4,199 research outputs found

    The Generalized Bin Packing Problem with bin-dependent item profits

    Get PDF
    In this paper, we introduce the Generalized Bin Packing Problem with bin-dependent item profits (GBPPI), a variant of the Generalized Bin Packing Problem. In GBPPI, various bin types are available with their own capacities and costs. A set of compulsory and non-compulsory items are also given, with volume and bin-dependent profits. The aim of GBPPI is to determine an assignment of items to bins such that the overall net cost is minimized. The importance of GBPPI is confirmed by a number of applications. The introduction of bin-dependent item profits enables the application of GBPPI to cross-country and multi-modal transportation problems at strategic and tactical levels as well as in last-mile logistic environments. Having provided a Mixed Integer Programming formulation of the problem, we introduce efficient heuristics that can effectively address GBPPI for instances involving up to 1000 items and problems with a mixed objective function. Extensive computational tests demonstrate the accuracy of the proposed heuristics. Finally, we present a case study of a well-known international courier operating in northern Italy. The problem approached by the international courier is GBPPI. In this case study, our methodology outperforms the policies of the company

    ANN Modelling to Optimize Manufacturing Process

    Get PDF
    Neural network (NN) model is an efficient and accurate tool for simulating manufacturing processes. Various authors adopted artificial neural networks (ANNs) to optimize multiresponse parameters in manufacturing processes. In most cases the adoption of ANN allows to predict the mechanical proprieties of processed products on the basis of given technological parameters. Therefore the implementation of ANN is hugely beneficial in industrial applications in order to save cost and material resources. In this chapter, following an introduction on the application of the ANN to the manufacturing process, it will be described an important study that has been published on international journals and that has investigated the use of the ANNs for the monitoring, controlling and optimization of the process. Experimental observations were collected in order to train the network and establish numerical relationships between process-related factors and mechanical features of the welded joints. Finally, an evaluation of time-costs parameters of the process, using the control of the ANN model, is conducted in order to identify the costs and the benefits of the prediction model adopted

    A user experience analysis for a mobile Mixed Reality application for cultural heritage

    Get PDF
    Mixed Reality has emerged as a valuable tool for the promotion of cultural heritage. In this context, in particular, the metaphor of virtual portals allows the virtual visit of monuments that are inaccessible or no longer exist in their original form, integrating them into the real environment. This paper presents the development of a Mixed Reality mobile application that proposes a virtual reconstruction of the church of Sant’Elia in Ruggiano, in the southern province of Lecce (Italy). By placing the virtual portal in the same place where the entrance of the church was located, the user can cross this threshold to enter inside and make a virtual journey into the past. The user experience was evaluated by administering a questionnaire to 60 users who tried the application. From the data collected, four user experience factors were identified (interest, focus of attention, presence and usability), which were compared between young and old, male and female users, and between users who had already visited the church in person and all other users. In general, the scores reveal a total independence of the other three factors from usability and a very high level of interest

    Robotics and Artificial Intelligence in Gastrointestinal Endoscopy: Updated Review of the Literature and State of the Art

    Get PDF
    Abstract Purpose of Review Gastrointestinal endoscopy includes a wide range of procedures that has dramatically evolved over the past decades. Robotic endoscopy and artificial intelligence are expanding the horizons of traditional techniques and will play a key role in clinical practice in the near future. Understanding the main available devices and procedures is a key unmet need. This review aims to assess the current and future applications of the most recently developed endoscopy robots. Recent Findings Even though a few devices have gained approval for clinical application, the majority of robotic and artificial intelligence systems are yet to become an integral part of the current endoscopic instrumentarium. Some of the innovative endoscopic devices and artificial intelligence systems are dedicated to complex procedures such as endoscopic submucosal dissection, whereas others aim to improve diagnostic techniques such as colonoscopy. Summary A review on flexible endoscopic robotics and artificial intelligence systems is presented here, showing the m3ost recently approved and experimental devices and artificial intelligence systems for diagnosis and robotic endoscopy

    What’s the best assessment of preload after cardiac surgery?

    Get PDF
    Objective: The assessment of the role of transesophageal echocardiography and invasive tests with pulmonary modified catheter to monitor the preload indexes in patients in intensive- care-unit after cardiac coronary surgery. Materials and Methods: Between January and December 2004 24 patients (14 male, 10 female) with coronary artery disease were prospectively enrolled for preload assessment during off-pump myocardial revascularization. Pulmonary Capillary Wedge Pressure (PCWP), Left Ventricular End Diastolic Indexed Area (LVEDAI), Δ Aortic Velocity (ΔVAo), Right Ventricular End Diastolic Volume (RVEDVI) as preload indexes were evaluated. Transesophageal echocardiography and pulmonary modified catheter monitoring were performed during the preoperative period at T1 and after fluid infusion (T2). Patients were considered Responders (R) or No Responders (NR) if the Stroke Volume Index increase at T2 was >20% with respect to T1. Results: Mean T1 PCWP was similar in both groups (12.8±2.2 in R vs. 11.4±3 mmHg in NR; p=NS) and mean increase of PCWP at T2 was similar in both groups (1.5±0.3% in R vs. 1.2±3% in NR; p=NS). Mean T1 RVEDVI was similar in both groups (97.33±34 in R vs. 101±21 ml/m2 in NR; p=NS); T2 RVEDVI was similar in R and NR Groups (122.11±49 vs. 138.54±30 ml/m2; p=NS); mean T1 and T2 LVEDAI was similar in R and NR (11.2±3.5 vs. 10.2±2.3 at T1 and 14.04±3.35 vs. 14.67±2.1 cm2/m2 at T2 respectively; p=NS). Higher mean value of T1 ΔVAo (20±7% in R vs. 10±2% in NR; p=0.006) were recorded while similar mean value of T2 ΔVAo were observed (11±3% in R vs. 5±2% in NR; p=0.743). Correlation index between T1 and T2 ΔVAo (R=0.82) in R was significant (p=0.0002), while correlation index between T1 and T2 ΔVAo (R=0.11) in NR was not significant. Conclusions: Our study showed in patients soon after coronary cardiac surgery ΔVAo is the only predictor of “fluid responsiveness” and of ventricular compliance

    Effects of abutment materials on peri-implant soft tissue health and stability: A network meta-analysis.

    Get PDF
    PURPOSE This systematic review aimed to evaluate the effect of the abutment material on peri-implant soft tissue health and stability. STUDY SELECTION An electronic and hand search was conducted until February 2022. Only prospective randomized trials (RCTs) and controlled clinical trials (CCTs) comparing titanium abutments with abutments made of different materials, with a follow-up of at least 6 months, were selected by two independent reviewers. Data on marginal bone loss (MBL) and peri-implant tissue indexes, i.e., plaque index (PI), bleeding on probing (BOP), probing depth (PD), and recession (REC), were collected. The risk of bias for RCTs and non-RCTs was evaluated according to the tool reported in the Cochrane Handbook for Systematic Reviews of Interventions and the ROBINS-I tool, respectively. Both pairwise and network meta-analyses (NMA) were performed. RESULTS We included 18 relevant studies from 1,437 identified studies. Overall, 612 patients were treated, and 848 abutments were inserted. Five studies presented a low risk of bias. Pairwise meta-analysis showed that, as compared to titanium, zirconia abutments presented a significantly reduced MBL (0.20 mm, 95% Confidence Interval CI [0.14-0.26], P < 0.00001). No significant differences were found for the other outcomes. In the NMA, zirconia abutments demonstrated an 83.3% probability of achieving the highest rank in PI, an 87.0% in BOP, and a 65.0% in PD outcome, suggesting that zirconia abutments generally performed better than titanium and alumina abutments. CONCLUSIONS Within the limits of the present study, zirconia abutments seem a viable alternative to titanium ones

    HPV and Cytology Testing in Women Undergoing 9-Valent HPV Opportunistic Vaccination: A Single-Cohort Follow Up Study

    Get PDF
    Background: This study evaluates the possible effect of 9-valent (9vHPV) vaccination on the results of HPV and cytological tests in a cohort of adult women. Methods: This study is a retrospective, single-cohort, monocentric study. Sexually active women aged 14–70 years, who underwent 9vHPV vaccination, were enrolled. Dose administration dates, side effects and data on Pap smears and HPV tests performed before and after the first vaccine dose were collected. Subjects were considered “unexposed” to the vaccine for all time intervals before the first dose administration, and “exposed” to the first, second and third vaccine doses in all time intervals following each specific dose. Results: A total of 512 women underwent the first 9vHPV dose administration and were enrolled in the study. Median age at vaccination was 30.5 (14–70). Log-rank tests and Cox regression analyses showed a highly statistically significant (p Conclusions: 9vHPV vaccination may play a role in shortening the clearance time of HPV HR+ or Pap positivity in sexually active adult women

    Integrated environmental analysis of urban waste separate collection in the Sorrento peninsula, in Italy

    Get PDF
    The main aim of this work was to study the kerbside collection system of two municipalities in the Sorrento peninsula (in Italy) with an integrated approach based on the three pillars of sustainability: society, environment and economy. The studied municipality are Sorrento (16,745 inhabitants, 1,681 inhabitants/km²) and Piano di Sorrento (13,159 inhabitants, 1,793 inhabitants/km2). Piano di Sorrento and especially Sorrento are tourist towns and this obviously has an impact on the quantity and quality of urban waste. In 2014, the percentage of separate collection was 63.3% in Piano di Sorrento with a per capita production of 465.7 kg/inhabitant/year, and 63.8% in Sorrento with 775 kg/inhabitant/day. In every municipality, there is a separate collection centre (SCC). In the SCC, the citizens can deliver the recyclables from urban waste obtaining economic benefits similarly to the system described in De Feo and Polito (2015). The sociological analysis was developed by means of a structured questionnaire similar to that developed by De Feo and Polito (2015). The economic analysis was conducted in the light of the Extended Producer Responsibility (EPR) system, evaluating the money recovery from the recyclable materials theoretically contained in the residual waste. The analysis was carried out considering three real scenarios: (1) 2000, without separate collection; (2) 2008, when the Campania region of Southern Italy was suffering serious problems with the management of urban waste because the region did not have enough waste management facilities; (3) 2014, when there was an effective kerbside collection system in the two municipalities. The environmental analysis was performed for scenarios (1), (2) and (3) applying the Life Cycle Assessment (LCA) approach to the urban waste management, internal collection and external transport systems. As shown in Figure 1, in 2014, the increasing percentages of separate collection allowed to avoid the production of environmental impacts, with greater benefits for the citizens of Piano di Sorrento. On the other hand, for Sorrento it was calculated the number of theoretical additional touristic bus/day in the case of a “Zero Waste” management of the hotels in terms of avoided production of equivalent CO2. The result was obtained as the ratio between the difference of the impact produced by the hotels all operated in a normal way and the hotels all managed with a Zero Waste approach, and the impact of a single bus (as a function of the distance). Please click Additional Files below to see the full abstract
    • …
    corecore