89 research outputs found

    Integrating Construction 4.0 Technologies: A Four-Layer Implementation Plan

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    This research explores the current state of Construction 4.0 and discusses a four-layer implementation of Construction 4.0 in the industry. The research methodology consists of an extensive literature review to gain insights about Construction 4.0 and frame the four-layer implementation plan. A case study is also presented to showcase the proposed implementation plan. Nine Construction 4.0 technologies were discussed, their integration throughout the project lifecycle was presented in a roadmap, their integration and connectivity with one another were outlined in an interaction roadmap, and the requirements necessary for achieving the 4.0 transformation were articulated. However, the proposed implementation plan is focused on nine Construction 4.0 technologies. The research presents a comprehensive plan for integrating Construction 4.0 technologies into the industry and serves as a guideline to help construction companies better understand the implications of Construction 4.0

    Mapping the capabilities and benefits of AR construction use-cases: A comprehensive map

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    The construction industry has undergone a radical transformation in its design and documentation process as it evolved from the days of the drafting board to today’s Building Information Modeling process. Despite the progress, a paradox of designing 3D in 2D space remains, calling for new visualization technologies that leverage the use of information in construction. Augmented Reality (AR) is an emerging technology that can serve as an information aggregator and a data-publishing platform, allowing users to view and interact with information while collaborating with others in real-time from remote locations. While AR holds the key to advance the construction industry, no research project has yet comprehensively investigated the holistic integration of AR in construction. Thus, this paper presents a comprehensive map that provides a holistic framework to understand the integration of AR into the construction phase. To achieve the research objective, the paper identifies and describes 23 use-cases of AR in the construction phase, nine AR capabilities, and 14 AR potential benefits. Then, four AR applications in construction are explored, where the underlying use-cases are discussed and mapped as a function of their corresponding AR capabilities and potential benefits. These AR applications provide an example to illustrate the concept behind the comprehensive map. Finally, the map is developed by outlining the relationships between the identified AR use-cases, capabilities, and potential benefits. The findings of this paper are crucial for the AR implementation roadmap as it provides industry practitioners an understanding of the capabilities and benefits of integrating AR into construction tasks

    Heart rate variability is related to disease severity in children and young adults with pulmonary hypertension

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    Background: Pulmonary hypertension (PH) is frequently associated with an increase in sympathetic tone. This may adversely affect cardiac autonomic control. Knowledge about the clinical impact of autonomic dysfunction in patients with PH is limited. We aimed to assess whether parameters of heart rate variability (HRV) are related to disease severity in children with PH. Methods: Parameters of HRV [SDNN, standard deviation of normal-to-normal intervals and SDANN, standard deviation of mean values for normal-to-normal intervals over 5 min] were determined from Holter electrocardiograms of 17 patients with PH without active intracardial shunt (10 female, mean age 12.8 ± 8.7 years). Patients were allocated to two groups according to their disease severity: patients with moderate PH [ratio of pulmonary to systemic arterial pressure (PAP/SAP ratio) 0.75) (n = 6). An additional group of five adolescents with Eisenmenger syndrome (PAP/SAP ratio 1.13 ± 0.36) was included. Results: Children with severe PH had significantly lower values of HRV [SDNN (73.8 ± 21.1 vs. 164.9 ± 38.1 ms), SDANN (62.2 ± 19.0 vs. 139.5 ± 33.3 ms)] compared to patients with moderate PH (p = 0.0001 for all). SDNN inversely correlated with ratio of PAP/SAP of PH patients without shunt (r = -0.82; p = 0.0002). Eisenmenger patients showed no significant difference of HRV [SDNN 157.6 ± 43.2 ms, SDANN 141.2 ± 45.3 ms] compared to patients with moderate PH without shunt (p > 0.05 for all). Conclusion: According to our results, children with severe PH may have alterations in HRV. Since HRV appears to be related to disease severity, it may therefore serve as an additional diagnostic marker of PH. Remarkably, although Eisenmenger patients have systemic pulmonary arterial pressures, they seem to have preserved HRV, which might reflect a more favorable autonomic adaptation

    Potts Shunt to Be Preferred Above Atrial Septostomy in Pediatric Pulmonary Arterial Hypertension Patients: A Modeling Study

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    Aims: To quantitatively evaluate the basic pathophysiological process involved in the creation of Eisenmenger syndrome in pediatric pulmonary arterial hypertension (PAH) patients by either atrial septostomy (AS) or Potts shunt (PS) as well as to predict the effects of AS or PS in future PAH patients.Methods: The multi-scale lumped parameter CircAdapt model of the cardiovascular system was used to investigate the effects of AS and PS on cardiovascular hemodynamics and mechanics, as well as on oxygen saturation in moderate to severe PAH. The reference simulation, with cardiac output set to 2.1 l/min and mean systemic pressure to 61 mmHg, was used to create a compensated moderate PAH simulation with mPAP 50 mmHg. Thereupon we created a range of decompensated PAH simulations in which mPAP was stepwise increased from 50 to 80 mmHg. Then we simulated for each level of mPAP the acute effects of either PS or AS with connection diameters ranging between 0–16 mm.Results: For any mPAP level, the effect on shunt flow size is much larger for the PS than for AS. Whereas right ventricular pump work in PS is mainly dependent on mPAP, in AS it depends on both mPAP and the size of the defect. The effects on total cardiac pump work were similar for PS and AS. As expected, PS resulted in a drastic decrease of lower body oxygen saturation, whereas in AS both the upper and lower body oxygen saturation decreased, though not as drastically as in PS.Conclusion: Our simulations support the opinion that a PS can transfer suprasystemic PAH to an Eisenmenger physiology associated with a right-to-left shunt at the arterial level. Contrary to the current opinion that PS in PAH will decompress and unload the right ventricle, we show that while a PS does lead to a decrease in mPAP toward mean systemic arterial pressure, it does not unload the right ventricle because it mainly diverts flow from the pulmonary arterial system toward the lower body systemic arteries

    Hemodynamic and prognostic impact of the diastolic pulmonary arterial pressure in children with pulmonary arterial hypertension-a registry-based analysis

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    BACKGROUND: Diastolic pulmonary arterial pressure (dPAP) is regarded to be less sensitive to flow metrics as compared to mean PAP (mPAP), and was therefore proposed for the assessment of a precapillary component in patients with postcapillary pulmonary hypertension (PH). To analyze the diagnostic and prognostic impact of dPAP in patients with pure precapillary PH, we purposed to compare the correlation between dPAP and mPAP, as well as hemodynamically-derived calculations [ratio of PAP to systemic arterial pressure (PAP/SAP), pulmonary vascular resistance index (PVRI), transpulmonary gradient (TPG)], using both dPAP and mPAP, at rest and during acute vasoreactivity testing (AVT) in children with idiopathic or heritable pulmonary arterial hypertension (IPAH/HPAH). Furthermore, we aimed to assess the association of these metrics (at baseline and changes after AVT) with transplant-free survival. METHODS: We conducted a retrospective analysis of the TOPP (Tracking Outcomes and Practice in Pediatric Pulmonary Hypertension) registry including 246 IPAH/HPAH patients. Of these, 45 children (18.3%) died, and 13 (5.3%) received lung transplantation during the observation period. RESULTS: dPAP and mPAP-derived variables showed almost linear relationship. Higher mPAP/mSAP, and dPAP-/mPAP-derived PVRI at rest was associated with time to death/transplantation. At maximum AVT-response, the decrease of dPAP and mPAP, diastolic pulmonary gradient (DPG) and TPG, as well as dPAP/dSAP and mPAP/mSAP was associated with time to death/transplantation, showing higher significance than corresponding baseline values. Remarkably, no predictive value was found for PVRI-reduction during AVT, neither dPAP- nor mPAP-derived. CONCLUSIONS: There is a strong relationship between dPAP and mPAP-derived variables. According to our results, hemodynamics during AVT (irrespectively of dPAP- or mPAP-derived) may have more prognostic implications than resting hemodynamics in children with IPAH/HPAH, except for PVRI

    Constructing Neural Network-Based Models for Simulating Dynamical Systems

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    Dynamical systems see widespread use in natural sciences like physics, biology, chemistry, as well as engineering disciplines such as circuit analysis, computational fluid dynamics, and control. For simple systems, the differential equations governing the dynamics can be derived by applying fundamental physical laws. However, for more complex systems, this approach becomes exceedingly difficult. Data-driven modeling is an alternative paradigm that seeks to learn an approximation of the dynamics of a system using observations of the true system. In recent years, there has been an increased interest in data-driven modeling techniques, in particular neural networks have proven to provide an effective framework for solving a wide range of tasks. This paper provides a survey of the different ways to construct models of dynamical systems using neural networks. In addition to the basic overview, we review the related literature and outline the most significant challenges from numerical simulations that this modeling paradigm must overcome. Based on the reviewed literature and identified challenges, we provide a discussion on promising research areas

    Propositions for a Resilient, Post-COVID-19 Future for the AEC Industry

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    The coronavirus outbreak has challenged and continues to challenge every aspect of the supply chain within the AEC industry, forcing stakeholders to cope with increasing uncertainties and continuous change. The notion of resilience is especially salient now. While the need for the AEC industry to focus on resilience has been highlighted in recent articles, there is a need for a comprehensive discussion on what resilience means for the AEC industry and how companies can create built-in resilience. This paper takes the form of a high-level overview of where the industry is headed and aims to establish eleven propositions for a resilient, post-COVID-19 future, for practitioners working in the design and construction industry. Moreover, this paper proposes a ‘decentralization of workforce and integration of data’ model in which the established propositions are manifested to support a resilient AEC industry

    Boxify: Full-fledged App Sandboxing for Stock Android

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    We present the first concept for full-fledged app sandboxing on stock Android. Our approach is based on application virtualization and process-based privilege separation to securely encapsulate untrusted apps in an isolated environment. In contrast to all related work on stock Android, we eliminate the necessity to modify the code of monitored apps, and thereby overcome existing legal concerns and deployment problems that rewriting-based approaches have been facing. We realize our concept as a regular Android app called Boxify that can be deployed without firmware modifications or root privileges. A systematic evaluation of Boxify demonstrates its capability to enforce established security policies without incurring a significant runtime performance overhead

    Hemodynamic and genetic analysis in children with idiopathic, heritable, and congenital heart disease associated pulmonary arterial hypertension

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    Background: Aim of this prospective study was to compare clinical and genetic findings in children with idiopathic or heritable pulmonary arterial hypertension (I/HPAH) with children affected with congenital heart defects associated PAH (CHD-APAH). Methods: Prospectively included were 40 consecutive children with invasively diagnosed I/HPAH or CHD-APAH and 117 relatives. Assessment of family members, pedigree analysis and systematic screening for mutations in TGFß genes were performed. Results: Five mutations in the bone morphogenetic protein type II receptor (BMPR2) gene, 2 Activin A receptor type II-like kinase-1 (ACVRL1) mutations and one Endoglin (ENG) mutation were found in the 29 I/HPAH children. Two mutations in BMPR2 and one mutation in ACVRL1 and ENG, respectively, are described for the first time. In the 11 children with CHD-APAH one BMPR2 gene mutation and one Endoglin gene mutation were found. Clinical assessment of relatives revealed familial aggregation of the disease in 6 children with PAH (HPAH) and one CHD-APAH patient. Patients with mutations had a significantly lower PVR. Conclusion: Mutations in different TGFß genes occurred in 8/29 (27.6%) I/HPAH patients and in 2/11 (18.2%) CHD-APAH patients and may influence the clinical status of the disease. Therefore, genetic analysis in children with PAH, especially in those with I/HPAH, may be of clinical relevance and shows the complexity of the genetic background

    Executive summary. Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

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    The European Paediatric Pulmonary Vascular Disease (PVD) Network is a registered, non-profit organisation that strives to define and develop effective, innovative diagnostic methods and treatment options in all forms of paediatric pulmonary hypertensive vascular disease, including specific forms such as pulmonary arterial hypertension (PAH)-congenital heart disease, pulmonary hypertension (PH) associated with bronchopulmonary dysplasia, persistent PH of the newborn, and related cardiac dysfunction. Methods The writing group members conducted searches of the PubMed/MEDLINE bibliographic database (1990-2015) and held five face-to-face meetings with votings. Clinical trials, guidelines, and reviews limited to paediatric data were searched using the terms 'pulmonary hypertension' and 5-10 other keywords, as outlined in the other nine articles of this special issue. Class of recommendation (COR) and level of evidence (LOE) were assigned based on European Society of Cardiology/American Heart Association definitions and on paediatric data only, or on adult studies that included >10% children. Results A total of 9 original consensus articles with graded recommendations (COR/LOE) were developed, and are summarised here. The topics included diagnosis/monitoring, genetics/biomarker, cardiac catheterisation, echocardiography, cardiac magnetic resonance/chest CT, associated forms of PH, intensive care unit/ventricular assist device/lung transplantation, and treatment of paediatric PAH. Conclusions The multipaper expert consensus statement of the European Paediatric PVD Network provides a specific, comprehensive, detailed but practical framework for the optimal clinical care of children with PH
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