Computer simulation model for room diffuse sound field

With the development of computer simulation technique for room acoustics, diffuse reflection is considered more and more important. In this paper, some models are developed by considering two diffuse factors in a room-diffuse reflection due to room surfaces and scattering due to objects. The surface diffusion is treated by two different methods on the basis of probability analysis or Energy Conservation Law, and the scattering among objects is simulated as a multiple random ray-tracing process. Thus the sound pressure level distribution in a diffuse sound field can be calculated more precisely and easily. Agreement between the computer simulation results and measurements shows the accuracy of the mathematical and physical model and the applicability of the computer simulation methods. These models can be used in noise control engineering, as well as in the practice of acoustical design.     

激光散射法测定非织造布纤维ODF的基本算法与检验

本讨论基于两维纤维分布模型的非织造布激光散射测定纤维取向分布函数的基本算法,给出了影响测量结果的漫散强度的确定方法,实际测定了四种不同加工方法的非织造布纤维取向分布函数,并将数据与显微投影法测得的纤维取向分布实测数据进行了比较。结果表明,本所述的方法适用于不同加工方法的非织造布纤维取向分布函数的测量。     

二元位相计算全息的二重位相匹配滤波

本文提出采用对二个物体进行位相编码的迂回位相计算全息图对该两物体实现二重位相匹配滤波。文中还进一步讨论了二元位相计算全息图的二重位相匹配滤波,并给出了计算机模拟结果。     

Adaptive Lagrange finite element methods for high precision vibrations and piezoelectric acoustic wave computations in SMT structures and plates with nano interfaces

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Game object model version II: a theoretical framework for educational game development

Complex computer and video games may provide a vehicle, based on appropriate theoretical concepts, to transform the educational landscape. Building on the original game object model (GOM) a new more detailed model is developed to support concepts that educational computer games should: be relevant, explorative, emotive, engaging, and include complex challenges; support authentic learning activities that are designed as narrative social spaces where learners are transformed through exploration of multiple representation, and reflection; be gender-inclusive, include non-confrontational outcomes, and provide appropriate role models; develop democracy, and social capital through dialogue that is supported by means of computer mediated-communication tools; and include challenges, puzzles or quests, which form the core of the learning process, where access to explicit knowledge, conversations, and reflection results in the construction of tacit knowledge. It is argued that the GOM version II can be used not only to support the development of educational computer games but to provide a mechanism to evaluate the use of computer games in the classroom.     

基于瞬态反射-透射技术的金属纳米薄膜电子和晶格传热动力学研究

使用飞秒瞬态反射-透射技术研究了金和铜纳米薄膜的电子和晶格动力学,应用双温和Curde近似模型分析了金属薄膜的非平衡热传导动力学.假设在瞬态反射中电子-晶格耦合常数为常数的情况下,计算超快脉冲加热后的电子和晶格温度.金和铜纳米薄膜的反射和透射信号在初始2 ps内相似,随后时间里信号明显不同,透射模式下的电子-晶格耦合效应要比反射模式下的更强和更敏感.这是由于沿着膜厚方向的温度变化受到金属薄膜和基底间的界面散射影响造成的.在研究半透明薄膜的超快动力学过程中,需要同时考虑反射和透射情况.     

文化进化的实验与非实验研究方法

文化进化的研究者认为文化同基因一样存在累积性的进化,可以用达尔文进化理论进行解释。文化的累积性进化是通过文化传递,即文化学习机制实现的,可以使用实验(包括传递链方法、置换方法和固定组方法)与非实验方法(包括历史研究方法、比较法和计算机模拟)进行研究。历史研究方法、比较法具有较高的本土文化契合性,但难以提供因果解释;计算机模拟可以对各种变量进行控制,但易缺少生态效度;实验方法通过对文化传递的情境模拟,能获得具有较高的因果解释力和生态效度的结果。     

Assessing reflective thinking in solving design problems: The development of a questionnaire

Reflection is a critical factor in solving design problems. Using good methods to observe designers' reflection is essential to inform the design of the learning environments that support the development of design problem‐solving skills. In this study, we have developed and validated a novel self‐reporting questionnaire as an efficient instrument to explore reflection, called Assessing Reflective Thinking in Solving Design Problems (ARTiD). This questionnaire has been developed based on the three‐dimensional model for reflective thinking: the timing, the objects and the levels of reflection. A total of 294 undergraduate and graduate students in the fields of engineering, computer science and instructional design were recruited to participate in one of four iterative, formative tests through which reliability and validity analyses were performed to revise and confirm the questionnaire. Examples of participants' reflection patterns were demonstrated to show the practical value of this questionnaire. In conclusion, the final version of ARTiD was presented as a valid instrument to explore students' reflection for research and educational practice. In addition, we found that ARTiD can be used as an effective learning tool to guide student designers' reflections toward better learning and performance.     

复杂目标激光雷达散射截面的数值计算

将粗糙面散射理论与计算图形学结合起来,利用基尔霍夫方法,建立复杂体粗糙面激光雷达散射截面(LRCS)理论模型。依据复杂目标粗糙面的散射特性,设计数值算法,对复杂目标进行精细几何建模。计算了激光(波长1.06μm)入射下,朗伯板以及一种组合复杂激光散射体的LRCS随接收天顶角的变化。该建模方法可根据不同工程需求进一步推广用于计算更复杂表面粗糙目标的激光雷达散射截面,应用于目标激光识别和光学特征提取。     

PITHC-SYNCHRONOUS ARTICULATORY SYNTHESIS INCORPORATED WITH THE INVERSE SOLUTION OF SPEECH PRODUCTION

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Physically based modeling and animation of tornado

INTRODUCTIONTornado is one of the most terrible natural phe- nomena in the world. It causes incredible amounts of damage and destroys significant numbers of facilities every year. No wonder it receives great attention as a major research topic in many fields. Realistic simu- lation of tornado is also a great challenge for com- puter graphics researchers. It provides useful infor- mation for natural disaster prevention and can be integrated into entertainment, computer games, etc. Most to…     

高校单片机教学模式的研究

嵌入式系统的概念很不规范,其实它就是以单片机为核心的监测、控制系统,计算机、机械、电子等专业都开设嵌入式系统方面的课程,但侧重点却有所不同。根据硬件实验条件的不同,单片机课程存在着多种教学模式。介绍了德州学院计算机系把单片机课程分为"单片机原理和接口技术"和"单片机应用开发"2门课,根据不同的教学对象和教学目的分别采用软件仿真和实验开发板2种不同的教学模式,既切实可行又能取得良好的教学效果。     

PLC控制教学实验系统的设计

在PLC教学的集中实践环节中，要求学生对许多对象进行编程控制，为了能直观地看到实际控制效果，使用Visual Basic设计了控制对象的仿真软件，实现了控制对象实际运行情况的计算机仿真，极大节约了教学经费。     

采暖房间的辐射换热计算分析

采暖的最终目的是利用物体间的换热规律,为室内人员营造一个舒适的热环境。而热环境的建立主要取决于房间内的换热状况。要对辐射采暖房间的换热计算进行探讨,建立辐射采暖房间的换热模型,列出反应房间换热状况的方程组;基于对建筑房间内换热特点的分析,对模型进行两种不同程度的简化。结合具体实例将各种换热模型的计算结果进行比较,得出简化的能综合反映房间换热状况的方程,计算求得的房间内的换热状况,大大简化辐射采暖房间的换热计算。     

水下声散射一致性时域有限差分法的并行算法

In this work, we treat scattering objects, water, surface and bottom in a truly unified manner in a parallel finite-difference time-domain (FDTD) scheme, which is suitable for distributed parallel computing in a message passing interface(MPI) programming environment. The algorithm is implemented on a cluster-based high performance computer system.Parallel computation is performed with different division methods in 2D and 3D situations. Based on analysis of main factorsaffecting the speedup rate and parallel efficiency, data communication is reduced by selecting a suitable scheme of task division.A desirable scheme is recommended, giving a higher speedup rate and better efficiency. The results indicate that the unifiedparallel FDTD algorithm provides a solution to the numerical computation of acoustic scattering.     

SAW reflection and scattering by electrodes

INTRODUCTION Electrodes or grooves in the path of surface acoustic wave (SAW) propagation give rise to SAW reflection and cause SAW scattering into bulk acous- tic wave. This is a fundamental SAW problem on which had been conducted many studies. It is espe- cially important for designing SAW radio frequency identification tags (RFID). Global SAW Tag (GST) (Hartmann, 2004) has many advantages over tradi- tional SAW RFID, but requires accurate knowledge of the reflectivity and …     

基于虚拟现实技术的动态水面仿真方法研究

在虚拟现实系统设计中,真实自然的动态水面效果可增强场景的逼真感,使虚拟环境更加绚丽.而水面动态模拟的关键技术是在水面的真实感、实时渲染速度、计算机软硬件资源需求及实现虚拟现实系统难易度等几个方面寻求平衡.提出利用层次细节技术,采用动态纹理映射、波动水面的物理模型并结合材质贴图方法,实现具有反射、折射等效果的流动水面.该方法应用于室外景观等环境表现中,使水面效果更逼真、计算复杂度减小、设计和实现更简洁方便.     

系统仿真:数码时代的艺术走向

系统仿真是利用模型对实际存在的或设想中的系统进行研究的计算机技术。它在艺术领域的应用，正在理论和实践两方面推动前所未有的变革。它促进了反映性真实向功能性真实转变，在影响制作中创造“仿真现实意义”的景观，在视频游戏中创造可供参与的仿真活动，在智能偶戏中创造可供交流的仿真人物。作为当代系统仿真之代表的分布式虚拟现实，正为艺术发展开辟新的空间。     

Using LBG quantization for particle-based collision detection algorithm

INTRODUCTION Collision detection is an important task in many fields such as robotics, computer games, computa- tional geometry (Gottschalk et al., 1996), computer simulation, virtual reality, etc. Most collision detec- tion algorithms work efficiently only with solid and rigid objects, so collision detection between de- formable objects is a challenge. A number of re- searches on non-rigid objects are proposed such as cloth simulation (Bridson et al., 2003; Teschner et al., 2004) and bi…     

关于虚拟现实场景中倒影实现技术的研究

湖面的倒影实现技术,是虚拟现实真实感表现的一项重要技术。基于图像模拟湖面的反射技术,利用不同视点获取的多方位倒影图像,作为交互场景中的倒影贴图,能快速地表现倒影。基于模型模拟湖面的反射技术,利用镜面成像原理,且简化模拟倒影的模型,并结合湖面的不透明度,能够真实再现湖边物体的倒影。此研究对于虚拟现实交互场景、游戏开发及其它相关应用具有实用价值。