Multiple template matching using the expansion filter

The paper describes a multiple-template generalization of a newly developed approach for template matching by signal expansion into a set of non-orthogonal template-similar basis functions. The single-template method is proven to be equivalent to "restoration" of undegraded images using the Wiener filter and optimizes a new and more practically defined matching quality criterion that the authors call discriminative signal-to-noise ratio (DSNR). Compared to the widely used matched filtering approach (also known as correlation matching) which is based an projection, expansion matching is based on decomposition and is shown to be more robust in conditions of noise, superposition and severe occlusion. In the paper, the authors extend the DSNR optimization approach to include more than one template. The generalized expansion filter presented is optimal in terms of DSNR and can be designed to elicit any desired response for each of the templates, while optimizing the DSNR criterion. The approach considers additive noise as a parameter and leads to a general formulation, of which many previous approaches (such as the synthetic discriminant function) form special cases. In the case of a single template, the formulation reverts to the previously mentioned Wiener restoration filter

Improving Robustness of Scale-Free Networks to Message Distortion

Vast numbers of organizations and individuals communicate every day by sending messages over social networks. These messages, however, are subject to change as they propagate through the network. This paper attempts to calculate the distortion of a message as it propagates in a social network with a scale free topology, and to establish a remedial process in which a node will correct the distortion during the diffusion process, in order to improve the robustness of scale-free networks to message distortion. We test a model that we created using a simulation of different types of scale-free networks, and we compared different sets of corrective nodes, hubs, regular (non-hubs) nodes, and a combination of hubs and regular nodes. The findings show that using hubs that correct the distorted message while it\u27s diffused, decrease a global error measurement of the distortion, and as a result improve the robustness of the network

Association between time to reperfusion and echocardiography assessed left ventricular filling pressure in patients with first ST-segment elevation myocardial infarction undergoing primary coronary intervention

  Background: Diastolic dysfunction and elevated left ventricular (LV) filling pressure fol­lowing acute myocardial infarction are associated with adverse outcomes. Although time to reperfusion is a powerful prognostic marker following acute myocardial infarction, little is known about its impact on diastolic function and LV filling pressure. We hypothesized that delayed time to reperfusion will be associated with worse diastolic function. Methods: This study included 180 consecutive patients with first ST elevation myocardial in­farction (STEMI) treated by primary percutaneous coronary intervention (PCI). They presen­ted of chest pain within 24 h and underwent echocardiography within 3 days of primary PCI. Results: Median time to reperfusion, defined as the time from symptom onset to reperfusion at the end of primary PCI, was 185 min (interquartile range 120–660). Patients with reperfu­sion time > 185 min (n = 92) had a significantly higher E/septal e’ (13.3 ± 5.0 vs. 9.7 ± 2.3, p < 0.001) and E/lateral e’ (9.8 ± 3.5 vs. 7.8 ± 2.2, p < 0.001) ratios, and more advanced diastolic grade (p < 0.001) compared to those having early reperfusion (n = 88). There were no significant differences in LV ejection fraction and left atrial volume between the two groups. Time to reperfusion was an independent predictor of early E/average e’ ratio. The adverse ef­fect of late reperfusion on diastolic dysfunction was more prominent in patients with anterior myocardial infarction. Conclusions: Longer time to reperfusion is associated with early elevated LV diastolic pres­sure in primary PCI-treated patients with STEMI.

AUK: a simple alternative to the AUC

The area under Receiver Operating Characteristic (ROC) curve, also known as the AUC-index, is commonly used for ranking the performance of data mining models. The AUC has many merits, such as objectivity and ease of interpretation. However, since it is class indifferent, its usefulness while dealing with hig

Distributed Protocols for Oblivious Transfer and Polynomial Evaluation

A secure multiparty computation (MPC) allows several parties to compute a function over their inputs while keeping their inputs private. In its basic setting, the protocol involves only parties that hold inputs. In distributed MPC, there are also external servers who perform a distributed protocol that executes the needed computation, without learning information on the inputs and outputs. Here we propose distributed protocols for several fundamental MPC functionalities. We begin with a Distributed Scalar Product (DSP) protocol for computing scalar products of private vectors. We build upon DSP in designing various protocols for Oblivious Transfer (OT): k-out-of-N OT, Priced OT, and Generalized OT. We also use DSP for Oblivious Polynomial Evaluation (OPE) and Oblivious Multivariate Polynomial Evaluation (OMPE). All those problems involve a sender and a receiver, both of whom hold private vectors; the goal is to let the receiver learn the scalar product of those two vectors. However, in each of these problems the receiver must submit a vector of a specified form. Hence, a crucial ingredient in our protocols is a sub-protocol for validating that the receiver’s vector complies with the relevant restrictions, without learning anything else on that vector. Therefore, while previous studies presented distributed protocols for 1-out-of-N OT and OPE, our protocols are the first ones that are secure against malicious receivers. Our distributed protocols for the other OT variants and for OMPE are the first ones that handle such problems. In addition, while previous art assumed semi-honest servers, we present protocols that are secure even when some of the servers are malicious. Our protocols offer information-theoretic security and they are very efficient

Expression of schizophrenia in black Xhosa-speaking and white English-speaking South Africans

Objective. To inv:estigate whether schizophrenia manifests itself differently in  Xhosa-speaking South Africans, compared with English-speaking white South  Africans.Design. A comparative study ·of the presentation of schizophrenia in two groups of patients.Settings and subjects. A sample of 63 patients (43 Xhosaspeaking and 20 English-speaking) admitted to a large psychiatric hospital for the first time with a diagnosis of schizophrenia.Outcome measures. The Present State Examination (PSE) was used to confirm the clinical diagnosis of schizophrenia. The Relatives' Rating of Symptoms and Social Behaviour (KAS-R) was used to obtain information on the behavioural and emotional expression of schizophrenia.Results. A significantly higher prevalence of aggressive and disruptive behaviour was reported by relatives of Xhosaspeaking patients with schizophrenia of recent onset compared with English-speaking patients. The PSE elicited significantly more delusions of persecution, sexual and fantastic delusions, self-neglect and irritability in the Xhosaspeaking patients.Canclusion. Significant differences in the presentation of schizophrenia, but not its core symptoms, were identified in . Xhosa-speaking blacks and English-speaking whites