Wind (Italy)

Segregated incompressible large eddy simulation and acoustic perturbation equations were used to obtain the flow field and sound field of 1:25 scale trains with three, six and eight coaches in a long tunnel, and the aerodynamic results were verified by wind tunnel test with the same scale two-coach train model. Time-averaged drag coefficients of the head coach of three trains are similar, but at the tail coach of the multi-group trains it is much larger than that of the three-coach train. The eight-coach train presents the largest increment from the head coach to the tail coach in the standard deviation (STD) of aerodynamic force coefficients: 0.0110 for drag coefficient (Cd), 0.0198 for lift coefficient (Cl) and 0.0371 for side coefficient (Cs). Total sound pressure level at the bottom of multi-group trains presents a significant streamwise increase, which is different from the three-coach train. Tunnel walls affect the acoustic distribution at the bottom, only after the coach number reaches a certain value, and the streamwise increase in the sound pressure fluctuation of multi-group trains is strengthened by coach number. Fourier transform of the turbulent and sound pressures presents that coach number has little influence on the peak frequencies, but increases the sound pressure level values at the tail bogie cavities. Furthermore, different from the turbulent pressure, the first two sound pressure proper orthogonal decomposition (POD) modes in the bogie cavities contain 90% of the total energy, and the spatial distributions indicate that the acoustic distributions in the head and tail bogies are not related to coach number.

Paragliding is a type of free-flying sport using cloth wings, commonly called a parachute. At the time of takeoff, this sport utilizes the thrust generated by the wind and lands using the feet. Based on the available data, there are still many tourists and amateur paragliding users who have difficulty finding weather information in the takeoff and landing areas. Weather is an important factor in this sport to minimize accidents and avoid flight failures due to not being able to control a parachute hit by strong winds. Therefore, based on the existing problems, a system is needed that can provide weather condition data for takeoff and landing safety with wind speed parameters using an anemometer sensor, for temperature and humidity using a DHT-22 sensor, and a wind direction sensor using a Wind Vane Direction sensor. The data processed by the Arduino Mega2560 will be displayed on a 20×4 LCD (Liquid Crystal Display). The results of the process are also sent through a data transmission system using LoRa (Long Range) technology. From the results of the tests carried out, it shows that the functionality of all sensors is running as it should. The average calibration error of the DHT sensor data is 22 for temperature, 2,14 % and humidity, 1,37% and the wind speed sensor is 2,85 %. In addition, the LoRa communication test between the node and the gateway shows good results with the average RSSI (Received Signal Strength Indicator) value at node 1 being -77 dBm and node 2 being -34 dBm ABSTRAK: Paralayang merupakan salah satu jenis olahraga terbang bebas dengan menggunakan sayap kain atau biasa disebut dengan parasut. Pada saat lepas landas olahraga ini memanfaatkan gaya dorong yang dihasilkan oleh angin dan mendarat menggunakan kaki. Berdasarkan data yang ada masih banyak wisatawan maupun pengguna paralayang amatir yang mengalami kesulitan untuk mengetahui informasi cuaca pada area lepas landas dan pendaratan. Cuaca menjadi faktor penting dalam olahraga ini untuk meminimalisir terjadinya kecelakaan dan menghindari terjadinya gagal terbang akibat tidak bisa mengendalikan parasut yang diterpa angin kencang. Maka dari itu, berdasarkan permasalahan yang ada diperlukan suatu sistem yang dapat memberikan data kondisi cuaca untuk keselamatan lepas landas dan mendarat dengan parameter kecepatan angin yang menggunakan sensor Anemometer, untuk suhu dan kelembaban menggunakan sensor DHT 22, dan sensor arah angin menggunakan sensor Wind Vane Direction dan data yang diproses oleh Arduino Mega2560 ditampilkan pada LCD (Liquid Crystal Display) 20×4, hasil dari proses tersebut juga dikirim melalui sistem transmisi data dengan menggunakan teknologi LoRa (Long Range). Dari hasil pengujian yang dilakukan menunjukkan bahwa fungsionalitas semua sensor sudah berjalan sebagaimana mestinya, rata-rata kesalahan kalibrasi data sensor DHT 22 untuk suhu 2,14% dan kelembaban 1,37%, dan sensor kecepatan angin sebesar 2,85%. Selain itu pengujian komunikasi LoRa antara node dan gateway menunjukan hasil yang baik dengan nilai RSSI (Received Signal Strength Indicator) rata-rata pada node 1 adalah -77 dBm dan node 2 adalah -34 dBm.

Cars capture and generate huge volumes of data in real-time about the driving dynamics, the environment, and the driver and passengers' activities. Due to the proliferation of cooperative, connected and automated mobility (CCAM), the value of data from vehicles is getting strategic, not just for the automotive industry, but also for many diverse stakeholders including small and medium-sized enterprises (SMEs) and start-ups. 5G can enable car-captured data to feed innovative applications and services deployed in the cloud ensuring lower latency and higher throughput than previous cellular technologies. This paper identifies and discusses the relevance of the main 5G features that can contribute to a scalable, flexible, reliable and secure data pipeline, pointing to the standards and technical reports that specify their implementation.

Background: Requirement engineering is often considered a critical activity in system development projects. The increasing complexity of software as well as number and heterogeneity of stakeholders motivate the development of methods and tools for improving large-scale requirement engineering. Aims: The empirical study presented in this paper aim to identify and understand the characteristics and challenges of a platform, as desired by experts, to support requirement engineering for individual stakeholders, based on the current pain-points of their organizations when dealing with a large number requirements. Method: We conducted a multiple case study with three companies in different domains. We collected data through ten semi-structured interviews with experts from these companies. Results: The main pain-point for stakeholders is handling the vast amount of data from different sources. The foreseen platform should leverage such data to manage changes in requirements according to customers' and users' preferences. It should also offer stakeholders an estimation of how long a requirements engineering task will take to complete, along with an easier requirements dependency identification and requirements reuse strategy. Conclusions: The findings provide empirical evidence about how practitioners wish to improve their requirement engineering processes and tools. The insights are a starting point for in-depth investigations into the problems and solutions presented. Practitioners can use the results to improve existing or design new practices and tools.

Pervasive services provided to the enterprise require from increased speed, performance, degree of personalization, ubiquitous access and reliability. 4G broadband wireless systems and multihoming technologies provide a working framework where such challenges could be met. In the context of a user driven broadband multimedia service and heterogeneous multiple-flow communication network supported system, this paper presents the MULTINET architecture as an enabler for next generation service delivery. The paper will discuss the main entities involved in the system, the main functionality supported and performance. The paper will also highlight initial architecture set-ups and evaluate benefits and drawbacks of the proposed configurations to meet the identified QoS requirements.

This chapter contains sections titled: 2D Pipeline 3D Pipeline Other Implementations Examples

In this article we consider methods for automatic query expansion from top retrieved documents (i.e., retrieval feedback) that make use of various functions for scoring expansion terms within Rocchio's classical reweighting scheme. An analytical comparison shows that the retrieval performance of methods based on distinct term-scoring functions is comparable on the whole query set but differs considerably on single queries, consistent with the fact that the ordered sets of expansion terms suggested for each query by the different functions are largely uncorrelated. Motivated by these findings, we argue that the results of multiple functions can be merged, by analogy with ensembling classifiers, and present a simple combination technique based on the rank values of the suggested terms. The combined retrieval feedback method is effective not only with respect to unexpanded queries but also to any individual method, with notable improvements on the system's precision. Furthermore, the combined method is robust with respect to variation of experimental parameters and it is beneficial even when the same information needs are expressed with shorter queries.