3,644 research outputs found
Wireless communication, identification and sensing technologies enabling integrated logistics: a study in the harbor environment
In the last decade, integrated logistics has become an important challenge in
the development of wireless communication, identification and sensing
technology, due to the growing complexity of logistics processes and the
increasing demand for adapting systems to new requirements. The advancement of
wireless technology provides a wide range of options for the maritime container
terminals. Electronic devices employed in container terminals reduce the manual
effort, facilitating timely information flow and enhancing control and quality
of service and decision made. In this paper, we examine the technology that can
be used to support integration in harbor's logistics. In the literature, most
systems have been developed to address specific needs of particular harbors,
but a systematic study is missing. The purpose is to provide an overview to the
reader about which technology of integrated logistics can be implemented and
what remains to be addressed in the future
Alkaline Water and Longevity: A Murine Study
The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of \u201cdeceleration aging factor\u201d as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models
Mitigation of and adaptation to UHI phenomena : the Padua case study
Elaborating solutions to counteract UHI effects can represents a relevant challenge for spatial planning and urban design. A specific experimentation has been developed on the city of Padua, analysing different scenarios of urban warming and using specific monitoring tools (Lidar/aerial survey) to define a DIM (Digital Surface Models) providing local situation in terms of green quality and extension, solar incidence/radiation, sky view factors, building materials. This chapter reconstruct the methodology followed during the survey and the elaboration of specific solutions to counteract UHI accordingly different scenarios
A deep learning approach for detection and localization of leaf anomalies
The detection and localization of possible diseases in crops are usually
automated by resorting to supervised deep learning approaches. In this work, we
tackle these goals with unsupervised models, by applying three different types
of autoencoders to a specific open-source dataset of healthy and unhealthy
pepper and cherry leaf images. CAE, CVAE and VQ-VAE autoencoders are deployed
to screen unlabeled images of such a dataset, and compared in terms of image
reconstruction, anomaly removal, detection and localization. The
vector-quantized variational architecture turns out to be the best performing
one with respect to all these targets.Comment: 23 pages, 8 figure
Electromechanical actuators affected by multiple failures: Prognostic method based on spectral analysis techniques
The proposal of prognostic algorithms able to identify precursors of incipient failures of primary flight command electromechanical actuators (EMA) is beneficial for the anticipation of the incoming failure: an early and correct interpretation of the failure degradation pattern, in fact, can trig an early alert of the maintenance crew, who can properly schedule the servomechanism replacement. An innovative prognostic model-based approach, able to recognize the EMA progressive degradations before his anomalous behaviors become critical, is proposed: the Fault Detection and Identification (FDI) of the considered incipient failures is performed analyzing proper system operational parameters, able to put in evidence the corresponding degradation path, by means of a numerical algorithm based on spectral analysis techniques. Subsequently, these operational parameters will be correlated with the actual EMA health condition by means of failure maps created by a reference monitoring model-based algorithm. In this work, the proposed method has been tested in case of EMA affected by combined progressive failures: in particular, partial stator single phase turn to turn short-circuit and rotor static eccentricity are considered. In order to evaluate the prognostic method, a numerical test-bench has been conceived. Results show that the method exhibit adequate robustness and a high degree of confidence in the ability to early identify an eventual malfunctioning, minimizing the risk of fake alarms or unannounced failures. © 2017 Author(s)
Influence of Ambient Humidityon The Conductivity of CH3NH3SnCl3 Hybrid Films
Organic-inorganic (CnH2n+1NH3)2MX4 hybrid perovskites (M=divalent metal, X=halide) are attracting much attention, due to their unique electronic properties and excellent film processability [1]. The Sn based CH3NH3MX3 compounds are a subclass of that hybrid family, with cubic structure, where the organic component is included in the extended three-dimensional inorganic cage. Studies concerning the structural properties of these compounds [2] prove that methylammonium ions are orientationally disordered due to their polar character. On cooling the disorder is removed through one or more phase transitions, that usually determine large conductivity variations. However, the chemical instability is a major problem for accurate transport measurements on Sn hybrids. Furthermore, most of reported conductivity results refer to iodine-based hybrids, that are conductive, while Br- and Cl- compounds are semiconducting or insulating. In this communication we study the influence of ambient humidity on the electrical properties of thermally ablated CH3NH3SnCl3 films. In particular we show that conductivity increases by more than four orders of magnitude when relative humidity increases from 0 to 80%. Measurements performed in sequence give reproducible results, thus indicating that conductivity increase does not originate from irreversible reactions between hybrid and water vapour. We investigate the mechanisms responsible for the conductivity increase by studying the DC and AC characteristics of two contact planar devices as a function of the relative humidity. The results of impedance spectroscopy measurements are interpreted by suitable equivalent circuits that allow us to study the dipendence of the different circuit components on relative humidity. On this base we discuss the device characteristics and suggest novel insights into humidity sensing properties of CH3NH3SnCl3 films
Fiber Bragg Grating Sensor Networks Enhance the In Situ Real-Time Monitoring Capabilities of MLI Thermal Blankets for Space Applications
The utilization of Fiber Bragg Grating (FBG) sensors in innovative optical sensor networks has displayed remarkable potential in providing precise and dependable thermal measurements in hostile environments on Earth. Multi-Layer Insulation (MLI) blankets serve as critical components of spacecraft and are employed to regulate the temperature of sensitive components by reflecting or absorbing thermal radiation. To enable accurate and continuous monitoring of temperature along the length of the insulative barrier without compromising its flexibility and low weight, FBG sensors can be embedded within the thermal blanket, thereby enabling distributed temperature sensing. This capability can aid in optimizing the thermal regulation of the spacecraft and ensuring the reliable and safe operation of vital components. Furthermore, FBG sensors offer sev eral advantages over traditional temperature sensors, including high sensitivity, immunity to electromagnetic interference, and the ability to operate in harsh environments. These properties make FBG sensors an excellent option for thermal blankets in space applications, where precise temperature regulation is crucial for mission success. Nevertheless, the calibration of temperature sensors in vacuum conditions poses a significant challenge due to the lack of an appropriate calibration reference. Therefore, this paper aimed to investigate innovative solutions for calibrating temperature sensors in vacuum conditions. The proposed solutions have the potential to enhance the accuracy and reliability of temperature measurements in space applications, which can enable engineers to develop more resilient and dependable spacecraft systems
EFFECT OF WIND LOADS ON NON REGULARLY SHAPED HIGH-RISE BUILDINGS
Wind loads have historically been recognized as one of the most important issue in high-rise buildings analysis and design. In particular, in regions of low seismic intensity, a high-rise building lateral design is controlled by wind loads. In wind analysis, Computational Fluid Dynamics (CFD) and/or wind tunnel testing are required to calculate the external pressures acting on a building.
In this paper, two case studies are presented to show how the wind loads are calculated and applied in design. The first case study is based on the CFD results for the New Marina Casablanca Tower in Casablanca, Morocco. The second case study considers the results from the wind tunnel test studies conducted for the Al- Hamra tower, in Kuwait City, Kuwait.
The New Marina Casablanca tower is a 167m tall concrete building, with a unique twisting shape generated from the relative rotation of two adjacent floors. Sloped columns are introduced in the perimeter to follow the tower outer geometry and to support the concrete slabs spanning between the central core and the perimeter frame. The effects of wind loads on the twisted geometry has been studied in details since the pressure coefficients are not easily identified for such a complex form. In addition, the effect of the wind loads on the structure presented unique challenges that required innovative structural solutions.
The Al-Hamra tower is a 412m tall concrete building with a sculpted twisting form which optimizes the views to the Arabian Gulf while minimizing the solar heat gain. The complex form is realized using sloped walls and vertical columns on the perimeter and a central concrete core. The unique shape of the tower presented several design challenges related to the wind loads on the structure.
This paper will discuss the unique challenges and solutions associated with wind loads effect on buildings of unique form
Evaluating the impact of smart technologies on harbor's logistics via BPMN modeling and simulation
A Smart Information and Communication Technology (ICT) enables a synchronized interplay of different key factors, aligning infrastructures, consumers, and governmental policy-making needs. In the harbor's logistics context, Smart ICT has been driving a multi-year wave of growth. Although there is a standalone value in the technological innovation of a task, the impact of a new smart technology is unknown without quantitative analysis methods on the end-to-end process. In this paper, we first present a review of the Smart ICT for marine container terminals, and then we propose to evaluate the impact of such Smart ICT via Business Process Model and Notation (BPMN) modeling and simulation. The proposed approach is discussed in a real-world modeling and simulation analysis, made on a pilot terminal of the Port of Leghorn (Italy)
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