Parameter identification for soil simulation based on the discrete element method and application to small scale shallow penetration tests

The Discrete Element Method (DEM) is well-established and widely used in soil-tool interaction related applications. As for all simulation tools, a proper calibration of the model parameters is crucial. In this contribution, we present the parametrization procedure of the DEM software GRAnular Physics Engine (GRAPE), developed and implemented at Fraunhofer ITWM, and attempt to use two parametrized soil samples for the simulation of small scale shallow penetration tests. The results are compared to laboratory measurements

Common carotid intima media thickness and ankle-brachial pressure index correlate with local but not global atheroma burden:a cross sectional study using whole body magnetic resonance angiography

Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA).50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50-70%, 3 = 70-99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated.The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β -0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β -0.45 p = 0.005).ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is primarily due to a strong correlation with ilio-femoral atheroma burden

Post-Operative Functional Outcomes in Early Age Onset Rectal Cancer

Background: Impairment of bowel, urogenital and fertility-related function in patients treated for rectal cancer is common. While the rate of rectal cancer in the young (&lt;50 years) is rising, there is little data on functional outcomes in this group. Methods: The REACCT international collaborative database was reviewed and data on eligible patients analysed. Inclusion criteria comprised patients with a histologically confirmed rectal cancer, &lt;50 years of age at time of diagnosis and with documented follow-up including functional outcomes. Results: A total of 1428 (n=1428) patients met the eligibility criteria and were included in the final analysis. Metastatic disease was present at diagnosis in 13%. Of these, 40% received neoadjuvant therapy and 50% adjuvant chemotherapy. The incidence of post-operative major morbidity was 10%. A defunctioning stoma was placed for 621 patients (43%); 534 of these proceeded to elective restoration of bowel continuity. The median follow-up time was 42 months. Of this cohort, a total of 415 (29%) reported persistent impairment of functional outcomes, the most frequent of which was bowel dysfunction (16%), followed by bladder dysfunction (7%), sexual dysfunction (4.5%) and infertility (1%). Conclusion: A substantial proportion of patients with early-onset rectal cancer who undergo surgery report persistent impairment of functional status. Patients should be involved in the discussion regarding their treatment options and potential impact on quality of life. Functional outcomes should be routinely recorded as part of follow up alongside oncological parameters

Αρχιτεκτονική και Ανάπτυξη Διεπαφών Δικτύου για Πολυεπεξεργαστικά Chip και Συστοιχίες Υπολογιστών

As computing and embedded systems evolve towards highly parallel multiprocessors, major research and development efforts are being focused on network interface (NI) architectures that enable efficient interprocessor communication (IPC). This thesis is focused on NI architecture, prototyping and design issues for cluster and chip multiprocessors. This work includes the development of a NI queue manager, key NI design issues with respect to IPC and a proposed NI design well suited to chip multiprocessors. The first part of this thesis presents the architecture design and implementation of a NI queue manager that supports Virtual Output Queuing, Variable-Size Multi-Packet Segmentation and QFC flow control. To increase the available network buffer space VOQs can migrate to external memory in the form of memory blocks connected in linked-lists. Free-List Bypass and Free Block Preallocation optimization techniques are employed to minimize the required number of accesses to external memory and achieve higher bandwidth. In addition, a novel packet processing mechanism that converts arbitrary traffic segments into autonomous network packets was implemented. Detailed FPGA hardware cost results are presented for each individual module, as well as for three different implementations of the queue manager. Network performance experiments were carried out using the developed queue manager on a FPGA-based prototyping platform and confirmed previous theoretical and simulation results about the behavior and performance of the buffered crossbar switch. The second part starts with a discussion of fundamental NI design issues that affect IPC. Various approaches and solutions are evaluated based on performance, scalability, reliability and protection. The issues addressed include NI placement, virtualization and protection, address translation, data transfer mechanisms and the software interface. Relevant academic and commercial approaches and solutions are referenced throughout the discussion. The second part also contains a proposal for a design of a NI that is lightweight and tightly coupled to the processor, making it well suited to future chip multiprocessors. Two powerful communication primitives are offered: Message Queues and Remote DMA. Message Queues are intended for low latency communication, mainly synchronization and control messages or small low-overhead data transfers. Remote DMA minimizes processor involvement in communication, is well suited for bulky data transfers and facilitates zero-copy protocols. Furthermore, the proposed NI supports a versatile protection and security solution, based on the existence of protection zones that can easily be adapted to the specific security requirements of a system.Καθώς τα υπολογιστικά και ενσωματωμένα συστήματα εξελίσσονται σε παράλληλους πολυεπεξεργαστές, γίνονται μεγάλες προσπάθειες στην έρευνα και ανάπτυξη αρχιτεκτονικών διεπαφών δικτύου (ΔΔ) που επιτρέπουν την αποδοτική επικοινωνία μεταξύ επεξεργαστών (ΕΜΕ). Αυτή η εργασία εστιάζει στην αρχιτεκτονική, ανάπτυξη και σχεδίαση ΔΔ για συστοιχίες υπολογιστών και πολυεπεξεργαστικά chip. Συγκεκριμένα παρουσιάζονται η ανάπτυξη ενός διαχειριστή ουρών ΔΔ, σημαντικά θέματα σχεδίασης ΔΔ για ΕΜΕ, καθώς και μια προτεινόμενη σχεδίαση ΔΔ κατάλληλη για πολυεπεξεργαστικά chip. Στο πρώτο κομμάτι αυτής της εργασίας παρουσιάζεται η σχεδίαση της αρχιτεκτονικής και η υλοποίηση ενός διαχειριστή ουρών ΔΔ που υποστηρίζει Πολλαπλές Ουρές Εξόδου (ΠΟΕ), κατάτμησης μεταβλητού μεγέθους πολλαπλών πακέτων και έλεγχο ροής QFC. Για την αύξηση του διαθέσιμου χώρου αποθήκευσης δικτυακής κίνησης οι ΠΟΕ μπορούν να μεταναστεύουν σε εξωτερική μνήμη σε μορφή συνδεδεμένων λιστών από μπλοκ μνήμης. Γίνεται χρήση των τεχνικών βελτιστοποίησης παράκαμψης λίστας ελεύθερων μπλοκ και προδέσμευσης ελεύθερων μπλοκ για την ελαχιστοποίηση των απαραίτητων προσβάσεων στην εξωτερική μνήμη και έτσι την βελτίωση εύρους ζώνης. Επιπλέον, αναπτύχθηκε ένας νεωτεριστικός μηχανισμός επεξεργασίας πακέτων για μετατροπή τυχαίων κομματιών δικτυακής κίνησης σε αυτόνομα πακέτα δικτύου. Παρουσιάζονται αναλυτικά το κόστος σε υλικό για κάθε υποτμήμα της ΔΔ, καθώς και για τρεις διαφορετικές υλοποιήσεις της ΔΔ. Χρησιμοποιώντας την παρούσα ΔΔ έγιναν πειράματα απόδοσης δικτύου που επιβεβαίωσαν την συμπεριφορά και απόδοση του buffered crossbar, όπως αυτή είχε προκύψει από θεωρητικές μελέτες και προσομοίωση. Το δεύτερο κομμάτι αυτής της εργασίας διαπραγματεύεται βασικά θέματα σχεδίασης ΔΔ που επηρεάζουν την ΕΜΕ. Εκτιμώνται διάφορες προσσεγγίσεις και λύσεις με βάση την απόδοση, δυνατότητα κλιμάκωσης, αξιοπιστία και προστασία. Τα θέματα που συζητώνται περιλαμβάνουν την τοποθέτηση της ΔΔ, ζητήματα προστασίας, μετάφρασης διευθύνσεων, μηχανισμών μεταφοράς δεδομένων καθώς και τη διεπαφή λογισμικού. Στην πορεία παρουσιάζονται διάφορες ακαδημαϊκές και εμπορικές προσεγγίσεις. Επίσης προτείνεται η σχεδίαση μιας ΔΔ μικρού κόστους προοριζομένη για τοποθέτηση κοντά στον επεξεργαστή, καθιστώντας την κατάλληλη για χρήση σε μελλοντικά πολυεπεξεργαστικά chip. Παρέχονται δύο ισχυροί μηχανισμοί για επικοινωνία: Ουρές Μηνυμάτων και Remote DMA. Οι ουρές μηνυμάτων προσφέρουν επικοινωνία ελάχιστης καθυστέρησης και απευθύνονται κυρίως σε μηνύματα ελέγχου και συγχρονισμού ή μικρές μεταφορές δεδομένων. Το Remote DMA ελαχιστοποιεί την ανάμειξη του επεξεργαστή στην επικοινωνία, προσφέρεται για μεταφορά μεγάλου όγκου δεδομένων και διευκολύνει την υλοποίηση πρωτοκόλλων zero-copy. Επιπροσθέτως, η προτεινόμενη ΔΔ υποστηρίζει έναν ευέλικτο μηχανισμό προστασίας, βασισμένο στην ύπαρξη ζωνών, που μπορεί εύκολα να προσαρμοστεί στις εκάστοτε ανάγκες ασφάλειας ενός συστήματος

EMPATHIC-N in a Greek-Cypriot sample: confirming its factorial structure

Abstract Background Family-centered care has been receiving increased attention during the last decades and health professionals recognize family satisfaction with care as an important health indicator. The Empowerment of Parents in The Intensive Care-Neonatology (EMPATHIC-N) is a newly developed, yet empirically reliable and valid measure for the assessment of parental satisfaction with the care provided by Neonatal Intensive Care Units (NICU). The present study aims to present the Greek version of the EMPATHIC-N and to confirm its factorial structure. Methods The EMPATHIC-N was translated in Greek using a forward-backward translation and was piloted before use. A sample of 256 families receiving intensive care at the NICU of Archbishop Makarios III Public Hospital in Cyprus which is the only NICU in Cyprus, participated in the validation study of the EMPATHIC-N. Confirmatory factor analyses were performed using SPSS and AMOS 24.0. Results The Greek version of the EMPATHIC-N had good psychometric characteristics (Cronbach’s alpha = .87). The CFAs for the separate subscales of professionalism, organization, information, parental involvement and intervention for the EMPATHIC-N showed that all five subscales represented five distinct components of parental satisfaction with care. The CFA of the general instrument supported that a second-order model with a higher-order factor reflecting the organizational structure (professionalism, intervention and organization loaded on this factor) fitted the data best [χ2 (259) = 405.332, p < .001, ΤLI = .887, CFI = .903, RMSEA = .065 (90% CI .058, .073), SRMR = .0597]. Conclusions EMPATHIC-N is a valid and reliable measure for the assessment of parental satisfaction with neonatal care in a Greek-Cypriot context. The organizational dimension of the NICUs is an important component with specific research and clinical implications for the enhancement of parental satisfaction with care

Thread Cluster Memory Scheduling: Exploiting Differences in Memory Access Behavior

In a modern chip-multiprocessor system, memory is a shared resource among multiple concurrently executing threads. The memory scheduling algorithm should resolve memory contention by arbitrating memory access in such a way that competing threads progress at a relatively fast and even pace, resulting in high system throughput and fairness. Previously proposed memory scheduling algorithms are predominantly optimized for only one of these objectives: no scheduling algorithm provides the best system throughput and best fairness at the same time. This paper presents a new memory scheduling algorithm that addresses system throughput and fairness separately with the goal of achieving the best of both. The main idea is to divide threads into two separate clusters and employ differen

High color rendering can enable better vision without requiring more power

For many people, the correct perception of the colors of objects is an important part of life, and today it is being threatened by misinformed policy-making and associated business decisions. Some conservationists and lamp manufacturers have concluded that the accurate color rendering provided by ordinary incandescent lamps is an unaffordable luxury that good citizens should forgo as we employ more energy-efficient alternatives. Though this is not as extreme as suggesting that we should live in cold darkness, it is in the same general direction of deprivation. Yet research has shown that color rendering is important to people and highefficiency lamps can now also provide high color rendering, so there is no longer any need to have lighting that distorts color appearance. This article focuses on the tradeoff between color rendering accuracy and lamp efficiency to show that high color rendering accuracy is appropriate and, contrary to a common misconception, does not intrinsically require greater electrical energy consumption.Peer reviewed: YesNRC publication: Ye