We propose a visual query system for risky enterprises. Based on a small number of input samples of risky enterprises, users can interactively analyze and obtain SQL statements that express the query results, facilitating subsequent task operations and understanding risk criteria. Due to the diversity of enterprises and the complexity of economic indicators, understanding, evaluating, and querying risky enterprises is a challenging task for ordinary users. To solve this problem, our visual query system integrates multicriteria decision-making techniques and data mining through a visual analysis interface. The system facilitates efficient identification of risky enterprises, leveraging knowledge gained from a small number of known risk company samples. Our system includes an analytic hierarchy model to express domain knowledge, a query tree construction algorithm, and a well-designed visual interface. Two real cases demonstrate the effectiveness of our system.

Threshold Elliptic Curve Digital Signature Algorithm (ECDSA) has attracted a lot of attention due to the wide applications of ECDSA in crypto asset. Although several variants of threshold signature protocols can provide functions, such as key generation and signing, they suffer from two shortfalls. First, these schemes only discuss a single signature computation task in a synchronous algorithm context, which is difficult to adapt to real crypto-asset applications, such as custody. Second, these schemes are computing intensive and not scalable, hence can hardly support large-scale processing operations in real life even after traditional optimization, such as multithreading, is applied. In this article, we propose an innovative computation method called asynchronous threshold ECDSA with batch processing, based on the interactive threshold signature protocols. The method provides a reliable solution for critical operational scenarios, such as threshold signing and distributed key generation (DKG) in crypto-asset custody, and can be a future reference in secure data distribution mechanisms. The performance and scalability of our methods are validated through a benchmark testing.

Real-time 3D rendering and interaction is important for virtual reality (VR) experimental education. Unfortunately, standard end-computing methods prohibitively escalate computational costs. Thus, reducing or distributing these requirements needs urgent attention, especially in light of the COVID-19 pandemic In this study, we design a cloud-to-end rendering and storage system for VR experimental education comprising two models: background and interactive. The cloud server renders items in the background and sends the results to an end terminal in a video stream. Interactive models are then lightweight-rendered and blended at the end terminal. An improved 3D warping and hole-filling algorithm is also proposed to improve image quality when the user’s viewpoint changes. We build three scenes to test image quality and network latency. The results show that our system can render 3D experimental education scenes with higher image quality and lower latency than any other cloud rendering systems. Our study is the first to use cloud and lightweight rendering for VR experimental education. The results demonstrate that our system provides good rendering experience without exceeding computation costs.

Cloud computing is an essential technology to Big Data analytics and services. A cloud computing system is often comprised of a large number of parallel computing and storage devices. Monitoring the usage and performance of such a system is important for efficient operations, maintenance, and security. Tracing every application on a large cloud system is untenable due to scale and privacy issues. But profile data can be collected relatively efficiently by regularly sampling the state of the system, including properties such as CPU load, memory usage, network usage, and others, creating a set of multivariate time series for each system. Adequate tools for studying such large-scale, multidimensional data are lacking. In this paper, we present a visual based analysis approach to understanding and analyzing the performance and behavior of cloud computing systems. Our design is based on similarity measures and a layout method to portray the behavior of each compute node over time. When visualizing a large number of behavioral lines together, distinct patterns often appear suggesting particular types of performance bottleneck. The resulting system provides multiple linked views, which allow the user to interactively explore the data by examining the data or a selected subset at different levels of detail. Our case studies, which use datasets collected from two different cloud systems, show that this visual based approach is effective in identifying trends and anomalies of the systems.

While visualization has been widely used as a data presentation tool in both desktop and mobile devices, the rapid visualization of information from images is still underexplored. In this work, we present a smartphone image acquisition and visualization approach for text-based data. Our prototype, ShotVis, takes images of text captured from mobile devices and extracts information for visualization. First, scattered characters in the text are processed and interactively reformulated to be stored as structured data (i.e., tables of numbers, lists of words, sentences). From there, ShotVis allows users to interactively bind visual forms to the underlying data and produce visualizations of the selected forms through touch-based interactions. In this manner, ShotVis can quickly summarize text from images into word clouds, scatterplots, and various other visualizations all through a simple click of the camera. In this way, ShotVis facilitates the interactive exploration of text data captured via cameras in smartphone devices. To demonstrate our prototype, several case studies are presented along with one user study to demonstrate the effectiveness of our approach.

Abstract Modelling trees according to desired shapes is important for many applications. Despite numerous methods having been proposed in tree modelling, it is still a non‐trivial task and challenging. In this paper, we present a new variational computing approach for generating realistic trees in specific shapes. Instead of directly modelling trees from symbolic rules, we formulate the tree modelling as an optimization process, in which a variational cost function is iteratively minimized. This cost function measures the difference between the guidance shape and the target tree crown. In addition, to faithfully capture the branch structure of trees, several botanical factors, including the minimum total branches volume and spatial branches patterns, are considered in the optimization to guide the tree modelling process. We demonstrate that our approach is applicable to generate trees with different shapes, from interactive design and complex polygonal meshes.

We propose an interactive sketching tool for exploring image database, called InSide. Our main contribution is a new solution of interactive image exploration that dynamically adapts to users' sketching and provides mixed feedback. A position-aware matching approach is proposed for InSide in order to support translation-free sketch searching. Based on demonstrated results, our method outperforms state-of-the-art approaches in aspects of user interface and matching results.

We present an interactive rendering solution that aims at visualizing large-scale mesh with hundred millions of triangles up to extremely high resolution on cloud computing platform. Firstly, we propose a novel adaptive parallel rasterization method based on MapReduce, whose results are stored in a data format called enhanced layered depth image (ELDI). In order to fully apply the powerful capabilities of cloud computing, our proposed method integrates pixel and triangle based strategies in one processing pipeline so as to significantly reduce data transfer between Map and Reduce steps. Consequently, a light-weight Web service for interactive rendering is also proposed to couple with the rasterization step, which enables user to interactively visualize large-scale mesh via browser on both mobile devices and work stations. According to demonstrated examples in the paper, once the rasterization results are obtained, users can freely adjust visualizing effects of complex mesh. Our rendering approach is promising for big data exploration, analysis or authoring.

Abstract In this paper, we propose a GPU‐friendly shape interpolation method. In contrast with state‐of‐the‐art interpolation algorithms, our method computes the trajectory of each vertex independently instead of solving large linear systems in every interpolation step. Given two poses being interpolated, we find trajectory parameters for each vertex by optimization with the consideration of the key pose reconstruction and as‐rigid‐as‐possible deformation in the pre‐computing stage. During run‐time, the vertices coordinates on the intermediate shape can be computed in parallel according to a close form formulation. In the results we demonstrate that our method achieves extremely high performance on modern GPU and can be extended easily to multi‐pose interpolation. Copyright © 2011 John Wiley & Sons, Ltd.

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Abstract We propose a novel approach for repairing topological inconsistency of mesh sequences with a few user interactions. The main idea of our approach is to leverage curve skeletons to detect the inconsistency of a mesh sequence. The skeleton of one mesh in the sequence is edited by user, which produces a prototype skeleton. We propagate this prototype using graph matching in‐between frames. By using temporal coherence cues, the matching procedure can be dramatically accelerated. Finally, the mesh sequence is repaired according to the inconsistencies by comparing matched skeletons and original skeletons. As demonstrated in the results, our approach avoids manually editing in all meshes, and is able to output a mesh sequence with consistent topology. Copyright © 2010 John Wiley & Sons, Ltd.

We present an interactive mesh cutting method in this paper, which is based on a formulation of semi-supervised learning. Users first assign foreground and background seed faces on a given triangular mesh by sketch lines. Then the system computes a scalar field across the mesh. After that a coarse segmentation boundary is computed out respect to a specific iso-value, which leads to a refined boundary by tracing the isoline in the scalar field. Our proposed methods are easy for implementing. The presented computing framework can not only do segmentation for single static mesh models using shape information, but also do segmentation for dynamic mesh models based on deformation information. By integrating the proposed mesh cutout tool, we also demonstrate a simple sketch-based mesh editing system. In our system the cutting results can be further deformed, morphed, or cut-and-pasted.

Abstract This paper presents a novel interactive mesh deformation method that can achieve various dynamic material effects, including elastic membrane and cloth effects. In our framework, a mesh is encoded by some differential quantities based on edge length and dihedral angle; and the deformation is formulated as a least square problem for preserving the edge length and dihedral angle via the differential quantities. In order to obtain anisotropic material effects, we further propose an edge‐weighting scheme based on a user‐specified vector field. To avoid specifying the local transformations, we set up an iterative scheme for solving the deformation. At last, several examples are presented to show that our approach can interactively generate visually pleasing deformations. Copyright © 2006 John Wiley & Sons, Ltd.

In this paper, we present an importance-driven texture encoding algorithm based on samples. Our algorithm determines a set of samples from source texture based on combined criteria which include compression ratio, visual attention and parameterization distortion. The sample set is used to encode the majority parts of the texture. The remaining regions are then encoded by traditional compression algorithm such as vector quantization. Our method can preserve details of important areas and be extended to dynamic textures. The decoding procedure is performed entirely in programmable graphics hardware, yielding real-time frame rates. Experimental results demonstrate the efficiency and performance of our algorithm.

In this paper, we propose a novel shape interpolation approach based on Poisson equation. We formulate the trajectory problem of shape interpolation as solving Poisson equations defined on a domain mesh. A non-linear gradient field interpolation method is proposed to take both vertex coordinates and surface orientation into account. With proper boundary conditions, the in-between shapes are reconstructed implicitly from the interpolated gradient fields, while traditional methods usually manipulate vertex coordinates directly. Besides of global shape interpolation, our method is also applicable to local shape interpolation, and can be further enhanced by incorporating with deformation. Our approach can generate visual pleasing and physical plausible morphing sequences with stable area and volume changes. Experimental results demonstrate that our technique can avoid the shrinkage problem appeared in linear shape interpolation.

Existing cut-and-paste editing methods over meshes are inapplicable to regions with non-zero genus. To overcome this drawback, we propose a novel method in this paper. Firstly, a base surface passing through the boundary vertices of the selected region is constructed using the boundary triangulation technique. Considering the connectivity between the neighboring vertices, a new detail encoding technique is then presented based on surface parameterization. Finally, the detail representation is transferred onto the target surface via the base surface. This strategy of creating a base surface as a detail carrier allows us to paste features of non-zero genus onto the target surface. By taking the physical relationship of adjacent vertices into account, our detail encoding method produces more natural and less distorted results. Therefore, our elegant method not only can eliminate the dependence on the topology of the selected feature, but also reduces the distortion effectively during pasting.

In this paper, we present an efficient voxelization algorithm for complex polygonal models by exploiting newest programmable graphics hardware. We first convert the model into three discrete voxel spaces according to its surface orientation. The resultant voxels are encoded as 2D textures and stored in three intermediate sheet buffers called directional sheet buffers. These buffers are finally synthesized into one worksheet, which records the volumetric representation of the target. The whole algorithm traverses the geometric model only once and is accomplished entirely in GPU (graphics processing unit), achieving real-time frame rate for models with up to 2 million triangles.

In this paper we present an interactive collision detection algorithm for complex and deformable objects. For two target models, our approach rapidly calculates their region of interests (ROI), which is the overlapping of their axis aligned bounding boxes (AABBs), in CPU. The surfaces of both models inside the ROI are then voxelized using a novel GPU-based real-time voxelization method. The resultant volumes are represented by two 2D textures in video memory. The collision query is efficiently accomplished by comparing these 2D textures in GPU. The algorithm is robust to handle arbitrary shapes, no matter geometric models are convex or concave, closed or open, rigid or deformable. Our preliminary implementation achieves interactive frame rate for complex models with up to one million triangles on commodity desktop PCs.

Abstract This paper presents a hybrid method for creating three‐dimensional shapes by sketching silhouette curves. Given a silhouette curve, we approximate its medial axis as a set of line segments, and convolve a linearly weighted kernel along each segment. By summing the fields of all segments, an analytical convolution surface is obtained. The resulting generic shape has circular cross‐section, but can be conveniently modified via sketched profile or shape parameters of a spatial transform. New components can be similarly designed by sketching on different projection planes. The convolution surface model lends itself to smooth merging between the overlapping components. Our method overcomes several limitations of previous sketched‐based systems, including designing objects of arbitrary genus, objects with semi‐sharp features, and the ability to easily generate variants of shapes.