An optical phantom of the maternal abdomen during pregnancy is an appropriate test environment to evaluate a non-invasive system for fetal pulse oximetry. To recreate the optical properties of maternal tissue, fetal t...
详细信息
ISBN:
(纸本)9781424479276
An optical phantom of the maternal abdomen during pregnancy is an appropriate test environment to evaluate a non-invasive system for fetal pulse oximetry. To recreate the optical properties of maternal tissue, fetal tissue and blood suitable substitutes are required. For this purpose, phantom materials are used, which consist of transparent silicone or water as host material. Cosmetic powder and India ink are investigated as absorbing materials, whereas titanium dioxide particles are examined as scattering medium. Transmittance and reflectance measurements of the samples were performed in the spectral range from 600 nm to 900 nm using integrating sphere technique. The scattering and absorption coefficients and the anisotropy factor were determined using Kubelka-Munk theory. The results were used to compute the required mixture ratios of the respective components to replicate the optical properties of maternal tissue, fetal tissue and blood, and corresponding samples were produced. Their optical properties were investigated in the same manner as mentioned above. The results conform to the values of various types of tissues and blood given in the scientific literature.
In this contribution we introduce the Parallel Factor 2 (PARAFAC2) analysis as a novel method for the simultaneous detection and classification of neural action potentials. In order to measure these action potentials ...
详细信息
In this contribution we introduce the Parallel Factor 2 (PARAFAC2) analysis as a novel method for the simultaneous detection and classification of neural action potentials. In order to measure these action potentials (spike signals), stem cell derived neuronal cells are cultivated on the surface of a Micro Electrode Array (MEA). Here, the neuronal cells produce ion currents, which can be measured as extracellular electric potentials. Whenever a cell or a group of cells produces ion currents, either spontaneously or evoked by a stimulus, a spike signal can be measured by the electrodes of the MEA. Stimulated cells produce spikes and groups of spikes (bursts) which propagate in space over the MEA. In the recorded data, different source types (e.g., cells which respond directly to external stimuli and cells which are triggered by other neural cells) are characterized by different spike shapes. The proposed PARAFAC2 method is able to separate these spike shapes (sources) in time, frequency and space (channels) enabling an improved performance in noisy scenarios. Furthermore, PARAFAC2 allows for a causality analysis on the measured spike signals (i.e. the identification of different signal paths). Thereby, the PARAFAC2 decomposition is able to exploit the multi-dimensional structure of the MEA data.
Textual passwords were first identified as a weak point in information system's security by Morris and Thompson in 1979. They found that 86% of the passwords were weak: being too short, containing lowercase letter...
详细信息
ISBN:
(纸本)9781479956579
Textual passwords were first identified as a weak point in information system's security by Morris and Thompson in 1979. They found that 86% of the passwords were weak: being too short, containing lowercase letters only, digits only or a combination of the two, being easily found in dictionaries. OBJECTIVE: Despite the importance of passwords as the first line of defense in most information systems, little attention has been given to the characteristics of their actual use. Thus, the objective of this paper is to identify any problems that may arise in creating and using textual passwords. METHOD: A systematic literature review of studies in the area of password use and password security. Our research is restricted to articles in journals and conference papers written in English and published between 1979 and 2014. The search is conducted through IEEEXplore, scienceDirect, Springer Link and ACM Digital Library. RESULTS: The computer community has not made a very much-needed shift in password management for more than 35 years. Users and their passwords are still considered the main weakness in any password system, because users often choose easily guessable passwords: words, names, birthdates, etc., because they are easy to remember. CONCLUSION: Password policies and password checkers can help users create strong and easy-to-remember passwords. This work will serve as a starting point for our further research in this area where we want to determine whether these password policies are useful to the users, and whether the users can easily apply them.
We describe formation of defect-colloidal superstructures induced by microspheres with normal surface anchoring dispersed in chiral nematic liquid crystals in confinement-unwound homeotropic cells. Using three-dimensi...
详细信息
We describe formation of defect-colloidal superstructures induced by microspheres with normal surface anchoring dispersed in chiral nematic liquid crystals in confinement-unwound homeotropic cells. Using three-dimensional nonlinear optical imaging of the director field, we demonstrate that some of the induced defects have nonsingular solitonic nature while others are singular point and line topological defects. The common director structures induced by individual microspheres have dipolar symmetry. These topological dipoles are formed by the particle and a hyperbolic point defect (or small disclination loop) of elementary hedgehog charge opposite to that of a sphere with perpendicular boundary conditions, which in cells with thickness over equilibrium cholesteric pitch ratio approaching unity are additionally interspaced by a looped double-twist cylinder of continuous director deformations. The long-range elastic interactions are probed by holographic optical tweezers and videomicroscopy, providing insights to the physical underpinnings behind self-assembled colloidal structures entangled by twisted solitons. computer-simulated field and defect configurations induced by the colloidal particles and their assemblies, which are obtained by numerically minimizing the Landau–de Gennes free energy, are in agreement with the experimental findings.
In this paper authors will expose a work developed with the aim to submit an educational innovation project proposal to a competitive call for Educational Innovation Projects 2013-2015 of the Education Advisory Servic...
详细信息
In this paper authors will expose a work developed with the aim to submit an educational innovation project proposal to a competitive call for Educational Innovation Projects 2013-2015 of the Education Advisory Service of the Basque Country University (UPV/EHU, Spain). This project is being carried out in the computer Structure and computer Architecture sub-module of the Degree in computer Management and Information Systems engineering of the University College of engineering of Vitoria-Gasteiz, University of the Basque Country (UPV/EHU). The project is based on the active learning, more specifically, on cooperative learning. In this paper we have given deeper insight the dependencies between all the subjects belonging to the analyzed sub-module, which is composed of two subjects named computer Structure and computer Architecture. We have included in such analysis a previous subject named Principles of Digital Systems Design, which does not belong to that sub-module, but plays an important role in the acquisition of the knowledge and competencies of the two previously referenced subjects.
The growth of online game development now a day makes us have to be more careful in doing trade or transactions inside the game. A transactions in the virtual world today is filled with virtual crime which known as cy...
详细信息
The growth of online game development now a day makes us have to be more careful in doing trade or transactions inside the game. A transactions in the virtual world today is filled with virtual crime which known as cyber crime. Common cyber crime in online games is fraud related to virtual goods or usually referred to the item mall [4]. In this study, the authors tried to suggest a method for prevention of fraud within transactions in the online game by tracing the phone number which been use from the form registration for online gaming. Analysis of this case is done by using the rules of the applicable rules in Indonesia is the ITE Law No. 11 of 2008 and Article 378 of the Criminal Code.
The critical infrastructures of a nation including the power grid and the communication network are highly interdependent. Recognizing the need for a deeper understanding of the interdependency in a multi-layered netw...
详细信息
The critical infrastructures of a nation including the power grid and the communication network are highly interdependent. Recognizing the need for a deeper understanding of the interdependency in a multi-layered network, significant efforts have been made by the research community in the last few years to achieve this goal. Accordingly a number of models have been proposed and analyzed. Unfortunately, most of the models are over simplified and, as such, they fail to capture the complex interdependency that exists between entities of the power grid and the communication networks involving a combination of conjunctive and disjunctive relations. To overcome the limitations of existing models, we propose a new model that is able to capture such complex interdependency relations. Utilizing this model, we provide techniques to identify the K most “vulnerable” nodes of an interdependent network. We show that the problem can be solved in polynomial time in some special cases, whereas for some others, the problem is NP-complete. We establish that this problem is equivalent to computation of a fixed point of a multilayered network system and we provide a technique for its computation utilizing Integer Linear programming. Finally, we evaluate the efficacy of our technique using real data collected from the power grid and the communication network that span the Maricopa County of Arizona.
Today, human detection and tracking is important challenge for many aims. In this study, we are used Ultra Wide Band (UWB) radar for human respiratory detection behind a wall. The modulated system to get the breathing...
详细信息
暂无评论