Identify Design Requirements Research Articles

A DEMATEL method in identifying design requirements for mobile environments: students’ perspectives

The understanding of the design of mobile phones is somewhat different from other devices and products. This is properly due to the limited design capacity of mobile phones which need to be maintained within a small screen. One aspect for consideration is the relationship between certain design elements and users’ usage behavior and perception of the device. This study examined the feasibility of multiple-criteria decision making, known as the decision-making trial evaluation laboratory (DEMATEL), for identifying the key design patterns necessary for promoting users use of mobile devices. Precisely, we studied users’ direct, indirect, and interdependent behaviors in relation to seven mobile design patterns, including dealing with data, providing input, navigation, notification, personalization, screen interaction, and social activity. A DEMATEL model was generated for 75 students using these dimensions. The results showed that patterns corresponding to users’ interactions with the screen, dealing with data, and navigation were the core factors that can potentially aid the design of mobile environments. Our findings can be used by educational designers of mobile applications to form better design scenarios that are closely connected to a specific task and setting.

Design of an Open-Source Binary Micromultileaf Collimator for a Small Animal Microradiotherapy System

Intensity modulated radiation therapy (IMRT) is performed on a regular basis in the clinic to create complex radiation fields to treat cancer, but it has not been implemented in microradiotherapy (mRT) for preclinical systems. A multileaf collimator (MLC) is an integral part of a radiotherapy system that allows IMRT application. Presented here is the development of a key component of an open source mRT system for preclinical research. We have designed and fabricated a binary micro multileaf collimator (bmMLC) for mRT that can provide 1 mm or better resolution at isocenter and attenuate over 98% of a 250 kVp X-ray beam. This is the smallest collimator system designed for RT systems, with 20 brass leaves, each 0.5 mm thick, creating a physical field opening of 1 cm × 1 cm. The mode of actuation for the leaves was rotational, rather than linear, which is typical in larger clinical RT systems. The design presented here met the identified design requirements and represents a rigorous design process, during which several less successful designs were investigated and eventually discarded. After the fabrication of the design, dosimetric characteristics were tested and requirements were met. The final bmMLC designs and technical documents are made available as open-source.

Performance of Equipment and Means of Internal Transport and Efficiency of Implementation of Warehouse Processes

In the article was presented the issue of performance of equipment and means of internal transport and its impact on the implementation of warehouse processes. In this aspect was presented the role of warehouse in the supply chain and its importance in the effective flow of material goods. Been identified design requirements for warehouse facilities and the issues of efficiency of functioning of warehouses in terms of implementation of warehouse processes. Was presented a procedure for selection of equipment and means of internal transport, as a function of realized warehouse processes and were made characteristics of performance parameters of equipment and loading machines. In the last stage of this research is presented a case study concerning the examination of dependence of the impact of the value of the correction coefficients on the number of means of internal transport in the zone of admissions and the value of efficiency ratio of exploitation at a given supply structure.

Using a contextualized sensemaking model for interaction design: A case study of tumor contouring

Sensemaking theories help designers understand the cognitive processes of a user when he/she performs a complicated task. This paper introduces a two-step approach of incorporating sensemaking support within the design of health information systems by: (1) modeling the sensemaking process of physicians while performing a task, and (2) identifying software interaction design requirements that support sensemaking based on this model. The two-step approach is presented based on a case study of the tumor contouring clinical task for radiotherapy planning. In the first step of the approach, a contextualized sensemaking model was developed to describe the sensemaking process based on the goal, the workflow and the context of the task. In the second step, based on a research software prototype, an experiment was conducted where three contouring tasks were performed by eight physicians respectively. Four types of navigation interactions and five types of interaction sequence patterns were identified by analyzing the gathered interaction log data from those twenty-four cases. Further in-depth study on each of the navigation interactions and interaction sequence patterns in relation to the contextualized sensemaking model revealed five main areas for design improvements to increase sensemaking support. Outcomes of the case study indicate that the proposed two-step approach was beneficial for gaining a deeper understanding of the sensemaking process during the task, as well as for identifying design requirements for better sensemaking support.

An additive manufacturing process model for product family design

ABSTRACTAdditive manufacturing (AM) is projected to have a profound impact on mass customisation. In order to benefit from this new technology, we need to incorporate AM into design processes. This paper addresses that need by introducing an AM process model for product family design. The proposed model reflects the ability of AM to produce customised and complex parts without tooling efforts. By utilising AM, we eliminate all constraints which arise in conventional product family designs from finding a compromise between commonality and performance. The proposed model starts by identifying design requirements and constraints. Subsequently, we use topology optimisation to determine an optimal design for each product. Next, finite element analysis and cost analysis are performed. We combine the analysis results in one three-dimensional plot, which displays the merits of the individual component realisations. Thus, a fair and competitive component evaluation is possible and the most suitable product family design can be selected. The final designs are fabricated using fused desposition modelling. A case study is conducted to illustrate how the proposed model facilitates the benefits of AM. The results show that the proposed model has the potential to provide affordable customisation.

INTEGRATED DESIGN APPROACH FOR BUILDING MAINTENANCE ISSUES

Maintenance and repair is a principal task in building operation in terms of time spent and cost. Therefore, improving maintenance performance can result in remarkable operational benefits. Traditionally, maintainability is not fully considered when designing a building, whereas many decisions to influence building maintenance are taken in design phase. Because of this, there is a need for a new approach to handle design and maintainability as a whole. Integrating design with maintenance eliminates design oriented maintenance issues and promotes knowledge transfer between designers and facility managers. This paper aims to identify design requirements for maintainability and present possible acquisitions of maintenance integration in design. Design parameters which are important for maintainability of a facility management are considered as accessibility, flexibility, standardization, modularization and selection of materials and equipment. Designers should give more attention to these parameters in order to create more valuable buildings for the users and to prolong the life cycle of the facility. A facility manager’s involvement in design steps would also improve maintainability of the building because of the specific technical details that a designer cannot fully designate. With a collaborative, new design approach considering maintainability, buildings profitability would be enhanced with less cost, time and labor.

Rotor Design for Diffuser Augmented Wind Turbines

Diffuser augmented wind turbines (DAWTs) can increase mass flow through the rotor substantially, but have often failed to fulfill expectations. We address high-performance diffusers, and investigate the design requirements for a DAWT rotor to efficiently convert the available energy to shaft energy. Several factors can induce wake stall scenarios causing significant energy loss. The causality between these stall mechanisms and earlier DAWT failures is discussed. First, a swirled actuator disk CFD code is validated through comparison with results from a far wake swirl corrected blade-element momentum (BEM) model, and horizontal-axis wind turbine (HAWT) reference results. Then, power efficiency versus thrust is computed with the swirled actuator disk (AD) code for low and high values of tip-speed ratios (TSR), for different centerbodies, and for different spanwise rotor thrust loading distributions. Three different configurations are studied: The bare propeller HAWT, the classical DAWT, and the high-performance multi-element DAWT. In total nearly 400 high-resolution AD runs are generated. These results are presented and discussed. It is concluded that dedicated DAWT rotors can successfully convert the available energy to shaft energy, provided the identified design requirements for swirl and axial loading distributions are satisfied.

DFA concepts applied in development of accessories for calibration

The purpose of this paper is to identify design requirements of a device to be used as an accessory in calibration. In this case study, a simple device to sample atmosphere from humidity generators used to calibrate air humidity meters is developed and it is proposed a model applying Design for Assembly concepts.

Field Trials Testing of a Mixed Potential Electrochemical Hydrogen Safety Sensor at a Commercial Hydrogen Filling Station

Hydrogen sensors are recognized as an important to critical component in the safety design for any hydrogen system. In this role, sensors can perform several important functions including indication of unintended hydrogen releases, activation of mitigation strategies to preclude the development of dangerous situations, activation of alarm systems and communications to first responders, and may even be called upon to autonomously initiate a system shutdown. The hydrogen sensors may be used is such a manner that they operate separate from the system being monitored, thereby providing an independent safety component that is not affected by the system itself. The importance of hydrogen sensors has been recognized by the DOE Safety and Codes Standards sub-program within the Fuel Cell Technologies Office and has for the past several years supported hydrogen safety sensor research and development. Since 2008, Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL) have been developing durable, high temperature electrochemical sensors based on zirconia oxygen ion-conducting solid electrolytes1 because, among the various modalities in hydrogen sensing, electrochemical solid-state sensors can be produced at low cost as evidenced by the widely used oxygen exhaust gas sensor. Also, solid-state electrochemical technology is well suited for meeting the most stringent requirements including operation over a wide temperature range, fast response times, and reliability under variations in humidity2-4. In 2013, several packaged prototype mixed-potential hydrogen safety sensors together with control electronics (designed and built by Custom Sensor Solutions, Inc. Oro Valley AZ) were tested in validation and verification experiments at the National Renewable Energy Laboratory (NREL) Hydrogen Sensor Test Laboratory5. This preliminary testing not only provided an independent evaluation and feedback for the performance of the sensor6, but also identified design requirements for the rest of sensing system that would be required to move forward with deployment in a field trials testing environment. Recently, we have started to test electrochemical, mixed-potential hydrogen sensor technology at a California commercial fuel cell vehicle hydrogen filling station. In the first field trials experiment, data were collected over a month time period during two modes of station operation: a) station hydrogen supplied by a hydrogen tube trailer and b) hydrogen generated on-site from a methane reformer. The sensor unit – comprised of a heater control board and commercial wireless transmitter inside of a NEMA-8 enclosure – was located inside the dispensing island at the City of Burbank Hydrogen Filling Station (Burbank CA). The inside of the dispensing island enclosure location was selected because it was in an area with least expectation of measuring a hydrogen exposure and because co-location with an existing commercial safety sensor was possible. The commercial sensor was one component of a larger safety system used to signal the authorities in case a customer ran into difficulties during refueling. Over the course of the testing, the mixed potential sensor was stable and showed no evidence of baseline drift and did not appear to be affected by over a month of unusually frequent and active weather systems that produced severe at times. The stable operation and lack of influence to temperature and humidity changes agreed well with earlier testing results from NREL. During the first field trials experiment, the mixed-potential sensor reported numerous hydrogen releases with some as high as 14% of LFL and these events correlated well to activities when customers resupplied their fuel cell vehicles. During periods that the station was supplied using hydrogen from the reformer, elevated levels of hydrogen (200-400 ppm) showed oscillations with regular periodicity over a 280hr experiment well within the 600hr reformer duty cycle. Releases up to 20% of LFL were reported from the mixed potential-based sensor system during this phase of station operation and these releases were attributed to the reformer and onsite compressor usage. In this presentation, we will present the first field trails results and discuss expansion of this work to include logging multiple mixed-potential sensors at distributed locations within the filling.

More than meets the eye: Using cognitive work analysis to identify design requirements for future rail level crossing systems

An increasing intensity of operations means that the longstanding safety issue of rail level crossings is likely to become worse in the transport systems of the future. It has been suggested that the failure to prevent collisions may be, in part, due to a lack of systems thinking during design, crash analysis, and countermeasure development. This paper presents a systems analysis of current active rail level crossing systems in Victoria, Australia that was undertaken to identify design requirements to improve safety in future rail level crossing environments. Cognitive work analysis was used to analyse rail level crossing systems using data derived from a range of activities. Overall the analysis identified a range of instances where modification or redesign in line with systems thinking could potentially improve behaviour and safety. A notable finding is that there are opportunities for redesign outside of the physical rail level crossing infrastructure, including improved data systems, in-vehicle warnings and modifications to design processes, standards and guidelines. The implications for future rail level crossing systems are discussed.

Patient engagement in the inpatient setting: a systematic review.

To systematically review existing literature regarding patient engagement technologies used in the inpatient setting. PubMed, Association for Computing Machinery (ACM) Digital Library, Institute of Electrical and Electronics Engineers (IEEE) Xplore, and Cochrane databases were searched for studies that discussed patient engagement ('self-efficacy', 'patient empowerment', 'patient activation', or 'patient engagement'), (2) involved health information technology ('technology', 'games', 'electronic health record', 'electronic medical record', or 'personal health record'), and (3) took place in the inpatient setting ('inpatient' or 'hospital'). Only English language studies were reviewed. 17 articles were identified describing the topic of inpatient patient engagement. A few articles identified design requirements for inpatient engagement technology. The remainder described interventions, which we grouped into five categories: entertainment, generic health information delivery, patient-specific information delivery, advanced communication tools, and personalized decision support. Examination of the current literature shows there are considerable gaps in knowledge regarding patient engagement in the hospital setting and inconsistent use of terminology regarding patient engagement overall. Research on inpatient engagement technologies has been limited, especially concerning the impact on health outcomes and cost-effectiveness.

Functional bracing of ACL injuries: current state and future directions

Functional braces are commonly prescribed to treat anterior cruciate ligament (ACL) injury. The results of the existing literature on functional brace use are mixed. The purpose of this study was to evaluate the history and current state of functional ACL bracing and to identify design criteria that could improve upon current bracing technologies. A literature search was performed through the PubMed MEDLINE database in April 2013 for the keywords "anterior cruciate ligament" and "brace". Articles published between January 1, 1980, and April 4, 2013, were retrieved and reviewed. Current functional braces used to treat ACL injury were identified. The function of the native ACL was carefully studied to identify design requirements that could improve upon current bracing technologies. Biomechanical evaluations of functional brace effects at time zero have been mixed. Functional brace use reportedly does not improve long-term patient outcomes following ACL reconstruction, but has been shown to reduce subsequent injury rates while skiing in both ACL-deficient and reconstructed skiers. In situ force in the ACL varies with flexion angle and activity. Currently, no brace has been designed and validated to replicate the force-flexion behavior of the native ACL. Biomechanical and clinical evidence suggests current functional bracing technologies do not sufficiently restore normal biomechanics to the ACL-deficient knee, protect the reconstructed ACL, and improve long-term patient outcomes. Further research into a functional brace designed to apply forces to the knee joint similar in magnitude to the native ACL should be pursued. III.

Designing a practical and rigorous framework for comprehensive evaluation and prioritisation of environmental projects

Context A framework was developed to help investors improve the delivery of environmental benefits from environmental programs. The framework, Investment Framework for Environmental Resources (INFFER), assists environmental managers to design projects, select delivery mechanisms and rank competing projects on the basis of benefits and costs. Aims To identify design requirements for an environmental investment framework on the basis of consideration of lessons from practical experience, and established theory from decision analysis and economics. Methods The design and delivery of the framework are based on extensive experience from working with environmental managers and policy makers. In addition, the developers have paid close attention to the need for processes that are theoretically rigorous, resulting in a tool that allows valid comparison of projects for different asset types, of different scales and durations. Key results From the practical experience outlined, several important lessons and implications are identified, including the need for simplicity, training and support of users, trusting relationships with users, transparency, flexibility, compatibility with the needs and contexts of users, and supportive institutional arrangements. Use of a theoretically correct metric to rank projects can deliver dramatically improved environmental values relative to a commonly used weighted additive metric. Conclusions Practical and theoretical considerations have strong implications for the design of a practical, effective and accurate tool to support decision making about environmental project priorities.

Supporting End User Development in Community Computing: Requirements, Opportunities, and Challenges

End user development (EUD) tools in community computing are not well-developed and typically do not take into consideration the unique characteristics of community groups such as lack of human, financial, and technological resources. Using a case study, we explore EUD in the domain of community computing. Situated in community computing context, we identify design requirements of EUD tools, demonstrate the use of conceptual scaffolds to support EUD, and illustrate the need of new evaluation methods of EUD tools. We discuss the tension between pushing EUD tools to community computing for local autonomy on technology issues and the long time practice of seeking and relying on external technical expertise. We call for research studies that address the tension and explore ways of creating and stimulating “pull” force from the community groups.

A study of argumentation-based negotiation in collaborative design

AbstractEngineering of complex systems often involves teamwork. The members of an engineering team must work together to identify design requirements, explore design spaces, generate design alternatives, and make both interactive and joint design decisions. Because of the latency of information and the disciplinary differences, it is often a difficult process for the members of a team to reach agreements when needed. Negotiation has been studied as a method for facilitating information exchange, mutual understanding, and joint decision making. An argumentation-based negotiation approach was previously proposed by the authors to support collaborative engineering design. In this paper, we present an experiment study that was conducted to evaluate the impact of this negotiation support approach on the process and the outcome of collaborative design. The results of the experiment show both positive effects and limitations of the approach.

A Microworld Approach to Identifying Issues of Human-Automation Systems Design for Supporting Operator's Situation Awareness

This article gives a microworld approach to identify design requirements for better situation awareness. Two experiments were designed and conducted. In the first experiment, behaviors of operators who lost situation awareness were analyzed, and the following two findings were obtained: (a) Automation must provide an operator with feedback information on the control mode, even when it is the operator who changed a control mode. (b) Authority for control may have to be passed from an operator to automation for attaining safety in highly urgent situations. The second experiment was done to investigate how human-interface may affect an operator's situation awareness. It is shown that human-interface must be carefully designed to externalize a mental model of the controlled process.

Development of transportable wheelchair design criteria using computer crash simulation.

The Americans with Disabilities Act (ADA) has led to an increase in disabled travelers, many of whom are unable to transfer to a vehicle seat and are required to use their wheelchair to fulfill this function. ANSI/RESNA is currently developing a transportable wheelchair standard which will identify design requirements and testing methods for wheelchairs suitable for transport. Wheelchair manufacturers should begin to modify their existing design criteria established for a normal mobility function to design criteria appropriate for a transportation function which may subject the wheelchair to large dynamic crash forces. A thorough understanding of the crash environment and its effect on the wheelchair is necessary to insure the safety of the wheelchair user. To assist manufacturers in the design effort, this study uses mathematical crash simulations to evaluate loads imposed upon a wheelchair when subjected to a 48 kph/20 g frontal crash. Using a four-point belt tiedown system to secure the wheelchair, securement point, seat, lap belt anchor, and wheel loads are evaluated under three different securement configurations. Results show that positioning of rear securement points near the wheelchair center of gravity can serve as an effective strategy for managing crash response and loadings on the wheelchair. Force ranges for each of the evaluated parameters, derived for a 50th percentile male using a simulated power wheelchair, are provided for use as a preliminary guide when designing transportable wheelchairs.

Radiation Protection Design Considerations for Man in Geosynchronous Orbits

A description is presented of preliminary studies which have been carried out to identify design requirements and mission constraints imposed by the geosynchronous radiation environment. The radiation species of dominant impact are the trapped electrons and solar flare particles. The criterion used in the conducted shielding design analysis has been to limit the skin dose to 100 rems for 3 months. The analysis included the optimization of an electron/bremsstrahlung shield for residence within the vehicle, the minimization of the dose received in extravehicular activity, and the calculation of special shield requirements for solar flares. An investigation was conducted of the potential benefits accruing from a three-layered composite shield with part of the aluminum layer replaced with a lower atomic number material. The materials considered were polyethylene, carbon, beryllium, and lithium hydride.

Service Structure Concepts for Post-Saturn Rockets

Future vehicles of the post-Saturn class will be much larger and heavier than the rockets presently in use, thus imposing critical new requirements on the facilities for these vehicles. A typical post-Saturn vehicle and a proposed complex at Kennedy Space Center, to provide for all prelaunch and operations associated with this vehicle, are described herein. One of the most important elements of the complex is the service structure. The unusual design requirements for a service structure capable of supporting a post-Saturn type vehicle are identified, including the requirement that the vehicle be launched directly from the building. These service structures are therefore referred to as launch buildings. A number of candidate building configurations meeting the identified design requirements are described, their features examined and a comparison made between candidates on the basis of cost and operational advantage. The optimum configuration is identified and described.