Database Design Method Research Articles

Optimizing the convergence of data-based controller tuning

Data-based control design methods most often consist of iterative adjustment of the controller’s parameters towards the parameter values which minimize an [Formula: see text] performance criterion. Typically, batches of input-output data collected from the system are used to feed directly a gradient descent optimization algorithm – no process model is used. Two topics are important regarding this algorithm: the convergence rate and the convergence to the global minimum. This paper discusses these issues and provides a method for choosing the step size to ensure convergence with high convergence rate, as well as a test to verify at each step whether or not the algorithm is converging to the global minimum.

The Design and Production of Map Symbol Database Based on ArcGIS

Map symbol is the basis of digital cartography, and ArcGIS is the best suited digital cartography GIS software in the current. As the same as other GIS software, symbol database of ArcGIS still cannot completely satisfy the requirement of digital chart production and display. Therefore, we must create symbol database according to the Map chart requirements. The paper described the design method of Map Symbol database under the condition of ArcGIS, and discussed respectively the production of different kinds of symbols, expanding ArcGIS symbol database.

Virtual Reference Feedback Tuning for non-minimum phase plants

Model reference control design methods fail when the plant has one or more non-minimum phase zeros that are not included in the reference model, leading possibly to an unstable closed loop. This is a very serious problem for data-based control design methods, where the plant is typically unknown. In this paper, we extend the Virtual Reference Feedback Tuning method to non-minimum phase plants. This extension is based on the idea proposed in Lecchini and Gevers (2002) for Iterative Feedback Tuning. We present a simple two-step procedure that can cope with the situation where the unknown plant may or may not have non-minimum phase zeros.

Analisis dan Perancangan Sistem Informasi Laboratorium Rumah Sakit Kanker Dharmais Dengan Menggunakan Total Architecture Syntesis

The purposes of this research are to design and implementation of laboratory information systems (LIS) at the Laboratory of Cancer Hospital Dharmais (Dharmais Cancer Hospital). The methods used are the method of analysis, design methodology using Total Architecture Synthesis (TAS) and database design methods. Methods include analysis of the survey directly into the clinical laboratory Dharmais Cancer Hospital, and interviews with users who running the current system in Dharmais Cancer Hospital Clinical Laboratory. The design method using TAS. The results of this study is a single integrated Laboratory Information System applications with other systems that exist in Dharmais Cancer Hospital and also the delivery of feature inspection results by using text service and email, in addition to be taken directly to Dharmais Cancer Hospital and sent to the address. The conclusions from this study are all the transactions contained in Dharmais Cancer Hospital Clinical Laboratory have been computerized and integrated.

Iterative minimization of [formula omitted] control performance criteria

Data-based control design methods most often consist of iterative adjustment of the controller’s parameters towards the parameter values which minimize an H 2 performance criterion. Typically, batches of input–output data collected from the system are used to feed directly a gradient descent optimization — no process model is used. A limiting factor in the application of these methods is the lack of useful conditions guaranteeing convergence to the global minimum; several adaptive control algorithms suffer from the same limitation. In this paper the H 2 performance criterion is analyzed in order to characterize and enlarge the set of initial parameter values from which a gradient descent algorithm can converge to its global minimum.

Data-Based LQI Controller Design from Plant Data

The performance of model-based controller design is strongly influenced by the quality of the underlying model. However, the development of an accurate first-principle model is not a trivial task. In this research, a data-based LQI controller design method directly from plant data is developed. By incorporating the just-intime learning technique, LQI design can be carried out without the need of a first-principle model, which is normally assumed to be available in the traditional LQI design. Simulation results are presented to illustrate the proposed method and a comparison with its conventional counterparts is made.

Supporting Semantic Diversity in the Relational Data Model: The Case of Multi-Face Attributes

In recent years various proposals have been offered for increasing the richness of the relational data model by addressing specific user requirements, particularly with regard to structural and behavioral expressiveness. Although there have been some criticisms of the semantic limitations of the model, few proposals have emerged to address them. In this paper we propose an extension of the model to address some of the semantic limitations around the use of multi-face attributes in everyday activity. We present a formal discussion of multi-face attributes and suggest how they can be accommodated in the relational model and relational database software systems. The resulting model offers a higher-level expressiveness and will provide the user with increased flexibility in the input, output and storage of data, and the specification of queries. Finally we outline some of the implications for database design methods that emerge for the extension.

MDO 프레임워크 개발을 통한 항공기 날개 통합최적화 설계

다분야 통합 최적화 설계 환경을 제공하는 소프트웨어 체계인 MDO 프레임워크 개발을 위해서는 다양한 운영체계와 언어에서 개발된 해석코드들의 통합, CAD 및 데이터베이스 시스템과의 통합, 복잡한 GUI 환경의 구현 등이 필수적으로 요구되고 해석코드의 추가, 새로운 MDO 기법의 도입에 따른 수정 및 확장에 대한 고려가 충분히 이루어져야 한다. 본 논문에서는 MDO 프레임워크의 설계단계부터 고려되어야 할 사항들과 각 구성요소들의 시스템 통합 방법을 연구, 적용 방안을 제시하며 이를 바탕으로 비행체 통합 최적설계 시스템 환경을 구현하였다. MDF 및 CO 기법 등 대표적인 MDO 기법을 적용할 수 있는 데이터베이스 설계과정을 정립하고, 구현된 통합 최적설계 시스템을 이용하여 전투기 날개 형상 최적 설계를 수행하여 개발된 MDO 프레임워크의 효율성 및 유용성을 검증하였다. 구배 기반 최적화 기법을 이용하여 삼십번의 설계 반복으로 최적 날개 형상을 도출하였다. MDO framework, which provides multidisciplinary system design and optimization environment, requires integration of the analyses codes developed at various computer languages and operating systems, integration of CAD and DBMS, and development of complex GUI. Emphases must be given to the software modification and upgrades in conjunction with the analysis code addition and MDO method implementation. In this study, techniques about system integration and analysis code interface have been studied extensively, and the database design and communication methods which can handle the MDO methods like MDF and CO have been studied. Using the dedicated MDO framework developed for the air vehicle design, the multidisciplinary fighter aircraft wing design has been performed to demonstrate the efficiency and usefulness of the software. Optimum wing configuration is derived using the gradient-based optimization methods within thirty design iterations.

Integration of storage characteristic with on-line service characteristic of AS/RS

Directed at how to integrated storage characteristic with on-line service characteristic of AS/RS, a solution based on database design and programming method is proposed. The results show that this model is reasonable and applicable while using in some small or middle enterprises material handling system.

Markov Data-Based LQG Control1

In this paper the Markov data-based LQG control problem is considered. The Markov data-based LQG control problem is to find the optimal control sequence which minimizes a quadratic cost function over some finite interval [0, N]. To solve this problem, we show that a complete input-output description of the system is not necessary. Obviously, a complete state space model is not necessary for this problem either. The main contributions of this paper include: (i) develop a new data-based LQG controller in a recursive form and a batch-form, (ii) derive a closed-form expression for the system’s optimal performance in terms of the Markov parameters, (iii) develop an algorithm for choosing the output weighting matrix, and (iv) demonstrate that the amount of information about the system required by the data-based controller design is less than the amount required to construct the full state space model. A numerical example is given to show the effectiveness of the data-based design method. [S0022-0434(00)02503-X]

A physical database design method for multidimensional file organizations

This paper presents a physical database design methodology for multidimensional file organizations. Physical database design is the process of determining the optimal configuration of physical files and access structures for a given set of queries. Recently, many multidimensional file organizations have been proposed in the literature. However, there has been no effort toward their physical database design. We first show that the performance of query processing is highly affected by the similarity between the shapes of query regions and page regions in the domain space, and then propose a method for finding the optimal configuration of the multidimensional file by controlling the interval ratio of different axes to achieve the similarity. For performance evaluation, we perform extensive experiments with the multilevel grid file, a multidimensional file organization, using various types of queries and record distributions. The results indicate that our proposed method builds optimal multilevel grid files regardless of the query types and record distributions. When the interval ratio of a two-dimensional query region is 1:1024, the performance of the proposed method is enhanced by as much as 7.5 times over that of the conventional method that has an interval ratio of 1:1 employing the cyclic splitting strategy. The performance is further enhanced for query types having higher interval ratios. The result is significant since interval ratios can be far from 1:1 for many practical applications, especially when different axes have different domains.

MOODD, a method for object-oriented database design

In this paper we propose a Method for Object-Oriented Database Design, called MOODD. Considerable recent research [22] has focused on object-oriented design techniques. MOODD distinguishes itself by generating an object-oriented data definition from requirements written in a natural language. Examples to illustrate the method are given for a particular OODBS called O2 [19]. MOODD consists of three phases. The first phase is to use a Requirement Specification Language (RSL) [27] to represent user requirements. Next, the RSL requirements are converted into an object-oriented conceptual model composed of the Nested Entity-Relationship (NER) [10]/ Update Protocol Model (UPM) [9]. Finally, the NER/UPM schemas are implemented by an object-oriented data model.

工具運用計画のための工具データベースの設計法

This paper deals with a design method of a tool database to be used in tool use planning. To increase the efficiency of the tool use in a flexible automated manufacturing system, it is necessary for the tool database to support information used in the whole field of the tool life cycle and in the tool use. A management system sharing with some tools in some machine tools and using them, can make the best use of tool capacity. For the realization of this system, the tool use needs information to select tool instance and to deploy it in the place just in time, based on tool status and machining schedule. An activity model of such a system for FMS is constructed for clarifying requirements for a tool database. Then to design such a tool database for satisfying the requirements, this study introduces an object-oriented method such as STEP technology, and implements the database using EXPRESS, C++, and object oriented database system.

Tailoring Database Training for End Users

Lack of familiarity with database design methods could prevent many end users from effectively implementing their database management system packages. An inexpensive solution would be for end users to learn required database design skills from software tutors tailored to their needs. This research describes two tutors developed to teach these skills to end users. The tutors were based on a modified Entity-Relationship database design method. They improved an end user's natural learning process by incorporating design principles and facilitators. Empirical comparison of the tutors tested the teaching effectiveness of the facilitators. The results lead to recommendations for closing the gap between skills required and skills learned by end users in database design. Development of tutors that teach specific database design skills irrespective of the software package used in implementation has important implications for practitioners and researchers.

An Efficient Logical Design Method for Physicochemical Property Database.

It is necessary for increasing the utility of process simulations on personal computers to improve the estimates for physicochemical properties, the performance of which depends on estimation methods and basic physicochemical property database (PCPDB). This study is concerned with an efficient logical database design method, which is composed of two procedures. The first is preliminary data analysis for identifying the initial entities by two steps i.e. partitioning the data of the PCPDB into subdivisions based on the data requirement of simulation computation and determining the initial entity for each subdivision based on the functional relationship of the relevant data. The second is a synthetic approach to constructing the relations

A database design method for finite element analysis

Recently, many application programs have been applied in design and analysis disciplines. With the increase in the numbers of programs, the absence of standardization and lack of coordination among software developers have resulted in difficulty in data communication from one program to another. The result is often manual transfer of data with the associated manpower loss, time delay, and potential for error. Therefore, the efficiency of design studies is often more dependent on the coordination programs and their data interchange requirements than on the processing speed of the computer. CIEM (computer integrated engineering and manufacturing system) was organized to realize a common need to integrate many standalone engineering analysis programs into a coordinated efficient design system. In order to integrate many programs, such as CAD/CAM, aeronautical and structural programs, a central database is used for data communication to all separated programs. To extract shareable information among programs, a data exchange specification was defined. By means of the specification, some support tools and automated procedures are developed to aid the database design process. These utilities are used to construct a data dictionary and database schema, generate the subroutines to read from or write to the database, and incorporate the analysis into the database.

An Analytical and Empirical Comparison of End-User Logical Database Design Methods

The current trend toward increasing database applications and end-user computing brings about the need for effective training and support tools that enable end users to perform logical database designs. This paper presents a unique comparison of a network-based data model (the extended entity relationship (EER)) and a hierarchical-based data model (the structured object model (SOM)) and their associated logical database design methods, LRDM (EER-based) and the SOM method, in end-user logical database design. The SOM method, based on an object-oriented knowledge representation scheme, is a new structured method designed to be less susceptible to designer errors and yet capable of maintaining ease of understanding and use. The Logical Relational Design Methodology (LRDM), based on the EER model, shares some common characteristics with the SOM method. In the analytic comparison the basic components and constructs of EER and SOM, as well as their use in the logical design process, are compared to derive a qualitative assessment of the two methods. Two experiments using novice database designers were conducted to examine the effectiveness of each method in leading to accurate logical designs, the time needed for task completion and the improvement in performance over a short training period. To confirm the findings from other studies on logical database design using non-graphic methods versus using graphic methods, the normalization method was included in one of the experiments. The results showed that end users performed better with graphic methods and also preferred them to the non-graphic (normalization) method. Furthermore, users learned and improved in a short period using LRDM (EER-based). However, users of the SOM method generated more accurate designs, were able to identify more complex relationships, and had more significant improvements during the training period than did users of LRDM (EER-based).

Information system analysis and conceptual database design in production environments with M ∗

A methodology, called M ∗, for information system analysis and database design of production environments is presented in detail. The originality of M ∗ is to recognize the importance of integrating factory analysis methods for data and user requirements definition with logical database design methods for database specification. M ∗ is a pragmatic, complete, manual methodology involving three major phases: Enterprise Modelling and Analysis which is the phase devoted to accurate analysis of the structure of the enterprise and precise definition of the scope of the future database application; Conceptual Design which is the phase concerned with data modelling of both static and dynamic properties of the enterprise; and Implementation Design which is the phase dealing with adaptation of the conceptual schema to the data model specifications of the physical database system used for application development and tuning performances of the physical system. The methodology is explained and illustrated by means of an example related to a Flexible Manufacturing System for mechanical parts.

An unnormalized relational data model based on user views

A description of a database design method according to user views is introduced. The database schema is decomposed by applying the operators: horizontal decomposition, vertical decomposition and derived horizontal decomposition. Resulting fragments (= effects of the decomposition) are controlled by a central Data Dictionary, consisting of two subschemata, the Application Subschema and the Data Subschema.

Hierarchical schemata for relational databases

Most database design methods for the relational model produce a flat database, that is, a family of relations with no explicit interrelational connections. The user of a flat database is likely to be unaware of certain interrelational semantics. In contrast, the entity-relationship model provides schema graphs as a description of the database, as well as for navigating the database. Nevertheless, the user of an entity-relationship database may still commit semantic errors, such as performing a lossy join. This paper proposes a nonflat, or hierarchical, view of relational databases. Relations are grouped together to form relation hierarchies in which lossless joins are explicitly shown whereas lossy joins are excluded. Relation hierarchies resemble the schema graphs in the entity-relationship model. An approach to the design of relation hierarchies is outlined in the context of data dependencies and relational decomposition. The approach consists of two steps; each is described as an algorithm. Algorithm DEC decomposes a given universal relation according to a given set of data dependencies and produces a set of nondecomposable relation schemes. This algorithm differs from its predecessors in that it produces no redundant relation schemes. Algorithm RH further structures the relation schemes produced by Algorithm DEC into a hierarchical schema. These algorithms can be useful software tools for database designers.