• Title/Summary/Keyword: logic database

Search Result 142, Processing Time 0.027 seconds

Semantics of Uncertain Databases based on Linear Logic (선형논리에 기반한 불확실성 데이터베이스 의미론)

  • Park, Sung-Woo
    • Journal of KIISE:Software and Applications
    • /
    • v.37 no.2
    • /
    • pp.148-154
    • /
    • 2010
  • In the study of the formal semantics of uncertain databases, we typically take an algebraic approach by mapping an uncertain database to possible worlds which are a set of relational databases. In this paper, we present a new semantics for uncertain databases which takes a logical approach by translating uncertain databases into logical theories. A characteristic feature of our semantics is that it uses linear logic, instead of propositional logic, as its logical foundation. Linear logic is suitable for a logical interpretation of uncertain information because unlike propositional logic, it treats logical formulae not as persistent facts but as consumable resources. As the main result, we show that our semantics is faithful to the operational account of uncertain databases in the algebraic approach.

Pre-earthquake fuzzy logic and neural network based rapid visual screening of buildings

  • Moseley, V.J.;Dritsos, S.E.;Kolaksis, D.L.
    • Structural Engineering and Mechanics
    • /
    • v.27 no.1
    • /
    • pp.77-97
    • /
    • 2007
  • When assessing buildings that may collapse during a large earthquake, conventional rapid visual screening procedures generally provide good results when identifying buildings for further investigation. Unfortunately, their accuracy at identify buildings at risk is not so good. In addition, there appears to be little room for improvement. This paper investigates an alternative screening procedure based on fuzzy logic and artificial neural networks. Two databases of buildings damaged during the Athens earthquake of 1999 are used for training purposes. Extremely good results are obtained from one database and not so good results are obtained from the second database. This finding illustrates the importance of specifically collecting data tailored to the requirements of the fuzzy logic based rapid visual screening procedure. In general, results demonstrate that the trained fuzzy logic based rapid visual screening procedure represents a marked improvement when identifying buildings at risk. In particular, when smaller percentages of the buildings with high damage scores are extracted for further investigation, the proposed fuzzy screening procedure becomes more efficient. This paper shows that the proposed procedure has a significant optimisation potential, is worth pursuing and, to this end, a strategy that outlines the future development of the fuzzy logic based rapid visual screening procedure is proposed.

Design of an Optoelectronic Database Filter Chip (고성능 병렬 광 데이터처리 가속기)

  • 나종화
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2000.04a
    • /
    • pp.36-38
    • /
    • 2000
  • An optoelectronic database filter chip for high performance database computers and applications is proposed. The proposed device is designed to perform the selection and projection operations of relational database operation on-the-fly in page-parallel manner to increase the overall performance of a database system. The device utilizes CMOS smart pixel array consists of detector and combinational logic circuit to perform the selection and projection operation.

  • PDF

The Controls of Client-Server System: Case Studies of Banks (클라이언트-서버 시스템에 대한 통제: 은행업체에 대한 사례연구)

  • 이상재
    • Korean Management Science Review
    • /
    • v.17 no.2
    • /
    • pp.97-113
    • /
    • 2000
  • The introduction of client server systems raises some serious IS control concerns. Although client server systems increase system flexibility and compatibility, and facilitates system downsizing and process restructuring, multiple operating systems, database management systems, and platforms of client-server system increase th potential exposures and risks of the system. It is needed to recommend the effective control framework to mitigate risks. This paper suggests risks and control framework for client server system. The results of two case studies indicate that program and database management are important as program and data should be located and maintained in client and servers. It becomes difficult to manage divided programs and data logic that are distributed across clients and servers that have different platforms. The case studies of two banks show that the extent of distribution of program and data logic affects the importance of program and database management controls.

  • PDF

A Study on Database Access Control using Least-Privilege Account Separation Model (최소 권한 계정 분리 모델을 이용한 데이터베이스 엑세스 제어 연구)

  • Jang, Youngsu
    • Journal of Korea Society of Digital Industry and Information Management
    • /
    • v.15 no.3
    • /
    • pp.101-109
    • /
    • 2019
  • In addition to enabling access, database accounts play a protective role by defending the database from external attacks. However, because only a single account is used in the database, the account becomes the subject of vulnerability attacks. This common practice is due to the lack of database support, large numbers of users, and row-based database permissions. Therefore if the logic of the application is wrong or vulnerable, there is a risk of exposing the entire database. In this paper, we propose a Least-Privilege Account Separation Model (LPASM) that serves as an information guardian to protect the database from attacks. We separate database accounts depending on the role of application services. This model can protect the database from malicious attacks and prevent damage caused by privilege escalation by an attacker. We classify the account control policies into four categories and propose detailed roles and operating plans for each account.

Construction of Linkage Database on Nursing Diagnoses, Interventions, Outcomes in Abdominal Surgery Patients (복부수술환자의 간호진단, 간호중재, 간호결과 연계 데이터베이스 구축)

  • Yoo, Hyung-Sook;Chi, Sung-Ai
    • Journal of Korean Academy of Nursing Administration
    • /
    • v.7 no.3
    • /
    • pp.425-437
    • /
    • 2001
  • This reserch was to develop database software in order to handle a lot of clinical nursing data with nursing diagnoses, related factors, defining characteristics, nursing interventions, nursing activities and nursing outcomes. MS Access2000 and SQL was selected to use a general purpose database logic with an efficiency. MS Visual Basic 6.0 was used to construct the circumstance of Graphic User Interface. The Linkage Database of abdominal surgery patients was constructed from the clinical data and questionnaire. This database system could add related factors, defining characteristics, nursing activities in the database and analyze the statistical results through Access query. In the final stage, end-users satisfaction analysis using 5 points Likert scale was dong with the response of using the database system. The accuracy/trustworthiness of the database system was verified with the highest average scores as 4.42 and also, the efficiency as 4.21, user friendly function as 4.1.

  • PDF

Development of Violin Self-Training Algorithm using Fuzzy Logic (퍼지제어를 이용한 바이올린 연주 연습 알고리즘 개발)

  • Min, Byung-Cheol;Kim, Dong-Han;Kim, Yoon-Hyuk;Kim, Ki-Yeoul;Park, Chong-Kug
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.19 no.4
    • /
    • pp.550-555
    • /
    • 2009
  • A violin plays an essential role among string instruments. It has an extremely strong expressive power that can be conveyed through beautiful timbre when played correctly. However, a beginner who attempts to play the violin will be most likely to face difficulties in placing his or her fingers on a specific point of the fingerboard or in bowing the violin on a specific string. In order to resolve this difficulty, the database of a professional violinist's bowing skills were inserted beforehand. By doing so, a beginner can emulate professional's violin by comparing his playing with the constructed database that is programmed in the computer. Accordingly, the results are displayed on the monitor after being evaluated by the performance evaluation function using a fuzzy logic.

Fuzzy inference systems based prediction of engineering properties of two-stage concrete

  • Najjar, Manal F.;Nehdi, Moncef L.;Azabi, Tareq M.;Soliman, Ahmed M.
    • Computers and Concrete
    • /
    • v.19 no.2
    • /
    • pp.133-142
    • /
    • 2017
  • Two-stage concrete (TSC), also known as pre-placed aggregate concrete, is characterized by its unique placement technique, whereby the coarse aggregate is first placed in the formwork, then injected with a special grout. Despite its superior sustainability and technical features, TSC has remained a basic concrete technology without much use of modern chemical admixtures, new binders, fiber reinforcement or other emerging additions. In the present study, an experimental database for TSC was built. Different types of cementitious binders (single, binary, and ternary) comprising ordinary portland cement, fly ash, silica fume, and metakaolin were used to produce the various TSC mixtures. Different dosages of steel fibres having different lengths were also incorporated to enhance the mechanical properties of TSC. The database thus created was used to develop fuzzy logic models as predictive tools for the grout flowability and mechanical properties of TSC mixtures. The performance of the developed models was evaluated using statistical parameters and error analyses. The results indicate that the fuzzy logic models thus developed can be powerful tools for predicting the TSC grout flowability and mechanical properties and a useful aid for the design of TSC mixtures.

Test Generation for Combinational Logic Circuits Using Neural Networks (신경회로망을 이용한 조합 논리회로의 테스트 생성)

  • 김영우;임인칠
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.30A no.9
    • /
    • pp.71-79
    • /
    • 1993
  • This paper proposes a new test pattern generation methodology for combinational logic circuits using neural networks based on a modular structure. The CUT (Circuit Under Test) is described in our gate level hardware description language. By conferring neural database, the CUT is compiled to an ATPG (Automatic Test Pattern Generation) neural network. Each logic gate in CUT is represented as a discrete Hopfield network. Such a neual network is called a gate module in this paper. All the gate modules for a CUT form an ATPG neural network by connecting each module through message passing paths by which the states of modules are transferred to their adjacent modules. A fault is injected by setting the activation values of some neurons at given values and by invalidating connections between some gate modules. A test pattern for an injected fault is obtained when all gate modules in the ATPG neural network are stabilized through evolution and mutual interactions. The proposed methodology is efficient for test generation, known to be NP-complete, through its massive paralelism. Some results on combinational logic circuits confirm the feasibility of the proposed methodology.

  • PDF

연역 대이터베이스에서 SQL을 아용한 순환적 질의의 설계

  • 김영준;김정태
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 1996.04a
    • /
    • pp.183-186
    • /
    • 1996
  • The relational database management systems sometimes require extremely long and complicated queries for a certain retreval. In this case, recursive retirevals are more efficient approach than the usual queries. Many researchers have tried to incorporate semantics in the traditional relational models using artificial intelligence techniques. This new concept becomes a deductive database and sometimes it is also called as a logic programming. However, the designer of a deductive database did not overcome the short of relational database. In this paper, we propose a new way of designing queries for the deductive database. We also provide relations for recursive retrieval in the deductive database. These approaches are applied for the material requirement planning.

  • PDF