16719880
Jikzi - a new framework for security policy, trusted publishing and electronic commerce
In this paper, we will describe a thread of research, which we have followed off and on at Cambridge for about three years. Our topic is the security of electronic documents, in the broad sense: how can we be sure of the authenticity of things that are published electronically? This started off as a relatively small project, which we thought would take only a few weeks. The goal was to help our medical informatics department publish information such as drug formularies and treatment protocols on the hospital LAN or PC diskettes, in an appropriately dependable way. It rapidly became clear that the problem was much larger and more complex; a general solution would not only cope with 'content' - text, audio, video, software, whatever - but also with objects such as public key certificates. If done properly, it would give us a systematic way to deal with security policy on the web. Our goal now is to let people build integrated publishing and e-commerce services using simple, uniform and appropriate mechanisms. Our proposed solution is a single transparent markup language that allows us to support multiple security policies, plus supporting material ranging from a test implementation to an authentication logic.
26803013
Jikzi: A New Framework for Secure Publishing
We present a new way to deal with security policy on the web. Our aim is to let people build integrated publishing and e-commerce services using appropriate, simple and uniform mechanisms. Our goal is a single framework that applies equally to the publication of catalogues, music, software, public key certificates and even old fashioned books. Our prototype framework, Jikzi, supports multiple security policies – even in the same document – with a single transparent markup language.
9196724
STRG-Index: spatio-temporal region graph indexing for large video databases
In this paper, we propose new graph-based data structure and indexing to organize and retrieve video data. Several researches have shown that a graph can be a better candidate for modeling semantically rich and complicated multimedia data. However, there are few methods that consider the temporal feature of video data, which is a distinguishable and representative characteristic when compared with other multimedia (i.e., images). In order to consider the temporal feature effectively and efficiently, we propose a new graph-based data structure called Spatio-Temporal Region Graph (STRG). Unlike existing graph-based data structures which provide only spatial features, the proposed STRG further provides temporal features, which represent temporal relationships among spatial objects. The STRG is decomposed into its subgraphs in which redundant subgraphs are eliminated to reduce the index size and search time, because the computational complexity of graph matching (subgraph isomorphism) is NP-complete. In addition, a new distance measure, called Extended Graph Edit Distance (EGED), is introduced in both non-metric and metric spaces for matching and indexing respectively. Based on STRG and EGED, we propose a new indexing method STRG-Index, which is faster and more accurate since it uses tree structure and clustering algorithm. We compare the STRG-Index with the M-tree, which is a popular tree-based indexing method for multimedia data. The STRG-Index outperforms the M-tree for various query loads in terms of cost and speed.
13494624
Security policies
A security policy is a high-level specification of the security properties that a given system should possess. It is a means for designers, domain experts and implementers to communicate with each other, and a blueprint that drives a project from design through implementation and validation. We offer a survey of the most significant security policy models in the literature, showing how “security” may mean very different things in different contexts, and we review some of the mechanisms typically used to implement a given security policy.
12522566
Real Time Video Data Mining for Surveillance Video Streams
We extend our previous work [1] of the general framework for video data mining to further address the issue such as how to mine video data using motions in video streams. To extract and characterize these motions, we use an accumulation of quantized pixel differences among all frames in a video segment. As a result, the accumulated motions of segment are represented as a two dimensional matrix. Further, we develop how to capture the location of motions occurring in a segment using the same matrix generated for the calculation of the amount. We study how to cluster those segmented pieces using the features (the amount and the location of motions) we extract by the matrix above. We investigate an algorithm to find whether a segment has normal or abnormal events by clustering and modeling normal events, which occur mostly. In addition to deciding normal or abnormal, the algorithm computes Degree of Abnormality of a segment, which represents to what extent a segment is distant to the existing segments in relation with normal events. Our experimental studies indicate that the proposed techniques are promising.
17811625
A Graph-Based Approach for Modeling and Indexing Video Data
In this work, we propose new graph-based data model and indexing to organize and manage video data. To consider spatial and temporal characteristics of video, we introduce a new graph-based data model called spatio-temporal region graph (STRG). Unlike existing graph-based data structures which provide only spatial features, the proposed STRG further provides temporal features, which represent temporal relationships among spatial objects. The STRG is decomposed into its subgraphs object graphs (OGs) and background graphs (BGs). In addition, a new distance measure, called extended graph edit distance (EGED), is introduced in metric space for matching and indexing. Based on clustering and EGED, we propose a new indexing method STRG-index, which is faster and more accurate. We compare the STRG-Index with the M-tree, which is a popular tree-based indexing method for multimedia data. The STRG-index outperforms the M-tree in terms of cost and speed
35999756
Guest Editor's Introduction
17910425
TMO-structured distributed location information system prototype
To realize location-based services, it is essential to handle the extreme situation that must cope with a very large volume, at least millions, of moving items. In this paper, we describe a location information system prototype of GALIS, which is a cluster-based scalable distributed computing system architecture which consists of multiple data processors, each dedicated to keeping records relevant to a different geographical zone and a different time zone. The proposed system contains all of the major computing nodes of GALIS architecture and is developed as a middleware on top of commercial main-memory database engines and spatial database engines, for short-term data and long-term data processing, respectively. To show the usefulness of our system, some experimental results showing clear advantages of distributed computing are also explained.
11135972
Challenges in Cross-Cultural/Multilingual Music Information Seeking
Understanding and meeting the needs of a broad range of music users across different cultures and languages are central in designing a global music digital library. This exploratory study examines cross-cultural/multilingual music information seeking behaviors and reveals some important characteristics of these behaviors by analyzing 107 authentic music information queries from a Korean knowledge search portal Naver 지식 (knowledge) iN and 150 queries from Google Answers website. We conclude that new sets of access points must be developed to accommodate music queries that cross cultural or language boundaries.
17895301
Optimal choice of data restructuring points
Maintaining access efficiency to a data base as updates and/or usage patterns change often requires restructuring the data base. While analytical methods are available for determining the optimal point to restructure, they assume the mean access cost is a smooth function of time or the number of accesses and can be measured exactly at any point in time. The access cost in practice often varies, at least in the short run, In a random manner. This implies a nonzero probability of deciding the optimal reorganization point has been reached when in fact it has not. Determination of the optimal reorganization point must take into account the random behavior of the access cost and the probability (and cost) of deciding too early or too late to perform the reorganization. A technique for choosing the optimal reorganization point subject to random variation in the access cost is developed and some examples are presented.
1805893
Secure Localization and Location Verification in Sensor Networks
Evolving networks of wireless sensing nodes have many attractive applications. Localization, that is to determine the locations of sensor nodes, is a key enabler for many applications of sensor networks. As sensor networks move closer to extensive deployments, security becomes a major concern, resulting in a new demand for secure localization and location proving systems. In this paper, we propose a secure localization system based on a secure hop algorithm. A location verification system that allows the base station to verify the locations of sensor nodes is also presented. It prevents a node from falsifying reported location information. The evaluation of the secure localization system shows that the proposed scheme performs well under a range of scenarios tested and is resilient against an attacker creating incorrect location information in other nodes.