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Articles 70291 - 70320 of 302581

Full-Text Articles in Physical Sciences and Mathematics

Research Of Satellite Tactical Communication Network Routing Protocol Simulation Based On Tdma, Yanfang Fu, Li Lu, Gao Xiang, Cheng Bing Aug 2020

Research Of Satellite Tactical Communication Network Routing Protocol Simulation Based On Tdma, Yanfang Fu, Li Lu, Gao Xiang, Cheng Bing

Journal of System Simulation

Abstract: In order to build a globally oriented efficient and seamless tactical communication network system, on the research of satellite and mobile communication network technology, using simulation software OPNET Modeler, a TDMA model and unique tactical communications network was designed. Its main feature is full-completion five layers network model which can satisfy the function of each network level, also provides a reliable basis for later work. After compared with DSR routing, the hierarchical routing shows some advantages in simulation. Some valuable conclusions were drawn, which can provide objective, reliable information for network planning and design.

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Simulation Of Performance Optimization Control About Transcritical Co2 Automotive Air Conditioning System, Jinghua Zhao, Tao Jing, Fangxi Xie, Kainan Zhao Aug 2020

Simulation Of Performance Optimization Control About Transcritical Co2 Automotive Air Conditioning System, Jinghua Zhao, Tao Jing, Fangxi Xie, Kainan Zhao

Journal of System Simulation

Abstract: According to the researching data of certain corporate, a semi-theoretical model of the transcritical CO2 automotive air conditioning system was established using AMESim Software. The research was carried out successively from the aspects of thermodynamics, system performance analysis and optimal control, in order to ensure that the coefficient of performance (COP) reached its maximum. According to the results of exergy loss analysis and performance analysis, the fuzzy PID controller was designed. Under the interference of the ambient temperature change, the controller could control high pressure to ensure COP reach its maximum. The comparison with the well-tuning PID controller …

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Visualocv: Refined Dataflow Programming Interface For Opencv, John Boggess Aug 2020

Visualocv: Refined Dataflow Programming Interface For Opencv, John Boggess

MS in Computer Science Project Reports

OpenCV is a popular tool for developing computer vision algorithms; however, prototyping OpenCV-based algorithms is a time consuming and iterative process. VisualOCV is an open source tool to help users better understand and create computer vision algorithms. A user can see how data is processed at each step in their algorithm, and the results of any changes to the algorithm will be displayed to the user immediately. This can allow the user to easily experiment with various computer vision methods and their parameters. EyeCalc 1.0 uses the Microsoft Foundation Class Library, an old GUI framework by Microsoft, and contains various …

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Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the latest developments in the field of decision agriculture are discussed. The practice of management zones in digital agriculture is described for efficient and smart faming. Accordingly, the methodology for delineating management zones is presented. Modeling of decision support systems is explained along with discussion of the issues and challenges in this area. Moreover, the precision agriculture technology is also considered. Moreover, the chapter surveys the state of the decision agriculture technologies in the countries such as Bulgaria, Denmark, France, Israel, Malaysia, Pakistan, United Kingdom, Ukraine, and Sweden. Finally, different field factors such as GPS accuracy and …

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Electromagnetic Characteristics Of The Soil, Abdul Salam, Usman Raza Aug 2020

Electromagnetic Characteristics Of The Soil, Abdul Salam, Usman Raza

Faculty Publications

The electromagnetic characteristics of the soil are discussed in this chapter. The characteristics of porous bedrock, soil medium, and impacts of rain attenuations are also presented. The models of dielectric soil properties are studied with a rigorous focus on the constitutive parameters of subsurface soil medium. Moreover, the permittivity and wavenumber in soil are explained. In addition, the frequency-dependent dielectric properties such as dispersion in soil, absorption characteristic, and penetration depth versus frequency are reviewed. Furthermore, the effective permittivity of soil–water mixture for through-the soil-propagation mechanism is analyzed thoroughly.

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Underground Phased Arrays And Beamforming Applications, Abdul Salam, Usman Raza Aug 2020

Underground Phased Arrays And Beamforming Applications, Abdul Salam, Usman Raza

Faculty Publications

This chapter presents a framework for adaptive beamforming in underground communication. The wireless propagation is thoroughly analyzed to develop a model using the soil moisture as an input parameter to provide feedback mechanism while enhancing the system performance. The working of array element in the soil is analyzed. Moreover, the effect of soil texture and soil moisture on the resonant frequency and return loss is studied in detail. The wave refraction from the soil–air interface highly degrades the performance of the system. Furthermore, to beam steering is done to achieve high gain for lateral component improving the UG communication. The …

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Study Of Light Extraction Efficiency For Thin-Film-Flip-Chip Light-Emitting Diodes With Periodic Spheroids, Xiaojie Yu, Li Kang, Fanmin Kong, Qingyang Yue Aug 2020

Study Of Light Extraction Efficiency For Thin-Film-Flip-Chip Light-Emitting Diodes With Periodic Spheroids, Xiaojie Yu, Li Kang, Fanmin Kong, Qingyang Yue

Journal of System Simulation

Abstract: The enhancement of light extraction efficiency for thin-film-flip-chip light-emitting diodes (LED) based gallium nitride (GaN) with triangular lattice periodic ellipsoid was studied. Three dimensional finite difference time domain methods (3D-FDTD) were applied to analyze the structural parameters (the period and ellipsoid height) effects on thin-film-flip-chip LED light extraction efficiency. FDTD numerical results prove that ellipsoids structure can improve LED light extraction efficiency and impair guide mode. Method rigorous coupled wave (RCWA) is adopted to analyze diffraction characteristics. This research results show that optimization of the periodic ellipsoid can improve thin-film-flip-chip LED light extraction efficiency increased by 2.8 times.

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Short -Term Prediction Of Wind Power Based On Ide-Wnn And Probabilistic Evaluation, Zengliang Liu, Songlin Zhou, Tongxu Zhou Aug 2020

Short -Term Prediction Of Wind Power Based On Ide-Wnn And Probabilistic Evaluation, Zengliang Liu, Songlin Zhou, Tongxu Zhou

Journal of System Simulation

Abstract: Wind power prediction usually concludes determined and uncertainly prediction. The former puts important on prediction accuracy and the later focus on the the risk of prediction results. For increase the prediction accuracy, an improved differential evolution algorithm was applied to widely search the optimal solution of wavelet neural network in different directions. By calculating joint conditional probability of wind power predictions about prediction error and power fluctuation, the risk of prediction results could be more fully assessed. The effectiveness of the proposed method was verified by simulation experiments.

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General Modeling Method Of Aircraft Constant-Altitude Flight, Xiaowen Duan, Xiaoguang Gao, Li Bo Aug 2020

General Modeling Method Of Aircraft Constant-Altitude Flight, Xiaowen Duan, Xiaoguang Gao, Li Bo

Journal of System Simulation

Abstract: An algorithm for the aircraft constant-altitude long-distance flight consider earth curvature studied. The required overload was calculated using the error between the real position and the ideal trajectory for two basic long-distance flight styles, i.e. great circle flight and circular flight, the simulation model of the two basic constant-altitude flight styles was established. On this basis, taking the modeling of constant-altitude box maneuvering and 8-shape constant-altitude flight as an example, the modeling process of constant-altitude combined model was studied. The simulation result shows the constant-altitude flight model can be widely used, easily implemented and easily expanded. Meanwhile, the model …

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Phy Security Transmission Based On Antenna Selection And Artificial Noise, Deng Dan, Wang Wei, Zhao Ming Aug 2020

Phy Security Transmission Based On Antenna Selection And Artificial Noise, Deng Dan, Wang Wei, Zhao Ming

Journal of System Simulation

Abstract: A physical-layer security enhancement scheme based on antenna selection and artificial noise (ASAN) was proposed. In broadcast phase, the Relay node selected the optimal antenna subset, and transmitted the beamforming matrix and artificial noise vector simultaneously. Simulation results show that the ASAN scheme outperforms classical beamforming scheme. Compared with beamforming scheme, the proposed scheme shows about 2.5dB gain in ergodic secrecy capacity when antenna number of Relay is three, and 3dB gain when the antenna number is six. Specifically, the combined selection criterion shows the similar curve compared with the one-direction criterion, in which the Relay only needs the …

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Cooperative Controller Design For Redundant Dual Arm Robot, Meiling Wang, Minzhou Luo Aug 2020

Cooperative Controller Design For Redundant Dual Arm Robot, Meiling Wang, Minzhou Luo

Journal of System Simulation

Abstract: Cooperative operation for a redundant dual arm robot can be divided into three modes, namely, independent mode, full constrained cooperative working mode and partly constrained cooperative working mode. The dynamic equations of both dual arms and the interactions between dual arms and the operating objects were established and derived based on the three modes, and a unified formulation was obtained. With focus on motion and force of the desired task being operated, a unified controller was designed which could be carried out based on two dynamic model based controllers, namely feedforward controller and computer torque controller. Simulations of dual …

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Trusted Modeling And Analysis Of Complex Software Systems Based On Spatial-Temporal Petri Nets, Li Gang, Longmei Han, Yongli Zhu Aug 2020

Trusted Modeling And Analysis Of Complex Software Systems Based On Spatial-Temporal Petri Nets, Li Gang, Longmei Han, Yongli Zhu

Journal of System Simulation

Abstract: Complexity of complex software system is not only due to the coupling correlation software itself, but also the Internet environment has great influence on the complex software system, and it has not existed independently from the external environment. Petri net uses of place and transition meet the modeling of distributed system, support concurrency and asynchronous, but the basic Petri net can't completely describe the characteristic of complex software systems with time constraints. A Petri net modeling method based on spatial and temporal was proposed. From aspects of synergetic and software behavior, constraints on the characteristics of spatial and temporal, …

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Signals In The Soil: An Introduction To Wireless Underground Communications, Abdul Salam, Usman Raza Aug 2020

Signals In The Soil: An Introduction To Wireless Underground Communications, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, wireless underground (UG) communications are introduced. A detailed overview of WUC is given. A comprehensive review of research challenges in WUC is presented. The evolution of underground wireless is also discussed. Moreover, different component of UG communications is wireless. The WUC system architecture is explained with a detailed discussion of the anatomy of an underground mote. The examples of UG wireless communication systems are explored. Furthermore, the differences of UG wireless and over-the-air wireless are debated. Different types of wireless underground channel (e.g., In-Soil, Soil-to-Air, and Air-to-Soil) are reported as well.

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Modulation Schemes And Connectivity In Wireless Underground Channel, Abdul Salam, Usman Raza Aug 2020

Modulation Schemes And Connectivity In Wireless Underground Channel, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, a thorough treatment of the modulation schemes for UG Wireless is presented. The effects of soil texture and water content on the capacity of multi-carrier modulation in WUC are discussed. The multi-carrier capacity model results are analyzed. Moreover, the underground MIMO design for underground communications is explained thoroughly. An analysis of medium access in wireless underground is done as well. Furthermore, the soil properties are considered for cross-layer communications of UG wireless. The performance analysis of traditional modulation schemes is also considered. The soil moisture-based modulation approach is also explored in this chapter. The connectivity and diversity …

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Underground Wireless Channel Bandwidth And Capacity, Abdul Salam, Usman Raza Aug 2020

Underground Wireless Channel Bandwidth And Capacity, Abdul Salam, Usman Raza

Faculty Publications

The UG channel bandwidth and capacity are vital parameters in wireless underground communication system design. In this chapter, a comprehensive analysis of the wireless underground channel capacity is presented. The impact of soil on return loss, bandwidth, and path loss is discussed. The results of underground multi-carrier modulation capacity are also outlined. Moreover, the single user capacity and multi-carrier capacity are also introduced with an in-depth treatment of soil texture, soil moisture, and distance effects on channel capacity. Finally, the chapter is concluded with a discussion of challenges and open research issues.

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Signals In The Soil: Underground Antennas, Abdul Salam, Usman Raza Aug 2020

Signals In The Soil: Underground Antennas, Abdul Salam, Usman Raza

Faculty Publications

Antenna is a major design component of Internet of Underground Things (IOUT) communication system. The use of antenna, in IOUT, differs from traditional communication in that it is buried in the soil. Therefore, one of the main challenges, in IOUT applications, is to establish a reliable communication. To that end, there is a need of designing an underground-specific antenna. Three major factors that can impact the performance of a buried antenna are: (1) effect of high soil permittivity changes the wavelength of EM waves, (2) variations in soil moisture with time affecting the permittivity of the soil, and (3) difference …

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Soil Moisture And Permittivity Estimation, Abdul Salam, Usman Raza Aug 2020

Soil Moisture And Permittivity Estimation, Abdul Salam, Usman Raza

Faculty Publications

The soil moisture and permittivity estimation is vital for the success of the variable rate approaches in the field of the decision agriculture. In this chapter, the development of a novel permittivity estimation and soil moisture sensing approach is presented. The empirical setup and experimental methodology for the power delay measurements used in model are introduced. Moreover, the performance analysis is explained that includes the model validation and error analysis. The transfer functions are reported as well for soil moisture and permittivity estimation. Furthermore, the potential applications of the developed approach in different disciplines are also examined.

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Current Advances In Internet Of Underground Things, Abdul Salam, Usman Raza Aug 2020

Current Advances In Internet Of Underground Things, Abdul Salam, Usman Raza

Faculty Publications

The latest developments in Internet of Underground Things are covered in this chapter. First, the IOUT Architecture is discussed followed by the explanation of the challenges being faced in this paradigm. Moreover, a comprehensive coverage of the different IOUT components is presented that includes communications, sensing, and system integration with the cloud. An in-depth coverage of the applications of the IOUT in various disciplines is also surveyed. These applications include areas such as decision agriculture, pipeline monitoring, border control, and oil wells.

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Signals In The Soil: Subsurface Sensing, Abdul Salam, Usman Raza Aug 2020

Signals In The Soil: Subsurface Sensing, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, novel subsurface soil sensing approaches are presented for monitoring and real-time decision support system applications. The methods, materials, and operational feasibility aspects of soil sensors are explored. The soil sensing techniques covered in this chapter include aerial sensing, in-situ, proximal sensing, and remote sensing. The underlying mechanism used for sensing is also examined as well. The sensor selection and calibration techniques are described in detail. The chapter concludes with discussion of soil sensing challenges.

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Autonomous Irrigation Management In Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Autonomous Irrigation Management In Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the important application of autonomous irrigation management in the field decision agriculture is discussed. The different types of sensor-guided irrigation systems are presented that includes center pivot systems and drip irrigation systems. Their sensing and actuator components are with detailed focus on real-time decision-making and integration to the cloud. This chapter also presents irrigation control systems which takes, as an input, soil moisture and temperature from IOUT and weather data from Internet and communicate with center pivot based irrigation systems. Moreover, the system architecture is explored where development of the nodes including sensing and actuators is presented. …

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Variable Rate Applications In Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Variable Rate Applications In Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the variable rate applications (VRA) are presented for the field of decision agriculture. The characteristics of VRA control systems are described along with control hardware. Different types of VRA systems are discussed (e.g., liquid VRA systems and dry VRA systems). A case study is also explored in this regard. Moreover, recent advances and future trends are also outlined. Accordingly, a sustainable variable-rate irrigation scheduling is studied where different hardware and software component of the cyber-physical system are considered. Finally, chapter is concluded with a novel sensor deployment methodology.

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Wireless Underground Channel Modeling, Abdul Salam, Usman Raza Aug 2020

Wireless Underground Channel Modeling, Abdul Salam, Usman Raza

Faculty Publications

A comprehensive treatment of wireless underground channel modeling is presented in this chapter. The impacts of the soil on bandwidth and path loss are analyzed. A mechanism for the UG channel sounding and multipath characteristics analysis is discussed. Moreover, novel time-domain impulse response model for WUC is reviewed with the explanation of model parameters and statistics. Furthermore, different types of the through-the-soil wireless communications are surveyed. Finally, the chapter concludes with discussion of the UG wireless statistical model and path loss model for through-the-soil wireless communications in decision agriculture. The model presented in this chapter is also validated with empirical …

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Slashing Quality Index Modeling And Simulation Based On Data Dispersion Clustering, Yuxian Zhang, Xiaoyi Qian, Dong Xiao, Jianhui Wang Aug 2020

Slashing Quality Index Modeling And Simulation Based On Data Dispersion Clustering, Yuxian Zhang, Xiaoyi Qian, Dong Xiao, Jianhui Wang

Journal of System Simulation

Abstract: For the sensitivity of noise and outliers data in the typical partitioning clustering algorithm, a clustering algorithm based on data dispersion was proposed. The data dispersion was defined and introduced to a non-Euclidean distance. The similarity metric was established, and the data clustering was realized. The optimal clustering number was obtained by the validity function based on improved partition coefficient. Then the proposed clustering algorithm was applied to quality index model in slashing process. A size add-on quality index model was built by radial basis function neural networks. The node number of hidden layer was determined and the center …

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Neogene Stratigraphy And Regional Correlation Of The Çeşme Peninsula, Western Anatolia, Turkey, Fikret Göktaş Aug 2020

Neogene Stratigraphy And Regional Correlation Of The Çeşme Peninsula, Western Anatolia, Turkey, Fikret Göktaş

Bulletin of the Mineral Research and Exploration

This study aims to investigate the stratigraphy and regional correlation of terrestrial Neogene sediments and volcanics in the Çeşme Peninsula. Neogene deposition is represented by two main sedimentary successions separated from each other by an angular unconformity. The lacustrine dominated Çeşme group characterized the Lower-Middle Miocene deposition is formed by Şifne, Ovacık and Çiftlik formations. The felsic pyroclastics (Alaçatı pyroclastics), which are the early products of the Armağandağı volcanism, laterally associated with the Çeşme group deposition, deposited on the Şifne formation and interrupted the lacustrine sedimentation. The lacustrine sedimentation continued uninterruptedly with Ovacık and Çiftlik formations after the deposition of …

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Artificial Neural Network Discovery Of A Switchable Metasurface Reflector, J. R. Thompson, J. A. Burrow, P. J. Shah, J. Slagle, E. S. Harper, A. Van Rynbach, I. Agha, M. S. Mills Aug 2020

Artificial Neural Network Discovery Of A Switchable Metasurface Reflector, J. R. Thompson, J. A. Burrow, P. J. Shah, J. Slagle, E. S. Harper, A. Van Rynbach, I. Agha, M. S. Mills

Electro-Optics and Photonics Faculty Publications

Optical materials engineered to dynamically and selectively manipulate electromag- netic waves are essential to the future of modern optical systems. In this paper, we simulate various metasurface configurations consisting of periodic 1D bars or 2D pillars made of the ternary phase change material Ge2Sb2Te5 (GST). Dynamic switching behavior in reflectance is exploited due to a drastic refractive index change between the crystalline and amorphous states of GST. Selectivity in the reflection and transmission spectra is manipulated by tailoring the geometrical parameters of the metasurface. Due to the immense number of possible metasurface configurations, we train deep neural networks capable of …

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Research On Cholecystectomy Virtual Surgery Simulation Training Platform, Wang Jun, Liu Dong Aug 2020

Research On Cholecystectomy Virtual Surgery Simulation Training Platform, Wang Jun, Liu Dong

Journal of System Simulation

Abstract: The main performance factors in virtual surgery system with immersion are real-time, realistic deformation and smooth feel handle. A kind of cholecystectomy simulation training platform with force feedback feel was built, putting forward a kind of collision detection method based on Capsule-Sphere mixture model of different model with different bounding box in the real-time and a kind of mass-spring deformation method based on mesh-skeleton model in the force-deformation, and being tested on the virtual surgery force feedback device in prophase research. The experimental results show that the two modes are applied to the virtual cholecystectomy simulation and the platform …

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Wood Structure Nondestructive Detection Based On Singular Spectrum Analysis And Svm, Guoxiong Zhou, Aibin Chen, Xianyan Zhou Aug 2020

Wood Structure Nondestructive Detection Based On Singular Spectrum Analysis And Svm, Guoxiong Zhou, Aibin Chen, Xianyan Zhou

Journal of System Simulation

Abstract: In view of unknown defect of wood component defect, a method of wood structure nondestructive recognition based on Singular spectrum analysis and SVM was proposed. The wood specimen was tested to obtain the test signal by ultrasonic testing instrument. In order to eliminate the testing effect of the tester gain control and defect size, angle variation on the test defect echo amplitude, the abnormal fluctuation was to filter and characteristic of the original signal was extracted by singular spectrum analysis, and SVM could train the parameters and distinguish the wood defects. Simulation results show that the proposed method …

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Segmentation And Recognition Of Hand-Drawn Situation Maps, Deng Wei, Lingda Wu, Yougen Zhang, Yang Chao Aug 2020

Segmentation And Recognition Of Hand-Drawn Situation Maps, Deng Wei, Lingda Wu, Yougen Zhang, Yang Chao

Journal of System Simulation

Abstract: Most of current research on online sketched military symbol recognition concerns the isolated samples. In pen-based situation marking systems, users prefer segmenting and recognizing the full sketched situation maps. However, it is a more difficult problem. The characteristics of hand-drawn situation maps and difficulties to segment them were analyzed, and a dynamic programming-based approach was proposed. A hand-drawn situation map was segmented coarsely by minimum spanning tree-based stroke clustering. The candidate segmentation path was evaluated by synthesizing geometric analysis and isolated symbol classifier together, using confidence transformation and fusion. The dynamic programming algorithm was used to search the …

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Evaluation Method Of Training Simulation Result Based On Grey Clustering And Analytic Hierarchy Process, Zhaobin Wu, Chen Li, Chunxia Zhao Aug 2020

Evaluation Method Of Training Simulation Result Based On Grey Clustering And Analytic Hierarchy Process, Zhaobin Wu, Chen Li, Chunxia Zhao

Journal of System Simulation

Abstract: An evaluation method based on grey relational analytic hierarchy process was proposed in order to improve rationality of evaluation training result of portable anti-air missile training simulation system. The evaluating indicators including definitions and calculation equations were proposed from three aspects including accuracy, rapidity and stationarity. The weights of the evaluating indicators were calculated by analytic hierarchy process of multiple experts, and the scores of the evaluating indicators were given by 0-1 process and grey clustering evaluation, and using the weights and scores of the evaluating indicators the training score could be obtained. An example of evaluation training result …

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Thermoresponsive Self-Immolative Polyglyoxylamides., Amir Rabiee Kenaree, Quinton E. A. Sirianni, Kyle Classen, Elizabeth R. Gillies Aug 2020

Thermoresponsive Self-Immolative Polyglyoxylamides., Amir Rabiee Kenaree, Quinton E. A. Sirianni, Kyle Classen, Elizabeth R. Gillies

Chemistry Publications

Thermoresponsive polymers with lower critical solution temperatures (LCSTs) are of significant interest for a wide range of applications from sensors to drug delivery vehicles. However, the most widely investigated LCST polymers have nondegradable backbones, limiting their applications

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