Ant Colony Optimization Inspired Algorithm for 3D Object Segmentation into its Constituent Parts

Neural Processing Letters - This work focuses on the use of an Ant colony optimization (ACO) based approach to the problem of 3D object segmentation. The ACO metaheuristic uses a set of agents...     

Path planning approach based on flock dynamics of moving particles

A novel method based on the behaviour of a flock of moving particles is proposed in order to solve the path planning problem of a mobile robot in two-dimensional dynamical sceneries. The mentioned particles search free obstacles zones into the scenery using a set of collective behaviour rules. The positions of the members of the flock form the search space. A heuristic method, referred to as dynamical particle chain (DPC), is used to join the position of the robot with the target through consecutive connections among the particles of the flock. The result is a free obstacle path, which is able to adapt its structure to environmental changes. The feasibility of the proposed method and its comparison with other algorithms are also discussed and illustrated.     

Explanation of Bitter Taste of Venom of Ponerine Ant, Pachycondyla apicalis

The venom gland of workers of Pachycondyla (= Neoponera) apicalis (Hymenoptera: Formicidae) contains the bitter-tasting cyclic dipeptide of leucine and phenylalanine [cyclo-leu-phe or 3-benzyl-6-(2-methylpropyl)-2,5-piperazinedione]. The venom also contains proteins of undetermined activity. It is suggested that the function of the venom may be both defensive and offensive. The mandibular glands of N. apicalis contains δ-decalactone and benzaldehyde.     

A two-warehouse inventory model for non-instantaneous deteriorating items with interval-valued inventory costs and stock-dependent demand under inflationary conditions

Neural Computing and Applications - This research work develops a two-warehouse inventory model for non-instantaneous deteriorating items with interval-valued inventory costs and stock-dependent...     

In situ syntheses of a suspension agent based on a styrene–acrylic acid copolymer for the suspension polymerization of styrene

We carried out the suspension polymerization of styrene, initiated with benzoyl peroxide at 80°C, in the presence of the simultaneous polymerization of acrylic acid in the water phase, initiated by potassium peroxidisulfate (KPS) at the same temperature. The polymerization in the water phase was started at certain times after the beginning of the polymerization of styrene. Then, a continuous addition of KPS was carried out at a given landing rate and during variable feeding times. The water‐phase polymerization actually produced a copolymer of styrene and acrylic acid, which displayed surface‐active properties. The particle size distribution depended on the variables mentioned earlier (starting time, KPS feeding rate, and addition time), being controlled by the molecular weight, and on the composition of the copolymer produced and its availability at the increasing conversion of styrene. A second distribution of submicronic particles was produced. Both families of particles had about the same molecular weight. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3271–3285, 2002     

Queen Volatiles as a Modulator of <Emphasis Type="BoldItalic">Tetragonisca angustula</Emphasis> Drone Behavior

Tetragonisca angustula mating occurs during the virgin queen nuptial flight, usually in the presence of a drone congregation area (DCA). The presence of virgin queen pheromone is considered the trigger for DCA establishment, although this has not been demonstrated experimentally. We established meliponaries, in different habitats, with T. angustula virgin queens during the main drone reproduction period. Eight DCAs were observed in urban areas, and all established outside or near colonies containing at least one virgin queen. The accumulation of drones in the DCAs occurred from 08:00 to 18:00 h and over 3–35 days. The number of drones in DCAs ranged from 60 to 2,000. In field trials, drones were attracted to virgin queens and also, unexpectedly, to physogastric queens. Volatiles collected from both virgin and physogastric queens elicited strong electoantennogram (EAG) responses from drones. Virgin and physogastric queen volatiles were qualitatively similar, but quantitatively different, in chemical composition. The queen’s abdomen was the principal source of these compounds. Isopropyl hexanoate (IPH), the most abundant compound in virgin queen volatiles and one of the most abundant in physogastric queen volatiles, was identified as one of the compounds that elicited EAG responses and was demonstrated to attract drones in a field test.     

Distribution of volatile organic compounds in Sicilian groundwaters analysed by head space-solid phase micro extraction coupled with gas chromatography mass spectrometry (SPME/GC/MS)

This work presents the results of an assessment of the existence and concentration of 13 volatile organic compounds (VOCs) in groundwaters from 14 hydrological basins in Sicily (25,710km(2)). On the basis of hydrological, hydrogeochemical and geological studies, 324 sampling points were selected. All groundwater sampled were collected twice, from October to December 2004 and from February to May 2005, and were analysed to determine the concentration and spatial distribution of the VOCs in the aquifers. The need to analyze a large number of samples in a short space of time so as to obtain quantitative analyses in trace concentration levels spurred us to create a new analytical method, both simple and sensitive, based on HS-SPME/GC/MS. The concentrations of VOCs measured in industrial and intensive agricultural unconfined aquifers were greater than those found in other aquifers. Tetrachloroethylene, chloroform, trichloroethylene and 1,2-dichloropropane were the most frequently detected VOCs. However, they exceeded the guideline values proposed by the EU in only three aquifers located near to industrial and intense agricultural areas.     

Active sound quality control of engine induced cavity noise

Active control solutions appear to be a feasible approach to cope with the steadily increasing requirements for noise reduction in the transportation industry. Active controllers tend to be designed with a target on the sound pressure level reduction. However, the perceived control efficiency for the occupants can be more accurately assessed if psychoacoustic metrics can be taken into account. Therefore, this paper aims to evaluate, numerically and experimentally, the effect of a feedback controller on the sound quality of a vehicle mockup excited with engine noise. The proposed simulation scheme is described and experimentally validated. The engine excitation is provided by a sound quality equivalent engine simulator, running on a real-time platform that delivers harmonic excitation in function of the driving condition. The controller performance is evaluated in terms of specific loudness and roughness. It is shown that the use of a quite simple control strategy, such as a velocity feedback, can result in satisfactory loudness reduction with slightly spread roughness, improving the overall perception of the engine sound.