Itinerant encounters beyond the metropolis : expanding sedentary perspectives on teaching through pop-up community classrooms

Peer reviewedPublisher PD

Aplikacija za zakrivanje podataka

U ovome seminarskom radu ćemo objasniti samu definiciju kriptografije kao znastvene discipline, njezinu primjenu u praksi i ciljeve kojima se kriptografija bavi. Također ćemo detaljnije objasniti tradicionalne sustave za raskrivanje i raskrivanje, razliku između transpozicijskih i supstitucijskih sustava za zakrivanje. Cilj samoga rada je čitateljima objasniti kako funkcioniraju Cezarov sustav, Vigenerov sustav i sustav zakrivanja dvostrukim stupačnim slovoredom uz pomoć ključa. Osim samih sustava za zakrivanje, ovaj rad će također objasniti kako je moguće kreirati aplikaciju za zakrivanje i raskrivanje podataka. Za razumijevanje je potrebno znanje programskog jezika Python pošto je i sama aplikacija zakodirana u njemu

LMS Infostudent - web and mobile application

U ovome diplomskom radu su opisane osnovne karakteristike Apache Cordova Frameworka, njegove korištene tehnologije i karakteristike hibridnih aplikacija koje su produkt ovog sučelja. Radi činjenice da je Apache Cordova zasnovana na web tehnologijama HTML, CSS i JavaScript,) one će također biti opisane. Osim teorijskog dijela, ovaj rad također ima i praktični dio u kojemu je prikazana aplikacija namijenjena studentima i profesorima za olakšanje komunikacije i lakše praćenje nastave. U radu su prikazani odlike dizajna, programski kod i serverska arhitektura, te se ovaj rad također može koristiti kao primjer za daljnji razvoj mobilnih aplikacija unutar ovog sučelja

LMS Infostudent - web and mobile application

U ovome diplomskom radu su opisane osnovne karakteristike Apache Cordova Frameworka, njegove korištene tehnologije i karakteristike hibridnih aplikacija koje su produkt ovog sučelja. Radi činjenice da je Apache Cordova zasnovana na web tehnologijama HTML, CSS i JavaScript,) one će također biti opisane. Osim teorijskog dijela, ovaj rad također ima i praktični dio u kojemu je prikazana aplikacija namijenjena studentima i profesorima za olakšanje komunikacije i lakše praćenje nastave. U radu su prikazani odlike dizajna, programski kod i serverska arhitektura, te se ovaj rad također može koristiti kao primjer za daljnji razvoj mobilnih aplikacija unutar ovog sučelja

Simulation and evaluation of freeze-thaw cryoablation scenarios for the treatment of cardiac arrhythmias

BACKGROUND: Cardiac cryoablation is a minimally invasive procedure to treat cardiac arrhythmias by cooling cardiac tissues responsible for the cardiac arrhythmia to freezing temperatures. Although cardiac cryoablation offers a gentler treatment than radiofrequency ablation, longer interventions and higher recurrence rates reduce the clinical acceptance of this technique. Computer models of ablation scenarios allow for a closer examination of temperature distributions in the myocardium and evaluation of specific effects of applied freeze-thaw protocols in a controlled environment. METHODS: In this work multiple intervention scenarios with two freeze-thaw cycles were simulated with varying durations and starting times of the interim thawing phase using a finite element model verified by in-vivo measurements and data from literature. To evaluate the effects of different protocols, transmural temperature distributions and iceball dimensions were compared over time. Cryoadhesion durations of the applicator were estimated in the interim thawing phase with varying thawing phase starting times. In addition, the increase of cooling rates was compared between the freezing phases, and the thawing rates of interim thawing phases were analyzed over transmural depth. RESULTS: It could be shown that the increase of cooling rate, the regions undergoing additional phase changes and depths of selected temperatures depend on the chosen ablation protocol. Only small differences of the estimated cryoadhesion duration were found for ablation scenarios with interim thawing phase start after 90 s freezing. CONCLUSIONS: By the presented model a quantification of effects responsible for cell death is possible, allowing for the analysis and optimization of cryoablation scenarios which contribute to a higher clinical acceptance of cardiac cryoablation

Structure-Preserving Signatures on Equivalence Classes and Constant-Size Anonymous Credentials

Structure-preserving signatures (SPS) are a powerful building block for cryptographic protocols. We introduce SPS on equivalence classes (SPS-EQ), which allow joint randomization of messages and signatures. Messages are projective equivalence classes defined on group element vectors, so multiplying a vector by a scalar yields a different representative of the same class. Our scheme lets one adapt a signature for one representative to a signature for another representative without knowledge of any secret. Moreover, given a signature, an adapted signature for a different representative is indistinguishable from a fresh signature on a random message. We propose a definitional framework for SPS-EQ and an efficient construction in Type-3 bilinear groups, which we prove secure against generic forgers. We also introduce set-commitment schemes that let one open subsets of the committed set. From this and SPS-EQ we then build an efficient multi-show attribute-based anonymous credential system for an arbitrary number of attributes. Our ABC system avoids costly zero-knowledge proofs and only requires a short interactive proof to thwart replay attacks. It is the first credential system whose bandwidth required for credential showing is independent of the number of its attributes, i.e., constant-size. We propose strengthened game-based security definitions for ABC and prove our scheme anonymous against malicious organizations in the standard model; finally, we discuss a concurrently secure variant in the CRS model

Hybrid Software and System Development in Practice: Waterfall, Scrum, and Beyond

Software and system development faces numerous challenges of rapidly changing markets. To address such challenges, companies and projects design and adopt specific development approaches by combining well-structured comprehensive methods and flexible agile practices. Yet, the number of methods and practices is large, and available studies argue that the actual process composition is carried out in a fairly ad-hoc manner. The present paper reports on a survey on hybrid software development approaches. We study which approaches are used in practice, how different approaches are combined, and what contextual factors influence the use and combination of hybrid software development approaches. Our results from 69 study participants show a variety of development approaches used and combined in practice. We show that most combinations follow a pattern in which a traditional process model serves as framework in which several fine-grained (agile) practices are plugged in. We further show that hybrid software development approaches are independent from the company size and external triggers. We conclude that such approaches are the results of a natural process evolution, which is mainly driven by experience, learning, and pragmatism

Implementing RLWE-based Schemes Using an RSA Co-Processor

We repurpose existing RSA/ECC co-processors for (ideal) lattice-based cryptography by exploiting the availability of fast long integer multiplication. Such co-processors are deployed in smart cards in passports and identity cards, secured microcontrollers and hardware security modules (HSM). In particular, we demonstrate an implementation of a variant of the Module-LWE-based Kyber Key Encapsulation Mechanism (KEM) that is tailored for high performance on a commercially available smart card chip (SLE 78). To benefit from the RSA/ECC co-processor we use Kronecker substitution in combination with schoolbook and Karatsuba polynomial multiplication. Moreover, we speed-up symmetric operations in our Kyber variant using the AES co-processor to implement a PRNG and a SHA-256 co-processor to realise hash functions. This allows us to execute CCA-secure Kyber768 key generation in 79.6 ms, encapsulation in 102.4 ms and decapsulation in 132.7 ms

Single-Beat Noninvasive Imaging of Ventricular Endocardial and Epicardial Activation in Patients Undergoing CRT

BACKGROUND: Little is known about the effect of cardiac resynchronization therapy (CRT) on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE) is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. METHODOLOGY/PRINCIPAL FINDINGS: NICE was performed in ten patients with congestive heart failure (CHF) undergoing CRT and in ten patients without structural heart disease (control group). NICE is a fusion of data from high-resolution ECG mapping with a model of the patient's individual cardiothoracic anatomy created from magnetic resonance imaging. Beat-to-beat endocardial and epicardial ventricular activation sequences were computed during native rhythm as well as during ventricular pacing using a bidomain theory-based heart model to solve the related inverse problem. During right ventricular (RV) pacing control patients showed a deterioration of the ventricular activation sequence similar to the intrinsic activation pattern of CHF patients. Left ventricular propagation velocities were significantly decreased in CHF patients as compared to the control group (1.6±0.4 versus 2.1±0.5 m/sec; p<0.05). CHF patients showed right-to-left septal activation with the latest activation epicardially in the lateral wall of the left ventricle. Biventricular pacing resulted in a resynchronization of the ventricular activation sequence and in a marked decrease of total LV activation duration as compared to intrinsic conduction and RV pacing (129±16 versus 157±28 and 173±25 ms; both p<0.05). CONCLUSIONS/SIGNIFICANCE: Endocardial and epicardial ventricular activation can be visualized noninvasively by NICE. Identification of individual ventricular activation properties may help identify responders to CRT and to further improve response to CRT by facilitating a patient-specific lead placement and device programming