the dynamic approach does under 'producer- consumer' scheme, and needs less dynamic overhead while exploiting more and-parallelism than DeGroot's approach does. [ABSTRACT FROM AUTHOR]