15418757
Fingerprint classification by directional fields
Fingerprint classification provides an important fingerprint index and can reduce fingerprint matching time in a large database. A good classification algorithm can give an accurate index that is able to search a fingerprint database more effectively. We present a fingerprint classification algorithm that is based on directional fields. We compute directional fields of fingerprint images and detect singular points (cores). Then, we extract features that we define from fingerprint images. We also use k-means classifier and 3-nearest neighbor to classify features and distinguish which fingerprint is Arch, Left Loop, Right Loop, or Whorl. Experimental results show a significant improvement in fingerprint classification performance. Moreover, the time required for the classification algorithm is reduced.
1211237
High Resolution Acquisition, Learning and Transfer of Dynamic 3D Facial Expressions
Synthesis and re-targeting of facial expressions is central to facial animation and often involves significant manual work in order to achieve realistic expressions, due to the difficulty of capturing high quality dynamic expression data. In this paper we address fundamental issues regarding the use of high quality dense 3-D data samples undergoing motions at video speeds, e.g. human facial expressions. In order to utilize such data for motion analysis and re-targeting, correspondences must be established between data in different frames of the same faces as well as between different faces. We present a data driven approach that consists of four parts: 1) High speed, high accuracy capture of moving faces without the use of markers, 2) Very precise tracking of facial motion using a multi-resolution deformable mesh, 3) A unified low dimensional mapping of dynamic facial motion that can separate expression style, and 4) Synthesis of novel expressions as a combination of expression styles. The accuracy and resolution of our method allows us to capture and track subtle expression details. The low dimensional representation of motion data in a unified embedding for all the subjects in the database allows for learning the most discriminating characteristics of each individual's expressions as that person's “expression style”. Thus new expressions can be synthesized, either as dynamic morphing between individuals, or as expression transfer from a source face to a target face, as demonstrated in a series of experiments. 
 
 
 
Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Animation; I.3.5 [Computer Graphics]: Curve, surface, solid, and object representations; I.3.3 [Computer Graphics]: Digitizing and scanning; I.2.10 [Artificial intelligence]: Motion ; I.2.10 [Artificial intelligence]: Representations, data structures, and transforms; I.2.10 [Artificial intelligence]: Shape; I.2.6 [Artificial intelligence]: Concept learning
1235699
High resolution tracking of non-rigid 3D motion of densely sampled data using harmonic maps
We present a novel fully automatic method for high resolution, nonrigid dense 3D point tracking. High quality dense point clouds of nonrigid geometry moving at video speeds are acquired using a phase-shifting structured light ranging technique. To use such data for the temporal study of subtle motions such as those seen in facial expressions, an efficient nonrigid 3D motion tracking algorithm is needed to establish inter-frame correspondences. The novelty of this paper is the development of an algorithmic framework for 3D tracking that unifies tracking of intensity and geometric features, using harmonic maps with added feature correspondence constraints. While the previous uses of harmonic maps provided only global alignment, the proposed introduction of interior feature constraints guarantees that nonrigid deformations are accurately tracked as well. The harmonic map between two topological disks is a diffeomorphism with minimal stretching energy and bounded angle distortion. The map is stable, insensitive to resolution changes and is robust to noise. Due to the strong implicit and explicit smoothness constraints imposed by the algorithm and the high-resolution data, the resulting registration/deformation field is smooth, continuous and gives dense one-to-one inter-frame correspondences. Our method is validated through a series of experiments demonstrating its accuracy and efficiency.
44372041
Software Engineering Process Benchmarking
This paper proposes a Software Engineering Process (SEP) benchmarking methodology and a benchmark-gap analysis technique to assist industrial practitioners in quantitative software engineering. This work adopts the comprehensive SEP Assessment model (SEPRM), as a foundation to SEP benchmarking. In this approach, a number of conventional benchmarking challenges may be overcome. Case studies are presented to demonstrate the usage of the benchmarking technologies and supporting tools.
961760
Revisiting Colored Networks and Privacy Preserving Censorship
Reliable networks are obviously an important aspect of critical information infrastructures. Dolev-Dwork-Waarts-Yung linked research on reliable point-to-point networks with privacy and authenticity. In their threat model the adversary can only take over a number of nodes bounded by a threshold k. Hirt-Maurer introduced the concept of an adversary structure (i.e. the complement of an access structure). Kumar-Goundan-Srinathan-Rangan and Desmedt-Wang-Burmester generalized Dolev-Dwork-Waarts-Yung scenarios to the case of a general adversary structure. 
 
Burmester-Desmedt introduced a special adversary structure, now called a color based adversary structure. Their argument in favor of their model is that using automated attacks (such as worms), a vulnerability can be exploited on all computers in the network running the same platform (color). In their model the adversary can control all nodes that use up to k different platforms (or colors). 
 
We will demonstrate one of the limitations of their model. Although the family of color based adversary structures has a trivial representation which size grows polynomial in the size of the graph, we will demonstrate in this paper that deciding reliability issues and security issues are co-NP-complete. 
 
In most societies censorship is common. Indeed, for centuries it has often been viewed by authorities as an essential security tool. We apply the computational complexity result to study censorship. Authorities may require network designers to demonstrate the capability to censor the internet. We present a zero-knowledge interactive proof for the case of a color based adversary structure.
19029975
Design and Implementation of an Automatic RTPA Code Generator
Real-time process algebra (RTPA) is a mathematics-based notation system for the specification and refinement of realtime and safety-critical systems. This paper presents the work on designing and developing a set of tools that facilitate automatic generation of C++ code from RTPA specifications of system architectures and behaviors. A two-phrase strategy has been employed in the design of the toolkit. In the first phrase, an RTPA specification is lexically and syntactically analyzed and type-checked, which results in a set of abstract syntax trees. In the second phrase, C++ code is generated using the RTPA-to-C++ mapping strategies and patterns when walking down the abstract syntax trees. The RTPA-to-C++ mapping strategies specify both the traditional sequential part of RTPA mapping onto the standard C++ library and the real-time features of RTPA, such as interrupt, concurrency, duration, and event/time-driven dispatch, mapping onto the RTPA run-time library, which provides real-time support and is implemented using real-time kernel techniques. The toolkit implemented includes an RTPA lexer, an RTPA parser, an RTPA type-checker, and an RTPA code-generator. The experimental results show that RTPA specifications can be rigorously checked and corresponding C++ code can be automatically generated from RTPA specifications using the toolkit. The automatically generated code is executable and effective under the support of the standard C++ library and the specially developed RTPA run-time library
15617422
R*-Histograms: efficient representation of spatial relations between objects of arbitrary topology
Representation of relative spatial relations between objects is often required in many multimedia database applications because spatial relations between objects in an image convey important information about the image. Quantitative representation of spatial relations taking into account shape, size, orientation and distance is often required. The R-Histogram is such a quantitative representation of spatial relations between two objects. However, this method only considers pixels on the object boundary, assuming that the objects are homeomorphic to a 2-ball. For objects with more complicated topology, we propose in this paper the R*-Histogram, a new extension to the R-Histogram. The R*-Histogram generalizes the R-Histogram by taking into account all the pixels in the objects. We also introduce an efficient O(kN log N) time algorithm to compute the R*-Histogram, which is asymptotically faster than the original O(N<sup>2</sup>) time algorithm for the R-Histogram even when k=O(n). Here, N=n<sup>2</sup> denotes the number of pixels in the processed n x n image and k is the number of different directions considered. The effectiveness of the R*-Histogram is evaluated empirically with a Query By Example (QBE) system on a database of 2000 synthetic images containing objects with complicated shape and topology. Experiments have shown that the similarly search results match human intuition very well.
15443235
Computing the Writhing Number of a Polygonal Knot
AbstractThe writhing number measures the global geometry of
 a closed space curve or knot.
 We show that this measure is related to the average winding number
 of its Gauss map.
 Using this relationship, we give an algorithm for computing
 the writhing number for a polygonal knot with n edges
 in time roughly proportional to n1.6.
 We also implement a different, simple algorithm and provide
 experimental evidence for its practical efficiency.

