Lean Application: An Assessment of 5S on Employee Attitudes and Productivity

This study examines the effect of the implementation of 5S on employee attitudes and productivity in an Asian based facility of a global manufacturing company. Utilizing an assessment of the 5S implementation in various areas of the facility and organizational performance data for each of those areas, a non-experimental, causal comparative approach is used to analyze the impact. The study concluded that statistically significant improvements from the implementation of 5S were found both in quality and product cost for this facility; however, the study also found statistical significance where the implementation of 5S led to a decrease in performance and an increase in maintenance costs. Additionally, the study identified non-statistically significant relationships between 5S implementation and management attitudes. Conversely, the study identified statistically significant relationships between 5S implementation and employee attitudes. The data for the management respondents indicated higher scores than the employee respondents. The study provided insight by offering additional knowledge on the effects of the implementation of 5S on attitudes and productivity. It expanded on previous research by also considering the relationships between groups with the outcome showing several groups having statistical significance. This enhances and allows future researchers and practitioners to understand the underlying influences that may have greater impacts on both attitudes and productivity

Effects of Asperity Distribution on Fluid Flow and Induced Seismicity During Deep Geothermal Exploitation

AbstractThis work investigates the injection-induced seismic response of a heterogeneous fault plane, featuring low-permeability asperities embedded into a high-permeability damage zone. We simulate the pressure evolution with a hydrogeological simulator, accounting for the heterogeneous fault plane. Seismicity occurs then on the asperities, represented as unstable patches reactivating by means of the Mohr-Coulomb criterion. The hydrological and seismic modules are implicitly coupled to account for effects of asperity reactivation on the permeability. Results show that permeability changes may cause at a later time a change in seismicity propagation. We also investigated such effects by varying the density of asperities

Induced seismicity risk analysis of the hydraulic stimulation of a geothermal well on Geldinganes, Iceland

The rapid increase in energy demand in the city of Reykjavik has posed the need for an additional supply of deep geothermal energy. The deep-hydraulic (re-)stimulation of well RV-43 on the peninsula of Geldinganes (north of Reykjavik) is an essential component of the plan implemented by Reykjavik Energy to meet this energy target. Hydraulic stimulation is often associated with fluid-induced seismicity, most of which is not felt on the surface but which, in rare cases, can be a nuisance to the population and even damage the nearby building stock. This study presents a first-of-its-kind pre-drilling probabilistic induced seismic hazard and risk analysis for the site of interest. Specifically, we provide probabilistic estimates of peak ground acceleration, European microseismicity intensity, probability of light damage (damage risk), and individual risk. The results of the risk assessment indicate that the individual risk within a radius of 2 km around the injection point is below 0.1 micromorts, and damage risk is below 10−2, for the total duration of the project. However, these results are affected by several orders of magnitude of variability due to the deep uncertainties present at all levels of the analysis, indicating a critical need in updating this risk assessment with in situ data collected during the stimulation. Therefore, it is important to stress that this a priori study represents a baseline model and starting point to be updated and refined after the start of the project

Modeling andsimulationofspeedselectiononleftventricular assist devices

The control problem for LVADs is to set pump speed such that cardiac output and pressure perfusion are within acceptable physiological ranges. However, current technology of LVADs cannot provide for a closed-loop control scheme that can make adjustments based on the patient\u27s level of activity. In this context, the SensorART Speed Selection Module (SSM) integrates various hardware and software components in order to improve the quality of the patients\u27 treatment and the workflow of the specialists. It enables specialists to better understand the patient-device interactions, and improve their knowledge. The SensorART SSM includes two tools of the Specialist Decision Support System (SDSS); namely the Suction Detection Tool and the Speed Selection Tool. A VAD Heart Simulation Platform (VHSP) is also part of the system. The VHSP enables specialists to simulate the behavior of a patient?s circulatory system, using different LVAD types and functional parameters. The SDSS is a web-based application that offers specialists with a plethora of tools for monitoring, designing the best therapy plan, analyzing data, extracting new knowledge and making informative decisions. In this paper, two of these tools, the Suction Detection Tool and Speed Selection Tool are presented. The former allows the analysis of the simulations sessions from the VHSP and the identification of issues related to suction phenomenon with high accuracy 93%. The latter provides the specialists with a powerful support in their attempt to effectively plan the treatment strategy. It allows them to draw conclusions about the most appropriate pump speed settings. Preliminary assessments connecting the Suction Detection Tool to the VHSP are presented in this paper

Accurate and reproducible reconstruction of coronary arteries and endothelial shear stress calculation using 3D OCT: Comparative study to 3D IVUS and 3D QCA

Background: Geometrically-correct 3D OCT is a new imaging modality with the potential to investigate the association of local hemodynamic microenvironment with OCT-derived high-risk features. We aimed to describe the methodology of 3D OCT and investigate the accuracy, inter- and intra-observer agreement of 3D OCT in reconstructing coronary arteries and calculating ESS, using 3D IVUS and 3D QCA as references. Methods-Results: 35 coronary artery segments derived from 30 patients were reconstructed in 3D space using 3D OCT. 3D OCT was validated against 3D IVUS and 3D QCA. The agreement in artery reconstruction among 3D OCT, 3D IVUS and 3D QCA was assessed in 3-mm-long subsegments using lumen morphometry and ESS parameters. The inter- and intra-observer agreement of 3D OCT, 3D IVUS and 3D QCA were assessed in a representative sample of 61 subsegments (n ¼ 5 arteries). The data processing times for each reconstruction methodology were also calculated. There was a very high agreement between 3D OCT vs. 3D IVUS and 3D OCT vs. 3D QCA in terms of total reconstructed artery length and volume, as well as in terms of segmental morphometric and ESS metrics with mean differences close to zero and narrow limits of agreement (BlandeAltman analysis). 3D OCT exhibited excellent inter- and intra-observer agreement. The analysis time with 3D OCT was significantly lower compared to 3D IVUS. Conclusions: Geometrically-correct 3D OCT is a feasible, accurate and reproducible 3D reconstruction technique that can perform reliable ESS calculations in coronary arteries

Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry

Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

The differential evolution method in single and multi objective aerodynamic optimization using parallel processing

120 σ.Η διπλωματική αυτή εργασία επικεντρώνεται στον αλγόριθμο Διαφορικής Εξέλιξης (ΔΕ), μία πληθυσμιακή στοχαστική μέθοδο βελτιστοποίησης. Η εργασία ξεκινά με τη βιβλιογραφική επισκόπηση των αλγορίθμων ΔΕ και συνεχίζεται με τον προγραμματισμό σε γλώσσα Fortran77 του σχετικού λογισμικού. Η μέθοδος, στη μορφή στην οποία κατέληξε η παρούσα εργασία, έχει αρκετά πρόσθετα στοιχεία συγκριτικά με τους “κλασικούς” αλγόριθμους ΔΕ, επεικτείνεται σε προβλήματα πολυκριτηριακής βελτιστοποίησης και χρησιμοποιεί πολυεπεξεργασία. Οι νέες ουσιαστικές παρεμβάσεις που έγιναν βασίζονται ουσιαστικά σε μετεμφυτεύσεις στοιχείων του γενικευμένού Εξελικτικού Αλγορίθμου (περιοχή στην οποία το Εργαστήριο Θερμικών Στροβιλομηχανών του Ε.Μ.Π. έχει πολυετή εμπειρία). Με τις νέες τροποποιήσεις η μέθοδος έγινε ακόμα πιο γρήγορη και σταθερή στη συμπεριφορά της. Στα νέα στοιχεία της μεθόδου συγκαταλέγεται μία καινούργια τεχνική αποδοχής των απογόνων και ανανέωσης του πληθυσμού σε προβλήματα πολλών στόχων. Ο κώδικας προγραμματίστηκε για να δουλεύει και σε πολυεπεξεργαστικό περιβάλλον, κάνοντας χρήση των βιβλιοθηκών του PVM και της λογικής συντονιστή-εργάτη ώστε να επιτευχθεί ταυτόχρονη αξιολόγηση μελών του πληθυσμού από τους διαθέσιμους επεξεργαστές. Ο κώδικας πιστοποιήθηκε επιτυχώς σε μαθηματικά προβλήματα ενός και περισσοτέρων στόχων και εφαρμόστηκε με επιτυχία σε πραγματικά προβλήματα αεροδυναμικής σχεδίασης στις στροβιλομηχανές.This diploma thesis centers upon the Differential Evolution Algorithm (DE), which is a stochastic population based optimization method. We start with a conspectus of the algorithms found to the bibliography and we programmed in Fortran77 the corresponding software. The final product of the above effort was generalized for use in multi objective optimization problems, uses parallel processing and many additional characteristics that do not exist in the theory of the classical DE algorithms have been introduced. These new additions were based on implants from the generalized Evolution Algorithm (an area in which the lab of Thermal Turbomachines is highly experienced). With the use of these alterations, the method becomes faster and more robust. Among the various characteristics implanted, it is also proposed a new technique for the acceptance of the offspring in multi objective problems. The software was programmed in order to to operate also by using parallel processing, by making use of the P.V.M. libraries and the master-slave logic, evaluating by that way the cost function of many members of the population in the same time using all the available processors. The software was tested successfully on mathematical problems of single and multi objective optimization problems and was implemented on real aerodynamic design problems in turbomachines.Δημήτριος Χ. Καρβούνη