Concepts and Strategies for Quality of Modeling

2010 ◽  
pp. 167-189
Author(s):  
Patrick van Bommel ◽  
Stijn Hoppenbrouwers ◽  
Erik Proper ◽  
Jeroen Roelofs
Keyword(s):  
Proof Of Concept ◽  
Formal Approach ◽  
Prototype Implementation ◽  
Process Oriented ◽  
Formal Rules

A process-oriented framework (QoMo) is presented that aims to further the study of analysis and support of processes for modeling. The framework is strongly goal-oriented, and expressed largely by means of formal rules. The concepts in the framework are partly derived from the SEQUAL framework for quality of modelling. A number of modelling goal categories is discussed in view of SEQUAL/QoMo, as well as a formal approach to the description of strategies to help achieve those goals. Finally, a prototype implementation of the framework is presented as an illustration and proof of concept.

scholarly journals A prescribed walking regimen plus arginine supplementation improves function and quality of life for patients with pulmonary arterial hypertension: a pilot study

2017 ◽  
Vol 8 (1) ◽  
pp. 204589321774396 ◽  
Author(s):  
Mary Beth Brown ◽  
Attie Kempf ◽  
Catherine M. Collins ◽  
Gary M. Long ◽  
Matthew Owens ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Current Evidence ◽  
Proof Of Concept ◽  
Concept Study ◽  
Sf 36 ◽  
Pulmonary Arterial ◽  
Arginine Supplementation

Current evidence suggests that exercise training is beneficial in pulmonary arterial hypertension (PAH). Unfortunately, the standard supervised, hospital-based programs limit patient accessibility to this important intervention. Our proof-of-concept study aimed to provide insight into the usefulness of a prescribed walking regimen along with arginine supplementation to improve outcomes for patients with PAH. Twelve PAH patients (all women) in New York Heart Association (NYHA) functional class (FC) II (n = 7) or III (n = 5) and in stable condition for ≥ 3 months were enrolled. Patients performed home- and fitness-center- based walking at 65–75% heart rate (HR) reserve for 45 min, six sessions/week for 12 weeks. Concomitant L-arginine supplementation (6000 mg/day) was provided to maximize beneficial endothelial training adaptations. Cardiopulmonary exercise testing, 6-min walk testing (6MWT), echocardiography, laboratory studies, and quality of life (QoL) survey (SF-36) were performed at baseline and 12 weeks. Eleven patients completed the study (72 session adherence rate = 96 ± 3%). Objective improvement was demonstrated by the 6MWT distance (increased by 40 ± 13 m, P = 0.01), VO2max (increased by 2 ± 0.7 mL/kg/min, P = 0.02), time-to-VO2max (increased by 2.5 ± 0.6 min, P = 0.001), VO2 at anaerobic threshold (increased by 1.3 ± 0.5 mL/kg/min, P = 0.04), HR recovery (reduced by 68 ± 23% in slope, P = 0.01), and SF-36 subscales of Physical Functioning and Energy/Fatigue (increased by 70 ± 34% and 74 ± 34%, respectively, P < 0.05). No adverse events occurred, and right ventricular function and brain natriuretic peptide levels remained stable, suggesting safety of the intervention. This proof-of-concept study indicates that a simple walking regimen with arginine supplementation is a safe and efficacious intervention for clinically stable PAH patients, with gains in objective function and QoL measures. Further investigation in a randomized controlled trial is warranted.

The effect of motor imagery on quality of movement when performing reaching tasks in healthy subjects: A proof of concept

2021 ◽  
Author(s):  
Barbora Kolářová ◽  
Jim Richards ◽  
Hana Ondráčková ◽  
Klára Lippertová ◽  
Louise Connell ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Healthy Subjects ◽  
Proof Of Concept ◽  
Reaching Tasks ◽  
Quality Of Movement

scholarly journals Enhancement of Region of Interest CT Reconstructions through Multimodal Data

2018 ◽  
Vol 4 (1) ◽  
pp. 331-335
Author(s):  
David Schote ◽  
Tim Pfeiffer ◽  
Georg Rose
Keyword(s):  
Substantial Reduction ◽  
Region Of Interest ◽  
Proof Of Concept ◽  
Multimodal Data ◽  
New Approach ◽  
Full Field ◽  
Lack Of Information ◽  
Ct Data ◽  
Flight Measurements

AbstractComputed tomography (CT) scans are frequently used intraoperatively, for example to control the positioning of implants during intervention. Often, to provide the required information, a full field of view is unnecessary. I nstead, the region-of-interest (ROI) imaging can be performed, allowing for substantial reduction in the applied X-ray dose. However, ROI imaging leads to data inconsistencies, caused by the truncation of the projections. This lack of information severely impairs the quality of the reconstructed images. This study presents a proof-of-concept for a new approach that combines the incomplete CT data with ultrasound data and time of flight measurements in order to restore some of the lacking information. The routine is evaluated in a simulation study using the original Shepp-Logan phantom in ROI cases with different degrees of truncation. Image quality is assessed by means of normalized root mean square error. The proposed method significantly reduces truncation artifacts in the reconstructions and achieves considerable radiation exposure reductions.

scholarly journals Thoracoscopic Ablation with Appendage Ligation versus Medical Therapy for Stroke Prevention a Proof-of-Concept Randomized Trial

2016 ◽  
Vol 11 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Thomas M. Beaver ◽  
Vishnumurthy Shushrutha Hedna ◽  
Anna Y. Khanna ◽  
William M. Miles ◽  
Catherine C. Price ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Medical Management ◽  
Stroke Prevention ◽  
Normal Sinus Rhythm ◽  
Recurrent Stroke ◽  
Outcome Variable ◽  
Concept Design ◽  
Proof Of Concept ◽  
Surgical Morbidity

Objective Atrial fibrillation (AF) has a demonstrable effect on quality of life (QOL). Recurrent stroke occurs in 10% of patients with AF. The objective of this study was to demonstrate proof of concept that thoracoscopic pulmonary vein isolation and atrial appendage ligation (TPVIAL) could prevent recurrent stroke and could potentially improve QOL in patients with AF with a previous stroke. Methods The study was a National Institutes of Health-funded single-center proof-of-concept design that randomized 23 patients with AF-related stroke to TPVIAL (n = 12) or to medical management (n = 11). Quality of life was the primary outcome variable; secondary end points included restoration of rhythm, recurrent stroke, and surgical morbidity. Results Quality-of-life subscores at 3 and 6 months revealed improvements in energy and decreases in fatigue in the TPVIAL arm [baseline, 33 (19.8); 3 months, 49.5 (20.6), P = 0.01; 6 months, 55.5 (14.4), P = 0.03]. At 12-month follow-up, there were no recurrent strokes in the TPVIAL group. In the medically treated arm, two patients at 6 months (P = 0.22) and three total patients at 12 months (P = 0.09) had recurrent ischemic stroke. There was one death in the medical management arm. In the TPVIAL arm, no AF recurrence occurred in patients with paroxysmal AF, and one patient had recurrence of persistent and long-standing AF. Seven patients in the TPVIAL arm discontinued warfarin therapy for secondary stroke prevention. Conclusions This small proof-of-concept study showed that TPVIAL improved QOL on two subscores and restored normal sinus rhythm in all but one patient, and it showed the potential to prevent secondary stroke. A larger study will be needed.

scholarly journals Προσαρμοστική επιδημική διάδοση σε ασύρματα αδόμητα δίκτυα

2018 ◽  
Author(s):  
Θεοφάνης Κοντός
Keyword(s):  
Quality Of Service ◽  
Ad Hoc ◽  
Proof Of Concept ◽  
One Stage ◽  
Look Ahead ◽  
Cross Layering

Το αντικείμενο της έρευνας αυτής είναι η επιδημική διάδοση (epidemic dissemination)πληροφορίας σε ασύρματα αδόμητα (ad hoc) δίκτυα με προσαρμοστικό τρόπο. Στό-χοι είναι η συμφιλίωση των απαιτήσεων για ευρεία διάδοση της πληροφορίας και γιαμειωμένο ενεργειακό κόστος, η εκτίμηση μιας βέλτιστης λύσης του προβλήματος αλ-λά και η επίτευξη της βέλτιστης απόδοσης στους εν λόγω τομείς με υψηλής ποιότηταςπληροφορία.Η προσαρμοστική επιδημική διάδοση (Π.Ε.Δ.) σε αδόμητα δίκτυα σε θορυβώδες περι-βάλλον είναι πρόβλημα με πολλές παραμέτρους.Με τη χρήση της διαστρωμάτωσης (cross-layering) με βάση την επίγνωση κατάστασηςκαναλιού μπορούν να κατασκευαστούν σχήματα προσαρμοστικής διάδοσης, τα οποίαεξοικονομούν ενέργεια διατηρώντας ταχεία και αποτελεσματική διάχυση πληροφορίαςή μόλυνση του δικτύου, σύμφωνα με την ορολογία της επιδημικής διάδοσης [1].Αυτού του είδους η αντιμετώπιση [1] είναι αναδραστική. Μπορεί όμως να σχεδιαστείμια εκδοχή σχημάτων με πρόβλεψη η οποία χρησιμοποιεί συναρτήσεις οφέλους για τηνπροσαρμογή των χαρακτηριστικών εκπομπής. Η προτεινόμενη λύση είναι μια απόδει-ξη της αρχής λειτουργίας (proof of concept, PoC) αυτής της ιδέας. Με την αντιμετώπισηαυτή εξοικονομείται ενέργεια ενώ και η διάχυση πληροφορίας είναι επιτυχής [2].Το πιο πάνω σχήμα μπορεί να ενισχυθεί με τη χρήση βελτιστοποίησης. Ελέγχονταςποια προσαρμογή είναι η πλέον σύμφορη σε κάθε χρονική στιγμή όπως στο [2], επι-τυγχάνεται μια έστω και «μυωπική» ορατότητα στο άμεσο μέλλον. Με τη χρήση τηςθεωρίας βέλτιστης παύσης (β.π.) μπορεί να αποκτηθεί καλύτερη ορατότητα σε βάθοςχρόνου και να προσεγγιστεί η βελτιστοποίηση. Η πραγματική βελτιστοποίηση εξαρτά-ται από την ικανοποίηση συνθηκών β.π. Αν αυτές δεν ικανοποιούνται πλήρως, τότεκαι οι αποκτώμενες λύσεις δεν είναι κατ’ ανάγκη βέλτιστες. Αυτό φαίνεται στην [3] μετη χρήση του κανόνα β.π. (one-stage-look-ahead, 1sla). Μπορεί να επιτευχθεί βελτί-ωση σε σχέση με μη προσαρμοστικές λύσεις ως προς την εξοικονόμηση ενέργειας. Ηευρεία μόλυνση του δικτύου εξακολουθεί να επιτυγχάνεται [3].Εξετάζεται στη συνέχεια ως πρόβλημα Π.Ε.Δ. ο χρονοπρογραμματισμός τακτικών εκ-πομπών. Η βελτιστοποίηση προσεγγίζεται με τη μετάβαση από αυστηρά περιοδικέςεκπομπές σε πλησιοπεριοδικό καθεστώς. Ο χρονοπρογραμματισμός πραγματοποιεί-ται με τη βοήθεια των ιδίων εργαλείων, δηλαδή διαστρωματικές συναρτήσεις οφέλουςκαι χρήση μηχανισμού β.π. Το πρόβλημα αυτό μοντελοποιείται ως κλασικό πρόβλημαγραμματέως, στο οποίο η χρήση β.π. προσφέρει βελτιστοποίηση. Σε σχέση με σχή-ματα χωρίς β.π. [2] και με μη προσαρμοστικά το σχήμα αυτό είναι αποδοτικότερο στηνεξοικονόμηση ενέργειας και επιτρέπει εξ ίσου επιτυχημένη μόλυνση του δικτύου. Είναιδυνατόν να συνυπολογιστεί και το ενεργειακό κόστος απόκτησης πληροφορίας κατά-στασης καναλιού (ΠΚΚ). Με τη βοήθεια αυτού του σχήματος, το δίκτυο συγκλίνει σεκατάσταση στην οποία το κόστος διάχυσης είναι σημαντικά ελαττωμένο ενώ σημαντικόποσοστό του εναπομένοντος κόστους οφείλεται στην ανάκτηση ΠΚΚ ([4]). Οι ακριβείςσυσχετισμοί εξαρτώνται από τις παραμέτρους του προβλήματος [4].Περαιτέρω θίγεται η δυνατότητα βελτίωσης της ποιότητας πληροφορίας με την αξιο-ποίηση σχημάτων σαν αυτό της [4]. Αρχικά θεωρείται ως ποιότητα η νεότητα της δια-χεόμενης πληροφορίας. Προτείνεται προσαρμογή των χαρακτηριστικών εκπομπής μεβάση τη νεότητα της μολύνουσας πληροφορίας με στόχο τη βελτίωση της μέσης ηλικί-ας της μολύνουσας τους κόμβους πληροφορίας. Με τον τρόπο αυτό εισάγεται η ιδέατης προσαρμογής των χαρακτηριστικών εκπομπής με βάση το περιεχόμενο της ίδιαςτης φερόμενης πληροφορίας.Ο μετριασμός των ευρυεκπομπών κατά τη φάση ανακάλυψης μονοπατιού στα πρω-τόκολλα δρομολόγησης είναι ένας ακόμη ελκυστικός στόχος και αντιμετωπίζεται σταπλαίσια του πρωτοκόλλου AODV. Εδώ αναδεικνύεται ο ανταγωνισμός μεταξύ εξοικο-νόμησης ενεργειακού κόστους και ταχείας εύρεσης πληροφορίας δρομολόγησης. Σεμια απόπειρα επέκτασης της τεχνικής στην εκπομπή της ίδιας της δρομολογούμενηςπληροφορίας (των δεδομένων δηλαδή), μεταπίπτουμε σε περιβάλλον μονοεκπομπών(unicast). Εδώ, ο μετριασμός εκπομπών μπορεί να έχει σοβαρές συνέπειες στη μετά-δοση πληροφορίας και καταδεικνύεται η ανάγκη εξέτασης του προβλήματος με τη βο-ήθεια μετρικών που εκφράζουν την έννοια της ποιότητας υπηρεσίας (quality of service,QoS) και κατ’ επέκταση της ποιότητας της πληροφορίας.Το εξεταζόμενο πρόβλημα χρονοπρογραμματισμού με την πρόσθετη νέα απαίτησηςτης βελτίωσης της ποιότητας πληροφορίας μπορεί να διατυπωθεί αυστηρά ως πρό-βλημα βέλτιστης παύσης με πεπερασμένο γνωστό ορίζοντα.Η ποιότητα πληροφορίας μπορεί να ορίζεται με βάση ιδιότητές της (όπως η νεότηταπου αναφέρθηκε) ή παραμέτρους του πρωτοκόλλου στα πλαίσια του οποίου γίνεται ηδιάχυσή της, όπως το TTL (time-to-live) στην περίπτωση του AODV.Έτσι η ποιότητα πληροφορίας αναδεικνύεται σε μια τρίτη συνιστώσα πέρα από το ε-νεργειακό κόστος και το ποσοστό μόλυνσης, η οποία λαμβάνει μέρος στον υπό εξέτασηαναδυόμενο ανταγωνισμό. Ανάλογα με την οριζόμενη ποιότητα πληροφορίας είναι δυ-νατή η εύρεση συμβιβασμού μεταξύ των τριών αυτών απαιτήσεων.

scholarly journals Enviromic assembly increases accuracy and reduces costs of the genomic prediction for yield plasticity

2021 ◽  
Author(s):  
Germano MF Costa-Neto ◽  
Jose M F Crossa ◽  
Roberto F Fritsche-Neto
Keyword(s):  
Phenotypic Variation ◽  
Field Trials ◽  
Proof Of Concept ◽  
Tropical Maize ◽  
Early Screening ◽  
Environmental Similarity ◽  
Genetic And Environmental Factors ◽  
Growing Conditions ◽  
Algorithm Scheme

Quantitative genetics states that phenotypic variation is a consequence of genetic and environmental factors and their subsequent interaction. Here, we present an enviromic assembly approach, which includes the use of ecophysiology knowledge in shaping environmental relatedness into whole-genome predictions (GP) for plant breeding (referred to as E-GP). We propose that the quality of an environment is defined by the core of environmental typologies (envirotype) and their frequencies, which describe different zones of plant adaptation. From that, we derive markers of environmental similarity cost-effectively. Combined with the traditional genomic sources (e.g., additive and dominance effects), this approach may better represent the putative phenotypic variation across diverse growing conditions (i.e., phenotypic plasticity). Additionally, we couple a genetic algorithm scheme to design optimized multi-environment field trials (MET), combining enviromic assembly and genomic kinships to provide in-silico realizations of the future genotype-environment combinations that must be phenotyped in the field. As a proof-of-concept, we highlight E-GP applications: (1) managing the lack of phenotypic information in training accurate GP models across diverse environments and (2) guiding an early screening for yield plasticity using optimized phenotyping efforts. Our approach was tested using two non-conventional cross-validation schemes to better visualize the benefits of enviromic assembly in sparse experimental networks. Results on tropical maize show that E-GP outperforms benchmark GP in all scenarios and cases tested. We show that for training accurate GP models, the genotype-environment combinations' representativeness is more critical than the MET size. Furthermore, we discuss theoretical backgrounds underlying how the intrinsic envirotype-phenotype covariances within the phenotypic records of (MET) can impact the accuracy of GP and limits the potentialities of predictive breeding approaches. The E-GP is an efficient approach to better use environmental databases to deliver climate-smart solutions, reduce field costs, and anticipate future scenarios.

scholarly journals Planning the Design and Execution of Student Performance Assessment in Serious Games

2021 ◽  
Vol 12 (1) ◽  
pp. 172-190
Author(s):  
Rháleff N. R. Oliveira ◽  
Rafaela V. Rocha ◽  
Denise H. Goya
Keyword(s):  
Performance Assessment ◽  
Student Performance ◽  
Serious Games ◽  
Proof Of Concept ◽  
Personalized Feedback ◽  
Student’S Performance ◽  
Good Internal Consistency ◽  
Learning Measurement ◽  
High Level

Serious Games (SGs) are used to support knowledge acquisition and skill development. For this, there is a need to measure the results achieved (both during and after students play) to ensure the game effectiveness. In this context, the aim is to develop and evaluate the AvaliaJS, a conceptual model to structure, guide and support the planning of the design and execution of the student's performance assessment in SGs. AvaliaJS has two artifacts: a canvas model, for high-level planning, and an assessment project document, for more detailed specifications of the canvas. To analyze and exemplify the use of the model, the artifacts were applied to three ready-made games as a proof of concept. In addition, the quality of AvaliaJS was evaluated by experts in SGs development and assessment using a questionnaire. The results of experts' answers confirm a good internal consistency (Cronbach's alpha α = 0.87) which indicates that AvaliaJS is correct, authentic, consistent, clear, unambiguous and flexible. However, the model will need to be validated during the process of creating a new game to ensure its usability and efficiency. In general, AvaliaJS can be used to support the team in the planning, documentation and development of artifacts and data collection in SGs, as well as in the execution of the assessment, learning measurement and constant and personalized feedback for students.

Process-Oriented Tolerance Synthesis for Multistage Manufacturing Systems

2000 ◽  
Author(s):  
Yu Ding ◽  
Jionghua Jin ◽  
Dariusz Ceglarek ◽  
Jianjun Shi
Keyword(s):  
Product Design ◽  
Process Design ◽  
Manufacturing Systems ◽  
Minimum Cost ◽  
Manufacturing Processes ◽  
Industrial Case Study ◽  
Multistage Manufacturing ◽  
Process Oriented ◽  
Design Characteristics

Abstract In multistage manufacturing systems, quality of final products is strongly affected not only by product design characteristics but also by key process design characteristics. However, historically, tolerance research has primarily focused on allocating tolerances based on product design characteristics for each component. Currently, there is no analytical approach for multistage manufacturing processes to optimally allocate tolerances to integrate product and process characteristics at minimum cost. One of the major obstacles is that the relationship between tolerances of process and product characteristics is not well understood and modeled. Under this motivation, this paper aims at presenting a framework addressing the process-oriented (rather than product-oriented) tolerancing technique for multistage manufacturing processes. Based on a developed state space model, tolerances of process design characteristics at each fabrication stage are related to the quality of final product. All key elements in the framework are described and then derived for a multistage assembly process. An industrial case study is used to illustrate the proposed approach.

A Formal Approach to Evaluating Medical Ontology Systems using Naturalness

2012 ◽  
pp. 1-18
Author(s):  
Yoo Jung An ◽  
Kuo-Chuan Huang ◽  
Soon Ae Chun ◽  
James Geller
Keyword(s):  
Cancer Patients ◽  
Formal Approach ◽  
Domain Experts ◽  
Semantic Relationships ◽  
The Future ◽  
The Web

Ontologies, terminologies and vocabularies are popular repositories for collecting the terms used in a domain. It may be expected that in the future more such ontologies will be created for domain experts. However, there is increasing interest in making the language of experts understandable to casual users. For example, cancer patients often research their cases on the Web. The authors consider the problem of objectively evaluating the quality of ontologies (QoO). This article formalizes the notion of naturalness as a component of QoO and quantitatively measures naturalness for well-known ontologies (UMLS, WordNet, OpenCyc) based on their concepts, IS-A relationships and semantic relationships. To compute numeric values characterizing the naturalness of an ontology, this article defines appropriate metrics. As absolute numbers in such a pursuit are often meaningless, we concentrate on using relative naturalness metrics. That allows us to say that a certain ontology is relatively more natural than another one.

scholarly journals A Genetic-Algorithm-Based DC Current Minimization Scheme for Transformless Grid-Connected Photovoltaic Inverters

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 746 ◽  
Author(s):  
Lei Song ◽  
Lijun Huang ◽  
Bo Long ◽  
Fusheng Li
Keyword(s):  
Genetic Algorithm ◽  
Back Propagation ◽  
The Novel ◽  
Proof Of Concept ◽  
Three Phase ◽  
Suppression Process ◽  
Dc Current ◽  
Three Phase Inverter ◽  
Minimization Scheme

Transformerless grid-connected inverters are of great industrial value in photovoltaic power generation. However, the direct current (DC) induced into the inverter’s output degrades the power quality of the grid. Recently, a back-propagation neural work proportional–integral–derivative (BP-PID) scheme has proven helpful in solving this problem. However, this scheme can be improved by reducing the suppressing time and overshoot. A genetic algorithm (GA)-based DC current minimization scheme, namely the genetic-algorithm-based BP-PID (GA-BP-PID) scheme, was established in this study. In this scheme, GA was used off-line to optimize the initial weights within the BP neural network. Subsequently, the optimal weight was applied to the online DC current suppression process. Compared with the BP-PID scheme, the proposed scheme can reduce the suppressing time by 59% and restrain the overshoot. A prototype of the proposed scheme was implemented and tested on experimental hardware as a proof of concept. The results of the scheme were verified using a three-phase inverter experiment. The novel GA-PB-PID scheme proposed in this study was proven efficient in reducing the suppressing time and overshoot.

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