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Geometry-based graphical methods for solar control in architecture:A digital framework
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作者 Federico Bertagna Valeria Piccioni Pierluigi D’Acunto 《Frontiers of Architectural Research》 CSCD 2023年第4期754-774,共21页
The form of a building is among the most critical design aspects concerning building energy consumption.Form-based passive design strategies,like solar control,can significantly reduce heating and cooling demands if i... The form of a building is among the most critical design aspects concerning building energy consumption.Form-based passive design strategies,like solar control,can significantly reduce heating and cooling demands if implemented early in the design process.In this sense,there is an evident need for tools that can adequately support designers in their decisions.This paper aims to illustrate how geometry-based graphical methods(GGM)can provide effective support in the conceptual design stage.The paper introduces a novel digital framework for designing and analysing shading devices that leverages geometrical models and graphical methods.The digital implementation of GGM allows extending their applicability to threedimensional and non-planar geometries.A comprehensive review of existing methods and tools for the design of shading devices lays the ground for the proposed digital framework,which is then demonstrated through two case studies.The results show that the diagrammatic nature of GGM facilitates a better and more direct understanding of the relationship between form and performance. 展开更多
关键词 Solar control GEOMETRY graphical methods Facade design Passive design Computational tools
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Systematic Review of Graphical Visual Methods in Honeypot Attack Data Analysis
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作者 Gbenga Ikuomenisan Yasser Morgan 《Journal of Information Security》 2022年第4期210-243,共34页
Mitigating increasing cyberattack incidents may require strategies such as reinforcing organizations’ networks with Honeypots and effectively analyzing attack traffic for detection of zero-day attacks and vulnerabili... Mitigating increasing cyberattack incidents may require strategies such as reinforcing organizations’ networks with Honeypots and effectively analyzing attack traffic for detection of zero-day attacks and vulnerabilities. To effectively detect and mitigate cyberattacks, both computerized and visual analyses are typically required. However, most security analysts are not adequately trained in visualization principles and/or methods, which is required for effective visual perception of useful attack information hidden in attack data. Additionally, Honeypot has proven useful in cyberattack research, but no studies have comprehensively investigated visualization practices in the field. In this paper, we reviewed visualization practices and methods commonly used in the discovery and communication of attack patterns based on Honeypot network traffic data. Using the PRISMA methodology, we identified and screened 218 papers and evaluated only 37 papers having a high impact. Most Honeypot papers conducted summary statistics of Honeypot data based on static data metrics such as IP address, port, and packet size. They visually analyzed Honeypot attack data using simple graphical methods (such as line, bar, and pie charts) that tend to hide useful attack information. Furthermore, only a few papers conducted extended attack analysis, and commonly visualized attack data using scatter and linear plots. Papers rarely included simple yet sophisticated graphical methods, such as box plots and histograms, which allow for critical evaluation of analysis results. While a significant number of automated visualization tools have incorporated visualization standards by default, the construction of effective and expressive graphical methods for easy pattern discovery and explainable insights still requires applied knowledge and skill of visualization principles and tools, and occasionally, an interdisciplinary collaboration with peers. We, therefore, suggest the need, going forward, for non-classical graphical methods for visualizing attack patterns and communicating analysis results. We also recommend training investigators in visualization principles and standards for effective visual perception and presentation. 展开更多
关键词 Honeypot Data Analysis Network Intrusion Detection Visualization and Visual Analysis graphical methods and Perception Systematic Literature Review
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Graphic Methods in Topological Dynamics
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作者 陈仁莲 何伟弘 罗俊 《Northeastern Mathematical Journal》 CSCD 2008年第2期109-117,共9页
This paper considers the graph sequence graph (f^n )={x×f^n : x ∈X} of the iterates f^n of a continuous map f : X →X on a compact metric space (X, d). The main aim is to introduce serval limit sets by usi... This paper considers the graph sequence graph (f^n )={x×f^n : x ∈X} of the iterates f^n of a continuous map f : X →X on a compact metric space (X, d). The main aim is to introduce serval limit sets by using different recurrent time sets, and discuss the relation between dynamics of the underlying compact system (X, f) and the structure of these limit sets, from a topological or fractal viewpoint. 展开更多
关键词 graphic method dynamical system topological dynamics topological superior limit topological inferior limit
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Characterization of Complex Fracture System in Volume Fracturing of Shale Gas Reservoir
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作者 Songru Mou Jie Tan +2 位作者 Wengtong Zhang Zhengyang Tan Zijin Li 《Journal of Geoscience and Environment Protection》 2023年第7期1-10,共10页
After volume fracturing of horizontal wells in shale gas reservoir, an extremely complex fracture system is formed. The space area of the fracture system is the reservoir reconstruction volume of shale gas reservoir. ... After volume fracturing of horizontal wells in shale gas reservoir, an extremely complex fracture system is formed. The space area of the fracture system is the reservoir reconstruction volume of shale gas reservoir. The geometric parameters such as crack length, crack width, crack height, and characteristic parameters such as crack permeability and fracture conductivity proposed for a single crack in conventional fracturing are insufficient to describe and characterize the complex network fracture system after volume fracturing. In this paper, the discrete fracture modeling method is used to establish the volume fracturing network fracture model of horizontal wells in shale gas reservoir by using the random modeling method within the determined reservoir space. The model is random and selective, and can fully provide different forms of volume fracturing fracture expansion, such as conventional fracture morphology, line network model and arbitrarily distributed network fractures. The research results provide a theoretical basis for the development plan and stimulation plan of shale gas reservoir, and have important reference value and significance for other unconventional gas reservoir fracturing. 展开更多
关键词 Reservoir Reconstruction Volume graphical Combination Method Boundary Analysis Method Probability Method Network Fracture Density
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Base Flow Index Evaluation for Yom River,Thailand
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作者 Kanokporn Sawatpru 《Journal of Civil Engineering and Architecture》 2023年第10期523-531,共9页
The most controversial river in Thailand is the Yom River.It has not been modified by large dam because of several valuable natural resources.Therefore,the river is flooded in rainy season and very low flow in dry sea... The most controversial river in Thailand is the Yom River.It has not been modified by large dam because of several valuable natural resources.Therefore,the river is flooded in rainy season and very low flow in dry season.The low flow causes drought which is much more serious than flooding.The Yom River Basin management is only way to circumvent the low flow problem by studying base flow index(BFI).Base flow analyses for 8 gauging stations along the river were performed by 2 techniques i.e.graphical and modified U.K.Institute of Hydrology(MIH).The mean BFI results from graphical and MIH are 0.37(0.05)and 0.45(0.12).The result from graphical is more reasonable due to its lower standard deviation.BFI values from MIH vary with watershed area which may result from the using of fixing value of N-day at 10.Solution for this problem is ongoing in this study. 展开更多
关键词 Base flow index graphical method low flow MIH method
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SELF-DEPENDENT LOCALITY PRESERVING PROJECTION WITH TRANSFORMED SPACE-ORIENTED NEIGHBORHOOD GRAPH
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作者 乔立山 张丽梅 孙忠贵 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2010年第3期261-268,共8页
Locality preserving projection (LPP) is a typical and popular dimensionality reduction (DR) method,and it can potentially find discriminative projection directions by preserving the local geometric structure in da... Locality preserving projection (LPP) is a typical and popular dimensionality reduction (DR) method,and it can potentially find discriminative projection directions by preserving the local geometric structure in data. However,LPP is based on the neighborhood graph artificially constructed from the original data,and the performance of LPP relies on how well the nearest neighbor criterion work in the original space. To address this issue,a novel DR algorithm,called the self-dependent LPP (sdLPP) is proposed. And it is based on the fact that the nearest neighbor criterion usually achieves better performance in LPP transformed space than that in the original space. Firstly,LPP is performed based on the typical neighborhood graph; then,a new neighborhood graph is constructed in LPP transformed space and repeats LPP. Furthermore,a new criterion,called the improved Laplacian score,is developed as an empirical reference for the discriminative power and the iterative termination. Finally,the feasibility and the effectiveness of the method are verified by several publicly available UCI and face data sets with promising results. 展开更多
关键词 graphic methods Laplacian transforms unsupervised learning dimensionality reduction locality preserving projection
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Analysis on the Interaction of Parameters of Single-contaminant Regeneration Recycling Water Systems 被引量:4
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作者 白洁 冯霄 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第1期21-25,共5页
Method for constructing the optimal water supply line and formulas for calculating the targets for single-contaminant regeneration recycling water systems are improved to apply to the situation of variational pararnet... Method for constructing the optimal water supply line and formulas for calculating the targets for single-contaminant regeneration recycling water systems are improved to apply to the situation of variational pararneters in this article. Based on these extending methods, the effect of varying freshwater consumption and regenerated water flow rate on the optimizing results are investigated. The interactions of parameters of regeneration recycling systems are summarized. Finally, all the conclusions are illustrated from the results of mathematical programming through an example. 展开更多
关键词 water system regeneration recycling graphical method mathematical prograrrmung interaction ot parameters
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Validation methodology for distribution-based degradation model 被引量:1
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作者 Yunxia Chen Zhiguo Zeng Rui Kang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第4期553-559,共7页
Distribution-based degradation models (or graphical approach in some literature) occur in a wide range of applications. However, few of existing methods have taken the validation of the built model into consideratio... Distribution-based degradation models (or graphical approach in some literature) occur in a wide range of applications. However, few of existing methods have taken the validation of the built model into consideration. A validation methodology for distribution-based models is proposed in this paper. Since the model can be expressed as consisting of assumptions of model structures and embedded model parameters, the proposed methodology carries out the validation from these two aspects. By using appropriate statistical techniques, the rationality of degradation distributions, suitability of fitted models and validity of degradation models are validated respectively. A new statistical technique based on control limits is also proposed, which can be implemented in the validation of degradation models' validity. The case study on degradation modeling of an actual accelerometer shows that the proposed methodology is an effective solution to the validation problem of distribution-based de qradation models. 展开更多
关键词 degradation model distribution-based degradationmodel graphical method model validation control limits.
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Dynamic Coverage with Wireless Sensor and Actor Networks in Underwater Environment 被引量:1
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作者 Xiaoyuan Luo Liu Feng +1 位作者 Jing Yan Xinping Guan 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI 2015年第3期274-281,共8页
This paper studies the problem of dynamic coverage with wireless sensor and actor networks (WSANs) in underwater environment. Different from most existing works, the WSANs consist of two kinds of nodes, i.e., sensor n... This paper studies the problem of dynamic coverage with wireless sensor and actor networks (WSANs) in underwater environment. Different from most existing works, the WSANs consist of two kinds of nodes, i.e., sensor nodes (SNs) which cannot move autonomously and actor nodes (ANs) which can move autonomously according to the performance requirement. The problem of how to coordinate two kinds of nodes to facilitate dynamic coverage in underwater environment is challenging due to their heterogeneous capabilities. To reduce redundancy of communication links and improve connectivity between ANs and SNs in underwater WSANs, a min-weighted rigid graph based topology optimization scheme is first developed, such that the underwater communication energy consumption can be saved. With the optimized topology, a dynamic coverage strategy is proposed to improve the coverage among SNs and ANs for underwater WSAN where underwater fluid motions are considered. Furthermore, it is proved that the network coverage area is connected by using the min-weighted rigid graph. Finally, simulation results are presented to show the effectiveness of the main results. © 2014 Chinese Association of Automation. 展开更多
关键词 Energy utilization Graphic methods Sensor nodes TOPOLOGY
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Numerical study and acceleration of LBM-RANS simulation of turbulent flow 被引量:1
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作者 Shuli Shu Ning Yang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第1期31-42,共12页
The coupled models of LBM (Lattice Boltzmann Method) and RANS (Reynolds-Averaged Navier-Stokes) are more practical for the transient simulation of mixing processes at large spatial and temporal scales such as crud... The coupled models of LBM (Lattice Boltzmann Method) and RANS (Reynolds-Averaged Navier-Stokes) are more practical for the transient simulation of mixing processes at large spatial and temporal scales such as crude oil mixing in large-diameter storage tanks. To keep the efficiency of parallel computation of LBM, the RANS model should also be explicitly solved; whereas to keep the numerical stability the implicit method should be better for PANS model. This article explores the numerical stability of explicit methods in 2D cases on one hand, and on the other hand how to accelerate the computation of the coupled model of LBM and an implicitly solved RANS model in 3D cases. To ensure the numerical stability and meanwhile avoid the use of empirical artificial lim- itations on turbulent quantities in 2D cases, we investigated the impacts of collision models in LBM (LBGK, MRT) and the numerical schemes for convection terms (WENO, TVD) and production terms (FDM, NEQM) in an explic- itly solved standard k-e model. The combination of MRT and TVD or MRT and NEQM can be screened out for the 2D simulation of backward-facing step flow even at Re = 107. This scheme combination, however, may still not guarantee the numerical stability in 3D cases and hence much finer grids are required, which is not suitable for the simulation of industrial-scale processes.Then we proposed a new method to accelerate the coupled model of LBM with RANS (implicitly solved). When implemented on multiple GPUs, this new method can achieve 13.5-fold accelera- tion relative to the original coupled model and 40-fold acceleration compared to the traditional CFD simulation based on Finite Volume (FV) method accelerated by multiple CPUs. This study provides the basis for the transient flow simulation of larger spatial and temporal scales in industrial applications with LBM-RANS methods. 展开更多
关键词 Lattice Boltzmann Method Reynolds-Averaged Navier-Stokes Graphic Processing Units mixing transient simulation
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An Investigative Study for Smart Home Security: Issues, Challenges and Countermeasures 被引量:1
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作者 Sudhir Chitnis Neha Deshpande Arvind Shaligram 《Wireless Sensor Network》 2016年第4期61-68,共8页
Home security should be a top concern for everyone who owns or rents a home. Moreover, safe and secure residential space is the necessity of every individual as most of the family members are working. The home is left... Home security should be a top concern for everyone who owns or rents a home. Moreover, safe and secure residential space is the necessity of every individual as most of the family members are working. The home is left unattended for most of the day-time and home invasion crimes are at its peak as constantly monitoring of the home is difficult. Another reason for the need of home safety is specifically when the elderly person is alone or the kids are with baby-sitter and servant. Home security system i.e. HomeOS is thus applicable and desirable for resident’s safety and convenience. This will be achieved by turning your home into a smart home by intelligent remote monitoring. Smart home comes into picture for the purpose of controlling and monitoring the home. It will give you peace of mind, as you can have a close watch and stay connected anytime, anywhere. But, is common man really concerned about home security? An investigative study was done by conducting a survey to get the inputs from different people from diverse backgrounds. The main motivation behind this survey was to make people aware of advanced HomeOS and analyze their need for security. This paper also studied the necessity of HomeOS investigative study in current situation where the home burglaries are rising at an exponential rate. In order to arrive at findings and conclusions, data were analyzed. The graphical method was employed to identify the relative significance of home security. From this analysis, we can infer that the cases of having kids and aged person at home or location of home contribute significantly to the need of advanced home security system. At the end, the proposed system model with its flow and the challenges faced while implementing home security systems are also discussed. 展开更多
关键词 HomeOS Smart Home Intelligent Remote Monitoring graphical Method Home Security System
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Modeling and inferring 2.1D sketch with mixed Markov random field
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作者 Anlong Ming Yu Zhou Tianfu Wu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期361-373,共13页
This paper presents a method of computing a 2.1D sketch (i.e., layered image representation) from a single image with mixed Markov random field (MRF) under the Bayesian framework. Our model consists of three layers: t... This paper presents a method of computing a 2.1D sketch (i.e., layered image representation) from a single image with mixed Markov random field (MRF) under the Bayesian framework. Our model consists of three layers: the input image layer, the graphical representation layer of the computed 2D atomic regions and 3-degree junctions (such as T or arrow junctions), and the 2.1D sketch layer. There are two types of vertices in the graphical representation of the 2D entities: (i) regions, which act as the vertices found in traditional MRF, and (ii) address variables assigned to the terminators decomposed from the 3-degree junctions, which are a new type of vertices for the mixed MRF. We formulate the inference problem as computing the 2.1D sketch from the 2D graphical representation under the Bayesian framework, which consists of two components: (i) region layering/coloring based on the Swendsen-Wang cuts algorithm, which infers partial occluding order of regions, and (ii) address variable assignments based on Gibbs sampling, which completes the open bonds of the terminators of the 3-degree junctions. The proposed method is tested on the D-Order dataset, the Berkeley segmentation dataset and the Stanford 3D dataset. The experimental results show the efficiency and robustness of our approach. © 2017 Beijing Institute of Aerospace Information. 展开更多
关键词 Graphic methods Image segmentation Inference engines Markov processes Structural frames
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Computer Processing of the Intersection of Two Cones with Their Axes Intersecting and a Method to Get the Special Points
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作者 杨培中 《Journal of Donghua University(English Edition)》 EI CAS 2008年第2期213-217,共5页
The analytic expression of the special points on the intersection of two cones with their axes intersecting(ITCTAI) is given. It also presents a method to construct the special points graphically according to the anal... The analytic expression of the special points on the intersection of two cones with their axes intersecting(ITCTAI) is given. It also presents a method to construct the special points graphically according to the analytic expression of them. Finally, with computer programming language, it gives a program to generate the intersection in several different cases. 展开更多
关键词 ITCTAI INTERSECTION special points graphical method computer processing
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TRANSPORTATION NETWORKS:OLD AND NEW
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作者 LIU YANPEI(Department of Mathematics,Northern Jiaotong University, Beijing 100044) 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1996年第3期251-272,共22页
This paper shows a number of Problems in pure and applied mathematicsthat are solved by constructing transportation networks.Moreover,it also shows thatall the solutions are characterized by forbidden configurations w... This paper shows a number of Problems in pure and applied mathematicsthat are solved by constructing transportation networks.Moreover,it also shows thatall the solutions are characterized by forbidden configurations which are not minors.However,all the characterizations are much related to the graphic method which wasfound by Chinese for solving a kind of the transportation problem in the fifties. 展开更多
关键词 Mathematical programming transportation problem network graphic method forbidden configuration.
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Ways of Determining the Focal Mechanisms in the Carpathian Region of Ukraine
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作者 Anastasiia Pavlova Oksana Hrytsai and Dmytro Malytskyy 《Journal of Earth Science and Engineering》 2014年第1期54-71,共18页
The modification to the matrix method for constructing the displacement field on the free surface of an anisotropic layered medium was presented. The source of seismic waves was modelled by a randomly oriented force a... The modification to the matrix method for constructing the displacement field on the free surface of an anisotropic layered medium was presented. The source of seismic waves was modelled by a randomly oriented force and seismic tensor. A trial and error method was presented for solving the inverse problem of determining parameters of the earthquake source. A number of analytical and numerical approaches to determining the earthquake source parameters, based on the direct problem solutions, were proposed. The focal mechanisms for the events in the Carpathian region of Ukraine are determined by the graphical method. The theory of determinating the angles of orientation of the fault plane and the earthquake's focal mechanism was presented. The focal mechanisms obtained by two different methods were compared. 展开更多
关键词 Matrix method wave propagator ANISOTROPY focal mechanism graphical method.
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A Study for the Environmental Design Supporting an Intellectual Activity
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作者 Keisuke Aoyagi Akiko Watanabe 《Journal of Civil Engineering and Architecture》 2014年第2期186-196,共11页
Japan is facing a demographic challenge of a falling birthrate coupled with an aging society that is already adversely affecting the economy. The situation is only expected to worsen as the working-age population cont... Japan is facing a demographic challenge of a falling birthrate coupled with an aging society that is already adversely affecting the economy. The situation is only expected to worsen as the working-age population continues to decrease. Well aware of this situation, businesses and offices are seeking ways to enhance the intellectual productivity of their workers. This paper explores environmental elements of work spaces that might stimulate intellectual activity. Using a CAD (AutoCAD) miniature garden program, subjects were asked to design a project room that is optimized for creative work using a certain number of elements--11 types of walls, 14 types of floors, 4 types of scenery, 3 types of furniture and 3 types of plantings--but the subjects were free to position and arrange these elements any way they want. The subjects were then interviewed using the evaluation grid method. Based on the results, we created an evaluation structure diagram by analyzing key words and phrases emphasized by subjects in the interviews. The overall evaluation structure represents a summary overview of all 30 subjects who participated in the experiment. This approach captures all the key elements of the office environment that might be used to stimulate intellectual activity of employees. 展开更多
关键词 Office environmental design intellectual productivity evaluation grid method CG (computer graphics) type miniaturegarden.
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Approximate graphical method of solving Fermi level and majority carrier density of semiconductors with multiple donors and multiple acceptors 被引量:2
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作者 Ken K.Chin 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2011年第6期1-6,共6页
We present a generic approximate graphical method for determining the equilibrium Fermi level and majority carrier density of a semiconductor with multiple donors and multiple acceptors compensating each other. Simple... We present a generic approximate graphical method for determining the equilibrium Fermi level and majority carrier density of a semiconductor with multiple donors and multiple acceptors compensating each other. Simple and easy-to-follow procedures of the graphical method are described.By graphically plotting two wrapping step functions facing each other,one for the positive hole-ionized donor and one for the negative electron-ionized acceptor,we have the crossing point that renders the Fermi level and majority carrier density.Using the graphical method,new equations are derived,such as the carrier compensation proportional to N;/N;,not the widely quoted N;-N;.Visual insight is offered to view not only the result of graphic determination of Fermi level and majority carrier density but also the dominant and critical pair of donors and acceptors in compensation.The graphical method presented in this work will help to guide the design,adjustment,and improvement of the multiply doped semiconductors.Comparison of this approximate graphical method with previous work on compensation,and with some experimental results,is made.Future work in the field is proposed. 展开更多
关键词 doping compensation Fermi level carrier density graphical method IONIZATION
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A graphical method of presenting property rights, building types, and residential behaviors: A case study of Xiaoxihu historic area, Nanjing 被引量:2
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作者 Yinan Dong Dongqing Han Marco Trisciuoglio 《Frontiers of Architectural Research》 CSCD 2022年第6期1077-1091,共15页
One of the main reasons for the decline of urban historic areas in China is the coexistence of multiple property rights.It also deeply affects conservation and regeneration practice.This paper aims to propose a graphi... One of the main reasons for the decline of urban historic areas in China is the coexistence of multiple property rights.It also deeply affects conservation and regeneration practice.This paper aims to propose a graphical method that illustrates the association between property rights,space,and resident behavior.Based on typological maps and justified graphs,a three-step method was proposed to visualize the relationships between these three elements.The final graph and quantitative data were used to observe the evolution of the courtyard building from a diachronic perspective,as well as to compare the residential behavior in different types from a synchronic perspective.The results show that following the subdivision of property rights,the building layout become more diverse due to various illegal additions,while the residential behavior within different building types tends to be consistent.Moreover,the study observed the traditional Chinese courtyard buildings’adaptability.The findings contribute to understand the evolution of Chinese urban historic areas and internal motivation,and provide guidance for the conservation and regeneration practice. 展开更多
关键词 Property rights Building types Residential behaviors graphical method Historic area
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Graphical method based on modified maximum force criterion to indicate forming limit curves of 22MnB5 boron steel sheets at elevated temperatures
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作者 Thanh Luyen Quoc-Tuan Pham +2 位作者 Thi-Bich Mac Tien-Long Banh Duc-Toan Nguyen 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2021年第8期1009-1018,共10页
A new approach for predicting forming limit curves(FLCs)at elevated temperatures was proposed herein.FLCs are often used to predict failure and determine the optimal forming parameters of automotive parts.First,a grap... A new approach for predicting forming limit curves(FLCs)at elevated temperatures was proposed herein.FLCs are often used to predict failure and determine the optimal forming parameters of automotive parts.First,a graphical method based on a modified maximum force criterion was applied to estimate the FLCs of 22MnB5 boron steel sheets at room temperature using various hardening laws.Subsequently,the predicted FLC data at room temperature were compared with corresponding data obtained from Nakazima's tests to obtain the best prediction.To estimate the FLC at elevated temperatures,tensile tests were conducted at various temperatures to determine the ratios of equivalent fracture strains between the corresponding elevated temperatures and room temperature.FLCs at elevated temperatures could be established based on obtained ratios.However,the predicted FLCs at elevated temperatures did not agree well with the corresponding FLC experimental data of Zhou et al.A new method was proposed herein to improve the prediction of FLCs at elevated temperatures.An FLC calculated at room tem-perature was utilized to predict the failure of Nakazima's samples via finite element simulation.Based on the simulation results at room temperature,the mathematical relationships between the equivalent ductile fracture strain versus stress triaxiality and strain ratio were established and then combined with ratios between elevated and room temperatures to calculate the FLCs at different temperatures.The predicted FLCs at elevated temperatures agree well with the corresponding experimental FLC data. 展开更多
关键词 Forming limit curve Modified maximum force criterion graphical method Hardening law Finite element method Boron steel sheet Elevated temperature
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Capacity of Sun-driven lunar swingby sequences and their application in asteroid retrieval
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作者 Hongru Chen 《Astrodynamics》 CSCD 2023年第3期315-334,共20页
For deep-space mission design,the gravity of the Sun and the Moon can be first considered and utilized.Their gravity can provide the energy change for launching spacecraft and retrieving spacecraft as well as asteroid... For deep-space mission design,the gravity of the Sun and the Moon can be first considered and utilized.Their gravity can provide the energy change for launching spacecraft and retrieving spacecraft as well as asteroids.Regarding an asteroid retrieval mission,it can lead to the mitigation of asteroid hazards and an easy exploration and exploitation of the asteroid.This paper discusses the application of the Sun-driven lunar swingby sequence for asteroid missions.Characterizing the capacity of this technique is not only interesting in terms of the dynamic insights but also non-trivial for trajectory design.The capacity of a Sun-driven lunar swingby sequence is elucidated in this paper with the help of the“Swingby-Jacobi”graph.The capacity can be represented by a range of the Jacobi integral that encloses around 660 asteroids currently cataloged.To facilitate trajectory design,a database of Sun-perturbed Moon-to-Moon transfers,including multi-revolution cases,is generated and employed.Massive trajectory options for spacecraft launch and asteroid capture can then be explored and optimized.Finally,a number of asteroid flyby,rendezvous,sample-return,and retrieval mission options enabled by the proposed technique are obtained. 展开更多
关键词 asteroid mining planetary defense gravity assists Moon-to-Moon transfers reachable sets graphical methods
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