A nonmonotone GRASP

A greedy randomized adaptive search procedure (GRASP) is an itera- tive multistart metaheuristic for difficult combinatorial optimization problems. Each GRASP iteration consists of two phases: a construction phase, in which a feasible solution is produced, and a local search phase, in which a local optimum in the neighborhood of the constructed solution is sought. Repeated applications of the con- struction procedure yields different starting solutions for the local search and the best overall solution is kept as the result. The GRASP local search applies iterative improvement until a locally optimal solution is found. During this phase, starting from the current solution an improving neighbor solution is accepted and considered as the new current solution. In this paper, we propose a variant of the GRASP framework that uses a new “nonmonotone” strategy to explore the neighborhood of the current solu- tion. We formally state the convergence of the nonmonotone local search to a locally optimal solution and illustrate the effectiveness of the resulting Nonmonotone GRASP on three classical hard combinatorial optimization problems: the maximum cut prob- lem (MAX-CUT), the weighted maximum satisfiability problem (MAX-SAT), and the quadratic assignment problem (QAP)

Hybridization of multi-objective deterministic particle swarm with derivative-free local searches

The paper presents a multi-objective derivative-free and deterministic global/local hybrid algorithm for the efficient and effective solution of simulation-based design optimization (SBDO) problems. The objective is to show how the hybridization of two multi-objective derivative-free global and local algorithms achieves better performance than the separate use of the two algorithms in solving specific SBDO problems for hull-form design. The proposed method belongs to the class of memetic algorithms, where the global exploration capability of multi-objective deterministic particle swarm optimization is enriched by exploiting the local search accuracy of a derivative-free multi-objective line-search method. To the authors best knowledge, studies are still limited on memetic, multi-objective, deterministic, derivative-free, and evolutionary algorithms for an effective and efficient solution of SBDO for hull-form design. The proposed formulation manages global and local searches based on the hypervolume metric. The hybridization scheme uses two parameters to control the local search activation and the number of function calls used by the local algorithm. The most promising values of these parameters were identified using forty analytical tests representative of the SBDO problem of interest. The resulting hybrid algorithm was finally applied to two SBDO problems for hull-form design. For both analytical tests and SBDO problems, the hybrid method achieves better performance than its global and local counterparts

High‐tech training for birds of prey

Raptors are some of the most at‐risk groups of birds in the world and saving these top predators is essential for maintaining the health of many ecosystems. After hospitalization, raptors are often released when muscular recovery is still unfitting when they are unable to hunt efficiently and are at risk of dying from starvation within a few days. On the other hand, if a convalescent bird is trained with the only use of classic falconry techniques, it is likely to remain dependent on the caretaker/falconer even long after the release, so unable to hunt independently. To overcome these problems, a new training method was conceived, which could improve raptors’ muscular strength while limiting habituation to humans. This has been possible due to the combination of classic falconry techniques and modern technologies, such as the introduction of specific workouts with drones. Three falconry raptors and one wild Eurasian hobby were trained through high‐tech falconry to develop the ability to catch, grasp, and airlift their prey at a different speed, altitude, and resistance. The main findings of this study were: (i) The rapid increase of the raptors’ speed; (ii) the muscular growth and endurance, and (iii) successful reintroduction of a wild bird

A derivative-free approach to constrained multiobjective nonsmooth optimization

open3noopenLiuzzi, G.; Lucidi, S.; Rinaldi, F.Liuzzi, G.; Lucidi, S.; Rinaldi, Francesc

A multi-objective DIRECT algorithm for ship hull optimization

The paper is concerned with black-box nonlinear constrained multi-objective optimization problems. Our interest is the definition of a multi-objective deterministic partition-based algorithm. The main target of the proposed algorithm is the solution of a real ship hull optimization problem. To this purpose and in pursuit of an efficient method, we develop an hybrid algorithm by coupling a multi-objective DIRECT-type algorithm with an efficient derivative-free local algorithm. The results obtained on a set of “hard” nonlinear constrained multi-objective test problems show viability of the proposed approach. Results on a hull-form optimization of a high-speed catamaran (sailing in head waves in the North Pacific Ocean) are also presented. In order to consider a real ocean environment, stochastic sea state and speed are taken into account. The problem is formulated as a multi-objective optimization aimed at (i) the reduction of the expected value of the mean total resistance in irregular head waves, at variable speed and (ii) the increase of the ship operability, with respect to a set of motion-related constraints. We show that the hybrid method performs well also on this industrial problem

RESCUE MANAGEMENT AND ASSESSMENT OF STRUCTURAL DAMAGE BY UAV IN POST-SEISMIC EMERGENCY

Abstract. The increasing frequency of emergencies urges the need for a detailed and thorough knowledge of the landscape. The first hours after a disaster are not only chaotic and problematic, but also decisive to successfully save lives and reduce damage to the building stock. One of the most important factors in any emergency response is to get an adequate awareness of the real situation, what is only possible after a thorough analysis of all the available information obtained through the Italian protocol Topography Applied to Rescue. To this purpose geomatic tools are perfectly suited to create, manage and dynamically enrich an organized archive of data to have a quick and functional access to information useful for several types of analysis, helping to develop solutions to manage the emergency and improving the success of rescue operations. Moreover, during an emergency like an earthquake, the conventional inspection to assess the damage status of buildings requires special tools and a lot of time. Therefore, given the large number of buildings requiring safety measures and rehabilitation, efficient use of limited resources such as time and equipment, as well as the safety of the involved personnel are important aspects. The applications shown in the paper are intended to underline how the above-mentioned objective, in particular the rehabilitation interventions of the built heritage, can be achieved through the use of data acquired from UAV platform integrated with geographic data stored in GIS platforms

Fishing activities overlap with bottlenose dolphin core habitats of Ischia and Procida islands

Tursiops truncatus – the common bottlenose dolphin – is a species of conservation interest, listed in Annex II and IV of Habitat Directive (92/43/CEE) that requires strict protection and the creation of specially protected areas for conservation, managed according to the ecological requirements of the species, within the “Nature 2000” network. A local population of bottlenose dolphins has been monitored over fifteen years in the sea waters around Ischia and Procida Islands in the frame of the Ischia Dolphin Project, an ongoing long-term research program on Tyrrhenian cetaceans. The study area lies partially within the boundaries of "Regno di Nettuno" Marine Protected Area (MPA), which is classified by IUCN as an Important Marine Mammal Area (IMMA), where pods of cetacean key species such as common dolphin (Delphinus Delphis), bottlenose dolphin, and fin whale (Balaenoptera physalus) live. Investigating habitat exploitation by bottlenose dolphins is crucial for conserving this protected species. Between 2004 and 2018, 1186 surveys were performed, resulting in 91 encounters with the species. To investigate bottlenose dolphins' habitat exploitation, we combined both behavioral observations and spatial analysis. Kernel Density Estimation and Hotspot analysis allowed to delineate fine-scale areas of higher concentration of critical activities (feeding, socializing/mating, resting) and interactions with fisheries (gillnets and trawlers). Results show a vital region for feeding, resting, social cohesion, and mating, i.e. essential habitat for bottlenose dolphins. Unfortunately, these critical habitats are only partially protected by the zonation of the MPA, because it overlaps with human activities, especially fishing. Although the influence of fisheries on dolphins' behavior and movements needs further investigation, the results thus far collected suggest that effective management measures should take into account the human-animal conflict that can arise in these critical areas

Severe bicompartmental bone bruise is associated with rotatory instability in anterior cruciate ligament injury

Purpose: The presence and severity of bone bruise is more and more investigated in the non-contact anterior cruciate ligament (ACL) injury context. Recent studies have advocated a correlation between bone bruise and preoperative knee laxity. The aim of the present study was to investigate the correlation between bone bruise and preoperative rotatory knee laxity. Methods: Twenty-nine patients (29.1 ± 9.8 years) with MRI images at a maximum of 3 months after ACL injury (1.6 ± 0.8 months) were included. The bone bruise severity was evaluated according to the International Cartilage Repair Society (ICRS) scale for lateral femoral condyle, lateral tibial plateau, medial femoral condyle, and medial tibial plateau. The intraoperative rotational knee laxity was evaluated through a surgical navigation system in terms of internal–external rotation at 30° and 90° of knee flexion (IE30, IE90) and internal–external rotation and acceleration during pivot-shift test (PS IE, PS ACC). The KOOS score was also collected. The association between ICRS grade of bone bruise and rotational laxity or KOOS was investigated. Results: Significant correlation (p < 0.05) was found between the bone bruise severity on the medial tibial plateau and rotational laxity (IE90, PS IE, and PS ACC) and between the severity of bone bruise on femoral lateral condyle and KOOS-Symptoms sub-score. The presence of bone bruise on the medial tibial plateau was significantly associated with a lateral femoral notch sign > 2 mm (very strong odds ratio). No kinematical differences were found between none-to-deep and extensive-generalized lateral bone bruise, while higher IE30 and IE90 were found in extensive-generalized bicompartmental bone bruise than isolated extensive-generalized lateral bone bruise. Conclusion: A severe bicompartmental bone bruise was related to higher rotatory instability in the intraoperative evaluation of ACL deficient knees. The severity of edema on the medial tibial plateau was directly correlated with higher intraoperative pivot shift, and the size of edema on the lateral femoral condyle was associated with lower preoperative clinical scores. Level of evidence: Level II