P. Reena Monica^1,*, V. T. Sreedevi²

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 577-591, 2019, DOI:10.32604/cmes.2019.04718

Abstract A mathematical model and experimental analysis of the impact of oxide thickness on the ambipolar conduction in Schottky Barrier Carbon Nanotubes (CNTs) Field Effect Transistor (SB CNTFETs) is presented. Suppression of ambipolar conduction in SB CNTFETs is imperative in order to establish them as the future of IC technology. The ambipolar nature of SB CNTFETs leads to a great amount of leakage current. Employing a gate oxide dielectric of thickness, t_ox~50 nm suppresses the ambipolar behavior. In an SB CNTFET, it is the electric field at the source/drain contacts that control the conductance and the band… More >

P. Shanmugapriya¹, J. Baskaran², C. Nayanatara^1,*, D. P. Kothari³

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 541-558, 2019, DOI:10.32604/cmes.2019.04074

Abstract The objective of this paper is to provide a robust Virtual Power Plant (VPP) network collaborated with Internet of Things (IoT) which uses a conceptual model to integrate each device in the grid. Based on the functionality all the devices which are purely distributed within the grid are networked initially from residential units to substations and up to service data and demand centres. To ensure the trapping of the available power and the efficient transfer of Distributed Generation (DG) power to the grid Distribution Active Control (DAC) strategy is used. Synchronized optimization of DG parameter… More >

Qiang Liu^1,*, Yanyun Zou^2,3, Xiaodong Liu⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 617-637, 2019, DOI:10.32604/cmes.2019.06272

Abstract Haze-fog, which is an atmospheric aerosol caused by natural or man-made factors, seriously affects the physical and mental health of human beings. PM_2.5 (a particulate matter whose diameter is smaller than or equal to 2.5 microns) is the chief culprit causing aerosol. To forecast the condition of PM_2.5, this paper adopts the related the meteorological data and air pollutes data to predict the concentration of PM_2.5. Since the meteorological data and air pollutes data are typical time series data, it is reasonable to adopt a machine learning method called Single Hidden-Layer Long Short-Term Memory Neural Network (SSHL-LSTMNN)… More >

Prasert Prapamonthon^1,2,*, Soemsak Yooyen¹, Suwin Sleesongsom¹

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 593-615, 2019, DOI:10.32604/cmes.2019.05579

Abstract Thermal parameters are important variables that have great influence on life time of turbine vanes. Therefore, accurate prediction of the thermal parameters is essential. In this study, a numerical approach for conjugate heat transfer (CHT) and computational fluid dynamics (CFD) is used to investigate thermal sensitivity of a transonic guide vane which is fully film-cooled by 199 film holes. Thermal barrier coating (TBC), i.e., the typical TBC and a new one as the candidate TBC, and turbulence intensity (Tu), i.e., Tu=3.3%, 10% and 20%, are two variables used for the present study. At first the… More >

P. R. Hemavathy^1,*, Y. Mohamed Shuaib², S. K. Lakshmanaprabu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 481-498, 2019, DOI:10.32604/cmes.2019.04731

Abstract Normally all real world process in a process industry will have time delay. For those processes with time delays, obtaining satisfactory closed loop performances becomes very difficult. In this work, three interacting cylindrical tank process is considered for study and the objective of the work is to compensate for time delays using smith predictor structure and to maintain the level in the third tank. Input/Output data is generated for the three interacting tank process. It is approximated as Integer First Order Plus Dead Time system (IFOPDT) and Fractional First Order Plus Dead Time system (FFOPDT). More >

Thamer A. Alrawashed^1,*, Ammar Almomani², Ahmad Althunibat¹, Abdelfatah Tamimi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 409-425, 2019, DOI:10.32604/cmes.2019.04681

Abstract Test complexity and test adequacy are frequently raised by software developers and testing agents. However, there is little research works at this aspect on specification-based testing at the use case description level. Thus, this research proposes an automatic test cases generator approach to reduce the test complexity and to enhance the percentage of test coverage. First, to support the infrastructure for performing automatic, this proposed approach refines the use cases using use case describing template and save it in the text file. Then, the saved file is input to the Algorithm of Control Flow Diagram… More >

Lihui Wang¹, Feng Qi¹, Xin Shen^2,3,*, Jinliang Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.2, pp. 331-348, 2019, DOI:10.32604/cmes.2019.04268

Abstract Multiple cropping index (MCI) is a very important indicator in crop production and agricultural intensification, which represents the utilizing degree of agriculture resources at time scale and the effective utilization situation of arable land. The objective of this paper is monitoring multiple cropping index of Henan province of China according to the time series of MODIS (Moderate-Resolution Imaging Spectroradiometer) EVI (Enhanced Vegetation Index) after Savitzky-Golay filter processing from the year 2006 to 2011.The results revealed that this method could provide an effective way to monitor multiple cropping index, and the method of no additional authentication More >

Yan Zou^1,2,3,*, Shaoliang Zhang¹, Yanhai Min¹

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.2, pp. 295-310, 2019, DOI:10.32604/cmes.2019.03873

Abstract The high precision population forecasting and spatial distribution modeling are very important for the theory and application of population sociology, city planning and Geo-Informatics. However, the two problems need to be solved for providing the high precision population information. One is how to improve the population forecasting precision of small area (e.g., street scale); another is how to improve the spatial resolution of urban population distribution model. To solve the two problems, some new methods are proposed in this contribution. (1) To improve the precision of small area population forecasting, a new method is developed… More >

Zhangzhen Sun¹, Tianhe Xu^1,*, Fan Gao¹, Chunhua Jiang¹, Guochang Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.2, pp. 263-280, 2019, DOI:10.32604/cmes.2019.04425

Abstract Abnormal effects in GPS broadcast ephemerides can have a significant effect on real-time navigation and positioning solutions that use the orbit and clock error data provided by GPS broadcast ephemerides. This paper describes three types of non-integer-hour navigation data in GPS broadcast ephemeris data. Compared with GPST integer hour data, we find that there are two types of data blocks for non-integer-hour navigation containing gross errors with different levels of precision, which is reflected in the user range accuracy (URA) of the broadcast ephemeris. These gross errors can cause large deviations when using the GPS… More >

Zhilin Li^1,∗, Baiying Dong², Fenghua Tong³, Weilong Wang³

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.1, pp. 63-72, 2019, DOI:10.32604/cmes.2019.04635

Abstract The immersed boundary method is well-known, popular, and has had vast areas of applications due to its simplicity and robustness even though it is only first order accurate near the interface. In this paper, an immersed boundary-augmented method has been developed for linear elliptic boundary value problems on arbitrary domains (exterior or interior) with a Dirichlet boundary condition. The new method inherits the simplicity, robustness, and first order convergence of the IB method but also provides asymptotic first order convergence of partial derivatives. Numerical examples are provided to confirm the analysis. More >