bluuebunny/crossref_metadata_2025 huggingface dataset:
Applying Web 2.0 Technologies to Traditional Teaching
Authors: Collins Royce Ann
Published: September 2010

Through out the years, teaching has evolved with each passing generation and adapted to the new technologies and new ways of instructing as the latest research is published. For example, once typing was taught with manual typewriters, then electric typewriters. Now, the courses are called keyboarding and they are taught on computers. Currently, the teaching platform is evolving into a virtual world with collaborative, interactive web technologies. Addressing teaching from a learner-centered approach, this chapter will discuss the evolution of teaching as new generations of adults enter the learning environment and examine a case study of one instructor’s journey in incorporating new Web 2.0 technologies into courses.
Women, Information and Communication Technologies, and Lifelong Learning
Authors: Irving Catherine J. , English Leona M.
Published: September 2010

This chapter arises from the authors’ research interests in gender and adult learning in the community, with a special focus on how gender is enacted in communities of practice such as nonprofit women’s organizations. These organizations play a key role in adult learning—nonformally through workshops and programs and informally through mentoring, collaboration, and information sharing. They also work informally and incidentally through advocacy work for social change to redress systemic gender-based discrimination. This chapter assesses how well the services and learning that happen in this context have evolved with the adoption of Information and Communication Technologies (ICTs) by women’s groups, in this case organizational websites. The authors place this discussion within the context of a small but growing literature examining the integration of ICTs within community development. In addition, we draw on feminist theoretical understandings and critiques of technology as it affects the lives of women. Although ICTs provide opportunities to further the cause of gender equality globally, inequalities persist to limit the realization of this potential.
Successful Strategies in the Online Learning Environment Based on Theories, Styles, and Characteristics
Authors: Skinner Leane B.
Published: September 2010

With the continuous increase in online student enrollment, it is important to examine the learning/teaching process in the online learning environment in order to develop the most effective model in this unique environment. This chapter will explore various e-learner and e-educator styles and teaching strategies in the online environment. Theories and an evaluation of their appropriateness in an online learning environment will be presented. The impact of learning styles, social styles, decision styles, and generational styles in the online learning environment will be analyzed. Additionally, there will be a discussion of the characteristics and traits of the successful e-learner, successful e-educator, and successful course and curriculum design model based on specific theories and styles.
Using Technology in the Assessment of Adult Learners in Online Settings
Authors: Schmidt Steven W. , Dickerson Jeremy , Kisling Eric
Published: September 2010

This chapter utilizes instructor experiences and reflections as the bases for framing assessment theory and practice of online learning in adult education. It begins with a general discussion of assessment in the field of adult education. Following that overview, the chapter describes ways to assess students by providing examples of methods, techniques, and technologies that can be utilized by adult educators as they endeavor to assess online learners. Lastly, the chapter concludes with an in-depth analysis of a specific assessment strategy and technology that utilizes software simulation to train and assess student skills in popular productivity software packages.
Self-Assessments in Contemporary Adult E-Learning
Authors: Hai-Jew Shalin
Published: September 2010

With the ever higher costs of human-led instruction, much of adult electronic learning (e-learning) has become automated, independent, dispersed to open-source locales, and open learning. There has been a growing focus on adult learner self-initiative in identifying and pursuing learning opportunities independently. Such discovery learning is not just for practical and informal work but has now reached well into formalized trainings and deeper lifelong learning. This phenomenon has led to a variety of methods for adult learner self-assessment of their own learning—ranging from pre-determined scripted responses to live human feedback to mixed-methods feedback. Feedback loops for learner self-assessment are critical to support learner engagement, actual learning, learner self-efficacy, decision-making, skills acquisition, and human development; these also enhance mutually supportive collaborations and innovations between co-learners; and they enable workplace and higher education credentialing needs. This chapter highlights the importance of self-assessments and learner feedback in e-learning, and proposes some foundational design strategies.
Digital Media
Authors: King Kathleen P.
Published: September 2010

Digital media, podcasting, digital video, and blogging all provide great opportunities for adult learners to become actively involved in expressing their knowledge and skills through project based learning. While this deep learning experience involves research, critical thinking and 21st Century learning skills, it also provides substantial opportunities for the cultivation of much needed affective benefits. Soft skills have long been recognized as a valid and valued realm within career and technical education (CTE), continuing education and adult education. This chapter reveals how to use digital media in instructional settings to cultivate voice and empowerment among adult learners. The author includes details of outcomes and practical strategies and processes.
Gender and Collaborative Knowledge Building in an Online Community of Inquiry
Authors: Wanstreet Constance E. , Stein David S.
Published: September 2010

This chapter addresses the implications of gender on participation, collaboration, and ultimately shared understanding and proposes a framework in which to examine collaborative knowledge building. Collaborative knowledge building depends more on the learning context and group member role than on gender exclusively. The collaborative knowledge-building process begins when group members become ready to participate by creating a welcoming climate, feeling emotionally and cognitively comfortable, and formulating initial thoughts on the discussion topic, among other activities. Connecting with one another to collaborate includes brainstorming, challenging perceptions, ensuring equality of voices, stretching their individual perspectives, and sharing experiences over time. Members achieve shared understanding by creating a new, joint perspective that emerges from their collective contributions.
Self-Efficacy Beliefs of Adult Learners Utilizing Information Communication Technologies
Authors: Petty Gregory C. , Carter Carol A.
Published: September 2010

The theory of self-efficacy has been shown to be a contributing factor to the success of adult learners’ in educational programs that utilize information communication technologies, specifically online learning. The determination of online learning self-efficacy is measured with the Tennessee Online Instruction Scale that measures self-efficacy beliefs using three factors of (1) internet; (2) collaborative/online learning, and (3) personal beliefs. It is the purpose of this chapter to help readers understand and use these findings that can contribute to the overall success of adult learners in an online environment. Included are summary results from Carol Carter’s 2004 dissertation on self-efficacy beliefs among college students.
Helping Faculty Design Online Courses in Higher Education
Authors: Hernández-Gantes Victor M.
Published: September 2010

The steady growth of online education has created increasing demands for faculty to design and teach online courses. At issue is the limited pedagogical preparation of higher education faculty hindering motivation to participate or the quality of their online teaching experiences. To address this issue faculty development supports are needed to help faculty transition into online teaching. This article provides an overview of related issues and a sample of emerging faculty development models followed with a description of a promising model integrating design, pedagogical, use of technology, and assessment considerations and adult development, learning, and planning principles. Emerging trends stemming from the review of related issues are also highlighted.
Informal Adult Learning in Simulated and Virtual Environments
Authors: Bennett Elisabeth E.
Published: September 2010

Sophisticated uses of Information and Communication Technology (ICT) have enabled informal learning in simulated and virtual environments. This chapter proposes a four-part informal learning model and explores adult learning in simulated and virtual environments, namely Inter/Intranets, Simulation, and Robust Virtual Environments. The chapter discusses using logic models for assessment and describes future trends of informal learning mediated by ICTs.
Boundaryless Work and the Role of Mobile ICT
Authors: Mogren Ragnhild , Thunborg Camilla
Published: September 2010

The change of structures of work towards fewer boundaries in time, space and tasks are sometimes referred to as boundaryless work. ICT is pointed out as one cause of this tendency. The aim of this chapter is to discuss the role of mobile ICT in the forming of the borderland between work and non-work and the identities formed in relation to this borderland: how is mobile ICT used in work and non-work, how is this use related to the forming of a borderland between work and non-work, what are the characteristics of the identities formed in this borderland? Narratives of experience of mobile ICT practices are analysed by means of social theories. The results show that mobile ICT is used as a boundary object between work and non-work. In distinguishing between functions and artefacts, between time and space, different identities are formed: extended work identity, border identity and boundaryless identity.
Knowledge Building Online
Authors: Stein David S. , Wanstreet Constance E. , Glazer Hilda R.
Published: September 2010

This chapter explores the promise and process of knowledge building in online environments. The promise lies in the dual capability of knowledge building to support the collective learning of future adult learners by building on the information artifacts produced by present learners, thus improving upon what is known about a subject. Electronic tools for sharing emerging thoughts facilitate knowledge building and expand its reach outside the immediate classroom to involve learners from any part of the world in inquiry-based discussions. The knowledge-building process involves participation, collaboration, and achieving shared understanding. A case study of adult learners attempting higher levels of learning shows knowledge building in process. The chapter proposes a staged approach to preparing adult learners to engage in knowledge building.
Adult Education and Globalization
Authors: Ahedo Manuel
Published: September 2010

The chapter discusses how globalization has affected institutional changes in adult education. In the background it introduces first the necessary definitions and presuppositions for the analysis of both adult education and globalization, and second, it highlights the underpinnings of the changes in adult education and learning in the last decades. The main thrust of the chapter deals with three main issues that relate adult education and globalization: first, the importance of contexts, systems and trends in changing adult education under the age of globalization; second, the relation between globalization and adult education and lifelong learning policies; and thirdly, the case of lifelong learning policies in the European Union is presented as an example of supra-national continental economic and political integration on national policies. Finally, after pointing to several future research directions, some concluding remarks are offered.
Optimal Design and Experimental Study on 500SM35 Type Centrifugal Pump
Authors: Hou Ming Wei
Published: September 2010

To make the high efficiency and energy-saving centrifugal pump, using multi-objective optimization design to make hydraulic design of the 500SM35 centrifugal pumps, using CFD technology to simulate the three-dimensional turbulence flow in pump, also make performance experiment and cavitation experiment of the 500SM35 centrifugal pump that have been self-developed. Experimental studies have shown that: the 500SM35 centrifugal pump’s prototype performance parameters all beyond design specification.
Research on Force Feedback-Based Tool Operation in Virtual Assembly
Authors: Chen Cheng Jun , Wu Yun Feng , Li Niu
Published: September 2010

To verify the accessibility and workspace of tool operation in virtual assembly system, this paper presented a tool-part operation method based on force feedback. According to characters of common tool-part operations, standard fastening tools and parts were modeled using features and parameters at initial stage. Then operator was enabled to conduct different kinds of fastening and unfastening operations in virtual assembly system by three steps namely identification, interactive positioning and operation. With feedback force, the operator can feel corresponding motion constraints of tool during virtual fastening and unfastening operation, so the immersion of virtual assembly operation is promoted.
Investigation of Micro-Milling Force Based on Miniature Machine Tool
Authors: Cao Zi Yang , Li Hua
Published: September 2010

Miniaturized components are increasingly in demand for various industries. Micro milling operations can fabricate miniaturized components with high relative accuracy. In micro milling process, the analysis of cutting force plays an important role in characterizing the machining process, as the tool wear and surface texture depending on the cutting force. In this paper, the orthogonal experiments under slot-milling and side-milling with typical micro three dimensional parts are done by the developed three-axis micro milling machine tool, and the micro milling force is measured and analyzed. In order to improve the processing efficiency and processing accuracy of micro milling process, the impact law of the spindle speed, axial cutting depth, feed per tooth and other parameters on cutting force is deeply studied, and the machining parameters is also optimized.
Configuration of Random Transducer Array in Irregular Region Based on Delaunay Triangulation
Authors: Wu Shi Lin , Zhang Qi , Huang Zhi Ping
Published: September 2010

To realize the configuration of a cymbal transducer array in an irregular region, Delaunay triangulation is adopted to mesh the irregular region and the vertices of the Delaunay triangular mesh are regarded as the positions of the array elements. In this way, a random array of cymbal transducers is formed. Minimum Variance Distortionless Response (MVDR) beamformer is used to optimize the beam of the random array, and the directivity simulation is carried out in MATLAB. The results show that the directivity of the random array within the irregular region is better than that of the uniform linear array and that of the uniform plane array configured in the same region.
Multi-Economic Agent Grid Resource Allocation Strategies in the Signaling Game Theory Analysis Model
Authors: Xie Jun , Li Ji Guang
Published: September 2010

The paper presents a market oriented resource allocation strategy for grid resource. The proposed model uses the utility functions for calculating the utility of a resource allocation. This paper is target to solve above issues by using utility-based optimization scheme. We firstly point out the factors that influence the resources’ prices; then make out the trading flow for resource consumer agents and provider agents. By doing these, the two trading agents can decide their price due to the dynamic changes of the Grid environment without any manmade interferences. Total user benefit of the computational grid is maximized when the equilibrium prices are obtained through the consumer’s market optimization and provider’s market optimization. The economic model is the basis of an iterative algorithm that, given a finite set of requests, is used to perform optimal resource allocation.
A Study on the Key Issues of Cloud Storage Technology
Authors: He Zhong Lin , He Yu Hua , Chen Li Yu
Published: September 2010

The rapid growth of mass data presents a huge demand for storage systems, thus, cloud storage technology is emerging. This paper briefly describes the concept of cloud storage. Combined with the high-performance requirements, the availability, reliability, security and scalability of cloud storage, it focuses on analyzing such key issues of cloud storage like the structure of cloud storage systems, public and private cloud, data types in cloud storage, internal technical resources and the prerequisite for development of cloud storage technologies, at the same time, it makes a conjecture on the development trend of cloud storage technology.
Improvement to the Expected Discounted Penalty Function for a Classical Risk Model with a Threshold Dividend Strategy
Authors: Yu Wen Guang , Liu Zhi
Published: September 2010

In this paper, we study the expected discounted penalty function for a classical risk model in which a threshold dividend strategy is used for a classical risk model and the discount interest force process is not a constant, but a stochastic process driven by Poisson process and Wiener process. In this model, we derive and solve an integro-differential equation for the expected discounted penalty function.
The Object Removal Detection Based on the Background Subtraction
Authors: Chen Lin Kai , Zhu Li Hua
Published: September 2010

Aiming at the preservation of costly objects in the video monitoring, this passage proposed a judgmental method based on the background subtraction of fixed foreground object. This algorithm checks foreground pixel area in the picture using background subtraction and check out the moving action based on the stability of target position and Invariance of Consecutive Frames Subtraction. This method is not complex in calculation. It is also fast and useful that it can meet the request of system immediacy.
A Fuzzy Knowledge Matching Method Based on Variable Weight IDM
Authors: Zhu Lin Li , Tang De Quan , Qin Xiao Kang , Dai Guo Hong
Published: September 2010

Fuzzy knowledge representation and processing is a very important topic in artificial intelligence research, the key of the fuzzy knowledge inference is the knowledge matching. Via our investigation on kinds of conventional methods in fuzzy knowledge matching, we propose a knowledge matching method based on variable weights IDM (Inscribed Diameter Matching). Through our comparative analysis, Variable weights IDM is able to overcome some drawbacks exist in the traditional methods. We also give a fusion model which can improve efficiency and accuracy of knowledge inference. The experimental results verify the practicability and availability of our method.
Transfer Orbit Design and Control Based on Forbes' Assumption
Authors: Zheng Li Li , Yuan Jian Ping , Zhu Zhan Xia
Published: September 2010

In order to meet the requirements of space operation, the spacecrafts must maneuver agilely with the artifical propulsion. The orbit under artificial control is termed as Non-Keplerian orbit which does not follow Kepler’s Laws. The transfer orbit design under the continuous thrust is one of the most important topics in this new field. Shape-based method for Non-Keplerian orbit design is developed in this paper. Firstly, the equations of motion are established in polar coordinates system. And then the nondimensional variables are introduced for computation accuracy and speed, which give rise to nondimensional equations of motion. The general equation is derived with which common curves could be utilized in orbit design. In addition, the orbit design method is described based on Forbes’ velocity assumption and the formulation of the radius r with respect to time t, which is a sinusoidal function. The determination of the coefficients causes the orbit design problem to translate into an orbit control problem. The requisite thrust magnitude and direction are available via the simplified nondimensional equations of motion. In the end, an example of the transfer orbit is given. The result demonstrates that the shape-based method is feasible for the transfer orbit design or control problem under the continuous thrust, and the fuel expenditure is practicable.
Study on Theoretical Analysis and Numerical Simulation of Smoke Flow during Gas Explosion
Authors: Qu Zhi Ming
Published: September 2010

In most cases, high gas concentration and oxygen consumption result in severe hypoxia after explosion. When the ventilation system is damaged, the air volume will be re-distributed so that explosion region is lack of oxygen. However, under mechanical ventilation and self-diffusion, the high temperature and toxic and harmful gases will constantly spread downwind of the roadway or certain areas, which threatens substations, winch room and workers’ escape. If the hot gas meets with gas concentration overrun areas or the coal dust explosion hazardous area, secondary disasters such as fire or explosion may be caused. Numerical simulation shows that high temperature, toxic and harmful gas will be disseminated. In conclusion, measures must be taken to withdraw the workers and to restore ventilation to prevent secondary disasters. If the gas explosion power is increased, the safety nearby working face would be threatened. To control and reduce the extent of gas explosion hazards and losses, a reasonable gas explosion disaster prevention and treatment plan should be established.
Computation of Reliability with Both Aleatory and Epistemic Uncertainty Based on Random Sets Theory
Authors: Guo Hui Xin , Chen Lei , He Hang Min , Lin Dai Yong
Published: September 2010

A method to handle hybrid uncertainties including aleatory and epistemic uncertainty is proposed for the computation of reliability. The aleatory uncertainty is modeled as random variable and the epistemic uncertainty is modeled with evidence theory. The two types of uncertainty are firstly transformed into random set, and the limit-state function of a product is mapped into a random set by using the extension principle of random set. Then, the belief function and the plausibility function of safety event are determined. The two functions are viewed as the lower and the upper cumulative distribution functions of reliability, respectively. The reliability of a product will be bounded by two cumulative distribution functions, and then an interval estimation of reliability can be obtained. The proposed method is demonstrated with an example.
Innovative Design Based on Topological Analysis of Rope-Type Long-Link Grippers
Authors: Zhou Wan Chun , Zhou Tong
Published: September 2010

In this thesis, the author first analyzed the topological structure of the original mechanism. On this basis, the topological map and a series of kinematic chain maps which meet the requirements have been constructed with graph theory. Then the types of various components were designated based on specific design constraints, and generalized kinematic chains were turned into the new mechanism having the same or similar function with the original mechanism. Designers can value them comprehensively and screen out the good structural type. The method is regarded as a workable and efficient method for development and design of new products.
The Allocating Point Solution for the Out-of-Plane Stability of Arches with the Double Symmetry Axis Section
Authors: Chen Yu Ji
Published: September 2010

In order to study the buckling mechanics behaviour of the out-of-plane stability of arches with the double symmetry axis section, by mean of potential variational theories, considering the out-of-plane deformation of arches, the out-of-plane stability governing equation of arches was obtained. The problem was solved by the spline function allocating point method. An example was calculated with this paper method. It is shown by comparing the result of this paper with the others that the paper method is reliable and accurate.
Finite Element Analyses of Modified Compact Tension Shear (MCTS)-Specimens under Mixed-Mode Loading Conditions
Authors: Qi Gui Ying , Li Qing Fen
Published: September 2010

In this paper a detailed 3D-finite element analyses results of modified compact tension shear (MCTS)-specimens with an inclined crack plane or crack front under mixed-mode loading conditions are presented. It is found that under mixed-mode loading, a superposition of all fracture modes I, II and III can be generated along the straight crack front of MCTS-specimens, and the maximum of the total SERR along the crack front of two different MCTS-specimens is found at right hand side of crack front corner，where the risk of crack initial growth is highest. The computational fracture analysis is based on the calculation of separated energy release rates GI, GII and GIII along the crack front by the numerically highly effective modified virtual crack closure integral(MVCCI)-method.
The Study about Flexural Performance of GFRP Bar Reinforced Concrete Beams Based on Numerical Calculation Method
Authors: Yang Qing Guo , Zhang Yu Wei , Tu Zhi Zhong
Published: September 2010

Replacing the steel bar with GFRP (Glass Fiber Reinforced Plastics) bar can improve the durability of concrete structure in the corrosive environment. Different ratios of GFRP bar lead huge difference performance of GFRP reinforced concrete beams; therefore, to reduce the workload, it is very necessary to study GFRP reinforced concrete beams’ performance with suitable numerical calculation method. In the study, first, GFRP reinforced concrete beams’ mechanical behavior and failure characteristics were researched through the flexural experiments of GFRP reinforced concrete beams with different ratio of GFRP bar; Second, the numerical calculation model of GFRP reinforced concrete beams was built according to experimental results which contain the load-displacement curve and the phenomenon that concrete in compression zone are crushed, then the calculation criterion of obtaining the beam’s bearing capacity was proposed. Lastly, the bending bearing capacity of GFRP bar reinforced concrete beams with different ratio of GFRP is obtained through the finite element calculation, and the practical and simple calculation formula is acquired.
High-Pressure Water Spray Research Based on Neural Network
Authors: Li Rui , Kou Zi Ming
Published: September 2010

The spray cleaning method is important and universal in many industrial processes and other occasion. Because the size of the waterdrop is one of key factors for cleaning, this paper not only studied the relationship between the size of waterdrop and other influencing factors, but also researched the forecasted method for the size of waterdrop. In lab, by measuring the size of the waterdrop, jetted by one kind of nozzle, data were acquired and were used to train the Back Propagation Neural Network ( BPNN ). Through comparing those diameters, between measured in lab and calculated by BPNN after trained. It was acquired that the maximum errors was smaller than 1.62%, between the computed results and the factual measured ones. The experimental results showed that BPNN is an effective tool to predict the variation of the non-linear waterdrop diameter.
Study on the Roller’s Thermal Stress of the Liquid Core Heavy Reduction Rolling Mill
Authors: Sun Deng Yue , Zhang Yuan Fang , Zha Xian Wen , Liu Wen Wu , Ma Hui Wen
Published: September 2010

The key technologies of heavy reduction on liquid core of thick slab rolling mill are designing the roller structure and the selection of high temperature high strength materials. This paper using finite element analysis method compared the temperature field, thermal stress field and strain field. Two material 2Cr12NiMoWV and 5Cr4W5Mo2V and two structures which is roll-sleeve and built-up welding roll in rolling process are analyzed. The results show that the 5Cr4W5Mo2V roll-sleeve type roller has advantages.
A Development of 3D-DDA with Finite Deformation Theory
Authors: Gao Ya Nan , Gao Feng , Yeung M.R. , Jiang Qing Hui
Published: September 2010

A post-adjustment method that makes DDA coupled with finite deformation theory was presented in this paper. The displacement post-adjustment equations were derived. We also calculated two examples to illustrate this method. The method was also compared with original DDA and reference’s. It shows that the method in this paper can work well on the block rotation error problems.
Flow and Heat-Transfer Simulation Based on CFD and Experimental Study during High-Pressure Gas Quenching
Authors: Wang Zhi Jian , Shang Xiao Feng
Published: September 2010

High-pressure gas quenching is the heat treatment technology which quenches the works by use of high-pressure and high-speed flow gas. FLUENT software is used to simulate the process of gas-solid coupling flow and heat transfer in the nozzle-type vacuum high-pressure gas quenching furnace. The hot wire anemometer is used to measure the inlet velocities of nozzles, which provides the boundary conditions for computer simulation. By the computer simulation, the gas flow fields, work temperature fields and work cooling curves are attained. The results show that the big eddy current occurs at the corner of the furnace and the cooling rate of the work is slow there. Contrasting the simulating result of work cooling rate at the center of furnace with the actual measured one by the thermocouple, we find when work is cooled to the temperature of 430K, the simulating result is faster than the actual one about 50 seconds. The simulating results basically correspond with the actual trend of the gas quenching.
An ICA-Based Method for Improving Cross-Correlation Performance in Estimating Stress Wave Propagation Time
Authors: Fang Yi Ming , Li Jian , Feng Hai Lin
Published: September 2010

This paper presented a new propagation time estimation method based on ICA-domain filter. The technique consists of two steps. Firstly, denoising in ICA domain by sparse code shrinkage was applied to each received signal to recover the original waveform. In the process, a new shrinkage function was designed to make the filter more adaptive. Then, the propagation time was found by locating the peak of the cross-correlation function. The propagation time estimations under several conditions were simulated to evaluate the performance of the method. The experiment results show that the proposed method performs better than classic correlation methods, which makes it an efficient method in wood nondestructive evaluation.
Experimental Investigation of Characteristics of Vibratory Compaction System with Different Water Saturation
Authors: Li Xiao Peng , Teng Yun Nan , Xin Li Li , Wen Bang Chun
Published: September 2010

In this work, the numerical equation has been established to simulate the vibratory compaction system based on the hysteresis loop of Davidenkov and with the gap ignored between the piston and the materials, and the dynamical characteristics and influence of parameters on the vibration compaction effect were analyzed with different stiffness, damping, amplitude and mass with different water saturation. The two types of experiments were carried out to study the dynamical characteristics and validate the numerical analysis and simulation. The first type of experiments was done with the different exciting vibration amplitude. A second type of experiments was done with the different water saturation (3%, 8% and 17%) instead of the stiffness and damping. The numerical and experimental results show that the equivalent natural frequency and vibration amplitude of the system increased with the stiffness, exciting amplitude increased and damping decreased. The experimental results agree well with results from a theoretical model in general. The research results will be used in intelligent soil compaction in the future.
Numerical Analysis of Joint Rock Shear Properties Considering Joint Geometrical Characters
Authors: Zhang Qiang , Ge Xiu Run , Wang Shui Lin
Published: September 2010

The purpose of this paper is to study the shear behavior of rock specimens containing joints with various distribution forms. Two sets of specimens are simulated by the rock failure process analysis code (RFPA2D). The friction-sliding failure pattern occurs with the lower undulation angle specimen, and the failure pattern turns to be tensile-shear failure mode gradually with the increase of undulation angle. The specimen possesses the highest peak shear load when the undulation angle is about 30º. And joint rock shear character also deteriorates with the increase of weak interlayer thickness. In the intermittent joint model, the unified connection ratio specimen’s peak shear load increases with rock bridge amount, and the multi-joint mode is beneficial to keep rock mass shear stiffness. This study comes to meaningful results to the expansion of joint rock strength evolution law with various joint distribution forms.
Reliability Analysis of Slope Stability at Seismic Action Based on Artificial Fish-Swarm Algorithm
Authors: Shi Bei Xiao , Liu Ya Min , Mu Zhi Yong
Published: September 2010

Based on transient analysis,stress value and values of principal stress of slope can be got at each time. Then based on partial failure discriminance, the only slip plane can be got to some initial point. Thirdly, based on sweden slice method, formula of the safety coefficient of the slope's stability can be as objective function, through artificial fish-swarm algorithm, slip plane can be established. Finally, through analyzing the safety coefficient of the slope's stability and initial point in each time, the structure reliability of slope stability and failure probability can be got. Finally, this method is verified by an example, which proved that the method is feasible and available.
Tool Wear Mechanisms in High Speed Machining Ductile Cast Iron
Authors: Yang Fa Zhan , Zhou Jian Qiang , Meng Guang Yao , Zhao Jun , Li Chang He
Published: September 2010

Wear behavior of WC based nanocomposite cutting tool when high speed cutting ductile
cast iron was investigated. Orthogonal cutting tests were carried out on a CA6140 lathe using three
speeds, namely, 100, 215 and 287m min-1. The WC based nanocomposite tool is found to be superior
to cemented carbide tools (YG8). The tool life is prolonged 60% as compared to cemented carbide, as
the width of the wear land (VB), which was monitored at selected time intervals. Meanwhile, the
topography of worn surfaces was scanned by a profilemeter. Wear characterization of the rake face
and the flank surfaces as well as of the collected chips was conducted using a scanning electron
microscopy (SEM). Results showed that distinctive traces of single abrasive tool wear event were
found on the rake face of the tool, additionally, the adhesion wear is the main wear mechanism in the
flank face of the tool. However, the extent of improvement in tool life depends strongly on the cutting
conditions, with the greatest benefits being seen at higher cutting speeds and feed rates.
New Damage Detection Method Based on Support Reaction and Mid-Span Displacement for Simply Supported Bridges
Authors: Ma Z.J. , Zhang S.J.
Published: September 2010

Capabilities to locate damage, and applicability to simply supported bridges are considered as basic characteristics of the method to be investigated in this paper. A new method which employs support reaction and mid-span displacement as indicators is presented to detect a certain type of damage. Unlike the existing study, this work proposes the direct relationship between the change in local mass caused by damage and the measured support reaction and mid-span displacement values. With the cooperation of inspection means, this method is capable of successfully identifying the location of local potential damage. The feasibility of this method is demonstrated by numerical simulation and model experiment.
Jumping Mechanism Analysis of the Humanoid Robot
Authors: Chen Yong
Published: September 2010

The jumping procedure of the human in the standing long jump was captured with a high-speed video camera. The geometrical configurations and motion postures of the human during jumping were analyzed from the high-speed photographs. By biological observation, the human jump was divided into stance phase, flight phase and land phase. The dynamic model of the humanoid jumping robot was established by the technology of virtual prototype. The joint angles of the robot during jumping were analyzed. The results would provide some theoretical and practical references for the biomimetic design to improve the reasonable motion of the humanoid jumping robot. This work may provide the basic theory in developing humanoid jumping robot in structural design. Besides, it provides an important reference to study the other bionic robots.
Improved Large Mass Method for Structural Base Excitation Analysis
Authors: Zhou Guo Liang , Li Xiao Jun
Published: September 2010

To verify the precision and possible applicability of the large mass method (LMM) widely used in multiple-supported structures subjected to non-uniform base excitations, numerical simulations of a two-degrees-of-freedom (2-DOF) finite element model using the Rayleigh damping assumption are performed respectively according to the LMM and the relative motion method (RMM). Through comparisons with the RMM, the error origins and the applicability of the LMM are discussed. Then the improved LMM is presented herein based on the modification of ground motions considering the influences of Rayleigh damping coefficient α. It indicates that the LMM is not applicable to multi-support excitation analysis in the case of Rayleigh damping, which can cause significant errors. And the errors depend on the damping coefficient α. It’s also proved that the improved LMM is able to yield results that are identical to those of the RMM.
Modeling and Simulation Research of Coaxial Parallel Hybrid Loader
Authors: Zou Nai Wei , Dai Qun Liang , Jia Yuan Hua , Zhang Wei , Ren You Cun
Published: September 2010

After analyzing the loader duty cycle with hybrid drive theory and gaining the characteristics of loader duty cycle, an integrated started generator-ISG based coaxial parallel hybrid loader is designed. Two simulation models are built with the simulation software Cruise, one is tradition loader another is hybrid loader. The simulation result of tradition loader model compare with the test data to amend the model. To gain same accuracy, the hybrid loader model is rebuilt based on the tradition loader model. According to the “I” type duty cycle, comparing the simulation result of tradition and hybrid loader, the result shows that hybrid loader can save fuel 10.4%.
A New Viewpoint on Ablation Mechanism Discrimination
Authors: Xu Xiao Liang , Huang Hai Ming
Published: September 2010

The ablation is coupled with chemistry, heat and mass transfer. Based on multidisciplinary theories, the heat flow field and the ablation loss are studied with the given gaseous mixture and assumed activation energy of H2; Furthermore, the formula for impaction effect of a single particle are deduced with an elastic impact theory, by which the most dangerous attack angle can be obtained. As results prove, the most fragile part may be the convergence region in front of the throat, and then the concentration and the activation energy of H2 determine the ablation mechanism discrimination in the most fragile part.
A Mathematical Modeling Method on Micro Heat Pipe with a Trapezium-Grooved Wick Structure
Authors: Li Xi Bing , Wang Shi Gang , Guo Jian Hua , Li Dong Sheng
Published: September 2010

With heat flux increasing and cooling space decreasing in the products in microelectronics and chemical engineering, micro heat pipe has become an ideal heat radiator for products with high heat flux. Through analyzing the factors influencing the structure, strength and heat transfer limits of circular micro heat pipe with trapezium-grooved wick structure, the heat transfer models are established in this paper, including the models of viscous limit, sonic limit, entrainment limit, capillary limit, condensing limit, boiling limit, continuous flow limit and frozen startup limit. The study lays a powerful theoretical foundation for the design and manufacture of circular micro heat pipe with a trapezium-grooved wick structure.
Performance Study for Storage-Type Domestic Electrical Water-Heaters with Double Tank Based on the CFD Simulation
Authors: Wang De Xi , Zhang Zhi Jun
Published: September 2010

The 3D physical model of the electrical water heater was built. The mathematical model of hot flow was resolved by computer fluid dynamics simulation (CFD). The effects of the rate of water draw on the heater performance have been investigated. The heater performance is characterized the discharge efficiency, extraction efficiency and fraction of heat recoverable. It was 85.9%, 66.0% and 70.9% respectively, and it was 74.0%, 27.3% and 39.9% respectively with discharge rate was 10L/min when all initial hot water temperature was 70°C. The water inner the water tank of draw rate 5L/min was well thermal stratification. It was also expatiated by the distribution temperature of CFD simulation.
Tensor Presentation of Algorithmic Tangent Modulus for Plastic-Damage Models
Authors: Zhang Ji , Zhang Zhong Xian , Huang Cai Ping
Published: September 2010

For a class of plastic-damage models, spectral return-mapping algorithm performed upon the principal effective stresses is efficient, while algorithmic tangent modulus formulated upon the general effective stress components is much simpler. In order to facilitate the transformation between these two sets of stress components in the formulation of algorithmic tangent modulus, a new concept of fictitious stress tensor, which is orthogonally similar to the real stress tensor, is proposed in this paper. The rank four Jacobian tensor of the fictitious effective stress is calculated from spectral decomposition; and a clear tensor formulation of algorithmic tangent modulus is presented.
Data Analysis and Application Research of Microhardness and Wear Resistance of Surface Detonation Spraying Coat
Authors: Xu Hong Wen , Zhang Qi Zhi , Zhang Lin
Published: September 2010

To improve the using life of screw, the paper focused on the research about microhardness and wear resistance of surface detonation spraying coat. The detonation spraying surface was important to extend the wear resistance of screw of low temperature screw press machine. The paper analyzed the phase composition and microstructure data of surface detonation spraying coat and tested the microhardness of coat and combination intensity between coat and substrate, and did contrasting wear resistance experiment between detonation spraying coat and traditional coat. The data analysis results showed that the wear resistance of detonation spraying coat was far beyond traditional coat and the detonation spraying coat would improve the using life of key screw of low temperature screw press machine.
Modeling the Effect of Permeability on Methane Gas Production from Hydrates in Porous Media
Authors: Ruan Xu Ke , Song Yong Chen , Liang Hai Feng
Published: September 2010

To make the recovery of methane from hydrates commercially viable, many uncertainties in hydrate dissociation process in porous media must be solved. In this study, the permeability variation with the pore-scale hydrate distributions was experimentally determined, and through the comparison of the experimental results with permeability correlations, the hydrate forming in the center of pore space was confirmed. To evaluate the effect of permeability reduction, absolute permeability and relative permeability on MH dissociation and gas production behavior, the Masuda permeability model was incorporated with a depressurization mathematical model, and some simulation runs was carried out. Based on the results of the numerical simulation, the effect of permeability variation on gas production from hydrate was analyzed.
Strain-Induced Modulations of Electro-Optic and Nonlinear Optical Properties of ZnO: A First-Principles Study
Authors: Li Chun , Yang Fan , Guo Wan Lin
Published: September 2010

Strain-dependent electro-optic constant r33 and nonlinear optical coefficient d33 of ZnO are investigated systematically using density-functional theory based linear-response perturbation method. Miscellaneous properties, such as dielectric constants, elastic constants, piezoelectric coefficients, nonlinear optical coefficients, and electro-optic constants of other II-VI compound semiconductors (both Wurtzite and Zinc-blende structures) are also calculated for comparison with the results of unstrained ZnO. Extensive first-principles calculations show that both r33 and d33 of ZnO decrease almost linearly with increasing strains, which indicates that appropriate compression along the [0001] direction of ZnO could enhance its electro-optic and nonlinear optical properties, while stretching may weaken the corresponding properties. Among the involved Wurtzite structures, ZnO has the highest elastic constant, piezoelectric coefficient and electro-optic constant, showing practical importance.
Laboratory Experiment on Porosity Variation of Crushed Rock Layer under Vibrating Load
Authors: Sun Bin Xiang , Yang Li Jun , Bai Wen Hui , Zhang Jin Zhao , Wang Shuang Jie
Published: September 2010

Under the background of the express-reconstruction of the Qinghai-Tibet Highway being proposed, it will be necessary to employ the special technique of cooling the ground temperature by the crushed rock embankment in order to protect from damage to highway embankment due to thaw settlement. Under vibrating load, the porosity variation of crushed rock layer may weaken the cooling effect of buoyancy-driven natural convection of the pore air in the crushed rock layer of the highway embankment, thus resulting in instability and failure of the road embankment structure. Under these conditions, the effect of vibrating load on the porosity of the crushed rock layer must be studied both theorectically and experimentally. In this work, laboratory experiment on the porosity variation of the crushed rock layer under vertically vibrating loads is developed based on the water flooding approach and the experimental method is introduced. The test results indicate that due to the vibrating load the crushed rock layer causes the compacting effect and the shapes of crushed rock grain tend to be non- angular.
Simulation and Prediction Studies on Harden Penetration Depth of AISI 5140 Alloy Steel in Surface Grinding
Authors: Zhang Lei , Gao Yu Fei , Bi Wen Bo
Published: September 2010

The grinding heat is utilized to induce martensitic phase transformation and strengthen the surface layer of AISI 5140 alloy steel by raising surface temperature higher than austenitic temperature and cooling quickly. The grinding temperature field is simulated by using finite element method (FEM). Then, the hardness penetration depth (HPD) is predicted from the temperature history and martensitic phase transformation conditions in surface grinding. The experiments of different grinding parameters are performed in surface grinding lathe. The hardness and hardness penetration depth of work piece surface layer are measured to validate the simulation and prediction. This method can be used to predict the HPD and optimize the grinding parameters forwardly.