Robust semi-automatic head pose labeling for real-world face video sequences

Automatic head pose estimation from real-world video sequences is of great interest to the computer vision community since pose provides prior knowledge for tasks, such as face detection and classification. However, developing pose estimation algorithms requires large, labeled real-world video databases on which computer vision systems can be trained and tested. Manual labeling of each frame is tedious, time consuming, and often difficult due to the high uncertainty in head pose angle estimate, particularly in unconstrained environments that include arbitrary facial expression, occlusion, illumination etc. To overcome these difficulties, a semi-automatic framework is proposed for labeling temporal head pose in real-world video sequences. The proposed multi-stage labeling framework first detects a subset of frames with distinct head poses over a video sequence, which is then manually labeled by the expert to obtain the ground truth for those frames. The proposed framework provides a continuous head pose label and corresponding confidence value over the pose angles. Next, the interpolation scheme over a video sequence estimates i) labels for the frames without manual labels and ii) corresponding confidence values for interpolated labels. This confidence value permits an automatic head pose estimation framework to determine the subset of frames to be used for further processing, depending on the labeling accuracy required. The experiments performed on an in-house, labeled, large, real-world face video database (which will be made publicly available) show that the proposed framework achieves 96.98 % labeling accuracy when manual labeling is only performed on 30 % of the video frames.     

A Black-Box Construction of Non-malleable Encryption from Semantically Secure Encryption

We show how to transform any semantically secure encryption scheme into a non-malleable one, with a black-box construction that achieves a quasi-linear blow-up in the size of the ciphertext. This improves upon the previous non-black-box construction of Pass, Shelat and Vaikuntanathan (Crypto ’06). Our construction also extends readily to guarantee non-malleability under a bounded-CCA2 attack, thereby simultaneously improving on both results in the work of Cramer et al. (Asiacrypt ’07). Our construction departs from the oft-used paradigm of re-encrypting the same message with different keys and then proving consistency of encryption. Instead, we encrypt an encoding of the message; the encoding is based on an error-correcting code with certain properties of reconstruction and secrecy from partial views, satisfied, e.g., by a Reed–Solomon code.     

Publication attributes of leadership: what do they mean?

The article evaluates 48 approaches to leadership for the first time for the period of 1965–2016 using bibliometric methods. Our analysis combines four parameters: the number of publications, citations, self-citations, and dispersion of literature (a new parameter). The question of what is the most influential approach to leadership is addressed. We argue that the interplay among the four attributes observed in this study shows that transformational leadership is the most influential and popular approach to leadership in leadership studies today. However, there is a question of whether the excessive self-citations in this approach to leadership play a role in its augmented visibility.     

Generation of mechanizing trajectories with a minimum number of points

A large number of coordinate points is available after digitizing a profile, a surface, or generating the points of the function that define the surface or the profile (if an equation to generate these points is available). These coordinate points are grouped according to the strategy followed for the digitization or the generation. But not all the coordinate points are equally important: More coordinate points are needed in the zones where the curvature is larger, in contrast to the zones where the curvature is smaller. A new selection method of coordinate points is presented in this study. It is based on the maximum allowed chord error. This method simplifies the selection of the important coordinate points for the shape reconstruction with a computer-aided design program or for the computer numerical control (CNC) mechanizing, using either less information, smaller number of points, or NC program lines. To accomplish this objective, any programming language can be applied. An Excel macro and MATLAB have been used in this study. This is interesting both in high-speed CNC machines and in old equipment. The first ones have “look ahead” benefits, because the number of blocks in the NC program are read in advance. Therefore, if a smaller number of lines are needed for the same required precision, the process speed will be higher. The use of old machines will also be improved by the smaller number of lines to process. It must be noted that this process is as fast as the slowest of its elements.     

Monitoring dynamic processes with alphanumeric and graphic displays

Three experiments assessed the relative efficiency of graphic and tabular displays for detecting changes in periodic sine functions, simulating a dynamic process. In all three experiments, line graphs had an advantage over tables for response times, for correct detections and identifications, and for false alarms. However, this advantage depended on the type of change that indicated a malfunction. The largest difference between the displays was evident for the detection of changes in a function's frequency and smaller differences were found for the detection of changes in amplitude and intercept. Results also indicated that participants adapted their detection methods to the types of possible changes. The findings demonstrate the value of graphic displays for process control and substantiate the claim that graphic displays have an advantage when the displayed information has inherent structure and when the task requires the use of this structure. In addition, task performance was the subject of adaptive changes, which depend on the context in which the task is performed.     

Signal amelioration of electrophoretically deposited whole-cell biosensors using external electric fields

This paper presents an integrated whole-cell biochip system where functioning cells are deposited on the solid micro-machined surfaces while specially designed indium tin oxide electrodes that can be used to apply controllable electric fields during various stages; for example during cell deposition. The electrodes can be used also for sensing currents associated with the sensing mechanisms of electrochemical whole-cell biosensors. In this work a new approach integrating live bacterial cells on a biochip using electrophoretic deposition is presented. The biomaterial deposition technique was characterized under various driving potentials and chamber configurations. An analytical model of the electrophoretic deposition kinetics was developed and presented here. The deposited biomass included genetically engineered bacterial cells that may respond to toxic material exposure by expressing proteins that react with specific analytes generating electrochemically active byproducts. In this study the effect of external electric fields on the whole-cell biochips has been successfully developed and tested. The research hypothesis was that by applying electric fields on bacterial whole-cells, their permeability to the penetration of external analytes can be increased. This effect was tested and the results are shown here. The effect of prolonged and short external electric fields on the bioelectrochemical signal generated by sessile bacterial whole-cells in response to the presence of toxins was studied. It was demonstrated that relatively short 10 ms external DC electric pulse improves the performance of bacterial biosensors by 15% relative to un-biased biosensors. The application of prolonged 1 h external alternating electric fields deteriorated the whole-cell performance in the presence of toxins. In this paper we present the electrode apparatus and methods, as well as the characterization results, e.g. signal vs. time and induction factor, of such chips and discussing the highlight and problems of this new concept.     

Construction and Characterization of Porous SiO2/Hydrogel Hybrids as Optical Biosensors for Rapid Detection of Bacteria

The use of a new class of hybrid nanomaterials as label‐free optical biosensors for bacteria detection (E. coli K12 as a model system) is demonstrated. The hybrids combine a porous SiO₂ (PSiO₂) optical nanostructure (a Fabry–Pérot thin film) used as the optical transducer element and a hydrogel. The hydrogel, polyacrylamide, is synthesized in situ within the nanostructure inorganic host and conjugated with specific monoclonal antibodies (IgGs) to provide the active component of the biosensor. The immobilization of the IgGs onto the hydrogel via a biotin‐streptavidin system is confirmed by fluorescent labeling experiments and reflective interferometric Fourier transform spectroscopy (RIFTS). Additionally, the immobilized IgGs maintain their immunoactivity and specificity when attached to the sensor surface. Exposure of these modified‐hybrids to the target bacteria results in “direct cell capture” onto the biosensor surface. These specific binding events induce predictable changes in the thin‐film optical interference spectrum of the hybrid. Preliminary studies demonstrate the applicability of these biosensors for the detection of low bacterial concentrations in the range of 10³–10⁵ cell mL^?1 within minutes.     

Cavitation in elastic and hyperelastic sheets

Plane stress, axially symmetric, cavitation patterns are examined for large sheets with an embedded central circular hole. Both (radially-uniform) remote tension and internal pressure loads are considered. Material behavior is modeled by finite strain Hookean-type elastic and hyperelastic constitutive relations with logarithmic strains.Governing field equations are reduced to a single ordinary differential equation with the principal stress difference as the independent variable. Calculations reveal that under internal pressure the usual definition of cavitation state does not apply as load increases monotonously along the deformation path.Introducing the specific cavitation energy, as a practical measure in cavitation analysis, provides a unified framework for assessment of cavitation phenomena. Comparison with related patterns of spherical and cylindrical cavitation fields supports the main findings of this study.     

Puzzle‐like Collage

Collages have been a common form of artistic expression since their first appearance in China around 200 BC. Recently, with the advance of digital cameras and digital image editing tools, collages have gained popularity also as a summarization tool. This paper proposes an approach for automating collage construction, which is based on assembling regions of interest of arbitrary shape in a puzzle‐like manner. We show that this approach produces collages that are informative, compact, and eye‐pleasing. This is obtained by following artistic principles and assembling the extracted cutouts such that their shapes complete each other.