This study aimed to enhance the thermal performance of liquid-vapor two-phase heat transfer devices by observing and understanding the liquid-vapor phase displacement in the drainage process between a wall and a porous medium. To achieve this, vapor was injected into a saturated porous medium from a microhole located at the center of a transparent nonheated wall, driven by a pump. Three different working fluids, two different porous media, and various vapor flow rates were used to investigate the effects of the viscosity ratio of liquid to vapor, capillary number, and contact angle. Capillary number-viscosity ratio diagrams were created for each porous medium, and two-phase displacement patterns of capillary and viscous fingering were observed depending on the capillary number. The results indicated that the length of the three-phase contact line at the contact surface between the wall and porous medium was longer under conditions of a lower contact angle and higher viscosity ratio, which could enhance heat transfer with evaporation in porous media placed in a two-phase loop.
A systematic-study is conducted using an innovative technology for paper drying by applying ultrasound mechanism. The advantages include greater energy efficiency, lower drying time and temperature, improvement of the product quality, and it is considered a green technology. The effects of initial moisture content, thickness, and refining condition are studied for different types of pulps (hardwood and softwood) using 2(3) factorial design of experiments. Analysis of Variance show that in the range of the studied parameters, thickness has the maximum effect on ultrasonic drying time followed by the initial moisture content. In addition, using a linear regression model, a relationships for the total time of drying is provided. The results confirmed that ultrasonic drying is more efficient at higher moisture content and higher thickness of the sample. These results are related to the structural characteristic of the samples such as porosity, pore distribution, and surface roughness.
In this study, we improved the drying efficiency of inorganic sludge by adding resin emulsion to the sludge to change its properties to those suitable for drying. In the experiment, various types of resin emulsions were added to sludge as drying accelerator, and resin emulsions suitable for sludge drying were selected. In addition, drying demonstration test was conducted using a full-scale dryer by mixing the selected resin emulsion. As a result, it was clarified that the drying efficiency can be significantly improved by adding the resin emulsion even in a full-scale dryer.
We have proposed a progressive querying environment that enables the user to interact with the database by a sequence of partial queries, and to visualize both database queries and retrieval results in many different representations.In our approach, the user can query the database in the Virtual Reality (VR) space, and then switch to the logical space to continue the formulation of the query.This paper provides a formal definition and characterization of VR queries, describes what database operators are applicable under the different interaction paradigms, and investigates how VR queries can be transformed into other types of queries, so that they can be utilized as part of a progressive querying system.
Interface design can overwhelm the effects of better or worse database engines.Progressively more systems use graphical interfaces but as with any new technologically-driven medium it takes time for notions of 'good' design to form and disseminate.Nowhere is this more obvious than in the nascent field of 3D interfaces where -much as in the days of font overkill which followed the introduction of laserwriters -3D is often used for its own sake.This leads to designs that may initially be eye-catching but later turn out to be cluttered and difficult to work with.I will discuss some issues that make the design and evaluation of information visualisation systems complex such as numerical metrics for interface assessment, the use (and abuse) of metaphor, taking advantage of 3D perception, and shared information environments.This discussion will draw upon images and experiences from the Bead system in order to examine the discipline we are involved in: is it more craft than science?
Query languages for RDBMSs lack in intuitive understanding; this precludes inexperienced users from taking advantage of them. The adoption of a visual interface can simplify the query formulation process by enabling users to interact with a friendly environment. In this work we propose a visual query language based on a hybrid iconic-diagrammatic paradigm, used for both data and query representation. The external data model is called vision and comprises the visual primitives of concept - represented by the combination of text and icon, and association - represented by a name and a multiplicity for each possible orientation. The external query model is based on the definition of a user viewpoint, which is a perspective for accessing data defined dynamically by selecting a concept of primary interest for formulating each query.
This paper presents a survey of query languages dedicated to Geographic Information Systems (GIS).Five categories of query languages can be identified : (1) natural languages, (2) extensions of SQL, (3) tabular languages : use of skeletons or forms, (4) graphical languages : use of symbols, which are only graphical conventions (like in the entity-relationship diagrams) and ( 5) visual languages : use of visual metaphors (e.g., icons, blackboard metaphor and map-overlay metaphor).The principles of each of them are presented.Respective strengths and weaknesses are pointed out, based on a set of predefined queries.The main objective of this paper is to present the state of the art of research work in a domain which is suitable for graphical querying.The last part of this paper describes hypermedia techniques.
As the wealth of information in molecular biology continues to grow there is a pressing need for powerful graphical tools to aid in the comprehension of this mass of data. This paper discusses a number of such tools that have been developed at EMBL that aim to provide data visualisation and graphical interface environments so that the molecular biologist can perform analysis of biological information more easily. A number of scientific disciplines that were once distinct from computer science are now inextricably interwoven with it such as molecular modeling, computational chemistry, astrophysics, and fluid dynamics. These are disciplines for which visualization is not simply a tool, but an enabling technology. [Computer Graphics World, July, 1989]
Data modelling is a crucial and early step in the design of all but the most trivial database systems.Although a fundamental skill for information systems designers, data modelling is not easy to do well and novices are known to have considerable difficulty a) in generating a satisfactory model from a given scenario and b) in appreciating the semantic nuances of a given model from its diagrammatic representation.Given a candidate model, novices typically find it difficult to envisage whether a set of specified query types can be met and what the implications of the model are for storage and access.One of the main differences between novice and expert performance is held to be this capacity to visualise the implications of a model from its diagrammatic representation.These two skills, generation and evaluation, are closely inter-linked: clearly, some competence in the second is necessary for self-monitoring during the model generation process; however, a high degree of facility is required if data modelling is to be truly a design process and not just a mechanistic activity whereby the model is derived from the scenario by simple transformation.The concept of data modelling as design, as a creative process, has been under-emphasised thus far in the pedagogic literature.We aim to broaden the prevalent convergent style of introductory texts (which tend to concentrate students towards the specimen 'correct' solution), by promoting a more divergent approach, namely, that there is likely to be a set of feasible solutions, candidate solutions will have advantages and disadvantages and creative solutions may involve a re-conceptualisation of the scenario.To promote these ideas in teaching, supporting tools are needed.While there are a number of software packages existing to help with the graphical aspects of model creation (modelling tools), there is a dearth of software offering modellers an environment in which they can create a model or partial model and then interact with it better to understand its 'behaviour'.This paper explains the rationale behind and work-in-progress on a concept-demonstrator TOTEM (TOol for TEaching Modelling) which owes much to the new generation of programming environments such as Visual Basic and Delphi.TOTEM is conceived as a Windows-based rapid 'design and test' environment for extended Entity-Relationship modelling that supports interaction with multiple candidate solutions, any of which can be explored with test data.We report a video study to assess the usability of design mode in single user, single model conditions and present the main ideas behind the next planned phase of work.
The importance of designing query systems which are effective and easy to use has been widely recognized i n the database area.Also, it is well known that the adequacy of a system should be tested against actual users i n a well monitored experiment.However, very few such experiments have been conducted.The objective of our study is to measure and understand the comparative ease with which subjects can construct queries in two kinds of visual languages, one diagrammatic and the other iconic.More specifically, we are interested i n determining if there is significant interaction between: 1) the query class and the query language type; and 2) the type of query language and the experience of the user.Experimental results indicate that the effectiveness of a diagrammatic or an iconic query language varies depending on the classes of queries and the kinds of users.This supports the opinion that an interface offering to the user various visual representations and query modalities is the most appropriate for a wide set of users and applications.
This paper describes a runtime user-interface development environment (UIDE) for the novel capability of interactively using and specifying user-interfaces to object-oriented databases (IDSs). A framework provides the foundation for IDSs constructed. This concerns interpreting an IDS, specified in a conceptual object-oriented data language, using a persistent meta model. A generic environment model facilitates dynamic integration of existing user-interface widgets into the meta model. This achieves the goal of providing a database representation independent visual environment (DRIVE). The architecture and use of DRIVE are described and the benefits of this approach are discussed.
In this paper, we discuss the potential for the application of the popular and well-known desktop metaphor to object-oriented databases (OODBs).We describe an initial prototype, the Oggetto Desktop, which supports browsing of both the type and structural lattices of an OODB and direct manipulation for accomplishing schema evolution.
With the Lyberworld system a new approach offering the user a convenient interface to the data stored within an information retrieval system has been introduced. Accessing database contents by using the visualisation metaphors search tree and relevance sphere has achieved two main benefits: first, the user can construct and pose queries much easier than using a query language and second, query results are presented in a way which in opposition to, e.g., tabular output displays the relations between the different queries and query results. In our most recent research work we are aiming at integrating the visualisation concepts of Lyberworld with the object oriented database system VODAK, a powerful tool to implement database applications which require a complex database schema. Posing queries against such a database is a complex task which requires profound knowledge of the database schema and a query language. The approach presented within this paper integrates the Lyberworld concepts with the requirements for a visual interface to the VODAK database system. Furthermore, it develops Lyberworld towards a system which integrates and visualises data from various heterogeneous data sources.
The user of a DBMS has a collection of schemas, programs, methods, etc... stored in different locations, all over her computer. At the moment no DBMS offers appropriate tools to manage these collections. In this paper, we propose a graph-based data dictionary for graph-based database models and languages. This data dictionary can be used as basis for tools that assists the user in searching large amounts of meta-information. Some example tools are proposed. Two types of aggregation are investigated as mechanisms to make the query graphs more compact. The first is based on the aggregation found in the entity-relationship model, the second uses the fact that the data-dictionary describes graphs.
This paper presents some experiences in the exploitation of a database interface development architecture in which the interface is implemented using the facilities of the database. It is shown how novel interfaces, specifically a multiparadigm query interface and a debugger for an active rule system, can benefit from and exploit the uniform representation of interface and database system concepts as database objects.
Over the past several years, a number of wide-area information navigation and discovery tools have been introduced, including WAIS[1], Gopher[2], World-Wide Web[3], etc. In this paper, we describe a graphical query interface to remote bibliographic databases that can be found on the internet. A library query client, called LibSearch, has been designed and implemented using a set of APIs based on Z39.50 protocol standard[4]. Z39.50 is an application-layer protocol within the OSI reference model designed to allow library users to remotely access the bibliographic records in the library systems. As increasing number of OPAC systems are being established as Z39.50 servers on the internet, Libsearch provides a user-friendly environment to specify search requests and retrieve bibliographic information from these servers. LibSearch supports: (1) the use of window icons to enable users to easily carry out their search activities, (2) remote accesses to diverse library catalogue systems through a simple and uniform interface, (3) the browsing of search results and storing them in files, and (4) simple user customization.
Many approaches have been used for querying spatial databases, but they rarely distinguish between expert users and "naive" ones.Two main approaches can be considered as interesting ways of querying and interacting with spatial and multimedia data, extended query languages on the one hand, and hypermedia techniques on the other hand.In this paper, we propose a framework for a navigational user interface model that will use both hypermedia and query language approaches.Navigation methods will use two types of links, explicit hypermedia links on the one hand, implicit and dynamic ones on the other hand which are based on spatial relationships between entities.We also propose different kinds of navigation strategies that will be usable and hopefully accepted by general public-like users.
One of the strangest paradoxes of the silicon era is the dichotomy between ’enjoyable’ recreational computer activities and ’mundane’ work-based computer operations. How can an activity as pointless as a computer game have so much appeal? The answer to this lies in the user interface, and not the functionality, of the program. Computer games rely heavily on an interface which is natural and enjoyable to use. We believe that an interface should appeal to the user, and to do so must capture the user's interest and imagination. To this end, we have been using high performance graphics to generate meaningful three dimensional representations for our graphical user interface. We propose new metaphors for both query construction and result representation.
Many proposals have been made for database interfaces which support a wide range of tasks in a variety of different ways using a wide selection of visual or textual languages. In this context of widespread experimentation, it is important that the proposals be effectively evaluated. If they are not, then flawed approaches could become widely accepted, good ideas could be let down by inappropriate implementations, or novel techniques overlooked in the absence of suitable supporting evidence. This paper summarises our experience using several different evaluation techniques in the context of a multi-paradigm query interface and a browser which supports visualisations of advanced data modelling constructs. It is shown how different evaluation techniques are suitable for evaluating different aspects of database interface functionality, and that different techniques yield different kinds of information on the usability of an interface.
