共查询到20条相似文献，搜索用时 31 毫秒
1.
What makes some human faces more attractive than others is an interesting phenomenon which is difficult to explain based on few facial features. Research indicated that many facial parameters contribute to generation of a “harmonious face” which is found appealing by most observers. There are different theories developed on which and how these parameters blend in to make a harmonious face. Determination of these parameters and the underlying mechanism is important since achieving a harmonious face is the primary goal in dental and aesthetic surgical procedures. This article presents a model developed for computer-aided assessment of facial harmony, which assesses the facial harmony of male patients and generates a score that reflect the level of harmony. The computer-aided tool presented in this paper uses “theory of averages” as a mechanism for measurement of facial harmony which is frequently used by aesthetic surgeons and orthodontists for assessment of facial proportions of the patient. The output of the developed model is an index which reflects the degree of harmony of facial features and how well they blend into each other. 相似文献
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A fast and efficient page ranking mechanism for web crawling and retrieval remains as a challenging issue. Recently, several link based ranking algorithms like PageRank, HITS and OPIC have been proposed. In this paper, we propose a novel recursive method based on reinforcement learning which considers distance between pages as punishment, called “DistanceRank” to compute ranks of web pages. The distance is defined as the number of “average clicks” between two pages. The objective is to minimize punishment or distance so that a page with less distance to have a higher rank. Experimental results indicate that DistanceRank outperforms other ranking algorithms in page ranking and crawling scheduling. Furthermore, the complexity of DistanceRank is low. We have used University of California at Berkeley’s web for our experiments. 相似文献
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Michihiro Hayashi Hiroshi Tachiya Naoki Asakawa Takuya Kawamura 《Journal of The Franklin Institute》2011,348(1):101-111
This study proposed a method for suppressing torques and consumed energy of manipulators considering an effect of inertial forces in order to achieve power-saved drive. The present paper describes the case that the start and end points of a work path of a manipulator are specified and the path between the points can be determined arbitrarily, which is so-called point-to-point (PTP) control. The proposed method determines both the initial pose of a manipulator and input motions of its joints so that the torque or consumed energy is suppressed. The input motion of the joint is expressed by a motion curve that indicates the time profiles of input displacements, velocities and accelerations. The proposed method determines the motion curve as a polynomial with appropriate coefficients. Those coefficients and their values are decided by a heuristic algorithm in order to suppress the input torques or consumed energy of a manipulator. The paper actually determines the power-saved drive motion of “PUMA560” by the proposed method and reveals its effectiveness. 相似文献
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A user study of aNobii was conducted with an aim to exploring possible criteria for evaluating social navigational tools. A set of measures designed to capture various aspects of the benefits provided by the tools was proposed. To test the applicability of these measures, a within-subject experimental design was adopted where fifty regular aNobii users searched alternately with three book-finding tools: browsing “friends’ bookshelves”, “similar bookshelves”, and “books by known authors”. Other than the self-report user experience and search result measures, the “choice set” model was used as a novel framework for navigational effectiveness. Further analyses were conducted to explore whether three aspects of reader preference, “preference insight”, “preference diversity”, and “reading involvement” might influence the performance of the tools. 相似文献
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The second French Community Innovation Survey (CIS) indicates that 14% of R&D collaborating firms had to abandon or delay their innovation projects due to difficulties in their partnerships, an outcome which we term “cooperation failures”. Controlling for sample selection on the cooperation decision, our estimates show that firms collaborating with competitors and public research organizations (PROs), especially when they are foreign, are more likely to delay or stop an innovation project because of difficulties encountered in their R&D partnerships. More surprisingly, firms collaborating with their suppliers also face a higher risk of “cooperation failures”. At least for PROs, firms can reduce the risk of “cooperation failures” through previous experiences in partnerships. Larger firms and group subsidiaries are less likely to face “cooperation failures”, and so do firms in industries with a strong appropriability regime. 相似文献
6.
Despite a number of studies looking at Web experience and Web searching tactics and behaviours, the specific relationships between experience and cognitive search strategies have not been widely researched. This study investigates how the cognitive search strategies of 80 participants might vary with Web experience as they engaged in two researcher-defined tasks and two participant-defined information seeking tasks. Each of the two researcher-defined tasks and participant-defined tasks included a directed search task and a general-purpose browsing task. While there were almost no significant performance differences between experience levels on any of the four tasks, there were significant differences in the use of cognitive search strategies. Participants with higher levels of Web experience were more likely to use “Parallel player”, “Parallel hub-and-spoke”, “Known address search domain” and “Known address” strategies, whereas participants with lower levels of Web experience were more likely to use “Virtual tourist”, “Link-dependent”, “To-the-point”, “Sequential player”, “Search engine narrowing”, and “Broad first” strategies. The patterns of use and differences between researcher-defined and participant-defined tasks and between directed search tasks and general-purpose browsing tasks are also discussed, although the distribution of search strategies by Web experience were not statistically significant for each individual task. 相似文献
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Mauro Lombardi 《Research Policy》2003,32(8):1443-1462
The aim of this paper is to propose an explanation of the changes of dynamic matching between systemic properties of local production systems (LPS) and characteristics of the competitive environment. An evolutionary sequence travelled during the last three decades by Italian LPS is identified and an explanation of long-term dynamics is based on how information flows and knowledge are structured within a local environment. The “traditional” pattern of interlocking behaviours of different agents is defined as cognitive architecture, which evolutionarily emerges as invisible mind. Evolutionary pressures lead new patterns of relationships and interlocking behaviours, which we define as a tendency for more visible “minds” to assert themselves. 相似文献
9.
This study uses bibliometric analysis and citation context analysis to identify the influence of the main concepts embedded in Taylor’s 1968 classic article entitled Question-Negotiation and Information-Seeking in Libraries. This study analyses articles published between 1969 and 2010 which cite Taylor’s article. The results show that Taylor’s article on a question-negotiation model is increasingly visible and its influence is not limited to the discipline of library and information science. Of the 14 cited concepts identified, the concept of “four levels of information needs” was cited most (31.7%), followed by “question negotiation” (20.5%) and “other concepts relating to information needs” (17.9%). The results indicate an increasing trend in the citations of “four levels of information needs” and this concept also received the most attention from information retrieval research. A decreasing trend was evident for the concept of “question negotiation” and this concept was frequently cited by reference service researchers. In addition, among the 10 citation functions, “related literature” was dominant (30.8%). Both “evidence” and “views” were in second place with the same percentage (18.7%), followed by “terms” (9.2%) and “background information” (7.2%). A decreasing trend was identified in the top three citation functions, whereas an increasing trend was observed in the “term” and “background information” functions. 相似文献
10.
This study examines how libraries within college and university settings in the United States have dealt with the influx of patron mobile telephone use. We contacted 150 colleges and universities throughout the United States and received 87 responses. These institutions were ranked by US News and World Report in their 2006 Edition of “America’s Best Colleges;” we sampled from their list stratified within the following categories: “top public universities;” “best liberal arts colleges;” “fourth tier liberal arts colleges;” “best national universities;” and “fourth tier national universities.” We found that those college and university libraries adopt an array of stances when approaching cell phone use within their library facilities. These approaches include structured guidelines that specifically address cell phone use posted on the library website, signs displayed throughout the library barring cell phone use, and signage that provides patrons with a list of areas in which use is permitted. Interestingly, we found that several libraries lack any kind of mobile phone policy and instead, assume all patrons will behave in a proper way. 相似文献
11.
Thomas K. Gaisser 《Journal of The Franklin Institute》2011,348(3):453-458
This award recognizes two specific discoveries that constitute the experimental discovery of neutrino oscillations. In 1998 the Super-Kamiokande group under the leadership of Yoji Totsuka published their paper, “Evidence for Oscillation of Atmospheric Neutrinos” in Physical Review Letters [1]. The paper describes a deficit of muon-type neutrinos from below the detector relative to those from above. It explains this “atmospheric neutrino anomaly” as a result of transformation of some of the muon neutrinos into another type of neutrino. Four years later, the group led by Arthur McDonald described “Direct Evidence for Neutrino Flavor Transformation from Neutral-Current Interactions in the Sudbury Neutrino Observatory” [2] in the same journal. This experiment detected lower energy neutrinos from deep inside the Sun. By measuring all flavors of neutrinos with large rates, the SNO collaboration showed definitively that the long-standing “solar neutrino puzzle” was another manifestation of neutrino oscillations. As a result of these two experiments, we now understand that neutrinos can change identities during propagation and that both the solar and atmospheric neutrino “problems” result from the same underlying phenomenon of oscillations. A consequence of neutrino oscillations is that neutrinos, previously thought to be massless, must have a non-zero rest mass. 相似文献
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A well-known challenge for multi-document summarization (MDS) is that a single best or “gold standard” summary does not exist, i.e. it is often difficult to secure a consensus among reference summaries written by different authors. It therefore motivates us to study what the “important information” is in multiple input documents that will guide different authors in writing a summary. In this paper, we propose the notions of macro- and micro-level information. Macro-level information refers to the salient topics shared among different input documents, while micro-level information consists of different sentences that act as elaborating or provide complementary details for those salient topics. Experimental studies were conducted to examine the influence of macro- and micro-level information on summarization and its evaluation. Results showed that human subjects highly relied on macro-level information when writing a summary. The length allowed for summaries is the leading factor that affects the summary agreement. Meanwhile, our summarization evaluation approach based on the proposed macro- and micro-structure information also suggested that micro-level information offered complementary details for macro-level information. We believe that both levels of information form the “important information” which affects the modeling and evaluation of automatic summarization systems. 相似文献
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Many authors have proposed categorizations for approaches to Knowledge Management; outstanding prospects including functionalist and interpretativist. In the first approach, knowledge is considered as a “static object” that exists in a number of ways and locations; in the second one, knowledge does not exist independently of human experience, social practice, of knowledge itself and its use, where it is shared by the social practices of communities, because it is “dynamic and active”. These articles constitute an extensive review on the subject, focused in reviewing, analyzing and presenting a study of the interpretativist perspective, and describe a maturity model for KM operational from it. 相似文献
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Recently, question series have become one focus of research in question answering. These series are comprised of individual factoid, list, and “other” questions organized around a central topic, and represent abstractions of user–system dialogs. Existing evaluation methodologies have yet to catch up with this richer task model, as they fail to take into account contextual dependencies and different user behaviors. This paper presents a novel simulation-based methodology for evaluating answers to question series that addresses some of these shortcomings. Using this methodology, we examine two different behavior models: a “QA-styled” user and an “IR-styled” user. Results suggest that an off-the-shelf document retrieval system is competitive with state-of-the-art QA systems in this task. Advantages and limitations of evaluations based on user simulations are also discussed. 相似文献
16.
Crowd science: The organization of scientific research in open collaborative projects 总被引：1，自引：0，他引：1
A growing amount of scientific research is done in an open collaborative fashion, in projects sometimes referred to as “crowd science”, “citizen science”, or “networked science”. This paper seeks to gain a more systematic understanding of crowd science and to provide scholars with a conceptual framework and an agenda for future research. First, we briefly present three case examples that span different fields of science and illustrate the heterogeneity concerning what crowd science projects do and how they are organized. Second, we identify two fundamental elements that characterize crowd science projects – open participation and open sharing of intermediate inputs – and distinguish crowd science from other knowledge production regimes such as innovation contests or traditional “Mertonian” science. Third, we explore potential knowledge-related and motivational benefits that crowd science offers over alternative organizational modes, and potential challenges it is likely to face. Drawing on prior research on the organization of problem solving, we also consider for what kinds of tasks particular benefits or challenges are likely to be most pronounced. We conclude by outlining an agenda for future research and by discussing implications for funding agencies and policy makers. 相似文献
17.
Richard R. Nelson 《Research Policy》2008,37(1):1-11
In recent years “institutions” have again become a central focus of economists and other scholars studying the processes of economic growth, and the reasons why nations have differed so greatly in their achievements on this front. However, with few exceptions the exploration of the role of institutions has not been connected with a coherent analysis of the relationships between institutions and institutional change and technological advance. This paper proposes a way of analyzing these relationships. The concept of “social technologies” which support “physical technologies” plays a key role in the analysis. 相似文献
18.
This article aimed to identify the effect of university-industry (U-I) collaborations on the innovative performance of firms operating in the advanced materials field, and by doing so, it proposed an original classification of the research organization partners. The main contribution resides in the estimation of the role played by collaborations with differently experienced scientists. In contrast with previous studies, whose empirical setting was the life science industry, in the advanced materials industry the most effective collaborations are not with “Star scientists”, but with “Pasteur scientists”. The latter concept was empirically tested first by the authors of this article, to deepen the present understanding of industrial heterogeneity in innovation processes and to offer new insights for the formulation of corporate innovation strategies. The results of the estimation of a negative binomial regression model applied to a sample of 455 firms active in the photocatalysis in Japan confirm the idea that engaging in research collaborations, measured as co-invention, with “Pasteur scientists” increases firms’ R&D productivity, measured as number of registered patents. In contrast, we found that firms’ collaborations with “Star scientists” exert little impact on their innovative output. 相似文献
19.
The need to economically identify rare subjects within large, poorly mapped search spaces is a frequently encountered problem for social scientists and managers. It is notoriously difficult, for example, to identify “the best new CEO for our company,” or the “best three lead users to participate in our product development project.” Mass screening of entire populations or samples becomes steadily more expensive as the number of acceptable solutions within the search space becomes rarer.The search strategy of “pyramiding” is a potential solution to this problem under many conditions. Pyramiding is a search process based upon the idea that people with a strong interest in a topic or field tend to know people more expert than themselves. In this paper we report upon four experiments empirically exploring the efficiency of pyramiding searches relative to mass screening. We find that pyramiding on average identified the most expert individual in a group on a specific topic with only 28.4% of the group interviewed - a great efficiency gain relative to mass screening. Further, pyramiding identified one of the top 3 experts in a population after interviewing only 15.9% of the group on average. We discuss conditions under which the pyramiding search method is likely to be efficient relative to screening. 相似文献
20.
Dirk Akkermans 《Research Policy》2009,38(1):181-191
In Varieties of Capitalism; The Institutional Foundations of Comparative Advantage, Peter A. Hall and David Soskice (H&S) argue that technological specialization patterns are largely determined by the prevailing “variety of capitalism”. They hypothesize that “liberal market economies” (LMEs) specialize in radical innovation, while “coordinated market economies” (CMEs) focus more on incremental innovation. Mark Zachary Taylor [Taylor, M.Z., 2004. Empirical evidence against varieties of capitalism's theory of technological innovation. International Organization 58, 601-631.] convincingly argued that Hall and Soskice's empirical test is fundamentally flawed and proposed a more appropriate test of their conjecture. He rejected the varieties of capitalism explanation of innovation patterns. We extend and refine Taylor's analysis, using a broader set of radicality indicators and making industry-level comparisons. Our results indicate that Hall and Soskice's conjecture cannot be upheld as a general rule, but that it survives closer scrutiny for a substantial number of industries and an important dimension of radicality. 相似文献