Framework for 4D medical data compression

U ovom radu predložen je novi programski okvir za kompresiju četvero-dimenzionalnih (4D) medicinskih podataka. Arhitektura ovog programskog okvira temelji se na različitim procedurama i algoritmima koji detektiraju vremenske i prostorne zalihosti u ulaznim 4D medicinskim podacima. Pokret kroz vrijeme analizira se pomoću vektora pomaka koji predstavljaju ulazne parametre za neuronske mreže koje se koriste za procjenu pokreta. Kombinacijom segmentacije, pronalaženja odgovarajućih blokova i predikcijom vektora pomaka, zajedno s ekspertnim znanjem moguće je optimirati performanse sustava. Frekvencijska svojstva se analiziraju proširenjem wavelet transformacije na tri dimenzije. Za mirne volumetrijske objekte, moguće je konstruirati različite wavelet pakete s različitim filtrima koji omogućavaju širok raspon analiza frekvencijskih zalihosti. Kombinacijom uklanjanja vremenskih i prostornih zalihosti moguće je postići vrlo visoke omjere kompresije.This work presents a novel framework for four-dimensional (4D) medical data compression architecture. This framework is based on different procedures and algorithms that detect time and spatial (frequency) redundancy in recorded 4D medical data. Motion in time is analyzed through the motion fields that produce input parameters for the neural network used for motion estimation. Combination of segmentation, block matching and motion field prediction along with expert knowledge are incorporated to achieve better performance. Frequency analysis is done through an extension of one dimensional wavelet transformation to three dimensions. For still volume objects different wavelet packets with different filter banks can be constructed, providing a wide range of frequency analysis. With combination of removing temporal and spatial redundancies, very high compression ratio is achieved

Skalabilna implementacija dekodera po normi MPEG korištenjem tokovnog programskog jezika

In this paper, we describe a scalable and portable parallelized implementation of a MPEG decoder using a streaming computation paradigm, tailored to new generations of multi--core systems. A novel, hybrid approach towards parallelization of both new and legacy applications is described, where only data--intensive and performance--critical parts are implemented in the streaming domain. An architecture--independent \u27StreamIt\u27 language is used for design, optimization and implementation of parallelized segments, while the developed \u27StreamGate\u27 interface provides a communication mechanism between the implementation domains. The proposed hybrid approach was employed in re--factoring of a reference MPEG video decoder implementation; identifying the most performance--critical segments and re-implementing them in \u27StreamIt\u27 language, with \u27StreamGate\u27 interface as a communication mechanism between the host and streaming kernel. We evaluated the scalability of the decoder with respect to the number of cores, video frame formats, sizes and decomposition. Decoder performance was examined in the presence of different processor load configurations and with respect to the number of simultaneously processed frames.U ovom radu opisujemo skalabilnu i prenosivu implementaciju dekodera po normi MPEG ostvarenu korištenjem paradigme tokovnog računarstva, prilagođenu novim generacijama višejezgrenih računala. Opisan je novi, hibridni pristup paralelizaciji novih ili postojećih aplikacija, gdje se samo podatkovno intenzivni i računski zahtjevni dijelovi implementiraju u tokovnoj domeni. Arhitekturno neovisni jezik StreamIt koristi se za oblikovanje, optimiranje i izvedbu paraleliziranih segmenata aplikacije, dok razvijeno sučelje \u27StreamGate\u27 omogućava komunikaciju između domena implementacije. Predloženi hibridni pristup razvoju paraleliziranih aplikacija iskorišten je u preoblikovanju referentnog dekodera video zapisa po normi MPEG; identificirani su računski zahtjevni segmenti aplikacije i ponovno implementirani u jeziku StreamIt, sa sučeljem \u27StreamGate\u27 kao poveznicom između slijedne i tokovne domene. Ispitivana su svojstva skalabilnosti s obzirom na ciljani broj jezgri, format video zapisa i veličinu okvira te dekompoziciju ulaznih podataka. Svojstva dekodera  su praćena u prisustvu različitih opterećenja ispitnog računala, i s obzirom na broj istovremeno obrađivanih okvira

Comparing Traditional and LLM-based Search for Consumer Choice: A Randomized Experiment

Recent advances in the development of large language models are rapidly changing how online applications function. LLM-based search tools, for instance, offer a natural language interface that can accommodate complex queries and provide detailed, direct responses. At the same time, there have been concerns about the veracity of the information provided by LLM-based tools due to potential mistakes or fabrications that can arise in algorithmically generated text. In a set of online experiments we investigate how LLM-based search changes people's behavior relative to traditional search, and what can be done to mitigate overreliance on LLM-based output. Participants in our experiments were asked to solve a series of decision tasks that involved researching and comparing different products, and were randomly assigned to do so with either an LLM-based search tool or a traditional search engine. In our first experiment, we find that participants using the LLM-based tool were able to complete their tasks more quickly, using fewer but more complex queries than those who used traditional search. Moreover, these participants reported a more satisfying experience with the LLM-based search tool. When the information presented by the LLM was reliable, participants using the tool made decisions with a comparable level of accuracy to those using traditional search, however we observed overreliance on incorrect information when the LLM erred. Our second experiment further investigated this issue by randomly assigning some users to see a simple color-coded highlighting scheme to alert them to potentially incorrect or misleading information in the LLM responses. Overall we find that this confidence-based highlighting substantially increases the rate at which users spot incorrect information, improving the accuracy of their overall decisions while leaving most other measures unaffected

Time Trends in Survival Following First Hemorrhagic or Ischemic Stroke Between 1991 and 2015 in the Rotterdam Study

Background and Purpose- The introduction of stroke units and the implementation of evidence-based interventions have been a breakthrough in the management

The Rotterdam Scan Study: design update 2016 and main findings

Imaging plays an essential role in research on neurological diseases in the elderly. The Rotterdam Scan Study was initiated as part of the ongoing Rotterdam Study with the aim to elucidate the causes of neurological disease by performing imaging of the brain in a prospective population-based setting. Initially, in 1995 and 1999, random subsamples of participants from the Rotterdam Study underwent neuroimaging, whereas from 2005 onwards MRI has been implemented into the core protocol of the Rotterdam Study. In this paper, we discuss the background and rationale of the Rotterdam Scan Study. Moreover, we describe the imaging protocol, image post-processing techniques, and the main findings to date. Finally, we provide recommendations for future research, which will also be topics of investigation in the Rotterdam Scan Study

Inequidades territoriales en Colombia: un balance del Sistema General de Regalías (SGR) en el cierre de la brecha interregional

The transformation of the General System of Royalties (Sistema General de Regalias) focuses on territorial development and the betterment of the conditions of wellbeing of municipal and departmental inhabitants. Because of this, a significant effect on the conditons of territorial imbalance is to be expected. This article evaluates the impact of the General System of Royalties transformation on territorial development. First, the change in the system, its causes and its benefitsare examined. Second, the dynamics of departmental economies are analyzed, as well as the departmental economic growth in the last 20 years, to establish the economic conditions on which the system was founded. Third, its contribution to territorial development, the sectors that it tends to, and the territorial entities that benefit from it are established. Finally, an evaluation of the relationship between municipal administrative capability and the distribution of resource royalties, which show indications of political influence in the approval of projects for territorial entities.La transformación del Sistema General de Regalías (SGR) atiende al desarrollo territorial y al mejoramiento de las condiciones de bienestar de los habitantes de municipios y departamentos, por lo que se esperaría un impacto significativo frente a las condiciones de desequilibrio territorial. Este artículo evalúa el impacto de la transformación del SGR en el desarrollo territorial. Primero, se examina el cambio en el sistema, sus causas y sus beneficios. Seguidamente, se analizan las dinámicas de las economías departamentales, así como el crecimiento económico departamental en los últimos veinte años, para establecer las condiciones sobre las que partió el sistema. En tercer lugar, se establece su contribución al desarrollo territorial, los sectores que atiende y las entidades territoriales beneficiarias del mismo. Finalmente, se evalúa la relación entre capacidad administrativa municipal y asignación de recursos de regalías, que muestran indicios de influencia política en la aprobación de proyectos a las entidades territoriales

Inequidades territoriales en Colombia: un balance del Sistema General de Regalías (SGR) en el cierre de la brecha interregional

The transformation of the General System of Royalties (Sistema General de Regalias) focuses on territorial development and the betterment of the conditions of wellbeing of municipal and departmental inhabitants. Because of this, a significant effect on the conditons of territorial imbalance is to be expected. This article evaluates the impact of the General System of Royalties transformation on territorial development. First, the change in the system, its causes and its benefitsare examined. Second, the dynamics of departmental economies are analyzed, as well as the departmental economic growth in the last 20 years, to establish the economic conditions on which the system was founded. Third, its contribution to territorial development, the sectors that it tends to, and the territorial entities that benefit from it are established. Finally, an evaluation of the relationship between municipal administrative capability and the distribution of resource royalties, which show indications of political influence in the approval of projects for territorial entities.La transformación del Sistema General de Regalías (SGR) atiende al desarrollo territorial y al mejoramiento de las condiciones de bienestar de los habitantes de municipios y departamentos, por lo que se esperaría un impacto significativo frente a las condiciones de desequilibrio territorial. Este artículo evalúa el impacto de la transformación del SGR en el desarrollo territorial. Primero, se examina el cambio en el sistema, sus causas y sus beneficios. Seguidamente, se analizan las dinámicas de las economías departamentales, así como el crecimiento económico departamental en los últimos veinte años, para establecer las condiciones sobre las que partió el sistema. En tercer lugar, se establece su contribución al desarrollo territorial, los sectores que atiende y las entidades territoriales beneficiarias del mismo. Finalmente, se evalúa la relación entre capacidad administrativa municipal y asignación de recursos de regalías, que muestran indicios de influencia política en la aprobación de proyectos a las entidades territoriales