Dynamic Link Library Research Articles

Application of Twin Shear Unified Elastoplastic Finite Difference Method in Metallic Structures

Twin shear unified strength theory is applied to the numerical simulation of metallic structures with the method of elastoplastic finite difference.This work has actual significance for the problem of metallic structures strength or processing research.Firstly,the twin shear unified strength theory and the method of Lagrangian finite difference are briefly introduced.Secondly,the finite difference formulation of twin shear failure criteria and flow rule is derived and the model is loaded into FLAC code with dynamic-link library file compiled by language of C++.Finally,the cases of thick-walled cylinder under internal pressure and perforated plate in tension are calculated.The calculation results of analyses suggest that the precision of Lagrangian finite difference method and finite element method are similar.Twin shear unified strength theory can be applied to the metallic materials with a ratio of shear strength to tension strength between 0.5 and 0.667,so that it will have wide application in numerical simulation of metallic structures.

Development of an on-line model to predict the in-cylinder residual gas fraction by using the measured intake/exhaust and cylinder pressures

The in-cylinder RGF (residual gas fraction) of internal combustion engines for new combustion concepts, such as CAI (controlled auto ignition) or HCCI (homogenous charged compression ignition), is a major parameter that affects the combustion characteristics. Thus, measurement or prediction of the cycle-by-cycle RGF and investigation into the relation between the RGF and the combustion phenomena are critical issues. However, on-line prediction of the cycle-by-cycle RGF during engine testing is not always practical due to the requirement of expensive, fast response exhaust-gas analyzers and/or theoretical models that are just too slow for application. In this study, an on-line model that can predict the RGF of each engine cycle and cylinder during the experiment in the test cell has been developed. This enhanced model can predict the in-cylinder charge conditions of each engine cycle during the test in three seconds by using the measured dynamic pressures of the intake, exhaust, and cylinder as the boundary conditions. A Fortran77 code was generated to solve the 1-D MOC (method of characteristics). This code was linked to Labview DAQ as a form of DLL (dynamic link library) to obtain three boundary pressures for each cycle. The model was verified at various speeds and valve timings under the CAI mode by comparing the results with those of the commercial code, GT-Power.

A surgical navigation system for oral and maxillofacial surgery and its application in the treatment of old zygomatic fractures

Nowadays, there is a trend towards computer-aided oral and maxillofacial surgery. However, due to complicated preoperative planning, traditional neurosurgery-orientated navigation systems are not suitable and have to be adapted. A surgical navigation system is presented for oral and maxillofacial surgery, named AccuNavi, which integrates 3D medical modelling, preoperative surgical planning and intraoperative tracking. Various algorithms were introduced, for each of which a set of dynamic link libraries (DLLs) were developed using C++, as well as the VTK and ITK, via object-orientated programming methodology, allowing for expandability, accessibility and maintainability in our system. The advantage of AccuNavi is validated through clinical applications, especially in a case report about the planning and subsequent precise treatment of old zygomatic fractures. The postoperative 3D-reconstructed CT image demonstrated that the fractured zygoma was fixed in the appropriate position and orientation. The clinical application demonstrates the feasibility and reliability of AccuNavi, and it can be extended to various areas in oral and maxillofacial surgery.

A new methane control and prediction software suite for longwall mines

This paper presents technical and application aspects of a new software suite, MCP (Methane Control and Prediction), developed for addressing some of the methane and methane control issues in longwall coal mines. The software suite consists of dynamic link library (DLL) extensions to MS-Access TM, written in C++. In order to create the DLLs, various statistical, mathematical approaches, prediction and classification artificial neural network (ANN) methods were used. The current version of MCP suite (version 1.3) discussed in this paper has four separate modules that (a) predict the dynamic elastic properties of coal-measure rocks, (b) predict ventilation emissions from longwall mines, (c) determine the type of degasification system that needs to be utilized for given situations and (d) assess the production performance of gob gas ventholes that are used to extract methane from longwall gobs. These modules can be used with the data from basic logs, mining, longwall panel, productivity, and coal bed characteristics. The applications of these modules separately or in combination for methane capture and control related problems will help improve the safety of mines. The software suite's version 1.3 is discussed in this paper. Currently, it's new version 2.0 is available and can be downloaded from http://www.cdc.gov/niosh/mining/products/product180.htm free of charge. The models discussed in this paper can be found under “ancillary models” and under “methane prediction models” for specific U.S. conditions in the new version.

The open source RFortran library for accessing R from Fortran, with applications in environmental modelling

The open source RFortran library is introduced as a convenient tool for accessing the functionality and packages of the R programming language from Fortran programs. It significantly enhances Fortran programming by providing a set of easy-to-use functions that enable access to R′s very rapidly growing statistical, numerical and visualization capabilities, and support a richer and more interactive model development, debugging and analysis setup. RFortran differs from current approaches that require calling Fortran Dynamic link libraries (DLL) from R, and instead enables the Fortran program to transfer data to/from R and invoke R-based procedures via the R command interpreter. More generally, RFortran obviates the need to re-organize Fortran code into DLLs callable from R, or to re-write existing R packages in Fortran, or to jointly compile their Fortran code with the R language itself. Code snippets illustrate the basic transfer of data and commmands to and from R using RFortran, while two case studies discuss its advantages and limitations in realistic environmental modelling applications. These case studies include the generation of automated and interactive inference diagnostics in hydrological model calibration, and the integration of R statistical packages into a Fortran-based numerical quadrature code for joint probability analysis of coastal flooding using numerical hydraulic models. Currently, RFortran uses the Component Object Model (COM) interface for data/command transfer and is supported on the Microsoft Windows operating system and the Intel and Compaq Visual Fortran compilers. Extending its support to other operating systems and compilers is planned for the future. We hope that RFortran expedites method and software development for scientists and engineers with primary programming expertise in Fortran, but who wish to take advantage of R′s extensive statistical, mathematical and visualization packages by calling them from their Fortran code. Further information can be found at www.rfortran.org.

Modular Preoperative Planning Software for Computer‐Aided Oral Implantology and the Application of a Novel Stereolithographic Template: A Pilot Study

In the field of oral implantology, there is a trend toward computer-aided implant surgery, especially the application of computerized tomography (CT)-derived surgical templates. However, because of relatively unsatisfactory match between the templates and receptor sites, conventional surgical templates may not be accurate enough for the severely resorbed edentulous cases during the procedure of transferring the preoperative plan to the actual surgery. The purpose of this study is to introduce a novel bone-tooth-combined-supported surgical guide, which is designed by utilizing a special modular software and fabricated via stereolithography technique using both laser scanning and CT imaging, thus improving the fit accuracy and reliability. A modular preoperative planning software was developed for computer-aided oral implantology. With the introduction of dynamic link libraries and some well-known free, open-source software libraries such as Visualization Toolkit (Kitware, Inc., New York, USA) and Insight Toolkit (Kitware, Inc.) a plug-in evolutive software architecture was established, allowing for expandability, accessibility, and maintainability in our system. To provide a link between the preoperative plan and the actual surgery, a novel bone-tooth-combined-supported surgical template was fabricated, utilizing laser scanning, image registration, and rapid prototyping. Clinical studies were conducted on four partially edentulous cases to make a comparison with the conventional bone-supported templates. The fixation was more stable than tooth-supported templates because laser scanning technology obtained detailed dentition information, which brought about the unique topography between the match surface of the templates and the adjacent teeth. The average distance deviations at the coronal and apical point of the implant were 0.66 mm (range: 0.3-1.2) and 0.86 mm (range: 0.4-1.2), and the average angle deviation was 1.84 degrees (range: 0.6-2.8 degrees ). This pilot study proves that the novel combined-supported templates are superior to the conventional ones. However, more clinical cases will be conducted to demonstrate their feasibility and reliability.

A GIS-based decision support system for regional eco-security assessment and its application on the Tibetan Plateau

Regional eco-security assessment is an intricate, challenging task. In previous studies, the integration of eco-environmental models and geographical information systems (GIS) usually takes two approaches: loose coupling and tight coupling. However, the present study used a full coupling approach to develop a GIS-based regional eco-security assessment decision support system (ESDSS). This was achieved by merging the pressure-state-response (PSR) model and the analytic hierarchy process (AHP) into ArcGIS 9 as a dynamic link library (DLL) using ArcObjects in ArcGIS and Visual Basic for Applications. Such an approach makes it easy to capitalize on the GIS visualization and spatial analysis functions, thereby significantly supporting the dynamic estimation of regional eco-security. A case study is presented for the Tibetan Plateau, known as the world’s “third pole” after the Arctic and Antarctic. Results verified the usefulness and feasibility of the developed method. As a useful tool, the ESDSS can also help local managers to make scientifically-based and effective decisions about Tibetan eco-environmental protection and land use.

Development and testing of a physically based, three-dimensional model of surface and subsurface hydrology

We present a numerical, catchment-scale model that solves flow equations of surface and subsurface flow in a three-dimensional domain. Surface flow is described by the two-dimensional parabolic approximation of the St. Venant equation, using Manning’s equation of motion; subsurface flow is described by the three-dimensional Richards’ equation for the unsaturated zone and by three-dimensional Darcy’s law for the saturated zone, using an integrated finite difference formulation. The hydrological component is a dynamic link library implemented within a comprehensive model which simulates surface energy, radiation budget, snow melt, potential evapotranspiration, plant development and plant water uptake. We tested the model by comparing distributed and integrated three-dimensional simulated and observed perched water depth (PWD), stream flow data, and soil water contents for a small catchment. Additional tests were performed for the snow melting algorithm as well as the different hydrological processes involved. The model successfully described the water balance and its components as evidenced by good agreement between measured and modelled data.

Modeling Skeletal Muscle Angiogenesis from the Molecular to the Tissue Level

We present a multiscale model of angiogenesis that integrates individual modules representing blood flow, oxygen transport, growth factor distribution and signaling, cell sensing, cell movement and cell proliferation. This integration will be used to better understand underlying biological mechanisms from the molecular level up through the organ systems level; examine the effects of pathological conditions on skeletal muscle capillary growth; and test new therapeutic strategies. Model methodology includes partial differential equations, stochastic models, complex logical rules, and agent‐based architectures. Spatial and time scales range from ligand‐receptor interactions and intracellular signaling occurring on the order of seconds and minutes, to cell‐level movement and cell‐matrix interactions over minutes to hours, to vessel formation and tissue level responses over hours to days.We introduce the individual modules and describe our methodology for integration, which involves wrapping models (written in different programming languages) in a Java‐based dynamic link library format that allows for a central controller to readily pass parameters between the models. We present results from the coordination of modules: the effects of hypoxia in skeletal muscle from the molecular‐detailed changes in HIF1‐initiated VEGF secretion and VEGF‐VEGFR signaling; to endothelial cell activation, cell movement in response to VEGF gradients, and capillary branching as a function of the Notch ligand DLL4; to the resulting new capillary network and altered pattern of blood flow. This angiogenesis multiscale modeling and integration will be a tool in rational drug development and therapeutic regime design, and encourage related angiogenesis experiments.

Run-time system based on LinSERCANS and Soft-PLC

Soft-PLC with open architecture is the direction of development in industrial automation. This paper discusses the method of communication between the interface functions of LinSERCANS under RTLinux and the external library of Soft-PLC underWindows. Based on the API HOOK theory, the communication between the interface functions of LinSERCANS and the external libraries of Soft-PLC is set up and it solves the calling functions of dynamic link libraries in different operation systems. It is able to combine LinSERCANS with the Soft-PLC, and a run-time system is developed based on the interface technology of the serial real-time communication system (SERCOS) and technology of soft-PLC. This runtime system has been used in all electronic injection molding machines and works very well.

Dynamic reconfiguration architectures for multi-context FPGAs

Field-programmable gate arrays (FPGAs) are being integrated with processors on the same motherboard or even chip in order to achieve flexible high-performance computing, and this may become main stream in chip multi-core architectures. However, the expensive FPGA area is often used inefficiently, with much of the logic idle at any given time. This work, motivated by the Dynamic-Link Library (DLL) concept in software, explores the possibility of “hardware DLLs” by finding ways for fast dynamic incremental reconfiguration of FPGAs. So doing would, among other things, enable same-function replication at any given time, with functions changing quickly over time, thereby enabling efficient exploitation of data parallelism at no additional hardware cost. We present two new multi-context FPGA architectures based on two different configuration storage architectures: local and centralized. Problems such as configuration storage and reconfiguration (time, power and space) overhead are considered. Well known area and power models are used in evaluating various approaches and in order to provide guidelines for matching architectures to target applications. Lastly, we provide insights into resulting scheduling issues. Our findings provide the foundation and “rules of the game” for subsequent development of reconfiguration schedulers and execution environments.

A software component to compute agro-meteorological indicators

ClimIndices is a software component to compute agro-meteorological indicators on yearly series of daily weather data. The component is released as .NET2 dynamic link libraries (DLL), allowing the development of clients under Windows using .NET languages. The design allows extending the computing capabilities without requiring re-compilation.

URBAN CRIME ANALYSIS THROUGH AREAL CATEGORIZED MULTIVARIATE ASSOCIATIONS MINING

As geospatial data grows explosively, there is a great demand for the incorporation of data mining techniques into a geospatial context. Association rules mining is a core technique in data mining and is a solid candidate for the associative analysis of large geospatial databases. In this article, we propose a geospatial knowledge discovery framework for automating the detection of multivariate associations based on a given areal base map. We investigate a series of geospatial preprocessing steps involving data conversion and classification so that the traditional Boolean and quantitative association rules mining can be applied. Our framework has been integrated into GISs using a dynamic link library to allow the automation of both the preprocessing and data mining phases to provide greater ease of use for users. Experiments with real-crime datasets quickly reveal interesting frequent patterns and multivariate associations, which demonstrate the robustness and efficiency of our approach.

A Dynamic Link Library for calculating true-coincidence summing correction factors

A Dynamic Link Library (DLL) was created for calculating true-coincidence correction factors in γ- and X-ray spectrometry applications. Calculations are done by Monte-Carlo method on the basis of the Evaluated Nuclear Structure Data File (ENSDF). In calculations the emission of cascade gammas, as well as γ-X, γ-γ511 and X-X coincidences are appropriately taken into account. A set of measurement geometries implemented includes combinations of coaxial, planar, low and broad energy as well as well-type detectors with point, disk, spherical, cylindrical and Marinelli beaker sources. Together with true-coincidence correction factors full-energy-peak efficiencies are calculated and reported. The DLL was tested by comparing its results with experimental data and results of similar calculations.

A dynamic backdoor detection system based on Dynamic Link Libraries

We present a two-layer backdoor detection system in the article. In the first-layer, Zhang and Paxson's method is applied to identify keystroke interactive connection from network traffic. In the second-layer, we adopt the Dynamic Link Library (DLL) injection technique to record all DLLs employed by the programme that evokes such interactive connection. Compared the recorded data with some pre-defined Common Feature Tables, the second-layer can then determine whether the monitored programme is a backdoor. By experiments, the best result of our system got 94.44% detection rate while False Positive was zero. In the case, the overall accuracy was 97.22%.

Lumped-Refined Multichannel Calculation Scheme for a High-Fidelity Thermal-Hydraulic Analysis by a Neutronics Code Coupling

A lumped-refined multichannel analysis scheme is developed for a high-fidelity thermal-hydraulic (T-H) calculation through neutronics code coupling and applied to a control element assembly (CEA) ejection accident of the Ulchin Unit 3 nuclear power plant to quantify the conservatism of the conventional scheme. The high-fidelity core minimum departure from nucleate boiling (DNB) ratio calculation is realized by coupling more than two TORC dynamic link libraries (DLLs) under the control of the neutronics code, one for the lumped multichannel calculation and the others for the refined subchannel calculations. Realistic radial boundary conditions are supplied from the lumped multichannel calculation to the refined TORC DLL through the neutronics code. The CEA ejection accident problem is simulated from the DNB limiting conditions for operation condition, which is searched by adjusting the core radial peaking factor at a 30% axial offset power shape. The results indicate that the simplified hot-channel model contains ~15 and 5% conservatism in the core minimum DNB ratio and in the number of failed fuel rods, respectively, and reveals that those conservatisms are mainly due to the unrealistic isolated boundary condition. Therefore, it is concluded that the developed scheme can be effectively used to quantify the conservatism of a conventional DNB evaluation scheme.

Dimensional measurements of a gray-iron object using a robot and a laser displacement sensor

This paper presents a system for noncontact dimensional measurement of a gray-iron grate by use of a laser dot triangulation displacement sensor and an industrial SCARA robot. A special kernel driver and an associated dynamic link library were written for this system, enabling a higher sampling rate of the robot world coordinate positions and of the laser measurements. For repair of the scan data and calculation of the coordinates of deburring points, another program was written, where a unique approach of polynomial approximation to the profile was developed. To determine the accuracy of the robot measurement system, a number of comparative measurements were performed on a reference cube with a coordinate-measuring machine. Comparative measurements on real gray-iron grates were also done. The results show that dimensional measurements on a grate, at 88 points, can be performed within 45 s and with ± 0.3 mm accuracy, which proved to be sufficient for robot deburring of gray-iron grates.

A scalable multi-level feature extraction technique to detect malicious executables

We present a scalable and multi-level feature extraction technique to detect malicious executables. We propose a novel combination of three different kinds of features at different levels of abstraction. These are binary n-grams, assembly instruction sequences, and Dynamic Link Library (DLL) function calls; extracted from binary executables, disassembled executables, and executable headers, respectively. We also propose an efficient and scalable feature extraction technique, and apply this technique on a large corpus of real benign and malicious executables. The above mentioned features are extracted from the corpus data and a classifier is trained, which achieves high accuracy and low false positive rate in detecting malicious executables. Our approach is knowledge-based because of several reasons. First, we apply the knowledge obtained from the binary n-gram features to extract assembly instruction sequences using our Assembly Feature Retrieval algorithm. Second, we apply the statistical knowledge obtained during feature extraction to select the best features, and to build a classification model. Our model is compared against other feature-based approaches for malicious code detection, and found to be more efficient in terms of detection accuracy and false alarm rate.

Linking one- and two-dimensional models for free surface flows

This paper presents integration of a one-dimensional (1D) numerical model with a two-dimensional (2D) numerical model for simulating shallow water flows. The dynamic link library (DLL) technique is used to link a 2D research code with a 1D commercial program. The 2D model has been refined to represent ground topography better and the flooding and drying process. Both mass and momentum transfers are allowed between the 1D and 2D solutions. Two test cases were used to verify the linked model. Smooth transitions between wet and dry areas were observed, with accurate mass conservation being achieved during wetting and drying. It has also been shown that the inclusion of momentum transfer between the two models leads to improved results by eliminating the unrealistic variations in the free surface, close to the common boundaries of the models. The combined 1D and 2D model has the capability to simulate hydraulic processes at different spatial scales simultaneously.

A computational interface for thermodynamic calculations software MTDATA

A novel computational interface between a thermodynamic calculations software MTDATA and a scientific computing software MATLAB is developed utilising the MATLAB interface to generic dynamic link libraries (DLLs). As such, runtine thermodynamic calculations can be performed in MATLAB environment with extended flexibility. In addition, combined thermodynamic-kinetic models developed in MATLAB can have a seamless link to MTDATA whenever thermodynamic parameters are required. Further extension of the interface to a multiphysics modelling software, COMSOL Multiphysics, is also introduced. The interface extends the capabilities of these three software packages and provides a methodology for sophisticated and even three dimensional combined thermodynamic-kinetic modelling. Applications of the interface in equilibrium thermodynamic calculation, nonequilibrium Scheil calculation, and diffusion in a multicomponent multiphase system are presented.