An efficient database transitive closure algorithm

The integration of logic rules and relational databases has recently emerged as an important technique for developing knowledge management systems. An important class of logic rules utilized by these systems is the so-called transitive closure rules, the processing of which requires the computation of the transitive closure of database relations referenced by these rules. This article presents a new algorithm suitable for computing the transitive closure of very large database relations. This algorithm proceeds in two phases. In the first phase, a general graph is condensed into an acyclic one, and at the same time a special sparse matrix is formed from the acyclic graph. The second phase is the main one, in which all the page I/O operations are minimized by removing most of the redundant operations that appear in previous algorithms. Using simulation, this article also studies and examines the performance of this algorithm and compares it with the previous algorithms.     

EDUA: An efficient algorithm for dynamic database mining

Maintaining frequent itemsets (patterns) is one of the most important issues faced by the data mining community. While many algorithms for pattern discovery have been developed, relatively little work has been reported on mining dynamic databases, a major area of application in this field. In this paper, a new algorithm, namely the Efficient Dynamic Database Updating Algorithm (EDUA), is designed for mining dynamic databases. It works well when data deletion is carried out in any subset of a database that is partitioned according to the arrival time of the data. A pruning technique is proposed for improving the efficiency of the EDUA algorithm. Extensive experiments are conducted to evaluate the proposed approach and it is demonstrated that the EDUA is efficient.     

数据库系统辅助测试工具

提出了一种数据库系统测试的辅助工具,用于解决规范化管理的数据库系统测试项目中测试数据构建及测试结果保留效率低下的问题.其具体做法是,采用Excel工作表规范设计输入数据和预期结果,再利用该工具完成一些简单设定,可实现构造数据库测试数据、获取测试结果及实现丸行结果与预期结果比较等功能.经多个数据库使用结果表明,该工具能生成规范的测试结果,并能减轻测试人员负担,提高了测试效率.     

An efficient quantum search engine on unsorted database

We consider the problem of finding one or more desired items out of an unsorted database. Patel has shown that if the database permits quantum queries, then mere digitization is sufficient for efficient search for one desired item. The algorithm, called factorized quantum search algorithm, presented by him can locate the desired item in an unsorted database using O( $log_4N$ ) queries to factorized oracles. But the algorithm requires that all the attribute values must be distinct from each other. In this paper, we discuss how to make a database satisfy the requirements, and present a quantum search engine based on the algorithm. Our goal is achieved by introducing auxiliary files for the attribute values that are not distinct, and converting every complex query request into a sequence of calls to factorized quantum search algorithm. The query complexity of our algorithm is O( $log_4N$ ) for most cases.     

An intelligent image database system

A prototype intelligent image database system (IIDS) that is based on a novel pictorial data structure is presented. This prototype system supports spatial reasoning, flexible image information retrieval, visualization, and traditional image database operations. A pictorial data structure, based on 2-D strings, provides an efficient means for iconic indexing in image database systems and spatial reasoning. The modular design of IIDS facilitates its implementation. Further extensions of the prototype system are discussed     

基于甲骨文数据库管理系统的化学结构检索数据库的设计与实现

设计了一种基于大型数据库管理系统Oracle的化学结构数据存储模式,并实现了相应于此模式的高效化学结构检索方法。结构检索方法建立在图子图匹配算法VF2的基础上,对其进行了必要的改造和扩展,使之适合于化学结构检索。在此基础上,针对美国NCl(National Cancer Institute)25万个化合物的2D结构建立了数据库,成功进行了结构检索试验。结果表明,这种实现方法不仅能高效存储并准确检索化合物的结构信息,而且也容易实现与药物研发过程中所产生的大量其它数据(如生物筛选数据和DNA芯片基因表达数据等)进行高效整合。这个设计的改进版已经集成于微芯公司的药物研发生化信息学软件系统——TASS(Target Activity Structure System)中。     

An adaptive neuro-fuzzy system for efficient implementations

A neuro-fuzzy system specially suited for efficient implementations is presented. The system is of the same type as the well-known “adaptive network-based fuzzy inference system” (ANFIS) method. However, different restrictions are applied to the system that considerably reduce the complexity of the inference mechanism. Hence, efficient implementations can be developed. Some experiments are presented which demonstrate the good performance of the proposed system despite its restrictions. Finally, an efficient digital hardware implementation is presented for a two-input single-output neuro-fuzzy system.     

PDB: A pictorial database oriented to data analysis

The paper describes a new pictorial database oriented to image analysis, implemented inside the MIDAS data analysis system. Pictorial databases need expressive data structures in order to represent a wide class of information from the numerical to the visual. The model of the database is relational; however, a full normalization is not achievable, owing to the complexity of the visual information. The paper reports the general design and notes on the software implementation. Preliminary experiments show the performance of the pictorial database.     

An object-oriented multimedia database system for a news-on-demand application

We describe the design of a multimedia database management system for a distributed news-on-demand multimedia information system. News-on-demand is an application that uses broadband network services to deliver news articles to subscribers in the form of multimedia documents. Different news providers insert articles into the database, which are then accessed by users remotely, over a broadband, asynchronous transfer-mode (ATM) network. The particulars of our design are an object-oriented approach and strict adherence to international standards, in particular the Standard Generalized Mark-up Language (SGML) and Hy-Time. The multimedia database system has a visual query facility, which is also described in this paper. The visual query interface provides three major facilities for end users: presentation, navigation, and querying of multimedia news documents. The main focus, however, is the querying of multimedia objects stored in the database.     

Isidd: An interactive system for inductive database design

When designing a deductive database, the designer has to decide for each predicate (or relation) whether it should be defined extensionally or intensionally and what the definition should look like. An intelligent interactive system is presented to assist the designer in this task. It starts from an example state ofa database in which all predicates are defined extensionally. It can then compact the database by transforming extensionally defined predicates into intensionally defined ones. These predicates can be chosen by the user or by the system itself. Further compaction is possible by inventing new predicates; this invention is controlled by user-specified templates. The systemalso proposes semantic integrity constraints to the user. These do not lead to extra compaction but can be used to make the database more robust. The intelligent system employs techniques from the area of inductive logic programming.     

INDIANA: An interactive system for assisting database exploration

We propose INDIANA, a system conceived to support a novel paradigm of database exploration. INDIANA assists the users who are interested in gaining insights about a database though an interactive and incremental process, like a conversation that does not happen in natural language. During this process, the system iteratively provides the user with some features of the data that might be “interesting” from the statistical viewpoint, receiving some feedbacks that are later used by the system to refine the features provided to the user in the next step. A key ability of INDIANA is to assist “data enthusiastic” users (i.e., inexperienced or casual users) in the exploration of transactional databases in an interactive way. For this purpose, we develop a number of novel, statistically-grounded algorithms to support the interactive exploration of the database. We report an in-depth experimental evaluation to show that the proposed system guarantees a very good trade-off between accuracy and scalability, and a user study that supports the claim that the system is effective in real-world database-exploration tasks.     

一种高效基于模式图的数据库关键字查询方法

针对基于模式图的数据库关键字查询方法中普遍存在的查询效率较低的问题,提出了合并网络查询方法(CCNE)。CCNE中设计了一种合并网络结构,可以有效地避免传统方法中因候选网络之间的重复结构造成的冗余操作。同时,给出一种改进的候选网络生成策略,可以避免产生冗余候选网络并缩小遍历范围,从而提高效率。最后,在合并网络的基础上,设计一种合并网络执行算法,在很大程度上减少了传统方法所需执行的大量复杂数据库查询操作,进一步提高查询效率。多组基于真实数据集的实验结果表明CCNE可以在保证查询结果无缺失的情况下有效提高查询效率。     

An efficient motion magnification system for real-time applications

The human eye cannot see subtle motion signals that fall outside human visual limits, due to either limited resolution of intensity variations or lack of sensitivity to lower spatial and temporal frequencies. Yet, these invisible signals can be highly informative when amplified to be observable by a human operator or an automatic machine vision system. Many video magnification techniques have recently been proposed to magnify and reveal these signals in videos and image sequences. Limitations, including noise level, video quality and long execution time, are associated with the existing video magnification techniques. Therefore, there is value in developing a new magnification method where these issues are the main consideration. This study presents a new magnification method that outperforms other magnification techniques in terms of noise removal, video quality at large magnification factor and execution time. The proposed method is compared with four methods, including Eulerian video magnification, phase-based video magnification, Riesz pyramid for fast phase-based video magnification and enhanced Eulerian video magnification. The experimental results demonstrate the superior performance of the proposed magnification method regarding all video quality metrics used. Our method is also 60–70% faster than Eulerian video magnification, whereas other competing methods take longer to execute than Eulerian video magnification.     

An efficient buffer memory system for subarray access

Many current graphical display systems utilize a buffer memory system to contain a two-dimensional image array to be modified and displayed. In order to speed up the update of the buffer memory system, it is required that the buffer memory system accesses many image points within an image subarray in parallel. This paper proposes an efficient buffer memory system for a fast and high-resolution graphical display system. The memory system provides parallel accesses to pq image points within a block(p×q), a horizontal (1×pq), a vertical (pq×1), a forward-diagonal, or a backward-diagonal subarray in a two-dimensional image array, M×N, where the design parameters p and q are all powers of two. In the address calculation and routing circuit of the proposed buffer memory system, the address differences of the five subarrays are prearranged according to the index numbers of memory modules and stored in two static random access memories (SRAMs), so that the address differences are simply added to the base address to obtain the addresses according to the index numbers of memory modules. In addition, for the fast address calculation, one single multiplication operation in the base address calculation is replaced by a SRAM access, so that the multiplication operation can be performed during the SRAM access for the address differences for the case when N is not a power of two. The address calculation and routing circuit proposed in this paper is improved in the hardware cost, the complexity of control, and the speed over the previous circuits     

An efficient modularized database structure for a high‐resolution column‐gridded Mars global terrain database

This paper discusses a modularised design for a Mars Global Terrain Database. The design provides for elevation data with respect to a triaxial ellipsoidal reference datum developed for Mars by USGS. Terrain data is recorded for 1‐second of arc almost square grid elements over the surface of Mars. A 2000‐Gigabyte column‐gridded relation called Terrain contains the surface terrain data. Data for Terrain is expected in 1999–2000 from the Mars Global Surveyor satellite currently in initial polar orbit around Mars. Each tuple of Terrain contains data for a N‐S column‐grid of 900 1‐second grid elements. There is thus a set of tuples per 1‐degree rectangle, with the number of tuples per set decreasing with the cosine of latitude. Surface resolution is 16.5 meters or better. The design constrains tuple sizes in Terrain to permit efficient blocking and manipulation of the records of the underlying storage file. Terrain contains a virtual‐attribute function for geodetic computations relating to the triaxial ellipsoidal reference datum. The database also relates Mars feature‐type relations to Terrain. Terrain's gridded structure is transparent to users writing SQL expressions to retrieve Terrain data on the basis of specific features. Many different distinct feature‐type relations can be included. At least two of these participate in recursive relationships. The design also allows attachment of additional feature‐type relations in a modular manner, correctly related to Terrain, without affecting the contents of Terrain. The design is intended to enable efficient exploration of the planet at all levels of scale. Copyright © 1999 John Wiley & Sons, Ltd.     

图象数据库建模分析与模型

为解决图象数据库建模，提出一种新的图象数据模型，将图象对象分解为由稳定属性组成的主表部分和若干个可变属性组成的副表部分，查询推理时对主表和副表临时组织以完成图象数据的存取管理等，它能对图象数据库５级模式结构的每级模式一致建模。     

An efficient dynamic system for real-time robot-path planning.

This paper presents a simple yet efficient dynamic-programming (DP) shortest path algorithm for real-time collision-free robot-path planning applicable to situations in which targets and barriers are permitted to move. The algorithm works in real time and requires no prior knowledge of target or barrier movements. In the case that the barriers are stationary, this paper proves that this algorithm always results in the robot catching the target, provided it moves at a greater speed than the target, and the dynamic-system update frequency is sufficiently large. Like most robot-path-planning approaches, the environment is represented by a topologically organized map. Each grid point on the map has only local connections to its neighboring grid points from which it receives information in real time. The information stored at each point is a current estimate of the distance to the nearest target and the neighbor from which this distance was determined. Updating the distance estimate at each grid point is done using only the information gathered from the point's neighbors, that is, each point can be considered an independent processor, and the order in which grid points are updated is not determined based on global knowledge of the current distances at each point or the previous history of each point. The robot path is determined in real time completely from the information at the robot's current grid-point location. The computational effort to update each point is minimal, allowing for rapid propagation of the distance information outward along the grid from the target locations. In the static situation, where both the targets and the barriers do not move, this algorithm is a DP solution to the shortest path problem, but is restricted by lack of global knowledge. In this case, this paper proves that the dynamic system converges in a small number of iterations to a state where the minimal distance to a target is recorded at each grid point and shows that this robot-path-planning algorithm can be made to always choose an optimal path. The effectiveness of this algorithm is demonstrated through a number of simulations.     

An efficient privacy-preserving pay-by-phone system for regulated parking areas

International Journal of Information Security - Traditional pay-and-display ticket machines are currently coexisting, but will probably be replaced in the near future, with pay-by-phone...