各向异性旅行时层析成像

利用地震数据估算速度时常常是以与方向性无关的时距曲线为基础的。尽管我们已经了解到许多岩石存在较强的各向异性,但多年来人们已根据各向同性估值得到了一些有益的结果。如果速度明显随方向变化,则各向同性假设将导致严重的构造解释误差。除此之外,与角度有关的信息将有助于更好地解释所测量的岩性。为了估算出每一波型的两个速度参数,VSP和井间数据的孔径是不够的。如果数据有一个对称的同相轴,我们可选择直达波速度(根据沿轴向的     

IBM公司三面受敌

曾经一度是世界上最有活力的蓝色巨人IBM军团发现自己处境不妙:前进方向不明、处于竞争对手的包围之中,对手的力量超过了自己。西部战线是令人畏惧的Microsoft。这个一度曾与IBM结盟的Microsoft军团,装备精良,下定决心只做一件事——称霸。IBM军团的东面驻扎着Lotus军团,它虽然没有Microsoft军团那么咄咄逼人,但是目标明确,清楚地知道自己应该干什么。IBM军团的南面是不断进逼的     

移动式破碎机在地下矿的应用前景

采用最新的设计,移动式破碎机与胶带输送机相结合,可使地下开采费用显著节约。     

PSoC-based embedded design and quartz tuning fork for low-temperature measurement system design

This article describes a commercial quartz tuning fork (QTF), 8 mm in height by 3 mm in diameter, holding a two-terminal electronic component with a nominal frequency of 32.768 kHz and 12.5 pF typical load capacitance packed in a vacuum-sealed metal container, which has been used as a sensor for low-temperature measurement with good sensitivity, repeatability, and reliability. An embedded readout design with the support of a programmable system on-chip (PSoC) and virtual instrument control program, which uses a personal computer as an input/output device, provides online data acquisition of the QTF frequency data, which will in turn provide the measurement of the low-temperature bath in which the QTF is immersed. The embedded PSoC readout captures the varying frequency signals from the QTF as a response to the measurement temperature, processes it, and sends the frequency value to a personal computer, where LabVIEW, a graphical language ("G" language), displays the data in a graphical format. The QTFs for low temperature (300 K to 77 K) are well studied, whereas a sensor using a PSoC embedded design as a readout is a novel design implementation.     

Electric equivalent circuit for flexural vibrations in piezoelectric materials

General expressions for the values of the components of an electric equivalent circuit are derived for flexural vibrations. These expressions are applied to some interesting electrode configurations. The obtained values are in good agreement with experimental values and values specified by manufacturers of watch crystals. It is noted that solving Laplace's equation for the dielectric field is sufficient in order to obtain the values of the vibration amplitude, the piezoelectric current, and the equivalent components. The piezoelectric part of the electric field need only be considered if very accurate values of the resonance frequencies are desired. It is shown how accurate estimates can be obtained without the need of advanced calculation tools.     

Interactive quadrangulation with Reeb atlases and connectivity textures

Creating high-quality quad meshes from triangulated surfaces is a highly nontrivial task that necessitates consideration of various application specific metrics of quality. In our work, we follow the premise that automatic reconstruction techniques may not generate outputs meeting all the subjective quality expectations of the user. Instead, we put the user at the center of the process by providing a flexible, interactive approach to quadrangulation design. By combining scalar field topology and combinatorial connectivity techniques, we present a new framework, following a coarse to fine design philosophy, which allows for explicit control of the subjective quality criteria on the output quad mesh, at interactive rates. Our quadrangulation framework uses the new notion of Reeb atlas editing, to define with a small amount of interactions a coarse quadrangulation of the model, capturing the main features of the shape, with user prescribed extraordinary vertices and alignment. Fine grain tuning is easily achieved with the notion of connectivity texturing, which allows for additional extraordinary vertices specification and explicit feature alignment, to capture the high-frequency geometries. Experiments demonstrate the interactivity and flexibility of our approach, as well as its ability to generate quad meshes of arbitrary resolution with high-quality statistics, while meeting the user’s own subjective requirements.     

A neuron membrane mesh representation for visualization of electrophysiological simulations

We present a process to automatically generate three-dimensional mesh representations of the complex, arborized cell membrane surface of cortical neurons (the principal information processing cells of the brain) from nonuniform morphological measurements. Starting from manually sampled morphological points (3D points and diameters) from neurons in a brain slice preparation, we construct a polygonal mesh representation that realistically represents the continuous membrane surface, closely matching the original experimental data. A mapping between the original morphological points and the newly generated mesh enables simulations of electrophysiolgical activity to be visualized on this new membrane representation. We compare the new mesh representation with the state of the art and present a series of use cases and applications of this technique to visualize simulations of single neurons and networks of multiple neurons.     

Human motion retrieval from hand-drawn sketch

The rapid growth of motion capture data increases the importance of motion retrieval. The majority of the existing motion retrieval approaches are based on a labor-intensive step in which the user browses and selects a desired query motion clip from the large motion clip database. In this work, a novel sketching interface for defining the query is presented. This simple approach allows users to define the required motion by sketching several motion strokes over a drawn character, which requires less effort and extends the users’ expressiveness. To support the real-time interface, a specialized encoding of the motions and the hand-drawn query is required. Here, we introduce a novel hierarchical encoding scheme based on a set of orthonormal spherical harmonic (SH) basis functions, which provides a compact representation, and avoids the CPU/processing intensive stage of temporal alignment used by previous solutions. Experimental results show that the proposed approach can well retrieve the motions, and is capable of retrieve logically and numerically similar motions, which is superior to previous approaches. The user study shows that the proposed system can be a useful tool to input motion query if the users are familiar with it. Finally, an application of generating a 3D animation from a hand-drawn comics strip is demonstrated.     

A system-on-chip development of a neuro-fuzzy embedded agent for ambient-intelligence environments

This paper presents the development of a neuro-fuzzy agent for ambient-intelligence environments. The agent has been implemented as a system-on-chip (SoC) on a reconfigurable device, i.e., a field-programmable gate array. It is a hardware/software (HW/SW) architecture developed around a MicroBlaze processor (SW partition) and a set of parallel intellectual property cores for neuro-fuzzy modeling (HW partition). The SoC is an autonomous electronic device able to perform real-time control of the environment in a personalized and adaptive way, anticipating the desires and needs of its inhabitants. The scheme used to model the intelligent agent is a particular class of an adaptive neuro-fuzzy inference system with piecewise multilinear behavior. The main characteristics of our model are computational efficiency, scalability, and universal approximation capability. Several online experiments have been performed with data obtained in a real ubiquitous computing environment test bed. Results obtained show that the SoC is able to provide high-performance control and adaptation in a life-long mode while retaining the modeling capabilities of similar agent-based approaches implemented on larger computing machines.