Measuring Visual Complexity of Cluster-Based Visualizations

Handling visual complexity is a challenging problem in visualization owing to the subjectiveness of its definition and the difficulty in devising generalizable quantitative metrics. In this paper we address this challenge by measuring the visual complexity of two common forms of cluster-based visualizations: scatter plots and parallel coordinatess. We conceptualize visual complexity as a form of visual uncertainty, which is a measure of the degree of difficulty for humans to interpret a visual representation correctly. We propose an algorithm for estimating visual complexity for the aforementioned visualizations using Allen's interval algebra. We first establish a set of primitive 2-cluster cases in scatter plots and another set for parallel coordinatess based on symmetric isomorphism. We confirm that both are the minimal sets and verify the correctness of their members computationally. We score the uncertainty of each primitive case based on its topological properties, including the existence of overlapping regions, splitting regions and meeting points or edges. We compare a few optional scoring schemes against a set of subjective scores by humans, and identify the one that is the most consistent with the subjective scores. Finally, we extend the 2-cluster measure to k-cluster measure as a general purpose estimator of visual complexity for these two forms of cluster-based visualization

Grupno izravnanje trigonometrijskih tačaka

Grupno izravnanje trigonometrijskih tačaka

Grupno izravnanje trigonometrijskih tačaka

Grupno izravnanje trigonometrijskih tačaka

Effects of aging and long-term dietary restrictions on cholesterol metabolism in the rat forebrain

Starenje centralnog nervnog sistema (CNS) praćeno je brojnim promenama koje dovode do narušavanja nervnih funkcija, pre svega kontrole motorike i kognitivnih sposobnosti. Smatra se da su kognitivni poremećaji tokom starenja posledica smanjene sinaptičke plastičnosti, naročito u korteksu i hipokampusu, regionima mozga izuzetno važnim za procese učenja i pamćenja. Najvažniji faktor sredine kojim se može uticati na starenje uopšte, a samim tim i na starenje mozga je režim redukovane ishrane, bez pothranjenosti. Pored toga što se već nekoliko decenija zna da redukovana ishrana produžava životni vek mnogih vrsta, uključujući i sisare, pokazano je da ona odlaže i ublažava starosno zavisne promene u nervnom sistemu. Holesterol je najzastupljeniji lipid u ćelijama sisara. Učestvujući u izgradnji fosfolipidnog dvosloja bioloških mambrana, on reguliše njihovu fluidnost, propustljivost i rigidnost, a samim tim i funkcionalna svojstva membranskih proteina, poput jonskih kanala i transmiterskih receptora. Metabolizam holesterola predstavlja važan aspekt sinaptičke plastičnosti, jer je pokazano da je holesterol neophodan za biogenezu i transport sinaptičkih vezikula, kao i za prvilnu funkcionalnu organizaciju lipidnih ostvaca. Od svih organa u telu, mozak sadrži najviše holesterola. Održavanje homeostaze holesterola neophodno je za normalno i neometano funkcionisanje CNS...Ageing of the central nervous system is associated with a number of changes that disturb nerve function, especially motor control and cognitive abilities. It is believed that cognitive disorders in aging are consequence of reduced synaptic plasticity, especially in the cortex and hippocampus, brain regions extremely important for learning and memory processes. Dominant factor that can influence aging in general, and therefore the aging of the brain is reduced diet regime, without malnutrition. In addition to being known for decades that reduced caloric intake prolongs life span of many species, including mammals, it is shown that it delays and alleviates age-dependent changes. Cholesterol is the most abundant lipid in mammalian cells. By participating in the construction of phospholipid bilayer of biological membranes, it regulates their fluidity, permeability and rigidity, and consequently the functional properties of membrane proteins, such as ion channels and transmmitters receptors. Cholesterol metabolism represents one aspect of synaptic plasticity, as has been shown that cholesterol is essential for biogenesis of synaptic vesicles, and vesicle transport, as well as for proper functional organization of lipid rafts. The brain contains the most cholesterol of all the organs in the body. Maintenance of cholesterol homeostasis is essential for proper functioning of the central nervous system..

Principles of sustainable architecture as a means of valorization of health tourism facilities, case study of Igalo

У овом раду се истражује међузависност и спрега одрживе архитектуре, здравственог туризма и салутогених простора у циљу дефинисања синтезног, интегративног пројектантског модела који би обухватио значајне принципе за све три области (домена) и чијом би се примјеном приликом реконструкције омогућило значајно унапријеђење постојећих здравствено-туристичких објеката, што се посебно односи на објекте грађене у другој половини 20. вијека, као што је то случај са Институтом за физикалну медицину, рехабилитацију и реуматологију „ Др Симо Милошевић“ у Игалу...This research explores interdependence and interaction between the sustainable architecture, health tourism and salutogenic spaces with the aim of defining a synthetic, integrated design model that would include significant principles for all the three fields (domains). The application of this model in reconstruction of the existing health tourism buildings (especially for those built in the second half of the 20th century, such as the Institute for Physical Medicine, Rehabilitation and Rheumatology “Dr Simo Milosevic” in Igalo) would significantly improve these facilities..

CAPTCHaStar! A novel CAPTCHA based on interactive shape discovery

Over the last years, most websites on which users can register (e.g., email providers and social networks) adopted CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart) as a countermeasure against automated attacks. The battle of wits between designers and attackers of CAPTCHAs led to current ones being annoying and hard to solve for users, while still being vulnerable to automated attacks. In this paper, we propose CAPTCHaStar, a new image-based CAPTCHA that relies on user interaction. This novel CAPTCHA leverages the innate human ability to recognize shapes in a confused environment. We assess the effectiveness of our proposal for the two key aspects for CAPTCHAs, i.e., usability, and resiliency to automated attacks. In particular, we evaluated the usability, carrying out a thorough user study, and we tested the resiliency of our proposal against several types of automated attacks: traditional ones; designed ad-hoc for our proposal; and based on machine learning. Compared to the state of the art, our proposal is more user friendly (e.g., only some 35% of the users prefer current solutions, such as text-based CAPTCHAs) and more resilient to automated attacks.Comment: 15 page

The aging brain - molecular and metabolic changes

Aging is a complex set of events that involves the whole body. However, disruption of the central nervous system (CNS) function is the aspect of aging that elderly people worry about most. Aging has different effects on different aspects of neurological function. Our knowledge of the basic molecular mechanism of brain aging has significantly improved over the past few decades. The rate of aging is not fixed, but is plastic and subject to modifications. The environmental factor proven to be very potent in modulating aging is reduced dietary intake. Dietary restriction (DR) is a vigorous nongenetic and nonpharmacological intervention that is known to delay ageing and increase an active and healthy lifespan in diverse species, from yeast to mammals. Additionally, DR can improve various brain functions, including learning and memory, synaptic plasticity and neurogenesis.Biologia Serbica (2017), 39(1): 26-3

Kulturni centar u Kotoru arhitekta Zdravka Moslavca; Interpolacija kao sredstvo valorizacije arhitektonskog naslijeđa

Reconstruction of the Cultural Center in the Old Town of Kotor designed by Zdravko Moslavac represents an artful urban-architectural synthesis of ”the new inside the old”. The analysis of this accomplishment contributes to the overall research and understanding of the creative body of work of the architect Moslavac and of works of Croatian architects in Montenegro, as well as of the ever popular phenomenon of architectural interpolation.Projekt rekonstrukcije Kulturnoga centra u Starom gradu Kotora djelo je arhitekta Zdravka Moslavca. Ono predstavlja umjetničku urbanističko-arhitektonsku sintezu „novoga unutar staroga”. Analiza ovoga ostvarenja pridonosi cjelokupnom istraživanju i razumijevanju kreativnog opusa arhitekta Moslavca i djelatnosti hrvatskih arhitekata u Crnoj Gori, kao i uvijek aktualnog fenomena interpolacija u arhitekturi

GraphUnit: Evaluating Interactive Graph Visualizations Using Crowdsourcing

We present GraphUnit, a framework and online service that automates the process of designing, running and analyzing results of controlled user studies of graph visualizations by leveraging crowdsourcing and a set of evaluation modules based on a graph task taxonomy. User studies play an important role in visualization research but conducting them requires expertise and is time consuming. GraphUnit simplifies the evaluation process by allowing visualization designers to easily configure user studies for their web-based graph visualizations, deploy them online, use Mechanical Turk to attract participants, collect user responses and store them in a database, and analyze incoming results automatically using appropriate statistical tools and graphs. We demonstrate the effectiveness of GraphUnit by replicating two published evaluation studies on network visualization, and showing that these studies could be configured in less than an hour. Finally, we discuss how GraphUnit can facilitate quick evaluations of alternative graph designs and thus encourage the frequent use of user studies to evaluate design decisions in iterative development processes