Use of Kriging Technique to Study Roundabout Performance

Road intersections are dangerous places because of the many conflicting points between motorized and nonmotorized vehicles. In the case of defined traffic volume, several research groups have proved that roundabouts reduced the number of injuries and fatal accident cases. In recent years, many countries have adopted roundabouts as a standard design solution for both urban and rural roads. Several recent studies have investigated the performance of roundabouts, including some with models that calculated the entering flow (Q sub e) as a function of the circulating flow (Q sub c). Most existing models have been constructed with the use of linear or exponential statistical regression. The interpolative techniques in classical statistics are based on the use of canonical forms (linear or polynomial) that completely ignore the correlation law between collected data. As such, the determined interpolation stems from the assumption that the data represent a random sample. In the research reported in this paper, a geostatistical approach was considered: the relationship Q sub e versus Q sub c is supposed to be a regionalized phenomenon. According to that supposition, collected data do not represent a random sample of values but are supposed to be related to each other with a defined law. This recognition allows the realization of interpolation on the basis of the real law of the phenomenon. This paper discusses the fundamental theories, the applied operating procedures, and the first results obtained in modeling the Q sub e versus Q sub c relationship with the application of geostatistics

Codifica fenologica e dinamica dell'assorbimento minerale in <i>Cynara cardunculus</i> var. <i>scolymus</i>

Cynara cardunculus var scolymus is a horticultural perennial crop, sometimes grown as annual. In this thesis we described the phenological traits of the crop and studied the mineral uptake of several globe artichoke varieties grown in Mediterranean environment. Despite its economical relevance, scarce scientific information on phenological and agronomical traits are available at present. In chapter 1 we present the phenological growth stages based on the Biologische Bundesanstalt, Bundessortenamt, CHemische Industrie (BBCH) scale and its associated decimal code. Nine principal growth stages have been defined and each principal stage has been subdivided into secondary growth stages. Descriptive keys with illustrations are also provided. A practical use of the scale is proposed, with particular reference to harvest time and management treatments. This scale aims to support farmers and researchers to efficiently plan management practices and experimental treatments. In chapter 2 we present globe artichoke nutrients uptake and partitioning, determined by successive destructive plant harvest and mineral analysis of plant organs of four field grown varieties (Tema 2000, Spinoso Sardo, Violetto and Romanesco C3). Potassium was the most important element in quantitative term, while phosphorus was the less one. Nitrogen showed a remarkable variability in relation to the variety traits. A practical use of the uptake ratio is proposed, with particular reference to the crop nutrition management

Measuring implicit European and Mediterranean landscape identity. A tool proposal

This study presents a tool - the Landscape Identity Implicit Association Test (LI-IAT) - devoted to measure the implicit identification with European and Mediterranean landscapes. To this aim, a series of prototypical landscapes was selected as stimulus, following an accurate multi-step procedure. Participants (N = 174), recruited in two Italian cities, performed two LI-IATs devoted to assess their identification with European vs. Not-European and Mediterranean vs. Not-Mediterranean prototypical landscapes. Psychometric properties and criterion validity of these measures were investigated. Two self-report measures, assessing, respectively, European and Mediterranean place identity and pleasantness of the target landscapes, were also administered. Results showed: (1) an adequate level of internal consistency for both LI-IATs; (2) a higher identification with European and Mediterranean landscapes than, respectively, with Not-European and Not-Mediterranean ones; and (3) a significant positive relationship between the European and Mediterranean LI-IATs and the corresponding place identity scores, also when pleasantness of landscapes was controlled for. Overall, these findings provide a first evidence supporting the reliability and criterion validity of the European and Mediterranean LI-IAT

G-R-sequences and incidence coalgebras of posets of full binomial type

AbstractA family of polynomial sequences, named G-R-sequences, is introduced and its connections with both graded coalgebras and posets of full binomial type are studied. Moreover, the G-R-sequences pn(x), such that pn is a divisor of pn + 1, are characterized in terms of roots of unity and linearly recursive sequences

Road signs: walking among shapes and colors

Road signs provide information through the combination of three elements: shape, color and pictogram. The current road signs are projected to ensure safety but are designed for adults and not for children. Kids are not small adults and they have a different perception of reality. While planning of home-school pedestrian routes, it is necessary to create road signs that are comprehensible for children aged 6-14. Therefore the elements of road signs were studied individually. The study revealed that both the knowledge of geometric shapes and colors perception are closely related to age and culture and to the teachings which children are submitted to. In fact, some geometric shapes, like the circle, are perfectly recognized from childhood and others less so, such as the rectangle. Moreover children are attracted to basic colors but they are aware of the existence of pastel colors only with teaching. Finally, pictogram must represent a simple symbol that is easily recognized especially from far away. The message generated by the three elements is understandable by children. In fact, children overcome the phase of syncretism after the age of 6, which corresponds to the phase in which children are unable to analyses and syntheses. The result of the research has allowed to design road signs, both vertical and horizontal, that are able to ensure the safety of home-school routes. A road signs study was conducted for Cagliari’s project on road safety. This project involves the use of questionnaires to verify if the road signs are properly designed

Geostatistical Approach for Operating Speed Modelling on Italian Roads

Injuries are one of the main causes of death according to W.H.O. For this reason the attention of road safety researchers especially regards the study of the relationship between driver and road environment. Several research works show that operating speed is an excellent driver behavior parameter. This article describes a different approach to the classical definition of prediction models for operating speed on horizontal curves. In this paper, the fundamental theories, the applied operating procedures and the first results obtained with the application of Geostatistics are discussed. The mathematical models expressing operating speed in function of horizontal curves characteristics found in International scientific literature, have mainly been built on the basis of Classical Statistics. For this reason, it needs to be pointed out that the interpolative techniques found in Classical Statistics are based upon the use of canonical forms (linear or polynomial regressions) that completely ignore the correlation law between collected data. As such, the determined interpolation stems from the assumption that the data represent a random sample. The models described in this article have instead been created with the geostatistical interpolation technique (i.e. Kriging). This technique allows to obtain the "best" estimates possible because it considers the true correlation law between the measured data. The applied methods are then described along with the results obtained in the field of road safety by applying Geostatistics which, for several years, have been used, with positive results, in all scientific and engineering fields dealing with empirical data analysis and processing

Supporting tourism through the promotion of cycling: GIS model applied in the metropolitan area of Cagliari (Italy)

In Italy, where bicycle culture is struggling to catch on, the Extraordinary Plan for Tourism Mobility 2017–22 aims to increase the accessibility of tourist sites through safe and pleasant cycling routes, interconnected with other modes of transport. These same objectives have been pursued by Sardinia, one of the Italian regions more attractive to tourists, through the design of a regional cycle network and a long-distance tourist cycling routes (Ciclovia della Sardegna). The current study focuses on tourism mobility in the metropolitan city of Cagliari, the largest urban area in Sardinia, and aims to explore how much the existing and planned cycling routes constitute an alternative mobility solution for tourists who intend to reach the beaches. In particular, the study aims to evaluate the level of accessibility offered by bicycling to the beaches, which are among the most visited and attractive places for tourists, before and after the implementation of a regional bike tourism network system. A GIS-based procedure was employed and the method comprised of three main steps: (1) data collection and preparation, (2) GIS analysis, and (3) assessment of results. We performed two main types of analysis using GIS. First, we delineated service areas around each beach for various distances. Then, we overlaid and analyzed these areas in conjunction with the accommodation facilities. Second, we measured the accessibility of beaches using a gravity-based accessibility index. Our results demonstrate that, following the implementation of the regional cycle network Sardinia, various zones in the metropolitan area of Cagliari significantly increased their level of accessibility to the beaches, while others did not. Importantly, the adopted methodology has proven to be a valid tool for assessing cycling accessibility for different infrastructure scenarios

Analysis, design and implementation of alternative solutions for data persistence on mobile devices

Data availability on mobile applications is a key feature required to have a better user experience, especially in offline scenarios. Mobile applications should be available both when the device is online and when it is offline. The assumption that the device is always connected to the Internet is in general too strict. Relational databases provide a solid but limited solution to store persistent data locally. In order to satisfy dynamic needs of mobile applications, alternative storage solutions should be used to offer a schema-free data layer. JSON can be used as a data interchange format for lightweight and easy manipulation. However, problems like performance and security must be considered in such mobile scenarios especially for enterprise applications. This thesis describes the analysis, design and development of a mobile storage solution. The proposed approach relies on JSON and it has been integrated into a proprietary enterprise framework in order to improve performances of the existing data layer. First of all, state-of-the-art data storages for mobile devices have been analysed, in terms of data and query model, concurrency, encryption, cross-platform support. After that, we designed and developed a new solution, based on SQLite with JSON1 extension. This standalone library has been integrated into a proprietary framework in order, to provide a performing schemafree data storage, able to store and query non-relational data in a very efficient way

Extremely Shaped Plasmas to Improve the Tokamak Concept

Energy is essential for human existence and our future depends on plentiful and accessible sources of energy. The world population is fast growing and the average energy used per capita increases. One of the greatest challenges for human beings is that of meeting the growing demand for energy in a responsible, equitable and sustainable way. The possibility to obtain energy by "fusing" light atoms addresses these needs. Nuclear fusion reactions are clean, safe and the amount of fuel present on Earth (hydrogen isotopes) is practically inexhaustible and well distributed. Nuclear fusion is a natural process that occurs in all active stars like our Sun. Since the first demonstration of a deuterium fusion reaction (Rutherford 1933), researchers worldwide have tried to replicate this process on Earth by building a thermonuclear fusion reactor. Nevertheless, the challenge posed by the construction of a nuclear fusion reactor is greater than the one presented earlier by the development of a fission reactor. During the IAEA Conference in Geneva in the early 1958, L.A.Artsimovich declared: "Plasma physics is very difficult. Worldwide collaboration is needed for progress" and E.Teller, at the same conference: "Fusion technology is very complex. It is almost impossible to build a fusion reactor in this century". They were right. The extremely high temperature and density necessary to fuse hydrogen isotopes makes it difficult indeed to create a successful fusion reactor. Even though the physics of the fusion reaction appears clear, we are still facing problems on the road towards bulding the "box" that can efficiently confine the hot gas in the state of plasma. The best results so far have been obtained confining a plasma with strong magnetic fields in a toroidal configuration ("tokamak"). The Centre de Recherches en Physique des Plasmas in Switzerland actively studies this promising configuration towards the development of a nuclear fusion reactor. The experimental activity of the Tokamak à Configuration Variable (TCV) mainly focuses on the research of optimized plasma shapes capable of improving the global performance and solve the technological challenges of a tokamak reactor. Several theoretical and experimental results show the importance of the plasma shape in tokamaks. The maximum value of β (an indicator of the confinement efficiency) is for example related to the ratio between the height and the width of the plasma. The plasma shape can also affect the power necessary to access improved confinement regimes, as well as the plasma stability. This thesis reports on a contribution towards the optimization of the tokamak plasma shape. In particular, it describes the theoretical and experimental studies carried out in the TCV tokamak on two innovative plasma shapes: the doublet shaped plasma and the snowflake divertor. Doublet shaped plasmas have been studied in the past by the General Atomics group. Since then, the development of new plasma diagnostics and the discovery of new confinement regimes have given new reasons for interest in this unusual configuration. TCV is the only tokamak worldwide theoretically able to establish and control this configuration. This thesis illustrates new motivations for creating doublet plasmas. The vertical stability of the configuration is studied using a rigid model and the results are compared with those obtained with the KINX MHD stability code. The best strategy for controlling a doublet on TCV is also investigated, and a possible setup of the TCV control system is suggested for the doublet configuration. Analyzing the possible scenarios for doublet creation, the most promising scenario consists of the creation of two independent plasmas, which are subsequently merged to establish a doublet. For this reason, particular attention needs to be devoted to the problem of the plasma start-up. In this thesis, a general analysis of the TCV ohmic and assisted with ECH plasma start-up is presented, and recent attempts to create a doublet plasma are reported. Since the magnetic field reconstruction at the breakdown time is important to better diagnose these plasmas, the entire magnetic system of TCV has been calibrated with an original technique, also described in the manuscript. The last part of this thesis is devoted to the snowflake divertor configuration. This innovative plasma shape has been proposed and theoretically studied by Dr. D.D.Ryutov from the Lawrence Livermore National Laboratory. In Ryutov's articles, this configuration was proposed to alleviate the problems of the plasma-wall interaction and possibly affect the plasma edge stability. The TCV tokamak was the first to report the creation and control of a snowflake configuration, and the candidate was the principal investigator of this work. These results are accordingly discussed in this thesis. Details are provided in particular on the strategy used to establish the configuration. An edge-localized mode (ELM) H-mode regime, supported by electron cyclotron heating, has been successfully established in a snowflake. This regime exhibits 2 to 3 times lower ELM frequency but only a 20%-30% increase in normalized ELM energy (ΔWELM/WP ) compared to an identically-shaped, conventional, single-null, diverted H-mode. Enhanced stability of mid- to high-toroidal-mode-number ideal modes is consistent with the different snowflake ELM phenomenology. Finally, the capability of the snowflake to redistribute the edge power on the additional strike points has been confirmed experimentally and is also reported in this thesis

The co-production of a workplace health promotion program: expected benefits, contested boundaries

Workplace health promotion (WHP) are often depicted as an opportunity for pursuing a better and broader well-being condition under the assumption that working environments affect the physical, mental, and social well-being of individuals who spend large proportion of waking hours at work. While most empirical studies provided medical evidence to the effectiveness of WHP programs, scholars question the instrumental purposes of these programs founded on the belief that “healthy workers are better workers”. Little is known, for instance, about the design of WHP programs and their acceptance by workers. Our study addresses this gap, analyzing the co-production of a WHP program in an Italian research institute promoted by the healthcare authority, the local government and the national center for prevention and security in the workplaces. To this aim, we adopt the notion of boundary object investigate how different stakeholders reclaim to take part and being involved in this process, re-shaping their goals and their boundaries and why a WHP program or parts of it may be rejected or re-negotiated by its recipients. Our analysis reveals how each stakeholder contributes to re-shape the WHP program which emerges as the modular product of the composition of each matter of concern. Most notably, the strong rooting in a clinical perspective and the original focus on only workers at risk is gradually flanked by initiatives to involve all employees. Moreover, workers draw a line as for the legitimacy of employers’ intervention in the personal sphere of health promotion, embracing interventions addressing diet and physical activity while rejecting measures targeting smoking and alcohol consumption