Local and territorial determinants in the realization of public–private–partnerships: an empirical analysis for Italian provinces

ABSTRACT Relational networks and intangible factors are crucial elements for the competitiveness of a territory. Public–Private–Partnerships (PPPs), in particular, allow for the provision of goods and services that favour the exploitation of complementarities between public and private resources. They aim at promoting an increase in the overall efficiency of investment projects through a complex mechanism that distributes risk and revenues among stakeholders. This paper examines the local and territorial determinants of PPPs through an econometric analysis based upon Italian municipal data, grouped at the provincial level. Using a tobit model, we analyse the relationship between the realization of successful PPP initiatives and different sets of factors, including less analysed local and territorial determinants. We stress the role of the local management of infrastructure assets, the administrative efficiency of local authorities and the diffusion of previous local development initiatives. Local management and territorial context factors explain most of the occurrence of successful PPP initiatives in the pre-crisis period while usual determinants (infrastructure endowment and financial distress) display a weaker effect

Detection of Duplicated Regions in Tampered Digital Images by Bit-Plane Analysis

In this paper we present a new method for searching duplicated areas in a digital image. The goal is to detect if an image has been tampered by a copy-move process. Our method works within a convenient domain. The image to be analyzed is decomposed in its bit-plane representation. Then, for each bitplane, block of bits are encoded with an ASCII code, and a sequence of strings is analyzed rather than the original bit-plane. The sequence is lexicographically sorted and similar groups of bits are extracted as candidate areas, and passed to the following plane to be processed. Output of the last planes indicates if, and where, the image has been altered

Scale detection via keypoint density maps in regular or near-regular textures

In this paper we propose a new method to detect the global scale of images with regular, near regular, or homogenous textures. We define texture ‘‘scale’’ as the size of the basic elements (texels or textons) that most frequently occur into the image. We study the distribution of the interest points into the image, at different scale, by using our Keypoint Density Maps (KDMs) tool. A ‘‘mode’’ vector is built computing the most frequent values (modes) of the KDMs, at different scales. We observed that the mode vector is quasi linear with the scale. The mode vector is properly subsampled, depending on the scale of observation, and compared with a linear model. Texture scale is estimated as the one which minimizes an error function between the related subsampled vector and the linear model. Results, compared with a state of the art method, are very encouraging

Copy-Move Forgery Detection by Matching Triangles of Keypoints

Copy-move forgery is one of the most common types of tampering for digital images. Detection methods generally use block-matching approaches, which first divide the image into overlapping blocks and then extract and compare features to find similar ones, or point-based approaches, in which relevant keypoints are extracted and matched to each other to find similar areas. In this paper, we present a very novel hybrid approach, which compares triangles rather than blocks, or single points. Interest points are extracted from the image, and objects are modeled as a set of connected triangles built onto these points. Triangles are matched according to their shapes (inner angles), their content (color information), and the local feature vectors extracted onto the vertices of the triangles. Our methods are designed to be robust to geometric transformations. Results are compared with a state-of-the-art block matching method and a point-based method. Furthermore, our data set is available for use by academic researchers

Detecting Multiple Copies in Tampered Images

Copy-move forgeries are parts of the image that are duplicated elsewhere into the same image, often after being modified by geometrical transformations. In this paper we present a method to detect these image alterations, using a SIFT-based approach. First we describe a state of the art SIFT-point matching method, which inspired our algorithm, then we compare it with our SIFT-based approach, which consists of three parts: keypoint clustering, cluster matching, and texture analysis. The goal is to find copies of the same object, i.e. clusters of points, rather than points that match. Cluster matching proves to give better results than single point matching, since it returns a complete and coherent comparison between copied objects. At last, textures of matching areas are analyzed and compared to validate results and to eliminate false positives

Multi-Directional Scratch Detection and Restoration in Digitized Images

Line scratches are common defects in old archived videos, but similar imperfections may occur in printed images, in most cases by reason of improper handling or inaccurate preservation of the support. Once an image is digitized, its defects become part of that image. Many state-of-the-art papers deal with long, thin, vertical lines in old movie frames, by exploiting both spatial and temporal information. In this paper we aim to face with a more challenging and general problem: the analysis of line scratches in still images, regardless of their orientation, color, and shape. We present a detection/restoration method to process this defect

ARCHITETTURA E BOTANICA DEL SACRO CALVARIO DI GANGI (SICILIA)

Il Calvario, dal latino Golgota che indica il luogo della Crocifissione di Cristo, è una tipologia di monumento di culto della religione cristiana la cui genesi si fa risalire al Medioevo, epoca dei lunghi pellegrinaggi di fedeli che, per tale ragione, sentivano l’esigenza di creare luoghi sostitutivi che richiamassero le mete Sante, troppo lontane. In Italia e, in particolare, in Piemonte e in Lombardia, l’edificazione di questi complessi prese inizio a seguito del Concilio di Trento soprattutto sotto forma di Sacri Monti che, per l’appunto, ne costituiscono la principale espressione. In Sicilia, la tradizione dei “Calvari” venne introdotta nel XVIII secolo dai Gesuiti che generalmente li costruivano su un’altura o, in alternativa, in presenza di un pianoro, utilizzando il mezzo scenico della scalinata, sia per simboleggiare la “via dolorosa” percorsa dal Nazareno sia per assolvere alla funzione di collegamento tra il luogo Sacro e l’abitato limitrofo. Se è vero che ciascun calvario possiede una sua unicità costruttiva, i diversi casi in Sicilia sono accomunati dalla presenza di tre elementi fondamentali: l’albero di cipresso; l’isolamento; l’orientamento a Nord, Nord-Est (Lima, 1984). Il Sacro Calvario di Gangi (Palermo) la cui realizzazione risale al 1826, anno in cui pervenne nel luogo una delle Missioni gesuite, fu completato e rifinito tra il 1843 ed il 1858. Oggi, esso si trova nel centro storico del paese delle basse Madonie, nel quartiere della chiesa di S. Maria di Gesù, e rappresenta il fulcro delle celebrazioni della Settimana Santa. L’indagine architettonica ha dimostrato l’esistenza di una rigorosissima e “colta” geometria che sottende l’intero impianto, sia per ciò che concerne la componente “minerale”, sia per quella “vegetale”. Anche le misure richiamno significati simbolici tutti riconducibili al senso del Lutto, come dimostra il lotto rettangolare entro cui insiste il giardino che contiene 4 cerchi del diametro di 10 m, per una lunghezza complessiva di 40 m. Inoltre, si individua un altro cerchio che, in parte materializzato nell’edicola centrale, si sviluppa fino a comprendere la scala esterna e il cui centro è perfettamente coincidente con l’asse orizzontale del giardino. Il complesso si sviluppa su un’area di 570 mq. La cancellata in ferro battuto, che si sviluppa sulla linea ideale posta tra la zona di mediazione e il giardino, sancisce la divisione tra l’ambito “celeste” del giardino e l’ambito “terreno” della città vera e propria. Tutto l’impianto è racchiuso su tre lati da alte mura, a formare uno spazio isolato. I viali sono ripartiti simmetricamente in due settori dall’asse centrale della scala e si sviluppa su tre livelli. I percorsi del giardino sono, quindi, strutturati per la rappresentazione della Via Crucis che si conclude con l’edicola della Madonna Addolorata, luogo delle tre croci. Lima A.I., 1984. La dimensione sacrale del paesaggio: ambiente e architettura popolare di Sicilia. Palermo. Flaccovio, Palermo

Copy-move Forgery Detection via Texture Description

Copy-move forgery is one of the most common type of tampering in digital images. Copy-moves are parts of the image that are copied and pasted onto another part of the same image. Detection methods in general use block-matching methods, which first divide the image into overlapping blocks and then extract features from each block, assuming similar blocks will yield similar features. In this paper we present a block-based approach which exploits texture as feature to be extracted from blocks. Our goal is to study if texture is well suited for the specific application, and to compare performance of several texture descriptors. Tests have been made on both uncompressed and JPEG compressed images