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Design Principles (design + principle)
Selected AbstractsRevealing the Design Principles of High-Performance Biological Composites Using Ab initio and Multiscale Simulations: The Example of Lobster CuticleADVANCED MATERIALS, Issue 4 2010Svetoslav Nikolov Natural materials are hierarchically structured nanocomposites. A bottom-up multiscale approach to model the mechanical response of the chitin-based mineralized cuticle material of Homarus americanus is presented, by combining quantum-mechanical ab initio calculations with hierarchical homogenization. The simulations show how the mechanical properties are transferred from the atomic scale through a sequence of specifically designed microstructures to realize optimal stiffness. [source] The Application of Design Principles to Innovate Clinical Care DeliveryJOURNAL FOR HEALTHCARE QUALITY, Issue 1 2009Michael D. Brennan Abstract: Clinical research centers that support hypothesis-driven investigation have long been a feature of academic medical centers but facilities in which clinical care delivery can be systematically assessed and evaluated have heretofore been nonexistent. The Institute of Medicine report "Crossing the Quality Chasm" identified six core attributes of an ideal care delivery system that in turn relied heavily on system redesign. Although manufacturing and service industries have leveraged modern design principles in new product development, healthcare has lagged behind. In this article, we describe a methodology utilized by our facility to study the clinical care delivery system that incorporates modern design principles. [source] Hemospan: Design Principles for a New Class of Oxygen TherapeuticARTIFICIAL ORGANS, Issue 2 2009Kim D. Vandegriff Abstract Hemoglobin-based oxygen carriers have been under development for decades, but safety concerns have prevented commercial approval. Early designs for modified hemoglobins by polymerization or intramolecular cross-linking reactions increased molecular size and decreased oxygen affinity, but all exhibited side effects of vasoconstriction and reduced blood flow. A new strategy has been established by applying principles of oxygen transport to cell-free hemoglobin. Sangart has developed a new oxygen therapeutic, Hemospan, using site-specific, poly(ethylene) glycol conjugation chemistry designed on two principles: (i) increased macromolecular size to prolong intravascular retention time, and (ii) increased oxygen affinity to prevent premature oxygen offloading in arterioles. In contrast to early-generation products, Hemospan infusion maintains normal arteriolar vascular tone and capillary flow. Phase I and Phase II clinical trials have been completed, showing that Hemospan is well-tolerated in humans, with evidence of efficacy to impart hemodynamic stability in surgical patients under anesthesia. Phase III trials in orthopedic surgery have recently completed enrollment in Europe. [source] Design principles for virtual patients: a focus group study among studentsMEDICAL EDUCATION, Issue 6 2009Sören Huwendiek Objectives, This study aimed to examine what students perceive as the ideal features of virtual patient (VP) design in order to foster learning with a special focus on clinical reasoning. Methods, A total of 104 Year 5 medical students worked through at least eight VPs representing four different designs during their paediatric clerkship. The VPs were presented in two modes and differed in terms of the authenticity of the user interface (with or without graphics support), predominant question type (long- versus short-menu questions) and freedom of navigation (relatively free versus predetermined). Each mode was presented in a rich and a poor version with regard to the use of different media and questions and explanations explicitly directed at clinical reasoning. Five groups of between four and nine randomly selected students (n = 27) participated in focus group interviews facilitated by a moderator using a questioning route. The interviews were videotaped, transcribed and analysed. Summary reports were approved by the students. Results, Ten principles of VP design emerged from the analysis. A VP should be relevant, of an appropriate level of difficulty, highly interactive, offer specific feedback, make optimal use of media, help students focus on relevant learning points, offer recapitulation of key learning points, provide an authentic web-based interface and student tasks, and contain questions and explanations tailored to the clinical reasoning process. Conclusions, Students perceived the design principles identified as being conducive to their learning. Many of these principles are supported by the results of other published studies. Future studies should address the effects of these principles using quantitative controlled designs. [source] A decentralized and fault-tolerant Desktop Grid system for distributed applications,CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 3 2010Heithem Abbes Abstract This paper proposes a decentralized and fault-tolerant software system for the purpose of managing Desktop Grid resources. Its main design principle is to eliminate the need for a centralized server, therefore to remove the single point of failure and bottleneck of existing Desktop Grids. Instead, each node can play alternatively the role of client or server. Our main contribution is to design the PastryGrid protocol (based on Pastry) for Desktop Grid in order to support a wider class of applications, especially the distributed application with precedence between tasks. Compared with a centralized system, we evaluate our approach over 205 machines executing 2500 tasks. The results we obtain show that our decentralized system outperforms XtremWeb-CH which is configured as a master/slave, with respect to the turnaround time. Copyright © 2009 John Wiley & Sons, Ltd. [source] Iminohydroxamato Early and Late Transition Metal Halide Complexes , New Precatalysts for Aluminoxane-Cocatalyzed Olefin Insertion PolymerizationEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2004Alexander Krajete Abstract We report on new families of non-metallocene metal precatalysts for olefin polymerization with titanium, zirconium, vanadium and nickel as the active metal sites. The novel ligand design concept is based on iminohydroxamic acids and their derivatives as the principal chelating units. Various anionic and neutral [N,O] and [N,N] ligand systems are easily accessible by a modular synthetic sequence of imidoyl chlorides with substituted hydroxylamines or hydrazines, respectively. Steric protection of the metal coordination site, a necessary requirement for suppression of chain termination pathways of non-metallocene catalysts, is brought about by bulky aryl substituents on the imino nitrogen atoms. Crystal structures of some of the hydroxamato ligands reveal interesting intermolecular hydrogen-bridged structures, whereas in the solid-state structure of one titanium precatalyst a five-membered chelate was observed, in line with the design principle of these systems. Preliminary ethylene polymerization studies with methylaluminoxane-activated metal complexes (M = Ti, Zr, V, Ni) show that the most active systems are [N,O]NiBr2 catalysts containing neutral O -alkyl iminohydroxamate ligands. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Influence of Structural Principles on the Mechanics of a Biological Fiber-Based Composite Material with Hierarchical Organization: The Exoskeleton of the Lobster Homarus americanusADVANCED MATERIALS, Issue 4 2009Helge-Otto Fabritius Abstract The cuticle of the lobster Homarus americanus is a nanocomposite, such as most structural biological materials. It consists of a matrix of chitin-protein fibers associated with various amounts of crystalline and amorphous calcium carbonate in the rigid parts of the body, and is organized hierarchically at all length scales. One prominent design principle found in the hierarchical structure of such biological fibrous composite materials is the twisted plywood structure. In the lobster cuticle, it is formed by superimposing and gradually rotating planes of parallel aligned chitin-protein fibers. To adjust the mechanical properties to the requirements on the macroscopic level, the spatial arrangement and the grade of mineralization of the fibers can be modified. A second design principle of lobster cuticle is its honeycomb-like structure, generated by the well-developed pore canal system, whose twisted ribbon-shaped canals penetrate the cuticle perpendicular to its surface. Due to the hierarchical structure, the mechanical properties of the lobster cuticle have to be investigated at different length scales, which is essential for the understanding of the structure,mechanical function relations of mineralized tissues (e.g., potentially also bone and teeth). In order to investigate the influence of the structural principles on the mechanical properties on the macroscopic scale miniaturized tensile, compression, and shear tests were carried out to obtain integral mechanical data. Characterization of the microstructure included scanning electron microscopy (SEM) combined with energy dispersive X-ray (EDX) measurements. [source] The Concept of Modularity in Management Studies: A Literature ReviewINTERNATIONAL JOURNAL OF MANAGEMENT REVIEWS, Issue 3 2010Diego Campagnolo During the last decade, modularity has attracted the attention of numerous management scholars, and both theoretical and empirical studies on this topic have flourished. However, this broad-based appeal has generated some controversies and ambiguities on how modularity should be defined, measured and used in managerially meaningful ways. This paper reviews the concept of modularity as a design principle of complex systems in management studies. Applying this criterion, 125 studies were selected and classified, grouped according to their prevalent unit of analysis: products, production systems and organizations. Although all these studies are based on Simon's seminal work on the hierarchical and nearly decomposable nature of complex systems (Simon, H.A. (1962). The architecture of complexity. Proceedings of the American Philosophical Society, 106, 467,482), this paper shows that they offer different definitions, measures and applications of the modularity concept. This review reveals the implicit structure of meanings underlying this literature and emphasizes that ambiguity in definitions and measures impedes rigorous empirical studies capable of understanding the relationship between modularity in product, in production and in organization design. Cautions and directions for future research are discussed. [source] Decisional autonomy of planetary roversJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 7 2007Félix Ingrand To achieve the ever increasing demand for science return, planetary exploration rovers require more autonomy to successfully perform their missions. Indeed, the communication delays are such that teleoperation is unrealistic. Although the current rovers (such as MER) demonstrate a limited navigation autonomy, and mostly rely on ground mission planning, the next generation (e.g., NASA Mars Science Laboratory and ESA Exomars) will have to regularly achieve long range autonomous navigation tasks. However, fully autonomous long range navigation in partially known planetary-like terrains is still an open challenge for robotics. Navigating hundreds of meters without any human intervention requires the robot to be able to build adequate representations of its environment, to plan and execute trajectories according to the kind of terrain traversed, to control its motions, and to localize itself as it moves. All these activities have to be planned, scheduled, and performed according to the rover context, and controlled so that the mission is correctly fulfilled. To achieve these objectives, we have developed a temporal planner and an execution controller, which exhibit plan repair and replanning capabilities. The planner is in charge of producing plans composed of actions for navigation, science activities (moving and operating instruments), communication with Earth and with an orbiter or a lander, while managing resources (power, memory, etc.) and respecting temporal constraints (communication visibility windows, rendezvous, etc.). High level actions also need to be refined and their execution temporally and logically controlled. Finally, in such critical applications, we believe it is important to deploy a component that protects the system against dangerous or even fatal situations resulting from unexpected interactions between subsystems (e.g., move the robot while the robot arm is unstowed) and/or software components (e.g., take and store a picture in a buffer while the previous one is still being processed). In this article we review the aforementioned capabilities, which have been developed, tested, and evaluated on board our rovers (Lama and Dala). After an overview of the architecture design principle adopted, we summarize the perception, localization, and motion generation functions required by autonomous navigation, and their integration and concurrent operation in a global architecture. We then detail the decisional components: a high level temporal planner that produces the robot activity plan on board, and temporal and procedural execution controllers. We show how some failures or execution delays are being taken care of with online local repair, or replanning. © 2007 Wiley Periodicals, Inc. [source] Design Vulnerability Analysis and Design Improvement by Using Warranty DataQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 2 2004Kai Yang Abstract Continuous improvement in reliability is one of the key factors to success in the world automobile market. Good reliability can only be achieved through good design and manufacturing practice. Manufacturers want to allocate their limited resources to improvement in such a way that they can get the highest benefits. The warranty claims database contains more information than any other test for the reliability of products in actual use. Assisted by a design vulnerability index derived from the axiomatic design principle, warranty data can be used to identify the areas of the product such that the improvement of these areas will maximize the gain in reliability improvement. In this paper, we provide a methodology of utilizing warranty data to prioritize design improvement efforts based on design vulnerability and the feedback from warranty data. The methodology is illustrated with an example case. Copyright © 2004 John Wiley & Sons, Ltd. [source] A Design Theory Approach to Building Strategic Network-Based Customer Service Systems,DECISION SCIENCES, Issue 3 2009M. Kathryn Brohman ABSTRACT Customer service is a key component of a firm's value proposition and a fundamental driver of differentiation and competitive advantage in nearly every industry. Moreover, the relentless coevolution of service opportunities with novel and more powerful information technologies has made this area exciting for academic researchers who can contribute to shaping the design and management of future customer service systems. We engage in interdisciplinary research,across information systems, marketing, and computer science,in order to contribute to the service design and service management literature. Grounded in the design-science perspective, our study leverages marketing theory on the service-dominant logic and recent findings pertaining to the evolution of customer service systems. Our theorizing culminates with the articulation of four design principles. These design principles underlie the emerging class of customer service systems that, we believe, will enable firms to better compete in an environment characterized by an increase in customer centricity and in customers' ability to self-serve and dynamically assemble the components of solutions that fit their needs. In this environment, customers retain control over their transactional data, as well as the timing and mode of their interactions with firms, as they increasingly gravitate toward integrated complete customer solutions rather than single products or services. Guided by these design principles, we iterated through, and evaluated, two instantiations of the class of systems we propose, before outlining implications and directions for further cross-disciplinary scholarly research. [source] Wilkhahn: A tradition of the cutting edgeDESIGN MANAGEMENT REVIEW, Issue 2 2002Brigitte Wolf Under the personal leadership of Fritz Hahne, Wilkhahn has created a niche for itself and earned a global reputation for designing high-quality, classically modern furniture that is both elegant and functional. In a rich overview of this German firm, Brigitte Wolf explores the business objectives, the work ethic, the design principles, the social and environmental values and, of course, the products and architecture that are the hallmark of this remarkable company. [source] Extending drug ethno-epidemiology using agent-based modellingADDICTION, Issue 12 2009David Moore ABSTRACT Aims To show how the inclusion of agent-based modelling improved the integration of ethno-epidemiological data in a study of psychostimulant use and related harms among young Australians. Methods Agent-based modelling, ethnographic fieldwork, in-depth interviews and epidemiological surveys. Setting Melbourne, Perth and Sydney, Australia. Participants Club drug users in Melbourne, recreational drug users in Perth and street-based injecting drug users in Sydney. Participants were aged 18,30 years and reported monthly or more frequent psychostimulant use. Findings Agent-based modelling provided a specific focus for structured discussion about integrating ethnographic and epidemiological methods and data. The modelling process was underpinned by collective and incremental design principles, and produced ,SimAmph', a data-driven model of social and environmental agents and the relationships between them. Using SimAmph, we were able to test the probable impact of ecstasy pill-testing on the prevalence of harms,a potentially important tool for policy development. The study also navigated a range of challenges, including the need to manage epistemological differences, changes in the collective design process and modelling focus, the differences between injecting and non-injecting samples and concerns over the dissemination of modelling outcomes. Conclusions Agent-based modelling was used to integrate ethno-epidemiological data on psychostimulant use, and to test the probable impact of a specific intervention on the prevalence of drug-related harms. It also established a framework for collaboration between research disciplines that emphasizes the synthesis of diverse data types in order to generate new knowledge relevant to the reduction of drug-related harms. [source] Serially concatenated continuous phase modulation with symbol interleavers: performance, properties and design principlesEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2006Ming Xiao Serially concatenated continuous phase modulation (SCCPM) systems with symbol interleavers are investigated. The transmitted signals are disturbed by additive white Gaussian noise (AWGN). Compared to bit interleaved SCCPM systems, this scheme shows a substantial improvement in the convergence threshold at the price of a higher error floor. In addition to showing this property, we also investigate the underlying reason by error event analysis. In order to estimate bit error rate (BER) performance, we generalise traditional union bounds for a bit interleaver to this non-binary interleaver. For the latter, both the order and the position of permuted non-zero symbols have to be considered. From the analysis, some principal properties are identified. Finally, some design principles are proposed. Our paper concentrates on SCCPM, but the proposed analysis methods and conclusions can be widely used in many other systems such as serially concatenated trellis coded modulation (SCTCM) et cetera. Copyright © 2006 AEIT [source] Bioinspired Material Approaches to SensingADVANCED FUNCTIONAL MATERIALS, Issue 16 2009Michael E. McConney Abstract Bioinspired design is an engineering approach that involves working to understand the design principles and strategies employed by biology in order to benefit the development of engineered systems. From a materials perspective, biology offers an almost limitless source of novel approaches capable of arousing innovation in every aspect of materials, including fabrication, design, and functionality. Here, recent and ongoing work on the study of bioinspired materials for sensing applications is presented. Work presented includes the study of fish flow receptor structures and the subsequent development of similar structures to improve flow sensor performance. The study of spider air-flow receptors and the development of a spider-inspired flexible hair is also discussed. Lastly, the development of flexible membrane based infrared sensors, highly influenced by the fire beetle, is presented, where a pneumatic mechanism and a thermal-expansion stress-mediated buckling-based mechanism are investigated. Other areas that are discussed include novel biological signal filtering mechanisms and reciprocal benefits offered through applying the biology lessons to engineered systems. [source] Social participation in health in Brazil and England: inclusion, representation and authorityHEALTH EXPECTATIONS, Issue 3 2009Marian Barnes BA MA PhD Abstract Aim, This article offers a brief description and analysis of public participation in health in Brazil and England in order to highlight different motivators and tensions within an acceptance of participation as official policy. Sources/methods, The article draws on a range of research in both countries and an analysis of official documents relating to participation. It is based on collaboration between researchers deriving from broad programmes of work on public participation in which the authors are involved. Argument, There is a tension between different principles underpinning collective public involvement in health both within and between countries. Different aspirations or claims have been made about what such participation will achieve and there are trade-offs between design principles that have consequences for issues such as who takes part and thus also for what can be achieved. The democratic origins of public participation are more evident in the Brazilian situation than in England, but there are still questions about the inclusivity of the practices through which this is achieved. The English picture is both more diverse and dynamic, but formal decision-making power of participatory forums is less than in Brazil. Whilst social justice claims for participation have been made in both countries, there is as yet limited evidence that these have been realized. [source] Applying the proximity compatibility and the control-display compatibility principles to engineering design interfacesHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 1 2006Ling Rothrock The authors determine the utility of applying two display design principles toward the development of interfaces for engineering design. The first principle, called the Proximity Compatibility Principle, specifies that displays relevant to a common task or mental operation should be rendered close together in perceptual space. The second principle, called the Control-Display Compatibility Principle, stipulates that the spatial arrangement and manipulation of controls should be easily distinguishable. To examine the utility of both principles, the authors conducted an experiment comparing the ability of subjects to find effective designs using a separable versus a configural interface in a multi-objective engineering design task. Results suggest that the proximity compatibility principle is an effective indicator of task performance. Moreover, the control-display compatibility principle can be used as an indicator of performance efficiency. © 2006 Wiley Periodicals, Inc. Hum Factors Man 16: 61,81, 2006. [source] Understanding the design of information technologies for knowledge management in organizations: a pragmatic perspectiveINFORMATION SYSTEMS JOURNAL, Issue 2 2007Tom Butler Abstract., Researchers report mixed findings on the successful application of information technologies (IT) for knowledge management (KM). The primary difficulty is argued to be the use of information management techniques and concepts to design and develop KM Tools. Also problematic is the existence of a multiplicity of KM technologies, the application and use of which differs across organizations. This paper argues that these problems stem, in part, from the information system field's over-reliance on design concepts from the functionalist paradigm. Hence, our contention that alternative perspectives, which bring into focus issues of ontology and epistemology, need to be brought to bear in order to understand the challenges involved in the design and deployment of IT artefacts in knowledge management systems (KMS). The philosophy of technology, with its emphasis on the primacy of praxis, and which incorporates ontological and epistemological concepts from phenomenology and hermeneutics, is applied to the findings of a participative action research study to illustrate how social actors interpret and understand worldly phenomena and subsequently share their knowledge of the life-world using IT. The outcome of this marriage of situated practical theory and philosophy is a set of design principles to guide the development of a core KM Tool for KMS. [source] Template elastic-plastic computations in geomechanicsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 14 2002Boris Jeremi Abstract In this paper we present a new approach to computations in elasto-plastic geomechanics. The approach is based on the object oriented design philosophy and observations on similarity of most incremental elastic,plastic material models. This new approach to elastic,plastic computations in geomechanics allows for creation of template material models. The analysis of template material models will in turn allow for an easy implementation of other elastic,plastic material models based on the object oriented design principles. Furthermore we present some illustrative implementation details. Finally we present analysis results that emphasize features of template elastic,plastic computations in geomechanics. Copyright © 2002 John Wiley & Sons, Ltd. [source] Cutting through the statistical fog: understanding and evaluating non-inferiority trialsINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 10 2010W. S. Weintraub Summary Every year, results from many important randomised, controlled trials are published. Knowing the elements of trial design and having the skills to critically read and incorporate results are important to medical practitioners. The goal of this article is to help physicians determine the validity of trial conclusions to improve patient care through more informed medical decision making. This article includes a review of 162 randomised, controlled non-inferiority (n = 116) and equivalence (n = 46) hypothesis studies as well as the larger Stroke Prevention using Oral Thrombin Inhibitor in atrial Fibrillation V study and the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial. Evaluation of data from small and large trials uncovers significant flaws in design and models employed and uncertainty about calculations of statistical measures. As one example of questionable study design, discussion includes a large (n = 3922), double-blind, randomised, multicentre trial comparing the efficacy of ximelagatran with warfarin for prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation and additional stroke risk factors. Investigators concluded that ximelagatran was effective compared with well-controlled warfarin for prevention of thromboembolism. However, deficiencies in design, as well as concerns about liver toxicity, resulted in the rejection of the drug by the US Food and Drug Administration. Many trials fail to follow good design principles, resulting in conclusions of questionable validity. Well-designed non-inferiority trials can provide valuable data and demonstrate efficacy for beneficial new therapies. Objectives and primary end-points must be clearly stated and rigorous standards met for sample size, establishing the margin, patient characteristics and adherence to protocol. [source] The Application of Design Principles to Innovate Clinical Care DeliveryJOURNAL FOR HEALTHCARE QUALITY, Issue 1 2009Michael D. Brennan Abstract: Clinical research centers that support hypothesis-driven investigation have long been a feature of academic medical centers but facilities in which clinical care delivery can be systematically assessed and evaluated have heretofore been nonexistent. The Institute of Medicine report "Crossing the Quality Chasm" identified six core attributes of an ideal care delivery system that in turn relied heavily on system redesign. Although manufacturing and service industries have leveraged modern design principles in new product development, healthcare has lagged behind. In this article, we describe a methodology utilized by our facility to study the clinical care delivery system that incorporates modern design principles. [source] From bar diagrams to letter-symbolic algebra: a technology-enabled bridgingJOURNAL OF COMPUTER ASSISTED LEARNING, Issue 4 2009C.-K. Looi Abstract In the Singapore primary school Mathematics curriculum, students are taught the model method that uses bar diagrams to visualize the problem structure in a given word problem. When these students progress to secondary school, they learn the algebraic way of solving word problems. Studies (e.g. Ng et al.) have shown that poor bridging of students from the use of bar diagrams to the use of letter-symbolic algebraic methods can hinder their learning of algebra. We design a software tool ,AlgeBAR' to scaffold the learning of the algebraic process, especially the formulation of equations to support a pedagogy that seeks to help students transit from bar diagrams to algebraic methods. In this paper, we report a cycle of evaluation of the intervention pedagogy by examining a class that uses the software tool as part of a holistic intervention package. This evaluation is in the context of an overall design research approach that sought to address complex problems in real classroom contexts in collaboration with practitioners and to integrate design principles with technological affordances to render plausible solutions. Our findings show that the software tool can be an important enabler of the bridging process. [source] Exploring the mathematics of motion through construction and collaborationJOURNAL OF COMPUTER ASSISTED LEARNING, Issue 2 2006G. Simpson Abstract In this paper, we give a detailed account of the design principles and construction of activities designed for learning about the relationships between position, velocity and acceleration, and corresponding kinematics graphs. Our approach is model-based, that is, it focuses attention on the idea that students constructed their own models , in the form of programs , to formalise and thus extend their existing knowledge. In these activities, students controlled the movement of objects in a programming environment, recording the motion data and plotting corresponding position,time and velocity,time graphs. They shared their findings on a specially designed Web-based collaboration system, and posted cross-site challenges to which others could react. We present learning episodes that provide evidence of students making discoveries about the relationships between different representations of motion. We conjecture that these discoveries arose from their activity in building models of motion and their participation in classroom and online communities. [source] Improving Construct Validity With Cognitive Psychology PrinciplesJOURNAL OF EDUCATIONAL MEASUREMENT, Issue 4 2001Susan Embretson Cognitive psychology principles have been heralded as possibly central to construct validity. In this paper, testing practices are examined in three stages: (a) the past, in which the traditional testing research paradigm left little role for cognitive psychology principles, (b) the present, in which testing research is enhanced by cognitive psychology principles, and (c) the future, for which we predict that cognitive psychology's potential will be fully realized through item design. An extended example of item design by cognitive theory is given to illustrate the principles. A spatial ability test that consists of an object assembly task highlights how cognitive design principles can lead to item generation. [source] Fabrication of Direct Fiber-Reinforced Posts: A Structural Design ConceptJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 4 2001DOUGLAS A. TERRY DDS ABSTRACT As the clinician continues the quest for optimal functional and esthetic success of a tooth-restorative complex, the current selection of restorative materials and techniques may prove overwhelming. Although no single system provides the ideal restorative solution for every clinical circumstance, understanding of general design criteria and the components for the various post and core systems available allow the clinician to appropriately select the method and materials compatible with the existing tooth structure and desired result. This article provides a discussion of the various post and core systems, the methods and materials inherent in these systems, and general design principles. Using that basic information and clinical experience, the authors offer an alternative procedure for the rehabilitation of the intraradicular anatomy of the post-endodontic channel with a direct composite resin,the fiber-reinforced post and core system. CLINICAL SIGNIFICANCE Using improved restorative materials that simulate the physical properties and other characteristics of natural teeth in combination with the proper design principles, the clinician can develop a tooth-restorative complex with optimal functional and esthetic results. [source] Promising Optoelectronic Materials: Polymers Containing Phosphorescent Iridium(III) ComplexesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 9-10 2010Qiang Zhao Abstract As one of the most promising optoelectronic materials, polymers that contain phosphorescent IrIII complexes have attracted more and more interest in recent years. They are a class of well-known electroluminescent materials with excellent performance. So far, efficient green-, red-, and white-emitting polymer light-emitting diodes based on polymers with on-chain IrIII complexes have been realized successfully. For the realization of this class of polymer material, IrIII complexes (as energy guest) can be introduced into the main-chain or side-chain of polymers (as energy host). In this article, we summarize the design principles, synthetic routes, structure,property relationships, and applications in optoelectronic devices of polymers that contain phosphorescent IrIII complexes. [source] Design principles for virtual patients: a focus group study among studentsMEDICAL EDUCATION, Issue 6 2009Sören Huwendiek Objectives, This study aimed to examine what students perceive as the ideal features of virtual patient (VP) design in order to foster learning with a special focus on clinical reasoning. Methods, A total of 104 Year 5 medical students worked through at least eight VPs representing four different designs during their paediatric clerkship. The VPs were presented in two modes and differed in terms of the authenticity of the user interface (with or without graphics support), predominant question type (long- versus short-menu questions) and freedom of navigation (relatively free versus predetermined). Each mode was presented in a rich and a poor version with regard to the use of different media and questions and explanations explicitly directed at clinical reasoning. Five groups of between four and nine randomly selected students (n = 27) participated in focus group interviews facilitated by a moderator using a questioning route. The interviews were videotaped, transcribed and analysed. Summary reports were approved by the students. Results, Ten principles of VP design emerged from the analysis. A VP should be relevant, of an appropriate level of difficulty, highly interactive, offer specific feedback, make optimal use of media, help students focus on relevant learning points, offer recapitulation of key learning points, provide an authentic web-based interface and student tasks, and contain questions and explanations tailored to the clinical reasoning process. Conclusions, Students perceived the design principles identified as being conducive to their learning. Many of these principles are supported by the results of other published studies. Future studies should address the effects of these principles using quantitative controlled designs. [source] Design of anticancer prodrugs for reductive activationMEDICINAL RESEARCH REVIEWS, Issue 1 2009Yu Chen Abstract Anticancer prodrugs designed to target specifically tumor cells should increase therapeutic effectiveness and decrease systemic side effects in the treatment of cancer. Over the last 20 years, significant advances have been made in the development of anticancer prodrugs through the incorporation of triggers for reductive activation. Reductively activated prodrugs have been designed to target hypoxic tumor tissues, which are known to overexpress several endogenous reductive enzymes. In addition, exogenous reductive enzymes can be delivered to tumor cells through fusion with tumor-specific antibodies or overexpressed in tumor cells through gene delivery approaches. Many anticancer prodrugs have been designed to use both the endogenous and exogenous reductive enzymes for target-specific activation and these prodrugs often contain functional groups such as quinones, nitroaromatics, N-oxides, and metal complexes. Although no new agents have been approved for clinical use, several reductively activated prodrugs are in various stages of clinical trial. This review mainly focuses on the medicinal chemistry aspects of various classes of reductively activated prodrugs including design principles, structure-activity relationships, and mechanisms of activation and release of active drug molecules. © 2008 Wiley Periodicals, Inc. Med Res Rev, 29, No. 1, 29,64, 2009 [source] e-Portfolios: A collaboration between student affairs and facultyNEW DIRECTIONS FOR STUDENT SERVICES, Issue 119 2007Glenn Johnson This chapter describes how a commitment to instructional design principles has prompted the evolution of collaborative interaction between student affairs professionals and academic faculty. Central to this collaboration are the opportunities that e-portfolios have made available. [source] Supportive teaching and learning strategies in STEM educationNEW DIRECTIONS FOR TEACHING & LEARNING, Issue 117 2009Karl A. Smith This chapter provides faculty with design principles based on the How People Learn framework, as well as current best practices for designing engaged learning environments in STEM classes in the hope of continuing improvement in STEM education. [source] | |||||||||||||||||||||||||||||||