WorldWideScience

Sample records for anonymized ons queries

  1. Evaluation of Anonymized ONS Queries

    CERN Document Server

    Garcia-Alfaro, Joaquin; Kranakis, Evangelos

    2009-01-01

    Electronic Product Code (EPC) is the basis of a pervasive infrastructure for the automatic identification of objects on supply chain applications (e.g., pharmaceutical or military applications). This infrastructure relies on the use of the (1) Radio Frequency Identification (RFID) technology to tag objects in motion and (2) distributed services providing information about objects via the Internet. A lookup service, called the Object Name Service (ONS) and based on the use of the Domain Name System (DNS), can be publicly accessed by EPC applications looking for information associated with tagged objects. Privacy issues may affect corporate infrastructures based on EPC technologies if their lookup service is not properly protected. A possible solution to mitigate these issues is the use of online anonymity. We present an evaluation experiment that compares the of use of Tor (The second generation Onion Router) on a global ONS/DNS setup, with respect to benefits, limitations, and latency.

  2. Private Queries and Trajectory Anonymization: a Dual Perspective on Location Privacy

    Directory of Open Access Journals (Sweden)

    Gabriel Ghinita

    2009-04-01

    Full Text Available The emergence of mobile devices with Internet connectivity (e.g., Wi-Fi and global positioning capabilities (e.g., GPS have triggered the widespread development of location-based applications. For instance, users are able to ask queries about points of interest in their proximity. Furthermore, users can act as mobile sensors to monitor traffic flow, or levels of air pollution. However, such applications require users to disclose their locations, which raises serious privacy concerns. With knowledge of user locations, a malicious attacker can infer sensitive information, such as alternative lifestyles or political affiliations. Preserving location privacy is an essential requirement towards the successful deployment of location-based services (LBS. Currently, two main LBS use scenarios exist: in the first one, users send location-based queries to an un-trusted server, and the privacy objective is to protect the location of the querying user. In the second setting, a trusted entity, such as a telephone company, gathers large amounts of location data (i.e., trajectory traces and wishes to publish them for data mining (e.g., alleviating traffic congestion. In this case, it is crucial to prevent an adversary from associating trajectories to user identities. In this survey paper, we give an overview of the state-of-the-art in location privacy protection from the dual perspective of query privacy and trajectory anonymization. We review the most prominent design choices and technical solutions, and highlight their relative strengths and weaknesses.

  3. On Backward-Style Anonymity Verification

    Science.gov (United States)

    Kawabe, Yoshinobu; Mano, Ken; Sakurada, Hideki; Tsukada, Yasuyuki

    Many Internet services and protocols should guarantee anonymity; for example, an electronic voting system should guarantee to prevent the disclosure of who voted for which candidate. To prove trace anonymity, which is an extension of the formulation of anonymity by Schneider and Sidiropoulos, this paper presents an inductive method based on backward anonymous simulations. We show that the existence of an image-finite backward anonymous simulation implies trace anonymity. We also demonstrate the anonymity verification of an e-voting protocol (the FOO protocol) with our backward anonymous simulation technique. When proving the trace anonymity, this paper employs a computer-assisted verification tool based on a theorem prover.

  4. Computing on Anonymous Quantum Network

    CERN Document Server

    Kobayashi, Hirotada; Tani, Seiichiro

    2010-01-01

    This paper considers distributed computing on an anonymous quantum network, a network in which no party has a unique identifier and quantum communication and computation are available. It is proved that the leader election problem can exactly (i.e., without error in bounded time) be solved with at most the same complexity up to a constant factor as that of exactly computing symmetric functions (without intermediate measurements for a distributed and superposed input), if the number of parties is given to every party. A corollary of this result is a more efficient quantum leader election algorithm than existing ones: the new quantum algorithm runs in O(n) rounds with bit complexity O(mn^2), on an anonymous quantum network with n parties and m communication links. Another corollary is the first quantum algorithm that exactly computes any computable Boolean function with round complexity O(n) and with smaller bit complexity than that of existing classical algorithms in the worst case over all (computable) Boolea...

  5. User perspectives on query difficulty

    DEFF Research Database (Denmark)

    Lioma, Christina; Larsen, Birger; Schütze, Hinrich

    2011-01-01

    The difficulty of a user query can affect the performance of Information Retrieval (IR) systems. What makes a query difficult and how one may predict this is an active research area, focusing mainly on factors relating to the retrieval algorithm, to the properties of the retrieval data, or to sta......The difficulty of a user query can affect the performance of Information Retrieval (IR) systems. What makes a query difficult and how one may predict this is an active research area, focusing mainly on factors relating to the retrieval algorithm, to the properties of the retrieval data......, or to statistical and linguistic features of the queries that may render them difficult. This work addresses query difficulty from a different angle, namely the users’ own perspectives on query difficulty. Two research questions are asked: (1) Are users aware that the query they submit to an IR system may...

  6. Anonymizing Unstructured Data

    CERN Document Server

    Motwani, Rajeev

    2008-01-01

    In this paper we consider the problem of anonymizing datasets in which each individual is associated with a set of items that constitute private information about the individual. Illustrative datasets include market-basket datasets and search engine query logs. We formalize the notion of k-anonymity for set-valued data as a variant of the k-anonymity model for traditional relational datasets. We define an optimization problem that arises from this definition of anonymity and provide a constant factor approximation algorithm for the same. We evaluate our algorithms on the America Online query log dataset.

  7. A query index for continuous queries on RFID streaming data

    Institute of Scientific and Technical Information of China (English)

    Jaekwan PARK; Bonghee HONG; Chaehoon BAN

    2008-01-01

    RFID middleware collects and filters RFID streaming data to process applications' requests called continuous queries, because they are executed continuously during tag movement. Several approaches to building an index on queries rather than data records, called a query index, have been proposed to evaluate continuous queries over streaming data. EPCgiobal proposed an Event Cycle Specification (ECSpec) model, which is a de facto standard query interface for RFID applications. Continuous queries based on ECSpec consist of a large number of segments that represent the query conditions. The problem when using any of the existing query indexes on these continuous queries is that it takes a long time to build the index, because it is necessary to insert a large number of segments into the index. To solve this problem, we propose a transform method that converts a group of segments into compressed data. We also propose an efficient query index scheme for the transformed space. Comparing with existing query indexes, the performance of proposed index outperforms the others on various datasets.

  8. Ranking Queries on Uncertain Data

    CERN Document Server

    Hua, Ming

    2011-01-01

    Uncertain data is inherent in many important applications, such as environmental surveillance, market analysis, and quantitative economics research. Due to the importance of those applications and rapidly increasing amounts of uncertain data collected and accumulated, analyzing large collections of uncertain data has become an important task. Ranking queries (also known as top-k queries) are often natural and useful in analyzing uncertain data. Ranking Queries on Uncertain Data discusses the motivations/applications, challenging problems, the fundamental principles, and the evaluation algorith

  9. Location anonymity method of mobile objects continuous query%移动对象连续查询位置匿名策略

    Institute of Scientific and Technical Information of China (English)

    赵洪斌; 马志强; 印桂生; 韩启龙

    2015-01-01

    Location-based services applications are increasingly entering people’s daily lives. Although a location-based service is quite convenient, privacy protection has received considerable attention in location-based services. Currently, there have been numerous studies on protecting location privacy and many methods have been proposed. However, most existing location anonymous method is for a snapshot query, without considering the location privacy leak in continuous LBS queries. This paper proposes a dummy-based anonymizing method based on user history location to protect location privacy in continuous LBS queries.%用户位置隐私保护已经成为基于位置服务领域研究的热点问题之一,现有的方法多是只针对用户单独一次查询的隐私保护,没有考虑移动过程中由于连续查询而造成的位置隐私泄露问题。主要针对连续查询下的移动对象位置隐私保护提出一种基于历史用户的虚假用户生成的位置匿名方法,该方法结合用户历史数据,通过确定合理的假用户生成区域及假用户生成时刻其空间位置,使虚假用户能够实时对真实用户位置进行保护,通过实验验证其可行性和有效性。

  10. Anonymous Fingerprinting Based on Electronic Cash

    Institute of Scientific and Technical Information of China (English)

    CHENXiaofeng; ZHANGFangguo; WANGJilin; WANGYumin

    2003-01-01

    A new anonymous fingerprinting protocol based on the principle of electronic cash is proposed in this paper.Redistributing a data item is equal to doublespending electronic cash.Contrasting with the previous coin-based anonymous fingerprinting protocol,we use the real electronic cash to trace traitors instead of the "coins" which serve only as a cryptographic primitive and have no monetary value,so it is easily understood and the bank does not need key-distribution and registration to prepare the "coina".

  11. Anonymous communication networks protecting privacy on the web

    CERN Document Server

    Peng, Kun

    2014-01-01

    In today's interactive network environment, where various types of organizations are eager to monitor and track Internet use, anonymity is one of the most powerful resources available to counterbalance the threat of unknown spectators and to ensure Internet privacy.Addressing the demand for authoritative information on anonymous Internet usage, Anonymous Communication Networks: Protecting Privacy on the Web examines anonymous communication networks as a solution to Internet privacy concerns. It explains how anonymous communication networks make it possible for participants to communicate with

  12. Lightweight query authentication on streams

    OpenAIRE

    2014-01-01

    We consider a stream outsourcing setting, where a data owner delegates the management of a set of disjoint data streams to an untrusted server. The owner authenticates his streams via signatures. The server processes continuous queries on the union of the streams for clients trusted by the owner. Along with the results, the server sends proofs of result correctness derived from the owner's signatures, which are easily verifiable by the clients. We design novel constructions for a collection o...

  13. On the Anonymity of Identity-Based Encryption

    Directory of Open Access Journals (Sweden)

    Song Luo

    2013-01-01

    Full Text Available Anonymity of identity-based encryption (IBE means that given a ciphertext, one cannot distinguish the target identity from a random identity. In this paper, we thoroughly discuss the anonymity of IBE systems. We found that the current definition of anonymity is obscure to describe some IBE systems, such as Gentry IBE system. Furthermore, current definition cannot express the degree of anonymity. So we divide the degree of anonymity into weak anonymity and strong anonymity based on indistinguishability between different games. For weakly anonymous IBE systems, the target identity in a ciphertext cannot be distinguished from a random identity. For strongly anonymous IBE systems, the whole ciphertext cannot be distinguished from a random tuple. We also discuss the type of anonymity and divide it into two types. Type 1 means that a random tuple can be seen as a valid ciphertext, while type 2 cannot. Based on our new definitions, we show that three famous IBE systems, Gentry IBE system, Boyen-Waters IBE system, and Lewko IBE system, have strong but different types of anonymity.

  14. On the Utility of Anonymized Flow Traces for Anomaly Detection

    CERN Document Server

    Burkhart, Martin; May, Martin

    2008-01-01

    The sharing of network traces is an important prerequisite for the development and evaluation of efficient anomaly detection mechanisms. Unfortunately, privacy concerns and data protection laws prevent network operators from sharing these data. Anonymization is a promising solution in this context; however, it is unclear if the sanitization of data preserves the traffic characteristics or introduces artifacts that may falsify traffic analysis results. In this paper, we examine the utility of anonymized flow traces for anomaly detection. We quantitatively evaluate the impact of IP address anonymization, namely variations of permutation and truncation, on the detectability of large-scale anomalies. Specifically, we analyze three weeks of un-sampled and non-anonymized network traces from a medium-sized backbone network. We find that all anonymization techniques, except prefix-preserving permutation, degrade the utility of data for anomaly detection. We show that the degree of degradation depends to a large exten...

  15. Octopus: A Secure and Anonymous DHT Lookup

    CERN Document Server

    Wang, Qiyan

    2012-01-01

    Distributed Hash Table (DHT) lookup is a core technique in structured peer-to-peer (P2P) networks. Its decentralized nature introduces security and privacy vulnerabilities for applications built on top of them; we thus set out to design a lookup mechanism achieving both security and anonymity, heretofore an open problem. We present Octopus, a novel DHT lookup which provides strong guarantees for both security and anonymity. Octopus uses attacker identification mechanisms to discover and remove malicious nodes, severely limiting an adversary's ability to carry out active attacks, and splits lookup queries over separate anonymous paths and introduces dummy queries to achieve high levels of anonymity. We analyze the security of Octopus by developing an event-based simulator to show that the attacker discovery mechanisms can rapidly identify malicious nodes with low error rate. We calculate the anonymity of Octopus using probabilistic modeling and show that Octopus can achieve near-optimal anonymity. We evaluate ...

  16. Spatial information semantic query based on SPARQL

    Science.gov (United States)

    Xiao, Zhifeng; Huang, Lei; Zhai, Xiaofang

    2009-10-01

    How can the efficiency of spatial information inquiries be enhanced in today's fast-growing information age? We are rich in geospatial data but poor in up-to-date geospatial information and knowledge that are ready to be accessed by public users. This paper adopts an approach for querying spatial semantic by building an Web Ontology language(OWL) format ontology and introducing SPARQL Protocol and RDF Query Language(SPARQL) to search spatial semantic relations. It is important to establish spatial semantics that support for effective spatial reasoning for performing semantic query. Compared to earlier keyword-based and information retrieval techniques that rely on syntax, we use semantic approaches in our spatial queries system. Semantic approaches need to be developed by ontology, so we use OWL to describe spatial information extracted by the large-scale map of Wuhan. Spatial information expressed by ontology with formal semantics is available to machines for processing and to people for understanding. The approach is illustrated by introducing a case study for using SPARQL to query geo-spatial ontology instances of Wuhan. The paper shows that making use of SPARQL to search OWL ontology instances can ensure the result's accuracy and applicability. The result also indicates constructing a geo-spatial semantic query system has positive efforts on forming spatial query and retrieval.

  17. Survey on Anonymity in Unstructured Peer-to-Peer Systems

    Institute of Scientific and Technical Information of China (English)

    Ren-Yi Xiao

    2008-01-01

    Although anonymizing Peer-to-Peer (P2P) networks often means extra cost in terms of transfer efficiency, many systems try to mask the identities of their users for privacy consideration. By comparison and analysis of existing approaches,we investigate the properties of unstructured P2P anonymity, and summarize current attack models on these designs. Most of these approaches are path-based, which require peers to pre-construct anonymous paths before transmission, thus suffering significant overhead and poor reliability. We also discuss the open problems in this field and propose several future research directions.

  18. Search Result Diversification Based on Query Facets

    Institute of Scientific and Technical Information of China (English)

    胡莎; 窦志成; 王晓捷; 继荣

    2015-01-01

    In search engines, different users may search for different information by issuing the same query. To satisfy more users with limited search results, search result diversification re-ranks the results to cover as many user intents as possible. Most existing intent-aware diversification algorithms recognize user intents as subtopics, each of which is usually a word, a phrase, or a piece of description. In this paper, we leverage query facets to understand user intents in diversification, where each facet contains a group of words or phrases that explain an underlying intent of a query. We generate subtopics based on query facets and propose faceted diversification approaches. Experimental results on the public TREC 2009 dataset show that our faceted approaches outperform state-of-the-art diversification models.

  19. Evaluating SPARQL queries on massive RDF datasets

    KAUST Repository

    Al-Harbi, Razen

    2015-08-01

    Distributed RDF systems partition data across multiple computer nodes. Partitioning is typically based on heuristics that minimize inter-node communication and it is performed in an initial, data pre-processing phase. Therefore, the resulting partitions are static and do not adapt to changes in the query workload; as a result, existing systems are unable to consistently avoid communication for queries that are not favored by the initial data partitioning. Furthermore, for very large RDF knowledge bases, the partitioning phase becomes prohibitively expensive, leading to high startup costs. In this paper, we propose AdHash, a distributed RDF system which addresses the shortcomings of previous work. First, AdHash initially applies lightweight hash partitioning, which drastically minimizes the startup cost, while favoring the parallel processing of join patterns on subjects, without any data communication. Using a locality-aware planner, queries that cannot be processed in parallel are evaluated with minimal communication. Second, AdHash monitors the data access patterns and adapts dynamically to the query load by incrementally redistributing and replicating frequently accessed data. As a result, the communication cost for future queries is drastically reduced or even eliminated. Our experiments with synthetic and real data verify that AdHash (i) starts faster than all existing systems, (ii) processes thousands of queries before other systems become online, and (iii) gracefully adapts to the query load, being able to evaluate queries on billion-scale RDF data in sub-seconds. In this demonstration, audience can use a graphical interface of AdHash to verify its performance superiority compared to state-of-the-art distributed RDF systems.

  20. Theoretical Results on De-Anonymization via Linkage Attacks

    Directory of Open Access Journals (Sweden)

    Martin M. Merener

    2012-08-01

    Full Text Available Consider a database D with records containing history of individuals' transactions, that has been de-identified, i.e., the variables that uniquely associate records with individuals have been removed from the data. An adversary de-anonymizes D via a linkage attack if using some auxiliary information about a certain individual in the database, it can determine which record of D corresponds to such individual. One example of this is given in the article Robust De-anonymization of Large Sparse Datasets, by Narayanan and Shmatikov [19], which shows that an anonymized database containing records with ratings of different movies rented by customers of Netflix, could in fact be de-anonymized using very little auxiliary information, even with errors. Besides the heuristic de-anonymization of the Netflix database, Narayanan and Shmatikov provide interesting theoretical results about database de-anonymization that an adversary can produce under general conditions. In this article we revisit these theoretical results, and work them further. Our first contribution is to exhibit different simple cases in which the algorithm Scoreboard, meant to produce the theoretical de-anonymization in [19], fails to do so. By requiring 1-sim to be a pseudo-metric, and that the algorithm producing the de-anonymization outputs a record with minimum support among the candidates, we obtain and prove deanonymization results similar to those described in [19]. We then consider a new hypothesis, motivated by the fact (observed in heuristic de-anonymizations that when the auxiliary information contains values corresponding to rare attributes, the de-anonymization achieved is stronger. We formalize this using the notion on long tail [4], and give new theorems expressing the level of de-anonymization in terms of the parameters of the tail of the database D. The improvement in the deanonymization is reflected in the fact that when at least one value in the auxiliary information

  1. Implementing Graph Pattern Queries on a Relational Database

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, I L; Abdulla, G M; Brugger, S T; Kohn, S R

    2007-12-26

    When a graph database is implemented on top of a relational database, queries in the graph query language are translated into relational SQL queries. Graph pattern queries are an important feature of a graph query language. Translating graph pattern queries into single SQL statements results in very poor query performance. By taking into account the pattern query structure and generating multiple SQL statements, pattern query performance can be dramatically improved. The performance problems encountered with the single SQL statements generated for pattern queries reflects a problem in the SQL query planner and optimizer. Addressing this problem would allow relational databases to better support semantic graph databases. Relational database systems that provide good support for graph databases may also be more flexible platforms for data warehouses.

  2. Effects of Help, Anonymity, and Privacy on Children's Academic Expectations.

    Science.gov (United States)

    Bird, Lisa

    This study examined the effect of three aspects of the testing context--physical privacy, anonymity, and offers of help from a tester--on children's expectations. Performance of 96 11-year-old boys and girls on a pictorial recall memory task in a simulated test was evaluated. The subjects were divided into eight different groups varying on the…

  3. Result diversification based on query-specific cluster ranking

    NARCIS (Netherlands)

    He, J.; Meij, E.; de Rijke, M.

    2011-01-01

    Result diversification is a retrieval strategy for dealing with ambiguous or multi-faceted queries by providing documents that cover as many facets of the query as possible. We propose a result diversification framework based on query-specific clustering and cluster ranking, in which diversification

  4. AATCT: Anonymously Authenticated Transmission on the Cloud with Traceability

    Directory of Open Access Journals (Sweden)

    Maged Hamada Ibrahim

    2015-09-01

    Full Text Available In Cloud computing, anonymous authentication is an important service that must be available to users in the Cloud. Users have the right to remain anonymous as long as they behave honestly. However, in case a malicious behavior is detected, the system – under court order – must be able to trace the user to his clear identity. Most of the proposed authentication schemes for the Cloud are either password-based authentication schemes that are vulnerable to offline dictionary attacks, or biometric-based authentication schemes that take a long time of execution specially in case of high security requirements. In this paper, we propose an efficient and secure scheme to non-interactively authenticate the users on the Cloud to the remote servers while preserving their anonymity. In case of accusations, the registration authority is able to trace any user to his clear identity. We avoid using low entropy passwords or biometric mechanisms, instead, we employ pseudonym systems in our design. The computation complexity and storage requirements are efficient and suitable to be implemented on smart cards/devices. Our proposed scheme withstands challenging adversarial attacks such as, stolen databases attacks, databases insertion attacks, impersonation attacks, replay attacks and malicious users/servers collaboration attacks.

  5. Quantum election scheme based on anonymous quantum key distribution

    Institute of Scientific and Technical Information of China (English)

    Zhou Rui-Rui; Yang Li

    2012-01-01

    An unconditionally secure authority-certified anonymous quantum key distribution scheme using conjugate coding is presented,based on which we construct a quantum election scheme without the help of an entanglement state.We show that this election scheme ensures the completeness,soundness,privacy,eligibility,unreusability,fairness,and verifiability of a large-scale election in which the administrator and counter are semi-honest.This election scheme can work even if there exist loss and errors in quantum channels.In addition,any irregularity in this scheme is sensible.

  6. Multidimensional Data Querying on Tree-Structured Overlay

    Institute of Scientific and Technical Information of China (English)

    XU Lizhen; WANG Shiyuan

    2006-01-01

    Multidimensional data query has been gaining much interest in database research communities in recent years, yet many of the existing studies focus mainly on centralized systems.A solution to querying in Peer-to-Peer(P2P) environment was proposed to achieve both low processing cost in terms of the number of peers accessed and search messages and balanced query loads among peers.The system is based on a balanced tree structured P2P network.By partitioning the query space intelligently, the amount of query forwarding is effectively controlled, and the number of peers involved and search messages are also limited.Dynamic load balancing can be achieved during space partitioning and query resolving.Extensive experiments confirm the effectiveness and scalability of our algorithms on P2P networks.

  7. The effect of query complexity on Web searching results

    Directory of Open Access Journals (Sweden)

    B.J. Jansen

    2000-01-01

    Full Text Available This paper presents findings from a study of the effects of query structure on retrieval by Web search services. Fifteen queries were selected from the transaction log of a major Web search service in simple query form with no advanced operators (e.g., Boolean operators, phrase operators, etc. and submitted to 5 major search engines - Alta Vista, Excite, FAST Search, Infoseek, and Northern Light. The results from these queries became the baseline data. The original 15 queries were then modified using the various search operators supported by each of the 5 search engines for a total of 210 queries. Each of these 210 queries was also submitted to the applicable search service. The results obtained were then compared to the baseline results. A total of 2,768 search results were returned by the set of all queries. In general, increasing the complexity of the queries had little effect on the results with a greater than 70% overlap in results, on average. Implications for the design of Web search services and directions for future research are discussed.

  8. Path-based Queries on Trajectory Data

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Pelekis, Nikos; Theodoridis, Yannis

    2014-01-01

    a specific path by only retrieving data from the first and last edge in the path. To correctly answer strict path queries existing network-constrained trajectory indexes must retrieve data from all edges in the path. An extensive performance study of NETTRA using a very large real-world trajectory data set....... To efficiently support strict path queries, we present a novel NETwork-constrained TRAjectory index (NETTRA). This index enables very efficient retrieval of trajectories that follow a specific path, i.e., strict path queries. NETTRA uses a new path encoding scheme that can determine if a trajectory follows......, consisting of 1.7 million trajectories (941 million GPS records) and a road network with 1.3 million edges, shows a speed-up of two orders of magnitude compared to state-of-the-art trajectory indexes....

  9. On the query complexity of finding a local maximum point

    NARCIS (Netherlands)

    Rastsvelaev, A.L.; Beklemishev, L.D.

    2008-01-01

    We calculate the minimal number of queries sufficient to find a local maximum point of a functiun on a discrete interval for a model with M parallel queries, M≥1. Matching upper and lower bounds are obtained. The bounds are formulated in terms of certain Fibonacci type sequences of numbers.

  10. On the Suitability of Skyline Queries for Data Exploration

    DEFF Research Database (Denmark)

    Chester, Sean; Mortensen, Michael Lind; Assent, Ira

    2014-01-01

    The skyline operator has been studied in database research for multi-criteria decision making. Until now the focus has been on the efficiency or accuracy of single queries. In practice, however, users are increasingly confronted with unknown data collections, where precise query formulation prove...

  11. Impact of Knowledge on Election Time in Anonymous Networks

    OpenAIRE

    Dieudonné, Yoann; Pelc, Andrzej

    2016-01-01

    Leader election is one of the basic problems in distributed computing. For anonymous networks, the task of leader election is formulated as follows: every node v of the network must output a simple path, which is coded as a sequence of port numbers, such that all these paths end at a common node, the leader. In this paper, we study deterministic leader election in arbitrary anonymous networks. It is well known that leader election is impossible in some networks, regardless of the allocated am...

  12. Against anonymity.

    Science.gov (United States)

    Baker, Robert

    2014-05-01

    In 'New Threats to Academic Freedom' Francesca Minerva argues that anonymity for the authors of controversial articles is a prerequisite for academic freedom in the Internet age. This argument draws its intellectual and emotional power from the author's account of the reaction to the on-line publication of ' After-birth abortion: why should the baby live?'--an article that provoked cascades of hostile postings and e-mails. Reflecting on these events, Minerva proposes that publishers should offer the authors of controversial articles the option of publishing their articles anonymously. This response reviews the history of anonymous publication and concludes that its reintroduction in the Internet era would recreate problems similar to those that led print journals to abandon the practice: corruption of scholarly discourse by invective and hate speech, masked conflicts of interest, and a diminution of editorial accountability. It also contends that Minerva misreads the intent of the hostile e-mails provoked by 'After-birth abortion,' and that ethicists who publish controversial articles should take responsibility by dialoguing with their critics--even those whose critiques are emotionally charged and hostile.

  13. External Data Structures for Shortest Path Queries on Planar Digraphs

    DEFF Research Database (Denmark)

    Arge, Lars; Toma, Laura

    2005-01-01

    In this paper we present space-query trade-offs for external memory data structures that answer shortest path queries on planar directed graphs. For any S = Ω(N 1 + ε) and S = O(N2/B), our main result is a family of structures that use S space and answer queries in O(N2/ S B) I/Os, thus obtaining...... optimal space-query product O(N2/B). An S space structure can be constructed in O(√S · sort(N)) I/Os, where sort(N) is the number of I/Os needed to sort N elements, B is the disk block size, and N is the size of the graph....

  14. Visibility and anonymity effects on attraction and group cohesiveness

    NARCIS (Netherlands)

    Lea, Martin; Spears, Russell; Watt, Susan E.

    2007-01-01

    This study investigated attraction and group cohesiveness under different visibility and anonymity conditions for social categories that differed in their capacity to be visually cued. Using computer-mediated communication in 36 mixed gender (visually cued category) and nationality (non-visually cue

  15. Study on consistent query answering in inconsistent databases

    Institute of Scientific and Technical Information of China (English)

    XIE Dong; YANG Luming

    2007-01-01

    Consistent query answering is an approach to retrieving consistent answers over databases that might be inconsistent with respect to some given integrity constraints The approach is based on a concept of repair.This paper surveys several recent researches on obtaining consistent information from inconsistent databases,such as the underlying semantic model,a number of approaches to computing consistent query answers and the computational complexity of this problem.Furthermore,the work outlines potential research directions in this area.

  16. Largest Empty Circle Centered on a Query Line

    CERN Document Server

    Augustine, John; Roy, Sasanka

    2008-01-01

    The Largest Empty Circle problem seeks the largest circle centered within the convex hull of a set $P$ of $n$ points in $\\mathbb{R}^2$ and devoid of points from $P$. In this paper, we introduce a query version of this well-studied problem. In our query version, we are required to preprocess $P$ so that when given a query line $Q$, we can quickly compute the largest empty circle centered at some point on $Q$ and within the convex hull of $P$. We present solutions for two special cases and the general case; all our queries run in $O(\\log n)$ time. We restrict the query line to be horizontal in the first special case, which we preprocess in $O(n \\alpha(n) \\log n)$ time and space, where $\\alpha(n)$ is the slow growing inverse of the Ackermann's function. When the query line is restricted to pass through a fixed point, the second special case, our preprocessing takes $O(n \\alpha(n)^{O(\\alpha(n))} \\log n)$ time and space. We use insights from the two special cases to solve the general version of the problem with pr...

  17. Secure Nearest Neighbor Query on Crowd-Sensing Data.

    Science.gov (United States)

    Cheng, Ke; Wang, Liangmin; Zhong, Hong

    2016-09-22

    Nearest neighbor queries are fundamental in location-based services, and secure nearest neighbor queries mainly focus on how to securely and quickly retrieve the nearest neighbor in the outsourced cloud server. However, the previous big data system structure has changed because of the crowd-sensing data. On the one hand, sensing data terminals as the data owner are numerous and mistrustful, while, on the other hand, in most cases, the terminals find it difficult to finish many safety operation due to computation and storage capability constraints. In light of they Multi Owners and Multi Users (MOMU) situation in the crowd-sensing data cloud environment, this paper presents a secure nearest neighbor query scheme based on the proxy server architecture, which is constructed by protocols of secure two-party computation and secure Voronoi diagram algorithm. It not only preserves the data confidentiality and query privacy but also effectively resists the collusion between the cloud server and the data owners or users. Finally, extensive theoretical and experimental evaluations are presented to show that our proposed scheme achieves a superior balance between the security and query performance compared to other schemes.

  18. Secure Nearest Neighbor Query on Crowd-Sensing Data

    Directory of Open Access Journals (Sweden)

    Ke Cheng

    2016-09-01

    Full Text Available Nearest neighbor queries are fundamental in location-based services, and secure nearest neighbor queries mainly focus on how to securely and quickly retrieve the nearest neighbor in the outsourced cloud server. However, the previous big data system structure has changed because of the crowd-sensing data. On the one hand, sensing data terminals as the data owner are numerous and mistrustful, while, on the other hand, in most cases, the terminals find it difficult to finish many safety operation due to computation and storage capability constraints. In light of they Multi Owners and Multi Users (MOMU situation in the crowd-sensing data cloud environment, this paper presents a secure nearest neighbor query scheme based on the proxy server architecture, which is constructed by protocols of secure two-party computation and secure Voronoi diagram algorithm. It not only preserves the data confidentiality and query privacy but also effectively resists the collusion between the cloud server and the data owners or users. Finally, extensive theoretical and experimental evaluations are presented to show that our proposed scheme achieves a superior balance between the security and query performance compared to other schemes.

  19. PHENOMENAL EXPLORATION INTO IMPACT OF ANONYMITY ON LAW AND ORDER IN CYBERSPACE

    OpenAIRE

    Li, Xingan

    2015-01-01

    While information systems provide modern society with great convenience, it also poses new problems in maintaining social order. One of its negative influences is the anonymity of cyberspace, which makes identity tracing a noteworthy predicament which poses obstacles in detection and investigations. It has been found that cyber anonymity has critical impacts on criminal motivation, and the phenomena of victimization, and should be tackled on different layers including technology and law enfor...

  20. Accelerating SPARQL Queries and Analytics on RDF Data

    KAUST Repository

    Al-Harbi, Razen

    2016-11-09

    The complexity of SPARQL queries and RDF applications poses great challenges on distributed RDF management systems. SPARQL workloads are dynamic and con- sist of queries with variable complexities. Hence, systems that use static partitioning su↵er from communication overhead for workloads that generate excessive communi- cation. Concurrently, RDF applications are becoming more sophisticated, mandating analytical operations that extend beyond SPARQL queries. Being primarily designed and optimized to execute SPARQL queries, which lack procedural capabilities, exist- ing systems are not suitable for rich RDF analytics. This dissertation tackles the problem of accelerating SPARQL queries and RDF analytics on distributed shared-nothing RDF systems. First, a distributed RDF en- gine, coined AdPart, is introduced. AdPart uses lightweight hash partitioning for sharding triples using their subject values; rendering its startup overhead very low. The locality-aware query optimizer of AdPart takes full advantage of the partition- ing to (i) support the fully parallel processing of join patterns on subjects and (ii) minimize data communication for general queries by applying hash distribution of intermediate results instead of broadcasting, wherever possible. By exploiting hash- based locality, AdPart achieves better or comparable performance to systems that employ sophisticated partitioning schemes. To cope with workloads dynamism, AdPart is extended to dynamically adapt to workload changes. AdPart monitors the data access patterns and dynamically redis- tributes and replicates the instances of the most frequent patterns among workers.Consequently, the communication cost for future queries is drastically reduced or even eliminated. Experiments with synthetic and real data verify that AdPart starts faster than all existing systems and gracefully adapts to the query load. Finally, to support and accelerate rich RDF analytical tasks, a vertex-centric RDF analytics framework is

  1. Efficient Execution of Multiple Queries on Deep Memory Hierarchy

    Institute of Scientific and Technical Information of China (English)

    Yan Zhang; Zhi-Feng Chen; Yuan-Yuan Zhou

    2007-01-01

    This paper proposes a complementary novel idea, called MiniTasking to further reduce the number of cachemisses by improving the data temporal locality for multiple concurrent queries. Our idea is based on the observation that, inmany workloads such as decision support systems (DSS), there is usually significant amount of data sharing among differentconcurrent queries. MiniTasking exploits such data sharing to improve data temporal locality by scheduling query executionat three levels: query level batching, operator level grouping and mini-task level scheduling. The experimental results withvarious types of concurrent TPC-H query workloads show that, with the traditional N-ary Storage Model (NSM) layout,MiniTasking significantly reduces the L2 cache misses by up to 83%, and thereby achieves 24% reduction in execution time.With the Partition Attributes Across (PAX) layout, MiniTasking further reduces the cache misses by 65% and the executiontime by 9%. For the TPC-H throughput test workload, MiniTasking improves the end performance up to 20%.

  2. Query Translation on the Fly in Deep Web Integration

    Institute of Scientific and Technical Information of China (English)

    JIANG Fangjiao; JIA Linlin; MENG Xiaofeng

    2007-01-01

    To facilitate users to access the desired information,many researches have dedicated to the Deep Web (i.e. Web databases) integration. We focus on query translation which is an important part of the Deep Web integration. Our aim is to construct automatically a set of constraints mapping rules so that the system can translate the query from the integrated interface to the Web database interfaces based on them. We construct a concept hierarchy for the attributes of the query interfaces, especially, store the synonyms and the types (e.g. Number, Text, etc.) for every concept.At the same time, we construct the data hierarchies for some concepts if necessary. Then we present an algorithm to generate the constraint mapping rules based on these hierarchies. The approach is suitable for the scalability of such application and can be extended easily from one domain to another for its domain independent feature. The results of experiment show its effectiveness and efficiency.

  3. On the Fly Query Entity Decomposition Using Snippets

    CERN Document Server

    Brenes, David J; Garcia, Rodrigo

    2010-01-01

    One of the most important issues in Information Retrieval is inferring the intents underlying users' queries. Thus, any tool to enrich or to better contextualized queries can proof extremely valuable. Entity extraction, provided it is done fast, can be one of such tools. Such techniques usually rely on a prior training phase involving large datasets. That training is costly, specially in environments which are increasingly moving towards real time scenarios where latency to retrieve fresh informacion should be minimal. In this paper an `on-the-fly' query decomposition method is proposed. It uses snippets which are mined by means of a na\\"ive statistical algorithm. An initial evaluation of such a method is provided, in addition to a discussion on its applicability to different scenarios.

  4. Analysis of DNS cache effects on query distribution.

    Science.gov (United States)

    Wang, Zheng

    2013-01-01

    This paper studies the DNS cache effects that occur on query distribution at the CN top-level domain (TLD) server. We first filter out the malformed DNS queries to purify the log data pollution according to six categories. A model for DNS resolution, more specifically DNS caching, is presented. We demonstrate the presence and magnitude of DNS cache effects and the cache sharing effects on the request distribution through analytic model and simulation. CN TLD log data results are provided and analyzed based on the cache model. The approximate TTL distribution for domain name is inferred quantificationally.

  5. Attacking Algorithms Against Continuous Queries in LBS and Anonymity Measurement%LBS中连续查询攻击算法及匿名性度量

    Institute of Scientific and Technical Information of China (English)

    林欣; 李善平; 杨朝晖

    2009-01-01

    k-匿名机制是LBS(location based service)中保证查询隐私性的重要手段.已有文献指出,现有的k-匿名机制不能有效保护连续性查询的隐私性.提出一种连续查询发送模型,该模型融合了查询发送时间的间隔模型和连续性模型,针对此模型下的两种k-匿名算法Clique Cloaking和Non-clique Cloaking,分别提出了一种连续查询攻击算法.在此攻击算法下,匿名集的势不再适合作为查询匿名性的度量,因此提出一种基于熵理论的度量方式AD(anonymity degree).实验结果表明,对连续性很强的查询,攻击算法重识别用户身份的成功率极高;AD比匿名集的势更能反映查询的匿名性.

  6. To Speak or Not to Speak: Developing Legal Standards for Anonymous Speech on the Internet

    Directory of Open Access Journals (Sweden)

    Tomas A. Lipinski

    2002-01-01

    Full Text Available This paper explores recent developments in the regulation of Internet speech, in specific, injurious or defamatory speech and the impact such speech has on the rights of anonymous speakers to remain anonymous as opposed to having their identity revealed to plaintiffs or other third parties. The paper proceeds in four sections.  First, a brief history of the legal attempts to regulate defamatory Internet speech in the United States is presented. As discussed below this regulation has altered the traditional legal paradigm of responsibility and as a result creates potential problems for the future of anonymous speech on the Internet.  As a result plaintiffs are no longer pursuing litigation against service providers but taking their dispute directly to the anonymous speaker. Second, several cases have arisen in the United States where plaintiffs have requested that the identity of an anonymous Internet speaker be revealed.  These cases are surveyed.  Third, the cases are analyzed in order to determine the factors that courts require to be present before the identity of an anonymous speaker will be revealed.  The release is typically accomplished by the enforcement of a discovery subpoena instigated by the party seeking the identity of the anonymous speaker. The factors courts have used are as follows: jurisdiction, good faith (both internal and external, necessity (basic and sometimes absolute, and at times proprietary interest. Finally, these factors are applied in three scenarios--e-commerce, education, and employment--to guide institutions when adopting policies that regulate when the identity of an anonymous speaker--a customer, a student or an employee--would be released as part of an internal initiative, but would nonetheless be consistent with developing legal standards.

  7. Evaluating XML-Extended OLAP Queries Based on a Physical Algebra

    DEFF Research Database (Denmark)

    Yin, Xuepeng; Pedersen, Torben Bach

    2006-01-01

    . In this paper, we extend previous work on the logical federation of OLAP and XML data sources by presenting a simplified query semantics, a physical query algebra and a robust OLAP-XML query engine as well as the query evaluation techniques. Performance experiments with a prototypical implementation suggest...

  8. Efficient Path Query and Reasoning Method Based on Rare Axis

    Institute of Scientific and Technical Information of China (English)

    姜洋; 冯志勇; 王鑫马晓宁

    2015-01-01

    A new concept of rare axis based on statistical facts is proposed, and an evaluation algorithm is designed thereafter. For the nested regular expressions containing rare axes, the proposed algorithm can reduce its evaluation complexity from polynomial time to nearly linear time. The distributed technique is also employed to construct the navigation axis indexes for resource description framework (RDF) graph data. Experiment results in DrugBank and BioGRID show that this method can improve the query efficiency significantly while ensuring the accuracy and meet the query requirements on Web-scale RDF graph data.

  9. Verbal Venting in the Social Web: Effects of Anonymity and Group Norms on Aggressive Language Use in Online Comments

    Directory of Open Access Journals (Sweden)

    Leonie Rösner

    2016-08-01

    Full Text Available Scholars often blame the occurrence of aggressive behavior in online discussions on the anonymity of the Internet; however, even on today’s less anonymous platforms, such as social networking sites, users write plenty of aggressive comments, which can elicit a whole wave of negative remarks. Drawing on the social identity and deindividuation effects (SIDE model, this research conducts a laboratory experiment with a 2 (anonymity vs. no anonymity × 2 (aggressive norm vs. non-aggressive norm between-subjects design in order to disentangle the effects of anonymity, social group norms, and their interactions on aggressive language use in online comments. Results reveal that participants used more aggressive expressions in their comments when peer comments on a blog included aggressive wording (i.e., the social group norm was aggressive. Anonymity had no direct effect; however, we found a tendency that users’ conformity to an aggressive social norm of commenting is stronger in an anonymous environment.

  10. On (dynamic) range minimum queries in external memory

    DEFF Research Database (Denmark)

    Arge, L.; Fischer, Johannes; Sanders, Peter

    2013-01-01

    We study the one-dimensional range minimum query (RMQ) problem in the external memory model. We provide the first space-optimal solution to the batched static version of the problem. On an instance with N elements and Q queries, our solution takes Θ(sort(N + Q)) = Θ( N+QB log M /B N+QB ) I....../O complexity and O(N + Q) space, where M is the size of the main memory and B is the block size. This is a factor of O(log M /B N) improvement in space complexity over the previous solutions. We also show that an instance of the batched dynamic RMQ problem with N updates and Q queries can be solved in O ( N...

  11. On performing semantic queries in small devices

    Science.gov (United States)

    Costea, C.; Petrovan, A.; Neamţ, L.; Chiver, O.

    2016-08-01

    The sensors have a well-defined role in control or monitoring industrial processes; the data given by them can generate valuable information of the trend of the systems to which they belong, but to store a large volume of data and then analysis offline is not always practical. One solution is on-line analysis, preferably as close to the place where data have been generated (edge computing). An increasing amount of data generated by a growing number of devices connected to the Internet resulted in processing data sensors to the edge of the network, in a middle layer where smart entities should interoperate. Diversity of communication technologies outlined the idea of using intermediate devices such as gateways in sensor networks and for this reason the paper examines the functionality of a SPARQL endpoint in the Raspberry Pi device.

  12. Query optimization for graph analytics on linked data using SPARQL

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seokyong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Sangkeun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lim, Seung -Hwan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sukumar, Sreenivas R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Vatsavai, Ranga Raju [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-07-01

    Triplestores that support query languages such as SPARQL are emerging as the preferred and scalable solution to represent data and meta-data as massive heterogeneous graphs using Semantic Web standards. With increasing adoption, the desire to conduct graph-theoretic mining and exploratory analysis has also increased. Addressing that desire, this paper presents a solution that is the marriage of Graph Theory and the Semantic Web. We present software that can analyze Linked Data using graph operations such as counting triangles, finding eccentricity, testing connectedness, and computing PageRank directly on triple stores via the SPARQL interface. We describe the process of optimizing performance of the SPARQL-based implementation of such popular graph algorithms by reducing the space-overhead, simplifying iterative complexity and removing redundant computations by understanding query plans. Our optimized approach shows significant performance gains on triplestores hosted on stand-alone workstations as well as hardware-optimized scalable supercomputers such as the Cray XMT.

  13. Anonymous Gossiping

    CERN Document Server

    Datta, Anwitaman

    2010-01-01

    In this paper we introduce a novel gossiping primitive to support privacy preserving data analytics (PPDA). In contrast to existing computational PPDA primitives such as secure multiparty computation and data randomization based approaches, the proposed primitive `anonymous gossiping' is a communication primitive for privacy preserving personalized information aggregation complementing such traditional computational analytics. We realize this novel primitive by composing existing gossiping mechanisms for peer sampling & information aggregation and onion routing technique for establishing anonymous communication. This is more an `ideas' paper, rather than providing concrete and quantified results.

  14. Knowing me, knowing you : Anonymity effects on social identity processes within groups

    NARCIS (Netherlands)

    Lea, M; Spears, R; de Groot, D

    2001-01-01

    The Social Identity Model of Deindividuation Effects (SIDE) proposes that depersonalization of self and others is responsible for the effects of visual anonymity on group behavior The authors investigated these mediating processes by assessing the effects of group-based self-categorization and stere

  15. Anonymous Gossiping

    OpenAIRE

    Datta, Anwitaman

    2010-01-01

    In this paper we introduce a novel gossiping primitive to support privacy preserving data analytics (PPDA). In contrast to existing computational PPDA primitives such as secure multiparty computation and data randomization based approaches, the proposed primitive `anonymous gossiping' is a communication primitive for privacy preserving personalized information aggregation complementing such traditional computational analytics. We realize this novel primitive by composing existing gossiping me...

  16. Multiple Query Evaluation Based on an Enhanced Genetic Algorithm.

    Science.gov (United States)

    Tamine, Lynda; Chrisment, Claude; Boughanem, Mohand

    2003-01-01

    Explains the use of genetic algorithms to combine results from multiple query evaluations to improve relevance in information retrieval. Discusses niching techniques, relevance feedback techniques, and evolution heuristics, and compares retrieval results obtained by both genetic multiple query evaluation and classical single query evaluation…

  17. Extended K-Anonymity Model for Privacy Preserving on Micro Data

    Directory of Open Access Journals (Sweden)

    Masoud Rahimi

    2015-11-01

    Full Text Available Today, information collectors, particularly statistical organizations, are faced with two conflicting issues. On one hand, according to their natural responsibilities and the increasing demand for the collected data, they are committed to propagate the information more extensively and with higher quality and on the other hand, due to the public concern about the privacy of personal information and the legal responsibility of these organizations in protecting the private information of their users, they should guarantee that while providing all the information to the population, the privacy is reasonably preserved. This issue becomes more crucial when the datasets published by data mining methods are at risk of attribute and identity disclosure attacks. In order to overcome this problem, several approaches, called p-sensitive k-anonymity, p+-sensitive k-anonymity, and (p, α-sensitive k-anonymity, were proposed. The drawbacks of these methods include the inability to protect micro datasets against attribute disclosure and the high value of the distortion ratio. In order to eliminate these drawbacks, this paper proposes an algorithm that fully protects the propagated micro data against identity and attribute disclosure and significantly reduces the distortion ratio during the anonymity process.

  18. Evaluating XML-Extended OLAP Queries Based on a Physical Algebra

    DEFF Research Database (Denmark)

    Yin, Xuepeng; Pedersen, Torben Bach

    2004-01-01

    is desirable. In this paper, we extend previous work on the logical federation of OLAP and XML data sources by presenting a simplified query semantics,a physical query algebra and a robust OLAP-XML query engine.Performance experiments with a prototypical implementation suggest that the performance for OLAP...

  19. Wild Card Queries for Searching Resources on the Web

    CERN Document Server

    Rafiei, Davood

    2009-01-01

    We propose a domain-independent framework for searching and retrieving facts and relationships within natural language text sources. In this framework, an extraction task over a text collection is expressed as a query that combines text fragments with wild cards, and the query result is a set of facts in the form of unary, binary and general $n$-ary tuples. A significance of our querying mechanism is that, despite being both simple and declarative, it can be applied to a wide range of extraction tasks. A problem in querying natural language text though is that a user-specified query may not retrieve enough exact matches. Unlike term queries which can be relaxed by removing some of the terms (as is done in search engines), removing terms from a wild card query without ruining its meaning is more challenging. Also, any query expansion has the potential to introduce false positives. In this paper, we address the problem of query expansion, and also analyze a few ranking alternatives to score the results and to r...

  20. Design on PKI-Based Anonymous Mobile Agent Security in E-Commerce

    Institute of Scientific and Technical Information of China (English)

    MENG Xiangsong; HAN Fengwu

    2006-01-01

    The security of mobile agent directly decides its usage width in e-commerce. Especially, to protect users' private information is becoming more important now and future. So an anonymous mobile agent security mechanism with the secure authentication infrastructure based on PKI(public key infrastructure) is proposed in the paper. The multi-agent system is programmed by java language and every agent must register itself in CA(certificate authority) before working in the net and express his legit identity which is temptly produced and used only once. The CA ensures the legal of all agents' identity which take part in communicaiton or trade. And every user agent identity only is used once which makes other agents cannot decipher users' private information. The security mechanism of the multi-agent system implements anonymity, integrity, data confidentiality of mobile agent based on the MH(multiple hop) integrity protection regard to PKI limit.

  1. THE WIKILEAKS´S CASE AND ANONYMITY: EFFECTS ON THE INFORMATION FREEDOM

    Directory of Open Access Journals (Sweden)

    Marlus Heriberto Arns de Oliveira

    2015-10-01

    Full Text Available The Constitution of the Federative Republic of Brazil, enacted in 1988 during the democratization process of the country after the end of an authoritarian regime preceded by several others that show a non-democratic tradition in the Brazilian Republic, remained still remnants an authoritarian Patronizing and Paternalist state, the example of the final part of the Article 5, item IV, which claims to be the free expression of thought, but forbids anonymity, prohibition which deserves to be rethought, especially on the internet, where the navigation data of people deserve protection, as well as their rights to remain anonymous, a fact which entails the need for reflection on the scope and how best to interpret the constitutional provision cited, a debate that, in the proposed article will deal think the ideas of paternalism, authoritarianism and freedom, whose focus will be about within the Internet, social networks and the Knowledge Society.

  2. Group Anonymity

    CERN Document Server

    Chertov, Oleg; 10.1007/978-3-642-14058-7_61

    2010-01-01

    In recent years the amount of digital data in the world has risen immensely. But, the more information exists, the greater is the possibility of its unwanted disclosure. Thus, the data privacy protection has become a pressing problem of the present time. The task of individual privacy-preserving is being thoroughly studied nowadays. At the same time, the problem of statistical disclosure control for collective (or group) data is still open. In this paper we propose an effective and relatively simple (wavelet-based) way to provide group anonymity in collective data. We also provide a real-life example to illustrate the method.

  3. A reciprocal framework for spatial K-anonymity

    KAUST Repository

    Ghinita, Gabriel

    2010-05-01

    Spatial K-anonymity (SKA) exploits the concept of K-anonymity in order to protect the identity of users from location-based attacks. The main idea of SKA is to replace the exact location of a user U with an anonymizing spatial region (ASR) that contains at least K-1 other users, so that an attacker can pinpoint U with probability at most 1/K. Simply generating an ASR that includes K users does not guarantee SKA. Previous work defined the reciprocity property as a sufficient condition for SKA. However, the only existing reciprocal method, Hilbert Cloak, relies on a specialized data structure. In contrast, we propose a general framework for implementing reciprocal algorithms using any existing spatial index on the user locations. We discuss ASR construction methods with different tradeoffs on effectiveness (i.e., ASR size) and efficiency (i.e., construction cost). Then, we present case studies of applying our framework on top of two popular spatial indices (namely, R*-trees and Quad-trees). Finally, we consider the case where the attacker knows the query patterns of each user. The experimental results verify that our methods outperform Hilbert Cloak. Moreover, since we employ general-purpose spatial indices, the proposed system is not limited to anonymization, but supports conventional spatial queries as well. © 2009 Elsevier B.V. All rights reserved.

  4. On Enhancing Data Utility in K-Anonymization for Data without Hierarchical Taxonomies

    Directory of Open Access Journals (Sweden)

    Mohammad Rasool Sarrafi Aghdam

    2015-05-01

    Full Text Available K-anonymity is the model that is widely used to protect the privacy of individuals in publishing micro-data. It could be defined as clustering with constrain of minimum k tuples in each group. K-anonymity cuts down the linking confidence between sensitive information and specific individual by the ration of 1/k. However, the accuracy of the data in k-anonymous dataset decreases due to information loss. Moreover, most of the current approaches are for numerical attributes or in case of categorical attributes they require extra information such as attribute hierarchical taxonomies which often do not exist. In this paper we propose a new model, based on clustering, defining the distance between tuples including numerical and categorical attributes which does not require extra information and present the SpatialDistance (SD heuristic algorithm. Comparisons of experimental results on real datasets between SD algorithm and existing well-known algorithms show that SD performs the best and offers much higher data utility and reduces the information loss significantly.

  5. 基于 SpaceTwist 的 k-匿名增量近邻查询位置隐私保护算法%SpaceTwist-based k-anonymity incremental nearest neighbor query algorithm for location privacy protection

    Institute of Scientific and Technical Information of China (English)

    胡德敏; 郑霞

    2016-01-01

    随着移动网络的持续进步,基于位置的服务在日常生活中被广泛应用,同时位置隐私保护也成为广大用户所关注的焦点。基于 SpaceTwist 和 k-匿名算法,结合路网环境提出一种新的位置隐私保护方法。该方法摆脱第三方可信匿名器,采用客户—服务器体系结构,根据用户的位置隐私需求结合用户所在路网环境设计出用户端匿名区生成算法,并且保证 k-匿名。用户端以该匿名区请求基于位置的服务,服务器根据用户请求返回检索点并满足用户期望的 K 近邻结果。根据不同的路网环境和用户隐私需求进行大量实验,证明该算法在满足用户基于位置服务需求的同时提高了对用户位置隐私的保护。%With continued advances in mobile Internet,the location-based services are widely used in daily life,more and more users focus on the location privacy protection.This paper proposed a new location privacy protection scheme which com-bined with the network environment and based on the SpaceTwist algorithm and k-anonymity algorithm.The approach prefered to client-server structure rather than trusted third party server and designed the anonymity algorithm in user end according to user’s request of location privacy and the network environment,which ensured the k-anonymity.The mobile end users could request the location-based services in its anonymous area,and the server would return the access points to meet user’s expect K-value.Finally,it evaluated the proposed approach by a large number of experiments according to different network environ-ment together with different users privacy needs.The results demonstrate this algorithm meets the user’s requests of location-based services and at the same time it improves the protection of user’s location privacy.

  6. A Deep Web Query Interfaces Classification Method Based on RBF Neural Network

    Institute of Scientific and Technical Information of China (English)

    YUAN Fang; ZHAO Yao; ZHOU Xu

    2007-01-01

    This paper proposes a new approach for classification for query interfaces of Deep Web, which extracts features from the form's text data on the query interfaces, assisted with the synonym library, and uses radial basic function neural network (RBFNN) algorithm to classify the query interfaces. The applied RBFNN is a kind of effective feed-forward artificial neural network, which has a simple networking structure but features with strength of excellent nonlinear approximation, fast convergence and global convergence. A TEL_8 query interfaces' data set from UIUC on-line database is used in our experiments, which consists of 477 query interfaces in 8 typical domains. Experimental results proved that the proposed approach can efficiently classify the query interfaces with an accuracy of 95.67%.

  7. Towards Hybrid Online On-Demand Querying of Realtime Data with Stateful Complex Event Processing

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Qunzhi; Simmhan, Yogesh; Prasanna, Viktor K.

    2013-10-09

    Emerging Big Data applications in areas like e-commerce and energy industry require both online and on-demand queries to be performed over vast and fast data arriving as streams. These present novel challenges to Big Data management systems. Complex Event Processing (CEP) is recognized as a high performance online query scheme which in particular deals with the velocity aspect of the 3-V’s of Big Data. However, traditional CEP systems do not consider data variety and lack the capability to embed ad hoc queries over the volume of data streams. In this paper, we propose H2O, a stateful complex event processing framework, to support hybrid online and on-demand queries over realtime data. We propose a semantically enriched event and query model to address data variety. A formal query algebra is developed to precisely capture the stateful and containment semantics of online and on-demand queries. We describe techniques to achieve the interactive query processing over realtime data featured by efficient online querying, dynamic stream data persistence and on-demand access. The system architecture is presented and the current implementation status reported.

  8. On the Querying for Places on the Mobile Web

    DEFF Research Database (Denmark)

    Jensen, Christian S.

    2011-01-01

    The web is undergoing a fundamental transformation: it is becoming mobile and is acquiring a spatial dimension. Thus, the web is increasingly being used from mobile devices, notably smartphones, that can be geo-positioned using GPS or technologies that exploit wireless communication networks....... In addition, web content is being geo-tagged. This transformation calls for new, spatio-textual query functionality. The research community is hard at work enabling efficient support for such functionality....

  9. Online Query Scheduling on Source Permutation for Big Data Integration

    OpenAIRE

    Yuan, Zimu; Guo, Shusheng

    2015-01-01

    Big data integration could involve a large number of sources with unpredictable redundancy information between them. The approach of building a central warehousing to integrate big data from all sources then becomes infeasible because of so large number of sources and continuous updates happening. A practical approach is to apply online query scheduling that inquires data from sources at runtime upon receiving a query. In this paper, we address the Time-Cost Minimization Problem for online qu...

  10. Anonymous Quantum Communication

    Science.gov (United States)

    Brassard, Gilles; Broadbent, Anne; Fitzsimons, Joseph; Gambs, Sébastien; Tapp, Alain

    We introduce the first protocol for the anonymous transmission of a quantum state that is information-theoretically secure against an active adversary, without any assumption on the number of corrupt participants. The anonymity of the sender and receiver is perfectly preserved, and the privacy of the quantum state is protected except with exponentially small probability. Even though a single corrupt participant can cause the protocol to abort, the quantum state can only be destroyed with exponentially small probability: if the protocol succeeds, the state is transferred to the receiver and otherwise it remains in the hands of the sender (provided the receiver is honest).

  11. An arbitrated quantum signature scheme based on entanglement swapping with signer anonymity

    Science.gov (United States)

    Li, Wei; Fan, Ming-Yu; Wang, Guang-Wei

    2012-12-01

    In this paper an arbitrated quantum signature scheme based on entanglement swapping is proposed. In this scheme a message to be signed is coded with unitary operators. Combining quantum measurement with quantum encryption, the signer can generate the signature for a given message. Combining the entangled states generated by the TTP's Bell measurement with the signature information, the verifier can verify the authentication of a signature through a single quantum state measurement. Compared with previous schemes, our scheme is more efficient and less complex, furthermore, our scheme can ensure the anonymity of the signer.

  12. Robust Runtime Optimization and Skew-Resistant Execution of Analytical SPARQL Queries on Pig

    NARCIS (Netherlands)

    Kotoulas, S; Urbani, J.; Boncz, P.A.; Mika, P.

    2012-01-01

    We describe a system that incrementally translates SPARQL queries to Pig Latin and executes them on a Hadoop cluster. This system is designed to work eciently on complex queries with many self-joins over huge datasets, avoiding job failures even in the case of joins with unexpected high-value skew.

  13. Optimization Query Process of Mediators Interrogation Based On Combinatorial Storage

    Directory of Open Access Journals (Sweden)

    L. Cherrat

    2013-05-01

    Full Text Available In the distributed environment where a query involves several heterogeneous sources, communication costs must be taken into consideration. In this paper we describe a query optimization approach using dynamic programming technique for set integrated heterogeneous sources. The objective of the optimization is to minimize the total processing time including load processing, request rewriting and communication costs, to facilitate communication inter-sites and to optimize the time of data transfer from site to others. Moreover, the ability to store data in more than one centre site provides more flexibility in terms of Security/Safety and overload of the network. In contrast to optimizers which are considered a restricted search space, the proposed optimizer searches the closed subsets of sources and independency relationship which may be deep laniary or hierarchical trees. Especially the execution of the queries can start traversal anywhere over any subset and not only from a specific source.

  14. 基于匿名化流表的网络数据分组实时匿名方法%Online trace anonymization based on anonymous flow table

    Institute of Scientific and Technical Information of China (English)

    韩春静; 葛敬国; 谢高岗; 李亮雄; 李佟; 刘韵洁

    2016-01-01

    A real-time network packet anonymous method named Fad-Pan (online trace anonymization based on the anonymous flow table) was proposed. The Fad-Pan algorithm was studied and an online trace anonymization prototype system based on DPDK library was developed. The experimental results prove that the Fad-Pan algorithm is faster more than 20 times than the existing method, and a single server can handle the real-time IPv4 and IPv6 traffic of the 10 Gbit/s link used by the Fad-Pan.%提出了基于匿名化流表的网络数据分组实时匿名方法(Fad-Pan,online trace anonymization based on the anonymous flow table),主要研究Fad-Pan算法以及研发基于DPDK的Fad-Pan原型系统。实验结果表明,Fad-Pan算法比已有的方法在匿名化速度上提高了20倍以上,单个普通服务器可以实时处理万兆链路的IPv4和IPv6流量数据。

  15. Efficient Queries of Stand-off Annotations for Natural Language Processing on Electronic Medical Records

    Science.gov (United States)

    Luo, Yuan; Szolovits, Peter

    2016-01-01

    In natural language processing, stand-off annotation uses the starting and ending positions of an annotation to anchor it to the text and stores the annotation content separately from the text. We address the fundamental problem of efficiently storing stand-off annotations when applying natural language processing on narrative clinical notes in electronic medical records (EMRs) and efficiently retrieving such annotations that satisfy position constraints. Efficient storage and retrieval of stand-off annotations can facilitate tasks such as mapping unstructured text to electronic medical record ontologies. We first formulate this problem into the interval query problem, for which optimal query/update time is in general logarithm. We next perform a tight time complexity analysis on the basic interval tree query algorithm and show its nonoptimality when being applied to a collection of 13 query types from Allen’s interval algebra. We then study two closely related state-of-the-art interval query algorithms, proposed query reformulations, and augmentations to the second algorithm. Our proposed algorithm achieves logarithmic time stabbing-max query time complexity and solves the stabbing-interval query tasks on all of Allen’s relations in logarithmic time, attaining the theoretic lower bound. Updating time is kept logarithmic and the space requirement is kept linear at the same time. We also discuss interval management in external memory models and higher dimensions. PMID:27478379

  16. Efficient Queries of Stand-off Annotations for Natural Language Processing on Electronic Medical Records.

    Science.gov (United States)

    Luo, Yuan; Szolovits, Peter

    2016-01-01

    In natural language processing, stand-off annotation uses the starting and ending positions of an annotation to anchor it to the text and stores the annotation content separately from the text. We address the fundamental problem of efficiently storing stand-off annotations when applying natural language processing on narrative clinical notes in electronic medical records (EMRs) and efficiently retrieving such annotations that satisfy position constraints. Efficient storage and retrieval of stand-off annotations can facilitate tasks such as mapping unstructured text to electronic medical record ontologies. We first formulate this problem into the interval query problem, for which optimal query/update time is in general logarithm. We next perform a tight time complexity analysis on the basic interval tree query algorithm and show its nonoptimality when being applied to a collection of 13 query types from Allen's interval algebra. We then study two closely related state-of-the-art interval query algorithms, proposed query reformulations, and augmentations to the second algorithm. Our proposed algorithm achieves logarithmic time stabbing-max query time complexity and solves the stabbing-interval query tasks on all of Allen's relations in logarithmic time, attaining the theoretic lower bound. Updating time is kept logarithmic and the space requirement is kept linear at the same time. We also discuss interval management in external memory models and higher dimensions.

  17. Mobile Database System: Role of Mobility on the Query Processing

    CERN Document Server

    Sharma, Samidha Dwivedi

    2010-01-01

    The rapidly expanding technology of mobile communication will give mobile users capability of accessing information from anywhere and any time. The wireless technology has made it possible to achieve continuous connectivity in mobile environment. When the query is specified as continuous, the requesting mobile user can obtain continuously changing result. In order to provide accurate and timely outcome to requesting mobile user, the locations of moving object has to be closely monitored. The objective of paper is to discuss the problem related to the role of personal and terminal mobility and query processing in the mobile environment.

  18. Extracting Result Schema Based on Query Instances in the Deep Web

    Institute of Scientific and Technical Information of China (English)

    NIE Tiezheng; YU Ge; SHEN Derong; KOU Yue; LIU Wei

    2007-01-01

    Deep Web sources contain a large of high-quality and query-related structured date. One of the challenges in the Deep Web is extracting result schemas of Deep Web sources. To address this challenge, this paper describes a novel approach that extracts both result data and the result schema of a Web database.The approach first models the query interface of a Deep Web source and fills in it with a specifically query instance. Then the result pages of the Deep Web sources are formatted in the tree structure to retrieve subtrees that contain elements of the query instance. Next, result schema of the Deep Web source is extracted by matching the subtree' nodes with the query instance, in which,a two-phase schema extraction method is adopted for obtaining more accurate result schema. Finally, experiments on real Deep Web sources show the utility of our approach, which provides a high precision and recall.

  19. Relaxing rdf queries based on user and domain preferences

    DEFF Research Database (Denmark)

    Dolog, Peter; Stueckenschmidt, Heiner; Wache, Holger

    2009-01-01

    knowledge and user preferences. We describe a framework for information access that combines query refinement and relaxation in order to provide robust, personalized access to heterogeneous resource description framework data as well as an implementation in terms of rewriting rules and explain its...

  20. Most Recent Match Queries in On-Line Suffix Trees

    DEFF Research Database (Denmark)

    Larsson, N. Jesper

    2014-01-01

    A suffix tree is able to efficiently locate a pattern in an indexed string, but not in general the most recent copy of the pattern in an online stream, which is desirable in some applications. We study the most general version of the problem of locating a most recent match: supporting queries...

  1. Unraveling an Old Cloak: k-anonymity for Location Privacy

    OpenAIRE

    Shokri, Reza; Troncoso, Carmela; Diaz, Claudia; Freudiger, Julien; Hubaux, Jean-Pierre

    2010-01-01

    There is a rich collection of literature that aims at protecting the privacy of users querying location-based services. One of the most popular location privacy techniques consists in cloaking users' locations such that k users appear as potential senders of a query, thus achieving k-anonymity. This paper analyzes the effectiveness of k-anonymity approaches for protecting location privacy in the presence of various types of adversaries. The unraveling of the scheme unfolds the inconsistency b...

  2. Anonymity in voting revisited

    NARCIS (Netherlands)

    Jonker, Hugo; Pieters, Wolter; Chaum, David; Jakobsson, Markus; Rivest, Ronald L.; Ryan, Peter Y.A.; Benaloh, Josh; Kutylowski, Miroslaw; Adida, Ben

    2010-01-01

    According to international law, anonymity of the voter is a fundamental precondition for democratic elections. In electronic voting, several aspects of voter anonymity have been identified. In this paper, we re-examine anonymity with respect to voting, and generalise existing notions of anonymity in

  3. Effects of anonymous peer observation on adolescents' preference for immediate rewards.

    Science.gov (United States)

    Weigard, Alexander; Chein, Jason; Albert, Dustin; Smith, Ashley; Steinberg, Laurence

    2014-01-01

    Research suggests that the presence of peers influences adolescent risk-taking by increasing the perceived reward value of risky decisions. While prior work has involved observation of participants by their friends, the current study examined whether observation by an anonymous peer could elicit similarly increased reward sensitivity. Late adolescent participants completed a delay discounting task either alone or under the belief that performance was being observed from a neighboring room by an unknown viewer of the same gender and age. Even in this limited social context, participants demonstrated a significantly increased preference for smaller, immediate rewards when they believed that they were being watched. This outcome challenges several intuitive accounts of the peer effect on adolescent risk-taking, and indicates that the peer influence on reward sensitivity during late adolescence is not dependent on familiarity with the observer. The findings have both theoretical and practical implications for our understanding of social influences on adolescents' risky behavior.

  4. QUERY TRANSLATION USING CONCEPTS SIMILARITY BASED ON QURAN ONTOLOGY FOR CROSS-LANGUAGE INFORMATION RETRIEVAL

    Directory of Open Access Journals (Sweden)

    Zulaini Yahya

    2013-01-01

    Full Text Available In Cross-Language Information Retrieval (CLIR process, the translation effects have a direct impact on the accuracy of follow-up retrieval results. In dictionary-based approach, we are dealing with the words that have more than one meaning which can decrease the retrieval performance if the query translation return an incorrect translations. These issues need to be overcome using efficient technique. In this study we proposed a Cross-Language Information Retrieval (CLIR method based on domain ontology using Quran concepts for disambiguating translation of the query and to improve the dictionary-based query translation. For experimentation, we use Quran ontology written in English and Malay languages as a bilingual parallel-corpora and Quran concepts as a resource for cross-language query translation along with dictionary-based translation. For evaluation, we measure the performance of three IR systems. IR1 is natural language query IR, IR2 is natural language query CLIR based on dictionary (as a Baseline and IR3 is the retrieval of this research proposed method using Mean Average Precision (MAP and average precision at 11 points of recall. The experimental result shows that our proposed method brings significant improvement in retrieval accuracy for English document collections, but deficient for Malay document collections. The proposed CLIR method can obtain query expansion effect and improve retrieval performance in certain language.

  5. Collective spatial keyword querying

    DEFF Research Database (Denmark)

    Cao, Xin; Cong, Gao; Jensen, Christian S.;

    2011-01-01

    With the proliferation of geo-positioning and geo-tagging, spatial web objects that possess both a geographical location and a textual description are gaining in prevalence, and spatial keyword queries that exploit both location and textual description are gaining in prominence. However......, the queries studied so far generally focus on finding individual objects that each satisfy a query rather than finding groups of objects where the objects in a group collectively satisfy a query. We define the problem of retrieving a group of spatial web objects such that the group's keywords cover the query...

  6. ANONYMIZATION BASED ON NESTED CLUSTERING FOR PRIVACY PRESERVATION IN DATA MINING

    Directory of Open Access Journals (Sweden)

    V.Rajalakshmi

    2013-07-01

    Full Text Available Privacy Preservation in data mining protects the data from revealing unauthorized extraction of information. Data Anonymization techniques implement this by modifying the data, so that the original values cannot be acquired easily. Perturbation techniques are variedly used which will greatly affect the quality of data,since there is a trade-off between privacy preservation and information loss which will subsequently affect the result of data mining. The method that is proposed in this paper is based on nested clustering of data andperturbation on each cluster. The size of clusters is kept optimal to reduce the information loss. The paper explains the methodology, implementation and results of nested clustering. Various metrics are also provided to explicate that this method overcomes the disadvantages of other perturbation methods.

  7. A Comparison of the Effects of K-Anonymity on Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Hayden Wimmer

    2014-11-01

    Full Text Available While research has been conducted in machine learning algorithms and in privacy preserving in data mining (PPDM, a gap in the literature exists which combines the aforementioned areas to determine how PPDM affects common machine learning algorithms. The aim of this research is to narrow this literature gap by investigating how a common PPDM algorithm, K-Anonymity, affects common machine learning and data mining algorithms, namely neural networks, logistic regression, decision trees, and Bayesian classifiers. This applied research reveals practical implications for applying PPDM to data mining and machine learning and serves as a critical first step learning how to apply PPDM to machine learning algorithms and the effects of PPDM on machine learning. Results indicate that certain machine learning algorithms are more suited for use with PPDM techniques.

  8. Supporting temporal queries on clinical relational databases: the S-WATCH-QL language.

    Science.gov (United States)

    Combi, C; Missora, L; Pinciroli, F

    1996-01-01

    Due to the ubiquitous and special nature of time, specially in clinical datábases there's the need of particular temporal data and operators. In this paper we describe S-WATCH-QL (Structured Watch Query Language), a temporal extension of SQL, the widespread query language based on the relational model. S-WATCH-QL extends the well-known SQL by the addition of: a) temporal data types that allow the storage of information with different levels of granularity; b) historical relations that can store together both instantaneous valid times and intervals; c) some temporal clauses, functions and predicates allowing to define complex temporal queries.

  9. Supporting K nearest neighbors query on high-dimensional data in P2P systems

    Institute of Scientific and Technical Information of China (English)

    Mei LI; Wang-Chien LEE; Anand SIVASUBRAMANIAM; Jizhong ZHAO

    2008-01-01

    Peer-to-peer systems have been widely used for sharing and exchanging data and resources among numerous computer nodes.Various data objects identifiable with high dimensional feature vectors,such as text,images,genome sequences,are starting to leverage P2P technology.Most of the existing works have been focusing on queries on data objects with one or few attributes and thus are not applicable on high dimensional data objects.In this study,we investigate K nearest neighbors query (KNN)on high dimensional data objects in P2P systems.Efficient query algorithm and solutions that address various technical challenges raised by high dimensionality,such as search space resolution and incremental search space refinement,are proposed.An extensive simulation using both synthetic and real data sets demonstrates that our proposal efficiently supports KNN query on high dimensional data in P2P systems.

  10. Anonymous Boh avatud kunsti maastikul / Raivo Kelomees

    Index Scriptorium Estoniae

    Kelomees, Raivo, 1960-

    2010-01-01

    Anonymous Bohi näitus Tartu Kunstimajas, avatud 30. juulini 2010. Anonymous Boh on koos Non Grataga läbi viinud performance´id Euroopas, Ameerikas ja Aasias. Anonymous Bohi vastused oma näituse ja loominguga seotud küsimustele

  11. Anonymous Credential Schemes with Encrypted Attributes

    NARCIS (Netherlands)

    Guajardo Merchan, J.; Mennink, B.; Schoenmakers, B.

    2011-01-01

    In anonymous credential schemes, users obtain credentials on certain attributes from an issuer, and later show these credentials to a relying party anonymously and without fully disclosing the attributes. In this paper, we introduce the notion of (anonymous) credential schemes with encrypted attribu

  12. Resource Planning for SPARQL Query Execution on Data Sharing Platforms

    DEFF Research Database (Denmark)

    Hagedorn, Stefan; Hose, Katja; Sattler, Kai-Uwe

    2014-01-01

    To increase performance, data sharing platforms often make use of clusters of nodes where certain tasks can be executed in parallel. Resource planning and especially deciding how many processors should be chosen to exploit parallel processing is complex in such a setup as increasing the number...... the optimum number of processors that should be used to evaluate a particular SPARQL query over a particular configuration and RDF dataset. Our first experiments show the general applicability of our approach but also how shortcomings in the used statistics limit the potential of optimization....

  13. Anonymous Authentication for Smartcards

    Directory of Open Access Journals (Sweden)

    J. Hajny

    2010-06-01

    Full Text Available The paper presents an innovative solution in the field of RFID (Radio-Frequency IDentification smartcard authentication. Currently the smartcards are used for many purposes - e.g. employee identification, library cards, student cards or even identity credentials. Personal identity is revealed to untrustworthy entities every time we use these cards. Such information could later be used without our knowledge and for harmful reasons like shopping pattern scanning or even movement tracking. We present a communication scheme for keeping one’s identity private in this paper. Although our system provides anonymity, it does not allow users to abuse this feature. The system is based on strong cryptographic primitives that provide features never available before. Besides theoretical design of the anonymous authentication scheme and its analysis we also provide implementation results.

  14. An overview of anonymity and anonymous communication

    NARCIS (Netherlands)

    Koot, M.

    2008-01-01

    Privacy is becoming an increasingly important aspect in distributed systems. In anonymous communication, privacy is provided to communicating parties by hiding their identities from each other and/or from others. This paper discusses the problem of anonymous communication and clarifies the notion of

  15. QUERY EXPANSION OF LOCAL CO-OCCURRENCE BASED ON QUERY LOG%基于查询日志的局部共现查询扩展

    Institute of Scientific and Technical Information of China (English)

    丁晓渊; 顾春华; 王明永

    2013-01-01

    Query extension is a key issue in information retrieval , the efficiency of query expansion determines the retrieval performance of retrieval system .Most of the query expansions are based on global analysis or local analysis , though the accuracies have been greatly improved, but they all have their own limitations .Query log is the record of long term query behaviour by a great quantity of users .In this paper, we propose a query log-based expansion method of local co-occurrence, through which we can build an associated diagram of user initial query and user document through mining the link between user ’ s initial query and user logs , and construct the related word list using local co-occurrence method , thus to realise the query expansion .The test on 50, 000 corpora shows that the precision has about 44%improvement after using this method .%查询扩展是信息检索中的一个关键问题,查询扩展的有效性决定了检索系统的检索性能。大多数的查询扩展基于全局分析或者局部分析法,虽然准确率有了很大的提高,但是都有各自的局限性。查询日志是大量用户长期查询行为的记录。提出了基于查询日志的局部共现查询扩展方法,该方法通过挖掘用户初始查询与查询日志之间的联系,构建一个用户初始查询与用户文档的关联关系图,并且使用局部共现的方法构建相关词表,从而实现查询扩展。在50000篇语料上的测试表明,该方法相对于未扩展时准确率提高了44%以上。

  16. Visual graph query formulation and exploration: a new perspective on information retrieval at the edge

    Science.gov (United States)

    Kase, Sue E.; Vanni, Michelle; Knight, Joanne A.; Su, Yu; Yan, Xifeng

    2016-05-01

    Within operational environments decisions must be made quickly based on the information available. Identifying an appropriate knowledge base and accurately formulating a search query are critical tasks for decision-making effectiveness in dynamic situations. The spreading of graph data management tools to access large graph databases is a rapidly emerging research area of potential benefit to the intelligence community. A graph representation provides a natural way of modeling data in a wide variety of domains. Graph structures use nodes, edges, and properties to represent and store data. This research investigates the advantages of information search by graph query initiated by the analyst and interactively refined within the contextual dimensions of the answer space toward a solution. The paper introduces SLQ, a user-friendly graph querying system enabling the visual formulation of schemaless and structureless graph queries. SLQ is demonstrated with an intelligence analyst information search scenario focused on identifying individuals responsible for manufacturing a mosquito-hosted deadly virus. The scenario highlights the interactive construction of graph queries without prior training in complex query languages or graph databases, intuitive navigation through the problem space, and visualization of results in graphical format.

  17. Superfund Query

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Superfund Query allows users to retrieve data from the Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) database.

  18. Probabilistic Anonymity and Admissible Schedulers

    CERN Document Server

    Garcia, Flavio D; Sokolova, Ana

    2007-01-01

    When studying safety properties of (formal) protocol models, it is customary to view the scheduler as an adversary: an entity trying to falsify the safety property. We show that in the context of security protocols, and in particular of anonymizing protocols, this gives the adversary too much power; for instance, the contents of encrypted messages and internal computations by the parties should be considered invisible to the adversary. We restrict the class of schedulers to a class of admissible schedulers which better model adversarial behaviour. These admissible schedulers base their decision solely on the past behaviour of the system that is visible to the adversary. Using this, we propose a definition of anonymity: for all admissible schedulers the identity of the users and the observations of the adversary are independent stochastic variables. We also develop a proof technique for typical cases that can be used to proof anonymity: a system is anonymous if it is possible to `exchange' the behaviour of two...

  19. Comment on "flexible protocol for quantum private query based on B92 protocol"

    Science.gov (United States)

    Chang, Yan; Zhang, Shi-Bin; Zhu, Jing-Min

    2017-03-01

    In a recent paper (Quantum Inf Process 13:805-813, 2014), a flexible quantum private query (QPQ) protocol based on B92 protocol is presented. Here we point out that the B92-based QPQ protocol is insecure in database security when the channel has loss, that is, the user (Alice) will know more records in Bob's database compared with she has bought.

  20. Anonymity in Voting Revisited

    Science.gov (United States)

    Jonker, Hugo; Pieters, Wolter

    According to international law, anonymity of the voter is a fundamental precondition for democratic elections. In electronic voting, several aspects of voter anonymity have been identified. In this paper, we re-examine anonymity with respect to voting, and generalise existing notions of anonymity in e-voting. First, we identify and categorise the types of attack that can be a threat to anonymity of the voter, including different types of vote buying and coercion. This analysis leads to a categorisation of anonymity in voting in terms of a) the strength of the anonymity achieved and b) the extent of interaction between voter and attacker. Some of the combinations, including weak and strong receipt-freeness, are formalised in epistemic logic.

  1. Effective Filtering of Query Results on Updated User Behavioral Profiles in Web Mining.

    Science.gov (United States)

    Sadesh, S; Suganthe, R C

    2015-01-01

    Web with tremendous volume of information retrieves result for user related queries. With the rapid growth of web page recommendation, results retrieved based on data mining techniques did not offer higher performance filtering rate because relationships between user profile and queries were not analyzed in an extensive manner. At the same time, existing user profile based prediction in web data mining is not exhaustive in producing personalized result rate. To improve the query result rate on dynamics of user behavior over time, Hamilton Filtered Regime Switching User Query Probability (HFRS-UQP) framework is proposed. HFRS-UQP framework is split into two processes, where filtering and switching are carried out. The data mining based filtering in our research work uses the Hamilton Filtering framework to filter user result based on personalized information on automatic updated profiles through search engine. Maximized result is fetched, that is, filtered out with respect to user behavior profiles. The switching performs accurate filtering updated profiles using regime switching. The updating in profile change (i.e., switches) regime in HFRS-UQP framework identifies the second- and higher-order association of query result on the updated profiles. Experiment is conducted on factors such as personalized information search retrieval rate, filtering efficiency, and precision ratio.

  2. Comparing NetCDF and SciDB on managing and querying 5D hydrologic dataset

    Science.gov (United States)

    Liu, Haicheng; Xiao, Xiao

    2016-11-01

    Efficiently extracting information from high dimensional hydro-meteorological modelling datasets requires smart solutions. Traditional methods are mostly based on files, which can be edited and accessed handily. But they have problems of efficiency due to contiguous storage structure. Others propose databases as an alternative for advantages such as native functionalities for manipulating multidimensional (MD) arrays, smart caching strategy and scalability. In this research, NetCDF file based solutions and the multidimensional array database management system (DBMS) SciDB applying chunked storage structure are benchmarked to determine the best solution for storing and querying 5D large hydrologic modelling dataset. The effect of data storage configurations including chunk size, dimension order and compression on query performance is explored. Results indicate that dimension order to organize storage of 5D data has significant influence on query performance if chunk size is very large. But the effect becomes insignificant when chunk size is properly set. Compression of SciDB mostly has negative influence on query performance. Caching is an advantage but may be influenced by execution of different query processes. On the whole, NetCDF solution without compression is in general more efficient than the SciDB DBMS.

  3. Fully Dynamic Data Structure for Top-k Queries on Uncertain Data

    CERN Document Server

    Patil, Manish; Thankachan, Sharma V

    2010-01-01

    Top-$k$ queries allow end-users to focus on the most important (top-$k$) answers amongst those which satisfy the query. In traditional databases, a user defined score function assigns a score value to each tuple and a top-$k$ query returns $k$ tuples with the highest score. In uncertain database, top-$k$ answer depends not only on the scores but also on the membership probabilities of tuples. Several top-$k$ definitions covering different aspects of score-probability interplay have been proposed in recent past~\\cite{R10,R4,R2,R8}. Most of the existing work in this research field is focused on developing efficient algorithms for answering top-$k$ queries on static uncertain data. Any change (insertion, deletion of a tuple or change in membership probability, score of a tuple) in underlying data forces re-computation of query answers. Such re-computations are not practical considering the dynamic nature of data in many applications. In this paper, we propose a fully dynamic data structure that uses ranking func...

  4. Social influence in computer-mediated communication : The effects of anonymity on group behavior

    NARCIS (Netherlands)

    Postmes, T; Spears, R; Sakhel, K; de Groot, D

    2001-01-01

    Two studies examined hypotheses derived from a Social Identity model of Deindividuation Effects (SIDE) as applied to social influence in computer-mediated communication (CMC) in groups. This model predicts that anonymity can increase social influence if a common group identity is salient. In a first

  5. KoralQuery -- A General Corpus Query Protocol

    DEFF Research Database (Denmark)

    Bingel, Joachim; Diewald, Nils

    2015-01-01

    The task-oriented and format-driven development of corpus query systems has led to the creation of numerous corpus query languages (QLs) that vary strongly in expressiveness and syntax. This is a severe impediment for the interoperability of corpus analysis systems, which lack a common protocol....... In this paper, we present KoralQuery, a JSON-LD based general corpus query protocol, aiming to be independent of particular QLs, tasks and corpus formats. In addition to describing the system of types and operations that KoralQuery is built on, we exemplify the representation of corpus queries in the serialized...

  6. Query recommendation for children

    NARCIS (Netherlands)

    Duarte Torres, Sergio; Hiemstra, Djoerd; Weber, Ingmar; Serdyukov, Pavel

    2012-01-01

    One of the biggest problems that children experience while searching the web occurs during the query formulation process. Children have been found to struggle formulating queries based on keywords given their limited vocabulary and their difficulty to choose the right keywords. In this work we propo

  7. PiCO QL: A software library for runtime interactive queries on program data

    Directory of Open Access Journals (Sweden)

    Marios Fragkoulis

    2016-01-01

    Full Text Available Pico ql is an open source c/c++ software whose scientific scope is real-time interactive analysis of in-memory data through sql queries. It exposes a relational view of a system’s or application’s data structures, which is queryable through sql. While the application or system is executing, users can input queries through a web-based interface or issue web service requests. Queries execute on the live data structures through the respective relational views. pico ql makes a good candidate for ad-hoc data analysis in applications and for diagnostics in systems settings. Applications of pico ql include the Linux kernel, the Valgrind instrumentation framework, a gis application, a virtual real-time observatory of stellar objects, and a source code analyser.

  8. PiCO QL: A software library for runtime interactive queries on program data

    Science.gov (United States)

    Fragkoulis, Marios; Spinellis, Diomidis; Louridas, Panos

    PiCO QL is an open source C/C++ software whose scientific scope is real-time interactive analysis of in-memory data through SQL queries. It exposes a relational view of a system's or application's data structures, which is queryable through SQL. While the application or system is executing, users can input queries through a web-based interface or issue web service requests. Queries execute on the live data structures through the respective relational views. PiCO QL makes a good candidate for ad-hoc data analysis in applications and for diagnostics in systems settings. Applications of PiCO QL include the Linux kernel, the Valgrind instrumentation framework, a GIS application, a virtual real-time observatory of stellar objects, and a source code analyser.

  9. PRESY: A Context Based Query Reformulation Tool for Information Retrieval on the Web

    Directory of Open Access Journals (Sweden)

    Abdelkrim Bouramoul

    2010-01-01

    Full Text Available Problem statement: The huge number of information on the web as well as the growth of new inexperienced users creates new challenges for information retrieval. It has become increasingly difficult for these users to find relevant documents that satisfy their individual needs. Certainly the current search engines (such as Google, Bing and Yahoo offer an efficient way to browse the web content. However, the result quality is highly based on uses queries which need to be more precise to find relevant documents. This task still complicated for the majority of inept users who cannot express their needs with significant words in the query. For that reason, we believe that a reformulation of the initial user's query can be a good alternative to improve the information selectivity. This study proposed a novel approach and presents a prototype system called Profile-based Reformulation System (PRESY for information retrieval on the web. Approach: It used an incremental approach to categorize users by constructing a contextual base. The latter was composed of two types of context (static and dynamic obtained using the users' profiles. The architecture proposed was implemented using .Net environment to perform queries reformulating tests. Results: The experiments gave at the end of this article show that the precision of the returned content is effectively improved. The tests were performed with the most popular searching engine (i.e., Google, Bind and Yahoo selected in particular for their high selectivity. Among the given results, we found that query reformulation improve the first three results by 10.7 and 11.7% of the next seven returned elements. So as we could see the reformulation of users' initial queries improves the pertinence of returned content. Conclusion/Recommendations: Therefore, we believed that the exploitation of contextual data based on users' profiles could be a very good way to reformulate user query. This complementary mechanism would

  10. Google BigQuery analytics

    CERN Document Server

    Tigani, Jordan

    2014-01-01

    How to effectively use BigQuery, avoid common mistakes, and execute sophisticated queries against large datasets Google BigQuery Analytics is the perfect guide for business and data analysts who want the latest tips on running complex queries and writing code to communicate with the BigQuery API. The book uses real-world examples to demonstrate current best practices and techniques, and also explains and demonstrates streaming ingestion, transformation via Hadoop in Google Compute engine, AppEngine datastore integration, and using GViz with Tableau to generate charts of query results. In addit

  11. A Secure Anonymous Internet Electronic Voting Scheme Based on the Polynomial

    Institute of Scientific and Technical Information of China (English)

    CAO Feng; CAO Zhenfu

    2006-01-01

    In this paper, we use the polynomial function and Chaum's RSA (Rivest, Shamir, Adleman) blind signature scheme to construct a secure anonymous internet electronic voting scheme. In our scheme, each vote does not need to be revealed in the tallying phase. The ballot number of each candidate gets is counted by computing the degrees of two polynomials' greatest common divisor. Our scheme does not require a special voting channel and communication can occur entirely over the current internet.

  12. A Parallelism-Based Approach to Network Anonymization

    CERN Document Server

    Margasinski, Igor

    2009-01-01

    Considering topologies of anonymous networks we used to organizing anonymous communication into hard to trace paths hiding its origin or destination. In anonymity the company is crucial, however the serial transportation imposes a costly tradeoff between a level of privacy and a speed of communication. This paper introduces a framework of a novel architecture for anonymous networks that hides initiators of communications by parallelization of anonymous links. The new approach, which is based on the grounds of the anonymous P2P network called P2Priv, does not require content forwarding via a chain of proxy nodes to assure high degree of anonymity. Contrary to P2Priv, the new architecture can be suited to anonymization of various network communications, including anonymous access to distributed as well as client-server services. In particular, it can be considered as an anonymization platform for these network applications where both privacy and low delays are required.

  13. 不确定数据查询处理%Query Processing on Uncertain Data

    Institute of Scientific and Technical Information of China (English)

    蒋涛; 高云君; 张彬; 周傲英; 乐光学

    2013-01-01

    数据的不确定性在现实世界中的经济、军事、物流、金融、电信等领域普遍存在.不确定数据广泛应用于环境维护、市场分析、基于位置的服务LBS以及数量经济研究等应用.由于这些应用的重要性以及收集和累积的不确定数据数量的快速增长,查询这些数据已经成为一个重要的任务,并日益受到广大数据库研究者的关注.本文介绍了不确定数据查询的基本原理,并对不确定数据的近邻查询、逆向近邻查询、排序查询、Top-k查询以及连接查询进行了详细的讨论.同时对这些技术的优缺点进行了分析、对比.最后给出了未来的研究方向.%Data uncertainty is pervasive in various fields,for example,economy,military,logistic,finance and telecommunication,etc.Uncertain data are inherent in some important applications,such as environmental surveillance,market analysis,LocationBased Service(LBS),and quantitative economics research.Due to the inportance of those applications and the rapidly increasing amount of uncertain data collected and accumulated,querying large collections of uncertain data has become an important task and has received more and more attention from the database community in recent years.This paper introduces the principle of uncertain data query,and surveys the advance of the research on uncertain data query processing,including Nearest Neighbor(NN) query,Reverse Nearest Neighbor(RNN) query,Ranking query,top-k query and join query.By a detailed comparison,the pros and cons of the techniques are discussed.In the end,the problems in current research and some future research issues are outlined.

  14. In-Network Historical Data Storage and Query Processing Based on Distributed Indexing Techniques in Wireless Sensor Networks

    Science.gov (United States)

    Ai, Chunyu; Du, Ruiying; Zhang, Minghong; Li, Yingshu

    Most of existing data processing approaches of wireless sensor networks are real-time. However, historical data of wireless sensor networks are also significant for various applications. No previous study has specifically addressed distributed historical data query processing. In this paper, we propose an Index based Historical Data Query Processing scheme which stores historical data locally and processes queries energy-efficiently by using a distributed index tree. The simulation study shows that our scheme achieves good performance on both query responding delay and network traffic.

  15. Purpose-restricted Anonymous Mobile Communications Using Anonymous Signatures in Online Credential Systems

    DEFF Research Database (Denmark)

    Fathi, Hanane; Shin, SeongHan; Kobara, Kazukuni

    2010-01-01

    To avoid the risk of long-term storage of secrets on a portable device, an online credential system supports the roaming user in retrieving securely at various locations his private key and other material to generate anonymous signatures. The protocol proposed here allows a roaming mobile user...... to access anonymously services such as whistle blowing and net-counselling. Our approach: (1) allows a mobile user, remembering a short password, to anonymously and securely retrieve the credentials necessary for his anonymous communication without assuming a pre-established anonymous channel...

  16. 一种基于XML小枝查询片段松弛的近似查询与结果排序方法%Approximate Query and Results Ranking Approach Based on XML Twig Query Fragment Relaxation

    Institute of Scientific and Technical Information of China (English)

    魏珂; 任建华; 孟祥福

    2012-01-01

    Based on XML twig query fragments relaxation, this paper proposed an approximate querying and results ranking approach to achieve the approximate query results against XML documents: our method gathers the query history to speculate the user's preferences, which is used to calculate the importance for each query fragment of the twig query,and relax the original query according to the sequence of the fragments' importance; based on the number of query fragments we adopt different relax way:if the number>2,relax the original query according to the granularity of the fragment; if the number<2, relax the original query according to the granularity of query node, and adopt a different way to relax the numerical query and non-numerical query,and then obtain the most relevant query results. Finally, the relevant query results are ranked based on their satisfaction degree to the original query and the user preferences. Our experiment shows that the approximate querying and the results ranking approach can efficiently meet the user's needs and user's preferences,has the high recall and precision.%提出了一种基于XML小枝查询片段松弛的近似查询与结果排序方法来实现用户在XML文档中的近似查询:通过收集用户的查询历史来推测用户偏好,并以此计算原始小枝查询分解得到的查询片段的重要程度,然后按照重要程度的排序进行查询松弛;在松弛方法中,根据查询片段数目的不同采用不同的松弛方法,若片段数目较多则以查询片段为粒度对其松弛,较少则以查询结点为粒度对数值查询与非数值查询采用不同的方法进行松弛,得到最为相关的近似查询结果;最后接近似查询结果对原始查询和用户偏好的满足程度进行排序并输出.实验证明,该近似查询方法能够较好地满足用户的需求和偏好,具有较高的查全率和准确率.

  17. A Semantic Query Transformation Approach Based on Ontology for Search Engine

    Directory of Open Access Journals (Sweden)

    SAJENDRA KUMAR

    2012-05-01

    Full Text Available These days we are using some popular web search engines for information retrieval in all areas, such engine are as Google, Yahoo!, and Live Search, etc. to obtain initial helpful information.Which information we retrieved via search engine may not be relevant to the search target in the search engine user's mind. When user not found relevant information he has to shortlist the results. Thesesearch engines use traditional search service based on "static keywords", which require the users to type in the exact keywords. This approach clearly puts the users in a critical situation of guessing the exact keyword. The users may want to define their search by using attributes of the search target. But the relevancy of results in most cases may not be satisfactory and the users may not be patient enough to browse through complete list of pages to get a relevant result. The reason behind this is the search engines performs search based on the syntax not on semantics. But they seemed to be less efficient to understand the relationship between the keywords which had an adverse effect on the results it produced. Semantic search engines – only solution to this; which returns concepts not documents according to user query matching. In This paper we proposed a semantic query interface which creates a semantic query according the user input query and study of current semantic search engine techniques for semantic search.

  18. Anonymization of Court Orders

    DEFF Research Database (Denmark)

    Povlsen, Claus; Jongejan, Bart; Hansen, Dorte Haltrup;

    We describe an anonymization tool that was commissioned by and specified together with Schultz, a publishing company specialized in Danish law related publications. Unavailability of training data and the need to guarantee compliance with pre-existing anonymization guidelines forced us to implement...

  19. How to Bootstrap Anonymous Communication

    DEFF Research Database (Denmark)

    Jakobsen, Sune K.; Orlandi, Claudio

    2015-01-01

    formal study in this direction. To solve this problem, we introduce the concept of anonymous steganography: think of a leaker Lea who wants to leak a large document to Joe the journalist. Using anonymous steganography Lea can embed this document in innocent looking communication on some popular website...... (such as cat videos on YouTube or funny memes on 9GAG). Then Lea provides Joe with a short key k which, when applied to the entire website, recovers the document while hiding the identity of Lea among the large number of users of the website. Our contributions include: { Introducing and formally dening...

  20. How to Bootstrap Anonymous Communication

    DEFF Research Database (Denmark)

    Jakobsen, Sune K.; Orlandi, Claudio

    2015-01-01

    formal study in this direction. To solve this problem, we introduce the concept of anonymous steganography: think of a leaker Lea who wants to leak a large document to Joe the journalist. Using anonymous steganography Lea can embed this document in innocent looking communication on some popular website...... (such as cat videos on YouTube or funny memes on 9GAG). Then Lea provides Joe with a short key $k$ which, when applied to the entire website, recovers the document while hiding the identity of Lea among the large number of users of the website. Our contributions include: - Introducing and formally...

  1. The Dynamic Programming Algorithm on Privacy Protection Model of Continuous Location Queries Based on LBS%基于 LBS 的连续查询位置隐私保护模型的动态规划算法

    Institute of Scientific and Technical Information of China (English)

    雷建云; 张镭钟

    2015-01-01

    针对现有的算法大多都是静态位置隐私保护的,如果将静态算法应用于动态的连续查询中,会导致位置隐私泄露,提出了一种基于连续查询的动态规划改进算法,旨在保护用户的位置隐私,仿真实验结果证明:该算法在匿名处理时间、匿名成功率和轨迹扭曲度等方面优于现有算法。%Most of the existing algorithms are static position for privacy , if the static algorithm applied in dynamically continuous query , it will lead to the disclosure of position privacy , An improved dynamic programming algorithm based on continuous queries is proposed , designed to protect the user's location privacy , The simulation results show that: The algorithm outperforms the existing methods in terms anonymous processing time , anonymous success rate and track twist .

  2. Query Performance Prediction for Information Retrieval Based on Covering Topic Score

    Institute of Scientific and Technical Information of China (English)

    Hao Lang; Bin Wang; Gareth Jones; Jin-Tao Li; Fan Ding; Yi-Xuan Liu

    2008-01-01

    We present a statistical method called Covering Topic Score (CTS) to predict query performance for information retrieval. Estimation is based on how well the topic of a user's query is covered by documents retrieved from a certain retrieval system. Our approach is conceptually simple and intuitive, and can be easily extended to incorporate features beyond bag-of-words such as phrases and proximity of terms. Experiments demonstrate that CTS significantly correlates with query performance in a variety of TREC test collections, and in particular CTS gains more prediction power benefiting from features of phrases and proximity of terms. We compare CTS with previous state-of-the-art methods for query performance prediction including clarity score and robustness score. Our experimental results show that CTS consistently performs better than, or at least as well as, these other methods. In addition to its high effectiveness, CTS is also shown to have very low computational complexity, meaning that it can be practical for real applications.

  3. Orthogonal Query Expansion

    CERN Document Server

    Ackerman, Margareta; Lopez-Ortiz, Alejandro

    2011-01-01

    Over the last fifteen years, web searching has seen tremendous improvements. Starting from a nearly random collection of matching pages in 1995, today, search engines tend to satisfy the user's informational need on well-formulated queries. One of the main remaining challenges is to satisfy the users' needs when they provide a poorly formulated query. When the pages matching the user's original keywords are judged to be unsatisfactory, query expansion techniques are used to alter the result set. These techniques find keywords that are similar to the keywords given by the user, which are then appended to the original query leading to a perturbation of the result set. However, when the original query is sufficiently ill-posed, the user's informational need is best met using entirely different keywords, and a small perturbation of the original result set is bound to fail. We propose a novel approach that is not based on the keywords of the original query. We intentionally seek out orthogonal queries, which are r...

  4. Query optimization over crowdsourced data

    KAUST Repository

    Park, Hyunjung

    2013-08-26

    Deco is a comprehensive system for answering declarative queries posed over stored relational data together with data obtained on-demand from the crowd. In this paper we describe Deco\\'s cost-based query optimizer, building on Deco\\'s data model, query language, and query execution engine presented earlier. Deco\\'s objective in query optimization is to find the best query plan to answer a query, in terms of estimated monetary cost. Deco\\'s query semantics and plan execution strategies require several fundamental changes to traditional query optimization. Novel techniques incorporated into Deco\\'s query optimizer include a cost model distinguishing between "free" existing data versus paid new data, a cardinality estimation algorithm coping with changes to the database state during query execution, and a plan enumeration algorithm maximizing reuse of common subplans in a setting that makes reuse challenging. We experimentally evaluate Deco\\'s query optimizer, focusing on the accuracy of cost estimation and the efficiency of plan enumeration.

  5. Moving Spatial Keyword Queries

    DEFF Research Database (Denmark)

    Wu, Dingming; Yiu, Man Lung; Jensen, Christian S.

    2013-01-01

    Web users and content are increasingly being geo-positioned. This development gives prominence to spatial keyword queries, which involve both the locations and textual descriptions of content. We study the efficient processing of continuously moving top-k spatial keyword (MkSK) queries over spatial...... text data. State-of-the-art solutions for moving queries employ safe zones that guarantee the validity of reported results as long as the user remains within the safe zone associated with a result. However, existing safe-zone methods focus solely on spatial locations and ignore text relevancy. We...

  6. Shark: SQL and Analytics with Cost-Based Query Optimization on Coarse-Grained Distributed Memory

    Science.gov (United States)

    2014-01-13

    Apache Hive and run machine learning programs on large datasets over 25 times faster than equivalent MapReduce programs on Apache Hadoop . Unlike...programs on large datasets over 25 times faster than equivalent MapReduce programs on Apache Hadoop . Unlike previous systems, Shark shows that it is...relational databases. HadoopDB [6] connects multiple single-node database systems using Hadoop as the communication layer. Queries can be parallelized

  7. Movement Data Anonymity through Generalization

    Directory of Open Access Journals (Sweden)

    Anna Monreale

    2010-08-01

    Full Text Available Wireless networks and mobile devices, such as mobile phones and GPS receivers, sense and track the movements of people and vehicles, producing society-wide mobility databases. This is a challenging scenario for data analysis and mining. On the one hand, exciting opportunities arise out of discovering new knowledge about human mobile behavior, and thus fuel intelligent info-mobility applications. On other hand, new privacy concerns arise when mobility data are published. The risk is particularly high for GPS trajectories, which represent movement of a very high precision and spatio-temporal resolution: the de-identification of such trajectories (i.e., forgetting the ID of their associated owners is only a weak protection, as generally it is possible to re-identify a person by observing her routine movements. In this paper we propose a method for achieving true anonymity in a dataset of published trajectories, by defining a transformation of the original GPS trajectories based on spatial generalization and k-anonymity. The proposed method offers a formal data protection safeguard, quantified as a theoretical upper bound to the probability of re-identification. We conduct a thorough study on a real-life GPS trajectory dataset, and provide strong empirical evidence that the proposed anonymity techniques achieve the conflicting goals of data utility and data privacy. In practice, the achieved anonymity protection is much stronger than the theoretical worst case, while the quality of the cluster analysis on the trajectory data is preserved.

  8. Deniable Anonymous Group Authentication

    Science.gov (United States)

    2014-02-13

    electronic mail, return addresses, and digital pseudonyms. Communications of the ACM, 24:84–88, February 1981. [16] D. Chaum. Blind signatures for...ASIACRYPT, 2004. [59] P. P. Tsang and V. K. Wei. Short linkable ring signatures for e- voting , e-cash and attestation. In ’05 ISPEC, 2005. [60] D. I...which we term anonymity, proportionality, forward anonymity, and deniability. Like ring signatures [50], DAGA allows a user to au- thenticate as an

  9. Optimal query error of quantum approximation on some Sobolev classes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We study the approximation of the imbedding of functions from anisotropic and general-ized Sobolev classes into Lq([0,1]d) space in the quantum model of computation. Based on the quantum algorithms for approximation of finite imbedding from LpN to LNq , we develop quantum algorithms for approximating the imbedding from anisotropic Sobolev classes B(Wpr ([0,1]d)) to Lq([0,1]d) space for all 1 q,p ∞ and prove their optimality. Our results show that for p < q the quantum model of computation can bring a speedup roughly up to a squaring of the rate in the classical deterministic and randomized settings.

  10. Bottom-up mining of XML query patterns to improve XML querying

    Institute of Scientific and Technical Information of China (English)

    Yi-jun BEI; Gang CHEN; Jin-xiang DONG; Ke CHEN

    2008-01-01

    Querying XML data is a computationally expensive process due to the complex nature of both the XML data and the XML queries. In this paper we propose an approach to expedite XML query processing by caching the results of frequent queries. We discover frequent query patterns from user-issued queries using an efficient bottom-up mining approach called VBUXMiner. VBUXMiner consists of two main steps. First, all queries are merged into a summary structure named "compressed global tree guide" (CGTG). Second, a bottom-up traversal scheme based on the CGTG is employed to generate frequent query patterns. We use the frequent query patterns in a cache mechanism to improve the XML query performance. Experimental results show that our proposed mining approach outperforms the previous mining algorithms for XML queries, such as XQPMinerTID and FastXMiner, and that by caching the results of frequent query patterns, XML query performance can be dramatically improved.

  11. Improving Estimation Accuracy of Aggregate Queries on Data Cubes

    Energy Technology Data Exchange (ETDEWEB)

    Pourabbas, Elaheh; Shoshani, Arie

    2008-08-15

    In this paper, we investigate the problem of estimation of a target database from summary databases derived from a base data cube. We show that such estimates can be derived by choosing a primary database which uses a proxy database to estimate the results. This technique is common in statistics, but an important issue we are addressing is the accuracy of these estimates. Specifically, given multiple primary and multiple proxy databases, that share the same summary measure, the problem is how to select the primary and proxy databases that will generate the most accurate target database estimation possible. We propose an algorithmic approach for determining the steps to select or compute the source databases from multiple summary databases, which makes use of the principles of information entropy. We show that the source databases with the largest number of cells in common provide the more accurate estimates. We prove that this is consistent with maximizing the entropy. We provide some experimental results on the accuracy of the target database estimation in order to verify our results.

  12. MHBase: A Distributed Real-Time Query Scheme for Meteorological Data Based on HBase

    Directory of Open Access Journals (Sweden)

    Tinghuai Ma

    2016-03-01

    Full Text Available Meteorological technology has evolved rapidly in recent years to provide enormous, accurate and personalized advantages in the public service. Large volumes of observational data are generated gradually by technologies such as geographical remote sensing, meteorological radar satellite, etc. that makes data analysis in weather forecasting more precise but also poses a threat to the traditional method of data storage. In this paper, we present MHBase, (Meteorological data based on HBase (Hadoop Database, a distributed real-time query scheme for meteorological data based on HBase. The calibrated data obtained from terminal devices will be partitioned into HBase and persisted to HDFS (the Hadoop Distributed File System. We propose two algorithms (the Indexed Store and the Indexed Retrieve Algorithms to implement a secondary index using HBase Coprocessors, which allow MHbase to provide high performance data querying on columns other than rowkey. Experimental results show that the performance of MHBase can satisfy the basic demands of meteorological business services.

  13. Bayesian Query-Focused Summarization

    CERN Document Server

    Daumé, Hal

    2009-01-01

    We present BayeSum (for ``Bayesian summarization''), a model for sentence extraction in query-focused summarization. BayeSum leverages the common case in which multiple documents are relevant to a single query. Using these documents as reinforcement for query terms, BayeSum is not afflicted by the paucity of information in short queries. We show that approximate inference in BayeSum is possible on large data sets and results in a state-of-the-art summarization system. Furthermore, we show how BayeSum can be understood as a justified query expansion technique in the language modeling for IR framework.

  14. Performance of Point and Range Queries for In-memory Databases using Radix Trees on GPUs

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Maksudul [ORNL; Yoginath, Srikanth B [ORNL; Perumalla, Kalyan S [ORNL

    2016-01-01

    In in-memory database systems augmented by hardware accelerators, accelerating the index searching operations can greatly increase the runtime performance of database queries. Recently, adaptive radix trees (ART) have been shown to provide very fast index search implementation on the CPU. Here, we focus on an accelerator-based implementation of ART. We present a detailed performance study of our GPU-based adaptive radix tree (GRT) implementation over a variety of key distributions, synthetic benchmarks, and actual keys from music and book data sets. The performance is also compared with other index-searching schemes on the GPU. GRT on modern GPUs achieves some of the highest rates of index searches reported in the literature. For point queries, a throughput of up to 106 million and 130 million lookups per second is achieved for sparse and dense keys, respectively. For range queries, GRT yields 600 million and 1000 million lookups per second for sparse and dense keys, respectively, on a large dataset of 64 million 32-bit keys.

  15. Ontological Queries: Rewriting and Optimization (Extended Version)

    CERN Document Server

    Gottlob, Georg; Pieris, Andreas

    2011-01-01

    Ontological queries are evaluated against an ontology rather than directly on a database. The evaluation and optimization of such queries is an intriguing new problem for database research. In this paper we discuss two important aspects of this problem: query rewriting and query optimization. Query rewriting consists of the compilation of an ontological query into an equivalent query against the underlying relational database. The focus here is on soundness and completeness. We review previous results and present a new rewriting algorithm for rather general types of ontological constraints. In particular, we show how a conjunctive query against an ontology can be compiled into a union of conjunctive queries against the underlying database. Ontological query optimization, in this context, attempts to improve this process so to produce possibly small and cost-effective UCQ rewritings for an input query. We review existing optimization methods, and propose an effective new method that works for linear Datalog+/-...

  16. Linked-Tree: An Aggregate Query Algorithm Based on Sliding Window over Data Stream

    Institute of Scientific and Technical Information of China (English)

    YU Yaxin; WANG Guoren; SU Dong; ZHU Xinhua

    2006-01-01

    How to process aggregate queries over data streams efficiently and effectively have been becoming hot research topics in both academic community and industrial community. Aiming at the issues, a novel Linked-tree algorithm based on sliding window is proposed in this paper. Due to the proposal of concept area, the Linked-tree algorithm reuses many primary results in last window and then avoids lots of unnecessary repeated comparison operations between two successive windows. As a result, execution efficiency of MAX query is improved dramatically. In addition, since the size of memory is relevant to the number of areas but irrelevant to the size of sliding window, memory is economized greatly. The extensive experimental results show that the performance of Linked-tree algorithm has significant improvement gains over the traditional SC (Simple Compared) algorithm and Ranked-tree algorithm.

  17. Head lice surveillance on a deregulated OTC-sales market: a study using web query data.

    Science.gov (United States)

    Lindh, Johan; Magnusson, Måns; Grünewald, Maria; Hulth, Anette

    2012-01-01

    The head louse, Pediculus humanus capitis, is an obligate ectoparasite that causes infestations of humans. Studies have demonstrated a correlation between sales figures for over-the-counter (OTC) treatment products and the number of humans with head lice. The deregulation of the Swedish pharmacy market on July 1, 2009, decreased the possibility to obtain complete sale figures and thereby the possibility to obtain yearly trends of head lice infestations. In the presented study we wanted to investigate whether web queries on head lice can be used as substitute for OTC sales figures. Via Google Insights for Search and Vårdguiden medical web site, the number of queries on "huvudlöss" (head lice) and "hårlöss" (lice in hair) were obtained. The analysis showed that both the Vårdguiden series and the Google series were statistically significant (pGoogle series were already included in the model, the Vårdguiden series were not statistically significant (p = 0.5689). In conclusion, web queries can detect if there is an increase or decrease of head lice infested humans in Sweden over a period of years, and be as reliable a proxy as the OTC-sales figures.

  18. Towards a Theory of Anonymous Networking

    CERN Document Server

    Ghaderi, J

    2009-01-01

    The problem of anonymous networking when an eavesdropper observes packet timings in a communication network is considered. The goal is to hide the identities of source-destination nodes, and paths of information flow in the network. One way to achieve such an anonymity is to use mixers. Mixers are nodes that receive packets from multiple sources and change the timing of packets, by mixing packets at the output links, to prevent the eavesdropper from finding sources of outgoing packets. In this paper, we consider two simple but fundamental scenarios: double input-single output mixer and double input-double output mixer. For the first case, we use the information-theoretic definition of the anonymity, based on average entropy per packet, and find an optimal mixing strategy under a strict latency constraint. For the second case, perfect anonymity is considered, and a maximal throughput strategy with perfect anonymity is found that minimizes the average delay.

  19. Semi-automatic semantic annotation of PubMed queries: a study on quality, efficiency, satisfaction.

    Science.gov (United States)

    Névéol, Aurélie; Islamaj Doğan, Rezarta; Lu, Zhiyong

    2011-04-01

    Information processing algorithms require significant amounts of annotated data for training and testing. The availability of such data is often hindered by the complexity and high cost of production. In this paper, we investigate the benefits of a state-of-the-art tool to help with the semantic annotation of a large set of biomedical queries. Seven annotators were recruited to annotate a set of 10,000 PubMed® queries with 16 biomedical and bibliographic categories. About half of the queries were annotated from scratch, while the other half were automatically pre-annotated and manually corrected. The impact of the automatic pre-annotations was assessed on several aspects of the task: time, number of actions, annotator satisfaction, inter-annotator agreement, quality and number of the resulting annotations. The analysis of annotation results showed that the number of required hand annotations is 28.9% less when using pre-annotated results from automatic tools. As a result, the overall annotation time was substantially lower when pre-annotations were used, while inter-annotator agreement was significantly higher. In addition, there was no statistically significant difference in the semantic distribution or number of annotations produced when pre-annotations were used. The annotated query corpus is freely available to the research community. This study shows that automatic pre-annotations are found helpful by most annotators. Our experience suggests using an automatic tool to assist large-scale manual annotation projects. This helps speed-up the annotation time and improve annotation consistency while maintaining high quality of the final annotations.

  20. Anonymization of Court Decisions: Are Restrictions on the Right to Information in “Accordance with the Law”?

    Directory of Open Access Journals (Sweden)

    Gruodytė Edita

    2016-12-01

    Full Text Available In Lithuania rules for the anonymization of court decisions were introduced in 2005. These rules require automatic anonymization of all court decisions, which in the opinion of the authors violates the public interest to know and freedom of expression is unjustifiably restricted on behalf of the right to privacy. This issue covers two diametrically opposed human rights: the right to privacy and the right to information. The first question is how the balance between two equivalent rights could be reached. The second question is whether this regulation is in accordance with the law as it is established in the national Constitution and revealed by the Constitutional Court of the Republic of Lithuania and developed by the jurisprudence of the European Court of Human Rights. The authors conclude that the legislator is not empowered to delegate to the Judicial Council issues which are a matter of legal regulation and suggest possible solutions evaluating practice of the Court of Justice of the European Union, the European Court of Human Rights, and selected EU countries.

  1. An Anonymous User Authentication and Key Agreement Scheme Based on a Symmetric Cryptosystem in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jaewook Jung

    2016-08-01

    Full Text Available In wireless sensor networks (WSNs, a registered user can login to the network and use a user authentication protocol to access data collected from the sensor nodes. Since WSNs are typically deployed in unattended environments and sensor nodes have limited resources, many researchers have made considerable efforts to design a secure and efficient user authentication process. Recently, Chen et al. proposed a secure user authentication scheme using symmetric key techniques for WSNs. They claim that their scheme assures high efficiency and security against different types of attacks. After careful analysis, however, we find that Chen et al.’s scheme is still vulnerable to smart card loss attack and is susceptible to denial of service attack, since it is invalid for verification to simply compare an entered ID and a stored ID in smart card. In addition, we also observe that their scheme cannot preserve user anonymity. Furthermore, their scheme cannot quickly detect an incorrect password during login phase, and this flaw wastes both communication and computational overheads. In this paper, we describe how these attacks work, and propose an enhanced anonymous user authentication and key agreement scheme based on a symmetric cryptosystem in WSNs to address all of the aforementioned vulnerabilities in Chen et al.’s scheme. Our analysis shows that the proposed scheme improves the level of security, and is also more efficient relative to other related schemes.

  2. An Anonymous User Authentication and Key Agreement Scheme Based on a Symmetric Cryptosystem in Wireless Sensor Networks

    Science.gov (United States)

    Jung, Jaewook; Kim, Jiye; Choi, Younsung; Won, Dongho

    2016-01-01

    In wireless sensor networks (WSNs), a registered user can login to the network and use a user authentication protocol to access data collected from the sensor nodes. Since WSNs are typically deployed in unattended environments and sensor nodes have limited resources, many researchers have made considerable efforts to design a secure and efficient user authentication process. Recently, Chen et al. proposed a secure user authentication scheme using symmetric key techniques for WSNs. They claim that their scheme assures high efficiency and security against different types of attacks. After careful analysis, however, we find that Chen et al.’s scheme is still vulnerable to smart card loss attack and is susceptible to denial of service attack, since it is invalid for verification to simply compare an entered ID and a stored ID in smart card. In addition, we also observe that their scheme cannot preserve user anonymity. Furthermore, their scheme cannot quickly detect an incorrect password during login phase, and this flaw wastes both communication and computational overheads. In this paper, we describe how these attacks work, and propose an enhanced anonymous user authentication and key agreement scheme based on a symmetric cryptosystem in WSNs to address all of the aforementioned vulnerabilities in Chen et al.’s scheme. Our analysis shows that the proposed scheme improves the level of security, and is also more efficient relative to other related schemes. PMID:27537890

  3. An Anonymous User Authentication and Key Agreement Scheme Based on a Symmetric Cryptosystem in Wireless Sensor Networks.

    Science.gov (United States)

    Jung, Jaewook; Kim, Jiye; Choi, Younsung; Won, Dongho

    2016-08-16

    In wireless sensor networks (WSNs), a registered user can login to the network and use a user authentication protocol to access data collected from the sensor nodes. Since WSNs are typically deployed in unattended environments and sensor nodes have limited resources, many researchers have made considerable efforts to design a secure and efficient user authentication process. Recently, Chen et al. proposed a secure user authentication scheme using symmetric key techniques for WSNs. They claim that their scheme assures high efficiency and security against different types of attacks. After careful analysis, however, we find that Chen et al.'s scheme is still vulnerable to smart card loss attack and is susceptible to denial of service attack, since it is invalid for verification to simply compare an entered ID and a stored ID in smart card. In addition, we also observe that their scheme cannot preserve user anonymity. Furthermore, their scheme cannot quickly detect an incorrect password during login phase, and this flaw wastes both communication and computational overheads. In this paper, we describe how these attacks work, and propose an enhanced anonymous user authentication and key agreement scheme based on a symmetric cryptosystem in WSNs to address all of the aforementioned vulnerabilities in Chen et al.'s scheme. Our analysis shows that the proposed scheme improves the level of security, and is also more efficient relative to other related schemes.

  4. INTEGRATIVE METHOD OF TEACHING INFORMATION MODELING IN PRACTICAL HEALTH SERVICE BASED ON MICROSOFT ACCESS QUERIES

    Directory of Open Access Journals (Sweden)

    Svetlana A. Firsova

    2016-06-01

    Full Text Available Introduction: this article explores the pedagogical technology employed to teach medical students foundations of work with MICROSOFT ACCESS databases. The above technology is based on integrative approach to the information modeling in public health practice, drawing upon basic didactic concepts that pertain to objects and tools databases created in MICROSOFT ACCESS. The article examines successive steps in teaching the topic “Queries in MICROSOFT ACCESS” – from simple queries to complex ones. The main attention is paid to such components of methodological system, as the principles and teaching methods classified according to the degree of learners’ active cognitive activity. The most interesting is the diagram of the relationship of learning principles, teaching methods and specific types of requests. Materials and Methods: the authors used comparative analysis of literature, syllabi, curricula in medical informatics taught at leading medical universities in Russia. Results: the original technique of training in putting queries with databases of MICROSOFT ACCESS is presented for analysis of information models in practical health care. Discussion and Conclusions: it is argued that the proposed pedagogical technology will significantly improve the effectiveness of teaching the course “Medical Informatics”, that includes development and application of models to simulate the operation of certain facilities and services of the health system which, in turn, increases the level of information culture of practitioners.

  5. EquiX-A Search and Query Language for XML.

    Science.gov (United States)

    Cohen, Sara; Kanza, Yaron; Kogan, Yakov; Sagiv, Yehoshua; Nutt, Werner; Serebrenik, Alexander

    2002-01-01

    Describes EquiX, a search language for XML that combines querying with searching to query the data and the meta-data content of Web pages. Topics include search engines; a data model for XML documents; search query syntax; search query semantics; an algorithm for evaluating a query on a document; and indexing EquiX queries. (LRW)

  6. A Novel Multi-Receiver Signcryption Scheme with Complete Anonymity.

    Science.gov (United States)

    Pang, Liaojun; Yan, Xuxia; Zhao, Huiyang; Hu, Yufei; Li, Huixian

    2016-01-01

    Anonymity, which is more and more important to multi-receiver schemes, has been taken into consideration by many researchers recently. To protect the receiver anonymity, in 2010, the first multi-receiver scheme based on the Lagrange interpolating polynomial was proposed. To ensure the sender's anonymity, the concept of the ring signature was proposed in 2005, but afterwards, this scheme was proven to has some weakness and at the same time, a completely anonymous multi-receiver signcryption scheme is proposed. In this completely anonymous scheme, the sender anonymity is achieved by improving the ring signature, and the receiver anonymity is achieved by also using the Lagrange interpolating polynomial. Unfortunately, the Lagrange interpolation method was proven a failure to protect the anonymity of receivers, because each authorized receiver could judge whether anyone else is authorized or not. Therefore, the completely anonymous multi-receiver signcryption mentioned above can only protect the sender anonymity. In this paper, we propose a new completely anonymous multi-receiver signcryption scheme with a new polynomial technology used to replace the Lagrange interpolating polynomial, which can mix the identity information of receivers to save it as a ciphertext element and prevent the authorized receivers from verifying others. With the receiver anonymity, the proposed scheme also owns the anonymity of the sender at the same time. Meanwhile, the decryption fairness and public verification are also provided.

  7. Anonymous Mobile Payment Solution

    Directory of Open Access Journals (Sweden)

    Alhaj Ali Jalila

    2015-09-01

    Full Text Available The evolution and increasing popularity of mobile handheld devices has led to the development of payment applications. The global acceptance of mobile payments is hindered by security and privacy concerns. One of the main problems evoked is the anonymity related with banking transactions. In this paper I propose a new secured architecture for mobile banking. Anonymity and privacy protection are the measures to be enhanced in order to satisfy people’s current needs. The banking platform must provide the highest level of security for messages exchanged between bank and the customer.

  8. Anonymous Broadcast Messages

    Directory of Open Access Journals (Sweden)

    Dragan Lazic

    2013-01-01

    Full Text Available The Dining Cryptographer network (or DC-net is a privacy preserving communication protocol devised by David Chaum for anonymous message publication. A very attractive feature of DC-nets is the strength of its security, which is inherent in the protocol and is not dependent on other schemes, like encryption. Unfortunately the DC-net protocol has a level of complexity that causes it to suffer from exceptional communication overhead and implementation difficulty that precludes its use in many real-world use-cases. We have designed and created a DC-net implementation that uses a pure client-server model, which successfully avoids much of the complexity inherent in the DC-net protocol. We describe the theory of DC-nets and our pure client-server implementation, as well as the compromises that were made to reduce the protocol’s level of complexity. Discussion centers around the details of our implementation of DC-net.

  9. Subsumption Checking between Concept Queries in Different Ontologies Based on Mutual Instances

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper proposes a checking method based on mutual instances and discusses three key problems in the method: how to deal with mistakes in the mutual instances and how to deal with too many or too few mutual instances. It provides the checking based on the weighted mutual instances considering fault tolerance, gives a way to partition the large-scale mutual instances, and proposes a process greatly reducing the manual annotation work to get more mutual instances. Intension annotation that improves the checking method is also discussed. The method is practical and effective to check subsumption relations between concept queries in different ontologies based on mutual instances.

  10. An Efficient Algorithm for Query Transformation in Semantic Query Optimization

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Semantic query optimization (SQO) is comparatively a recent approach for the transformation of given query into equivalent alternative query using matching rules in order to select an optimal query based on the costs of executing alternative queries. The key aspect of the algorithm proposed here is that previous proposed SQO techniques can be considered equally in the uniform cost model, with which optimization opportunities will not be missed. At the same time, the authors used the implication closure to guarantee that any matched rule will not be lost. The authors implemented their algorithm for the optimization of decomposed sub-query in local database in Multi-Database Integrator (MDBI), which is a multidatabase project. The experimental results verify that this algorithm is effective in the process of SQO.

  11. Foreword for the special issue of selected papers from the 7th EDBT/ICDT Workshop on Privacy and Anonymity in Information Society (PAIS 2014

    Directory of Open Access Journals (Sweden)

    Traian Marius Truta

    2015-04-01

    Full Text Available The seventh Workshop on Privacy and Anonymity in Information Society (PAIS 2014 was held in conjunction with the International Conference on Extending Database Technology (EDBT and International Conference on Database Theory (ICDT in Athens, Greece. The PAIS 2014 workshop provided an open yet focused platform for researchers and practitioners from fields such as computer science, statistics, healthcare informatics, and law to discuss and present current research challenges and advances in data privacy and anonymity research. The present special issue contains three extended papers that have been selected as the best three papers presented at PAIS 2014 workshop.

  12. Optimizing queries in distributed systems

    Directory of Open Access Journals (Sweden)

    Ion LUNGU

    2006-01-01

    Full Text Available This research presents the main elements of query optimizations in distributed systems. First, data architecture according with system level architecture in a distributed environment is presented. Then the architecture of a distributed database management system (DDBMS is described on conceptual level followed by the presentation of the distributed query execution steps on these information systems. The research ends with presentation of some aspects of distributed database query optimization and strategies used for that.

  13. Preserving Communities in Anonymized Social Networks

    Directory of Open Access Journals (Sweden)

    Alina Campan

    2015-04-01

    Full Text Available Social media and social networks are embedded in our society to a point that could not have been imagined only ten years ago. Facebook, LinkedIn, and Twitter are already well known social networks that have a large audience in all age groups. The amount of data that those social sites gather from their users is continually increasing and this data is very valuable for marketing, research, and various other purposes. At the same time, this data usually contain a significant amount of sensitive information which should be protected against unauthorized disclosure. To protect the privacy of individuals, this data must be anonymized such that the risk of re-identification of specific individuals is very low. In this paper we study if anonymized social networks preserve existing communities from the original social networks. To perform this study, we introduce two approaches to measure the community preservation between the initial network and its anonymized version. In the first approach we simply count how many nodes from the original communities remained in the same community after the processes of anonymization and de-anonymization. In the second approach we consider the community preservation for each node individually. Specifically, for each node, we compare the original and final communities to which the node belongs. To anonymize social networks we use two models, namely, k-anonymity for social networks and k-degree anonymity. To determine communities in social networks we use an existing community detection algorithm based on modularity quality function. Our experiments on publically available datasets show that anonymized social networks satisfactorily preserve the community structure of their original networks.

  14. Hardware Acceleration of SQL-Queries Processing in MDM-Systems Based on MISDSolution

    Directory of Open Access Journals (Sweden)

    V. E. Podol'skii

    2015-01-01

    Full Text Available In this article we examine the possibility of hardware support for functions of mobile device management platform (MDM-platform using a Multiple Instructions and Single Data stream computer system, developed within the framework of the project in Bauman Moscow State Technical University. At the universities the MDM-platform is used to provide various mobile services for the faculty, students and administration to facilitate the learning process: a mobile schedule, document sharing, text messages, and other interactive activities. Most of these services are provided by the extensive use of data stored in MDM-platform databases. When accessing the databases SQL- queries are commonly used. These queries comprise operators of SQL-language that are based on mathematical sets theory. Hardware support for operations on sets is implemented in Multiple Instructions and Single Data stream computer system (MISD System. This allows performance improvement of algorithms and operations on sets. Thus, the hardware support for the processing of SQL-queries in MISD system allows us to benefit from the implementation of SQL-queries in the MISD paradigm.The scientific novelty of the work lies in the fact that it is the first time a set of algorithms for basic SQL statements has been presented in a format supported by MISD system. In addition, for the first time operators INNER JOIN, LEFT JOIN and LEFT OUTER JOIN have been implemented for MISD system and tested for it (testing was done for FPGA Xilinx Virtex-II Pro XC2VP30 implementation of MISD system. The practical significance of the work lies in the fact that the results of the study will be used in the project "Development of the Russian analogue of the system software for centralized management of personal devices and platforms in enterprise networks" of the St. Petersburg Polytechnic University (with the financial support of the state represented by the Ministry of Education and Science of the Russian

  15. Working with jqTouch to build websites on top of jQuery

    CERN Document Server

    David, Matthew

    2012-01-01

    Using jqTouch, an open source solution, is a fast way for you to convert a static Web page into looking like a native iPhone or Android app. In this short ebook find out how you can use the Open Source jqTouch Library to extend the functionality built into jQuery to build Web sites that run on your iOS and Android phones but look and interact as if they are native apps. You will also discover how to create custom interfaces, screen flipping, and set themes with jqTouch.

  16. Code query by example

    Science.gov (United States)

    Vaucouleur, Sebastien

    2011-02-01

    We introduce code query by example for customisation of evolvable software products in general and of enterprise resource planning systems (ERPs) in particular. The concept is based on an initial empirical study on practices around ERP systems. We motivate our design choices based on those empirical results, and we show how the proposed solution helps with respect to the infamous upgrade problem: the conflict between the need for customisation and the need for upgrade of ERP systems. We further show how code query by example can be used as a form of lightweight static analysis, to detect automatically potential defects in large software products. Code query by example as a form of lightweight static analysis is particularly interesting in the context of ERP systems: it is often the case that programmers working in this field are not computer science specialists but more of domain experts. Hence, they require a simple language to express custom rules.

  17. Research Issues in Mobile Querying

    DEFF Research Database (Denmark)

    Breunig, M.; Jensen, Christian Søndergaard; Klein, M.

    2004-01-01

    This document reports on key aspects of the discussions conducted within the working group. In particular, the document aims to offer a structured and somewhat digested summary of the group's discussions. The document first offers concepts that enable characterization of "mobile queries" as well...... as the types of systems that enable such queries. It explores the notion of context in mobile queries. The document ends with a few observations, mainly regarding challenges....

  18. Data Caching for XML Query

    Institute of Scientific and Technical Information of China (English)

    SU Fei; CI Lin-lin; ZHU Li-ping; ZHAO Xin-xin

    2006-01-01

    In order to apply the technique of data cache to extensible markup language (XML) database system, the XML-cache system to support data cache for XQuery is presented. According to the character of XML, the queries with nesting are normalized to facilitate the following operation. Based on the idea of incomplete tree, using the document type definition (DTD) schema tree and conditions from normalized XQuery, the results of previous queries are maintained to answer new queries, at the same time, the remainder queries are sent to XML database at the back. The results of experiment show all applications supported by XML database can use this technique to cache data for future use.

  19. jQuery Mobile

    CERN Document Server

    Reid, Jon

    2011-01-01

    Native apps have distinct advantages, but the future belongs to mobile web apps that function on a broad range of smartphones and tablets. Get started with jQuery Mobile, the touch-optimized framework for creating apps that look and behave consistently across many devices. This concise book provides HTML5, CSS3, and JavaScript code examples, screen shots, and step-by-step guidance to help you build a complete working app with jQuery Mobile. If you're already familiar with the jQuery JavaScript library, you can use your existing skills to build cross-platform mobile web apps right now. This b

  20. XPath Whole Query Optimization

    CERN Document Server

    Maneth, Sebastian

    2010-01-01

    Previous work reports about SXSI, a fast XPath engine which executes tree automata over compressed XML indexes. Here, reasons are investigated why SXSI is so fast. It is shown that tree automata can be used as a general framework for fine grained XML query optimization. We define the "relevant nodes" of a query as those nodes that a minimal automaton must touch in order to answer the query. This notion allows to skip many subtrees during execution, and, with the help of particular tree indexes, even allows to skip internal nodes of the tree. We efficiently approximate runs over relevant nodes by means of on-the-fly removal of alternation and non-determinism of (alternating) tree automata. We also introduce many implementation techniques which allows us to efficiently evaluate tree automata, even in the absence of special indexes. Through extensive experiments, we demonstrate the impact of the different optimization techniques.

  1. Geospatial-Enabled RuleML in a Study on Querying Respiratory Disease Information

    DEFF Research Database (Denmark)

    Gao, Sheng; Boley, Harold; Mioc, Darka;

    2009-01-01

    health data query and representation framework is proposed through the formalization of spatial information. We include the geometric representation in RuleML deduction, and apply ontologies and rules for querying and representing health information. Corresponding geospatial built-ins were implemented...... as an extension to OO jDREW. Case studies were carried out using geospatial-enabled RuleML queries for respiratory disease information. The paper thus demonstrates the use of RuleML for geospatial-semantic querying and representing of health information....

  2. Complex dynamics of our economic life on different scales: insights from search engine query data.

    Science.gov (United States)

    Preis, Tobias; Reith, Daniel; Stanley, H Eugene

    2010-12-28

    Search engine query data deliver insight into the behaviour of individuals who are the smallest possible scale of our economic life. Individuals are submitting several hundred million search engine queries around the world each day. We study weekly search volume data for various search terms from 2004 to 2010 that are offered by the search engine Google for scientific use, providing information about our economic life on an aggregated collective level. We ask the question whether there is a link between search volume data and financial market fluctuations on a weekly time scale. Both collective 'swarm intelligence' of Internet users and the group of financial market participants can be regarded as a complex system of many interacting subunits that react quickly to external changes. We find clear evidence that weekly transaction volumes of S&P 500 companies are correlated with weekly search volume of corresponding company names. Furthermore, we apply a recently introduced method for quantifying complex correlations in time series with which we find a clear tendency that search volume time series and transaction volume time series show recurring patterns.

  3. Privacy Preserving Quantum Anonymous Transmission via Entanglement Relay

    Science.gov (United States)

    Yang, Wei; Huang, Liusheng; Song, Fang

    2016-06-01

    Anonymous transmission is an interesting and crucial issue in computer communication area, which plays a supplementary role to data privacy. In this paper, we put forward a privacy preserving quantum anonymous transmission protocol based on entanglement relay, which constructs anonymous entanglement from EPR pairs instead of multi-particle entangled state, e.g. GHZ state. Our protocol achieves both sender anonymity and receiver anonymity against an active adversary and tolerates any number of corrupt participants. Meanwhile, our protocol obtains an improvement in efficiency compared to quantum schemes in previous literature.

  4. On Mobility Management in Multi-Sink Sensor Networks for Geocasting of Queries

    Directory of Open Access Journals (Sweden)

    Paul Havinga

    2011-12-01

    Full Text Available In order to efficiently deal with location dependent messages in multi-sink wireless sensor networks (WSNs, it is key that the network informs sinks what geographical area is covered by which sink. The sinks are then able to efficiently route messages which are only valid in particular regions of the deployment. In our previous work (see the 5th and 6th cited documents, we proposed a combined coverage area reporting and geographical routing protocol for location dependent messages, for example, queries that are injected by sinks. In this paper, we study the case where we have static sinks and mobile sensor nodes in the network. To provide up-to-date coverage areas to sinks, we focus on handling node mobility in the network. We discuss what is a better method for updating the routing structure (i.e., routing trees and coverage areas to handle mobility efficiently: periodic global updates initiated from sinks or local updates triggered by mobile sensors. Simulation results show that local updating perform very well in terms of query delivery ratio. Local updating has a better scalability to increasing network size. It is also more energy efficient than ourpreviously proposed approach, where global updating in networks have medium mobility rate and speed.

  5. A Comparison of Anonymous versus Identifiable e-Peer Review on College Student Writing Performance and the Extent of Critical Feedback

    Science.gov (United States)

    Lu, Ruiling; Bol, Linda

    2007-01-01

    Peer review has become commonplace in composition courses and is increasingly employed in the context of telecommunication technology. The purpose of this experiment was to compare the effects of anonymous and identifiable electronic peer (e-peer) review on college student writing performance and the extent of critical peer feedback. Participants…

  6. A solution of spatial query processing and query optimization for spatial databases

    Institute of Scientific and Technical Information of China (English)

    YUAN Jie; XIE Kun-qing; MA Xiu-jun; ZHANG Min; SUN Le-bin

    2004-01-01

    Recently, attention has been focused on spatial query language which is used to query spatial databases. A design of spatial query language has been presented in this paper by extending the standard relational database query language SQL. It recognizes the significantly different requirements of spatial data handling and overcomes the inherent problems of the application of conventional database query languages. This design is based on an extended spatial data model, including the spatial data types and the spatial operators on them. The processing and optimization of spatial queries have also been discussed in this design. In the end, an implementation of this design is given in a spatial query subsystem.

  7. Query-Driven Strategy for On-the-Fly Term Spotting in Spontaneous Speech

    Directory of Open Access Journals (Sweden)

    Mickael Rouvier

    2010-01-01

    Full Text Available Spoken utterance retrieval was largely studied in the last decades, with the purpose of indexing large audio databases or of detecting keywords in continuous speech streams. While the indexing of closed corpora can be performed via a batch process, on-line spotting systems have to synchronously detect the targeted spoken utterances. We propose a two-level architecture for on-the-fly term spotting. The first level performs a fast detection of the speech segments that probably contain the targeted utterance. The second level refines the detection on the selected segments, by using a speech recognizer based on a query-driven decoding algorithm. Experiments are conducted on both broadcast and spontaneous speech corpora. We investigate the impact of the spontaneity level on system performance. Results show that our method remains effective even if the recognition rates are significantly degraded by disfluencies.

  8. On-demand information retrieval in sensor networks with localised query and energy-balanced data collection.

    Science.gov (United States)

    Teng, Rui; Zhang, Bing

    2011-01-01

    On-demand information retrieval enables users to query and collect up-to-date sensing information from sensor nodes. Since high energy efficiency is required in a sensor network, it is desirable to disseminate query messages with small traffic overhead and to collect sensing data with low energy consumption. However, on-demand query messages are generally forwarded to sensor nodes in network-wide broadcasts, which create large traffic overhead. In addition, since on-demand information retrieval may introduce intermittent and spatial data collections, the construction and maintenance of conventional aggregation structures such as clusters and chains will be at high cost. In this paper, we propose an on-demand information retrieval approach that exploits the name resolution of data queries according to the attribute and location of each sensor node. The proposed approach localises each query dissemination and enable localised data collection with maximised aggregation. To illustrate the effectiveness of the proposed approach, an analytical model that describes the criteria of sink proxy selection is provided. The evaluation results reveal that the proposed scheme significantly reduces energy consumption and improves the balance of energy consumption among sensor nodes by alleviating heavy traffic near the sink.

  9. Efficient Evaluation of Probabilistic Advanced Spatial Queries on Existentially Uncertain Data

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Mamoulis, Nikos; Dai, Xiangyuan;

    2009-01-01

    We study the problem of answering spatial queries in databases where objects exist with some uncertainty and they are associated with an existential probability. The goal of a thresholding probabilistic spatial query is to retrieve the objects that qualify the spatial predicates with probability ...

  10. Flexible Query Answering Systems

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the 10th International Conference on Flexible Query Answering Systems, FQAS 2013, held in Granada, Spain, in September 2013. The 59 full papers included in this volume were carefully reviewed and selected from numerous submissions. The papers are ...

  11. Query Driven Visualization

    CERN Document Server

    Buddelmeijer, Hugo

    2011-01-01

    The request driven way of deriving data in Astro-WISE is extended to a query driven way of visualization. This allows scientists to focus on the science they want to perform, because all administration of their data is automated. This can be done over an abstraction layer that enhances control and flexibility for the scientist.

  12. A sentence scoring method for extractive text summarization based on Natural language queries

    Directory of Open Access Journals (Sweden)

    R.V.V Murali Krishna

    2012-05-01

    Full Text Available The developments in storage devices and computer networks have given the scope for the world to become a paperless community, for example Digital news paper systems and digital library systems. A paperless community is heavily dependent on information retrieval systems. Text summarization is an area that supports the cause of information retrieval systems by helping the users to get their needed information. This paper discusses on the relevance of using traditional stoplists for text summarization and the use of Statistical analysis for sentence scoring. A new methodology is proposed for implementing the stoplist concept and statistical analysis concept based on parts of speech tagging. A sentence scoring mechanism has been developed by combining the above methodologies with semantic analysis. This sentence scoring method has given good results when applied to find out the relation between natural language queries and the sentences in a document.

  13. Anonymization of big data based on hybrid tree%基于混合式子树算法的大数据匿名化

    Institute of Scientific and Technical Information of China (English)

    孙炯宁

    2015-01-01

    The top-down specialization( TDS) and the bottom-up generalization( BUG) are two ways to fulfill the sub-tree anonymization. However,existing approaches for sub-tree anonymization fall short of parallelization capability,thereby lacking scalability in handling big data on cloud. Still,both the TDS and the BUG suffer from poor performances for certain value of the K anonymity parameter when they are utilized individually. In view of that,a hybrid approach combining the TDS and the BUG for efficient sub-tree anonymization over big data is proposed. Further,the MapReduce is designed based algorithms for two components ( TDS and BUG ) to gain the high scalability by exploiting powerful computation capability of cloud. Experiment evaluations demonstrate that the hybrid approach significantly improves the scalability and the efficiency of the sub-tree anonymization scheme over existing approaches.%自顶而下具体化( TDS)和自底向上泛化( BUG)是子树匿名化的主要方法,但其并行能力不足,易导致在云数据处理中缺乏可扩展性。当TDS和BUG分开使用时,很难准确确定K匿名参数。针对这一问题,该文提出一种在大数据中进行有效数据匿名化的基于TDS和BUG的混合方法,设计了基于该混合方法的MapReduce模型,以提高云计算能力的可扩展性。实验表明,与现有方法相比,该混合法可以显著提高扩展性和子树匿名化的效率。

  14. Cache-Based Aggregate Query Shipping: An Efficient Scheme of Distributed OLAP Query Processing

    Institute of Scientific and Technical Information of China (English)

    Hua-Ming Liao; Guo-Shun Pei

    2008-01-01

    Our study introduces a novel distributed query plan refinement phase in an enhanced architecture of distributed query processing engine (DQPE). Query plan refinement generates potentially efficient distributed query plan by reusable aggregate query shipping (RAQS) approach. The approach improves response time at the cost of pre-processing time. If theoverheads could not be compensated by query results reusage, RAQS is no more favorable. Therefore a global cost estimation model is employed to get proper operators: RR_Agg, R_Agg, or R_Scan. For the purpose of reusing results of queries with aggregate function in distributed query processing, a multi-level hybrid view caching (HVC) scheme is introduced. The scheme retains the advantages of partial match and aggregate query results caching. By our solution, evaluations with distributed TPC-H queries show significant improvement on average response time.

  15. Domainwise Web Page Optimization Based On Clustered Query Sessions Using Hybrid Of Trust And ACO For Effective Information Retrieval

    Directory of Open Access Journals (Sweden)

    Dr. Suruchi Chawla

    2015-08-01

    Full Text Available Abstract In this paper hybrid of Ant Colony OptimizationACO and trust has been used for domainwise web page optimization in clustered query sessions for effective Information retrieval. The trust of the web page identifies its degree of relevance in satisfying specific information need of the user. The trusted web pages when optimized using pheromone updates in ACO will identify the trusted colonies of web pages which will be relevant to users information need in a given domain. Hence in this paper the hybrid of Trust and ACO has been used on clustered query sessions for identifying more and more relevant number of documents in a given domain in order to better satisfy the information need of the user. Experiment was conducted on the data set of web query sessions to test the effectiveness of the proposed approach in selected three domains Academics Entertainment and Sports and the results confirm the improvement in the precision of search results.

  16. The Metadata Anonymization Toolkit

    OpenAIRE

    2012-01-01

    This document summarizes the experience of Julien Voisin during the 2011 edition of the well-known \\emph{Google Summer of Code}. This project is a first step in the domain of metadata anonymization in Free Software. This article is articulated in three parts. First, a state of the art and a categorization of usual metadata, then the privacy policy is exposed/discussed in order to find the right balance between information lost and privacy enhancement. Finally, the specification of the Metadat...

  17. jQuery Pocket Reference

    CERN Document Server

    Flanagan, David

    2010-01-01

    "As someone who uses jQuery on a regular basis, it was surprising to discover how much of the library I'm not using. This book is indispensable for anyone who is serious about using jQuery for non-trivial applications."-- Raffaele Cecco, longtime developer of video games, including Cybernoid, Exolon, and Stormlord jQuery is the "write less, do more" JavaScript library. Its powerful features and ease of use have made it the most popular client-side JavaScript framework for the Web. This book is jQuery's trusty companion: the definitive "read less, learn more" guide to the library. jQuery P

  18. jQuery UI cookbook

    CERN Document Server

    Boduch, Adam

    2013-01-01

    Filled with a practical collection of recipes, jQuery UI Cookbook is full of clear, step-by-step instructions that will help you harness the powerful UI framework in jQuery. Depending on your needs, you can dip in and out of the Cookbook and its recipes, or follow the book from start to finish.If you are a jQuery UI developer looking to improve your existing applications, extract ideas for your new application, or to better understand the overall widget architecture, then jQuery UI Cookbook is a must-have for you. The reader should at least have a rudimentary understanding of what jQuery UI is

  19. Approximate dictionary queries

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Gasieniec, Leszek

    1996-01-01

    Given a set of n binary strings of length m each. We consider the problem of answering d-queries. Given a binary query string of length m, a d-query is to report if there exists a string in the set within Hamming distance d of . We present a data structure of size O(nm) supporting 1-queries in ti...

  20. 基于Struts2+jQuery+JSON实现Ajax数据显示%Implementation of Ajax Data Display Based on Struts2+jQuery+JSON

    Institute of Scientific and Technical Information of China (English)

    施俊

    2014-01-01

    Through asynchronous interaction technology, Ajax enchances the transmission efficiency and the speed of response between the server and the client side based on the B/S application. Introduces how to bring about the Ajax function by utilizing the intergerated framework of Struts2 and jQuery as well as JSON data format., the development of Web system change easier, more efficient. Through the example of data display expound the realization process.%Ajax通过异步交互技术,提高在B/S模式下服务器与客户端之间的传输效率和响应速度。通过整合Struts2框架、jQuery框架以及JSON数据格式,介绍如何实现Ajax功能,使Web系统开发变得更容易、更有效率,并通过数据显示实例讲解了实现过程。

  1. Implementation of SPARQL Query Engine Based on CouchDB%基于CouchDB的SPARQL查询引擎实现

    Institute of Scientific and Technical Information of China (English)

    彭义; 倪传蕾; 柏文阳

    2014-01-01

    Traditional SPARQL query engines optimize queries in terms of triple pattern as basic unit. This brings too many join operations in the face of SPARQL queries comprising many triple patterns,which lead to much query overhead. In this paper,taking the advantage of storing and quering of document-oriented database,propose a subject-classification approach to store RDF triples. RDF triples are parti-tioned into various classes in terms of identical subjects,and saved to the documents of the database. Triple patterns are classified accord-ing to their subjects as well,composing the query graph based on subject-related block. The method of selectivity estimation is improved on the new query graph. Using a document-oriented databse CouchDB to build a SPARQL query engine,the experiment proves the ap-proach is capable of improving the efficiency of SPARQL basic graph pattern query handling.%传统的SPARQL查询引擎在处理查询时以三元组模式为基本单位做查询优化处理,在三元组模式较多时存在着过多的连接操作,开销比较大。文中基于文档数据库的存储和查询特点,提出一种利用主语分类的方式来存储RDF数据的方法,将不同的RDF三元组按主语分成不同的类,并存入文档数据库的文档中。在处理SPARQL查询时将三元组模式也按照主语分类,构成以主语相关块为单位的查询图,并提出一种基于属性相关性的选择度估计方法来优化查询执行计划。文中利用文档数据库CouchDB实现了新的SPARQL查询引擎,实验证明文中的方法能够提高SPARQL基本图模式查询的效率。

  2. An Examination of Natural Language as a Query Formation Tool for Retrieving Information on E-Health from Pub Med.

    Science.gov (United States)

    Peterson, Gabriel M.; Su, Kuichun; Ries, James E.; Sievert, Mary Ellen C.

    2002-01-01

    Discussion of Internet use for information searches on health-related topics focuses on a study that examined complexity and variability of natural language in using search terms that express the concept of electronic health (e-health). Highlights include precision of retrieved information; shift in terminology; and queries using the Pub Med…

  3. Reflections on the Ritual process in Mexican Communities of Alcoholics Anonymous

    Directory of Open Access Journals (Sweden)

    Palacios Ramírez, José

    2008-12-01

    Full Text Available The author conveys his reflections on the symbolic aspects and ritual character of the therapeutic communities of rehabilitation of alcoholics, known as “Alcoholic Anonymous” (AA. He did ethnographic fieldwork among AA communities of Ciudad Victoria, in Tamaulipas, northern Mexico. These communities, facing a problem often neglected by both government and society in Mexico, yet holding a position of subalternity and marginality in the country, offer a spiritual way out to those alcoholics who approach them. Their activities are of interest for a discussion of ritual in current contexts. In addition, the communities are illuminating for many of the key aspects of the comparative ethnographic analysis of ritual.

    El objeto de este trabajo es apuntar algunas líneas de reflexión sobre los aspectos simbólicos y de carácter ritual que presentan las comunidades terapéuticas de rehabilitación de alcohólicos, Alcohólicos Anónimos (AA. Para ello parto del trabajo de campo etnográfico realizado en agrupaciones de AA en Ciudad Victoria, Tamaulipas, al norte de México. Estas comunidades de apoyo a alcohólicos, desde una posición de subalternidad y marginalidad, ante una problemática casi siempre obviada por la sociedad y el gobierno mexicano, ofrecen una “salida” de corte espiritual a quienes se acercan a ellas, por lo que resultan interesantes para la reflexión sobre el ritual en contextos actuales. Por otro lado, estas comunidades presentan muchos de los aspectos clave en el análisis etnográfico comparativo de los ritos.

  4. Predecessor queries in dynamic integer sets

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting

    1997-01-01

    We consider the problem of maintaining a set of n integers in the range 0.2w–1 under the operations of insertion, deletion, predecessor queries, minimum queries and maximum queries on a unit cost RAM with word size w bits. Let f (n) be an arbitrary nondecreasing smooth function satisfying n...

  5. Deterministic Leader Election Among Disoriented Anonymous Sensors

    CERN Document Server

    dieudonné, Yoann; Petit, Franck; Villain, Vincent

    2012-01-01

    We address the Leader Election (LE) problem in networks of anonymous sensors sharing no kind of common coordinate system. Leader Election is a fundamental symmetry breaking problem in distributed computing. Its goal is to assign value 1 (leader) to one of the entities and value 0 (non-leader) to all others. In this paper, assuming n > 1 disoriented anonymous sensors, we provide a complete charac- terization on the sensors positions to deterministically elect a leader, provided that all the sensors' positions are known by every sensor. More precisely, our contribution is twofold: First, assuming n anonymous sensors agreeing on a common handedness (chirality) of their own coordinate system, we provide a complete characterization on the sensors positions to deterministically elect a leader. Second, we also provide such a complete chararacterization for sensors devoided of a common handedness. Both characterizations rely on a particular object from combinatorics on words, namely the Lyndon Words.

  6. The Query-commit Problem

    CERN Document Server

    Molinaro, Marco

    2011-01-01

    In the query-commit problem we are given a graph where edges have distinct probabilities of existing. It is possible to query the edges of the graph, and if the queried edge exists then its endpoints are irrevocably matched. The goal is to find a querying strategy which maximizes the expected size of the matching obtained. This stochastic matching setup is motivated by applications in kidney exchanges and online dating. In this paper we address the query-commit problem from both theoretical and experimental perspectives. First, we show that a simple class of edges can be queried without compromising the optimality of the strategy. This property is then used to obtain in polynomial time an optimal querying strategy when the input graph is sparse. Next we turn our attentions to the kidney exchange application, focusing on instances modeled over real data from existing exchange programs. We prove that, as the number of nodes grows, almost every instance admits a strategy which matches almost all nodes. This resu...

  7. Anonymous Proxy Signcryption Scheme Based on Quadratic Residue%基于二次剩余的匿名代理者签密方案

    Institute of Scientific and Technical Information of China (English)

    刘祯; 杨启良; 杨波

    2015-01-01

    由于现有签密方案大多基于双线性对,配对运算计算量较大,且实现效率不高,不能满足对代理签密者的匿名要求,因此无需配对的签密方案是密码学的研究方向。而基于二次剩余的签名方案不仅具有描述简单,能够抵抗选择密文攻击的优点,且相较于基于配对的签名方案具有更高的实现效率。为此,将二次剩余的方法应用到签密方案中,并结合匿名性,提出一种基于二次剩余的匿名代理者签密方案。分析结果表明,该方案具有匿名性与公开验证性。%Most of the existing signcryptions are based on bilinear pairing,but the signcryption without bilinear pairing is a research of cryptography,because the pairing operation requires a lot of computations,and it can not anonymous the proxy signcrypter. The signature scheme based on quadratic residue is widely used with its advantages such as simple description,resistance of chosen ciphertext attack and high efficiency. Its efficient is higher compared with signcryption schemes based on bilinear pairing. This paper adds anonymity to the scheme based on quadratic residue to realize anonymous proxy signcryption. Analysis results show that the scheme not only provides anonymity, but also provides public verifiability.

  8. Semantic Normalization and Query Abstraction Based on SNOMED-CT and HL7: Supporting Multicentric Clinical Trials.

    Science.gov (United States)

    Paraiso-Medina, Sergio; Perez-Rey, David; Bucur, Anca; Claerhout, Brecht; Alonso-Calvo, Raul

    2015-05-01

    Advances in the use of omic data and other biomarkers are increasing the number of variables in clinical research. Additional data have stratified the population of patients and require that current studies be performed among multiple institutions. Semantic interoperability and standardized data representation are a crucial task in the management of modern clinical trials. In the past few years, different efforts have focused on integrating biomedical information. Due to the complexity of this domain and the specific requirements of clinical research, the majority of data integration tasks are still performed manually. This paper presents a semantic normalization process and a query abstraction mechanism to facilitate data integration and retrieval. A process based on well-established standards from the biomedical domain and the latest semantic web technologies has been developed. Methods proposed in this paper have been tested within the EURECA EU research project, where clinical scenarios require the extraction of semantic knowledge from biomedical vocabularies. The aim of this paper is to provide a novel method to abstract from the data model and query syntax. The proposed approach has been compared with other initiatives in the field by storing the same dataset with each of those solutions. Results show an extended functionality and query capabilities at the cost of slightly worse performance in query execution. Implementations in real settings have shown that following this approach, usable interfaces can be developed to exploit clinical trial data outcomes.

  9. Secure Electronic Cash Scheme with Anonymity Revocation

    Directory of Open Access Journals (Sweden)

    Baoyuan Kang

    2016-01-01

    Full Text Available In a popular electronic cash scheme, there are three participants: the bank, the customer, and the merchant. First, a customer opens an account in a bank. Then, he withdraws an e-cash from his account and pays it to a merchant. After checking the electronic cash’s validity, the merchant accepts it and deposits it to the bank. There are a number of requirements for an electronic cash scheme, such as, anonymity, unforgeability, unreusability, divisibility, transferability, and portability. Anonymity property of electronic cash schemes can ensure the privacy of payers. However, this anonymity property is easily abused by criminals. In 2011, Chen et al. proposed a novel electronic cash system with trustee-based anonymity revocation from pairing. On demand, the trustee can disclose the identity for e-cash. But, in this paper we point out that Chen et al.’s scheme is subjected to some drawbacks. To contribute secure electronic cash schemes, we propose a new offline electronic cash scheme with anonymity revocation. We also provide the formally security proofs of the unlinkability and unforgeability. Furthermore, the proposed scheme ensures the property of avoiding merchant frauds.

  10. Recommendation Sets and Choice Queries

    DEFF Research Database (Denmark)

    Viappiani, Paolo Renato; Boutilier, Craig

    2011-01-01

    Utility elicitation is an important component of many applications, such as decision support systems and recommender systems. Such systems query users about their preferences and offer recommendations based on the system's belief about the user's utility function. We analyze the connection between...... the problem of generating optimal recommendation sets and the problem of generating optimal choice queries, considering both Bayesian and regret-based elicitation. Our results show that, somewhat surprisingly, under very general circumstances, the optimal recommendation set coincides with the optimal query....

  11. Multi-Dimensional Path Queries

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    1998-01-01

    We present the path-relationship model that supports multi-dimensional data modeling and querying. A path-relationship database is composed of sets of paths and sets of relationships. A path is a sequence of related elements (atoms, paths, and sets of paths). A relationship is a binary path...... to create nested path structures. We present an SQL-like query language that is based on path expressions and we show how to use it to express multi-dimensional path queries that are suited for advanced data analysis in decision support environments like data warehousing environments...

  12. How To Break Anonymity of the Netflix Prize Dataset

    OpenAIRE

    Narayanan, Arvind; Shmatikov, Vitaly

    2006-01-01

    We present a new class of statistical de-anonymization attacks against high-dimensional micro-data, such as individual preferences, recommendations, transaction records and so on. Our techniques are robust to perturbation in the data and tolerate some mistakes in the adversary's background knowledge. We apply our de-anonymization methodology to the Netflix Prize dataset, which contains anonymous movie ratings of 500,000 subscribers of Netflix, the world's largest online movie rental service. ...

  13. Research of Query Translation on Deep Web%Deep Web搜索中查询转换的研究

    Institute of Scientific and Technical Information of China (English)

    邵秀丽; 李云龙; 张文龙

    2012-01-01

    The mapping mechanism of query translation has been advanced, which is based on synonymous attributes and group attributes. The problem of how to realize the more accurate comprehensive mapping from the source query string to the target query string has been solved. The query substring to each source site for the realization of retrieval has been provided, the solution of this paper has been applied to 20 representative Deep Web sites which are selected from domestic books area, and the Deep Web search to these sites* book information is implemented.%基于同义属性和成组属性给出了查询转换映射机制,解决了如何从源查询串到目标查询串的较为准确的映射,实现了检索对应各源网址的转换查询子串,相应的方案应用于国内20个代表性的图书领域的DeepWeb站点,较好地实现了对这些站点的Deep Web图书信息的搜索.

  14. Intelligent query by humming system based on score level fusion of multiple classifiers

    Science.gov (United States)

    Pyo Nam, Gi; Thu Trang Luong, Thi; Ha Nam, Hyun; Ryoung Park, Kang; Park, Sung-Joo

    2011-12-01

    Recently, the necessity for content-based music retrieval that can return results even if a user does not know information such as the title or singer has increased. Query-by-humming (QBH) systems have been introduced to address this need, as they allow the user to simply hum snatches of the tune to find the right song. Even though there have been many studies on QBH, few have combined multiple classifiers based on various fusion methods. Here we propose a new QBH system based on the score level fusion of multiple classifiers. This research is novel in the following three respects: three local classifiers [quantized binary (QB) code-based linear scaling (LS), pitch-based dynamic time warping (DTW), and LS] are employed; local maximum and minimum point-based LS and pitch distribution feature-based LS are used as global classifiers; and the combination of local and global classifiers based on the score level fusion by the PRODUCT rule is used to achieve enhanced matching accuracy. Experimental results with the 2006 MIREX QBSH and 2009 MIR-QBSH corpus databases show that the performance of the proposed method is better than that of single classifier and other fusion methods.

  15. Intelligent query by humming system based on score level fusion of multiple classifiers

    Directory of Open Access Journals (Sweden)

    Park Sung-Joo

    2011-01-01

    Full Text Available Abstract Recently, the necessity for content-based music retrieval that can return results even if a user does not know information such as the title or singer has increased. Query-by-humming (QBH systems have been introduced to address this need, as they allow the user to simply hum snatches of the tune to find the right song. Even though there have been many studies on QBH, few have combined multiple classifiers based on various fusion methods. Here we propose a new QBH system based on the score level fusion of multiple classifiers. This research is novel in the following three respects: three local classifiers [quantized binary (QB code-based linear scaling (LS, pitch-based dynamic time warping (DTW, and LS] are employed; local maximum and minimum point-based LS and pitch distribution feature-based LS are used as global classifiers; and the combination of local and global classifiers based on the score level fusion by the PRODUCT rule is used to achieve enhanced matching accuracy. Experimental results with the 2006 MIREX QBSH and 2009 MIR-QBSH corpus databases show that the performance of the proposed method is better than that of single classifier and other fusion methods.

  16. Anonymity and Openness in Donor Conception: the New Danish Model

    DEFF Research Database (Denmark)

    Herrmann, Janne Rothmar

    2013-01-01

    model in donor conception which offers women/couples a choice of anonymity or openness in donation.This paper is based on my talk on June 20, 2013 at London School of Economics at the conference “New Families and Genetic Identities: Developments in law, policy and research” organised by the Morgan...... bank is based in Denmark and consequently anonymous sperm is also exported abroad, even into jurisdictions where anonymity is banned illegal. This commentary traces the raison d’être of anonymity in Danish law, accounts for the legal framework for the internet sale of sperm and examines the new Danish...

  17. GeoVanet: A Routing Protocol for Query Processing in Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Thierry Delot

    2011-01-01

    Full Text Available In a vehicular ad hoc network (VANET, cars can exchange information by using short-range wireless communications. Along with the opportunities offered by vehicular networks, a number of challenges also arise. In particular, most works so far have focused on a push model, where potentially useful data are pushed towards vehicles. The use of pull models, that would allow users to send queries to a set of cars in order to find the desired information, has not been studied in depth. The main challenge for pull models is the difficulty to route the different results towards the query originator in a highly dynamic network where the nodes move very quickly. To solve this issue, we propose GeoVanet, an anonymous and non-intrusive geographic routing protocol which ensures that the sender of a query can get a consistent answer. Our goal is to ensure that the user will be able to retrieve the query results within a bounded time. To prove the effectiveness of GeoVanet, an extensive experimental evaluation has been performed, that proves the interest of the proposal for both rural and urban areas. It shows that up to 80% of the available query results are delivered to the user.

  18. 基于隐私决策度的改进k-匿名算法%Improved Algorithm of k-anonymity Based on Degree of Privacy Preservation

    Institute of Scientific and Technical Information of China (English)

    申艳光; 闫晶星; 刘永红; 郭高尚

    2015-01-01

    现有的匿名化隐私保护技术在进行数据发布和数据共享前对于敏感属性的个性化隐私保护的支持存在不足,为了实现更为合理的个性化隐私保护,结合粒计算粗糙集理论和k-匿名理论的最新研究成果,针对电子商务中隐私保护个性化决策选择度的不同,从粒化角度出发,提出一种基于隐私决策度的改进k-匿名算法。经实验验证,该算法更好的实现了隐私保护的个性化,同时其隐私保护精度方面优于已有的p-Sensitive k-匿名算法。%In the existing anonymous privacy protection technology, there is a shortage of personalized privacy protection support for sensitive attributes before data release and sharing. In order to achieve more reasonable personalized privacy preservation and improve the precision of privacy preservation, this paper reviewed the latest researches in granular computing theory, rough set theory and k-anonymity theory, and presented an improved algorithm of k-anonymity based on the personalized decision degree of privacy preservation, in view of different personalized granularity decision selectivity of privacy preservation in E-business.The experimental results show that the novel algorithm can achieve privacy preservation with more reasonable personalization, and its accuracy of privacy preservation is superior to p-sensitive k-anonymity algorithm.

  19. Anonymous Authentication Scheme Based on Role Model of PMI%基于PMI角色模型的匿名认证方案

    Institute of Scientific and Technical Information of China (English)

    贺靖靖; 刘景森; 史强; 傅慧明

    2012-01-01

    隐私保护是当前网络应用中最受关注的问题之一,越来越多的用户希望加强隐私保护,在不泄露个人敏感信息的情况下实现资源访问.针对匿名访问控制提出了一种基于PKI/PMI证书的认证方案,即在用户和服务提供者之间引入可信第三方,利用角色说明属性证书RS-AC和角色分配属性证书RA-AC,实现匿名认证.理论分析证明,该方案具有安全性、匿名性和不关联性.%Nowadays,the privacy protection is one of the most concerned problems. More and more users want to strengthen their own privacy preservation and hope that they can access the resources without providing personal sensitive informations. An anonymous access control scheme is proposed which is based on PKI/PMI certificates. The trusted third party is introduced between users and the service provider. The role stated-attribute certificate(RS-AC) and role assigned attribute certificate(RA-AC) are used to implement the anonymous authentication. Theoretical analysis shows that this solution provides the security,anonymity and no relevance.

  20. QuerySpaces on Hadoop for the ATLAS EventIndex

    CERN Document Server

    Hrivnac, Julius; The ATLAS collaboration; Cranshaw, Jack; Favareto, Andrea; Prokoshin, Fedor; Glasman, Claudia; Toebbicke, Rainer

    2015-01-01

    A Hadoop-based implementation of the adaptive query engine serving as the back-end for the ATLAS EventIndex. The QuerySpaces implementation handles both original data and search results providing fast and efficient mechanisms for new user queries using already accumulated knowledge for optimization. Detailed descriptions and statistics about user requests are collected in HBase tables and HDFS files. Requests are associated to their results and a graph of relations between them is created to be used to find the most efficient way of providing answers to new requests The environment is completely transparent to users and is accessible over several command-line interfaces, a Web Service and a programming API.

  1. QuerySpaces on Hadoop for the ATLAS EventIndex

    CERN Document Server

    Hrivnac, Julius; The ATLAS collaboration; Cranshaw, Jack; Glasman, Claudia; Favareto, Andrea; Prokoshin, Fedor

    2015-01-01

    Hadoop-based implementation of the adaptive query engine serving as the back-end for the ATLAS EventIndex. The QuerySpaces implementation handles both original data and search results providing fast and efficient mechanisms for new user queries using already accumulated knowledge for optimisation. Detailed description and statistics about user requests are collected in HBase tables and HDFS files. Requests are associated to their results and a graph of relations between them is created to be used to find the most efficient way of providing answers to new requests The environment is completely transparent to users and is accessible over several command-line interfaces, a Web Service and a programming API.

  2. Web development with jQuery

    CERN Document Server

    York, Richard

    2015-01-01

    Newly revised and updated resource on jQuery's many features and advantages Web Development with jQuery offers a major update to the popular Beginning JavaScript and CSS Development with jQuery from 2009. More than half of the content is new or updated, and reflects recent innovations with regard to mobile applications, jQuery mobile, and the spectrum of associated plugins. Readers can expect thorough revisions with expanded coverage of events, CSS, AJAX, animation, and drag and drop. New chapters bring developers up to date on popular features like jQuery UI, navigation, tables, interacti

  3. Authentication Without Identification using Anonymous Credential System

    CERN Document Server

    Damodaram, A

    2009-01-01

    Privacy and security are often intertwined. For example, identity theft is rampant because we have become accustomed to authentication by identification. To obtain some service, we provide enough information about our identity for an unscrupulous person to steal it (for example, we give our credit card number to Amazon.com). One of the consequences is that many people avoid e-commerce entirely due to privacy and security concerns. The solution is to perform authentication without identification. In fact, all on-line actions should be as anonymous as possible, for this is the only way to guarantee security for the overall system. A credential system is a system in which users can obtain credentials from organizations and demonstrate possession of these credentials. Such a system is anonymous when transactions carried out by the same user cannot be linked. An anonymous credential system is of significant practical relevance because it is the best means of providing privacy for users.

  4. Optimizing Temporal Queries

    DEFF Research Database (Denmark)

    Toman, David; Bowman, Ivan Thomas

    2003-01-01

    translated SQL queries by taking into account the properties of the encoding used for temporal attributes. For concreteness, this translation technique is presented in the context of SQL/TP; however, these techniques are also applicable to other temporal query languages......., these query languages are implemented by translating temporal queries into standard relational queries. However, the compiled queries are often quite cumbersome and expensive to execute even using state-of-the-art relational products. This paper presents an optimization technique that produces more efficient......Recent research in the area of temporal databases has proposed a number of query languages that vary in their expressive power and the semantics they provide to users. These query languages represent a spectrum of solutions to the tension between clean semantics and efficient evaluation. Often...

  5. Multi-Classifier Based on a Query-by-Singing/Humming System

    Directory of Open Access Journals (Sweden)

    Gi Pyo Nam

    2015-06-01

    Full Text Available With the increase in the number of music files on various devices, it can be difficult to locate a desired file, especially when the title of the song or the name of the singer is not known. We propose a new query-by-singing/humming (QbSH system that can find music files that match what the user is singing or humming. This research is novel in the following three ways: first, the Fourier descriptor (FD method is proposed as the first classifier; it transforms the humming or music waveform into the frequency domain. Second, quantized dynamic time warping (QDTW using symmetrical search space and quantized linear scaling (QLS are used as the second and third classifiers, respectively, which increase the accuracy of the QbSH system compared to the conventional DTW and LS methods. Third, five classifiers, which include the three already mentioned along with the conventional DTW using symmetrical search space and LS methods, are combined using score level fusion, which further enhances performance. Experimental results with the 2009 MIR-QbSH corpus and the AFA MIDI 100 databases show that the proposed method outperforms those using a single classifier and other fusion methods.

  6. The role of economics in the QUERI program: QUERI Series

    Directory of Open Access Journals (Sweden)

    Smith Mark W

    2008-04-01

    Full Text Available Abstract Background The United States (U.S. Department of Veterans Affairs (VA Quality Enhancement Research Initiative (QUERI has implemented economic analyses in single-site and multi-site clinical trials. To date, no one has reviewed whether the QUERI Centers are taking an optimal approach to doing so. Consistent with the continuous learning culture of the QUERI Program, this paper provides such a reflection. Methods We present a case study of QUERI as an example of how economic considerations can and should be integrated into implementation research within both single and multi-site studies. We review theoretical and applied cost research in implementation studies outside and within VA. We also present a critique of the use of economic research within the QUERI program. Results Economic evaluation is a key element of implementation research. QUERI has contributed many developments in the field of implementation but has only recently begun multi-site implementation trials across multiple regions within the national VA healthcare system. These trials are unusual in their emphasis on developing detailed costs of implementation, as well as in the use of business case analyses (budget impact analyses. Conclusion Economics appears to play an important role in QUERI implementation studies, only after implementation has reached the stage of multi-site trials. Economic analysis could better inform the choice of which clinical best practices to implement and the choice of implementation interventions to employ. QUERI economics also would benefit from research on costing methods and development of widely accepted international standards for implementation economics.

  7. Community engagement research and dual diagnosis anonymous.

    Science.gov (United States)

    Roush, Sean; Monica, Corbett; Pavlovich, Danny; Drake, Robert E

    2015-01-01

    Community engagement research is widely discussed but rarely implemented. This article describes the implementation of a community engagement research project on Dual Diagnosis Anonymous, a rapidly spreading peer support program in Oregon for people with co-occurring mental illness and substance use disorders. After three years of discussions, overcoming barriers, and involving several institutions, this grassroots research project has been implemented and is expanding. Active participants in Dual Diagnosis Anonymous inspired and instructed policy makers, professionals, and students. Community engagement research requires frontline participants, community members, and professional collaborators to overcome multiple barriers with persistence and steadfastness. Building trust, collaboration, and structures for community engagement research takes time and a community effort.

  8. Efficient Query Rewrite for Structured Web Queries

    CERN Document Server

    Gollapudi, Sreenivas; Ntoulas, Alexandros; Paparizos, Stelios

    2011-01-01

    Web search engines and specialized online verticals are increasingly incorporating results from structured data sources to answer semantically rich user queries. For example, the query \\WebQuery{Samsung 50 inch led tv} can be answered using information from a table of television data. However, the users are not domain experts and quite often enter values that do not match precisely the underlying data. Samsung makes 46- or 55- inch led tvs, but not 50-inch ones. So a literal execution of the above mentioned query will return zero results. For optimal user experience, a search engine would prefer to return at least a minimum number of results as close to the original query as possible. Furthermore, due to typical fast retrieval speeds in web-search, a search engine query execution is time-bound. In this paper, we address these challenges by proposing algorithms that rewrite the user query in a principled manner, surfacing at least the required number of results while satisfying the low-latency constraint. We f...

  9. Learning semantic query suggestions

    NARCIS (Netherlands)

    E. Meij; M. Bron; L. Hollink; B. Huurnink; M. de Rijke

    2009-01-01

    An important application of semantic web technology is recognizing human-defined concepts in text. Query transformation is a strategy often used in search engines to derive queries that are able to return more useful search results than the original query and most popular search engines provide faci

  10. XML Multidimensional Modelling and Querying

    CERN Document Server

    Boucher, Serge; Zimányi, Esteban

    2009-01-01

    As XML becomes ubiquitous and XML storage and processing becomes more efficient, the range of use cases for these technologies widens daily. One promising area is the integration of XML and data warehouses, where an XML-native database stores multidimensional data and processes OLAP queries written in the XQuery interrogation language. This paper explores issues arising in the implementation of such a data warehouse. We first compare approaches for multidimensional data modelling in XML, then describe how typical OLAP queries on these models can be expressed in XQuery. We then show how, regardless of the model, the grouping features of XQuery 1.1 improve performance and readability of these queries. Finally, we evaluate the performance of query evaluation in each modelling choice using the eXist database, which we extended with a grouping clause implementation.

  11. A Query Optimization Method Based on Virtual Data Warehouse%一种基于虚拟数据仓库的查询优化方法

    Institute of Scientific and Technical Information of China (English)

    郭爱章; 王新刚

    2009-01-01

    For trans-regional enterprises, it is an important researchful problem to get information from data warehouses of different regions for decision-making. In this paper, the author proposes a query optimization algorithm based on virtual data warehouse. In addition, the author introduces the concept of metadata and quick query table. Through quick query table, you can get query scheme quickly. And then through mapping between quick query table and each metadata, you can form query scheme and finally get query results. Analysis data illustrate query efficiency can get improved by using this method.%跨地区企业集团如何从分布在各地数据仓库的数据中获取信息以帮助他们决策是数据仓库研究的一个重要问题.本文提出了一种虚拟数据仓库三层模型及其查询优化方法,引入了虚拟元数据、查询快表等概念,通过查询快表可以快速得到查询方案,通过虚拟元数据与各结点元数据的映射,可形成查询方案,从而获得查询结果.分析表明,该方法能够有效地提高查询效率.

  12. An Efficient Query Rewriting Approach for Web Cached Data Management

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With the internet development, querying data on the Web is an attention problem of involving information from distributed, and often dynamically, related Web sources. Basically, some sub-queries can be effectively cached from previous queries or materialized views in order to achieve a better query performance based on the notion of rewriting queries. In this paper, we propose a novel query-rewriting model, called Hierarchical Query Tree, for representing Web queries. Hierarchical Query Tree is a labeled tree that is suitable for representing the inherent hierarchy feature of data on the Web. Based on Hierarchical Query Tree, we use case-based approach to determine what the query results should be. The definitions of queries and query results are both represented as labeled trees. Thus, we can use the same model for representing cases and the medium query results can also be dynamically updated by the user queries. We show that our case-based method can be used to answer a new query based on the combination of previous queries, including changes of requirements and various information sources.

  13. Robust Query Processing for Personalized Information Access on the Semantic Web

    DEFF Research Database (Denmark)

    Dolog, Peter; Stuckenschmidt, Heiner; Wache, Holger

    and user preferences. We describe a framework for information access that combines query refinement and relaxation in order to provide robust, personalized access to heterogeneous RDF data as well as an implementation in terms of rewriting rules and explain its application in the context of e...

  14. Chaotic Order Preserving Encryption for Efficient and Secure Queries on Databases

    Science.gov (United States)

    Lee, Seungmin; Park, Tae-Jun; Lee, Donghyeok; Nam, Taekyong; Kim, Sehun

    The need for data encryption that protects sensitive data in a database has increased rapidly. However, encrypted data can no longer be efficiently queried because nearly all of the data should be decrypted. Several order-preserving encryption schemes that enable indexes to be built over encrypted data have been suggested to solve this problem. They allow any comparison operation to be directly applied to encrypted data. However, one of the main disadvantages of these schemes is that they expose sensitive data to inference attacks with order information, especially when the data are used together with unencrypted columns in the database. In this study, a new order-preserving encryption scheme that provides secure queries by hiding the order is introduced. Moreover, it provides efficient queries because any user who has the encryption key knows the order. The proposed scheme is designed to be efficient and secure in such an environment. Thus, it is possible to encrypt only sensitive data while leaving other data unencrypted. The encryption is not only robust against order exposure, but also shows high performance for any query over encrypted data. In addition, the proposed scheme provides strong updates without assumptions of the distribution of plaintext. This allows it to be integrated easily with the existing database system.

  15. Anonymous Web Browsing and Hosting

    Directory of Open Access Journals (Sweden)

    MANOJ KUMAR

    2013-02-01

    Full Text Available In today’s high tech environment every organization, individual computer users use internet for accessing web data. To maintain high confidentiality and security of the data secure web solutions are required. In this paper we described dedicated anonymous web browsing solutions which makes our browsing faster and secure. Web application which play important role for transferring our secret information including like email need more and more security concerns. This paper also describes that how we can choose safe web hosting solutions and what the main functions are which provides more security over server data. With the browser security network security is also important which can be implemented using cryptography solutions, VPN and by implementing firewalls on the network. Hackers always try to steal our identity and data, they track our activities using the network application software’s and do harmful activities. So in this paper we described that how we can monitor them from security purposes.

  16. Privacy-preserving location-based query using location indexes and parallel searching in distributed networks.

    Science.gov (United States)

    Zhong, Cheng; Liu, Lei; Zhao, Jing

    2014-01-01

    An efficient location-based query algorithm of protecting the privacy of the user in the distributed networks is given. This algorithm utilizes the location indexes of the users and multiple parallel threads to search and select quickly all the candidate anonymous sets with more users and their location information with more uniform distribution to accelerate the execution of the temporal-spatial anonymous operations, and it allows the users to configure their custom-made privacy-preserving location query requests. The simulated experiment results show that the proposed algorithm can offer simultaneously the location query services for more users and improve the performance of the anonymous server and satisfy the anonymous location requests of the users.

  17. 采用RDF的查询扩展研究%ON QUERY EXTENSION USING RDF

    Institute of Scientific and Technical Information of China (English)

    姜旭; 张波

    2011-01-01

    由于传统的P2P查询处理将用户查询作为独立的关键字对待,只考虑其字面符号意义而不考虑其语义.因此,用户的查询需求往往得不到真实的体现.基于本体的P2P资源匹配使用本体对网络资源进行了描述,在很大程度上反映了资源的语义,然而仍需要对查询请求进行语义扩展才适合在资源的本体中进行查询处理.使用RDF三元组描述用户请求,并扩展其语义表达能力,分析本体中概念间的上下位关系,对查询请求进行语义扩展,扩展后的查询适合于利用本体进行查询匹配.分析表明,这种扩展是有效的合理的.%Traditional P2P query processing method regards user's query as independent key words, considering just its literal meaning without digging its semantics, therefore user's query requirement can't be comprehended rightly. Ontology-based P2P matchmaking depicts network resources using ontology, though the semantics of resource has been greatly exposed, but it still need proper query extension in semantics to fit for matchmaking in resource ontology. In this paper we use RDF triple to describe query, and extend its semantic expression ability, analyse the inheriting relationship between concepts in ontology to extend the query semantically; the extended query is more suitable for matchmaking with ontology. Analysis indicates that the extension is more effective and reasonable.

  18. Structured Query Language for Virtual Observatory

    CERN Document Server

    Shirasaki, Y; Mizumoto, Y; Tanaka, M; Honda, S; Oe, M; Yasuda, N; Masunaga, Y; Shirasaki, Yuji; Ohishi, Masatoshi; Mizumoto, Yoshihiko; Tanaka, Masahiro; Honda, Satoshi; Oe, Masafumi; Yasuda, Naoki; Masunaga, Yoshifumi

    2004-01-01

    Currently two query languages are defined as standards for the Virtual Observatory (VO). Astronomical Data Query Language (ADQL) is used for catalog data query and Simple Image Access Protocol (SIAP) is for image data query. As a result, when we query each data service, we need to know in advance which language is supported and then construct a query language accordingly. The construct of SIAP is simple, but they have a limited capability. For example, there is no way to specify multiple regions in one query, and it is difficult to specify complex query conditions. In this paper, we propose a unified query language for any kind of astronomical database on the basis of SQL99. SQL is a query language optimized for a table data, so to apply the SQL to the image and spectrum data set, the data structure need to be mapped to a table like structure. We present specification of this query language and an example of the architecture for the database system.

  19. A Mixed Anonymous System based on Tor%基于Tor的混合匿名转发系统

    Institute of Scientific and Technical Information of China (English)

    郑光; 薛质

    2011-01-01

    随着互联网应用的不断增加,人们对网络通信的保密性也越来越重视。Tor匿名通信系统具有低时延、数据加密传输,安全信道等优点,能够有效保护通信者的信息安全,目前正成为一种流行的匿名通信系统。但随着Tor系统使用和研究的人增多,Tor系统本身的一些缺陷给其安全带来了隐患。为此,在现有Tor系统分析的基础上,文中提出了一种安全新型的混合匿名转发系统H—Tor。该系统由Hordes和Tor有效级联组合,充分发挥了两者的优势。分析表明,H—Tor可以抵御通信流攻击和端对端攻击,有效保护通信者的匿名安全。%With the continuous increase of lnternet applications, people pay much attention to the confidentiality of network communications. Tor anonymous communication system, with low latency, data eneryption transmission, secure channel, etc., could effectively protect the information security of the correspondents, and thus becomes a popular anonymous communication system. However, with in-depth study wide use of the Tor system, Tor presents some defects in security risks. Currently, a new system called H-Tor is proposed upon the analysis of Tor. The system combines Hordes with Tor and gives full play to their advantages. Analysis shows that the H-Tor integration can effectively protect the anonymity of the correspondents.

  20. 本体的查询与推理研究%Research on Ontology Querying and Inference

    Institute of Scientific and Technical Information of China (English)

    王晓慧; 罗军; 余淑良

    2012-01-01

    Nowadays,computer network is widely used in various aspects of life. But searching for what people need from the mass information has a lot of questions. Consequently,the concept of ontology has appeared. And then ontology querying and inference is the important component of the application based on ontology. The purposes of this research are to make the knowledge to the fullest expression and querying the information more accurate and complete. Firstly, introduced the concept of ontology and constructed an ontology model. Then used ontology query language,SPARQL,to query me existed model. And also used SWRL to extend the semantic rules. Finally,introduced lena with which obtained more knowledge by reasoning on the model. Thus concluded,in the process of querying and inference with SPARQL and Jena,inference could develop the ability of querying,and the rules were the key to increase the power of inference.%现今,计算机网络被广泛应用于生活的方方面面,而从海量的信息中搜寻出人们所需要的还存在诸多问题,于是产生了本体的概念.而本体的查询和推理是基于本体的应用中重要的组成部分,研究的目的是为了使知识得以充分表达并且对信息的查询更加精确、完备.首先介绍了本体的概念并建立本体模型,然后用本体查询语言SPARQL对已有模型进行查询并用SWRL对模型进行语义规则的扩充;最后介绍了Jena,并对本体模型进行推理,由此获得了更多知识.结论就是,在利用SPARQL和Jena进行查询与推理的过程中,推理将提高查询能力,而规则是提高推理能力的关键.

  1. An Applet-based Anonymous Distributed Computing System.

    Science.gov (United States)

    Finkel, David; Wills, Craig E.; Ciaraldi, Michael J.; Amorin, Kevin; Covati, Adam; Lee, Michael

    2001-01-01

    Defines anonymous distributed computing systems and focuses on the specifics of a Java, applet-based approach for large-scale, anonymous, distributed computing on the Internet. Explains the possibility of a large number of computers participating in a single computation and describes a test of the functionality of the system. (Author/LRW)

  2. KDS-CM: A Cache Mechanism Based on Top-K Data Source for Deep Web Query

    Institute of Scientific and Technical Information of China (English)

    KOU Yue; SHEN Derong; YU Ge; LI Dong; NIE Tiezheng

    2007-01-01

    Caching is an important technique to enhance the efficiency of query processing. Unfortunately, traditional caching mechanisms are not efficient for deep Web because of storage space and dynamic maintenance limitations. In this paper, we present on providing a cache mechanism based on Top-K data source (KDS-CM) instead of result records for deep Web query.By integrating techniques from IR and Top-K, a data reorganization strategy is presented to model KDS-CM. Also some measures about cache management and optimization are proposed to improve the performances of cache effectively. Experimental results show the benefits of KDS-CM in execution cost and dynamic maintenance when compared with various alternate strategies.

  3. Anonymous publication of sensitive transactional data

    KAUST Repository

    Ghinita, Gabriel

    2011-02-01

    Existing research on privacy-preserving data publishing focuses on relational data: in this context, the objective is to enforce privacy-preserving paradigms, such as k-anonymity and ℓ-diversity, while minimizing the information loss incurred in the anonymizing process (i.e., maximize data utility). Existing techniques work well for fixed-schema data, with low dimensionality. Nevertheless, certain applications require privacy-preserving publishing of transactional data (or basket data), which involve hundreds or even thousands of dimensions, rendering existing methods unusable. We propose two categories of novel anonymization methods for sparse high-dimensional data. The first category is based on approximate nearest-neighbor (NN) search in high-dimensional spaces, which is efficiently performed through locality-sensitive hashing (LSH). In the second category, we propose two data transformations that capture the correlation in the underlying data: 1) reduction to a band matrix and 2) Gray encoding-based sorting. These representations facilitate the formation of anonymized groups with low information loss, through an efficient linear-time heuristic. We show experimentally, using real-life data sets, that all our methods clearly outperform existing state of the art. Among the proposed techniques, NN-search yields superior data utility compared to the band matrix transformation, but incurs higher computational overhead. The data transformation based on Gray code sorting performs best in terms of both data utility and execution time. © 2006 IEEE.

  4. Distributed Top-k Queries in E-commerce Environment

    Institute of Scientific and Technical Information of China (English)

    JiangZhan; YiqingSong; HaixiaZhang

    2004-01-01

    This paper focus on how to make distributed top-k query in e-commerce environment through web service. We first give the query process in such environment, then we present an algorithms for processing such queries, which based on the query model we defined. Experimental results show that the algorithms is efficient.

  5. Practical Quantum Private Database Queries Based on Passive Round-Robin Differential Phase-shift Quantum Key Distribution

    Science.gov (United States)

    Li, Jian; Yang, Yu-Guang; Chen, Xiu-Bo; Zhou, Yi-Hua; Shi, Wei-Min

    2016-08-01

    A novel quantum private database query protocol is proposed, based on passive round-robin differential phase-shift quantum key distribution. Compared with previous quantum private database query protocols, the present protocol has the following unique merits: (i) the user Alice can obtain one and only one key bit so that both the efficiency and security of the present protocol can be ensured, and (ii) it does not require to change the length difference of the two arms in a Mach-Zehnder interferometer and just chooses two pulses passively to interfere with so that it is much simpler and more practical. The present protocol is also proved to be secure in terms of the user security and database security.

  6. Probabilistic Adaptive Anonymous Authentication in Vehicular Networks

    Institute of Scientific and Technical Information of China (English)

    Yong Xi; Ke-Wei Sha; Wei-Song Shi; Loren Schwiebert; Tao Zhang

    2008-01-01

    Vehicular networks have attracted extensive attention in recent years for their promises in improving safety and enabling other value-added services. Most previous work focuses on designing the media access and physical layer protocols.Privacy issues in vehicular systems have not been well addressed. We argue that privacy is a user-specific concept, and a good privacy protection mechanism should allow users to select the levels of privacy they wish to have. To address this requirement, we propose an adaptive anonymous authentication mechanism that can trade off the anonymity level with computational and communication overheads (resource usage). This mechanism, to our knowledge, is the first effort on adaptive anonymous authentication. The resources used by our protocol are few. A high traffic volume of 2000 vehicles per hour consumes about 60kbps bandwidth, which is less than one percent of the bandwidth of DSRC (Dedicated Short Range Communications). By using adaptive anonymity, the protocol response time can further be improved 2~4 times with lessthan 20% bandwidth overheads.

  7. Distributed location-based query processing on large volumes of moving items

    Institute of Scientific and Technical Information of China (English)

    JEON Se-gil; LEE Chung-woo; NAH Yunmook; KIM Moon-hae; HAN Ki-joon

    2004-01-01

    Recently, new techniques to efficiently manage current and past location information of moving objects have received significant interests in the area of moving object databases and location-based service systems. In this paper, we exploit query processing schemes for location management systems, which consist of multiple data processing nodes to handle massive volume of moving objects such as cellular phone users.To show the usefulness of the proposed schemes, some experimental results showing performance factors regarding distributed query processing are explained. In our experiments, we use two kinds of data set: one is generated by the extended GSTD simulator and another is generated by the real-time data generator which generates location sensing reports of various types of users having different movement patterns.

  8. “We are Anonymous.” Anonymity in the Public Sphere – Challenges of Free and Open Communication

    Directory of Open Access Journals (Sweden)

    Saskia Sell

    2013-05-01

    Full Text Available Anonymity, the stealth mode of public communication, challenges different actors who deal with freedom of communication issues in their day to day life – be it professional journalists, information and communication scientists, technicians or political activists. This article aims to deliver theoretical background on the concept of anonymity on the macro-level, as well as to shed light on how different communicators deal with anonymity on the micro-level. Based on the example of the Anonymous movement, communicative actions are put in relation to media technological artifacts and their surrounding media environment with a focus on journalistic practice and public response to the phenomenon. The analysis concludes with the need for a preservation of options for anonymous public communication as a dimension of freedom of communication after carefully considering both the advantages and the potential risks connected to that mode of private-public communication.

  9. The Bridge project: A visualisation exercise on Free Association and internet query and search procedures

    OpenAIRE

    Ayiter, Elif

    2007-01-01

    The aim of this project is to visually demonstrate my personal understanding of the evolution of the computer generated "image work", by means of a free associative process that utilises the search and query mechanisms of the internet. I have tried to create a structure that displays this process by showing the data gathered in detail as well as in its entirety: Zooming in and out of objects and virtual navigation following free associations that can be evoked through online thesauruses, inte...

  10. Comment on "Secure quantum private information retrieval using phase-encoded queries"

    Science.gov (United States)

    Shi, Run-hua; Mu, Yi; Zhong, Hong; Zhang, Shun

    2016-12-01

    In this Comment, we reexamine the security of phase-encoded quantum private query (QPQ). We find that the current phase-encoded QPQ protocols, including their applications, are vulnerable to a probabilistic entangle-and-measure attack performed by the owner of the database. Furthermore, we discuss how to overcome this security loophole and present an improved cheat-sensitive QPQ protocol without losing the good features of the original protocol.

  11. Altruism and Anonymity: A Behavioral Analysis

    Science.gov (United States)

    Locey, Matthew L.; Rachlin, Howard

    2015-01-01

    The effect of anonymity on altruism was examined in a social discounting task with hypothetical rewards. Social discounting – the rate at which increases in social distance decrease value to the participant – was compared across three groups. Participants in the Anonymous group were told that recipients would not know who they were. Participants in the Observed group were asked to imagine that each of their choices was being observed by the recipient. Participants in the Standard group were given no special instructions with respect to anonymity or identity. Social discounting was measured at each of 7 social distances ranging from first closest friend or relative to the 100th closest. Social discount rates for all three groups were well described by hyperbolic functions. Participants in the Observed group were willing to forgo more money for the benefit of others (were more altruistic) than were those in the other two groups. Although participants in the Anonymous group, with no prospect of reciprocation, were willing to forgo less money for the sake of others than were those in the Observed group, they did express willingness to forgo significant amounts. This is some evidence that individual altruistic acts cannot be explained wholly by the possibility of reciprocation. PMID:26051191

  12. SPARQL Query Re-writing Using Partonomy Based Transformation Rules

    Science.gov (United States)

    Jain, Prateek; Yeh, Peter Z.; Verma, Kunal; Henson, Cory A.; Sheth, Amit P.

    Often the information present in a spatial knowledge base is represented at a different level of granularity and abstraction than the query constraints. For querying ontology's containing spatial information, the precise relationships between spatial entities has to be specified in the basic graph pattern of SPARQL query which can result in long and complex queries. We present a novel approach to help users intuitively write SPARQL queries to query spatial data, rather than relying on knowledge of the ontology structure. Our framework re-writes queries, using transformation rules to exploit part-whole relations between geographical entities to address the mismatches between query constraints and knowledge base. Our experiments were performed on completely third party datasets and queries. Evaluations were performed on Geonames dataset using questions from National Geographic Bee serialized into SPARQL and British Administrative Geography Ontology using questions from a popular trivia website. These experiments demonstrate high precision in retrieval of results and ease in writing queries.

  13. Research on Semantic Data Query Method Based on Hadoop%基于Hadoop平台的语义数据查询策略研究

    Institute of Scientific and Technical Information of China (English)

    胡志刚; 景冬梅; 陈柏林; 杨柳

    2016-01-01

    In order to achieve the efficient query for large-scale RDF (resource description framework) data, this paper analyzes the storage method of RDF triples in HBase and designs a two-stage query strategy for large-scale RDF data based on MapReduce, which is divided into two stages:the SPARQL (simple protocol and RDF query language) pre-treatment stage and the distributed query execution stage. In the SPARQL pretreatment stage, an SPARQL query classi-fication algorithm—JOVR (join on variable relation) is implemented, which determines the join order of connection variables by calculating the correlation between the variables in an SPARQL query statement, then the join between SPARQL clauses is divided into the minimum number of MapReduce jobs according to the connection variables. The distributed query execution stage accomplishes large-scale RDF data query concurrently based on MapRdecue jobs from SPARQL pretreatment stage. The experimental results on the LUMB benchmark set indicate that JOVR can query large-scale RDF data efficiently with good stability and scalability.%为了实现对海量RDF(resource description framework)数据的高效查询,研究了RDF三元组在分布式数据库HBase中的存储方法,基于MapReduce设计了海量RDF数据的两阶段查询策略,将查询分为SPARQL (simple protocol and RDF query language)预处理阶段与分布式查询执行阶段。SPARQL预处理阶段设计实现了基于SPARQL变量关联度的查询划分算法JOVR(join on variable relation),通过计算SPARQL查询语句中变量的关联度确定连接变量的连接顺序,根据连接变量将SPARQL子句连接操作划分到最小数量的Map-Reduce任务中;分布式查询执行阶段执行SPARQL预处理阶段划分的MapReduce任务,实现对海量RDF数据的并行查询。在LUBM标准测试数据集中的实验表明,JOVR算法能够高效地实现对海量RDF数据的查询,并具有良好的稳定性与可扩展性。

  14. Implementation of Quantum Private Queries Using Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan; HAO Liang; ZHAO Lian-Jie

    2011-01-01

    @@ We present a modified protocol for the realization of a quantum private query process on a classical database.Using one-qubit query and CNOT operation,the query process can be realized in a two-mode database.In the query process,the data privacy is preserved as the sender would not reveal any information about the database besides her query information,and the database provider cannot retain any information about the query.We implement the quantum private query protocol in a nuclear magnetic resonance system.The density matrix of the memory registers are constructed.

  15. Compressed Data Cube for Approximate OLAP Query Processing

    Institute of Scientific and Technical Information of China (English)

    冯玉; 王珊

    2002-01-01

    Approximate query processing has emerged as an approach to dealing with thehuge data volume and complex queries in the environment of data warehouse. In this paper,we present a novel method that provides approximate answers to OLAP queries. Our methodis based on building a compressed (approximate) data cube by a clustering technique and usingthis compressed data cube to provide answers to queries directly, so it improves the performanceof the queries. We also provide the algorithm of the OLAP queries and the confidence intervalsof query results. An extensive experimental study with the OLAP council benchmark showsthe effectiveness and scalability of our cluster-based approach compared to sampling.

  16. Exploring features for automatic identification of news queries through query logs

    Institute of Scientific and Technical Information of China (English)

    Xiaojuan; ZHANG; Jian; LI

    2014-01-01

    Purpose:Existing researches of predicting queries with news intents have tried to extract the classification features from external knowledge bases,this paper tries to present how to apply features extracted from query logs for automatic identification of news queries without using any external resources.Design/methodology/approach:First,we manually labeled 1,220 news queries from Sogou.com.Based on the analysis of these queries,we then identified three features of news queries in terms of query content,time of query occurrence and user click behavior.Afterwards,we used 12 effective features proposed in literature as baseline and conducted experiments based on the support vector machine(SVM)classifier.Finally,we compared the impacts of the features used in this paper on the identification of news queries.Findings:Compared with baseline features,the F-score has been improved from 0.6414 to0.8368 after the use of three newly-identified features,among which the burst point(bst)was the most effective while predicting news queries.In addition,query expression(qes)was more useful than query terms,and among the click behavior-based features,news URL was the most effective one.Research limitations:Analyses based on features extracted from query logs might lead to produce limited results.Instead of short queries,the segmentation tool used in this study has been more widely applied for long texts.Practical implications:The research will be helpful for general-purpose search engines to address search intents for news events.Originality/value:Our approach provides a new and different perspective in recognizing queries with news intent without such large news corpora as blogs or Twitter.

  17. Time Lag and Anonymity as Variables in Student Evaluation of Curricula

    Science.gov (United States)

    Pierce, Walter D.; Getz, Howard G.

    1975-01-01

    The major concern of this study was the effect on evaluation data of anonymity and differing time spans between completion of specific programs by students and their responses to anonymous questionnaires. (Author)

  18. Privacy-Aware Location Database Service for Granular Queries

    Science.gov (United States)

    Kiyomoto, Shinsaku; Martin, Keith M.; Fukushima, Kazuhide

    Future mobile markets are expected to increasingly embrace location-based services. This paper presents a new system architecture for location-based services, which consists of a location database and distributed location anonymizers. The service is privacy-aware in the sense that the location database always maintains a degree of anonymity. The location database service permits three different levels of query and can thus be used to implement a wide range of location-based services. Furthermore, the architecture is scalable and employs simple functions that are similar to those found in general database systems.

  19. Querying moving objects detected by sensor networks

    CERN Document Server

    Bestehorn, Markus

    2012-01-01

    Declarative query interfaces to Sensor Networks (SN) have become a commodity. These interfaces allow access to SN deployed for collecting data using relational queries. However, SN are not confined to data collection, but may track object movement, e.g., wildlife observation or traffic monitoring. While rational approaches are well suited for data collection, research on ""Moving Object Databases"" (MOD) has shown that relational operators are unsuitable to express information needs on object movement, i.e., spatio-temporal queries. ""Querying Moving Objects Detected by Sensor Networks"" studi

  20. Oceanographic ontology-based spatial knowledge query

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The construction of oceanographic ontologies is fundamental to the "digital ocean". Therefore, on the basis of introduction of new concept of oceanographic ontology, an oceanographic ontology-based spatial knowledge query (OOBSKQ) method was proposed and developed. Because the method uses a natural language to describe query conditions and the query result is highly integrated knowledge,it can provide users with direct answers while hiding the complicated computation and reasoning processes, and achieves intelligent,automatic oceanographic spatial information query on the level of knowledge and semantics. A case study of resource and environmental application in bay has shown the implementation process of the method and its feasibility and usefulness.

  1. On tourism information query system in Panjin based on WebGIS%基于WebGIS的盘锦市旅游信息查询系统

    Institute of Scientific and Technical Information of China (English)

    杨帆; 任东风

    2016-01-01

    文中基于盘锦旅游资源和旅游信息查询现状,以Visual Studio 2010为开发环境,采用Silver-light开发方案,调用天地图为地图底图数据,C#为编程语言进行开发。除了基本的地图浏览功能,还可通过分类查询、模糊查询等来实现景点、餐饮等信息的查询,并借助多媒体增加景点的表现力,面向游客提供交通、住宿、娱乐等旅游相关信息。该系统的建立将进一步树立盘锦市旅游业发展的新形象。%Based on present situation of tourism resources and tourism information query in Panjin, the paper establi-shes an tourism information query system in Panjin with technologies such as Visual Studio 2010, Silverlight, C # language, and data of Tianditu. Besides the basis function of map browsing, it can also provide scenery spots query and catering query through classification query and fuzzy query. And with the help of multimedia, further query of transportation, accommodation, entertainment and other related travel information are also available. This system will further build up the new image of the tourism development in Panjin.

  2. Social Indispensability in Spite of Temporal and Spatial Separation: Motivation Gains in a Sequential Task During Anonymous Cooperation on the Internet

    Directory of Open Access Journals (Sweden)

    Marion Wittchen

    2007-12-01

    Full Text Available Recent research has demonstrated motivation gains during synchronous group work compared to individual work when group members’ contribution was indispensable for the group’s success (e.g., Hertel, Kerr, & Messé, 2000, Hertel, Deter, & Konradt, 2003. The current study extends this earlier research (a by examining indispensability effects during sequential cooperation (temporal separation, and (b by exploring these effects under conditions of high anonymity on the Internet (spatial separation. A 2 (Internet vs. laboratory context x 3 (high vs. low vs. no impact of personal contribution for a group x 2 (individual vs. group trial design was used with the last factor measured within subjects (N = 231. Motivation was measured with a vigilance task that simulated an Internet travel agency selling package holidays according to incoming customer requests. During all trials, participants received contemporaneous feedback about their own performance. During the group trials, participants additionally received information about their partner’s alleged previous performance at this point of the trial, which suggested that the partner had always performed slightly better than the participant. As expected, both in the laboratory and the Internet setting, the highest motivation gains occurred when participants’ contribution to the group’s outcome was indispensable for the group. This finding provides evidence that motivation gains among inferior group members are possible even during sequential group work under highly anonymous conditions.

  3. Indexing for summary queries

    DEFF Research Database (Denmark)

    Yi, Ke; Wang, Lu; Wei, Zhewei

    2014-01-01

    ), of a particular attribute of these records. Aggregation queries are especially useful in business intelligence and data analysis applications where users are interested not in the actual records, but some statistics of them. They can also be executed much more efficiently than reporting queries, by embedding...

  4. WATERS Expert Query Tool

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Expert Query Tool is a web-based reporting tool using the EPA’s WATERS database.There are just three steps to using Expert Query:1. View Selection – Choose what...

  5. Mastering jQuery

    CERN Document Server

    Libby, Alex

    2015-01-01

    If you are a developer who is already familiar with using jQuery and wants to push your skill set further, then this book is for you. The book assumes an intermediate knowledge level of jQuery, JavaScript, HTML5, and CSS.

  6. An Efficient Data Fingerprint Query Algorithm Based on Two-Leveled Bloom Filter

    Directory of Open Access Journals (Sweden)

    Bin Zhou

    2013-04-01

    Full Text Available The function of the comparing fingerprints algorithm was to judge whether a new partitioned data chunk was in a storage system a decade ago.  At present, in the most de-duplication backup system the fingerprints of the big data chunks are huge and cannot be stored in the memory completely. The performance of the system is unavoidably retarded by data chunks accessing the storage system at the querying stage. Accordingly, a new query mechanism namely Two-stage Bloom Filter (TBF mechanism is proposed. Firstly, as a representation of the entirety for the first grade bloom filter, each bit of the second grade bloom filter in the TBF represents the chunks having the identical fingerprints reducing the rate of false positives. Secondly, a two-dimensional list is built corresponding to the two grade bloom filter for the absolute addresses of the data chunks with the identical fingerprints.  Finally, a new hash function class with the strong global random characteristic is set up according to the data fingerprints’ random characteristics. To reduce the comparing data greatly, TBF decreases the number of accessing disks, improves the speed of detecting the redundant data chunks, and reduces the rate of false positives which helps the improvement of the overall performance of system.

  7. Query-By-Keywords (QBK): Query Formulation Using Semantics and Feedback

    Science.gov (United States)

    Telang, Aditya; Chakravarthy, Sharma; Li, Chengkai

    The staples of information retrieval have been querying and search, respectively, for structured and unstructured repositories. Processing queries over known, structured repositories (e.g., Databases) has been well-understood, and search has become ubiquitous when it comes to unstructured repositories (e.g., Web). Furthermore, searching structured repositories has been explored to a limited extent. However, there is not much work in querying unstructured sources. We argue that querying unstructured sources is the next step in performing focused retrievals. This paper proposed a new approach to generate queries from search-like inputs for unstructured repositories. Instead of burdening the user with schema details, we believe that pre-discovered semantic information in the form of taxonomies, relationship of keywords based on context, and attribute & operator compatibility can be used to generate query skeletons. Furthermore, progressive feedback from users can be used to improve the accuracy of query skeletons generated.

  8. Querying and Manipulating Temporal Databases

    Directory of Open Access Journals (Sweden)

    Mohamed Mkaouar

    2011-03-01

    Full Text Available Many works have focused, for over twenty five years, on the integration of the time dimension indatabases (DB. However, the standard SQL3 does not yet allow easy definition, manipulation andquerying of temporal DBs. In this paper, we study how we can simplify querying and manipulatingtemporal facts in SQL3, using a model that integrates time in a native manner. To do this, we proposenew keywords and syntax to define different temporal versions for many relational operators andfunctions used in SQL. It then becomes possible to perform various queries and updates appropriate totemporal facts. We illustrate the use of these proposals on many examples from a real application.

  9. Effective Density Queries of Continuously Moving Objects

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Lin, D.; Ooi, B.C.

    2006-01-01

    control system, we need to identify the places that are or would be affected by a traffic jam, and report this information to drivers so that they can choose a less congested route. As a naive way to solve the problem is prohibitively expensive, we first introduce a framework which makes the problem......In this paper, we study a newly emerging type of queries on moving objects - the density query. Basically, this query locates regions in the data space where the density of the objects is high. This type of queries is especially useful in Location Based Services (LBS). For example, in a traffic...

  10. Anonymity And Accountability In Web Based Transactions

    Directory of Open Access Journals (Sweden)

    H.Jayasree

    2012-04-01

    Full Text Available Decreased privacy is an unavoidable consequence in the drive to make the world a more secure, safer place, according to some analysts. In the on-line world, the conflict between privacy and security manifests itself in a debate between anonymity and accountability. Balance between Anonymity and Accountability is a major concern in web based transactions. The protection of users’ privacy when performing web-based transactions is an important factor in the acceptance and use of Internet and web services. There is a tremendous improvement in the automation of the way we pay for goods and services by the variety and growth of electronic banking services available to the consumers. Hence there is a need for the ultimate structure of the new electronic transaction system that has a substantial impact on the personal privacy as well as on the nature and extent of criminal use of E- transactions. This paper presents an approach for such structure.

  11. Structure Preserving Anonymization of Router Configuration Data

    Science.gov (United States)

    2009-04-01

    2009 IEEE Authorized licensed use limited to: Naval Postgraduate School. Downloaded on December 18, 2009 at 13:53 from IEEE Xplore . Restrictions apply... IEEE Xplore . Restrictions apply. MALTZ et al.: STRUCTURE PRESERVING ANONYMIZATION OF ROUTER CONFIGURATION DATA 351 1 hostname cr1.lax.foo.com 2 ! 3... IEEE Xplore . Restrictions apply. 352 IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 27, NO. 3, APRIL 2009 lines 14 and 30 (255.255.255.252

  12. Head First jQuery

    CERN Document Server

    Benedetti, Ryan

    2011-01-01

    Want to add more interactivity and polish to your websites? Discover how jQuery can help you build complex scripting functionality in just a few lines of code. With Head First jQuery, you'll quickly get up to speed on this amazing JavaScript library by learning how to navigate HTML documents while handling events, effects, callbacks, and animations. By the time you've completed the book, you'll be incorporating Ajax apps, working seamlessly with HTML and CSS, and handling data with PHP, MySQL and JSON. If you want to learn-and understand-how to create interactive web pages, unobtrusive scrip

  13. Improve Query Performance On Hierarchical Data. Adjacency List Model Vs. Nested Set Model

    Directory of Open Access Journals (Sweden)

    Cornelia Gyorödi

    2016-04-01

    Full Text Available Hierarchical data are found in a variety of database applications, including content management categories, forums, business organization charts, and product categories. In this paper, we will examine two models deal with hierarchical data in relational databases namely, adjacency list model and nested set model. We analysed these models by executing various operations and queries in a web-application for the management of categories, thus highlighting the results obtained during performance comparison tests. The purpose of this paper is to present the advantages and disadvantages of using an adjacency list model compared to nested set model in a relational database integrated into an application for the management of categories, which needs to manipulate a big amount of hierarchical data.

  14. Remote Electronic Voting with Revocable Anonymity

    Science.gov (United States)

    Smart, Matt; Ritter, Eike

    We present a new remote, coercion-free electronic voting protocol which satisfies a number of properties previously considered contradictory. We introduce (and justify) the idea of revocable anonymity in electronic voting, on the grounds of it being a legal requirement in the United Kingdom, and show a method of proving the validity of a ballot to a verifier in zero knowledge, by extension of known two-candidate proofs.

  15. Anonymous electronic trading versus floor trading

    OpenAIRE

    Franke, Günter; Hess, Dieter

    1995-01-01

    This paper compares the attractiveness of floor trading and anonymous electronic trading systems. It is argued that in times of low information intensity the insight into the order book of the electronic trading system provides more valuable information than floor trading, but in times of high information intensity the reverse is true. Thus, the electronic system's market share in trading activity should decline in times of high information intensity. This hypothesis is tested by data on BUND...

  16. An Internet Based Anonymous Electronic Cash System

    Directory of Open Access Journals (Sweden)

    Israt Jahan

    2015-04-01

    Full Text Available There is an increase activity in research to improve the current electronic payment system which is parallel with the progress of internet. Electronic cash system is a cryptographic payment system which offers anonymity during withdrawal and purchase. Electronic cash displays serial numbers which can be recorded to allow further tracing. Contrary to their physical counterparts, e-cash have an inherent limitation; they are easy to copy and reuse (double-spending. An observer is a tamper-resistant device, issued by the Internet bank, which is incorporated with the Internet user’s computer that prevents double-spending physically, i.e., the user has no access to her e-cash and therefore he cannot copy them. In this paper, we shall present an anonymous electronic cash scheme on the internet which incorporates tamper-resistant device with user-module.

  17. A NEW ANONYMITY CONTROLLED E-CASH SCHEME

    Institute of Scientific and Technical Information of China (English)

    Zhang Fangguo; Wang Changjie; Wang Yumin

    2002-01-01

    E-cash is a type of very important electronic payment systems. The complete anonymity of E-cash can be used for criminal activities, so E-cash should be anonymity controlled.Moreover, Elliptic Curve Cryptography(ECC) has been regard as the mainstream of current public cryptography . In this paper, a new anonymity controlled E-cash scheme based on ECC for the first time and using a new technology-one-time key pairs digital signature is designed, and its security and efficiency are analyzed. In our scheme, the coin tracing and owner tracing can be implemented.

  18. Path Minima Queries in Dynamic Weighted Trees

    DEFF Research Database (Denmark)

    Davoodi, Pooya; Brodal, Gerth Stølting; Satti, Srinivasa Rao

    2011-01-01

    In the path minima problem on a tree, each edge is assigned a weight and a query asks for the edge with minimum weight on a path between two nodes. For the dynamic version of the problem, where the edge weights can be updated, we give data structures that achieve optimal query time\\todo{what about...

  19. Quantum associative memory with improved distributed queries

    CERN Document Server

    Njafa, J -P Tchapet; Woafo, Paul

    2012-01-01

    The paper proposes an improved quantum associative algorithm with distributed query based on model proposed by Ezhov et al. We introduce two modifications of the query that optimized data retrieval of correct multi-patterns simultaneously for any rate of the number of the recognition pattern on the total patterns. Simulation results are given.

  20. jQuery cookbook

    CERN Document Server

    2010-01-01

    jQuery simplifies building rich, interactive web frontends. Getting started with this JavaScript library is easy, but it can take years to fully realize its breadth and depth; this cookbook shortens the learning curve considerably. With these recipes, you'll learn patterns and practices from 19 leading developers who use jQuery for everything from integrating simple components into websites and applications to developing complex, high-performance user interfaces. Ideal for newcomers and JavaScript veterans alike, jQuery Cookbook starts with the basics and then moves to practical use cases w

  1. 基于jQuery的高校网络心理咨询系统的设计与实现%Design and implementation of college counseling network system based on jQuery

    Institute of Scientific and Technical Information of China (English)

    陈国耀; 王清心

    2011-01-01

    网络心理咨询具有便于为当事人保密、方便快捷、便于存储和查询案例等传统心理咨询方式所不具备的优势,jQuery使用户能更方便地处理HTML documents、events、实现动画效果,并且方便地为网站提供Ajax交互.介绍了基于jQuery的高校心理咨询系统的设计与实现的整个过程,展示了采用jQuery框架开发系统的便利性和优越性.%Some obvious advantages that are only available through online counseling are as follow:It is usually convenient; Information is easier to be found. Used and stored; Privacy and anonymity are' assured. It is imperative to popularize on-line psychological counseling in the colleges. HTML document traversing, event handling, animating, and Ajax interactions for rapid web development are simplied by using Jquery. College Counseling Network System based on jQuery relevant analysis and designs,realize course and method are showed in this text, and the benefits in software development is also demonstrated.

  2. Anonymity, ethics and credibility in the blogosphere and on Twitter: gastronomic criticism in “Alhos, passas & maçãs” and in @carapuceiro

    Directory of Open Access Journals (Sweden)

    Renata Maria do Amaral

    2012-07-01

    Full Text Available This article intends to understand the anonymous restaurant critic currently made on the Internet, based on the cases of the Alhos, passas & maçãs blog and the @carapuceiro Twitter. Before considered as personal diaries or means of communication among friends, today blogs and social networks have no limits – and, when used to criticize restaurants negatively, its impact reaches unpremeditated boundaries, including reactions of chefs and journalists themselves. At the same time that these tools extend the possibilities of subjective comments written by ordinary people, without a degree in journalism, the press loses credibility by choosing to criticize in a courteous way, submitting itself to the invitations sent by press offices and to the “cordial journalism”.

  3. 基于DNS查询行为的Bot检测%Bot detection based on DNS query activities

    Institute of Scientific and Technical Information of China (English)

    李晓利; 汤光明; 初晓

    2015-01-01

    This paper proposes a new method of identifying Bot based on DNS query activities. Firstly, as Bots usually run automatically, detection rage is narrowed down from the point of view of DNS query. Secondly, a Bot-DNS detection model is created on differences of DNS reaction behavior between Bots and normal processes, to judge whether the suspi-cious process is Bot. The experimental results show that the method can detect Bots in the early stage. It is independent of protocol and structure, and has a better detection effect.%提出一种基于DNS查询行为的检测方法。根据Bot的自动运行特性,从DNS查询的角度对主机中的进程进行初步过滤,缩小检测范围;分析Bot与其他进程的DNS反应行为模式的异同,构建Bot-DNS检测模型,在此基础上判断可疑进程是否为Bot。实验结果表明,该方法能够检测出处于生命周期早期阶段的Bot,且检测过程与Bot采用的协议结构无关,具有较好的检测效果。

  4. Meet Charles, big data query advisor

    NARCIS (Netherlands)

    Sellam, T.; Kersten, M.

    2013-01-01

    In scientific data management and business analytics, the most informative queries are a holy grail. Data collection becomes increasingly simpler, yet data exploration gets significantly harder. Exploratory querying is likely to return an empty or an overwhelming result set. On the other hand, data

  5. Query Intent Disambiguation of Keyword-Based Semantic Entity Search in Dataspaces

    Institute of Scientific and Technical Information of China (English)

    Dan Yang; De-Rong Shen; Ge Yu; Yue Kou; Tie-Zheng Nie

    2013-01-01

    Keyword query has attracted much research attention due to its simplicity and wide applications.The inherent ambiguity of keyword query is prone to unsatisfied query results.Moreover some existing techniques on Web query,keyword query in relational databases and XML databases cannot be completely applied to keyword query in dataspaces.So we propose KeymanticES,a novel keyword-based semantic entity search mechanism in dataspaces which combines both keyword query and semantic query features.And we focus on query intent disambiguation problem and propose a novel three-step approach to resolve it.Extensive experimental results show the effectiveness and correctness of our proposed approach.

  6. Localized Geometric Query Problems

    CERN Document Server

    Augustine, John; Maheshwari, Anil; Nandy, Subhas C; Roy, Sasanka; Sarvattomananda, Swami

    2011-01-01

    A new class of geometric query problems are studied in this paper. We are required to preprocess a set of geometric objects $P$ in the plane, so that for any arbitrary query point $q$, the largest circle that contains $q$ but does not contain any member of $P$, can be reported efficiently. The geometric sets that we consider are point sets and boundaries of simple polygons.

  7. Accomplishing Deterministic XML Query Optimization

    Institute of Scientific and Technical Information of China (English)

    Dun-Ren Che

    2005-01-01

    As the popularity of XML (eXtensible Markup Language) keeps growing rapidly, the management of XML compliant structured-document databases has become a very interesting and compelling research area. Query optimization for XML structured-documents stands out as one of the most challenging research issues in this area because of the much enlarged optimization (search) space, which is a consequence of the intrinsic complexity of the underlying data model of XML data. We therefore propose to apply deterministic transformations on query expressions to most aggressively prune the search space and fast achieve a sufficiently improved alternative (if not the optimal) for each incoming query expression. This idea is not just exciting but practically attainable. This paper first provides an overview of our optimization strategy, and then focuses on the key implementation issues of our rule-based transformation system for XML query optimization in a database environment. The performance results we obtained from experimentation show that our approach is a valid and effective one.

  8. A topological framework for interactive queries on 3D models in the Web.

    Science.gov (United States)

    Figueiredo, Mauro; Rodrigues, José I; Silvestre, Ivo; Veiga-Pires, Cristina

    2014-01-01

    Several technologies exist to create 3D content for the web. With X3D, WebGL, and X3DOM, it is possible to visualize and interact with 3D models in a web browser. Frequently, three-dimensional objects are stored using the X3D file format for the web. However, there is no explicit topological information, which makes it difficult to design fast algorithms for applications that require adjacency and incidence data. This paper presents a new open source toolkit TopTri (Topological model for Triangle meshes) for Web3D servers that builds the topological model for triangular meshes of manifold or nonmanifold models. Web3D client applications using this toolkit make queries to the web server to get adjacent and incidence information of vertices, edges, and faces. This paper shows the application of the topological information to get minimal local points and iso-lines in a 3D mesh in a web browser. As an application, we present also the interactive identification of stalactites in a cave chamber in a 3D web browser. Several tests show that even for large triangular meshes with millions of triangles, the adjacency and incidence information is returned in real time making the presented toolkit appropriate for interactive Web3D applications.

  9. LPPS: A Distributed Cache Pushing Based K-Anonymity Location Privacy Preserving Scheme

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2016-01-01

    Full Text Available Recent years have witnessed the rapid growth of location-based services (LBSs for mobile social network applications. To enable location-based services, mobile users are required to report their location information to the LBS servers and receive answers of location-based queries. Location privacy leak happens when such servers are compromised, which has been a primary concern for information security. To address this issue, we propose the Location Privacy Preservation Scheme (LPPS based on distributed cache pushing. Unlike existing solutions, LPPS deploys distributed cache proxies to cover users mostly visited locations and proactively push cache content to mobile users, which can reduce the risk of leaking users’ location information. The proposed LPPS includes three major process. First, we propose an algorithm to find the optimal deployment of proxies to cover popular locations. Second, we present cache strategies for location-based queries based on the Markov chain model and propose update and replacement strategies for cache content maintenance. Third, we introduce a privacy protection scheme which is proved to achieve k-anonymity guarantee for location-based services. Extensive experiments illustrate that the proposed LPPS achieves decent service coverage ratio and cache hit ratio with lower communication overhead compared to existing solutions.

  10. Design and analysis of two-layer anonymous communication system

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-ping; WANG Jian-xin

    2007-01-01

    A new architecture for scalable anonymous communication system(SACS) was proposed. The users were divided into several subgroups managed by different sub-blenders, and all sub-blenders were managed by the main-blender using two layers management scheme. The identity information of members are distributed on different sub-blenders, which makes each member keep much less information and network overload greatly reduce. The anonymity and the overhead of the new scheme were analyzed and compared with that of Crowds, which shows the cost of storage and network overhead for the new scheme largely decreases while the anonymity is little degraded. The experiment results also show that the new system architecture is well scalable. The ratio of management cost of SACS to that of Crowds is about 1:25 while the value of P(I|H1+) only increases by 0.001-0.020, which shows that SACS keeps almost the same anonymity with Crowds.

  11. Anonymity and verifiability in multi-attribute reverse auction

    CERN Document Server

    Srinath, T R; Pais, Alwyn Roshan; 10.5121/ijitcs.2011.1401

    2011-01-01

    The use of e-Auction services has been increasing in recent years. Security requirements in conducting e-Auctions are mainly bid privacy, anonymity and public verifiability. Most of the secure protocols concentrate on privacy and anonymity, which are achieved through bidder-resolved multi-party computation, assuming two or more trusted third parties, either through numerous auctioneers or with asymmetric models in which the commercial entity of an auction issuer or registration manager is assumed in addition to the auctioneer. Multi-attribute reverse auctions promise higher market efficiency and effective information exchange. This work extends and uses the existing schemes. This scheme uses scoring function, winner determination in multi-attribute auctions to implement public verifiability. Anonymity is achieved through bidder side pseudonym generation. By results and analysis we say this is very simple and effective scheme. This scheme ensures public verifiability and anonymity in multi-attribute auctions w...

  12. An Effective Information Retrieval for Ambiguous Query

    CERN Document Server

    Roul, R K

    2012-01-01

    Search engine returns thousands of web pages for a single user query, in which most of them are not relevant. In this context, effective information retrieval from the expanding web is a challenging task, in particular, if the query is ambiguous. The major question arises here is that how to get the relevant pages for an ambiguous query. We propose an approach for the effective result of an ambiguous query by forming community vector based on association concept of data minning using vector space model and the freedictionary. We develop clusters by computing the similarity between community vectors and document vectors formed from the extracted web pages by the search engine. We use Gensim package to implement the algorithm because of its simplicity and robust nature. Analysis shows that our approach is an effective way to form clusters for an ambiguous query.

  13. Research on the Index and Query of Spatial Data%空间数据索引与查询的研究

    Institute of Scientific and Technical Information of China (English)

    余冬梅

    2011-01-01

    The function of spatial database become more and more important in social and economic development nowadays, and the research on it is more and more urgent too. The article introduces spatial index, spatial query and their development, researchs on difference of index and query between spatial data and traditional relation dadabase, and analyses research thinking of optimizing spatial index and spatial query.%空间数据库在当今社会经济发展中的作用变得日趋重要,对其进行的研究也日趋迫切.对空间索引及其发展分类、空间数据查询及其与传统关系数据库的区别进行了研究,并对优化空间索引和空间数据查询的研究思路进行了分析说明.

  14. A Privacy-Preserving Location-Based System for Continuous Spatial Queries

    Directory of Open Access Journals (Sweden)

    Doohee Song

    2016-01-01

    Full Text Available K-anonymization generated a cloaked region (CR that was K-anonymous; that is, the query issuer was indistinguishable from K-1 other users (nearest neighbors within the CR. This reduced the probability of the query issuer’s location being exposed to untrusted parties (1/K. However, location cloaking is vulnerable to query tracking attacks, wherein the adversary can infer the query issuer by comparing the two regions in continuous LBS queries. This paper proposes a novel location cloaking method to resist this attack. The target systems of the proposed method are road networks where the mobile clients’ trajectories are fixed (the road network is preknown and fixed, instead of the trajectories, such as subways, railways, and highways. The proposed method, called adaptive-fixed K-anonymization (A-KF, takes this issue into account and generates smaller CRs without compromising the privacy of the query issuer’s location. Our results show that the proposed A-KF method outperforms previous location cloaking methods.

  15. k-Nearest Neighbor Query Processing Algorithms for a Query Region in Road Networks

    Institute of Scientific and Technical Information of China (English)

    Hyeong-Il Kim; Jae-Woo Chang

    2013-01-01

    Recent development of wireless communication technologies and the popularity of smart phones are making location-based services (LBS) popular.However,requesting queries to LBS servers with users' exact locations may threat the privacy of users.Therefore,there have been many researches on generating a cloaked query region for user privacy protection.Consequently,an efficient query processing algorithm for a query region is required.So,in this paper,we propose k-nearest neighbor query (k-NN) processing algorithms for a query region in road networks.To efficiently retrieve k-NN points of interest (POIs),we make use of the Island index.We also propose a method that generates an adaptive Island index to improve the query processing performance and storage usage.Finally,we show by our performance analysis that our k-NN query processing algorithms outperform the existing k-Range Nearest Neighbor (kRNN) algorithm in terms of network expansion cost and query processing time.

  16. Automated Query Learning with Wikipedia and Genetic Programming

    CERN Document Server

    Malo, Pekka; Sinha, Ankur

    2010-01-01

    Most of the existing information retrieval systems are based on bag of words model and are not equipped with common world knowledge. Work has been done towards improving the efficiency of such systems by using intelligent algorithms to generate search queries, however, not much research has been done in the direction of incorporating human-and-society level knowledge in the queries. This paper is one of the first attempts where such information is incorporated into the search queries using Wikipedia semantics. The paper presents an essential shift from conventional token based queries to concept based queries, leading to an enhanced efficiency of information retrieval systems. To efficiently handle the automated query learning problem, we propose Wikipedia-based Evolutionary Semantics (Wiki-ES) framework where concept based queries are learnt using a co-evolving evolutionary procedure. Learning concept based queries using an intelligent evolutionary procedure yields significant improvement in performance whic...

  17. Learning jQuery

    CERN Document Server

    Chaffer, Jonathan

    2013-01-01

    Step through each of the core concepts of the jQuery library, building an overall picture of its capabilities. Once you have thoroughly covered the basics, the book returns to each concept to cover more advanced examples and techniques.This book is for web designers who want to create interactive elements for their designs, and for developers who want to create the best user interface for their web applications. Basic JavaScript programming and knowledge of HTML and CSS is required. No knowledge of jQuery is assumed, nor is experience with any other JavaScript libraries.

  18. 空间数据库中的线段k近邻查询研究%Research on line segment kNN query in spatial database

    Institute of Scientific and Technical Information of China (English)

    周屹; 杨泽雪

    2015-01-01

    K-nearest neighbor query is one of the most important queries in spatial database. K-nearest neighbor query has important applications in the content similarity search, pattern recognition and geographic information systems. Exist-ing k-nearest neighbor query is the query based on the point. The line segment k-nearest neighbor queries are put forward. That is finding k line segments whose distances to query point are the nearest. The algorithm of line segment kNN query based on Voronoi diagram is proposed and the relevant theorem and proof are given. The algorithm finds a candidate set with the adjacent properties of the segment Voronoi diagram, then finds the final results. Experiments on synthetic data sets show that the proposed algorithm outperforms brute-force method and the algorithm based on R-tree.%K近邻查询是空间数据库中的重要查询之一,k近邻查询在内容的相似性检索、模式识别、地理信息系统中有重要应用。针对现有k近邻查询都是基于点查询的情况,提出基于平面线段的k近邻查询,查找线段集中给定查询点的k个最近线段。给出基于Voronoi图的线段k近邻查询算法及给出相关定理和证明。该算法通过线段Voronoi图的邻接特性找到一个候选集,然后从中找到最终结果。通过随机数据的实验证明,所提算法明显优于线性扫描算法和基于R树的k近邻查询算法。

  19. A NEW TOP-K CONDITIONAL XML PREFERENCE QUERIES

    Directory of Open Access Journals (Sweden)

    Shaikhah Alhazmi

    2014-09-01

    Full Text Available Preference querying technology is a very important issue in a variety of applications ranging from ecommerce to personalized search engines. Most of recent research works have been dedicated to this topic in the Artificial Intelligence and Database fields. Several formalisms allowing preference reasoning and specification have been proposed in the Artificial Intelligence domain. On the other hand, in the Database field the interest has been focused mainly in extending standard Structured Query Language (SQL and also eXtensible Markup Language (XML with preference facilities in order to provide personalized query answering. More precisely, the interest in the database context focuses on the notion of Top-k preference query and on the development of efficient methods for evaluating these queries. A Top-k preference query returns k data tuples which are the most preferred according to the user’s preferences. Of course, Top-k preference query answering is closely dependent on the particular preference model underlying the semantics of the operators responsible for selecting the best tuples. In this paper, we consider the Conditional Preference queries (CP-queries where preferences are specified by a set of rules expressed in a logical formalism. We introduce Top-k conditional preference queries (Top-k CP-queries, and the operators BestK-Match and Best-Match for evaluating these queries will be presented.

  20. Tomograph: Highlighting query parallelism in a multi-core system

    NARCIS (Netherlands)

    Gawade, M.M.; Kersten, M.L.

    2013-01-01

    Query parallelism improves serial query execution performance by orders of magnitude. Getting optimal performance from an already parallelized query plan is however difficult due to its dependency on run time factors such as correct operator scheduling, memory pressure, disk io performance, and oper

  1. Tomograph: highlighting query parallelism in a multi-core system

    NARCIS (Netherlands)

    M. Gawade; M. Kersten

    2013-01-01

    Query parallelism improves serial query execution performance by orders of magnitude. Getting optimal performance from an already parallelized query plan is however difficult due to its dependency on run time factors such as correct operator scheduling, memory pressure, disk io performance, and oper

  2. Discrete-query quantum algorithm for NAND trees

    CERN Document Server

    Childs, A M; Jordan, S P; Yeung, D; Childs, Andrew M.; Cleve, Richard; Jordan, Stephen P.; Yeung, David

    2007-01-01

    Recently, Farhi, Goldstone, and Gutmann gave a quantum algorithm for evaluating NAND trees that runs in time O(sqrt(N log N)) in the Hamiltonian query model. In this note, we point out that their algorithm can be converted into an algorithm using O(N^{1/2 + epsilon}) queries in the conventional quantum query model, for any fixed epsilon > 0.

  3. The Research on Automatic Construction of Domain Model Based on Deep Web Query Interfaces

    Science.gov (United States)

    JianPing, Gu

    The integration of services is transparent, meaning that users no longer face the millions of Web services, do not care about the required data stored, but do not need to learn how to obtain these data. In this paper, we analyze the uncertainty of schema matching, and then propose a series of similarity measures. To reduce the cost of execution, we propose the type-based optimization method and schema matching pruning method of numeric data. Based on above analysis, we propose the uncertain schema matching method. The experiments prove the effectiveness and efficiency of our method.

  4. A method of personalized privacy preservation based on K-anonymization%基于K-匿名的个性化隐私保护方法研究

    Institute of Scientific and Technical Information of China (English)

    康海燕; 杨孔雨; 陈建明

    2014-01-01

    Aiming at the shortcomings of the global and local algorithms of the privacy preserving in data publishing,a method of top-down personalized generalization backtracking algorithm and its expansion algorithm based on the K-a-nonymous were proposed.The method combines the L-diversity and (s,d)-anonymization and dynamically build gen-eralization tree structure,by which users can customize the privacy security levels and separate the similar level of safety as far as possible,so as to guarantee the availability and security of the information,which can effectively prevent hom-ogeneity attack and background knowledge attack.Based on the above thinking.A system of personalized privacy pres-ervation based on K-anonymization was developed on J2SE platform.The comprehensive experimental data shows that the algorithm can improves security and guarantee the availability of information effectively.%针对数据发布隐私保护问题的全域与局域算法的不足,基于K-匿名的思想,提出了自顶向下个性化泛化回溯算法及其拓展算法,实现了数据匿名化,即结合L-多样性(s,d)个性化的规则,动态构建泛化树结构,使用户能够自定义隐私的安全等级,尽量分离相似的安全等级,从而保证信息的可用性和安全性,有效防止同质攻击和背景知识攻击。在J2 S E平台上开发了基于K-匿名的个性化隐私保护系统,并对系统进行了全面测试。实验数据表明该算法在提高安全性的同时,能有效地保证信息的可用性。

  5. XIRAF: Ultimate Forensic Querying

    NARCIS (Netherlands)

    Alink, W.; Bhoedjang, R.; Vries, A.P. de; Boncz, P.A.

    2006-01-01

    This paper describes a novel, XML-based approach towards managing and querying forensic traces extracted from digital evidence. This approach has been implemented in XIRAF, a prototype system for forensic analysis. XIRAF systematically applies forensic analysis tools to evidence files (e.g., hard di

  6. Conceptual querying through ontologies

    DEFF Research Database (Denmark)

    Andreasen, Troels; Bulskov, Henrik

    2009-01-01

    We present here ail approach to conceptual querying where the aim is, given a collection of textual database objects or documents, to target an abstraction of the entire database content in terms of the concepts appearing in documents, rather than the documents in the collection. The approach is ...

  7. Spatial Keyword Querying

    DEFF Research Database (Denmark)

    Cao, Xin; Chen, Lisi; Cong, Gao;

    2012-01-01

    The web is increasingly being used by mobile users. In addition, it is increasingly becoming possible to accurately geo-position mobile users and web content. This development gives prominence to spatial web data management. Specifically, a spatial keyword query takes a user location and user-sup...... different kinds of functionality as well as the ideas underlying their definition....

  8. Evaluating Trajectory Queries over Imprecise Location Data

    DEFF Research Database (Denmark)

    Xie, Scott, Xike; Cheng, Reynold; Yiu, Man Lung

    2012-01-01

    Trajectory queries, which retrieve nearby objects for every point of a given route, can be used to identify alerts of potential threats along a vessel route, or monitor the adjacent rescuers to a travel path. However, the locations of these objects (e.g., threats, succours) may not be precisely......, the query is quite time-consuming, since all the points on the trajectory are considered. In this paper, we study how to efficiently evaluate trajectory queries over imprecise location data, by proposing a new concept called the u-bisector. In general, the u-bisector is an extension of bisector to handle...

  9. Query Load Balancing For Visible Object Extraction

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    2004-01-01

    Interactive visual data explorations impose rigid real-time requirements on the extraction of visible objects. Often these requirements are met by deploying powerful hardware that maintains the entire data set in huge main memory structures. In this paper we propose an approach that retrieves...... objects along the path. The visible objects are retrieved incrementally, and it is possible to precisely control the query load and the number of retrieved objects. The minimal distance path method issues frequent queries and retrieves the lowest possible number of objects at each query point. The end...

  10. Query Through Heterogeneous Ontologies Using Association Matrix

    Institute of Scientific and Technical Information of China (English)

    KANG Da-zhou; XU Bao-wen; LU Jian-jiang; WANG Peng; LI Yan-hui

    2004-01-01

    This paper introduces the definition and calculation of the association matrix between ontologies.It uses the association matrix to describe the relations between concepts in different ontologies and uses concept vectors to represent queries; then computes the vectors with the association matrix in order to rewrite queries.This paper proposes a simple method of querying through heterogeneous Ontology using association matrix.This method is based on the correctness of approximate information filtering theory; and it is simple to be implemented and expected to run quite fast.

  11. Broadcast-Based Spatial Queries

    Institute of Scientific and Technical Information of China (English)

    Kwang-Jin Park; Moon-Bae Song; Chong-Sun Hwang

    2005-01-01

    Indexing techniques have been developed for wireless data broadcast environments, in order to conserve the scarce power resources of the mobile clients. However, the use of interleaved index segments in a broadcast cycle increases the average access latency for the clients. In this paper, the broadcast-based spatial query processing methods (BBS)are presented for the location-based services. In the BBS, broadcasted data objects are sorted sequentially based on their locations, and the server broadcasts the location dependent data along with an index segment. Then, a sequential prefetching and caching scheme is designed to reduce the query response time. The performance of this scheme is investigated in relation to various environmental variables, such as the distributions of the data objects, the average speed of the clients and the size of the service area.

  12. Querying Sentiment Development over Time

    DEFF Research Database (Denmark)

    Andreasen, Troels; Christiansen, Henning; Have, Christian Theil

    2013-01-01

    A new language is introduced for describing hypotheses about fluctuations of measurable properties in streams of timestamped data, and as prime example, we consider trends of emotions in the constantly flowing stream of Twitter messages. The language, called EmoEpisodes, has a precise semantics...... that measures how well a hypothesis characterizes a given time interval; the semantics is parameterized so it can be adjusted to different views of the data. EmoEpisodes is extended to a query language with variables standing for unknown topics and emotions, and the query-answering mechanism will return...... instantiations for topics and emotions as well as time intervals that provide the largest deflections in this measurement. Experiments are performed on a selection of Twitter data to demonstrates the usefulness of the approach....

  13. A Preliminary Mapping of Web Queries Using Existing Image Query Schemes.

    Science.gov (United States)

    Jansen, Bernard J.

    End user searching on the Web has become the primary method of locating images for many people. This study investigates the nature of Web image queries by attempting to map them to known image classification schemes. In this study, approximately 100,000 image queries from a major Web search engine were collected in 1997, 1999, and 2001. A…

  14. Query Adaptive Image Retrieval System

    Directory of Open Access Journals (Sweden)

    Amruta Dubewar

    2014-03-01

    Full Text Available Images play a crucial role in various fields such as art gallery, medical, journalism and entertainment. Increasing use of image acquisition and data storage technologies have enabled the creation of large database. So, it is necessary to develop appropriate information management system to efficiently manage these collections and needed a system to retrieve required images from these collections. This paper proposed query adaptive image retrieval system (QAIRS to retrieve images similar to the query image specified by user from database. The goal of this system is to support image retrieval based on content properties such as colour and texture, usually encoded into feature vectors. In this system, colour feature extracted by various techniques such as colour moment, colour histogram and autocorrelogram and texture feature extracted by using gabor wavelet. Hashing technique is used to embed high dimensional image features into hamming space, where search can be performed by hamming distance of compact hash codes. Depending upon minimum hamming distance it returns the similar image to query image.

  15. Practical anonymity hiding in plain sight online

    CERN Document Server

    Loshin, Peter

    2013-01-01

    For those with legitimate reason to use the Internet anonymously--diplomats, military and other government agencies, journalists, political activists, IT professionals, law enforcement personnel, political refugees and others--anonymous networking provides an invaluable tool, and many good reasons that anonymity can serve a very important purpose. Anonymous use of the Internet is made difficult by the many websites that know everything about us, by the cookies and ad networks, IP-logging ISPs, even nosy officials may get involved. It is no longer possible to turn off browser cookies to be l

  16. Browsing the Internet: good-bye anonymity!

    CERN Multimedia

    Computer Security Team

    2012-01-01

    Do you consider browsing the Internet to be your private business? When visiting random web-sites, how far do you assume you are anonymous? Would it matter to you that Google or Facebook can profile your browsing behaviour in order to better target you with advertisements? Did you notice that you already get targeted ads when you are logged on to Google or Facebook even if you are visiting completely different websites? If matters to you, note that browsing anonymously on the Internet is far from easy.   When you are connected to the Internet, you give away a variety of information: your PC’s IP address, some browser settings like language or screen size, and, probably, your login information. So how private is private? You might argue that your current IP address has been picked from a pool of addresses and therefore regularly changes, so it does not necessarily always pinpoint you. On the other hand, with the dawn of IPv6 there is no need any more for shared IP addresses as the...

  17. EHR query language (EQL)--a query language for archetype-based health records.

    Science.gov (United States)

    Ma, Chunlan; Frankel, Heath; Beale, Thomas; Heard, Sam

    2007-01-01

    OpenEHR specifications have been developed to standardise the representation of an international electronic health record (EHR). The language used for querying EHR data is not as yet part of the specification. To fill in this gap, Ocean Informatics has developed a query language currently known as EHR Query Language (EQL), a declarative language supporting queries on EHR data. EQL is neutral to EHR systems, programming languages and system environments and depends only on the openEHR archetype model and semantics. Thus, in principle, EQL can be used in any archetype-based computational context. In the EHR context described here, particular queries mention concepts from the openEHR EHR Reference Model (RM). EQL can be used as a common query language for disparate archetype-based applications. The use of a common RM, archetypes, and a companion query language, such as EQL, semantic interoperability of EHR information is much closer. This paper introduces the EQL syntax and provides example clinical queries to illustrate the syntax. Finally, current implementations and future directions are outlined.

  18. Mining tree-query associations in graphs

    CERN Document Server

    Hoekx, Eveline

    2010-01-01

    New applications of data mining, such as in biology, bioinformatics, or sociology, are faced with large datasetsstructured as graphs. We introduce a novel class of tree-shapedpatterns called tree queries, and present algorithms for miningtree queries and tree-query associations in a large data graph. Novel about our class of patterns is that they can containconstants, and can contain existential nodes which are not counted when determining the number of occurrences of the patternin the data graph. Our algorithms have a number of provableoptimality properties, which are based on the theory of conjunctive database queries. We propose a practical, database-oriented implementation in SQL, and show that the approach works in practice through experiments on data about food webs, protein interactions, and citation analysis.

  19. Efficient Approximate OLAP Querying Over Time Series

    DEFF Research Database (Denmark)

    Perera, Kasun Baruhupolage Don Kasun Sanjeewa; Hahmann, Martin; Lehner, Wolfgang;

    2016-01-01

    are either costly or require continuous maintenance. In this paper we propose an approach for approximate OLAP querying of time series that offers constant latency and is maintenance-free. To achieve this, we identify similarities between aggregation cuboids and propose algorithms that eliminate......The ongoing trend for data gathering not only produces larger volumes of data, but also increases the variety of recorded data types. Out of these, especially time series, e.g. various sensor readings, have attracted attention in the domains of business intelligence and decision making. As OLAP...... queries play a major role in these domains, it is desirable to also execute them on time series data. While this is not a problem on the conceptual level, it can become a bottleneck with regards to query run-time. In general, processing OLAP queries gets more computationally intensive as the volume...

  20. A Query Language for Formal Mathematical Libraries

    CERN Document Server

    Rabe, Florian

    2012-01-01

    One of the most promising applications of mathematical knowledge management is search: Even if we restrict attention to the tiny fragment of mathematics that has been formalized, the amount exceeds the comprehension of an individual human. Based on the generic representation language MMT, we introduce the mathematical query language QMT: It combines simplicity, expressivity, and scalability while avoiding a commitment to a particular logical formalism. QMT can integrate various search paradigms such as unification, semantic web, or XQuery style queries, and QMT queries can span different mathematical libraries. We have implemented QMT as a part of the MMT API. This combination provides a scalable indexing and query engine that can be readily applied to any library of mathematical knowledge. While our focus here is on libraries that are available in a content markup language, QMT naturally extends to presentation and narration markup languages.

  1. Algebra-Based Optimization of XML-Extended OLAP Queries

    DEFF Research Database (Denmark)

    Yin, Xuepeng; Pedersen, Torben Bach

    is desirable. This report presents a complete foundation for such OLAP-XML federations. This includes a prototypical query engine, a simplified query semantics based on previous work, and a complete physical algebra which enables precise modeling of the execution tasks of an OLAP-XML query. Effective algebra......-based and cost-based query optimization and implementation are also proposed, as well as the execution techniques. Finally, experiments with the prototypical query engine w.r.t. federation performance, optimization effectiveness, and feasibility suggest that our approach, unlike the physical integration...

  2. Performance Oriented Query Processing In GEO Based Location Search Engines

    CERN Document Server

    Umamaheswari, M

    2010-01-01

    Geographic location search engines allow users to constrain and order search results in an intuitive manner by focusing a query on a particular geographic region. Geographic search technology, also called location search, has recently received significant interest from major search engine companies. Academic research in this area has focused primarily on techniques for extracting geographic knowledge from the web. In this paper, we study the problem of efficient query processing in scalable geographic search engines. Query processing is a major bottleneck in standard web search engines, and the main reason for the thousands of machines used by the major engines. Geographic search engine query processing is different in that it requires a combination of text and spatial data processing techniques. We propose several algorithms for efficient query processing in geographic search engines, integrate them into an existing web search query processor, and evaluate them on large sets of real data and query traces.

  3. A Semantic Graph Query Language

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, I L

    2006-10-16

    Semantic graphs can be used to organize large amounts of information from a number of sources into one unified structure. A semantic query language provides a foundation for extracting information from the semantic graph. The graph query language described here provides a simple, powerful method for querying semantic graphs.

  4. Mastering jQuery mobile

    CERN Document Server

    Lambert, Chip

    2015-01-01

    You've started down the path of jQuery Mobile, now begin mastering some of jQuery Mobile's higher level topics. Go beyond jQuery Mobile's documentation and master one of the hottest mobile technologies out there. Previous JavaScript and PHP experience can help you get the most out of this book.

  5. Range Query Processing in Multidisk Systems

    Institute of Scientific and Technical Information of China (English)

    李建中

    1992-01-01

    In order to reduce the disk access time,a database can be stored on several simultaneously accessible disks.In this paper,we are concerned with the dynamic d-attribute database allocation problem for range queries,An allocation method,called coordinate moule allocation method,is proposed to allocate data in a d-attribute database among disks so that the maximum disk accessing concurrency can be achieved for range queries.Our analysis and experiments show that the method achieves the optimum or near-optimum parallelism for range queries.The paper offers the conditions under which the method is optimal .The worst case bounds of the performance of the method are also given.In addition,the parallel algorithm of processing range queries in described at the end of the paper.The method has been used in the statistic and scientific database management system whic is being designed by us.

  6. Querying genomic databases

    Energy Technology Data Exchange (ETDEWEB)

    Baehr, A.; Hagstrom, R.; Joerg, D.; Overbeek, R.

    1991-09-01

    A natural-language interface has been developed that retrieves genomic information by using a simple subset of English. The interface spares the biologist from the task of learning database-specific query languages and computer programming. Currently, the interface deals with the E. coli genome. It can, however, be readily extended and shows promise as a means of easy access to other sequenced genomic databases as well.

  7. COMPLEX QUERY AND METADATA

    OpenAIRE

    Nakatoh, Tetsuya; Omori, Keisuke; Yamada, Yasuhiro; Hirokawa, Sachio

    2003-01-01

    We are developing a search system DAISEn which integrates multiple search engines and generates a metasearch engine automatically. The target search engines of DAISEn are not general search engines, but are search engines specialized in some area. Integration of such engines yields efficiency and quality. There are search engines of new type which accept complex query and return structured data. Integration of such search engines is much harder than that of simple search engines which accept ...

  8. Semantic Query Expansion Based on Unsupervised Word Sense Disambiguation%基于无导词义消歧的语义查询扩展

    Institute of Scientific and Technical Information of China (English)

    王瑞琴; 孔繁胜

    2011-01-01

    一个构造良好的查询是信息检索质量的基本保证,语义查询扩展技术解决了传统信息检索系统不能很好理解用户查询意图的问题,在提高检索查全率的同时保证了检索准确率.本文以查询关键字之间的语义关联为切入点,辅以隐式反馈技术获取消歧上下文,以WordNet本体库和WordNet Domains扩展库作为消歧数据源,使用基于局部上下文和基于图论的两类无导词义消歧方法进行查询关键字到本体概念的映射,最后基于概念词汇关联完成基于语义的查询扩展.综合WordNet本体库和WordNet Domains扩展库中的各项知识源对查询词义进行判定,保证了词义消歧的精度;采用无导词义消歧实现查询词义的快速判定,保证了信息检索的实时性;根据查询关键词的多寡分别提出两类消歧方法,满足了各种查询需求.%A well-formed query is a basic guarantee for the quality of information retrieval. Semantic query expansion technology solves the problem of not well understanding user' s query intention in traditional information retrieval systems, and it can improve the retrieval recall while maintaining the retrieval accuracy. This article took the semantic association between query keywords as the starting point, supplemented by implicit feedback technique to get disambiguation context. Taking WordNet ontology and WordNet Domains expansion library as disambiguation data source, we provided two Word Sense Disambiguation methods, namely local context based Unsupervised Word Sense Disambiguation and graph theory based Unsupervised Word Sense Disambiguation, to mapping query keywords to ontology concepts. Finally, Semantic query expansion is done based on the concept-terminology associations. Integrating the knowledge of WordNet ontology database and WordNet Domains expanding library to determine the meaning of the query keywords ensuring the accuracy of word sense disambiguation; using Unsupervised Word

  9. Collecting substance use data with an anonymous mailed survey.

    Science.gov (United States)

    Trinkoff, A M; Storr, C L

    1997-10-25

    Because mailed surveys minimize personal contact, they are useful for collecting sensitive data on substance use, as long as the problems of achieving adequate response rates can be conquered. To address these issues, we report on an anonymous mailed survey of substance use with a 78% response rate, including data collection and survey methods. Analysis of sociodemographic effects on responding found certain groups required additional contacts. Substance use estimates were not affected by non-response bias, suggesting that anonymous mailed surveys can be a feasible means of collecting data on substance use.

  10. A Self-Encryption Remote User Anonymous Authentication Scheme Using Smart Cards

    Institute of Scientific and Technical Information of China (English)

    LU Rong-xing; CAO Zhen-fu; SU Ren-wang

    2006-01-01

    Remote user authentication is essential in distributed network environment to protect unauthorized access of a networked system. However, most of those existing remote user authentication schemes have not provided the user identity anonymity, while user anonymity is particularly important in some practical applications.Therefore, based on self-encryption mechanism, a new remote user authentication scheme was proposed. The scheme not only has no need of maintaining a password table at the remote server, but also can protect the user's anonymity.

  11. Managing and querying whole slide images

    Science.gov (United States)

    Wang, Fusheng; Oh, Tae W.; Vergara-Niedermayr, Cristobal; Kurc, Tahsin; Saltz, Joel

    2012-02-01

    High-resolution pathology images provide rich information about the morphological and functional characteristics of biological systems, and are transforming the field of pathology into a new era. To facilitate the use of digital pathology imaging for biomedical research and clinical diagnosis, it is essential to manage and query both whole slide images (WSI) and analytical results generated from images, such as annotations made by humans and computed features and classifications made by computer algorithms. There are unique requirements on modeling, managing and querying whole slide images, including compatibility with standards, scalability, support of image queries at multiple granularities, and support of integrated queries between images and derived results from the images. In this paper, we present our work on developing the Pathology Image Database System (PIDB), which is a standard oriented image database to support retrieval of images, tiles, regions and analytical results, image visualization and experiment management through a unified interface and architecture. The system is deployed for managing and querying whole slide images for In Silico brain tumor studies at Emory University. PIDB is generic and open source, and can be easily used to support other biomedical research projects. It has the potential to be integrated into a Picture Archiving and Communications System (PACS) with powerful query capabilities to support pathology imaging.

  12. Electronic voting systems for defending free will and resisting bribery and coercion based on ring anonymous signcryption scheme

    Directory of Open Access Journals (Sweden)

    Tsung-Chih Hsiao

    2017-01-01

    Full Text Available Vote by ballot is the feature in a democratic society and the process of decision-making, tending to achieve the philosophy of democratic politics by having the public who are eligible to vote for competent candidates or leaders. With the rapid development of technologies and network applications, electronization has been actively promoted globally during the social transformation period that the concept of electronic voting is further derived. The major advantages of electronic voting, comparing with traditional voting, lie in the mobility strength of electronic voting, reducing a large amount of election costs and enhancing the convenience for the public. Electronic voting allows voters completing voting on the Internet that not only are climate and location restrictions overcome, but the voter turnout is also increased and the voting time is reduced for the public. With the development in the past three decades, electronic voting presents outstanding performance theoretically and practically. Nevertheless, it is regrettable that electronic voting schemes still cannot be completely open because of lures by money and threats. People to lure by money and threats would confirm the voters following their instructions through various methods that more factors would appear on election results, affecting the quality and fairness of the election. In this study, this project aims to design an electronic voting scheme which could actually defend voters’ free will so that lure of money and threats would fail. Furthermore, an electronic voting system based on Elliptic Curve Cryptography is proposed to ensure the efficiency and security, and Ring Signature and Signcryption are applied to reducing the computing costs. Moreover, this project also focuses on applying voting system to mobile devices. As the system efficiency and security are emphasized, voters do not need to participate in the election, but simply complete voting with smart phones, i

  13. Is it OK to be an Anonymous?

    NARCIS (Netherlands)

    Serracino Inglott, P.

    2013-01-01

    Do the deviant acts carried out by the collective known as Anonymous qualify as vigilante activity, and if so, can they be justified? Addressing this question helps expose the difficulties of morally evaluating technologically enabled deviance. Anonymous is a complex, fluid actor but not as mysterio

  14. Anonymity-Preserving Public-Key Encryption

    DEFF Research Database (Denmark)

    Kohlweiss, Markulf; Maurer, Ueli; Onete, Cristina

    2013-01-01

    A receiver-anonymous channel allows a sender to send a message to a receiver without an adversary learning for whom the message is intended. Wireless broadcast channels naturally provide receiver anonymity, as does multi-casting one message to a receiver population containing the intended receive...

  15. Anonymity in Classroom Voting and Debating

    Science.gov (United States)

    Ainsworth, Shaaron; Gelmini-Hornsby, Giulia; Threapleton, Kate; Crook, Charles; O'Malley, Claire; Buda, Marie

    2011-01-01

    The advent of networked environments into the classroom is changing classroom debates in many ways. This article addresses one key attribute of these environments, namely anonymity, to explore its consequences for co-present adolescents anonymous, by virtue of the computer system, to peers not to teachers. Three studies with 16-17 year-olds used a…

  16. In-Network Processing of an Iceberg Join Query in Wireless Sensor Networks Based on 2-Way Fragment Semijoins

    Directory of Open Access Journals (Sweden)

    Hyunchul Kang

    2015-03-01

    Full Text Available We investigate the in-network processing of an iceberg join query in wireless sensor networks (WSNs. An iceberg join is a special type of join where only those joined tuples whose cardinality exceeds a certain threshold (called iceberg threshold are qualified for the result. Processing such a join involves the value matching for the join predicate as well as the checking of the cardinality constraint for the iceberg threshold. In the previous scheme, the value matching is carried out as the main task for filtering non-joinable tuples while the iceberg threshold is treated as an additional constraint. We take an alternative approach, meeting the cardinality constraint first and matching values next. In this approach, with a logical fragmentation of the join operand relations on the aggregate counts of the joining attribute values, the optimal sequence of 2-way fragment semijoins is generated, where each fragment semijoin employs a Bloom filter as a synopsis of the joining attribute values. This sequence filters non-joinable tuples in an energy-efficient way in WSNs. Through implementation and a set of detailed experiments, we show that our alternative approach considerably outperforms the previous one.

  17. Structure and Anonymity of the Bitcoin Transaction Graph

    Directory of Open Access Journals (Sweden)

    Kay Hamacher

    2013-05-01

    Full Text Available The Bitcoin network of decentralized payment transactions has attracted a lot of attention from both Internet users and researchers in recent years. Bitcoin utilizes a peer-to-peer network to issue anonymous payment transactions between different users. In the currently used Bitcoin clients, the full transaction history is available at each node of the network to prevent double spending without the need for a central authority, forming a valuable source for empirical research on network structure, network dynamics, and the implied anonymity challenges, as well as guidance on the future evolution of complex payment systems. We found dynamical effects of which some increase anonymity while others decrease it. Most importantly, several parameters of the Bitcoin transaction graph seem to have become stationary over the last 12–18 months. We discuss the implications.

  18. The Grid File: A Data Structure Designed to Support Proximity Queries on Spatial Objects.

    Science.gov (United States)

    1983-06-01

    report of December 1982, on the personal computer Lilith , developed at ETH Zfirich. 1. Mintyli (Helsinki University of Technology) and 3. Nievergelt...Hinrichs has implemented the grid file on the Lilith personal computer and on a DEC VAX 11. On the Lilith there exists a graphic user interface as

  19. Application of Steganography for Anonymity through the Internet

    CERN Document Server

    Bahi, Jacques M; Friot, Nicolas; Guyeux, Christophe

    2012-01-01

    In this paper, a novel steganographic scheme based on chaotic iterations is proposed. This research work takes place into the information hiding security framework. The applications for anonymity and privacy through the Internet are regarded too. To guarantee such an anonymity, it should be possible to set up a secret communication channel into a web page, being both secure and robust. To achieve this goal, we propose an information hiding scheme being stego-secure, which is the highest level of security in a well defined and studied category of attacks called "watermark-only attack". This category of attacks is the best context to study steganography-based anonymity through the Internet. The steganalysis of our steganographic process is also studied in order to show it security in a real test framework.

  20. Constraint-based query distribution framework for an integrated global schema

    DEFF Research Database (Denmark)

    Malik, Ahmad Kamran; Qadir, Muhammad Abdul; Iftikhar, Nadeem

    2009-01-01

    Distributed heterogeneous data sources need to be queried uniformly using global schema. Query on global schema is reformulated so that it can be executed on local data sources. Constraints in global schema and mappings are used for source selection, query optimization, and querying partitioned...

  1. An Anonymous Node State Transition Model Based on Semi-Markov Process%一种基于半马尔可夫过程的匿名节点状态转移模型

    Institute of Scientific and Technical Information of China (English)

    郝建国; 刘卫东; 戴一奇

    2011-01-01

    To reveal the effect of node misbehaviors and defense mechanisms against them on the node cooperation in anonymous routing protocol for MANET (Mobile Ad-hoc NETworks) ,an anonymous node state transition model based on semi-Markov process is proposed on the features of anonymous node state transition. Under this model, according to the characteristics of large energy consumption and high de mand for privacy protection of anonymous node,we give a theoretical estimation of the limiting probability of node states,and present a model of the node state transition probability matrix and transition time expectation matrix. An experimental analysis to the effect of different model paranetres on the limiting probability of node states verifies the model' s validity at last.%为揭示MANET(Mobile Ad-hoc NETworks)匿名路由协议中节点不端行为及其抵御机制对节点协作性的影响,本文根据匿名节点状态转移的特点,提出了一种基于半马尔可夫过程的匿名节点状态转移模型.在该模型下,针对MANET匿名路由协议中节点能量消耗大和隐私保护要求高的特点,对节点状态极限概率进行了理论估计,给出了节点状态转移概率矩阵和转移期望时间矩阵的理论模型.最后,用实验分析了不同模型参数对节点状态极限概率的影响,验证了本文模型的有效性.

  2. Anonymous-address-resolution model

    Institute of Scientific and Technical Information of China (English)

    Guang-jia SONG; Zhen-zhou JI

    2016-01-01

    Address-resolution protocol (ARP) is an important protocol of data link layers that aims to obtain the corresponding relationship between Internet Protocol (IP) and Media Access Control (MAC) addresses. Traditional ARPs (address-resolution and neighbor-discovery protocols) do not consider the existence of malicious nodes, which reveals destination addresses in the resolution process. Thus, these traditional protocols allow malicious nodes to easily carry out attacks, such as man-in-the-middle attack and denial-of-service attack. To overcome these weaknesses, we propose an anonymous-address-resolution (AS-AR) protocol. AS-AR does not publicize the destination address in the address-resolution process and hides the IP and MAC addresses of the source node. The malicious node cannot obtain the addresses of the destination and the node which initiates the address resolution; thus, it cannot attack. Analyses and experiments show that AS-AR has a higher security level than existing security methods, such as secure-neighbor discovery.

  3. Authority and Hierarchy within Anonymous Internet Relay Chat Networks

    Directory of Open Access Journals (Sweden)

    Stewart Kenton Bertram

    2015-09-01

    Full Text Available 'The protest group Anonymous has emerged as one of the most significant social movements of recent years, announcing their arrival as a globally recognized brand with regular disruptive cyber attacks and the leak of large volumes of sensitive data. Despite the obvious significance of Anonymous, to date, little academic research has been focused on what role hierarchy and internal authority play (if any within the group. Bespoke software was used to structure over 5000 examples of IRC log files, so that a base line descriptive statistical picture could be drawn, as well as a more granular enumeration of the privileges associated with individual users.'

  4. Instant Cassandra query language

    CERN Document Server

    Singh, Amresh

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. It's an Instant Starter guide.Instant Cassandra Query Language is great for those who are working with Cassandra databases and who want to either learn CQL to check data from the console or build serious applications using CQL. If you're looking for something that helps you get started with CQL in record time and you hate the idea of learning a new language syntax, then this book is for you.

  5. Semantic Web Query on e-Governance Data and Designing Ontology for Agriculture Domain

    Directory of Open Access Journals (Sweden)

    Swaran Lata

    2013-07-01

    Full Text Available Indian agriculture has made rapid progress on the agricultural front during the past three decades and isin a queue of the major producer in the world. But still it has long way to go and meet challenges aheadsuch as communication, resources, and availability at right time at right place. The web has had an amazingexistence and it has been the driving force for a cause to grow information across boundaries, enablingeffective communication and 24x7 service availability all leading to a digital information based economythat we have today. Despite that, its direct influence has reached to a small percentage of human population.Since localization populated with India and the applications are translated and adapted for Indian users.With the possible localization of spread raw formatted Indian government data, at different locationsare thought to have integrated with each other using the internet web technology as – Semantic Web Network.

  6. RESEARCH ON ANONYMOUS COMMUNICATION TECHNOLOGIES IN AD HOC NETWORKS%无线 Ad hoc 网络匿名通信技术研究

    Institute of Scientific and Technical Information of China (English)

    王秀芝; 石志东; 房卫东; 张小珑; 单联海

    2016-01-01

    无线 Ad hoc 网络(MANET)的多跳、自组织、无固定设施以及运算资源有限等特性,使得传统网络中复杂度高的安全算法难以应用于其中。而采用与匿名技术相结合的安全机制,可较好地解决节点隐私和通信关系保密的安全问题。针对现有的匿名技术,采用对比分析的方法,对传统网络的匿名技术进行分析,总结技术上的优缺点,研究 Ad hoc 网络的匿名技术,并对比分析各种匿名通信协议的安全性能,为后续的研究与应用提供帮助。%Due to the features of Ad hoc networks such as multi-hop,self-organisation,non-infrastructure and limited resource,the security algorithms with high complexity in traditional networks are hard to be used in it.However to use the security mechanism combining with anonymous technology can well solve the security problem in regard to nodes’privacy and communication relationship secret.In this paper,targeted at existing anonymous technologies,we analyse their use in traditional networks with the method of comparative analysis, summarise the advantages and disadvantages in terms of technology,and meanwhile study the anonymous technologies used in Ad hoc networks,as well as compare and analyse the security performances of various anonymous communication protocol,these provide the help for subsequent researches and applications.

  7. Semantic Web Query on E-Governance Data and Designing Ontology for Agriculture Domain

    Directory of Open Access Journals (Sweden)

    Swaran Lata

    2013-07-01

    Full Text Available Indian agriculture has made rapid progress on the a gricultural front during the past three decades and is in a queue of the major producer in the world. But still it has long way to go and meet challenges ahead such as communication, resour ces, and availability at right time at right place. The web has had an amazing existence and it has been the driving force for a cause to grow information across boundaries, enabling effect ive communication and 24x7 service availability all leading to a digital information b ased economy that we have today. Despite that, its direct influence has reached to a small percent age of human population. Since localization populated with India and the applications are trans lated and adapted for Indian users. With the possible localization of spread raw formatted India n government data, at different locations are thought to have integrated with each other using th e internet web technology as – Semantic Web Network

  8. Study and Practice of the Anonymity Technology Model for Electronic Commerce Based on MPLS%基于MPLS的电子商务匿名技术模型研究与实践

    Institute of Scientific and Technical Information of China (English)

    解争龙; 吴振强; 弋改珍; 王芳

    2012-01-01

    电子商务作为贸易手段已经进入人们的日常生活,如何保护商业机密、个人隐私是电子商务贸易中急需解决的问题.根据MPLS工作原理,在Onion匿名技术的基础上,建立基于MPLS的电子商务匿名模型,使用Nettrace对纯Onion匿名模型与基于MPLS匿名模型从安全和效率进行了比较.结果表明,基于MPLS匿名技术在保护用户隐私的同时,提高Onion匿名模型的通信效率.%Electronic Commerce has stepped into the daily life of people.But how to protect the business confidentiality and personal privacy is one of the problems resolved quickly.According to the operating principle of MPLS,on the anonymity technology of Onion,their security and efficiency has been compared for the anonymity models of the pure Onion and the MPLS.The results show that the anonymity technology of MPLS-based protected the user's privacy,while developed the efficiency of the model of Onion.

  9. 基于C++的关系代数产生的安全SQL查询%Safe SQL Queries Generated by Relational Algebra Based on C++ Language

    Institute of Scientific and Technical Information of China (English)

    顾坤鹏; 宋顺林

    2011-01-01

    在使用C++开发数据库相关的应用程序时,SQL语句的产生在程序编译期间并不会进行必要的检查.本文研究在编译期间使用C++编译器对关系代数运算作检查,由关系代数生成正确的SQL查询,将运行期SQL查询的部分检查工作提前到程序的编译期间处理.%When developing applications based on a database with C++ , the SQL queries are not necessarily checked for correctness at compile-time but only at runtime. The paper studies on using C++ compiler to check the relational algebra, which generates correct SQL queries, that brings forward some part of runtime work to be done at compile-time.

  10. ANONYMOUS OFF-LINE ELECTRONIC PAYMENT SYSTEM WITH MULTIPLE BANKS

    Institute of Scientific and Technical Information of China (English)

    Liang Jian; Ao Qingyun; Chen Ying

    2001-01-01

    This letter presents an anonymous off-line electronic payment model with multiple issuing-banks and gives an implementation scheme based on the discrete logarithm problem and the random oracle model. Comparing with previous works, the proposed scheme benefits from no involvement of customer group authority and its security depends on the known difficulty of resolving general discrete logarithm problem.

  11. Cooperative Answering of Fuzzy Queries

    Institute of Scientific and Technical Information of China (English)

    Narjes Hachani; Mohamed Ali Ben Hassine; Hanène Chettaoui; Habib Ounelli

    2009-01-01

    The majority of existing information systems deals with crisp data through crisp database systems. Traditional Database Management Systems (DBMS) have not taken into account imprecision so one can say there is some sort of lack of flexibility. The reason is that queries retrieve only elements which precisely match to the given Boolean query. That is, an element belongs to the result if the query is true for this element; otherwise, no answers are returned to the user. The aim of this paper is to present a cooperative approach to handling empty answers of fuzzy conjunctive queries by referring to the Formal Concept Analysis (FCA) theory and fuzzy logic. We present an architecture which combines FCA and databases. The processing of fuzzy queries allows detecting the minimal reasons of empty answers. We also use concept lattice in order to provide the user with the nearest answers in the case of a query failure.

  12. 基于jQuery前端框架提升Web用户体验的研究%Research on Enhancing Web User Experience with jQuery

    Institute of Scientific and Technical Information of China (English)

    侯海平

    2013-01-01

      越来越多互联网公司注重用户体验,jQuery正是顺应这一趋势而诞生的JavaScript轻量级框架,在提升Web用户体验方面有着很大的优势,并且这一效果正在逐渐扩大。本文主要介绍jQuery这一框架的技术特点,并分析如何提升用户体验。%More and more Internet companies focus on user expe-rience, jQuery is the one generated for this tendency. It is a lightweight framework of JavaScript. It has great advantage for enhancing Web user experience, and the effective now is enlarg-ing. This essay mainly introduces the features of jQuery and ana-lyze how to realize it.

  13. A Method for Geo Semantic Spatial Index on SPARQL Query%面向SPARQL查询的地理语义空间索引构建方法

    Institute of Scientific and Technical Information of China (English)

    段红伟; 孟令奎; 黄长青; 李颖; 李继园

    2014-01-01

    In order to query geo semantic data efficiently,based on the analysis of traditional RDF(resource description framework)data organization methods and spatial index methods, Firstly,a geospatial quad data model-GeoQuad was proposed,and then ,on the basis of this model a geo semantic spatial index method was constructed.Finally,using tools such as Jena, ARQ and JTS topology suite,a Geo SPARQL spatial query was achieved,which supported semantic query specification--SPARQL.Experiments show that this method is feasible,which is not only able to locate the spatial RDF nodes quickly,but also can quickly spatial query on RDF data by returning the results in the form of RDF node.%为了实现地理语义数据的快速有效的空间查询,在分析和研究传统 RDF(resource description framework)数据组织方法和空间索引的基础上,提出地理空间四元组(GeoQuad)模型,并基于该模型构建了地理语义空间索引,最后利用 Jena、ARQ 和 JTS Topology Suite 实现了支持语义查询规范-SPARQL的地理语义空间查询.试验表明,方法高效可行,不仅能够快速定位空间 RDF 节点,而且能够快速进行空间查询并返回 RDF结果.

  14. Attributes extraction of Deep Web query interface based on DOM%基于DOM的Deep Web查询接口属性抽取方法

    Institute of Scientific and Technical Information of China (English)

    石龙; 强保华; 何倩; 吴春明; 谌超

    2012-01-01

    Query interface schema extraction is the precondition of Deep Web data integration. Generally query interface schema consists of a set of domain-related attributes, and one attribute is formed by a single element or a combination of multi-elements. The current researches on attribute extraction are mostly based on the single element fashion, and those multi-elements based are few. Aiming at the case of multi-elements attribute extraction, a DOM-based method for query interface schema extraction is proposed. This method parses query interface to become a DOM and extracts the form elements base on the corresponding DOM nodes. The method employs two-phase clustering algorithms to cluster the form elements, mines the combination relationship of them and combines elements to realize attributes extraction. This method has a favorable performance at both single-element and multi-elements attribute extraction. The experimental result shows that this method is effective.%属性抽取主要基于单元素属性抽取,而多元素属性抽取的研究较少.针对多元素组成属性情况进行研究,提出一种基于查询接口DOM结构的属性抽取方法,该方法将查询接口解析成DOM,基于DOM节点提取查询接口上对应的表单元素,对从查询接口上提取获得的元素集合进行二次聚类,挖掘元素之间的组合关系,最终将元素组合形成属性.这种方法能很好地抽取接口上的单元素属性和多元素属性,实验结果表明了方法的有效性.

  15. 基于HTML5+jQuery Mobile的移动Web应用开发研究%Study of mobile web application development based on HTML5 and jQuery Mobile

    Institute of Scientific and Technical Information of China (English)

    覃凤萍

    2015-01-01

    With the rapidly growing popularity of smart devices such as iphone and Android,mobile web technology has gradually become a new hot spot of concern,traditional site will be transferred to the mobile terminal due to market demand . Using jQuery Mobile and HTML5 to do mobile web application development, with the development of simple, short release cycle, cross-platform, cross-platform advantages . In this paper, jQuery Mobile and HTML5 mobile web application development made a presentation and analysis.%随着iphone、Android等智能设备的迅速普及,移动Web技术逐渐成为关注的新热点,传统信息类和电子商务网站因市场需求向移动终端转移。使用jQuery Mobile和HTML5做移动Web应用开发,具有开发简单,发布周期短、跨平台跨设备的优点。文章对jQuery Mobile和HTML5的移动Web应用开发做了介绍和分析。

  16. Multi-Dimensional Top-k Dominating Queries

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Mamoulis, Nikos

    2009-01-01

    The top-k dominating query returns k data objects which dominate the highest number of objects in a dataset. This query is an important tool for decision support since it provides data analysts an intuitive way for finding significant objects. In addition, it combines the advantages of top...... attention from the research community. This paper is an extensive study on the evaluation of topk dominating queries. First, we propose a set of algorithms that apply on indexed multi-dimensional data. Second, we investigate query evaluation on data that are not indexed. Finally, we study a relaxed variant...... of the query which considers dominance in dimensional subspaces. Experiments using synthetic and real datasets demonstrate that our algorithms significantly outperform a previous skyline-based approach. We also illustrate the applicability of this multi-dimensional analysis query by studying the meaningfulness...

  17. Research Advance on Similarity Join Queries%相似性连接查询技术研究进展

    Institute of Scientific and Technical Information of China (English)

    庞俊; 谷峪; 许嘉; 于戈

    2013-01-01

    Similarity join query is to find similar data object pairs for a wide range of applications, such as near duplicate Web page detection, entity resolution, data cleaning and similar image retrieval. Nowadays, similarity join query becomes one of the hot topics in the field of big data processing. This paper discusses the challenges of similarity join query. Meanwhile, it analyzes and classifies the existing similarity join queries according to different standards, then summarizes and compares the existing string, set, vector and graph similarity join algorithms respectively. Finally, it explores the research focus and trend of this area.%  相似性连接查询,即查找相似的数据对象对,具有广泛的应用领域,例如相似网页检测、实体解析、数据清洗和相似图像检索等。相似性连接查询是当前大数据处理领域的热点问题之一。讨论了相似性连接查询面临的挑战;根据不同的标准对现有的相似性连接查询进行了分类;总结并比较了现有的字符串、集合、向量和图相似性连接算法;探讨了今后的研究重点和发展趋势。

  18. Index and query methods in road networks

    CERN Document Server

    Feng, Jun

    2015-01-01

    This book presents the index and query techniques on road network and moving objects which are limited to road network. Here, the road network of non-Euclidean space has its unique characteristics such that two moving objects may be very close in a straight line distance. The index used in two-dimensional Euclidean space is not always appropriate for moving objects on road network. Therefore, the index structure needs to be improved in order to obtain suitable indexing methods, explore the shortest path and acquire nearest neighbor query and aggregation query methods under the new index structures. Chapter 1 of this book introduces the present situation of intelligent traffic and index in road network, Chapter 2 introduces the relevant existing spatial indexing methods. Chapter 3-5 focus on several issues of road network and query, they involves: traffic road network models (see Chapter 3), index structures (see Chapter 4) and aggregate query methods (see Chapter 5). Finally, in Chapter 6, the book briefly de...

  19. Indexing Reverse Top-k Queries

    CERN Document Server

    Chester, Sean; Venkatesh, S; Whitesides, Sue

    2012-01-01

    We consider the recently introduced monochromatic reverse top-k queries which ask for, given a new tuple q and a dataset D, all possible top-k queries on D union {q} for which q is in the result. Towards this problem, we focus on designing indexes in two dimensions for repeated (or batch) querying, a novel but practical consideration. We present the insight that by representing the dataset as an arrangement of lines, a critical k-polygon can be identified and used exclusively to respond to reverse top-k queries. We construct an index based on this observation which has guaranteed worst-case query cost that is logarithmic in the size of the k-polygon. We implement our work and compare it to related approaches, demonstrating that our index is fast in practice. Furthermore, we demonstrate through our experiments that a k-polygon is comprised of a small proportion of the original data, so our index structure consumes little disk space.

  20. A Study of Library Databases by Translating Those SQL Queries into Relational Algebra and Generating Query Trees

    Directory of Open Access Journals (Sweden)

    Santhi Lasya

    2011-09-01

    Full Text Available Even in this World Wide Web era where there is unrestricted access to a lot of articles and books at a mouses click, the role of an organized library is immense. It is vital to have effective software to manage various functions in a library and the fundamental for effective software is the underlying database access and the queries used. And hence library databases become our use-case for this study. This paper starts off with considering a basic ER model of a typical library relational database. We would also list all the basic use-cases in a library management system. The next part of the paper deals with the sql queries used for performing certain functions in a library database management system. Along with the queries, we would generate reports for some of the use cases. The final section of the paper forms the crux of this library database study, wherein we would dwell on the concepts of query processing and query optimization in the relational database domain. We would analyze the above mentioned queries, by translating the query into a relational algebra expression and generating a query tree for the same. By converting algebra, we look at optimizing the query, and by generating a query tree, we would come up a cheapest cost plan.

  1. Anonymous pastoral care for problems pertaining to sexuality

    NARCIS (Netherlands)

    A. van Drie; R.R. Ganzevoort; M. Spiering

    2013-01-01

    Anonymous pastoral care is one of the options for help in problems pertaining to sexuality. This paper explores the topics they seek help for, the religious aspects involved, and the relation between the normativity of their church tradition on the one hand and sexual and spiritual health criteria o

  2. Anonymous pastoral care for problems pertaining to sexuality

    NARCIS (Netherlands)

    van Drie, A.; Ganzevoort, R.R.; Spiering, M.

    2014-01-01

    Anonymous pastoral care is one of the options for help in problems pertaining to sexuality. This paper explores the topics they seek help for, the religious aspects involved, and the relation between the normativity of their church tradition on the one hand and sexual and spiritual health criteria o

  3. Leader election in anonymous rings: Franklin goes probabilistic

    NARCIS (Netherlands)

    Bakhshi, R.; Fokkink, W.J.; Pang, J.; Pol, J.C. van de; Ausiello, G.

    2008-01-01

    We present a probabilistic leader election algorithm for anonymous, bidirectional, asynchronous rings. It is based on an algorithm from Franklin, augmented with random identity selection, hop counters to detect identity clashes, and round numbers modulo 2. As a result, the algorithm is finite-state,

  4. Leader Election in Anonymous Rings: Franklin Goes Probabilistic

    NARCIS (Netherlands)

    Bakhshi, Rena; Fokkink, Wan; Pang, Jun; Pol, van de Jaco; Ausiello, G.; Karhumäki, J.; Mauri, G.; Ong, L.

    2008-01-01

    We present a probabilistic leader election algorithm for anonymous, bidirectional, asynchronous rings. It is based on an algorithm from Franklin, augmented with random identity selection, hop counters to detect identity clashes, and round numbers modulo 2. As a result, the algorithm is finite-state,

  5. 基于Hadoop的高效连接查询处理算法CHMJ%Efficient Join Query Processing Algorithm CHMJ Based on Hadoop

    Institute of Scientific and Technical Information of China (English)

    赵彦荣; 王伟平; 孟丹; 张书彬; 李均

    2012-01-01

    This paper proposes a join query processing algorithm CoLocationHashMapJoin (CHMJ). First the study designs a multi-copy consistency hash algorithm. The algorithm distributes the data of tables over the cluster according to the hash values of the join property, which improves the data locality while ensure data availability. Second, based on the multi-copy consistency hash algorithm, the study proposes a parallel join query processing algorithm called HashMapJoin. HashMapJoin improves the efficiency of join query significantly. CHMJ has been used in Tencent's data warehouse system, and plays an important role in Tencent's daily analysis tasks. The results show that CHMJ improves the efficiency of join query processing by five times comparing to Hive.%提出了一种并行连接查询处理算法CoLocationHashMapJoin(CHMJ).首先,设计了多副本一致性哈希算法,将具有连接关系的表根据其连接属性的哈希值在机群中进行分布,在提升了连接查询处理中数据本地性的同时,保证了数据的可用性;其次,基于多副本一致性哈希数据分布,提出了HashMapJoin并行连接查询处理算法,有效地提高了连接查询的处理效率.CHMJ算法在腾讯公司的数据仓库系统中进行了应用,结果表明,CHMJ连接查询的处理效率比Hive系统提高了近5倍.

  6. Northeastern University in TREC 2009. Million Query Track

    Science.gov (United States)

    2009-11-01

    queries in the collection had at least one click on documents in the .gov collection. Given the computational complexity of feature extraction and...ranking functions (by employing SVM) over two different collections, (a) the Million Query 2008 (MQ08) collection (GOV2 corpus and queries with at least one ... click on doc- uments in the .gov domain), and (b) a Bing generated collection (described in Section 2.1) and employed the constructed ranking

  7. A k-anonymous algorithm in location privacy protection based on circular zoning%圆形区域划分的k-匿名位置隐私保护方法

    Institute of Scientific and Technical Information of China (English)

    赵泽茂; 胡慧东; 张帆; 张品; 周建钦

    2013-01-01

    用户位置信息的准确度反比于用户的隐私保护安全系数k(privacy protection level),正比于查询服务质量;为了平衡由位置信息的准确性引起的隐私保护安全与查询服务质量之间的矛盾,借助位置k-匿名模型,提出了圆形区域划分匿名方法.将整个区域划分为相切圆及相邻的4个相切圆的顶点组成的曲边菱形形成的组合区域,当用户位置区域含有的用户数量不满足隐私保护安全系数要求时,利用区域扩充公式得到合适的匿名区域.实验结果表明该方法减小了匿名区域的面积,提高了相对匿名度,从而平衡了k与QoS的矛盾;并从匿名成功率、服务质量和信息处理时间3个角度确定了基于位置k-匿名隐私保护方法的评估模型.%To some extent,the more accuracy of user's location information is,the user's privacy protection level k is lower,but the higher of quality of service (QoS) is.In order to resolve the contradiction between k and QoS,we propose circular zoning method,which divides the whole area into tangent to circle and the curved edge of diamond-shaped area which composed by the adjacent tangent circle's vertices.When the number of users in an anonymous area is less than k,anonymous area is get by using the regional expansion formula.The experimental results show the algorithm can obtain better QoS under high privacy level,reduce the anonymous area and increase the relative anonymous,so the QoS is improved.We also analysis the impact factors of the assessment model based on k-anonymous location privacy protection from different aspects.

  8. An adaptive range-query optimization technique with distributed replicas

    Institute of Scientific and Technical Information of China (English)

    Sayar Ahmet; Pierce Marlon; Fox C.Geoffrey

    2014-01-01

    Replication is an approach often used to speed up the execution of queries submitted to a large dataset. A compile-time/run-time approach is presented for minimizing the response time of 2-dimensional range when a distributed replica of a dataset exists. The aim is to partition the query payload (and its range) into subsets and distribute those to the replica nodes in a way that minimizes a client’s response time. However, since query size and distribution characteristics of data (data dense/sparse regions) in varying ranges are not known a priori, performing efficient load balancing and parallel processing over the unpredictable workload is difficult. A technique based on the creation and manipulation of dynamic spatial indexes for query payload estimation in distributed queries was proposed. The effectiveness of this technique was demonstrated on queries for analysis of archived earthquake-generated seismic data records.

  9. A Novel Adaptive Cuckoo Search for Optimal Query Plan Generation

    Directory of Open Access Journals (Sweden)

    Ramalingam Gomathi

    2014-01-01

    Full Text Available The emergence of multiple web pages day by day leads to the development of the semantic web technology. A World Wide Web Consortium (W3C standard for storing semantic web data is the resource description framework (RDF. To enhance the efficiency in the execution time for querying large RDF graphs, the evolving metaheuristic algorithms become an alternate to the traditional query optimization methods. This paper focuses on the problem of query optimization of semantic web data. An efficient algorithm called adaptive Cuckoo search (ACS for querying and generating optimal query plan for large RDF graphs is designed in this research. Experiments were conducted on different datasets with varying number of predicates. The experimental results have exposed that the proposed approach has provided significant results in terms of query execution time. The extent to which the algorithm is efficient is tested and the results are documented.

  10. A novel adaptive Cuckoo search for optimal query plan generation.

    Science.gov (United States)

    Gomathi, Ramalingam; Sharmila, Dhandapani

    2014-01-01

    The emergence of multiple web pages day by day leads to the development of the semantic web technology. A World Wide Web Consortium (W3C) standard for storing semantic web data is the resource description framework (RDF). To enhance the efficiency in the execution time for querying large RDF graphs, the evolving metaheuristic algorithms become an alternate to the traditional query optimization methods. This paper focuses on the problem of query optimization of semantic web data. An efficient algorithm called adaptive Cuckoo search (ACS) for querying and generating optimal query plan for large RDF graphs is designed in this research. Experiments were conducted on different datasets with varying number of predicates. The experimental results have exposed that the proposed approach has provided significant results in terms of query execution time. The extent to which the algorithm is efficient is tested and the results are documented.

  11. Goal Directed Relative Skyline Queries in Time Dependent Road Networks

    CERN Document Server

    Iyer, K B Priya

    2012-01-01

    The Wireless GIS technology is progressing rapidly in the area of mobile communications. Location-based spatial queries are becoming an integral part of many new mobile applications. The Skyline queries are latest apps under Location-based services. In this paper we introduce Goal Directed Relative Skyline queries on Time dependent (GD-RST) road networks. The algorithm uses travel time as a metric in finding the data object by considering multiple query points (multi-source skyline) relative to user location and in the user direction of travelling. We design an efficient algorithm based on Filter phase, Heap phase and Refine Skyline phases. At the end, we propose a dynamic skyline caching (DSC) mechanism which helps to reduce the computation cost for future skyline queries. The experimental evaluation reflects the performance of GD-RST algorithm over the traditional branch and bound algorithm for skyline queries in real road networks.

  12. Semantic Query Expansion Based on Multilingual Ontology%基于多语本体的语义查询扩展研究

    Institute of Scientific and Technical Information of China (English)

    司莉; 潘秋玉

    2016-01-01

    查询扩展是改善信息检索结果的有效方法。针对用户获取多语言信息的需求以及当前跨语言信息检索存在的翻译歧异性问题,提出一种基于多语本体的语义查询扩展方法,介绍其基本原理、查询扩展模型及实现过程,使跨语言信息检索从字符匹配变成语义层面的匹配,实现跨语言信息检索中的查询扩展,以提高多语言信息检索的查全率和查准率。%Query expansion is an effective method to enhance information retrieval performance. Aiming at the requirements of acquiring multilingual information and solving the problems of semantic disambiguation of cross language information retrieval (CLIR), the article proposed a new semantic query expansion method based on multilingual ontology, and introduced its fundamentals, model and realization process, to turn character-matching into semantic matching for CLIR, implementing query expansion in CLIR, which may optimize system’s recal and precision.

  13. Anonymous Agencies, Backstreet Businesses and Covert Collectives

    DEFF Research Database (Denmark)

    Krause Hansen, Hans; Schoeneborn, Dennis

    2015-01-01

    Book review of: Anonymous Agencies, Backstreet Businesses and Covert Collectives: rethinking Organizations in the 21st Century, C. R. Scott. Stanford, CA: Stanford University Press, 2013. 272 pp. £45.90. ISBN 9780804781381......Book review of: Anonymous Agencies, Backstreet Businesses and Covert Collectives: rethinking Organizations in the 21st Century, C. R. Scott. Stanford, CA: Stanford University Press, 2013. 272 pp. £45.90. ISBN 9780804781381...

  14. From Questions to Queries

    Directory of Open Access Journals (Sweden)

    M. Drlík

    2007-12-01

    Full Text Available The extension of (Internet databases forceseveryone to become more familiar with techniques of datastorage and retrieval because users’ success often dependson their ability to pose right questions and to be able tointerpret their answers. University programs pay moreattention to developing database programming skills than todata exploitation skills. To educate our students to become“database users”, the authors intensively exploit supportivetools simplifying the production of database elements astables, queries, forms, reports, web pages, and macros.Videosequences demonstrating “standard operations” forcompleting them have been prepared to enhance out-ofclassroomlearning. The use of SQL and other professionaltools is reduced to the cases when the wizards are unable togenerate the intended construct.

  15. Social distance and anonymity modulate fairness consideration: An ERP study

    Science.gov (United States)

    Yu, Rongjun; Hu, Pan; Zhang, Ping

    2015-01-01

    Previous research indicated that fairness consideration can be influenced by social distance. However, it is not clear whether social distance and anonymity have an interactive impact on fairness evaluation during asset distribution and whether these processes can be documented in brain activity. Using a modified ultimatum game combined with measures of event related potential (ERP), we examined how social distance and anonymity modulate brain response to inequality. At the behavior level, we found that acceptance rate and reaction time can be substantially modified by social distance and anonymity. Feedback-related negativity, an ERP component associated with conflict between cognitive and emotion motives, was more negative in response to unfairness than fairness from strangers; however, it showed an opposite trend for unfair offers provided by friends, suggesting that the influence of social distance on fairness perception is relatively fast. The P300 in response to fair offers was more positive when the proposers made offers when uncertain about partner identity than when certain about partner identity. These results suggest that unfairness is evaluated in a fast conflict detection stage and a slower stage that integrates more complex social contextual factors such as anonymity. PMID:26293456

  16. Social distance and anonymity modulate fairness consideration: An ERP study.

    Science.gov (United States)

    Yu, Rongjun; Hu, Pan; Zhang, Ping

    2015-08-21

    Previous research indicated that fairness consideration can be influenced by social distance. However, it is not clear whether social distance and anonymity have an interactive impact on fairness evaluation during asset distribution and whether these processes can be documented in brain activity. Using a modified ultimatum game combined with measures of event related potential (ERP), we examined how social distance and anonymity modulate brain response to inequality. At the behavior level, we found that acceptance rate and reaction time can be substantially modified by social distance and anonymity. Feedback-related negativity, an ERP component associated with conflict between cognitive and emotion motives, was more negative in response to unfairness than fairness from strangers; however, it showed an opposite trend for unfair offers provided by friends, suggesting that the influence of social distance on fairness perception is relatively fast. The P300 in response to fair offers was more positive when the proposers made offers when uncertain about partner identity than when certain about partner identity. These results suggest that unfairness is evaluated in a fast conflict detection stage and a slower stage that integrates more complex social contextual factors such as anonymity.

  17. jQuery Mobile Up and Running

    CERN Document Server

    Firtman, Maximiliano

    2012-01-01

    Would you like to build one mobile web application that works on iPad and Kindle Fire as well as iPhone and Android smartphones? This introductory guide to jQuery Mobile shows you how. Through a series of hands-on exercises, you'll learn the best ways to use this framework's many interface components to build customizable, multiplatform apps. You don't need any programming skills or previous experience with jQuery to get started. By the time you finish this book, you'll know how to create responsive, Ajax-based interfaces that work on a variety of smartphones and tablets, using jQuery Mobile

  18. Querying and Extracting Timeline Information from Road Traffic Sensor Data.

    Science.gov (United States)

    Imawan, Ardi; Indikawati, Fitri Indra; Kwon, Joonho; Rao, Praveen

    2016-08-23

    The escalation of traffic congestion in urban cities has urged many countries to use intelligent transportation system (ITS) centers to collect historical traffic sensor data from multiple heterogeneous sources. By analyzing historical traffic data, we can obtain valuable insights into traffic behavior. Many existing applications have been proposed with limited analysis results because of the inability to cope with several types of analytical queries. In this paper, we propose the QET (querying and extracting timeline information) system-a novel analytical query processing method based on a timeline model for road traffic sensor data. To address query performance, we build a TQ-index (timeline query-index) that exploits spatio-temporal features of timeline modeling. We also propose an intuitive timeline visualization method to display congestion events obtained from specified query parameters. In addition, we demonstrate the benefit of our system through a performance evaluation using a Busan ITS dataset and a Seattle freeway dataset.

  19. Querying Big Data:Bridging Theory and Practice

    Institute of Scientific and Technical Information of China (English)

    樊文飞; 怀进鹏

    2014-01-01

    Big data introduces challenges to query answering, from theory to practice. A number of questions arise. What queries are “tractable” on big data? How can we make big data “small” so that it is feasible to find exact query answers? When exact answers are beyond reach in practice, what approximation theory can help us strike a balance between the quality of approximate query answers and the costs of computing such answers? To get sensible query answers in big data, what else do we necessarily do in addition to coping with the size of the data? This position paper aims to provide an overview of recent advances in the study of querying big data. We propose approaches to tackling these challenging issues, and identify open problems for future research.

  20. Structured Query Translation in Peer to Peer Database Sharing Systems

    Directory of Open Access Journals (Sweden)

    Mehedi Masud

    2009-10-01

    Full Text Available This paper presents a query translation mechanism between heterogeneous peers in Peer to Peer Database Sharing Systems (PDSSs. A PDSS combines a database management system with P2P functionalities. The local databases on peers are called peer databases. In a PDSS, each peer chooses its own data model and schema and maintains data independently without any global coordinator. One of the problems in such a system is translating queries between peers, taking into account both the schema and data heterogeneity. Query translation is the problem of rewriting a query posed in terms of one peer schema to a query in terms of another peer schema. This paper proposes a query translation mechanism between peers where peers are acquainted in data sharing systems through data-level mappings for sharing data.

  1. Querying and Extracting Timeline Information from Road Traffic Sensor Data

    Directory of Open Access Journals (Sweden)

    Ardi Imawan

    2016-08-01

    Full Text Available The escalation of traffic congestion in urban cities has urged many countries to use intelligent transportation system (ITS centers to collect historical traffic sensor data from multiple heterogeneous sources. By analyzing historical traffic data, we can obtain valuable insights into traffic behavior. Many existing applications have been proposed with limited analysis results because of the inability to cope with several types of analytical queries. In this paper, we propose the QET (querying and extracting timeline information system—a novel analytical query processing method based on a timeline model for road traffic sensor data. To address query performance, we build a TQ-index (timeline query-index that exploits spatio-temporal features of timeline modeling. We also propose an intuitive timeline visualization method to display congestion events obtained from specified query parameters. In addition, we demonstrate the benefit of our system through a performance evaluation using a Busan ITS dataset and a Seattle freeway dataset.

  2. Towards the Formalization of Fuzzy Relational Database Queries

    Directory of Open Access Journals (Sweden)

    Aleksandar Perović

    2009-03-01

    Full Text Available The aim of this paper is to give guidelines on how to formalize fuzzy relationaldatabase queries using 1LΠ 2 fuzzy logic. After the short introduction, we give anoverview of the1LΠ 2 logic. In the continuation we give a brief overview of the FRDBqueries and query-database similarity relation. We conclude the paper with the descriptionof FRDB query formalization using presented definitions.

  3. Performance Analysis of Two Big Data Technologies on a Cloud Distributed Architecture. Results for Non-Aggregate Queries on Medium-Sized Data

    Directory of Open Access Journals (Sweden)

    Fotache Marin

    2016-12-01

    Full Text Available Big Data systems manage and process huge volumes of data constantly generated by various technologies in a myriad of formats. Big Data advocates (and preachers have claimed that, relative to classical, relational/SQL Data Base Management Systems, Big Data technologies such as NoSQL, Hadoop and in-memory data stores perform better. This paper compares data processing performance of two systems belonging to SQL (PostgreSQL/Postgres XL and Big Data (Hadoop/Hive camps on a distributed five-node cluster deployed in cloud. Unlike benchmarks in use (YCSB, TPC, a series of R modules were devised for generating random non-aggregate queries on different subschema (with increasing data size of TPC-H database. Overall performance of the two systems was compared. Subsequently a number of models were developed for relating performance on the system and also on various query parameters such as the number of attributes in SELECT and WHERE clause, number of joins, number of processing rows etc.

  4. Role Engagement and Anonymity in Synchronous Online Role Play

    Directory of Open Access Journals (Sweden)

    Sarah Cornelius

    2011-06-01

    Full Text Available Role play activities provide opportunities for learners to adopt unfamiliar roles, engage in interactions with others, and get involved in realistic tasks. They are often recommended to foster the development of soft skills and a wider perspective of the world. Such activities are widely used as an online teaching approach, with examples ranging from the simple use of email to the employment of virtual worlds and Web 2.0 technologies.This paper provides a case study of a role play activity which employs real-time anonymous discussion forums and aims to improve our understanding of effective role play and the impact of anonymity. This role play has been effective in educating learners about different perspectives on the issue of Quality in Further Education. The context and implementation of the role play are outlined, and the learners’ interactions and experiences are explored using an investigative analysis of discussion transcripts and semi-structured interviews with participants. The findings suggest that role engagement and anonymity are important components for success in synchronous online role play. Evidence is presented that provides an insight into the factors which encourage role engagement, including prior experiences and contributions from peers. The impact of anonymity is also explored since many participants did not regard the study environment as real and attempted to identify their peers.

  5. A Generic Framework for Anonymous Authentication in Mobile Networks

    Institute of Scientific and Technical Information of China (English)

    Jing Xu; Wen-Tao Zhu

    2013-01-01

    Designing an anonymous user authentication scheme in global mobility networks is a non-trivial task because wireless networks are susceptible to attacks and mobile devices powered by batteries have limited communication,processing and storage capabilities.In this paper,we present a generic construction that converts any existing secure password authentication scheme based on a smart card into an anonymous authentication scheme for roaming services.The security proof of our construction can be derived from the underlying password authentication scheme employing the same assumptions.Compared with the original password authentication scheme,the transformed scheme does not sacrifice the authentication efficiency,and additionally,an agreed session key can be securely established between an anonymous mobile user and the foreign agent in charge of the network being visited.Furthermore,we present an instantiation of the proposed generic construction.The performance analysis shows that compared with other related anonymous authentication schemes,our instantiation is more efficient.

  6. How Do Search Engines Handle Chinese Queries?

    Directory of Open Access Journals (Sweden)

    Hong Cui

    2005-10-01

    Full Text Available The use of languages other than English has been growing exponentially on the Web. However, the major search engines have been lagging behind in providing indexes and search features to handle these languages. This article explores the characteristics of the Chinese language and how queries in this language are handled by different search engines. Queries were entered in two major search engines (Google and AlltheWeb and two search engines developed for Chinese (Sohu and Baidu. Criteria such as handling word segmentation, number of retrieved documents, and correct display and identification of Chinese characters were used to examine how the search engines handled the queries. The results showed that the performance of the two major search engines was not on a par with that of the search engines developed for Chinese.

  7. Animating the Web with jQuery

    Directory of Open Access Journals (Sweden)

    Asokan M

    2013-02-01

    Full Text Available World globalization and present day technology increases the web users rapidly. Every website is trying to attract the web users. The web site creators /developers add different kind of animations to their websites. There are many softwares available to create animation. jQuery can be used to create interactive and powerful web pages with animations. JQuery is a JavaScript library intendedto make Java Script programming easier and more fun. A JavaScript library is a complex JavaScript program that both simplifies difficult tasks and solves cross-browser problems. With jQuery, we canaccomplish tasks in a single line of code. JQuery is used on millions of websites. This paper discuss about the advantages and usage statistics of jQuery on the web. A complete procedure to create a slider and banner plug-ins are also included. They are tested with different browsers.

  8. Automatic Building Information Model Query Generation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yufei; Yu, Nan; Ming, Jiang; Lee, Sanghoon; DeGraw, Jason; Yen, John; Messner, John I.; Wu, Dinghao

    2015-12-01

    Energy efficient building design and construction calls for extensive collaboration between different subfields of the Architecture, Engineering and Construction (AEC) community. Performing building design and construction engineering raises challenges on data integration and software interoperability. Using Building Information Modeling (BIM) data hub to host and integrate building models is a promising solution to address those challenges, which can ease building design information management. However, the partial model query mechanism of current BIM data hub collaboration model has several limitations, which prevents designers and engineers to take advantage of BIM. To address this problem, we propose a general and effective approach to generate query code based on a Model View Definition (MVD). This approach is demonstrated through a software prototype called QueryGenerator. By demonstrating a case study using multi-zone air flow analysis, we show how our approach and tool can help domain experts to use BIM to drive building design with less labour and lower overhead cost.

  9. The Semantics of Query Modification

    NARCIS (Netherlands)

    Hollink, V.; Tsikrika, T.; Vries, A.P. de

    2010-01-01

    We present a method that exploits `linked data' to determine semantic relations between consecutive user queries. Our method maps queries onto concepts in linked data and searches the linked data graph for direct or indirect relations between the concepts. By comparing relations between large number

  10. Usability of XML Query Languages

    NARCIS (Netherlands)

    Graaumans, J.P.M.

    2005-01-01

    The eXtensible Markup Language (XML) is a markup language which enables re-use of information. Specific query languages for XML are developed to facilitate this. There are large differences between history, design goal, and syntax of the XML query languages. However, in practice these languages are

  11. Priming the Query Specification Process.

    Science.gov (United States)

    Toms, Elaine G.; Freund, Luanne

    2003-01-01

    Tests the use of questions as a technique in the query specification process. Using a within-subjects design, 48 people interacted with a modified Google interface to solve four information problems in four domains. Half the tasks were entered as typical keyword queries, and half as questions or statements. Results suggest the typical search box…

  12. Web Database Schema Identification through Simple Query Interface

    Science.gov (United States)

    Lin, Ling; Zhou, Lizhu

    Web databases provide different types of query interfaces to access the data records stored in the backend databases. While most existing works exploit a complex query interface with multiple input fields to perform schema identification of the Web databases, little attention has been paid on how to identify the schema of web databases by simple query interface (SQI), which has only one single query text input field. This paper proposes a new method of instance-based query probing to identify WDBs' interface and result schema for SQI. The interface schema identification problem is defined as generating the fullcondition query of SQI and a novel query probing strategy is proposed. The result schema is also identified based on the result webpages of SQI's full-condition query, and an extended identification of the non-query attributes is proposed to improve the attribute recall rate. Experimental results on web databases of online shopping for book, movie and mobile phone show that our method is effective and efficient.

  13. The anonymity paradox in patient engagement: reputation, risk and web-based public feedback.

    Science.gov (United States)

    Speed, Ewen; Davison, Charlie; Gunnell, Caroline

    2016-06-01

    The UK National Health Service (NHS) has long espoused patient and public engagement. Recent years have seen increasing use of internet-based methods of collecting feedback about patient experience and public and staff views about NHS services and priorities. Often hailed as a means of facilitating participative democratic patient engagement, these processes raise a number of complex issues. A key aspect of it is the opportunity for comment to be made anonymously. Our research reveals an anonymity paradox whereby patients clearly demonstrate a perception that anonymity is a prerequisite for effective use of these feedback processes, whereas professionals demonstrate a perception that patient anonymity is a barrier to effective use. The risks of anonymity are constructed very differently by patients and professionals. Patient concerns around anonymity were not motivated by a general concern about a loss of privacy, but more that a positive identification might compromise future care. For professionals, concerns were voiced more around risks of reputational damage for specific practitioners or practices (in that anyone could say anything) and also that this anonymous feedback was available publicly and that it might go against the medical opinion of the professional. These concerns pointed to important differences in perceptions of patient and professional vulnerability. In the qualitative analysis that follows the key finding was that while anonymity makes service users feel less vulnerable, it can have the opposite effect on managers and clinical staff. This raises important implications for the use and utility of internet-based methods of collecting patient feedback.

  14. Instant jQuery selectors

    CERN Document Server

    De Rosa, Aurelio

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. Instant jQuery Selectors follows a simple how-to format with recipes aimed at making you well versed with the wide range of selectors that jQuery has to offer through a myriad of examples.Instant jQuery Selectors is for web developers who want to delve into jQuery from its very starting point: selectors. Even if you're already familiar with the framework and its selectors, you could find several tips and tricks that you aren't aware of, especially about performance and how jQuery ac

  15. Optimal Planar Orthogonal Skyline Counting Queries

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Larsen, Kasper Green

    2014-01-01

    The skyline of a set of points in the plane is the subset of maximal points, where a point (x,y) is maximal if no other point (x',y') satisfies x'≥ x and y'≥ x. We consider the problem of preprocessing a set P of n points into a space efficient static data structure supporting orthogonal skyline...... counting queries, i.e. given a query rectangle R to report the size of the skyline of P\\cap R. We present a data structure for storing n points with integer coordinates having query time O(lg n/lglg n) and space usage O(n). The model of computation is a unit cost RAM with logarithmic word size. We prove...

  16. Query strategy for sequential ontology debugging

    CERN Document Server

    Shchekotykhina, Kostyantyn; Fleiss, Philipp; Rodler, Patrick

    2011-01-01

    Debugging of ontologies is an important prerequisite for their wide-spread application, especially in areas that rely upon everyday users to create and maintain knowledge bases, as in the case of the Semantic Web. Recent approaches use diagnosis methods to identify causes of inconsistent or incoherent ontologies. However, in most debugging scenarios these methods return many alternative diagnoses, thus placing the burden of fault localization on the user. This paper demonstrates how the target diagnosis can be identified by performing a sequence of observations, that is, by querying an oracle about entailments of the target ontology. We exploit a-priori probabilities of typical user errors to formulate information-theoretic concepts for query selection. Our evaluation showed that the proposed method significantly reduces the number of required queries compared to myopic strategies. We experimented with different probability distributions of user errors and different qualities of the a-priori probabilities. Ou...

  17. Transfer active learning by querying committee

    Institute of Scientific and Technical Information of China (English)

    Hao SHAO; Feng TAO; Rui XU

    2014-01-01

    In real applications of inductive learning for classifi cation, labeled instances are often defi cient, and labeling them by an oracle is often expensive and time-consuming. Active learning on a single task aims to select only informative unlabeled instances for querying to improve the classifi cation accuracy while decreasing the querying cost. However, an inevitable problem in active learning is that the informative measures for selecting queries are commonly based on the initial hypotheses sampled from only a few labeled instances. In such a circumstance, the initial hypotheses are not reliable and may deviate from the true distribution underlying the target task. Consequently, the informative measures will possibly select irrelevant instances. A promising way to compensate this problem is to borrow useful knowledge from other sources with abundant labeled information, which is called transfer learning. However, a signifi cant challenge in transfer learning is how to measure the similarity between the source and the target tasks. One needs to be aware of different distributions or label assignments from unrelated source tasks;otherwise, they will lead to degenerated performance while transferring. Also, how to design an effective strategy to avoid selecting irrelevant samples to query is still an open question. To tackle these issues, we propose a hybrid algorithm for active learning with the help of transfer learning by adopting a divergence measure to alleviate the negative transfer caused by distribution differences. To avoid querying irrelevant instances, we also present an adaptive strategy which could eliminate unnecessary instances in the input space and models in the model space. Extensive experiments on both the synthetic and the real data sets show that the proposed algorithm is able to query fewer instances with a higher accuracy and that it converges faster than the state-of-the-art methods.

  18. Predictors of anonymous cyber aggression: the role of adolescents' beliefs about anonymity, aggression, and the permanency of digital content.

    Science.gov (United States)

    Wright, Michelle F

    2014-07-01

    Little attention has been given to whether adolescents' beliefs about anonymity and their normative beliefs about cyber aggression jointly increase their perpetration of cyber aggression. To this end, the present longitudinal study examined the moderating influence of these variables on the relationships among adolescents' attitudes toward the permanency of digital content, confidence with not getting caught, and anonymous cyber aggression (ACA) assessed 1 year later (Time 2). These associations were examined among 274 7th and 8th graders and through five technologies, including social networking sites (SNS), e-mail, instant messenger (IM), mobile phones, and chatrooms. Findings indicated that increases in Time 2 ACA and attitudes toward the permanency of digital content were more strongly related when adolescents reported greater confidence with not getting caught and higher normative beliefs concerning cyber aggression through SNS and mobile phones. In addition, higher levels of attitudes toward the permanency of digital content, confidence with not getting caught, beliefs about anonymity, and normative beliefs regarding cyber aggression were related to greater Time 2 ACA through e-mail, IM, and chatrooms. All findings are discussed in the context of adolescents' positive attitudes toward ACA, and an appeal for additional research is made to understand more about anonymity in cyberspace.

  19. A structural query system for Han characters

    DEFF Research Database (Denmark)

    Skala, Matthew

    2016-01-01

    The IDSgrep structural query system for Han character dictionaries is presented. This dictionary search system represents the spatial structure of Han characters using Extended Ideographic Description Sequences (EIDSes), a data model and syntax based on the Unicode IDS concept. It includes a query...... language for EIDS databases, with a freely available implementation and format translation from popular third-party IDS and XML character databases. The system is designed to suit the needs of font developers and foreign language learners. The search algorithm includes a bit vector index inspired by Bloom...

  20. Performance evaluation of various K- anonymity techniques

    Science.gov (United States)

    Maheshwarkar, Nidhi; Pathak, Kshitij; Chourey, Vivekanand

    2011-12-01

    Today's advanced scenario where each information is available in one click, data security is the main aspect. Individual information which sometimes needs to be hiding is easily available using some tricks. Medical information, income details are needed to be kept away from adversaries and so, are stored in private tables. Some publicly released information contains zip code, sex, birth date. When this released information is linked with the private table, adversary can detect the whole confidential information of individuals or respondents, i.e. name, medical status. So to protect respondents identity, a new concept k-anonymity is used which means each released record has at least (k-1) other records in the release whose values are distinct over those fields that appear in the external data. K-anonymity can be achieved easily in case of single sensitive attributes i.e. name, salary, medical status, but it is quiet difficult when multiple sensitive attributes are present. Generalization and Suppression are used to achieve k-anonymity. This paper provides a formal introduction of k-anonymity and some techniques used with it l-diversity, t-closeness. This paper covers k-anonymity model and the comparative study of these concepts along with a new proposed concept for multiple sensitive attributes.

  1. 基于Hibernate JPA和JQuery框架的数据查询研究与实现%Research and Implementation of Data Query Based on Hibernate JPA and JQuery Framework

    Institute of Scientific and Technical Information of China (English)

    谭莹宇

    2012-01-01

    This article researches the base theory of Hibernate JPA query framework, and describes the method and process of data query designed and implemented by JPA and Jquery. In addition, the article summarizes the characteristics and advantages of data query based on Hibernate JPA query framework.%在研究Hibernate JPA查询技术理论的基础上,阐述JPA结合视图组件JQuery框架技术设计和实现数据查询的方法过程.着重总结Hibernate JPA结合JQuery框架实现数据查询的特点以及相对其它技术的优势.

  2. Object-Extended OLAP Querying

    DEFF Research Database (Denmark)

    Pedersen, Torben Bach; Gu, Junmin; Shoshani, Arie

    2009-01-01

    inherent in data in non-standard applications are not accommodated well by OLAP systems. In contrast, object database systems are built to handle such complexity, but do not support OLAP-type querying well. This paper presents the concepts and techniques underlying a flexible, "multi-model" federated...... system that enables OLAP users to exploit simultaneously the features of OLAP and object systems. The system allows data to be handled using the most appropriate data model and technology: OLAP systems for dimensional data and object database systems for more complex, general data. This allows data...... analysis on the OLAP data to be significantly enriched by the use of additional object data. Additionally, physical integration of the OLAP and the object data can be avoided. As a vehicle for demonstrating the capabilities of the system, a prototypical OLAP language is defined and extended to naturally...

  3. Flexible Query Answering Systems 2006

    DEFF Research Database (Denmark)

    -classical Logics, Computational Linguistics and Natural Language Processing, Multimedia Information Systems, and Human--Computer Interaction, including reports of interesting applications. We wish to thank the contributors for their excellent papers and the referees, publisher, and sponsors for their effort......, and intuitive access to information for every type of need. This multidisciplinary conference draws on several research areas, including information retrieval, database management, information filtering, knowledge representation, soft computing, management of multimedia information, and human-computer...... interaction. The overall theme of the FQAS conferences is innovative query systems aimed at providing easy, flexible, and intuitive access to information. Such systems are intended to facilitate retrieval from information repositories such as databases, libraries, and the World-Wide Web. These repositories...

  4. Templates and Queries in Contextual Hypermedia

    DEFF Research Database (Denmark)

    Anderson, Kenneth Mark; Hansen, Frank Allan; Bouvin, Niels Olof

    2006-01-01

    This paper presents a new definition of context for context-aware computing based on a model that relies on dynamic queries over structured objects. This new model enables developers to flexibly specify the relationship between context and context data for their context-aware applications. We dis...

  5. A Knowledge Based Approach for Query Optimization in Preferential Mapping Relational Databases

    Directory of Open Access Journals (Sweden)

    P.Ranjani

    2014-10-01

    Full Text Available Relational query databases provide a high level declarative interface to access data stored in relational databases. Two key components of the query evaluation component of a SQL database system are the query optimizer and the query execution engine. System R optimization framework since this was a remarkably elegant approach that helped fuel much of the subsequent work in optimization. Transparent and efficient evaluations of preferential queries are allowed by relational database systems. This results in experimenting extensive evaluation on two real world data sets which illustrates the feasibility and advantages of the framework. Early pruning of results based on score or confidence during query processing are enabled by combining the prefer operator with the rank and rank join operators. During preference evaluation, both the conditional and the scoring part of a preference are used. The conditional part acts as a soft constraint that determines which records are scored without disqualifying any duplicates from the query result. To introduce a preferences mapping relational data model that extends database with profile preferences for query optimizing and an extended algebra that captures the essence of processing queries with ranking method. Based on a set of algebraic properties and a cost model that to propose, to provide several query optimization strategies for extended query plans. To describe a query execution algorithm that blends preference evaluation with query execution, while making effective use of the native query engine.

  6. Approximate furthest neighbor with application to annulus query

    DEFF Research Database (Denmark)

    Pagh, Rasmus; Silvestri, Francesco; Sivertsen, Johan von Tangen;

    2016-01-01

    -dimensional Euclidean space. The method builds on the technique of Indyk (SODA 2003), storing random projections to provide sublinear query time for AFN. However, we introduce a different query algorithm, improving on Indyk׳s approximation factor and reducing the running time by a logarithmic factor. We also present...

  7. The Acoi Algebra: a Query Algebra for Image Retrieval Systems

    NARCIS (Netherlands)

    Nes, N.J.; Kersten, M.L.

    1998-01-01

    Content-based image retrieval systems rely on a query-by-example technique often using a limited set of global image features. This leads to a rather coarse-grain approach to locate images. The next step is to concentrate on queries over spatial relations amongst objects within the images. This call

  8. Real SQL queries 50 challenges : practice for reporting and analysis

    CERN Document Server

    Cohen, Brian; Mishra, Neerja

    2015-01-01

    Queries improve when challenges are authentic. This book sets your learning on the fast track with realistic problems to solve. Topics span sales, marketing, human resources, purchasing, and production. Real SQL Queries: 50 Challenges is perfect for analysts, report writers, or anyone searching for a hands-on approach to learning SQL Server.

  9. Is it OK to be an Anonymous?

    Directory of Open Access Journals (Sweden)

    Philip Serracino-Inglott

    2013-12-01

    Full Text Available Do the deviant acts carried out by the collective known as Anonymous qualify as vigilante activity, and if so, can they be justified? Addressing this question helps expose the difficulties of morally evaluating technologically enabled deviance. Anonymous is a complex, fluid actor but not as mysterious as popularly portrayed. Under a definition of vigilantism that includes reprobative punishment rather than violence as a key element, Anonymous are vigilantes. Many of its Ops can be justified in view of the mismatch between formal norm enforcement practice and Internet natives’ experience of it. Anons are more like eco-warriors than terrorists. While their actions are contentious, their force is framed in a vision of common good that is not unreasonable. Engaging with online deviants is shown to be a productive way of identifying the weaknesses in concepts underpinning moral evaluation of Internet-enabled phenomena.

  10. Study of query expansion techniques and their application in the biomedical information retrieval.

    Science.gov (United States)

    Rivas, A R; Iglesias, E L; Borrajo, L

    2014-01-01

    Information Retrieval focuses on finding documents whose content matches with a user query from a large document collection. As formulating well-designed queries is difficult for most users, it is necessary to use query expansion to retrieve relevant information. Query expansion techniques are widely applied for improving the efficiency of the textual information retrieval systems. These techniques help to overcome vocabulary mismatch issues by expanding the original query with additional relevant terms and reweighting the terms in the expanded query. In this paper, different text preprocessing and query expansion approaches are combined to improve the documents initially retrieved by a query in a scientific documental database. A corpus belonging to MEDLINE, called Cystic Fibrosis, is used as a knowledge source. Experimental results show that the proposed combinations of techniques greatly enhance the efficiency obtained by traditional queries.

  11. 基于本体的语义查询扩展应用研究%Application Research of Semantic Query Expansion Based on Ontology

    Institute of Scientific and Technical Information of China (English)

    王红霞

    2016-01-01

    传统的基于关键词匹配的信息检索方式已无法满足智慧城市建设进程中海量数据处理的要求,而基于本体的语义查询扩展智能化搜索技术借助于本体的语义信息与扩展推理使查询条件更符合用户意图,能够提高查全率和查准率,优化检索结果.在本体语义查询扩展技术的研究基础上,使用主流的本体编辑工具Protégé创建了一个"计算机"领域的本体,并根据现实需要进行规则修改,最终将其应用于智慧城市远程教育资源的个性化搜索中,能取得较理想的效果.%With the rapid development of smart city, the traditional search method based on key words can 't satisfy users. Semantic query expansion based on ontology is an important intelligent search technique which with the help of semantic information and expansion reasoning. The precision and recall can be improved and the research result can be optimized. This article studies carefully the semantic query expansion theory, built domain ontology of the computer science based on Protégé and Chinese Library Classification. In the same way, the rules are modified according to the reality. Eventually, the query expansion was used to distance education resources of smart city for personalized search with good effect.

  12. Cooperative Scalable Moving Continuous Query Processing

    DEFF Research Database (Denmark)

    Li, Xiaohui; Karras, Panagiotis; Jensen, Christian S.

    2012-01-01

    A range of applications call for a mobile client to continuously monitor others in close proximity. Past research on such problems has covered two extremes: It has offered totally centralized solutions, where a server takes care of all queries, and totally distributed solutions, in which there is...

  13. Anytime skyline query processing for interactive systems

    DEFF Research Database (Denmark)

    Magnani, Matteo; Assent, Ira; Mortensen, Michael L.

    In this paper we introduce the concept of anytime skyline query . The skyline database operator returns the top-1record for every possible monotone record scoring function.However, computing a skyline can be very time-consumingdepending on the size, distribution and dimensionality of the data, ma...

  14. Approximate Nearest Neighbor Queries among Parallel Segments

    DEFF Research Database (Denmark)

    Emiris, Ioannis Z.; Malamatos, Theocharis; Tsigaridas, Elias

    2010-01-01

    We develop a data structure for answering efficiently approximate nearest neighbor queries over a set of parallel segments in three dimensions. We connect this problem to approximate nearest neighbor searching under weight constraints and approximate nearest neighbor searching on historical data...

  15. Query Classification and Study of University Students' Search Trends

    Science.gov (United States)

    Maabreh, Majdi A.; Al-Kabi, Mohammed N.; Alsmadi, Izzat M.

    2012-01-01

    Purpose: This study is an attempt to develop an automatic identification method for Arabic web queries and divide them into several query types using data mining. In addition, it seeks to evaluate the impact of the academic environment on using the internet. Design/methodology/approach: The web log files were collected from one of the higher…

  16. Group-by Skyline Query Processing in Relational Engines

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Luk, Ming-Hay; Lo, Eric

    2009-01-01

    the missing cost model for the BBS algorithm. Experimental results show that our techniques are able to devise the best query plans for a variety of group-by skyline queries. Our focus is on algorithms that can be directly implemented in today's commercial database systems without the addition of new access...

  17. Design of Database Query Software of Shortwave Signals based on Python%基于Python的短波信号数据库查询软件设计

    Institute of Scientific and Technical Information of China (English)

    刘燕; 王磊

    2015-01-01

    The number of radio communication is becoming larger, and the databases of corresponding supervision department are constantly being updated, in order to improve the speed of querying databases and the monitoring efficiency, combined with daily monitoring work experience and used the existing databases of shortwave signals, this paper researches and designs the software for querying database based on Python programming language. This paper introduces the advantages of Python and the design process of this software in detail. And applies the existing databases of shortwave signals, we did a lot of test and veriifed the software’s practicability and high efifciency. The software also can query the databases of other types of radio signals and help to improve work efifciency.%无线电通信数量日益增多,其监管部门的数据库也在不断更新,为提高数据库查询速度,提高监测工作效率,本文基于Python程序设计语言,结合实际工作,针对短波通信信号数据库设计实现了一款数据库查询软件。文章详细介绍了Python语言的优势及数据库查询软件的设计流程,且使用现有的短波信号数据库进行反复测试,验证了其实用性与高效性。该软件也可以应用在其他无线电信号数据库查询工作中,对提高工作效率有一定的帮助。

  18. 基于全文检索的XML存储查询系统%STORING AND QUERYING SYSTEM FOR XML BASED ON FULL TEXT RETRIEVAL

    Institute of Scientific and Technical Information of China (English)

    乔长昭; 廖畅

    2011-01-01

    XML database has been an important part of the field of databases, but its business products are put into effect mainly based on the relational databases,which definitely bring in some troubles. Facing the situation of storing XML data in relational databases,a new XML index code is provided, with which the problem of integrating full text retrieval technology and XML structural join querying in relational databases is resolved, and XML querying can be expedited with the help of full text retrieval. The solution is used in an actual software developing program which has well dealt with the management of relational database store of XML documents and shows a good querying efficiency.%XML数据库已经成为数据库领域的重要成员,但是在商业数据库产品中它主要构建在关系数据库基础之上,这自然引入很多难题.针对XML的关系数据库存储,提出一种新的XML索引编码,解决了在关系数据库中集成全文检索技术和XML结构连接查询算法的问题,同时借助全文检索技术达到XML查询加速的效果.该方案应用于实际软件开发项目中.很好地解决了XML文档的关系数据库存储管理工作,并且具有很高的查询效率.

  19. jQuery For Dummies

    CERN Document Server

    Beighley, Lynn

    2010-01-01

    Learn how jQuery can make your Web page or blog stand out from the crowd!. jQuery is free, open source software that allows you to extend and customize Joomla!, Drupal, AJAX, and WordPress via plug-ins. Assuming no previous programming experience, Lynn Beighley takes you through the basics of jQuery from the very start. You'll discover how the jQuery library separates itself from other JavaScript libraries through its ease of use, compactness, and friendliness if you're a beginner programmer. Written in the easy-to-understand style of the For Dummies brand, this book demonstrates how you can a

  20. Schedule Sales Query Raw Data

    Data.gov (United States)

    General Services Administration — Schedule Sales Query presents sales volume figures as reported to GSA by contractors. The reports are generated as quarterly reports for the current year and the...

  1. A new approach to query expansion in information retrieval

    Institute of Scientific and Technical Information of China (English)

    Li Weijiang; Zhao Tiejun; Wang Xiangang

    2008-01-01

    To eliminate the mismatch between words of relevant documents and user's query and more serious negative effects it has on the performance of information retrieval,a method of query expansion on the basis of new terms co-occurrence representation was put forward by analyzing the process of producing query. The expansion terms were selected according to their correlation to the whole query. At the same time, the position information between terms were considered. The experimental result on test retrieval conference (TREC) data collection shows that the method proposed in the paper has made an improvement of 5%~19% all the time than the language modeling method without expansion. Compared to the popular approach of query expansion, pseudo feedback, the precision of the proposed method is competitive.

  2. Dynamic Planar Range Maxima Queries

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Tsakalidis, Konstantinos

    2011-01-01

    We consider the dynamic two-dimensional maxima query problem. Let P be a set of n points in the plane. A point is maximal if it is not dominated by any other point in P. We describe two data structures that support the reporting of the t maximal points that dominate a given query point, and allow...... for insertions and deletions of points in P. In the pointer machine model we present a linear space data structure with O(logn + t) worst case query time and O(logn) worst case update time. This is the first dynamic data structure for the planar maxima dominance query problem that achieves these bounds...... in the worst case. The data structure also supports the more general query of reporting the maximal points among the points that lie in a given 3-sided orthogonal range unbounded from above in the same complexity. We can support 4-sided queries in O(log^2 n + t) worst case time, and O(log^2 n) worst case...

  3. Mining the SDSS SkyServer SQL queries log

    Science.gov (United States)

    Hirota, Vitor M.; Santos, Rafael; Raddick, Jordan; Thakar, Ani

    2016-05-01

    SkyServer, the Internet portal for the Sloan Digital Sky Survey (SDSS) astronomic catalog, provides a set of tools that allows data access for astronomers and scientific education. One of SkyServer data access interfaces allows users to enter ad-hoc SQL statements to query the catalog. SkyServer also presents some template queries that can be used as basis for more complex queries. This interface has logged over 330 million queries submitted since 2001. It is expected that analysis of this data can be used to investigate usage patterns, identify potential new classes of queries, find similar queries, etc. and to shed some light on how users interact with the Sloan Digital Sky Survey data and how scientists have adopted the new paradigm of e-Science, which could in turn lead to enhancements on the user interfaces and experience in general. In this paper we review some approaches to SQL query mining, apply the traditional techniques used in the literature and present lessons learned, namely, that the general text mining approach for feature extraction and clustering does not seem to be adequate for this type of data, and, most importantly, we find that this type of analysis can result in very different queries being clustered together.

  4. Evaluation of Query Generators for Entity Search Engines

    CERN Document Server

    Endrullis, Stefan; Rahm, Erhard

    2010-01-01

    Dynamic web applications such as mashups need efficient access to web data that is only accessible via entity search engines (e.g. product or publication search engines). However, most current mashup systems and applications only support simple keyword searches for retrieving data from search engines. We propose the use of more powerful search strategies building on so-called query generators. For a given set of entities query generators are able to automatically determine a set of search queries to retrieve these entities from an entity search engine. We demonstrate the usefulness of query generators for on-demand web data integration and evaluate the effectiveness and efficiency of query generators for a challenging real-world integration scenario.

  5. Multiple k Nearest Neighbor Query Processing in Spatial Network Databases

    DEFF Research Database (Denmark)

    Xuegang, Huang; Jensen, Christian Søndergaard; Saltenis, Simonas

    2006-01-01

    This paper concerns the efficient processing of multiple k nearest neighbor queries in a road-network setting. The assumed setting covers a range of scenarios such as the one where a large population of mobile service users that are constrained to a road network issue nearest-neighbor queries...... for points of interest that are accessible via the road network. Given multiple k nearest neighbor queries, the paper proposes progressive techniques that selectively cache query results in main memory and subsequently reuse these for query processing. The paper initially proposes techniques for the case...... where an upper bound on k is known a priori and then extends the techniques to the case where this is not so. Based on empirical studies with real-world data, the paper offers insight into the circumstances under which the different proposed techniques can be used with advantage for multiple k nearest...

  6. Secure Web Transaction with Anonymous Mobile Agent over Internet

    Institute of Scientific and Technical Information of China (English)

    WANG ChangJie(王常杰); ZHANG FangGuo(张方国); WANG YuMin(王育民)

    2003-01-01

    A major problem of mobile agents is their apparent inability to authenticate transactions in hostile environments. In this paper, a new secure anonymous mobile agent scheme is proposed for the prevention of agent tempering without compromising the mobility or autonomy of the agent. In the scheme, a mobile agent can produce valid signature on website's bid (it means to transact a contact with the web site) on behalf of its customer, without revealing the customer's real private key. In addition, the anonymity of the customer is also achieved when its agent transacts with the websites. Furthermore, the customer who issues a malicious agent or denies the transaction can be identified and detected by Agent Management Center (AMC). Therefore, the scheme is practical in the future electronic commerce over Internet.

  7. Topology-free querying of protein interaction networks.

    Science.gov (United States)

    Bruckner, Sharon; Hüffner, Falk; Karp, Richard M; Shamir, Ron; Sharan, Roded

    2010-03-01

    In the network querying problem, one is given a protein complex or pathway of species A and a protein-protein interaction network of species B; the goal is to identify subnetworks of B that are similar to the query in terms of sequence, topology, or both. Existing approaches mostly depend on knowledge of the interaction topology of the query in the network of species A; however, in practice, this topology is often not known. To address this problem, we develop a topology-free querying algorithm, which we call Torque. Given a query, represented as a set of proteins, Torque seeks a matching set of proteins that are sequence-similar to the query proteins and span a connected region of the network, while allowing both insertions and deletions. The algorithm uses alternatively dynamic programming and integer linear programming for the search task. We test Torque with queries from yeast, fly, and human, where we compare it to the QNet topology-based approach, and with queries from less studied species, where only topology-free algorithms apply. Torque detects many more matches than QNet, while giving results that are highly functionally coherent.

  8. Dynamic Query Optimization Approach for Semantic Database Grid

    Institute of Scientific and Technical Information of China (English)

    Xiao-Qing Zheng; Hua-Jun Chen; Zhao-Hui Wu; Yu-Xin Mao

    2006-01-01

    Fundamentally, semantic grid database is about bringing globally distributed databases together in order to coordinate resource sharing and problem solving in which information is given well-defined meaning, and DartGrid Ⅱ is the implemented database gird system whose goal is to provide a semantic solution for integrating database resources on the Web.Although many algorithms have been proposed for optimizing query-processing in order to minimize costs and/or response time, associated with obtaining the answer to query in a distributed database system, database grid query optimization problem is fundamentally different from traditional distributed query optimization. These differences are shown to be the consequences of autonomy and heterogeneity of database nodes in database grid. Therefore, more challenges have arisen for query optimization in database grid than traditional distributed database. Following this observation, the design of a query optimizer in DartGrid Ⅱ is presented, and a heuristic, dynamic and parallel query optimization approach to processing query in database grid is proposed. A set of semantic tools supporting relational database integration and semantic-based information browsing has also been implemented to realize the above vision.

  9. Multidimensional indexing structure for use with linear optimization queries

    Science.gov (United States)

    Bergman, Lawrence David (Inventor); Castelli, Vittorio (Inventor); Chang, Yuan-Chi (Inventor); Li, Chung-Sheng (Inventor); Smith, John Richard (Inventor)

    2002-01-01

    Linear optimization queries, which usually arise in various decision support and resource planning applications, are queries that retrieve top N data records (where N is an integer greater than zero) which satisfy a specific optimization criterion. The optimization criterion is to either maximize or minimize a linear equation. The coefficients of the linear equation are given at query time. Methods and apparatus are disclosed for constructing, maintaining and utilizing a multidimensional indexing structure of database records to improve the execution speed of linear optimization queries. Database records with numerical attributes are organized into a number of layers and each layer represents a geometric structure called convex hull. Such linear optimization queries are processed by searching from the outer-most layer of this multi-layer indexing structure inwards. At least one record per layer will satisfy the query criterion and the number of layers needed to be searched depends on the spatial distribution of records, the query-issued linear coefficients, and N, the number of records to be returned. When N is small compared to the total size of the database, answering the query typically requires searching only a small fraction of all relevant records, resulting in a tremendous speedup as compared to linearly scanning the entire dataset.

  10. Dissent in Numbers: Making Strong Anonymity Scale

    Science.gov (United States)

    2012-10-01

    transmit anonymously in each bit-time with- out colliding and yielding garbled output, an arbitration or scheduling mechanism is needed. Second, any misbe...http://www.nytimes.com/2010/05/ 14/technology/personaltech/14talk.html. [62] J. Wright, T. de Souza, and I. Brown. Fine-grained censorship mapping information sources, legality and ethics . In FOCI, Aug. 2011. 14

  11. Pareto-depth for multiple-query image retrieval.

    Science.gov (United States)

    Hsiao, Ko-Jen; Calder, Jeff; Hero, Alfred O

    2015-02-01

    Most content-based image retrieval systems consider either one single query, or multiple queries that include the same object or represent the same semantic information. In this paper, we consider the content-based image retrieval problem for multiple query images corresponding to different image semantics. We propose a novel multiple-query information retrieval algorithm that combines the Pareto front method with efficient manifold ranking. We show that our proposed algorithm outperforms state of the art multiple-query retrieval algorithms on real-world image databases. We attribute this performance improvement to concavity properties of the Pareto fronts, and prove a theoretical result that characterizes the asymptotic concavity of the fronts.

  12. Cross Lingual Information Retrieval With SMT And Query Mining

    Directory of Open Access Journals (Sweden)

    Suneet Kumar Gupta

    2011-10-01

    Full Text Available In this paper, we have taken the English Corpus and Queries, both translated and transliterated form. We use Statistical Machine Translator to find the result under translated and transliterated queries and then analyzed the result. These queries wise results can then be undergone mining and therefore a new list of queries is created. We have design an experimental setup followed by various steps which calculate Mean Average Precision. We have taken assistance ship of Terrier Open Source for the Information Retrieval. On the basis of created new query list, we calculate the Mean Average Precision and find a significant result i.e. 93.24% which is very close to monolingual results calculated for English language.

  13. Estimation of Anonymous Email Network Characteristics through Statistical Disclosure Attacks

    Science.gov (United States)

    Portela, Javier; García Villalba, Luis Javier; Silva Trujillo, Alejandra Guadalupe; Sandoval Orozco, Ana Lucila; Kim, Tai-Hoon

    2016-01-01

    Social network analysis aims to obtain relational data from social systems to identify leaders, roles, and communities in order to model profiles or predict a specific behavior in users’ network. Preserving anonymity in social networks is a subject of major concern. Anonymity can be compromised by disclosing senders’ or receivers’ identity, message content, or sender-receiver relationships. Under strongly incomplete information, a statistical disclosure attack is used to estimate the network and node characteristics such as centrality and clustering measures, degree distribution, and small-world-ness. A database of email networks in 29 university faculties is used to study the method. A research on the small-world-ness and Power law characteristics of these email networks is also developed, helping to understand the behavior of small email networks. PMID:27809275

  14. Compromising Tor Anonymity Exploiting P2P Information Leakage

    CERN Document Server

    Manils, Pere; Blond, Stevens Le; Kaafar, Mohamed Ali; Castelluccia, Claude; Legout, Arnaud; Dabbous, Walid

    2010-01-01

    Privacy of users in P2P networks goes far beyond their current usage and is a fundamental requirement to the adoption of P2P protocols for legal usage. In a climate of cold war between these users and anti-piracy groups, more and more users are moving to anonymizing networks in an attempt to hide their identity. However, when not designed to protect users information, a P2P protocol would leak information that may compromise the identity of its users. In this paper, we first present three attacks targeting BitTorrent users on top of Tor that reveal their real IP addresses. In a second step, we analyze the Tor usage by BitTorrent users and compare it to its usage outside of Tor. Finally, we depict the risks induced by this de-anonymization and show that users' privacy violation goes beyond BitTorrent traffic and contaminates other protocols such as HTTP.

  15. Anonymous Card Shuffling and its Applications to Parallel Mixnets

    CERN Document Server

    Goodrich, Michael T

    2012-01-01

    We study the question of how to shuffle $n$ cards when faced with an opponent who knows the initial position of all the cards {\\em and} can track every card when permuted, {\\em except} when one takes $K< n$ cards at a time and shuffles them in a private buffer "behind your back," which we call {\\em buffer shuffling}. The problem arises naturally in the context of parallel mixnet servers as well as other security applications. Our analysis is based on related analyses of load-balancing processes. We include extensions to variations that involve corrupted servers and adversarially injected messages, which correspond to an opponent who can peek at some shuffles in the buffer and who can mark some number of the cards. In addition, our analysis makes novel use of a sum-of-squares metric for anonymity, which leads to improved performance bounds for parallel mixnets and can also be used to bound well-known existing anonymity measures.

  16. Mobile Anonymous Trust Based Routing Using Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    R. Kalpana

    2012-01-01

    Full Text Available Problem statement: Ad hoc networks are susceptible to malicious attacks through denial of services, traffic analysis and spoofing. The security of the ad hoc routing protocol depends upon encryption, authentication, anonymity and trust factors. End-to-end security of data is provided by encryption and authentication, topology information of the nodes can be obtained by studying traffic and routing data. This security problem of ad hoc network is addressed by the use of anonymity mechanisms and trust levels. Identification information like traffic flow, network topology, paths from malicious attackers is hidden in anonymous networks. Similarly, trust plays a very important role in the intermediate node selection in ad hoc networks. Trust is essential as selfish and malicious nodes not only pose a security issue but also decreases the Quality of Service. Approach: In this study, a routing to address anonymous routing with a trust which improves the overall security of the ad hoc network was proposed. A new approach for an on demand ad-hoc routing algorithm, which was based on swarm intelligence. Ant colony algorithms were a subset of swarm intelligence and considered the ability of simple ants to solve complex problems by cooperation. The interesting point was, that the ants do not need any direct communication for the solution process, instead they communicate by stigmergy. The notion of stigmergy means the indirect communication of individuals through modifying their environment. Several algorithms which were based on ant colony problems were introduced in recent years to solve different problems, e.g., optimization problems. Results and Conclusion: It is observed that the overall security in the network improves when the trust factor is considered. It is seen that non performing nodes are not considered due to the proposed ACO technique.

  17. Deep Web信息资源的查询接口集成研究%Query Interfaces Integrating on Deep Web

    Institute of Scientific and Technical Information of China (English)

    林爱群; 习万球

    2011-01-01

    The Hidden Web databases contain much more searchable information than the Surface Web databases. If the query interfaces on the Deep Web are integrated, the recall and precision of web information retrieval will be highly improved. This paper discusses the clustering analysis for query schema integration problem. The query' interface schema integration method costs less, compared with the Deep Web data source integration.%Deep Web信息是隐藏在Web服务器中可搜索的数据库信息资源,其信息量远比表面web信息量大。将Deep Web信息查询的接口模式集成为统一的查询接口,将极大地提高web信息检索的查全率和查准率。讨论了查询模式集成问题的聚类分析方法,相对于直接对Deep Web数据源的进行集成,对查询模式加以集成的思路成本更低。

  18. Improved query difficulty prediction for the web

    NARCIS (Netherlands)

    Hauff, C.; Murdock, V.; Baeza-Yates, R.

    2008-01-01

    Query performance prediction aims to predict whether a query will have a high average precision given retrieval from a particular collection, or low average precision. An accurate estimator of the quality of search engine results can allow the search engine to decide to which queries to apply query

  19. Query for Semantic Web Service Based on SPARQL-DL%基于SPARQL-DL的语义Web服务查询

    Institute of Scientific and Technical Information of China (English)

    王海; 高岭; 范琳; 李增智

    2011-01-01

    The Semantic Web service discovery is a hot spot in the current web service research field. Its core research content is service descriptions and the corresponding discovery methods. Service description can be divided into the service request description and advertisement description. Service advertisement descriptions are usually complete, descriptive, information-rich descriptions; while service request description is concemed only with some of the characteristics of services,usually does not constitute a complete description of the service. Current methods of service discovery using the same mechanism to describe both request and advertisement. Compare and identify the identity or similarity of the corresponding part between the two as matching basis. Build a complete fictive service description as service request limit the practicability of the method. In this paper, we propose to use semantic web query language SPARQL-DL as the service request description language to retrieve OWL-S form published services. Treat the service discovery issue as query against the knowledge base. Through the experiment, confinned that the method is practical, simple, reliable and easy-to-use.%语义Web服务发现是当前Web服务研究领域的热点,其核心研究内容是服务描述及相应的发现方法.服务描述分为请求描述与发布描述,发布描述具有描述完整,信息丰富的特征,而服务请求描述仅关注服务的部分特征,通常不构成一个完整的服务描述.现有方法使用相同机制进行请求描述与发布描述,以比对请求与发布中对应部分的同一性或相似性作为匹配依据.构建假想的完整服务描述作为服务请求既不合理也难以实施,从而限制了方法的实用性.本文提出以语义Web查询语言SPARQL-DL作为服务请求描述语言,以OWL-S作为服务发布描述语言,将服务发现问题转化为知识库的查询,从而进行有效的服务发现.通过实验,证实了该方

  20. An Analysis of Anonymity in the Bitcoin System

    CERN Document Server

    Reid, Fergal

    2011-01-01

    Anonymity in Bitcoin, a peer-to-peer electronic currency system, is a complicated issue. Within the system, users are identified by public-keys only. An attacker wishing to de-anonymize its users will attempt to construct the oneto- many mapping between users and public-keys and associate information external to the system with the users. Bitcoin frustrates this attack by storing the mapping of a user to his or her public-keys on that user's node only and by allowing each user to generate as many public-keys as required. In this paper we consider the topological structure of two networks derived from Bitcoin's public transaction history. We show that the two networks have a non-trivial topological structure, provide complementary views of the Bitcoin system and have implications for anonymity. We combine these structures with external information and techniques such as context discovery and flow analysis to investigate an alleged theft of Bitcoins, which, at the time of the theft, had a market value of approx...

  1. Utility-guided Clustering-based Transaction Data Anonymization

    Directory of Open Access Journals (Sweden)

    Aris Gkoulalas-Divanis

    2012-04-01

    Full Text Available Transaction data about individuals are increasingly collected to support a plethora of applications, spanning from marketing to biomedical studies. Publishing these data is required by many organizations, but may result in privacy breaches, if an attacker exploits potentially identifying information to link individuals to their records in the published data. Algorithms that prevent this threat by transforming transaction data prior to their release have been proposed recently, but they may incur significant utility loss due to their inability to: (i accommodate a range of different privacy requirements that data owners often have, and (ii guarantee that the produced data will satisfy data owners’ utility requirements. To address this issue, we propose a novel clustering-based framework to anonymizing transaction data, which provides the basis for designing algorithms that better preserve data utility. Based on this framework, we develop two anonymization algorithms which explore a larger solution space than existing methods and can satisfy a wide range of privacy requirements. Additionally, the second algorithm allows the specification and enforcement of utility requirements, thereby ensuring that the anonymized data remain useful in intended tasks. Experiments with both benchmark and real medical datasets verify that our algorithms significantly outperform the current state-of-the-art algorithms in terms of data utility, while being comparable in terms of efficiency.

  2. How to Bootstrap Anonymous Communication

    DEFF Research Database (Denmark)

    Jakobsen, Sune K.; Orlandi, Claudio

    2015-01-01

    (such as cat videos on YouTube or funny memes on 9GAG). Then Lea provides Joe with a short key $k$ which, when applied to the entire website, recovers the document while hiding the identity of Lea among the large number of users of the website. Our contributions include: - Introducing and formally...

  3. How to Bootstrap Anonymous Communication

    DEFF Research Database (Denmark)

    Jakobsen, Sune K.; Orlandi, Claudio

    2015-01-01

    (such as cat videos on YouTube or funny memes on 9GAG). Then Lea provides Joe with a short key k which, when applied to the entire website, recovers the document while hiding the identity of Lea among the large number of users of the website. Our contributions include: { Introducing and formally dening...

  4. Querying Schemas With Access Restrictions

    CERN Document Server

    Benedikt, Michael; Ley, Clemens

    2012-01-01

    We study verification of systems whose transitions consist of accesses to a Web-based data-source. An access is a lookup on a relation within a relational database, fixing values for a set of positions in the relation. For example, a transition can represent access to a Web form, where the user is restricted to filling in values for a particular set of fields. We look at verifying properties of a schema describing the possible accesses of such a system. We present a language where one can describe the properties of an access path, and also specify additional restrictions on accesses that are enforced by the schema. Our main property language, AccLTL, is based on a first-order extension of linear-time temporal logic, interpreting access paths as sequences of relational structures. We also present a lower-level automaton model, Aautomata, which AccLTL specifications can compile into. We show that AccLTL and A-automata can express static analysis problems related to "querying with limited access patterns" that h...

  5. Static dictionaries on AC0 RAMs: query time (√log n/log log n) is necessary and sufficient

    DEFF Research Database (Denmark)

    Andersson, Arne; Miltersen, Peter Bro; Riis, Søren;

    1996-01-01

    ) on the time for answering membership queries in a set of size n when reasonable space is used for the data structure storing the set; the upper bound can be obtained using O(n) space, and the lower bound holds even if we allow space 2polylog n. Several variations of this result are also obtained. Among others......In this paper we consider solutions to the static dictionary problem on AC0 RAMs, i.e. random access machines where the only restriction on the finite instruction set is that all computational instructions are in AC0. Our main result is a tight upper and lower bound of θ(√log n/log log n...

  6. 基于本体和奇异值分解的图像数据索引查询算法%An Image Data Query Algorithm Based on Ontology and Singular Value Decomposition

    Institute of Scientific and Technical Information of China (English)

    黄霞

    2014-01-01

    An image data query algorithm based on latent semantic indexing in domain ontology and singular value decompo-sition is proposed .It projects query expansion vector on latent semantic area .A new method to computing similarity between query vectors and query documents is proposed .Users can get accurate and effective retrieval results using the similarity .The experimental results show that the proposed solution can improve image index query recall ratio and precision ratio .%提出一种基于领域本体潜在语义索引和奇异值分解的图像数据查询算法,将查询扩展向量映射到潜在语义空间,根据相似度计算方法计算查询向量与图像文档之间的相似度,并将相似度大于阀值的文档作为检索结果降序排列返回给用户。该算法能更有效地提高图像检索的查准率和查全率。

  7. Yahtzee: An Anonymized Group Level Matching Procedure

    CERN Document Server

    Jones, Jason J; Fariss, Christopher J; Settle, Jaime E; Kramer, Adam; Marlow, Cameron; Fowler, James H

    2011-01-01

    Researchers often face the problem of needing to protect the privacy of subjects while also needing to integrate data that contains personal information from diverse data sources in order to conduct their research. The advent of computational social science and the enormous amount of data about people that is being collected makes protecting the privacy of research subjects evermore important. However, strict privacy procedures can make joining diverse sources of data that contain information about specific individual behaviors difficult. In this paper we present a procedure to keep information about specific individuals from being "leaked" or shared in either direction between two sources of data. To achieve this goal, we randomly assign individuals to anonymous groups before combining the anonymized information between the two sources of data. We refer to this method as the Yahtzee procedure, and show that it performs as expected theoretically when we apply it to data from Facebook and public voter records.

  8. The Anonymity vs. Utility Dilemma

    Science.gov (United States)

    Bezzi, Michele; Pazzaglia, Jean-Christophe

    The number, the type of users and their usage of the internet, computers and phones have evolved considerably, due to the emergence of the web 2.0, the decreasing cost of portable devices, the expansion of wired and wireless internet access and the digitalization of the main entertainment media. Protecting the assets of service and software providers has been the main driver for the development of security solutions in the past ten years. However, the users/customers/citizen rights have been too often neglected since the risk related to the wrong usage of personal related information was not considered by the other stakeholders. Today, the Right to Privacy is appearing on everyone’s radar and factors as regulations, increasing number of news stories on privacy breaches, brand damages, are forcing organizations to address user privacy as a priority. In this paper, we will briefly review the main business drivers behind the raising of privacy concerns, and outline some of the current technology solutions to address privacy requirements. Finally, we will describe some of the future challenges in the area of privacy.

  9. Research on the Search Engine Cache RepIacement Strategy Based on MuItipIe Query Attributes%基于多查询特性的搜索引擎缓存替换策略研究

    Institute of Scientific and Technical Information of China (English)

    房耘耘

    2015-01-01

    Cache is a very important technology in search engine, which can significantly save query computation processing, improve query re-sponse and improve system throughput, which are widely applied by the academia and the industry. Current cache replacement policy does not take full advantage of search engine queries of multiple access feature information, does not take advantage of query distribution, also deficiencies exist in the traditional replacement policy when used in search engines. For the above problems, studies query distribu-tion features, analyses the insufficient of existing cache replace strategies, then proposes integrated value function model represent query future heat value based on query access features, analyses search engine query log for fine grain degrees, gets each query's daily access characteristics of detailed records, and based on multiple return analysis in the minimum II multiplication calculation to get the unknown parameter in the function model, designs cache management policy integrate current dynamic access attributes with the heat value of the query in the future, hit ratio test of replace management strategy through real query shows that, in contrast with traditional cache replace-ment strategy, this replacement strategy significantly exceeds them in hit rate.%缓存是搜索引擎中的重要技术,能显著节省查询处理计算量,缩短查询请求响应时间和提高系统吞吐量,得到学术界的关注和业界的广泛应用。当前搜索引擎缓存替换策略没有充分利用查询的多种访问特征信息,没有充分利用查询分布特性,传统替换策略用在搜索引擎中存在各种不足。针对以上问题研究查询请求的分布特征,分析现有缓存替换策略的不足,然后基于查询词访问特征提出代表查询词未来热度值的综合价值函数模型,然后通过对搜索引擎查询日志进行细粒度的统计分析,得到每个查询词每日各访问

  10. Date restricted queries in web search engines

    OpenAIRE

    Lewandowski, Dirk

    2004-01-01

    Search engines usually offer a date restricted search on their advanced search pages. But determining the actual update of a web page is not without problems. We conduct a study testing date restricted queries on the search engines Google, Teoma and Yahoo!. We find that these searches fail to work properly in the examined engines. We discuss implications of this for further research and search engine development.

  11. Towards A Streams-Based Framework for Defining Location-Based Queries

    DEFF Research Database (Denmark)

    Huang, Xuegang; Jensen, Christian S.

    2004-01-01

    queries that are particularly relevant in this context. Rather than inventing an entirely new framework, the paper proposes a framework that builds on concepts from data streams and temporal databases. Definitions of example queries demonstrates how the framework enables clear formulation of query...

  12. Research on storage and query of large-scale multidimensional data.%海量多维数据的存储与查询研究

    Institute of Scientific and Technical Information of China (English)

    宋爱波; 万雨桐; 贡欢; 薛荧荧

    2016-01-01

    The OLAP(Online Analytical Processing) system built on warehouse is the most popular tool to analyze large-scale multidimensional data. With the development of information technology, data volume grows rapidly and data structure becomes more and more complicated, so the performance of OLAP system has dropped severely, failing to meet daily data analysis needs. This paper proposes new methods to store large-scale multidimensional data and perform aggre-gation query with Hadoop, a parallel computing system. The paper implements a new column-store format HCFile(HDFS column file), and proposals a new storage solution based on it. This project can improve the efficiency of aggregation, with a good scalability. Meanwhile, this paper leverages the hierarchy schema to build dimension hierarchy index, and uses MapReduce to perform efficiency aggregation query. Through comparison experiments with Hive, it proves that the proposed storage solution and aggregation query can effectively improve the efficiency of large-scale multidimensional data analysis.%基于数据仓库的OLAP系统是当前海量多维数据分析的主要工具.随着信息技术的发展,海量多维数据的规模急剧增长,结构日益复杂,OLAP系统的性能严重下降,已经无法满足人们的数据分析需求.基于分布式计算系统Hadoop给出了新的海量多维数据的存储方法和查询方法.设计了HDFS上的列存储文件格式HCFile,基于HCFile给出了海量多维数据存储方案,该方案能够提高聚集计算效率,并有很好的可扩展性.同时,利用多维数据的层次性语义特征,设计了维层次索引,并给出了利用维层次索引和MapReduce进行聚集计算的方法.通过和Hive的对比实验,表明了数据存储方案和查询方法能够有效提高海量多维数据分析的性能.

  13. Probabilistic Reverse Skyline Query Processing on Uncertain Data Streams%不确定数据流上的概率反轮廓查询处理

    Institute of Scientific and Technical Information of China (English)

    白梅; 信俊昌; 东韩; 王国仁

    2011-01-01

    Reverse skyline query has played an important role in making effective market decisions. Because the flow property and uncertainty of data are more and more apparent, probabilistic reverse skyline query on uncertain data streams has become a new study task. In order to solve the problem of probabilistic reverse skyline query on uncertain data streams efficiently, firstly, through analyzing practical applications' requirements, the definition of probabilistic reverse skyline on uncertain data streams is proposed; and then according to the relevant concepts, the index model of probabilistic reverse skyline on uncertain data streams is proposed. Next, through the detailed and in-depth analysis of probabilistic reverse skyline's properties on uncertain data streams, a novel algorithm,probabilistic reverse skyline on uncertain data streams based on R-tree index (RT2RS), is proposed. RT2RS algorithm makes use of an efficient pruning strategy to avoid a large number of invalid operations. Finally, the performance of RT2RS algorithm is verified by a large number of simulation experiments. The experimental results show that RT2 RS algorithm is an effective way to solve the problem of probabilistic reverse skyline on uncertain data streams; it could significantly reduce the execution time of probabilistic reverse skyline query on uncertain data streams and meet the requirements of practical applications.%反轮廓查询在制定有效的市场决策方面具有重要的作用,随着数据流特征和不确定性的表现日益明显,不确定数据流上概率反轮廓查询已经成为一个新的研究课题.为了高效解决不确定数据流上概率反轮廓查询问题,首先,通过对实际应用需求进行分析,提出了不确定数据流上概率反轮廓查询的定义,并根据相关概念,提出了不确定数据流上概率反轮廓查询的索引模型;其次,通过对不确定数据流上概率反轮廓的性质进行深入分析,提出了一种新颖高

  14. Universally composable anonymous Hash certification model

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fan; MA JianFeng; SangJae MOON

    2007-01-01

    Ideal function is the fundamental component in the universally composable security model. However, the certification ideal function defined in the universally composable security model realizes the identity authentication by binding identity to messages and the signature, which fails to characterize the special security requirements of anonymous authentication with other kind of certificate. Therefore,inspired by the work of Marten, an anonymous hash certification ideal function and a more universal certificate CA model are proposed in this paper. We define the security requirements and security notions for this model in the framework of universal composable security and prove in the plain model (not in the random-oracle model) that these security notions can be achieved using combinations of a secure digital signature scheme, a symmetrical encryption mechanism, a family of pseudorandom functions, and a family of one-way collision-free hash functions. Considering the limitation of wireless environment and computation ability of wireless devices, this anonymous Hash certification ideal function is realized by using symmetry primitives.

  15. Keyword Query over Error-Tolerant Knowledge Bases

    Institute of Scientific and Technical Information of China (English)

    Yu-Rong Cheng; Ye Yuan; Jia-Yu Li; Lei Chen; Guo-Ren Wang

    2016-01-01

    With more and more knowledge provided by WWW, querying and mining the knowledge bases have attracted much research attention. Among all the queries over knowledge bases, which are usually modelled as graphs, a keyword query is the most widely used one. Although the problem of keyword query over graphs has been deeply studied for years, knowledge bases, as special error-tolerant graphs, lead to the results of the traditional defined keyword queries out of users’ satisfaction. Thus, in this paper, we define a new keyword query, called confident r-clique, specific for knowledge bases based on the r-clique definition for keyword query on general graphs, which has been proved to be the best one. However, as we prove in the paper, finding the confident r-cliques is #P-hard. We propose a filtering-and-verification framework to improve the search efficiency. In the filtering phase, we develop the tightest upper bound of the confident r-clique, and design an index together with its search algorithm, which suits the large scale of knowledge bases well. In the verification phase, we develop an efficient sampling method to verify the final answers from the candidates remaining in the filtering phase. Extensive experiments demonstrate that the results derived from our new definition satisfy the users’ requirement better compared with the traditional r-clique definition, and our algorithms are efficient.

  16. Research in Mobile Database Query Optimization and Processing

    Directory of Open Access Journals (Sweden)

    Agustinus Borgy Waluyo

    2005-01-01

    Full Text Available The emergence of mobile computing provides the ability to access information at any time and place. However, as mobile computing environments have inherent factors like power, storage, asymmetric communication cost, and bandwidth limitations, efficient query processing and minimum query response time are definitely of great interest. This survey groups a variety of query optimization and processing mechanisms in mobile databases into two main categories, namely: (i query processing strategy, and (ii caching management strategy. Query processing includes both pull and push operations (broadcast mechanisms. We further classify push operation into on-demand broadcast and periodic broadcast. Push operation (on-demand broadcast relates to designing techniques that enable the server to accommodate multiple requests so that the request can be processed efficiently. Push operation (periodic broadcast corresponds to data dissemination strategies. In this scheme, several techniques to improve the query performance by broadcasting data to a population of mobile users are described. A caching management strategy defines a number of methods for maintaining cached data items in clients' local storage. This strategy considers critical caching issues such as caching granularity, caching coherence strategy and caching replacement policy. Finally, this survey concludes with several open issues relating to mobile query optimization and processing strategy.

  17. Joint Top-K Spatial Keyword Query Processing

    DEFF Research Database (Denmark)

    Wu, Dingming; Yiu, Man Lung; Cong, Gao

    2012-01-01

    Web users and content are increasingly being geopositioned, and increased focus is being given to serving local content in response to web queries. This development calls for spatial keyword queries that take into account both the locations and textual descriptions of content. We study...... keyword queries. Empirical studies show that the proposed solution is efficient on real data sets. We also offer analytical studies on synthetic data sets to demonstrate the efficiency of the proposed solution. Index Terms IEEE Terms Electronic mail , Google , Indexes , Joints , Mobile communication...

  18. Scalable Social Coordination using Enmeshed Queries

    CERN Document Server

    Chen, Jianjun; Varghese, George

    2012-01-01

    Social coordination allows users to move beyond awareness of their friends to efficiently coordinating physical activities with others. While specific forms of social coordination can be seen in tools such as Evite, Meetup and Groupon, we introduce a more general model using what we call {\\em enmeshed queries}. An enmeshed query allows users to declaratively specify an intent to coordinate by specifying social attributes such as the desired group size and who/what/when, and the database returns matching queries. Enmeshed queries are continuous, but new queries (and not data) answer older queries; the variable group size also makes enmeshed queries different from entangled queries, publish-subscribe systems, and dating services. We show that even offline group coordination using enmeshed queries is NP-hard. We then introduce efficient heuristics that use selective indices such as location and time to reduce the space of possible matches; we also add refinements such as delayed evaluation and using the relative...

  19. A Faceted Query Engine Applied to Archaeology

    Directory of Open Access Journals (Sweden)

    Kenneth A. Ross

    2007-04-01

    Full Text Available In this article we present the Faceted Query Engine, a system developed at Columbia University under the aegis of the inter-disciplinary project Computational Tools for Modeling, Visualizing and Analyzing Historic and Archaeological Sites. Our system is based on novel Database Systems research that has been published in Computer Science venues (Ross and Janevski, 2004 and Ross et al., 2005. The goal of this article is to introduce our system to the target user audience - the archaeology community. We demonstrate the use of the Faceted Query Engine on a previously unpublished dataset: the Thulamela (South Africa collection. This dataset is comprised of iron-age finds from the Thulamela site at the Kruger National Park. Our project is the first to systematically compile and classify this dataset. We also use a larger dataset, a collection of ancient Egyptian artifacts from the Memphis site (Giddy,1999, to demonstrate some of the features of our system.

  20. A Distributed Approach to Continuous Monitoring of Constrained k-Nearest Neighbor Queries in Road Networks

    Directory of Open Access Journals (Sweden)

    Hyung-Ju Cho

    2012-01-01

    Full Text Available Given two positive parameters k and r, a constrained k-nearest neighbor (CkNN query returns the k closest objects within a network distance r of the query location in road networks. In terms of the scalability of monitoring these CkNN queries, existing solutions based on central processing at a server suffer from a sudden and sharp rise in server load as well as messaging cost as the number of queries increases. In this paper, we propose a distributed and scalable scheme called DAEMON for the continuous monitoring of CkNN queries in road networks. Our query processing is distributed among clients (query objects and server. Specifically, the server evaluates CkNN queries issued at intersections of road segments, retrieves the objects on the road segments between neighboring intersections, and sends responses to the query objects. Finally, each client makes its own query result using this server response. As a result, our distributed scheme achieves close-to-optimal communication costs and scales well to large numbers of monitoring queries. Exhaustive experimental results demonstrate that our scheme substantially outperforms its competitor in terms of query processing time and messaging cost.

  1. Link Prediction by De-anonymization: How We Won the Kaggle Social Network Challenge

    CERN Document Server

    Narayanan, Arvind; Rubinstein, Benjamin I P

    2011-01-01

    This paper describes the winning entry to the IJCNN 2011 Social Network Challenge run by Kaggle.com. The goal of the contest was to promote research on real-world link prediction, and the dataset was a graph obtained by crawling the popular Flickr social photo sharing website, with user identities scrubbed. By de-anonymizing much of the competition test set using our own Flickr crawl, we were able to effectively game the competition. Our attack represents a new application of de-anonymization to gaming machine learning contests, suggesting changes in how future competitions should be run. We introduce a new simulated annealing-based weighted graph matching algorithm for the seeding step of de-anonymization. We also show how to combine de-anonymization with link prediction---the latter is required to achieve good performance on the portion of the test set not de-anonymized---for example by training the predictor on the de-anonymized portion of the test set, and combining probabilistic predictions from de-anony...

  2. Exploiting Conceptual Knowledge for Querying Information Systems

    CERN Document Server

    Selke, Joachim

    2011-01-01

    Whereas today's information systems are well-equipped for efficient query handling, their strict mathematical foundations hamper their use for everyday tasks. In daily life, people expect information to be offered in a personalized and focused way. But currently, personalization in digital systems still only takes explicit knowledge into account and does not yet process conceptual information often naturally implied by users. We discuss how to bridge the gap between users and today's systems, building on results from cognitive psychology.

  3. Query Expansion Using Heterogeneous Thesauri.

    Science.gov (United States)

    Mandala, Rila; Tokunaga, Takenobu; Tanaka, Hozumi

    2000-01-01

    Proposes a method to improve the performance of information retrieval systems by expanding queries using heterogeneous thesauri. Experiments show that using heterogeneous thesauri with an appropriate weighting method results in better retrieval performance than using only one type of thesaurus. (Author/LRW)

  4. Querying Large Biological Network Datasets

    Science.gov (United States)

    Gulsoy, Gunhan

    2013-01-01

    New experimental methods has resulted in increasing amount of genetic interaction data to be generated every day. Biological networks are used to store genetic interaction data gathered. Increasing amount of data available requires fast large scale analysis methods. Therefore, we address the problem of querying large biological network datasets.…

  5. Enhancing Recall in Semantic Querying

    DEFF Research Database (Denmark)

    Rouces, Jacobo

    2013-01-01

    RDF and SPARQL are currently state-of-the-art W3C standards to respectively represent and query structured information, especially when information from different sources must be federated. However, there are various reasons for which the same knowledge can be modeled in RDF graphs that are both ...

  6. Logical Querying of Relational Databases

    Directory of Open Access Journals (Sweden)

    Luminita Pistol

    2016-12-01

    Full Text Available This paper aims to demonstrate the usefulness of formal logic and lambda calculus in database programming. After a short introduction in propositional and first order logic, we implement dynamically a small database and translate some SQL queries in filtered java 8 streams, enhanced with Tuples facilities from jOOλ library.

  7. Explanations for Skyline Query Results

    DEFF Research Database (Denmark)

    Chester, Sean; Assent, Ira

    2015-01-01

    Skyline queries are a well-studied problem for multidimensional data, wherein points are returned to the user iff no other point is preferable across all attributes. This leaves only the points most likely to appeal to an arbitrary user. However, some dominated points may still be interesting, an...

  8. Intelligent query processing for semantic mediation of information systems

    Directory of Open Access Journals (Sweden)

    Saber Benharzallah

    2011-11-01

    Full Text Available We propose an intelligent and an efficient query processing approach for semantic mediation of information systems. We propose also a generic multi agent architecture that supports our approach. Our approach focuses on the exploitation of intelligent agents for query reformulation and the use of a new technology for the semantic representation. The algorithm is self-adapted to the changes of the environment, offers a wide aptitude and solves the various data conflicts in a dynamic way; it also reformulates the query using the schema mediation method for the discovered systems and the context mediation for the other systems.

  9. Materialized View Selection by Query Clustering in XML Data Warehouses

    CERN Document Server

    Mahboubi, Hadj; Darmont, Jérôme

    2008-01-01

    XML data warehouses form an interesting basis for decision-support applications that exploit complex data. However, native XML database management systems currently bear limited performances and it is necessary to design strategies to optimize them. In this paper, we propose an automatic strategy for the selection of XML materialized views that exploits a data mining technique, more precisely the clustering of the query workload. To validate our strategy, we implemented an XML warehouse modeled along the XCube specifications. We executed a workload of XQuery decision-support queries on this warehouse, with and without using our strategy. Our experimental results demonstrate its efficiency, even when queries are complex.

  10. Design of Intelligent layer for flexible querying in databases

    CERN Document Server

    Nihalani, Mrs Neelu; Motwani, Dr Mahesh

    2009-01-01

    Computer-based information technologies have been extensively used to help many organizations, private companies, and academic and education institutions manage their processes and information systems hereby become their nervous centre. The explosion of massive data sets created by businesses, science and governments necessitates intelligent and more powerful computing paradigms so that users can benefit from this data. Therefore most new-generation database applications demand intelligent information management to enhance efficient interactions between database and the users. Database systems support only a Boolean query model. A selection query on SQL database returns all those tuples that satisfy the conditions in the query.

  11. Optimal Succinctness for Range Minimum Queries

    CERN Document Server

    Fischer, Johannes

    2008-01-01

    For an array A of n objects from a totally ordered universe, a range minimum query (RMQ) asks for the position of the minimum element in the sub-array A[i,j]. We focus on the setting where the array $A$ is static and known in advance, and can hence be preprocessed into a scheme in order to answer future queries faster. We make the further assumption that the input array A cannot be used at query time. Under this assumption, a natural lower bound of 2n bits for RMQ-schemes exists. We give the first truly succinct preprocessing scheme for O(1)-RMQs. Its final space consumption is 2n+o(n) bits, thus being asymptotically optimal. We also give a simple linear-time construction algorithm for this scheme that needs only n+o(n) bits of space in addition to the 2n+o(n) bits needed for the final data structure, thereby lowering the peak space consumption of previous schemes from O(n\\log n) to O(n) bits. We also improve on LCA-computation in BPS- and DFUDS-encoded trees.

  12. 一种基于匿名区域变换的位置隐私保护方法%A Location Privacy Protection Method Based on Anonymous Region Transformation

    Institute of Scientific and Technical Information of China (English)

    肖燕芳; 徐红云

    2013-01-01

    针对基于位置服务的应用中存在的用户位置隐私泄露问题,提出一种基于匿名区域变换的位置隐私保护方法.在离用户一定距离处选择一个锚点生成匿名区域后,利用邻近节点处理法计算用户邻近节点查询结果与用户真实位置之间的距离,从而实现在保护用户位置隐私的同时得到精确的查询结果.理论分析和实验结果表明,与Cloaking Region和SpaceTwist算法相比,该方法在保证较低通信开销的前提下,具有较好的位置隐私保护性能.%Aiming at the problem of location privacy leakage in location-based service systems, this paper proposes a method to protect user's location privacy based on Anonymous Region Transformation(ART). An anonymous region is generated around a location different from the user's location which the user's location is not included in, then the neighbor-object-process method is employed to compute the distance between the neighbor objects and the user's location, so that the accurate inquire results can get while protecting the user's location privacy. Theory and experimental results show that compared with Cloaking Region(CR) algorithm and SpaceTwist algorithm, the method proposed can guarantee the lower communication overhead, and provide effective location privacy protection.

  13. Authorization query method for RBAC based on partial MAX-SAT solver%基于Partial MAX-SAT求解法的RBAC授权查询方法

    Institute of Scientific and Technical Information of China (English)

    孙伟; 李艳灵; 鲁骏

    2013-01-01

    In order to ensure system security and reflect availability in authorization management, a method for querying authorization was proposed based on solvers for partial maximal satisfiability problem. Static authorization descriptions and dynamic mutually exclusive constraints were translated into hard clauses. The algorithm was adopted to update hard clauses and translate requested permissions into soft clauses. Soft clauses were effectively encoded, and the recursive algorithm was utilized to satisfy all hard clauses and as many soft clauses as possible. The experimental results show that the method can ensure system security, it follows the least privilege principle, and the query efficiency outperforms solvers for maximal satisfiability problem.%为保证系统的安全性并体现授权的有效性,结合部分最大可满足性问题(Partial MAX-SAT)的研究,提出一种基于Partial MAX-SAT求解法的授权查询方法.使用转换规则将静态授权逻辑和动态互斥角色约束转化为严格子句,采用子句更新算法将满足不同匹配的请求权限转化为松弛子句,并利用子句编码及递归算法寻求真值指派,以满足所有严格子句和尽可能多的松弛子句.实验结果表明,该方法搜索的角色组合能够保证系统的安全性,并满足最小权限分配要求,且最大、精确匹配请求的查询效率优于MAX-SAT求解法.

  14. Approximate algorithm for median query based on WSN%无线传感器网络中中位数查询近似算法研究

    Institute of Scientific and Technical Information of China (English)

    刘彩苹; 毛建旭; 李仁发; 付彬

    2011-01-01

    An approximate algorithm for median query (AAMQ) based on WSN was proposed. In AAMQ, each node could estimate the value of the distinct number, and created a subsequence samples which get K percent of the most commonly used values in its own observed values, and then broadcasted its subsequence to the parents. Finally, these samples were combined to a single sample in the root node which its data structure was far smaller than the size of the whole data set. The approximate value for median query could be introduced from the sample quickly. Experimental results show that the proposed algorithm can greatly reduce the communication, has the advantages of low error range, and is able to significantly prolong system life.%提出一种基于WSN的中位数查询近似算法-AAMQ.在AAMQ中,节点分别统计出每个感知值出现的不重复次数,从而抽取节点的K%个最常用感知值作为子样本,然后将子样本传递给父节点,最终在根节点形成全网的样本.最后使用这个远小于全网数据集规模的、可用于代表全网数据集结构的全网样本迅速获得中位数的近似结果,从而避免了将各节点的数据都传输至根节点.实验结果显示,该算法能较大减少网络通信量、具有较小的误差,能有效地延长网络的生存期.

  15. Queries, Influencers and Vocational Interests of Junior High School Students

    Science.gov (United States)

    Woal, S. Theodore

    1974-01-01

    The study, based on questionnaire results from 207 ninth grade students, investigates: student familiarity with occupations; influencers of their tentative occupational choices; post high school plans; and student queries and concerns pertinent to preparation for entry into a job. (MW)

  16. Determinacy in Static Analysis of jQuery

    DEFF Research Database (Denmark)

    Andreasen, Esben; Møller, Anders

    2014-01-01

    Static analysis for JavaScript can potentially help programmers find errors early during development. Although much progress has been made on analysis techniques, a major obstacle is the prevalence of libraries, in particular jQuery, which apply programming patterns that have detrimental conseque......Static analysis for JavaScript can potentially help programmers find errors early during development. Although much progress has been made on analysis techniques, a major obstacle is the prevalence of libraries, in particular jQuery, which apply programming patterns that have detrimental...... present a static dataflow analysis for JavaScript that infers and exploits determinacy information on-the-fly, to enable analysis of some of the most complex parts of jQuery. The techniques are implemented in the TAJS analysis tool and evaluated on a collection of small programs that use jQuery. Our...

  17. An introduction to XML query processing and keyword search

    CERN Document Server

    Lu, Jiaheng

    2013-01-01

    This book systematically and comprehensively covers the latest advances in XML data searching. It presents an extensive overview of the current query processing and keyword search techniques on XML data.

  18. An Algorithm Reformulation of XQuery Queries Using GLAV Mapping for Mediator-based System

    Directory of Open Access Journals (Sweden)

    Benharzallah SABER

    2014-03-01

    Full Text Available This paper describes an algorithm for reformulation of XQuery queries. The mediation is based on an essential component called mediator. The main role of the mediator is to reformulate a user query, written in terms of global schema, in queries written in terms of sources schemas. Our algorithm is based on the principle of logical equivalence, simple and complex unification, to obtain a better reformulation. It takes as parameter the query XQuery, the global schema (written in XMLSchema, mappings GLAV and gives as a result a query written in terms of sources schemas. The results of implementation show the proper functioning of the algorithm.

  19. Format SPARQL Query Results into HTML Report

    Directory of Open Access Journals (Sweden)

    Dr Sunitha Abburu

    2013-07-01

    Full Text Available SPARQL is one of the powerful query language for querying semantic data. It is recognized by the W3C as a query language for RDF. As an efficient query language for RDF, it has defined several query result formats such as CSV, TSV and XML etc. These formats are not attractive, understandable and readable. The results need to be converted in an appropriate format so that user can easily understand. The above formats require additional transformations or tool support to represent the query result in user readable format. The main aim of this paper is to propose a method to build HTML report dynamically for SPARQL query results. This enables SPARQL query result display, in HTML report format easily, in an attractive understandable format without the support of any additional or external tools or transformation.

  20. Optimizing Temporal Queries: Efficient Handling of Duplicates

    DEFF Research Database (Denmark)

    Toman, David; Bowman, Ivan Thomas

    2001-01-01

    translated SQL queries by taking into account the properties of the encoding used for temporal attributes. For concreteness, this translation technique is presented in the context of SQL/TP; however, these techniques are also applicable to other temporal query languages......., these query languages are implemented by translating temporal queries into standard relational queries. However, the compiled queries are often quite cumbersome and expensive to execute even using state-of-the- art relational products. This paper presents an optimization technique that produces more efficient......Recent research in the area of temporal databases has proposed a number of query languages that vary in their expressive power and the semantics they provide to users. These query languages represent a spectrum of solutions to the tension between clean semantics and efficient evaluation. Often...

  1. Comparing and Combining Methods for Automatic Query Expansion

    CERN Document Server

    Pérez-Agüera, José R

    2008-01-01

    Query expansion is a well known method to improve the performance of information retrieval systems. In this work we have tested different approaches to extract the candidate query terms from the top ranked documents returned by the first-pass retrieval. One of them is the cooccurrence approach, based on measures of cooccurrence of the candidate and the query terms in the retrieved documents. The other one, the probabilistic approach, is based on the probability distribution of terms in the collection and in the top ranked set. We compare the retrieval improvement achieved by expanding the query with terms obtained with different methods belonging to both approaches. Besides, we have developed a na\\"ive combination of both kinds of method, with which we have obtained results that improve those obtained with any of them separately. This result confirms that the information provided by each approach is of a different nature and, therefore, can be used in a combined manner.

  2. Cluster Analysis and Fuzzy Query in Ship Maintenance and Design

    Science.gov (United States)

    Che, Jianhua; He, Qinming; Zhao, Yinggang; Qian, Feng; Chen, Qi

    Cluster analysis and fuzzy query win wide-spread applications in modern intelligent information processing. In allusion to the features of ship maintenance data, a variant of hypergraph-based clustering algorithm, i.e., Correlation Coefficient-based Minimal Spanning Tree(CC-MST), is proposed to analyze the bulky data rooting in ship maintenance process, discovery the unknown rules and help ship maintainers make a decision on various device fault causes. At the same time, revising or renewing an existed design of ship or device maybe necessary to eliminate those device faults. For the sake of offering ship designers some valuable hints, a fuzzy query mechanism is designed to retrieve the useful information from large-scale complicated and reluctant ship technical and testing data. Finally, two experiments based on a real ship device fault statistical dataset validate the flexibility and efficiency of the CC-MST algorithm. A fuzzy query prototype demonstrates the usability of our fuzzy query mechanism.

  3. Query cost estimation through remote system contention states analysis over the Internet

    OpenAIRE

    Liu, Weiru; Liao, Z; Hong, Jun

    2004-01-01

    Query processing over the Internet involving autonomous data sources is a major task in data integration. It requires the estimated costs of possible queries in order to select the best one that has the minimum cost. In this context, the cost of a query is affected by three factors: network congestion, server contention state, and complexity of the query. In this paper, we study the effects of both the network congestion and server contention state on the cost of a query. We refer to these tw...

  4. Identifying Aspects for Web-Search Queries

    OpenAIRE

    Wu, Fei; Madhavan, Jayant; Halevy, Alon

    2014-01-01

    Many web-search queries serve as the beginning of an exploration of an unknown space of information, rather than looking for a specific web page. To answer such queries effec- tively, the search engine should attempt to organize the space of relevant information in a way that facilitates exploration. We describe the Aspector system that computes aspects for a given query. Each aspect is a set of search queries that together represent a distinct information need relevant to the original search...

  5. Advanced Query Techniques.

    Science.gov (United States)

    1979-10-01

    whicn is the right one in the intermediate translator, we enter an amniilnous patn and rely on intermediate luery resolution in the tarjet data base...tvae olus relational identifier. Output list noees aill have the tollojoi.nq format: I ryte oftset of requested tiela in tarjet data record d tyte

  6. Labeling Schemes with Queries

    OpenAIRE

    2006-01-01

    We study the question of ``how robust are the known lower bounds of labeling schemes when one increases the number of consulted labels''. Let $f$ be a function on pairs of vertices. An $f$-labeling scheme for a family of graphs $\\cF$ labels the vertices of all graphs in $\\cF$ such that for every graph $G\\in\\cF$ and every two vertices $u,v\\in G$, the value $f(u,v)$ can be inferred by merely inspecting the labels of $u$ and $v$. This paper introduces a natural generalization: the notion of $f$-...

  7. Optimizing Aggregate SPARQL Queries Using Materialized RDF Views

    DEFF Research Database (Denmark)

    Ibragimov, Dilshod; Hose, Katja; Pedersen, Torben Bach;

    2016-01-01

    During recent years, more and more data has been published as native RDF datasets. In this setup, both the size of the datasets and the need to process aggregate queries represent challenges for standard SPARQL query processing techniques. To overcome these limitations, materialized views can......, this paper proposes MARVEL (MAterialized Rdf Views with Entailment and incompLetness). The approach consists of a view selection algorithm based on an associated RDF-specific cost model, a view definition syntax, and an algorithm for rewriting SPARQL queries using materialized RDF views. The experimental...... be created and used as a source of precomputed partial results during query processing. However, materialized view techniques as proposed for relational databases do not support RDF specifics, such as incompleteness and the need to support implicit (derived) information. To overcome these challenges...

  8. An Adaptive Mechanism for Accurate Query Answering under Differential Privacy

    CERN Document Server

    Li, Chao

    2012-01-01

    We propose a novel mechanism for answering sets of count- ing queries under differential privacy. Given a workload of counting queries, the mechanism automatically selects a different set of "strategy" queries to answer privately, using those answers to derive answers to the workload. The main algorithm proposed in this paper approximates the optimal strategy for any workload of linear counting queries. With no cost to the privacy guarantee, the mechanism improves significantly on prior approaches and achieves near-optimal error for many workloads, when applied under (\\epsilon, \\delta)-differential privacy. The result is an adaptive mechanism which can help users achieve good utility without requiring that they reason carefully about the best formulation of their task.

  9. Chinese college students’ Web querying behaviors:A case study of Peking University

    Institute of Scientific and Technical Information of China (English)

    QU; Peng; LIU; Chang; LAI; Maosheng

    2010-01-01

    This study examined users’querying behaviors based on a sample of 30 Chinese college students from Peking University.The authors designed 5 search tasks and each participant conducted two randomly selected search tasks during the experiment.The results show that when searching for pre-designed search tasks,users often have relatively clear goals and strategies before searching.When formulating their queries,users often select words from tasks,use concrete concepts directly,or extract"central words"or keywords.When reformulating queries,seven query reformulation types were identified from users’behaviors,i.e.broadening,narrowing,issuing new query,paralleling,changing search tools,reformulating syntax terms,and clicking on suggested queries.The results reveal that the search results and/or the contexts can also influence users’querying behaviors.

  10. A Novel Ranking Algorithm of Query Words Stored in QIIIEP Server

    Directory of Open Access Journals (Sweden)

    Dilip Kumar Sharma

    2010-11-01

    Full Text Available This paper proposes a novel algorithm for the ranking of query words stored in QIIIEP server which are used for posting the query to extract the contents from deep web (Sharma and Sharma, 2009. These words can be collected from either by auto query words extraction module or submitted by web master of third party sites. This paperanalyze different existing algorithms for ranking of query words and suggest an improved algorithm for the same by including newer parameters for ranking of query words. An elaborate analysis is carried on the concept of query words ranking so as to come up with an improved algorithm with enhanced efficiency and one in conformance with the global standards. Proposed algorithm analyzes the context of web page with respect to the supplied keywords and frequency of simultaneous occurrence for same keyword on surface web to assign a numerical weighting to each query word with the purpose of "measuring" its relative importance within the set.

  11. Building interactive queries with LINQPad

    CERN Document Server

    Finot, Sébastien

    2013-01-01

    A step-by-step practical guide that will introduce you to LINQPad's key features, thereby helping you to query databases interactively.This book is aimed at C#/.Net developers who wish to learn LINQ programming and leverage the easy way of using LINQPad. No prior knowledge of LINQ or LINQPad is expected. A basic knowledge of SQL and XML is required for some chapters.

  12. A distributed query execution engine of big attributed graphs.

    Science.gov (United States)

    Batarfi, Omar; Elshawi, Radwa; Fayoumi, Ayman; Barnawi, Ahmed; Sakr, Sherif

    2016-01-01

    A graph is a popular data model that has become pervasively used for modeling structural relationships between objects. In practice, in many real-world graphs, the graph vertices and edges need to be associated with descriptive attributes. Such type of graphs are referred to as attributed graphs. G-SPARQL has been proposed as an expressive language, with a centralized execution engine, for querying attributed graphs. G-SPARQL supports various types of graph querying operations including reachability, pattern matching and shortest path where any G-SPARQL query may include value-based predicates on the descriptive information (attributes) of the graph edges/vertices in addition to the structural predicates. In general, a main limitation of centralized systems is that their vertical scalability is always restricted by the physical limits of computer systems. This article describes the design, implementation in addition to the performance evaluation of DG-SPARQL, a distributed, hybrid and adaptive parallel execution engine of G-SPARQL queries. In this engine, the topology of the graph is distributed over the main memory of the underlying nodes while the graph data are maintained in a relational store which is replicated on the disk of each of the underlying nodes. DG-SPARQL evaluates parts of the query plan via SQL queries which are pushed to the underlying relational stores while other parts of the query plan, as necessary, are evaluated via indexless memory-based graph traversal algorithms. Our experimental evaluation shows the efficiency and the scalability of DG-SPARQL on querying massive attributed graph datasets in addition to its ability to outperform the performance of Apache Giraph, a popular distributed graph processing system, by orders of magnitudes.

  13. CrossQuery: a web tool for easy associative querying of transcriptome data.

    Science.gov (United States)

    Wagner, Toni U; Fischer, Andreas; Thoma, Eva C; Schartl, Manfred

    2011-01-01

    Enormous amounts of data are being generated by modern methods such as transcriptome or exome sequencing and microarray profiling. Primary analyses such as quality control, normalization, statistics and mapping are highly complex and need to be performed by specialists. Thereafter, results are handed back to biomedical researchers, who are then confronted with complicated data lists. For rather simple tasks like data filtering, sorting and cross-association there is a need for new tools which can be used by non-specialists. Here, we describe CrossQuery, a web tool that enables straight forward, simple syntax queries to be executed on transcriptome sequencing and microarray datasets. We provide deep-sequencing data sets of stem cell lines derived from the model fish Medaka and microarray data of human endothelial cells. In the example datasets provided, mRNA expression levels, gene, transcript and sample identification numbers, GO-terms and gene descriptions can be freely correlated, filtered and sorted. Queries can be saved for later reuse and results can be exported to standard formats that allow copy-and-paste to all widespread data visualization tools such as Microsoft Excel. CrossQuery enables researchers to quickly and freely work with transcriptome and microarray data sets requiring only minimal computer skills. Furthermore, CrossQuery allows growing association of multiple datasets as long as at least one common point of correlated information, such as transcript identification numbers or GO-terms, is shared between samples. For advanced users, the object-oriented plug-in and event-driven code design of both server-side and client-side scripts allow easy addition of new features, data sources and data types.

  14. CrossQuery: a web tool for easy associative querying of transcriptome data.

    Directory of Open Access Journals (Sweden)

    Toni U Wagner

    Full Text Available Enormous amounts of data are being generated by modern methods such as transcriptome or exome sequencing and microarray profiling. Primary analyses such as quality control, normalization, statistics and mapping are highly complex and need to be performed by specialists. Thereafter, results are handed back to biomedical researchers, who are then confronted with complicated data lists. For rather simple tasks like data filtering, sorting and cross-association there is a need for new tools which can be used by non-specialists. Here, we describe CrossQuery, a web tool that enables straight forward, simple syntax queries to be executed on transcriptome sequencing and microarray datasets. We provide deep-sequencing data sets of stem cell lines derived from the model fish Medaka and microarray data of human endothelial cells. In the example datasets provided, mRNA expression levels, gene, transcript and sample identification numbers, GO-terms and gene descriptions can be freely correlated, filtered and sorted. Queries can be saved for later reuse and results can be exported to standard formats that allow copy-and-paste to all widespread data visualization tools such as Microsoft Excel. CrossQuery enables researchers to quickly and freely work with transcriptome and microarray data sets requiring only minimal computer skills. Furthermore, CrossQuery allows growing association of multiple datasets as long as at least one common point of correlated information, such as transcript identification numbers or GO-terms, is shared between samples. For advanced users, the object-oriented plug-in and event-driven code design of both server-side and client-side scripts allow easy addition of new features, data sources and data types.

  15. QUESEM: Towards building a Meta Search Service utilizing Query Semantics

    Directory of Open Access Journals (Sweden)

    Neelam Duhan

    2011-01-01

    Full Text Available Current Web Search Engines are built to serve needs of all users, independent of the special needs of any individual. The documents are returned by matching their queries with available documents, with no emphasis on the semantics of query. As a result, the generated information is often very large and inaccurate that results in increased user perceived latency. In this paper, a Semantic Search Service is being developed to help users gather relevant documents more efficiently unlike traditional Web search engines. The approach relies on the online web resource such as dictionary based sites to retrieve possible semantics of the query keywords, which are stored in a definition repository. The service works as a meta-layer above the keyword-based search engine to generate sub-queries based on different meanings of user query, which in turn are sent to the keyword-based search engine to perform Web search. This approach relieves the user in finding the desired information content and improves the search quality for certain types of complex queries. Experiments depict its efficiency as it results in reduced search space.

  16. Complete Bipartite Anonymity for Location Privacy

    Institute of Scientific and Technical Information of China (English)

    董恺; 顾涛; 陶先平; 吕建

    2014-01-01

    Users are vulnerable to privacy risks when providing their location information to location-based services (LBS). Existing work sacrifices the quality of LBS by degrading spatial and temporal accuracy for ensuring user privacy. In this paper, we propose a novel approach, Complete Bipartite Anonymity (CBA), aiming to achieve both user privacy and quality of service. The theoretical basis of CBA is that: if the bipartite graph of k nearby users’ paths can be transformed into a complete bipartite graph, then these users achieve k-anonymity since the set of “end points connecting to a specific start point in a graph”is an equivalence class. To achieve CBA, we design a Collaborative Path Confusion (CPC) protocol which enables nearby users to discover and authenticate each other without knowing their real identities or accurate locations, predict the encounter location using users’ moving pattern information, and generate fake traces obfuscating the real ones. We evaluate CBA using a real-world dataset, and compare its privacy performance with existing path confusion approach. The results show that CBA enhances location privacy by increasing the chance for a user confusing his/her path with others by 4 to 16 times in low user density areas. We also demonstrate that CBA is secure under the trace identification attack.

  17. Yahtzee: an anonymized group level matching procedure.

    Directory of Open Access Journals (Sweden)

    Jason J Jones

    Full Text Available Researchers often face the problem of needing to protect the privacy of subjects while also needing to integrate data that contains personal information from diverse data sources. The advent of computational social science and the enormous amount of data about people that is being collected makes protecting the privacy of research subjects ever more important. However, strict privacy procedures can hinder the process of joining diverse sources of data that contain information about specific individual behaviors. In this paper we present a procedure to keep information about specific individuals from being "leaked" or shared in either direction between two sources of data without need of a trusted third party. To achieve this goal, we randomly assign individuals to anonymous groups before combining the anonymized information between the two sources of data. We refer to this method as the Yahtzee procedure, and show that it performs as predicted by theoretical analysis when we apply it to data from Facebook and public voter records.

  18. Caching Stars in the Sky: A Semantic Caching Approach to Accelerate Skyline Queries

    CERN Document Server

    Bhattacharya, Arnab; Dutta, Sourav

    2011-01-01

    Multi-criteria decision making has been made possible with the advent of skyline queries. However, processing such queries for high dimensional datasets remains a time consuming task. Real-time applications are thus infeasible, especially for non-indexed skyline techniques where the datasets arrive online. In this paper, we propose a caching mechanism that uses the semantics of previous skyline queries to improve the processing time of a new query. In addition to exact queries, utilizing such special semantics allow accelerating related queries. We achieve this by generating partial result sets guaranteed to be in the skyline sets. We also propose an index structure for efficient organization of the cached queries. Experiments on synthetic and real datasets show the effectiveness and scalability of our proposed methods.

  19. VIQI: A New Approach for Visual Interpretation of Deep Web Query Interfaces

    CERN Document Server

    Boughamoura, Radhouane; Omri, Mohamed Nazih

    2012-01-01

    Deep Web databases contain more than 90% of pertinent information of the Web. Despite their importance, users don't profit of this treasury. Many deep web services are offering competitive services in term of prices, quality of service, and facilities. As the number of services is growing rapidly, users have difficulty to ask many web services in the same time. In this paper, we imagine a system where users have the possibility to formulate one query using one query interface and then the system translates query to the rest of query interfaces. However, interfaces are created by designers in order to be interpreted visually by users, machines can not interpret query from a given interface. We propose a new approach which emulates capacity of interpretation of users and extracts query from deep web query interfaces. Our approach has proved good performances on two standard datasets.

  20. Privately Releasing Conjunctions and the Statistical Query Barrier

    CERN Document Server

    Gupta, Anupam; Roth, Aaron; Ullman, Jonathan

    2010-01-01

    Suppose we would like to know all answers to a set of statistical queries C on a data set up to small error, but we can only access the data itself using statistical queries. A trivial solution is to exhaustively ask all queries in C. Can we do any better? + We show that the number of statistical queries necessary and sufficient for this task is---up to polynomial factors---equal to the agnostic learning complexity of C in Kearns' statistical query (SQ) model. This gives a complete answer to the question when running time is not a concern. + We then show that the problem can be solved efficiently (allowing arbitrary error on a small fraction of queries) whenever the answers to C can be described by a submodular function. This includes many natural concept classes, such as graph cuts and Boolean disjunctions and conjunctions. In doing so we also give a new learning algorithm for submodular functions that improves upon recent results in a different context. While interesting from a learning theoretic point of v...

  1. 基于NoSQL数据库的大数据查询技术%Large data query technology based on NoSQL database

    Institute of Scientific and Technical Information of China (English)

    忻禾登

    2016-01-01

    Provide a consumer with the continuous development and innovation of science and technology, the Internet is gradually people, entertainment and communication as the core platform for various. At the same time, more and more data also continue to emerge, these data showing various characteristics, form and content are more diverse. Therefore, based on the framework of NoSQL data query technology was born. And the advanced technology gradually become hot topics in academic research. This paper focuses on the classification of NoSQL database from the, characteristics of NoSQL framework of data query technology based on, the advantages and limitations of the theory.%随着科学技术的不断发展和创新,网络时代迎来新高潮,互联网逐渐为老百姓提供了一个消费、娱乐与沟通为一体的核心平台。与此同时,越来越多的数据也在不断涌现,这些数据呈现出各种特点,形式和内容都是多样化的。可以认为,原始的、较为不成熟的关系型数据库是无法再满足社会发展和人类自身需要的。因此,基于基于NoSQL框架的数据查询技术由此诞生,而且这一先进技术逐步成为学界研究的热点领域。本文重点从NoSQL数据库的分类、基于NoSQL框架的数据查询技术的特点、基于NoSQL框架的数据查询技术的优势和长处以及不足等方面进行论述。

  2. Improving query services of web map by web mining

    Science.gov (United States)

    Huang, Maojun

    2007-11-01

    Web map is the hybrid of map and the World Wide Web (known as Web). It is usually created with WebGIS techniques. With the rapid social development, web maps oriented the public are facing pressure that dissatisfy the increased demanding. The geocoding database plays a key role in supporting query services effectively. The traditional geocoding method is laborious and time-consuming. And there is much online spatial information, which would be the supplementary information source for geocoding. Therefore, this paper discusses how to improve query services by web mining. The improvement can be described from three facets: first, improving location query by discovering and extracting address information from the Web to extend geocoding database. Second, enhancing the ability of optimum path query of public traffic and buffer query by spatial analyzing and reasoning on the extended geocoding database. Third, adjusting strategies of collecting data according to patterns discovered by web map query mining. Finally, this paper presents the designing of the application system and experimental results.

  3. Measuring the achievable error of query sets under differential privacy

    CERN Document Server

    Li, Chao

    2012-01-01

    A common goal of privacy research is to release synthetic data that satisfies a formal privacy guarantee and can be used by an analyst in place of the original data. To achieve reasonable accuracy, a synthetic data set must be tuned to support a specified set of queries accurately, sacrificing fidelity for other queries. This work considers methods for producing synthetic data under differential privacy and investigates what makes a set of queries "easy" or "hard" to answer. We consider answering sets of linear counting queries using the matrix mechanism, a recent differentially-private mechanism that can reduce error by adding complex correlated noise adapted to a specified workload. Our main result is a novel lower bound on the minimum total error required to simultaneously release answers to a set of workload queries. The bound reveals that the hardness of a query workload is related to the spectral properties of the workload when it is represented in matrix form. The bound is tight and, because it satisfi...

  4. Data stream range query authentication scheme based on PMD in outsourced database%基于PMD的外包数据流范围查询验证方案

    Institute of Scientific and Technical Information of China (English)

    谢晴晴; 王良民

    2015-01-01

    数据流外包服务验证问题受到广泛的关注。目前主流的外包数据查询验证技术是基于Merkle哈希树(Merkle Hash tree,MHT)的,但是其具有验证对象较大,验证过程存在冗余,安全性低,无法快速实现篡改定位的不足。针对这些不足,提出了一种基于偏序实体化摘取(partially materialized digest,PMD)策略的外包数据流范围查询验证新方案。该方案将PMD嵌入到传统MHT中,来选择MHT的部分中间节点以及根节点进行签名,那么在数据验证阶段重构MHT时无需计算大量冗余哈希值,即可验证查询结果的真实性和完整性。最后将所提方案具体应用到数据流单次和滑动窗口范围查询中,使得客户端能够高效率地验证由第三方所提供的结果是真实和完整的。%Data stream range query authentication problem has been receiving widespread attention. The main query authentication method is based on Merkle Hash tree (MHT), which has disadvantages such as large verification object (VO), redundant verification procedures, low security and disability to locate tampering quickly. To over-come the above disadvantages, this paper proposes a new data stream range query authentication method based on partially materialized digest (PMD) scheme, where the PMD scheme is embedded in the traditional MHT, and some internal nodes and the root node in MHT are signed, instead of only the root node. Thus in the process of query results authentication, there is no need to compute much redundant hash value when reconstructing the MHT and verifying the authenticity and completeness of the query answers. Finally, the proposed scheme is applied into one-shot and sliding window range queries over data stream, where the authenticity and completeness of the query answers can be proved efficiently.

  5. Perspectives on the Use of “Anonymous” Discussion Forums in Undergraduate Education Courses / Perspectives sur l’usage des forums de discussion « partiellement anonymes » dans le cadre de cours universitaires de premier cycle en éducation

    Directory of Open Access Journals (Sweden)

    G. Michael Bowen

    2012-07-01

    Full Text Available This paper theorizes issues involved with conflicts between participation in on-line settings and real-world social commitments, such as has recently happened in schools with students using public discussion forums. We problematize how real-world social commitments negatively affect participation in online learning environments frequently used in classrooms. Drawing on interviews with, observations by, and written submissions from our students who participated in “hybrid” courses using an approach where identity was concealed in online discussions from other class participants, we discuss implications of this issue for evaluating forum submissions by students. Our analysis uses a cultural-historical activity theory framework to conceptualize implications from this anonymous forum approach and the resultant changes in participation in the learning environment. Cet article élabore une théorie des enjeux associés aux conflits entre la participation dans un environnement en ligne et les engagements sociaux réels, comme ce qui se produit actuellement dans les écoles, les étudiants se servant de forums publics de discussion pour leurs cours. Nous schématisons la façon dont les engagements sociaux réels ont des effets négatifs sur la participation aux environnements d’apprentissage en ligne fréquemment utilisés dans les salles de classe. À partir d’entrevues, d’observations et de communications écrites par les étudiants qui ont participé à nos cours « hybrides » en adoptant une approche par laquelle l’identité était gardée cachée des autres étudiants (mais non des instructeurs dans les discussions en ligne, nous discutons des implications de cet enjeu dans l’évaluation des soumissions des étudiants dans les forums. Notre analyse se sert d’un cadre théorique de l’activité historico-culturelle pour conceptualiser les implications de cette approche de forum « partiellement anonyme » et les changements de

  6. Framing memories: How the retrieval query format shapes the neural bases of remembering.

    Science.gov (United States)

    Raposo, Ana; Frade, Sofia; Alves, Mara

    2016-08-01

    The way memory questions are framed influences the information that is searched, retrieved, and monitored during remembering. This fMRI study aimed at clarifying how the format of the retrieval query shapes the neural basis of source recollection. During encoding, participants made semantic (pleasantness) or perceptual (number of letters) judgments about words. Subsequently, in a source memory test, the retrieval query was manipulated such that for half of the items from each encoding task, the retrieval query emphasized the semantic source (i.e., semantic query format: "Is this word from the pleasantness task?"), whereas for the other half the retrieval query emphasized the alternate, perceptual source (i.e., perceptual query format: "Is this word from the letter task?"). The results showed that the semantic query format was associated with higher source recognition than the perceptual query format. This behavioral advantage was accompanied by increased activation in several regions associated to controlled semantic elaboration and monitoring of internally-generated features about the past event. In particular, for items semantically encoded, the semantic query, relative to the perceptual query, induced activation in medial prefrontal cortex (PFC), hippocampal, parahippocampal and middle temporal cortex. Conversely, for items perceptually encoded, the semantic query recruited the lateral PFC and occipital-fusiform areas. Interestingly, the semantic format also influenced the processing of new items, eliciting greater L lateral and medial PFC activation. In contrast, the perceptual query format (versus the semantic format) only prompted greater activation in R orbitofrontal cortex and the R inferior parietal lobe, for items encoded in a perceptual manner and for new items, respectively. The results highlight the role of the retrieval query format in source remembering, showing that the retrieval query that emphasizes the semantic source promotes the use of semantic

  7. Applying Stylometric Analysis Techniques to Counter Anonymity in Cyberspace

    Directory of Open Access Journals (Sweden)

    Jianwen Sun

    2012-02-01

    Full Text Available Due to the ubiquitous nature and anonymity abuses in cyberspace, it’s difficult to make criminal identity tracing in cybercrime investigation. Writeprint identification offers a valuable tool to counter anonymity by applying stylometric analysis technique to help identify individuals based on textual traces. In this study, a framework for online writeprint identification is proposed. Variable length character n-gram is used to represent the author’s writing style. The technique of IG seeded GA based feature selection for Ensemble (IGAE is also developed to build an identification model based on individual author level features. Several specific components for dealing with the individual feature set are integrated to improve the performance. The proposed feature and technique are evaluated on a real world data set encompassing reviews posted by 50 Amazon customers. The experimental results show the effectiveness of the proposed framework, with accuracy over 94% for 20 authors and over 80% for 50 ones. Compared with the baseline technique (Support Vector Machine, a higher performance is achieved by using IGAE, resulting in a 2% and 8% improvement over SVM for 20 and 50 authors respectively. Moreover, it has been shown that IGAE is more scalable in terms of the number of authors, than author group level based methods.

  8. LBS privacy protective method based on collaborative proxy incremental query%协作代理增量查询的LBS隐私保护方法

    Institute of Scientific and Technical Information of China (English)

    毛典辉; 蔡强; 李海生; 黄今慧

    2013-01-01

    In order to solve the problem of the current privacy protective method restricted by the location-based service (LBS) system architecture, a LBS privacy protective method based on collaborative proxy incremental query was proposed. Mobile users were self-organized as a P2P network according to Chord protocol, which utilized the mechanism of cluster node state maintenance as well as loading balance to ensure the stability of P2P network. User who consumed services blured his real position point and selected a proxy user who held higher degree of collaborative willingness, which achieved incremental nearest neighbor queries with service provider. It was analyzed that the method had a higher level of privacy protection in theory, and meanwhile, experiment was done for the P2P network performance and the algorithm efficiency. The results show that the method has higher level of computational efficiency without sacrificing service quality, realizing the balance between the degree of privacy protection and service quality.%针对基于位置服务(LBS)应用中现有隐私保护方法受系统体系结构局限,提出了一种协作代理增量查询的LBS隐私保护方法:移动用户通过Chord协议自组织为P2P网络,同时采用簇节点状态维护机制,以及负载均衡机制来保证系统稳定,用户消费服务时,通过模糊自身真实位置,并在网络内选择协作意愿度高的代理用户,由其完成代理增量近邻查询.从理论上对P2P网络性能及算法效率进行了实验,结果表明:该方法在不牺牲服务质量的同时具有较高的计算效率,实现了隐私保护度与服务质量的平衡.

  9. Query Specific Rank Fusion for Image Retrieval.

    Science.gov (United States)

    Zhang, Shaoting; Yang, Ming; Cour, Timothee; Yu, Kai; Metaxas, Dimitris N

    2015-04-01

    Recently two lines of image retrieval algorithms demonstrate excellent scalability: 1) local features indexed by a vocabulary tree, and 2) holistic features indexed by compact hashing codes. Although both of them are able to search visually similar images effectively, their retrieval precision may vary dramatically among queries. Therefore, combining these two types of methods is expected to further enhance the retrieval precision. However, the feature characteristics and the algorithmic procedures of these methods are dramatically different, which is very challenging for the feature-level fusion. This motivates us to investigate how to fuse the ordered retrieval sets, i.e., the ranks of images, given by multiple retrieval methods, to boost the retrieval precision without sacrificing their scalability. In this paper, we model retrieval ranks as graphs of candidate images and propose a graph-based query specific fusion approach, where multiple graphs are merged and reranked by conducting a link analysis on a fused graph. The retrieval quality of an individual method is measured on-the-fly by assessing the consistency of the top candidates' nearest neighborhoods. Hence, it is capable of adaptively integrating the strengths of the retrieval methods using local or holistic features for different query images. This proposed method does not need any supervision, has few parameters, and is easy to implement. Extensive and thorough experiments have been conducted on four public datasets, i.e., the UKbench, Corel-5K, Holidays and the large-scale San Francisco Landmarks datasets. Our proposed method has achieved very competitive performance, including state-of-the-art results on several data sets, e.g., the N-S score 3.83 for UKbench.

  10. IdentiDroid: Android can finally Wear its Anonymous Suit

    Directory of Open Access Journals (Sweden)

    Bilal Shebaro

    2014-04-01

    from applications when the smartphone is used under the anonymous modality. They are re-instated back when the smartphone returns to work in the normal modality. In addition, both solutions offer protection from applications that identify their users through traces left in the application's data storage or through exchanging identifying data messages. We developed IdentiDroid, a customized Android operating system, to deploy these solutions and built IdentiDroid Profile Manager, a profile-based configuration tool that allows one to set different configurations for each installed Android application. With this tool, applications running within the same device are configured to be given different identifications and privileges to limit the uniqueness of device and user information. We analyzed 250 Android applications to determine what information, services, and permissions can identify users and devices. Our experiments show that when IdentiDroid is deployed and properly configured on Android devices, users' anonymity is better guaranteed by either of the proposed solutions with no significant impact on most device applications.

  11. Nonexposure Accurate Location K-Anonymity Algorithm in LBS

    Directory of Open Access Journals (Sweden)

    Jinying Jia

    2014-01-01

    Full Text Available This paper tackles location privacy protection in current location-based services (LBS where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. Location cloaking has been proposed and well studied to protect user privacy. It blurs the user’s accurate coordinate and replaces it with a well-shaped cloaked region. However, to obtain such an anonymous spatial region (ASR, nearly all existent cloaking algorithms require knowing the accurate locations of all users. Therefore, location cloaking without exposing the user’s accurate location to any party is urgently needed. In this paper, we present such two nonexposure accurate location cloaking algorithms. They are designed for K-anonymity, and cloaking is performed based on the identifications (IDs of the grid areas which were reported by all the users, instead of directly on their accurate coordinates. Experimental results show that our algorithms are more secure than the existent cloaking algorithms, need not have all the users reporting their locations all the time, and can generate smaller ASR.

  12. Nonexposure accurate location K-anonymity algorithm in LBS.

    Science.gov (United States)

    Jia, Jinying; Zhang, Fengli

    2014-01-01

    This paper tackles location privacy protection in current location-based services (LBS) where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. Location cloaking has been proposed and well studied to protect user privacy. It blurs the user's accurate coordinate and replaces it with a well-shaped cloaked region. However, to obtain such an anonymous spatial region (ASR), nearly all existent cloaking algorithms require knowing the accurate locations of all users. Therefore, location cloaking without exposing the user's accurate location to any party is urgently needed. In this paper, we present such two nonexposure accurate location cloaking algorithms. They are designed for K-anonymity, and cloaking is performed based on the identifications (IDs) of the grid areas which were reported by all the users, instead of directly on their accurate coordinates. Experimental results show that our algorithms are more secure than the existent cloaking algorithms, need not have all the users reporting their locations all the time, and can generate smaller ASR.

  13. Anonymous and Traceable Copyright Protection Protocol Based on Mobile Devices%基于移动设备的匿名可追踪版权保护协议

    Institute of Scientific and Technical Information of China (English)

    姜堃; 王晓明

    2012-01-01

    Anonymous and traceable copyright protection protocol based on mobile devices was put forward in this paper. Firstly,others can not track the user by using the changing identity to replace user's true identity in the protocol. The anonymous nature exists in the protocol. Secondly, the protocol uses the method that one password only applies one fingerprint watermark so that the protocol resists the fake attack. Thirdly, while using one-way hash function to verify the identity of participators and the digital content, the protocol transfers the calculating works to the trusted center RA with enough computing ability from mobile users. The two behaviors reduce the mobile's calculating works, and improve efficiency. In addition, the copyright watermark and fingerprint watermark embedded in the digital product are used to trace the traitor when finding one or more illegal copies of the digital product So the protocol has the ability of traitor tracing. The analysis indicates that the protocol is secure and practical.%提出了基于移动设备的匿名可追踪的版权管理协议.首先,它使用不断变换的临时身份来代替用户的真实身份,使其他人不可能跟踪到用户,它关注用户动态,具有匿名性;其次,使用一次口令申请一个水印的方法来抵抗假冒攻击;再次,采用单向哈希函数的认证方法对用户身份、数字内容进行验证;协议中的一些计算由可信中心完成,以减少移动用户的计算量,提高效率.另外在数字产品中嵌入版权水印和指纹水印,当发现非法副本时,它可以对叛逆者进行追踪,具有可追踪性.分析表明,该协议是安全有效的.

  14. Query Optimization of Database Based on Gauss Mutation Quantum Behaved Particle Swarm of Optimization Algorithm%高斯扰动粒子群算法的数据库查询优化

    Institute of Scientific and Technical Information of China (English)

    李国芳; 李静

    2014-01-01

    In order to solve the defect of quantum particle swarm algorithm, mutation operator of the genetic algorithm is introduced into quantum particle swarm optimization algorithm. It produces a novel query optimization method of database(GM-QPSO). Firstly, the mathematic model is established for database query optimization problems. And then the optimal scheme of database query optimization problems is found by the sharing message of quantum particle. Finally, the simulation experiments is carried out on Matlab 2012. The results show that the proposed algorithm has solved the defect of quantum particle swarm algorithm, and improved query speed of database and can obtain better query scheme.%针对量子粒子群算法存在的不足,将变异算子引入其中,提出一种高斯变异量子粒子群算法(GM-QPSO),并将其应用于数据库查询优化中。首先建立数据库查询优化数学模型,然后采用量子粒子代表一个可行的数据库查询方案,然后通过量子粒子之间的信息交流,找到数据库查询最优解,最后在 Matlab 2012上进行了仿真实验。仿真结果表明, GM-QPSO克服了量子粒子群算法存在的不足,不仅提高了数据库查询速度,而且获得了更加理想的查询优化方案。

  15. Gregory Bateson, Alcoholics Anonymous, and stoicism.

    Science.gov (United States)

    Brundage, V

    1985-02-01

    In 1971 Gregory Bateson put forward an "entirely new epistemology," or view of the world, that he described as cybernetic. In a very influential article, which appeared in this journal, Bateson claimed that his cybernetic epistemology "coincides closely" with the epistemology of Alcoholics Anonymous (AA), for which he claimed "the only outstanding record of success" in the treatment of alcoholism (1971, p. 310). However, Bateson's discussion of AA dealt with only four of the Twelve Steps of AA's program. Although the epistemology of cybernetics and AA congrue in some respects, they contradict each other in many others. Common ground is found in the ancient philosophical tradition of Stoicism. In Stoicism the contradictions between the two are sources for an ethics and psychology of great power. Stoicism offers the cybernetic epistemologist a solid base for theory. It offers the clinician who deals with chemical dependency practical insights into the process of recovery.

  16. Classification via Clustering for Anonymization Data

    Directory of Open Access Journals (Sweden)

    Sridhar Mandapati

    2014-02-01

    Full Text Available Due to the exponential growth of hardware technology particularly in the field of electronic data storage media and processing such data, has raised serious issues related in order to protect the individual privacy like ethical, philosophical and legal. Data mining techniques are employed to ensure the privacy. Privacy Preserving Data Mining (PPDM techniques aim at protecting the sensitive data and mining results. In this study, the different Clustering techniques via classification with and without anonymization data using mining tool WEKA is presented. The aim of this study is to investigate the performance of different clustering methods for the diabetic data set and to compare the efficiency of privacy preserving mining. The accuracy of classification via clustering is evaluated using K-means, Expectation-Maximization (EM and Density based clustering methods.

  17. Design of Anonymous Attribute Authentication Mechanism

    Science.gov (United States)

    Kiyomoto, Shinsaku; Fukushima, Kazuhide; Tanaka, Toshiaki

    Privacy remains an issue for IT services. Users are concerned that their history of service use may be traceable since each user is assigned a single identifier as a means of authentication.In this paper, we propose a perfectly anonymous attribute authentication scheme that is both unidentifiable and untraceable. Then, we present the evaluation results of a prototype system using a PC and mobile phone with the scheme. The proposed scheme employs a self-blindable certificate that a user can change randomly; thus the certificate is modified for each authentication, and the authentication scheme is unidentifiable and untraceable. Furthermore, our scheme can revoke self-blindable certificates without leaks of confidential private information and check the revocation status without online access.

  18. Quantum anonymous voting with unweighted continuous-variable graph states

    Science.gov (United States)

    Guo, Ying; Feng, Yanyan; Zeng, Guihua

    2016-08-01

    Motivated by the revealing topological structures of continuous-variable graph state (CVGS), we investigate the design of quantum voting scheme, which has serious advantages over the conventional ones in terms of efficiency and graphicness. Three phases are included, i.e., the preparing phase, the voting phase and the counting phase, together with three parties, i.e., the voters, the tallyman and the ballot agency. Two major voting operations are performed on the yielded CVGS in the voting process, namely the local rotation transformation and the displacement operation. The voting information is carried by the CVGS established before hand, whose persistent entanglement is deployed to keep the privacy of votes and the anonymity of legal voters. For practical applications, two CVGS-based quantum ballots, i.e., comparative ballot and anonymous survey, are specially designed, followed by the extended ballot schemes for the binary-valued and multi-valued ballots under some constraints for the voting design. Security is ensured by entanglement of the CVGS, the voting operations and the laws of quantum mechanics. The proposed schemes can be implemented using the standard off-the-shelf components when compared to discrete-variable quantum voting schemes attributing to the characteristics of the CV-based quantum cryptography.

  19. Private anonymous fingerprinting for color images in the wavelet domain

    Science.gov (United States)

    Abdul, W.; Gaborit, P.; Carré, P.

    2010-01-01

    An online buyer of multimedia content does not want to reveal his identity or his choice of multimedia content whereas the seller or owner of the content does not want the buyer to further distribute the content illegally. To address these issues we present a new private anonymous fingerprinting protocol. It is based on superposed sending for communication security, group signature for anonymity and traceability and single database private information retrieval (PIR) to allow the user to get an element of the database without giving any information about the acquired element. In the presence of a semi-honest model, the protocol is implemented using a blind, wavelet based color image watermarking scheme. The main advantage of the proposed protocol is that both the user identity and the acquired database element are unknown to any third party and in the case of piracy, the pirate can be identified using the group signature scheme. The robustness of the watermarking scheme against Additive White Gaussian Noise is also shown.

  20. Downloading Multiple Records Using Query Strings

    Directory of Open Access Journals (Sweden)

    Adam Crymble

    2012-11-01

    Full Text Available Downloading a single record from a website is easy, but downloading many records at a time – an increasingly frequent need for a historian – is much more efficient using a programming language such as Python. In this lesson, we will write a program that will download a series of records from the Old Bailey Online using custom search criteria, and save them to a directory on our computer. This process involves interpreting and manipulating URL Query Strings. In this case, the tutorial will seek to download sources that contain references to people of African descent that were published in the Old Bailey Proceedings between 1700 and 1750.