990 resultados para Two-way recommendation


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The research was carried out in the Aviation Division of Dunlop Limited and was initiated as a search for more diverse uses for carbon/carbon composites. An assumed communication model of adoption was refined by introducing the concept of a two way search after making cross industry comparisons of supplier and consumer behaviour. This research has examined methods of searching for new uses for advanced technology materials. Two broad approaches were adopted. First, a case history approach investigated materials that had been in a similar oosition to carbon/carbon to see how other material producing firms had tackled the problem. Second, a questionnaire survey among industrialists examined: the role and identity of material decision makers in different sized firms; the effectiveness of various information sources and channels; and the material adoption habits of different industries. The effectiveness of selected information channels was further studied by monitoring the response to publicity given to carbon/carbon. A flow chart has been developed from the results of this research which should help any material producing firm that is contemplating the introduction of a new material to the world market. Further benefit to our understanding of the innovation and adoption of new materials would accrue from work in the followino areas: "micro" type case histories; understanding more fully the role of product champions or promoters; investigating the phase difference between incremental and radical type innovations for materials; examining the relationship between the adoption rate of new materials and the advance of technology; studying the development of cost per unit function methods for material selection; and reviewing the benefits that economy of scale studies can have on material developments. These are all suggested areas for further work.

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Agent-based technology is playing an increasingly important role in today’s economy. Usually a multi-agent system is needed to model an economic system such as a market system, in which heterogeneous trading agents interact with each other autonomously. Two questions often need to be answered regarding such systems: 1) How to design an interacting mechanism that facilitates efficient resource allocation among usually self-interested trading agents? 2) How to design an effective strategy in some specific market mechanisms for an agent to maximise its economic returns? For automated market systems, auction is the most popular mechanism to solve resource allocation problems among their participants. However, auction comes in hundreds of different formats, in which some are better than others in terms of not only the allocative efficiency but also other properties e.g., whether it generates high revenue for the auctioneer, whether it induces stable behaviour of the bidders. In addition, different strategies result in very different performance under the same auction rules. With this background, we are inevitably intrigued to investigate auction mechanism and strategy designs for agent-based economics. The international Trading Agent Competition (TAC) Ad Auction (AA) competition provides a very useful platform to develop and test agent strategies in Generalised Second Price auction (GSP). AstonTAC, the runner-up of TAC AA 2009, is a successful advertiser agent designed for GSP-based keyword auction. In particular, AstonTAC generates adaptive bid prices according to the Market-based Value Per Click and selects a set of keyword queries with highest expected profit to bid on to maximise its expected profit under the limit of conversion capacity. Through evaluation experiments, we show that AstonTAC performs well and stably not only in the competition but also across a broad range of environments. The TAC CAT tournament provides an environment for investigating the optimal design of mechanisms for double auction markets. AstonCAT-Plus is the post-tournament version of the specialist developed for CAT 2010. In our experiments, AstonCAT-Plus not only outperforms most specialist agents designed by other institutions but also achieves high allocative efficiencies, transaction success rates and average trader profits. Moreover, we reveal some insights of the CAT: 1) successful markets should maintain a stable and high market share of intra-marginal traders; 2) a specialist’s performance is dependent on the distribution of trading strategies. However, typical double auction models assume trading agents have a fixed trading direction of either buy or sell. With this limitation they cannot directly reflect the fact that traders in financial markets (the most popular application of double auction) decide their trading directions dynamically. To address this issue, we introduce the Bi-directional Double Auction (BDA) market which is populated by two-way traders. Experiments are conducted under both dynamic and static settings of the continuous BDA market. We find that the allocative efficiency of a continuous BDA market mainly comes from rational selection of trading directions. Furthermore, we introduce a high-performance Kernel trading strategy in the BDA market which uses kernel probability density estimator built on historical transaction data to decide optimal order prices. Kernel trading strategy outperforms some popular intelligent double auction trading strategies including ZIP, GD and RE in the continuous BDA market by making the highest profit in static games and obtaining the best wealth in dynamic games.

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Design of casting entails the knowledge of various interacting factors that are unique to casting process, and, quite often, product designers do not have the required foundry-specific knowledge. Casting designers normally have to liaise with casting experts in order to ensure the product designed is castable and the optimum casting method is selected. This two-way communication results in long design lead times, and lack of it can easily lead to incorrect casting design. A computer-based system at the discretion of a design engineer can, however, alleviate this problem and enhance the prospect of casting design for manufacture. This paper proposes a knowledge-based expert system approach to assist casting product designers in selecting the most suitable casting process for specified casting design requirements, during the design phase of product manufacture. A prototype expert system has been developed, based on production rules knowledge representation technique. The proposed system consists of a number of autonomous but interconnected levels, each dealing with a specific group of factors, namely, casting alloy, shape and complexity parameters, accuracy requirements and comparative costs, based on production quantity. The user interface has been so designed to allow the user to have a clear view of how casting design parameters affect the selection of various casting processes at each level; if necessary, the appropriate design changes can be made to facilitate the castability of the product being designed, or to suit the design to a preferred casting method.

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Objective: The purpose of this study was to determine the extent to which mobility indices (such as walking speed and postural sway), motor initiation, and cognitive function, specifically executive functions, including spatial planning, visual attention, and within participant variability, differentially predicted collisions in the near and far sides of the road with increasing age. Methods: Adults aged over 45 years participated in cognitive tests measuring executive function and visual attention (using Useful Field of View; UFoV®), mobility assessments (walking speed, sit-to-stand, self-reported mobility, and postural sway assessed using motion capture cameras), and gave road crossing choices in a two-way filmed real traffic pedestrian simulation. Results: A stepwise regression model of walking speed, start-up delay variability, and processing speed) explained 49.4% of the variance in near-side crossing errors. Walking speed, start-up delay measures (average & variability), and spatial planning explained 54.8% of the variance in far-side unsafe crossing errors. Start-up delay was predicted by walking speed only (explained 30.5%). Conclusion: Walking speed and start-up delay measures were consistent predictors of unsafe crossing behaviours. Cognitive measures, however, differentially predicted near-side errors (processing speed), and far-side errors (spatial planning). These findings offer potential contributions for identifying and rehabilitating at-risk older pedestrians.

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Cochran's Q-test is a non-parametric analysis which can be applied to a two-way design in which the data are binomial and can take only two possible outcomes, e.g., 0 or 1, alive or dead, present or absent, clean or dirty, infected or non-infected, and is an extension to the binomial tests introduced in Statnote 39 . This statnote describes the application of this test in the analysis of the changes which occur in the fungal flora of forestry nursery beds after two different sterilization procedures .

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An effective aperture approach is used as a tool for analysis and parameter optimization of mostly known ultrasound imaging systems - phased array systems, compounding systems and synthetic aperture imaging systems. Both characteristics of an imaging system, the effective aperture function and the corresponding two-way radiation pattern, provide information about two of the most important parameters of images produced by an ultrasound system - lateral resolution and contrast. Therefore, in the design, optimization of the effective aperture function leads to optimal choice of such parameters of an imaging systems that influence on lateral resolution and contrast of images produced by this imaging system. It is shown that the effective aperture approach can be used for optimization of a sparse synthetic transmit aperture (STA) imaging system. A new two-stage algorithm is proposed for optimization of both the positions of the transmitted elements and the weights of the receive elements. The proposed system employs a 64-element array with only four active elements used during transmit. The numerical results show that Hamming apodization gives the best compromise between the contrast of images and the lateral resolution.

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Typical Double Auction (DA) models assume that trading agents are one-way traders. With this limitation, they cannot directly reflect the fact individual traders in financial markets (the most popular application of double auction) choose their trading directions dynamically. To address this issue, we introduce the Bi-directional Double Auction (BDA) market which is populated by two-way traders. Based on experiments under both static and dynamic settings, we find that the allocative efficiency of a static continuous BDA market comes from rational selection of trading directions and is negatively related to the intelligence of trading strategies. Moreover, we introduce Kernel trading strategy designed based on probability density estimation for general DA market. Our experiments show it outperforms some intelligent DA market trading strategies. Copyright © 2013, International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved.

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Background: Self-affirmation (i.e., focusing on a valued aspect of the self-concept) can promote health behaviour change. This study aimed to see if self-affirmation increased physical activity (PA) regardless of threat level presented in health messages. Methods: Sixty-eight participants were randomly allocated to condition in a 2 (self-affirmation, no affirmation) x 2 (high threat, low threat) between-participants design. Participants completed the Godin Leisure-Time Exercise Questionnaire at baseline and one week later to assess PA. Findings: A two-way ANCOVA with affirmation condition and threat level as predictor variables, controlling for baseline PA, was performed on follow up PA. Baseline PA was a significant predictor (F(1,63) = 399.63, p<0.001) and the main effect of affirmation condition approached significance (F(1,63) = 3.55, p=0.06). There were no other significant effects. Discussion: This study provides further evidence that self-affirmation can increase PA, but found no interaction between self-affirmation and threat level presented in health messages.

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In the new social media context, it is gradually more common to say that each party can itself be considered a media content provider, firms included (through their brand pages). This tendency is reflected in a rising professional field called “content marketing”. This study incorporates the perspective of small and medium-sized enterprises (SMEs) into the scope of social media (SM) as a marketing communications and media content distribution system. In an exploratory content analysis of 20 official SM brand pages with 1281 analyzed posts the authors study how SMEs respond to the advent of a new paradigm of marketing communications with special attention to their usage of media-specific contents. SM impels companies to eventually rethink the traditional one-way communication flow of their marketing messages and to incorporate a new, two-way communication into their marketing strategy, where (their engaged and involved) users can create, modify, share and discuss content related to the firm’s activity. This study’s preliminary results show that diffusing content generally acts for SMEs as a facilitator to involve fans by offering a thematized space for them to manifest themselves in company-related topics. Therefore, content adds to the firms’ possibilities of brand positioning by offering a reflection of fans’ company- and contentrelated behavior, which is a supplementary source of information.

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Van egy szó, ami egyre fontosabb lesz a társadalom és a vállalatok számára is, ez a szó a közösség. A közösséghez tevékenységek tartoznak, és ezen a ponton kapcsolódik be a vállalat. A vállalkozások az elmúlt években a közösségi igényeket a CRM-(Customer Relationship Management) megoldásokkal szolgálták ki. Informatikailag a közösségi hálózatok, már nemcsak vállalkozási folyamatot, hanem ehhez kapcsoltan az emberek társadalmi igényét is megpróbálják lefedni az elektronika lehetőségeivel. Egyre inkább a közösségi vállalkozások korát éljük, melyben a folyamathoz tartozó közösségek megosztják, egymás rendelkezésére bocsátják az információkat. A korábbi klasszikus CRM-rendszerek csak begyűjtötték az információkat, ezzel ellenben a közösségi CRM-rendszerek kétirányú kommunikációt folytatnak, párbeszédet kezdeményeznek az ügyfelekkel, buzdítják őket, hogy mondják el a véleményüket. Vajon ez az új stratégia,egy teljesen új világot hoz el a vállalatok számára, vagy csak a CRM fejlődésének egy újabb fokát jelenti? A szerzők erre a kérdésre keresik a választ gyakorlati esetek és szakirodalmi publikációk feldolgozásával. ______ There is a word that begins to be more and more important for the society and the companies, and this word is community. We can talk about social networks, people seek the social demand they already had as a part of their lives for a long time, and this means that it appears in the electronic society as an essential need too. The community is not enough, activities are also needed and this is the point where the companies link in, who promote their goods and facilities to the outside world and with this they use the next stage of customer relationship management, the fulfilment of social needs. We live in the age of social shopping, communities are everywhere and everyone shares information, and up to the present classic CR M systems ran from static databases. On the contrary social CR M systems perform a two-way communication, start a conversation with customers and encourage them to tell their opinions, which always changes on social media, so they build a dynamic database and communicate with customers through response-reactions. Does this new strategy bring a whole new world to companies or is it only another step in the development and another channel of CRM?

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This paper investigates the drivers of agri-food intra-industry trade (IIT) indices in the European Union (EU-27) member states during the period from 2000–2011. The increased proportion of IIT in matched two-way agri-food trade of the EU-27 member states is consistent with economic integration and economic growth. When export prices were at least 15% higher than the import prices, high-vertical IIT, increased for most member states. This finding suggests that quality improvements occurred when comparing agri-food exports to similar imports of agri-food products. The IIT indices for both horizontal and vertical IIT are positively associated with higher economic development levels, new EU membership and EU enlargement. Additionally, as higher levels of economic development decreases, the size of the economy and marginal IIT increases the effects of agri-food trade liberalization on the costs of the labor market adjustment. Understanding how improvements in agri-food trade quality impact agribusiness and managerial competitiveness reveal significant policy implications.

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The purpose of this study was to assess the knowledge of public school administrators with respect to special education (ESE) law. The study used a sample of 220 public school administrators. A survey instrument was developed consisting of 19 demographic questions and 20 situational scenarios. The scenarios were based on ESE issues of discipline, due process (including IEP procedures), identification, evaluation, placement, and related services. The participants had to decide whether a violation of the ESE child's rights had occurred by marking: (a) Yes, (b) No, or (c) Undecided. An analysis of the scores and demographic information was done using a two-way analysis of variance, chi-square, and crosstabs after a 77% survey response rate.^ Research questions addressed the administrators' overall level of knowledge. Comparisons were made between principals and assistant principals and differences between the levels of schooling. Exploratory questions were concerned with ESE issues deemed problematic by administrators, effects of demographic variables on survey scores, and the listing of resources utilized by administrators to access ESE information.^ The study revealed: (a) a significant difference was found when comparing the number of ESE courses taken and the score on the survey, (b) the top five resources of ESE information were the region office, school ESE department chairs, ESE teachers, county workshops, and county inservices, (c) problematic areas included discipline, evaluation procedures, placement issues, and IEP due process concerns, (d) administrators as a group did not exhibit a satisfactory knowledge of ESE law with a mean score of 12 correct and 74% of responding administrators scoring in the unsatisfactory level (below 70%), (e) across school levels, elementary administrators scored significantly higher than high school administrators, and (f) a significant implication that assistant principals consistently scored higher than principals on each scenario with a significant difference at the high school level.^ The study reveals a vital need for administrators to receive additional preparation in order to possess a basic understanding of ESE school law and how it impacts their respective schools and school districts so that they might meet professional obligations and protect the rights of all individuals involved. Recommendations for this additional administrative preparation and further research topics were discussed. ^

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This study was designed to address questions regarding the effects of sex and leadership style on teacher perceptions of principal effectiveness. On a researcher-designed instrument, middle school teachers rated the effectiveness of a scenario principal's response in several situations. The responses reflected varying levels of Task and Relationship Behavior.^ The design incorporated two between subjects factors (Teacher Sex and Principal Sex) and one within subjects factor (Leadership Style) which was treated as a repeated measure. An analysis of variance revealed no significant effects except for Leadership Style. Overall, High Task/High Relationship behavior rated significantly higher and Low Task/Low Relationship rated significantly lower than the others. The null hypothesis concerning differences could not be rejected and the stated research hypotheses were not supported.^ Additional analyses of variance were conducted substituting subject demographic variables for Teacher Sex in the research design. No significant interactions or main effects other than Leadership Style were noted when either Age or Ethnicity were substituted.^ A significant two-way interaction was noted for Teacher Experience and Leadership Style (p =.0316). Less experienced teachers rated principal's performance lower when exhibiting High Task/Low Relationship style than did more experienced teachers. A significant three-way interaction was noted for Administrative Aspiration x Principal Sex x Leadership Style (p =.0294). Teachers who indicated an intent to enter administration differed more on their ratings between male and female principals exhibiting mixed styles of High Task/Low Relationship and Low Task/High Relationship than did teachers who indicated no or undecided.^ Sex of the teacher appears less important than sex of the principal on performance ratings. Results suggest further study of the effects of teacher experience and teacher administrative aspiration on perceptions of principal effectiveness. ^

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Current views of the nature of knowledge and of learning suggest that instructional approaches in science education pay closer attention to how students learn rather than on teaching. This study examined the use of approaches to teaching science based on two contrasting perspectives in learning, social constructivist and traditional, and the effects they have on students' attitudes and achievement. Four categories of attitudes were measured using the Upper Secondary Attitude Questionnaire: Attitude towards school, towards the importance of science, towards science as a career, and towards science as a subject in school. Achievement was measured by average class grades and also with a researcher/teacher constructed 30-item test that involved three sub-scales of items based on knowledge, and applications involving near-transfer and far-transfer of concepts. The sample consisted of 202 students in nine intact classrooms in chemistry at a large high school in Miami, Florida, and involved two teachers. Results were analyzed using a two-way analysis of covariance (ANCOVA) with a pretest in attitude as the covariate for attitudes and prior achievement as the covariate for achievement. A comparison of the adjusted mean scores was made between the two groups and between females and males. ^ With constructivist-based teaching, students showed more favorable attitude towards science as a subject, obtained significantly higher scores in class achievement, total achievement and achievement on the knowledge sub-scale of the knowledge and application test. Students in the traditional group showed more favorable attitude towards school. Females showed significantly more positive attitude towards the importance of science and obtained significantly higher scores in class achievement. No significant interaction effects were obtained for method of instruction by gender. ^ This study lends some support to the view that constructivist-based approaches to teaching science is a viable alternative to traditional modes of teaching. It is suggested that in science education, more consideration be given to those aspects of classroom teaching that foster closer coordination between social influences and individual learning. ^

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The case study is a qualitative study of the perceptions of a purposeful sample of intern principal participants in Broward County Public School's 2001-2003 principal leadership induction program through survey, interview and document analysis of their experiences concerning their success or failure in achieving the position of principal. The study focused on constructs of professional and organizational socialization and instructional leadership that research suggests are vital and integrated components of the effective development of aspiring instructional leaders. ^ The findings revealed that purposeful mentoring, a variety of site placement, hands on practical experiences, in addition to the quality of experience measured by the number of years prior experience are positively reported to affect the degrees of success perceived by intern principals. The study validated the interrelatedness of the three constructs professional and organizational socialization and instructional leadership as components that are realized in the development process through formal and informal characteristics of socialization. The data gathered would be of benefit to principal leadership program designers to assist in their understanding of participants' successes and failures that influence individual needs based on their experience as perceived by this group. ^ Implications for further study are the need for better understanding of leadership development, continued reinforcement of best practices such as mentoring, site shadowing and coaching, clarification of the administrator's role, data analysis, curriculum implementation and student achievement. Organizations need to implement a common set of expectations, reasoning, attitudes, and understanding of purpose that guide behaviors. Recommendations are to design leadership induction programs to meet individual strengths and weaknesses not a one-size-fits-all program including a constructive and prescriptive two-way feedback system, select and assign mentors based on their expertise and candidate needs, varied site placements, develop skills to build collaborative relationships, and a standards based monitoring and assessment system to document program mastery and completion. ^