User's Viewpoint Research Articles

Limit strains in the sheet metals by using the new Hill's yield criterion (1993)

Information upon the formability of thin metal sheets is important for both sheet manufacturers and users. From the producer's point of view, the most significant is the knowledge of the characteristics of the metal sheet correlated to its formability and ability to influence the manufactured process, being able to produce semi-products with previously established properties. From the user's view-point, it is of importance to be able to select the semi-product that allows him to obtain finished products of definite size and shape at the lowest price possible. More procedures have evolved with time for evaluating metal sheet formability. Some of them are based upon simulative tests, others on mechanical tests. A more realistic and general method has been introduced recently, this being the Forming Limit Diagram (FLD). The present paper presents a new approach to FLD modelling. The yield criterion proposed recently by Hill [R. Hill, Int. J. Mech. Sci. 35 (1993) 19] is used for the calculation of the limit strains in connection with the Swift's instability condition for diffuse necking.

The Forgotten Voice: Probation Service Users and Partnerships

Throughout the 1990s this journal has featured articles discussing themes and issues related to probation partnerships with the voluntary sector. A missing element and valid perspective in these articles has been the viewpoint of the service user. In seeking to remedy this omission the author draws on her PhD research, which included interviews with 15 probation service users attending partnership projects. An overview of the users'experiences and feelings about being involved in partnerships is provided, as well as a discussion of the key issues which influence the way partnership is both constructed and implemented in relation to service provision for such users.

Radiance interpolants for accelerated bounded-error ray tracing

Ray tracers, which sample radiance, are usually regarded as offline rendering algorithms that are too slow for interactive use. In this article we present a system that exploits object-space, ray-space, image-space, and temporal coherence to accelerate ray tracing. Our system uses per-surface interpolants to approximate radiance both interactive and batch ray tracers. Our approach explicity decouples the two primary operations of a ray tracer—shading and visibility determination—and accelerates each of them independently. Shading is accelerated by quadrilinearily interpolating lazily acquired radiance samples. Interpolation error does not exceed a user-specified bound, allowing the user to control performance/quality tradeoffs. Error is bounded by adaptive sampling at discontinuities and radiance nonlinearities. Visibility determination at pixels is accelerated by reprojecting interpolants as the user's viewpoint changes. A fast scan-line alogoithm then achieves high performance without sacrificing image quality. For a smoothly varying viewpoint, the combination of lazy interpolants and projection substantially accelerates the ray tracer. Additionally, an efficient cache management algorithm keeps the memory footprint of the system small with negilgible overhead.

Using digital libraries as a community hall for worldwide information spiral development

Our concept of a digital library from a user's viewpoint is explained by using a three-layer model of information distribution: information provider, information broker, and information user. Our worldwide communication-hall prototype consists of the virtual personal library client, called Webshelf, an information publishing server, and a hypermedia archive server, Webarchive. It allows users to virtually personalize information on the Web, organize it, create new information, and publish this new information. Webarchive offers an effective solution to the information volatility problem by storing all of the information obtained by users and managing link consistency. © 1999 Scripta Technica, Syst Comp Jpn, 30(1): 1–12, 1999

SCHEMA: A Knowledge Edition Interface for Obtaining Program Code from Structured Descriptions of PSMs: Two Case Studies

The basic conjecture in this paper is that besides the basic libraries of tasks and problem-solving methods (PSMs), it is necessary to develop two complementary twin libraries. One of them consists of knowledge-acquisition schemas, as they are required by PSMs, and the other one contains those PSMs‘ reduction methods, from the knowledge level to the symbol level. In order to support this conjecture, we first describe the reduction method fundamentals based on hierarchical graphs representing the underlying computational model. Then we shall comment on the development of the SCHEMA interfaces by using this interface, we can directly obtain the program code, provided the task knowledge, PSM, and application domain are edited following the knowledge acquisition schemas by means of structured natural language sentences. This kind of editing unmistakably and in reversibly establishes the relationships with the underlying model. Since the reduction method links the underlying model with the program code, the reduction process is completed. Conversely, we can retrieve the underlying model graph and the knowledge-level model from the program code because of the reversibility of the reduction method. In order to make clear the reduction method and SCHEMA interface functioning from the user viewpoint, we shall apply them to a classification and diagnose generic task (Hierarchical Classification), which will be decomposed by using the “Establish and Define” PSM, and another task to carry out a plan, which will be decomposed by using the “act-check-decide” PSM. We shall finish this paper with a reflection on the knowledge-level modelling and the necessity of an increase of the available reduction methods and knowledge acquisition schemas which are included in our SCHEMA interface.

Conceptual clustering in information retrieval

Clustering is used in information retrieval systems to enhance the efficiency and effectiveness of the retrieval process. Clustering is achieved by partitioning the documents in a collection into classes such that documents that are associated with each other are assigned to the same cluster. This association is generally determined by examining the index term representation of documents or by capturing user feedback on queries on the system. In cluster-oriented systems, the retrieval process can be enhanced by employing characterization of clusters. In this paper, we present the techniques to develop clusters and cluster characterizations by employing user viewpoint. The user viewpoint is elicited through a structured interview based on a knowledge acquisition technique, namely personal construct theory. It is demonstrated that the application of personal construct theory results in a cluster representation that can be used during query as well as to assign new documents to the appropriate clusters.

User viewpoint modelling: understanding and representing user viewpoints during requirements definition

There has been increasing awareness of the impact of the early stages of systems development on the quality of information systems. A critical early activity is requirements definition, when the requirements for an information system are determined. Traditional requirements capture techniques do not support the collaborative nature of requirements definition or the emergent nature of requirements themselves. This paper focuses on viewpoint development as a means of resolving some of the difficulties of requirements definition. It proposes a user viewpoint model for capturing and representing the viewpoints of users during requirements acquisition. The model can facilitate communication and interaction between analysts and users and help build a shared understanding of requirements. It can be used to structure the requirements acquisition process. The model provides for evaluation of requirements acquisition techniques to guide the selection of appropriate techniques for developing user viewpoint models. The paper reports a multiple‐case study of requirements definition efforts that examined user viewpoint development in practice and used the cases to validate empirically the concepts of the user viewpoint model. The implications of the case study findings for requirements definition practice are discussed, and some areas for future research are identified.

Evaluation of the quality of public health care for children from the user's viewpoint

This paper presents results from research that used a qualitative approach to identify evaluation criteria from an user viewpoint, and tries also to evaluate the work of the Whole Care for Children's Health Program (WCCHP), which directs actions in the children care services at the basic level. Dates were obtained th partly structured interviewing at home with ten adults in charge of children registered in October 1992 at four units of the Barra-Rio Vermelho District. Through a simultaneous process of gathering and analyzing dates, using a content analysis technique it was possible to classify the results in five groups: "motivations" to look for the service; having expectations; "choosing" a health service; evaluating the service used; and suggesting improvements. The evaluation criteria found are closely related to: access; interpersonal relation; results; and continuing care, which possess different value degrees according to the motives for service need. The results of the evaluation show that the model of clinical assistance and the form organization of the services do not fulfill the objectives of PAISC, breeding access difficulties, and poor results on account of the lack of material resources, coordination and care continuity.

Use of a modified kalman filter for a visually coupled system application

Spatial tracking devices are frequently used in virtual environments, such as in the case of helmet mounted displays, to dynamically determine the user's viewpoint and line of sight. Temporal distortion effects are perceived by the user as a result of the lag between head movement and visual feedback. Measurements of phase lag have been made and to help alleviate these problems, predictive filtering techniques are frequently used. We report on studies that have been made in the use of a modified Kalman filter algorithm. The implementation provides favourable results in terms of reduction on the effect of phase lag.

Experimental comparison between automatic and manual menu interface design methods

An experimental comparison between two methods of designing a menu-tree interface for an information system is described. The ‘automatic’ method is based on the ADISSA methodology (architectural design of information systems based on structured analysis) according to which the interface is derived automatically from dataflow diagrams (DFD) as a by-product of the system analysis stage. In the ‘manual’ (‘conventional’) method the designer constructs an appropriate interface by applying common principles of interface design. The objective of the experiment is to find out which design method yields a better initial interface, before it is given to users for further improvements. The user's viewpoint is adopted i.e., the interface was evaluated subjectively. The hypothesis is that menutrees designed automatically are as good as those designed by people. The experiment included six information system development projects. One menu-tree interface was designed automatically for each system. Four others were designed manually by different designers who were assigned randomly to the systems. The five different interfaces of each system were given to 16 potential users for evaluation and comparison. Analysis of the results revealed no significant difference between the mean scores of the two types of interface. Noting that the automatic menus are obtained as a by-product of the system analysis stage, and that they can be improved by users during prototyping, it is concluded that the method provides a good start for the interface design.

シースルー型ＨＭＤにおける視覚パラメータの距離に関する較正法

For the purpose of coinciding the virtual environment displayed by See-Through Head-Mounted Display (STHMD) with the actual environment, a new calibration method is proposed. The method is for the calibration of the difference between supposed position and actual position of the user's viewpoint, which is mainly caused by the individual difference of inter-pupil distance. This method is efficient to minimize the error concerning distance. The efficiency is evaluated by sensitivity analysis of visual parameters. It is also confirmed by experiment in which visual parameters of STHMD are calibrated individually, and the calibrated virtual environment matched the actual environment.

Facilitating engineering analysis via a graphical database

The advent of Microsoft Windows and other graphical user interface (GUI) platforms has ushered in a host of "visual" applications that greatly simplify the task of data entry, as compared to conventional methods. This paper describes a unique Windows GUI application that enables an engineer to draw a one-line diagram, interactively enter bus end device parameters into dialog box fields, and then save this data to a power systems database. This innovative method of "visually" entering data into a power systems database is a significant addition to the one-line drawing capabilities of this application. In addition, the application makes extensive use of Windows features which enhance the robustness of the software from both the developer's and user's viewpoint.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

3D direct manipulation interface: Development of the Zashiki-Warashi system

We are researching a three-dimensional version of direct manipulation interface. In our prototype system “Zashiki-Warashi,” users can directly manipulate furniture and lighting to design a virtual room. In this paper, we will describe our goals for the prototype and our results. Zashiki-Warashi has three main features: 1. 1. Beam Cursor: This cursor emits a beam similar to that of a laser, with which users can easily select objects in a virtual world. 2. 2. Direct Manipulation of Environment: In Zashiki-Warashi, not only objects but also lighting and user's viewpoint can be manipulated directly. 3. 3. Gravity: In the gravitational environment of Zashiki-Warashi, solids fall naturally. Solids can be picked up, moved, and dropped in a realistic manner inside the virtual world.

An object‐oriented approach to dynamic service descriptions

AbstractThe former CCITT has defined a methodology, consisting of three stages, to evolve from a set of service descriptions to a protocol definition that supports these services. In the first stage, the service is described from a user's viewpoint. A part of this first stage consists of the descriptions of the dynamic behaviour of the service. The introduction of this paper elaborates on the interpretation of the ‘user's viewpoint’ of dynamic service descriptions. In the subsequent sections we introduce an object‐oriented approach to define a framework for the dynamic service descriptions. The flexible definition of services is facilitated by decomposing the service into a standard set of building blocks, referred to as service objects. A service object is the smallest service element that a user can independently reference and manipulate. By modelling in terms of service objects, we avoid the presumption that the total service consists of a specific number of parties or connections. The definition of a service mainly consists of imposing additional semantic rules on the way service objects can be manipulated within the context of that service. The complete system will thus consist of a servicespecific part and a generic part, i.e. a part which is common to all services. An overview of the system configuration and the behaviour of the generic part is illustrated by SDL Descriptions. Finally, we illustrate the method by describing a typical multiconnection multiparty service. The work presented within this paper is based on the results of the RACE MAGIC project.

A multilevel framework for the attribute description of telecommunication services

AbstractTelecommunication services are traditionally described from the terminal viewpoint, including the user interaction with the service, as well as the specific terminal characteristics to the network that it is meant for. Also traditionally the instance of the telecommunication service was a call and a connection as a one‐to‐one couple.Nowadays networks with powerful multimedia/multiconnection/multiparty capabilities require that a telecommunication service should not be described any more as a conglomerate, but by its main service elements, which in turn are supported by other service elements, so that a service may be built up by building blocks in a levelled model.The criteria to be considered to find these elements are the user viewpoint, the information coding (or terminal) viewpoint and the network access viewpoint. This leads to the telecommunication service, party, party edge, user service module and abstract service module as pure user‐dependent service elements, the service module for the terminal aspect, and the access connection element for transfer of the information over the network.All these basic service elements are ordered in a levelled structure called a multilevel framework. Each level or co‐level represents a service element type which may be instantiated as a service object, and which is described statically by a table of attributes. Attributes for each level are listed and clarified.An example describing a well‐known service is given to illustrate the use of the framework.The views expressed in this document have been developed by the RACE 2044 MAGIC.RACE: Research into Advanced Communication Technologies for Europe. MAGIC: Multi‐service Applications Governing Integrated Control. The concepts presented are related to Release 2 and 3 for BISDN as defined in ITU‐T.

The IBA Market Data Base—A User's Viewpoint

The IBA Market Data Base—A User's Viewpoint

Computer Networks and Advanced Communications: Weighing the Pros and Cons

Summary One main method for optimizing computer usage is networking. However, for those who are contemplating a change from standalone computers to a network system, investigation of actual networks in use presents a paradox: network systems can be highly productive and beneficial, but they can create many complex, frustrating problems. The issue becomes a question of whether the benefits of networking are worth the extra effort and cost. Here we review the implementation and management of an actual network in the Louisiana State U. (LSU) Petroleum Engineering Dept. The network, which has been in operation 4 years, is large and diverse (50 computers, 2 sites, PC's, UNIX RISC workstations, etc.). The benefits, costs, and method of operation of this network are described, and an effort is made to weigh these elements objectively from the viewpoint of the average computer user. Our intent is to provide those who may be considering the change to a network system with the benefit of experience gained in the actual operation of such a system.

Q-analysis of user-database interaction

This study jointly employed two research approaches in developing a process oriented methodology for studying information seeking during user-database interaction. A "time-line" structured interview technique was used to gather 26 novice-user accounts of search sessions on NEXIS. These accounts included a description of the search session, questions that occurred to users during this session, and indications on whether answers were obtained. A 17 category descriptive content analysis scheme was developed and Q-analysis was performed on the accounts as coded into this scheme. Results provide a rich description of the search process from the user's viewpoint. Searchers below the mean on a document relevance measure most frequently had questions after being in some way rebuffed by the system. Above mean searchers were also active questionners, but their questions were most frequently associated with string design rather than being rebuffed. The above mean group also rated their questions as less important than did the below mean group. In addition, above mean searchers were more active users of system help features and information provided onscreen in general.

Interfaces to hypermedia: Communicating the structure and interaction possibilities to the users

In this paper the hypermedia paradigm is discussed from the viewpoint of user interfaces. The problems of interacting with vast hypermedia structures are presented. First, the attention is drawn to the presentation of the information structures in multi and hypermedia application interfaces. Secondly, it is discussed how the user's interaction with these structures can be made more intuitive. Furthermore, it is pointed out how interaction through shared multimedia environments needs to be addressed. We claim that interface metaphors and additional information structures will provide a solution to these problems. Finally, our multimedia authoring tool ShareME and its first test environment for multimedia information acquisition is presented to illustrate how the suggested solutions are successfully applied.

Analysis and an Improvement of Transient Characteristics of Pole-Changing Induction Motor with Single Primary Winding.

Pole-changing is a simple method for changing the speed of a cage induction motor. However, excessive currents and torques appear during deceleration of the motor by pole-changing. These characteristics are unfavorable for shafts and couplings of the motor system. And further, these cause the sudden voltage drop of the supply. From user's viewpoint, it is desirable to control these currents and torques as low as possible.In order to decelerate the speed by pole-changing, first, the supply is removed from the delta connected high speed terminals. Next, the supply is connected to low speed terminals, and finally, the winding is changed to the parallel _??_ connection. From the simulation results, the authors discuss the effects of the supply removal period, impressed voltage phase and the period between the supply impression and the changing to the parallel _??_ on the motor. This discussion gives the conclusion that the transient current and torque can not sufficiently controlled even when the above conditions are appropriately selected.In order to reduce these transient current and torque sufficiently, this paper proposes a method in which external resistors are inserted in series with the three-phase primary winding. From the simulation results, it is found that the inserted resistance of 1.55 times the locked rotor impedance of the induction motor, can sufficiently reduce the excessive transients.