CLT-koetalon rakennusfysikaaliset tutkimukset

OpenAIRE

Tytti, Ahoranta; Tuomas, Alakunnas; Juha, Autioniemi; Antti, Niemelä; Kari, Peisa; Valtteri, Pirttinen; Mikko, Vatanen

2016-01-01

CLT-pientalon kokeellisessa rakennushankkeessa testattiin CLT-rakenteiden toimivuutta, kerättiin tietoja ja esiteltiin CLT-rakentamista. Koetalossa tehdyt tutkimukset osoittivat, että CLT-rakenteinen pientalo soveltuu hyvin suomalaisiin olosuhteisiin. Hankkeen aikana tuotettiin paljon lisätietoa CLT-rakentamisesta. CLT-koetalo-hanke oli luonteeltaan investointi- ja kehittämishanke. Se toteutettiin 1.4.2013–30.4.2015. Hanke oli Euroopan aluekehitysrahaston osittain rahoittama, rahoittajavi...

The relationship between EFL Teachers’ Attitudes towards CLT and Perceived Difficulties of Implementing CLT in Language Classes

Directory of Open Access Journals (Sweden)

Mehrak Rahimi

2014-05-01

Full Text Available The present study investigated the relationship between EFL teachers’ attitudes towards CLT and perceived difficulties of implementing CLT in language classes. Two hundred and three EFL teachers participated in the study. Their attitudes towards CLT and their perceptions of the problems of implementing CLT were assessed by two questionnaires. The results of the descriptive statistics showed that EFL teachers had positive attitudes towards CLT in general and group work in communicative classes in particular. Further, while EFL teachers generally did not find much difficulty in implementing CLT in language classes, they found the difficulties the educational system creates as a major obstacle to use CLT. Moreover, CLT attitudes and perceived difficulties of CLT implementation were not found to be related; however, when subscales of CLT attitudes and perceived difficulties questionnaires were considered, three correlations were found to be statistically significant. Difficulties caused by students in communicative classes were found to be inversely and significantly related to (a attitudes to CLT as a whole (r=-.160, p<.05 and (b attitudes towards group/pair work in CLT (r=-.156, p<.05. Further, attitudes towards the role of teacher in a communicative class were found to be positively related to difficulties inherent in the CLT method itself (r= .181, p<.01.

Applying cognitive load theory to the redesign of a conventional database systems course

Science.gov (United States)

Mason, Raina; Seton, Carolyn; Cooper, Graham

2016-01-01

Cognitive load theory (CLT) was used to redesign a Database Systems course for Information Technology students. The redesign was intended to address poor student performance and low satisfaction, and to provide a more relevant foundation in database design and use for subsequent studies and industry. The original course followed the conventional structure for a database course, covering database design first, then database development. Analysis showed the conventional course content was appropriate but the instructional materials used were too complex, especially for novice students. The redesign of instructional materials applied CLT to remove split attention and redundancy effects, to provide suitable worked examples and sub-goals, and included an extensive re-sequencing of content. The approach was primarily directed towards mid- to lower performing students and results showed a significant improvement for this cohort with the exam failure rate reducing by 34% after the redesign on identical final exams. Student satisfaction also increased and feedback from subsequent study was very positive. The application of CLT to the design of instructional materials is discussed for delivery of technical courses.

Mindstorms robots and the application of cognitive load theory in introductory programming

Science.gov (United States)

Mason, Raina; Cooper, Graham

2013-12-01

This paper reports on a series of introductory programming workshops, initially targeting female high school students, which utilised Lego Mindstorms robots. Cognitive load theory (CLT) was applied to the instructional design of the workshops, and a controlled experiment was also conducted investigating aspects of the interface. Results indicated that a truncated interface led to better learning by novice programmers as measured by test performance by participants, as well as enhanced shifts in self-efficacy and lowered perception of difficulty. There was also a transfer effect to another programming environment (Alice). It is argued that the results indicate that for novice programmers, the mere presence on-screen of additional (redundant) entities acts as a form of tacit distraction, thus impeding learning. The utility of CLT to analyse, design and deliver aspects of computer programming environments and instructional materials is discussed.

Hybrid system of unbonded post-tensioned CLT panels and light-frame wood shear walls

Science.gov (United States)

T. Ho; T. Dao; S. Aaleti; J. van de Lindt; Douglas Rammer

2016-01-01

Cross-laminated timber (CLT) is a relatively new type of massive timber system that has shown to possess excellent mechanical properties and structural behavior in building construction. When post-tensioned with high-strength tendons, CLT panels perform well under cyclic loadings because of two key characteristics: their rocking behavior and self-centering capacity....

CLT:n ominaisuudet ja käyttö rakennusmateriaalina

OpenAIRE

Pulkkinen, Hanna-Liisa

2016-01-01

Opinnäytetyössä käsitellään CLT:n ominaisuuksia ja käyttöä rakennusmateriaalina. CLT muodostuu sanoista Cross Laminated Timber, joka tarkoittaa ristiinliimatuista puulevykerroksista valmistettua puulevyä. CLT-levyistä on jatkojalostettu CLT-elementtejä ja CLT-rakentamisesta on tullut jo yksi suosituimmista rakennusmenetelmistä Keski-Euroopassa. Suomessa CLT-rakentaminen on vielä melko harvinaista. Opinnäytetyössä tavoitteena oli kerätä CLT:stä ja CLT-rakentamisesta jo olemassa oleva tieto ja ...

CLT:n käyttömahdollisuudet tilaelementtituotannossa

OpenAIRE

Ahlberg, Aku

2015-01-01

Tämän opinnäytetyön tarkoituksena oli tutkia CLT:n - Cross Laminated Timber - käyttömahdollisuuksia tilaele-menttirakentamisessa. Työn tilaajana toimi Elemenco Oy, joka valmistaa puurankaisia tilaelementtejä ja rakentaa niistä mm. kouluja, päiväkoteja, toimistoja ja asuntoja. Tavoitteena oli selvitää, miten Elemenco voisi yrityksenä käyttää CLT:tä hyväksi omassa liiketoiminnassaan. Työssä pohdittiin CLT:n vahvuuksia rakennusmateriaalina. CLT on uusi puurakennejärjestelmä, joka on kasvattan...

Metacognitive Load--Useful, or Extraneous Concept? Metacognitive and Self-Regulatory Demands in Computer-Based Learning

Science.gov (United States)

Schwonke, Rolf

2015-01-01

Instructional design theories such as the "cognitive load theory" (CLT) or the "cognitive theory of multimedia learning" (CTML) explain learning difficulties in (computer-based) learning usually as a result of design deficiencies that hinder effective schema construction. However, learners often struggle even in well-designed…

What does germane load mean? An empirical contribution to the cognitive load theory.

Science.gov (United States)

Debue, Nicolas; van de Leemput, Cécile

2014-01-01

While over the last decades, much attention has been paid to the mental workload in the field of human computer interactions, there is still a lack of consensus concerning the factors that generate it as well as the measurement methods that could reflect workload variations. Based on the multifactorial Cognitive Load Theory (CLT), our study aims to provide some food for thought about the subjective and objective measurement that can be used to disentangle the intrinsic, extraneous, and germane load. The purpose is to provide insight into the way cognitive load can explain how users' cognitive resources are allocated in the use of hypermedia, such as an online newspaper. A two-phase experiment has been conducted on the information retention from online news stories. Phase 1 (92 participants) examined the influence of multimedia content on performance as well as the relationships between cognitive loads and cognitive absorption. In Phase 2 (36 participants), eye-tracking data were collected in order to provide reliable and objective measures. Results confirmed that performance in information retention was impacted by the presence of multimedia content such as animations and pictures. The higher number of fixations on these animations suggests that users' attention could have been attracted by them. Results showed the expected opposite relationships between germane and extraneous load, a positive association between germane load and cognitive absorption and a non-linear association between intrinsic and germane load. The trends based on eye-tracking data analysis provide some interesting findings about the relationship between longer fixations, shorter saccades and cognitive load. Some issues are raised about the respective contribution of mean pupil diameter and Index of Cognitive Activity.

Towards a Cognitive Theory of Multimedia Assessment (CTMMA)

NARCIS (Netherlands)

Kirschner, Paul A.; Park, Babette; Malone, Sarah; Jarodzka, Halszka

2017-01-01

Much is known about assessment in all its forms and the corpus of theory and knowledge is growing daily. In a similar vein, the use of multimedia for learning also has a sound basis in research and theory, such as the Cognitive Load Theory (CLT; Sweller, Van Merriënboer, & Paas, 1998), human

External representation of argumentation in CSCL and the management of cognitive load

NARCIS (Netherlands)

Bruggen, J.M.; Kirschner, P.A.; Jochems, W.

2002-01-01

Computer-supported collaborative learning (CSCL) environments, particularly environments where students share external representations, are discussed as an interesting area for the application of cognitive load theory (CLT). CSCL environments share a number of characteristics that will induce

Using Multiple Ways to Investigate Cognitive Load Theory in the Context of Physics Instruction

Science.gov (United States)

Zu, Tianlong

Cognitive load theory (CLT) (Sweller 1988, 1998, 2010) provides us a guiding framework for designing instructional materials. CLT differentiates three subtypes of cognitive load: intrinsic, extraneous, and germane cognitive load. The three cognitive loads are theorized based on the number of simultaneously processed elements in working memory. Intrinsic cognitive load depends upon the number of interacting elements in the instructional material that are related to the learning objective. Extraneous cognitive load is the mental resources allocated to processing unnecessary information which does not contribute to learning as caused by non- optimal instructional procedure. It is determined by the number of interacting elements which are not related to learning goal. Both intrinsic and extraneous load vary according to prior knowledge of learners. Germane cognitive load is indirectly related to interacting elements. It represents the cognitive resources deployed for processing intrinsic load, chunking information and constructing and automating schema. Germane cognitive load is related to level of motivation of the learner. Given this triarchic model of cognitive load and their different roles in learning activities, different learning outcomes can be expected depending upon the characteristics of the educational materials, learner characteristics, and instructional setting. In three experiments, we investigated cognitive load theory following different approaches. Given the triarchic nature of cognitive load construct, it is critical to find non- intrusive ways to measure cognitive load. In study one, we replicated and extended a previous landmark study to investigate the use of eye movements related metrics to measure the three kinds of cognitive load independently. We also collected working memory capacity of students using a cognitive operation-span task. Two of the three types of cognitive load (intrinsic and extraneous) were directly manipulated, and the third

The Need for Maintaining CLT in Indonesia

Science.gov (United States)

Ariatna

2016-01-01

Recent decades have shown growing interest among outer circle language researchers and practitioners in the discussion of communicative language teaching (CLT), as both a leading teaching model and a frequently disputed dimension of language pedagogy. Repeatedly, the debate returns to the question of how to best implement CLT as a Western product…

Behaviour of Mechanically Laminated CLT Members

Science.gov (United States)

Kuklík, P.; Velebil, L.

2015-11-01

Cross laminated timber (CLT) is one of the structural building systems based on the lamination of multiple layers, where each layer is oriented perpendicularly to each other. Recent requirements are placed to develop an alternative process based on the mechanical lamination of the layers, which is of particular interest to our research group at the University Centre for Energy Efficient Buildings. The goal is to develop and verify the behaviour of mechanically laminated CLT wall panels exposed to shear stresses in the plane. The shear resistance of mechanically jointed CLT is ensured by connecting the layers by screws. The paper deals with the experimental analysis focused on the determination of the torsional stiffness and the slip modulus of crossing areas for different numbers of orthogonally connected layers. The results of the experiments were compared with the current analytical model.

Exploring CLT Practices in Saudi International Schools

Science.gov (United States)

Abdel-Salam, Ahmed Saad

2014-01-01

This is a research study conducted on 17 teachers who teach English in Saudi international schools. It mainly aims at exploring teaching practices in these schools in terms of the principles of communicative language teaching (CLT). It also investigates the appropriateness of CLT in this context from the point of view of teachers. Two research…

Manipulation of Cognitive Load Variables and Impact on Auscultation Test Performance

Science.gov (United States)

Chen, Ruth; Grierson, Lawrence; Norman, Geoffrey

2015-01-01

Health profession educators have identified auscultation skill as a learning need for health professional students. This article explores the application of cognitive load theory (CLT) to designing cardiac and respiratory auscultation skill instruction for senior-level undergraduate nursing students. Three experiments assessed student auscultation…

Linking Theory to Practice: Implementation of CLT by Taiwanese University Teachers of English

Science.gov (United States)

Hung, Yu-ju

2009-01-01

For the past several decades, Asian teachers of English have been traveling to English L1 countries to do graduate work and return home ready to try new teaching approaches (Golombek & Jordan, 2005; Liu, 1999; Major & Yamashiro, 2004). Among these approaches, Communicative language Teaching (CLT) of English is a teaching innovation that…

Language Games in Communicative Language Teaching (CLT)

Institute of Scientific and Technical Information of China (English)

韩颖

2012-01-01

　　Games are an indispensible part of Communicative Language Teaching (CLT). They not only reduce EFL learners’ stress and increase their learning motivation, but also improve their communication competence and promote fluency. It is advo⁃cated that games should be implemented by EFL teachers in CLT, meanwhile paying attention to the communicative characteris⁃tics of games in the application and design of games.

Measuring Cognitive Load during Simulation-Based Psychomotor Skills Training: Sensitivity of Secondary-Task Performance and Subjective Ratings

Science.gov (United States)

Haji, Faizal A.; Khan, Rabia; Regehr, Glenn; Drake, James; de Ribaupierre, Sandrine; Dubrowski, Adam

2015-01-01

As interest in applying cognitive load theory (CLT) to the study and design of pedagogic and technological approaches in healthcare simulation grows, suitable measures of cognitive load (CL) are needed. Here, we report a two-phased study investigating the sensitivity of subjective ratings of mental effort (SRME) and secondary-task performance…

Chapter 1: CLT Introduction to cross-laminated timber

Science.gov (United States)

Sylvan Gagnon; E.M.(Ted) Bilek; Lisa Podesto; Pablo Crespell

2013-01-01

Cross-laminated timber ( CLT), a new generation of engineered wood product developed initially in Europe, has been gaining increased popularity in residential and non-residential applications in several countries. Many impressive low- and mid-rise buildings built around the world using CLT showcase the many advantages this product has to offer to the construction...

α5β1-Integrin inhibitor (CLT-28643) effective in rabbit trabeculectomy model.

Science.gov (United States)

Schultheiss, Maximilian; Schnichels, Sven; Konrad, Eva-Maria; Bartz-Schmidt, Karl U; Zahn, Grit; Caldirola, Patrizia; Fsadni, Mario G; Caram-Lelham, Ninus; Spitzer, Martin S

2017-02-01

Glaucoma filtration surgery (GFS) fails due to fibrosis. The α5β1-integrin plays a pivotal role in fibrosis, angiogenesis and inflammation. This is the first experiment evaluating the prevention of fibrosis after GFS by a specific small molecule α5β1-integrin inhibitor (CLT-28643). Twenty-four rabbits received trabeculectomy on their right eyes. The rabbits were randomized into three groups of eight eyes each. CLT-28643 was given as a single subconjunctival injection intraoperatively to two of the right eye groups followed by postoperative vehicle eye drops (CLT+ group) or CLT-28643 eye drops 4 times daily (CLT++ group). A third group received mitomycin-C (MMC) intraoperatively (sponge application, 0.04%, 2 min) followed by vehicle eye drops postoperatively. The control-surgery group consisted of 12 left eyes having trabeculectomy with no adjunctive therapy. The remaining 12 left eyes formed the untreated group. Clinical assessment included intraocular pressure (IOP) measurement, slit-lamp examination (including bleb survival and morphology) and bleb photography. The rabbits were killed after four weeks for histology. Both CLT-28643-treated groups showed significantly prolonged bleb survival, and better bleb score compared to the control-surgery group. At end of the study, most functioning blebs were found in the MMC group (MMC group 75%; CLT+ group 12.5%, CLT++ group 25%; CLT+ group 12.5%, control-surgery group 0%). CLT-28643 was non-toxic and well tolerated. This rabbit GFS study indicates that inhibition of α5β1-integrin by the novel α5β1-integrin antagonist CLT-28643 significantly improved the outcome. The effect of a single intro-operative application of CLT-28643 seems to be inferior to 0.04% MMC. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Instructional Design for Advanced Learners: Establishing Connections between the Theoretical Frameworks of Cognitive Load and Deliberate Practice

NARCIS (Netherlands)

Van Gog, Tamara; Ericsson, K. A.; Rikers, Remy; Paas, Fred

2007-01-01

Cognitive load theory (CLT) has been successful in identifying instructional formats that are more effective and efficient than conventional problem solving in the initial, novice phase of skill acquisition. However, recent findings regarding the “expertise reversal effect” have begun to stimulate

CLT and CLS job responsibilities: current distinctions and updates.

Science.gov (United States)

Doig, K; Beck, S J; Kolenc, K

2001-01-01

This study was undertaken to address the following questions: 1. What tasks distinguish the job of a clinical laboratory scientist (CLS) from that of a clinical laboratory technician (CLT)? 2. What changes in role distinctions, have occurred for entry-level CLS and CLT practitioners over the five-year period 1993-98? 3. What tasks have been deleted from the CLT and CLS content outlines because they were not frequently performed or not considered entry-level? 4. What changes in practice are reflected in the current job analyses? A national job analysis of tasks constituting the job of clinical laboratory scientists (CLSs) and clinical laboratory technicians (CLTs) was conducted in 1998-99 as part of a standard setting process for the certifying examinations of the National Credentialing Agency for Laboratory Personnel (NCA). The job analyses relied upon mail surveys to 1200 individuals for each job level asking respondents to identify tasks significant to effective practice at job entry. The task lists resulting from statistical analysis of those surveys were examined to answer the study questions. The sample for each survey included 1200 practitioners, educators and laboratory managers selected at random from membership in professional organizations or from NCA certificant lists. Sampling was stratified to insure adequate practitioner representation. The mean rating on a four point scale for each item on the surveys was evaluated for overall significance as well as significance across geographic regions. The tasks meeting specified criteria were retained in the final task lists. Tasks were counted and their content evaluated to compare CLS and CLT job tasks. The response rates to the surveys were 33% for CLT and 21% for CLS. Reliability was judged based on average intraclass correlation coefficients of .86 and .82 for the CLT and CLS surveys, respectively. There were 952 tasks retained on the CLS content outline and 725 retained on the CLT content outline of the

A Dissipative Connector for CLT Buildings: Concept, Design and Testing.

Science.gov (United States)

Scotta, Roberto; Marchi, Luca; Trutalli, Davide; Pozza, Luca

2016-02-26

This paper deals with the conception and characterization of an innovative connection for cross-laminated timber (CLT) panels. The connection is designed to provide an adequate level of dissipative capacity to CLT structures also when realized with large horizontal panels and therefore prone to fragile shear sliding failure. The connector, named X-bracket, has been theorized and designed by means of numerical parametric analyses. Furthermore, its cyclic behavior has been verified with experimental tests and compared to that of traditional connectors. Numerical simulations of cyclic tests of different CLT walls anchored to the foundation with X-brackets were also performed to assess their improved seismic performances. Finally, the analysis of the response of a 6 m × 3 m squat wall demonstrates that the developed connection provides good ductility and dissipation capacities also to shear walls realized with a single CLT panel.

CLT-koetalon lämpö- ja kosteusteknisen toiminnan analysointiraportti Q2/2014

OpenAIRE

Autioniemi, Juha; Pirttinen, Valtteri; Vatanen, Mikko

2014-01-01

CLT-koetalo-projektin yhtenä päätavoitteena on tutkia CLT-materiaalin rakennusfysikaalista toimintaa Suomen haastavissa olosuhteissa. Tämä Q2-raportti on toinen CLT-koetalon lämpö- ja kosteusteknisen toiminnan analysointiraportista, joita julkaistaan vuoden 2014 aikana yhteensä neljä. Q2/2014 -raportissa analysoidaan Kemissä sijaitsevasta CLT-koetalon rakenteista saatua mittausdataa. Koetalon rakenteissa sijaitsee yhteensä 48 mittausanturia, jotka mittaavat lämpötilaa ja suhteellista kosteutt...

Grammar-translation and CLT in L2 Grammar Teaching

Institute of Scientific and Technical Information of China (English)

缪杉莎

2013-01-01

This paper puts forward to compare teaching method between grammar-translation and CLT in grammar teaching. Gram⁃mar leaning is a basic concept in English learning as grammar is an important element in a communicative approach to language. This paper discussed CLT method can help and encourage student to study, however, grammar-translation method is able to under⁃stand.

A Dissipative Connector for CLT Buildings: Concept, Design and Testing

Science.gov (United States)

Scotta, Roberto; Marchi, Luca; Trutalli, Davide; Pozza, Luca

2016-01-01

This paper deals with the conception and characterization of an innovative connection for cross-laminated timber (CLT) panels. The connection is designed to provide an adequate level of dissipative capacity to CLT structures also when realized with large horizontal panels and therefore prone to fragile shear sliding failure. The connector, named X-bracket, has been theorized and designed by means of numerical parametric analyses. Furthermore, its cyclic behavior has been verified with experimental tests and compared to that of traditional connectors. Numerical simulations of cyclic tests of different CLT walls anchored to the foundation with X-brackets were also performed to assess their improved seismic performances. Finally, the analysis of the response of a 6 m × 3 m squat wall demonstrates that the developed connection provides good ductility and dissipation capacities also to shear walls realized with a single CLT panel. PMID:28773265

Cloning and expression of clt genes encoding milk-clotting proteases from Myxococcus xanthus 422.

Science.gov (United States)

Poza, M; Prieto-Alcedo, M; Sieiro, C; Villa, T G

2004-10-01

The screening of a gene library of the milk-clotting strain Myxococcus xanthus 422 constructed in Escherichia coli allowed the description of eight positive clones containing 26 open reading frames. Only three of them (cltA, cltB, and cltC) encoded proteins that exhibited intracellular milk-clotting ability in E. coli, Saccharomyces cerevisiae, and Pichia pastoris expression systems.

Validity of Cognitive Load Measures in Simulation-Based Training: A Systematic Review.

Science.gov (United States)

Naismith, Laura M; Cavalcanti, Rodrigo B

2015-11-01

Cognitive load theory (CLT) provides a rich framework to inform instructional design. Despite the applicability of CLT to simulation-based medical training, findings from multimedia learning have not been consistently replicated in this context. This lack of transferability may be related to issues in measuring cognitive load (CL) during simulation. The authors conducted a review of CLT studies across simulation training contexts to assess the validity evidence for different CL measures. PRISMA standards were followed. For 48 studies selected from a search of MEDLINE, EMBASE, PsycInfo, CINAHL, and ERIC databases, information was extracted about study aims, methods, validity evidence of measures, and findings. Studies were categorized on the basis of findings and prevalence of validity evidence collected, and statistical comparisons between measurement types and research domains were pursued. CL during simulation training has been measured in diverse populations including medical trainees, pilots, and university students. Most studies (71%; 34) used self-report measures; others included secondary task performance, physiological indices, and observer ratings. Correlations between CL and learning varied from positive to negative. Overall validity evidence for CL measures was low (mean score 1.55/5). Studies reporting greater validity evidence were more likely to report that high CL impaired learning. The authors found evidence that inconsistent correlations between CL and learning may be related to issues of validity in CL measures. Further research would benefit from rigorous documentation of validity and from triangulating measures of CL. This can better inform CLT instructional design for simulation-based medical training.

A geometric theory for Lévy distributions

International Nuclear Information System (INIS)

Eliazar, Iddo

2014-01-01

Lévy distributions are of prime importance in the physical sciences, and their universal emergence is commonly explained by the Generalized Central Limit Theorem (CLT). However, the Generalized CLT is a geometry-less probabilistic result, whereas physical processes usually take place in an embedding space whose spatial geometry is often of substantial significance. In this paper we introduce a model of random effects in random environments which, on the one hand, retains the underlying probabilistic structure of the Generalized CLT and, on the other hand, adds a general and versatile underlying geometric structure. Based on this model we obtain geometry-based counterparts of the Generalized CLT, thus establishing a geometric theory for Lévy distributions. The theory explains the universal emergence of Lévy distributions in physical settings which are well beyond the realm of the Generalized CLT

A geometric theory for Lévy distributions

Science.gov (United States)

Eliazar, Iddo

2014-08-01

Lévy distributions are of prime importance in the physical sciences, and their universal emergence is commonly explained by the Generalized Central Limit Theorem (CLT). However, the Generalized CLT is a geometry-less probabilistic result, whereas physical processes usually take place in an embedding space whose spatial geometry is often of substantial significance. In this paper we introduce a model of random effects in random environments which, on the one hand, retains the underlying probabilistic structure of the Generalized CLT and, on the other hand, adds a general and versatile underlying geometric structure. Based on this model we obtain geometry-based counterparts of the Generalized CLT, thus establishing a geometric theory for Lévy distributions. The theory explains the universal emergence of Lévy distributions in physical settings which are well beyond the realm of the Generalized CLT.

Exploring ESL Teacher Beliefs and Classroom Practices of CLT: A Case Study

Science.gov (United States)

Rahman, Mohammad Mosiur; Singh, Manjet Kaur Mehar; Pandian, Ambigapathy

2018-01-01

This paper presents a case study that investigated and compared the stated beliefs and observed classroom practices relating to Communicative Language Teaching (CLT) of two ESL teachers. The findings of the study revealed that both the teachers hold similar complex beliefs that mostly contradict the philosophy of CLT. The practices were not in…

THE IMPLEMENTATION OF COMMUNICATIVE LANGUAGE TEACHING (CLT TO TEACH SPOKEN RECOUNTS IN SENIOR HIGH SCHOOL

Directory of Open Access Journals (Sweden)

Eri Rusnawati

2016-10-01

Full Text Available Tujuan dari penelitian ini adalah untuk menggambarkan penerapan metode Communicative Language Teaching/CLT untuk pembelajaran spoken recount. Penelitian ini menelaah data yang kualitatif. Penelitian ini mengambarkan fenomena yang terjadi di dalam kelas. Data studi ini adalah perilaku dan respon para siswa dalam pembelajaran spoken recount dengan menggunakan metode CLT. Subjek penelitian ini adalah para siswa kelas X SMA Negeri 1 Kuaro yang terdiri dari 34 siswa. Observasi dan wawancara dilakukan dalam rangka untuk mengumpulkan data dalam mengajarkan spoken recount melalui tiga aktivitas (presentasi, bermain-peran, serta melakukan prosedur. Dalam penelitian ini ditemukan beberapa hal antara lain bahwa CLT meningkatkan kemampuan berbicara siswa dalam pembelajaran recount. Berdasarkan pada grafik peningkatan, disimpulkan bahwa tata bahasa, kosakata, pengucapan, kefasihan, serta performa siswa mengalami peningkatan. Ini berarti bahwa performa spoken recount dari para siswa meningkat. Andaikata presentasi ditempatkan di bagian akhir dari langkah-langkah aktivitas, peforma spoken recount para siswa bahkan akan lebih baik lagi. Kesimpulannya adalah bahwa implementasi metode CLT beserta tiga praktiknya berkontribusi pada peningkatan kemampuan berbicara para siswa dalam pembelajaran recount dan bahkan metode CLT mengarahkan mereka untuk memiliki keberanian dalam mengonstruksi komunikasi yang bermakna dengan percaya diri. Kata kunci: Communicative Language Teaching (CLT, recount, berbicara, respon siswa

Secondary EFL School Teachers' Perceptions of CLT Principles and Practices: An Exploratory Survey

Directory of Open Access Journals (Sweden)

Mohammad Reza Anani Sarab

2016-10-01

Full Text Available Communicative Language Teaching (CLT is advocated by many applied linguists as a common vehicle to curriculum innovation in many ELT contexts. It represents a change of focus in language teaching from linguistic structures to learners’ need for developing communication skills. In recent years, the Iranian Ministry of Education has introduced the development of a new English curriculum for secondary schools with the aim of establishing the use of communicative activities in language classes. The present study was an attempt to investigate Iranian teachers’ perception of CLT principles and practices through a survey of 75 secondary school teachers in the context of the newly introduced English language curriculum developed based on CLT principles. Based on a combination of quantitative and qualitative data using a semi-structured questionnaire supplemented with interviews with a smaller group of teachers, the results of the survey revealed that a change in classroom arrangements is required before CLT can be practiced in secondary school English classes in Iran. The results also showed that the employment of CLT procedures at the local level is at its beginning stages and might take time to take root. The conclusion is that for the suggested changes in the curriculum to be implemented and realized in English education in Iran, the findings of more comprehensive surveys complemented with observation of teachers’ instructional practices is required to inform the change implementation.

Implementing CLT at Higher Secondary Level in Bangladesh: A Review of Change Management

Science.gov (United States)

Rahman, Md Shidur

2015-01-01

CLT (Communicative Language Teaching) was substituted for GTM (Grammar Translation Method) at higher secondary level in Bangladesh in 2001. This replacement of ELT method was a significant change in the English curriculum. This study aimed to determine that the mismanagement of the change is a prime cause of not getting expected CLT outcomes at…

A Case Study of Academic Writing Development Through Principled Versus Standard Clt Method at Binus University

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Almodad Biduk Asmani

2013-10-01

Full Text Available The purpose of the research project is to investigate how far the academic writing skills of Binus University students can be developed through two conflicting CLT methods: standard and principled. The research project is expected to result in computer-animated format which can be used as one of the main tools in teaching and learning grammar at Binus University. The research project uses the qualitative approach, and thus uses verbal data. The research project involves two subject groups (experimental and control. The experimental group will receive the treatment of grammar learning by using the Principled CLT approach, while the control group receives the standard CLT approach. Survey is then conducted to the two groups so as to find out their comments on the two teaching methods. From the results of the questionnaires, it is found that Principled CLT method is favored for its knowledge and accuracy factors, while the Standard CLT is preferred for its fun and independence factors.   

Grammar Translation Method (GTM) versus Communicative Language Teaching (CLT); A Review of Literature

Science.gov (United States)

Natsir, Muhammad; Sanjaya, Dedi

2014-01-01

Methodology is one of the important elements to implement the objective of education in teaching learning process particularly in English classes. To give the information about two phenomenal methods namely GTM and CLT is the main purpose of this scientific writing since GTM is commonly used previously and CLT is very famous nowadays. In so doing,…

Load theory behind the wheel; perceptual and cognitive load effects.

Science.gov (United States)

Murphy, Gillian; Greene, Ciara M

2017-09-01

Perceptual Load Theory has been proposed as a resolution to the longstanding early versus late selection debate in cognitive psychology. There is much evidence in support of Load Theory but very few applied studies, despite the potential for the model to shed light on everyday attention and distraction. Using a driving simulator, the effect of perceptual and cognitive load on drivers' visual search was assessed. The findings were largely in line with Load Theory, with reduced distractor processing under high perceptual load, but increased distractor processing under high cognitive load. The effect of load on driving behaviour was also analysed, with significant differences in driving behaviour under perceptual and cognitive load. In addition, the effect of perceptual load on drivers' levels of awareness was investigated. High perceptual load significantly increased inattentional blindness and deafness, for stimuli that were both relevant and irrelevant to driving. High perceptual load also increased RTs to hazards. The current study helps to advance Load Theory by illustrating its usefulness outside of traditional paradigms. There are also applied implications for driver safety and roadway design, as the current study suggests that perceptual and cognitive load are important factors in driver attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Phlebotomy skills expected of career entry CLS/CLT graduates: a Missouri hospital perspective.

Science.gov (United States)

Millstead, C

2000-01-01

To determine how much, what type, and what proficiency of phlebotomy experience CLS/CLT students should have during the training program to be prepared to meet the needs of the majority of Missouri hospital employers. Survey to determine the role healthcare professionals, inside and outside the laboratory, play in today's blood collection patterns and phlebotomy management. The Missouri Organization of Clinical Laboratory Science mailed 204 surveys to the Missouri Hospital Association member laboratories. MAIN OUTCOMES/CONCLUSIONS: This research examined the need for modifying phlebotomy skills of clinical laboratory science students. Data gathered from employers support the premise that entry-level competencies of CLS/CLT graduates will vary according to clinical facility size. CLS/CLT programs may use data from this study to plan phlebotomy practicums. It can be extrapolated that Missouri employers who are most likely to employ career entry graduates expect them to draw blood from 9.3 patients within one hour. Fifty-three percent of 40 to 400 bed hospitals expect graduates to perform difficult draws in at least eight types of hospital units. Laboratories are the major managers of hospital wide phlebotomy services; thus, CLS/CLT curricula should include phlebotomy management methods.

CORRECTIVE FEEDBACKS INTERACTION IN CLT-ADOPTED CLASSROOMS

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Ayu Liskinasih

2016-07-01

Full Text Available This case study aimed to examine corrective feedback (CF pattern in the interactions of Indonesian EFL (English as Foreign Language classrooms (a speaking and a grammar classrooms which adopt CLT (Communicative Language Teaching. Two lecturers and twenty undergraduate English department students of an A-class university in Indonesia were involved as research participants. The findings revealed that the lecturers employed all types of CF to treat all types of errors. Explicit corrections were dominant in Speaking class as well as other explicit CF; whereas reformulations and prompt were equally distributed. Elicitation was dominant in Grammar class as well as other prompts; meanwhile, explicit and implicit CFs had similar proportion. The lecturers’ preferences were based on their beliefs on how their students learn foreign language and some factors such as the importance of CF to the instructional focus of the lesson, the possibility to generate student’s uptake, and also their empathetic values about students’ current language development. It was concluded that the provisions of CF in EFL classrooms reflect the application of CLT.

Power Load Prediction Based on Fractal Theory

OpenAIRE

Jian-Kai, Liang; Cattani, Carlo; Wan-Qing, Song

2015-01-01

The basic theories of load forecasting on the power system are summarized. Fractal theory, which is a new algorithm applied to load forecasting, is introduced. Based on the fractal dimension and fractal interpolation function theories, the correlation algorithms are applied to the model of short-term load forecasting. According to the process of load forecasting, the steps of every process are designed, including load data preprocessing, similar day selecting, short-term load forecasting, and...

Effects of Reducing the Cognitive Load of Mathematics Test Items on Student Performance

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Susan C. Gillmor

2015-01-01

Full Text Available This study explores a new item-writing framework for improving the validity of math assessment items. The authors transfer insights from Cognitive Load Theory (CLT, traditionally used in instructional design, to educational measurement. Fifteen, multiple-choice math assessment items were modified using research-based strategies for reducing extraneous cognitive load. An experimental design with 222 middle-school students tested the effects of the reduced cognitive load items on student performance and anxiety. Significant findings confirm the main research hypothesis that reducing the cognitive load of math assessment items improves student performance. Three load-reducing item modifications are identified as particularly effective for reducing item difficulty: signalling important information, aesthetic item organization, and removing extraneous content. Load reduction was not shown to impact student anxiety. Implications for classroom assessment and future research are discussed.

The Benefits and Influential Factors of CLT in the Japanese University Classroom

OpenAIRE

FRITZ, Robinson

2011-01-01

コミュニカティブ・ランゲージ・ティーチング(CLT)は、コミュニケーションに使えるべく言語運用能力を高めることを目的とした教授法で、これまで、国内外での教室内における言語教育に強い影響を与えてきた。本稿は、本学にてCLT を実践する利点と、CLT を行うに当たって障害となりうる社会・文化的な要因について議論したものである。

DEVELOPING MATERIAL FOR COMMUNICATIVE LANGUAGE TEACHING (CLT TO TEACH ENGLISH FOR ECONOMICS STUDENTS

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Aulia Hanifah Qomar

2017-11-01

Full Text Available The objectives of this research are to develop materials for CLT as an interesting media to learn English grammar, to know how material in CLT works as a media to learn and evaluate English grammar facilitates students to learn more grammar and to know the responses from the students to the materials in CLT. This research is Research and Development (R&D which use ADDIE design for the procedure. ADDIE design is stand for the procedure itself, these are Analyzing, Designing, Developing, Implementing and Evaluating. This research is designed by book material. The subject of this research is university students of Economic Faculty of Muhammadiyah University of Metro in the second semester. The instrument of this research is questionnaire. The questionnaire in this research is used to collect data which is divided into one aspects, is readability. The data is analyzed using Percentage Analysis Data. The data shows that the product is developed well. For the readability aspect, the result of expert is valid, one-to-one is valid, then in small group is increased to valid, and in the field test it is valid. Therefore, the product is developed well after each phase of the research. Based on the result of the research, the researcher concluds that the materials in CLT book can be learned attractively and interestingly. The students can understand the materials well. The learning process can be fun and comfortable for the students. The materials of CLT book media can be used in the class as a breakthrough of attractive and interactive learning which is very interesting for the students of earlier grade.

Validating the psycholinguistic aspects of LITMUS-CLT: Evidence from Polish and Norwegian.

Science.gov (United States)

Hansen, Pernille; Simonsen, Hanne Gram; Łuniewska, Magdalena; Haman, Ewa

2017-01-01

The novel assessment tool Cross-Linguistic Lexical Tasks (LITMUS-CLT) aims for comparable cross-linguistic assessment of multilingual children's lexical skills by basing each language version on two language-specific variables: age of acquisition (AoA) and complexity index (CI), a novel measure related to phonology, morphology, exposure and etymology. This article investigates the validity of this methodology, asking whether the underlying properties are robust predictors of children's performance. The Polish and Norwegian CLTs were used to assess 32 bilingual Polish-Norwegian, 34 monolingual Norwegian and 36 monolingual Polish children. The effects of AoA and CI were contrasted with frequency in child directed speech (CDS) and imageability, two known predictors of lexical development. AoA was a reliable predictor of performance within all parts of CLT, in contrast to CI. Apart from AoA, only exposure and CDS frequency had a significant effect within both monolinguals and bilinguals. These results indicate that CLT assesses lexical skills in a cross-linguistically comparable manner, but suggest a revision of the CI measure.

Cognitive load theory

NARCIS (Netherlands)

Kirschner, Paul A.; Kirschner, Femke; Paas, Fred

2010-01-01

Kirschner, P. A., Kirschner, F. C., & Paas, F. (2009). Cognitive load theory. In E. M. Anderman & L. H. Anderman (Eds.). Psychology of classroom learning: An encyclopedia, Volume 1, a-j (pp. 205-209). Detroit, MI: Macmillan Reference.

Cognitive Load Theory: How Many Types of Load Does It Really Need?

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Kalyuga, Slava

2011-01-01

Cognitive load theory has been traditionally described as involving three separate and additive types of load. Germane load is considered as a learning-relevant load complementing extraneous and intrinsic load. This article argues that, in its traditional treatment, germane load is essentially indistinguishable from intrinsic load, and therefore…

TRACC_PB SOSS Integrated Traffic Simulation for CLT Ramp Operation

Science.gov (United States)

Okuniek, Nikolai; Zhu, Zhifan

2017-01-01

This presentation provides the current task under the NASA-DLR research collaboration for airport surface. It presents the effort done to adapt TRACC and SOSS software components to simulate airport (CLT) ramp area traffic management using TRACC's conflict free taxi trajectory optimization and SOSS's fast time simulation platform.

In Search for Instructional Techniques to Maximize the Use of Germane Cognitive Resources: A Case of Teaching Complex Tasks in Physics

Science.gov (United States)

Sliva, Yekaterina

2014-01-01

The purpose of this study was to introduce an instructional technique for teaching complex tasks in physics, test its effectiveness and efficiency, and understand cognitive processes taking place in learners' minds while they are exposed to this technique. The study was based primarily on cognitive load theory (CLT). CLT determines the amount of…

Does the Modality Effect Exist? And if so, Which Modality Effect?

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Reinwein, Joachim

2012-01-01

The modality effect is a central issue in multimedia learning [see Mayer (Cambridge University Press, 2005a), for a review]. Sweller's Cognitive Load Theory (CLT), for example, presumes that an illustrated text is better understood when presented visually rather than orally. The predictive power of CLT lies in how it links in to Baddeley's (1986)…

Using low-grade hardwoods for CLT production: a yield analysis

Science.gov (United States)

R. Edward Thomas; Urs. Buehlmann

2017-01-01

Low-grade hardwood logs are the by-product of logging operations and, more frequently today, urban tree removals. The market prices for these logs is low, as is the value recovered from their logs when producing traditional forest products such as pallet parts, railroad ties, landscaping mulch, or chips for pulp. However, the emergence of cross-laminated timber (CLT)...

Determination of seismic performance factors for CLT shear wall systems

Science.gov (United States)

M. Omar Amini; John W. van de Lindt; Douglas Rammer; Shiling Pei; Philip Line; Marjan Popovski

2016-01-01

This paper presents selected results of connector testing and wall testing which were part of a Forest Products Lab-funded project undertaken at Colorado State University in an effort to determine seismic performance factors for cross laminated timber (CLT) shear walls in the United States. Archetype development, which is required as part of the process, is also...

An Overview of CLT Research and Implementation in North America

Science.gov (United States)

Shiling Pei; Douglas Rammer; Marjan Popovski; Tom Williamson; Philip Line; John W. van de Lindt

2016-01-01

Although not yet seen as common practice, building with cross laminated timber (CLT) is gaining momentum in North America. Behind the scenes of the widely publicized project initiatives such as the Wood Innovation Design Centre Building in Canada and the recent U.S. Tall Wood Building Competition, substantial research, engineering, and development has been completed or...

PEMBELAJARAN BERBANTUAN MULTIMEDIA BERDASARKAN COGNITIVE LOAD THEORY PADA PELAJARAN MATEMATIKA SD

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Rissa Prima Kurniawati

2016-11-01

Full Text Available Multimedia is media that combine two or more elements are composed of text, graphics, images, photographs, audio, video, and animation are integrated. In multimedia-assisted learning, students are given the opportunity to learn not only of learning resources such as teachers, but give the opportunity to students to develop better cognitive, creative, and innovative. Cognitive Load Theory is a theory that was introduced as a teaching theory based on the knowledge of human cognitive architecture that we have. The main principle of Cognitive Load Theory is the quality of learning is enhanced if attention is concentrated on the role and limitations of working memory. Three cognitive load in working memory, which is intrinsic cognitive load, Germany cognitive load, and extraneous cognitive load.   Keywords: Multimedia, Cognitive Load Theory, intrinsic cognitive load, Germany cognitive load, and extraneous cognitive load.

Cognitive Load Theory: Advances in Research on Worked Examples, Animations, and Cognitive Load Measurement

NARCIS (Netherlands)

T.A.J.M. van Gog (Tamara); G.W.C. Paas (Fred); J. Sweller (John)

2010-01-01

textabstractThe contributions to this special issue document some recent advances of cognitive load theory, and are based on contributions to the Third International Cognitive Load Theory Conference (2009), Heerlen, The Netherlands. The contributions focus on developments in example-based learning,

MIL-L-87177 and CLT:X-10 Lubricants Improve Electrical Connector Fretting Corrosion Behavior

International Nuclear Information System (INIS)

AUKLAND, NEIL R.; HANLON, JAMES T.

1999-01-01

We have conducted a fretting research project using MIL-L-87177 and CLT: X-10 lubricants on Nano-miniature connectors. When they were fretted without lubricant, individual connectors first exceeded our 0.5 ohm failure criteria from 2,341 to 45,238 fretting cycles. With additional fretting, their contact resistance increased to more than 100,000 ohms. Unmodified MIL-L-87177 lubricant delayed the onset of first failure to between 430,000 and over 20,000,000 fretting cycles. MIL-L-87177 modified by addition of Teflon powder delayed first failure to beyond 5 million fretting cycles. Best results were obtained when Teflon was used and also when both the straight and modified lubricants were poured into and then out of the connector. CLT: X-10 lubricant delayed the onset of first failure to beyond 55 million cycles in one test where a failure was actually observed and to beyond 20 million cycles in another that was terminated without failure. CLT: X-10 recovered an unlubricated connector driven deeply into failure, with six failed pins recovering immediately and four more recovering during an additional 420 thousand fretting cycles. MIL-L-87177 was not able to recover a connector under similar conditions

Cognitive load theory: Practical implications and an important challenge

Directory of Open Access Journals (Sweden)

Jimmie Leppink, Ph.D.

2017-10-01

Full Text Available The field of medical education has adopted a wide variety of theories from other fields. A fairly recent example is cognitive load theory, which originated in educational psychology. Several empirical studies inspired by cognitive load theory and reviews of practical implications of cognitive load theory have contributed to guidelines for the design of medical education. Simultaneously, several research groups have developed instruments for the measurement of cognitive load in a medical education context. These developments notwithstanding, obtaining evidence for different types of cognitive load remains an important challenge. Therefore, the aim of this article is twofold: to provide medical educators with three key guidelines for the design of instruction and assessment and to discuss several fundamental issues in the remaining challenges presented by different types of cognitive load. The guidelines revolve around minimizing cognitive activity that does not contribute to learning, working with specific learning goals in mind, and appreciating the multifaceted relation between learning and assessment. Key issues around the types of cognitive load include the context in which learning occurs, the continued use of single-item mental effort ratings, and the timing of cognitive load and learning outcome measurements.

Cognitive Load Theory: New Conceptualizations, Specifications, and Integrated Research Perspectives

Science.gov (United States)

Paas, Fred; van Gog, Tamara; Sweller, John

2010-01-01

Over the last few years, cognitive load theory has progressed and advanced rapidly. The articles in this special issue, which document those advances, are based on contributions to the 3rd International Cognitive Load Theory Conference (2009), Heerlen, The Netherlands. The articles of this special issue on cognitive load theory discuss new…

Integrin α5β1 Inhibition by CLT-28643 Reduces Postoperative Wound Healing in a Mouse Model of Glaucoma Filtration Surgery.

Science.gov (United States)

Van Bergen, Tine; Zahn, Grit; Caldirola, Patrizia; Fsadni, Mario; Caram-Lelham, Ninus; Vandewalle, Evelien; Moons, Lieve; Stalmans, Ingeborg

2016-11-01

To evaluate the therapeutic potential of the small molecule integrin α5β1 inhibitor, CLT-28643, to improve the filtering surgery outcome in a mouse model. Different dose regimens and administration routes of the inhibitor were compared with mitomycin C (MMC), the gold standard in clin ical practice. The efficacy of CLT-28643 on surgical outcome was studied in a mouse model for filtering surgery (n = 40 eyes from 20 mice per group). Single and repeated subconjunctival (SCJ) injections (1 or 2 μg) and topical eye drops (10 μg) of the integrin inhibitor were compared with 2-minute administration of MMC 0.02%. Bleb size, survival, and signs of toxicity were examined until 28 days after surgery. Immunohistochemical analysis of angiogenesis, inflammation, collagen deposition, and integrin α5β1 expression were performed on postoperative days 3, 8, 14, and 28. A masked observer performed all the assessments. Immunostaining showed that integrin α5β1 was highly expressed in the bleb at early time-points after surgery and that CLT-28643 inhibited this upregulation. Efficacy was shown to be dose-dependent for the integrin inhibitor CLT-28643 for bleb area and survival, and the wound healing process. While 2-μg single injection of CLT-28643 improved bleb characteristics in a similar way as 10-μg administered by eye drops and MMC, repeated injections of 2 μg showed superior efficacy compared to MMC, with no corneal toxicity. Administration of the integrin α5β1 inhibitor CLT-28643 has therapeutic potential as an adjunct to glaucoma surgery, possibly with a superior efficacy and tolerability compared with MMC when used at the optimal dose.

Load Theory of Selective Attention and Cognitive Control

Science.gov (United States)

Lavie, Nilli; Hirst, Aleksandra; de Fockert, Jan W.; Viding, Essi

2004-01-01

A load theory of attention in which distractor rejection depends on the level and type of load involved in current processing was tested. A series of experiments demonstrates that whereas high perceptual load reduces distractor interference, working memory load or dual-task coordination load increases distractor interference. These findings…

Backward Yakudoku: An Attempt to Implement CLT at a Japanese High School

Science.gov (United States)

Thompson, Gene; Yanagita, Mayuno

2017-01-01

How can Japanese teachers of English go about introducing more communicative activities suitable for their contexts? This article discusses an attempt by a high school teacher to implement communicative language teaching (CLT) in her classes while responding to institutional pressure to use "yakudoku" (a traditional grammar translation…

Comprehensive Review on Divisible Load Theory: Concepts, Strategies, and Approaches

Directory of Open Access Journals (Sweden)

Shamsollah Ghanbari

2014-01-01

Full Text Available There is extensive literature concerning the divisible load theory. The divisible load theory is mainly applied for scheduling in the area of distributed computing. It is based on the fact that the load can be divided into some arbitrarily independent parts, in which each part can be processed independently by a processor. This paper reviews the literature concerning the divisible load theory, while focusing on the details of the basic concepts, approaches, strategies, typologies, and open problems.

Direct repeat sequences are essential for function of the cis-acting locus of transfer (clt) of Streptomyces phaeochromogenes plasmid pJV1.

Science.gov (United States)

Franco, Bernardo; González-Cerón, Gabriela; Servín-González, Luis

2003-11-01

The functionality of direct and inverted repeat sequences inside the cis acting locus of transfer (clt) of the Streptomyces plasmid pJV1 was determined by testing the effect of different deletions on plasmid transfer. The results show that the single most important element for pJV1 clt function is a series of evenly spaced 9 bp long direct repeats which match the consensus CCGCACA(C/G)(C/G), since their deletion caused a dramatic reduction in plasmid transfer. The presence of these repeats in the absence of any other clt sequences allowed plasmid transfer to occur at a frequency that was at least two orders of magnitude higher than that obtained in the complete absence of clt. A database search revealed regions with a similar organization, and in the same position, in Streptomyces plasmids pSN22 and pSLS, which have transfer proteins homologous to those of pJV1.

A brief analysis of the necessity of grammar teaching in CLT

Institute of Scientific and Technical Information of China (English)

胡晓; 王榛

2017-01-01

Grammar teaching is the important component of communicative language teaching, and also the teaching content of communicative approach. This study is going to analyze the status of English grammar learning, the theoretical basis of CLT, and some difficulties with regard to grammar education in China, while discussing teachers might try to adjust the current grammar approach in communicative English teaching.

Chronic lymphocytic thyroiditis (CLT) has a positive prognostic value in papillary thyroid cancer (PTC) patients: the potential key role of Foxp3+ T lymphocytes.

Science.gov (United States)

Pilli, T; Toti, P; Occhini, R; Castagna, M G; Cantara, S; Caselli, M; Cardinale, S; Barbagli, L; Pacini, F

2017-12-11

An impact of chronic lymphocytic thyroiditis (CLT) on papillary thyroid cancer (PTC) outcome has long been advocated but it is still controversial. The aim of this study was to evaluate the prognostic value of CLT in a retrospective cohort of PTC patients and to characterize the lymphocytic subpopulations and infiltrate (LI). We assessed 375 PTC patients, aged 45.2 ± 16.4 years, and treated with thyroidectomy and radioiodine remnant ablation, with a mean follow-up of 6.28 ± 3.86 years. In a subgroup of patients (n = 81) tissue sections were reviewed for the presence of CLT or lymphocytes associated with tumor in absence of background thyroiditis (TAL); cytotoxic CD8+/regulatory Foxp3+ T lymphocyte (CD8+/Foxp3+) ratio was characterized by immunohistochemistry: a low ratio is suggestive of a less effective anti tumor immune response. Seventy-five/375 patients (20%) had a histological diagnosis of CLT and showed at the last follow-up a significantly better outcome compared to those with no CLT (cure rate: 91.8 versus 76.3%, p = 0.003). LI was characterized in 81 PTC patients (24 with CLT and 57 with TAL): the peri-tumoral CD8+/Foxp3+ ratio was lower in patients not cured at the final evaluation. Our data suggest that concurrent CLT has a protective effect on PTC outcome and that the imbalance between cytotoxic and regulatory T lymphocytes in the peri-tumoral TAL may affect the tumor-specific immune response favoring a more aggressive behavior of cancer.

The Impact of Cognitive Load Theory on Learning Astronomy

Science.gov (United States)

Foster, Thomas M.

2010-01-01

Every student is different, which is the challenge of astronomy education research (AER) and teaching astronomy. This difference also provides the greatest goal for education researchers - our GUT - we need to be able to quantify these differences and provide explanatory and predictive theories to curriculum developers and teachers. One educational theory that holds promise is Cognitive Load Theory. Cognitive Load Theory begins with the well-established fact that everyone's working memory can hold 7 ± 2 unique items. This quirk of the human brain is why phone numbers are 7 digits long. This quirk is also why we forget peoples’ names after just meeting them, leave the iron on when we leave the house, and become overwhelmed as students of new material. Once the intricacies of Cognitive Load are understood, it becomes possible to design learning environments to marshal the resources students have and guide them to success. Lessons learned from Cognitive Load Theory can and should be applied to learning astronomy. Classroom-ready ideas will be presented.

Making EFL Instruction More CLT-Oriented through Individual Accountability in Cooperative Learning

Science.gov (United States)

Astuti, Puji; Lammers, Jayne C.

2017-01-01

This article attempts to add to the literature supporting Communicative Language Teaching (CLT) by proposing the use of Cooperative Learning (CL), specifically focusing on the enactment of a key principle of CL, i.e., individual accountability. It illustrates how to train students on CL and its individual accountability work and demonstrates how…

Conceptual and methodological concerns in the theory of perceptual load.

Science.gov (United States)

Benoni, Hanna; Tsal, Yehoshua

2013-01-01

The present paper provides a short critical review of the theory of perceptual load. It closely examines the basic tenets and assumptions of the theory and identifies major conceptual and methodological problems that have been largely ignored in the literature. The discussion focuses on problems in the definition of the concept of perceptual load, on the circularity in the characterization and manipulation of perceptual load and the confusion between the concept of perceptual load and its operationalization. The paper also selectively reviews evidence supporting the theory as well as inconsistent evidence which proposed alternative dominant factors influencing the efficacy of attentional selection.

Conceptual and Methodological Concerns in the Theory of Perceptual Load

Directory of Open Access Journals (Sweden)

Hanna eBenoni

2013-08-01

Full Text Available The present paper provides a short critical review of the theory of perceptual load. It closely examines the basic tenets and assumptions of the theory and identifies major conceptual and methodological problems that have been largely ignored in the literature. The discussion focuses on problems in the definition of the concept of perceptual load, on the circularity in the characterization and manipulation of perceptual load and the confusion between the concept of perceptual load and its operationalization. The paper also selectively reviews evidence supporting the theory as well as inconsistent evidence which proposed alternative dominant factors influencing the efficacy of attentional selection.

Minimal and contributing sequence determinants of the cis-acting locus of transfer (clt) of streptomycete plasmid pIJ101 occur within an intrinsically curved plasmid region.

Science.gov (United States)

Ducote, M J; Prakash, S; Pettis, G S

2000-12-01

Efficient interbacterial transfer of streptomycete plasmid pIJ101 requires the pIJ101 tra gene, as well as a cis-acting plasmid function known as clt. Here we show that the minimal pIJ101 clt locus consists of a sequence no greater than 54 bp in size that includes essential inverted-repeat and direct-repeat sequences and is located in close proximity to the 3' end of the korB regulatory gene. Evidence that sequences extending beyond the minimal locus and into the korB open reading frame influence clt transfer function and demonstration that clt-korB sequences are intrinsically curved raise the possibility that higher-order structuring of DNA and protein within this plasmid region may be an inherent feature of efficient pIJ101 transfer.

Secondary EFL School Teachers' Perceptions of CLT Principles and Practices: An Exploratory Survey

Science.gov (United States)

Anani Sarab, Mohammad Reza; Monfared, Abbas; Safarzadeh, Mohammad Meisam

2016-01-01

Communicative Language Teaching (CLT) is advocated by many applied linguists as a common vehicle to curriculum innovation in many ELT contexts. It represents a change of focus in language teaching from linguistic structures to learners' need for developing communication skills. In recent years, the Iranian Ministry of Education has introduced the…

An Investigation of the Communicative Approach Teaching in Primary English Textbooks in Hong Kong and Malaysia: A Search into Communicative Language Teaching (CLT) Textbooks, and How CLT Is Applied in Textbooks

Science.gov (United States)

Ko, Charles

2014-01-01

In the present research, it will be shown how grammar activities in textbooks still retain the structural method of teaching grammar. The results found by previous scholars' research will be covered, and illustrated by excerpts of textbooks, including comparison of Hong Kong and Malaysian textbooks. Communicative Language Teaching (CLT)…

Cognitive load theory: New conceptualizations, specifications, and integrated research perspectives

NARCIS (Netherlands)

G.W.C. Paas (Fred); T.A.J.M. van Gog (Tamara); J. Sweller (John)

2010-01-01

textabstractOver the last few years, cognitive load theory has progressed and advanced rapidly. The articles in this special issue, which document those advances, are based on contributions to the 3rd International Cognitive Load Theory Conference (2009), Heerlen, The Netherlands. The articles of

The effects of bilingual status on lexical comprehension and production in Maltese five-year-old children: A LITMUS-CLT study.

Science.gov (United States)

Gatt, Daniela; Attard, Donna; Łuniewska, Magdalena; Haman, Ewa

2017-01-01

This article investigates whether the bilingual status of 56 typically developing children aged 60-69 months influenced their lexical abilities. The participants were identified as Maltese-dominant (Me) (n = 21), English-dominant (Em) (n = 15) and balanced bilingual (ME) (n = 20) on the basis of language exposure and proficiency, as reported by their parents. Comprehension and production of nouns and verbs were measured using Cross-Linguistic Lexical Tasks (LITMUS-CLT) in Maltese (CLT-MT) and British English (CLT-EN). Significant effects of bilingual group were identified for performance on lexical comprehension. For production, consistent bilingual group effects resulted when accurate concepts lexicalised in the test language were scored. Lexical mixing was more pronounced when children were tested in their non-dominant language. Maltese noun production elicited the highest levels of mixing across all groups. Findings point towards the need to consider specific exposure dynamics to each language within a single language pair when assessing children's bilingual lexical skills.

The limit distribution in the q-CLT for q\\,\\geqslant \\,1 is unique and can not have a compact support

Science.gov (United States)

Umarov, Sabir; Tsallis, Constantino

2016-10-01

In a paper by Umarov et al (2008 Milan J. Math. 76 307-28), a generalization of the Fourier transform, called the q-Fourier transform, was introduced and applied for the proof of a q-generalized central limit theorem (q-CLT). Subsequently, Hilhorst illustrated (2009 Braz. J. Phys. 39 371-9 2010 J. Stat. Mech. P10023) that the q-Fourier transform for q\\gt 1, is not invertible in the space of density functions. Indeed, using an invariance principle, he constructed a family of densities with the same q-Fourier transform and noted that ‘as a consequence, the q-CLT falls short of achieving its stated goal’. The distributions constructed there have compact support. We prove now that the limit distribution in the q-CLT is unique and can not have a compact support. This result excludes all the possible counterexamples which can be constructed using the invariance principle and fills the gap mentioned by Hilhorst.

Processing Capacity under Perceptual and Cognitive Load: A Closer Look at Load Theory

Science.gov (United States)

Fitousi, Daniel; Wenger, Michael J.

2011-01-01

Variations in perceptual and cognitive demands (load) play a major role in determining the efficiency of selective attention. According to load theory (Lavie, Hirst, Fockert, & Viding, 2004) these factors (a) improve or hamper selectivity by altering the way resources (e.g., processing capacity) are allocated, and (b) tap resources rather than…

A Case Study Analysis of Clt Methods to Develop Grammar Competency for Academic Writing Purposes at Tertiary Level

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Almodad Biduk Asmani

2013-10-01

Full Text Available The purpose of the research project is to find out how effective grammar teaching and learning using the Principled CLT method can improve the ability of freshman Binus University students to understand and use grammar knowledge for academic writing purposes. The research project is expected to result in computer-animated format which can be used as one of the main tools in teaching and learning grammar at tertiary level. The research project applies the descriptive quantitative approach, and thus uses numeric data. The research project involves two subject groups, which are experimental and control. The two groups are pre-tested so as to find out their level of grammar competency by their academic writing works. The experimental group receives the treatment of grammar learning by using the Principled CLT approach, while the control group receives the standard CLT approach. Then, the two groups have the post-test, and the results are compared. Through statistics, the numerical data show that there is no significant difference between the two methods’ results, and as a result, either method has its own strength and weaknesses. If one is to be implemented, it must be linked to the specific goals and purposes that each entails.  

A comparison of proficiency levels in 4-year-old monolingual and trilingual speakers of Afrikaans, isiXhosa and South African English across SES boundaries, using LITMUS-CLT.

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Perold Potgieter, Anneke; Southwood, Frenette

2016-01-01

This study investigated how trilinguals fare on the cross-linguistic lexical tasks (CLT)-Afrikaans, -isiXhosa and -South African English (SAE) (cf. Haman et al., 2015) compared to monolingual controls, and whether the CLT-Afrikaans renders comparable results across socioeconomic status (SES) backgrounds. The LITMUS-CLTs were administered to 41 low SES 4-year-olds (11 trilinguals; 10 monolingual speakers of Afrikaans, isiXhosa and SAE) and the LITMUS-CLT-Afrikaans to 11 mid-SES 4-year-old monolinguals. Results (a) indicate that trilinguals' proficiency in their exposure-dominant language did not differ significantly from monolinguals' proficiency, but their proficiency in their additional two languages was significantly lower than monolinguals' proficiency; (b) reflect the extent, but not current amount, of exposure trilinguals had had over time to each of their languages; and (c) show that low and mid-SES monolinguals differed significantly on noun-related, but not verb-related, CLT measures. Possible reasons for and the clinical implications of these results are discussed.

The more total cognitive load is reduced by cues, the better retention and transfer of multimedia learning: A meta-analysis and two meta-regression analyses.

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Xie, Heping; Wang, Fuxing; Hao, Yanbin; Chen, Jiaxue; An, Jing; Wang, Yuxin; Liu, Huashan

2017-01-01

Cueing facilitates retention and transfer of multimedia learning. From the perspective of cognitive load theory (CLT), cueing has a positive effect on learning outcomes because of the reduction in total cognitive load and avoidance of cognitive overload. However, this has not been systematically evaluated. Moreover, what remains ambiguous is the direct relationship between the cue-related cognitive load and learning outcomes. A meta-analysis and two subsequent meta-regression analyses were conducted to explore these issues. Subjective total cognitive load (SCL) and scores on a retention test and transfer test were selected as dependent variables. Through a systematic literature search, 32 eligible articles encompassing 3,597 participants were included in the SCL-related meta-analysis. Among them, 25 articles containing 2,910 participants were included in the retention-related meta-analysis and the following retention-related meta-regression, while there were 29 articles containing 3,204 participants included in the transfer-related meta-analysis and the transfer-related meta-regression. The meta-analysis revealed a statistically significant cueing effect on subjective ratings of cognitive load (d = -0.11, 95% CI = [-0.19, -0.02], p < 0.05), retention performance (d = 0.27, 95% CI = [0.08, 0.46], p < 0.01), and transfer performance (d = 0.34, 95% CI = [0.12, 0.56], p < 0.01). The subsequent meta-regression analyses showed that dSCL for cueing significantly predicted dretention for cueing (β = -0.70, 95% CI = [-1.02, -0.38], p < 0.001), as well as dtransfer for cueing (β = -0.60, 95% CI = [-0.92, -0.28], p < 0.001). Thus in line with CLT, adding cues in multimedia materials can indeed reduce SCL and promote learning outcomes, and the more SCL is reduced by cues, the better retention and transfer of multimedia learning.

Surface loading of a viscoelastic earth-I. General theory

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Tromp, Jeroen; Mitrovica, Jerry X.

1999-06-01

We present a new normal-mode formalism for computing the response of an aspherical, self-gravitating, linear viscoelastic earth model to an arbitrary surface load. The formalism makes use of recent advances in the theory of the Earth's free oscillations, and is based upon an eigenfunction expansion methodology, rather than the tradi-tional Love-number approach to surface-loading problems. We introduce a surface-load representation theorem analogous to Betti's reciprocity relation in seismology. Taking advantage of this theorem and the biorthogonality of the viscoelastic modes, we determine the complete response to a surface load in the form of a Green's function. We also demonstrate that each viscoelastic mode has its own unique energy partitioning, which can be used to characterize it. In subsequent papers, we apply the theory to spherically symmetric and aspherical earth models.

Progress on the development of seismic resilient Tall CLT Buildings in the Pacific Northwest

Science.gov (United States)

Shiling Pei; Jeffrey Berman; Daniel Dolan; John van de Lindt; James Ricles; Richard Sause; Hans-Erik Blomgren; Marjan Popovski; Douglas Rammer

2014-01-01

As urban densification occurs in U.S. regions of high seismicity, there is a natural demand for seismically resilient tall buildings that are reliable, economically viable, and can be rapidly constructed. In urban regions on the west coast of the U.S., specifically the Pacific Northwest, there is significant interest in utilizing CLT in 8-20 story residential and...

EFD and CFD Characterization of a CLT Propeller

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Daniele Bertetta

2012-01-01

Full Text Available In the present paper an experimental and numerical analysis of an unconventional CLT propeller is carried out. Two different numerical approaches, a potential panel method and an RANSE solver, are employed. Cavitation tunnel experiments are carried out in order to measure, as usual, thrust, torque, and cavity extension for different propeller working points. Moreover, LDV measurements are performed to have a deep insight into the complex wake behind the propeller and to analyze the dynamics of generated tip vortexes. The numerical/experimental analysis and comparison of results highlight the peculiarities of this kind of propellers, the possibility to increase efficiency and reduce cavitation risk, in order to exploit the design approaches already well proven for conventional propellers also in the case of these unconventional geometries.

Limitations of subjective cognitive load measures in simulation-based procedural training.

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Naismith, Laura M; Cheung, Jeffrey J H; Ringsted, Charlotte; Cavalcanti, Rodrigo B

2015-08-01

The effective implementation of cognitive load theory (CLT) to optimise the instructional design of simulation-based training requires sensitive and reliable measures of cognitive load. This mixed-methods study assessed relationships between commonly used measures of total cognitive load and the extent to which these measures reflected participants' experiences of cognitive load in simulation-based procedural skills training. Two groups of medical residents (n = 38) completed three questionnaires after participating in simulation-based procedural skills training sessions: the Paas Cognitive Load Scale; the NASA Task Load Index (TLX), and a cognitive load component (CLC) questionnaire we developed to assess total cognitive load as the sum of intrinsic load (how complex the task is), extraneous load (how the task is presented) and germane load (how the learner processes the task for learning). We calculated Pearson's correlation coefficients to assess agreement among these instruments. Group interviews explored residents' perceptions about how the simulation sessions contributed to their total cognitive load. Interviews were audio-recorded, transcribed and subjected to qualitative content analysis. Total cognitive load scores differed significantly according to the instrument used to assess them. In particular, there was poor agreement between the Paas Scale and the TLX. Quantitative and qualitative findings supported intrinsic cognitive load as synonymous with mental effort (Paas Scale), mental demand (TLX) and task difficulty and complexity (CLC questionnaire). Additional qualitative themes relating to extraneous and germane cognitive loads were not reflected in any of the questionnaires. The Paas Scale, TLX and CLC questionnaire appear to be interchangeable as measures of intrinsic cognitive load, but not of total cognitive load. A more complete understanding of the sources of extraneous and germane cognitive loads in simulation-based training contexts is

Practising what we preach: using cognitive load theory for workshop design and evaluation.

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Naismith, Laura M; Haji, Faizal A; Sibbald, Matthew; Cheung, Jeffrey J H; Tavares, Walter; Cavalcanti, Rodrigo B

2015-12-01

Theory-based instructional design is a top priority in medical education. The goal of this Show and Tell article is to present our theory-driven approach to the design of instruction for clinical educators. We adopted cognitive load theory as a framework to design and evaluate a series of professional development workshops that were delivered at local, national and international academic conferences in 2014. We used two rating scales to measure participants' cognitive load. Participants also provided narrative comments as to how the workshops could be improved. Cognitive load ratings from 59 participants suggested that the workshop design optimized learning by managing complexity for different levels of learners (intrinsic load), stimulating cognitive processing for long-term memory storage (germane load), and minimizing irrelevant distracters (extraneous load). Narrative comments could also be classified as representing intrinsic, extraneous, or germane load, which provided specific directions for ongoing quality improvement. These results demonstrate that a cognitive load theory approach to workshop design and evaluation is feasible and useful in the context of medical education.

Professionalism--a required CLS/CLT curricular component.

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Latshaw, Sandra; Honeycutt, Karen

2010-01-01

Determine the impact of requiring Clinical Laboratory Science (CLS) students to participate in approved professionalism activities as part of a mandatory management course. Quasi-experimental, case study reporting qualitative results of 25 CLS students. During the admission interview, students complete a written response to questions about their perceptions related to professionalism. During the clinical educational year, students are required to complete approved professionalism activities as part of a management course. At the end of the course, students write a reflective paper focusing on their professional activities and how these experiences will influence their future professional practice. Overall themes of student reflections are provided. University of Nebraska Medical Center (UNMC) CLS Program in Omaha. After participating in a mandatory professionalism curricular component requiring active student participation in professional activities, student reflective writings provide evidence this is one successful approach to nurture professional identity within future Clinical Laboratory Science/Clinical Laboratory Technician (CLS/CLT) practitioners.

Airspace Technology Demonstration 2 (ATD-2): ATD-2 CLT Pilot Community Engagement

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Capps, Al; Hooey, Becky

2017-01-01

The Airspace Technology Demonstration 2 (ATD-2) project conducted a pilot community workshop at Charlotte Douglas International Airport (CLT) in Charlotte, North Carolina. The goal was to familiarize pilots with the ATD-2 project, with an emphasis on procedures that may affect pilots during the Phase 1 Field Demonstration (beginning September 30, 2017). At this workshop, the high-level goals and objectives of ATD-2, expected benefits for pilots, changes to procedures, training requirements, and data sharing elements were presented.

Load theory behind the wheel: an experimental application of a cognitive model to simulated driving

OpenAIRE

Murphy, Gillian

2017-01-01

Load Theory is a prominent model of selective attention first proposed over twenty years ago. Load Theory is supported by a great many experimental and neuroimaging studies. There is however, little evidence that Load Theory can be applied to real world attention, though it has great practical potential. Driving, as an everyday task where failures of attention can have profound consequences, stands to benefit from the understanding of selective attention that Load Theory provides. The aim of ...

Examining Graphing Calculator Affordances in Learning Pre-Calculus among Undergraduate Students

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Nzuki, Francis

2016-01-01

This study examines graphing calculator affordances in learning mathematics among college precalculus students. The study draws from the Cognitive Load Theory (CLT) and the "Intelligent Technology" theoretical framework proposed by Salomon, Perkins, and Globerson (1991). From these perspectives the effects "with" the graphing…

Culture in teaching English as an international language in CLT curriculum

Institute of Scientific and Technical Information of China (English)

韩笑晨

2017-01-01

This thesis explored the role of culture in EIL teaching on the basis of CLT contexts by reviewing plentiful previous studies. Generally speaking, this thesis emphasized the relationship between language and culture, the necessity and importance of culture teaching in language teaching, what kind of culture should be included in cultural content for culture teaching and challenges of culture teaching in EIL teaching as well. In a word, Culture is correlated with language. Culture teaching plays a significant role in EIL teaching. In culture teaching, not only the target culture, but also various cultures related to EIL learners' daily life should be included.

Towards Cognitive Load Theory as Guideline for Instructional Design in Science Education

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Meissner, Barbara; Bogner, Franz X.

2013-01-01

We applied cognitive load theory in an heuristic out-of-school science lesson. The lesson comprises experiments concerning major attributes of NaCl and was designed for 5th to 8th grade students. Our interest focused on whether cognitive load theory provides sufficient guidelines for instructional design in the field of heuristic science…

Twenty years of load theory-Where are we now, and where should we go next?

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Murphy, Gillian; Groeger, John A; Greene, Ciara M

2016-10-01

Selective attention allows us to ignore what is task-irrelevant and focus on what is task-relevant. The cognitive and neural mechanisms that underlie this process are key topics of investigation in cognitive psychology. One of the more prominent theories of attention is perceptual load theory, which suggests that the efficiency of selective attention is dependent on both perceptual and cognitive load. It is now more than 20 years since the proposal of load theory, and it is a good time to evaluate the evidence in support of this influential model. The present article supplements and extends previous reviews (Lavie, Trends in Cognitive Sciences, 9, 75-82. doi: 10.1016/j.tics.2004.12.004 , 2005, Current Directions in Psychological Science, 19, 143-148. doi: 10.1177/0963721410370295 , 2010) by examining more recent research in what appears to be a rapidly expanding area. The article comprises five parts, examining (1) evidence for the effects of perceptual load on attention, (2) cognitive load, (3) individual differences under load, (4) alternative theories and criticisms, and (5) the future of load theory. We argue that the key next step for load theory will be the application of the model to real-world tasks. The potential benefits of applied attention research are numerous, and there is tentative evidence that applied research would provide strong support for the theory itself, as well as real-world benefits related to activities in which attention is crucial, such as driving and education.

Cognitive Load Theory--Sometimes Less Is More

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Taylor, Cody

2013-01-01

The following paper represents review of the literature examining the current research related to cognitive load theory and more specifically the negative aspects of the redundant on-screen text. The authors describe working and long-term memory and how both factor into human learning through the facilitation of knowledge transfer. Limited working…

Beliefs and Perceptions of DPRK teachers of English towards CLT Instruction and Factors That Influence Program Implementation

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Park, Vickie Bin

2012-01-01

Similar to its neighboring countries of China, South Korea, and Japan, the Democratic People's Republic of Korea (DPRK) (also known as North Korea) has made English a compulsory subject for middle school to university level students, and teacher training programs based on the Communicative Language Teaching (CLT) approach have also been…

Consolidation Theory for a Stone Column Composite Foundation under Multistage Loading

OpenAIRE

Huang, Shenggen; Feng, Yingtao; Liu, Hao; Wu, Wenbing; Mei, Guoxiong

2016-01-01

The consolidation theories considering instant load cannot fully reveal the consolidation mechanism of a stone column composite foundation used in the expressway embankments due to the time effect of loading; that is, the expressway embankments are often constructed in several stages for a long time. Meanwhile, owing to the special property that the pile-soil stress ratio is larger than 1, the consolidation theory for sand drain well foundation cannot be used directly in the consolidation ana...

Rethinking the Boundaries of Cognitive Load Theory in Complex Learning

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Kalyuga, Slava; Singh, Anne-Marie

2016-01-01

In the traditional framework of cognitive load theory, it is assumed that the acquisition of domain-specific knowledge structures (or schemas) is the only instructional goal, and therefore, the theory is applicable to any instructional task. Accordingly, the basic concepts of intrinsic (productive) and extraneous (unproductive) types of cognitive…

Consolidation Theory for a Stone Column Composite Foundation under Multistage Loading

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Shenggen Huang

2016-01-01

Full Text Available The consolidation theories considering instant load cannot fully reveal the consolidation mechanism of a stone column composite foundation used in the expressway embankments due to the time effect of loading; that is, the expressway embankments are often constructed in several stages for a long time. Meanwhile, owing to the special property that the pile-soil stress ratio is larger than 1, the consolidation theory for sand drain well foundation cannot be used directly in the consolidation analysis of stone column composite foundation. Based on the principle that the vertical load applied on the composite foundation is shared by the stone column and the surrounding soil, the governing solutions for the stone column composite foundation under a multistage load are established. By virtue of the separation of variables, the corresponding solutions of degree of consolidation for loading stage and maintaining load stage are derived separately. According to the Carrillo theorem, the solution for the average total degree of consolidation of entire composite foundation is also obtained. Finally, the reasonableness of the present solution has been verified by comparing the consolidation curve calculated by the present solution with that measured by site test.

Competition explains limited attention and perceptual resources: implications for perceptual load and dilution theories.

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Scalf, Paige E; Torralbo, Ana; Tapia, Evelina; Beck, Diane M

2013-01-01

Both perceptual load theory and dilution theory purport to explain when and why task-irrelevant information, or so-called distractors are processed. Central to both explanations is the notion of limited resources, although the theories differ in the precise way in which those limitations affect distractor processing. We have recently proposed a neurally plausible explanation of limited resources in which neural competition among stimuli hinders their representation in the brain. This view of limited capacity can also explain distractor processing, whereby the competitive interactions and bias imposed to resolve the competition determine the extent to which a distractor is processed. This idea is compatible with aspects of both perceptual load and dilution models of distractor processing, but also serves to highlight their differences. Here we review the evidence in favor of a biased competition view of limited resources and relate these ideas to both classic perceptual load theory and dilution theory.

Competition explains limited attention and perceptual resources: implications for perceptual load and dilution theories

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Paige E. Scalf

2013-05-01

Full Text Available Both perceptual load theory and dilution theory purport to explain when and why task-irrelevant information, or so-called distractors are processed. Central to both explanations is the notion of limited resources, although the theories differ in the precise way in which those limitations affect distractor processing. We have recently proposed a neurally plausible explanation of limited resources in which neural competition among stimuli hinders their representation in the brain. This view of limited capacity can also explain distractor processing, whereby the competitive interactions and bias imposed to resolve the competition determine the extent to which a distractor is processed. This idea is compatible with aspects of both perceptual load and dilution models of distractor processing, but also serves to highlight their differences. Here we review the evidence in favor of a biased competition view of limited resources and relate these ideas to both classic perceptual load theory and dilution theory.

Cognitive load theory, educational research, and instructional design; some food for thought

NARCIS (Netherlands)

de Jong, Anthonius J.M.

2010-01-01

Cognitive load is a theoretical notion with an increasingly central role in the educational research literature. The basic idea of cognitive load theory is that cognitive capacity in working memory is limited, so that if a learning task requires too much capacity, learning will be hampered. The

PEMBELAJARAN BERBANTUAN MULTIMEDIA BERDASARKAN COGNITIVE LOAD THEORY PADA PELAJARAN MATEMATIKA SD

OpenAIRE

Rissa Prima Kurniawati

2016-01-01

Multimedia is media that combine two or more elements are composed of text, graphics, images, photographs, audio, video, and animation are integrated. In multimedia-assisted learning, students are given the opportunity to learn not only of learning resources such as teachers, but give the opportunity to students to develop better cognitive, creative, and innovative. Cognitive Load Theory is a theory that was introduced as a teaching theory based on the knowledge of human cognitive architectur...

Pembelajaran Berbantuan Multimedia Berdasarkan Cognitive Load Theory Pada Pelajaran Matematika SD

OpenAIRE

Kurniawati, Rissa Prima

2014-01-01

Multimedia is media that combine two or more elements are composed of text, graphics, images, photographs, audio, video, and animation are integrated. In multimedia-assisted learning, students are given the opportunity to learn not only of learning resources such as teachers, but give the opportunity to students to develop better cognitive, creative, and innovative. Cognitive Load Theory is a theory that was introduced as a teaching theory based on the knowledge of human cognitive architectur...

Noun and verb knowledge in monolingual preschool children across 17 languages: Data from Cross-linguistic Lexical Tasks (LITMUS-CLT).

Science.gov (United States)

Haman, Ewa; Łuniewska, Magdalena; Hansen, Pernille; Simonsen, Hanne Gram; Chiat, Shula; Bjekić, Jovana; Blažienė, Agnė; Chyl, Katarzyna; Dabašinskienė, Ineta; Engel de Abreu, Pascale; Gagarina, Natalia; Gavarró, Anna; Håkansson, Gisela; Harel, Efrat; Holm, Elisabeth; Kapalková, Svetlana; Kunnari, Sari; Levorato, Chiara; Lindgren, Josefin; Mieszkowska, Karolina; Montes Salarich, Laia; Potgieter, Anneke; Ribu, Ingeborg; Ringblom, Natalia; Rinker, Tanja; Roch, Maja; Slančová, Daniela; Southwood, Frenette; Tedeschi, Roberta; Tuncer, Aylin Müge; Ünal-Logacev, Özlem; Vuksanović, Jasmina; Armon-Lotem, Sharon

2017-01-01

This article investigates the cross-linguistic comparability of the newly developed lexical assessment tool Cross-linguistic Lexical Tasks (LITMUS-CLT). LITMUS-CLT is a part the Language Impairment Testing in Multilingual Settings (LITMUS) battery (Armon-Lotem, de Jong & Meir, 2015). Here we analyse results on receptive and expressive word knowledge tasks for nouns and verbs across 17 languages from eight different language families: Baltic (Lithuanian), Bantu (isiXhosa), Finnic (Finnish), Germanic (Afrikaans, British English, South African English, German, Luxembourgish, Norwegian, Swedish), Romance (Catalan, Italian), Semitic (Hebrew), Slavic (Polish, Serbian, Slovak) and Turkic (Turkish). The participants were 639 monolingual children aged 3;0-6;11 living in 15 different countries. Differences in vocabulary size were small between 16 of the languages; but isiXhosa-speaking children knew significantly fewer words than speakers of the other languages. There was a robust effect of word class: accuracy was higher for nouns than verbs. Furthermore, comprehension was more advanced than production. Results are discussed in the context of cross-linguistic comparisons of lexical development in monolingual and bilingual populations.

What does germane load mean? An empirical contribution to the cognitive load theory

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Nicolas eDebue

2014-10-01

Full Text Available While over the last decades, much attention has been paid to the mental workload in the field of human computer interactions, there is still a lack of consensus concerning the factors that generate it as well as the measurement methods that could reflect workload variations. Based on the multifactorial Cognitive Load Theory, our study aims to provide some food for thought about the subjective and objective measurement that can be used to disentangle the intrinsic, extraneous and germane load. The purpose is to provide insight into the way cognitive load can explain how users’ cognitive resources are allocated in the use of hypermedia, such as an online newspaper. A two-phase experiment has been conducted on the information retention from online news stories. Phase 1 (92 participants examined the influence of multimedia content on performance as well as the relationships between cognitive loads and cognitive absorption. In Phase 2 (36 participants, eye-tracking data were collected in order to provide reliable and objective measures. Results confirmed that performance in information retention was impacted by the presence of multimedia content such as animations and pictures. The higher number of fixations on these animations suggests that users’ attention could have been attracted by them. Results showed the expected opposite relationships between Germane and Extraneous Load, a positive association between GL and cognitive absorption and a nonlinear association between Intrinsic and Germane Load. The trends based on eye-tracking data analysis provide some interesting findings about the relationships between longer fixations, shorter saccades and cognitive load. Some issues are raised about the respective contribution of mean pupil diameter and Index of Cognitive Activity.

Cognitive load disrupts implicit theory-of-mind processing.

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Schneider, Dana; Lam, Rebecca; Bayliss, Andrew P; Dux, Paul E

2012-08-01

Eye movements in Sally-Anne false-belief tasks appear to reflect the ability to implicitly monitor the mental states of other individuals (theory of mind, or ToM). It has recently been proposed that an early-developing, efficient, and automatically operating ToM system subserves this ability. Surprisingly absent from the literature, however, is an empirical test of the influence of domain-general executive processing resources on this implicit ToM system. In the study reported here, a dual-task method was employed to investigate the impact of executive load on eye movements in an implicit Sally-Anne false-belief task. Under no-load conditions, adult participants displayed eye movement behavior consistent with implicit belief processing, whereas evidence for belief processing was absent for participants under cognitive load. These findings indicate that the cognitive system responsible for implicitly tracking beliefs draws at least minimally on executive processing resources. Thus, even the most low-level processing of beliefs appears to reflect a capacity-limited operation.

Effect of perceptual load on conceptual processing: an extension of Vermeulen's theory.

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Xie, Jiushu; Wang, Ruiming; Sun, Xun; Chang, Song

2013-10-01

The effect of color and shape load on conceptual processing was studied. Perceptual load effects have been found in visual and auditory conceptual processing, supporting the theory of embodied cognition. However, whether different types of visual concepts, such as color and shape, share the same perceptual load effects is unknown. In the current experiment, 32 participants were administered simultaneous perceptual and conceptual tasks to assess the relation between perceptual load and conceptual processing. Keeping color load in mind obstructed color conceptual processing. Hence, perceptual processing and conceptual load shared the same resources, suggesting embodied cognition. Color conceptual processing was not affected by shape pictures, indicating that different types of properties within vision were separate.

Developing feasible loading patterns using perturbation theory methods

International Nuclear Information System (INIS)

White, J.R.; Avila, K.M.

1990-01-01

This work illustrates an approach to core reload design that combines the power of integer programming with the efficiency of generalized perturbation theory. The main use of the method is as a tool to help the design engineer identify feasible loading patterns with minimum time and effort. The technique is highly successful for the burnable poison (BP) loading problem, but the unpredictable behavior of the branch-and-bound algorithm degrades overall performance for large problems. Unfortunately, the combined fuel shuffling plus BP optimization problem falls into this latter classification. Overall, however, the method shows great promise for significantly reducing the manpower time required for the reload design process. And it may even give the further benefit of better designs and improved performance

Cognitive Load Theory, Educational Research, and Instructional Design: Some Food for Thought

Science.gov (United States)

de Jong, Ton

2010-01-01

Cognitive load is a theoretical notion with an increasingly central role in the educational research literature. The basic idea of cognitive load theory is that cognitive capacity in working memory is limited, so that if a learning task requires too much capacity, learning will be hampered. The recommended remedy is to design instructional systems…

Applying Cognitive Load Theory Principles to Library Instructional Guidance

Science.gov (United States)

Pickens, Kathleen E.

2017-01-01

If the goal of library instructional guidance is to provide students with the knowledge needed to acquire new skills in order to accomplish their learning objectives, then it is prudent to consider factors that impact learning. Cognitive load theory addresses several of these factors and is applicable to a wide-range of instructional devices used…

Development of a VVER-1000 core loading pattern optimization program based on perturbation theory

International Nuclear Information System (INIS)

Hosseini, Mohammad; Vosoughi, Naser

2012-01-01

Highlights: ► We use perturbation theory to find an optimum fuel loading pattern in a VVER-1000. ► We provide a software for in-core fuel management optimization. ► We consider two objectives for our method (perturbation theory). ► We show that perturbation theory method is very fast and accurate for optimization. - Abstract: In-core nuclear fuel management is one of the most important concerns in the design of nuclear reactors. Two main goals in core fuel loading pattern design optimization are maximizing the core effective multiplication factor in order to extract the maximum energy, and keeping the local power peaking factor lower than a predetermined value to maintain the fuel integrity. Because of the numerous possible patterns of fuel assemblies in the reactor core, finding the best configuration is so important and challenging. Different techniques for optimization of fuel loading pattern in the reactor core have been introduced by now. In this study, a software is programmed in C language to find an order of the fuel loading pattern of a VVER-1000 reactor core using the perturbation theory. Our optimization method is based on minimizing the radial power peaking factor. The optimization process launches by considering an initial loading pattern and the specifications of the fuel assemblies which are given as the input of the software. The results on a typical VVER-1000 reactor reveal that the method could reach to a pattern with an allowed radial power peaking factor and increases the cycle length 1.1 days, as well.

Cognitive Load and Self-Determination Theories Applied to E-Learning : Impact on Students' Participation and Academic Performance

NARCIS (Netherlands)

de Araujo Guerra Grangeia, Tiago; de Jorge, Bruno; Franci, Daniel; Martins Santos, Thiago; Vellutini Setubal, Maria Silvia; Schweller, Marcelo; de Carvalho-Filho, Marco Antonio

2016-01-01

BACKGROUND: Emergency clerkships expose students to a stressful environment that require multiple tasks, which may have a direct impact on cognitive load and motivation for learning. To address this challenge, Cognitive Load Theory and Self Determination Theory provided the conceptual frameworks to

Elevated temperature inelastic analysis of metallic media under time varying loads using state variable theories

International Nuclear Information System (INIS)

Kumar, V.; Mukherjee, S.

1977-01-01

In the present paper a general time-dependent inelastic analysis procedure for three-dimensional bodies subjected to arbitrary time varying mechanical and thermal loads using these state variable theories is presented. For the purpose of illustrations, the problems of hollow spheres, cylinders and solid circular shafts subjected to various combinations of internal and external pressures, axial force (or constraint) and torque are analyzed using the proposed solution procedure. Various cyclic thermal and mechanical loading histories with rectangular or sawtooth type waves with or without hold-time are considered. Numerical results for these geometrical shapes for various such loading histories are presented using Hart's theory (Journal of Engineering Materials and Technology 1976). The calculations are performed for nickel in the temperature range of 25 0 C to 400 0 C. For integrating forward in time, a method of solving a stiff system of ordinary differential equations is employed which corrects the step size and order of the method automatically. The limit loads for hollow spheres and cylinders are calculated using the proposed method and Hart's theory, and comparisons are made against the known theoretical results. The numerical results for other loading histories are discussed in the context of Hart's state variable type constitutive relations. The significance of phenomena such as strain rate sensitivity, Bauschinger's effect, crep recovery, history dependence and material softening with regard to these multiaxial problems are discussed in the context of Hart's theory

Commentary: Should Gender Differences Be Included in the Evolutionary Upgrade to Cognitive Load Theory?

Science.gov (United States)

Bevilacqua, Andy

2017-01-01

Recent upgrades to cognitive load theory suggest that evolutionary processes have shaped the way that working memory processes cultural and social information. According to evolutionarily educational psychologists, some forms of information are processed with lower working memory loads than other forms. The former are evolutionarily salient and…

Vibration Analysis of Inclined Laminated Composite Beams under Moving Distributed Masses

Directory of Open Access Journals (Sweden)

E. Bahmyari

2014-01-01

Full Text Available The dynamic response of laminated composite beams subjected to distributed moving masses is investigated using the finite element method (FEM based on the both first-order shear deformation theory (FSDT and the classical beam theory (CLT. Six and ten degrees of freedom beam elements are used to discretize the CLT and FSDT equations of motion, respectively. The resulting spatially discretized beam governing equations including the effect of inertial, Coriolis, and centrifugal forces due to moving distributed mass are evaluated in time domain by applying Newmark’s scheme. The presented approach is first validated by studying its convergence behavior and comparing the results with those of existing solutions in the literature. Then, the effect of incline angle, mass, and velocity of moving body, layer orientation, load length, and inertial, Coriolis, and centrifugal forces due to the moving distributed mass and friction force between the beam and the moving distributed mass on the dynamic behavior of inclined laminated composite beams are investigated.

Normal loads program for aerodynamic lifting surface theory. [evaluation of spanwise and chordwise loading distributions

Science.gov (United States)

Medan, R. T.; Ray, K. S.

1974-01-01

A description of and users manual are presented for a U.S.A. FORTRAN 4 computer program which evaluates spanwise and chordwise loading distributions, lift coefficient, pitching moment coefficient, and other stability derivatives for thin wings in linearized, steady, subsonic flow. The program is based on a kernel function method lifting surface theory and is applicable to a large class of planforms including asymmetrical ones and ones with mixed straight and curved edges.

The investigation of MCM-48-type and MCM-41-type mesoporous silica as oral solid dispersion carriers for water insoluble cilostazol.

Science.gov (United States)

Wang, Yanzhu; Sun, Lizhang; Jiang, Tongying; Zhang, Jinghai; Zhang, Chen; Sun, Changshan; Deng, Yihui; Sun, Jin; Wang, Siling

2014-06-01

To explore the suitable application of MCM-41 (Mobil Composition of Matter number forty-one)-type and MCM-48-type mesoporous silica in the oral water insoluble drug delivery system. Cilostazol (CLT) as a model drug was loaded into synthesized MCM-48 (Mobil Composition of Matter number forty-eight) and commercial MCM-41 by three common methods. The obtained MCM-41, MCM-48 and CLT-loaded samples were characterized by means of nitrogen adsorption, thermogravimetric analysis, ultraviolet-visible spectrophotometry, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry and powder X-ray diffractometer. It was found that solvent evaporation method was preferred according to the drug loading efficiency and the maximum percent cumulative drug dissolution. MCM-48 with 3D cubic pore structure and MCM-41 with 2D long tubular structure are nearly spherical particles in 300-500 nm. Nevertheless, the silica carriers with similar large specific surface areas and concentrating pore size distributions (978.66 m(2)/g, 3.8 nm for MCM-41 and 1108.04 m(2)/g, 3.6 nm for MCM-48) exhibited different adsorption behaviors for CLT. The maximum percent cumulative drug release of the two CLT/silica solid dispersion (CLT-MCM-48 and CLT-MCM-41) was 63.41% and 85.78% within 60 min, respectively; while in the subsequent 12 h release experiment, almost 100% cumulative drug release were both obtained. In the pharmacokinetics aspect, the maximum plasma concentrations of CLT-MCM-48 reached 3.63 mg/L by 0.92 h. The AUC0-∞ values of the CLT-MCM-41 and CLT-MCM-48 were 1.14-fold and 1.73-fold, respectively, compared with the commercial preparation. Our findings suggest that MCM-41-type and MCM-48-type mesoporous silica have great promise as solid dispersion carriers for sustained and immediate release separately.

Assessing Cognitive Load Theory to Improve Student Learning for Mechanical Engineers

Science.gov (United States)

Impelluso, Thomas J.

2009-01-01

A computer programming class for students of mechanical engineering was redesigned and assessed: Cognitive Load Theory was used to redesign the content; online technologies were used to redesign the delivery. Student learning improved and the dropout rate was reduced. This article reports on both attitudinal and objective assessment: comparing…

Pupillary response to complex interdependent tasks: A cognitive-load theory perspective.

Science.gov (United States)

Mitra, Ritayan; McNeal, Karen S; Bondell, Howard D

2017-10-01

Pupil dilation is known to indicate cognitive load. In this study, we looked at the average pupillary responses of a cohort of 29 undergraduate students during graphical problem solving. Three questions were asked, based on the same graphical input. The questions were interdependent and comprised multiple steps. We propose a novel way of analyzing pupillometry data for such tasks on the basis of eye fixations, a commonly used eyetracking parameter. We found that pupil diameter increased during the solution process. However, pupil diameter did not always reflect the expected cognitive load. This result was studied within a cognitive-load theory model. Higher-performing students showed evidence of germane load and schema creation, indicating use of the interdependent nature of the tasks to inform their problem-solving process. However, lower-performing students did not recognize the interdependent nature of the tasks and solved each problem independently, which was expressed in a markedly different pupillary response pattern. We discuss the import of our findings for instructional design.

THE APPLICATION OF MASSING HANDLING THEORY FOR EVALUATION OF THE APPLICATION OF WHARVES AND LOADING FACILITIES IN THE MARITIME PORT

Directory of Open Access Journals (Sweden)

Zbigniew Matuszak

2016-09-01

Full Text Available This work presents the general characteristics of the port system. It defines sets and functions describing the structure and work of the port. Moreover, it characterizes foundations of the massive handling theory. It provides basic literature information about selected processes and models of the massive handling theory. On the example of a transportation company serving the loading on ships in the port of Szczecin, it shows the loading method. The material loading onto ships was the sodium water glass. There are observation results of operation times comprising the data available to determine parameters of the massive handling theory. Operations covered in the analysis include: the arrival of the ship at the port’s road, waiting for enter the port, passing through the fairway, waiting for loading, loading, determination of the cargo’s weight, preparation of documents and waiting for leaving the port. It presents critical remarks about possibilities of using the data obtained to describe loading cargo on a ship with the use of elements of the massive handling theory.

Improving the Quality of Online Discussion: The Effects of Strategies Designed Based on Cognitive Load Theory Principles

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Darabi, Aubteen; Jin, Li

2013-01-01

This article focuses on heavy cognitive load as the reason for the lack of quality associated with conventional online discussion. Using the principles of cognitive load theory, four online discussion strategies were designed specifically aiming at reducing the discussants' cognitive load and thus enhancing the quality of their online discussion.…

Central Limit Theorem: New SOCR Applet and Demonstration Activity

Science.gov (United States)

Dinov, Ivo D.; Christou, Nicolas; Sanchez, Juana

2011-01-01

Modern approaches for information technology based blended education utilize a variety of novel instructional, computational and network resources. Such attempts employ technology to deliver integrated, dynamically linked, interactive content and multifaceted learning environments, which may facilitate student comprehension and information retention. In this manuscript, we describe one such innovative effort of using technological tools for improving student motivation and learning of the theory, practice and usability of the Central Limit Theorem (CLT) in probability and statistics courses. Our approach is based on harnessing the computational libraries developed by the Statistics Online Computational Resource (SOCR) to design a new interactive Java applet and a corresponding demonstration activity that illustrate the meaning and the power of the CLT. The CLT applet and activity have clear common goals; to provide graphical representation of the CLT, to improve student intuition, and to empirically validate and establish the limits of the CLT. The SOCR CLT activity consists of four experiments that demonstrate the assumptions, meaning and implications of the CLT and ties these to specific hands-on simulations. We include a number of examples illustrating the theory and applications of the CLT. Both the SOCR CLT applet and activity are freely available online to the community to test, validate and extend (Applet: http://www.socr.ucla.edu/htmls/SOCR_Experiments.html and Activity: http://wiki.stat.ucla.edu/socr/index.php/SOCR_EduMaterials_Activities_GeneralCentralLimitTheorem). PMID:21833159

Attentional selection within and across hemispheres: implications for the perceptual load theory.

Science.gov (United States)

Wei, Ping; Kang, Guanlan; Zhou, Xiaolin

2013-03-01

The perceptual load of a given task affects attentional selection, with the selection occurring earlier when the load is high and later when the load is low. Recent evidence suggests that local competitive interaction may underlie the perceptual load effect and determine to what extent a task-irrelevant distractor is processed. Here, we asked participants to search for a target bar among homogeneously oriented bars (the low load conditions) or heterogeneously oriented bars (the high load conditions) in the central display, while ignoring a congruent or incongruent flanker bar presented to the left or right side of the central display, or a bar presented at one of the six positions outer to the central display. Importantly, we differentiated conditions in which the target in the central display and the peripheral flanker was presented within the same hemifield or across different hemifields. Results showed a significant flanker effect for the low load condition, but not for the high load condition, when the target and the flanker were across hemifields. However, when the target and the flanker were presented within the same hemifield, there was no flanker effect for either low or high load conditions. These findings demonstrate that the ability to ignore the task-irrelevant distractor is affected by local competition within hemisphere and that the perceptual load theory needs to be supplemented with detailed analysis of cognitive processes and mechanisms underlying the consumption of attentional resources.

Development of an interactive anatomical three-dimensional eye model.

Science.gov (United States)

Allen, Lauren K; Bhattacharyya, Siddhartha; Wilson, Timothy D

2015-01-01

The discrete anatomy of the eye's intricate oculomotor system is conceptually difficult for novice students to grasp. This is problematic given that this group of muscles represents one of the most common sites of clinical intervention in the treatment of ocular motility disorders and other eye disorders. This project was designed to develop a digital, interactive, three-dimensional (3D) model of the muscles and cranial nerves of the oculomotor system. Development of the 3D model utilized data from the Visible Human Project (VHP) dataset that was refined using multiple forms of 3D software. The model was then paired with a virtual user interface in order to create a novel 3D learning tool for the human oculomotor system. Development of the virtual eye model was done while attempting to adhere to the principles of cognitive load theory (CLT) and the reduction of extraneous load in particular. The detailed approach, digital tools employed, and the CLT guidelines are described herein. © 2014 American Association of Anatomists.

On the application of the dynamic plasticity theory for the treatment of reinforced concrete structures under transient loading

International Nuclear Information System (INIS)

Ammann, W.

1983-01-01

After a short introduction of the theory of dynamic plasticity, the possible applications of this theory on reinforced concrete structures under transient loading are discussed. Estimates can be obtained by relations giving lower and upper limits for dynamically loaded supporting beams. A procedure similar for the mode approximation method is described for the calculation of beams after a sudden failure of a support. (orig.) [de

Trunk Muscle Function Deficit in Youth Baseball Pitchers With Excessive Contralateral Trunk Tilt During Pitching.

Science.gov (United States)

Oyama, Sakiko; Waldhelm, Andrew G; Sosa, Araceli R; Patel, Ravina R; Kalinowski, Derick L

2017-09-01

Pitching technique is one of many factors that affect injury risk. Exhibiting excessive contralateral trunk tilt (CLT) during pitching has been linked to higher ball speed but also to increased joint loading. Deficit in trunk muscle strength has been suggested as an underlying cause of this movement pattern. The purpose of the study was to compare trunk muscle strength between youth baseball pitchers with varying degree of CLT during pitching. Cross-sectional study. Baseball practice fields. Twenty-eight youth baseball pitchers. Pitching technique was captured using a video camera. Based on the 2-dimensional trunk contralateral flexion angle, pitchers were categorized into low (30 degrees) CLT groups. Maximum isometric strength tests for trunk flexion, extension, and bilateral rotation, measured using a dynamometer. The pitchers with high CLT (n = 10) had longer pitching experience (P = 0.014), produced higher ball speed (P = 0.003) compared with the pitchers with moderate (n = 10) and low (n = 8) CLT, but demonstrated greater asymmetry in trunk rotation strength (relative weakness in rotation strength toward dominant side) compared with the pitchers with low CLT (P = 0.015). Excessive CLT may be a strategy that young pitchers learn to achieve higher ball velocity but also may be associated with imbalance between the oblique muscles on dominant and nondominant side, which may be acquired from repetitive pitching. Strengthening and emphasizing the use of dominant side oblique muscles may keep pitchers from leaning excessively during pitching and thus decrease joint loading.

Speed maintenance under cognitive load - Implications for theories of driver behaviour.

Science.gov (United States)

Lewis-Evans, Ben; de Waard, Dick; Brookhuis, Karel A

2011-07-01

No theory of driver behaviour has yet managed to achieve widespread acceptance and use in the field of Traffic Psychology, partly due to the difficulty in testing many of the theories. However, one class of theories, the motivational theories, can be usefully split into two groups and the differences between them can then be examined. One group posits the constant monitoring and targeting of a certain subjective variable, often risk, as the controlling factor in driving. The other group however states that subjective variables such as risk are only relevant once a certain threshold has been passed. In this study we aimed to examine this difference by manipulating both speed of travel and the amount of cognitive load participants were under. Participants were asked to initially drive at their preferred speed for 1min in a driving simulator. Participant's speed was then automatically increased or decreased by 10, 20 30km/h or left unchanged. Participants were then required to maintain the new speed for 1min. After this 1min the speed was again automatically changed and had to be maintained for one more minute, but this time participants also carried out a secondary mental arithmetic task. Finally participants were asked to again drive for another 1min at their preferred speed. This procedure was repeated seven times, once for each speed manipulation; -30, -20, -10, +0, +10, +20 and +30km/h. After each 1min interval verbal ratings of task difficulty, effort, feeling of risk and the typicality of the speed were collected. The results show a threshold effect in ratings of task difficulty, effort and feeling of risk, with no significant difference given between the ratings during the baseline period and the experimentally decreased speed periods until after participant's preferred speed of travel had been exceeded. Furthermore, even when under cognitive load the threshold relationship was still apparent, if diminished. Finally it appears that when under cognitive load

Self-Instructional Module Based on Cognitive Load Theory: A Study on Information Retention among Trainee Teachers

Science.gov (United States)

Ong, Chiek Pin; Tasir, Zaidatun

2015-01-01

The aim of the research is to study the information retention among trainee teachers using a self-instructional printed module based on Cognitive Load Theory for learning spreadsheet software. Effective pedagogical considerations integrating the theoretical concepts related to cognitive load are reflected in the design and development of the…

Energy Dependent Divisible Load Theory for Wireless Sensor Network Workload Allocation

Directory of Open Access Journals (Sweden)

Haiyan Shi

2012-01-01

Full Text Available The wireless sensor network (WSN, consisting of a large number of microsensors with wireless communication abilities, has become an indispensable tool for use in monitoring and surveillance applications. Despite its advantages in deployment flexibility and fault tolerance, the WSN is vulnerable to failures due to the depletion of limited onboard battery energy. A major portion of energy consumption is caused by the transmission of sensed results to the master processor. The amount of energy used, in fact, is related to both the duration of sensing and data transmission. Hence, in order to extend the operation lifespan of the WSN, a proper allocation of sensing workload among the sensors is necessary. An assignment scheme is here formulated on the basis of the divisible load theory, namely, the energy dependent divisible load theory (EDDLT for sensing workload allocations. In particular, the amount of residual energies onboard sensors are considered while deciding the workload assigned to each sensor. Sensors with smaller amount of residual energy are assigned lighter workloads, thus, allowing for a reduced energy consumption and the sensor lifespan is extended. Simulation studies are conducted and results have illustrated the effectiveness of the proposed workload allocation method.

Sound as Affective Design Feature in Multimedia Learning--Benefits and Drawbacks from a Cognitive Load Theory Perspective

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Königschulte, Anke

2015-01-01

The study presented in this paper investigates the potential effects of including non-speech audio such as sound effects into multimedia-based instruction taking into account Sweller's cognitive load theory (Sweller, 2005) and applied frameworks such as the cognitive theory of multimedia learning (Mayer, 2005) and the cognitive affective theory of…

The effect of implementing cognitive load theory-based design principles in virtual reality simulation training of surgical skills: a randomized controlled trial

DEFF Research Database (Denmark)

Andersen, Steven Arild Wuyts; Mikkelsen, Peter Trier; Konge, Lars

2016-01-01

training of mastoidectomy. Methods Eighteen novice medical students received 1 h of self-directed virtual reality simulation training of the mastoidectomy procedure randomized for standard instructions (control) or cognitive load theory-based instructions with a worked example followed by a problem......Background Cognitive overload can inhibit learning, and cognitive load theory-based instructional design principles can be used to optimize learning situations. This study aims to investigate the effect of implementing cognitive load theory-based design principles in virtual reality simulation....... Increased cognitive load when part tasks needed to be integrated in the post-training procedures could be a possible explanation for this. Other instructional designs and methods are needed to lower the cognitive load and improve the performance in virtual reality surgical simulation training of novices....

Stroop-like effects in a new-code learning task: A cognitive load theory perspective.

Science.gov (United States)

Hazan-Liran, Batel; Miller, Paul

2017-09-01

To determine whether and how learning is biased by competing task-irrelevant information that creates extraneous cognitive load, we assessed the efficiency of university students with a learning paradigm in two experiments. The paradigm asked participants to learn associations between eight words and eight digits. We manipulated congruity of the digits' ink colour with the words' semantics. In Experiment 1 word stimuli were colour words (e.g., blue, yellow) and in Experiment 2 colour-related word concepts (e.g., sky, banana). Marked benefits and costs on learning due to variation in extraneous cognitive load originating from processing task-irrelevant information were evident. Implications for cognitive load theory and schooling are discussed.

Generalized perturbation theory error control within PWR core-loading pattern optimization

International Nuclear Information System (INIS)

Imbriani, J.S.; Turinsky, P.J.; Kropaczek, D.J.

1995-01-01

The fuel management optimization code FORMOSA-P has been developed to determine the family of near-optimum loading patterns for PWR reactors. The code couples the optimization technique of simulated annealing (SA) with a generalized perturbation theory (GPT) model for evaluating core physics characteristics. To ensure the accuracy of the GPT predictions, as well as to maximize the efficient of the SA search, a GPT error control method has been developed

Cognitive Load Theory and the Effects of Transient Information on the Modality Effect

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Leahy, Wayne; Sweller, John

2016-01-01

Based on cognitive load theory and the "transient information effect," this paper investigated the "modality effect" while interpreting a contour map. The length and complexity of auditory and visual text instructions were manipulated. Experiment 1 indicated that longer audio text information within a presentation was inferior…

The effects of interstimulus interval on event-related indices of attention: an auditory selective attention test of perceptual load theory.

Science.gov (United States)

Gomes, Hilary; Barrett, Sophia; Duff, Martin; Barnhardt, Jack; Ritter, Walter

2008-03-01

We examined the impact of perceptual load by manipulating interstimulus interval (ISI) in two auditory selective attention studies that varied in the difficulty of the target discrimination. In the paradigm, channels were separated by frequency and target/deviant tones were softer in intensity. Three ISI conditions were presented: fast (300ms), medium (600ms) and slow (900ms). Behavioral (accuracy and RT) and electrophysiological measures (Nd, P3b) were observed. In both studies, participants evidenced poorer accuracy during the fast ISI condition than the slow suggesting that ISI impacted task difficulty. However, none of the three measures of processing examined, Nd amplitude, P3b amplitude elicited by unattended deviant stimuli, or false alarms to unattended deviants, were impacted by ISI in the manner predicted by perceptual load theory. The prediction based on perceptual load theory, that there would be more processing of irrelevant stimuli under conditions of low as compared to high perceptual load, was not supported in these auditory studies. Task difficulty/perceptual load impacts the processing of irrelevant stimuli in the auditory modality differently than predicted by perceptual load theory, and perhaps differently than in the visual modality.

Self-extinguishment of cross-laminated timber

NARCIS (Netherlands)

Crielaard, R.; van de Kuilen, J.W.G.; Terwel, K.C.; Ravenshorst, G.J.P.; Steenbakkers, P.; Breunesse, A.

2016-01-01

Cross-laminated timber, or CLT, is receiving attention for its potential use in tall buildings. As a combustible material, one of the challenges for the construction of these buildings is the fire risk that results from its use in the structure. Unprotected CLT can burn along with the fuel load

Dynamic analysis of isotropic nanoplates subjected to moving load using state-space method based on nonlocal second order plate theory

Energy Technology Data Exchange (ETDEWEB)

Nami, Mohammad Rahim [Shiraz University, Shiraz, Iran (Iran, Islamic Republic of); Janghorban, Maziar [Islamic Azad University, Marvdash (Iran, Islamic Republic of)

2015-06-15

In this work, dynamic analysis of rectangular nanoplates subjected to moving load is presented. In order to derive the governing equations of motion, second order plate theory is used. To capture the small scale effects, the nonlocal elasticity theory is adopted. It is assumed that the nanoplate is subjected to a moving concentrated load with the constant velocity V in the x direction. To solve the governing equations, state-space method is used to find the deflections of rectangular nanoplate under moving load. The results obtained here reveal that the nonlocality has significant effect on the deflection of rectangular nanoplate subjected to moving load.

The effect of implementing cognitive load theory-based design principles in virtual reality simulation training of surgical skills: a randomized controlled trial

DEFF Research Database (Denmark)

Andersen, Steven Arild Wuyts; Mikkelsen, Peter Trier; Konge, Lars

2016-01-01

Cognitive overload can inhibit learning, and cognitive load theory-based instructional design principles can be used to optimize learning situations. This study aims to investigate the effect of implementing cognitive load theory-based design principles in virtual reality simulation training...

In Respect to the Cognitive Load Theory: Adjusting Instructional Guidance with Student Expertise.

Science.gov (United States)

Schilling, Jim

2017-01-01

The amount of guidance supplied by educators to students in allied health programs is a factor in student learning. According to the cognitive load theory of learning, without adequate instructional support, novice learners will be overwhelmed and unable to store information, while unnecessary guidance supplied to advanced students will cause extraneous cognitive load on the working memory system. Adjusting instructional guidance for students according to their level of expertise to minimize extraneous cognitive load and optimize working memory storage capacity will enhance learning effectiveness. Novice students presented with complex subject matter require significant guidance during the initial stages, using strategies such as worked examples. As students comprehend information, instructional guidance needs to gradually fade to avoid elevated extraneous cognitive load from the expertise reversal effect. An instructional strategy that utilizes a systemic (fixed) or adjustable (adaptive) tapering of guidance to students in allied health programs depending on their expertise will optimize learning capability.

Load reduction test method of similarity theory and BP neural networks of large cranes

Science.gov (United States)

Yang, Ruigang; Duan, Zhibin; Lu, Yi; Wang, Lei; Xu, Gening

2016-01-01

Static load tests are an important means of supervising and detecting a crane's lift capacity. Due to space restrictions, however, there are difficulties and potential danger when testing large bridge cranes. To solve the loading problems of large-tonnage cranes during testing, an equivalency test is proposed based on the similarity theory and BP neural networks. The maximum stress and displacement of a large bridge crane is tested in small loads, combined with the training neural network of a similar structure crane through stress and displacement data which is collected by a physics simulation progressively loaded to a static load test load within the material scope of work. The maximum stress and displacement of a crane under a static load test load can be predicted through the relationship of stress, displacement, and load. By measuring the stress and displacement of small tonnage weights, the stress and displacement of large loads can be predicted, such as the maximum load capacity, which is 1.25 times the rated capacity. Experimental study shows that the load reduction test method can reflect the lift capacity of large bridge cranes. The load shedding predictive analysis for Sanxia 1200 t bridge crane test data indicates that when the load is 1.25 times the rated lifting capacity, the predicted displacement and actual displacement error is zero. The method solves the problem that lifting capacities are difficult to obtain and testing accidents are easily possible when 1.25 times related weight loads are tested for large tonnage cranes.

Maximized gust loads for a nonlinear airplane using matched filter theory and constrained optimization

Science.gov (United States)

Scott, Robert C.; Perry, Boyd, III; Pototzky, Anthony S.

1991-01-01

This paper describes and illustrates two matched-filter-theory based schemes for obtaining maximized and time-correlated gust-loads for a nonlinear airplane. The first scheme is computationally fast because it uses a simple one-dimensional search procedure to obtain its answers. The second scheme is computationally slow because it uses a more complex multidimensional search procedure to obtain its answers, but it consistently provides slightly higher maximum loads than the first scheme. Both schemes are illustrated with numerical examples involving a nonlinear control system.

Central limit theorem and deformed exponentials

International Nuclear Information System (INIS)

Vignat, C; Plastino, A

2007-01-01

The central limit theorem (CLT) can be ranked among the most important ones in probability theory and statistics and plays an essential role in several basic and applied disciplines, notably in statistical thermodynamics. We show that there exists a natural extension of the CLT from exponentials to so-called deformed exponentials (also denoted as q-Gaussians). Our proposal applies exactly in the usual conditions in which the classical CLT is used. (fast track communication)

Limit Theory for Panel Data Models with Cross Sectional Dependence and Sequential Exogeneity.

Science.gov (United States)

Kuersteiner, Guido M; Prucha, Ingmar R

2013-06-01

The paper derives a general Central Limit Theorem (CLT) and asymptotic distributions for sample moments related to panel data models with large n . The results allow for the data to be cross sectionally dependent, while at the same time allowing the regressors to be only sequentially rather than strictly exogenous. The setup is sufficiently general to accommodate situations where cross sectional dependence stems from spatial interactions and/or from the presence of common factors. The latter leads to the need for random norming. The limit theorem for sample moments is derived by showing that the moment conditions can be recast such that a martingale difference array central limit theorem can be applied. We prove such a central limit theorem by first extending results for stable convergence in Hall and Hedye (1980) to non-nested martingale arrays relevant for our applications. We illustrate our result by establishing a generalized estimation theory for GMM estimators of a fixed effect panel model without imposing i.i.d. or strict exogeneity conditions. We also discuss a class of Maximum Likelihood (ML) estimators that can be analyzed using our CLT.

Comparison of Different Assembling Techniques Regarding Cost, Durability, and Ecology - A Survey of Multi-layer Wooden Panel Assembly Load-Bearing Construction Elements

Directory of Open Access Journals (Sweden)

Dietrich Buck

2015-10-01

Full Text Available Wood is a pure, sustainable, renewable material. The increasing use of wood for construction can improve its sustainability. There are various techniques to assemble multi-layer wooden panels into prefabricated, load-bearing construction elements. However, comparative market and economy studies are still scarce. In this study, the following assembling techniques were compared: laminating, nailing, stapling, screwing, stress laminating, doweling, dovetailing, and wood welding. The production costs, durability, and ecological considerations were presented. This study was based on reviews of published works and information gathered from 27 leading wood product manufacturing companies in six European countries. The study shows that the various techniques of assembling multi-layer wooden construction panel elements are very different. Cross laminated timber (CLT exhibited the best results in terms of cost and durability. With regard to ecological concerns, dovetailing is the best. Taking into account both durability and ecological considerations, wooden screw-doweling is the best. These alternatives give manufacturers some freedom of choice regarding the visibility of surfaces and the efficient use of lower-quality timber. CLT is the most cost-effective, is not patented, and is a well-established option on the market today.

The future bias in marketing : a longitudinal approach

OpenAIRE

Omland, Anne Line Holck

2011-01-01

This study set out to explore consumer responses to pre-launch advertising, i.e. the advertising of products prior to launch. According to the construal level theory (CLT) people’s representation of future objects and events change with temporal distance. Drawing inferences from CLT to marketing, consumers’ attraction towards forthcoming products is explained. Further, using theory on consumer judgments the effects of pre-launch advertising is explored over time. A longitudi...

Cooling-load prediction by the combination of rough set theory and an artificial neural-network based on data-fusion technique

International Nuclear Information System (INIS)

Hou Zhijian; Lian Zhiwei; Yao Ye; Yuan Xinjian

2006-01-01

A novel method integrating rough sets (RS) theory and an artificial neural network (ANN) based on data-fusion technique is presented to forecast an air-conditioning load. Data-fusion technique is the process of combining multiple sensors data or related information to estimate or predict entity states. In this paper, RS theory is applied to find relevant factors to the load, which are used as inputs of an artificial neural-network to predict the cooling load. To improve the accuracy and enhance the robustness of load forecasting results, a general load-prediction model, by synthesizing multi-RSAN (MRAN), is presented so as to make full use of redundant information. The optimum principle is employed to deduce the weights of each RSAN model. Actual prediction results from a real air-conditioning system show that, the MRAN forecasting model is better than the individual RSAN and moving average (AMIMA) ones, whose relative error is within 4%. In addition, individual RSAN forecasting results are better than that of ARIMA

Plastic limit loads for cylindrical shell intersections under combined loading

International Nuclear Information System (INIS)

Skopinsky, V.N.; Berkov, N.A.; Vogov, R.A.

2015-01-01

In this research, applied methods of nonlinear analysis and results of determining the plastic limit loads for shell intersection configurations under combined internal pressure, in-plane moment and out-plane moment loadings are presented. The numerical analysis of shell intersections is performed using the finite element method, geometrically nonlinear shell theory in quadratic approximation and plasticity theory. For determining the load parameter of proportional combined loading, the developed maximum criterion of rate of change of relative plastic work is employed. The graphical results for model of cylindrical shell intersection under different two-parameter combined loadings (as generalized plastic limit load curves) and three-parameter combined loading (as generalized plastic limit load surface) are presented on the assumption that the internal pressure, in-plane moment and out-plane moment loads were applied in a proportional manner. - Highlights: • This paper presents nonlinear two-dimensional FE analysis for shell intersections. • Determining the plastic limit loads under combined loading is considered. • Developed maximum criterion of rate of change of relative plastic work is employed. • Plastic deformation mechanism in shell intersections is discussed. • Results for generalized plastic limit load curves of branch intersection are presented

The effect of implementing cognitive load theory-based design principles in virtual reality simulation training of surgical skills: a randomized controlled trial.

Science.gov (United States)

Andersen, Steven Arild Wuyts; Mikkelsen, Peter Trier; Konge, Lars; Cayé-Thomasen, Per; Sørensen, Mads Sølvsten

2016-01-01

Cognitive overload can inhibit learning, and cognitive load theory-based instructional design principles can be used to optimize learning situations. This study aims to investigate the effect of implementing cognitive load theory-based design principles in virtual reality simulation training of mastoidectomy. Eighteen novice medical students received 1 h of self-directed virtual reality simulation training of the mastoidectomy procedure randomized for standard instructions (control) or cognitive load theory-based instructions with a worked example followed by a problem completion exercise (intervention). Participants then completed two post-training virtual procedures for assessment and comparison. Cognitive load during the post-training procedures was estimated by reaction time testing on an integrated secondary task. Final-product analysis by two blinded expert raters was used to assess the virtual mastoidectomy performances. Participants in the intervention group had a significantly increased cognitive load during the post-training procedures compared with the control group (52 vs. 41 %, p  = 0.02). This was also reflected in the final-product performance: the intervention group had a significantly lower final-product score than the control group (13.0 vs. 15.4, p  virtual reality surgical simulation training of novices.

Simplified Theory of Plastic Zones for cyclic loading and multilinear hardening

International Nuclear Information System (INIS)

Hübel, Hartwig

2015-01-01

The Simplified Theory of Plastic Zones (STPZ) is a direct method based on Zarka's method, primarily developed to estimate post-shakedown quantities of structures under cyclic loading, avoiding incremental analyses through a load histogram. In a different paper the STPZ has previously been shown to provide excellent estimates of the elastic–plastic strain ranges in the state of plastic shakedown as required for fatigue analyses. In the present paper, it is described how the STPZ can be used to predict the strains accumulated through a number of loading cycles due to a ratcheting mechanism, until either elastic or plastic shakedown is achieved, so that strain limits can be satisfied. Thus, a consistent means of estimating both, strain ranges and accumulated strains is provided for structural integrity assessment as required by pressure vessel codes. The computational costs involved typically consist of few linear elastic analyses and some local calculations. Multilinear kinematic hardening and temperature dependent yield stresses are accounted for. The quality of the results and the computational burden involved are demonstrated through four examples. - Highlights: • A method is provided to estimate accumulated elastic–plastic strains. • A consistent method is provided to estimate elastic–plastic strain ranges. • Effect of multilinear kinematic hardening is captured. • Temperature dependent material properties are accounted for. • Few linear elastic analyses required

Trampoline exercise vs. strength training to reduce neck strain in fighter pilots.

Science.gov (United States)

Sovelius, Roope; Oksa, Juha; Rintala, Harri; Huhtala, Heini; Ylinen, Jari; Siitonen, Simo

2006-01-01

Fighter pilots' muscular strength and endurance are subjected to very high demands. Pilots' fatigued muscles are at higher risk for injuries. The purpose of this study was to compare the effects of two different training methods in reducing muscular loading during in-flight and cervical loading testing (CLT). There were 16 volunteer Finnish Air Force cadets who were divided into 2 groups: a strength training group (STG) and a trampoline training group (TTG). During the 6-wk training period, the STG performed dynamic flexion and extension and isometric rotation exercises, and the TTG performed trampoline bouncing exercises. During in-flight and CLT, muscle strain from the sternocleidomastoid, cervical erector spinae, trapezius, and thoracic erector spinae muscles was recorded with EMG. In-flight muscle strain in the STG after the training period decreased in the sternocleidomastoid 50%, cervical erector spinae 3%, trapezius 4%, and thoracic erector spinae 8%. In the TTG, the decrease was 41%, 30%, 20%, and 6%, respectively. In CLT, the results were similar. After a 3-mo follow-up period with intensive high +Gz flying, EMG during CLT was still lower than in baseline measurements. Both training methods were found to be effective in reducing muscle strain during in-flight and CLT, especially in the cervical muscles. There was no statistically significant difference between the training groups. Introduced exercises expand muscles' capacities in different ways and the authors recommend both strength and trampoline training programs to be included in fighter pilots' physical education programs.

Aerodynamic loads calculation and analysis for large scale wind turbine based on combining BEM modified theory with dynamic stall model

Energy Technology Data Exchange (ETDEWEB)

Dai, J.C. [College of Mechanical and Electrical Engineering, Central South University, Changsha (China); School of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan (China); Hu, Y.P.; Liu, D.S. [School of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan (China); Long, X. [Hara XEMC Windpower Co., Ltd., Xiangtan (China)

2011-03-15

The aerodynamic loads for MW scale horizontal-axis wind turbines are calculated and analyzed in the established coordinate systems which are used to describe the wind turbine. In this paper, the blade element momentum (BEM) theory is employed and some corrections, such as Prandtl and Buhl models, are carried out. Based on the B-L semi-empirical dynamic stall (DS) model, a new modified DS model for NACA63-4xx airfoil is adopted. Then, by combing BEM modified theory with DS model, a set of calculation method of aerodynamic loads for large scale wind turbines is proposed, in which some influence factors such as wind shear, tower, tower and blade vibration are considered. The research results show that the presented dynamic stall model is good enough for engineering purpose; the aerodynamic loads are influenced by many factors such as tower shadow, wind shear, dynamic stall, tower and blade vibration, etc, with different degree; the single blade endures periodical changing loads but the variations of the rotor shaft power caused by the total aerodynamic torque in edgewise direction are very small. The presented study approach of aerodynamic loads calculation and analysis is of the university, and helpful for thorough research of loads reduction on large scale wind turbines. (author)

Cognitive Load and Self-Determination Theories Applied to E-Learning: Impact on Students' Participation and Academic Performance.

Science.gov (United States)

de Araujo Guerra Grangeia, Tiago; de Jorge, Bruno; Franci, Daniel; Martins Santos, Thiago; Vellutini Setubal, Maria Silvia; Schweller, Marcelo; de Carvalho-Filho, Marco Antonio

2016-01-01

Emergency clerkships expose students to a stressful environment that require multiple tasks, which may have a direct impact on cognitive load and motivation for learning. To address this challenge, Cognitive Load Theory and Self Determination Theory provided the conceptual frameworks to the development of a Moodle-based online Emergency Medicine course, inspired by real clinical cases. Three consecutive classes (2013-2015) of sixth-year medical students (n = 304) participated in the course, during a curricular and essentially practical emergency rotation. "Virtual Rounds" provided weekly virtual patients in narrative format and meaningful schemata to chief complaints, in order to simulate real rounds at Emergency Unit. Additional activities such as Extreme Decisions, Emergency Quiz and Electrocardiographic challenge offered different views of emergency care. Authors assessed student´s participation and its correlation with their academic performance. A survey evaluated students´ opinions. Students graduating in 2015 answered an online questionnaire to investigate cognitive load and motivation. Each student produced 1965 pageviews and spent 72 hours logged on. Although Clinical Emergency rotation has two months long, students accessed the online course during an average of 5.3 months. Virtual Rounds was the most accessed activity, and there was positive correlations between the number of hours logged on the platform and final grades on Emergency Medicine. Over 90% of students felt an improvement in their clinical reasoning and considered themselves better prepared for rendering Emergency care. Considering a Likert scale from 1 (minimum load) to 7 (maximum load), the scores for total cognitive load were 4.79±2.2 for Virtual Rounds and 5.56±1.96 for real medical rounds(pcognitive and motivational conceptual frameworks, seems to be a strong tool to engage students in learning. It may support them to manage the cognitive challenges involved in clinical care and

Opposite Effects of Capacity Load and Resolution Load on Distractor Processing

OpenAIRE

Zhang, Weiwei; Luck, Steven J.

2014-01-01

According to the load theory of attention, an increased perceptual load reduces distractor processing whereas an increased working memory load facilitates distractor processing. Here we raise the possibility that the critical distinction may instead be between an emphasis on resolution and an emphasis on capacity. That is, perceptual load manipulations typically emphasize resolution (fine-grained discriminations), whereas working memory load manipulations typically emphasize capacity (simulta...

An Evolutionary Upgrade of Cognitive Load Theory: Using the Human Motor System and Collaboration to Support the Learning of Complex Cognitive Tasks

NARCIS (Netherlands)

G.W.C. Paas (Fred); J. Sweller (John)

2012-01-01

textabstractCognitive load theory is intended to provide instructional strategies derived from experimental, cognitive load effects. Each effect is based on our knowledge of human cognitive architecture, primarily the limited capacity and duration of a human working memory. These limitations are

Concurrent Working Memory Load Can Facilitate Selective Attention: Evidence for Specialized Load

Science.gov (United States)

Park, Soojin; Kim, Min-Shik; Chun, Marvin M.

2007-01-01

Load theory predicts that concurrent working memory load impairs selective attention and increases distractor interference (N. Lavie, A. Hirst, J. W. de Fockert, & E. Viding, see record 2004-17825-003). Here, the authors present new evidence that the type of concurrent working memory load determines whether load impairs selective attention or not.…

An efficient approach for electric load forecasting using distributed ART (adaptive resonance theory) and HS-ARTMAP (Hyper-spherical ARTMAP network) neural network

International Nuclear Information System (INIS)

Cai, Yuan; Wang, Jian-zhou; Tang, Yun; Yang, Yu-chen

2011-01-01

This paper presents a neural network based on adaptive resonance theory, named distributed ART (adaptive resonance theory) and HS-ARTMAP (Hyper-spherical ARTMAP network), applied to the electric load forecasting problem. The distributed ART combines the stable fast learning capabilities of winner-take-all ART systems with the noise tolerance and code compression capabilities of multi-layer perceptions. The HS-ARTMAP, a hybrid of an RBF (Radial Basis Function)-network-like module which uses hyper-sphere basis function substitute the Gaussian basis function and an ART-like module, performs incremental learning capabilities in function approximation problem. The HS-ARTMAP only receives the compressed distributed coding processed by distributed ART to deal with the proliferation problem which ARTMAP (adaptive resonance theory map) architecture often encounters and still performs well in electric load forecasting. To demonstrate the performance of the methodology, data from New South Wales and Victoria in Australia are illustrated. Results show that the developed method is much better than the traditional BP and single HS-ARTMAP neural network. -- Research highlights: → The processing of the presented network is based on compressed distributed data. It's an innovation among the adaptive resonance theory architecture. → The presented network decreases the proliferation the Fuzzy ARTMAP architectures usually encounter. → The network on-line forecasts electrical load accurately, stably. → Both one-period and multi-period load forecasting are executed using data of different cities.

Perceptual load in sport and the heuristic value of the perceptual load paradigm in examining expertise-related perceptual-cognitive adaptations.

Science.gov (United States)

Furley, Philip; Memmert, Daniel; Schmid, Simone

2013-03-01

In two experiments, we transferred perceptual load theory to the dynamic field of team sports and tested the predictions derived from the theory using a novel task and stimuli. We tested a group of college students (N = 33) and a group of expert team sport players (N = 32) on a general perceptual load task and a complex, soccer-specific perceptual load task in order to extend the understanding of the applicability of perceptual load theory and further investigate whether distractor interference may differ between the groups, as the sport-specific processing task may not exhaust the processing capacity of the expert participants. In both, the general and the specific task, the pattern of results supported perceptual load theory and demonstrates that the predictions of the theory also transfer to more complex, unstructured situations. Further, perceptual load was the only determinant of distractor processing, as we neither found expertise effects in the general perceptual load task nor the sport-specific task. We discuss the heuristic utility of using response-competition paradigms for studying both general and domain-specific perceptual-cognitive adaptations.

Cognitive Load Theory and the Acquisition of Complex Cognitive Skills in the Elderly: Towards an Integrative Framework.

Science.gov (United States)

Van Gerven, Pascal W. M.; Paas, Fred G. W. C.; Van Merrienboer, Jeroen J. G.; Schmidt, Henk G.

2000-01-01

Cognitive load (CL) theory suggests minimizing extraneous CL and maximizing germane CL in order not to overload working memory. Instructional design for older adults should therefore include goal-free problems, worked examples, and different modalities and avoid splitting attention and including redundant information. (SK)

Role of experimental resolution in measurements of critical layer thickness for strained-layer epitaxy

International Nuclear Information System (INIS)

Fritz, I.J.

1987-01-01

Experimental measurements of critical layer thicknesses (CLT's) in strained-layer epitaxy are considered. Finite experimental resolution can have a major effect on measured CLT's and can easily lead to spurious results. The theoretical approach to critical layer thicknesses of J. W. Matthews [J. Vac. Sci. Technol. 12, 126 (1975)] has been modified in a straightforward way to predict the apparent critical thickness for an experiment with finite resolution in lattice parameter. The theory has also been modified to account for the general empirical result that fewer misfit dislocations are generated than predicted by equilibrium calculation. The resulting expression is fit to recent x-ray diffraction data on InGaAs/GaAs and SiGe/Si. The results suggest that CLT's in these systems may not be significantly larger than predicted by equilibrium theory, in agreement with high-resolution measurements

Complete mechanical behavior analysis of FG Nano Beam under non-uniform loading using non-local theory

Science.gov (United States)

Ghaffari, I.; Parhizkar Yaghoobi, M.; Ghannad, M.

2018-01-01

The purpose of this study is to offer a complete solution to analyze the mechanical behavior (bending, buckling and vibration) of Nano-beam under non-uniform loading. Furthermore, the effects of size (nonlocal parameters), non-homogeneity constants, and different boundary conditions are investigated by using this method. The exact solution presented here reduces costs incurred by experiments. In this research, the displacement field obeys the kinematics of the Euler-Bernoulli beam theory and non-local elasticity theory has been used. The governing equations and general boundary conditions are derived for a beam by using energy method. The presented solution enables us to analyze any kind of loading profile and boundary conditions with no limitations. Furthermore, this solution, unlike previous studies, is not a series-solution; hence, there is no limitation prior to existing with the series-solution, nor does it need to check convergence. Based on the developed analytical solution, the influence of size, non-homogeneity and non-uniform loads on bending, buckling and vibration behaviors is discussed. Also, the obtained result is highly accurate and in good agreement with previous research. In theoretical method, the allowable range for non-local parameters can be determined so as to make a major contribution to the reduction of the cost of experiments determining the value of non-local parameters.

Understanding Cognitive Load Using On-line Dictionaries

OpenAIRE

Robert F. , Dilenschneider

2017-01-01

Cognitive Load Theory may useful for language instructors to understand how the look up conditions ofusing an on-line dictionary might influence learning. This paper first reviews previous studies that haveinvestigated dictionary use for vocabulary acquisition and reading comprehension Second, it explainsthe various elements of Cognitive Load Theory. Third, it describes how Cognitive Load Theory appliesto language learners' to learn unknown words and comprehend texts Last, it discusses the pe...

Precursor Evolution and Stress Corrosion Cracking Initiation of Cold-Worked Alloy 690 in Simulated Pressurized Water Reactor Primary Water

Energy Technology Data Exchange (ETDEWEB)

Zhai, Ziqing [Pacific Northwest National Laboratory, 622 Horn Rapids Road, P.O. Box 999, Richland, Washington 99352.; Toloczko, Mychailo [Pacific Northwest National Laboratory, 622 Horn Rapids Road, P.O. Box 999, Richland, Washington 99352.; Kruska, Karen [Pacific Northwest National Laboratory, 622 Horn Rapids Road, P.O. Box 999, Richland, Washington 99352.; Bruemmer, Stephen [Pacific Northwest National Laboratory, 622 Horn Rapids Road, P.O. Box 999, Richland, Washington 99352.

2017-05-22

Stress corrosion crack initiation of two thermally-treated, cold-worked (CW) alloy 690 (UNS N06690) materials was investigated in 360oC simulated PWR primary water using constant load tensile (CLT) tests and blunt notch compact tension (BNCT) tests equipped with direct current potential drop (DCPD) for in-situ detection of cracking. SCC initiation was not detected by DCPD for either the 21% or 31%CW CLT specimens loaded at their yield stress after ~9,220 hours, however intergranular (IG) precursor damage and isolated surface cracks were observed on the specimens. The two 31%CW BNCT specimens loaded at moderate stress intensity after several cyclic loading ramps showed DCPD-indicated crack initiation after 10,400 hours of exposure at constant stress intensity, which was resulted from significant growth of IG cracks. The 21%CW BNCT specimens only exhibited isolated small IG surface cracks and showed no apparent DCPD change throughout the test. Post-test cross-section examinations revealed many grain boundary (GB) nano-cavities in the bulk of all the CLT and BNCT specimens particularly for the 31%CW materials. Cavities were also found along GBs extending to the surface suggesting an important role in crack nucleation. This paper provides an overview of the evolution of GB cavities and discusses their effects on crack initiation in CW alloy 690.

Precursor evolution and SCC initiation of cold-worked alloy 690 in simulated PWR primary water

Energy Technology Data Exchange (ETDEWEB)

Zhai, Ziqing; Kruska, Karen; Toloczko, Mychailo B.; Bruemmer, Stephen M.

2017-03-27

Stress corrosion crack initiation of two thermally-treated, cold-worked (CW) alloy 690 materials was investigated in 360oC simulated PWR primary water using constant load tensile (CLT) tests and blunt notch compact tension (BNCT) tests equipped with direct current potential drop (DCPD) for in-situ detection of cracking. SCC initiation was not detected by DCPD for the 21% and 31%CW CLT specimens loaded at their yield stress after ~9,220 h, however intergranular (IG) precursor damage and isolated surface cracks were observed on the specimens. The two 31%CW BNCT specimens loaded at moderate stress intensity after several cyclic loading ramps showed DCPD-indicated crack initiation after 10,400h exposure at constant stress intensity, which resulted from significant growth of IG cracks. The 21%CW BNCT specimens only exhibited isolated small IG surface cracks and showed no apparent DCPD change throughout the test. Interestingly, post-test cross-section examinations revealed many grain boundary (GB) nano-cavities in the bulk of all the CLT and BNCT specimens particularly for the 31%CW materials. Cavities were also found along GBs extending to the surface suggesting an important role in crack nucleation. This paper provides an overview of the evolution of GB cavities and will discuss their effects on crack initiation in CW alloy 690.

Failure mechanism and coupled static-dynamic loading theory in deep hard rock mining: A review

Directory of Open Access Journals (Sweden)

Xibing Li

2017-08-01

Full Text Available Rock failure phenomena, such as rockburst, slabbing (or spalling and zonal disintegration, related to deep underground excavation of hard rocks are frequently reported and pose a great threat to deep mining. Currently, the explanation for these failure phenomena using existing dynamic or static rock mechanics theory is not straightforward. In this study, new theory and testing method for deep underground rock mass under coupled static-dynamic loading are introduced. Two types of coupled loading modes, i.e. “critical static stress + slight disturbance” and “elastic static stress + impact disturbance”, are proposed, and associated test devices are developed. Rockburst phenomena of hard rocks under coupled static-dynamic loading are successfully reproduced in the laboratory, and the rockburst mechanism and related criteria are demonstrated. The results of true triaxial unloading compression tests on granite and red sandstone indicate that the unloading can induce slabbing when the confining pressure exceeds a certain threshold, and the slabbing failure strength is lower than the shear failure strength according to the conventional Mohr-Column criterion. Numerical results indicate that the rock unloading failure response under different in situ stresses and unloading rates can be characterized by an equivalent strain energy density. In addition, we present a new microseismic source location method without premeasuring the sound wave velocity in rock mass, which can efficiently and accurately locate the rock failure in hard rock mines. Also, a new idea for deep hard rock mining using a non-explosive continuous mining method is briefly introduced.

An Evolutionary Upgrade of Cognitive Load Theory: Using the Human Motor System and Collaboration to Support the Learning of Complex Cognitive Tasks

Science.gov (United States)

Paas, Fred; Sweller, John

2012-01-01

Cognitive load theory is intended to provide instructional strategies derived from experimental, cognitive load effects. Each effect is based on our knowledge of human cognitive architecture, primarily the limited capacity and duration of a human working memory. These limitations are ameliorated by changes in long-term memory associated with…

Cognitive Load and Self-Determination Theories Applied to E-Learning: Impact on Students' Participation and Academic Performance.

Directory of Open Access Journals (Sweden)

Tiago de Araujo Guerra Grangeia

Full Text Available Emergency clerkships expose students to a stressful environment that require multiple tasks, which may have a direct impact on cognitive load and motivation for learning. To address this challenge, Cognitive Load Theory and Self Determination Theory provided the conceptual frameworks to the development of a Moodle-based online Emergency Medicine course, inspired by real clinical cases.Three consecutive classes (2013-2015 of sixth-year medical students (n = 304 participated in the course, during a curricular and essentially practical emergency rotation. "Virtual Rounds" provided weekly virtual patients in narrative format and meaningful schemata to chief complaints, in order to simulate real rounds at Emergency Unit. Additional activities such as Extreme Decisions, Emergency Quiz and Electrocardiographic challenge offered different views of emergency care. Authors assessed student´s participation and its correlation with their academic performance. A survey evaluated students´ opinions. Students graduating in 2015 answered an online questionnaire to investigate cognitive load and motivation.Each student produced 1965 pageviews and spent 72 hours logged on. Although Clinical Emergency rotation has two months long, students accessed the online course during an average of 5.3 months. Virtual Rounds was the most accessed activity, and there was positive correlations between the number of hours logged on the platform and final grades on Emergency Medicine. Over 90% of students felt an improvement in their clinical reasoning and considered themselves better prepared for rendering Emergency care. Considering a Likert scale from 1 (minimum load to 7 (maximum load, the scores for total cognitive load were 4.79±2.2 for Virtual Rounds and 5.56±1.96 for real medical rounds(p<0,01.A real-world inspired online course, based on cognitive and motivational conceptual frameworks, seems to be a strong tool to engage students in learning. It may support them to

A large deformation theory of solids subject to electromagnetic loads and its application

International Nuclear Information System (INIS)

Nishiguchi, I.; Sasaki, M.

1993-01-01

A large deformation theory of deformable solids is proposed in which the interaction with electromagnetic fields is taken into account. Weak forms of the Maxwell's equations in a fixed reference configuration together with the balance of momentum constitute the governing equations for our theory. The weak forms of the Maxwell's equations in a reference configuration can be derived by the direct transformation from spatial weak forms. The results coincide with the weak forms obtained from the local expressions by Lax and Nelson though we made a distinction between the covariant and contravariant vector explicitly. For the deformable body subject to the electromagnetic fields, weak forms of the Ampere's law and/or the Faraday's law, when combined with the weak form of the balance of momentum, can serve as the governing equations of the theory. As is known, however, these equations are not sufficient to describe the response of a specific material due to a given loading. As for the momentum balance, we need the dependency of stress on the deformation and objective constitutive equations of hyperelasticity, hypoelasticity and inelasticity are available. Parallel to these, objective constitutive equations for the electromagnetism are discussed. As an application of the theory, linearized equations for quasi-static deformation under magnetic field is derived based on the vector potential formulation. (author)

Diluting the Burden of Load: Perceptual Load Effects Are Simply Dilution Effects

Science.gov (United States)

Tsal, Yehoshua; Benoni, Hanna

2010-01-01

The substantial distractor interference obtained for small displays when the target appears alone is reduced in large displays when the target is embedded among neutral letters. This finding has been interpreted as reflecting low-load and high-load processing, respectively, thereby supporting the theory of perceptual load (Lavie & Tsal, 1994).…

Advancing Lie Detection by Inducing Cognitive Load on Liars: A Review of Relevant Theories and Techniques Guided by Lessons from Polygraph-Based Approaches

Science.gov (United States)

Walczyk, Jeffrey J.; Igou, Frank P.; Dixon, Alexa P.; Tcholakian, Talar

2013-01-01

This article critically reviews techniques and theories relevant to the emerging field of “lie detection by inducing cognitive load selectively on liars.” To help these techniques benefit from past mistakes, we start with a summary of the polygraph-based Controlled Question Technique (CQT) and the major criticisms of it made by the National Research Council (2003), including that it not based on a validated theory and administration procedures have not been standardized. Lessons from the more successful Guilty Knowledge Test are also considered. The critical review that follows starts with the presentation of models and theories offering insights for cognitive lie detection that can undergird theoretically load-inducing approaches. This is followed by evaluation of specific research-based, load-inducing proposals, especially for their susceptibility to rehearsal and other countermeasures. To help organize these proposals and suggest new direction for innovation and refinement, a theoretical taxonomy is presented based on the type of cognitive load induced in examinees (intrinsic or extraneous) and how open-ended the responses to test items are. Finally, four recommendations are proffered that can help researchers and practitioners to avert the corresponding mistakes with the CQT and yield new, valid cognitive lie detection technologies. PMID:23378840

Creating an engaging and stimulating anatomy lecture environment using the Cognitive Load Theory-based Lecture Model: Students' experiences

Directory of Open Access Journals (Sweden)

Siti N.H. Hadie, PhD

2018-04-01

�بير في نطاق التحفيز الذاتي. بالإضافة إلى ذلك، لمست مجموعة التدخل تجربة تعلم جيدة من المحاضرات. الاستنتاجات: حفزت القواعد الإرشادية بنجاح المشاركة المعرفية للطلبة وخبرة التعلم، مما يدل على التحفيز الناجح للموارد ذات الصلة للطلبة. تحفيز هذه الموارد المعرفية ضروري لنجاح المعالجة المعرفية خصوصا عند تعلم موضوع صعب كعلم التشريح. Abstract: Objective: There is a need to create a standard interactive anatomy lecture that can engage students in their learning process. This study investigated the impact of a new lecturing guideline, the Cognitive Load Theory-based Lecture Model (CLT-bLM, on students' cognitive engagement and motivation. Methods: A randomised controlled trial involving 197 participants from three institutions was conducted. The control group attended a freestyle lecture on the gross anatomy of the heart, delivered by a qualified anatomist from each institution. The intervention group attended a CLT-bLM-based lecture on a similar topic, delivered by the same lecturer, three weeks thereafter. The lecturers had attended a CLT-bLM workshop that allowed them to prepare for the CLT-bLM-based lecture over the course of three weeks. The students' ratings on their cognitive engagement and internal motivation were evaluated immediately after the lecture using a validated Learners' Engagement and Motivation Questionnaire. The differences between variables were analysed and the results were triangulated with the focus group discussion findings that explored students' experience while attending the lecture. Results: The intervention group has a significantly higher level of cognitive engagement than the control group; however, no significant difference in internal motivation score was found. In addition, the

Features of Representations in General Chemistry Textbooks: A Peek through the Lens of the Cognitive Load Theory

Science.gov (United States)

Nyachwaya, James M.; Gillaspie, Merry

2016-01-01

The goals of this study were (1) determine the prevalence of various features of representations in five general chemistry textbooks used in the United States, and (2) use cognitive load theory to draw implications of the various features of analyzed representations. We adapted the Graphical Analysis Protocol (GAP) (Slough et al., 2010) to look at…

Mass defect of 37Cl(t, p)39Cl: Coulomb displacement energy of the T=5/2, Jsup(π)=3+/2 states in 39Cl-39Ar

International Nuclear Information System (INIS)

Antony, M.S.; Britz, J.; Bueb, J.B.; Pape, A.

1984-01-01

From the Q-value (5701.9+-2.5)keV of the reaction 37 Cl(t, p) 39 Cl, the ground-state mass defect of 39 Cl is found to be (-29802.8+-2.5)keV, an improvement upon the existing value of (-29803+-18)keV. The Coulomb displacement energy of the mirror nuclei 39 Cl- 39 Ar for T=5/2, Jsup(π)=3 + /2 is found to be (6422.1+-10.6)keV. The r 0 parameter of the charge radius is approximately 1.32 fm for A=39

Load Frequency Control in Isolated Micro-Grids with Electrical Vehicles Based on Multivariable Generalized Predictive Theory

Directory of Open Access Journals (Sweden)

Jun Yang

2015-03-01

Full Text Available In power systems, although the inertia energy in power sources can partly cover power unbalances caused by load disturbance or renewable energy fluctuation, it is still hard to maintain the frequency deviation within acceptable ranges. However, with the vehicle-to-grid (V2G technique, electric vehicles (EVs can act as mobile energy storage units, which could be a solution for load frequency control (LFC in an isolated grid. In this paper, a LFC model of an isolated micro-grid with EVs, distributed generations and their constraints is developed. In addition, a controller based on multivariable generalized predictive control (MGPC theory is proposed for LFC in the isolated micro-grid, where EVs and diesel generator (DG are coordinated to achieve a satisfied performance on load frequency. A benchmark isolated micro-grid with EVs, DG, and wind farm is modeled in the Matlab/Simulink environment to demonstrate the effectiveness of the proposed method. Simulation results demonstrate that with MGPC, the energy stored in EVs can be managed intelligently according to LFC requirement. This improves the system frequency stability with complex operation situations including the random renewable energy resource and the continuous load disturbances.

Effect of practice on perceptual load

OpenAIRE

Mejia-Ramirez, Manuel

2013-01-01

Within attention studies, Lavie's load theory (Lavie & Tsal, 1994; Lavie, Hirst, de Fockert, & Viding, 2004) presented an account that could settle the question whether attention selects stimuli to be processed at an early or late stage of cognitive processing. This theory relied on the concepts of "perceptual load" and "attentional capacity", proposing that attentional resources are automatically allocated to stimuli, but when the perceptual load of the stimuli exceeds person's capacity, tas...

Review: Optimising cognitive load and usability to improve the ...

African Journals Online (AJOL)

Cognitive load theory views learning as involving active processing of information by working memory via separate visual and auditory channels. This system is of ... The fields of cognitive load theory and human-computer interaction share a common goal in striving to reduce extraneous cognitive load. The load induced by ...

Opposite effects of capacity load and resolution load on distractor processing.

Science.gov (United States)

Zhang, Weiwei; Luck, Steven J

2015-02-01

According to the load theory of attention, an increased perceptual load reduces distractor processing whereas an increased working memory load facilitates distractor processing. Here we raise the possibility that the critical distinction may instead be between an emphasis on resolution and an emphasis on capacity. That is, perceptual load manipulations typically emphasize resolution (fine-grained discriminations), whereas working memory load manipulations typically emphasize capacity (simultaneous processing of multiple relevant stimuli). To test the plausibility of this hypothesis, we used a visual working memory task that emphasized either the number of items to be stored (capacity load, retaining 2 vs. 4 colors) or the precision of the representations (resolution load, detecting small vs. large color changes). We found that an increased capacity load led to increased flanker interference (a measure of distractor processing), whereas an increased resolution load led to reduced flanker interference. These opposite effects of capacity load and resolution load on distractor processing mirror the previously described opposite effects of perceptual load and working memory load.

Large deformation of uniaxially loaded slender microbeams on the basis of modified couple stress theory: Analytical solution and Galerkin-based method

Science.gov (United States)

Kiani, Keivan

2017-09-01

Large deformation regime of micro-scale slender beam-like structures subjected to axially pointed loads is of high interest to nanotechnologists and applied mechanics community. Herein, size-dependent nonlinear governing equations are derived by employing modified couple stress theory. Under various boundary conditions, analytical relations between axially applied loads and deformations are presented. Additionally, a novel Galerkin-based assumed mode method (AMM) is established to solve the highly nonlinear equations. In some particular cases, the predicted results by the analytical approach are also checked with those of AMM and a reasonably good agreement is reported. Subsequently, the key role of the material length scale on the load-deformation of microbeams is discussed and the deficiencies of the classical elasticity theory in predicting such a crucial mechanical behavior are explained in some detail. The influences of slenderness ratio and thickness of the microbeam on the obtained results are also examined. The present work could be considered as a pivotal step in better realizing the postbuckling behavior of nano-/micro- electro-mechanical systems consist of microbeams.

The vocabulary profile of Slovak children with primary language impairment compared to typically developing Slovak children measured by LITMUS-CLT.

Science.gov (United States)

Kapalková, Svetlana; Slančová, Daniela

2017-01-01

This study compared a sample of children with primary language impairment (PLI) and typically developing age-matched children using the crosslinguistic lexical tasks (CLT-SK). We also compared the PLI children with typically developing language-matched younger children who were matched on the basis of receptive vocabulary. Overall, statistical testing showed that the vocabulary of the PLI children was significantly different from the vocabulary of the age-matched children, but not statistically different from the younger children who were matched on the basis of their receptive vocabulary size. Qualitative analysis of the correct answers revealed that the PLI children showed higher rigidity compared to the younger language-matched children who are able to use more synonyms or derivations across word class in naming tasks. Similarly, an examination of the children's naming errors indicated that the language-matched children exhibited more semantic errors, whereas PLI children showed more associative errors.

Load Induced Blindness

Science.gov (United States)

Macdonald, James S. P.; Lavie, Nilli

2008-01-01

Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005, for a review). Here we varied the level of…

Comparison of the lifting-line free vortex wake method and the blade-element-momentum theory regarding the simulated loads of multi-MW wind turbines

International Nuclear Information System (INIS)

Hauptmann, S; Bülk, M; Cheng, P W; Schön, L; Erbslöh, S; Boorsma, K; Grasso, F; Kühn, M

2014-01-01

Design load simulations for wind turbines are traditionally based on the blade- element-momentum theory (BEM). The BEM approach is derived from a simplified representation of the rotor aerodynamics and several semi-empirical correction models. A more sophisticated approach to account for the complex flow phenomena on wind turbine rotors can be found in the lifting-line free vortex wake method. This approach is based on a more physics based representation, especially for global flow effects. This theory relies on empirical correction models only for the local flow effects, which are associated with the boundary layer of the rotor blades. In this paper the lifting-line free vortex wake method is compared to a state- of-the-art BEM formulation with regard to aerodynamic and aeroelastic load simulations of the 5MW UpWind reference wind turbine. Different aerodynamic load situations as well as standardised design load cases that are sensitive to the aeroelastic modelling are evaluated in detail. This benchmark makes use of the AeroModule developed by ECN, which has been coupled to the multibody simulation code SIMPACK

Comparison of the lifting-line free vortex wake method and the blade-element-momentum theory regarding the simulated loads of multi-MW wind turbines

Science.gov (United States)

Hauptmann, S.; Bülk, M.; Schön, L.; Erbslöh, S.; Boorsma, K.; Grasso, F.; Kühn, M.; Cheng, P. W.

2014-12-01

Design load simulations for wind turbines are traditionally based on the blade- element-momentum theory (BEM). The BEM approach is derived from a simplified representation of the rotor aerodynamics and several semi-empirical correction models. A more sophisticated approach to account for the complex flow phenomena on wind turbine rotors can be found in the lifting-line free vortex wake method. This approach is based on a more physics based representation, especially for global flow effects. This theory relies on empirical correction models only for the local flow effects, which are associated with the boundary layer of the rotor blades. In this paper the lifting-line free vortex wake method is compared to a state- of-the-art BEM formulation with regard to aerodynamic and aeroelastic load simulations of the 5MW UpWind reference wind turbine. Different aerodynamic load situations as well as standardised design load cases that are sensitive to the aeroelastic modelling are evaluated in detail. This benchmark makes use of the AeroModule developed by ECN, which has been coupled to the multibody simulation code SIMPACK.

Effect of thermal loading due to laser pulse on thermoelastic porous medium under G-N theory

Directory of Open Access Journals (Sweden)

Mohamed I.A. Othman

Full Text Available The aim of this paper is to study the wave propagation of generalized thermoelastic medium with voids under the effect of thermal loading due to laser pulse with energy dissipation. The material is a homogeneous isotropic elastic half-space and heated by a non-Gaussian laser beam with the pulse duration of 0.2 ps. A normal mode method is proposed to analyse the problem and obtain numerical solutions for the displacement components, stresses, temperature distribution and the change in the volume fraction field. The results of the physical quantities have been illustrated graphically by comparison between both types II and III of Green-Naghdi theory for two values of time, as well as with and without void parameters. Keywords: Laser pulse, Voids, Energy dissipation, Green-Naghdi theory, Wave propagation, Thermoelasticity

Lightening the load: perceptual load impairs visual detection in typical adults but not in autism.

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Remington, Anna M; Swettenham, John G; Lavie, Nilli

2012-05-01

Autism spectrum disorder (ASD) research portrays a mixed picture of attentional abilities with demonstrations of enhancements (e.g., superior visual search) and deficits (e.g., higher distractibility). Here we test a potential resolution derived from the Load Theory of Attention (e.g., Lavie, 2005). In Load Theory, distractor processing depends on the perceptual load of the task and as such can only be eliminated under high load that engages full capacity. We hypothesize that ASD involves enhanced perceptual capacity, leading to the superior performance and increased distractor processing previously reported. Using a signal-detection paradigm, we test this directly and demonstrate that, under higher levels of load, perceptual sensitivity was reduced in typical adults but not in adults with ASD. These findings confirm our hypothesis and offer a promising solution to the previous discrepancies by suggesting that increased distractor processing in ASD results not from a filtering deficit but from enhanced perceptual capacity.

Multimedia instructions and cognitive load theory: effects of modality and cueing.

Science.gov (United States)

Tabbers, Huib K; Martens, Rob L; van Merriënboer, Jeroen J G

2004-03-01

Recent research on the influence of presentation format on the effectiveness of multimedia instructions has yielded some interesting results. According to cognitive load theory (Sweller, Van Merriënboer, & Paas, 1998) and Mayer's theory of multimedia learning (Mayer, 2001), replacing visual text with spoken text (the modality effect) and adding visual cues relating elements of a picture to the text (the cueing effect) both increase the effectiveness of multimedia instructions in terms of better learning results or less mental effort spent. The aim of this study was to test the generalisability of the modality and cueing effect in a classroom setting. The participants were 111 second-year students from the Department of Education at the University of Gent in Belgium (age between 19 and 25 years). The participants studied a web-based multimedia lesson on instructional design for about one hour. Afterwards they completed a retention and a transfer test. During both the instruction and the tests, self-report measures of mental effort were administered. Adding visual cues to the pictures resulted in higher retention scores, while replacing visual text with spoken text resulted in lower retention and transfer scores. Only a weak cueing effect and even a reverse modality effect have been found, indicating that both effects do not easily generalise to non-laboratory settings. A possible explanation for the reversed modality effect is that the multimedia instructions in this study were learner-paced, as opposed to the system-paced instructions used in earlier research.

Blade-element/momentum theory

DEFF Research Database (Denmark)

Sørensen, Jens Nørkær

2016-01-01

Although there exists a large variety of methods for predicting performance and loadings of wind turbines, the only approach used today by wind turbine manufacturers is based on the blade-element/momentum (BEM) theory by Glauert (Aerodynamic theory. Springer, Berlin, pp. 169-360, 1935). A basic...... assumption in the BEM theory is that the flow takes place in independent stream tubes and that the loading is determined from two-dimensional sectional airfoil characteristics....

A High-Order Theory for the Analysis of Circular Cylindrical Composite Sandwich Shells with Transversely Compliant Core Subjected to External Loads

DEFF Research Database (Denmark)

Rahmani, Omid; Khalili, S.M.R.; Thomsen, Ole Thybo

2012-01-01

A new model based on the high order sandwich panel theory is proposed to study the effect of external loads on the free vibration of circular cylindrical composite sandwich shells with transversely compliant core, including also the calculation of the buckling loads. In the present model......, which is based on a 3D elasticity solution for the core material, can be used as a benchmark in future studies of the free vibration and buckling of circular cylindrical composite sandwich shells with a transversely compliant core....

CLT and AE methods of in-situ load testing : comparison and development of evaluation criteria : in-situ evaluation of post-tensioned parking garage, Kansas City, Missouri

Science.gov (United States)

2008-02-01

The objective of the proposed research project is to compare the results of two recently introduced nondestructive load test methods to the existing 24-hour load test method described in Chapter 20 of ACI 318-05. The two new methods of nondestructive...

Patterns of interactions at grade 5 classroom in learning the topic of statistics viewed from cognitive load theory

Science.gov (United States)

Setianingsih, R.

2018-01-01

The nature of interactions that occurs among teacher, students, learning sources, and learning environment creates different settings to enhance learning. Any setting created by a teacher is affected by 3 (three) types of cognitive load: intrinsic cognitive load, extraneous cognitive load, and germane cognitive load. This study is qualitative in nature, aims to analyse the patterns of interaction that are constituted in mathematics instructions by taking into account the cognitive load theory. The subjects of this study are 21 fifth-grade students who learn mathematics in small groups and whole-class interactive lessons. The data were collected through classroom observations which were videotaped, while field notes were also taken. The data analysis revealed that students engaged in productive interaction and inquiry while they were learning mathematics in small groups or in whole class setting, in which there was a different type of cognitive load that dominantly affecting the learning processes at each setting. During learning mathematics in whole class setting, the most frequently found interaction patterns were to discuss and compare solution based on self-developed models, followed by expressing opinions. This is consistent with the principles of mathematics learning, which gives students wide opportunities to construct mathematical knowledge through individual learning, learning in small groups as well as learning in whole class settings. It means that by participating in interactive learning, the students are habitually engaged in productive interactions and high level of mathematical thinking.

The Role of Perceptual Load in Inattentional Blindness

Science.gov (United States)

Cartwright-Finch, Ula; Lavie, Nilli

2007-01-01

Perceptual load theory offers a resolution to the long-standing early vs. late selection debate over whether task-irrelevant stimuli are perceived, suggesting that irrelevant perception depends upon the perceptual load of task-relevant processing. However, previous evidence for this theory has relied on RTs and neuroimaging. Here we tested the…

A novel reformulation of the Theory of Critical Distances to design notched metals against dynamic loading

International Nuclear Information System (INIS)

Yin, T.; Tyas, A.; Plekhov, O.; Terekhina, A.; Susmel, L.

2015-01-01

Highlights: • The proposed method is successful in estimating dynamic strength of metals. • The critical distance varies as the loading/strain/displacement rate increases. • The reference strength varies as the loading/strain/displacement rate increases. • This method is recommended to be used with safety factors larger than 1.25. - Abstract: In the present study the linear-elastic Theory of Critical Distances (TCD) is reformulated to make it suitable for predicting the strength of notched metallic materials subjected to dynamic loading. The accuracy and reliability of the proposed reformulation of the TCD was checked against a number of experimental results generated by testing, under different loading/strain rates, notched cylindrical samples of aluminium alloy 6063-T5, titanium alloy Ti–6Al–4V, aluminium alloy AlMg6, and an AlMn alloy. To further validate the proposed design method also different data sets taken from the literature were considered. Such an extensive validation exercise allowed us to prove that the proposed reformulation of the TCD is successful in predicting the dynamic strength of notched metallic materials, this approach proving to be capable of estimates falling within an error interval of ±20%. Such a high level of accuracy is certainly remarkable, especially in light of the fact that it was reached without the need for explicitly modelling the stress vs. strain dynamic behaviour of the investigated ductile metals

In search for instructional techniques to maximize the use of germane cognitive resources: A case of teaching complex tasks in physics

Science.gov (United States)

Sliva, Yekaterina

The purpose of this study was to introduce an instructional technique for teaching complex tasks in physics, test its effectiveness and efficiency, and understand cognitive processes taking place in learners' minds while they are exposed to this technique. The study was based primarily on cognitive load theory (CLT). CLT determines the amount of total cognitive load imposed on a learner by a learning task as combined intrinsic (invested in comprehending task complexity) and extraneous (wasteful) cognitive load. Working memory resources associated with intrinsic cognitive load are defined as germane resources caused by element interactivity that lead to learning, in contrast to extraneous working memory resources that are devoted to dealing with extraneous cognitive load. However, the amount of learner's working memory resources actually devoted to a task depends on how well the learner is engaged in the learning environment. Since total cognitive load has to stay within limits of working memory capacity, both extraneous and intrinsic cognitive load need to be reduced. In order for effective learning to occur, the use of germane cognitive resources should be maximized. In this study, the use of germane resources was maximized for two experimental groups by providing a learning environment that combined problem-solving procedure with prompts to self-explain with and without completion problems. The study tested three hypotheses and answered two research questions. The first hypothesis predicting that experimental treatments would reduce total cognitive load was not supported. The second hypothesis predicting that experimental treatments would increase performance was supported for the self-explanation group only. The third hypothesis that tested efficiency measure as adopted from Paas and van Merrienboer (1993) was not supported. As for the research question of whether the quality of self-explanations would change with time for the two experimental conditions, it was

Randomized central limit theorems: A unified theory.

Science.gov (United States)

Eliazar, Iddo; Klafter, Joseph

2010-08-01

The central limit theorems (CLTs) characterize the macroscopic statistical behavior of large ensembles of independent and identically distributed random variables. The CLTs assert that the universal probability laws governing ensembles' aggregate statistics are either Gaussian or Lévy, and that the universal probability laws governing ensembles' extreme statistics are Fréchet, Weibull, or Gumbel. The scaling schemes underlying the CLTs are deterministic-scaling all ensemble components by a common deterministic scale. However, there are "random environment" settings in which the underlying scaling schemes are stochastic-scaling the ensemble components by different random scales. Examples of such settings include Holtsmark's law for gravitational fields and the Stretched Exponential law for relaxation times. In this paper we establish a unified theory of randomized central limit theorems (RCLTs)-in which the deterministic CLT scaling schemes are replaced with stochastic scaling schemes-and present "randomized counterparts" to the classic CLTs. The RCLT scaling schemes are shown to be governed by Poisson processes with power-law statistics, and the RCLTs are shown to universally yield the Lévy, Fréchet, and Weibull probability laws.

Local Stretching Theories

Science.gov (United States)

2010-06-24

diffusivity of the scalar. (If the scalar is heat, then the Schmidt number becomes the Prandtl number.) Momentum diffuses significantly faster than the...derive the Cramér function explicitly in the simple case where the xi have a Bernoulli distribution, though the general formula for S may be derived by...an analogous procedure. 5 Large deviation CLT for the Bernoulli distribution Let xi have the PDF of a fair coin, p(xi) = 1 2δ(xi + 1) + 1 2δ(xi − 1

Attentional capture under high perceptual load.

Science.gov (United States)

Cosman, Joshua D; Vecera, Shaun P

2010-12-01

Attentional capture by abrupt onsets can be modulated by several factors, including the complexity, or perceptual load, of a scene. We have recently demonstrated that observers are less likely to be captured by abruptly appearing, task-irrelevant stimuli when they perform a search that is high, as opposed to low, in perceptual load (Cosman & Vecera, 2009), consistent with perceptual load theory. However, recent results indicate that onset frequency can influence stimulus-driven capture, with infrequent onsets capturing attention more often than did frequent onsets. Importantly, in our previous task, an abrupt onset was present on every trial, and consequently, attentional capture might have been affected by both onset frequency and perceptual load. In the present experiment, we examined whether onset frequency influences attentional capture under conditions of high perceptual load. When onsets were presented frequently, we replicated our earlier results; attentional capture by onsets was modulated under conditions of high perceptual load. Importantly, however, when onsets were presented infrequently, we observed robust capture effects. These results conflict with a strong form of load theory and, instead, suggest that exposure to the elements of a task (e.g., abrupt onsets) combines with high perceptual load to modulate attentional capture by task-irrelevant information.

Quantum load balancing in ad hoc networks

Science.gov (United States)

Hasanpour, M.; Shariat, S.; Barnaghi, P.; Hoseinitabatabaei, S. A.; Vahid, S.; Tafazolli, R.

2017-06-01

This paper presents a novel approach in targeting load balancing in ad hoc networks utilizing the properties of quantum game theory. This approach benefits from the instantaneous and information-less capability of entangled particles to synchronize the load balancing strategies in ad hoc networks. The quantum load balancing (QLB) algorithm proposed by this work is implemented on top of OLSR as the baseline routing protocol; its performance is analyzed against the baseline OLSR, and considerable gain is reported regarding some of the main QoS metrics such as delay and jitter. Furthermore, it is shown that QLB algorithm supports a solid stability gain in terms of throughput which stands a proof of concept for the load balancing properties of the proposed theory.

Lifetime and residual strength of wood subjected to static and variable load

DEFF Research Database (Denmark)

Nielsen, Lauge Fuglsang

1997-01-01

of load amplitude, load average, fractional time under maximum load, and load frequency. The analysis includes prediction of residual strength (re-cycle strength) during the process of load cycling. It is concluded that number of cycles to failure is a very poor design criterion. The theory......).It is demonstrated how the theory developed can be generalised also to consider non-harmonic load variations. An algorithm is presented for this purpose which might be suggested as a qualified alternative to the Palmgren-Miner’s method normally used in fatigue analysis of materials under arbitrary load variations...

Blinded by the load: attention, awareness and the role of perceptual load

OpenAIRE

Lavie, Nilli; Beck, Diane M.; Konstantinou, Nikos

2014-01-01

What is the relationship between attention and conscious awareness? Awareness sometimes appears to be restricted to the contents of focused attention, yet at other times irrelevant distractors will dominate awareness. This contradictory relationship has also been reflected in an abundance of discrepant research findings leading to an enduring controversy in cognitive psychology. Lavie's load theory of attention suggests that the puzzle can be solved by considering the role of perceptual load....

Blinded by the load: attention, awareness and the role of perceptual load.

OpenAIRE

Lavie, N.; Beck, D. M.; Konstantinou, N.

2014-01-01

What is the relationship between attention and conscious awareness? Awareness sometimes appears to be restricted to the contents of focused attention, yet at other times irrelevant distractors will dominate awareness. This contradictory relationship has also been reflected in an abundance of discrepant research findings leading to an enduring controversy in cognitive psychology. Lavie's load theory of attention suggests that the puzzle can be solved by considering the role of perceptual load....

Cognitive Load Theory and the Use of Worked Examples as an Instructional Strategy in Physics for Distance Learners: A Preliminary Study

Science.gov (United States)

Saw, Kim Guan

2017-01-01

This article revisits the cognitive load theory to explore the use of worked examples to teach a selected topic in a higher level undergraduate physics course for distance learners at the School of Distance Education, Universiti Sains Malaysia. With a break of several years from receiving formal education and having only minimum science…

Pointing and tracing gestures may enhance anatomy and physiology learning.

Science.gov (United States)

Macken, Lucy; Ginns, Paul

2014-07-01

Currently, instructional effects generated by Cognitive load theory (CLT) are limited to visual and auditory cognitive processing. In contrast, "embodied cognition" perspectives suggest a range of gestures, including pointing, may act to support communication and learning, but there is relatively little research showing benefits of such "embodied learning" in the health sciences. This study investigated whether explicit instructions to gesture enhance learning through its cognitive effects. Forty-two university-educated adults were randomly assigned to conditions in which they were instructed to gesture, or not gesture, as they learnt from novel, paper-based materials about the structure and function of the human heart. Subjective ratings were used to measure levels of intrinsic, extraneous and germane cognitive load. Participants who were instructed to gesture performed better on a knowledge test of terminology and a test of comprehension; however, instructions to gesture had no effect on subjective ratings of cognitive load. This very simple instructional re-design has the potential to markedly enhance student learning of typical topics and materials in the health sciences and medicine.

Auditory working memory load impairs visual ventral stream processing: toward a unified model of attentional load.

Science.gov (United States)

Klemen, Jane; Büchel, Christian; Bühler, Mira; Menz, Mareike M; Rose, Michael

2010-03-01

Attentional interference between tasks performed in parallel is known to have strong and often undesired effects. As yet, however, the mechanisms by which interference operates remain elusive. A better knowledge of these processes may facilitate our understanding of the effects of attention on human performance and the debilitating consequences that disruptions to attention can have. According to the load theory of cognitive control, processing of task-irrelevant stimuli is increased by attending in parallel to a relevant task with high cognitive demands. This is due to the relevant task engaging cognitive control resources that are, hence, unavailable to inhibit the processing of task-irrelevant stimuli. However, it has also been demonstrated that a variety of types of load (perceptual and emotional) can result in a reduction of the processing of task-irrelevant stimuli, suggesting a uniform effect of increased load irrespective of the type of load. In the present study, we concurrently presented a relevant auditory matching task [n-back working memory (WM)] of low or high cognitive load (1-back or 2-back WM) and task-irrelevant images at one of three object visibility levels (0%, 50%, or 100%). fMRI activation during the processing of the task-irrelevant visual stimuli was measured in the lateral occipital cortex and found to be reduced under high, compared to low, WM load. In combination with previous findings, this result is suggestive of a more generalized load theory, whereby cognitive load, as well as other types of load (e.g., perceptual), can result in a reduction of the processing of task-irrelevant stimuli, in line with a uniform effect of increased load irrespective of the type of load.

The Effects of Technical Illustrations on Cognitive Load.

Science.gov (United States)

Purnell, Kenneth N.; And Others

1992-01-01

Outlines two theories of cognitive science that are relevant for instructional design, i.e., schema theory and cognitive load theory; and describes four experiments with Australian secondary school geography students that used these theories to examine the effects of splitting attention between technical illustrations and related text. (20…

Element Interactivity and Intrinsic, Extraneous, and Germane Cognitive Load

Science.gov (United States)

Sweller, John

2010-01-01

In cognitive load theory, element interactivity has been used as the basic, defining mechanism of intrinsic cognitive load for many years. In this article, it is suggested that element interactivity underlies extraneous cognitive load as well. By defining extraneous cognitive load in terms of element interactivity, a distinct relation between…

Performance of a cognitive load inventory during simulated handoffs: Evidence for validity.

Science.gov (United States)

Young, John Q; Boscardin, Christy K; van Dijk, Savannah M; Abdullah, Ruqayyah; Irby, David M; Sewell, Justin L; Ten Cate, Olle; O'Sullivan, Patricia S

2016-01-01

Advancing patient safety during handoffs remains a public health priority. The application of cognitive load theory offers promise, but is currently limited by the inability to measure cognitive load types. To develop and collect validity evidence for a revised self-report inventory that measures cognitive load types during a handoff. Based on prior published work, input from experts in cognitive load theory and handoffs, and a think-aloud exercise with residents, a revised Cognitive Load Inventory for Handoffs was developed. The Cognitive Load Inventory for Handoffs has items for intrinsic, extraneous, and germane load. Students who were second- and sixth-year students recruited from a Dutch medical school participated in four simulated handoffs (two simple and two complex cases). At the end of each handoff, study participants completed the Cognitive Load Inventory for Handoffs, Paas' Cognitive Load Scale, and one global rating item for intrinsic load, extraneous load, and germane load, respectively. Factor and correlational analyses were performed to collect evidence for validity. Confirmatory factor analysis yielded a single factor that combined intrinsic and germane loads. The extraneous load items performed poorly and were removed from the model. The score from the combined intrinsic and germane load items associated, as predicted by cognitive load theory, with a commonly used measure of overall cognitive load (Pearson's r = 0.83, p load during handoffs may be measured via a self-report measure. Additional work is required to develop an adequate measure of extraneous load.

Direct push driven in situ color logging tool (CLT): technique, analysis routines, and application

Science.gov (United States)

Werban, U.; Hausmann, J.; Dietrich, P.; Vienken, T.

2014-12-01

Direct push technologies have recently seen a broad development providing several tools for in situ parameterization of unconsolidated sediments. One of these techniques is the measurement of soil colors - a proxy information that reveals to soil/sediment properties. We introduce the direct push driven color logging tool (CLT) for real-time and depth-resolved investigation of soil colors within the visible spectrum. Until now, no routines exist on how to handle high-resolved (mm-scale) soil color data. To develop such a routine, we transform raw data (CIEXYZ) into soil color surrogates of selected color spaces (CIExyY, CIEL*a*b*, CIEL*c*h*, sRGB) and denoise small-scale natural variability by Haar and Daublet4 wavelet transformation, gathering interpretable color logs over depth. However, interpreting color log data as a single application remains challenging. Additional information, such as site-specific knowledge of the geological setting, is required to correlate soil color data to specific layers properties. Hence, we exemplary provide results from a joint interpretation of in situ-obtained soil color data and 'state-of-the-art' direct push based profiling tool data and discuss the benefit of additional data. The developed routine is capable of transferring the provided information obtained as colorimetric data into interpretable color surrogates. Soil color data proved to correlate with small-scale lithological/chemical changes (e.g., grain size, oxidative and reductive conditions), especially when combined with additional direct push vertical high resolution data (e.g., cone penetration testing and soil sampling). Thus, the technique allows enhanced profiling by means of providing another reproducible high-resolution parameter for analysis subsurface conditions. This opens potential new areas of application and new outputs for such data in site investigation. It is our intention to improve color measurements by means method of application and data

Effects of the Physical Environment on Cognitive Load and Learning: Towards a New Model of Cognitive Load

Science.gov (United States)

Choi, Hwan-Hee; van Merriënboer, Jeroen J. G.; Paas, Fred

2014-01-01

Although the theoretical framework of cognitive load theory has acknowledged a role for the learning environment, the specific characteristics of the physical learning environment that could affect cognitive load have never been considered, neither theoretically nor empirically. In this article, we argue that the physical learning environment, and…

On load paths and load bearing topology from finite element analysis

International Nuclear Information System (INIS)

Kelly, D; Reidsema, C; Lee, M

2010-01-01

Load paths can be mapped from vector plots of 'pointing stress vectors'. They define a path along which a component of load remains constant as it traverses the solution domain. In this paper the theory for the paths is first defined. Properties of the plots that enable a designer to interpret the structural behavior from the contours are then identified. Because stress is a second order tensor defined on an orthogonal set of axes, the vector plots define separate paths for load transfer in each direction of the set of axes. An algorithm is therefore presented that combines the vectors to define a topology to carry the loads. The algorithm is shown to straighten the paths reducing bending moments and removing stress concentration. Application to a bolted joint, a racing car body and a yacht hull demonstrate the usefulness of the plots.

Experimental assessment of unvalidated assumptions in classical plasticity theory.

Energy Technology Data Exchange (ETDEWEB)

Brannon, Rebecca Moss (University of Utah, Salt Lake City, UT); Burghardt, Jeffrey A. (University of Utah, Salt Lake City, UT); Bauer, Stephen J.; Bronowski, David R.

2009-01-01

This report investigates the validity of several key assumptions in classical plasticity theory regarding material response to changes in the loading direction. Three metals, two rock types, and one ceramic were subjected to non-standard loading directions, and the resulting strain response increments were displayed in Gudehus diagrams to illustrate the approximation error of classical plasticity theories. A rigorous mathematical framework for fitting classical theories to the data, thus quantifying the error, is provided. Further data analysis techniques are presented that allow testing for the effect of changes in loading direction without having to use a new sample and for inferring the yield normal and flow directions without having to measure the yield surface. Though the data are inconclusive, there is indication that classical, incrementally linear, plasticity theory may be inadequate over a certain range of loading directions. This range of loading directions also coincides with loading directions that are known to produce a physically inadmissible instability for any nonassociative plasticity model.

An experiment for determining the Euler load by direct computation

Science.gov (United States)

Thurston, Gaylen A.; Stein, Peter A.

1986-01-01

A direct algorithm is presented for computing the Euler load of a column from experimental data. The method is based on exact inextensional theory for imperfect columns, which predicts two distinct deflected shapes at loads near the Euler load. The bending stiffness of the column appears in the expression for the Euler load along with the column length, therefore the experimental data allows a direct computation of bending stiffness. Experiments on graphite-epoxy columns of rectangular cross-section are reported in the paper. The bending stiffness of each composite column computed from experiment is compared with predictions from laminated plate theory.

Coexistence of chronic lymphocytic thyroiditis with papillary thyroid carcinoma: clinical manifestation and prognostic outcome.

Science.gov (United States)

Jeong, Jun Soo; Kim, Hyun Ki; Lee, Cho-Rok; Park, Seulkee; Park, Jae Hyun; Kang, Sang-Wook; Jeong, Jong Ju; Nam, Kee-Hyun; Chung, Woong Youn; Park, Cheong Soo

2012-08-01

The study aimed to identify the clinical characteristics of coexisting chronic lymphocytic thyroiditis (CLT) in papillary thyroid carcinoma (PTC) and to evaluate the influence on prognosis. A total of 1,357 patients who underwent thyroid surgery for PTC were included. The clinicopathological characteristics were identified. Patients who underwent total thyroidectomy (n = 597) were studied to evaluate the influence of coexistent CLT on prognosis. Among the total 1,357 patients, 359 (26.5%) had coexistent CLT. In the CLT group, the prevalence of females was higher than in the control group without CLT (P CLT were smaller than without CLT (P = 0.040, P = 0.047, respectively). Extrathyroidal extension in the patients with CLT was significantly lower than without CLT (P = 0.016). Among the subset of 597 patients, disease-free survival rate in the patients with CLT was significantly higher than without CLT (P = 0.042). However, the multivariate analysis did not reveal a negative association between CLT coexistence and recurrence. Patients with CLT display a greater female preponderance, smaller size, younger and lower extrathyroidal extension. CLT is not a significant independent negative predictive factor for recurrence, although presence of CLT indicates a reduced risk of recurrence.

Attentional sets influence perceptual load effects, but not dilution effects.

Science.gov (United States)

Benoni, Hanna; Zivony, Alon; Tsal, Yehoshua

2014-01-01

Perceptual load theory [Lavie, N. (1995). Perceptual load as a necessary condition for selective attention. Journal of Experimental Psychology: Human Perception and Performance, 21, 451-468.; Lavie, N., & Tsal, Y. (1994) Perceptual load as a major determinant of the locus of selection in visual attention. Perception & Psychophysics, 56, 183-197.] proposes that interference from distractors can only be avoided in situations of high perceptual load. This theory has been supported by blocked design manipulations separating low load (when the target appears alone) and high load (when the target is embedded among neutral letters). Tsal and Benoni [(2010a). Diluting the burden of load: Perceptual load effects are simply dilution effects. Journal of Experimental Psychology: Human Perception and Performance, 36, 1645-1656.; Benoni, H., & Tsal, Y. (2010). Where have we gone wrong? Perceptual load does not affect selective attention. Vision Research, 50, 1292-1298.] have recently shown that these manipulations confound perceptual load with "dilution" (the mere presence of additional heterogeneous items in high-load situations). Theeuwes, Kramer, and Belopolsky [(2004). Attentional set interacts with perceptual load in visual search. Psychonomic Bulletin & Review, 11, 697-702.] independently questioned load theory by suggesting that attentional sets might also affect distractor interference. When high load and low load were intermixed, and participants could not prepare for the presentation that followed, both the low-load and high-load trials showed distractor interference. This result may also challenge the dilution account, which proposes a stimulus-driven mechanism. In the current study, we presented subjects with both fixed and mixed blocks, including a mix of dilution trials with low-load trials and with high-load trials. We thus separated the effect of dilution from load and tested the influence of attentional sets on each component. The results revealed that whereas

Cognitive Load Theory and the Use of Worked Examples as an Instructional Strategy in Physics for Distance Learners: A Preliminary Study

Directory of Open Access Journals (Sweden)

Kim Guan SAW

2017-10-01

Full Text Available This article revisits the cognitive load theory to explore the use of worked examples to teach a selected topic in a higher level undergraduate physics course for distance learners at the School of Distance Education, Universiti Sains Malaysia. With a break of several years from receiving formal education and having only minimum science background, distance learners need an appropriate instructional strategy for courses that require complex conceptualization and mathematical manipulations. As the working memory is limited, distance learners need to acquire domain specific knowledge in stages to lessen cognitive load. This article charts a learning task with a lower cognitive load to teach Fermi-Dirac distribution and demonstrates the use of sequential worked examples. Content taught in stages using worked examples can be presented as a form of didactic conversation to reduce transactional distance. This instructional strategy can be applied to similar challenging topics in other well-structured domains in a distance learning environment.

A Conceptual Paper on the Application of the Picture Word Inductive Model Using Bruner's Constructivist View of Learning and the Cognitive Load Theory

Science.gov (United States)

Jiang, Xuan; Perkins, Kyle

2013-01-01

Bruner's constructs of learning, specifically the structure of learning, spiral curriculum, and discovery learning, in conjunction with the Cognitive Load Theory, are used to evaluate the Picture Word Inductive Model (PWIM), an inquiry-oriented inductive language arts strategy designed to teach K-6 children phonics and spelling. The PWIM reflects…

Blinded by the load: attention, awareness and the role of perceptual load.

Science.gov (United States)

Lavie, Nilli; Beck, Diane M; Konstantinou, Nikos

2014-05-05

What is the relationship between attention and conscious awareness? Awareness sometimes appears to be restricted to the contents of focused attention, yet at other times irrelevant distractors will dominate awareness. This contradictory relationship has also been reflected in an abundance of discrepant research findings leading to an enduring controversy in cognitive psychology. Lavie's load theory of attention suggests that the puzzle can be solved by considering the role of perceptual load. Although distractors will intrude upon awareness in conditions of low load, awareness will be restricted to the content of focused attention when the attended information involves high perceptual load. Here, we review recent evidence for this proposal with an emphasis on the various subjective blindness phenomena, and their neural correlates, induced by conditions of high perceptual load. We also present novel findings that clarify the role of attention in the response to stimulus contrast. Overall, this article demonstrates a critical role for perceptual load across the spectrum of perceptual processes leading to awareness, from the very early sensory responses related to contrast detection to explicit recognition of semantic content.

Distraction and mind-wandering under load.

Science.gov (United States)

Forster, Sophie

2013-01-01

Attention research over the last several decades has provided rich insights into the determinants of distraction, including distractor characteristics, task features, and individual differences. Load Theory represented a particularly important breakthrough, highlighting the critical role of the level and nature of task-load in determining both the efficiency of distractor rejection and the stage of processing at which this occurs. However, until recently studies of distraction were restricted to those measuring rather specific forms of distraction by external stimuli which I argue that, although intended to be irrelevant, were in fact task-relevant. In daily life, attention may be distracted by a wide range of stimuli, which may often be entirely unrelated to any task being performed, and may include not only external stimuli but also internally generated stimuli such as task-unrelated thoughts. This review outlines recent research examining these more general, entirely task-irrelevant, forms of distraction within the framework of Load Theory. I discuss the relation between different forms of distraction, and the universality of load effects across different distractor types and individuals.

Distraction and mind-wandering under load

Directory of Open Access Journals (Sweden)

Sophie eForster

2013-05-01

Full Text Available Attention research over the last several decades has provided rich insights into the determinants of distraction, including distractor characteristics, task features and individual differences. Load Theory represented a particularly important breakthrough, highlighting the critical role of the level and nature of task load in determining both the efficiency of distractor rejection and the stage of processing at which this occurs. However, until recently studies of distraction were restricted to those measuring rather specific forms of distraction by external stimuli which I argue that, although intended to be irrelevant, were in fact task-relevant. In daily life, attention may be distracted by a wide range of stimuli, which may often be entirely unrelated to any task being performed, and may include not only external stimuli but also internally generated stimuli such as task-unrelated thoughts. This review outlines recent research examining these more general, entirely task-irrelevant, forms of distraction within the framework of Load Theory. I discuss the relation between different forms of distraction, and the universality of load effects across different distractor types and individuals.

Perceptual Load Affects Eyewitness Accuracy & Susceptibility to Leading Questions

OpenAIRE

Gillian Murphy; Ciara Mary Greene

2016-01-01

Load Theory (Lavie, 1995; 2005) states that the level of perceptual load in a task (i.e. the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The c...

Modal and Wave Load Identification by ARMA Calibration

DEFF Research Database (Denmark)

Jensen, Jens Kristian Jehrbo; Kirkegaard, Poul Henning; Brincker, Rune

1992-01-01

In this note, modal parameter and wave load identification by calibration of ARMA models are considered for a simple offshore structure. The theory of identification by ARMA calibration is introduced as an identification technique in the time domain, which can be applied for white noise–excited s......In this note, modal parameter and wave load identification by calibration of ARMA models are considered for a simple offshore structure. The theory of identification by ARMA calibration is introduced as an identification technique in the time domain, which can be applied for white noise...... by an experimental example of a monopile model excited by random waves. The identification results show that the approach is able to give very reliable estimates of the modal parameters. Furthermore, a comparison of the identified wave load process and the calculated load process based on the Morison equation shows...

Visual short-term memory load strengthens selective attention.

Science.gov (United States)

Roper, Zachary J J; Vecera, Shaun P

2014-04-01

Perceptual load theory accounts for many attentional phenomena; however, its mechanism remains elusive because it invokes underspecified attentional resources. Recent dual-task evidence has revealed that a concurrent visual short-term memory (VSTM) load slows visual search and reduces contrast sensitivity, but it is unknown whether a VSTM load also constricts attention in a canonical perceptual load task. If attentional selection draws upon VSTM resources, then distraction effects-which measure attentional "spill-over"-will be reduced as competition for resources increases. Observers performed a low perceptual load flanker task during the delay period of a VSTM change detection task. We observed a reduction of the flanker effect in the perceptual load task as a function of increasing concurrent VSTM load. These findings were not due to perceptual-level interactions between the physical displays of the two tasks. Our findings suggest that perceptual representations of distractor stimuli compete with the maintenance of visual representations held in memory. We conclude that access to VSTM determines the degree of attentional selectivity; when VSTM is not completely taxed, it is more likely for task-irrelevant items to be consolidated and, consequently, affect responses. The "resources" hypothesized by load theory are at least partly mnemonic in nature, due to the strong correspondence they share with VSTM capacity.

The effect of chronic lymphocytic thyroiditis on patients with thyroid cancer.

Science.gov (United States)

Zhang, Yi; Ma, Xiao-Peng; Deng, Fu-Sheng; Liu, Zheng-Rong; Wei, Hou-Qing; Wang, Xi-Hong; Chen, Hao

2014-09-01

The purpose of this study was to investigate the association between chronic lymphocytic thyroiditis (CLT) and malignant tumors of the thyroid. A retrospective review of 647 patients who underwent thyroid surgery at the Department of Breast and Thyroid Surgery in Anhui Provincial Hospital, China in 2012 was performed. The clinicopathological characteristics of patients with thyroid malignancies and CLT were collected. CLT was diagnosed by histopathological method. Among 647 patients, 144 patients had thyroid malignancies and 108 patients had been diagnosed with CLT. Moreover, in total, 44 patients had thyroid malignancies coexistent with CLT: forty-one (93.2%) patients had been diagnosed with the papillary thyroid cancer (PTC); two (4.5%) patients suffered from medullary carcinoma; and one (2.3%) patient suffered from lymphoma. The morbidity of thyroid malignancies in patients with CLT was significantly higher than that in patients without CLT (40.7% versus 18.6%; P CLT compared with those without CLT (P CLT and without CLT. Female predominance was observed in patients with CLT. CLT may have no effect on the progression of thyroid malignant tumor. Nevertheless, the influences of CLT on the prognosis of the thyroid carcinoma still need to be investigated with a larger sample size.

A modification to linearized theory for prediction of pressure loadings on lifting surfaces at high supersonic Mach numbers and large angles of attack

Science.gov (United States)

Carlson, H. W.

1979-01-01

A new linearized-theory pressure-coefficient formulation was studied. The new formulation is intended to provide more accurate estimates of detailed pressure loadings for improved stability analysis and for analysis of critical structural design conditions. The approach is based on the use of oblique-shock and Prandtl-Meyer expansion relationships for accurate representation of the variation of pressures with surface slopes in two-dimensional flow and linearized-theory perturbation velocities for evaluation of local three-dimensional aerodynamic interference effects. The applicability and limitations of the modification to linearized theory are illustrated through comparisons with experimental pressure distributions for delta wings covering a Mach number range from 1.45 to 4.60 and angles of attack from 0 to 25 degrees.

Teachers' understanding of the communicative language teaching ...

African Journals Online (AJOL)

Teachers' understanding of the communicative language teaching approach: The case of English language teachers in Thohoyandou. ... with CLT theories and practice. Keywords: communicative competence, approach versus method, Grammar translation method, direct method, first additional language, second language ...

Designs of goal-free problems for trigonometry learning

Science.gov (United States)

Retnowati, E.; Maulidya, S. R.

2018-03-01

This paper describes the designs of goal-free problems particularly for trigonometry, which may be considered a difficult topic for high school students.Goal-free problem is an instructional design developed based on a Cognitive load theory (CLT). Within the design, instead of asking students to solve a specific goal of a mathematics problem, the instruction is to solve as many Pythagoras as possible. It was assumed that for novice students, goal-free problems encourage students to pay attention more to the given information and the mathematical principles that can be applied to reveal the unknown variables. Hence, students develop more structured knowledge while solving the goal-free problems. The resulted design may be used in regular mathematics classroom with some adjustment on the difficulty level and the allocated lesson time.

Coexistence of chronic lymphocytic thyroiditis is associated with lower recurrence rates in patients with papillary thyroid carcinoma.

Science.gov (United States)

Kim, Eui Young; Kim, Won Gu; Kim, Won Bae; Kim, Tae Yong; Kim, Jung Min; Ryu, Jin-Sook; Hong, Suck Joon; Gong, Gyungyub; Shong, Young Kee

2009-10-01

The effect of coexistent chronic lymphocytic thyroiditis (CLT) on prognosis in papillary thyroid carcinoma (PTC) patients remains controversial. We evaluated the influence of coexistent CLT on prognostic outcome and the association of coexistent CLT with clinicopathological parameters. A retrospective study with a median follow-up of 70 months. Patients with PTC who underwent total thyroidectomy followed by (131)I remnant ablation between 1995 and 2003 at Asan Medical Center, Seoul, Korea were enrolled. CLT was diagnosed histopathologically. Among 1441 patients, 214 (14.9%) had coexistent CLT. A greater female preponderance was noted in the patients with CLT compared with those without CLT (P CLT was smaller than that in patients without CLT (2.0 +/- 1.2 vs. 2.2 +/- 1.4 cm; P = 0.02). One hundred and fifty-one (12.3%) patients without CLT had recurrence, whereas 14 (7.1%) patients with CLT had recurrence during the follow-up period (P = 0.016). In patients with cervical lymph node metastases, those with coexistent CLT showed a significantly lower recurrence rate than those without CLT (P = 0.012). However, this association was lost on multivariate analysis adjusting for other clinicopathological predictors for recurrence. In this study, CLT was commonly associated with PTC and was associated with smaller size of the primary tumour at presentation. CLT was also associated with a reduced risk of recurrence during follow-up, although this was not significant after adjustment for other prognostic factors.

Perceptual Load Influences Selective Attention across Development

Science.gov (United States)

Couperus, Jane W.

2011-01-01

Research suggests that visual selective attention develops across childhood. However, there is relatively little understanding of the neurological changes that accompany this development, particularly in the context of adult theories of selective attention, such as N. Lavie's (1995) perceptual load theory of attention. This study examined visual…

Load Balancing in Hypergraphs

Science.gov (United States)

Delgosha, Payam; Anantharam, Venkat

2018-03-01

Consider a simple locally finite hypergraph on a countable vertex set, where each edge represents one unit of load which should be distributed among the vertices defining the edge. An allocation of load is called balanced if load cannot be moved from a vertex to another that is carrying less load. We analyze the properties of balanced allocations of load. We extend the concept of balancedness from finite hypergraphs to their local weak limits in the sense of Benjamini and Schramm (Electron J Probab 6(23):13, 2001) and Aldous and Steele (in: Probability on discrete structures. Springer, Berlin, pp 1-72, 2004). To do this, we define a notion of unimodularity for hypergraphs which could be considered an extension of unimodularity in graphs. We give a variational formula for the balanced load distribution and, in particular, we characterize it in the special case of unimodular hypergraph Galton-Watson processes. Moreover, we prove the convergence of the maximum load under some conditions. Our work is an extension to hypergraphs of Anantharam and Salez (Ann Appl Probab 26(1):305-327, 2016), which considered load balancing in graphs, and is aimed at more comprehensively resolving conjectures of Hajek (IEEE Trans Inf Theory 36(6):1398-1414, 1990).

Visual short-term memory load reduces retinotopic cortex response to contrast.

Science.gov (United States)

Konstantinou, Nikos; Bahrami, Bahador; Rees, Geraint; Lavie, Nilli

2012-11-01

Load Theory of attention suggests that high perceptual load in a task leads to reduced sensory visual cortex response to task-unrelated stimuli resulting in "load-induced blindness" [e.g., Lavie, N. Attention, distraction and cognitive control under load. Current Directions in Psychological Science, 19, 143-148, 2010; Lavie, N. Distracted and confused?: Selective attention under load. Trends in Cognitive Sciences, 9, 75-82, 2005]. Consideration of the findings that visual STM (VSTM) involves sensory recruitment [e.g., Pasternak, T., & Greenlee, M. Working memory in primate sensory systems. Nature Reviews Neuroscience, 6, 97-107, 2005] within Load Theory led us to a new hypothesis regarding the effects of VSTM load on visual processing. If VSTM load draws on sensory visual capacity, then similar to perceptual load, high VSTM load should also reduce visual cortex response to incoming stimuli leading to a failure to detect them. We tested this hypothesis with fMRI and behavioral measures of visual detection sensitivity. Participants detected the presence of a contrast increment during the maintenance delay in a VSTM task requiring maintenance of color and position. Increased VSTM load (manipulated by increased set size) led to reduced retinotopic visual cortex (V1-V3) responses to contrast as well as reduced detection sensitivity, as we predicted. Additional visual detection experiments established a clear tradeoff between the amount of information maintained in VSTM and detection sensitivity, while ruling out alternative accounts for the effects of VSTM load in terms of differential spatial allocation strategies or task difficulty. These findings extend Load Theory to demonstrate a new form of competitive interactions between early visual cortex processing and visual representations held in memory under load and provide a novel line of support for the sensory recruitment hypothesis of VSTM.

Distancing from experienced self: how global versus local perception affects estimation of psychological distance

NARCIS (Netherlands)

Liberman, N.; Förster, J.

2009-01-01

In 4 studies, the authors examined the prediction derived from construal level theory (CLT) that higher level of perceptual construal would enhance estimated egocentric psychological distance. The authors primed participants with global perception, local perception, or both (the control condition).

Optimizing load transfer in multiwall nanotubes through interwall coupling: Theory and simulation

International Nuclear Information System (INIS)

Byrne, E.M.; Letertre, A.; McCarthy, M.A.; Curtin, W.A.; Xia, Z.

2010-01-01

An analytical model is developed to determine the length scales over which load is transferred from outer to inner walls of multiwall carbon nanotubes (MWCNTs) as a function of the amount of bonding between walls. The model predicts that the characteristic length for load transfer scales as l∼t√(E/μ-bar), where t is the CNT wall spacing, E is the effective wall Young's modulus, and μ-bar is the average interwall shear modulus due to interwall coupling. Molecular dynamics simulations for MWCNTs with up to six walls, and with interwall coupling achieved by interwall sp 3 bonding at various densities, provide data against which the model is tested. For interwall bonding having a uniform axial distribution, the analytic and simulation models agree well, showing that continuum mechanics concepts apply down to the atomic scale in this problem. The simulation models show, however, that load transfer is sensitive to natural statistical fluctuations in the spatial distribution of the interwall bonding between pairs of walls, and such fluctuations generally increase the net load transfer length needed to fully load an MWCNT. Optimal load transfer is achieved when bonding is uniformly distributed axially, and all interwall regions have the same shear stiffness, implying a linear decrease in the number of interwall bonds with distance from the outer wall. Optimal load transfer into an n-wall MWCNT is shown to occur over a length of ∼1.5nl. The model can be used to design MWCNTs for structural materials, and to interpret load transfer characteristics deduced from experiments on individual MWCNTs.

Perceptual load-dependent neural correlates of distractor interference inhibition.

Directory of Open Access Journals (Sweden)

Jiansong Xu

2011-01-01

Full Text Available The load theory of selective attention hypothesizes that distractor interference is suppressed after perceptual processing (i.e., in the later stage of central processing at low perceptual load of the central task, but in the early stage of perceptual processing at high perceptual load. Consistently, studies on the neural correlates of attention have found a smaller distractor-related activation in the sensory cortex at high relative to low perceptual load. However, it is not clear whether the distractor-related activation in brain regions linked to later stages of central processing (e.g., in the frontostriatal circuits is also smaller at high rather than low perceptual load, as might be predicted based on the load theory.We studied 24 healthy participants using functional magnetic resonance imaging (fMRI during a visual target identification task with two perceptual loads (low vs. high. Participants showed distractor-related increases in activation in the midbrain, striatum, occipital and medial and lateral prefrontal cortices at low load, but distractor-related decreases in activation in the midbrain ventral tegmental area and substantia nigra (VTA/SN, striatum, thalamus, and extensive sensory cortices at high load.Multiple levels of central processing involving midbrain and frontostriatal circuits participate in suppressing distractor interference at either low or high perceptual load. For suppressing distractor interference, the processing of sensory inputs in both early and late stages of central processing are enhanced at low load but inhibited at high load.

Perceptual load-dependent neural correlates of distractor interference inhibition.

Science.gov (United States)

Xu, Jiansong; Monterosso, John; Kober, Hedy; Balodis, Iris M; Potenza, Marc N

2011-01-18

The load theory of selective attention hypothesizes that distractor interference is suppressed after perceptual processing (i.e., in the later stage of central processing) at low perceptual load of the central task, but in the early stage of perceptual processing at high perceptual load. Consistently, studies on the neural correlates of attention have found a smaller distractor-related activation in the sensory cortex at high relative to low perceptual load. However, it is not clear whether the distractor-related activation in brain regions linked to later stages of central processing (e.g., in the frontostriatal circuits) is also smaller at high rather than low perceptual load, as might be predicted based on the load theory. We studied 24 healthy participants using functional magnetic resonance imaging (fMRI) during a visual target identification task with two perceptual loads (low vs. high). Participants showed distractor-related increases in activation in the midbrain, striatum, occipital and medial and lateral prefrontal cortices at low load, but distractor-related decreases in activation in the midbrain ventral tegmental area and substantia nigra (VTA/SN), striatum, thalamus, and extensive sensory cortices at high load. Multiple levels of central processing involving midbrain and frontostriatal circuits participate in suppressing distractor interference at either low or high perceptual load. For suppressing distractor interference, the processing of sensory inputs in both early and late stages of central processing are enhanced at low load but inhibited at high load.

Fire Resistance of Large-Scale Cross-Laminated Timber Panels

Science.gov (United States)

Henek, Vladan; Venkrbec, Václav; Novotný, Miloslav

2017-12-01

Wooden structures are increasingly being used in the construction of residential buildings. A common and often published reason to avoid wooden structures is their insufficient fire resistance, which reduces bearing capacity. For this reason, composite sandwich structures began to be designed to eliminate this drawback, as well as others. Recently, however, the trend is for a return to the original, wood-only variant and a search is underway for new technical means of improving the properties of such structures. Many timber structure technologies are known, but structures made from cross-laminated timber (CLT) panels have been used very often in recent years. CLT panels, also known as X-LAM, are currently gaining popularity in Europe. In the case of CLT panels composed of several layers of boards, they can be said to offer a certain advantage in that after the surface layer of a board has burnt and the subsurface layer has dried, oxygen is not drawn to the unburned wood for further combustion and thus the burning process ceases. CLT panels do not need to be specially modified or coated with fire resistant materials, although they are usually lined with gypsum-fibre fire resistant boards due to guidelines set out in the relevant standards. This paper presents a new method for the assessment of load-bearing perimeter walls fabricated from CLT panels without the use of an inner fire-retardant lining to ensure fire resistance at the level required by European standards (i.e. those harmonized for the Czech construction industry). The calculations were verified through laboratory tests which show that better parameters can be achieved during the classification of structures from the fire resistance point of view. The aim of the article is to utilize the results of assessment and testing by an accredited laboratory in order to demonstrate the possibilities of using CLT panels for the construction of multistorey as well as multi-purpose buildings in the Czech Republic.

Elasticity Theory Solution of the Problem on Plane Bending of a Narrow Layered Cantilever Beam by Loads at Its Free End

Science.gov (United States)

Goryk, A. V.; Koval'chuk, S. B.

2018-05-01

An exact elasticity theory solution for the problem on plane bending of a narrow layered composite cantilever beam by tangential and normal loads distributed on its free end is presented. Components of the stress-strain state are found for the whole layers package by directly integrating differential equations of the plane elasticity theory problem by using an analytic representation of piecewise constant functions of the mechanical characteristics of layer materials. The continuous solution obtained is realized for a four-layer beam with account of kinematic boundary conditions simulating the rigid fixation of its one end. The solution obtained allows one to predict the strength and stiffness of composite cantilever beams and to construct applied analytical solutions for various problems on the elastic bending of layered beams.

Perceptual Load Affects Eyewitness Accuracy and Susceptibility to Leading Questions

OpenAIRE

Murphy, Gillian; Greene, Ciara M.

2016-01-01

Load Theory (Lavie, 1995, 2005) states that the level of perceptual load in a task (i.e., the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The ...

Data of evolutionary structure change: 1EFPA-3CLTD [Confc[Archive

Lifescience Database Archive (English)

Full Text Available 1EFPA-3CLTD 1EFP 3CLT A D -AVLLLGEVTNGALNRDATAKAVAAVKAL-----GDVTV...ine> VAL CA 462 3CLT D 3CLT...177 TRP CA 187 VAL CA 111 3CLT D 3CLTD APSVQSRSQNK LEU CA 424 THR CA 436 3CLT

Interactive Distance Education: A Cognitive Load Perspective

Science.gov (United States)

Kalyuga, Slava

2012-01-01

Evidence-based approaches to the design of the next generation of interactive distance education need to take into account established multimedia learning principles. Cognitive load theory is a theory that has significantly contributed to the development of such principles. It has applied our knowledge of major features and processing limitations…

Selective Impairment of Auditory Selective Attention under Concurrent Cognitive Load

Science.gov (United States)

Dittrich, Kerstin; Stahl, Christoph

2012-01-01

Load theory predicts that concurrent cognitive load impairs selective attention. For visual stimuli, it has been shown that this impairment can be selective: Distraction was specifically increased when the stimulus material used in the cognitive load task matches that of the selective attention task. Here, we report four experiments that…

The Role of Perceptual Load in Object Recognition

Science.gov (United States)

Lavie, Nilli; Lin, Zhicheng; Zokaei, Nahid; Thoma, Volker

2009-01-01

Predictions from perceptual load theory (Lavie, 1995, 2005) regarding object recognition across the same or different viewpoints were tested. Results showed that high perceptual load reduces distracter recognition levels despite always presenting distracter objects from the same view. They also showed that the levels of distracter recognition were…

Visual perceptual load induces inattentional deafness.

Science.gov (United States)

Macdonald, James S P; Lavie, Nilli

2011-08-01

In this article, we establish a new phenomenon of "inattentional deafness" and highlight the level of load on visual attention as a critical determinant of this phenomenon. In three experiments, we modified an inattentional blindness paradigm to assess inattentional deafness. Participants made either a low- or high-load visual discrimination concerning a cross shape (respectively, a discrimination of line color or of line length with a subtle length difference). A brief pure tone was presented simultaneously with the visual task display on a final trial. Failures to notice the presence of this tone (i.e., inattentional deafness) reached a rate of 79% in the high-visual-load condition, significantly more than in the low-load condition. These findings establish the phenomenon of inattentional deafness under visual load, thereby extending the load theory of attention (e.g., Lavie, Journal of Experimental Psychology. Human Perception and Performance, 25, 596-616, 1995) to address the cross-modal effects of visual perceptual load.

Theory of reversal nonisothermal elastic-plastic deformation

International Nuclear Information System (INIS)

Shorr, B.F.

1979-01-01

Considered is approximated theory of nonisothermal elastic-plastic deformation at arbitrary laws of loading, permitting to describe nonisothermal isotropic and anisotropic strengthening of the material, Bauschinger effect and different tempo of plastic deformation development over different directions of loading depending on the deformation prehistory. The comparison of the theory with the experimental data showed good coincidence and sufficient simplicity permits to use it in technical calcualtions

Examining the Relationships of Different Cognitive Load Types Related to User Interface in Web-Based Instruction

Science.gov (United States)

Cheon, Jongpil; Grant, Michael

2012-01-01

This study proposes a new instrument to measure cognitive load types related to user interface and demonstrates theoretical assumptions about different load types. In reconsidering established cognitive load theory, the inadequacies of the theory are criticized in terms of the adaption of learning efficiency score and distinction of cognitive load…

A new perspective on the perceptual selectivity of attention under load.

Science.gov (United States)

Giesbrecht, Barry; Sy, Jocelyn; Bundesen, Claus; Kyllingsbaek, Søren

2014-05-01

The human attention system helps us cope with a complex environment by supporting the selective processing of information relevant to our current goals. Understanding the perceptual, cognitive, and neural mechanisms that mediate selective attention is a core issue in cognitive neuroscience. One prominent model of selective attention, known as load theory, offers an account of how task demands determine when information is selected and an account of the efficiency of the selection process. However, load theory has several critical weaknesses that suggest that it is time for a new perspective. Here we review the strengths and weaknesses of load theory and offer an alternative biologically plausible computational account that is based on the neural theory of visual attention. We argue that this new perspective provides a detailed computational account of how bottom-up and top-down information is integrated to provide efficient attentional selection and allocation of perceptual processing resources. © 2014 New York Academy of Sciences.

Extreme and First-Passage Time of Ship Collision Loads

DEFF Research Database (Denmark)

Nielsen, Søren R. K.; Thoft-Christensen, Palle

1983-01-01

The paper outlines a general theory from which the distribution function of the extreme peak collision load encountered during a certain intended lifetime can be cal culated assuming the arrival of ship collisions to be specified by a Poisson counting proces s.......The paper outlines a general theory from which the distribution function of the extreme peak collision load encountered during a certain intended lifetime can be cal culated assuming the arrival of ship collisions to be specified by a Poisson counting proces s....

Missing a trick: Auditory load modulates conscious awareness in audition.

Science.gov (United States)

Fairnie, Jake; Moore, Brian C J; Remington, Anna

2016-07-01

In the visual domain there is considerable evidence supporting the Load Theory of Attention and Cognitive Control, which holds that conscious perception of background stimuli depends on the level of perceptual load involved in a primary task. However, literature on the applicability of this theory to the auditory domain is limited and, in many cases, inconsistent. Here we present a novel "auditory search task" that allows systematic investigation of the impact of auditory load on auditory conscious perception. An array of simultaneous, spatially separated sounds was presented to participants. On half the trials, a critical stimulus was presented concurrently with the array. Participants were asked to detect which of 2 possible targets was present in the array (primary task), and whether the critical stimulus was present or absent (secondary task). Increasing the auditory load of the primary task (raising the number of sounds in the array) consistently reduced the ability to detect the critical stimulus. This indicates that, at least in certain situations, load theory applies in the auditory domain. The implications of this finding are discussed both with respect to our understanding of typical audition and for populations with altered auditory processing. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Performances of synchrotron X-ray monochromators under heat load. Part 2. Application of the Takagi-Taupin diffraction theory

International Nuclear Information System (INIS)

Mocella, V.; Ferrero, C.; Freund, A.K.; Hoszowska, J.; Zhang, L.; Epelboin, Y.

2001-01-01

The aim of this work is to generate the rocking curves of monochromators exposed to heat load in synchrotron radiation beams with a computer code performing diffraction calculations based on the theory of Takagi and Taupin. The model study starts with the calculation of deformation by finite element analysis and from an accurate characterization of the incident wave and includes the simulation of the wavefront propagation between the first and the second crystal (analyzer) of a double crystal monochromator. A monochromatic plane wave as well as a polychromatic spherical wave approach is described. The theoretical predictions of both methods are compared with experimental data measured in Bragg geometry and critically discussed

Performances of synchrotron X-ray monochromators under heat load. Part 2. Application of the Takagi-Taupin diffraction theory

CERN Document Server

Mocella, V; Freund, A K; Hoszowska, J; Zhang, L; Epelboin, Y

2001-01-01

The aim of this work is to generate the rocking curves of monochromators exposed to heat load in synchrotron radiation beams with a computer code performing diffraction calculations based on the theory of Takagi and Taupin. The model study starts with the calculation of deformation by finite element analysis and from an accurate characterization of the incident wave and includes the simulation of the wavefront propagation between the first and the second crystal (analyzer) of a double crystal monochromator. A monochromatic plane wave as well as a polychromatic spherical wave approach is described. The theoretical predictions of both methods are compared with experimental data measured in Bragg geometry and critically discussed.

Evaluating the role of attention in the context of unconscious thought theory: differential impact of attentional scope and load on preference and memory.

Science.gov (United States)

Srinivasan, Narayanan; Mukherjee, Sumitava; Mishra, Maruti V; Kesarwani, Smriti

2013-01-01

Attention is a key process used to conceptualize and define modes of thought, but we lack information about the role of specific attentional processes on preferential choice and memory in multi-attribute decision making. In this study, we examine the role of attention based on two dimensions, attentional scope and load on choice preference strength and memory using a paradigm that arguably elicits unconscious thought. Scope of attention was manipulated by using global or local processing during distraction (Experiment 1) and before the information-encoding stage (Experiment 2). Load was manipulated by using the n-back task in Experiment 1. Results from Experiment 1 show that global processing or distributed attention during distraction results in stronger preference irrespective of load but better memory only at low cognitive load. Task difficulty or load did not have any effect on preference or memory. In Experiment 2, distributed attention before attribute encoding facilitated only memory but did not influence preference. Results show that attentional processes at different stages of processing like distraction and information-encoding influence decision making processes. Scope of attention not only influences preference and memory but the manner in which attentional scope influences them depends on both load and stage of information processing. The results indicate the important role of attention in processes critical for decision making and calls for a re-evaluation of the unconscious thought theory (UTT) and the need for reconceptualizing the role of attention.

Evaluating the role of attention in the context of unconscious thought theory: Differential impact of attentional scope and load on preference and memory

Directory of Open Access Journals (Sweden)

Narayanan eSrinivasan

2013-02-01

Full Text Available Attention is a key process used to conceptualize and define modes of thought, but we lack information on the role of specific attentional processes on preferential choice and memory in multi-attribute decision making. In this study, we examine the role of attention based on two dimensions, attentional scope and load on choice preference strength and memory using a paradigm that arguably elicits unconscious thought. Scope of attention was manipulated by using global or local processing during distraction (Experiment 1 and before the information encoding stage (Experiment 2. Load was manipulated by using the n-back task in Experiment 1. Results from Experiment 1 show that global processing or distributed attention during distraction results in stronger preference irrespective of load but better memory only at low cognitive load. Task difficulty or load did not have any effect on preference or memory. In Experiment 2, distributed attention before attribute encoding facilitated only memory but did not influence preference. Results show that attentional processes at different stages of processing like distraction and information-encoding influence decision making processes. Scope of attention not only influences preference and memory but the manner in which attentional scope influences them depends on both load and stage of information processing. The results indicate the important role of attention in processes critical for decision making and calls for a re-evaluation of the unconscious thought theory (UTT and the need for reconceptualizing the role of attention.

Perceptual load interacts with stimulus processing across sensory modalities.

Science.gov (United States)

Klemen, J; Büchel, C; Rose, M

2009-06-01

According to perceptual load theory, processing of task-irrelevant stimuli is limited by the perceptual load of a parallel attended task if both the task and the irrelevant stimuli are presented to the same sensory modality. However, it remains a matter of debate whether the same principles apply to cross-sensory perceptual load and, more generally, what form cross-sensory attentional modulation in early perceptual areas takes in humans. Here we addressed these questions using functional magnetic resonance imaging. Participants undertook an auditory one-back working memory task of low or high perceptual load, while concurrently viewing task-irrelevant images at one of three object visibility levels. The processing of the visual and auditory stimuli was measured in the lateral occipital cortex (LOC) and auditory cortex (AC), respectively. Cross-sensory interference with sensory processing was observed in both the LOC and AC, in accordance with previous results of unisensory perceptual load studies. The present neuroimaging results therefore warrant the extension of perceptual load theory from a unisensory to a cross-sensory context: a validation of this cross-sensory interference effect through behavioural measures would consolidate the findings.

Dynamic backcalculation with different load-time histories

DEFF Research Database (Denmark)

Madsen, Stine Skov; Levenberg, Eyal

2017-01-01

This paper focused attention to the falling weight deflectometer (FWD) load-time history. For a commonly used device, it studied the pulse generation mechanism and the influence of different load histories on backcalculation results. In this connection, a semi-analytic impact theory was first...... for an experimental dataset that resulted from operating an FWD with different loading configurations. It was found that backcalculated parameters are sensitive to the FWD pulse features. Consequently, it is recommended that, whenever advanced pavement characterisation is sought, experimental attention should...

Fifty years of genetic load

International Nuclear Information System (INIS)

Wallace, B.

1991-01-01

This book discusses the radiation effects on Drosophila. It was originally thought that irradiating Drosophila would decrease the average fitness of the population, thereby leading to information about the detrimental effects of mutations. Surprisingly, the fitness of the irradiated population turned out to be higher than that of the control population. The original motivation for the experiment was as a test of genetic load theory. The average fitness of a population is depressed by deleterious alleles held in the population by the balance between mutation and natural selection. The depression is called the genetic load of the population. The load dose not depend on the magnitude of the deleterious effect of alleles, but only on the mutation rate

Investigation of Squeeze Film Damping and Associated Loads

DEFF Research Database (Denmark)

Johansen, Per; Bender, Niels Christian; Hansen, Anders Hedegaard

2017-01-01

-viscous case. In consequence, this enable insights concerning the influence of piezo-viscosity on this damping effect. These models are used to investigate the loads, which the approaching surfaces experiences. Based on Hertzian theory, comparisons of impact loads and the dynamic squeeze loading are performed......Digital hydraulics have attracted attention towards fast switching valves and the increased focus on reliable fluid power entail that the lifetime of such valves is of great concern. An inherent feature of most valves for digital hydraulics is that of a mechanical end stop. Consequently...... is reviewed with a focus on maximum surface stresses. Using the Barus relation for viscosity-pressure dependency and different film geometries, the classical lubrication theory is applied together with the equation of motion, to obtain the gap height motion equation, both for the iso-viscous and piezo...

A study of cognitive loading in dual-coding theory.

Science.gov (United States)

Ishi, H; Yamauchi, H

1994-08-01

15 university students were engaged in a task of recalling sentences with and without figures. Analysis of the number recalled indicated that cognitive loading for sentences with figures was more effective than for recall of sentences without figures.

Weight Multispectral Reconstruction Strategy for Enhanced Reconstruction Accuracy and Stability With Cerenkov Luminescence Tomography.

Science.gov (United States)

Hongbo Guo; Xiaowei He; Muhan Liu; Zeyu Zhang; Zhenhua Hu; Jie Tian

2017-06-01

Cerenkov luminescence tomography (CLT) provides a novel technique for 3-D noninvasive detection of radiopharmaceuticals in living subjects. However, because of the severe scattering of Cerenkov light, the reconstruction accuracy and stability of CLT is still unsatisfied. In this paper, a modified weight multispectral CLT (wmCLT) reconstruction strategy was developed which split the Cerenkov radiation spectrum into several sub-spectral bands and weighted the sub-spectral results to obtain the final result. To better evaluate the property of the wmCLT reconstruction strategy in terms of accuracy, stability and practicability, several numerical simulation experiments and in vivo experiments were conducted and the results obtained were compared with the traditional multispectral CLT (mCLT) and hybrid-spectral CLT (hCLT) reconstruction strategies. The numerical simulation results indicated that wmCLT strategy significantly improved the accuracy of Cerenkov source localization and intensity quantitation and exhibited good stability in suppressing noise in numerical simulation experiments. And the comparison of the results achieved from different in vivo experiments further indicated significant improvement of the wmCLT strategy in terms of the shape recovery of the bladder and the spatial resolution of imaging xenograft tumors. Overall the strategy reported here will facilitate the development of nuclear and optical molecular tomography in theoretical study.

Experiments and theory on deck and girder crushing

DEFF Research Database (Denmark)

Simonsen, Bo Cerup; Ocakli, Hasan

1999-01-01

-deflection curves and modes of deformation for decks, stringer decks and deep thin-walled beams subjected to central or excentric point loads between transverse frames. Based on theory and experiments, various modelling aspects of the local/global failure of the beams are discussed. The agreement between......This paper is concerned with theoretical and experimental analysis of deep plastic collapse of a deck or deep girder subjected to an in-plane, concentrated load. A theory is derived which is valid until initition of fracture in the structure. The presented experimental results show load...

Evaluative pressure overcomes perceptual load effects.

Science.gov (United States)

Normand, Alice; Autin, Frédérique; Croizet, Jean-Claude

2015-06-01

Perceptual load has been found to be a powerful bottom-up determinant of distractibility, with high perceptual load preventing distraction by any irrelevant information. However, when under evaluative pressure, individuals exert top-down attentional control by giving greater weight to task-relevant features, making them more distractible from task-relevant distractors. One study tested whether the top-down modulation of attention under evaluative pressure overcomes the beneficial bottom-up effect of high perceptual load on distraction. Using a response-competition task, we replicated previous findings that high levels of perceptual load suppress task-relevant distractor response interference, but only for participants in a control condition. Participants under evaluative pressure (i.e., who believed their intelligence was assessed) showed interference from task-relevant distractor at all levels of perceptual load. This research challenges the assumptions of the perceptual load theory and sheds light on a neglected determinant of distractibility: the self-relevance of the performance situation in which attentional control is solicited.

Influence of thermal aging on primary water stress corrosion cracking of cast duplex stainless steel (second report). Consideration on fractography after slow strain rate technique

International Nuclear Information System (INIS)

Yamada, Takuyo; Chiba, Goro; Totsuka, Nobuo; Arioka, Koji

2003-01-01

In order to evaluate the stress corrosion cracking (SCC) susceptibility of cast duplex stainless steel which is used for the main coolant pipe of pressurized water reactors (PWRs), the slow strain rate technique (SSRT) and the constant load test (CLT) of the materials were performed in simulated primary water at 360degC. The cast duplex stainless steel contains ferrite phase with ranging from 8 to 23% and its mechanical properties are affected by long time thermal aging. Therefore, we paid attention to the influence of its ferrite content and thermal aging on the SCC susceptibility of this unaged and aged stainless steel and prepared three kinds of specimen with different ferrite contents (23%, 15% and 8%). The brittle fracture of the unaged specimens after SSRT mainly consists of quasi-cleavage fracture in austenitic phase. After aging, it changes to a mixture of quasi-cleavage fracture in both austenitic and ferritic phases. Microcracks were observed on the unaged specimen surfaces and aged ones for 10,000 hours at 400degC after about 10,000 hours of the CLT under the load condition of 1.2∼2.0 times of yield strength. The crack initiation sites of CLT specimens are similar to SSRT fracture surfaces. The SCC susceptibility of this 23% ferrite material increases with aging time at 400degC. The SCC susceptibility of 15% and 23% ferrite materials are higher than that of 8% ferrite material with aging condition for 30,000h at 400degC. (author)

The clinicopathologic differences in papillary thyroid carcinoma with or without co-existing chronic lymphocytic thyroiditis.

Science.gov (United States)

Yoon, Yeo-Hoon; Kim, Hak Joon; Lee, Jin Woo; Kim, Jin Man; Koo, Bon Seok

2012-03-01

The goal of this study is to determine the clinicopathologic differences in patients with papillary thyroid carcinoma (PTC) with or without chronic lymphocytic thyroiditis (CLT). We reviewed the medical records of 195 consecutive PTC patients who underwent total thyroidectomy and bilateral central lymph node dissection from April 2008 to March 2010. The differences in clinicopathologic factors, such as age, gender, size of primary tumor, perithyroidal invasion, lymphovascular invasion, capsular invasion, and central lymph node (CLN) metastasis, were analyzed in PTC patients with or without CLT. Among 195 patients, 56 (28.7%) had co-existing CLT. Patients with CLT had the following characteristics as compared to patients without CLT: significantly younger, female predominance, smaller tumor size, and lower incidence of capsular invasion (p = 0.038, 0.006, 0.037, and 0.026, respectively). Also, patients with CLT (12.5%) had a significantly lower incidence of CLN metastases than patients without CLT (28.1%; p = 0.025) based on univariate analysis. Moreover, multivariate analysis showed that younger age (p = 0.042, odds ratio = 1.033) and female gender (p = 0.012, odds ratio = 6.865) are independent clinical factors in patients with CLT compared to patients without CLT. CLT was shown to be commonly associated with PTC. Compared to patients with PTC without CLT, patients with CLT were younger with a female predominance, which are the most important and well-known prognostic variables for thyroid cancer mortality.

Genome scan of clot lysis time and its association with thrombosis in a protein C deficient kindred

Science.gov (United States)

Meltzer, M.E.; Hasstedt, S.J.; Vossen, C.Y.; Callas, P.W.; de Groot, Ph.G.; Rosendaal, F.R.; Lisman, T.; Bovill, E.G.

2011-01-01

Summary Background Previously we found increased clot lysis time (CLT), as measured with a plasma-based assay, to increase the risk of venous thrombosis in two population-based case-control studies. Genes influencing CLT are yet unknown. Objectives and Patients/Methods We tested CLT as risk factor for venous thrombosis in Kindred Vermont II (n=346), a pedigree suffering from a high thrombosis risk, partially attributable to a type I protein C deficiency. Furthermore we tested for quantitative trait loci (QTL) for CLT using variance component linkage analysis. Results Protein C deficient family members had shorter CLT than non-deficient members (median CLT 67 versus 75 minutes). One standard deviation increase in CLT increased risk of venous thrombosis 2.4-fold in non-deficient family members. Protein C deficiency without elevated CLT increased risk 6.9-fold. Combining both risk factors yielded a 27.8-fold increased risk. Heritability of CLT was 42-52%. We found suggestive evidence of linkage on chromosome 11 (62 cM), partly explained by the prothrombin 20210A mutation, and on chromosome 13 (52 cM). Thrombin Activatable Fibrinolysis Inhibitor genotypes did not explain the variation in CLT. Conclusion Hypofibrinolysis appears to increase thrombosis risk in this family especially in combination with protein C deficiency. Protein C deficiency is associated with short CLT. CLT is partly genetically regulated. Suggestive QTL were found on chromosome 11 and 13. PMID:21575129

Nonlinear kinematic hardening under non-proportional loading

International Nuclear Information System (INIS)

Ottosen, N.S.

1979-07-01

Within the framework of conventional plasticity theory, it is first determined under which conditions Melan-Prager's and Ziegler's kinematic hardening rules result in identical material behaviour. Next, assuming initial isotropy and adopting the von Mises yield criterion, a nonlinear kinematic hardening function is proposed for prediction of metal behaviour. The model assumes that hardening at a specific stress point depends on the direction of the new incremental loading. Hereby a realistic response is obtained for general reversed loading, and a smooth behaviour is assured, even when loading deviates more and more from proportional loading and ultimately results in reversed loading. The predictions of the proposed model for non-proportional loading under plane stress conditions are compared with those of the classical linear kinematic model, the isotropic model and with published experimental data. Finally, the limitations of the proposaed model are discussed. (author)

Application of porous-media theory to the investigation of water ADC changes in rabbit Achilles tendon caused by tensile loading

Science.gov (United States)

Wellen, J.; Helmer, K. G.; Grigg, P.; Sotak, C. H.

2004-09-01

The water apparent diffusion coefficient (ADC) in rabbit Achilles tendon is anisotropic, diffusion-time dependent, and changes as a function of tensile load. Water ADC changes of tendon under mechanical load are thought to be due to the extrusion of water from the more restricted tendon core to a relatively unrestricted bulk phase at the periphery (rim) of the tendon. Tensile loading may influence water ADC values by changing the spatial separation of restricting barriers (e.g., increasing the tendon fibril packing density). To explore this issue, we have applied porous-media theory to the investigation of water ADC changes in rabbit Achilles tendon under two different mechanical loading conditions (a baseline condition with a minimal tensile stress and a second in which the tensile stress was approximately 1 MPa). Diffusion sensitivity was applied in directions parallel and perpendicular to the long axis of the tendon. The short diffusion-time behavior of the resulting time-dependent ADC curves was used to indirectly infer information regarding the average surface area to volume ratio of the space available for molecular diffusion. From these values, we estimated a 40% reduction in volume available for diffusion in the perpendicular direction after tensile loading, but only a 10% reduction in the parallel direction. These differences are consistent with the known geometry of the tendon microstructure and suggest an increase in fibril packing density upon loading. The long diffusion-time behavior of the time-dependent ADC curves was used to indirectly infer the tortuosity of the diffusion pathways through the interstitial space. The tortuosity in the direction perpendicular to the tendon long axis was approximately 2.5 times greater than that in the parallel direction. Stimulated-echo measurement of the ADC values at longer diffusion times resulted in T1 spin editing of water with shorter T1 values (and correspondingly lower ADC values). The resulting increase in

Cognitive task load analysis : Allocating tasks and designing support

NARCIS (Netherlands)

Neerincx, M.A.

2003-01-01

We present a method for Cognitive Task Analysis that guides the early stages of software development, aiming at an optimal cognitive load for operators of process control systems. The method is based on a practical theory of cognitive task load and support. In addition to the classical measure

Effect of loading speed on the stress-induced magnetic behavior of ferromagnetic steel

Energy Technology Data Exchange (ETDEWEB)

Bao, Sheng, E-mail: longtubao@zju.edu.cn; Gu, Yibin; Fu, Meili; Zhang, Da; Hu, Shengnan

2017-02-01

The primary goal of this research is to investigate the effect of loading speed on the stress-induced magnetic behavior of a ferromagnetic steel. Uniaxial tension tests on Q235 steel were carried out with various stress levels under different loading speeds. The variation of the magnetic signals surrounding the tested specimen was detected by a fluxgate magnetometer. The results indicated that the magnetic signal variations depended not only on the tensile load level but on the loading speed during the test. The magnetic field amplitude seemed to decrease gradually with the increase in loading speed at the same tensile load level. Furthermore, the evolution of the magnetic reversals is also related to the loading speed. Accordingly, the loading speed should be considered as one of the influencing variables in the Jies-Atherton model theory of the magnetomechanical effect. - Highlights: • Magnetic behaviors induced by different loading speeds were investigated. • Loading speed imposes strong impact on the variation of the magnetic field signals. • The magnetic field amplitude reduces gradually with the increasing loading speed. • The Jies-Atherton model theory should consider the effect of loading speed.

Effect of loading speed on the stress-induced magnetic behavior of ferromagnetic steel

International Nuclear Information System (INIS)

Bao, Sheng; Gu, Yibin; Fu, Meili; Zhang, Da; Hu, Shengnan

2017-01-01

The primary goal of this research is to investigate the effect of loading speed on the stress-induced magnetic behavior of a ferromagnetic steel. Uniaxial tension tests on Q235 steel were carried out with various stress levels under different loading speeds. The variation of the magnetic signals surrounding the tested specimen was detected by a fluxgate magnetometer. The results indicated that the magnetic signal variations depended not only on the tensile load level but on the loading speed during the test. The magnetic field amplitude seemed to decrease gradually with the increase in loading speed at the same tensile load level. Furthermore, the evolution of the magnetic reversals is also related to the loading speed. Accordingly, the loading speed should be considered as one of the influencing variables in the Jies-Atherton model theory of the magnetomechanical effect. - Highlights: • Magnetic behaviors induced by different loading speeds were investigated. • Loading speed imposes strong impact on the variation of the magnetic field signals. • The magnetic field amplitude reduces gradually with the increasing loading speed. • The Jies-Atherton model theory should consider the effect of loading speed.

A Rapid Embryonic Stem Cell-Based Mouse Model for B-cell Lymphomas Driven by Epstein-Barr Virus Protein LMP1.

Science.gov (United States)

Ba, Zhaoqing; Meng, Fei-Long; Gostissa, Monica; Huang, Pei-Yi; Ke, Qiang; Wang, Zhe; Dao, Mai N; Fujiwara, Yuko; Rajewsky, Klaus; Zhang, Baochun; Alt, Frederick W

2015-06-01

The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) contributes to oncogenic human B-cell transformation. Mouse B cells conditionally expressing LMP1 are not predisposed to B-cell malignancies, as LMP1-expressing B cells are eliminated by T cells. However, mice with conditional B-cell LMP1 expression and genetic elimination of α/β and γ/δ T cells ("CLT" mice) die early in association with B-cell lymphoproliferation and lymphomagenesis. Generation of CLT mice involves in-breeding multiple independently segregating alleles. Thus, although introduction of additional activating or knockout mutations into the CLT model is desirable for further B-cell expansion and immunosurveillance studies, doing such experiments by germline breeding is time-consuming, expensive, and sometimes unfeasible. To generate a more tractable model, we generated clonal CLT embryonic stem (ES) cells from CLT embryos and injected them into RAG2-deficient blastocysts to generate chimeric mice, which, like germline CLT mice, harbor splenic CLT B cells and lack T cells. CLT chimeric mice generated by this RAG2-deficient blastocyst complementation ("RDBC") approach die rapidly in association with B-cell lymphoproliferation and lymphoma. Because CLT lymphomas routinely express the activation-induced cytidine deaminase (AID) antibody diversifier, we tested potential AID roles by eliminating the AID gene in CLT ES cells and testing them via RDBC. We found that CLT and AID-deficient CLT ES chimeras had indistinguishable phenotypes, showing that AID is not essential for LMP1-induced lymphomagenesis. Beyond expanding accessibility and utility of CLT mice as a cancer immunotherapy model, our studies provide a new approach for facilitating generation of genetically complex mouse cancer models. ©2015 American Association for Cancer Research.

Allocation of Load-Loss Cost Caused by Voltage Sag

Science.gov (United States)

Gao, X.

2017-10-01

This paper focuses on the allocation of load-loss cost caused by voltage sag in the environment of electricity market. To compensate the loss of loads due to voltage sags, the load-loss cost is allocated to both sources and power consumers. On the basis of Load Drop Cost (LDC), a quantitative evaluation index of load-loss cost caused by voltage sag is identified. The load-loss cost to be allocated to power consumers themselves is calculated according to load classification. Based on the theory of power component the quantitative relation between sources and loads is established, thereby a quantitative calculation method for load-loss cost allocated to each source is deduced and the quantitative compensation from individual source to load is proposed. A simple five-bus system illustrates the main features of the proposed method.

Distracted and confused?: selective attention under load.

Science.gov (United States)

Lavie, Nilli

2005-02-01

The ability to remain focused on goal-relevant stimuli in the presence of potentially interfering distractors is crucial for any coherent cognitive function. However, simply instructing people to ignore goal-irrelevant stimuli is not sufficient for preventing their processing. Recent research reveals that distractor processing depends critically on the level and type of load involved in the processing of goal-relevant information. Whereas high perceptual load can eliminate distractor processing, high load on "frontal" cognitive control processes increases distractor processing. These findings provide a resolution to the long-standing early and late selection debate within a load theory of attention that accommodates behavioural and neuroimaging data within a framework that integrates attention research with executive function.

Auditory perceptual load: A review.

Science.gov (United States)

Murphy, Sandra; Spence, Charles; Dalton, Polly

2017-09-01

Selective attention is a crucial mechanism in everyday life, allowing us to focus on a portion of incoming sensory information at the expense of other less relevant stimuli. The circumstances under which irrelevant stimuli are successfully ignored have been a topic of scientific interest for several decades now. Over the last 20 years, the perceptual load theory (e.g. Lavie, 1995) has provided one robust framework for understanding these effects within the visual modality. The suggestion is that successful selection depends on the perceptual demands imposed by the task-relevant information. However, less research has addressed the question of whether the same principles hold in audition and, to date, the existing literature provides a mixed picture. Here, we review the evidence for and against the applicability of perceptual load theory in hearing, concluding that this question still awaits resolution. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

The natural compound codonolactone attenuates TGF-β1-mediated epithelial-to-mesenchymal transition and motility of breast cancer cells.

Science.gov (United States)

Fu, Jianjiang; Ke, Xiaoqin; Tan, Songlin; Liu, Ting; Wang, Shan; Ma, Junchao; Lu, Hong

2016-01-01

Codonolactone (CLT), a natural product, is the major bioactive component of Atractylodes lancea, and also found in a range of other medical herbs, such as Codonopsis pilosula, Chloranthus henryi Hemsl and Atractylodes macrocephala Koidz. This sesquiterpene lactone has been demonstrated to exhibit a range of activities, including anti-allergic activity, anti-inflammatory, anticancer, gastroprotective and neuroprotective activity. Previously, we found that CLT showed significant anti-metastatic properties in vitro and in vivo. In order to determine whether EMT-involved mechanisms contribute to the anti-metastatic effects of CLT, we checked the anti-EMT properties of CLT and its potential mechanisms. Here it was demonstrated that CLT inhibited TGF-β1-induced epithelial-mesenchymal transition (EMT) in vitro and in vivo. Furthermore, downregulation of TGF-β signaling was associated with the anti-EMT properties of CLT. Data from western blotting showed that, in breast cancer cells, TGF-β1 stimulated the activation of Runx2, and CLT blocked the activation of Runx2. Finally, to verify whether CLT-induced EMT inhibition leads to suppression of metastatic potential, the effects of CLT on cell invasion and migration were determined. It was found that TGF-β1-induced migration and invasion was significantly blocked by CLT in both MDA-MB-231 and MDA-MB-468 cells. Collectively, our findings demonstrated that CLT inhibited programming of EMT in vitro and in vivo, resulting in inhibition of motility of metastatic breast cancer cells. The inhibitory effect of CLT was due to its ability to inhibit TGF-β signaling and Runx2 phosphorylation.

Clotrimazole enhances lysis of human erythrocytes induced by t-BHP.

Science.gov (United States)

Lisovskaya, Irene L; Shcherbachenko, Irina M; Volkova, Rimma I; Ataullakhanov, Fazoil I

2009-08-14

Clotrimazole (CLT) is an antifungal and antimalarial agent also effective as a Gardos channel inhibitor. In addition, CLT possesses antitumor properties. Recent data provide evidence that CLT forms a complex with heme (hemin), which produces a more potent lytic effect than heme alone. This study addressed the effect of CLT on the lysis of normal human erythrocytes induced by tert-butyl hydroperoxide (t-BHP). For the first time, it was shown that 10 microM CLT significantly enhanced the lytic effect of t-BHP on erythrocytes in both Ca(2+)-containing and Ca(2+)-free media, suggesting that the effect is not related to Gardos channels. CLT did not affect the rate of free radical generation, the kinetics of GSH degradation, methemoglobin formation and TBARS generation; therefore, we concluded that CLT does not cause additional oxidative damage to erythrocytes treated with t-BHP. It is tempted to speculate that CLT enhances t-BHP-induced changes in erythrocyte volume and lysis largely by forming a complex with hemin released during hemoglobin oxidation in erythrocytes: the CLT-hemin complex destabilizes the cell membrane more potently than hemin alone. If so, the effect of CLT on cell membrane damage during free-radical oxidation may be used to increase the efficacy of antitumor therapy.

Impact load time histories for viscoelastic missiles

International Nuclear Information System (INIS)

Stoykovich, M.

1977-01-01

Generation of the impact load time history at the contact point between a viscoelastic missile and its targets is presented. In the past, in the case of aircraft striking containment shell structure, the impact load history was determined on the basis of actual measurements by subjecting a rigid wall to aircraft crash. The effects of elastic deformation of the target upon the impact load time history is formulated in this paper. The missile is idealized by a linear mass-spring-dashpot combination using viscoelastic models. These models can readily be processed taking into account the elastic as well as inelastic deformations of the missiles. The target is assumed to be either linearly elastic or rigid. In the case of the linearly elastic target, the normal mode theory is used to express the time-dependent displacements of the target which is simulated by lumped masses, elastic properties and dashpots in discrete parts. In the case of Maxwell viscoelastic model, the time-dependent displacements of the missile and the target are given in terms of the unknown impact load time history. This leads to an integral equation which may be solved by Laplace transformation. The normal mode theory is provided. Examples are given for bricks with viscoelastic materials as missiles against a rigid target. (Auth.)

An Analysis of Three Curriculum Approaches to Teaching English in Public-Sector Schools

Science.gov (United States)

Graves, Kathleen; Garton, Sue

2017-01-01

This article explores three current, influential English language teaching (ELT) curriculum approaches to the teaching of English in public-sector schools at the primary and secondary level and how the theory of each approach translates into curriculum practice. These approaches are communicative language teaching (CLT), genre-based pedagogy, and…

Genome scan of clot lysis time and its association with thrombosis in a protein C-deficient kindred.

Science.gov (United States)

Meltzer, M E; Hasstedt, S J; Vossen, C Y; Callas, P W; DE Groot, Ph G; Rosendaal, F R; Lisman, T; Bovill, E G

2011-07-01

 Previously, we found increased clot-lysis time (CLT), as measured with a plasma-based assay, to increase the risk of venous thrombosis in two population-based case-control studies. The genes influencing CLT are as yet unknown.  We tested CLT as risk factor for venous thrombosis in Kindred Vermont II (n = 346), a pedigree suffering from a high thrombosis risk, partially attributable to a type I protein C deficiency. Furthermore, we tested for quantitative trait loci (QTLs) for CLT, using variance component linkage analysis.  Protein C-deficient family members had shorter CLTs than non-deficient members (median CLT 67 min vs. 75 min). One standard deviation increase in CLT increased the risk of venous thrombosis 2.4-fold in non-deficient family members. Protein C deficiency without elevated CLT increased the risk 6.9-fold. Combining both risk factors yielded a 27.8-fold increased risk. The heritability of CLT was 42-52%. We found suggestive evidence of linkage on chromosome 11 (62 cM), partly explained by the prothrombin 20210A mutation, and on chromosome 13 (52 cM). Thrombin-activatable fibrinolysis inhibitor genotypes did not explain the variation in CLT. Hypofibrinolysis appears to increase thrombosis risk in this family, especially in combination with protein C deficiency. Protein C deficiency is associated with short CLT. CLT is partly genetically regulated. Suggestive QTLs were found on chromosomes 11 and 13. © 2011 International Society on Thrombosis and Haemostasis.

An analytical study of the effects of transverse shear deformation and anisotropy on buckling loads of laminated cylinders. M.S. Thesis - George Washington Univ.

Science.gov (United States)

Jegley, Dawn C.

1987-01-01

Buckling loads of thick-walled orthotropic and anisotropic simply supported circular cylinders are predicted using a higher-order transverse-shear deformation theory. A comparison of buckling loads predicted by the conventional first-order transverse-shear deformation theory and the higher-order theory show that the additional allowance for transverse shear deformation has a negligible effect on the predicted buckling loads of medium-thick metallic isotropic cylinders. However, the higher-order theory predicts buckling loads which are significantly lower than those predicted by the first-order transverse-shear deformation theory for certain short, thick-walled cylinders which have low through-the-thickness shear moduli. A parametric study of the effects of ply orientation on the buckling load of axially compressed cylinders indicates that laminates containing 45 degree plies are most sensitive to transverse-shear deformation effects. Interaction curves for buckling loads of cylinders subjected to axial compressive and external pressure loadings indicate that buckling loads due to external pressure loadings are as sensitive to transverse-shear deformation effects as buckling loads due to axial compressive loadings. The effects of anisotropy are important over a much wider range of cylinder geometries than the effects of transverse shear deformation.

Biological variation in tPA-induced plasma clot lysis time.

Science.gov (United States)

Talens, Simone; Malfliet, Joyce J M C; Rudež, Goran; Spronk, Henri M H; Janssen, Nicole A H; Meijer, Piet; Kluft, Cornelis; de Maat, Moniek P M; Rijken, Dingeman C

2012-10-01

Hypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Sufficient information about assay variation and biological variation in CLT is not yet available. Thus, this study aimed to determine the analytical, within-subject and between-subject variation in CLT. We collected blood samples from 40 healthy individuals throughout a period of one year (average 11.8 visits) and determined the CLT of each plasma sample in duplicate. The mean (± SD) CLT was 83.8 (± 11.1) minutes. The coefficients of variation for total variation, analytical variation, within-subject variation and between-subject variation were 13.4%, 2.6%, 8.2% and 10.2%, respectively. One measurement can estimate the CLT that does not deviate more than 20% from its true value. The contribution of analytical variation to the within-subject variation was 5.0%, the index of individuality was 0.84 and the reference change value was 23.8%. The CLT was longer in the morning compared to the afternoon and was slightly longer in older individuals (> 40 years) compared to younger (≤40 years) individuals. There was no seasonal variation in CLT and no association with air pollution. CLT correlated weakly with fibrinogen, C-reactive protein, prothrombin time and thrombin generation. This study provides insight into the biological variation of CLT, which can be used in future studies testing CLT as a potential risk factor for thrombosis.

The effects of crystallization and residual glass on the chemical durability of iron phosphate waste forms containing 40 wt% of a high MoO3 Collins-CLT waste

Science.gov (United States)

Hsu, Jen-Hsien; Bai, Jincheng; Kim, Cheol-Woon; Brow, Richard K.; Szabo, Joe; Zervos, Adam

2018-03-01

The effects of cooling rate on the chemical durability of iron phosphate waste forms containing up to 40 wt% of a high MoO3 Collins-CLT waste simulant were determined at 90 °C using the product consistency test (PCT). The waste form, designated 40wt%-5, meets appropriate Department of Energy (DOE) standards when rapidly quenched from the melt (as-cast) and after slow cooling following the CCC (canister centerline cooling)-protocol, although the quenched glass is more durable. The analysis of samples from the vapor hydration test (VHT) and the aqueous corrosion test (differential recession test) reveals that rare earth orthophosphate (monazite) and Zr-pyrophosphate crystals that form on cooling are more durable than the residual glass in the 40wt%-5 waste form. The residual glass in the CCC-treated samples has a greater average phosphate chain length and a lower Fe/P ratio, and those contribute to its faster corrosion kinetics.

Cognitive Load Theory: An Empirical Study of Anxiety and Task Performance in Language Learning

Science.gov (United States)

Chen, I-Jung; Chang, Chi-Cheng

2009-01-01

Introduction: This study explores the relationship among three variables--cognitive load, foreign language anxiety, and task performance. Cognitive load refers to the load imposed on working memory while performing a particular task. The authors hypothesized that anxiety consumes the resources of working memory, leaving less capacity for cognitive…

Cognitive load and the acquisition of a problem solving skill

NARCIS (Netherlands)

Hoe, van R.R.G.; Brouwer-Janse, M.D.; Harrington, T.L.

1994-01-01

Current theories of leaming consider the restructuring of the components of a weak problem solving sequence into a domain-specific procedure to be the fundamental leaming mechanism in complex knowledge domains. Within the context of cognitive load theory, there is growing evidence that applying weak

Level density approach to perturbation theory and inverse-energy-weighted sum-rules

International Nuclear Information System (INIS)

Halemane, T.R.

1983-01-01

The terms in the familiar Rayleigh-Schroedinger perturbation series involve eigenvalues and eigenfunctions of the unperturbed operator. A level density formalism, that does not involve computation of eigenvalues and eigenfunctions, is given here for the perturbation series. In the CLT (central limit theorem) limit the expressions take very simple linear forms. The evaluation is in terms of moments and traces of operators and operator products. 3 references

Moving beyond Communicative Language Teaching: A Situated Pedagogy for Japanese EFL Classrooms

Science.gov (United States)

Lochland, Paul W.

2013-01-01

This article questions the appropriateness of communicative language teaching (CLT) in classrooms teaching English as a foreign language (EFL) to Japanese students. The four main criticisms of CLT are the ambiguity of its description, the benefits of CLT for language learning, the amalgamation of CLT methods with local classroom practices, and the…

Examining Hypermedia Learning: The Role of Cognitive Load and Self-Regulated Learning

Science.gov (United States)

Moos, Daniel

2013-01-01

Distinct theoretical perspectives, Cognitive Load Theory and Self-Regulated Learning (SRL) theory, have been used to examine individual differences the challenges faced with hypermedia learning. However, research has tended to use these theories independently, resulting in less robust explanations of hypermedia learning. This study examined the…

Decreasing Cognitive Load for Learners: Strategy of Web-Based Foreign Language Learning

Science.gov (United States)

Zhang, Jianfeng

2013-01-01

Cognitive load is one of the important factors that influence the effectiveness and efficiency of web-based foreign language learning. Cognitive load theory assumes that human's cognitive capacity in working memory is limited and if it overloads, learning will be hampered, so that high level of cognitive load can affect the performance of learning…

The prediction of rotor rotational noise using measured fluctuating blade loads

Science.gov (United States)

Hosier, R. N.; Pegg, R. J.; Ramakrishnan, R.

1974-01-01

In tests conducted at the NASA Langley Research Center Helicopter Rotor Test Facility, simultaneous measurements of the high-frequency fluctuating aerodynamic blade loads and far-field radiated noise were made on a full-scale, nontranslating rotor system. After their characteristics were determined, the measured blade loads were used in an existing theory to predict the far-field rotational noise. A comparison of the calculated and measured rotational noise is presented with specific attention given to the effect of blade loading coefficients, chordwise loading distributions, blade loading phases, and observer azimuthal position on the predictions.

Where have we gone wrong? Perceptual load does not affect selective attention.

Science.gov (United States)

Benoni, Hanna; Tsal, Yehoshua

2010-06-18

The theory of perceptual load (Lavie & Tsal, 1994) proposes that with low load in relevant processing left over resources spill over to process irrelevant distractors. Interference could only be prevented under High-Load Conditions where relevant processing exhausts attentional resources. The theory is based primarily on the finding that distractor interference obtained in low load displays, when the target appears alone, is eliminated in high load displays when it is embedded among neutral letters. However, a possible alternative interpretation of this effect is that the distractor is similarly processed in both displays, yet its interference in the large displays is diluted by the presence of the neutral letters. We separated the possible effects of load and dilution by adding dilution displays that were high in dilution and low in perceptual load. In the first experiment these displays contained as many letters as the high load displays, but their neutral letters were clearly distinguished from the target, thereby allowing for a low load processing mode. In the second experiment we presented identical multicolor displays in the Dilution and High-Load Conditions. However, in the former the target color was known in advance (thereby preserving a low load processing mode) whereas in the latter it was not. In both experiments distractor interference was completely eliminated under the Dilution Condition. Thus, it is dilution not perceptual load affecting distractor processing. 2010 Elsevier Ltd. All rights reserved.

Stress corrosion cracking of steam generator tube and primary pipe in PWR type nuclear power plants

International Nuclear Information System (INIS)

Zhang Weiguo; Gao Fengqin; Zhou Hongyi

1992-03-01

The behavior of stress corrosion cracking (SCC) was studied by slow strain rate test (SSRT), constant load test (CLT) and low frequency cyclic loading test (LFCLT). The purpose of these tests is to get the test data for evaluating the integrity of pressurized boundary of pipes in Qinshan and Guangdong nuclear power plants (NPPs). Tested materials are 316 nuclear grade stainless steel (SS) for primary pipes in welded heat affected zone (WHAZ) and tubes of heat transfer, such as Incoloy-800, Inconel-600 and 321 SS which are used for steam generator in PWR NPPs. The effects of material metallurgy, shot peening treatment, tensile load, strain rate, cyclic load and water chemistry on the behavior of SCC were considered

Stress corrosion cracking of steam generator tube and primary pipe in PWR type nuclear power plants

International Nuclear Information System (INIS)

Zhang Weiguo; Gao Fengqin; Zhou Hongyi

1993-01-01

The behavior of stress corrosion cracking (SCC) is studied by slow strain rate test (SSRT), constant load test (CLT) and low frequency cyclic loading test (LFCLT). The purpose of these tests is to get the test data for evaluating the integrity of pressurized boundary of pipes in Qinshan and Guangdong nuclear power plants. Tested materials are 316 nuclear grade stainless steel (SS) for primary pipes in welded heat affected zone (WHAZ) and steam generator tubes, such as Incoloy-800, Inconel-600, Inconel-690 and 321 SS which are used for steam generator in PWR. The effects of material metallurgy, shot-peening treatment, tensile load, strain rate, cyclic load and water chemistry on the behavior of SCC are investigated

The association between thyroid malignancy and chronic lymphocytic thyroiditis: should it alter the surgical approach?

Science.gov (United States)

Büyükaşık, Oktay; Hasdemir, Ahmet Oğuz; Yalçın, Erol; Celep, Bahadır; Sengül, Serkan; Yandakçı, Kemal; Tunç, Gündüz; Küçükpınar, Tevfik; Alkoy, Seval; Cöl, Cavit

2011-01-01

The relation between thyroid neoplasms and chronic lymphocytic thyroiditis (CLT) is controversial. While it is accepted that focal lymphocytic thyroiditis develops secondarily to malignancy, it is not clear whether diffuse lymphocytic thyroiditis has a tendency to develop into thyroid cancer. The aim of this study was to investigate the relation between CLT and malignant tumours of the thyroid and evaluate the surgical approach to CLT cases. In this study, 917 patients operated on for thyroid diseases were investigated retrospectively. Seventy-seven (8.4%) patients histopathologically diagnosed as having CLT (either non-specific or Hashimoto's thyroiditis) were investigated for any concurrent malignant neoplasm. Fifteen patients in whom CLT and thyroid malignancy were coexisting were included in the study. In the pathological evaluation of 917 cases, malignancy in the thyroid was found in 97 (10.6%) cases. Seventy-seven cases were categorised as CLT. Of these 77, 16 (20.8%) were Hashimoto's thyroiditis (specific CLT) and the other 61 (79.2%) were non-specific CLT. In 15 cases, thyroid malignancy was found to be concurrent with CLT. Of the malignities, nine (60%) were papillary carcinoma, three (20%) medullar carcinoma, one (6.6%) follicular carcinoma, one (6.6%) Hurthle cell carcinoma, and one (6.6%) lymphoma. In our series, the rate of the development of malignancy against the background of CLT was 19.48%, while the rate in the groups without CLT was 9.76%, with a statistically significant difference between the groups (p = 0.008). CLT cases should be evaluated more carefully in terms of malignancy. If a nodule is detected on thyroiditis, the minimal surgical intervention should be lobectomy. Total thyroidectomy should be considered as preferable to subtotal thyroidectomy because of its many advantages such as controlling thyroiditis, removing the probability of reoperation, and hormonal stability.

78 FR 76784 - Proposed Modification, Revocation, and Establishment of Area Navigation (RNAV) Routes; Charlotte, NC

Science.gov (United States)

2013-12-19

... ``final box'' for Charlotte/Douglas International Airport (CLT) when CLT is landing to the north. The proposed modification of T-202 (see below) would provide routing through the south end of the CLT Class B... its current position. The shift would move the route to the east of the CLT Class B airspace area...

A research on motion design for APP's loading pages based on time perception

Science.gov (United States)

Cao, Huai; Hu, Xiaoyun

2018-04-01

Due to restrictions caused by objective reasons like network bandwidth, hardware performance and etc., waiting is still an inevitable phenomenon that appears in our using mobile-terminal products. Relevant researches show that users' feelings in a waiting scenario can affect their evaluations on the whole product and services the product provides. With the development of user experience and inter-facial design subjects, the role of motion effect in the interface design has attracted more and more scholars' attention. In the current studies, the research theory of motion design in a waiting scenario is imperfect. This article will use the basic theory and experimental research methods of cognitive psychology to explore the motion design's impact on user's time perception when users are waiting for loading APP pages. Firstly, the article analyzes the factors that affect waiting experience of loading APP pages based on the theory of time perception, and then discusses motion design's impact on the level of time-perception when loading pages and its design strategy. Moreover, by the operation analysis of existing loading motion designs, the article classifies the existing loading motions and designs an experiment to verify the impact of different types of motions on the user's time perception. The result shows that the waiting time perception of mobile's terminals' APPs is related to the loading motion types, the combination type of loading motions can effectively shorten the waiting time perception as it scores a higher mean value in the length of time perception.

Brown World Invertebrates Contradict Green World Biodiversity Theory

International Nuclear Information System (INIS)

Patrick, L.B.; Kershner, M.W.; Fraser, L.H.

2008-01-01

Biodiversity-productivity theory predicts that ecosystems with increased productivity due to excessive limiting-nutrient loading will have decreased taxonomic diversity. In this 4-year study, we elevated productivity by adding NPK fertilizer to 20 m diameter plots in an old-field grassland to test the effects of anthropogenically mediated nutrient loading on plant and epigeal arthropod communities. While plants responded as predicted by the biodiversity-productivity theory, the epigeal arthropod community had highest species richness within the fertilized high-productivity treatments. We conclude that the contradictory response of the largely detrital-based epigeal community should alter conventional biodiversity-productivity theory and could affect terrestrial biodiversity conservation strategies.

A theoty of fast search for feul loading pattern in lWRs

International Nuclear Information System (INIS)

Suo Changan

1990-01-01

In order to fast search for fuel loading pattern without trial and error, a theory for predicting in-core reactivity distribution, according to power necessity and available assemblies, has been developed on basis of the fast computing nodal method and two group diffusion theory. In that, the fast group flux distribution can be predicted from power necessity and the approximation of fast group constants to be independent of nodes. Then, the thermal group fluxes are expressed by both known powers and predicted fast fluxes. After replacing thermal flux, the thermal diffusion equations turn into some equations that have only unknown group constants. The unknown constants are expressed approximately by making use of some expansions of infinite multiplication factors of available assemblies. In such a way, the non-linear reactivity equations are developed and then solved, where node reactivities are the only unknown physical quantities, Finally, the loading pattern is obtained by setting some of available assemblies at each node location where corresponds to a closest reactivity of between laid assembly and node. A computer code LOADMP based on the theory has been made. The theory has been tested numerically on IAEA benchmark problem, and gives an accurate prediction of reactivity distribution and loading pattern. The CPU-time for making a loading pattern search is saved very much, about one second on the CYPER-825/170 machine

Influence of Thermal Aging on Primary Water Stress Corrosion Cracking of Cast Duplex Stainless Steels

International Nuclear Information System (INIS)

Yamada, T.; Totsuka, N.; Nakajima, N.; Arioka, K.; Negishi, K.

2002-01-01

In order to evaluate the SCC (stress corrosion cracking) susceptibility of cast duplex stainless steels which are used for the main coolant piping material of pressurized water reactors (PWRs), the slow strain rate test (SSRT) and the constant load test (CLT) were performed in simulated PWR primary water at 360 C. The main coolant piping materials contain ferrite phase with ranging from 8 to 23 % and its mechanical properties are affected by long time thermal aging. The 23% ferrite material was prepared for test as the maximum ferrite content of main coolant pipes in Japanese PWRs. The brittle fracture in the non-aged materials after SSRT is mainly caused by quasi-cleavage fracture in austenitic phase. On the other hand, a mixture of quasi-cleavage fracture in austenite and ferrite phases was observed on long time aged material. Also on CLT, (2 times σ y ), after 3,000 hours exposure, microcracks were observed on the surface of non-aged and aged for 10,000 hours at 400 C materials. The crack initiation site of CLT is similar to that of SSRT. The SCC susceptibility of the materials increases with aging time. It is suggested that the ferrite hardening with aging affect SCC susceptibility of cast duplex stainless steels. (authors)

Study on environment-sensitive cracking time for 316Ti stainless steel

International Nuclear Information System (INIS)

Zhang Pingzhu; Liu Xinghua; Hu Shilin; Zhang Weiguo

1999-01-01

The time of environmentally assisted cracking of 316Ti stainless steel is studied by slow strain rate test (SSRT) and constant load test (CLT) methods. The experimental results under the simulating water chemical conditions of PWR primary side show that the initial fracture time τ desponds on the concentration of Cl - ion w(Cl - ) and the load σ. The relationships between lgτ and lgw (Cl - ), Δlgτ and Δσ are all linear. The threshold of stress corrosion cracking (SCC) is decreased with the increasing of w(Cl - ) and σ

Study on Determination Method of Fatigue Testing Load for Wind Turbine Blade

Science.gov (United States)

Liao, Gaohua; Wu, Jianzhong

2017-07-01

In this paper, the load calculation method of the fatigue test was studied for the wind turbine blade under uniaxial loading. The characteristics of wind load and blade equivalent load were analyzed. The fatigue property and damage theory of blade material were studied. The fatigue load for 2MW blade was calculated by Bladed, and the stress calculated by ANSYS. Goodman modified exponential function S-N curve and linear cumulative damage rule were used to calculate the fatigue load of wind turbine blades. It lays the foundation for the design and experiment of wind turbine blade fatigue loading system.

One-third of an Archivial Series of Papillary Thyroid Cancer (Years 2007–2015 Has Coexistent Chronic Lymphocytic Thyroiditis, Which Is Associated with a More Favorable Tumor-Node-Metastasis Staging

Directory of Open Access Journals (Sweden)

Antonio Ieni

2017-12-01

Full Text Available The significance and impact of the coexistence of chronic lymphocytic thyroiditis (CLT with thyroid cancer is still debated. To verify the influence of CLT on papillary thyroid cancer (PTC, we retrospectively collected 505 PTC cases and analyzed age at diagnosis, sex, size, lymph node status, and staging. We found that CLT was present in 168 PTC (33.3%. Compared with the 337 patients without CLT (non-CLT, CLT patients were younger (44.42 ± 13.72 vs. 47.21 ± 13.76 years, P = 0.03, had smaller tumors (9.39 ± 6.10 vs. 12 ± 9.71 mm, P = 0.002, and lower rate of lymph node metastases (12.5 vs. 21.96%, P = 0.01, OR = 0.508. Tumor-node-metastasis (TNM staging (T1a through T4 was more favorable for the CLT group compared to the non-CLT group (for instance, T1a = 65.5 vs. 49.8%, T3 = 4.8 vs. 23.4%. This study shows that one in three patients with PTC harbors CLT, which is associated with a more favorable TNM staging, consistently with a favorable outlook of PTC.

Modeling of porous concrete elements under load

Directory of Open Access Journals (Sweden)

Demchyna B.H.

2017-12-01

Full Text Available It is known that cell concretes are almost immediately destroyed under load, having reached certain critical stresses. Such kind of destruction is called a “catastrophic failure”. Process of crack formation is one of the main factors, influencing process of concrete destruction. Modern theory of crack formation is mainly based on the Griffith theory of destruction. However, the mentioned theory does not completely correspond to the structure of cell concrete with its cell structure, because the theory is intended for a solid body. The article presents one of the possible variants of modelling of the structure of cell concrete and gives some assumptions concerning the process of crack formation in such hollow, not solid environment.

Modeling of porous concrete elements under load

Science.gov (United States)

Demchyna, B. H.; Famuliak, Yu. Ye.; Demchyna, Kh. B.

2017-12-01

It is known that cell concretes are almost immediately destroyed under load, having reached certain critical stresses. Such kind of destruction is called a "catastrophic failure". Process of crack formation is one of the main factors, influencing process of concrete destruction. Modern theory of crack formation is mainly based on the Griffith theory of destruction. However, the mentioned theory does not completely correspond to the structure of cell concrete with its cell structure, because the theory is intended for a solid body. The article presents one of the possible variants of modelling of the structure of cell concrete and gives some assumptions concerning the process of crack formation in such hollow, not solid environment.

Loads and loads and loads: The influence of prospective load, retrospective load, and ongoing task load in prospective memory

Directory of Open Access Journals (Sweden)

Beat eMeier

2015-06-01

Full Text Available In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load can affect prospective memory performance. The existence of multiple target events increases prospective load and adding complexity to the to-be-remembered action increases retrospective load. In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of prospective load on costs in the ongoing task for categorical targets (Experiment 2, but not for specific targets (Experiment 1. Retrospective load and ongoing task load both affected remembering the retrospective component of the prospective memory task. We suggest that prospective load can enhance costs in the ongoing task due to additional monitoring requirements. Retrospective load and ongoing task load seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

The effect of manufacturing tolerances on the load carrying capacity ...

Indian Academy of Sciences (India)

bearings based on Hertz theory. The nonlinear connector elements are used to model ... Keywords. Slewing bearing; Hertz theory; load distribution; nonlinear connector elements; tolerance. 1. ..... Ngoi B K A, Lim B H and Ang P S 2000 Nexus method for stack analysis of geometric dimensioning and tolerancing problems.

[Development and effectiveness of a drug dosage calculation training program using cognitive loading theory based on smartphone application].

Science.gov (United States)

Kim, Myoung Soo; Park, Jung Ha; Park, Kyung Yeon

2012-10-01

This study was done to develop and evaluate a drug dosage calculation training program using cognitive loading theory based on a smartphone application. Calculation ability, dosage calculation related self-efficacy and anxiety were measured. A nonequivalent control group design was used. Smartphone application and a handout for self-study were developed and administered to the experimental group and only a handout was provided for control group. Intervention period was 4 weeks. Data were analyzed using descriptive analysis, χ²-test, t-test, and ANCOVA with the SPSS 18.0. The experimental group showed more 'self-efficacy for drug dosage calculation' than the control group (t=3.82, psmartphone application is effective in improving dosage calculation related self-efficacy and calculation ability. Further study should be done to develop additional interventions for reducing anxiety.

Buckling analysis for anisotropic laminated plates under combined inplane loads

Science.gov (United States)

Viswanathan, A. V.; Tamekuni, M.; Baker, L. L.

1974-01-01

The buckling analysis presented considers rectangular flat or curved general laminates subjected to combined inplane normal and shear loads. Linear theory is used in the analysis. All prebuckling deformations and any initial imperfections are ignored. The analysis method can be readily extended to longitudinally stiffened structures subjected to combined inplane normal and shear loads.

Determination of post-shakedown quantities of a pipe bend via the simplified theory of plastic zones compared with load history dependent incremental analysis

Science.gov (United States)

Vollrath, Bastian; Hübel, Hartwig

2018-01-01

The Simplified Theory of Plastic Zones (STPZ) may be used to determine post-shakedown quantities such as strain ranges and accumulated strains at plastic or elastic shakedown. The principles of the method are summarized. Its practical applicability is shown by the example of a pipe bend subjected to constant internal pressure along with cyclic in-plane bending or/and cyclic radial temperature gradient. The results are compared with incremental analyses performed step-by-step throughout the entire load history until the state of plastic shakedown is achieved.

Time- & Load-Dependence of Triboelectric Effect.

Science.gov (United States)

Pan, Shuaihang; Yin, Nian; Zhang, Zhinan

2018-02-06

Time- and load-dependent friction behavior is considered as important for a long time, due to its time-evolution and force-driving characteristics. However, its electronic behavior, mainly considered in triboelectric effect, has almost never been given the full attention and analyses from the above point of view. In this paper, by experimenting with fcc-latticed aluminum and copper friction pairs, the mechanical and electronic behaviors of friction contacts are correlated by time and load analyses, and the behind physical understanding is provided. Most importantly, the difference of "response lag" in force and electricity is discussed, the extreme points of coefficient of friction with the increasing normal loads are observed and explained with the surface properties and dynamical behaviors (i.e. wear), and the micro and macro theories linking tribo-electricity to normal load and wear (i.e. the physical explanation between coupled electrical and mechanical phenomena) are successfully developed and tested.

The Effects of Metaphorical Interface on Germane Cognitive Load in Web-Based Instruction

Science.gov (United States)

Cheon, Jongpil; Grant, Michael M.

2012-01-01

The purpose of this study was to examine the effects of a metaphorical interface on germane cognitive load in Web-based instruction. Based on cognitive load theory, germane cognitive load is a cognitive investment for schema construction and automation. A new instrument developed in a previous study was used to measure students' mental activities…

Distributed computer systems theory and practice

CERN Document Server

Zedan, H S M

2014-01-01

Distributed Computer Systems: Theory and Practice is a collection of papers dealing with the design and implementation of operating systems, including distributed systems, such as the amoeba system, argus, Andrew, and grapevine. One paper discusses the concepts and notations for concurrent programming, particularly language notation used in computer programming, synchronization methods, and also compares three classes of languages. Another paper explains load balancing or load redistribution to improve system performance, namely, static balancing and adaptive load balancing. For program effici

Airway complications have a greater impact on the outcomes of living-donor lobar lung transplantation recipients than cadaveric lung transplantation recipients.

Science.gov (United States)

Sugimoto, Seiichiro; Yamane, Masaomi; Otani, Shinji; Kurosaki, Takeshi; Okahara, Shuji; Hikasa, Yukiko; Toyooka, Shinichi; Kobayashi, Motomu; Oto, Takahiro

2018-04-21

Airway complications (ACs) after living-donor lobar lung transplantation (LDLLT) could have different features from those after cadaveric lung transplantation (CLT). We conducted this study to compare the characteristics of ACs after LDLLT vs. those after CLT and investigate their impact on outcomes. We reviewed, retrospectively, data on 163 recipients of lung transplantation, including 83 recipients of LDLLT and 80 recipients of CLT. The incidence of ACs did not differ between LDLLT and CLT. The initial type of AC after LDLLT was limited to stenosis in all eight patients, whereas that after CLT consisted of stenosis in three patients and necrosis in ten patients (p = 0.0034). ACs after LDLLT necessitated significantly earlier initiation of treatment than those after CLT (p = 0.032). The overall survival rate of LDLLT recipients with an AC was significantly lower than that of those without an AC (p = 0.030), whereas the overall survival rate was comparable between CLT recipients with and those without ACs (p = 0.25). ACs after LDLLT, limited to bronchial stenosis, require significantly earlier treatment and have a greater adverse impact on survival than ACs after CLT.

The relationship between chronic lymphocytic thyroiditis and central neck lymph node metastasis in North American patients with papillary thyroid carcinoma.

Science.gov (United States)

Jara, Sebastian M; Carson, Kathryn A; Pai, Sara I; Agrawal, Nishant; Richmon, Jeremy D; Prescott, Jason D; Dackiw, Alan; Zeiger, Martha A; Bishop, Justin A; Tufano, Ralph P

2013-12-01

Several studies have reported that concurrent chronic lymphocytic thyroiditis (CLT) with papillary thyroid carcinoma (PTC) is associated with improved prognosis of the PTC, including decreased lymph node metastasis. We sought to assess the incidence of central nodal metastasis (CNM) in patients with PTC and concurrent CLT. We studied 495 consecutive patients who underwent thyroidectomy with nodal excision for PTC. Pathology reports identified the presence of CLT and the extent of CNM. There were 226 patients (46%) with CLT and 220 (44%) with CNM. Patients with CLT were more often female (88% vs. 71%; P CLT was associated with a 39% decreased odds of CNM after adjusting for age, gender, tumor size, PTC histopathologic subtype, and presence of lymphovascular invasion (odds ratio, 0.61; 95% confidence interval, 0.38-0.99; P = .046). Predicted probability modeling showed that all females with CLT and no suspicious nodal findings on ultrasonography had a 9-11% risk of CNM with pT1a tumors. Female patients of all ages with CLT and small PTCs have the least incidence of CNM. Copyright © 2013 Mosby, Inc. All rights reserved.

Dilution: A Theoretical Burden or Just Load? A Reply to Tsal and Benoni (2010)

Science.gov (United States)

Lavie, Nilli; Torralbo, Ana

2010-01-01

Load theory of attention proposes that distractor processing is reduced in tasks with high perceptual load that exhaust attentional capacity within task-relevant processing. In contrast, tasks of low perceptual load leave spare capacity that spills over, resulting in the perception of task-irrelevant, potentially distracting stimuli. Tsal and…

The fate of task-irrelevant visual motion: perceptual load versus feature-based attention.

Science.gov (United States)

Taya, Shuichiro; Adams, Wendy J; Graf, Erich W; Lavie, Nilli

2009-11-18

We tested contrasting predictions derived from perceptual load theory and from recent feature-based selection accounts. Observers viewed moving, colored stimuli and performed low or high load tasks associated with one stimulus feature, either color or motion. The resultant motion aftereffect (MAE) was used to evaluate attentional allocation. We found that task-irrelevant visual features received less attention than co-localized task-relevant features of the same objects. Moreover, when color and motion features were co-localized yet perceived to belong to two distinct surfaces, feature-based selection was further increased at the expense of object-based co-selection. Load theory predicts that the MAE for task-irrelevant motion would be reduced with a higher load color task. However, this was not seen for co-localized features; perceptual load only modulated the MAE for task-irrelevant motion when this was spatially separated from the attended color location. Our results suggest that perceptual load effects are mediated by spatial selection and do not generalize to the feature domain. Feature-based selection operates to suppress processing of task-irrelevant, co-localized features, irrespective of perceptual load.

Fast-forward scaling theory for phase imprinting on a BEC: creation of a wave packet with uniform momentum density and loading to Bloch states without disturbance

Science.gov (United States)

Masuda, Shumpei; Nakamura, Katsuhiro; Nakahara, Mikio

2018-02-01

We study phase imprinting on Bose-Einstein condensates (BECs) with the fast-forward scaling theory revealing a nontrivial scaling property in quantum dynamics. We introduce a wave packet with uniform momentum density (WPUM) which has peculiar properties but is short-lived. The fast-forward scaling theory is applied to derive the driving potential for creation of the WPUMs in a predetermined time. Fast manipulation is essential for the creation of WPUMs because of the instability of the state. We also study loading of a BEC into a predetermined Bloch state in the lowest band from the ground state of a periodic potential. Controlled linear potential is not sufficient for creation of the Bloch state with large wavenumber because the change in the amplitude of the order parameter is not negligible. We derive the exact driving potential for creation of predetermined Bloch states using the obtained theory.

Buckling analysis of micro- and nano-rods/tubes based on nonlocal Timoshenko beam theory

International Nuclear Information System (INIS)

Wang, C M; Zhang, Y Y; Ramesh, Sai Sudha; Kitipornchai, S

2006-01-01

This paper is concerned with the elastic buckling analysis of micro- and nano-rods/tubes based on Eringen's nonlocal elasticity theory and the Timoshenko beam theory. In the former theory, the small scale effect is taken into consideration while the effect of transverse shear deformation is accounted for in the latter theory. The governing equations and the boundary conditions are derived using the principle of virtual work. Explicit expressions for the critical buckling loads are derived for axially loaded rods/tubes with various end conditions. These expressions account for a better representation of the buckling behaviour of micro- and nano-rods/tubes where small scale effect and transverse shear deformation effect are significant. By comparing it with the classical beam theories, the sensitivity of the small scale effect on the buckling loads may be observed

A Randomized Central Limit Theorem

International Nuclear Information System (INIS)

Eliazar, Iddo; Klafter, Joseph

2010-01-01

The Central Limit Theorem (CLT), one of the most elemental pillars of Probability Theory and Statistical Physics, asserts that: the universal probability law of large aggregates of independent and identically distributed random summands with zero mean and finite variance, scaled by the square root of the aggregate-size (√(n)), is Gaussian. The scaling scheme of the CLT is deterministic and uniform - scaling all aggregate-summands by the common and deterministic factor √(n). This Letter considers scaling schemes which are stochastic and non-uniform, and presents a 'Randomized Central Limit Theorem' (RCLT): we establish a class of random scaling schemes which yields universal probability laws of large aggregates of independent and identically distributed random summands. The RCLT universal probability laws, in turn, are the one-sided and the symmetric Levy laws.

[Significance of the alteration of Th17 cells in patients with chronic lymphocytic thyroiditis].

Science.gov (United States)

Song, Jin-Zhan; Wu, Han-Ni; Qian, Wei

2009-10-01

To investigate the alteration and its significance of T help 17 cells (Th17) in patients with chronic lymphocytic thyroiditis (CLT). Patients were divided into 3 groups: CLT patients with euthyroidism (n=15), CLT patients with hypothyroidism (n=30) and healthy control group (n=20). The ratio of Th17 lymphocytes subpopulations in the peripheral blood were evaluated by technique of flow cytometry. Production of thyroid autoantibody (TPO-Ab, TG-Ab) were measured by electro-chemiluminescence immunoassay (ECLIA). Compared with the healthy control group, in CLT group: The frequencies of Th17 in peripheral blood were found to be significantly higher in patients with CLT than healthy control group (PCLT patients than healthy control group (PCLT which may suggest a potential role for Th17 in the progression and happen of CLT.

On the lamb wave propagation in anisotropic laminated composite plates

International Nuclear Information System (INIS)

Park, Soo Keun; Jeong, Hyun Jo; Kim, Moon Saeng

1998-01-01

This paper examines the propagation of Lamb (or plate) waves in anisotropic laminated composite plates. The dispersion relations are explicitly derived using the classical plate theory (CLT), the first-order shear deformation theory (FSDT) and the exact solution (ES), Attention is paid to the lowest antisymmetric (flexural) and lowest symmetric(extensional) modes in the low frequency, long wavelength limit. Different values of shear correction factor were tested in FSDT and comparisons between flexural wave dispersion curves were made with exact results to asses the range of validity of approximate plate theories in the frequency domain.

Joint time-frequency analysis of ultrasonic signal

International Nuclear Information System (INIS)

Oh, Sae Kyu; Nam, Ki Woo; Oh, Jung Hwan; Lee, Keun Chan; Jang, Hong Keun

1998-01-01

This paper examines the propagation of Lamb (or plate) waves in anisotropic laminated composite plates. The dispersion relations are explicitly derived using the classical plate theory (CLT), the first-order shear deformation theory (FSDT) and the exact solution (ES), Attention is paid to the lowest antisymmetric (flexural) and lowest symmetric(extensional) modes in the low frequency, long wavelength limit. Different values of shear correction factor were tested in FSDT and comparisons between flexural wave dispersion curves were made with exact results to asses the range of validity of approximate plate theories in the frequency domain.

Minimum weight design of composite laminates for multiple loads

International Nuclear Information System (INIS)

Krikanov, A.A.; Soni, S.R.

1995-01-01

A new design method of constructing optimum weight composite laminates for multiple loads is proposed in this paper. A netting analysis approach is used to develop an optimization procedure. Three ply orientations permit development of optimum laminate design without using stress-strain relations. It is proved that stresses in minimum weight laminate reach allowable values in each ply with given load. The optimum ply thickness is defined at maximum value among tensile and compressive loads. Two examples are given to obtain optimum ply orientations, thicknesses and materials. For comparison purposes, calculations of stresses are done in orthotropic material using classical lamination theory. Based upon these calculations, matrix degrades at 30 to 50% of ultimate load. There is no fiber failure and therefore laminates withstand all applied loads in both examples

Instructional Control of Cognitive Load in the Design of Complex Learning Environments

NARCIS (Netherlands)

Kester, Liesbeth; Paas, Fred; Van Merriënboer, Jeroen

2010-01-01

Kester, L., Paas, F., & Van Merriënboer, J. J. G. (2010). Instructional control of cognitive load in the design of complex learning environments. In J. L. Plass, R. Moreno, & Roland Brünken (Eds.), Cognitive Load Theory (pp. 109-130). New York: Cambridge University Press.

Improving "At-Action" Decision-Making in Team Sports through a Holistic Coaching Approach

Science.gov (United States)

Light, Richard L.; Harvey, Stephen; Mouchet, Alain

2014-01-01

This article draws on Game Sense pedagogy and complex learning theory (CLT) to make suggestions for improving decision-making ability in team sports by adopting a holistic approach to coaching with a focus on decision-making "at-action". It emphasizes the complexity of decision-making and the need to focus on the game as a whole entity,…

Decreased staging of differentiated thyroid cancer in patients with chronic lymphocytic thyroiditis.

Science.gov (United States)

Borowczyk, M; Janicki, A; Dworacki, G; Szczepanek-Parulska, E; Danieluk, M; Barnett, J; Antonik, M; Kałużna, M; Bromińska, B; Czepczyński, R; Bączyk, M; Ziemnicka, K; Ruchała, M

2018-04-04

The biological association between chronic lymphocytic thyroiditis (CLT) and differentiated thyroid cancer (DTC) has not been elucidated yet. The aim of the study was to assess whether the presence of CLT exerts any influence on clinical or histological presentation of DTC. Nine hundred and seven consecutive patients with DTC treated in the years 1998-2016 were divided into two groups according to the presence or absence of concomitant CLT. The statistical differences were analysed. Out of 907 patients included in the study, 331 were diagnosed with DTC and CLT (studied group), while 576 patients with DTC but without CLT constituted a control group. The distribution of papillary and follicular thyroid cancer did not differ. In CLT group, the prevalence of pT1 was greater than for pT2-pT4 DTC (P = 0.0003; OR = 1.69, 95% CI 1.27-2.24) compared to controls (68.3 vs. 56.1%, respectively). The presence of multifocal lesions was similar. The thyroid capsule infiltration without extrathyroidal invasion (P CLT (P = 0.004; OR = 1.66; 95% CI 1.17-2.34) as well as nodal involvement (P = 0.048; OR = 0.65, 95% CI 0.42-0.99). The collected data indicate a protective role of CLT in preventing the spread of the DTC. The presence of CLT might limit tumour growth to the primary site.

Cuff leak test and laryngeal survey for predicting post-extubation stridor.

Science.gov (United States)

Patel, Anit B; Ani, Chizobam; Feeney, Colin

2015-02-01

Evidence for the predictive value of the cuff leak test (CLT) for post-extubation stridor (PES) is conflicting. We evaluated the association and accuracy of CLT alone or combined with other laryngeal parameters with PES. Fifty-one mechanically ventilated adult patients in a medical-surgical intensive care unit were tested prior to extubation using; CLT, laryngeal ultrasound and indirect laryngoscopy. Biometric, laryngeal and endotracheal tube (ETT) parameters were recorded. PES incidence was 4%. CLT demonstrated 'no leak' in 20% of patients. Laryngeal oedema was present in 10% of the patients on indirect laryngoscopy, and 71% of the patients had a Grades 1-3 indirect laryngoscopic view. Mean air column width on laryngeal ultrasound was 0.66 ± 0.15 cm (cuff deflated), mean ratio of ETT to laryngeal diameter was 0.48 ± 0.07, and the calculated CLT and laryngeal survey composite was 0.86 ± 1.25 (range 0-5). CLT and the CLT and Laryngeal survey composite measure were not associated with or predict PES. Age, sex, peri-extubation steroid use, intubation duration and body mass index were not associated with PES. Even including ultrasonographic and indirect laryngoscopic examination of the airway, no single aspect of the CLT or combination with laryngeal parameters accurately predicts PES.

Variable Resistance to Plasminogen Activator Initiated Fibrinolysis for Intermediate-Risk Pulmonary Embolism.

Science.gov (United States)

Stubblefield, William B; Alves, Nathan J; Rondina, Matthew T; Kline, Jeffrey A

2016-01-01

We examine the clinical significance and biomarkers of tissue plasminogen activator (tPA)-catalyzed clot lysis time (CLT) in patients with intermediate-risk pulmonary embolism (PE). Platelet-poor, citrated plasma was obtained from patients with PE. Healthy age- and sex-matched patients served as disease-negative controls. Fibrinogen, α2-antiplasmin, plasminogen, thrombin activatable fibrinolysis inhibitor (TAFI), plasminogen activator Inhibitor 1 (PAI-1), thrombin time and D-dimer were quantified. Clotting was induced using CaCl2, tissue factor, and phospholipid. Lysis was induced using 60 ng/mL tPA. Time to 50% clot lysis (CLT) was assessed by both thromboelastography (TEG) and turbidimetry (A405). Compared with disease-negative controls, patients with PE exhibited significantly longer mean CLT on TEG (+2,580 seconds, 95% CI 1,380 to 3,720 sec). Patients with PE and a short CLT who were treated with tenecteplase had increased risk of bleeding, whereas those with long CLT had significantly worse exercise tolerance and psychometric testing for quality of life at 3 months. A multivariate stepwise removal regression model selected PAI-1 and TAFI as predictive biomarkers of CLT. The CLT from TEG predicted increased risk of bleeding and clinical failure with tenecteplase treatment for intermediate-risk PE. Plasmatic PAI-1 and TAFI were independent predictors of CLT.

Can we "apply" the findings of Forster and Lavie (2008)? On the generalizability of attentional capture effects under varying levels of perceptual load.

Science.gov (United States)

Lleras, Alejandro; Chu, Hengqing; Buetti, Simona

2017-06-01

Perceptual Load theory states that the degree of perceptual load on a display determines the amount of leftover attentional resources that the system can use to process distracting information. An important corollary of this theory is that the amount of perceptual load determines the vulnerability of the attention system to being captured by completely irrelevant stimuli, predicting larger amounts of capture with low perceptual load than with high perceptual load. This prediction was first confirmed by Forster and Lavie (2008). Here, we report 6 experiments that followed up on those earlier results, where we find that in many cases, the opposite pattern is obtained: attentional capture increased with increasing perceptual load. Given the lack of generalizability of the theory to new experimental contexts with fairly minor methodological differences, we conclude that Perceptual Load may not be a useful framework for understanding attentional capture. The theoretical and applied importance of these findings is discussed. In particular, we caution against using this theory in applied tasks and settings because best-use recommendations stemming from this theory regarding strategies to decrease distractibility may in fact produce the opposite effect: an increase in distractibility (with distractibility being indexed by the magnitude of the capture effect). (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A new perspective on the perceptual selectivity of attention under load

DEFF Research Database (Denmark)

Giesbrecht, Barry; Sy, Jocelyn; Bundesen, Claus

2014-01-01

The human attention system helps us cope with a complex environment by supporting the selective processing of information relevant to our current goals. Understanding the perceptual, cognitive, and neural mechanisms that mediate selective attention is a core issue in cognitive neuroscience. One...... prominent model of selective attention, known as load theory, offers an account of how task demands determine when information is selected and an account of the efficiency of the selection process. However, load theory has several critical weaknesses that suggest that it is time for a new perspective. Here...... is integrated to provide efficient attentional selection and allocation of perceptual processing resources....

Perceptual Load Affects Eyewitness Accuracy & Susceptibility to Leading Questions

Directory of Open Access Journals (Sweden)

Gillian Murphy

2016-08-01

Full Text Available Load Theory (Lavie, 1995; 2005 states that the level of perceptual load in a task (i.e. the amount of information involved in processing task-relevant stimuli determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator, the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals.

Comparison of Theory and Experiment on Aeroacoustic Loads and Deflections

Science.gov (United States)

Campos, L. M. B. C.; Bourgine, A.; Bonomi, B.

1999-01-01

The correlation of acoustic pressure loads induced by a turbulent wake on a nearby structural panel is considered: this problem is relevant to the acoustic fatigue of aircraft, rocket and satellite structures. Both the correlation of acoustic pressure loads and the panel deflections, were measured in an 8-m diameter transonic wind tunnel. Using the measured correlation of acoustic pressures, as an input to a finite-element aeroelastic code, the panel response was reproduced. The latter was also satisfactorily reproduced, using again the aeroelastic code, with input given by a theoretical formula for the correlation of acoustic pressures; the derivation of this formula, and the semi-empirical parameters which appear in it, are included in this paper. The comparison of acoustic responses in aeroacoustic wind tunnels (AWT) and progressive wave tubes (PWT) shows that much work needs to be done to bridge that gap; this is important since the PWT is the standard test means, whereas the AWT is more representative of real flight conditions but also more demanding in resources. Since this may be the first instance of successful modelling of acoustic fatigue, it may be appropriate to list briefly the essential ``positive'' features and associated physical phenomena: (i) a standard aeroelastic structural code can predict acoustic fatigue, provided that the correlation of pressure loads be adequately specified; (ii) the correlation of pressure loads is determined by the interference of acoustic waves, which depends on the exact evaluation of multiple scattering integrals, involving the statistics of random phase shifts; (iii) for the relatively low frequencies (one to a few hundred Hz) of aeroacoustic fatigue, the main cause of random phase effects is scattering by irregular wakes, which are thin on wavelength scale, and appear as partially reflecting rough interfaces. It may also be appropriate to mention some of the ``negative'' features, to which may be attached illusory

Load transfer of nanocomposite film on aluminum substrate.

Science.gov (United States)

Her, Shiuh-Chuan; Chien, Pao-Chu

2018-01-01

Nanocomposite films have attracted much attention in recent years. Depending on the composition of the film and fabrication method, a large range of applications has been employed for nanocomposite films. In this study, nanocomposite films reinforced with multi-walled carbon nanotubes (MWCNTs) were deposited on the aluminum substrate through hot press processing. A shear lag model and Euler beam theory were employed to evaluate the stress distribution and load carrying capability of the nanocomposite film subjected to tensile load and bending moment. The influence of MWCNT on the Young's modulus and load carrying capability of the nanocomposite film was investigated through a parametric study. The theoretical predictions were verified by comparison with experimental tests. A close agreement with difference less than 6% was achieved between the theoretical prediction and experimental measurements. The Young's modulus and load transfer of the nanocomposite film reinforced with MWCNTs increases with the increase of the MWCNT loading. Compared to the neat epoxy film, nanocomposite film with 1 wt % of MWCNT exhibits an increase of 20% in both the Young's modulus and load carrying capability.

A novel economy reflecting short-term load forecasting approach

International Nuclear Information System (INIS)

Lin, Cheng-Ting; Chou, Li-Der

2013-01-01

Highlights: ► We combine MA line of TAIEX and SVR to overcome the load demands over-prediction problems caused by the economic downturn. ► The Taiwan island-wide electricity power system was used as the case study. ► Short- to middle-term MA lines of TAIEX are found to be good economic input variables for load forecasting models. - Abstract: The global economic downturn in 2008 and 2009, which was spurred by the bankruptcy of Lehman Brothers, sharply reduced the demand for electricity load. Conventional load-forecasting approaches were unable to respond to sudden changes in the economy, because these approaches do not consider the effect of economic factors. Therefore, the over-prediction problem occurred. To overcome this problem, this paper proposes a novel, economy-reflecting, short-term load forecasting (STLF) approach based on theories of moving average (MA) line of stock index and machine learning. In this approach, the stock indices decision model is designed to reflect fluctuations in the Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) series, which is selected as an optimal input variable in support vector regression load forecasting model at an appropriate timing. The Taiwan island-wide hourly electricity load demands from 2008 to 2010 are used as the case study for performance benchmarking. Results show that the proposed approach with a 60-day MA of the TAIEX as economic learning pattern achieves good forecasting performance. It outperforms the conventional approach by 29.16% on average during economic downturn-affected days. Overall, the proposed approach successfully overcomes the over-prediction problems caused by the economic downturn. To the best of our knowledge, this paper is the first attempt to apply MA line theory of stock index on STLF.

Theory Study and Application of the BP-ANN Method for Power Grid Short-Term Load Forecasting

Institute of Scientific and Technical Information of China (English)

Xia Hua; Gang Zhang; Jiawei Yang; Zhengyuan Li

2015-01-01

Aiming at the low accuracy problem of power system short⁃term load forecasting by traditional methods, a back⁃propagation artifi⁃cial neural network (BP⁃ANN) based method for short⁃term load forecasting is presented in this paper. The forecast points are re⁃lated to prophase adjacent data as well as the periodical long⁃term historical load data. Then the short⁃term load forecasting model of Shanxi Power Grid (China) based on BP⁃ANN method and correlation analysis is established. The simulation model matches well with practical power system load, indicating the BP⁃ANN method is simple and with higher precision and practicality.

Theoretical prediction on corrugated sandwich panels under bending loads

Science.gov (United States)

Shu, Chengfu; Hou, Shujuan

2018-05-01

In this paper, an aluminum corrugated sandwich panel with triangular core under bending loads was investigated. Firstly, the equivalent material parameters of the triangular corrugated core layer, which could be considered as an orthotropic panel, were obtained by using Castigliano's theorem and equivalent homogeneous model. Secondly, contributions of the corrugated core layer and two face panels were both considered to compute the equivalent material parameters of the whole structure through the classical lamination theory, and these equivalent material parameters were compared with finite element analysis solutions. Then, based on the Mindlin orthotropic plate theory, this study obtain the closed-form solutions of the displacement for a corrugated sandwich panel under bending loads in specified boundary conditions, and parameters study and comparison by the finite element method were executed simultaneously.

Dynamic response analysis of an aircraft structure under thermal-acoustic loads

International Nuclear Information System (INIS)

Cheng, H; Li, H B; Zhang, W; Wu, Z Q; Liu, B R

2016-01-01

Future hypersonic aircraft will be exposed to extreme combined environments includes large magnitude thermal and acoustic loads. It presents a significant challenge for the integrity of these vehicles. Thermal-acoustic test is used to test structures for dynamic response and sonic fatigue due to combined loads. In this research, the numerical simulation process for the thermal acoustic test is presented, and the effects of thermal loads on vibro-acoustic response are investigated. To simulate the radiation heating system, Monte Carlo theory and thermal network theory was used to calculate the temperature distribution. Considering the thermal stress, the high temperature modal parameters are obtained with structural finite element methods. Based on acoustic finite element, modal-based vibro-acoustic analysis is carried out to compute structural responses. These researches are very vital to optimum thermal-acoustic test and structure designs for future hypersonic vehicles structure (paper)

Feasibility of combining linear theory and impact theory methods for the analysis and design of high speed configurations

Science.gov (United States)

Brooke, D.; Vondrasek, D. V.

1978-01-01

The aerodynamic influence coefficients calculated using an existing linear theory program were used to modify the pressures calculated using impact theory. Application of the combined approach to several wing-alone configurations shows that the combined approach gives improved predictions of the local pressure and loadings over either linear theory alone or impact theory alone. The approach not only removes most of the short-comings of the individual methods, as applied in the Mach 4 to 8 range, but also provides the basis for an inverse design procedure applicable to high speed configurations.

Accelerated fatigue testing of dentin-composite bond with continuously increasing load.

Science.gov (United States)

Li, Kai; Guo, Jiawen; Li, Yuping; Heo, Young Cheul; Chen, Jihua; Xin, Haitao; Fok, Alex

2017-06-01

The aim of this study was to evaluate an accelerated fatigue test method that used a continuously increasing load for testing the dentin-composite bond strength. Dentin-composite disks (ϕ5mm×2mm) made from bovine incisor roots were subjected to cyclic diametral compression with a continuously increasingly load amplitude. Two different load profiles, linear and nonlinear with respect to the number of cycles, were considered. The data were then analyzed by using a probabilistic failure model based on the Weakest-Link Theory and the classical stress-life function, before being transformed to simulate clinical data of direct restorations. All the experimental data could be well fitted with a 2-parameter Weibull function. However, a calibration was required for the effective stress amplitude to account for the difference between static and cyclic loading. Good agreement was then obtained between theory and experiments for both load profiles. The in vitro model also successfully simulated the clinical data. The method presented will allow tooth-composite interfacial fatigue parameters to be determined more efficiently. With suitable calibration, the in vitro model can also be used to assess composite systems in a more clinically relevant manner. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

From Theory Use to Theory Building in Learning Analytics: A Commentary on "Learning Analytics to Support Teachers during Synchronous CSCL"

Science.gov (United States)

Chen, Bodong

2015-01-01

In this commentary on Van Leeuwen (2015, this issue), I explore the relation between theory and practice in learning analytics. Specifically, I caution against adhering to one specific theoretical doctrine while ignoring others, suggest deeper applications of cognitive load theory to understanding teaching with analytics tools, and comment on…

Three-dimensional noninvasive monitoring iodine-131 uptake in the thyroid using a modified Cerenkov luminescence tomography approach.

Science.gov (United States)

Hu, Zhenhua; Ma, Xiaowei; Qu, Xiaochao; Yang, Weidong; Liang, Jimin; Wang, Jing; Tian, Jie

2012-01-01

Cerenkov luminescence tomography (CLT) provides the three-dimensional (3D) radiopharmaceutical biodistribution in small living animals, which is vital to biomedical imaging. However, existing single-spectral and multispectral methods are not very efficient and effective at reconstructing the distribution of the radionuclide tracer. In this paper, we present a semi-quantitative Cerenkov radiation spectral characteristic-based source reconstruction method named the hybrid spectral CLT, to efficiently reconstruct the radionuclide tracer with both encouraging reconstruction results and less acquisition and image reconstruction time. We constructed the implantation mouse model implanted with a 400 µCi Na(131)I radioactive source and the physiological mouse model received an intravenous tail injection of 400 µCi radiopharmaceutical Iodine-131 (I-131) to validate the performance of the hybrid spectral CLT and compared the reconstruction results, acquisition, and image reconstruction time with that of single-spectral and multispectral CLT. Furthermore, we performed 3D noninvasive monitoring of I-131 uptake in the thyroid and quantified I-131 uptake in vivo using hybrid spectral CLT. Results showed that the reconstruction based on the hybrid spectral CLT was more accurate in localization and quantification than using single-spectral CLT, and was more efficient in the in vivo experiment compared with multispectral CLT. Additionally, 3D visualization of longitudinal observations suggested that the reconstructed energy of I-131 uptake in the thyroid increased with acquisition time and there was a robust correlation between the reconstructed energy versus the gamma ray counts of I-131 (r(2) = 0.8240). The ex vivo biodistribution experiment further confirmed the I-131 uptake in the thyroid for hybrid spectral CLT. Results indicated that hybrid spectral CLT could be potentially used for thyroid imaging to evaluate its function and monitor its treatment for thyroid cancer.

Perceptual Load Affects Eyewitness Accuracy and Susceptibility to Leading Questions.

Science.gov (United States)

Murphy, Gillian; Greene, Ciara M

2016-01-01

Load Theory (Lavie, 1995, 2005) states that the level of perceptual load in a task (i.e., the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator), the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals.

An Approach to Stochastic Peridynamic Theory.

Energy Technology Data Exchange (ETDEWEB)

Demmie, Paul N.

2018-04-01

In many material systems, man-made or natural, we have an incomplete knowledge of geometric or material properties, which leads to uncertainty in predicting their performance under dynamic loading. Given the uncertainty and a high degree of spatial variability in properties of materials subjected to impact, a stochastic theory of continuum mechanics would be useful for modeling dynamic response of such systems. Peridynamic theory is such a theory. It is formulated as an integro- differential equation that does not employ spatial derivatives, and provides for a consistent formulation of both deformation and failure of materials. We discuss an approach to stochastic peridynamic theory and illustrate the formulation with examples of impact loading of geological materials with uncorrelated or correlated material properties. We examine wave propagation and damage to the material. The most salient feature is the absence of spallation, referred to as disorder toughness, which generalizes similar results from earlier quasi-static damage mechanics. Acknowledgements This research was made possible by the support from DTRA grant HDTRA1-08-10-BRCWM. I thank Dr. Martin Ostoja-Starzewski for introducing me to the mechanics of random materials and collaborating with me throughout and after this DTRA project.

Design of digital load torque observer in hybrid electric vehicle

Science.gov (United States)

Sun, Yukun; Zhang, Haoming; Wang, Yinghai

2008-12-01

In hybrid electric vehicle, engine begain to work only when motor was in high speed in order to decrease tail gas emission. However, permanent magnet motor was sensitive to its load, adding engine to the system always made its speed drop sharply, which caused engine to work in low efficiency again and produced much more environment pollution. Dynamic load torque model of permanent magnet synchronous motor is established on the basic of motor mechanical equation and permanent magnet synchronous motor vector control theory, Full- digital load torque observer and compensation control system is made based on TMS320F2407A. Experiment results prove load torque observer and compensation control system can detect and compensate torque disturbing effectively, which can solve load torque disturbing and decrease gas pollution of hybrid electric vehicle.

Variable Resistance to Plasminogen Activator Initiated Fibrinolysis for Intermediate-Risk Pulmonary Embolism.

Directory of Open Access Journals (Sweden)

William B Stubblefield

Full Text Available We examine the clinical significance and biomarkers of tissue plasminogen activator (tPA-catalyzed clot lysis time (CLT in patients with intermediate-risk pulmonary embolism (PE.Platelet-poor, citrated plasma was obtained from patients with PE. Healthy age- and sex-matched patients served as disease-negative controls. Fibrinogen, α2-antiplasmin, plasminogen, thrombin activatable fibrinolysis inhibitor (TAFI, plasminogen activator Inhibitor 1 (PAI-1, thrombin time and D-dimer were quantified. Clotting was induced using CaCl2, tissue factor, and phospholipid. Lysis was induced using 60 ng/mL tPA. Time to 50% clot lysis (CLT was assessed by both thromboelastography (TEG and turbidimetry (A405.Compared with disease-negative controls, patients with PE exhibited significantly longer mean CLT on TEG (+2,580 seconds, 95% CI 1,380 to 3,720 sec. Patients with PE and a short CLT who were treated with tenecteplase had increased risk of bleeding, whereas those with long CLT had significantly worse exercise tolerance and psychometric testing for quality of life at 3 months. A multivariate stepwise removal regression model selected PAI-1 and TAFI as predictive biomarkers of CLT.The CLT from TEG predicted increased risk of bleeding and clinical failure with tenecteplase treatment for intermediate-risk PE. Plasmatic PAI-1 and TAFI were independent predictors of CLT.

Study of the effects of the casein derived bitter tastant on the melanophores in milieu with the melatonin receptors.

Science.gov (United States)

Mubashshir, Md; Ahmed, Fraz; Ovais, Mohd

2011-10-01

The present study was undertaken to ascertain whether the casein derived bitter tastant Cyclo (Leu-Trp) [CLT] has an affinity or not for the particular receptors of the pineal hormone, melatonin, on the melanophores of a major carp Labeo rohita (Ham.). The bitter tastant CLT, in the dose range of 3.34×10(-16) M to 3.34×10(-4) M, has induced an aggregatory effect but not in a dose dependent manner. Binding of CLT with the receptors may vary at different concentrations. Denervation of the melanophores has shown a complete inhibition of the CLT mediated aggregation. Prazosin has partially inhibited the aggregatory effect of CLT. Moreover, the bitter tastant's response is mediated through the α2 adrenoceptors only at particular dose ranges. The MT1 and MT2 melatonin receptor antagonist luzindole and the MT2 specific antagonist K185 have perfectly blocked the aggregatory effects of CLT. We have found that the CLT mediated aggregatory effect is dependent upon the release of neurotransmitters and the two subtypes of melatonin (MT) receptors (MT1 and MT2) possess a perfect affinity towards the bitter tastant CLT. Our study demands a need to further make a clinical research on the effects of bitter tastants on the physiology of the biological rhythm maintaining hormone melatonin.

Auditory Figure-Ground Segregation is Impaired by High Visual Load

OpenAIRE

Lavie, Nilli; Chait, Maria; Molloy, Katharine

2017-01-01

Figure-ground segregation is fundamental to listening in complex acoustic environments. An ongoing debate pertains to whether segregation requires attention or is 'automatic' and pre-attentive. In this magnetoencephalography (MEG) study we tested a prediction derived from Load Theory of attention (1) that segregation requires attention, but can benefit from the automatic allocation of any 'leftover' capacity under low load. Complex auditory scenes were modelled with Stochastic Figure Ground s...

Psychological distance modulates the performance of the embodiment effect: Evidence from behavioral and ERP studies.

Science.gov (United States)

Wang, Hanlin; Mo, Lei; Luo, Qiuling; Xiang, Yanhui; Hu, Yunyang

2016-04-01

Research on embodied cognition suggests the ubiquity of embodiment effects during interaction with the environment. However, construal level theory (CLT) holds that these effects could be moderated by the psychological distance between self and objects and are attenuated by higher-level mental construal. The current research explored the "action-evaluation" embodiment effect in the evaluation of words located at different spatial distances. Results showed that for "short-distance" words, the response model conflicted with this embodiment effect slower reaction time and induced a larger P2 component than the opposite response model. However, evaluation of "long-distance" words was not significantly influenced by the response model. The results are consistent with CLT and suggest that the action-evaluation embodiment effect influences the coding and execution of evaluating actions, but only for stimuli at close psychological distance locations. © 2015 Society for Psychophysiological Research.

The Role of Language Glossing in a Rooted Theory: The Involvement Load Hypothesis

Directory of Open Access Journals (Sweden)

Hassan Soleimani

2014-07-01

Full Text Available This study builds on the innovative construct of task-induced involvement. It investigates different first and second language glossing in “involvement load hypothesis”. In order to do our study, 66 learners from two different English institutes were classified into two major high and low proficient groups based on Nelson Proficiency Test. Among them 22 low proficient students were randomly assigned to two different subgroups in order to complete two different types of tasks with different language glossing. The behaviors of the two groups in the immediate and delayed posttests did not confirm the predictions of involvement load hypothesis. Although the second task had a higher involvement index, no sign of superiority was observed in its performance. The study suggests that the predictions of involvement load hypothesis need to be more finely grained especially when the tasks have different language glossing.

Modeling the effects of perceptual load: saliency, competitive interactions, and top-down biases.

Directory of Open Access Journals (Sweden)

Kleanthis eNeokleous

2016-01-01

Full Text Available A computational model of visual selective attention has been implemented to account for experimental findings on the Perceptual Load Theory (PLT of attention. The model was designed based on existing neurophysiological findings on attentional processes with the objective to offer an explicit and biologically plausible formulation of PLT. Simulation results verified that the proposed model is capable of capturing the basic pattern of results that support the Perceptual Load Theory as well as findings that are considered contradictory to the theory. Importantly, the model is able to reproduce the behavioral results from a dilution experiment, providing thus a way to reconcile PLT with the competing Dilution account. Overall, the model presents a novel account for explaining PLT effects on the basis of the low-level competitive interactions among neurons that represent visual input and the top-down signals that modulate neural activity. The implications of the model concerning the debate on the locus of selective attention as well as the origins of distractor interference in visual displays of varying load are discussed.

Harmonic Differential Quadrature Analysis of Soft-Core Sandwich Panels under Locally Distributed Loads

Directory of Open Access Journals (Sweden)

Xinwei Wang

2016-11-01

Full Text Available Sandwich structures are widely used in practice and thus various engineering theories adopting simplifying assumptions are available. However, most engineering theories of beams, plates and shells cannot recover all stresses accurately through their constitutive equations. Therefore, the soft-core is directly modeled by two-dimensional (2D elasticity theory without any pre-assumption on the displacement field. The top and bottom faces act like the elastic supports on the top and bottom edges of the core. The differential equations of the 2D core are then solved by the harmonic differential quadrature method (HDQM. To circumvent the difficulties in dealing with the locally distributed load by point discrete methods such as the HDQM, a general and rigorous way is proposed to treat the locally distributed load. Detailed formulations are provided. The static behavior of sandwich panels under different locally distributed loads is investigated. For verification, results are compared with data obtained by ABAQUS with very fine meshes. A high degree of accuracy on both displacement and stress has been observed.

Beam loading effects in a standing wave accelerator structure

International Nuclear Information System (INIS)

Arai, Shigeaki; Katayama, Takeshi; Tojyo, Eiki; Yoshida, Katsuhide.

1978-11-01

The steady-state beam loading effects on the accelerating field in the disk-loaded structure of a standing wave type have been systematically studied. The electron bunch from a 15 MeV electron linac is injected at arbitrary phase of the external driving field in the test structure. The change of the phase shift of the accelerating field and that of the stored energy are measured as a function of the phase on which the bunch rides. The former shows drastic change when the bunch is around the crest of the driving field and when the beam loading is heavy, whereas the latter varies sinusoidally for any beam loading. The resonant frequency shift of the structure due to beam loading is estimated by using the measured results. All the experimental results are well explained by the normal mode analysis of the microwave cavity theory. (author)

Contact-Free Cognitive Load Recognition Based on Eye Movement

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Xin Liu

2016-01-01

Full Text Available The cognitive overload not only affects the physical and mental diseases, but also affects the work efficiency and safety. Hence, the research of measuring cognitive load has been an important part of cognitive load theory. In this paper, we proposed a method to identify the state of cognitive load by using eye movement data in a noncontact manner. We designed a visual experiment to elicit human’s cognitive load as high and low state in two light intense environments and recorded the eye movement data in this whole process. Twelve salient features of the eye movement were selected by using statistic test. Algorithms for processing some features are proposed for increasing the recognition rate. Finally we used the support vector machine (SVM to classify high and low cognitive load. The experimental results show that the method can achieve 90.25% accuracy in light controlled condition.

Thrombin activatable fibrinolysis inhibitor and clot lysis time in pregnant patients with antiphospholipid syndrome: relationship with pregnancy outcome and thrombosis.

Science.gov (United States)

Martinez-Zamora, Maria Angeles; Tassies, Dolors; Carmona, Francisco; Espinosa, Gerard; Cervera, Ricard; Reverter, Juan Carlos; Balasch, Juan

2009-12-01

Antiphospholipid syndrome (APS) pregnancies are associated with thrombotic obstetric complications, despite treatment. This study evaluated Thrombin Activatable Fibrinolysis Inhibitor (TAFI) levels, TAFI gene polymorphisms and Clot Lysis Time (CLT) in pregnant patients with APS in relation to pregnancy outcome and thrombosis. Group 1 consisted of 67 pregnant patients with APS. Group 2 included 66 pregnant patients with uneventful term pregnancies and delivery. Patients were sampled during each trimester and at baseline. TAFI antigen and CLT and two polymorphisms of the TAFI gene, Ala147Thr and +1542C/G, were determined. Significantly prolonged CLT was found at baseline in Group 1. Allele distribution of the TAFI gene polymorphisms was similar in both groups. Basal TAFI and CLT in patients with APS having an adverse or a good obstetrical outcome were similar. Comparison of TAFI and CLT baseline levels in patients with APS with or without previous thrombosis showed no statistical differences. Patients with APS have impairment in fibrinolysis evidenced by prolonged CLT at baseline. TAFI and CLT do not seem to be useful as markers of obstetric outcome or risk of thrombosis in patients with APS.

A point-of-care chemistry test for reduction of turnaround and clinical decision time.

Science.gov (United States)

Lee, Eui Jung; Shin, Sang Do; Song, Kyoung Jun; Kim, Seong Chun; Cho, Jin Seong; Lee, Seung Chul; Park, Ju Ok; Cha, Won Chul

2011-06-01

Our study compared clinical decision time between patients managed with a point-of-care chemistry test (POCT) and patients managed with the traditional central laboratory test (CLT). This was a randomized controlled multicenter trial in the emergency departments (EDs) of 5 academic teaching hospitals. We randomly assigned patients to POCT or CLT stratified by the Emergency Severity Index. A POCT chemistry analyzer (Piccolo; Abaxis, Inc, Union City, Calif), which is able to test liver panel, renal panel, pancreas enzymes, lipid panel, electrolytes, and blood gases, was set up in each ED. Primary and secondary end point was turnaround time and door-to-clinical-decision time. The total 2323 patients were randomly assigned to the POCT group (n = 1167) or to the CLT group (n = 1156). All of the basic characteristics were similar in the 2 groups. The turnaround time (median, interquartile range [IQR]) of the POCT group was shorter than that of the CLT group (14, 12-19 versus 55, 45-69 minutes; P CLT group (46, 33-61 versus 86, 68-107 minutes; P CLT group (P CLT. Copyright © 2011 Elsevier Inc. All rights reserved.

Influence of chlorothalonil on the removal of organic matter in horizontal subsurface flow constructed wetlands.

Science.gov (United States)

Casas-Zapata, Juan C; Ríos, Karina; Florville-Alejandre, Tomás R; Morató, Jordi; Peñuela, Gustavo

2013-01-01

This study investigates the effects of chlorothalonil (CLT) on chemical oxygen demand (COD) and dissolved organic carbon (DOC) in pilot-scale horizontal subsurface flow constructed wetlands (HSSFCW) planted with Phragmites australis. Physicochemical parameters of influent and effluent water samples, microbial population counting methods and statistical analysis were used to evaluate the influence of CLT on organic matter removal efficiency. The experiments were conducted on four planted replicate wetlands (HSSFCW-Pa) and one unplanted control wetland (HSSFCW-NPa). The wetlands exhibited high average organic matter removal efficiencies (HSSFCW-Pa: 80.6% DOC, 98.0% COD; HSSFCW-NPa: 93.2% DOC, 98.4% COD). The addition of CLT did not influence organic removal parameters. In all cases CLT concentrations in the effluent occurred in concentrations lower than the detection limit of the analytical method. Microbial population counts from HSSFCW-Pa showed significant correlations among different microbial groups and with different physicochemical variables. The apparent independence of organic matter removal and CLT inputs, along with the CLT depletion observed in effluent samples demonstrated that HSSFCW are a viable technology for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT.

Effects of Chronic Lymphocytic Thyroiditis on the Clinicopathological Features of Papillary Thyroid Cancer.

Science.gov (United States)

Babli, Saleha; Payne, Richard J; Mitmaker, Elliot; Rivera, Juan

2018-03-01

The effects of chronic lymphocytic thyroiditis (CLT) on the presentation and outcome of papillary thyroid carcinoma (PTC) have long been a topic of controversy. To evaluate the effect of coexistent CLT on the clinicopathological features of PTC. Retrospective study. All patients with PTC who had been followed by the 2 co-investigators (Juan Rivera and Richard J. Payne) between 2006 and 2011 were included. CLT was present in 35% (166) of the included patients and was associated with a higher proportion of patients with TNM stage I ( p = 0.027) and fewer patients with persistent disease ( p = 0.014) in comparison with the PTC-only group. Analysis of the data based on age (45 years) revealed that in the older group, the presence of CLT was associated with fewer patients with persistent disease ( p = 0.03) and capsular invasion ( p = 0.05). However, in patients CLT was associated with more capsular invasion ( p = 0.003) and extrathyroidal extension ( p = 0.004) compared with the PTC-only group. CLT in patients with PTC was associated with lower-stage disease and less disease persistence in patients >45 years of age. In patients CLT appeared to be associated with unfavorable pathological features.

Convergence of Crowdsourcing Ideas: A Cognitive Load perspective

DEFF Research Database (Denmark)

Fu, Shixuan; de Vreede, Gert-Jan; Cheng, Xusen

2017-01-01

and satisfaction with the convergence process and outcomes. We propose an experimental study that adopts Cognitive Load Theory as its theoretical lens to investigate the effects of task complexity, idea presentation, and instructional guidance on convergence quality and satisfaction. This study has the potential...

Effects of Motion in the Far Peripheral Visual Field on Cognitive Test Performance and Cognitive Load.

Science.gov (United States)

Bevilacqua, Andy; Paas, Fred; Krigbaum, Genomary

2016-04-01

Cognitive load theory posits that limited attention is in actuality a limitation in working memory resources. The load theory of selective attention and cognitive control sees the interplay between attention and awareness as separate modifying functions that act on working memory. Reconciling the theoretical differences in these two theories has important implications for learning. Thirty-nine adult participants performed a cognitively demanding test, with and without movement in the far peripheral field. Although the results for movement effects on cognitive load in this experiment were not statistically significant, men spent less time on the cognitive test in the peripheral movement condition than in the conditions without peripheral movement. No such difference was found for women. The implications of these results and recommendations for future research that extends the present study are presented. © The Author(s) 2016.

Modal and Wave Load Identification by ARMA Calibration

DEFF Research Database (Denmark)

Jensen, Jens Kristian Jehrbo; Kirkegaard, Poul Henning; Brincker, Rune

In this paper modal parameter as well as wave load identification by calibration of ARMA models is considered for a simple offshore structure. The theory of identification by ARMA calibration is presented as an identification technique in the time domain which can be applied for white noise excited...... systems. The technique is generalized also to include the case of ambient excitation processes such as wave excitation which are non-white processes. Due to those results a simple but effective approach for identification of the load process is proposed. Finally the theoretical presentation is illustrated...

MVDR Algorithm Based on Estimated Diagonal Loading for Beamforming

Directory of Open Access Journals (Sweden)

Yuteng Xiao

2017-01-01

Full Text Available Beamforming algorithm is widely used in many signal processing fields. At present, the typical beamforming algorithm is MVDR (Minimum Variance Distortionless Response. However, the performance of MVDR algorithm relies on the accurate covariance matrix. The MVDR algorithm declines dramatically with the inaccurate covariance matrix. To solve the problem, studying the beamforming array signal model and beamforming MVDR algorithm, we improve MVDR algorithm based on estimated diagonal loading for beamforming. MVDR optimization model based on diagonal loading compensation is established and the interval of the diagonal loading compensation value is deduced on the basis of the matrix theory. The optimal diagonal loading value in the interval is also determined through the experimental method. The experimental results show that the algorithm compared with existing algorithms is practical and effective.

Simulation of reinforced concrete short shear wall subjected to cyclic loading

International Nuclear Information System (INIS)

Parulekar, Y.M.; Reddy, G.R.; Vaze, K.K.; Pegon, P.; Wenzel, H.

2014-01-01

Highlights: • Prediction of the capacity of squat shear wall using tests and analysis. • Modification of model of concrete in the softening part. • Pushover analysis using softened truss theory and FE analysis is performed. • Modified concrete model gives reasonable accurate peak load and displacement. • The ductility, ultimate load and also crack pattern can be accurately predicted. - Abstract: This paper addresses the strength and deformation capacity of stiff squat shear wall subjected to monotonic and pseudo-static cyclic loading using experiments and analysis. Reinforced concrete squat shear walls offer great potential for lateral load resistance and the failure mode of these shear walls is brittle shear mode. Shear strength of these shear walls depend strongly on softening of concrete struts in principal compression direction due to principal tension in other direction. In this work simulation of the behavior of a squat shear wall is accurately predicted by finite element modeling by incorporating the appropriate softening model in the program. Modification of model of concrete in the softening part is suggested and reduction factor given by Vecchio et al. (1994) is used in the model. The accuracy of modeling is confirmed by comparing the simulated response with experimental one. The crack pattern generated from the 3D model is compared with that obtained from experiments. The load deflection for monotonic loads is also obtained using softened truss theory and compared with experimental one

[Autoimmune thyroiditis and thyroid cancer].

Science.gov (United States)

Krátký, Jan; Jiskra, Jan

2015-10-01

Association between autoimmune thyroiditis (CLT) and thyroid cancer remains not clear. Although both diseases often occur simultaneously in histological samples, it is not yet clear whether CLT can be regarded as a risk factor for thyroid malignancy. This review focus on the known epidemiological and molecular genetics links between both diseases. Most studies have shown a significant association between thyroid cancer and positive antibodies to thyroglobulin and histological evidence of CLT, as well. Both disorders share some risk factors (greater incidence in women, in areas with adequate supply of iodine and in patients after radiotherapy of the neck) and molecular genetics linkage. For example: RET/PTC rearrangements could be more often found in carcinomas associated with CLT, but this mutation could be found in benign lesions such as CLT, as well. CLT seems to be a positive prognostic factor in patients with differentiated thyroid cancer. It is associated with less invasive forms of tumor, lower occurrence of infiltrated lymphatic nodes and a lower risk of recurrence.

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory

Science.gov (United States)

Meier, Beat; Zimmermann, Thomas D.

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially. PMID:26082709

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory.

Science.gov (United States)

Meier, Beat; Zimmermann, Thomas D

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

The relationship between loads and power of a rotor and an actuator disc

NARCIS (Netherlands)

Van Kuik, G.A.M.

2014-01-01

Most state of the art rotor design methods are based on the actuator disc theory developed about one century ago. The actuator disc is an axisymmetric permeable surface carrying a load that represents the load on a real rotor with a finite number of blades N. However, the mathematics of the

Workshop on high heat load x-ray optics

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

A workshop on High Heat Load X-Ray Optics'' was held at Argonne National Laboratory on August 3--5, 1989. The object of this workshop was to discuss recent advances in the art of cooling x-ray optics subject to high heat loads from synchrotron beams. The cooling of the first optical element in the intense photon beams that will be produced in the next generation of synchrotron sources is recognized as one of the major challenges that must be faced before one will be able to use these very intense beams in future synchrotron experiments. Considerable advances have been made in this art during the last few years, but much work remains to be done before the heating problem can be said to be completely solved. Special emphasis was placed on recent cooling experiments and detailed finite element'' and finite difference'' calculations comparing experiment with theory and extending theory to optimize performance.

Workshop on high heat load x-ray optics

International Nuclear Information System (INIS)

1990-01-01

A workshop on ''High Heat Load X-Ray Optics'' was held at Argonne National Laboratory on August 3--5, 1989. The object of this workshop was to discuss recent advances in the art of cooling x-ray optics subject to high heat loads from synchrotron beams. The cooling of the first optical element in the intense photon beams that will be produced in the next generation of synchrotron sources is recognized as one of the major challenges that must be faced before one will be able to use these very intense beams in future synchrotron experiments. Considerable advances have been made in this art during the last few years, but much work remains to be done before the heating problem can be said to be completely solved. Special emphasis was placed on recent cooling experiments and detailed ''finite element'' and ''finite difference'' calculations comparing experiment with theory and extending theory to optimize performance

Thyroiditis: a Clinico-cytomorphological Study with a Reference to the Ethnic Groups of Northeast Regions of India.

Science.gov (United States)

Kalita, Abhijit; Baruah, Ronica

2015-12-01

Definite clinico-cytological criterion is outlined for thyroid lesions. Fine needle aspiration cytology (FNAC) makes it easier to segregate cases of thyroiditis (Chronic lymphocytic thyroiditis/Hashimoto's thyroiditis-CLT/HT, and subacute thyroiditis-SAT) from other benign and malignant lesions of thyroid. The study was done for a period of 5½ years at a diagnostic centre in Guwahati. Patients underwent FNAC and smears were studied for cytomorphology. A correlation with clinical features and thyroid function, including antithyroid antibody estimation, was done, wherever possible. 792 thyroid lesions were encountered during the study, of which 213 (26.89 %) were cases of thyroiditis (70.43 % CLT/HT, 24.9 % SAT and 3.76 % having overlapping features of CLT/HT and SAT); 2 cases (0.9 %) of CLT showed suspicion of Non-Hodgkin's Lymphoma (NHL), which was confirmed on histopathology. 24 cases (11.26 %) belonged to different ethnic tribal groups of Northeast India. CLT/HT presented predominantly with diffuse thyroid enlargement, but 12 cases (8 % of CLT/HT cases) had nodular enlargement. Patients presented with predominantly hypothyroidism; however occasional hyperthyroid cases were also seen. SAT showed signs of inflammation and presented with hyperthyroidism. Overlap cases of CLT/HT and SAT showed combined clinico-cytomorphological features of both lesions. 37.5 % cases with overlapping features belonged to tribal communities. A rise in incidence of thyroiditis, particularly CLT/HT, was seen. Overlap features of CLT/HT and SAT was noticed in significant percentage. No bias was noticed amongst any specific tribal community. FNAC, coupled with clinico-serological study, helps to diagnose thyroiditis at early stage.

Multiaxial creep of tubes from Incoloy 800 H and Inconel 617 under static and cyclic loading conditions

International Nuclear Information System (INIS)

Penkalla, H.J.; Nickel, H.; Schubert, F.

1989-01-01

At temperatures above 800 0 C the material behaviour under mechanical load is determined by creep. The service of heat exchanging components leads to multiaxial loading conditions. For design and inelastic analysis of the component behaviour time dependent design values and suitable constitutive equations are necessary. The present report gives a survey of the approaches to describing creep under multiaxial loading. Norton's law and v. Mises' theory are applied. The load combinations of internal pressure, tensile and torsional stress are studied more closely, cyclic stress superposition in the tensile-pulsating range is discussed and cases of partial relaxation are examined. Experimental results are presented for the loading conditions discussed, and satisfactory agreement between theory and experiment has been found up to now for these results. Regarding lifetime determination under multiaxial creep load, a more precise analysis of creep damage is presented suggesting a suitable deviatoric stress for evaluation in the long-time range. (orig.)

Impact load time histories for viscoelastic missiles

International Nuclear Information System (INIS)

Stoykovich, M.

1977-01-01

Generation of the impact load time history at the contact point between a viscoelastic missile and its targets is presented. In the past, in the case of aircraft striking containment shell structure, the impact load time history was determined on the basis of actual measurements by subjecting a rigid wall to aircraft crash. The effects of elastic deformation of the target upon the impact load time history is formulated in this paper. The missile is idealized by a linear mass-spring-dashpot combination using viscoelastic models. These models can readily be processed taking into account the elastic as well as inelastic deformations of the missiles. The target is assumed to be either linearly elastic or rigid. In the case of the linearly elastic target, the normal mode theory is used to express the time-dependent displacements of the target which is simulated by lumped masses, elastic properties and dashpots in discrete parts. In the case of Maxwell viscoelastic model, the time-dependent displacements of the missile and the target are given in terms of the unknown impact load time history. This leads to an integral equation which may be solved by Laplace transformation. The normal mode theory is provided. The target structure may be composed of different materials with different components. Concrete and steel structural components have inherently different viscous friction damping properties. Hence, the equivalent modal damping depends on the degree of participation of these components in the modal response. An approximate rule for determining damping in any vibration mode by weighting the damping of each component according to the modal energy stored in each component is considered

Stress analysis in a functionally graded disc under mechanical loads ...

Indian Academy of Sciences (India)

They have therefore attracted considerable attention in recent ... vessels subjected to internal pressure by using the small deformation theory. ..... sure (Pi = 50 MPa), external pressure (Po = 100 MPa), centrifugal load with a constant angular.

Attentional load modulates responses of human primary visual cortex to invisible stimuli.

Science.gov (United States)

Bahrami, Bahador; Lavie, Nilli; Rees, Geraint

2007-03-20

Visual neuroscience has long sought to determine the extent to which stimulus-evoked activity in visual cortex depends on attention and awareness. Some influential theories of consciousness maintain that the allocation of attention is restricted to conscious representations [1, 2]. However, in the load theory of attention [3], competition between task-relevant and task-irrelevant stimuli for limited-capacity attention does not depend on conscious perception of the irrelevant stimuli. The critical test is whether the level of attentional load in a relevant task would determine unconscious neural processing of invisible stimuli. Human participants were scanned with high-field fMRI while they performed a foveal task of low or high attentional load. Irrelevant, invisible monocular stimuli were simultaneously presented peripherally and were continuously suppressed by a flashing mask in the other eye [4]. Attentional load in the foveal task strongly modulated retinotopic activity evoked in primary visual cortex (V1) by the invisible stimuli. Contrary to traditional views [1, 2, 5, 6], we found that availability of attentional capacity determines neural representations related to unconscious processing of continuously suppressed stimuli in human primary visual cortex. Spillover of attention to cortical representations of invisible stimuli (under low load) cannot be a sufficient condition for their awareness.

Theory of timber connections with slender dowel type fasteners

DEFF Research Database (Denmark)

Svensson, Staffan; Munch-Andersen, Jørgen

2018-01-01

A theory on the lateral load-carrying capacity of timber connections with slender fasteners is presented. The base of the theory is the coupled mechanical phenomena acting in the connection, while the wood and the slender fastener deform and yield prior to failure. The objective is to derive...... a sufficient description of actions and responses which have determining influence on the load-carrying capacity of timber connections with slender fasteners. Model assumptions are discussed and made, but simplifications are left out. Even so, simple mathematical equations describing the lateral capacity......-carrying capacity of the tested connections....

Improving Conceptions in Analytical Chemistry: The Central Limit Theorem

Science.gov (United States)

Rodriguez-Lopez, Margarita; Carrasquillo, Arnaldo, Jr.

2006-01-01

This article describes the central limit theorem (CLT) and its relation to analytical chemistry. The pedagogic rational, which argues for teaching the CLT in the analytical chemistry classroom, is discussed. Some analytical chemistry concepts that could be improved through an understanding of the CLT are also described. (Contains 2 figures.)

Chronic lymphocytic thyroiditis and BRAF V600E in papillary thyroid carcinoma.

Science.gov (United States)

Kim, Seo Ki; Woo, Jung-Woo; Lee, Jun Ho; Park, Inhye; Choe, Jun-Ho; Kim, Jung-Han; Kim, Jee Soo

2016-01-01

It has been reported that papillary thyroid carcinoma (PTC) with chronic lymphocytic thyroiditis (CLT) is less associated with extrathyroidal extension (ETE), advanced tumor stage and lymph node (LN) metastasis. Other studies have suggested that concurrent CLT could antagonize PTC progression, even in BRAF-positive patients. Since the clinical significance of the BRAF mutation has been particularly associated with conventional PTC, the purpose of this study was to determine the clinical significance of CLT according to BRAF mutation status in conventional PTC patients. We retrospectively reviewed the medical records of 3332 conventional PTC patients who underwent total thyroidectomy with bilateral central neck dissection at the Thyroid Cancer Center of Samsung Medical Center between January 2008 and June 2015. In this study, the prevalence of BRAF mutation was significantly less frequent in conventional PTC patients with CLT (76.9% vs 86.6%). CLT was an independent predictor for low prevalence of ETE in both BRAF-negative (OR=0.662, P=0.023) and BRAF-positive (OR=0.817, P=0.027) conventional PTC patients. In addition, CLT was an independent predictor for low prevalence of CLNM in both BRAF-negative (OR=0.675, P=0.044) and BRAF-positive (OR=0.817, P=0.030) conventional PTC patients. In conclusion, BRAF mutation was significantly less frequent in conventional PTC patients with CLT. However, CLT was an independent predictor for less aggressiveness in conventional PTC patients regardless of BRAF mutation status. © 2016 Society for Endocrinology.

Chronic lymphocytic thyroiditis is associated with invasive characteristics of differentiated thyroid carcinoma in children and adolescents.

Science.gov (United States)

Iliadou, Paschalia K; Effraimidis, Grigoris; Konstantinos, Michalakis; Grigorios, Panagiotou; Mitsakis, Periklis; Patakiouta, Frideriki; Pazaitou-Panayiotou, Kalliopi

2015-12-01

The association between chronic lymphocytic thyroiditis (CLT) and thyroid cancer is an interesting topic. The aim of the present study was to evaluate if demographic and histological characteristics as well as the long-term outcome of thyroid cancer was different in children and adolescents with and without CLT. The medical records of children and adolescents (≤21 years old) were reviewed. The following data were recorded: gender, year and age at diagnosis, family history of thyroid cancer, history of external radiation therapy, histological type (papillary and variants, follicular and variants), tumour size, multifocality, infiltration of thyroid parenchyma or surrounding soft tissues, vascular invasion, presence of lymph node and distant metastases. Information about the presence of TgAb and TPOAb was also collected. One hundred eight children and adolescents (median age 19.0, interquartile range 4.0 years) were diagnosed with differentiated thyroid carcinoma (DTC); 31 patients (28.7%) presented histological characteristics compatible with CLT. Infiltration of thyroid parenchyma was more frequent in patients with CLT compared to patients without (74.2% vs 48.1% respectively, P=0.024). Familial papillary thyroid carcinoma (PTC) was more frequent in patients with CLT compared to those without CLT (20.7% vs 2.8% respectively, P=0.009). There was no better outcome with respect to the presence of CLT or not. Children and adolescents with CLT present more frequently familial PTC as well as thyroid cancer with invasive characteristics. © 2015 European Society of Endocrinology.

Contribution of apparently non-operating loadings to the buckling of thin shells and plates

International Nuclear Information System (INIS)

Delaigue, Didier.

1980-02-01

This work includes four parts: in the first part, the Kirchhoff-Love theory of thin shells is described, a theory taken up and developed by Koiter and whose modelling seems to meet the problems of engineers. The second part deals with the buckling of a thin plate subjected to a load along a part of its edge, of which a part or all is seemingly inoperative. In the third part the study is extended to shells of any shape subjected to a conservative loading of the ''dead-loading'' type along part of their edges. On the basis of the results of the previous study, a study is then made on the taking into account of any load applied to the edge of a thin shell. In the fourth part the previous results are applied to the study of the buckling of a thin shell with a circular base subjected along a part of its edge to a normal prestress and to twisting moments linear density [fr

Study of the behavior of welded assemblies subjected to cyclic loads of variable amplitudes

International Nuclear Information System (INIS)

Plumier, A.

1977-01-01

The optimum design of structures subjected to variable loads requires the fatigue loading to be defined not only by the extreme stresses which can occur in the structure, but also by the distribution of the amplitudes of loadings. This emphasizes the importance of relations allowing the definition of permissible stresses under variable amplitude loading on the basis of permissible stresses under constant amplitude loading: such relations lead to a thorough use of the very numerous results acquired in classical fatigue testings. The statistical analysis of our tests results confirms, for four as welded joints, the good fit of theoretical values calculated on the basis of BIERETT's theory, so that this theory seems precise enough for calculations rules. However, the differences between theory and experiments, as well as regards the passage from classical fatigue to programmed fatigue, as for the definition of resistance of a welded joint on the basis of classes in classial fatigue, can reach as much as 30%. This lack of precision can be reduced by precise definition of joints classes, also defining permissible sizes of welds defects, on the one hand, and by the precise definition of a curve taking account of an influence of the severity of the notch effect of joints on the passage from classical fatigue to programmed fatigue, on the other hand. Our tests results, which were obtained on joints with very weak or very strong notches led to suggest such a curve

Measuring cognitive load during procedural skills training with colonoscopy as an exemplar.

Science.gov (United States)

Sewell, Justin L; Boscardin, Christy K; Young, John Q; Ten Cate, Olle; O'Sullivan, Patricia S

2016-06-01

Few studies have investigated cognitive factors affecting learning of procedural skills in medical education. Cognitive load theory, which focuses on working memory, is highly relevant, but methods for measuring cognitive load during procedural training are not well understood. Using colonoscopy as an exemplar, we used cognitive load theory to develop a self-report instrument to measure three types of cognitive load (intrinsic, extraneous and germane load) and to provide evidence for instrument validity. We developed the instrument (the Cognitive Load Inventory for Colonoscopy [CLIC]) using a multi-step process. It included 19 items measuring three types of cognitive load, three global rating items and demographics. We then conducted a cross-sectional survey that was administered electronically to 1061 gastroenterology trainees in the USA. Participants completed the CLIC following a colonoscopy. The two study phases (exploratory and confirmatory) each lasted for 10 weeks during the 2014-2015 academic year. Exploratory factor analysis determined the most parsimonious factor structure; confirmatory factor analysis assessed model fit. Composite measures of intrinsic, extraneous and germane load were compared across years of training and with global rating items. A total of 477 (45.0%) invitees participated (116 in the exploratory study and 361 in the confirmatory study) in 154 (95.1%) training programmes. Demographics were similar to national data from the USA. The most parsimonious factor structure included three factors reflecting the three types of cognitive load. Confirmatory factor analysis verified that a three-factor model was the best fit. Intrinsic, extraneous and germane load items had high internal consistency (Cronbach's alpha 0.90, 0.87 and 0.96, respectively) and correlated as expected with year in training and global assessment of cognitive load. The CLIC measures three types of cognitive load during colonoscopy training. Evidence of validity is

Redirecting learners' attention during training: effects on cognitive load, transfer test performance and training efficiency

NARCIS (Netherlands)

van Merriënboer, J.J.G.; Schuurman, Jan Gerrit; de Croock, M.B.M.; Paas, F.G.W.C.

2002-01-01

Cognitive load theory provides guidelines for improving the training of complex cognitive skills and their transfer to new situations. One guideline states that extraneous cognitive load that is irrelevant to the construction of cognitive schemata should be minimised. Experiment 1 (N=26) compares

Research on loading pattern optimization for VVER reactor

International Nuclear Information System (INIS)

Tran Viet Phu; Nguyen Thi Mai Huong; Nguyen Huu Tiep; Ta Duy Long; Tran Vinh Thanh; Tran Hoai Nam

2017-01-01

A study on fuel loading pattern optimization of a VVER reactor was performed. In this study, a core physics simulator was developed based on a multi-group diffusion theory for the use in the problem of fuel loading optimization of VVER reactors. The core simulator could handle the triangular meshes of the core and the computational speed is fast. Verification of the core simulator was confirmed against a benchmark problem of a VVER-1000 reactor. Several optimization methods such as DS, SA, TS and a combination of them were investigated and implemented in coupling with the core simulator. Calculations was performed for optimizing the fuel loading pattern of the core using these methods based on a benchmark core model in comparison with the reference core. Comparison among these methods have shown that a combination of SA+TS is the most effective for the problem of fuel loading pattern optimization. Advanced methods are being researched continuously. (author)

Clinical implications of the BRAF mutation in papillary thyroid carcinoma and chronic lymphocytic thyroiditis.

Science.gov (United States)

Kim, Woon Won; Ha, Tae Kwun; Bae, Sung Kwon

2018-01-09

The purpose of this study was to examine the possible prognostics and clinicopathologic characteristics underlying the BRAFV600E mutation and papillary thyroid carcinoma (PTC) coexisting or in absence of chronic lymphocytic thyroiditis (CLT). This study was conducted on 172 patients who had undergone total thyroidectomy or unilateral total thyroidectomy for PTC; the patients were then examined for the BRAFV600E mutation using specimens obtained after their surgery from January 2013 to August 2015. BRAF mutations were found in 130 of 172 patients (75.6%). CLT was present in 27.9% of patients (48/172). The incidence of the BRAFV600E mutation was significantly increased in the group with no CLT (P = 0.001). The findings of the multivariate analysis pertaining to the coexistence of CLT and PTC showed no significant correlation other than the BRAFV600E mutation. No significant difference was noted in the clinicopathologic factors between the two groups based on the coexistence of CLT in univariate and multivariate analyses. The BRAFV600E mutation is less frequent in PTC coexisting with CLT presumably because CLT and the BRAFV600E mutation operate independently in the formation and progression of thyroid cancer.

Age-specific effects of mirror-muscle activity on cross-limb adaptations under mirror and non-mirror visual feedback conditions.

Directory of Open Access Journals (Sweden)

Paola eReissig

2015-12-01

Full Text Available Cross-limb transfer (CLT describes the observation of bilateral performance gains due to unilateral motor practice. Previous research has suggested that CLT may be reduced, or absent, in older adults, possibly due to age-related structural and functional brain changes. Based on research showing increases in CLT due to the provision of mirror visual feedback (MVF during task execution in young adults, our study aimed to investigate whether MVF can facilitate CLT in older adults, who are known to be more reliant on visual feedback for accurate motor performance. Participants (N = 53 engaged in a short-term training regime (300 movements involving a ballistic finger task using their dominant hand, while being provided with either visual feedback of their active limb, or a mirror reflection of their active limb (superimposed over the quiescent limb. Bilateral performance was examined before, during and following the training. Furthermore, we measured corticospinal excitability (using TMS at these time points, and assessed muscle activity bilaterally during the task via EMG; these parameters were used to investigate the mechanisms mediating and predicting CLT. Training resulted in significant bilateral performance gains that did not differ as a result of age or visual feedback (all ps > 0.1. Training also elicited bilateral increases in corticospinal excitability (p < 0.05. For younger adults, CLT was significantly predicted by performance gains in the trained hand (β = 0.47, whereas for older adults it was significantly predicted by mirror activity in the untrained hand during training (β = 0.60. The present study suggests that older adults are capable of exhibiting CLT to a similar degree to younger adults. The prominent role of mirror activity in the untrained hand for CLT in older adults indicates that bilateral cortical activity during unilateral motor tasks is a compensatory mechanism. In this particular task, MVF did not facilitate the

Unified strength theory and its applications

CERN Document Server

Yu, Mao-Hong

2004-01-01

This is a completely new theory dealing with the yield and failure of materials under multi-axial stresses. It provides a system of yield and failure criteria adopted for most materials, from metallic materials to rocks, concretes, soils, polymers etc. The Unified Strength Theory has been applied successfully to analyse the elastic limit, plastic limit capacities, the dynamic response behavior for some structures under static and moderate impulsive load, and may be implemented in some elasto-plastic finite element computer codes. The Unified Strength Theory is described in detail and by using this theory a series of results can be obtained. The Unified Strength Theory can improve the conservative Mohr-Coulomb Theory, and since intermediate principal stress is not taken into account in the Mohr-Coulomb theory and most experimental data is not pertainable to the Mohr-Coulomb Theory, a considerable economic benefit may be obtained. The book can also increase the effect of most commercial finite element computer ...

Keeping "Community" in a Community Land Trust

Science.gov (United States)

Gray, Karen A.; Galande, Mugdha

2011-01-01

This instrumental case study examined the role of grassroots community organizing in a community land trust (CLT) in a southern U.S. city. Twenty-nine homeowners, renters, board members, community members, and current and former CLT employees were interviewed. In addition, two focus groups of 11 and six participants composed of CLT residents and…

Communicative Language Teaching: A Practical Scenario in the Context of Bangladesh

Directory of Open Access Journals (Sweden)

Md. Kawser Ahmed

2016-10-01

Full Text Available Communicative Language Teaching, popularly known as CLT, has become a newly adopted methodology in the teaching and learning context of Bangladesh. This methodology, since the initiation, has encountered and is still encountering a number of hurdles that need to be dealt with best care and feasible strategy. Of all methods, most of the educational institutes be- it secondary or higher secondary are inclined to accept and apply the CLT in classroom, though there has been a lack of resources, materials and language experts. Ignoring the reality, the policy makers would like to follow the other countries, though they are self-sufficient and self-dependent on their strategic plans and strong funds who have already executed CLT with success. This paper attempts to present the reality behind the implementation of CLT in the language teaching and learning environment and outlines the malpractices widely obvious in educational institutes of Bangladesh. This paper also focuses on the strategic points, data collection and analysis and probable remedy regarding the real picture of CLT in Bangladesh. Keywords: CLT, methodology, context, hurdles, Bangladesh

Distancing from experienced self: how global-versus-local perception affects estimation of psychological distance.

Science.gov (United States)

Liberman, Nira; Förster, Jens

2009-08-01

In 4 studies, the authors examined the prediction derived from construal level theory (CLT) that higher level of perceptual construal would enhance estimated egocentric psychological distance. The authors primed participants with global perception, local perception, or both (the control condition). Relative to the control condition, global processing made participants estimate larger psychological distances in time (Study 1), space (Study 2), social distance (Study 3), and hypotheticality (Study 4). Local processing had the opposite effect. Consistent with CLT, all studies show that the effect of global-versus-local processing did emerge when participants estimated egocentric distances, which are distances from the experienced self in the here and now, but did not emerge with temporal distances not from now (Study 1), spatial distances not from here (Study 2), social distances not from the self (Study 3), or hypothetical events that did not involve altering an experienced reality (Study 4).

Machine learning of the reactor core loading pattern critical parameters

International Nuclear Information System (INIS)

Trontl, K.; Pevec, D.; Smuc, T.

2007-01-01

The usual approach to loading pattern optimization involves high degree of engineering judgment, a set of heuristic rules, an optimization algorithm and a computer code used for evaluating proposed loading patterns. The speed of the optimization process is highly dependent on the computer code used for the evaluation. In this paper we investigate the applicability of a machine learning model which could be used for fast loading pattern evaluation. We employed a recently introduced machine learning technique, Support Vector Regression (SVR), which has a strong theoretical background in statistical learning theory. Superior empirical performance of the method has been reported on difficult regression problems in different fields of science and technology. SVR is a data driven, kernel based, nonlinear modelling paradigm, in which model parameters are automatically determined by solving a quadratic optimization problem. The main objective of the work reported in this paper was to evaluate the possibility of applying SVR method for reactor core loading pattern modelling. The starting set of experimental data for training and testing of the machine learning algorithm was obtained using a two-dimensional diffusion theory reactor physics computer code. We illustrate the performance of the solution and discuss its applicability, i.e., complexity, speed and accuracy, with a projection to a more realistic scenario involving machine learning from the results of more accurate and time consuming three-dimensional core modelling code. (author)

Load compensation for single phase system using series active filter

African Journals Online (AJOL)

user

Keywords: Active power filter (APF), current source type of harmonic load ... Single phase active filters could attract less attention than three phase due to its low ..... Generalised single-phase p-q theory for active power filtering: simulation and.

Voice Use Among Music Theory Teachers: A Voice Dosimetry and Self-Assessment Study.

Science.gov (United States)

Schiller, Isabel S; Morsomme, Dominique; Remacle, Angélique

2017-07-25

This study aimed (1) to investigate music theory teachers' professional and extra-professional vocal loading and background noise exposure, (2) to determine the correlation between vocal loading and background noise, and (3) to determine the correlation between vocal loading and self-evaluation data. Using voice dosimetry, 13 music theory teachers were monitored for one workweek. The parameters analyzed were voice sound pressure level (SPL), fundamental frequency (F0), phonation time, vocal loading index (VLI), and noise SPL. Spearman correlation was used to correlate vocal loading parameters (voice SPL, F0, and phonation time) and noise SPL. Each day, the subjects self-assessed their voice using visual analog scales. VLI and self-evaluation data were correlated using Spearman correlation. Vocal loading parameters and noise SPL were significantly higher in the professional than in the extra-professional environment. Voice SPL, phonation time, and female subjects' F0 correlated positively with noise SPL. VLI correlated with self-assessed voice quality, vocal fatigue, and amount of singing and speaking voice produced. Teaching music theory is a profession with high vocal demands. More background noise is associated with increased vocal loading and may indirectly increase the risk for voice disorders. Correlations between VLI and self-assessments suggest that these teachers are well aware of their vocal demands and feel their effect on voice quality and vocal fatigue. Visual analog scales seem to represent a useful tool for subjective vocal loading assessment and associated symptoms in these professional voice users. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Development of a self-managed loaded exercise programme for rotator cuff tendinopathy.

Science.gov (United States)

Littlewood, Chris; Malliaras, Peter; Mawson, Sue; May, Stephen; Walters, Stephen

2013-12-01

This paper describes a self-managed loaded exercise programme which has been designed to address the pain and disability associated with rotator cuff tendinopathy. The intervention has been developed with reference to current self-management theory and with reference to the emerging benefit of loaded exercise for tendinopathy. This self-managed loaded exercise programme is being evaluated within the mixed methods SELF study (ISRCTN 84709751) which includes a pragmatic randomised controlled trial conducted within the UK National Health Service. Copyright © 2012 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

FLANGE-ORNL, Flanged Pipe Joint Stress Analysis, Internal Pressure, Moment Loads, Temperature

International Nuclear Information System (INIS)

Rodabaugh, E.C.; Moore, S.E.

1979-01-01

1 - Description of problem or function: FLANGE-ORNL calculates appropriate loads, stresses, and displacements for the flanges, bolts, and gaskets that comprise a flanged piping joint for internal pressure or moment loading on the pipe, temperature difference between the flange hub and ring, and variations in bolt load that result from pressure, hub-ring temperature gradient and/or bolt-ring temperature differences. Flanges considered may be tapered-hub, straight or blind. 2 - Method of solution: The solution is based on discontinuity analysis and the theory of plates and shells

Averaging in SU(2) open quantum random walk

International Nuclear Information System (INIS)

Ampadu Clement

2014-01-01

We study the average position and the symmetry of the distribution in the SU(2) open quantum random walk (OQRW). We show that the average position in the central limit theorem (CLT) is non-uniform compared with the average position in the non-CLT. The symmetry of distribution is shown to be even in the CLT

Averaging in SU(2) open quantum random walk

Science.gov (United States)

Clement, Ampadu

2014-03-01

We study the average position and the symmetry of the distribution in the SU(2) open quantum random walk (OQRW). We show that the average position in the central limit theorem (CLT) is non-uniform compared with the average position in the non-CLT. The symmetry of distribution is shown to be even in the CLT.

SU-F-T-678: Clotrimazole Sensitizes MCF-7 Breast Cancer Cell Line to Radiation

Energy Technology Data Exchange (ETDEWEB)

Garcia, L; Tambasco, M [San Diego State University, San Diego, CA (United States)

2016-06-15

Purpose: To study the effects of Clotrimazole (CLT) on radiosensitivity of MCF-7 Cells in correlation to detachment of Hexokinase II from the Voltage Dependent Anion Channel on the outer membrane of the mitochondria. Apoptotic fractions were also analyzed in relation to the detachment of Hexokinase. Methods: This study focused on the mammary adenocarcinoma cell line, MCF-7. Colony forming assays were used to analyze radiosensitization by CLT. Flow cytometry methods were used to analyze apoptotic vs necrotic fractions after treatment with CLT. Spectrophotometery was used to analyze the mitochondrial bound and soluble fraction of Hexokinase by means of relative enzymatic activity. Results: Our preliminary data have shown that CLT sensitizes MCF-7 cells to radiation in a dose and incubation time dependent manner up. We have also demonstrated that there are two radiosensitizing periods in MCF-7 cells with the first corresponding to the cycle arrest after 24 hours observed in other cell lines. The second radiosensitizing period occurs with incubation in CLT after irradiation which reaches maximum effect around 24 hours of incubation time. Preliminary data from our Hexokinase detachment assay show a factor of two increase in the ratio of unbound to bound Hexokinase when comparing incubation for 24 hours in media containing 0 and 20 µM CLT. Conclusion: This study and others indicate CLT as a possible radiosensitizing agent in cancer therapies. While CLT itself shows toxicity to the liver in high doses, this study further demonstrates that disruption of the Warburg Effect and unbinding of mitochondrial bound Hexokinase as a possible pathway for cancer treatment.

An assessment of early Child Life Therapy pain and anxiety management: A prospective randomised controlled trial.

Science.gov (United States)

Hyland, Ela J; D'Cruz, Rachel; Harvey, John G; Moir, Jordyn; Parkinson, Christina; Holland, Andrew J A

2015-12-01

Burns remain extremely painful and distressing in young children. The consequences of poorly managed pain and anxiety can be life-long. Whilst Child Life Therapy (CLT) has been shown to be effective in many situations, few studies have looked at the effectiveness of CLT in regard to reducing pain and anxiety in children undergoing burn dressing changes. A prospective, randomised controlled trial was conducted, comparing CLT versus standard care in relation to pain and anxiety scores of children undergoing their initial burn dressing change. Pain and anxiety were assessed by an independent observer and questionnaires completed by the child, parent/caregiver and nursing staff. 50 subjects were recruited in each treatment group; median age 2.3 years (CLT) and 2.2 years (standard care). The median total body surface area (TBSA) burnt was 0.8% (CLT) and 0.5% (standard care). The majority were partial thickness dermal burns (88% CLT, 94% standard care). Rates of parent anxiety and pre-procedural child pain and anxiety were similar. Combined and scaled pain and anxiety scores in the CLT group were significantly less than in the standard treatment group (p=0.03). Whilst pain was significantly better in the CLT group (p=0.02), fear scores, wound outcomes and the need for skin grafting were not statistically different in either group. The presence of a Child Life Therapist, with their ability to adapt to the environment, the child and their family, significantly reduced the experience of pain during paediatric burn dressings. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

SU-F-T-678: Clotrimazole Sensitizes MCF-7 Breast Cancer Cell Line to Radiation

International Nuclear Information System (INIS)

Garcia, L; Tambasco, M

2016-01-01

Purpose: To study the effects of Clotrimazole (CLT) on radiosensitivity of MCF-7 Cells in correlation to detachment of Hexokinase II from the Voltage Dependent Anion Channel on the outer membrane of the mitochondria. Apoptotic fractions were also analyzed in relation to the detachment of Hexokinase. Methods: This study focused on the mammary adenocarcinoma cell line, MCF-7. Colony forming assays were used to analyze radiosensitization by CLT. Flow cytometry methods were used to analyze apoptotic vs necrotic fractions after treatment with CLT. Spectrophotometery was used to analyze the mitochondrial bound and soluble fraction of Hexokinase by means of relative enzymatic activity. Results: Our preliminary data have shown that CLT sensitizes MCF-7 cells to radiation in a dose and incubation time dependent manner up. We have also demonstrated that there are two radiosensitizing periods in MCF-7 cells with the first corresponding to the cycle arrest after 24 hours observed in other cell lines. The second radiosensitizing period occurs with incubation in CLT after irradiation which reaches maximum effect around 24 hours of incubation time. Preliminary data from our Hexokinase detachment assay show a factor of two increase in the ratio of unbound to bound Hexokinase when comparing incubation for 24 hours in media containing 0 and 20 µM CLT. Conclusion: This study and others indicate CLT as a possible radiosensitizing agent in cancer therapies. While CLT itself shows toxicity to the liver in high doses, this study further demonstrates that disruption of the Warburg Effect and unbinding of mitochondrial bound Hexokinase as a possible pathway for cancer treatment.

Elastic-plastic-creep response of structures under composite time history of loadings

International Nuclear Information System (INIS)

Zudans, Z.

1975-01-01

The purpose of this work is to derive the theory, to develop efficient numerical techniques accounting for plasticity, creep and overall equilibrium, to describe the overall structure of the resulting computer program, and to demonstrate the capability of this analysis on a real structure. Classical plasticity theory is used to develop a novel method based on the concept of 'plastic stress' for consideration of inelastic behavior. It is shown that materials stres-strain curves can be followed to any desired degree of accuracy both for isotropic and kinematic hardening. It is further shown that for kinematic hardening it is necessary to base the incremental change on the state corresponding to the mean of the initial and the final states in order to satisfy the yield condition at the final state. The equation of state and strain hardening is used to describe the creep behavior. A novel numerical technique to describe a complex load history is developed by using time as a parameter, history breakpoint determination by scanning of various load vectors and by linear interpolation between any two breakpoints in the load history. The 'plastic stress' load vector concept is utilized with iteration and extrapolation to converge to the equilibrium states with simultaneous satisfaction of the stress-strain relations for each of the iterated states. The essential features of the computer program DYPLAS-FSH, based on the theory and techniques described above, and a postprocessor program POR-FSH, based on RDT F9-5T for ratcheting and fatigue evaluation, are identified and discussed. These computer programs are used to analyse the ellipsoidal pressure vessel head of the intermediate heat exchanger of EBR-II, penetrated by two closely spaced non-radial nozzles, subjected to four consecutive composite cycles of complex mechanical and thermal loads

Perceptual load corresponds with factors known to influence visual search.

Science.gov (United States)

Roper, Zachary J J; Cosman, Joshua D; Vecera, Shaun P

2013-10-01

One account of the early versus late selection debate in attention proposes that perceptual load determines the locus of selection. Attention selects stimuli at a late processing level under low-load conditions but selects stimuli at an early level under high-load conditions. Despite the successes of perceptual load theory, a noncircular definition of perceptual load remains elusive. We investigated the factors that influence perceptual load by using manipulations that have been studied extensively in visual search, namely target-distractor similarity and distractor-distractor similarity. Consistent with previous work, search was most efficient when targets and distractors were dissimilar and the displays contained homogeneous distractors; search became less efficient when target-distractor similarity increased irrespective of display heterogeneity. Importantly, we used these same stimuli in a typical perceptual load task that measured attentional spillover to a task-irrelevant flanker. We found a strong correspondence between search efficiency and perceptual load; stimuli that generated efficient searches produced flanker interference effects, suggesting that such displays involved low perceptual load. Flanker interference effects were reduced in displays that produced less efficient searches. Furthermore, our results demonstrate that search difficulty, as measured by search intercept, has little bearing on perceptual load. We conclude that rather than be arbitrarily defined, perceptual load might be defined by well-characterized, continuous factors that influence visual search. PsycINFO Database Record (c) 2013 APA, all rights reserved.

On computing the geoelastic response to a disk load

Science.gov (United States)

Bevis, M.; Melini, D.; Spada, G.

2016-06-01

We review the theory of the Earth's elastic and gravitational response to a surface disk load. The solutions for displacement of the surface and the geoid are developed using expansions of Legendre polynomials, their derivatives and the load Love numbers. We provide a MATLAB function called diskload that computes the solutions for both uncompensated and compensated disk loads. In order to numerically implement the Legendre expansions, it is necessary to choose a harmonic degree, nmax, at which to truncate the series used to construct the solutions. We present a rule of thumb (ROT) for choosing an appropriate value of nmax, describe the consequences of truncating the expansions prematurely and provide a means to judiciously violate the ROT when that becomes a practical necessity.

The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission.

Science.gov (United States)

Kiani, Mehdi; Ghovanloo, Maysam

2012-09-01

Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor ( Q ) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory.

Can manipulations of cognitive load be used to test evolutionary hypotheses?

Science.gov (United States)

Barrett, H Clark; Frederick, David A; Haselton, Martie G; Kurzban, Robert

2006-09-01

D. DeSteno, M. Y. Bartlett, J. Braverman, and P. Salovey proposed that if sex-differentiated responses to infidelity are evolved, then they should be automatic, and therefore cognitive load should not attenuate them. DeSteno et al. found smaller sex differences in response to sexual versus emotional infidelity among participants under cognitive load, an effect interpreted as evidence against the evolutionary hypothesis. This logic is faulty. Cognitive load probably affects mechanisms involved in simulating infidelity experiences, thus seriously challenging the usefulness of cognitive load manipulations in testing hypotheses involving simulation. The method also entails the assumption that evolved jealousy mechanisms are necessarily automatic, an assumption not supported by theory or evidence. Regardless of how the jealousy debate is eventually settled, cognitive load manipulations cannot rule out the operation of evolved mechanisms. ((c) 2006 APA, all rights reserved).

Folded Plate Structures as Building Envelopes

DEFF Research Database (Denmark)

Falk, Andreas; Buelow, Peter von; Kirkegaard, Poul Henning

2012-01-01

This paper treats applications of cross-laminated timber (CLT) in structural systems for folded façade solutions. Previous work on CLT-based systems for folded roofs has shown a widening range of structural possibilities to develop timber-based shells. Geometric and material properties play...... CLT-based systems, which are studied and analysed by using a combination of digital tools for structural and environmental design and analysis. The results show gainful, rational properties of folded systems and beneficial effects from an integration of architectural and environmental performance...... criteria in the design of CLT-based façades....

Is blade element momentum theory (BEM) enough for smart rotor design

NARCIS (Netherlands)

Yu, W.; Simao Ferreira, C.J.; van Kuik, G.A.M.

2014-01-01

Smart rotor emerges as an innovation technique to reduce the impact of dynamic loading on wind turbines. Local movements of distributed aerodynamic devices will enhance the non-uniformity and dynamic effects of loading, which will challenge the applicability of the blade element momentum theory

Cerenkov Luminescence Tomography for In Vivo Radiopharmaceutical Imaging

Directory of Open Access Journals (Sweden)

Jianghong Zhong

2011-01-01

Full Text Available Cerenkov luminescence imaging (CLI is a cost-effective molecular imaging tool for biomedical applications of radiotracers. The introduction of Cerenkov luminescence tomography (CLT relative to planar CLI can be compared to the development of X-ray CT based on radiography. With CLT, quantitative and localized analysis of a radiopharmaceutical distribution becomes feasible. In this contribution, a feasibility study of in vivo radiopharmaceutical imaging in heterogeneous medium is presented. Coupled with a multimodal in vivo imaging system, this CLT reconstruction method allows precise anatomical registration of the positron probe in heterogeneous tissues and facilitates the more widespread application of radiotracers. Source distribution inside the small animal is obtained from CLT reconstruction. The experimental results demonstrated that CLT can be employed as an available in vivo tomographic imaging of charged particle emitters in a heterogeneous medium.

Channel layer thickness dependence of In-Ti-Zn-O thin-film transistors fabricated using pulsed laser deposition

International Nuclear Information System (INIS)

Zhang, Q.; Shan, F. K.; Liu, G. X.; Liu, A.; Lee, W. J.; Shin, B. C.

2014-01-01

Amorphous indium-titanium-zinc-oxide (ITZO) thin-film transistors (TFTs) with various channel thicknesses were fabricated at room temperature by using pulsed laser deposition. The channel layer thickness (CLT) dependence of the TFTs was investigated. All the ITZO thin films were amorphous, and the surface roughnesses decreased slightly first and then increased with increasing CLT. With increasing CLT from 35 to 140 nm, the on/off current ratio and the field-effect mobility increased, and the subthreshold swing decreased. The TFT with a CLT of 210 nm exhibited the worst performance, while the ITZO TFT with a CLT of 140 nm exhibited the best performance with a subthreshold voltage of 2.86 V, a mobility of 53.9 cm 2 V -1 s -1 , a subthreshold swing of 0.29 V/decade and an on/off current ratio of 10 9 .

Aesthetic Qualities of Cross Laminated Timber

DEFF Research Database (Denmark)

Bejder, Anne Kirkegaard

to its sustainable profile. In parallel to this, new production methods and further refined timber products have been developed. Among these are the engineered timber-based product Cross Laminated Timber (CLT) that show enhanced structural properties compared to unrefined timber. However, the question...... an undefined aesthetic potential that may innovate how we construct and perceive timber architecture, the overall aim of the thesis is to inquire into the architectural and aesthetic qualities of CLT. Through three chapters this thesis examines and discusses 1) the architectural qualities of CLT, 2......) the materiality of CLT, and 3) how one can deal with these qualitative aspects in the design process. This leads to: firstly, the development of an explicit model to help structuring the analysis and evaluation of the materiality of CLT, and secondly, a clarification and articulation of the aesthetic qualities...

Analysis of Dynamic Properties of Piezoelectric Structure under Impact Load

Directory of Open Access Journals (Sweden)

Taotao Zhang

2015-10-01

Full Text Available An analytical model of the dynamic properties is established for a piezoelectric structure under impact load, without considering noise and perturbations in this paper. Based on the general theory of piezo-elasticity and impact mechanics, the theoretical solutions of the mechanical and electrical fields of the smart structure are obtained with the standing and traveling wave methods, respectively. The comparisons between the two methods have shown that the standing wave method is better for studying long-time response after an impact load. In addition, good agreements are found between the theoretical and the numerical results. To simulate the impact load, both triangle and step pulse loads are used and comparisons are given. Furthermore, the influence of several parameters is discussed so as to provide some advices for practical use. It can be seen that the proposed analytical model would benefit, to some extent, the design and application (especially the airport runway of the related smart devices by taking into account their impact load performance.

Plasma clot lysis time and its association with cardiovascular risk factors in black Africans.

Directory of Open Access Journals (Sweden)

Zelda de Lange

Full Text Available Studies in populations of European descent show longer plasma clot lysis times (CLT in patients with cardiovascular disease (CVD than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid urbanisation with increased CVD prevalence. We investigated associations between known CVD risk factors and CLT in black Africans and whether CLTs differ between rural and urban participants in light of differences in CVD risk.Data from 1000 rural and 1000 urban apparently healthy black South Africans (35-60 years were cross-sectionally analysed.Increased PAI-1(act, BMI, HbA1c, triglycerides, the metabolic syndrome, fibrinogen concentration, CRP, female sex and positive HIV status were associated with increased CLTs, while habitual alcohol consumption associated with decreased CLT. No differences in CLT were found between age and smoking categories, contraceptive use or hyper- and normotensive participants. Urban women had longer CLT than rural women while no differences were observed for men.CLT was associated with many known CVD risk factors in black Africans. Differences were however observed, compared to data from populations of European descent available in the literature, suggesting possible ethnic differences. The effect of urbanisation on CLT is influenced by traditional CVD risk factors and their prevalence in urban and rural communities.

Plasma clot lysis time and its association with cardiovascular risk factors in black Africans.

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de Lange, Zelda; Pieters, Marlien; Jerling, Johann C; Kruger, Annamarie; Rijken, Dingeman C

2012-01-01

Studies in populations of European descent show longer plasma clot lysis times (CLT) in patients with cardiovascular disease (CVD) than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid urbanisation with increased CVD prevalence. We investigated associations between known CVD risk factors and CLT in black Africans and whether CLTs differ between rural and urban participants in light of differences in CVD risk.Data from 1000 rural and 1000 urban apparently healthy black South Africans (35-60 years) were cross-sectionally analysed.Increased PAI-1(act), BMI, HbA1c, triglycerides, the metabolic syndrome, fibrinogen concentration, CRP, female sex and positive HIV status were associated with increased CLTs, while habitual alcohol consumption associated with decreased CLT. No differences in CLT were found between age and smoking categories, contraceptive use or hyper- and normotensive participants. Urban women had longer CLT than rural women while no differences were observed for men.CLT was associated with many known CVD risk factors in black Africans. Differences were however observed, compared to data from populations of European descent available in the literature, suggesting possible ethnic differences. The effect of urbanisation on CLT is influenced by traditional CVD risk factors and their prevalence in urban and rural communities.

Cognitive Load Imposed by Ultrasound-Facilitated Teaching Does Not Adversely Affect Gross Anatomy Learning Outcomes

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Jamniczky, Heather A.; Cotton, Darrel; Paget, Michael; Ramji, Qahir; Lenz, Ryan; McLaughlin, Kevin; Coderre, Sylvain; Ma, Irene W. Y.

2017-01-01

Ultrasonography is increasingly used in medical education, but its impact on learning outcomes is unclear. Adding ultrasound may facilitate learning, but may also potentially overwhelm novice learners. Based upon the framework of cognitive load theory, this study seeks to evaluate the relationship between cognitive load associated with using…

Application of Hierarchy Theory to Cross-Scale Hydrologic Modeling of Nutrient Loads

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We describe a model called Regional Hydrologic Modeling for Environmental Evaluation 16 (RHyME2) for quantifying annual nutrient loads in stream networks and watersheds. RHyME2 is 17 a cross-scale statistical and process-based water-quality model. The model ...

Non-Linear Wave Loads and Ship responses by a time-domain Strip Theory

DEFF Research Database (Denmark)

Xia, Jinzhu; Wang, Zhaohui; Jensen, Jørgen Juncher

1998-01-01

. Based on this time-domain strip theory, an efficient non-linear hyroelastic method of wave- and slamming-induced vertical motions and structural responses of ships is developed, where the structure is represented by the Timoshenko beam theory. Numerical calculations are presented for the S175...

Plasma fibrin clot properties in the G20210A prothrombin mutation carriers following venous thromboembolism: the effect of rivaroxaban.

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Janion-Sadowska, Agnieszka; Natorska, Joanna; Siudut, Jakub; Ząbczyk, Michal; Stanisz, Andrzej; Undas, Anetta

2017-08-30

We sought to investigate whether the G20210A prothrombin mutation modifies plasma fibrin clot properties in patients after venous thromboembolism (VTE) and how rivaroxaban treatment affects these alterations. We studied 34 prothrombin mutation heterozygous carriers and sex- and age-matched 34 non-carriers, all at least three months since the first VTE episode, before and during treatment with rivaroxaban. Clot permeability (K s ) and clot lysis time (CLT) with or without elimination of thrombin activatable fibrinolysis inhibitor (TAFI) were assessed at baseline, 2-6 hours (h) after and 20-25 h after intake of rivaroxaban (20 mg/day). At baseline, the prothrombin mutation group formed denser clots (K s -12 %, p=0.0006) and had impaired fibrinolysis (CLT +14 %, p=0.004, and CLT-TAFI +13 %, p=0.03) compared with the no mutation group and were similar to those observed in 15 healthy unrelated prothrombin mutation carriers. The G20210A prothrombin mutation was the independent predictor for K s and CLT before rivaroxaban intake. At 2-6 h after rivaroxaban intake, clot properties improved in both G20210A carriers and non-carriers (K s +38 %, and +37 %, CLT -25 % and -25 %, CLT-TAFI -20 % and -24 %, respectively, all pCLT +17 %, CLT-TAFI +13 %, all p<0.001). Rivaroxaban concentration correlated with fibrin clot properties. After 20-25 h since rivaroxaban intake most clot properties returned to baseline. Rivaroxaban-related differences in clot structure were confirmed by scanning electron microscopy images. In conclusion, rivaroxaban treatment, though improves fibrin clot properties, cannot abolish more prothrombotic fibrin clot phenotype observed in prothrombin mutation carriers following VTE.

Perceptual load manipulation reveals sensitivity of the face-selective N170 to attention.

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Mohamed, Tarik N; Neumann, Markus F; Schweinberger, Stefan R

2009-05-27

It has been controversial whether the face-sensitive N170 is affected by selective attention. We manipulated attention sensu Lavie's perceptual load theory to short (200 ms) presentations of task-irrelevant unfamiliar faces or houses, while participants identified superimposed target letters 'X' versus 'N'. These targets were strings of either six identical (low load) or six different letters (high load). Under low load, we found a prominent face-selective N170 response. Under high load, however, we not only observed a dramatic reduction of the face N170 but also an unexpected enhancement of the house N170, such that face selectivity was almost completely lost. We conclude that the early stages of face processing indexed by the N170 strongly depend on selective attention.

Reconceptualizing perceptual load as a rate problem: The role of time in the allocation of selective attention.

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Li, Zhi; Xin, Keyun; Li, Wei; Li, Yanzhe

2018-04-30

In the literature about allocation of selective attention, a widely studied question is when will attention be allocated to information that is clearly irrelevant to the task at hand. The present study, by using convergent evidence, demonstrated that there is a trade-off between quantity of information present in a display and the time allowed to process it. Specifically, whether or not there is interference from irrelevant distractors depends not only on the amount of information present, but also on the amount of time allowed to process that information. When processing time is calibrated to the amount of information present, irrelevant distractors can be selectively ignored successfully. These results suggest that the perceptual load in the load theory of selective attention (i.e., Lavie, 2005) should be thought about as a dynamic rate problem rather than a static capacity limitation. The authors thus propose that rather than conceiving of perceptual load as a quantity of information, they should consider it as a quantity of information per unit of time. In other words, it is the relationship between the quantity of information in the task and the time for processing the information that determines the allocation of selective attention. Thus, the present findings extended load theory, allowing it to explain findings that were previously considered as counter evidence of load theory. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Enhancement and suppression in the visual field under perceptual load.

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Parks, Nathan A; Beck, Diane M; Kramer, Arthur F

2013-01-01

The perceptual load theory of attention proposes that the degree to which visual distractors are processed is a function of the attentional demands of a task-greater demands increase filtering of irrelevant distractors. The spatial configuration of such filtering is unknown. Here, we used steady-state visual evoked potentials (SSVEPs) in conjunction with time-domain event-related potentials (ERPs) to investigate the distribution of load-induced distractor suppression and task-relevant enhancement in the visual field. Electroencephalogram (EEG) was recorded while subjects performed a foveal go/no-go task that varied in perceptual load. Load-dependent distractor suppression was assessed by presenting a contrast reversing ring at one of three eccentricities (2, 6, or 11°) during performance of the go/no-go task. Rings contrast reversed at 8.3 Hz, allowing load-dependent changes in distractor processing to be tracked in the frequency-domain. ERPs were calculated to the onset of stimuli in the load task to examine load-dependent modulation of task-relevant processing. Results showed that the amplitude of the distractor SSVEP (8.3 Hz) was attenuated under high perceptual load (relative to low load) at the most proximal (2°) eccentricity but not at more eccentric locations (6 or 11°). Task-relevant ERPs revealed a significant increase in N1 amplitude under high load. These results are consistent with a center-surround configuration of load-induced enhancement and suppression in the visual field.

Enhancement and Suppression in the Visual Field under Perceptual Load

Directory of Open Access Journals (Sweden)

Nathan A Parks

2013-05-01

Full Text Available The perceptual load theory of attention proposes that the degree to which visual distractors are processed is a function of the attentional demands of a task – greater demands increase filtering of irrelevant distractors. The spatial configuration of such filtering is unknown. Here, we used steady-state visual evoked potentials (SSVEPs in conjunction with time-domain event-related potentials (ERPs to investigate the distribution of load-induced distractor suppression and task-relevant enhancement in the visual field. Electroencephalogram (EEG was recorded while subjects performed a foveal go/no-go task that varied in perceptual load. Load-dependent distractor suppression was assessed by presenting a contrast reversing ring at one of three eccentricities (2°, 6°, or 11° during performance of the go/no-go task. Rings contrast reversed at 8.3 Hz, allowing load-dependent changes in distractor processing to be tracked in the frequency-domain. ERPs were calculated to the onset of stimuli in the load task to examine load-dependent modulation of task-relevant processing. Results showed that the amplitude of the distractor SSVEP (8.3Hz was attenuated under high perceptual load (relative to low load at the most proximal (2° eccentricity but not at more eccentric locations (6˚ or 11˚. Task-relevant ERPs revealed a significant increase in N1 amplitude under high load. These results are consistent with a center-surround configuration of load-induced enhancement and suppression in the visual field.

Dissociable Roles of Different Types of Working Memory Load in Visual Detection

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Konstantinou, Nikos; Lavie, Nilli

2013-01-01

We contrasted the effects of different types of working memory (WM) load on detection. Considering the sensory-recruitment hypothesis of visual short-term memory (VSTM) within load theory (e.g., Lavie, 2010) led us to predict that VSTM load would reduce visual-representation capacity, thus leading to reduced detection sensitivity during maintenance, whereas load on WM cognitive control processes would reduce priority-based control, thus leading to enhanced detection sensitivity for a low-priority stimulus. During the retention interval of a WM task, participants performed a visual-search task while also asked to detect a masked stimulus in the periphery. Loading WM cognitive control processes (with the demand to maintain a random digit order [vs. fixed in conditions of low load]) led to enhanced detection sensitivity. In contrast, loading VSTM (with the demand to maintain the color and positions of six squares [vs. one in conditions of low load]) reduced detection sensitivity, an effect comparable with that found for manipulating perceptual load in the search task. The results confirmed our predictions and established a new functional dissociation between the roles of different types of WM load in the fundamental visual perception process of detection. PMID:23713796

Theory of multiwave mixing within the superconducting kinetic-inductance traveling-wave amplifier

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Erickson, R. P.; Pappas, D. P.

2017-03-01

We present a theory of parametric mixing within the coplanar waveguide (CPW) of a superconducting nonlinear kinetic-inductance traveling-wave (KIT) amplifier engineered with periodic dispersion loadings. This is done by first developing a metamaterial band theory of the dispersion-engineered KIT using a Floquet-Bloch construction and then applying it to the description of mixing of the nonlinear RF traveling waves. Our theory allows us to calculate signal gain versus signal frequency in the presence of a frequency stop gap, based solely on loading design. We present results for both three-wave mixing (3WM), with applied dc bias, and four-wave mixing (4WM), without dc. Our theory predicts an intrinsic and deterministic origin to undulations of 4WM signal gain with signal frequency, apart from extrinsic sources, such as impedance mismatch, and shows that such undulations are absent from 3WM signal gain achievable with dc. Our theory is extensible to amplifiers based on Josephson junctions in a lumped LC-ladder transmission line (TWPA).

Modeling of concrete exposed to severe loading conditions - impact and fire

International Nuclear Information System (INIS)

Ozbolt, J.; Periskic, G.; Bosnjak, J.; Reinhardt, H.W.; Sharma, A.; Travas, V.

2011-01-01

It is well known that the behavior of concrete structures is strongly influenced by loading rate. Compared to quasi-static loading, concrete loaded by impact loading acts in different ways. First, there is a strain-rate influence on strength, stiffness, and ductility, and second, there are inertia forces activated. Both influences are clearly demonstrated in experiments. Moreover, for concrete structures, which exhibit damage and fracture phenomena, the failure mode and cracking pattern depend on loading rate. In general, there is a tendency that with the increase of loading rate the failure mode changes from mode-I to mixed mode. Furthermore, theoretical and experimental investigations indicate that after the crack reaches critical speed of propagation there is crack branching. First part of the present paper focuses on 3D finite-element studies of concrete structures of different kind exposed to impact loading. In the numerical studies the rate sensitive microplane model is used as a constitutive law. The strain-rate influence is captured by the activation energy theory. Inertia forces are implicitly accounted for through dynamic finite element analysis. The results of the study show that the failure mode and structural resistance strongly depend on the loading rate

Complex Mobile Learning That Adapts to Learners' Cognitive Load

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Deegan, Robin

2015-01-01

Mobile learning is cognitively demanding and frequently the ubiquitous nature of mobile computing means that mobile devices are used in cognitively demanding environments. This paper examines the use of mobile devices from a Learning, Usability and Cognitive Load Theory perspective. It suggests scenarios where these fields interact and presents an…

Individual differences at high perceptual load: the relation between trait anxiety and selective attention.

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Sadeh, Naomi; Bredemeier, Keith

2011-06-01

Attentional control theory (Eysenck et al., 2007) posits that taxing attentional resources impairs performance efficiency in anxious individuals. This theory, however, does not explicitly address if or how the relation between anxiety and attentional control depends upon the perceptual demands of the task at hand. Consequently, the present study examined the relation between trait anxiety and task performance using a perceptual load task (Maylor & Lavie, 1998). Sixty-eight male college students completed a visual search task that indexed processing of irrelevant distractors systematically across four levels of perceptual load. Results indicated that anxiety was related to difficulty suppressing the behavioural effects of irrelevant distractors (i.e., decreased reaction time efficiency) under high, but not low, perceptual loads. In contrast, anxiety was not associated with error rates on the task. These findings are consistent with the prediction that anxiety is associated with impairments in performance efficiency under conditions that tax attentional resources.

A Dual Coding Model of Processing Chinese as a Second Language: A Cognitive-Load Approach

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Sham, Diana Po Lan

2002-01-01

The research was conducted in Sydney and Hong Kong using students, from grades 5 to 9, whose first language or teaching medium was English, learning to read Chinese as second language. According to cognitive load theory, the processing of single Chinese characters accompanied by pictures should impose extraneous cognitive load and thus hinders…

Efektifitas Load Balancing Dalam Mengurangi Kemacetan Lalu Lintas

Directory of Open Access Journals (Sweden)

Erwin Harahap

2017-12-01

Full Text Available Abstrak. Kemacetan jalan raya merupakan permasalahan umum di setiap kota yang memerlukan penanganan serius. Pemecahan permasalahan kemacetan jalan raya tidak hanya dapat diselesaikan dengan hanya meningkatkan kualitas dan kuantitas infrastruktur, namun juga manajemen lalu lintas. Pada artikel diusulkan suatu metode untuk mengurangi kemacetan lalu lintas, yaitu dengan menyeimbangkan beban ke berbagai ruas jalan yang disebut dengan load balancing. Melalui metode ini diharapkan beban lalu lintas terbagi secara merata ke berbagai jalur alternatif sedemikian sehingga antrian panjang kendaraan dapat dihindari. Evaluasi efektifitas dari metode load balancing ini dilakukan melalui simulasi dengan mengimplementasikan salah satu bidang ilmu Matematika, yaitu teori Antrian. Simulasi dibuat dengan menggunakan toolbox SimEvents yang dijalankan pada software MATLAB. Kata Kunci: load balancing, kemacetan, lalu lintas, sim-events, matlab Abstract. (the effectiveness of load balancing in reducing the road traffic congestion Road congestion is a common problem in any city that needs serious handling. The solution of the road congestion problems can not only be solved by simply improving the quality and quantity of infrastructure, but also the traffic management. In this article, we proposed a method to reduce the traffic congestion by balancing the vehicle loads to a various road segments, called as load balancing. Through this method, it is expected that the traffic load is evenly distributed to various alternative routes, such that, long queues and traffic jam can be avoided. Evaluation of the load balancing’s effectiveness is performed through a simulation by implementing the Queueing Theory. Simulations are created using the SimEvents toolbox that runs on MATLAB software. Keywords: load balancing, road congestion, traffic, simevents, matlab.

Beam loading in high-energy storage rings

International Nuclear Information System (INIS)

Wilson, P.B.

1974-06-01

The analysis of beam loading in the RF systems of high-energy storage rings (for example, the PEP e/sup /minus//e/sup +/ ring) is complicated by the fact that the time, T/sub b/, between the passage of successive bunches is comparable to the cavity filling time, T/sub b/. In this paper, beam loading expressions are first summarized for the usual case in which T/sub b/ /much lt/ T/sub f/. The theory of phase oscillations in the heavily-beam-loaded case is considered, and the dependence of the synchrotron frequency and damping constant for the oscillations on beam current and cavity tuning is calculated. Expressions for beam loading are then derived which are valid for any value of the ratio T/sub b//T/sub f/. It is shown that, for the proposed PEP e/sup /minus//e/sup +/ ring parameters, the klystron power required is increased by about 3% over that calculated using the standard beam loading expressions. Finally, the analysis is extended to take into account the additional losses associated with the excitation of higher-order cavity modes. A rough numerical estimate is made of the loss enhancement to be expected for PEP RF system. It is concluded that this loss enhancement might be substantial unless appropriate measures are taken in the design and tuning of the accelerating structure

Chronic lymphocytic thyroiditis: could it be influenced by a petrochemical complex? Data from a cytological study in South-Eastern Sicily.

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Arena, Salvatore; Latina, Adele; Baratta, Roberto; Burgio, Giuseppe; Gullo, Damiano; Benvenga, Salvatore

2015-04-01

In genetically predisposed individuals, exogenous factors (including pollution) influence the development of Hashimoto's thyroiditis/chronic lymphocytic thyroiditis (CLT). CLT may also be a risk factor for associated thyroid cancer. Few data are available on the role of pollution from petrochemical complexes, one of which is located in the Siracusa province (South-Eastern Sicily), in the pathogenesis of CLT. i) To study the frequency of CLT in fine-needle aspiration cytology (FNAC)-interrogated thyroid nodules from patients who were stably resident in their zones, comparing it in patients living in the petrochemical complex area (zone A) with that of patients from a control area (zone B). ii) To study the frequency of CLT in the FNAC categories of malignancy risk, comparing the two zones. We retrospectively evaluated cytologically adequate slides of 1323 nodules in 1013 outpatients who underwent ultrasound-guided FNAC from 2006 to 2012. We stratified by area of residence, gender, and FNAC categories of malignancy risk. CLT was detected with significantly greater frequency in either patients or nodules from zone A compared with zone B (32.0% vs 23.1%, P=0.002 or 28.2% vs 18.8%, P=0.0001), with a female preponderance (F=35.2% vs M=21.1% or 30.4% vs 20.4%, zone A and F=26.5% vs 12.3% or 21.6% vs 9.5%, zone B). Regardless of zone, CLT was approximately twofold more frequent in the suspiciously malignant+malignant classes (TH4+THY5=47.6%, zone A and 32.4%, zone B) compared with the benign+intermediate classes (THY2+THY3=27.3%, zone A and 18.2%, zone B), but with a clear stepwise THY2 through THY5 increase only in zone A (THY2=25.3%, THY5=66.7%; THY2=18.6%, THY5=28.6% in zone B). The petrochemical complex-related pollution is an environmental factor involved in the development of CLT and, likely, in the CLT association with thyroid neoplasms. © 2015 European Society of Endocrinology.

Diagnosis of Esophageal Motility Disorders: Esophageal Pressure Topography vs. Conventional Line Tracing.

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Carlson, Dustin A; Ravi, Karthik; Kahrilas, Peter J; Gyawali, C Prakash; Bredenoord, Arjan J; Castell, Donald O; Spechler, Stuart J; Halland, Magnus; Kanuri, Navya; Katzka, David A; Leggett, Cadman L; Roman, Sabine; Saenz, Jose B; Sayuk, Gregory S; Wong, Alan C; Yadlapati, Rena; Ciolino, Jody D; Fox, Mark R; Pandolfino, John E

2015-07-01

Enhanced characterization of esophageal peristaltic and sphincter function provided by esophageal pressure topography (EPT) offers a potential diagnostic advantage over conventional line tracings (CLT). However, high-resolution manometry (HRM) and EPT require increased equipment costs over conventional systems and evidence demonstrating a significant diagnostic advantage of EPT over CLT is limited. Our aim was to investigate whether the inter-rater agreement and/or accuracy of esophageal motility diagnosis differed between EPT and CLT. Forty previously completed patient HRM studies were selected for analysis using a customized software program developed to perform blinded independent interpretation in either EPT or CLT (six pressure sensors) format. Six experienced gastroenterologists with a clinical focus in esophageal disease (attendings) and six gastroenterology trainees with minimal manometry experience (fellows) from three academic centers interpreted each of the 40 studies using both EPT and CLT formats. Rater diagnoses were assessed for inter-rater agreement and diagnostic accuracy, both for exact diagnosis and for correct identification of a major esophageal motility disorder. The total group agreement was moderate (κ=0.57; 95% CI: 0.56-0.59) for EPT and fair (κ=0.32; 0.30-0.33) for CLT. Inter-rater agreement between attendings was good (κ=0.68; 0.65-0.71) for EPT and moderate (κ=0.46; 0.43-0.50) for CLT. Inter-rater agreement between fellows was moderate (κ=0.48; 0.45-0.50) for EPT and poor to fair (κ=0.20; 0.17-0.24) for CLT. Among all raters, the odds of an incorrect exact esophageal motility diagnosis were 3.3 times higher with CLT assessment than with EPT (OR: 3.3; 95% CI: 2.4-4.5; PCLT than with EPT (OR: 3.4; 2.4-5.0; PCLT among our selected raters. On the basis of these findings, EPT may be the preferred assessment modality of esophageal motility.

The effect of carbon distribution on deformation and cracking of Ni-16Cr-9Fe-C alloys

International Nuclear Information System (INIS)

Hertzberg, J.L.; Was, G.S.

1995-01-01

Constant extension rate tensile (CERT) tests and constant load tensile (CLT) tests were conducted on controlled purity Ni-16Cr-9Fe-C alloys. The amount and form of carbon were varied in order to investigate the roles of carbon in solution and as intergranular (IG) carbides in the deformation and IG cracking behavior in 360 C argon and primary water environments. Results show that the strength, ductility and creep resistance of these alloys are increased with carbon present in solid solution, while IG cracking on the fracture surface is suppressed. Alloys containing carbon in the form of IG carbides, however, exhibit reduced strength and ductility relative to carbon in solution, while maintaining high IG cracking resistance with respect to carbon-free alloys. CERT results of commercial alloy 600 and controlled purity, carbon containing alloys yield comparable failure strains and IG cracking amounts. CLT comparisons with creep tests of alloy 600 suggest that alloys containing IG carbides are more susceptible to creep than those containing all carbon in solid solution

An automated optimization of core fuel loading pattern for pressurized water reactors

International Nuclear Information System (INIS)

Chen Renji

1988-11-01

An optimum method was adopted to search for an optimum fuel loading pattern in pressurized water reactors. A radial power peak factor was chosen as the objective function of the optimum loading. The direct search method with shuffling rules is used to find optimum solution. The search for an optimum loading pattern with the smallest radial power peak by exchanging fuel assemblies was made. The search process is divided into two steps. In the first step fresh fuels or high reactivity fuels are arranged which are placed in core interior to have a reasonable fuel loading pattern. To further reduce the radial power peak factor, the second step will be necessary to rearrange the exposed lower reactivity fuel around the assemblies which has the radial power peak. In optimum process 1.5 group coarse mesh diffusion theory or two group nodal Green function diffusion theory is utilized to calculate the two dimensional power distribution after each shuffle. Also, above two methods are combinatively utilized to calculate the state quantity. It is not only true to save CPU time, but also can obtian exact results. Besides above function, the code MSOFEL is used to search critical boron concentration and to predict burn-up. The code has been written with FORTRAN-4. The optimum loading pattern was chosen for OCONEE and QINSHAN nuclear power plants as reference examples. The validity and feasibility of MSOFEL was demonstrated