460 research outputs found

    A multistage hierarchical algorithm for hand shape recognition

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    This paper represents a multistage hierarchical algorithm for hand shape recognition using principal component analysis (PCA) as a dimensionality reduction and a feature extraction method. The paper discusses the effect of image blurring to build data manifolds using PCA and the different ways to construct these manifolds. In_order to classify the hand shape of an incoming sign object and to be invariant to linear transformations like translation and rotation, a multistage hierarchical classifier structure is used. Computer generated images for different Irish Sign Language shapes are used in testing. Experimental results are given to show the accuracy and performance of the proposed algorithm

    Cloud-based Quadratic Optimization with Partially Homomorphic Encryption

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    The development of large-scale distributed control systems has led to the outsourcing of costly computations to cloud-computing platforms, as well as to concerns about privacy of the collected sensitive data. This paper develops a cloud-based protocol for a quadratic optimization problem involving multiple parties, each holding information it seeks to maintain private. The protocol is based on the projected gradient ascent on the Lagrange dual problem and exploits partially homomorphic encryption and secure multi-party computation techniques. Using formal cryptographic definitions of indistinguishability, the protocol is shown to achieve computational privacy, i.e., there is no computationally efficient algorithm that any involved party can employ to obtain private information beyond what can be inferred from the party's inputs and outputs only. In order to reduce the communication complexity of the proposed protocol, we introduced a variant that achieves this objective at the expense of weaker privacy guarantees. We discuss in detail the computational and communication complexity properties of both algorithms theoretically and also through implementations. We conclude the paper with a discussion on computational privacy and other notions of privacy such as the non-unique retrieval of the private information from the protocol outputs

    A Satisfiability Modulo Theory Approach to Secure State Reconstruction in Differentially Flat Systems Under Sensor Attacks

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    We address the problem of estimating the state of a differentially flat system from measurements that may be corrupted by an adversarial attack. In cyber-physical systems, malicious attacks can directly compromise the system's sensors or manipulate the communication between sensors and controllers. We consider attacks that only corrupt a subset of sensor measurements. We show that the possibility of reconstructing the state under such attacks is characterized by a suitable generalization of the notion of s-sparse observability, previously introduced by some of the authors in the linear case. We also extend our previous work on the use of Satisfiability Modulo Theory solvers to estimate the state under sensor attacks to the context of differentially flat systems. The effectiveness of our approach is illustrated on the problem of controlling a quadrotor under sensor attacks.Comment: arXiv admin note: text overlap with arXiv:1412.432

    Nonlinearity reduction of manifolds using Gaussian blur for handshape recognition based on multi-dimensional grids

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    This paper presents a hand-shape recognition algorithm based on using multi-dimensional grids (MDGs) to divide the feature space of a set of hand images. Principal Component Analysis (PCA) is used as a feature extraction and dimensionality reduction method to generate eigenspaces from example images. Images are blurred by convolving with a Gaussian kernel as a low pass filter. Image blurring is used to reduce the non-linearity in the manifolds within the eigenspaces where MDG structure can be used to divide the spaces linearly. The algorithm is invariant to linear transformations like rotation and translation. Computer generated images for different hand-shapes in Irish Sign Language are used in testing. Experimental results show accuracy and performance of the proposed algorithm in terms of blurring level and MDG size

    Association between Low Adiponectin Level and Cardiovascular Complications in Diabetic and non Diabetic Patients with End Stage Renal Disease

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    Introduction: Adiponectin is a collagen-like protein synthesized by adipose tissue that has anti-inflammatory and anti-atherogenic properties. We aimed to evaluate adiponectin levels in end stage renal disease (ESRD) patients with and without diabetes mellitus and its relation to the presence of cardiovascular complications (CVC). Methods: The study included 20 healthy subjects who served as controls (group I), 20 non-diabetic ESRD patients without CVC (group IIA), 20 non-diabetic ESRD patients with CVC (group IIB), 20 diabetic ESRD patients without CVC (group IIIA) and 20 diabetic ESRD patients with CVC (group IIIB). Evaluation included mean arterial blood pressure (MABP), body mass index (BMI), fasting plasma glucose, fasting plasma insulin, homeostasis model assessment for insulin resistance (HOMA-IR), lipid profile, and serum adiponectin levels. Results: Adiponectin level in the control group was 6.4±1.2 mcg/ml, and was significantly lower than both group II and III (

    Diorganotin(IV) Complexes with Methionine Methyl Ester. Equilibria and Displacement by DNA Constituents

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    The coordination of methionine methyl ester with dimethyltin(IV) (DMT), dibutyltin(IV) (DBT) and  diphenyltin(IV) (DPT) was investigated at 25 °C and 0.1 mol dm–3 ionic strength in water for dimethyltin(IV) and in 50 % dioxane–water mixture for dibutyltin(IV) and diphenyltin(IV). Methionine methyl ester forms1:1 and 1:2 complexes with diorganotin(IV). The corresponding formation constants were calculated by using the non-linear least-squares programMINIQUAD-75. The concentration distribution of the various complex species was evaluated as a function of pH. The displacement of coordinated methionine methyl ester with some DNA constituents was calculated based on equilibrium aspects.KEYWORDS: Dimethyltin(IV), dibutyltin(IV), diphenyltin(IV), methionine methyl ester, stability constant

    Rolled vaginal wall flap for the treatment of stress urinary incontinence

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    Objectives: Anterior vaginal wall slings (AVWS) have been used for decades in the treatment of female stress urinary incontinence (SUI). The main drawback of using the vaginal wall as a sling is its tendency to weaken and stretch over the course of years. The use of synthetic tapes for the treatment of SUI is effective but costly. For patients who cannot afford synthetic tapes, we describe the preliminary results of a modified AVWS technique for the treatment of SUI types II and III.Patients and Methods: In this series, a modification of the AVWS was applied in 35 female patients with SUI. A fortified and rolled flap is used to provide compression and support of the urethra. The vaginal mucosal surface of the flap is cauterized and two diagonal sutures are placedacross it. The flap is then rolled on itself with a running 2/0 vicryl suture. Two sutures attached to both ends are passed retropubically to the anterior abdominal wall and tied over the rectus sheath.Results: All 35 female patients had type II/III SUI. After a median follow up of 43 months, 91% of the patients were dry or used 0-1 pad per day. Only one patient suffered from transient retention for one week post-operatively.Conclusion: This is a simple method to reinforce vaginal wall flaps. It could offer a durable and effective option for the treatment of SUI in patients who can not afford synthetic tapes. Long-term follow up is required to evaluate the durability of the procedur

    Synthesis and thermodynamics of the reactions of [Pd(Eten)(H2O)2]2+ with ligands of biological significane with reference to the antitumour activity

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    Pd(Eten)Cl2  complex, where Eten = N-ethylethylenediamine , was synthesized and characterized by elemental analysis and spectroscopic techniques. The stoichiometry and stability of the complexes formed between [Pd(Eten)(H2O)2]2+ and various biologically relevant ligands  as adenine, adenosine, adenosine-5’-monophosphate  and some selected peptides  were investigated at 25ºC and 0.1 M ionic strength. The speciation diagrams of the complexes formed in solutions are evaluated. Thermodynamic parameters for Pd(Eten)-glycylglycine complexes were estimated

    Response to comment on "Human-specific gain of function in a developmental enhancer"

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    Duret and Galtier argue that human-specific sequence divergence and gain of function in the HACNS1 enhancer result from deleterious biased gene conversion (BGC) with no contribution from positive selection. We reinforce our previous conclusion by analyzing hypothesized BGC events genomewide and assessing the effect of recombination rates on human-accelerated conserved noncoding sequence ascertainment. We also provide evidence that AT → GC substitution bias can coexist with positive selection
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