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Sample records for high communication apprehensives

  1. Loneliness and Communication Apprehension.

    Science.gov (United States)

    Spitzberg, Brian H.

    Calling upon attribution theory, a study was conducted to determine whether chronically lonely individuals would manifest significantly more communication apprehension (CA) than would situationally lonely individuals. The UCLA loneliness scale (LS) and the Personal Report of Communication Apprehension (PRCA) were administered to 170 college…

  2. An Online Alternative to Alleviate Communication Apprehension

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    Seyit Ahmet Çapan

    2013-05-01

    Full Text Available Anxiety is an affective factor commonly associated with one’s overall performance in a foreign language. As a component of foreign language anxiety, communication apprehension specifically correlates with successful oral production. A plethora of research (Bailey, Onwuegbuzie & Daley, 2003; Foss & Reitzel, 1988 has indicated that high levels of communication apprehension negatively affects one’s L2 communication abilities. Thus, this study intends to remedy negative effects of communication apprehension on EFL learners by virtual meetings held through computer-mediated communication. The participants (N: 18 in this study were selected through purposive sampling. The study employed both quantitative and qualitative techniques. To analyze the data collected, a non-parametric test, Wilcoxon Signed Rank Test, was utilized. The results indicated that computer-mediated communication via voice over IP tools made a significant contribution to alleviate communication apprehension levels in the participants with varying degrees of apprehension levels. The study yielded the most drastic reduction in the high apprehension group, since the participants in this group made a significant progress and ended up with moderate levels of communication apprehension. Also, the participants’ self-reports revealed that computer-mediated communication yielded remarkably positive changes in their attitudes towards communicating in the target language. Moreover, the study revealed that computer-mediated communication helped to increase their intercultural awareness. Finally, participants provided a bunch of practical suggestions as possible solutions for reducing communication apprehension. Keywords: apprehension, communication, computer-mediated, attitudes

  3. COPE Method Implementation Program to Reduce Communication Apprehension Level in Full Day Yunior High School Students

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    Prasetyo, A. R.

    2017-02-01

    This study was aimed to explore the effect of COPE method to reduce communication apprehension level of students in Early Adolescence who become Full Day Junior High School students. Full Day Junior High School students, especially in Surabaya coastal area, have more demands to develop the communication aspects such as group discussions and presentations and extracurricular activities. Higher demands to develop such aspects of communication may cause them to experience communication apprehension. The subject was Full Day School students totaling 31 students. The design of the research was experimental design. The experimental method used was a non-randomized pretest posttest control group design and purposive sampling was also used. COPE method is a process that consists of four main stages where people are trying to deal with and control of stressful situations as a result of the problem being faced by conducting cognitive and behavioral changes. Four main stages COPE method is Calming the nervous system, Originating an imaginative plan, Persisting in the face of obstacles and failure, and Evaluating and adjusting the plan. Results of quantitative analysis based on U-Mann Whitney Test shows significant effect on the COPE Method to decrease anxiety levels of communication (0.000 <0.005).

  4. High Oral Communication Apprehensives: How Can Students be Helped to Reduce Their Fear of Public Speaking?

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    Dan Shanahan

    2015-05-01

    Full Text Available The literature has identified oral communication as a skill that employers desire of their workforce. Even though accounting and business education programmes place considerable emphasis on the advancement of communication competencies among students, not all students appear to benefit from communication skills development. This may arise from of a fear of communicating with others, commonly known as oral communication apprehension, a factor which inhibits an individual’s willingness to communicate in one or a number of contexts - one to one conversations, communicating in groups, at meetings and making a presentation in public – and which may inhibit development of effective communication skills. Prior studies have measured oral communication apprehension of students in different disciplines, and there has been some qualitative exploration of the phenomenon. This paper reports on study conducted in the School of Accounting and Finance, DIT. Levels of apprehension were measured for 368 students. The views of a number of students were received and analysed and compared to their oral communication apprehension scores. Some students who indicated that they found presenting extremely difficult were identified, and their views are reported. Their perspectives and fears demonstrate ‘the pain’ that many suffer when called on to present. The study concludes with a recommendation on a possible oral communications approach which could be adopted to help students to overcome fear of presenting in public

  5. A Qualitative Exploration of Oral Communication Apprehension

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    Byrne, Marann; Flood, Barbara; Shanahan, Dan

    2012-01-01

    Prior research has identified communication apprehension (CA), or fear of communicating, as a major factor which inhibits an individual's willingness to communicate and his/her capability to develop effective communication skills. While many prior studies have measured oral communication apprehension of students, there has been little qualitative…

  6. A Qualitative Exploration of Oral Communication Apprehension

    Science.gov (United States)

    Byrne, Marann; Flood, Barbara; Shanahan, Dan

    2012-01-01

    Prior research has identified communication apprehension (CA), or fear of communicating, as a major factor which inhibits an individual's willingness to communicate and his/her capability to develop effective communication skills. While many prior studies have measured oral communication apprehension of students, there has been little qualitative…

  7. Communication Apprehension among Nilai College Students

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    Uryani Sabri

    2014-10-01

    Full Text Available In recent years, ESL studies have found that most graduates are critically lacking in speaking skills, especially among Malaysia graduates. With constant struggle to communicate in English which is their second language, they become apprehensive when the need to use the language arises. The purpose of this study is to investigate communication apprehension among students from Nilai University College and whether the communication apprehension would differ among students from different semester. The respondents for the study were two classes from two different semesters with 30 students each. In this study, the PRCA-24 was used to collect data. By conducting this study, it is hoped to provide valuable insights on students’ communication apprehension.

  8. What You Feel Is What You Might Get: Exploring Communication Apprehension and Sexual Communication Satisfaction.

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    Wheeless, Lawrence R.; Parsons, Lonnie A.

    1995-01-01

    Finds a combination of interpersonal communication apprehension and receiver apprehension to be negatively correlated with sexual communication satisfaction in sexually intimate relationships, and that the combination of interpersonal communication apprehension and receiver apprehension was more strongly associated with sexual communication…

  9. Communication Apprehension among Nilai College Students

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    Sabri, Uryani; Qin, Teah Yu

    2014-01-01

    In recent years, ESL studies have found that most graduates are critically lacking in speaking skills, especially among Malaysia graduates. With constant struggle to communicate in English which is their second language, they become apprehensive when the need to use the language arises. The purpose of this study is to investigate communication…

  10. Correlates between Communication Apprehension and Listening Style Preferences.

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    Sargent, Stephanie Lee; Weaver, James B.; Kiewitz, Christian

    1997-01-01

    Asks how apprehensions about communicating with others intertwine with self-perceptions about listening. Examines correlations between communication apprehension in four settings and four listening styles. Reveals that the listening style of people with few apprehensions prefers receiving complex information that can be evaluated before…

  11. Exploring Agricultural Communications Students' Perceptions of Communication Apprehension and Writing Apprehension in the Classroom

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    Ahrens, Chelsey Ann; Meyers, Courtney; Irlbeck, Erica; Burris, Scott; Roach, David

    2016-01-01

    Employers have identified oral and written communications skills to be the most important skills graduates should possess when entering the workforce. In order for faculty to better understand their students' oral and written communications skills, they should understand what apprehension the students have toward oral and written communications.…

  12. Gender-dependent language anxiety in Polish communication apprehensives

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    Ewa Piechurska-Kuciel

    2012-01-01

    This paper analyzes the relationship between communication apprehension and language anxiety from the perspective of gender. As virtually no empirical studies have addressed the explicit influence of gender on language anxiety in communication apprehensives, this paper proposes that females are generally more sensitive to anxiety, as reflected in various spheres of communication. For this reason, language anxiety levels in communication apprehensive females should be higher, unlike those of c...

  13. Gender-dependent language anxiety in Polish communication apprehensives

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    Ewa Piechurska-Kuciel

    2012-10-01

    Full Text Available This paper analyzes the relationship between communication apprehension and language anxiety from the perspective of gender. As virtually no empirical studies have addressed the explicit influence of gender on language anxiety in communication apprehensives, this paper proposes that females are generally more sensitive to anxiety, as reflected in various spheres of communication. For this reason, language anxiety levels in communication apprehensive females should be higher, unlike those of communication apprehensive males. Comparisons between them were made using a student t test, two-way ANOVA, and post-hoc Tukey test. The results revealed that Polish communication apprehensive secondary grammar school males and females do not differ in their levels of language anxiety, although nonapprehensive males experience significantly lower language anxiety than their female peers. It is argued that the finding can be attributed to developmental patterns, gender socialization processes, classroom practices, and the uniqueness of the FL learning process, which is a stereotypically female domain.

  14. Rethinking communication apprehension: a Myers-Briggs perspective.

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    Opt, S K; Loffredo, D A

    2000-09-01

    This study is an examination of relationships between Myers-Briggs personality type preferences, based on Jungian theory, and communication apprehension. Results showed that participants who preferred introversion or sensing reported significantly higher levels of communication apprehension in general and across the group, dyadic, meeting, and public contexts than did participants who preferred extraversion or intuition. In addition, participants who preferred feeling reported higher levels of communication anxiety in the public context than those who preferred thinking. Findings support the assumption that communication apprehension is biologically based, suggest that the Myers-Briggs type preference framework offers an alternative way of understanding communication apprehension, and point out the need for new approaches to understanding the phenomenon of communication apprehension.

  15. The Confidence Model: An Alternative Approach to Alleviating Communication Apprehension.

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    Watson, Arden K.

    Recognizing that each student is different in terms of communication apprehension and needed skills, the confidence model attempts to provide instruction in anxiety reduction and skill development, combining the features of both the behavior therapy and the rhetoritherapy theories of communication apprehension. The rational emotive therapy used in…

  16. THE TYPES OF COMMUNICATION STRATEGIES USED BY SPEAKING CLASS STUDENTS WITH DIFFERENT COMMUNICATION APPREHENSION LEVELS IN ENGLISH DEPARTMENT OF PETRA CHRISTIAN UNIVERSITY, SURABAYA

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    Agatha Sylvia

    2004-01-01

    Full Text Available This article reports on a study that aims to find out the types of Communication Strategies used and mostly used by students with high and low levels of Communication Apprehension and whether students with high level of Communication Apprehension used more numbers of Communication Strategies. The subjects in a created classroom were asked to retell a pictorial story and a pictorial instruction. The results showed that students with high Communication Apprehension level used more numbers of Communication Strategies.

  17. The Relationship of Communication Apprehension to Communication Behavior: A Meta-Analysis.

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    Allen, Mike; Bourhis, John

    Communication apprehension (CA) refers to a family of related terms: (a) reticence, (b) shyness, (c) unwillingness to communicate; and (d) stage fright. One pervasive but not totally substantiated assumption in current literature is the relationship between the level of communication apprehension and the level of communication skill demonstrated…

  18. The Prediction of Long-Term Changes in Communication Apprehension in the Communication Classroom.

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    Daly, John A.; Friedrich, Gustav W.

    Previous research on communication apprehension has revealed a reduction in student apprehension over a semester-length course in speech communication. Further research indicates, however, that, while most students do experience a reduction, a sizable percentage actually report an increase. This study sought to determine the difference between…

  19. Sex differences in intercultural communication apprehension, ethnocentrism, and intercultural willingness to communicate.

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    Lin, Yang; Rancer, Andrew S

    2003-02-01

    Communication predispositions influence interactions between individuals from different cultures. Three such predispositions have been found to affect behavior in intercultural contexts: Apprehension about intercultural communication, ethnocentrism, and intercultural willingness to communicate. This study examined differences between men (n = 130) and women (n = 175) on those three predispositions. The analysis showed that men reported experiencing higher apprehension about intercultural communication, being more ethnocentric than women, and being less willing to communicate interculturally than women. Implications of these findings are discussed.

  20. A study on relationship between organizational culture and communication apprehension

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    Aliakbar Farhangi

    2013-07-01

    Full Text Available This paper presents a study to investigate the relationship between organizational culture and communication apprehension among some employees who worked for Iran broadcasting channel. The study has adopted two well-known questionnaires developed by Hofstede (1984 [Hofstede, G. (1984. Culture's Consequences: International Differences in Work-Related Values (2nd ed.. Beverly Hills CA: SAGE Publications. ISBN 0-8039-1444-X] for organizational culture and McCroskey et al. (1985 [McCroskey, J. C., Beatty, M. J., Kearney, P., & Plax, T. G. (1985. The content validity of the PRCA‐24 as a measure of communication apprehension across communication contexts. Communication Quarterly, 33(3, 165-173.] for communication apprehension (CA. We have used Chi-Square test to verify different hypotheses of the survey and the results of the survey have indicated that while there was no relationship between CA and three components including cultures of masculinity, individualistic culture and ambiguity aversion, there was a significance relationship between CA and power distance. The results of our survey indicate that as the power distance increases we may expect a higher level on CA.

  1. Nice to Meet You? Inter/Intrapersonal Perceptions of Communication Apprehension in Initial Interactions.

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    Colby, Noelle; And Others

    1993-01-01

    Finds that self-efficacy shared a significant relationship with communication apprehension (CA) whereas self-worth did not; high CAs rated themselves lower on self-efficacy and self-worth but were viewed equal to low CAs; and high CAs were rated by interaction partners as less attractive, less trustworthy, and less satisfying to interact with than…

  2. Communication Apprehension Levels of Student Governance Leaders

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    Miller, Michael T.; Nadler, Daniel P.

    2009-01-01

    A major component of the college student experience is the engagement with out-of-class activities. This involvement has been linked to a variety of success indicators, including higher levels of academic achievement, high retention and matriculation, and overall collegiate satisfaction. One of the key areas for student engagement is college…

  3. Communication Apprehension. Focused Access to Selected Topics (FAST) Bibliography No. 15.

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    Shermis, Michael

    This annotated bibliography contains 31 references of articles and papers in the ERIC database that deal with communication apprehension (CA). The first section provides strategies for instructors and students to alleviate communication apprehension, speech anxiety, stage fright, and other problems people have with public speaking. The second…

  4. Prevalence and Levels of Communication Apprehension among Leaders and Employees of a Texas Community College

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    Degner, Rosemary K.

    2009-01-01

    The purpose of the quantitative correlational study was to explore the relationships between communication apprehension and the organizational structure of a Texas community college. The two survey instruments were the Personal Report of Communication Apprehension-24 and a demographic questionnaire. Participants self-reported feelings about…

  5. Social Desirability as a Predictor of Argumentativeness, Communication Apprehension, and Communication Competence.

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    Chen, Guo-Ming

    A study investigated the relationships between social desirability (the tendency to seek socially and culturally approved behaviors) and argumentativeness, communication apprehension, and communication competence. Using R. Strahan and K. C. Gerbasi's Social Desirability Scales, from a pool of 259 undergraduate students, 70 students were identified…

  6. The Impact of a Group Communication Course on Veterinary Medical Students' Perceptions of Communication Competence and Communication Apprehension.

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    Kedrowicz, April A

    2016-01-01

    This paper explores the impact of a group communication course on veterinary medical students' perceptions of communication competence and communication anxiety. Students enrolled in the Group Communication in Veterinary Medicine course completed the Personal Report of Communication Apprehension and the Communicative Competence Scale at the beginning (Time 1) and end (Time 2) of the semester. Results show that first-year veterinary students' self-perceptions of communication competence increased and their self-reported levels of communication apprehension decreased across multiple contexts from Time 1 to Time 2. This research provides support for experiential communication training fostering skill development and confidence.

  7. Relationship between Intermediate EFL Learners' Communication Apprehension, Willingness to Communicate, and Speaking Ability

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    Maryam Rahmatollahi

    2015-11-01

    Full Text Available Speaking is the first to be acquired in the process of language production. In parallel, the absence of communication apprehension and the presence of willingness to communicate are the essential prerequisites for stringing words together. The purpose of the current study, therefore, was to investigate the underlying patterns of the relationship between communication apprehension (CA, willingness to communicate (WTC, and speaking ability with regard to different contexts and receivers. In so doing, to assign the homogeneity of the sample, Nelson English Language Test was administered and 120 individuals were selected out of 253. Subsequently, Personal Report of Communication Apprehension (PRCA-24 and Willingness to Communicate Questionnaire were employed in order to determine language learners' levels of WTC and CA. Moreover, the researchers utilised the sample interview questions from Task 1 of the intermediate Speaking Test and the speaking scale provided by Farhady, Birjandi, and Ja'farpur (1994 to interview with individuals and determine their speaking ability. Then, the non-parametric data were analyzed using a Spearman's rank order rho correlation. The results illustrated that individuals' speaking ability was neither related to their level of CA nor to their WTC. Moreover, the findings showed that CA and WTC had a negative correlation. Consequently, CA can be considered as one of the predicators of WTC in academic contexts.

  8. Oral Communication Apprehension: an Exploration in Addressing Fear of Public Speaking

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    Shanahan, Dan

    2012-01-01

    Several research studies have identified oral communication as a skill employers desire of their workforce, and so, accounting and business education programmes place considerable emphasis on the development of communication competencies among students. However, not all students appear to benefit as desired from communication skills development. Prior research indicates this may arise from a fear of communicating, commonly known as oral communication apprehension, a factor which inhibits his/...

  9. Helping Communication Apprehensive Students as Part of the Developmental Speech Course.

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    Watson, Arden K.

    The developmental college student, distinguished by lower than average academic scores, may also experience the inhibiting fear of communication, speech anxiety. Students who are both developmental and communication apprehensive lack confidence in their personal academic abilities, and thus develop poor attitudes toward learning and low academic…

  10. The Effects of Nonverbal Involvement and Communication Apprehension on State Anxiety, Interpersonal Attraction, and Speech Duration.

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    Remland, Martin S.; Jones, Tricia S.

    1989-01-01

    Examines whether communication apprehension mediates the effect of nonverbal involvement cues (head nods, eye contact, body orientation, etc.) on state anxiety, interpersonal attraction, and speech duration in information gathering interviews. Finds that nonverbal cues affect loquacity and liking, but that a speaker's communication apprehension…

  11. Effects of Video Streaming Technology on Public Speaking Students' Communication Apprehension and Competence

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    Dupagne, Michel; Stacks, Don W.; Giroux, Valerie Manno

    2007-01-01

    This study examines whether video streaming can reduce trait and state communication apprehension, as well as improve communication competence, in public speaking classes. Video streaming technology has been touted as the next generation of video feedback for public speaking students because it is not limited by time or space and allows Internet…

  12. A Narrative Inquiry Exploring How College Communication Professors Engage Students with Public Speaking Apprehension

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    Riedel, Derek

    2012-01-01

    The purpose of this qualitative study was to discover how communication professors at four-year private universities help students who exhibit public speaking apprehension (PSA) learn to cope with their anxiety. The research was framed in the narrative inquiry paradigm, interviewing eight college communication professors about their experiences…

  13. Effects of Video Streaming Technology on Public Speaking Students' Communication Apprehension and Competence

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    Dupagne, Michel; Stacks, Don W.; Giroux, Valerie Manno

    2007-01-01

    This study examines whether video streaming can reduce trait and state communication apprehension, as well as improve communication competence, in public speaking classes. Video streaming technology has been touted as the next generation of video feedback for public speaking students because it is not limited by time or space and allows Internet…

  14. Assessing Undergraduate Business Students\\' Oral Communication Apprehension: Implications of Stakes and Situations

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    Matuszak, Steve C.

    2013-01-01

    Modern businesses place a premium on employees\\' oral communication skills.  Business schools are meant to develop future employees and leaders with the requisite skills for success.  Industry representatives, however, consistently express dissatisfaction with business graduates\\' oral communication skills.  There appears to remain a gap between business students\\' oral skills and marketplace demands. Research demonstrates that among many possible factors, oral communication apprehension (OCA...

  15. Butterflies in Formation: Predicting How Speech Order in College Public Speaking Affects Student Communication Apprehension

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    Osmond, Erica R.

    2013-01-01

    This study addressed pedagogical practices in the public speaking classroom in an attempt to help control communication apprehension (CA) levels and improve retention rates among college students in the basic public speaking course. Guided by the theoretical frameworks of Berger and Calabrese's uncertainty reduction theory and Weiner's attribution…

  16. Communication Apprehension and Resting Alpha Range Asymmetry in the Anterior Cortex

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    Beatty, Michael J.; Heisel, Alan D.; Lewis, Robert J.; Pence, Michelle E.; Reinhart, Amber; Tian, Yan

    2011-01-01

    In this study, we examined the relationship between trait-like communication apprehension (CA) and resting alpha range asymmetry in the anterior cortex (AC). Although theory and research in cognitive neuroscience suggest that asymmetry in the AC constitutes a relatively stable, inborn, substrate of emotion, some studies indicate that asymmetry can…

  17. Butterflies in Formation: Predicting How Speech Order in College Public Speaking Affects Student Communication Apprehension

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    Osmond, Erica R.

    2013-01-01

    This study addressed pedagogical practices in the public speaking classroom in an attempt to help control communication apprehension (CA) levels and improve retention rates among college students in the basic public speaking course. Guided by the theoretical frameworks of Berger and Calabrese's uncertainty reduction theory and Weiner's attribution…

  18. COMMUNICATION APPREHENSION AMONG PART ONE BUSINESS STUDENTS IN UNIVERSITI TEKNOLOGI MARA (UiTM KELANTAN

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    Wan Nuur Fazliza Wan Zakaria

    2015-01-01

    Full Text Available Students who face communicative anxiety have either fear or uneasiness about their learning experience. This kind of feelings has hindered and impeded the language learning process and their abilities to perform well in any oral presentation. This present study aims at exploring the factors that lead to communication apprehension among Part One Diploma students from Business and Management Faculty, Universiti Teknologi Mara (UiTM Kelantan, Malaysia from psychological and socio-cultural perspectives. The study which involved 51 ESL students is conducted through a survey method using a set of questionnaire. The data were analysed using the SPSS statistical computer package (Statistical Package for Social Science. The means and percentages of each item in the questionnaire were used to look at the factors which contribute to communicative anxiety among the learners. The study revealed that both psychological and sociocultural factors do affect English learners‟ communication apprehension.

  19. Communication Apprehension and Maths Anxiety as Barriers to Communication and Numeracy Skills Development in Accounting and Business Education

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    Joyce, John; Hassall, Trevor; Montano, Jose Luis Arquero; Anes, Jose Antonio Donoso

    2006-01-01

    Purpose: To establish the existence of barriers to communication and numeracy skills development and to establish the levels of these exhibited by accounting and business students at the commencement of their courses in higher education. Design/methodology/approach: Uses questionnaires to establish the levels of communication apprehension (CA) and…

  20. Applying innovation method to assess english speaking performance on communication apprehension

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    Wang, Li-Jyu

    2010-01-01

    Full Text Available A growing number of research studies are now available to shed some light on ELT methods. Currently, educational portfolios are implemented in Science, Mathematics and Geography and also have become widely used in ELT. When the students prepared their own portfolios, they self-monitored their performances. The purpose of this study was to investigate the effects of self-monitoring and portfolios on college students’ English speaking performance. The participants involved in this study were 60 college students majoring in the Department of Applied Foreign Languages at one university of technology in Taiwan. In the study, descriptive statistics and t-tests were used to test the effects of using communication apprehension. In the portfolio group, the students’ communication apprehension was lowered. In conducting this study, the researcher hoped that this research could provide valuable perspective on the use of portfolios and self-monitoring

  1. Methods for Dealing with Communication Apprehension in Higher Education Speech Instruction via Use of Small Group Modalities.

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    Crump, Charla A.; Dudley, Jack A.

    Noting that many university speech students suffer from communication apprehension (CA) and must face the fear and anxiety of performance in front of the class, a study examined the effectiveness of group discussion, interpersonal communication, public speaking, and small group activities and interactions in reducing CA. Subjects, 57 students,…

  2. A Comparative Analysis of the Relationship between Communication Apprehension and Loneliness for Elderly Nursing Home and Non-Nursing Home Residents.

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    Downs, Valerie C.; And Others

    1988-01-01

    Utilizes the socio-environmental perspective to compare feelings of communication apprehension and perceived loneliness between nursing home and non-nursing home residents. Finds that communication apprehension consistently and significantly predicts perceived loneliness for non-nursing home residents, but fails to predict perceived loneliness for…

  3. Iranian EFL Learners' Willingness to Communicate, Self-Perceived Communication Competence, and Communication Apprehension in L1 and L2: A Comparative Study

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    Ghazaleh Cheraghpour Samvati

    2017-07-01

    Full Text Available The present study investigated the relationships among willingness to communicate, communication apprehension, and self-perceived communication competence in Persian (L1 versus English (L2. A total number of 235 adult native Persian EFL learners were selected through convenience sampling to participate in the study. The population consisted of 118 intermediate learners and 113 upper-intermediate learners. The transferability and predictability of these communication variables across L1 and L2 was checked through correlational analyses and linear regression. The findings showed that among these variables communication apprehension was more of a trait-like predisposition which was transferred across first language and foreign language. WTC in Persian had little predictive effect on WTC in English; also, self-perceived communication competence in Persian predicted only 15% of SPCC in English. Implications of findings could provide teachers insight into the extent to which these communication variables are trait-like or situational.

  4. Virtual Reality Training in Aid of Communication Apprehension in Classroom Environments

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    Max M. North

    2008-06-01

    Full Text Available The major goal of this study was to observe theeffectiveness of Virtual Reality Training (VRT in assistingstudents who suffer from Communication Apprehension(CA. CA seems to be prevalent throughout a large portionof the human population. Apparently, this study has only afew precedents and can be considered a novel step intreatment of CA. Thirty undergraduate volunteer studentsenrolled at a university in Georgia participated in thisstudy. A virtual auditorium scene for CA training wascreated. Virtual Auditorium was a simulation of a 48 footwide, 100 foot long, and 55 foot high auditorium with threesections of chairs that accommodated over 100 spectators.The virtual auditorium program was designed to allow theaudience to enter the auditorium one at a time, then by fiveat a time until the whole auditorium was filled. Also,several audio clips were used to react to and create a desiredeffect upon the participant. The audio clips includedmaking comments, encouraging the participant to speaklouder, ignoring the participant, laughing, holdingconversations with others, and clapping hands at thebeginning or end of the entire session. An amplifier wasused in conjunction with the virtual reality software inorder for the participant to hear the echo of their own voice.A Subjective Units of Disturbance (SUD scale was used forall five sessions to measure the participant’s anxiety level.SUD scale ranged from 0 (no anxiety to 10 (panic-levelanxiety. Sessions lasted approximately 40 to 45 minutes.After analyzing the data, the result of this research showedVRT to be effective at reducing CA anxiety. While therewas fluctuation in the standard deviation of data, meaningparticipants responded the VRT at different rates, theaverage level of anxiety reported during the post-test wassignificantly less than that of the pre-test. The participantsreported experiencing the same symptoms during VRTsessions just as they would experience in a real situation.The symptoms were

  5. The Assessment of the Relationships among Loneliness, Affinity-Seeking Competence, and Communication Apprehension.

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    Woltjen, Lisa M.; Zakahi, Walter R.

    A study investigated the relationships among dyadic apprehension and levels of loneliness, dyadic apprehension and affinity-seeking competence, and affinity-seeking competence and levels of loneliness. Subjects, 198 undergraduate students, completed the Revised University of California at Los Angeles (UCLA) Loneliness Scale, the Personal Report of…

  6. Relationships between communication apprehension, ambiguity tolerance and learning styles in accounting students

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    José Luis Arquero

    2017-01-01

    Full Text Available The dynamics of the global business environment have led to changes in the skills required by accountants in order to add value for their clients. Consequently, there is a growing pressure on accounting educators to design and implement educational programmes that could contribute to the development of the relevant skills. In such a context, it is possible that some characteristics of students (for example communication apprehension, ambiguity tolerance, or learning styles could be constraints on both skills development and pedagogical change. Previous studies have reported that accounting students tend to have higher levels of the constraining characteristics than students from other disciplines. However, previous research has not considered the extent to which those characteristics are inter-related or have possible synergistic effects in accounting students. The results of this study, based on a sample of accounting students, indicate that those relationships exist. The patterns of correlations are indicative of the constraints that an accounting educator must overcome to effectively develop certain skills. Implications of the results are discussed.

  7. Gratifications, collective self-esteem, online emotional openness, and traitlike communication apprehension as predictors of Facebook uses.

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    Zhang, Yin; Tang, Leo Shing-Tung; Leung, Louis

    2011-12-01

    This study explores whether and how gratifications and psychological traits impact people's Facebook use. First, a factor analysis of an online survey (N= 437) outlined a unique set of gratifications obtained from the use of Facebook. Six aspects of gratifications (i.e., social surveillance, entertainment, recognition, emotional support, network extension, and maintenance) were identified. Results from regression analyses showed that psychological traits (i.e., collective self-esteem, online emotional openness, and traitlike communication apprehension) were strong predictors of most Facebook gratifications. Additionally, gratifications and, to a lesser extent, psychological traits significantly predicted Facebook usage, both in perceived importance and different indicators in the level of Facebook use.

  8. 灾后护理中护士应对方式与交流恐惧研究%Nurse's Coping Styles and Communication Apprehension in Post-disaster Care

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    安云霞; 张秀芬; 李丹琳; 王艳波

    2015-01-01

    目的:探讨灾后护理中护士应对方式与交流恐惧状况及其相关性,并提出对策,为提高该群体心理健康水平、构建灾难心理护理体系提供参考。方法:抽取甘肃省9所医院中承担灾后护理任务的护士132名,采用特质应对方式问卷、交流恐惧自陈量表进行调查。结果:交流恐惧低度者占2.3%,中度者占64.4%,高度者占33.3%;积极应对和消极应对得分均高于健康人群常模,积极应对和消极应对与高度交流恐惧分别呈负相关和正相关,积极应对与中度交流恐惧无相关性,消极应对与中度交流恐惧呈正相关。结论:承担灾后护理任务的护士交流恐惧程度与消极应对方式关系密切,在特殊环境下,加强护理人员的心理健康监测,建立主动、系统、科学的应对体系,是亟待探讨的问题。%Objective:To discuss the relativity between nurse's coping styles and communication apprehension in post-disaster care, and take some countermeasures, in order to provide the reference for improving mental health level of the nurses and building disaster psychological care system. Methods: All 132 nurses who accepted the responsibility for post-disaster care were chose from nine hospitals from Gansu province, and investigated by trait coping-style questionnaire and communication apprehension self-test scales. Results: The nurses in low-grade communication apprehension accounted for 2.3%, the ones in moderate communication apprehension reached 64.4%, the ones in high-grade 33.3%;positive coping scores and negative coping scores were higher than norms of healthy people, positive coping styles and negative coping styles were negative and positive correlation to high degree communication apprehension respectively, positive coping styles had no connection to moderare communication apprehension, negative coping styles were positively connected to moderate communication apprehension. Conclusion

  9. An Explanatory Mixed Method Study on Pre-Service Language Teachers' Communication Apprehension towards Their Instructors

    Science.gov (United States)

    Kavanoz, Suzan

    2017-01-01

    Promoting higher communication efficiency among teacher candidates and acting as models are among the main professional responsibilities of teacher educators. This makes the task of teachers even more important in language education classes where students are prospective language teachers and their development as language teachers highly depend on…

  10. The Impact of Doing Problem-Solving Tasks on Willingness to Communicate, Self-perceived Communication Competence, and Communication Apprehension among Iranian EFL Learners

    Directory of Open Access Journals (Sweden)

    Amir Marzban

    2013-11-01

    Full Text Available Willingness to communicate (WTC plays a central role in learning a second/foreign language. The present study was conducted to investigate the effect of doing problem-solving task on learners’ WTC in English. To fulfill the purpose of the study, 61 pre-intermediate learners were chosen by means of administrating a placement test. Learners were pretested through three scales of WTC and its two antecedents: self-perceived communication competence (SPCC and communication apprehension (CA. Of course, the experimental group was provided with fifteen problem-solving tasks during the course, while the control group was not. After fifteen sessions of the treatment, two groups were posttested through the same three scales. The results demonstrated that the experimental group outperformed the control group in terms of their WTC’s level. Moreover, the learners’ WTC was found to be directly related to their SPCC and indirectly related to CA. So based on the MacIntyre’s path model (1994, these both antecedents can be the best predictors of WTC. The analysis of the data was done through multivariate analysis of variances (MANOVA statistical programs.

  11. An Exploratory Study of Neuro Linguistic Programming and Communication Anxiety

    Science.gov (United States)

    1993-12-01

    interpersonally attractive than their peers, both by low communication apprehensive and other high communication apprehensive. The perceived leadership...A nationwide survey of American adults found that the most frequently reported fear experienced was that of speaking in public ( McCroskey , 1977...given two questionnaires to complete immediately after their presentation. The first questionnaire measured state communication apprehension using the

  12. Communication Apprehension in the Classroom: A Study of Nontraditional Graduate Students at Ohio University

    Science.gov (United States)

    Love, Jill Annette

    2013-01-01

    A common practice in colleges and universities throughout the United States is to make verbal communication and class participation a requirement for academic success. However, for some students this type of verbal communication in the classroom can produce physical and emotional anxiety that can profoundly affect their ability to succeed in the…

  13. 中国大学生面众恐惧的心理测量学再探%Psychometric Re- exploring of Facing- audience Communication Apprehension Scale for Chinese College Students

    Institute of Scientific and Technical Information of China (English)

    王洪礼; 邹维兴; 刘红; 袁宜; 谢玲平; 余昭琼; 谢其利

    2012-01-01

    针对《心理科学》2011年第3期发表的《大学生面众交流恐惧的心理测量学初探》研究中存在的不足,通过理论与实践的深入反思,重新设计、研制了调查中国大学生面众恐惧的调研工具。在我国东、南、西、北、中各大地区随机抽取了17个省(市)共24所高校,用含有79个题项的预测量表进行预测,获得1057个有效预测样本,再将其划分为两组样本,分别进行探索性因素分析和验证性因素分析,研究结果表明:《中国大学生面众恐惧调查量表》(2011修订版)修订为新的四个维度和32个题项后,更能覆盖大学生面众恐惧现象的各个主要方面,量表具有更高的信效度,更好地达到了心理测量学的要求;四个维度分别是上台恐惧、面试恐惧、办事恐惧、团组与校外交流恐惧,可作为中国大学生面众交流恐惧的调研工具。%Objective:Based on previous studies on communication apprehension, a new concept named Facing - audience apprehen- sion was given initially in 2007 by Hongli-Wang, a professor of Education Science School of Guizhou Normal University. Facing - audi- ence apprehension, namely facing - audience communication apprehension, is an emotional state characterized by constant worries, fear because of lacking self confidence in such situations as interpersonal communication, interview, answering questions or having speech on platform, etc. People with facing - audience apprehension may intentionally avoid or escape from communicating with others. To improve the earlier study on facing - audience ( see Psychometric Exploring of College Facing - audience Communication Ap- prehension, Chinese Journal of Psychological Science ,2011 (3) ), a new scale was designed to investigate the facing -audience appre- hension of Chinese college students after insightful rethinking and elaborate redesign. The purpose of this study is to develop a better scale

  14. EFL Writing Apprehension: The Macro or the Micro?

    Directory of Open Access Journals (Sweden)

    Mohammad Alnufaie

    2013-06-01

    Full Text Available This study was part of a doctoral project to explore the writing apprehension levels of 121 second-year undergraduate Saudi student writers who were studying English as a foreign language and for specific purposes in a Saudi industrial college.The study draws on Dörnyei’s (1994 framework of L2 motivation levels and their micro-motivational conditions in L2 learning situations, and addresses EFL writing apprehension in strategy-related conditions. For data collection, aWriting Strategy Apprehension Scale (WSAS was developed and adapted from a test designed by John Daly and Michael Miller (1975 and from the Second Language Writing Anxiety Inventory (SLWAI designed by Cheng (2004.The participants were classified into three levels of apprehension (apprehensive strategy users, average apprehensive strategy users, and low apprehensive strategy users. The results showwhile the majority of the participants (57.9% were average in their stress and apprehension levels towards writing strategies, almost a third of them (31.4% were highly apprehensive. In addition, the most stressful strategies were those that indicate the lack of generating ideas, the care about accuracy, and the follow of teacher’s expectations.

  15. The Impact of Intercultural Sensitivity on Ethnocentrism and Intercultural Communication Apprehension%跨文化敏感对我族中心主义和跨文化交际焦虑的影响

    Institute of Scientific and Technical Information of China (English)

    赵翔

    2016-01-01

    With questionnaires,this study explores the impact of intercultural sensitivity on ethnocentrism and intercultural communication apprehension of Chinese college students. The results show that (1) among the five dimensions of intercultural sensitivity,participants get the highest score at respect for cultural differences,followed by interaction engagement, interaction enjoyment and interaction attentiveness in sequence,and the lowest score at in-teraction confidence;( 2 ) there are significant negative correlations between intercultural sensitivity and both ethnocentrism and intercultural communication apprehension;( 3 ) eth-nocentrism can be best predicted by respect for cultural differences,and intercultural com-munication apprehension can be best predicted by interaction enjoyment.%文章通过问卷调查,以中国大学生为研究对象,探讨了跨文化敏感对我族中心主义和跨文化交际焦虑的影响。结果表明:(1)在跨文化敏感的五项因素中,受试的差异认同感最强,其次是交际参与度、交际愉悦感、交际专注度,交际信心最弱;(2)跨文化敏感和我族中心主义、跨文化交际焦虑均呈显著负相关关系;(3)差异认同感对我族中心主义的预测能力最强,交际愉悦感对跨文化交际焦虑的预测能力最强。

  16. Sources of L2 Writing Apprehension: A Study of Egyptian University Students

    Science.gov (United States)

    Abdel Latif, Muhammad M.

    2015-01-01

    High levels of apprehension cause students to have writing difficulties. This study attempted to identify the sources of Egyptian university students' English writing apprehension. The study made use of both quantitative and qualitative data. The scores of 57 students on a writing apprehension scale were compared to their scores on another scale…

  17. From Diagnosis to Prognosis: What Instructors Know about Their Students' Writing Apprehension

    Science.gov (United States)

    Apawu, David Dankwa; Anani, Gifty Edna

    2017-01-01

    Different students enter institutions of higher learning with varying degrees of writing apprehension. The apprehension ranges from anxiety from writing tasks to avoiding courses that involve a lot of writing. For many universities, the writing centers or academic writing courses are meant to equip students to be able to deal with the high writing…

  18. Students' Predispositions and Orientations toward Communication and Perceptions of Instructor Reciprocity and Learning

    Science.gov (United States)

    Allen, Jerry L.; Long, Kathleen M.; O'mara, Joan; Judd, Ben B.

    2008-01-01

    This study examined whether college students' communication avoidance and socio-communicative orientation were related to perceptions of instructors' immediacy, socio-communication style, satisfaction with instructors and learning. Students high in communication apprehension and/or less immediate perceived their instructors as less immediate and…

  19. Effect of Problem - based Learning in A Large Class on Reducing Communication Apprehension of Medical Students in General Practice Education%在全科医学教学中开展大班以问题为基础的学习对改善医学生交流恐惧的作用研究

    Institute of Scientific and Technical Information of China (English)

    齐殿君; 于晓松; 王爽; 何旖旎; 朱亮亮; 燕怡; 许多

    2016-01-01

    Objective To investigate the effect of problem - based learning( PBL)in a large class on reducing communication apprehension of medical students in general medical education. Methods A total of 120 5 - year clinical medical specialty students of Grade 2008 in China Medical University were enrolled as study objects. The students were divided into experimental group and control group by random number table and each group included 60 students. The experimental group adopted PBL teaching method in a large class,where students were helped to overcome communication apprehension by guiding and encouraging students to speak;the control group adopted traditional teaching methods. The two groups had the lessons of Introduction of General Practice taught by the same teachers for 24 credit hours. The communication apprehension of the students was evaluated by Personal Report of Communication Apprehension(PRCA-24)before and after class. Results Before teaching, the difference of PRCA-24 scale total point and Item - subscale point between the experimental group and the control group was not significant(P > 0. 05). After teaching,PRCA-24 scale total point of the experimental group was lower than the control group and the difference was significant( P 0. 05). Conclusion PBL in a large class can reduce total points,team points and public points of PRCA-24 scale in general medical teaching and is in favour of relieving the communication apprehension of medical students.%目的:探讨在全科医学教学中开展大班以问题为基础的学习(PBL)对改善医学生交流恐惧的作用。方法以中国医科大学2008级五年制临床医学专业的120名四年级学生为研究对象,采用随机数字表法分为试验组和对照组各60人。试验组采用大班 PBL 教学方法,采用引导、鼓励发言的办法帮助学生克服交流恐惧;对照组采用传统教学方法,两组均由相同教师教授《全科医学概论》24个学时。教学前后

  20. High-energy communication

    CERN Multimedia

    CERN Communication Group

    2015-01-01

    On Wednesday at 10.40 a.m., the LHC operators declared “stable beams” after two years of technical stop and a few months of commissioning. It was an exciting day for all the teams involved, including those who worked on communicating the news to the public and the media on multiple platforms.   CERN’s most successful tweet on 3 June featured collision images from ALICE, ATLAS, CMS and LHCb and was shared 800 times by the Twitter audience. Live blogging, social media posts, a live webcast, and a constant outpouring of photos and videos: Wednesday morning was a crazy time for the communication teams from CERN, the experiments and various institutes around the world. Even though the event started very early in the morning (the live CCC blog started at 7 a.m. and the live webcast at 8.20 a.m.), the public and the media tuned in to follow and generously cover the start of the LHC’s physics run at an unprecedented energy of 13 TeV. The statistics showed th...

  1. Using a Speech Apprehension Questionnaire as a Tool to Reduce Students' Fear of Public Speaking

    Science.gov (United States)

    Ablamowicz, Halina

    2005-01-01

    This article presents an activity that makes use of a questionnaire similar to a Personal Report of Communication Apprehension (PRCA) which elicit students' responses about their previous speaking experiences, their own definitions of anxiety and its causes, and their plans for future careers. This activity is aimed at helping students overcome…

  2. Relationship of facing-audience communication apprehension,parental rearing style and loneliness among col-lege freshmen%大学新生面众恐惧与父母教养方式、孤独感的关系

    Institute of Scientific and Technical Information of China (English)

    邹维兴; 谢玲平; 王洪礼

    2016-01-01

    Objective To explore relationship of facing-audience communication apprehension to parental rea-ring style and loneliness in college freshmen.Methods Totally 1072 college freshmen were selected.They were assessed with the Facing-audience Communication Apprehension Scale (revised version of 201 1),the Short-form Egna Minnen av Barndoms Uppfostran for Chinese (s-EMBU-C)and UCLA Loneliness Scale (Version 3).The relationship among these factors was analyzed by structural equation modeling.Results The scores of FACA were higher in female students than in males [(67.25 ±19.66)vs (74.47 ±20.71),t =-5.815,P <0.001,d =0.367],and the scores of FACA were lower in the freshmen who come from city than freshmen who come from country [(65.99 ±20.69 ) vs (71.96 ± 20.41),t =-3.307,P <0.001,d =0.293].The FACA and loneliness scores were negatively correlated with paren-tal warmth (r =-0.18, -0.15),while the FACA and loneliness scores were positively correlated with the scores of parental denial,parental over-protect (r =0.13,0.15,0.15,0.15,0.43).Structural equation model found loneli-ness played a partly mediating role between positively parenting styles and facing-audience communication apprehension, mediation effect accounted for 63.8%,and played a completely mediating role between negatively parenting styles and fa-cing-audience communication apprehension.Conclusion There may be a close relation of parenting styles and facing-au-dience communication apprehension, and parenting styles could affect facing-audience communication apprehension through loneliness.%目的:探讨大学新生面众恐惧与父母教养方式、孤独感之间的具体关系。方法采取整群抽样方法,选取贵州省4所省直重点高校的1072名大一新生,采用《中国大学生面众恐惧调查量表》(2011修订版)、《简式父母教养方式问卷中文版》(s-EMBU-C)、UCLA 孤独量表对大学新生进行测评,运用矩结构方程分析变量之间关系。结

  3. Phenomenology of consciousness from apprehension to judgment.

    Science.gov (United States)

    Arecchi, F Tito

    2011-07-01

    We explore two different moments of human cognition, namely apprehension (A), whereby a coherent perception emerges by recruitment of large neuron groups and judgment (B), whereby memory retrieval of different (A) units coded in a suitable language and comparison of them leads to the formulation of a judgment. The first one has a duration around 1 sec (from 0.5 to 3 sec), it appears as an a-temporal present and its neural correlate is a wide synchronization in the EEG gamma band. It may be described as an interpretation of sensorial stimuli in terms of some stored algorithm, via a Bayes procedure. The second one entails the comparison of two apprehensions acquired at different times, coded in a given language, and retrieved by memory. It lasts around 3 sec and requires self-consciousness, as the judging agent must be well aware that he/she is the same one who faces the two coded apprehensions under scrutiny in order to extract a mutual relation. At variance with (A), (B) does not presuppose an algorithm, but it rather builds a new behavioural model by an inverse Bayes procedure. It will be shown how this build up of a novel model is related to creativity and free will.

  4. Parent Communication about Sexual Issues with Adolescents in Vietnam: Content, Contexts, and Barriers

    Science.gov (United States)

    Trinh, Thang; Steckler, Allan; Ngo, Anh; Ratliff, Eric

    2009-01-01

    This qualitative study examines parent-adolescent communication on sexual topics in Thai Binh province, Vietnam. Data were collected from 45 in-depth interviews and seven focus groups with parents and adolescents of high school age. Results indicate that parents were apprehensive when it comes to sexual communication. Parents warned their children…

  5. Counterpoint in Explanation of Originative Apprehension

    Directory of Open Access Journals (Sweden)

    Michael Ewbank

    2016-09-01

    Full Text Available Originative apprehension often has been examined in recent decades in light of Aquinas’ reflections. Yet there has not always been agreement in regard to what constitutes such, often due to different emphases given by interpreters to aspects of St. Thomas’ analyses articulated in different contexts. Arguably, it is possible to reconcile certain seemingly divergent important interpretations by reflecting on an important, yet somewhat recessive, theme that Thomas adverted to sparingly throughout his career in utilizing analyses of predecessors to forge his own synthesis to explain cognition in terms of being that is centered on the reciprocal priorities of judging and concomitant incomplex abstracting.

  6. Post-Election Apprehension, Activism, and Educational Justice

    Science.gov (United States)

    Catone, Keith C.

    2017-01-01

    Following the election of Donald Trump, the author, his wife, and colleagues from the Annenberg Institute for Social Reform (AISR) experienced different forms of apprehension: "anxious" apprehension, which can also be a moment of activist birth that sets the stage for a new level of consciousness to be awakened; "critical"…

  7. High-speed Power Line Communications

    Directory of Open Access Journals (Sweden)

    Matthew N. O. Sadiku,

    2015-11-01

    Full Text Available This is the idea of using existing power lines for communication purposes. Power line communications (PLC enables network communication of voice, data, and video over direct power lines. High-speed PLC involves data rates in excess of 10 Mbps. PLC has attracted a lot of attention and has become an interesting subject of research lately.

  8. Attaining High Performance Communications A Vertical Approach

    CERN Document Server

    Gavrilovska, Ada

    2009-01-01

    Technological Advances and Problems of High Performance Communications. An ecosystem of solutions along a stack of technology layers. Cohesively collecting state-of-the-art contributions from leading researchers in industry, national laboratories, and academia, Attaining High Performance Communications: A Vertical Approach discusses various issues pertaining to high performance communications in a particular layer of a vertical stack. It explores efficient interconnection hardware, the architectural aspects of network adapters and their integration with processor cores, the design of scalable

  9. An Investigation of the Relationships among Technology Experiences, Communication Apprehension, Writing Apprehension, and Computer Anxiety.

    Science.gov (United States)

    McDowell, Earl

    1998-01-01

    Finds significant relationships between computer anxiety and computer/word processing, between computer anxiety and computer electronic discussion group, and between computer anxiety and online computer service among 130 students from a variety of undergraduate rhetoric classes at a large midwestern university. Finds also significant differences…

  10. Spacecraft design project: High latitude communications satellite

    Science.gov (United States)

    Josefson, Carl; Myers, Jack; Cloutier, Mike; Paluszek, Steve; Michael, Gerry; Hunter, Dan; Sakoda, Dan; Walters, Wes; Johnson, Dennis; Bauer, Terry

    1989-01-01

    The spacecraft design project was part of AE-4871, Advanced Spacecraft Design. The project was intended to provide experience in the design of all major components of a satellite. Each member of the class was given primary responsibility for a subsystem or design support function. Support was requested from the Naval Research Laboratory to augment the Naval Postgraduate School faculty. Analysis and design of each subsystem was done to the extent possible within the constraints of an eleven week quarter and the design facilities (hardware and software) available. The project team chose to evaluate the design of a high latitude communications satellite as representative of the design issues and tradeoffs necessary for a wide range of satellites. The High-Latitude Communications Satellite (HILACS) will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites, i.e., the area above approximately 60 N latitude. HILACS will also provide a communications link to stations below 60 N via a relay Net Control Station (NCS), which is located with access to both the HILACS and geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specified coverage.

  11. Technology Development for High Efficiency Optical Communications

    Science.gov (United States)

    Farr, William H.

    2012-01-01

    Deep space optical communications is a significantly more challenging operational domain than near Earth space optical communications, primarily due to effects resulting from the vastly increased range between transmitter and receiver. The NASA Game Changing Development Program Deep Space Optical Communications Project is developing four key technologies for the implementation of a high efficiency telecommunications system that will enable greater than 10X the data rate of a state-of-the-art deep space RF system (Ka-band) for similar transceiver mass and power burden on the spacecraft. These technologies are a low mass spacecraft disturbance isolation assembly, a flight qualified photon counting detector array, a high efficiency flight laser amplifier and a high efficiency photon counting detector array for the ground-based receiver.

  12. Cause Analysis of English Writing Apprehension of Secondary Vocational Students

    Institute of Scientific and Technical Information of China (English)

    刘芩利

    2015-01-01

    English writing apprehension is an inevitable problem in secondary vocational schools.In the paper,the author analyzes causes in terms of second language proficiency,self-efficacy,first language writing competence and other factors,ultimately,gives teachers some practical proposals.

  13. Cause Analysis of English Writing Apprehension of Secondary Vocational Students

    Institute of Scientific and Technical Information of China (English)

    刘芩利

    2015-01-01

    English writing apprehension is an inevitable problem in secondary vocational schools.In the paper,the author analyzes causes in terms of second language proficiency,selfefficacy,first language writing competence and other factors,ultimately,gives teachers some practical proposals.

  14. High Spectral Density Optical Communication Technologies

    CERN Document Server

    Nakazawa, Masataka; Miyazaki, Tetsuya

    2010-01-01

    The latest hot topics of high-spectral density optical communication systems using digital coherent optical fibre communication technologies are covered by this book. History and meaning of a "renaissance" of the technology, requirements to the Peta-bit/s class "new generation network" are also covered in the first part of this book. The main topics treated are electronic and optical devices, digital signal processing including forward error correction, modulation formats as well as transmission and application systems. The book serves as a reference to researchers and engineers.

  15. High performance computing and communications panel report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    In FY92, a presidential initiative entitled High Performance Computing and Communications (HPCC) was launched, aimed at securing U.S. preeminence in high performance computing and related communication technologies. The stated goal of the initiative is threefold: extend U.S. technological leadership in high performance computing and computer communications; provide wide dissemination and application of the technologies; and spur gains in U.S. productivity and industrial competitiveness, all within the context of the mission needs of federal agencies. Because of the importance of the HPCC program to the national well-being, especially its potential implication for industrial competitiveness, the Assistant to the President for Science and Technology has asked that the President's Council of Advisors in Science and Technology (PCAST) establish a panel to advise PCAST on the strengths and weaknesses of the HPCC program. The report presents a program analysis based on strategy, balance, management, and vision. Both constructive recommendations for program improvement and positive reinforcement of successful program elements are contained within the report.

  16. User apprehensions and expectations in healthcare IS implementations

    DEFF Research Database (Denmark)

    Hansen, Magnus Rotvit Perlt; Ejnefjäll, Thomas

    We report on the initial findings from a qualitative user expectations study of a Patient Data Management System implementation in an Intensive Care Unit in a Swedish hospital. By drawing on grounded theory we take an open focus on the concepts of fears and beliefs and find that specifically...... the users’ stories of their expectations towards the implementation project seem to influence their apprehensions on similar terms as their existing experiences. The main theoretical contribution here is a framework showing that apprehensions are derived from not only past experience but also new...... expectations. We also contribute with the finding that uncertain aspects of users’ existing work practices lead to positively valued expectations. Practically, we argue that users’ certainties toward the IS implementation may actually lead to uncertainty in other areas and propose that further research should...

  17. Writing apprehension and academic procrastination among graduate students.

    Science.gov (United States)

    Onwuegbuzie, A J; Collins, K M

    2001-04-01

    Academic procrastination has been associated with both fear of failure and task aversiveness. Researchers have reported that most undergraduate and graduate students delay academic tasks. Among the latter, a large proportion report procrastination in writing term papers. Such procrastination may originate from and lead to anxiety about writing so the present purpose was to investigate the relationship between scores on Daly and Miller's 1975 Writing Apprehension Test and on the two dimensions, i.e., fear of failure and task aversiveness, of Solomon and Rothblum's 1984 Procrastination Assessment Scale-Students. Participants were 135 graduate students of varied disciplinary backgrounds. Correlations between writing apprehension and academic procrastination stemmed from fear of failure (29) and task aversiveness (.41). Implications are discussed.

  18. Cognition and Language: From Apprehension to Judgment -- Quantum Conjectures

    Science.gov (United States)

    Arecchi, F. T.

    2014-12-01

    We critically discuss the two moments of human cognition, namely, apprehension (A), whereby a coherent perception emerges from the recruitment of neuronal groups, and judgment (B), that entails the comparison of two apprehensions acquired at different times, coded in a suitable language and recalled by memory. (B) requires selfconsciousness, in so far as the agent who expresses the judgment must be aware that the two apprehensions are submitted to his/her own scrutiny and that it is his/her duty to extract a mutual relation. Since (B) lasts around 3 seconds, the semantic value of the pieces under comparison must be decided within this time. This implies a fast search of the memory contents. As a fact, exploring human subjects with sequences of simple words, we find evidence of a limited time window, corresponding to the memory retrieval of a linguistic item in order to match it with the next one in a text flow (be it literary, or musical,or figurative). Classifying the information content of spike trains, an uncertainty relation emerges between the bit size of a word and its duration. This uncertainty is ruled by a constant that can be given a numerical value and that has nothing to do with Planck's constant. A "quantum conjecture" in the above sense might explain the onset and decay of the memory window connecting successive pieces of a linguistic text. The conjecture here formulated is applicable to other reported evidences of quantum effects in human cognitive processes, so far lacking a plausible framework since no efforts to assign a quantum constant have been associated.

  19. The Application of Communicative Approach in High School English Teaching

    Institute of Scientific and Technical Information of China (English)

    张晓敏

    2015-01-01

    This article will give a brief illustration of the application of communicative approach in high school English teaching(speaking,reading and listening).The purpose of communicative approach is to help students learn English knowledge,evaluate students' communicative competence.

  20. The Application of Communicative Approach in High School English Teaching

    Institute of Scientific and Technical Information of China (English)

    Zhang; Xiaomin

    2015-01-01

    This article will give a brief illustration of the application of communicative approach in high school English teaching(speaking,reading and listening).The purpose of communicative approach is to help students learn English knowledge,evaluate students’ communicative competence.

  1. Apprehensions and Expectations of the Adoption of Systematically Planned, Outcome-Oriented Practice

    Science.gov (United States)

    Savaya, Riki; Altschuler, Dorit; Melamed, Sharon

    2013-01-01

    Objectives: The study examined social workers' apprehensions and expectations of the impending adoption of systematically planned, empirically based, outcome-oriented practice (SEOP). Method: Employing a mixed methods longitudinal design, the study used concept mapping to identify and map workers' apprehensions and expectations and a self-reported…

  2. Exploring the Relationship between Writing Apprehension and Writing Performance: A Qualitative Study

    Science.gov (United States)

    Badrasawi, Kamal J. I.; Zubairi, Ainol; Idrus, Faizah

    2016-01-01

    Writing skill is seen as a cornerstone of university students' success in both academic and career life. This qualitative study was conducted to further explore the teachers' and students' perceptions on the relationship between writing apprehension and writing performance, contributing factors of writing apprehension, and strategies to reduce…

  3. Investigation of Writing Strategies, Writing Apprehension, and Writing Achievement among Saudi EFL-Major Students

    Science.gov (United States)

    Al Asmari, AbdulRahman

    2013-01-01

    The tenet of this study is to investigate the use of writing strategies in reducing writing apprehension and uncovering its effect on EFL students' writing achievement. It also attempts to explore associations between foreign language apprehension, writing achievement and writing strategies. The primary aims of the study were to explore the…

  4. 622 Mbps High-speed satellite communication system for WINDS

    Science.gov (United States)

    Ogawa, Yasuo; Hashimoto, Yukio; Yoshimura, Naoko; Suzuki, Ryutaro; Gedney, Richard T.; Dollard, Mike

    2006-07-01

    WINDS is the experimental communications satellite currently under joint development by Japanese Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). The high-speed satellite communication system is very effective for quick deployment of high-speed networks economically. The WINDS will realize ultra high-speed networking and demonstrate operability of satellite communication systems in high-speed internet. NICT is now developing high-speed satellite communication system for WINDS. High-speed TDMA burst modem with high performance TPC error correction is underdevelopment. Up to the DAC on the transmitter and from the ADC on the receiver, all modem functions are performed in the digital processing technology. Burst modem has been designed for a user data rate up to 1244 Mbps. NICT is developing the digital terminal as a user interface and a network controller for this earth station. High compatibility with the Internet will be provided.

  5. Working with physics High-energy communicator

    CERN Multimedia

    Bradshaw, Kate

    2006-01-01

    "Kate Bradshaw is a science communicator working at CERN, the world's largest particle physics Laboratory. She talked to Physics Review about her route from A-level physics to her present job." (3 pages)

  6. Extreme Environment High Temperature Communication Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop and demonstrate a communications system capable of operation at extreme temperatures and pressures in hostile and corrosive...

  7. An Analysis of Senior High School English Textbook Oral-Communication B : How Communicative Are Oral Communication Textbooks?

    OpenAIRE

    深澤, 清治; 上西, 幸治

    1996-01-01

    The purpose of the present article is to analyze the communicativeness of English Oral Communication B textbooks currently used in senior high schools in Japan. As part of the present Course of Study, the Ministry of Education introduced a new kind of course, Oral Communication A, B, and C and the actual instructions began in the classroom in 1994. In line with the recent communicative trend, there has been a growing expectation of dramatic changes in the teaching of oral English. There has b...

  8. Design of high-bit-rate coherent communication links

    Science.gov (United States)

    Konyshev, V. A.; Leonov, A. V.; Nanii, O. E.; Novikov, A. G.; Treshchikov, V. N.; Ubaydullaev, R. R.

    2016-12-01

    We report an analysis of the problems encountered in the design of modern high-bit-rate coherent communication links. A phenomenological communication link model is described, which is suitable for solving applied tasks of the network design with nonlinear effects taken into account. We propose an engineering approach to the design that is based on the use of fundamental nonlinearity coefficients calculated in advance for the experimental configurations of communication links. An experimental method is presented for calculating the nonlinearity coefficient of communication links. It is shown that the proposed approach allows one to successfully meet the challenges in designing communication networks.

  9. Communication Skills of Anatolian Vocational Health High School Students

    Directory of Open Access Journals (Sweden)

    Sevgi Gaskar

    2013-04-01

    Full Text Available Introduction: This research is conducted to determine the level of communication and influencing skills students studying in classes 9 and 12 in Bursa Anatolian Vocational Health High School. Materials and Methods: The research group consisted of 218 students. Data communication with the inventory collected with a questionnaire containing demographic characteristics of the students. Percentile of the data analysis, Kruskal-Vallis, correlation test was used. Results: The mean score of students’ communicative skills inventory was 164.61+17.20. No significant difference was found between success in school and communication skills with the students’ gender, number of siblings. While there is no difference between free time activities watching TV and communication skills of students, there is a significant difference between the habit of using the computer and communication skills of students between the total score and subscales. Conclusions: Students’ communication skills scores are higher in girls than in boys, school achievement and communication skills scores increased parallel to the increase number of siblings. The habit of reading a book, while the positive affect on the mental score communication skills, scores of all the communication skills of students negative affects the increase in computer usage time. Effect on student reading scores for class communication skills to improve communication skills courses put the quality and increasing the recommend hours. (The Jo­ur­nal of Cur­rent Pe­di­at­rics 2014;1:20-5

  10. Public apprehension of emerging infectious diseases: are changes afoot?

    Science.gov (United States)

    Joffe, Helene

    2011-07-01

    Using social representations theory this paper casts light on the pattern of content that characterises the public response to emerging and re-emerging infectious diseases (EID). The pattern is: distancing the disease from the self/ one's in-groups; blame of particular entities for the disease's origin and/or spread; and stigmatisation of those who have contracted it and/or who are represented as having intensified its spread. This pattern is not unique to EID but extends to many risks, making EID fruitful events for understanding public apprehension of potential dangers. This process may be driven by worry, fear and anxiety since when levels of these are low, as has arguably been the case with the 2009/10 "Swine Flu" pandemic, the pattern transforms. The distancing-blame-stigma pattern may also be transformed by growing reflexivity, a feature of late modern societies, as well as material features of the epidemic and "EID fatigue".

  11. A High-Performance Communication Service for Parallel Servo Computing

    Directory of Open Access Journals (Sweden)

    Cheng Xin

    2010-11-01

    Full Text Available Complexity of algorithms for the servo control in the multi-dimensional, ultra-precise stage application has made multi-processor parallel computing technology needed. Considering the specific communication requirements in the parallel servo computing, we propose a communication service scheme based on VME bus, which provides high-performance data transmission and precise synchronization trigger support for the processors involved. Communications service is implemented on both standard VME bus and user-defined Internal Bus (IB, and can be redefined online. This paper introduces parallel servo computing architecture and communication service, describes structure and implementation details of each module in the service, and finally provides data transmission model and analysis. Experimental results show that communication services can provide high-speed data transmission with sub-nanosecond-level error of transmission latency, and synchronous trigger with nanosecond-level synchronization error. Moreover, the performance of communication service is not affected by the increasing number of processors.

  12. Interpersonal Communication in High Tech Culture: Eastern or Western?

    Science.gov (United States)

    Isenhart, Myra W.

    1987-01-01

    Investigates interpersonal communication in a high tech organization to test the association between high tech organizations and Western styles of symbolic interaction. Takes a diagnostic, rather than prescriptive, approach to organizational change. (MM)

  13. PC Cluster Machine Equipped with High-Speed Communication Software

    CERN Document Server

    Tanaka, M

    2004-01-01

    A high performance Beowulf (PC cluster) machine installed with Linux operating system and MPI (Message Passing Interface) for interprocessor communications has been constructed using Gigabit Ethernet and the communication software GAMMA (Genoa Active Message Machine), instead of the standard TCP/IP protocol. Fast C/Fortran compilers have been exploited with the GAMMA communication libraries. This method has eliminated large communication overhead of TCP/IP and resulted in significant increase in the computational performance of real application programs including the first-principle molecular dynamics simulation code. (Keywords: non TCP/IP, active messages, small latency, fast C/Fortran compilers, materials science, first-principle molecular dynamics)

  14. Visual Communications Studies at Roberto Clemente High School.

    Science.gov (United States)

    Karzen, Michael

    1981-01-01

    Roberto Clemente High School in Chicago has an interdisciplinary communications program involving seven subject areas: Graphic Design, Graphic Arts, Photography, Photocomposition, TV Radio/Film, Communications in Spanish, and Latin American Literature. The instructors in these classes form a team. This article is part of a theme issue on career…

  15. Trend on High-speed Power Line Communication Technology

    Science.gov (United States)

    Ogawa, Osamu

    High-speed power line communication (PLC) is useful technology to easily build the communication networks, because construction of new infrastructure is not necessary. In Europe and America, PLC has been used for broadband networks since the beginning of 21th century. In Japan, high-speed PLC was deregulated only indoor usage in 2006. Afterward it has been widely used for home area network, LAN in hotels and school buildings and so on. And recently, PLC is greatly concerned as communication technology for smart grid network. In this paper, the author surveys the high-speed PLC technology and its current status.

  16. Willingness to Communicate Among Bosnian and Turkish Students at International University of Sarajevo

    Directory of Open Access Journals (Sweden)

    AlmasaMulalic

    2016-06-01

    Full Text Available This study examines the willingness to communicate, communication apprehension and communication competence among Turkish and Bosnian students at IUS. Willingness to communicate as defined by McCroskey and Richard (1987 means an individual personal’s general personality orientation towards talking. Communication apprehension according to McCroskey (1984 is an individual level of fear or anxiety associated with either real or anticipated communication with other person or persons. Communication competence according to McCroskey and McCroskey (1986 is ones people’s perception of his/her communication competence. Data for this study was collected from students enrolled in freshman classes at IUS. Survey method was used to collect data from the participants using questionnaires. T-test was used to analyze data for this study for all measures (WTC, PRCA, and SPCC in order to determine the difference in willingness to communicate, communication apprehension and communication competence among Bosnian and Turkish students. The results of this study showed that there is no statistically significant difference between Turkish and Bosnian students regarding their willingness to communicate. However, the results showed that there are differences among Bosnian and Turkish students regarding their communication apprehension. The results also showed that there is difference between Bosnian and Turkish students regarding communication competence. However, the results did not show any statistically significant difference between Turkish and Bosnian students regarding student’s willingness to communicate, communication apprehension and communication competence.

  17. Chinese high-proficiency learners'communication strategy use

    Institute of Scientific and Technical Information of China (English)

    高煜

    2010-01-01

    @@ 1 Introduction This essay intends to clarify Chinese high-proficiency learners' communication strategy use to some extent, The analysis is based on the data from the corpus group in my MA course collected in 2008.

  18. High Power Uplink Amplifier for Deep Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Critical to the success of delivering on the promise of deep space optical communications is the creation of a stable and reliable high power multichannel optical...

  19. High Power Uplink Amplifier for Deep Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Critical to the success of delivering on the promise of deep space optical communications is the creation of a stable and reliable high power multichannel optical...

  20. Application of Beyond Bound Decoding for High Speed Optical Communications

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Vegas Olmos, Juan José;

    2013-01-01

    This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB.......This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB....

  1. A Multiprocessor Communication Architecture For High Speed Networks

    CERN Document Server

    S, Iyengar; Roy, A A; Sanyal, S; Singhi, N M; Feng, Wu Geng

    2010-01-01

    Over the years, communication speed of networks has increased from a few Kbps to several Mbps, as also the bandwidth demand, Communication Protocols, however have not improved to that extent. With the advent of Wavelength Division Multiplexing (WDM), it is now possible to "tune" protocols to current and future demands. The purpose of this paper is to evolve a High Speed Network architecture, which will cater to the needs of bandwidth-consuming applications, such as voice, video and high definition image transmission.

  2. Model and Implementation of Communication Link Management Supporting High Availability

    Institute of Scientific and Technical Information of China (English)

    Luo Juan; Cao Yang; He Zheng; Li Feng

    2004-01-01

    Despite the rapid evolution in all aspects of computer technology, both the computer hardware and software are prone to numerous failure conditions. In this paper, we analyzed the characteristic of a computer system and the methods of constructing a system , proposed a communication link management model supporting high availability for network applications, Which will greatly increase the high availability of network applications. Then we elaborated on heartbeat or service detect, fail-over, service take-over, switchback and error recovery process of the model. In the process of constructing the communication link, we implemented the link management and service take-over with high availability requirement, and discussed the state and the state transition of building the communication link between the hosts, depicted the message transfer and the start of timer. At Last, we applied the designed high availability system to a network billing system, and showed how the system was constructed and implemented, which perfectly satisfied the system requirements.

  3. Quantum data locking for high-rate private communication

    Science.gov (United States)

    Lupo, Cosmo; Lloyd, Seth

    2015-03-01

    We show that, if the accessible information is used as a security quantifier, quantum channels with a certain symmetry can convey private messages at a tremendously high rate, as high as less than one bit below the rate of non-private classical communication. This result is obtained by exploiting the quantum data locking effect. The price to pay to achieve such a high private communication rate is that accessible information security is in general not composable. However, composable security holds against an eavesdropper who is forced to measure her share of the quantum system within a finite time after she gets it.

  4. Overlay Share Mesh for Interactive Group Communication with High Dynamic

    Institute of Scientific and Technical Information of China (English)

    WU Yan-hua; CAI Yun-ze; XU Xiao-ming

    2007-01-01

    An overlay share mesh infrastructure is presented for high dynamic group communication systems, such as distributed interactive simulation (DIS) and distributed virtual environments (DVE). Overlay share mesh infrastructure can own better adapting ability for high dynamic group than tradition multi-tree multicast infrastructure by sharing links among different groups. The mechanism of overlay share mesh based on area of interest (AOI) was discussed in detail in this paper. A large number of simulation experiments were done and the permance of mesh infrastructure was studied. Experiments results proved that overlay mesh infrastructure owns better adaptability than traditional multi-tree infrastructure for high dynamic group communication systems.

  5. Patterns of communication in high-fidelity simulation.

    Science.gov (United States)

    Anderson, Judy K; Nelson, Kimberly

    2015-01-01

    High-fidelity simulation is commonplace in nursing education. However, critical thinking, decision making, and psychomotor skills scenarios are emphasized. Scenarios involving communication occur in interprofessional or intraprofessional settings. The importance of effective nurse-patient communication is reflected in statements from the American Nurses Association and Quality and Safety Education for Nurses, and in the graduate outcomes of most nursing programs. This qualitative study examined the patterns of communication observed in video recordings of a medical-surgical scenario with 71 senior students in a baccalaureate program. Thematic analysis revealed patterns of (a) focusing on tasks, (b) communicating-in-action, and (c) being therapeutic. Additional categories under the patterns included missing opportunities, viewing the "small picture," relying on informing, speaking in "medical tongues," offering choices…okay?, feeling uncomfortable, and using therapeutic techniques. The findings suggest the importance of using high-fidelity simulation to develop expertise in communication. In addition, the findings reinforce the recommendation to prioritize communication aspects of scenarios and debriefing for all simulations.

  6. Multiplexed CV quantum teleportation for high rates in quantum communication

    CERN Document Server

    Christ, Andreas; Silberhorn, Christine

    2012-01-01

    A major challenge of today's quantum communication systems lies in the transmission of quantum information with high rates over long distances in the presence of unavoidable losses. Thereby the achievable quantum communication rate is fundamentally limited by the amount of energy that can be transmitted per use of the channel. It is hence vital to develop quantum communication protocols which encode quantum information as energy efficiently as possible. To this aim we investigate continuous-variable quantum teleportation as a method of distributing quantum information. We explore the possibility to encode information on multiple optical modes and derive upper and lower bounds on the achievable quantum channel capacities. This analysis enables us to benchmark single-mode vs. multi-mode entanglement resources. Our research reveals that multiplexing does not only feature an enhanced energy efficiency, significantly increasing the achievable quantum communication rates in comparison to single-mode coding, but als...

  7. An Architecture for High Data Rate Very Low Frequency Communication

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2013-01-01

    Full Text Available Very low frequency (VLF communication is used for long range shore-to-ship broadcasting applications. This paper proposes an architecture for high data rate VLF communication using Gaussian minimum shift keying (GMSK modulation and low delay parity check (LDPC channel coding. Non-data aided techniques are designed and used for carrier phase synchronization, symbol timing recovery, and LDPC code frame synchronization. These require the estimation of the operative Eb/N0 for which a kurtosis based algorithm is used. Also, a method for modeling the probability density function of the received signal under the bit condition is presented in this regard. The modeling of atmospheric radio noise (ARN that corrupts VLF signals is described and an algorithm for signal enhancement in the presence of ARN in given. The BER performance of the communication system is evaluated for bit rates of 400 bps, 600 bps, and 800 bps for communication bandwidth of ~200 Hz.

  8. OFDM-based Low-voltage Powerline High Rate Communication

    Institute of Scientific and Technical Information of China (English)

    ZHANG You-bing(张有兵); CHENG Shi-jie(程时杰); Joseph Nguimbis; XIONG Lan(熊兰)

    2004-01-01

    Based on the experimental results, a simplified model for low-voltage powerline used as a high frequency communication channel is presented. With this model, the Orthogonal Frequency Division Multiplexing (OFDM) based high rate digital communication over low-voltage powerline is analyzed and simulated. The capability of thc signal transmission system in overcoming multi-path interference and selection of the system parameters are discussed. And time-domain simulation is carried out to investigate the transmission capability of the OFDM cammunication system for different mapping schemes and transmission power levels. Simulation results show that it is possible to realize high rate digital communication over iow-voltage powerliue using OFDM when the transmitted power is large enough.

  9. No reserved communication lanes for high energy

    Directory of Open Access Journals (Sweden)

    Nico Pitrelli

    2006-06-01

    Full Text Available The American particle physics community is in jeopardy and may end up drowning in a boundless sea trying to grasp at non-existing funds, dragging US physics and science as a whole to the bottom. This is a price the most powerful and high-tech country of the world cannot afford, as warned by the editors of a report published in late April by the National Academy of Sciences1. Behind so much alarm is the International Linear Collider (ILC – a large particle accelerator facility which, according to the report, should be built on American territory, if research on the elementary constituents of nature is to survive in the United States. The ILC will probably cost a total of five hundred million dollars in the first five years, whereas billions will have to be invested in the subsequent seven years. Hardly impressive, however, if compared with the Superconducting Super Collider (SSC, the biggest and costliest machine ever conceived in the history of science. Devised to describe the first instants of the universe, as many will recall, the SSC project was severely hampered by political and bureaucratic plots in 1993, when the Clinton administration decided to halt work on the accelerator, after ten years and approximately two billion dollars already spent.

  10. Exploring writing apprehension amongst Afrikaans-speaking first-year students

    Directory of Open Access Journals (Sweden)

    Louise Olivier

    2016-03-01

    Full Text Available Writing apprehension relates to a reluctance to write or even fear of writing and little research has been done on this phenomenon in the South African context, especially in terms of compulsory academic literacy and academic linguistic modules. This article aimed at determining the nature of writing apprehension in these two modules in terms of the Daly and Miller’s Writing Apprehension Test (DM-WAT, essay marks and gender at a South African university. The DM-WAT was conducted with two groups of first-year students. An exploratory factor analysis was administered and this led to the identification of four distinct factors which are also associated with related aspects in the literature: positivity towards writing, negativity towards writing, evaluation apprehension and selfefficacy and writing. It is evident that in the context of this study, the chosen instrument could not be used to measure writing apprehension, rather the four identified factors. No linear relationships between essay marks and the identified constructs were clear. Also a practical significant difference between genders was found in terms of the identified constructs. Significantly, students in the compulsory academic literacy module showed a greater tendency towards apprehension in terms of the four identified factors than students from the linguistics module. The chosen instrument could be used to gauge the identified factors. Writing in compulsory academic literacy modules should be taught through individualised student-centred methods, affective support and reflective instruction, positive personal feedback, with additional support through counselling as well as effective modelled writing behaviour from lecturers.

  11. The Relationship of Writing Apprehension Level and Self-Efficacy Beliefs on Writing Proficiency Level among Pre-University Students

    Science.gov (United States)

    Singh, Termit Kaur Ranjit; Rajalingam, Saravana Kumar

    2012-01-01

    The purpose of this study was to determine the level of writing apprehension and how writing apprehension level and writing self-efficacy beliefs influences writing proficiency level among pre-university students. Participants were 320 pre-university students from a northern region college offering this programme. All the respondents were…

  12. Exploring THz band for high speed wireless communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Zhang, Hangkai; Jia, Shi;

    2016-01-01

    We overview recent trend in developing high speed wireless communication systems by exploring large bandwidth available in the THz band, and we also present our recent experimental achievements on 400 GHz wireless transmission with a data rate of up to 60 Gbit/s by using a uni-travelling carrier...

  13. Scientific Recognition and Communication Behavior in High Energy Physics.

    Science.gov (United States)

    Zeltman, Gerald

    The study is concerned with scientific (i.e., professional) recognition and communication behavior in theoretical high energy physics. The sample consists of 977 respondents working in thirty-eight countries. The conferral of two components of professional recognition, research leadership and advisorship, as they are affected by geopolitical and…

  14. A secure communications infrastructure for high-performance distributed computing

    Energy Technology Data Exchange (ETDEWEB)

    Foster, I.; Koenig, G.; Tuecke, S. [and others

    1997-08-01

    Applications that use high-speed networks to connect geographically distributed supercomputers, databases, and scientific instruments may operate over open networks and access valuable resources. Hence, they can require mechanisms for ensuring integrity and confidentially of communications and for authenticating both users and resources. Security solutions developed for traditional client-server applications do not provide direct support for the program structures, programming tools, and performance requirements encountered in these applications. The authors address these requirements via a security-enhanced version of the Nexus communication library; which they use to provide secure versions of parallel libraries and languages, including the Message Passing Interface. These tools permit a fine degree of control over what, where, and when security mechanisms are applied. In particular, a single application can mix secure and nonsecure communication, allowing the programmer to make fine-grained security/performance tradeoffs. The authors present performance results that quantify the performance of their infrastructure.

  15. Ka-band MMIC microstrip array for high rate communications

    Science.gov (United States)

    Lee, R. Q.; Raquet, C. A.; Tolleson, J. B.; Sanzgiri, S. M.

    1991-01-01

    In a recent technology assessment of alternative communication systems for the space exploration initiative (SEI), Ka-band (18 to 40 GHz) communication technology was identified to meet the mission requirements of telecommunication, navigation, and information management. Compared to the lower frequency bands, Ka-band antennas offer higher gain and broader bandwidths; thus, they are more suitable for high data rate communications. Over the years, NASA has played an important role in monolithic microwave integrated circuit (MMIC) phased array technology development, and currently, has an ongoing contract with Texas Instrument (TI) to develop a modular Ka-band MMIC microstrip subarray (NAS3-25718). The TI contract emphasizes MMIC integration technology development and stipulates using existing MMIC devices to minimize the array development cost. The objective of this paper is to present array component technologies and integration techniques used to construct the subarray modules.

  16. A highly innovative global broadband mobile communication system concept

    Science.gov (United States)

    Wittig, Manfred

    2010-04-01

    Global mobile communication systems deployed in the 1990s (Iridium and Globalstar) failed to achieve the expected market success. However, recently a second generation of these two LEO constellations have been or will be procured. This shows evidence that global mobile satellite communications are attractive for a certain class of users. Basic requirements for mobile satellite communication networks are global coverage at high elevation angles, continuous availability and most important attractive service offers. For the first two reasons LEO constellations were designed and deployed. The large number of required satellites (remember the original Teledesic concept was designed containing 860 satellites) increases the CAPEX and consequently the service cost. This is probably the major reason for the limited commercial success of Iridium and Globalstar. An ideal global mobile (broadband) communication system shall provide global coverage at high elevation angles (not below e.g. 30°) with the lowest number of satellites. This seems to be contradictory. However, a solution will be presented that achieves global coverage which requires only five satellites and achieves high elevation angles even at polar locations. This orbit constellation is to be complemented with innovative payloads to achieve cost efficient broadband mobile services all over the Globe. Innovative L/S-band payload concepts will be introduced as well as Ka-band payloads.

  17. Communication

    NARCIS (Netherlands)

    Sigafoos, J.; Lancioni, G.E.; O'Reilly, M.F.; Lang, R.; Singh, N.N.; Didden, H.C.M.; Green, V.A.; Marschik, P.B.

    2016-01-01

    Communication disorders are common among people with intellectual disabilities. Consequently, enhancing the communication skills of such individuals is a major intervention priority. This chapter reviews the nature and prevalence of the speech, language, and communication problems associated with

  18. Ultra-high-speed serial optical communications: Enabling technologies

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen

    2008-01-01

    This paper will present recently identified and demonstrated key technologies for ultra-high-speed serial communications. Certain key components such as stabilised highly non-linear fibre switches, periodically poled Lithium Niobate devices and semiconductor optical amplifiers will be described...... with demonstrations of 640 Gb/s transmission, clock recovery, demultiplexing, add/drop, wavelength conversion and channel identification. Timing jitter tolerance is addressed through techniques to create flat-top pulses....

  19. High-street fashion brand communication amongst female adolescents

    OpenAIRE

    Methanuntakul, Kanwipa

    2010-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. The nature of high-street fashion brands amongst female adolescents is a combined set of fast fashion movements and early adopter demands within a compressed timeframe. This research has investigated the need for a communication plan to appropriately deliver the brand message for this sector. There are a number of information barriers for high-street fashion brands to build customer value and...

  20. Photonics and other approaches to high speed communications

    Science.gov (United States)

    Maly, Kurt

    1992-01-01

    Our research group of 4 faculty and about 10-15 graduate students was actively involved (as a group) in the development of computer communication networks for the last five years. Many of its individuals have been involved in related research for a much longer period. The overall research goal is to extend network performance to higher data rates, to improve protocol performance at most ISO layers and to improve network operational performance. We briefly state our research goals, then discuss the research accomplishments and direct your attention to attached and/or published papers which cover the following topics: scalable parallel communications; high performance interconnection between high data rate networks; and a simple, effective media access protocol system for integrated, high data rate networks.

  1. High power, high efficiency millimeter wavelength traveling wave tubes for high rate communications from deep space

    Science.gov (United States)

    Dayton, James A., Jr.

    1991-01-01

    The high-power transmitters needed for high data rate communications from deep space will require a new class of compact, high efficiency traveling wave tubes (TWT's). Many of the recent TWT developments in the microwave frequency range are generically applicable to mm wave devices, in particular much of the technology of computer aided design, cathodes, and multistage depressed collectors. However, because TWT dimensions scale approximately with wavelength, mm wave devices will be physically much smaller with inherently more stringent fabrication tolerances and sensitivity to thermal dissipation.

  2. High-rate wireless data communications: An underwater acoustic communications framework at the physical layer

    Directory of Open Access Journals (Sweden)

    Bessios Anthony G.

    1996-01-01

    Full Text Available A variety of signal processing functions are performed by Underwater Acoustic Systems. These include: 1 detection to determine presence or absence of information signals in the presence of noise, or an attempt to describe which of a predetermined finite set of possible messages { m i , i , ... , M } the signal represents; 2 estimation of some parameter θ ˆ associated with the received signal (i.e. range, depth, bearing angle, etc.; 3 classification and source identification; 4 dynamics tracking; 5 navigation (collision avoidance and terminal guidance; 6 countermeasures; and 7 communications. The focus of this paper is acoustic communications. There is a global current need to develop reliable wireless digital communications for the underwater environment, with sufficient performance and efficiency to substitute for costly wired systems. One possible goal is a wireless system implementation that insures underwater terminal mobility. There is also a vital need to improve the performance of the existing systems in terms of data-rate, noise immunity, operational range, and power consumption, since, in practice, portable high-speed, long range, compact, low-power systems are desired. We concede the difficulties associated with acoustic systems and concentrate on the development of robust data transmission methods anticipating the eventual need for real time or near real time video transmission. An overview of the various detection techniques and the general statistical digital communication problem is given based on a statistical decision theory framework. The theoretical formulation of the underwater acoustic data communications problem includes modeling of the stochastic channel to incorporate a variety of impairments and environmental uncertainties, and proposal of new compensation strategies for an efficient and robust receiver design.

  3. Collaborative Blended Learning Writing Environment: Effects on EFL Students' Writing Apprehension and Writing Performance

    Science.gov (United States)

    Challob, Ala'a Ismael; Bakar, Nadzrah Abu; Latif, Hafizah

    2016-01-01

    This study examined the effects of collaborative blended learning writing environment on students' writing apprehension and writing performance as perceived by a selected group of EFL students enrolled in one of the international schools in Malaysia. Qualitative case study method was employed using semi-structured interview, learning diaries and…

  4. Participation Apprehensive Students: The Influence of Face Support and Instructor-Student Rapport on Classroom Participation

    Science.gov (United States)

    Frisby, Brandi N.; Berger, Erin; Burchett, Molly; Herovic, Emina; Strawser, Michael G.

    2014-01-01

    Participation is considered a positive student classroom behavior that can also create a face-threatening classroom climate that may be alleviated through interpersonal relationships with the instructor. Participants (N?=?189) categorized as low apprehensives perceived less face threat and more face support when participating; moderate…

  5. An Investigation of Palestinian EFL Majors' Writing Apprehension: Causes and Remedies

    Science.gov (United States)

    Abu Shawish, Jaber I.; Abdelraheem, Mohammad Atea

    2010-01-01

    A considerable number of research and reports attempted to tackle the different aspects of writing apprehension. The current research dealt with the topic quantitatively and qualitatively in an attempt to know why Palestinian university students majoring in English feel anxious and stressed when they are asked to write. The possible remedies for…

  6. High performance computing and communications: FY 1996 implementation plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-16

    The High Performance Computing and Communications (HPCC) Program was formally authorized by passage of the High Performance Computing Act of 1991, signed on December 9, 1991. Twelve federal agencies, in collaboration with scientists and managers from US industry, universities, and research laboratories, have developed the Program to meet the challenges of advancing computing and associated communications technologies and practices. This plan provides a detailed description of the agencies` HPCC implementation plans for FY 1995 and FY 1996. This Implementation Plan contains three additional sections. Section 3 provides an overview of the HPCC Program definition and organization. Section 4 contains a breakdown of the five major components of the HPCC Program, with an emphasis on the overall directions and milestones planned for each one. Section 5 provides a detailed look at HPCC Program activities within each agency.

  7. Soliton-based ultra-high speed optical communications

    Indian Academy of Sciences (India)

    Akira Hasegawa

    2001-11-01

    Multi-terabit/s, ultra-high speed optical transmissions over several thousands kilometers on fibers are becoming a reality. Most use RZ (Return to Zero) format in dispersion-managed fibers. This format is the only stable waveform in the presence of fiber Kerr nonlinearity and dispersion in all optical transmission lines with loss compensated by periodic amplifications. The nonlinear Schrödinger equation assisted by the split step numerical solutions is commonly used as the master equation to describe the information transfer in optical fibers. All these facts are the outcome of research on optical solitons in fibers in spite of the fact that the commonly used RZ format is not always called a soliton format. The overview presented here attempts to incorporate the role of soliton-based communications research in present day ultra-high speed communications.

  8. An Architecture for High Data Rate Very Low Frequency Communication

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2013-01-01

    Full Text Available Very low frequency (VLF communication is used for long range shore-to-ship broadcasting applications. This paper proposes an architecture for high data rate VLF communication using Gaussian minimum shift keying (GMSK modulation and low delay parity check (LDPC channel coding. Non-data aided techniques are designed and used for carrier phase synchronization, symbol timing recovery, and LDPC code frame synchronization. These require the estimation of the operative Eb/N0 for which a kurtosis based algorithm is used. Also, a method for modeling the probability density function of the received signal under the bit condition is presented in this regard. The modeling of atmospheric radio noise (ARN that corrupts VLF signals is described and an algorithm for signal enhancement in the presence of ARN in given. The BER performance of the communication system is evaluated for bit rates of 400 bps, 600 bps, and 800 bps for communication bandwidth of ~200 Hz.Defence Science Journal, 2013, 63(1, pp.25-33, DOI:http://dx.doi.org/10.14429/dsj.63.3760

  9. Cultivation of Intercultural Communicative Competence of Senior High School Students

    Institute of Scientific and Technical Information of China (English)

    苏丹

    2014-01-01

    With the trend of globalization in education and the strengthened position of English as a foreign language in China, the need to understand the cultural differences between Chinese and Western culture is becoming increasingly urgent, especially for the students in senior high schools in China. This paper is aimed to arouse the awareness of the urgency to improve the inter-cultural communication competence of the students in senior high school in China. It proposes four feasible and conducive sug-gestions for senior high schools in China to set up curriculum about Western culture to meet the needs of their students.

  10. Talking in Order To Learn: Willingness To Communicate and Intensive Language Programs.

    Science.gov (United States)

    MacIntyre, Peter D.; Baker, Susan C.; Clement, Richard; Donovan, Leslie A.

    2003-01-01

    Evaluates differences between immersion and non-immersion university-level students' willingness to communicate, communication apprehension, perceived competence, and frequency of communicating . Also examines elements of integrative motivation. Differences between immersion and non-immersion groups are observed in the communication-related…

  11. Analysis of OFDM Applied to Powerline High Speed Digital Communication

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Jian; YANG Gong-xu

    2003-01-01

    The low voltage powerline is becoming a powerful solution to home network, building automation, and internet access as a result of its wide distribution, easy access and little maintenance. The character of powerline channel is very complicated because it is an open net. This article analysed the character of the powerline channel,introduced the basics of OFDM(Orthogonal Frequency Division Multiplexing), and studied the OFDM applied into powerline high speed digital communication.

  12. Highly survivable communications: Complementary media packet switched networks

    Science.gov (United States)

    Yavuz, D.; Eken, F.; Karavassilis, N.

    1994-07-01

    The requirement for highly survivable communications (HSC) for essential command functions in military operations does not need any justification. The ability to communicate under extreme jamming levels and adverse propagation conditions, including high altitude nuclear events, is a very important requirement. There are also many natural disaster related requirements that also need such highly survivable communications. The prevalent and in a sense classical, approach to provide highly assured connectivity can be summarized as follows: Take a particular propagation medium and try to obtain the ultimate performance from it. There are many examples of this philosophy some successful, most not. Our approach, on the other hand, is to use complementary multi-media or mixed-media where communication links utilizing essentially commercial-off-the-shelf (COTS) equipment are integrated using packet radio (PR) techniques. There is also, in our view, an even more fundamental, recently discovered consideration why the expectation of continuous incremental refinement of a system using a given single media may be be achievable. This is derived from the theory of 'deterministic uncertainty' or more popularly known as 'theory of CHAOS', systems whose state space behavior has fractal characteristics. We will elaborate on this novel argument. Complementary multi-media approach has been the focus for all HSC communications activities at STC since 1982. The original STC studies and prototypes were in response to requirements of broadcasting (i.e., one-way transmission) information. A high frequency (HF)/meteorburst (MB) system was developed/prototyped/tested demonstrating the cost effectiveness of the approach. These results are reviewed. More recently, in 1992 STC has completed the development/test of an Open Systems Interconnection (OSI) HF packet radio protocol as no such open or non-proprietary protocol exists. This protocol has been fully tested, documented and made available to

  13. High-speed laser communications in UAV scenarios

    Science.gov (United States)

    Griethe, Wolfgang; Gregory, Mark; Heine, Frank; Kämpfner, Hartmut

    2011-05-01

    Optical links, based on coherent homodyne detection and BPSK modulation with bidirectional data transmission of 5.6 Gbps over distances of about 5,000 km and BER of 10-8, have been sufficiently verified in space. The verification results show that this technology is suitable not only for space applications but also for applications in the troposphere. After a brief description of the Laser Communication Terminal (LCT) for space applications, the paper consequently discusses the future utilization of satellite-based optical data links for Beyond Line of Sight (BLOS) operations of High Altitude Long Endurance (HALE) Unmanned Aerial Vehicles (UAV). It is shown that the use of optical frequencies is the only logical consequence of an ever-increasing demand for bandwidth. In terms of Network Centric Warfare it is highly recommended that Unmanned Aircraft Systems (UAS) of the future should incorporate that technology which allows almost unlimited bandwidth. The advantages of optical communications especially for Intelligence, Surveillance and Reconnaissance (ISR) are underlined. Moreover, the preliminary design concept of an airborne laser communication terminal is described. Since optical bi-directional links have been tested between a LCT in space and a TESAT Optical Ground Station (OGS), preliminary analysis on tracking and BER performance and the impact of atmospheric disturbances on coherent links will be presented.

  14. An Analysis of Different Addressing Terms in High Context Communication and Low Context Communication from the Perspective of Frame Theory

    Institute of Scientific and Technical Information of China (English)

    LIU Peng-li

    2014-01-01

    Within the scope of human beings, some addressing terms are similar. However, different addressing terms still exist, which are influenced by the background of high context communication or low context communication. A good example is that Chinese traditional culture, a typical instance of high context communication, puts much emphasis on etiquette, which is repre-sented in addressing terms as more complex and definite;In western, with the background of low context communication, every individual is more equal and they address each other more generally and much simpler. This paper tries to explore the addressing terms both in Chinese and in English from the perspective of frame theory.

  15. High performance computing and communications: FY 1997 implementation plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The High Performance Computing and Communications (HPCC) Program was formally authorized by passage, with bipartisan support, of the High-Performance Computing Act of 1991, signed on December 9, 1991. The original Program, in which eight Federal agencies participated, has now grown to twelve agencies. This Plan provides a detailed description of the agencies` FY 1996 HPCC accomplishments and FY 1997 HPCC plans. Section 3 of this Plan provides an overview of the HPCC Program. Section 4 contains more detailed definitions of the Program Component Areas, with an emphasis on the overall directions and milestones planned for each PCA. Appendix A provides a detailed look at HPCC Program activities within each agency.

  16. High-speed analog fiber optic links for satellite communication

    Science.gov (United States)

    Daryoush, A. S.; Herczfeld, P. R.; Kunath, R. R.

    1988-01-01

    Large-aperture phased array antennas operating at millimeter wave frequencies are designed for space-based communications and imaging. Array elements are comprised of active transmit/receive (T/R) modules which are linked to the central processing unit through a high-speed fiberoptic network. This paper demonstrates optical control of active modules for satellite communication at 24 GHz. An approach called T/R level data mixing, which utilizes fiberoptic transmission of a data signal to individual T/R modules to be upconverted by an optically synchronized local oscillator, is demonstrated at 24 GHz. A free-running HEMT oscillator, used as local oscillator at 24 GHz, is synchronized using indirect subharmonic optical injection locking over a locking range of 14 MHz. Results of data link performance over 500-1000 MHz is also reported in terms of gain-bandwidth, linearity and third-order intercept, sensitivity, and dynamic range.

  17. DEVELOPING COMMUNICATIVE LANGUAGE TESTS FOR SENIOR HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    Y. M. Harsono

    2005-01-01

    Full Text Available The Communicative Approach of teaching English in senior high school in Indonesia has been adopted since the implementation of The 1984 Curriculum, but the tests–the communicative language tests–(CL Tests have not been developed and used properly. The objective of the study is to develop CL Tests for senior high school. The procedure of conducting the study consists of three major steps, that is, identifying the objectives, developing the test specification, and developing the CL Tests. The development of the CL Tests in detail consists of fifteen sub-steps from determining what language skills tested, selecting the suitable source materials, up to rewriting the CL Tests to be used as CL Tests alternative for senior high school. The results of the test development reveal that there are fifteen CL Tests consisting of three tests of listening, three reading, three speaking, and three writing tests. The whole tests have construct and content validity, no complete evidence of concurrent validity with report marks and semester test scores, high to very high inter-rater reliability, and no complete practicality.

  18. Emerging applications of high temperature superconductors for space communications

    Science.gov (United States)

    Heinen, Vernon O.; Bhasin, Kul B.; Long, Kenwyn J.

    1990-01-01

    Proposed space missions require longevity of communications system components, high input power levels, and high speed digital logic devices. The complexity of these missions calls for a high data bandwidth capacity. Incorporation of high temperature superconducting (HTS) thin films into some of these communications system components may provide a means of meeting these requirements. Space applications of superconducting technology has previously been limited by the requirement of cooling to near liquid helium temperatures. Development of HTS materials with transition temperatures above 77 K along with the natural cooling ability of space suggest that space applications may lead the way in the applications of high temperature superconductivity. In order for HTS materials to be incorporated into microwave and millimeter wave devices, the material properties such as electrical conductivity, current density, surface resistivity and others as a function of temperature and frequency must be well characterized and understood. The millimeter wave conductivity and surface resistivity were well characterized, and at 77 K are better than copper. Basic microwave circuits such as ring resonators were used to determine transmission line losses. Higher Q values than those of gold resonator circuits were observed below the transition temperature. Several key HTS circuits including filters, oscillators, phase shifters and phased array antenna feeds are feasible in the near future. For technology to improve further, good quality, large area films must be reproducibly grown on low dielectric constant, low loss microwave substrates.

  19. Resonant communicators, effective communicators. Communicator’s flow and credibility

    Directory of Open Access Journals (Sweden)

    Irene García-Ureta, Ph.D

    2012-01-01

    Full Text Available Communication studies have been integrating the latest developments in cognitive sciences and acknowledging the importance of understanding the subjective processes involved in communication. This article argues that communication studies should also take into account the psychology of the communicator. This article presents the theoretical basis and the results of a training programme designed for audiovisual communicators. The programme is based on the theories of self-efficacy and flow and seeks to improve students’ communication competencies through the use of presentation techniques and psychological skills to tackle communication apprehension. The programme involves an active methodology that is based on modelling, visualisation, immediate feedback and positive reinforcement. A repeated-measures ANOVA shows that the programme successfully decreases the level of communication apprehension, improves the perceived self-efficacy, improves the psychological state needed to perform better in front of the cameras (flow, and improves students’ communication skills. A path analysis proved that the perceived self-efficacy and anxiety levels predict the level of flow during the communication act. At the end of the training programme, those who experienced higher levels of flow and enjoyment during the communication task achieved higher quality levels in their communication exercise. It is concluded that the concepts of self-efficacy and flow facilitate advancing in the understanding of the factors that determine a communicator’s credibility and ability to connect with the audience.

  20. The Role of Cognitive "Performance Orientation" in Communication Anxiety.

    Science.gov (United States)

    Booth-Butterfield, Melanie; Booth-Butterfield, Steve

    1993-01-01

    Finds that M. Motley's measurement (in the Performance/Communication Orientation Scale) of "performance orientation" (the presentation must be perfect and will be closely scrutinized by the audience) was not associated with communication apprehension, public speaking anxiety, nor with public self-consciousness, thus proving to be internally…

  1. High-Throughput Network Communication with NetIO

    CERN Document Server

    Schumacher, J\\"orn; The ATLAS collaboration; Vandelli, Wainer

    2016-01-01

    HPC network technologies like Infiniband, TrueScale or OmniPath provide low-latency and high-throughput communication between hosts, which makes them attractive options for data-acquisition systems in large-scale high-energy physics experiments. Like HPC networks, DAQ networks are local and include a well specified number of systems. Unfortunately traditional network communication APIs for HPC clusters like MPI or PGAS target exclusively the HPC community and are not suited well for DAQ applications. It is possible to build distributed DAQ applications using low-level system APIs like Infiniband Verbs (and this has been done), but it requires a non negligible effort and expert knowledge. On the other hand, message services like 0MQ have gained popularity in the HEP community. Such APIs allow to build distributed applications with a high-level approach and provide good performance. Unfortunately their usage usually limits developers to TCP/IP-based networks. While it is possible to operate a TCP/IP stack on to...

  2. Iridium: Global OTH data communications for high altitude scientific ballooning

    Science.gov (United States)

    Denney, A.

    While the scientific community is no stranger to embracing commercially available technologies, the growth and availability of truly affordable cutting edge technologies is opening the door to an entirely new means of global communications. For many years high altitude ballooning has provided science an alternative to costly satellite based experimental platforms. As with any project, evolution becomes an integral part of development. Specifically in the NSBF ballooning program, where flight durations have evolved from the earlier days of hours to several weeks and plans are underway to provide missions up to 100 days. Addressing increased flight durations, the harsh operational environment, along with cumbersome and outdated systems used on existing systems, such as the balloon vehicles Support Instrumentation Package (SIP) and ground-based systems, a new Over-The-Horizon (OTH) communications medium is sought. Current OTH equipment planning to be phased-out include: HF commanding systems, ARGOS PTT telemetry downlinks and INMARSAT data terminals. Other aspects up for review in addition to the SIP to utilize this communications medium include pathfinder balloon platforms - thereby, adding commanding abilities and increased data rates, plus providing a package for ultra-small experiments to ride aloft. Existing communication systems employed by the National Scientific Balloon Facility ballooning program have been limited not only by increased cost, slow data rates and "special government use only" services such as TDRSS (Tracking and Data Relay Satellite System), but have had to make special provisions to geographical flight location. Development of the Support Instrumentation Packages whether LDB (Long Duration Balloon), ULDB (Ultra Long Duration Balloon) or conventional ballooning have been plagued by non-standard systems configurations requiring additional support equipment for different regions and missions along with a myriad of backup for redundancy. Several

  3. Radio Synthesis Imaging - A High Performance Computing and Communications Project

    Science.gov (United States)

    Crutcher, Richard M.

    The National Science Foundation has funded a five-year High Performance Computing and Communications project at the National Center for Supercomputing Applications (NCSA) for the direct implementation of several of the computing recommendations of the Astronomy and Astrophysics Survey Committee (the "Bahcall report"). This paper is a summary of the project goals and a progress report. The project will implement a prototype of the next generation of astronomical telescope systems - remotely located telescopes connected by high-speed networks to very high performance, scalable architecture computers and on-line data archives, which are accessed by astronomers over Gbit/sec networks. Specifically, a data link has been installed between the BIMA millimeter-wave synthesis array at Hat Creek, California and NCSA at Urbana, Illinois for real-time transmission of data to NCSA. Data are automatically archived, and may be browsed and retrieved by astronomers using the NCSA Mosaic software. In addition, an on-line digital library of processed images will be established. BIMA data will be processed on a very high performance distributed computing system, with I/O, user interface, and most of the software system running on the NCSA Convex C3880 supercomputer or Silicon Graphics Onyx workstations connected by HiPPI to the high performance, massively parallel Thinking Machines Corporation CM-5. The very computationally intensive algorithms for calibration and imaging of radio synthesis array observations will be optimized for the CM-5 and new algorithms which utilize the massively parallel architecture will be developed. Code running simultaneously on the distributed computers will communicate using the Data Transport Mechanism developed by NCSA. The project will also use the BLANCA Gbit/s testbed network between Urbana and Madison, Wisconsin to connect an Onyx workstation in the University of Wisconsin Astronomy Department to the NCSA CM-5, for development of long

  4. High performance computing and communications: FY 1995 implementation plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-04-01

    The High Performance Computing and Communications (HPCC) Program was formally established following passage of the High Performance Computing Act of 1991 signed on December 9, 1991. Ten federal agencies in collaboration with scientists and managers from US industry, universities, and laboratories have developed the HPCC Program to meet the challenges of advancing computing and associated communications technologies and practices. This plan provides a detailed description of the agencies` HPCC implementation plans for FY 1994 and FY 1995. This Implementation Plan contains three additional sections. Section 3 provides an overview of the HPCC Program definition and organization. Section 4 contains a breakdown of the five major components of the HPCC Program, with an emphasis on the overall directions and milestones planned for each one. Section 5 provides a detailed look at HPCC Program activities within each agency. Although the Department of Education is an official HPCC agency, its current funding and reporting of crosscut activities goes through the Committee on Education and Health Resources, not the HPCC Program. For this reason the Implementation Plan covers nine HPCC agencies.

  5. The Apprehension and views of the students of music education department about studio recording performance

    Directory of Open Access Journals (Sweden)

    Alaattin CANBAY

    2015-07-01

    Full Text Available Being individually staged of music has been a performance process that always requires intensive concentration, attention and long - running work for performers. At the end of this process, generally during their performance, musicians feel apprehensive and excited about some reasons like carrying out work's musical and technical factors properly and sense of being appreciated by audiences. In many surveys, it is known that ,in concerts and their own instrument exams, the apprehension of undergraduate student s of music education department ,who have experienced this process, affects their performances negatively. Thus, the aim of this study is to specify the music education undergraduate students' apprehension level before a studio recording that needs a very special performance according to different variables. Also in this study, students' views about their studio recording experiences are taken. In the study, descriptive research is used and the technical qualitative research is imposed. In the study carried out for two months, working party is designated by the students of Çomu - Faculty of Education, Department of Fine arts education, Department of music education.

  6. Applying innovation method to assess english speaking performance on communication apprehension

    OpenAIRE

    Wang, Li-Jyu; Chang, Hung-Fan

    2010-01-01

    A growing number of research studies are now available to shed some light on ELT methods. Currently, educational portfolios are implemented in Science, Mathematics and Geography and also have become widely used in ELT. When the students prepared their own portfolios, they self-monitored their performances. The purpose of this study was to investigate the effects of self-monitoring and portfolios on college students’ English speaking performance. The participants involved in this study were 60...

  7. Intercultural Communication Apprehension and Emotional Intelligence in Higher Education: Preparing Business Students for Career Success

    Science.gov (United States)

    Fall, Lisa T.; Kelly, Stephanie; MacDonald, Patrick; Primm, Charles; Holmes, Whitney

    2013-01-01

    Given the expanding globalized workforce, business educators continue to seek new ways to prepare students for intercultural encounters. Although immersion in other cultures is the optimal strategy, this method is not always feasible. As such, educators seek other mechanisms to simulate intercultural experiences. This study examines emotional…

  8. Intercultural Communication Apprehension and Emotional Intelligence in Higher Education: Preparing Business Students for Career Success

    Science.gov (United States)

    Fall, Lisa T.; Kelly, Stephanie; MacDonald, Patrick; Primm, Charles; Holmes, Whitney

    2013-01-01

    Given the expanding globalized workforce, business educators continue to seek new ways to prepare students for intercultural encounters. Although immersion in other cultures is the optimal strategy, this method is not always feasible. As such, educators seek other mechanisms to simulate intercultural experiences. This study examines emotional…

  9. Using Classroom Layout to Help Reduce Students' Apprehension and Increase Communication

    Science.gov (United States)

    Rae, Kirsten; Sands, John

    2013-01-01

    When teaching introductory management accounting courses at undergraduate level, the authors noticed that some students experience difficulty in integrating theoretical and technical knowledge of management accounting and applying it to specific scenarios. However, based on the authors' experience, the problems faced by students when learning…

  10. Training-Based Schemes are Suboptimal for High Rate Asynchronous Communication

    CERN Document Server

    Chandar, Venkat; Wornell, Gregory W

    2009-01-01

    We consider asynchronous point-to-point communication. Building on a recently developed model, we show that training based schemes, i.e., communication strategies that separate synchronization from information transmission, perform suboptimally at high rate.

  11. Capacity of High-Speed Powerline Communication in Vehicles

    Directory of Open Access Journals (Sweden)

    Deny Hamdani

    2010-10-01

    Full Text Available Powerline Communication (PLC Systems intents to use the mains network in vehicles for high-speed data transmission. Carrier frequencies in the range of MHz are required to establish data rates of some megabits per second. In this paper, typical reference channels extracted from channel measurements are presented and computation results of their capacities according to Shannon's theorem are presented. Furthermore, the effect of limitations of frequency range and power spectral density of transmitted signal on achievable capacity is investigated. This paper outlines an assessment for theoretical channel capacity and achievable data rates of vehicular PLC transmission schemes. Finally, EMC (Electromagnetics Compatibility constraint according to CISPR 25 (Comite International Special des Perturbations Radioelectrique - The International Special Committee on Radio Interference is deeply considered.

  12. Influence of Speech Anxiety on Oral Communication Skills among ESL/EFL Learners

    Directory of Open Access Journals (Sweden)

    Said Muhammad Khan

    2015-12-01

    Full Text Available The realization of speech anxiety among ESL/EFL learners is important. Once understood, these feelings of fear or nervousness may be relieved and the desired objectives of learning the target language may be achieved.  The study has attempted to measure the level of anxiety among ESL/EFL learners at HITEC University, Taxila, Pakistan. The current research has arrived at the conclusion that the target population is highly anxious in situation where they are required to speak English. The findings show that sources such as pedagogical, psychological, socio-economic, linguistic and cultural generate anxiety among the EFL learners. The study has suggested variety of strategies to treat anxiety in the academic context. It was found that communicative approach in classroom may be helpful in minimizing the negative impact of anxiety among language learners. Keywords:  speech anxiety, communicative approach, communication apprehension, FLA

  13. The design of space optical communications terminal with high efficient

    Science.gov (United States)

    Deng, Xiaoguo; Li, Gang; Jiang, Bo; Yang, Xiaoxu; Yan, Peipei

    2015-02-01

    In order to improve high-speed laser space optical communications terminal receive energy and emission energy, meet the demand of mini-type and light-type for space-based bear platform, based on multiple-reflect coaxial optical receiving antenna structure, while considering the installation difficulty, a high-efficient optical system had been designed, which aperture is off-axial, both signal-receiving sub-optical system and emission sub-optical system share a same primary optical path. By the separating light lens behind the primary optical path, the received light with little energy will be filtered and shaped and then transmitted to each detector, at the same time, by the coupling element, the high-power laser will be coupling into optical antenna, and then emitted to outside. Applied the power-detected optical system evaluate principle, the optimized off-axial optical system's efficiency had been compared with the coaxial optical system. While, analyzed the Gauss beam energy distribution by numerical theory, discussed that whether off-axis optical system can be an emission terminal, verify the feasibility of the theory of the design of the system.

  14. Improving Communicative Ability in English Task-based Teaching in senior high school

    Institute of Scientific and Technical Information of China (English)

    熊洁

    2016-01-01

    Language is an important means of human communication. More and more people have realized that improving the English communicative competence, especially oral English communicative ability is very important. However, the senior high school students’ oral English communicative competence is not optimistic. This paper analyzes the problems existing in the high school students’ communication based on the study of the task-based teaching theory. Task-based teaching method gradually popularized in the high school English classroom teaching due to its emphasis on the change of students’ learning style and the way of teachers’ teaching.

  15. Communications

    Science.gov (United States)

    Bailenson, Jeremy; Buzzanell, Patrice; Deetz, Stanley; Tewksbury, David; Thompson, Robert J.; Turow, Joseph; Bichelmeyer, Barbara; Bishop, M. J.; Gayeski, Diane

    2013-01-01

    Scholars representing the field of communications were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Jeremy Bailenson, Patrice Buzzanell, Stanley Deetz, David Tewksbury, Robert J. Thompson, and…

  16. A Comparison of the Turkish and Romanian Students' Willingness to Communicate and Its Affecting Factors in English

    Science.gov (United States)

    Asmali, Mehmet; Bilki, Ufuk; Duban, Carina Adriana

    2015-01-01

    The present study attempts to offer a small-scale investigation of the willingness to communicate and its key antecedents, namely the self-perceived communication competence and the communication apprehension in Turkish and Romanian contexts. A total of 130 participants took part in this quantitative approach based study. The data suggested…

  17. A DSP Based POD Implementation for High Speed Multimedia Communications

    Directory of Open Access Journals (Sweden)

    Chang Nian Zhang

    2002-09-01

    Full Text Available In the cable network services, the audio/video entertainment contents should be protected from unauthorized copying, intercepting, and tampering. Point-of-deployment (POD security module, proposed by OpenCableTM, allows viewers to receive secure cable services such as premium subscription channels, impulse pay-per-view, video-on-demand as well as other interactive services. In this paper, we present a digital signal processor (DSP (TMS320C6211 based POD implementation for the real-time applications which include elliptic curve digital signature algorithm (ECDSA, elliptic curve Diffie Hellman (ECDH key exchange, elliptic curve key derivation function (ECKDF, cellular automata (CA cryptography, communication processes between POD and Host, and Host authentication. In order to get different security levels and different rates of encryption/decryption, a CA based symmetric key cryptography algorithm is used whose encryption/decryption rate can be up to 75 Mbps. The experiment results indicate that the DSP based POD implementation provides high speed and flexibility, and satisfies the requirements of real-time video data transmission.

  18. Modelling high data rate communication network access protocol

    Science.gov (United States)

    Khanna, S.; Foudriat, E. C.; Paterra, Frank; Maly, Kurt J.; Overstreet, C. Michael

    1990-01-01

    Modeling of high data rate communication systems is different from the low data rate systems. Three simulations were built during the development phase of Carrier Sensed Multiple Access/Ring Network (CSMA/RN) modeling. The first was a model using SIMCRIPT based upon the determination and processing of each event at each node. The second simulation was developed in C based upon isolating the distinct object that can be identified as the ring, the message, the node, and the set of critical events. The third model further identified the basic network functionality by creating a single object, the node which includes the set of critical events which occur at the node. The ring structure is implicit in the node structure. This model was also built in C. Each model is discussed and their features compared. It should be stated that the language used was mainly selected by the model developer because of his past familiarity. Further the models were not built with the intent to compare either structure or language but because the complexity of the problem and initial results contained obvious errors, so alternative models were built to isolate, determine, and correct programming and modeling errors. The CSMA/RN protocol is discussed in sufficient detail to understand modeling complexities. Each model is described along with its features and problems. The models are compared and concluding observations and remarks are presented.

  19. Multiplexed communication over a high-speed quantum channel

    CERN Document Server

    Heurs, M; Dunlop, A E; Harb, C C; Ralph, T C; Huntington, E H

    2010-01-01

    In quantum information systems it is of particular interest to consider the best way in which to use the non-classical resources consumed by that system. Quantum communication protocols are integral to quantum information systems and are amongst the most promising near-term applications of quantum information science. Here we show that a multiplexed, digital quantum communications system supported by comb of vacuum squeezing has a greater channel capacity per photon than a source of broadband squeezing with the same analogue bandwidth. We report on the time-resolved, simultaneous observation of the first dozen teeth in a 2.4 GHz comb of vacuum squeezing produced by a sub-threshold OPO, as required for such a quantum communications channel. We also demonstrate multiplexed communication on that channel.

  20. Capacity analysis for high-speed terahertz wireless communications

    DEFF Research Database (Denmark)

    Dogadaev, Anton Konstantinovich; Lavrinenko, Andrei; Tafur Monroy, Idelfonso

    2012-01-01

    We report on the analytical capacity analysis of terahertz wireless communications supporting 275–325 GHz frequency band. Our goal in this paper is to provide design guidelines for close proximity links with transmission capacity beyond 100 Gbit/s.......We report on the analytical capacity analysis of terahertz wireless communications supporting 275–325 GHz frequency band. Our goal in this paper is to provide design guidelines for close proximity links with transmission capacity beyond 100 Gbit/s....

  1. Walking the straight and narrow: the moderating effect of evaluation apprehension on the relationship between collectivism and corruption.

    Science.gov (United States)

    Huang, Zhen-wei; Liu, Li; Zheng, Wen-wen; Tan, Xu-yun; Zhao, Xian

    2015-01-01

    Previous studies obtained mixed results regarding the association between collectivism and corruption. To make sense of the mixed results, the current research examined the moderating role of evaluation apprehension on the relationship between collectivism and corruption. Study 1, using a bribery scenario, indicated that collectivism facilitated corruption only when evaluation apprehension was low. Study 2, using a real money bribery game, confirmed the moderated model found in Study 1. Study 3 further demonstrated the different effects of vertical/horizontal collectivism on corruption. Our results suggest that a society may effectively combat corruption by increasing its social costs while, at the same time, retaining its collectivistic values.

  2. Communication in high technology product development projects:project personnel’s viewpoint for improvement

    OpenAIRE

    Väänänen, M. (Mirja)

    2010-01-01

    Abstract Product development plays a crucial role in the survival of high technology companies. High technology product development projects typically are multi-technical, multicultural, geographically dispersed, inter-connected and organized in a network of companies. These settings pose extra challenges for communication. In this qualitative multiple-case study, communication challenges and possible solutions for developing communication were studied. The empirical data were collect...

  3. Remote Control: Identity, Power, and Technology in the Communication Classroom

    Science.gov (United States)

    Wood, Andrew F.; Fassett, Deanna L.

    2003-01-01

    Instructional communication researchers, by focusing attention on "how-to" matters and forays into conventional areas of study (i.e., immediacy, apprehension), neglect a nuanced treatment of student and teacher identity. Such a perspective is relatively disembodied and fails to engage actual classroom interactions. By engaging in autoethnographic…

  4. The Effects of Students' Predispositions toward Communication, Learning Styles, and Sex on Academic Achievement

    Science.gov (United States)

    Allen, Jerry L.; Long, Kathleen M.; O'Mara, Joan; Judd, Ben B.

    2007-01-01

    The purpose of this study was to examine the relationships among students' biological sex, communication avoidance behaviors, individual learning styles, and classroom achievement. Additionally, the relationship of instructors' gender to students' perceptions of immediacy and learning outcomes was examined. Communication apprehension and nonverbal…

  5. High available and fault tolerant mobile communications infrastructure

    DEFF Research Database (Denmark)

    Beiroumi, Mohammad Zib

    2006-01-01

    as it is the case for many recovery techniques. In addition, the method does not require any modification to mobile clients. The Communicating Extended Finite State Machine (CEFSM) is used to model the behavior of the infrastructure applications. The model based recovery scheme is integrated in the application...... using rollback or replication techniques inapplicable. This dissertation presents a novel failure recovery approach based on a behavioral model of the communication protocols. The new recovery method is able to deal with software and hardware faults and is particularly suitable for mobile communications...... infrastructure. The method enables the faulty applications in the infrastructure to quickly and effectively resume their services to their mobile clients with no or minimal loss of work after failure. In our approach, we do not assume a specific fault behavior for example failstop or transient behavior...

  6. Verifying cell loss requirements in high-speed communication networks

    Directory of Open Access Journals (Sweden)

    Kerry W. Fendick

    1998-01-01

    Full Text Available In high-speed communication networks it is common to have requirements of very small cell loss probabilities due to buffer overflow. Losses are measured to verify that the cell loss requirements are being met, but it is not clear how to interpret such measurements. We propose methods for determining whether or not cell loss requirements are being met. A key idea is to look at the stream of losses as successive clusters of losses. Often clusters of losses, rather than individual losses, should be regarded as the important “loss events”. Thus we propose modeling the cell loss process by a batch Poisson stochastic process. Successive clusters of losses are assumed to arrive according to a Poisson process. Within each cluster, cell losses do not occur at a single time, but the distance between losses within a cluster should be negligible compared to the distance between clusters. Thus, for the purpose of estimating the cell loss probability, we ignore the spaces between successive cell losses in a cluster of losses. Asymptotic theory suggests that the counting process of losses initiating clusters often should be approximately a Poisson process even though the cell arrival process is not nearly Poisson. The batch Poisson model is relatively easy to test statistically and fit; e.g., the batch-size distribution and the batch arrival rate can readily be estimated from cell loss data. Since batch (cluster sizes may be highly variable, it may be useful to focus on the number of batches instead of the number of cells in a measurement interval. We also propose a method for approximately determining the parameters of a special batch Poisson cell loss with geometric batch-size distribution from a queueing model of the buffer content. For this step, we use a reflected Brownian motion (RBM approximation of a G/D/1/C queueing model. We also use the RBM model to estimate the input burstiness given the cell loss rate. In addition, we use the RBM model to

  7. High-context and Low-context communication:A Case Study of A Chinese Refusal

    Institute of Scientific and Technical Information of China (English)

    吴建晓; 钱敏

    2013-01-01

    Edward Hall offers us an effective means of examining cultural similarities and differences, that is the classification of high-context and low-context culture. The paper attempts to analyze a case of a Chinese refusal from the perspective of high-context and low-context communication and explores the differences between the two types of communication.

  8. Investigation of the Effect of Sport on Submissive Behavior and Communication Skills of High School Students

    Science.gov (United States)

    Abakay, Ugur

    2013-01-01

    This study was carried out to detect the differences in submissive behaviors and communication skills of high school students in terms of sports activities and relationship between communication skills and properties of submissive behavior of high school students who are actively involved in sports activities. In this respect at the study, 728…

  9. Investigation of the Effect of Sport on Submissive Behavior and Communication Skills of High School Students

    Science.gov (United States)

    Abakay, Ugur

    2013-01-01

    This study was carried out to detect the differences in submissive behaviors and communication skills of high school students in terms of sports activities and relationship between communication skills and properties of submissive behavior of high school students who are actively involved in sports activities. In this respect at the study, 728…

  10. COMMUNICATIONS

    CERN Document Server

    A. Petrilli

    2013-01-01

    The organisation of the Open Days at the end of September was the single biggest effort of the CMS Communications Group this year. We would like to thank all volunteers for their hard work to show our Point 5 facilities and explain science and technology to the general public. During two days more than 5,000 people visited the CMS detector underground and profited from the surface activities, which included an exhibition on CMS, a workshop on superconductivity, and an activity for our younger visitors involving wooden Kapla blocks. The Communications Group took advantage of the preparations to produce new CMS posters that can be reused at other venues. Event display images have been produced not just for this occasion but also for other exhibits, education purposes, publications etc. During the Open Days, Gilles Jobin, 2012 winner of CERN Collide@CERN prize, performed his Quantum show in Point 5, with the light installation of German artist Julius von Bismarck. Image 3: CERN Open Days at CMS wel...

  11. COMMUNICATIONS

    CERN Multimedia

    L. Taylor and D. Barney

    2010-01-01

    CMS Centres, Outreach and the 7 TeV Media Event The new CMS Communications group is now established and is addressing three areas that are critical to CMS as it enters the physics operations phase: - Communications Infrastructure, including almost 50 CMS Centres Worldwide, videoconferencing systems, and CERN meeting rooms - Information systems, including the internal and external Web sites as well as the document preparation and management systems - Outreach and Education activities, including working with print, radio and TV media, visits to CMS, and exhibitions. The group has been active in many areas, with the highest priority being accorded to needs of CMS operations and preparations for the major media event planned for 7 TeV collisions. Unfortunately the CMS Centre@CERN suffered a major setback when, on 21st December, a cooling water pipe froze and burst on the floor above the CMS Centre main room. Water poured through the ceiling, flooding the floor and soaking some of the consoles, before e...

  12. The social and communication impact of stuttering on adolescents and their families.

    Science.gov (United States)

    Erickson, Shane; Block, Susan

    2013-12-01

    Stuttering can cause wide ranging psychosocial impact. This is particularly the case for adolescents who may face additional physical, emotional and personality changes as they become adults. This study reports the findings of an investigation into the social and communication impacts of stuttering on Australian adolescents seeking treatment for stuttering and their families. A cross-sectional design utilising questionnaires assessed the self-perceived communication competence and apprehension, stigma and disclosure, and experiences of teasing and bullying of 36 adolescents who stutter. Additionally, the impact of stuttering on the families of these adolescents was investigated. Adolescents who stutter have below average self-perceived communication competence, heightened communication apprehension, are teased and bullied more often than fluent peers, and they try to keep their stuttering secret. The families of the adolescents in the study reported high levels of emotional strain, family conflict and difficulty managing their child's frustrations. The findings from this study emphasise the wide-ranging impact of stuttering beyond the surface level behaviours. Clinicians working with adolescents who stutter should take note of both the outcomes of this study and the suggestions for more effectively coping with the condition in this population. The reader will be able to: (a) summarise findings with regards to the impact of stuttering on an adolescent's social and communication skills; (b) summarise areas of impact on the families of adolescents who stutter; (c) compare these findings with previous reported data for this population; (d) discuss the clinical implications of the results for working with adolescents who stutter and their families. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Communications Through Media: A Career Program for High School Students.

    Science.gov (United States)

    Finkelstein, Norman H.

    The Brookline, Massachusetts, Public School System's career education program includes a Communications Through Media curriculum. The four-year sequence is designed primarily for students oriented to media careers, but is also open to others with media interests. The program's core course is taught in the 9th grade and seeks to acquaint students…

  14. High Performing Teams: The Moderating Effects of Communication Channels

    Science.gov (United States)

    2008-03-01

    3 LITERATURE REVIEW ............................................................................................................................ 4...in Mogadishu, Somalia, Operation GOTHIC SERPENT quickly ran into several complications before turning into a rescue operation (Bowden, 1999). For...have on verbal team member communication and team performance? 3 CHAPTER 2 LITERATURE REVIEW Collaborative Environments Because

  15. When Are High-Tech Communicators Effective in Parkinson's Disease?

    Science.gov (United States)

    Ferriero, Giorgio; Caligari, Marco; Ronconi, Gianpaolo; Franchignoni, Franco

    2012-01-01

    This report describes a 63-year-old woman with Parkinson's disease showing loss of intelligibility of speech and severely impaired handwriting, despite undergoing physical and speech therapies. As the patient had sufficient residual motor abilities and adequate cognitive function and motivation, a computer-based communication aid with a software…

  16. Application of Communicative Approach in High School English Teaching

    Institute of Scientific and Technical Information of China (English)

    段静

    2009-01-01

    In recent decades, More and more linguistic teachers have accepted communicative approach and have become more concerned for the effectiveness of classroom teaching. CLT has exerted its importances and advantages in China.This paper will focus on the application of CLT in specific classrooms of Middle School through the recognization of the significance of CLT.

  17. Programmable High-Rate Multi-Mission Receiver for Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current and upcoming NASA space links require both highly reliable low-rate communications links supporting critical TT&C, ranging and voice services and highly...

  18. FY 1995 Blue Book: High Performance Computing and Communications: Technology for the National Information Infrastructure

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — The Federal High Performance Computing and Communications HPCC Program was created to accelerate the development of future generations of high performance computers...

  19. Are International Students Quiet in Class? The Influence of Teacher Confirmation on Classroom Apprehension and Willingness to Talk in Class

    Science.gov (United States)

    Hsu, Chia-Fang; Huang, I-Ting

    2017-01-01

    This study investigated the influence of teacher confirmation (TC) on classroom apprehension (CCA) and willingness to talk in class (WTT) among international students in the United States. The participants (N = 121) completed a battery of self-report instruments online. Results confirmed a path model that TC positively predicts classroom…

  20. Reliability analysis for the 220 kV Libyan high voltage communication system

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, O.S.A.; AlAthram, A.Y. [General Electric Company of Libya (Libyan Arab Jamahiriya). Development Dept.

    2007-07-01

    Electric utilities are expanding their networks to include fiber-optic communications, which offer high capacity with reliable performance at low cost. Fiber-optic networks offer a feasible technical solution for leasing excess capacity. They can be readily deployed under a wide range of network configurations and can be upgraded rapidly. This study evaluated the reliability index for the communication network of Libya's 220 kV high voltage subsystem operated by the General Electric Company of Libya (GECOL). The schematic diagrams of the communication networks were presented for both power line carriers and fiber optics networks. A reliability analysis for the two communication networks was performed through the existing communication equipment. The reliability values revealed that the fiber optics system has several advantages such as a large bandwidth for high quality data transmission; immunity to electromagnetic interference; low attenuation which allows for extended cable transmission; ability to be used in dangerous environments; a higher degree of security; and, a high capacity through existing conduits due to its light weight and small diameter. However, it was noted that although fiber optic communications may be more reliable and provide the clearest signal, the powerline communication (PLC) system has more redundancy, particularly in the case of outdoor components where the PLC has more power line to carry the signals, while the fiber optic communications depend only on the earthing wire of the high voltage transmission line. 4 refs., 8 tabs., 6 figs.

  1. Propagation Impact on Modern HF (High Frequency) Communications System Design

    Science.gov (United States)

    1986-03-01

    US Gvt Printing Office, Washington DC. Piggot, W.R., Rawer, K. (1972). URSI Handbook for lonogram Interpretation and... Handbook ", Communications Research Centre Report No. 1255, 1974. Widrow B., Mantey P.E., Griffiths L.J. and Goode B.B., "Adaptive Antenna Systems...implemented in modified form by the terminal node controller (TNC). In the U.S., Amateur Radio Relay League ( ARRL ) radio amateurs have held four annual

  2. Startle reflex modulation and autonomic responding during anxious apprehension in panic disorder patients.

    Science.gov (United States)

    Melzig, Christiane A; Weike, Almut I; Zimmermann, Jörg; Hamm, Alfons O

    2007-11-01

    The present study explored anxious apprehension in panic disorder patients and controls in two threat conditions, darkness and threat of shock. Autonomic arousal and startle eyeblink reflexes were recorded in 26 panic disorder patients and 22 controls during adaptation, a safe condition, threat of shock, and darkness. Exposure to darkness resulted in a clear potentiation of the startle reflex. Panic patients but not controls responded with an increase in heart rate that was positively related to severity of agoraphobic avoidance. Threat of shock resulted in a startle potentiation that tended to be stronger in panic patients without comorbid depression than controls and attenuated in those patients who suffered from severe depression. These data suggest that only panic patients without depression belong to the fear disorders spectrum whereas panic patients with comorbid depression might rather belong to the distress disorders profile.

  3. Space Link Extension (SLE) Emulation for High-Throughput Network Communication

    Science.gov (United States)

    Murawski, Robert W.; Tchorowski, Nicole; Golden, Bert

    2014-01-01

    As the data rate requirements for space communications increases, significant stress is placed not only on the wireless satellite communication links, but also on the ground networks which forward data from end-users to remote ground stations. These wide area network (WAN) connections add delay and jitter to the end-to-end satellite communication link, effects which can have significant impacts on the wireless communication link. It is imperative that any ground communication protocol can react to these effects such that the ground network does not become a bottleneck in the communication path to the satellite. In this paper, we present our SCENIC Emulation Lab testbed which was developed to test the CCSDS SLE protocol implementations proposed for use on future NASA communication networks. Our results show that in the presence of realistic levels of network delay, high-throughput SLE communication links can experience significant data rate throttling. Based on our observations, we present some insight into why this data throttling happens, and trace the probable issue back to non-optimal blocking communication which is sup-ported by the CCSDS SLE API recommended practices. These issues were presented as well to the SLE implementation developers which, based on our reports, developed a new release for SLE which we show fixes the SLE blocking issue and greatly improves the protocol throughput. In this paper, we also discuss future developments for our end-to-end emulation lab and how these improvements can be used to develop and test future space communication technologies.

  4. Communicating about risk: strategies for situations where public concern is high but the risk is low

    Directory of Open Access Journals (Sweden)

    Claire Hooker

    2017-02-01

    Full Text Available In this article, we summarise research that identifies best practice for communicating about hazards where the risk is low but public concern is high. We apply Peter Sandman’s ‘risk = hazard + outrage’ formulation to these risks, and review factors associated with the amplification of risk signals. We discuss the structures that determine the success of risk communication strategies, such as the capacity for early communication to ‘capture’ the dominant representation of risk issues, the importance of communicating uncertainty, and the usefulness of engaging with communities. We argue that, when facing trade-offs in probable outcomes from communication, it is always best to choose strategies that maintain or build trust, even at the cost of initial overreactions. We discuss these features of successful risk communication in relation to a range of specific examples, particularly opposition to community water fluoridation, Ebola, and routine childhood immunisation.

  5. Measuring University Students' Perceived Self-Efficacy in Science Communication in Middle and High Schools

    Science.gov (United States)

    Chi, Shaohui; Liu, Xiufeng; Gardella, Joseph A.

    2016-01-01

    Service learning typically involves university students in teaching and learning activities for middle and high school students, however, measurement of university students' self-efficacy in science communication is still lacking. In this study, an instrument to measure university students' perceived self-efficacy in communicating science to…

  6. The Application of Communicative Approach in Spoken English Teaching in High School

    Institute of Scientific and Technical Information of China (English)

    蔡媚

    2015-01-01

    This paper first discusses main problems in spoken English teaching in Chinese high school.Then,it explores communicative approach as a possible solution to those problems by elaborating its definition,characteristics,principles.Finally,the paper suggests some possible corresponding solutions to overcome the defects of communicative approach in spoken English teaching.

  7. The Application of Communicative Approach in Spoken English Teaching in High School

    Institute of Scientific and Technical Information of China (English)

    蔡媚

    2015-01-01

    This paper first discusses main problems in spoken English teaching in Chinese high school.Then,it explores communicative approach as a possible solution to those problems by elaborating its definition,characteristics,principles. Finally,the paper suggests some possible corresponding solutions to overcome the defects of communicative approach in spoken English teaching.

  8. Cultural Terms for Communication Events among Some American High School Adolescents.

    Science.gov (United States)

    Baxter, Leslie A.; Goldsmith, Daena

    1990-01-01

    Examines the natural language descriptions employed by American high school adolescents in talking about the kinds of communication events they experience in everyday life. Finds that adolescents describe communication events through use of setting, participant, speech act, and purpose marker terms. Differentiates nine basic clusters of…

  9. Current Trends of High capacity Optical Interconnection Data Link in High Performance Optical Communication Systems

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2013-02-01

    Full Text Available Optical technologies are ubiquitous in telecommunications networks and systems, providing multiple wavelength channels of transport at 2.5 Gbit/sec to 40 Gbit/sec data rates over single fiber optic cables. Market pressures continue to drive the number of wavelength channels per fiber and the data rate per channel. This trend will continue for many years to come as electronic commerce grows and enterprises demand higher and reliable bandwidth over long distances. Electronic commerce, in turn, is driving the growth curves for single processor and multiprocessor performance in data base transaction and Web based servers. Ironically, the insatiable taste for enterprise network bandwidth, which has driven up the volume and pushed down the price of optical components for telecommunications, is simultaneously stressing computer system bandwidth increasing the need for new interconnection schemes and providing for the first time commercial opportunities for optical components in computer systems. The evolution of integrated circuit technology is causing system designs to move towards communication based architectures. We have presented the current tends of high performance system capacity of optical interconnection data transmission link in high performance optical communication and computing systems over wide range of the affecting parameters.

  10. Scholarly communication in High-Energy Physics past, present and future innovations

    CERN Document Server

    Aymar, Robert

    2009-01-01

    Unprecedented technological advancements have radically changed the way we communicate and, at the same time, are effectively transforming science into e-Science. In turn, this transformation calls for an evolution in scholarly communication. This review describes several innovations, spanning the last decades of scholarly communication in High Energy Physics: the first repositories, their interaction with peer-reviewed journals, a proposed model for Open Access publishing and a next-generation repository for the field. We hope that some of these innovations, which are deeply rooted in the highly-interconnected and world-wide flavour of the High-Energy Physics community can serve as an inspiration to other communities.

  11. FY 1992 Blue Book: Grand Challenges: High Performance Computing and Communications

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — High performance computing and computer communications networks are becoming increasingly important to scientific advancement, economic competition, and national...

  12. FY 1996 Blue Book: High Performance Computing and Communications: Foundations for America`s Information Future

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — The Federal High Performance Computing and Communications HPCC Program will celebrate its fifth anniversary in October 1996 with an impressive array of...

  13. FY 1997 Blue Book: High Performance Computing and Communications: Advancing the Frontiers of Information Technology

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — The Federal High Performance Computing and Communications HPCC Program will celebrate its fifth anniversary in October 1996 with an impressive array of...

  14. FY 1993 Blue Book: Grand Challenges 1993: High Performance Computing and Communications

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — High performance computing and computer communications networks are becoming increasingly important to scientific advancement, economic competition, and national...

  15. Hierarchical Cellular Structures in High-Capacity Cellular Communication Systems

    CERN Document Server

    Jain, R K; Agrawal, N K

    2011-01-01

    In the prevailing cellular environment, it is important to provide the resources for the fluctuating traffic demand exactly in the place and at the time where and when they are needed. In this paper, we explored the ability of hierarchical cellular structures with inter layer reuse to increase the capacity of mobile communication network by applying total frequency hopping (T-FH) and adaptive frequency allocation (AFA) as a strategy to reuse the macro and micro cell resources without frequency planning in indoor pico cells [11]. The practical aspects for designing macro- micro cellular overlays in the existing big urban areas are also explained [4]. Femto cells are inducted in macro / micro / pico cells hierarchical structure to achieve the required QoS cost effectively.

  16. Innovation in scholarly communications. Vision and projects from High-Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Heuer, R.D.; Holtkamp, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Mele, S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

    2008-05-15

    Having always been at the forefront of information management and open access, High-Energy Physics (HEP) proves to be an ideal test-bed for innovations in scholarly communication including new information and communication technologies. Three selected topics of scholarly communication in High-Energy Physics are presented here: A new open access business model, SCOAP, a world-wide sponsoring consortium for peer-reviewed HEP literature; the design, development and deployment of an e-infrastructure for information management; and the emerging debate on long-term preservation, re-use and (open) access to HEP data. (orig.)

  17. Innovation in Scholarly Communication Vision and Projects from High-Energy Physics

    CERN Document Server

    Heuer, Rolf-Dieter; Mele, Salvatore

    2008-01-01

    Having always been at the forefront of information management and open access, High-Energy Physics (HEP) proves to be an ideal test-bed for innovations in scholarly communication including new information and communication technologies. Three selected topics of scholarly communication in High-Energy Physics are presented here: A new open access business model, SCOAP3, a world-wide sponsoring consortium for peer-reviewed HEP literature; the design, development and deployment of an e-infrastructure for information management; and the emerging debate on long-term preservation, re-use and (open) access to HEP data.

  18. Highly reconfigurable communication protocol multiplexing element for SCOPH

    Science.gov (United States)

    Brebner, Gordon

    2001-07-01

    The Soft Circuitry Optimised Protocol Harness (SCOPH) project is concerned with implementing streaming data paths that perform communication protocol functions. The data paths are implemented dynamically using soft circuitry on a programmed logic array, based upon a small set of parameterised function blocks that are instantiated and linked together on a per-connection basis, and may also be modified during connections. This allows the use of optimised bespoke protocols, with handling of protocol functions at hardware speeds. This paper focuses on one particular pair of function blocks, for the demultiplexing and multiplexing of multiple connections sharing a single communication channel. An example would be multiple TCP port connections simultaneously active over a single IP channel. In the SCOPH context, a single data stream emanating from a main processor or from a network interface would be split into multiple data streams, which undergo protocol processing, and are then recombined into a single stream to a network interface or main processor respectively. The demultiplexor block always requires a means of selecting one of a number of streams, given addressing information in the data stream itself. Symmetrically, the multiplexor block must insert appropriate addressing information into the data stream. However, the main thrust of the paper is in comparing area-time trade-offs between using blocks with a (small) fixed number of streams always configured and using blocks that vary in size and shape with the current number of active streams. Both options are being investigated on a Xilinx Virtex FPGA, using JBits for the dynamic configuration.

  19. How to Improve Current Situation of the Communicative Approach in High School EFL Teaching

    Institute of Scientific and Technical Information of China (English)

    张丽芳

    2009-01-01

    The Communicative Approach has been used in EFL teaching of China for years; but still there are some problems centers around it when it is applied in high school English teaching. This paper explores the current situation of the Communicative Approach in Chinese high school EFL teaching by first looking at a simple case study, and then some suggestions are given as to how to improve this situation.

  20. VERY HIGH-SPEED DRILL STRING COMMUNICATIONS NETWORK

    Energy Technology Data Exchange (ETDEWEB)

    David S. Pixton

    2002-11-01

    Testing of a high-speed digital data transmission system for drill pipe is described. Passive transmission of digital data through 1000 ft of telemetry drill pipe has been successfully achieved. Data rates of up to 2 Mbit/sec have been tested through the 1000 ft system with very low occurrence of data errors: required error correction effort is very low or nonexistent. Further design modifications have been made to improve manufacturability and high pressure robustness of the transmission line components. Failure mechanisms of previous designs at high pressure and high temperature are described. Present design limitations include high temperature application.

  1. Communication and Memory Architecture Design of Application-Specific High-End Multiprocessors

    Directory of Open Access Journals (Sweden)

    Yahya Jan

    2012-01-01

    Full Text Available This paper is devoted to the design of communication and memory architectures of massively parallel hardware multiprocessors necessary for the implementation of highly demanding applications. We demonstrated that for the massively parallel hardware multiprocessors the traditionally used flat communication architectures and multi-port memories do not scale well, and the memory and communication network influence on both the throughput and circuit area dominates the processors influence. To resolve the problems and ensure scalability, we proposed to design highly optimized application-specific hierarchical and/or partitioned communication and memory architectures through exploring and exploiting the regularity and hierarchy of the actual data flows of a given application. Furthermore, we proposed some data distribution and related data mapping schemes in the shared (global partitioned memories with the aim to eliminate the memory access conflicts, as well as, to ensure that our communication design strategies will be applicable. We incorporated these architecture synthesis strategies into our quality-driven model-based multi-processor design method and related automated architecture exploration framework. Using this framework, we performed a large series of experiments that demonstrate many various important features of the synthesized memory and communication architectures. They also demonstrate that our method and related framework are able to efficiently synthesize well scalable memory and communication architectures even for the high-end multiprocessors. The gains as high as 12-times in performance and 25-times in area can be obtained when using the hierarchical communication networks instead of the flat networks. However, for the high parallelism levels only the partitioned approach ensures the scalability in performance.

  2. High-Capacity Short-Range Optical Communication Links

    DEFF Research Database (Denmark)

    Tatarczak, Anna

    Over the last decade, we have observed a tremendous spread of end-user mobile devices. The user base of a mobile application can grow or shrink by millions per day. This situation creates a pressing need for highly scalable server infrastructure; a need nowadays satisfied through cloud computing...... offered by data centers. As the popularity of cloud computing soars, the demand for high-speed, short-range data center links grows. Vertical cavity surface emitting lasers (VCSEL) and multimode fibers (MMF) prove especially well-suited for such scenarios. VCSELs have high modulation bandwidths...

  3. Quantum Communication with a High-Rate Entangled Photon Source

    Science.gov (United States)

    Wilson, Nathaniel C.; Chaffee, Dalton W.; Lekki, John D.; Wilson, Jeffrey D.

    2016-01-01

    A high generation rate photon-pair source using a dual element periodically-poled potassium titanyl phosphate (PP KTP) waveguide is described. The photon-pair source features a high pair generation rate, a compact power-efficient package, and continuous wave (CW) or pulsed operation. Characterization and test results are presented. Details and preliminary results of a laboratory free-space QKD experiment with the B92 protocol are also presented.

  4. Design of an Omnidirectional Multibeam Transmitter for High-Speed Indoor Wireless Communications

    OpenAIRE

    Jaw-Luen Tang; Yao-Wen Chang

    2010-01-01

    For future high speed indoor wireless communication, diffuse wireless optical communications offer more robust optical links against shadowing than line-of-sight links. However, their performance may be degraded by multipath dispersion arising from surface reflections. We have developed a multipath diffusive propagation model capable of providing channel impulse responses data. It is aimed to design and simulate any multibeam transmitter under a variety of indoor environments. In this paper,...

  5. WAVELET-BASED OFDM-CDMA HIGH SPEED POWER LINE COMMUNICATION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Zhou Lerong; Guo Jinghong; Wei Gang

    2004-01-01

    This letter derives the Equivalent M-band Discrete Wavelet(EMDW) transmission mode of Orthogonal Frequency Division Multiplexing(OFDM) transmission systems, and presents a new Quadrature M-band Discrete Wavelet(QMDW) based OFDM-CDMA(Code Division Multiple Access) communication systems for high speed Power Line Communication (PLC) channels.This system gives much better robustness to Inter-Channel Interference (ICI), Multi-User Interference (MUI) and noise interference, which is verified by simulation.

  6. On the give and take between event apprehension and utterance formulation.

    Science.gov (United States)

    Gleitman, Lila R; January, David; Nappa, Rebecca; Trueswell, John C

    2007-11-01

    Two experiments are reported which examine how manipulations of visual attention affect speakers' linguistic choices regarding word order, verb use and syntactic structure when describing simple pictured scenes. Experiment 1 presented participants with scenes designed to elicit the use of a perspective predicate (The man chases the dog/The dog flees from the man) or a conjoined noun phrase sentential Subject (A cat and a dog/A dog and a cat). Gaze was directed to a particular scene character by way of an attention-capture manipulation. Attention capture increased the likelihood that this character would be the sentential Subject and altered the choice of perspective verb or word order within conjoined NP Subjects accordingly. Experiment 2 extended these results to word order choice within Active versus Passive structures (The girl is kicking the boy/The boy is being kicked by the girl) and symmetrical predicates (The girl is meeting the boy/The boy is meeting the girl). Experiment 2 also found that early endogenous shifts in attention influence word order choices. These findings indicate a reliable relationship between initial looking patterns and speaking patterns, reflecting considerable parallelism between the on-line apprehension of events and the on-line construction of descriptive utterances.

  7. The elementary level science methods course: Breeding ground of an apprehension toward science? a case study

    Science.gov (United States)

    Duschl, Richard A.

    Ethnographic research methodologies were used to examine the training of elementary education majors in science in an attempt to gain insight on whether or not their training in science contributes to the apprehension elementary teachers have toward science. The field study consisted of 14 weeks of weekly observations in the elementary education majors science methods class. Interviews with the students and the instructors as well as survey instruments to assess students' preparation in science were used. Two different approaches to the study of science, one content oriented, the other process oriented, may contribute to the students' confusion, insecurity, and avoidance of science. The students' perception that science is learning content, an objective of introductory level science courses, and the science methods class's objectives of teaching science as a process sets up an antagonistic dilemma between the two. Such antagonistic dilemma may be manifest in the lack of instructional time accorded to science by elementary educators. The type of science experiences an individual encounters influences their perceptions. To offset student perceptions developed in science courses which stress principally content, the students need science experiences which truly represent science as inquiry. New strategies for the training of elementary education majors in science need to be examined.

  8. Radiation Hardened, Modulator ASIC for High Data Rate Communications

    Science.gov (United States)

    McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene

    2000-01-01

    Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).

  9. A RESEARCH ON HIGH -PERFORMANCE ANALOG-TO-DIGITAL CONVERTERS IN WIRELESS COMMUNICATION SYSTEMSIN

    OpenAIRE

    伊藤, 朋彦; ITO,Tomohiko

    2014-01-01

    To realize next-generation high-throughput wireless communication systems, it is essential to develop analog-to-digital converters (ADC) with high conversion speed, high resolution, low power, and low operational supply voltage. In this work, the design methodologies and the new circuit architectures for these high-performance ADCs are researched.First, the methods to optimize these performances for ADCs were confirmed. In a pipeline ADC which is promising to realize the high-throughput syste...

  10. Communication system for emergency

    Energy Technology Data Exchange (ETDEWEB)

    Ajioka, Yoshiteru [Shizuoka Prefecture (Japan)

    1996-12-01

    People are apprehensive that a strong earthquake with a magnitude of nearly 8 may occur in Tokai area. The whole area of Shizuoka Prefecture has been specified as the specially strengthened region for earthquake disaster measures. This report outlines the communication system for emergency with respect to atomic disaster caused by an earthquake. Previously, wireless receiving system is stationed in the whole area to simultaneously inform the related news to the residents and so, communications with them are possible at any time by using the system. Since mobile wireless receiving sets are stationed in all town halls, self defense organizations and all the places of refuge, mutual communications are possible. These communication system can be utilized for either earthquake or nuclear disaster. Further, Shizuoka general information network system has been established as a communication system for anti-disaster organization and a wireless network via a communication satellite, ``super bird`` has been constructed in addition to the ground network. Therefore, the two communication routes became usable at emergency and the systems are available in either of nuclear disaster or earthquake. (M.N.)

  11. VERY HIGH-SPEED DRILL STRING COMMUNICATIONS NETWORK

    Energy Technology Data Exchange (ETDEWEB)

    David S. Pixton

    2002-08-01

    Testing of recent upgrades to the drill pipe telemetry system in a 1000-ft vertical well has shown that the new system can achieve at least 1,000 ft passive transmission distance with sufficient bandwidth to accommodate a digital transmission rate of 2 Mbit/sec. Digitized data from a module at the bottom of the well has been successfully transmitted through the transmission line to the top of the well for a period of approximately one month. Manufacture of 30 prototype range 2 drill pipes has demonstrated greater simplicity of manufacturing and greater consistency of electrical characteristics from part to part, as compared to the first production run previously reported. Further work is needed to improve the high pressure capability of the system and to improve the robustness of the system in a high-vibration environment.

  12. The research of high-speed clock in space laser communication

    Science.gov (United States)

    Yang, Hong-kun; Tong, Shou-feng; Zhang, Lei; Wang, Hao-zeng

    2013-08-01

    Space laser communication is moving in a wider bandwidth, greater distances, is more accurate and more narrow laser communication beam direction, faster bandwidth as well as communication interface chip high-speed clock more demanding requirements of the low frequency noise, and good reliability, small size and low power consumption characteristics. Production of ADI's ADF4350 integrated voltage-controlled oscillator (VCO) bandwidth frequency synthesizer just to meet this requirement clock frequency This paper describes the basic principles and operating characteristics of the broadband frequency synthesizer. In this paper we use CPLD to control the ADF4350 and give a control electric circuit with CPLD structure and based on Verilog program. Simulation and experimental results show that the lock-in effect is good, easy to control, and reliable performance. It is able to generate stable clock, suitable for applications in laser communication.

  13. Study of High-Temperature Superconductor Diplexers for Satellite Communications

    Institute of Scientific and Technical Information of China (English)

    LIU Juan-xiu; YANG Kai; LUO Zheng-xiang; BU Shi-rong; NING Jun-song; ZHANG Tian-liang

    2005-01-01

    The high-temperature superconductor (HTSC) resonator and diplexer are simulated by full-wave tools.A newly developed miniature HTSC diplexer is designed and fabricated on double sided YBa2Cu3O7 (YBCO) film (YBCO/LaAlO3/YBCO), the thickness of which is 400 nm for YBCO and 0.5 mm for the LaAlO3. The measured results show a good agreement with the simulation. The volume and mass of the diplexers are greatly reduced by miniaturized configuration.

  14. A performance model for the communication in fast multipole methods on high-performance computing platforms

    KAUST Repository

    Ibeid, Huda

    2016-03-04

    Exascale systems are predicted to have approximately 1 billion cores, assuming gigahertz cores. Limitations on affordable network topologies for distributed memory systems of such massive scale bring new challenges to the currently dominant parallel programing model. Currently, there are many efforts to evaluate the hardware and software bottlenecks of exascale designs. It is therefore of interest to model application performance and to understand what changes need to be made to ensure extrapolated scalability. The fast multipole method (FMM) was originally developed for accelerating N-body problems in astrophysics and molecular dynamics but has recently been extended to a wider range of problems. Its high arithmetic intensity combined with its linear complexity and asynchronous communication patterns make it a promising algorithm for exascale systems. In this paper, we discuss the challenges for FMM on current parallel computers and future exascale architectures, with a focus on internode communication. We focus on the communication part only; the efficiency of the computational kernels are beyond the scope of the present study. We develop a performance model that considers the communication patterns of the FMM and observe a good match between our model and the actual communication time on four high-performance computing (HPC) systems, when latency, bandwidth, network topology, and multicore penalties are all taken into account. To our knowledge, this is the first formal characterization of internode communication in FMM that validates the model against actual measurements of communication time. The ultimate communication model is predictive in an absolute sense; however, on complex systems, this objective is often out of reach or of a difficulty out of proportion to its benefit when there exists a simpler model that is inexpensive and sufficient to guide coding decisions leading to improved scaling. The current model provides such guidance.

  15. High Performance Interconnection Technology in Avionics (Short Communication

    Directory of Open Access Journals (Sweden)

    C. R. Raghunath

    2011-07-01

    Full Text Available Avionics subsystems continue to get smaller and more functional, driving the total circuit package itself to become denser, causing the printed wiring board (PWB to evolve new laminates to meet these needs. There is a continuous scope for improvement to match the requirement of wireability demand from high density and high speed integrated circuits. Development of control processing units and rapid expansion of memory device capabilities were realised by the development of large-scale integrated circuits and other electronic devices with higher integration and with new functionalities. Enormous efforts have been put on the development of the system-on-chip (SOC, where a single semiconductor chip constituting complete system is bonded on substrate. These innovations in packaging technology made a big impact on laminates used in printed circuit boards. Aircraft systems are expected to withstand disturbances due to unexpected threats. Under such situations, passengers' safety, emergency landing and timely information to pilot become of paramount importance, hence, new innovative laminate systems are being developed. Various aspects of laminates and the current developments that are taking place are facilitating scientists and engineers in selecting appropriate laminate systems, have been discussed.Defence Science Journal, 2011, 61(4, pp.354-363, DOI:http://dx.doi.org/10.14429/dsj.61.1085

  16. High-Efficiency, High-Power Laser Transmitter for Deep-Space Communication Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is demand for vastly improved deep space satellite communications links. As data rates dramatically increase due to new sensor technologies and the desire to...

  17. No reserved communication lanes for high energy (Italian original version

    Directory of Open Access Journals (Sweden)

    Nico Pitrelli

    2006-06-01

    Full Text Available The American particle physics community is in jeopardy and may end up drowning in a boundless sea trying to grasp at non-existing funds, dragging US physics and science as a whole to the bottom. This is a price the most powerful and high-tech country of the world cannot afford, as warned by the editors of a report published in late April by the National Academy of Sciences1. Behind so much alarm is the International Linear Collider (ILC – a large particle accelerator facility which, according to the report, should be built on American territory, if research on the elementary constituents of nature is to survive in the United States. The ILC will probably cost a total of five hundred million dollars in the first five years, whereas billions will have to be invested in the subsequent seven years. Hardly impressive, however, if compared with the Superconducting Super Collider (SSC, the biggest and costliest machine ever conceived in the history of science. Devised to describe the first instants of the universe, as many will recall, the SSC project was severely hampered by political and bureaucratic plots in 1993, when the Clinton administration decided to halt work on the accelerator, after ten years and approximately two billion dollars already spent.

  18. Coherent DWDM technology for high speed optical communications

    Science.gov (United States)

    Saunders, Ross

    2011-10-01

    The introduction of coherent digital optical transmission enables a new generation of high speed optical data transport and fiber impairment mitigation. An initial implementation of 40 Gb/s coherent systems using Dual Polarization Quadrature Phase Shift Keying (DP-QPSK) is already being installed in carrier networks. New systems running at 100 Gb/s DP-QPSK data rate are in development and early technology lab and field trial phase. Significant investment in the 100 Gb/s ecosystem (optical components, ASICs, transponders and systems) bodes well for commercial application in 2012 and beyond. Following in the footsteps of other telecommunications fields such as wireless and DSL, we can expect coherent optical transmission to evolve from QPSK to higher order modulations schemes such as Mary PSK and/or QAM. This will be an interesting area of research in coming years and poses significant challenges in terms of electro-optic, DSP, ADC/DAC design and fiber nonlinearity mitigation to reach practical implementation ready for real network deployments.

  19. K-band high power latching switch. [communication satellite system

    Science.gov (United States)

    Mlinar, M. J.; Piotrowski, W. S.; Raue, J. E.

    1980-01-01

    A 19 GHz waveguide latching switch with a bandwidth of 1400 MHz and an exceptionally low insertion loss of 0.25 dB was demonstrated. The RF and driver ferrites are separate structures and can be optimized individually. This analysis for each structure is separately detailed. Basically, the RF section features a dual turnstile junction. The circulator consists of a dielectric tube which contains two ferrite rods, and a dielectric spacer separating the ferrite parts along the center of symmetry of the waveguide to form two turnstiles. This subassembly is indexed and locked in the center of symmetry of a uniform junction of three waveguides by the metallic transformers installed in the top and bottom walls of the housing. The switching junction and its actuating circuitry met all RF performance objectives and all shock and vibration requirements with no physical damage or performance degradation. It exceeds thermal requirements by operating over a 100 C temperature range (-44 C to +56 C) and has a high power handling capability allowing up to 100 W of CW input power.

  20. Gender differences in high school coaches' knowledge, attitudes, and communication about the female athlete triad.

    Science.gov (United States)

    Kroshus, Emily; Sherman, Roberta T; Thompson, Ron A; Sossin, Karen; Austin, S Bryn

    2014-01-01

    The objective of this study was to assess high school coaches' knowledge, attitudes, communication, and management decisions with respect to the Female Athlete Triad and to determine whether results are patterned by coach gender. Data were obtained through an online survey of high school coaches (n = 227). Significant differences were found between male and female coaches in certain attitudes and communication behaviors related to eating and menstrual irregularity. School or district level policies may help reduce these differences and may help mitigate the health consequences for athletes related to possible differential prevention and detection of the comorbidities of the Female Athlete Triad.

  1. Patient and caregiver perceptions of communication of prognosis in high grade glioma.

    Science.gov (United States)

    Lobb, E A; Halkett, G K B; Nowak, A K

    2011-08-01

    This study sought the views of patients and their caregivers on their experience of being diagnosed with high grade glioma. Purposive sampling was used to recruit 19 patients and 21 caregivers from the medical oncology unit of a tertiary hospital. A semi-structured face-to-face interview was conducted. Interviews were audio-taped and transcribed verbatim. Data was analysed based on Grounded Theory and using the constant comparison method. This paper focuses on patient and carer perceptions of the initial communication about the diagnosis of high grade glioma and its prognosis. Themes identified included: (a) shock at hearing the diagnosis; (b) trying to understand and process prognostic information when still in shock; (c) the perception of hope being taken away; (d) individualizing prognostic information; and (e) clinicians' lack of communication skills. This study shows that the first communication of prognosis to patients with high grade glioma and their caregivers requires careful negotiation. It illustrates the inability of individuals to process detailed prognostic information when in a state of initial shock and distress. The importance of balancing honesty with hope in the communication of a poor prognosis is highlighted. We recommend that clinicians seek patient preferences for the amount and type of information they require and that prognostic information be individualized. Detailed discussions of prognosis should only take place with senior medical staff, or advanced trainees who have demonstrated acceptable communication skills.

  2. Short pulse generation and high speed communication system

    Science.gov (United States)

    Fan, Honglei

    Ultrahigh-speed optical time-division-multiplexing (TDM) transmission technologies are essential to construct ultrahigh-speed all-optical networks needed in the multimedia era. In order to realize high-speed optical TDM systems, ultra-short pulses should be generated. In this dissertation, the gain switching and mode locking techniques have been analyzed and used to produce ultra- short pulses. Gain-switched pulses with a width of ~18ps have been obtained. The theoretical analysis on gain-switching phenomena has been carried out. A new approach for the simulation of the spectrum of a gain- switched laser has been developed. The principle of mode locking has been discussed. ~6.5ps, pulses have been obtained from a monolithic mode-locked distributed Bragg reflector (DBR) laser, which are the shortest pulses from the actively mode- locked DBR lasers as we know. ~1.1ps pulses have been achieved from a colliding-pulse mode-locked (CPM) laser. The operation principle of CPM lasers has been discussed. Pulse compression using dispersion-compensating fiber has been applied in order to get shorter pulses. The semiconductor optical amplifier (SOA) plays a very important role in TDM systems. The cross gain modulation (XGM) measurements on a 2-section SOA, using both cw and pulsed pump and probe beams, have been performed. A theoretical analysis has been carried out. Wavelength conversion and fiber transmission experiments have been achieved at different bit rates. The basic idea of TDM system has been discussed. Multiplexing has been achieved using fibers. Demulitplexing has been demonstrated using XGM in SOA, four-wave mixing (FWM) in SOA, and cascaded modulators. The operation principles have been discussed in detail. The FWM experiments between two optical pulses have been performed.

  3. The Relation between Event Apprehension and Utterance Formulation in Children: Evidence from Linguistic Omissions

    Science.gov (United States)

    Bunger, Ann; Trueswell, John C.; Papafragou, Anna

    2011-01-01

    The relation between event apprehension and utterance formulation was examined in children and adults. English-speaking adults and 4-year-olds viewed motion events while their eye movements were monitored. Half of the participants in each age group described each event (Linguistic task), whereas the other half studied the events for an upcoming memory test (Nonlinguistic task). All participants then completed a memory test in which they identified changes to manners of motion and path endpoints in target events. In the Nonlinguistic task, eye movements and memory responses revealed striking similarities across age groups. Adults and preschoolers attended to manner and path endpoints with similar timing, and in the memory test both successfully detected manner and path changes at similar rates. Substantial differences in production emerged between age groups in the Linguistic task: whereas adults usually mentioned both manners and paths in their event descriptions, preschoolers tended to omit one event component or the other. However, eyegaze patterns remained equivalent across the two age groups, with both children and adults allocating more attention to event components that they planned to talk about. Children in the Linguistic task were at chance in the memory test, whereas adults actually showed a memory benefit as compared to the Nonlinguistic task. We conclude that developmental differences in the description of motion events are not due to pure attentional differences between adults and children, but leave open the possibility that they stem from limitations that are solely linguistic in nature or that arise at the interface of attention and language production. PMID:22055989

  4. High throughput satellites in 5G and MIMO interference limited communications

    Directory of Open Access Journals (Sweden)

    Pérez-Neria Ana

    2016-01-01

    Full Text Available Classically, thermal noise has been the workhorse of satellite communications due to the long distances to be covered between the satellite and the user terminal (UT. Lately, LDPC (Low-Density Parity-Check codes allow the noise threshold to be set very close to the Shannon limit for the memory-less satellite channel; thus, solving the noise problem that turbo codes were not able to solve. However, recently, the high target rates in next generation 5G wireless terrestrial system are pushing the required spectral efficiency in Satellite Communications; therefore, shifting the SatCom paradigm towards an interference limited one. This paper revisits the 5G scene and the role of next generation satellite communications, with a special focus on high throughput satellites (HTS together with the future accompanying MIMO interference mitigation techniques.

  5. Impact of Sport-related Games on High School Students’ Communication Skills

    Directory of Open Access Journals (Sweden)

    Ozturk Ozden Tepekoylu

    2015-09-01

    Full Text Available In Recent studies underline the fact that adolescents are, at many times, likely to experience serious communication problems with their families and close environments. So, the aim of this study is to determine positive impact of sport-related games, which are performed as extracurricular activities, on high school students’ communication skills. In the study, pre, & post-tests was utilized with the control group’s experimental patterns. Two participant groups were made up of totally 30 high school students, 15 of whom would be in the experimental group and the rest of whom were in the control group. The former group was given sport- related 20 applications for 10 weeks during which the latter group would not deal with any extracurricular activities. Meanwhile, before and after the applications, data was collected by means of “The Communication Skills Scale” which was developed by Korkut (1996 and then analysed through “two-way ANCOVA” test techniques. Results clarify that the considerable gap in scores of the students’ pre, & post-tests perception concerning their communication skills are clearly attributed to sport-related games and it was also established that scores of the students in the experimental group were meaningfully higher than ones in the control group. However, perception of communication skills in the both groups was not significantly different by sex of the students. Moreover, the common effect of sex and participation on sport- related games was not found statistically meaningful in terms of communication skills. Consequently, it could be said that sport-related games impact positively communication skills.

  6. Designing and implementing Multibeam Smart Antennas for high bandwidth UAV communications using FPGAs

    Science.gov (United States)

    Porcello, J. C.

    Requirements for high bandwidth UAV communications are often necessary in order to move large amounts of mission information to/from Users in real-time. The focus of this paper is antenna beamforming for point-to-point, high bandwidth UAV communications in order to optimize transmit and receive power and support high data throughput communications. Specifically, this paper looks at the design and implementation of Multibeam Smart Antennas to implement antenna beamforming in an aerospace communications environment. The Smart Antenna is contrasted against Fast Fourier Transform (FFT) based beamforming in order to quantify the increase in both computational load and FPGA resources required for multibeam adaptive signal processing in the Smart Antenna. The paper begins with an overall discussion of Smart Antenna design and general beamforming issues in high bandwidth communications. Important design considerations such as processing complexity in a constrained Size, Weight and Power (SWaP) environment are discussed. The focus of the paper is with respect to design and implementation of digital beamforming wideband communications waveforms using FPGAs. A Multibeam Time Delay element is introduced based on Lagrange Interpolation. Design data for Multibeam Smart Antennas in FPGAs is provided in the paper as well as reference circuits for implementation. Finally, an example Multibeam Smart Antenna design is provided based on a Xilinx Virtex-7 FPGA. The Multibeam Smart Antenna example design illustrates the concepts discussed in the paper and provides design insight into Multibeam Smart Antenna implementation from the point of view of implementation complexity, required hardware, and overall system performance gain.

  7. Taipei's use of a multi-channel mass risk communication program to rapidly reverse an epidemic of highly communicable disease.

    Directory of Open Access Journals (Sweden)

    Muh-Yong Yen

    , communication-based intervention proved effective at preventing a dangerous spike in AHC and was able to bring this high-risk disease under control. We recommend that public health officials incorporate similar methods into existing guidelines for preventing pandemic influenza and other emerging infectious diseases.

  8. Computer-mediated communication in adults with high-functioning autism spectrum disorders and controls

    NARCIS (Netherlands)

    van der Aa, Christine; Pollmann, Monique; Plaat, Aske; van der Gaag, Rutger Jan

    2016-01-01

    It has been suggested that people with Autism Spectrum Disorders (ASD) are attracted to computer-mediated communication (CMC). In this study, we compare CMC use in adults with high-functioning ASD (N = 113) and a control group (N = 72). We find that people with ASD spend more time on CMC than contro

  9. Can You Hear Me Now? We Control the High Ground USASMDC/ARSTRAT and Satellite Communications

    Science.gov (United States)

    2011-01-01

    cables did not extend to Southeast Asia and radio communications were unreliable in the tropical atmosphere and high frequencies were easily jammed...Tunisia before joint the assault landings of the Sicily campaign and moving up the Italian peninsula. At the end of the war, the 53rd was inactivated

  10. Multiband carrierless amplitude/phase modulation for ultra-wideband high data rate wireless communications

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Altabas, Jose A.

    2016-01-01

    We report on the first experimental demonstration of carrierless amplitude/phase modulation in a flexible multiband approach for ultrawideband high-data-rate wireless communications. An effective bitrate of 2 GB/s is achieved while complying with the restrictions on the effective radiated power e...

  11. Electronic Communication and Its Influence on Parental Involvement in High School

    Science.gov (United States)

    Watkins, Aaron

    2013-01-01

    This study investigated the effect of electronic communication has on parent's involvement with their high school child's education. The No Child Left Behind Act of 2001 (NCLB) specifically requires that schools find ways to increase parental involvement; this requirement stemmed from evidence that involvement tends to decline as the students…

  12. Challenge Study: A Project-Based Learning on a Wireless Communication System at Technical High School

    Science.gov (United States)

    Terasawa, Ikuo

    2016-01-01

    The challenge study is a project based learning curriculum at Technical High School aimed at the construction of a wireless communication system. The first period was engineering issues in the construction of an artificial satellite and the second period was a positional locating system based on the general purpose wire-less device--ZigBee device.…

  13. Communication Satisfaction, Organizational Citizenship Behavior and the Relationship to Student Achievement in High Schools

    Science.gov (United States)

    Blanchard, Gayle A.

    2012-01-01

    This study used a correlational design that allowed the researcher to examine the relationship among communication satisfaction, organizational citizenship behaviors (OCB) and student achievement. High school teachers were surveyed from a convenience sample of 12 school districts in Arizona. Established instruments were used to survey teachers'…

  14. Dispersion Monitoring techniques in High Bit-rate Optical Communication Systems

    Institute of Scientific and Technical Information of China (English)

    SANG Xin-zhu; YU Chong-xiu; ZHANG Qi; WANG Xu

    2004-01-01

    For the efficient dynamic dispersion compensation, it is essential to monitor the dispersion accurately. The existing main dispersion monitoring techniques in high bit- rate optical communication systems are presented as well as their operating principles and research progress. The advantages and disadvantages of these methods are analyzed and discussed.

  15. Communication Satisfaction, Organizational Citizenship Behavior and the Relationship to Student Achievement in High Schools

    Science.gov (United States)

    Blanchard, Gayle A.

    2012-01-01

    This study used a correlational design that allowed the researcher to examine the relationship among communication satisfaction, organizational citizenship behaviors (OCB) and student achievement. High school teachers were surveyed from a convenience sample of 12 school districts in Arizona. Established instruments were used to survey…

  16. Communication about Contraception and Knowledge of Oral Contraceptives amongst Norwegian High School Students.

    Science.gov (United States)

    Hansen, Thomas; Skjeldestad, Finn Egil

    2003-01-01

    Examines communication about contraception and specific knowledge of oral contraceptives (OCs) in a sample of Norwegian high school students. More females than males discussed contraception at least monthly. Discussions were predominantly held with peers and not adults. Females were far more knowledgeable about OCs than males. The most significant…

  17. Quantum Secure Communication by Using GHZ State in High-Dimensional Hilbert Space

    Institute of Scientific and Technical Information of China (English)

    GAO Gan

    2008-01-01

    We propose a quantum superdense coding secure communication scheme by using GHZ state. This scheme combines the ideas of quantum superdense coding and sequence transmission. Its distinct advantage is high source capacity. In addition, in checking eavesdropping, we need not to destroy quantum entanglement.

  18. Aspects of High-Q Tunable Antennas and Their Deployment for 4G Mobile Communications

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Jagielski, Ole; Svendsen, Simon;

    2016-01-01

    Tunable antennas are very promising for future generations of mobile communications, where broad frequency coverage will be required increasingly. This work describes the design of small high-Quality factor (Q) tunable antennas based on Micro-Electro-Mechanical Systems (MEMS), which are capable...

  19. High phase noise tolerant pilot-tone-aided DP-QPSK optical communication systems

    DEFF Research Database (Denmark)

    Zhang, Xu; Pang, Xiaodan; Deng, Lei

    2012-01-01

    In this paper we experimentally demonstrate a novel, high phase-noise tolerant, optical dual polarization (DP) quadrature phase-shift keying (QPSK) communication system based on pilot-tone-aided phase noise cancellation (PNC) algorithm. Vertical cavity surface emitting lasers (VCSELs...

  20. Persuading girls to take elective physical science courses in high school: Who are the credible communicators?

    Science.gov (United States)

    Koballa, Thomas R., Jr.

    Eighth-grade girls (N=257) randomly selected from nine different public junior high schools in central Texas were questioned in order to identify the communicators whom they perceive as highly credible regarding reasons for taking elective physical science courses in high school and the attributes associated with these communicators. Four persons were each identified by better than 10 percent of the sample as the best person to try to convince junior high school girls to take elective physical science courses in high school. In order of perceived credibility, these persons are father, woman science teacher, mother, and boy high school student. Slight variations in the order of perceived credibility were found when the responses from girls of the different ethnic groups represented in the sample (Caucasian, Hispanic, Black, and Asian) were examined separately. Attributes listed by the respondents for father, woman science teacher, mother, and boy high school student were examined and classified into the categories of prestige, trustworthiness, similarity, attractiveness, and power. Prestige and trustworthiness are the attributes associates most frequently with communicators identified as highly credible. Implications of the present study and suggestions for further research are discussed.

  1. [Research on the High Efficiency Data Communication Repeater Based on STM32F103].

    Science.gov (United States)

    Zhang, Yahui; Li, Zheng; Chen, Guangfei

    2015-11-01

    To improve the radio frequency (RF) transmission distance of the wireless terminal of the medical internet of things (LOT), to realize the real-time and efficient data communication, the intelligent relay system based on STM32F103 single chip microcomputer (SCM) is proposed. The system used nRF905 chip to achieve the collection, of medical and health information of patients in the 433 MHz band, used SCM to control the serial port to Wi-Fi module to transmit information from 433 MHz to 2.4 GHz wireless Wi-Fi band, and used table look-up algorithm of ready list to improve the efficiency of data communications. The design can realize real-time and efficient data communication. The relay which is easy to use with high practical value can extend the distance and mode of data transmission and achieve real-time transmission of data.

  2. [Psychological processes predicting the English communication behavior of Japanese high school students].

    Science.gov (United States)

    Ito, Takehiko

    2013-12-01

    This study presents a new model of psychological processes to predict English communication behaviors of Japanese high school students. Various models have been proposed in Japan, based mainly on Canadian models, to predict second-language communication behaviors. This study shows problems with the previous models in Japan and introduces a new model from the perspective of "Expectancy-Value Theory". Questionnaire Survey 1 compared the previous model and the modified models which suggested that a new psychological variable, "Value in English Communication", was necessary to construct the new model. In Survey 2, the new model was further modified by incorporating into it various English learning values which the Japanese have. This study makes a significant contribution to studies and practices of teaching English as a foreign language in Japan.

  3. Development of highly reliable power and communication system for essential instruments under severe accidents in NPP

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Hwan; Jang, Gi Chan; Shin, Sung Min; Kang, Hyun Gook; Rim, Chun Taek [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Lee, Soo Ill [I and C Group, Korea Hydro and Nuclear Power Co., Ltd, Central Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    This article proposes a highly reliable power and communication system that guarantees the protection of essential instruments in a nuclear power plant under a severe accident. Both power and communication lines are established with not only conventional wired channels, but also the proposed wireless channels for emergency reserve. An inductive power transfer system is selected due to its robust power transfer characteristics under high temperature, high pressure, and highly humid environments with a large amount of scattered debris after a severe accident. A thermal insulation box and a glass-fiber reinforced plastic box are proposed to protect the essential instruments, including vulnerable electronic circuits, from extremely high temperatures of up to 627 .deg. C and pressure of up to 5 bar. The proposed wireless power and communication system is experimentally verified by an inductive power transfer system prototype having a dipole coil structure and prototype Zigbee modules over a 7-m distance, where both the thermal insulation box and the glass-fiber reinforced plastic box are fabricated and tested using a high-temperature chamber. Moreover, an experiment on the effects of a high radiation environment on various electronic devices is conducted based on the radiation test having a maximum accumulated dose of 27 Mrad.

  4. The Link between Pronunciation Anxiety and Willingness to Communicate in the Foreign-Language Classroom: The Polish EFL Context

    Science.gov (United States)

    Baran-Lucarz, Malgorzata

    2014-01-01

    Anxiety and L2 self-confidence have been suggested as vital determinants of willingness to communicate (WTC) in a foreign-language (FL) learning environment. Studies also demonstrate that it is a concern over pronunciation mistakes that is particularly likely to cause embarrassment and apprehension in FL students. Linking these two facts may lead…

  5. Dimensions of Communication Apprehension beyond Boundaries: A Cross-Cultural Comparative Study of U.S. and Japanese Management Personnel.

    Science.gov (United States)

    Pucel, Joanna K.; And Others

    A study explored the self-reported nonverbal stress behaviors perceived by men and women in management positions in both Japan and the United States who were required to give public speeches as part of their employment or daily lives. The sample included 136 subjects from the United States (60 males, 76 females) and 99 Japanese subjects (86 males,…

  6. High Operation Efficiency of Semiconductor Electrooptic Modulators in Advanced Lightwave Communication Systems

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-07-01

    Full Text Available Photonic links have been proposed to transport radio frequency (RF signals over optical fiber communication systems. External optical modulation is commonly used in high performance RF photonic links. The practical use of optical fiber communication systems to transport RF signals is still limited due to high RF signal loss. In order to reduce the RF signal loss, highly efficient modulators are needed. For many applications, modulators with broad bandwidths are required. However, there are applications that require only a narrow bandwidth. For these narrow band applications, the modulation efficiency can be improved through the resonant enhancement technique at the expense of reduced transmission bandwidth. Therefore we have been investigated to get the best performance of the transmission bit rate capacity and product of different semiconductor materials based electrooptic (EO modulators over wide range of the affecting parameters.

  7. SPARCL: a high-altitude tethered balloon-based optical space-to-ground communication system

    Science.gov (United States)

    Badesha, Surjit S.

    2002-12-01

    The Johns Hopkins University Applied Physics Laboratory (JHU/APL) has conducted a feasibility study to determine if a high altitude (20 km) tethered balloon-based space-to-ground optical communication system is a feasible concept. To support this effort, a detailed concept definition was developed and associated issues were identified and analyzed systematically. Of all the adverse atmospheric phenomena, cloud coverage was identified as the most prohibitive obstacle for a space-to-ground optical communication link. However, by placing a receiver on a balloon at a 20 km altitude, the proposed high altitude system avoids virtually all atmospheric effects. A practical notional scenario was developed (i.e. surveillance and/or reconnaissance of a regional conflict) involving end-to-end optical communication architecture to identify system elements, system level requirements, and to quantify realistic data rate requirements. Analysis of the proposed space-to-ground communication elements indicates that while significant development is required, the system is technically feasible and is a very cost effective 24/7solution.

  8. High-Capacity Quantum Secure Direct Communication Based on Quantum Hyperdense Coding with Hyperentanglement

    Institute of Scientific and Technical Information of China (English)

    WANG Tie-Jun; LI Tao; DU Fang-Fang; DENG Fu-Guo

    2011-01-01

    We present a quantum hyperdense coding protocol with hyperentanglement in polarization and spatial-mode degrees of freedom of photons first and then give the details for a quantum secure direct communication (QSDC)protocol based on this quantum hyperdense coding protocol. This QSDC protocol has the advantage of having a higher capacity than the quantum communication protocols with a qubit system. Compared with the QSDC protocol based on superdense coding with d-dimensional systems, this QSDC protocol is more feasible as the preparation of a high-dimension quantum system is more difficult than that of a two-level quantum system at present.%@@ We present a quantum hyperdense coding protocol with hyperentanglement in polarization and spatial-mode degrees of freedom of photons first and then give the details for a quantum secure direct communication(QSDC)protocol based on this quantum hyperdense coding protocol.This QSDC protocol has the advantage of having a higher capacity than the quantum communication protocols with a qubit system.Compared with the QSDC protocol based on superdense coding with d-dimensional systems, this QSDC protocol is more feasible as the preparation of a high-dimension quantum system is more difficult than that of a two-level quantum system at present.

  9. New high performance SAW convolvers used in high bit rate and wideband spread spectrum CDMA communications system.

    Science.gov (United States)

    Hikita, M; Takubo, C; Asai, K

    2000-01-01

    New surface acoustic wave (SAW) convolver structures with high conversion efficiency and self-temperature compensation characteristics have been developed. Strong piezoelectric substrates, regardless of temperature coefficients of delay (TCD), can be used in these convolvers. New demodulation techniques using the developed SAW convolver for high bit rate and wideband spread spectrum code division multiple access (CDMA) communications have also been developed. I- and Q-channel demodulation data can be derived directly from binary phase shift keying (BPSK) or quadri-phase shift keying (QPSK) CDMA signals. In an experiment using a 128 degrees YX-LiNbO(3) substrate, CDMA signals of 9 Mbps (megabits per second) with 60 Mcps (megachips per second) spread by 13-chip Barker code and 11 Mbps with 140 Mcps spread by 25-chip Shiba's code were clearly demodulated, demonstrating the effectiveness of these techniques for use in future CDMA communications.

  10. A FAST BIT-LOADING ALGORITHM FOR HIGH SPEED POWER LINE COMMUNICATIONS

    Institute of Scientific and Technical Information of China (English)

    Zhang Shengqing; Zhao Li; Zou Cairong

    2012-01-01

    Adaptive bit-loading is a key technology in high speed power line communications with the Orthogonal Frequency Division Multiplexing (OFDM) modulation technology.According to the real situation of the transmitting power spectrum limited in high speed power line communications,this paper explored the adaptive bit loading algorithm to maximize transmission bit number when transmitting power spectral density and bit error rate are not exceed upper limit.With the characteristics of the power line channel,first of all,it obtains the optimal bit loading algorithm,and then provides the improved algorithm to reduce the computational complexity.Based on the analysis and simulation,it offers a non-iterative bit allocation algorithm,and finally the simulation shows that this new algorithm can greatly reduce the computational complexity,and the actual bit allocation results close to optimal.

  11. The Utilization of High-Frequency Gravitational Waves for Global Communications

    Directory of Open Access Journals (Sweden)

    Robert M L Baker

    2012-10-01

    Full Text Available For over 1000 years electromagnetic radiation has been utilized for long-distance communication. Smoke signals, heliographs, telegraphs, telephones and radio have all served our previous communication needs. Nevertheless, electromagnetic radiation has one major difficulty: it is easily absorbed. In this paper we consider a totally different radiation, a radiation that is not easily absorbed: gravitational radiation. Such radiation, like gravity itself, is not absorbed by earth, water or any material substance. In particular we discuss herein means to generate and detect high-frequency gravitational waves or HFGWs, and how they can be utilized for communication. There are two barriers to their practical utilization: they are extremely difficult to generate (a large power required to generate very weak GWs and it is extremely difficult to detect weak GWs. We intend to demonstrate theoretically in this paper their phase-coherent generation utilizing an array of in-phase microelectro-mechanical systems or MEMS resonator elements in which the HFGW flux is proportional to the square of the number of elements. This process solves the transmitter difficulty. Three HFGW detectors have previously been built; but their sensitivity is insufficient for meaningful HFGW reception; greater sensitivity is necessary. A new Li-Baker HFGW detector, discussed herein, is based upon a different measurement technique than the other detectors and is predicted to achieve a sensitivity to satisfy HFGW communication needs.

  12. ScalaTrace: Scalable Compression and Replay of Communication Traces for High Performance Computing

    Energy Technology Data Exchange (ETDEWEB)

    Noeth, M; Ratn, P; Mueller, F; Schulz, M; de Supinski, B R

    2008-05-16

    Characterizing the communication behavior of large-scale applications is a difficult and costly task due to code/system complexity and long execution times. While many tools to study this behavior have been developed, these approaches either aggregate information in a lossy way through high-level statistics or produce huge trace files that are hard to handle. We contribute an approach that provides orders of magnitude smaller, if not near-constant size, communication traces regardless of the number of nodes while preserving structural information. We introduce intra- and inter-node compression techniques of MPI events that are capable of extracting an application's communication structure. We further present a replay mechanism for the traces generated by our approach and discuss results of our implementation for BlueGene/L. Given this novel capability, we discuss its impact on communication tuning and beyond. To the best of our knowledge, such a concise representation of MPI traces in a scalable manner combined with deterministic MPI call replay are without any precedent.

  13. Development of Highly Survivable Power and Communication System for NPP Instruments under Severe Accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seung J.; Gu, Beom W.; Nguyen, Duy T.; Choi, Bo H.; Rim, Chun T. [KAIST, Daejeon (Korea, Republic of); Lee, So I. [KHNP CRI, Daejeon (Korea, Republic of)

    2014-10-15

    According to the detail report from the Fukushima nuclear accident, the failure of conventional instruments is mainly due to the following reasons. 1) Insufficient backup battery capacity after the station black out (SBO) 2) The malfunction or damage of instruments due to the extremely harsh ambient condition after the severe accident 3) The cut-off of power and communication cable due to the physical shocks of hydrogen explosion after the severe accident Since the current equipment qualification (EQ) for the NPP instruments is based on the design basis accident such as loss of coolant accident (LOCA), conventional instruments, which are examined under EQ condition, cannot guarantee their normal operation during the severe accident. A 7m-long-distance wireless power transfer and a radio frequency (RF) communication were introduced with conventional wired system to increase a redundancy. A heat isolation box and a harness are adopted to provide a protection from the expected physical shocks such as missiles and drastic increase of ambient temperature and pressure. A detail design principle of the highly survivable power and communication system, which has 4 sub-systems of a DCRS wireless power transfer, a Zigbee wireless communication, a GFRP harness, and a passive type router with a fly back regulator, has been presented in this paper. Each sub-system has been designed to have a robust operation characteristic regardless of the estimated physical shocks after the severe accident.

  14. Efficient high speed communications over electrical powerlines for a large number of users

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.; Tripathi, K.; Latchman, H.A. [Florida Univ., Gainesville, FL (United States). Dept. of Electrical and Computer Engineering

    2007-07-01

    Affordable broadband Internet communication is currently available for residential use via cable modem and other forms of digital subscriber lines (DSL). Powerline communication (PLC) systems were never considered seriously for communications due to their low speed and high development cost. However, due to technological advances PLCs are now spreading to local area networks and broadband over power line systems. This paper presented a newly proposed modification to the standard HomePlug 1.0 MAC protocol to make it a constant contention window-based scheme. The HomePlug 1.0 was developed based on orthogonal frequency division multiplexing (OFDM) and carrier sense multiple access with collision avoidance (CSMA/CA). It is currently the most commonly used technology of power line communications, supporting a transmission rate of up to 14 Mbps on the power line. However, the throughput performance of this original scheme becomes critical when the number of users increases. For that reason, a constant contention window based medium access control protocol algorithm of HomePlug 1.0 was proposed under the assumption that the number of active stations is known. An analytical framework based on Markov Chains was developed in order to model this modified protocol under saturation conditions. Modeling results accurately matched the actual performance of the system. This paper revealed that the performance can be improved significantly if the variables were parameterized in terms of the number of active stations. 15 refs., 1 tab., 6 figs.

  15. High Precision Ranging and Range-Rate Measurements over Free-Space-Laser Communication Link

    Science.gov (United States)

    Yang, Guangning; Lu, Wei; Krainak, Michael; Sun, Xiaoli

    2016-01-01

    We present a high-precision ranging and range-rate measurement system via an optical-ranging or combined ranging-communication link. A complete bench-top optical communication system was built. It included a ground terminal and a space terminal. Ranging and range rate tests were conducted in two configurations. In the communication configuration with 622 data rate, we achieved a two-way range-rate error of 2 microns/s, or a modified Allan deviation of 9 x 10 (exp -15) with 10 second averaging time. Ranging and range-rate as a function of Bit Error Rate of the communication link is reported. They are not sensitive to the link error rate. In the single-frequency amplitude modulation mode, we report a two-way range rate error of 0.8 microns/s, or a modified Allan deviation of 2.6 x 10 (exp -15) with 10 second averaging time. We identified the major noise sources in the current system as the transmitter modulation injected noise and receiver electronics generated noise. A new improved system will be constructed to further improve the system performance for both operating modes.

  16. Robust Short-Pulse, High-Peak-Power Laser Transmitter for Optical Communications

    Science.gov (United States)

    Wright, Malcolm W.

    2009-01-01

    We report on a pulsed fiber based master oscillator power amplifier laser at 1550 nm to support moderate data rates with high peak powers in a compact package suitable for interplanetary optical communications. To accommodate pulse position modulation, the polarization maintaining laser transmitter generates pulses from 0.1 to 1 ns with variable duty cycle over a pulse repetition frequency range of 10 to 100 MHz.

  17. Infrared thermographic surveying of building debris: Tomsk High Military School of Communication Engineering catastrophe case study

    Science.gov (United States)

    Vavilov, Vladimir P.

    1998-03-01

    IR thermography was used in surveying dormitory debris of Tomsk High Military School of Communication Engineering in Siberia that collapsed on July 17, 1997, with 12 students dead. In total, the debris had the ambient temperature but plentiful joints between vertical brick-made columns and horizontal concrete beams were detected to be abnormally warm. The reasons for this temperature elevation are discussed. The arguments pro and contra possibility to identify temperature patterns as abnormal mechanical stresses are considered.

  18. Delay-Aware Online Service Scheduling in High-Speed Railway Communication Systems

    OpenAIRE

    Shengfeng Xu; Gang Zhu; Chao Shen; Yan Lei; Zhangdui Zhong

    2014-01-01

    We investigate the downlink service scheduling problem in relay-assisted high-speed railway (HSR) communication systems, taking into account stochastic packet arrivals and quality-of-service (QoS) requirements. The scheduling problem is formulated as an infinite-horizon average cost constrained Markov decision process (MDP), where the scheduling actions depend on the channel state information (CSI) and the queue state information (QSI). Our objective is to find a policy that minimizes the ave...

  19. Nonlocality Distillation and Trivial Communication Complexity for High-Dimensional Systems

    Institute of Scientific and Technical Information of China (English)

    Yan Li; Xiang-Jun Ye; Jing-Ling Chen

    2016-01-01

    A nonlocality distillation protocol for arbitrary high-dimensional systems is proposed.We study the nonlocality distillation in the 2-input d-output bi-partite case.Firstly,we give the one-parameter nonlocal boxes and their correlated distilling protocol.Then,we generalize the one-parameter nonlocality distillation protocol to the two-parameter case.Furthermore,we introduce a contracting protocol testifying that the 2-input d-output nonlocal boxes make communication complexity trivial.

  20. Extremely high frequency (EHF) satellite communications (SATCOM) technology-transmitters and receivers

    Science.gov (United States)

    Raue, Jorg E.

    1983-10-01

    During the past three years, interest in satellite communications in the frequency bands above Ku-band has expanded dramatically. As a result, a number of key technology developments, targeted to meet specific next generation spaceborne needs, were undertaken. The state-of-the-art in solid state power transmitters and low noise receivers, including critical passive component technology, is presented. This includes filters as well as a series of rugged high performance ferrite components such as isolators, circulators and latching switches.

  1. Programming Environment for a High-Performance Parallel Supercomputer with Intelligent Communication

    OpenAIRE

    A. Gunzinger; BÄumle, B.; Frey, M.; Klebl, M.; Kocheisen, M.; Kohler, P.; Morel, R.; Müller, U; Rosenthal, M

    1996-01-01

    At the Electronics Laboratory of the Swiss Federal Institute of Technology (ETH) in Zürich, the high-performance parallel supercomputer MUSIC (MUlti processor System with Intelligent Communication) has been developed. As applications like neural network simulation and molecular dynamics show, the Electronics Laboratory supercomputer is absolutely on par with those of conventional supercomputers, but electric power requirements are reduced by a factor of 1,000, weight is reduced by a factor of...

  2. High-Efficiency Device Positioning and Location-Aware Communications in Dense 5G Networks

    OpenAIRE

    Koivisto, Mike; Hakkarainen, Aki; Costa, Mário; Kela, Petteri; Leppänen, Kari; Valkama, Mikko

    2016-01-01

    In this article, the prospects and enabling technologies for high-efficiency device positioning and location-aware communications in emerging 5G networks are reviewed. We will first describe some key technical enablers and demonstrate by means of realistic ray-tracing and map based evaluations that positioning accuracies below one meter can be achieved by properly fusing direction and delay related measurements on the network side, even when tracking moving devices. We will then discuss the p...

  3. Using UDP Datagram to Realize a Distributed Control Mode at High-Speed Data Communication

    Science.gov (United States)

    Zhao, Lindi

    This article presents a distributed control mode at high-speed data communication by using UDP datagram based on a dual-port RAM, with the purpose of exploring an efficient, low CPU occupancy, high-speed, reliable and large amounts of data exchange mode. One port of the proposed dual-port RAM mode is connected to local CPU, which can be easily read and write data and the other port is connected to the reading and writing and communication control dedicated logic, which is responsible for organizing, sending, receiving and analyzing UDP datagram and also for completing the tasks of reading and writing dual-port RAM and sending interrupt request to the local processor. This model not only realizes efficient data exchange, but also provides real-time interrupt response mechanism. In this article, it discusses the functional modules required for these functions, describes the composition of the system and the advantages of technical performance. It also analyzes the feasibility of its development, and demonstrates that this model is an advanced, high performance distributed control communication program with great promising.

  4. A High Density Electrophysiological Data Analysis System for a Peripheral Nerve Interface Communicating with Individual Neurons in the Brain

    Science.gov (United States)

    2016-11-14

    of-the-art instrumentation to communicate with individual neurons in the brain and the peripheral nervous system. The major theme of the research is...Nerve Interface Communicating with Individual Neurons in the Brain The views, opinions and/or findings contained in this report are those of the author...Communicating with Individual Neurons in the Brain Report Title The high density electrophysiological data acquisition system obtained through this

  5. High speed visible light communication using blue GaN laser diodes

    Science.gov (United States)

    Watson, S.; Viola, S.; Giuliano, G.; Najda, S. P.; Perlin, P.; Suski, T.; Marona, L.; Leszczyński, M.; Wisniewski, P.; Czernecki, R.; Targowski, G.; Watson, M. A.; White, H.; Rowe, D.; Laycock, L.; Kelly, A. E.

    2016-10-01

    GaN-based laser diodes have been developed over the last 20 years making them desirable for many security and defence applications, in particular, free space laser communications. Unlike their LED counterparts, laser diodes are not limited by their carrier lifetime which makes them attractive for high speed communication, whether in free space, through fiber or underwater. Gigabit data transmission can be achieved in free space by modulating the visible light from the laser with a pseudo-random bit sequence (PRBS), with recent results approaching 5 Gbit/s error free data transmission. By exploiting the low-loss in the blue part of the spectrum through water, data transmission experiments have also been conducted to show rates of 2.5 Gbit/s underwater. Different water types have been tested to monitor the effect of scattering and to see how this affects the overall transmission rate and distance. This is of great interest for communication with unmanned underwater vehicles (UUV) as the current method using acoustics is much slower and vulnerable to interception. These types of laser diodes can typically reach 50-100 mW of power which increases the length at which the data can be transmitted. This distance could be further improved by making use of high power laser arrays. Highly uniform GaN substrates with low defectivity allow individually addressable laser bars to be fabricated. This could ultimately increase optical power levels to 4 W for a 20-emitter array. Overall, the development of GaN laser diodes will play an important part in free space optical communications and will be vital in the advancement of security and defence applications.

  6. High performance communication by people with paralysis using an intracortical brain-computer interface.

    Science.gov (United States)

    Pandarinath, Chethan; Nuyujukian, Paul; Blabe, Christine H; Sorice, Brittany L; Saab, Jad; Willett, Francis R; Hochberg, Leigh R; Shenoy, Krishna V; Henderson, Jaimie M

    2017-02-21

    Brain-computer interfaces (BCIs) have the potential to restore communication for people with tetraplegia and anarthria by translating neural activity into control signals for assistive communication devices. While previous pre-clinical and clinical studies have demonstrated promising proofs-of-concept (Serruya et al., 2002; Simeral et al., 2011; Bacher et al., 2015; Nuyujukian et al., 2015; Aflalo et al., 2015; Gilja et al., 2015; Jarosiewicz et al., 2015; Wolpaw et al., 1998; Hwang et al., 2012; Spüler et al., 2012; Leuthardt et al., 2004; Taylor et al., 2002; Schalk et al., 2008; Moran, 2010; Brunner et al., 2011; Wang et al., 2013; Townsend and Platsko, 2016; Vansteensel et al., 2016; Nuyujukian et al., 2016; Carmena et al., 2003; Musallam et al., 2004; Santhanam et al., 2006; Hochberg et al., 2006; Ganguly et al., 2011; O'Doherty et al., 2011; Gilja et al., 2012), the performance of human clinical BCI systems is not yet high enough to support widespread adoption by people with physical limitations of speech. Here we report a high-performance intracortical BCI (iBCI) for communication, which was tested by three clinical trial participants with paralysis. The system leveraged advances in decoder design developed in prior pre-clinical and clinical studies (Gilja et al., 2015; Kao et al., 2016; Gilja et al., 2012). For all three participants, performance exceeded previous iBCIs (Bacher et al., 2015; Jarosiewicz et al., 2015) as measured by typing rate (by a factor of 1.4-4.2) and information throughput (by a factor of 2.2-4.0). This high level of performance demonstrates the potential utility of iBCIs as powerful assistive communication devices for people with limited motor function.Clinical Trial No: NCT00912041.

  7. Development of data communication system with ultra high frequency radio wave for implantable artificial hearts.

    Science.gov (United States)

    Tsujimura, Shinichi; Yamagishi, Hiroto; Sankai, Yoshiyuki

    2009-01-01

    In order to minimize infection risks of patients with artificial hearts, wireless data transmission methods with electromagnetic induction or light have been developed. However, these methods tend to become difficult to transmit data if the external data transmission unit moves from its proper position. To resolve this serious problem, the purpose of this study is to develop a prototype wireless data communication system with ultra high frequency radio wave and confirm its performance. Due to its high-speed communication rate, low power consumption, high tolerance to electromagnetic disturbances, and secure wireless communication, we adopted Bluetooth radio wave technology for our system. The system consists of an internal data transmission unit and an external data transmission unit (53 by 64 by 16 mm, each), and each has a Bluetooth module (radio field intensity: 4 dBm, receiver sensitivity: -80 dBm). The internal unit also has a micro controller with an 8-channel 10-bit A/D converter, and the external unit also has a RS-232C converter. We experimented with the internal unit implanted into pig meat, and carried out data transmission tests to evaluate the performance of this system in tissue thickness of up to 3 mm. As a result, data transfer speeds of about 20 kbps were achieved within the communication distance of 10 m. In conclusion, we confirmed that the system can wirelessly transmit the data from the inside of the body to the outside, and it promises to resolve unstable data transmission due to accidental movements of an external data transmission unit.

  8. High performance communication by people with paralysis using an intracortical brain-computer interface

    Science.gov (United States)

    Pandarinath, Chethan; Nuyujukian, Paul; Blabe, Christine H; Sorice, Brittany L; Saab, Jad; Willett, Francis R; Hochberg, Leigh R

    2017-01-01

    Brain-computer interfaces (BCIs) have the potential to restore communication for people with tetraplegia and anarthria by translating neural activity into control signals for assistive communication devices. While previous pre-clinical and clinical studies have demonstrated promising proofs-of-concept (Serruya et al., 2002; Simeral et al., 2011; Bacher et al., 2015; Nuyujukian et al., 2015; Aflalo et al., 2015; Gilja et al., 2015; Jarosiewicz et al., 2015; Wolpaw et al., 1998; Hwang et al., 2012; Spüler et al., 2012; Leuthardt et al., 2004; Taylor et al., 2002; Schalk et al., 2008; Moran, 2010; Brunner et al., 2011; Wang et al., 2013; Townsend and Platsko, 2016; Vansteensel et al., 2016; Nuyujukian et al., 2016; Carmena et al., 2003; Musallam et al., 2004; Santhanam et al., 2006; Hochberg et al., 2006; Ganguly et al., 2011; O’Doherty et al., 2011; Gilja et al., 2012), the performance of human clinical BCI systems is not yet high enough to support widespread adoption by people with physical limitations of speech. Here we report a high-performance intracortical BCI (iBCI) for communication, which was tested by three clinical trial participants with paralysis. The system leveraged advances in decoder design developed in prior pre-clinical and clinical studies (Gilja et al., 2015; Kao et al., 2016; Gilja et al., 2012). For all three participants, performance exceeded previous iBCIs (Bacher et al., 2015; Jarosiewicz et al., 2015) as measured by typing rate (by a factor of 1.4–4.2) and information throughput (by a factor of 2.2–4.0). This high level of performance demonstrates the potential utility of iBCIs as powerful assistive communication devices for people with limited motor function. Clinical Trial No: NCT00912041 DOI: http://dx.doi.org/10.7554/eLife.18554.001 PMID:28220753

  9. A highly directional transducer for multipath mitigation in high-frequency underwater acoustic communications.

    Science.gov (United States)

    Freeman, Simon E; Emokpae, Lloyd; Nicholas, Michael; Edelmann, Geoffrey F

    2015-08-01

    This paper presents a transducer design of the hollow cylinder type designed to minimize transmission multipath and the need for channel equalization over short acoustic communication distances in shallow water. Operating at 750 kHz, the half-maximum envelope of the main lobe is approximately 3°. The transducer was incorporated into a low-complexity modem system in which it acted as both transmitter and receiver. At-sea testing indicated that the system is capable of operating over horizontal distances of 5 m without evidence of multipath distortion. The system was also found to be effective as an omnidirectional transmitter/receiver in the 10-60 kHz band.

  10. Incorporating risk communication into highly pathogenic avian influenza preparedness and response efforts.

    Science.gov (United States)

    Voss, Shauna J; Malladi, Sasidhar; Sampedro, Fernando; Snider, Tim; Goldsmith, Timothy; Hueston, William D; Lauer, Dale C; Halvorson, David A

    2012-12-01

    A highly pathogenic avian influenza (HPAI) outbreak in the United States will initiate a federal emergency response effort that will consist of disease control and eradication efforts, including quarantine and movement control measures. These movement control measures will not only apply to live animals but also to animal products. However, with current egg industry "just-in-time" production practices, limited storage is available to hold eggs. As a result, stop movement orders can have significant unintended negative consequences, including severe disruptions to the food supply chain. Because stakeholders' perceptions of risk vary, waiting to initiate communication efforts until an HPAI event occurs can hinder disease control efforts, including the willingness of producers to comply with the response, and also can affect consumers' demand for the product. A public-private-academic partnership was formed to assess actual risks involved in the movement of egg industry products during an HPAI event through product specific, proactive risk assessments. The risk analysis process engaged a broad representation of stakeholders and promoted effective risk management and communication strategies before an HPAI outbreak event. This multidisciplinary team used the risk assessments in the development of the United States Department of Agriculture, Highly Pathogenic Avian Influenza Secure Egg Supply Plan, a comprehensive response plan that strives to maintain continuity of business. The collaborative approach that was used demonstrates how a proactive risk communication strategy that involves many different stakeholders can be valuable in the development of a foreign animal disease response plan and build working relationships, trust, and understanding.

  11. How anxiety about communication affects the role of nurse leaders in international social networks.

    Science.gov (United States)

    Benton, David; Ferguson, Stephanie

    2016-05-01

    Social network analysis examines the way individuals are connected within groups or networks, and the role they play in these groups. In terms of its application to issues related to nurse leaders, much of the research focuses on the structure of their networks, the roles they play, and whether the networks can be changed to improve communication flows. This article reports results of a study that aimed to deepen understanding of how a particular trait - communication apprehension - can affect the roles that nurse leaders play within network structures. It also shows how the research expands understanding of the factors that influence connections between senior nurse leaders internationally, and describes the communication apprehension instrument used, which provides a practical tool to assist aspirant nurse leaders to identify areas for personal development.

  12. Single Carrier Architecture for High Data Rate Wireless PAN Communications System

    CERN Document Server

    Rakotondrainibe, Lahatra; Zaharia, Gheorghe; Grunfelder, Guy; Zein, Ghaïs El

    2010-01-01

    A 60 GHz wireless Gigabit Ethernet (G.E.) communication system is developed at IETR. As the 60 GHz radio link operates only in a single-room configuration, an additional Radio over Fibre (RoF) link is used to ensure the communications in all the rooms of a residential environment. The realized system covers 2 GHz bandwidth. Due to the hardware constraints, a symbol rate at 875 Mbps is attained using simple single carrier architecture. In the baseband (BB) processing block, an original byte/frame synchronization process is designed to provide a smaller value of the preamble missing detection and false alarm probabilities. Bit error rate (BER) measurements have been realized in a large gym for line-of-sight (LOS) conditions. A Tx-Rx distance greater than 30 meters was attained with low BER using high gain antennas and forward error correction RS (255, 239) coding.

  13. Experimental implant communication of high data rate video using an ultra wideband radio link.

    Science.gov (United States)

    Chávez-Santiago, Raúl; Balasingham, Ilangko; Bergsland, Jacob; Zahid, Wasim; Takizawa, Kenichi; Miura, Ryu; Li, Huan-Bang

    2013-01-01

    Ultra wideband (UWB) is one of the radio technologies adopted by the IEEE 802.15.6™-2012 standard for on-body communication in body area networks (BANs). However, a number of simulation-based studies suggest the feasibility of using UWB for high data rate implant communication too. This paper presents an experimental verification of said predictions. We carried out radio transmissions of H.264/1280×720 pixels video at 80 Mbps through a UWB multiband orthogonal frequency division multiplexing (MB-OFDM) interface in a porcine chirurgical model. The results demonstrated successful transmission up to a maximum depth of 30 mm in the abdomen and 33 mm in the thorax within the 4.2-4.8 GHz frequency band.

  14. Method of high speed flow field influence and restrain on laser communication

    Science.gov (United States)

    Meng, Li-xin; Wang, Chun-hui; Qian, Cun-zhu; Wang, Shuo; Zhang, Li-zhong

    2013-08-01

    For laser communication performance which carried by airplane or airship, due to high-speed platform movement, the air has two influences in platform and laser communication terminal window. The first influence is that aerodynamic effect causes the deformation of the optical window; the second one is that a shock wave and boundary layer would be generated. For subsonic within the aircraft, the boundary layer is the main influence. The presence of a boundary layer could change the air density and the temperature of the optical window, which causes the light deflection and received beam spot flicker. Ultimately, the energy hunting of the beam spot which reaches receiving side increases, so that the error rate increases. In this paper, aerodynamic theory is used in analyzing the influence of the optical window deformation due to high speed air. Aero-optics theory is used to analyze the influence of the boundary layer in laser communication link. Based on this, we focused on working on exploring in aerodynamic and aero-optical effect suppression method in the perspective of the optical window design. Based on planning experimental aircraft types and equipment installation location, we optimized the design parameters of the shape and thickness of the optical window, the shape and size of air-management kit. Finally, deformation of the optical window and air flow distribution were simulated by fluid simulation software in the different mach and different altitude fly condition. The simulation results showed that the optical window can inhibit the aerodynamic influence after optimization. In addition, the boundary layer is smoothed; the turbulence influence is reduced, which meets the requirements of the airborne laser communication.

  15. Understanding Positive and Negative Communication Instances between Special Educators and Parents of High School Students with EBD

    Science.gov (United States)

    Mires, Carolyn B.

    2015-01-01

    Using a multiple case study methodology, interviews were conducted to examine current practices and perceptions of the communication practices of teachers working with high school students with emotional and behavioral disorders (EBD). These interviews involved questions about general communication instances which occurred each week, communication…

  16. The Relative Importance of Selected Communication Skills for Adolescents' Interactions with Their Teachers: High School Teachers' Opinions.

    Science.gov (United States)

    Reed, Vicki A.; Spicer, Lynette

    2003-01-01

    High school teachers (n=143) ranked 14 communication skills according to the perceived order of importance for Grade 10 adolescents' communication with them as teachers. Teachers tended to perceive skills associated with discourse management strategies as relatively more important than other skills. Science teachers ranked turn taking higher than…

  17. Modulation of low-density lipoprotein-induced inhibition of intercellular communication by antioxidants and high-density lipoproteins

    NARCIS (Netherlands)

    Zwijsen, R M; de Haan, L. H. J.; Kuivenhoven, J A; Nusselder, I C

    1991-01-01

    In order to study the capacity of antioxidants and high-density lipoproteins (HDL) to modulate the effects of low-density lipoprotein (LDL) on intercellular communication, arterial smooth muscle cells and a dye transfer method were used. LDL, in contrast to HDL, inhibited the communication between a

  18. Understanding Positive and Negative Communication Instances between Special Educators and Parents of High School Students with EBD

    Science.gov (United States)

    Mires, Carolyn B.

    2015-01-01

    Using a multiple case study methodology, interviews were conducted to examine current practices and perceptions of the communication practices of teachers working with high school students with emotional and behavioral disorders (EBD). These interviews involved questions about general communication instances which occurred each week, communication…

  19. Modulation of low-density lipoprotein-induced inhibition of intercellular communication by antioxidants and high-density lipoproteins

    NARCIS (Netherlands)

    Zwijsen, R M; de Haan, L. H. J.; Kuivenhoven, J A; Nusselder, I C

    In order to study the capacity of antioxidants and high-density lipoproteins (HDL) to modulate the effects of low-density lipoprotein (LDL) on intercellular communication, arterial smooth muscle cells and a dye transfer method were used. LDL, in contrast to HDL, inhibited the communication between

  20. Secured Wireless Communication using Fuzzy Logic based High Speed Public-Key Cryptography (FLHSPKC

    Directory of Open Access Journals (Sweden)

    Arindam Sarkar

    2012-10-01

    Full Text Available In this paper secured wireless communication using fuzzy logic based high speed public-key cryptography (FLHSPKC has been proposed by satisfying the major issues likes computational safety, power management and restricted usage of memory in wireless communication. Wireless Sensor Network (WSN has several major constraints likes’ inadequate source of energy, restricted computational potentiality and limited memory. Though conventional Elliptic Curve Cryptography (ECC which is a sort of public-key cryptography used in wireless communication provides equivalent level of security like other existing public–key algorithm using smaller parameters than other but this traditional ECC does not take care of all these major limitations in WSN. In conventional ECC consider Elliptic curve point p, an arbitrary integer k and modulus m, ECC carry out scalar multiplication kP mod m, which takes about 80% of key computation time on WSN. In this paper proposed FLHSPKC scheme provides some novel strategy including novel soft computing based strategy to speed up scalar multiplication in conventional ECC and which in turn takes shorter computational time and also satisfies power consumption restraint, limited usage of memory without hampering the security level. Performance analysis of the different strategies under FLHSPKC scheme and comparison study with existing conventional ECC methods has been done.

  1. High-precision satellite relative-trajectory simulating servosystem for inter-satellite laser communications

    Science.gov (United States)

    Zhang, Lei; Liu, Liren; Luan, Zhu; Liu, Hongzhan; Xu, Rongwei

    2004-10-01

    Because PAT (pointing-acquisition-tracking) parameters and integrated technical specifications of laser communication terminals for inter-satellite link must be pre-verified and assessed thoroughly on a ground-based test-bed before launched into the space, it is necessary to develop a system as a primary part of the test bed to simulate the relative trajectory between the satellites. In this paper, an original high-precision satellite relative-trajectory simulating servosystem is introduced in detail as well as its structures and characteristics. The system is used to simulate the motion of relative-trajectory between satellites in different orbits. The principle of the system is to import the data of two satellites" orbits into a computer-based control system in advance. After processed and analyzed, the data is transformed into the angular displacement of the servomotor which drives the gimbal directly. The angular displacement of the two axes of the gimbal can simulate precisely the relative-trajectory, namely elevation angle and azimuth angle of the two satellites in communication. A laser communication terminal mounted on the gimbal then performs the PAT mechanisms to evaluate the system"s capacity.

  2. A highly reliable, autonomous data communication subsystem for an advanced information processing system

    Science.gov (United States)

    Nagle, Gail; Masotto, Thomas; Alger, Linda

    1990-01-01

    The need to meet the stringent performance and reliability requirements of advanced avionics systems has frequently led to implementations which are tailored to a specific application and are therefore difficult to modify or extend. Furthermore, many integrated flight critical systems are input/output intensive. By using a design methodology which customizes the input/output mechanism for each new application, the cost of implementing new systems becomes prohibitively expensive. One solution to this dilemma is to design computer systems and input/output subsystems which are general purpose, but which can be easily configured to support the needs of a specific application. The Advanced Information Processing System (AIPS), currently under development has these characteristics. The design and implementation of the prototype I/O communication system for AIPS is described. AIPS addresses reliability issues related to data communications by the use of reconfigurable I/O networks. When a fault or damage event occurs, communication is restored to functioning parts of the network and the failed or damage components are isolated. Performance issues are addressed by using a parallelized computer architecture which decouples Input/Output (I/O) redundancy management and I/O processing from the computational stream of an application. The autonomous nature of the system derives from the highly automated and independent manner in which I/O transactions are conducted for the application as well as from the fact that the hardware redundancy management is entirely transparent to the application.

  3. High Speed Submarine Optical Fiber Communication System:Pressure and Temperature Effects

    Directory of Open Access Journals (Sweden)

    A. A. Mohammed

    2012-07-01

    Full Text Available In the present paper, the performance of high speed submarine optical fiber cable systems is investigated, taking into account both the pressure and the temperature effects. Both the pressure and the temperature are depth-dependent variables, while both the spectral losses and the dispersion effects are temperature as well as wavelength dependent variables. Two important cases with real fibers are processed: a case with dispersion cancellation and a case without dispersion cancellation. It is found that the ocean pressure (due to the depth shifts the dispersion-free wavelength towards the third communication window. In general, as the depth increases the maximum transmitted bit rate increases in the range of interest. The system capacity as well as the spectral losses, and the dispersion effects are parametrically investigated over wide-range ranges of the set of affecting parameters {wavelength, ocean depth (and consequently the ocean pressure and temperature, and the chemical structure}. Key Words: Submarine Optical Fiber, Undersea Optical Communication, Pressure and Temperature Effects, Transoceanic Optical Communications

  4. When asking questions is not enough: an observational study of social communication differences in high functioning children with autism.

    Science.gov (United States)

    Jones, Christopher D; Schwartz, Ilene S

    2009-03-01

    This investigation examined communication patterns between high functioning children with autism and their families and typically developing children and their families within traditional dinner time conversation. Twenty families with a child with autism (3.5-7 years.) and ten families with typically developing children (3.5-6 years) were video recorded during dinner and their interactions were coded. Results revealed that children with autism initiated fewer bids for interactions, commented less often, continued ongoing interactions through fewer conversational turns, and responded less often to family member communication bids. Results are interpreted with respect to how communication patterns may be indicative of social communication deficits not previously examined in high functioning children with autism. Strategies for social communication interventions within the family and other natural contexts are discussed.

  5. Multi-disciplinary communication networks for skin risk assessment in nursing homes with high IT sophistication.

    Science.gov (United States)

    Alexander, Gregory L; Pasupathy, Kalyan S; Steege, Linsey M; Strecker, E Bradley; Carley, Kathleen M

    2014-08-01

    The role of nursing home (NH) information technology (IT) in quality improvement has not been clearly established, and its impacts on communication between care givers and patient outcomes in these settings deserve further attention. In this research, we describe a mixed method approach to explore communication strategies used by healthcare providers for resident skin risk in NH with high IT sophistication (ITS). Sample included NH participating in the statewide survey of ITS. We incorporated rigorous observation of 8- and 12-h shifts, and focus groups to identify how NH IT and a range of synchronous and asynchronous tools are used. Social network analysis tools and qualitative analysis were used to analyze data and identify relationships between ITS dimensions and communication interactions between care providers. Two of the nine ITS dimensions (resident care-technological and administrative activities-technological) and total ITS were significantly negatively correlated with number of unique interactions. As more processes in resident care and administrative activities are supported by technology, the lower the number of observed unique interactions. Additionally, four thematic areas emerged from staff focus groups that demonstrate how important IT is to resident care in these facilities including providing resident-centered care, teamwork and collaboration, maintaining safety and quality, and using standardized information resources. Our findings in this study confirm prior research that as technology support (resident care and administrative activities) and overall ITS increases, observed interactions between staff members decrease. Conversations during staff interviews focused on how technology facilitated resident centered care through enhanced information sharing, greater virtual collaboration between team members, and improved care delivery. These results provide evidence for improving the design and implementation of IT in long term care systems to support

  6. Dispersive and nonlinear effects in high-speed reconfigurable WDM optical fiber communication systems

    Science.gov (United States)

    Yu, Changyuan

    Chromatic dispersion, polarization mode dispersion (PMD) and nonlinear effects are important issues on the physical layer of high-speed reconfigurable WDM optical fiber communication systems. For beyond 10 Gbit/s optical fiber transmission system, it is essential that chromatic dispersion and PMD be well managed by dispersion monitoring and compensation. One the other hand, dispersive and nonlinear effects in optical fiber systems can also be beneficial and has applications on pulse management, all-optical signal processing and network function, which will be essential for high bite-rate optical networks and replacing the expensive optical-electrical-optical (O/E/O) conversion. In this Ph.D. dissertation, we present a detailed research on dispersive and nonlinear effects in high-speed optical communication systems. We have demonstrated: (i) A novel technique for optically compensating the PMD-induced RF power fading that occurs in single-sideband (SSB) subcarrier-multiplexed systems. By aligning the polarization states of the optical carrier and the SSB, RF power fading due to all orders of PMD can be completely compensated. (ii) Chromatic-dispersion-insensitive PMD monitoring by using a narrowband FBG notch filter to recover the RF clock power for 10Gb/s NRZ data, and apply it as a control signal for PMD compensation. (iii) Chirp-free high-speed optical pulse generation with a repetition rate of 160 GHz (which is four times of the frequency of the electrical clock) using a phase modulator and polarization maintaining (PM) fiber. (iv) Polarization-insensitive all-optical wavelength conversion based on four-wave mixing in dispersion-shifted fiber (DSF) with a fiber Bragg grating and a Faraday rotator mirror. (v) Width-tunable optical RZ pulse train generation based on four-wave mixing in highly-nonlinear fiber. By electrically tuning the delay between two pump pulse trains, the pulse-width of a generated pulse train is continuously tuned. (vi) A high-speed all

  7. Assessment of risk factors of non-communicable diseases among high school students in Mangalore, India

    Directory of Open Access Journals (Sweden)

    Animesh Jain

    2012-01-01

    Full Text Available Context: Non-communicable diseases are ever increasing and will soon outnumber the prevalence of communicable diseases. This study aims to detect prevalence of risk factors of non-communicable diseases in high school students and its comparison among students of private and government schools, Mangalore. Materials and Methods: A cross-sectional questionnaire based study was conducted amongst consenting high-school students. The data collected included socio-demographic factors, dietary habits, smoking, alcohol consumption, physical activity, height and weight. Data was tabulated and analyzed using Microsoft excel and SPSS version 11.5 software. Chi square test was used to determine the association of various factors with risk factors, P < 0.05 was considered significant. The results were presented as tables. Result: 413 students were surveyed from private and government schools. Age range was 13-15 years. One-tenth of the students had adequate dietary habits. Though most students were physically active, the type and duration of activity was inadequate. Two students were obese, both females. There were statistically significant differences among various socioeconomic classes, type of school and the presence of certain risk factors. Alcohol intake among students of upper class was significant ( P = 0.006. Conclusion: The prevalence of risk factors for NCD is low among high-school students of Mangalore. Students should be educated about having adequate amount of fruits and vegetables and advised to reduce the consumption of fast food. Vigorous activity should be encouraged amongst the students to prevent them from getting obese.

  8. 42 CFR 70.6 - Apprehension and detention of persons with specific diseases.

    Science.gov (United States)

    2010-10-01

    ... diseases. 70.6 Section 70.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... specific diseases. Regulations prescribed in this part authorize the detention, isolation, quarantine, or... of the communicable diseases listed in an Executive Order setting out a list of...

  9. EVALUATION OF POWER SPECTRAL DENSITY OF PASSIVE INTERMODULATION DISTORTION IN HIGH-POWER COMMUNICATION SATELLITE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Zhang Shiquan; Ge Debiao

    2005-01-01

    In order to analyze the deleterious effects of Passive InterModulation (PIM) on high power communication satellite systems, the basic concept of PIM is introduced, and an equation for the power spectral density of the n-th order PIM distortion insuch systems is derived by applying flat signal-power spectrum assumption and Fourier transform method. It is indicated that PIM level generally decreases with order and the lowest frequency receive channel in the receive band is the channel of most affected by PIM interference.

  10. Circuit for Communication over DC Power Line Using High Temperature Electronics

    Science.gov (United States)

    Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor)

    2014-01-01

    A high temperature communications circuit includes a power conductor for concurrently conducting electrical energy for powering circuit components and transmitting a modulated data signal, and a demodulator for demodulating the data signal and generating a serial bit stream based on the data signal. The demodulator includes an absolute value amplifier for conditionally inverting or conditionally passing a signal applied to the absolute value amplifier. The absolute value amplifier utilizes no diodes to control the conditional inversion or passing of the signal applied to the absolute value amplifier.

  11. CTS United States experiments - A progress report. [Communications Technology Satellite for high power broadcasting

    Science.gov (United States)

    Robbins, W. H.; Donoughe, P. L.

    1976-01-01

    The Communications Technology Satellite (CTS) is a high-power broadcast satellite launched by NASA on January 17, 1976. CTS is the first satellite to operate at a frequency of 12 gigahertz and incorporates technology making possible new satellite telecommunications services. CTS is a cooperative program of the United States and Canada. This paper presents the results of the United States experimental activity to date. Wide segments of the population are involved in the Experiments Program, including the scientific community, other government agencies, industry, and the education and health entities. The experiments are associated with both technological objectives and the demonstration of new community and social services via satellite.

  12. Wireless and photonic high-speed communication technologies, circuits and design tools

    DEFF Research Database (Denmark)

    Krozer, Viktor; Johansen, Tom Keinicke; Jiang, Chenhui

    2009-01-01

    Wireless and Ethernet communications aim at millimeter-wave frequency operation and gigabit-per-second data transmission. Increased data rates in wireless systems can only be achieved at frequencies beyond 60 GHz or 80 GHz and in 100 Gbit/s (100-G) data transmission over fibre. Both systems are f...... performances obtained in various technologies (Si, SiGe, GaAs and InP) will be presented and discussed. Finally, modeling, measurements and packaging problems at such high frequencies/speeds will be also addressed....

  13. Demonstration of high-speed multi-user multi-carrier CDMA visible light communication

    Science.gov (United States)

    Yang, Chao; Wang, Yuanquan; Wang, Yiguang; Huang, Xingxing; Chi, Nan

    2015-02-01

    We experimentally demonstrated a high-speed multi-user multi-carrier code-division multiple access (MC-CDMA) visible light communication (VLC) system. By employing a commercially available red light emitting diode (LED) and an avalanche photo diode (APD), we achieved a 16-user VLC system enabled by MC-CDMA, pre- and post-equalization, with an overall bit rate of 750 Mb/s over 1.5 m free-space transmission. The measured bit error ratio (BER) of each user is below the 7% pre-forward-error-correction (pre-FEC) threshold of 3.8×10-3.

  14. Trends for International Standards of the High Speed Powerline Communication Technologies

    Science.gov (United States)

    Aramaki, Michimasa; Koga, Hisao; Atsuta, Akira

    The high speed powerline communication (PLC) technology is useful for a variety of applications especially for Smart Grid. Although the standardization of this technology has been desired for a long time, recently IEEE P1901 and ITU-T SG15 made significant progress and both of the Standards are expected to be completed by the end of 2010. The frame work of the coexistence mechanism among the different types of PLC technologies is also going to be resolved with the collaborative work between IEEE and ITU-T. In this paper, the authors introduce the summary of the International Standardizations of this technology, and also the future prospects of the Standards.

  15. Programming Environment for a High-Performance Parallel Supercomputer with Intelligent Communication

    Directory of Open Access Journals (Sweden)

    A. Gunzinger

    1996-01-01

    Full Text Available At the Electronics Laboratory of the Swiss Federal Institute of Technology (ETH in Zürich, the high-performance parallel supercomputer MUSIC (MUlti processor System with Intelligent Communication has been developed. As applications like neural network simulation and molecular dynamics show, the Electronics Laboratory supercomputer is absolutely on par with those of conventional supercomputers, but electric power requirements are reduced by a factor of 1,000, weight is reduced by a factor of 400, and price is reduced by a factor of 100. Software development is a key issue of such parallel systems. This article focuses on the programming environment of the MUSIC system and on its applications.

  16. Understanding the differentiating impacts of the communication strategies of a high involvement service (investment advisory services) and a high involvement product (precious jewellery) on customer satisfaction and loyalty.

    OpenAIRE

    Gupta, Gauri

    2009-01-01

    While marketing literature has largely focused on high and low involvement purchases and the positive relationship between customer satisfaction and loyalty; the differentiating impacts of communication strategies for a high involvement service and a high involvement product on customer satisfaction and loyalty has received little academic attention. Consequently, this study examines the differentiating impacts of the communication strategies for investment advisory services and precious jewe...

  17. High-Throughput and Low-Latency Network Communication with NetIO

    CERN Document Server

    AUTHOR|(CDS)2088631; The ATLAS collaboration

    2017-01-01

    HPC network technologies like Infiniband, TrueScale or OmniPath provide low-latency and high-throughput communication between hosts, which makes them attractive options for data-acquisition systems in large-scale high-energy physics experiments. Like HPC networks, DAQ networks are local and include a well specified number of systems. Unfortunately traditional network communication APIs for HPC clusters like MPI or PGAS target exclusively the HPC community and are not suited well for DAQ applications. It is possible to build distributed DAQ applications using low-level system APIs like Infiniband Verbs, but it requires a non-negligible effort and expert knowledge. At the same time, message services like ZeroMQ have gained popularity in the HEP community. They allow building distributed applications with a high-level approach and provide good performance. Unfortunately their usage usually limits developers to TCP/IP-based networks. While it is possible to operate a TCP/IP stack on top of Infiniband and OmniPath...

  18. High security chaotic multiple access scheme for visible light communication systems with advanced encryption standard interleaving

    Science.gov (United States)

    Qiu, Junchao; Zhang, Lin; Li, Diyang; Liu, Xingcheng

    2016-06-01

    Chaotic sequences can be applied to realize multiple user access and improve the system security for a visible light communication (VLC) system. However, since the map patterns of chaotic sequences are usually well known, eavesdroppers can possibly derive the key parameters of chaotic sequences and subsequently retrieve the information. We design an advanced encryption standard (AES) interleaving aided multiple user access scheme to enhance the security of a chaotic code division multiple access-based visible light communication (C-CDMA-VLC) system. We propose to spread the information with chaotic sequences, and then the spread information is interleaved by an AES algorithm and transmitted over VLC channels. Since the computation complexity of performing inverse operations to deinterleave the information is high, the eavesdroppers in a high speed VLC system cannot retrieve the information in real time; thus, the system security will be enhanced. Moreover, we build a mathematical model for the AES-aided VLC system and derive the theoretical information leakage to analyze the system security. The simulations are performed over VLC channels, and the results demonstrate the effectiveness and high security of our presented AES interleaving aided chaotic CDMA-VLC system.

  19. High-Throughput and Low-Latency Network Communication with NetIO

    CERN Document Server

    Schumacher, Jorn; The ATLAS collaboration

    2017-01-01

    HPC network technologies like Infiniband, TrueScale or OmniPath provide low-latency and high-throughput communication between hosts, which makes them attractive options for data-acquisition systems in large-scale high-energy physics experiments. Like HPC networks, DAQ networks are local and include a well specified number of systems. Unfortunately traditional network communication APIs for HPC clusters like MPI or PGAS target exclusively the HPC community and are not suited well for DAQ applications. It is possible to build distributed DAQ applications using low-level system APIs like Infiniband Verbs, but it requires a non-negligible effort and expert knowledge. At the same time, message services like ZeroMQ have gained popularity in the HEP community. They allow building distributed applications with a high-level approach and provide good performance. Unfortunately their usage usually limits developers to TCP/IP-based networks. While it is possible to operate a TCP/IP stack on top of Infiniband and OmniPath...

  20. Application of Single-Mode Fiber-Coupled Receivers in Optical Satellite to High-Altitude Platform Communications

    Directory of Open Access Journals (Sweden)

    Oswald Wallner

    2008-05-01

    Full Text Available In a free-space optical communication system employing fiber-optic components, the phasefront distortions induced by atmospheric turbulence limit the efficiency with which the laser beam is coupled into a single-mode fiber. We analyze different link scenarios including a geostationary (GEO satellite, a high-altitude platform (HAP, and an optical ground station (OGS. Single-mode coupled optically preamplified receivers allow for efficient suppression of background noise and highly sensitive detection. While GEO-to-OGS communication suffers from atmospheric turbulence, we demonstrate that GEO-to-HAP communication allows for close to diffraction-limited performance when applying tip-tilt correction.

  1. Application of Single-Mode Fiber-Coupled Receivers in Optical Satellite to High-Altitude Platform Communications

    Directory of Open Access Journals (Sweden)

    Fidler Franz

    2008-01-01

    Full Text Available Abstract In a free-space optical communication system employing fiber-optic components, the phasefront distortions induced by atmospheric turbulence limit the efficiency with which the laser beam is coupled into a single-mode fiber. We analyze different link scenarios including a geostationary (GEO satellite, a high-altitude platform (HAP, and an optical ground station (OGS. Single-mode coupled optically preamplified receivers allow for efficient suppression of background noise and highly sensitive detection. While GEO-to-OGS communication suffers from atmospheric turbulence, we demonstrate that GEO-to-HAP communication allows for close to diffraction-limited performance when applying tip-tilt correction.

  2. 4 Gbps direct modulation of 450 nm GaN laser for high-speed visible light communication.

    Science.gov (United States)

    Lee, Changmin; Zhang, Chong; Cantore, Michael; Farrell, Robert M; Oh, Sang Ho; Margalith, Tal; Speck, James S; Nakamura, Shuji; Bowers, John E; DenBaars, Steven P

    2015-06-15

    We demonstrate high-speed data transmission with a commercial high power GaN laser diode at 450 nm. 2.6 GHz bandwidth was achieved at an injection current of 500 mA using a high-speed visible light communication setup. Record high 4 Gbps free-space data transmission rate was achieved at room temperature.

  3. 4 Gbps direct modulation of 450 nm GaN laser for high-speed visible light communication

    KAUST Repository

    Lee, Changmin

    2015-06-10

    We demonstrate high-speed data transmission with a commercial high power GaN laser diode at 450 nm. 2.6 GHz bandwidth was achieved at an injection current of 500 mA using a high-speed visible light communication setup. Record high 4 Gbps free-space data transmission rate was achieved at room temperature.

  4. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication

    Science.gov (United States)

    Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert

    2017-01-01

    In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80–100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes. PMID:28145513

  5. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication

    Science.gov (United States)

    Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert

    2017-02-01

    In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80–100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes.

  6. RAPID COMMUNICATION: High performance superconducting wire in high applied magnetic fields via nanoscale defect engineering

    Science.gov (United States)

    Wee, Sung Hun; Goyal, Amit; Zuev, Yuri L.; Cantoni, Claudia

    2008-09-01

    High temperature superconducting (HTS) wires capable of carrying large critical currents with low dissipation levels in high applied magnetic fields are needed for a wide range of applications. In particular, for electric power applications involving rotating machinery, such as large-scale motors and generators, a high critical current, Ic, and a high engineering critical current density, JE, in applied magnetic fields in the range of 3-5 Tesla (T) at 65 K are required. In addition, exceeding the minimum performance requirements needed for these applications results in a lower fabrication cost, which is regarded as crucial to realize or enable many large-scale bulk applications of HTS materials. Here we report the fabrication of short segments of a potential superconducting wire comprised of a 4 µm thick YBa2Cu3O7-δ (YBCO) layer on a biaxially textured substrate with a 50% higher Ic and JE than the highest values reported previously. The YBCO film contained columns of self-assembled nanodots of BaZrO3 (BZO) roughly oriented along the c-axis of YBCO. Although the YBCO film was grown at a high deposition rate, three-dimensional self-assembly of the insulating BZO nanodots still occurred. For all magnetic field orientations, minimum Ic and JE at 65 K, 3 T for the wire were 353 A cm-1 and 65.4 kA cm-2, respectively.

  7. Efficient Ultra-High Speed Communication with Simultaneous Phase and Amplitude Regenerative Sampling (SPARS)

    Science.gov (United States)

    Carlowitz, Christian; Girg, Thomas; Ghaleb, Hatem; Du, Xuan-Quang

    2017-08-01

    For ultra-high speed communication systems at high center frequencies above 100 GHz, we propose a disruptive change in system architecture to address major issues regarding amplifier chains with a large number of amplifier stages. They cause a high noise figure and high power consumption when operating close to the frequency limits of the underlying semiconductor technologies. Instead of scaling a classic homodyne transceiver system, we employ repeated amplification in single-stage amplifiers through positive feedback as well as synthesizer-free self-mixing demodulation at the receiver to simplify the system architecture notably. Since the amplitude and phase information for the emerging oscillation is defined by the input signal and the oscillator is only turned on for a very short time, it can be left unstabilized and thus come without a PLL. As soon as gain is no longer the most prominent issue, relaxed requirements for all the other major components allow reconsidering their implementation concepts to achieve further improvements compared to classic systems. This paper provides the first comprehensive overview of all major design aspects that need to be addressed upon realizing a SPARS-based transceiver. At system level, we show how to achieve high data rates and a noise performance comparable to classic systems, backed by scaled demonstrator experiments. Regarding the transmitter, design considerations for efficient quadrature modulation are discussed. For the frontend components that replace PA and LNA amplifier chains, implementation techniques for regenerative sampling circuits based on super-regenerative oscillators are presented. Finally, an analog-to-digital converter with outstanding performance and complete interfaces both to the analog baseband as well as to the digital side completes the set of building blocks for efficient ultra-high speed communication.

  8. Development of high-reliable real-time communication network protocol for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Sang; Kim, Young Sik [Korea National University of Education, Chongwon (Korea); No, Hee Chon [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    1999-04-01

    In this research, we first define protocol subsets for SMART(System-integrated Modular Advanced Reactor) communication network based on the requirement of SMART MMIS transmission delay and traffic requirements and OSI(Open System Interconnection) 7 layers' network protocol functions. Also, current industrial purpose LAN protocols are analyzed and the applicability of commercialized protocols are checked. For the suitability test, we have applied approximated SMART data traffic and maximum allowable transmission delay requirement. With the simulation results, we conclude that IEEE 802.5 and FDDI which is an ANSI standard, is the most suitable for SMART. We further analyzed the FDDI and token ring protocols for SMART and nuclear plant network environment including IEEE 802.4, IEEE 802.5, and ARCnet. The most suitable protocol for SMART is FDDI and FDDI MAC and RMT protocol specifications have been verified with LOTOS and the verification results show that FDDI MAC and RMT satisfy the reachability and liveness, but does not show deadlock and livelock. Therefore, we conclude that FDDI MAC and RMT is highly reliable protocol for SMART MMIS network. After that, we consider the stacking fault of IEEE 802.5 token ring protocol and propose a fault tolerant MAM(Modified Active Monitor) protocol. The simulation results show that the MAM protocol improves lower priority traffic service rate when stacking fault occurs. Therefore, proposed MAM protocol can be applied to SMART communication network for high reliability and hard real-time communication purpose in data acquisition and inter channel network. (author). 37 refs., 79 figs., 39 tabs.

  9. Reconfigurable Antennas for High Data Rate Multi-beam Communication Systems

    Science.gov (United States)

    Bernhard, Jennifer T.; Michielssen, Eric

    2005-01-01

    High-speed (2-100 Mb/sec) wireless data communication - whether land- or satellite-based - faces a major challenge: high error rates caused by interference and unpredictable environments. A planar antenna system that can be reconfigured to respond to changing conditions has the potential to dramatically improve data throughput and system reliability. Moreover, new planar antenna designs that reduce array size, weight, and cost can have a significant impact on terrestrial and satellite communication system performance. This research developed new individually-reconfigurable planar antenna array elements that can be adjusted to provide multiple beams while providing increased scan angles and higher aperture efficiency than traditional diffraction-limited arrays. These new elements are microstrip spiral antennas with specialized tuning mechanisms that provide adjustable radiation patterns. We anticipate that these new elements can be used in both large and small arrays for inter-satellite communication as well as tracking of multiple mobile surface-based units. Our work has developed both theoretical descriptions as well as experimental prototypes of the antennas in both single element and array embodiments. The technical summary of the results of this work is divided into six sections: A. Cavity model for analysis and design of pattern reconfigurable antennas; B. Performance of antenna in array configurations for broadside and endfire operation; C. Performance of antenna in array configurations for beam scanning operation; D. Simulation of antennas in infinite phased arrays; E. Demonstration of antenna with commercially-available RF MEMS switches; F. Design of antenna MEMS switch combinations for direct simultaneous fabrication.

  10. Analysis of electromagnetic field emitted from home plug power line used for indoor high-speed broadband communication

    Institute of Scientific and Technical Information of China (English)

    Yong XU; Yinghua LV; Biao YANG; Hongxin ZHANG

    2009-01-01

    High-speed broadband power line communication (BPL) is a novel and practicable technique for NetatHome or home area local area networking (LAN).Because of the characteristics of BPL, the electromagnetic wave emitted from the BPL transmission media will influence the indoor electromagnetic environment, which would also affect the performance of other wireless communications. Based on the analysis of the communication channel characteristic, network impedance and attenuation characteristic of the BPL, this paper proposes a novel model for calculating the BPL radiation and the computer simulation model, which are proved by the coherence of the simulation and the test data. The interferences from the high-speed BPL to indoor wireless communications are analyzed to stipulate the standards of high-speed BPL in the future.

  11. GaAs Photonic Integrated Circuit (PIC) development for high performance communications

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, C.T.

    1998-03-01

    Sandia has established a foundational technology in photonic integrated circuits (PICs) based on the (Al,Ga,In)As material system for optical communication, radar control and testing, and network switching applications at the important 1.3{mu}m/1.55{mu}m wavelengths. We investigated the optical, electrooptical, and microwave performance characteristics of the fundamental building-block PIC elements designed to be as simple and process-tolerant as possible, with particular emphasis placed on reducing optical insertion loss. Relatively conventional device array and circuit designs were built using these PIC elements: (1) to establish a baseline performance standard; (2) to assess the impact of epitaxial growth accuracy and uniformity, and of fabrication uniformity and yield; (3) to validate our theoretical and numerical models; and (4) to resolve the optical and microwave packaging issues associated with building fully packaged prototypes. Novel and more complex PIC designs and fabrication processes, viewed as higher payoff but higher risk, were explored in a parallel effort with the intention of meshing those advances into our baseline higher-yield capability as they mature. The application focus targeted the design and fabrication of packaged solitary modulators meeting the requirements of future wideband and high-speed analog and digital data links. Successfully prototyped devices are expected to feed into more complex PICs solving specific problems in high-performance communications, such as optical beamforming networks for phased array antennas.

  12. Raising the Ante of Communication: Evidence for Enhanced Gesture Use in High Stakes Situations

    Directory of Open Access Journals (Sweden)

    Judith Holler

    2011-10-01

    Full Text Available Theorists of language have argued that co-speech hand gestures are an intentional part of social communication. The present study provides evidence for these claims by showing that speakers adjust their gesture use according to their perceived relevance to the audience. Participants were asked to read about items that were and were not useful in a wilderness survival scenario, under the pretense that they would then explain (on camera what they learned to one of two different audiences. For one audience (a group of college students in a dormitory orientation activity, the stakes of successful communication were low; for the other audience (a group of students preparing for a rugged camping trip in the mountains, the stakes were high. In their explanations to the camera, participants in the high stakes condition produced three times as many representational gestures, and spent three times as much time gesturing, than participants in the low stakes condition. This study extends previous research by showing that the anticipated consequences of one’s communication—namely, the degree to which information may be useful to an intended recipient—influences speakers’ use of gesture.

  13. VCM-OFDM technique for advanced space communications system with high spectral efficiency

    Science.gov (United States)

    Li, Jionghui; Zhou, Qing; Xiong, Weiming; Zhang, Ying; Yao, Chen

    2016-11-01

    The development of precise scientific payloads brings higher demand on the efficiency of space communications system to transmit the increasing volume of scientific data. Aiming to this issue, Orthogonal Frequency Division Multiplexing (OFDM) is chosen for its inherent capability of high-rate data transmission. Further, considering the dynamic link condition due to satellite orbital motion, we propose a new technique which combines Variable Coding Modulation (VCM) with OFDM to enhance the communication link spectral efficiency with required transmission reliability. With VCM-OFDM technique, the channel coding and modulation mode can be variable with time according to the link conditions, in order to fit the link budget curve and maintain a relatively fixed link margin. Hence, link resource waste can be reduced and throughput can be remarkably improved. Considering that OFDM-based systems are sensitive to Doppler shifts/spread, the coding and modulation mode (CODMOD) selection should be optimized subject to this scenario. This paper introduces the architecture of near-earth space data transmission system based on VCM-OFDM technique. The Doppler influence is analyzed through simulation and the CODMOD selection algorithm is discussed. The results prove the high performance on spectral efficiency enhancement of VCM-OFDM by comparison with several existing alternative methods.

  14. Design of an Omnidirectional Multibeam Transmitter for High-Speed Indoor Wireless Communications

    Directory of Open Access Journals (Sweden)

    Jaw-Luen Tang

    2010-01-01

    Full Text Available For future high speed indoor wireless communication, diffuse wireless optical communications offer more robust optical links against shadowing than line-of-sight links. However, their performance may be degraded by multipath dispersion arising from surface reflections. We have developed a multipath diffusive propagation model capable of providing channel impulse responses data. It is aimed to design and simulate any multibeam transmitter under a variety of indoor environments. In this paper, a multi-beam transmitter system associated with hemisphere structure is proposed to fight against the diverse effects of multipath distortion albeit, at the cost of increased laser power and cost. Simulation results of multiple impulse responses showed that this type of multi-beam transmitter can significantly improve the performance of BER suitable for high bit rate application. We present the performance and simulation results for both line-of-sight and diffuse link configurations. We propose a design of power radiation pattern for a transmitter in achieving uniform and full coverage of power distributions for diffuse indoor optical wireless systems.

  15. Application of high performance asynchronous socket communication in power distribution automation

    Science.gov (United States)

    Wang, Ziyu

    2017-05-01

    With the development of information technology and Internet technology, and the growing demand for electricity, the stability and the reliable operation of power system have been the goal of power grid workers. With the advent of the era of big data, the power data will gradually become an important breakthrough to guarantee the safe and reliable operation of the power grid. So, in the electric power industry, how to efficiently and robustly receive the data transmitted by the data acquisition device, make the power distribution automation system be able to execute scientific decision quickly, which is the pursuit direction in power grid. In this paper, some existing problems in the power system communication are analysed, and with the help of the network technology, a set of solutions called Asynchronous Socket Technology to the problem in network communication which meets the high concurrency and the high throughput is proposed. Besides, the paper also looks forward to the development direction of power distribution automation in the era of big data and artificial intelligence.

  16. High-Fidelity Down-Conversion Source for Secure Communications Using On-Demand Single Photons

    Science.gov (United States)

    Roberts, Tony

    2015-01-01

    AdvR, Inc., has built an efficient, fully integrated, waveguide-based source of spectrally uncorrelated photon pairs that will accelerate research and development (R&D) in the emerging field of quantum information science. Key to the innovation is the use of submicron periodically poled waveguides to produce counter propagating photon pairs, which is enabled by AdvR's patented segmented microelectrode poling technique. This novel device will provide a high brightness source of down-conversion pairs with enhanced spectral properties and low attenuation, and it will operate in the visible to the mid-infrared spectral region. A waveguide-based source of spectrally and spatially pure heralded photons will contribute to a wide range of NASA's advanced technology development efforts, including on-demand single photon sources for high-rate spaced-based secure communications.

  17. High-Capacity Hybrid Optical Fiber-Wireless Communications Links in Access Networks

    DEFF Research Database (Denmark)

    Pang, Xiaodan

    techniques with both coherent and incoherent optical sources are studied and demonstrated. Employments of advanced modulation formats including phase-shift keying (PSK), M-quadrature amplitude modulation (QAM) and orthogonal frequency-division multiplexing (OFDM) for high speed photonic-wireless transmission......Integration between fiber-optic and wireless communications systems in the "last mile" access networks is currently considered as a promising solution for both service providers and users, in terms of minimizing deployment cost, shortening upgrading period and increasing mobility and flexibility...... techniques. In conclusion, the results presented in the thesis show the feasibility of employing mm-wave signals, advanced modulation formats and spatial multiplexing technologies in next generation high capacity hybrid optical fiber-wireless access systems....

  18. Optical Amplication for Terabit-per-Second Ultra-High Speed Communication Systems

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh

    The present thesis is concerned with fiber optical parametric amplification and regeneration for high-speed optical communication systems. Fiber optical parametric amplifiers (FOPAs) have multi-functional applications depending on their implementation in optical systems. Based on a few femtosecond...... amplification response time and flexible operation spectral range, FOPAs are able to simultaneously operate as amplifiers and all-optical signal processors in high-speed Tbaud networks. In this thesis, we study the performance of FOPAs in detail in the linear and nonlinear (saturated) regimes where they can...... be utilized as all-optical regenerators. The optical gain and amplitude regeneration properties of FOPAs are investigated for monochromatic waves, short optical pulses and data modulated signals up to 640 Gbit/s. In the fundamental study part of the thesis, an original physical explanation behind an observed...

  19. High performance computing and communications: Advancing the frontiers of information technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This report, which supplements the President`s Fiscal Year 1997 Budget, describes the interagency High Performance Computing and Communications (HPCC) Program. The HPCC Program will celebrate its fifth anniversary in October 1996 with an impressive array of accomplishments to its credit. Over its five-year history, the HPCC Program has focused on developing high performance computing and communications technologies that can be applied to computation-intensive applications. Major highlights for FY 1996: (1) High performance computing systems enable practical solutions to complex problems with accuracies not possible five years ago; (2) HPCC-funded research in very large scale networking techniques has been instrumental in the evolution of the Internet, which continues exponential growth in size, speed, and availability of information; (3) The combination of hardware capability measured in gigaflop/s, networking technology measured in gigabit/s, and new computational science techniques for modeling phenomena has demonstrated that very large scale accurate scientific calculations can be executed across heterogeneous parallel processing systems located thousands of miles apart; (4) Federal investments in HPCC software R and D support researchers who pioneered the development of parallel languages and compilers, high performance mathematical, engineering, and scientific libraries, and software tools--technologies that allow scientists to use powerful parallel systems to focus on Federal agency mission applications; and (5) HPCC support for virtual environments has enabled the development of immersive technologies, where researchers can explore and manipulate multi-dimensional scientific and engineering problems. Educational programs fostered by the HPCC Program have brought into classrooms new science and engineering curricula designed to teach computational science. This document contains a small sample of the significant HPCC Program accomplishments in FY 1996.

  20. High-Counting Rate Photon Detectors for Long-Range Space Optical Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Long range, RF space communications do not meet anymore the bandwidth requirements or power constraints of future NASA missions. Optical communications offer the...

  1. High Fidelity Down-Conversion Source for Secure Communications using On-Demand Single Photons Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To provide reliably secure communications, development of quantum optical devices for encrypted ground-to-space communications is a necessity. The overall goal of...

  2. Laser Communications and Fiber Optics Lab Manual. High-Technology Training Module.

    Science.gov (United States)

    Biddick, Robert

    This laboratory training manual on laser communications and fiber optics may be used in a general technology-communications course for ninth graders. Upon completion of this exercise, students achieve the following goals: match concepts with laser communication system parts; explain advantages of fiber optic cable over conventional copper wire;…

  3. High-speed chaotic communication using an optical fibre ring as a key

    Institute of Scientific and Technical Information of China (English)

    Zou Lin; Feng Ye; Yang Yi-Biao; Wang An-Bang; Yang Ling-Zhen; Zhang Jian-Zhong

    2011-01-01

    A chaotic communication scheme with a fibre ring inserted in the optical feedback of the transmitter laser as an additional key is proposed under anticipating synchronization. The numerical results show that the key can enhance the communication security effectively. It is theoretically safe for the communication scheme to transmit messages with a frequency beyond the relaxation oscillation frequency.

  4. Link and Network Layers Design for Ultra-High-Speed Terahertz-Band Communications Networks

    Science.gov (United States)

    2017-01-01

    MATYJAS Work Unit Manager Technical Advisor, Computing & Communications Division Information Directorate This report is published in the...technological advantage. Second, the huge transmission bandwidth associated with the THz-band can satisfy demand for higher data rates in communication ...technological advantage. Second, the huge transmission bandwidth associated with the THz-band can satisfy demand for higher data rates in communication

  5. Invited Article: Polarization diversity and modulation for high-speed optical communications: architectures and capacity

    Directory of Open Access Journals (Sweden)

    William Shieh

    2016-07-01

    Full Text Available Polarization is one of the fundamental properties of optical waves. To cope with the exponential growth of the Internet traffic, optical communications has advanced by leaps and bounds within the last decade. For the first time, the polarization domain has been extensively explored for high-speed optical communications. In this paper, we discuss the general principle of polarization modulation in both Jones and Stokes spaces. We show that there is no linear optical device capable of transforming an arbitrary input polarization into one that is orthogonal to itself. This excludes the receiver self-polarization diversity architecture by splitting the signal into two branches, and then transferring one of the branches into orthogonal polarization. We next propose a novel Stokes vector (SV detection architecture using four single-ended photodiodes (PD that can recover a full set of SV. We then derive a closed-form expression for the information capacity of different SV detection architectures and compare the capacity of our proposed architectures with that of intensity-modulated directly-detected (IM/DD method. We next study the 3-PD SV detection architecture where a subset of SV is detected, and devise a novel modulation algorithm that can achieve 2-dimensional modulation with the 3-PD detection. By using cost-effective SV receivers, polarization modulation and multiplexing offers a powerful solution for short-reach optical networks where the wavelength domain is quickly exhausted.

  6. A High-Speed Optical Modem Communication System for CORK Seafloor Observatories

    Science.gov (United States)

    Farr, N.; Tivey, M.; Ware, J.; Pontbriand, C.; Pelletier, L. P.

    2014-12-01

    High-speed communications underwater is an increasing requirement for data intensive seafloor sensors. Acoustic modems provide dependable long-range communications underwater, but data rates are limited to ship with an SDSL link over the conducting wire. Other methods utilized OMs mounted to both ROV Jason and submersible Alvin. We deployed OMs at two CORKs in 2012 in the northeast pacific at sites 857D and 1025C. The CORKs were visited in 2013 by a vessel of opportunity to download data and were put into sleep mode. The CORKs were revisited in 2014, woken up and successfully interrogated for data. ALVIN retrieved the CORK-OMs for corrosion, biofouling and battery performance assessment. We also performed tests of a next generation OM using a deployed seafloor modem and AUV Sentry. A complete lambertian optical field was quantitatively mapped by Sentry and test data was successfully downloaded from 20 to 150 m slant range. The AUV modality demonstrates the capability of 'data-mule' operations to autonomously recover data from a seafloor observatory with minimal human intervention.

  7. A Simple Semaphore Signaling Technique for Ultra-High Frequency Spacecraft Communications

    Science.gov (United States)

    Butman, S.; Satorius, E.; Ilott, P.

    2005-01-01

    For planetary lander missions such as the upcoming Phoenix mission to Mars, the most challenging phase of the spacecraft-to-ground communications is during the critical phase termed entry, descent, and landing (EDL). At 8.4 GHz (X-band), the signals received by the largest Deep Space Network (DSN) antennas can be too weak for even 1 bit per second (bps) and therefore not able to communicate critical information to Earth. Fortunately, the lander s ultra-high frequency (UHF) link to an orbiting relay can meet the EDL requirements, but the data rate needs to be low enough to fit the capability of the UHF link during some or all of EDL. On Phoenix, the minimum data rate of the as-built UHF radio is 8 kbps and requires a signal level at the Odyssey orbiter of at least -120 dBm. For lower signaling levels, the effective data rate needs to be reduced, but without incurring the cost of rebuilding and requalifying the equipment. To address this scenario, a simple form of frequency-shift keying (FSK) has been devised by appropriately programming the data stream that is input to the UHF transceiver. This article describes this technique and provides performance estimates. Laboratory testing reveals that input signal levels at -140 dBm and lower can routinely be demodulated with the proposed signaling scheme, thereby providing a 20-dB and greater margin over the 8-kbps threshold.

  8. Invited Article: Polarization diversity and modulation for high-speed optical communications: architectures and capacity

    Science.gov (United States)

    Shieh, William; Khodakarami, Hamid; Che, Di

    2016-07-01

    Polarization is one of the fundamental properties of optical waves. To cope with the exponential growth of the Internet traffic, optical communications has advanced by leaps and bounds within the last decade. For the first time, the polarization domain has been extensively explored for high-speed optical communications. In this paper, we discuss the general principle of polarization modulation in both Jones and Stokes spaces. We show that there is no linear optical device capable of transforming an arbitrary input polarization into one that is orthogonal to itself. This excludes the receiver self-polarization diversity architecture by splitting the signal into two branches, and then transferring one of the branches into orthogonal polarization. We next propose a novel Stokes vector (SV) detection architecture using four single-ended photodiodes (PD) that can recover a full set of SV. We then derive a closed-form expression for the information capacity of different SV detection architectures and compare the capacity of our proposed architectures with that of intensity-modulated directly-detected (IM/DD) method. We next study the 3-PD SV detection architecture where a subset of SV is detected, and devise a novel modulation algorithm that can achieve 2-dimensional modulation with the 3-PD detection. By using cost-effective SV receivers, polarization modulation and multiplexing offers a powerful solution for short-reach optical networks where the wavelength domain is quickly exhausted.

  9. Application of communication theory to high-speed structured light illumination

    Science.gov (United States)

    Hassebrook, Laurence G.; Daley, Raymond C.; Chimitt, William J., Jr.

    1997-12-01

    Structured light illumination has been used for several decades to extract three-dimensional information from surface topology. Most of the research and development has been in the light structuring methodology and the electronic processing while a unified theoretical description has been lacking. With the advent of programmable spatial light modulators having high frame rates, structured light illumination methods using spatial and temporal patterns are practical. We present structured light systems using spatial light modulation as communication systems and use communications theory in their description. This theory is applied to the specific method of successive binary light striping and the tradeoffs between surface encoding quality and processing speeds are discussed. Shannon's theorem of channel capacity provides an objective measure to evaluate some of these tradeoffs and compare a variety of different approaches to structured light illumination. Another result of our analysis is the unification of structured light projection with pattern recognition. Methods of image recognition using Fourier expansion via orthogonal pattern projection are presented. The results of this analysis establish some physical limitations which guide us to effectively utilize both the methodology and the technology applicable to both 3-D data acquisition as well as pattern recognition. Both numerical and experimental results are presented to demonstrate concepts.

  10. Communicating the Benefits of a Full Sequence of High School Science Courses

    Science.gov (United States)

    Nicholas, Catherine Marie

    High school students are generally uninformed about the benefits of enrolling in a full sequence of science courses, therefore only about a third of our nation's high school graduates have completed the science sequence of Biology, Chemistry and Physics. The lack of students completing a full sequence of science courses contributes to the deficit in the STEM degree production rate needed to fill the demand of the current job market and remain competitive as a nation. The purpose of the study was to make a difference in the number of students who have access to information about the benefits of completing a full sequence of science courses. This dissertation study employed qualitative research methodology to gain a broad perspective of staff through a questionnaire and document review and then a deeper understanding through semi-structured interview protocol. The data revealed that a universal sequence of science courses in the high school district did not exist. It also showed that not all students had access to all science courses; students were sorted and tracked according to prerequisites that did not necessarily match the skill set needed for the courses. In addition, the study showed a desire for more support and direction from the district office. It was also apparent that there was a disconnect that existed between who staff members believed should enroll in a full sequence of science courses and who actually enrolled. Finally, communication about science was shown to occur mainly through counseling and peers. A common science sequence, detracking of science courses, increased communication about the postsecondary and academic benefits of a science education, increased district direction and realistic mathematics alignment were all discussed as solutions to the problem.

  11. 民族危机中的死亡焦虑与谣言事件的产生%The Apprehension of Death During National Crisis and the Occurrence of Rumor Incidents

    Institute of Scientific and Technical Information of China (English)

    刘雪怡

    2011-01-01

    The psychological responses of Chinese society to foreign invasion in modern Chinese history have been rather complicated.It developed into patriotism and nationalism in some cases,while in other cases it might lead to serious apprehension of death as well.And the latter could be clearly observed in some rumor incidents.Based on the case study of such a rumor incident occurred in Sichuan in 1936,shortly before the anti-Japanese War,the article reveals the horror,social unrest and violence caused by rumor,and explores the communicational process,the psychological factors,and the historical influences of such rumor incidents.%近现代史上,因列强侵略而带来的民族危机在中国社会引发的心理反应可谓错综复杂。它一方面激发了中华民族的爱国主义和民族主义心态,另一方面,"亡国灭种"的危机感也时常演化为严重的死亡焦虑。关于后者,一些有关死亡主题的谣言事件即为典型的表现。

  12. Conflicts and communication between high-achieving Chinese American adolescents and their parents.

    Science.gov (United States)

    Qin, Desiree Baolian; Chang, Tzu-Fen; Han, Eun-Jin; Chee, Grace

    2012-01-01

    Drawing on in-depth interview data collected on 18 high-achieving Chinese American students, the authors examine domains of acculturation-based conflicts, parent and child internal conflicts, and conflict resolution in their families. Their analyses show that well-established negative communication patterns in educational expectations, divergent attitudes toward other races and country of origin, and cultural and language barriers contributed to parent-child conflicts. Their findings also illustrate important internal conflicts both adolescents and parents had along the cultural tightrope of autonomy and relatedness. Finally, the vertical in-group conflict resolution style that was evidenced in youths' accounts raises questions about cultural differences in constructive versus destructive conflict resolution styles. © 2012 Wiley Periodicals, Inc., A Wiley Company.

  13. NEMO5: Achieving High-end Internode Communication for Performance Projection Beyond Moore's Law

    CERN Document Server

    Andrawis, Robert; Charles, James; Fang, Jianbin; Fonseca, Jim; He, Yu; Klimeck, Gerhard; Jiang, Zhengping; Kubis, Tillmann; Mejia, Daniel; Lemus, Daniel; Povolotskyi, Michael; Rubiano, Santiago Alonso Perez; Sarangapani, Prasad; Zeng, Lang

    2015-01-01

    Electronic performance predictions of modern nanotransistors require nonequilibrium Green's functions including incoherent scattering on phonons as well as inclusion of random alloy disorder and surface roughness effects. The solution of all these effects is numerically extremely expensive and has to be done on the world's largest supercomputers due to the large memory requirement and the high performance demands on the communication network between the compute nodes. In this work, it is shown that NEMO5 covers all required physical effects and their combination. Furthermore, it is also shown that NEMO5's implementation of the algorithm scales very well up to about 178176CPUs with a sustained performance of about 857 TFLOPS. Therefore, NEMO5 is ready to simulate future nanotransistors.

  14. The Channel Estimation and Modeling in High Altitude Platform Station Wireless Communication Dynamic Network

    Directory of Open Access Journals (Sweden)

    Xiaoyang Liu

    2017-01-01

    Full Text Available In order to analyze the channel estimation performance of near space high altitude platform station (HAPS in wireless communication system, the structure and formation of HAPS are studied in this paper. The traditional Least Squares (LS channel estimation method and Singular Value Decomposition-Linear Minimum Mean-Squared (SVD-LMMS channel estimation method are compared and investigated. A novel channel estimation method and model are proposed. The channel estimation performance of HAPS is studied deeply. The simulation and theoretical analysis results show that the performance of the proposed method is better than the traditional methods. The lower Bit Error Rate (BER and higher Signal Noise Ratio (SNR can be obtained by the proposed method compared with the LS and SVD-LMMS methods.

  15. Fabrication and laboratory testing of a high-temperature superconducting subsystem for DSC1800 mobile communications

    CERN Document Server

    LiuKun; Zhu Mei Hong; Wei Bin; Liu Bang Chang; Zhang Xia; Gao Long Ma; Zhang Guo Yong; He Wen Jun; Gao Bao Xin

    2002-01-01

    In this paper, we report on the design, fabrication and testing of a 20-pole high-temperature superconducting (HTS) filter for DSC1800 mobile communications with the pass band from 1710 to 1785 MHz. The test results show that the insertion loss of the pass band is less than 0.3 dB, the out-of-band rejection is better than 65 dB, and the steepness of the band edges is greater than 14 dB MHz sup - sup 1. We also tested an HTS subsystem, which consists of the HTS filter, a low-noise amplifier (LNA) with 21 dB gain and a Stirling Cooler, and a traditional subsystem, which consists of a traditional filter and a LNA with 23 dB gain. The results show that the HTS subsystem is much better than the conventional subsystem.

  16. Adaptive Modulation with Channel Estimation in High-Speed Packet-Based OFDM Communication Systems

    Institute of Scientific and Technical Information of China (English)

    HOU Xiao-lin; WU Jun-li; YIN Chang-chuan; YUE Guang-xin

    2004-01-01

    In this paper, adaptive modulation with channel estimation in high-speed packet-based Orthogonal Frequency Division Multiplexing (OFDM) communication systems for beyond 3G are discussed. Different adaptive modulation and channel estimation methods are presented and compared, then those methods suitable for our intended application are chosen. Conclusions can be drawn from computer simulations that with proper selection of packet length and subband width, wide subband adaptive modulation with Least Square plus Discrete-time Fourier Transform (LS-DFT) channel estimation can give an acceptable performance with low complexity for channel with low Doppler shift and small path delay. Otherwise, narrow subband or subcarrier adaptive modulation together with LS-DFT plus Decision Directed (LS-DFT-DD) must be used.

  17. Department of Energy Mathematical, Information, and Computational Sciences Division: High Performance Computing and Communications Program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    This document is intended to serve two purposes. Its first purpose is that of a program status report of the considerable progress that the Department of Energy (DOE) has made since 1993, the time of the last such report (DOE/ER-0536, The DOE Program in HPCC), toward achieving the goals of the High Performance Computing and Communications (HPCC) Program. The second purpose is that of a summary report of the many research programs administered by the Mathematical, Information, and Computational Sciences (MICS) Division of the Office of Energy Research under the auspices of the HPCC Program and to provide, wherever relevant, easy access to pertinent information about MICS-Division activities via universal resource locators (URLs) on the World Wide Web (WWW).

  18. Department of Energy: MICS (Mathematical Information, and Computational Sciences Division). High performance computing and communications program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    This document is intended to serve two purposes. Its first purpose is that of a program status report of the considerable progress that the Department of Energy (DOE) has made since 1993, the time of the last such report (DOE/ER-0536, {open_quotes}The DOE Program in HPCC{close_quotes}), toward achieving the goals of the High Performance Computing and Communications (HPCC) Program. The second purpose is that of a summary report of the many research programs administered by the Mathematical, Information, and Computational Sciences (MICS) Division of the Office of Energy Research under the auspices of the HPCC Program and to provide, wherever relevant, easy access to pertinent information about MICS-Division activities via universal resource locators (URLs) on the World Wide Web (WWW). The information pointed to by the URL is updated frequently, and the interested reader is urged to access the WWW for the latest information.

  19. Optoelectronics for high-speed, wavelength-division- multiplexed optical communications networks

    Science.gov (United States)

    Hudgings, Janice Anne

    1999-11-01

    All-optical wavelength division multiplexed (WDM) communications networks have the potential to revolutionize future high-speed communications. All- optical networks offer enormous bandwidth capacity on the order of 25 THz, which is orders of magnitude greater than the capacity of radio or copper coaxial cable. In addition, wavelength division multiplexing offers a natural method of supporting with a single network multiple simultaneous applications with widely varying bandwidth requirements, modulation formats, and quality of service requirements. However, future implementation of all-optical WDM networks relies on further development of optical device technology. We present an experimental demonstration of a step- tunable, all-optical wavelength converter using cavity- enhanced four wave mixing (FWM) in a semiconductor laser. The converter is modulation format transparent, has a high conversion efficiency (> -10 dB), and is step- tunable over a large conversion range (> 2.5 THz). In addition, we derive a mathematical model of the wavelength converter, which is used to simulate step- tuning and to examine the relationship between the conversion efficiency and information bandwidth of the device. Likewise, the development of appropriate optical sources is critical to the success of all-optical communications networks. Vertical-cavity surface-emitting lasers (VCSELs) are rapidly emerging as strong competitors to the conventional edge-emitting semiconductor lasers. We have developed a novel three-contact VCSEL with an intracavity quantum-well absorber. The three-contact design of this structure enables independent control of the gain and absorber regions. If the VCSEL is designed such that the lasing wavelength is shorter than the bandedge of the intracavity absorber, the laser exhibits broad negative differential resistance, due to changes in the cavity photon density as the relative absorption is varied. With this design, the device is useful as an integrated

  20. RF and Optical Communications: A Comparison of High Data Rate Returns From Deep Space in the 2020 Timeframe

    Science.gov (United States)

    Williams, W. Dan; Collins, Michael; Boroson, Don M.; Lesh, James; Biswas, Abihijit; Orr, Richard; Schuchman, Leonard; Sands, O. Scott

    2007-01-01

    As NASA proceeds with plans for increased science data return and higher data transfer capacity for science missions, both RF and optical communications are viable candidates for significantly higher-rate communications from deep space to Earth. With the inherent advantages, smaller apertures and larger bandwidths, of optical communications, it is reasonable to expect that at some point in time and combination of increasing distance and data rate, the rapidly emerging optical capabilities would become more advantageous than the more mature and evolving RF techniques. This paper presents a comparison of the burden to a spacecraft by both RF and optical communications systems for data rates of 10, 100, and 1000 Mbps and large distances. Advanced technology for RF and optical communication systems have been considered for projecting capabilities in the 2020 timeframe. For the comparisons drawn, the optical and RF ground terminals were selected to be similar in cost. The RF system selected is composed of forty-five 12-meter antennas, whereas the selected optical system is equivalent to a 10-meter optical telescope. Potential differences in availability are disregarded since the focus of this study is on spacecraft mass and power burden for high-rate mission data, under the assumption that essential communications will be provided by low-rate, high availability RF. For both the RF and optical systems, the required EIRP, for a given data rate and a given distance, was achieved by a design that realized the lowest possible communications subsystem mass (power + aperture) consistent with achieving the lowest technology risk. A key conclusion of this paper is that optical communications has great potential for high data rates and distances of 2.67 AU and beyond, but requires R&D and flight demonstrations to prove out technologies.

  1. WISC-IV profile in high-functioning autism spectrum disorders: impaired processing speed is associated with increased autism communication symptoms and decreased adaptive communication abilities.

    Science.gov (United States)

    Oliveras-Rentas, Rafael E; Kenworthy, Lauren; Roberson, Richard B; Martin, Alex; Wallace, Gregory L

    2012-05-01

    Changes in the Wechsler Intelligence Scales for Children-IV (WISC-IV) may affect the IQ profile characteristic of autism spectrum disorders (ASD). Moreover, the association of particular component cognitive abilities (unlike overall IQ) with symptomatology and adaptive functioning in ASD remains unclear. This archival study characterizes the WISC-IV IQ profile among 56 high-functioning (IQ > 70) children with ASD and correlates WISC-IV performance with ASD and ADHD symptomatology and adaptive functioning. The ASD WISC-IV profile included strengths on Matrix Reasoning and Similarities, weaknesses on Comprehension (which correlated negatively with social symptoms) and the subtests comprising the Processing Speed Index (Coding, Symbol Search). Processing speed task performance correlated negatively with communication symptoms and positively with communication abilities, indicating its importance to functional outcomes in ASD.

  2. The critique of the constitution model of “apprehension - content of apprehension” in Husserl’s On the Phenomenology of the Consciousness of Internal Time

    Directory of Open Access Journals (Sweden)

    Scheila Cristiane Thomé

    2013-12-01

    Full Text Available The aim of this article is to analyze the problems found by Husserl regarding the application of the constitution scheme of “apprehension-content of apprehension” as a model of understanding the deepest levels (tiefsten Stufe of time constitution. Such analysis will deal with the first period, in which Husserl investigates in a systematic way time constitution, i.e. in texts from Husserliana X (1893-1917. Firstly, in texts from Husserliana X, Husserl applies the scheme of constitution apprehension-content of apprehension as a way to describe all temporal constitution. Secondly (from 1909 on Husserl observes that the application of this interpretative scheme to describe the lowest levels (untersten Stufen of temporal constitution leads to serious problems, such as an inevitable infinite regression and a fall into an understanding founded on “prejudices of the now”. To overcome such obstacles, Husserl tried to deepen his analysis of the lowest level of temporal constitution and found out that the absolute flow (and its own modes of consciousness, viz., primal impression, retention, protention is the last level of all constitution of temporality.

  3. High speed fault tolerant secure communication for muon chamber using FPGA based GBTx emulator

    Science.gov (United States)

    Sau, Suman; Mandal, Swagata; Saini, Jogender; Chakrabarti, Amlan; Chattopadhyay, Subhasis

    2015-12-01

    The Compressed Baryonic Matter (CBM) experiment is a part of the Facility for Antiproton and Ion Research (FAIR) in Darmstadt at the GSI. The CBM experiment will investigate the highly compressed nuclear matter using nucleus-nucleus collisions. This experiment will examine lieavy-ion collisions in fixed target geometry and will be able to measure hadrons, electrons and muons. CBM requires precise time synchronization, compact hardware, radiation tolerance, self-triggered front-end electronics, efficient data aggregation schemes and capability to handle high data rate (up to several TB/s). As a part of the implementation of read out chain of Muon Cliamber(MUCH) [1] in India, we have tried to implement FPGA based emulator of GBTx in India. GBTx is a radiation tolerant ASIC that can be used to implement multipurpose high speed bidirectional optical links for high-energy physics (HEP) experiments and is developed by CERN. GBTx will be used in highly irradiated area and more prone to be affected by multi bit error. To mitigate this effect instead of single bit error correcting RS code we have used two bit error correcting (15, 7) BCH code. It will increase the redundancy which in turn increases the reliability of the coded data. So the coded data will be less prone to be affected by noise due to radiation. The data will go from detector to PC through multiple nodes through the communication channel. The computing resources are connected to a network which can be accessed by authorized person to prevent unauthorized data access which might happen by compromising the network security. Thus data encryption is essential. In order to make the data communication secure, advanced encryption standard [2] (AES - a symmetric key cryptography) and RSA [3], [4] (asymmetric key cryptography) are used after the channel coding. We have implemented GBTx emulator on two Xilinx Kintex-7 boards (KC705). One will act as transmitter and other will act as receiver and they are connected

  4. A Framework for Assessing High School Students' Intercultural Communicative Competence in a Computer-Mediated Language Learning Project

    Science.gov (United States)

    Peng, Hsinyi; Lu, Wei-Hsin; Wang, Chao-I

    2009-01-01

    The purposes of this study were to identify the essential dimensions of intercultural communicative competence (ICC) and to establish a framework for assessing the ICC level of high school students that included a self-report inventory and scoring rubrics for online interaction in intercultural contexts. A total of 472 high school students from…

  5. Typical Responses in Giving Evaluation: An Analysis of High and Low Context Culture Communication

    Directory of Open Access Journals (Sweden)

    Ferany Arifin

    2013-05-01

    Full Text Available This paper aims at discussing high and low context in responses given by the students to evaluate their friend’s impromptu speech performance. The study focuses on the characteristics of high and low context represented specifically on (1 direct-indirect (2 simple-complex response, and (3 relationship orientation. The study is based on the analysis of ten responses given by ten students with different sexes. Classroom observation followed by transcription analysis is used. The data were collected naturally at undergraduate campus. The result shows that using indirect and complex responses can maintain harmonious relationship with others. The basic asumption is that the students tend to communicate in high level context. Penelitian ini bertujuan untuk membahas konteks tinggi dan rendah dalam mengevaluasi performansi pidato tanpa persiapan temannya. Penelitian ini memusatkan perhatian pada ciri konteks tinggi dan rendah yang direpresentasikan oleh (1 tanggapan langsung-tak langsung (2 sederhana-kompleks, dan (3 orientasi hubungan. Penelitian ini didasarkan pada sepuluh tanggapan yang diberikan oleh sepuluh mahasiswa pria dan wanita. Pengamatan kelas yang diikuti dengan analisis transkripsi digunakan untuk pengumpulan data. Data dikumpulkan di kampus diploma. Analisis menunjukkan bahwa siswa cenderung menggunakan tanggapan kompleks dan tak langsung agar dapat menjaga keharmonisan hubungan dengan temannya. Oleh karena itu asumsi dasarnya adalah bahwa siswa cenderung berkomunikasi dalam konteks level tinggi.

  6. Evaluation of compressed digital high-definition video transmitted through the NASA communications system

    Science.gov (United States)

    Beakley, Guy W.; Kohn, Elliott S.

    1993-01-01

    A series of experiments was conducted over the past three years to prepare NASA for the use of high-definition television. In 1989 and in 1990, HDTV technology was evaluated for potential use in launch operations, real-time image analysis, and media dissemination at the Kennedy Space Center (KSC). Evaluation of camera and lens performance is reported here. In November 1991, an experiment was done at the Johnson Space Center (JSC) to evaluate the quality of HDTV that was digitized, compressed to a 45 Mbps data stream, and transmitted through the NASA communications network. The JSC experiment consisted of back-to-back bench tests of the Alcatel/Telettra high-definition coder/decoder (codec), followed by data transmission through the NASA Shuttle communications simulator, and most importantly, actual transmission through the NASA Tracking and Data Relay Satellite System (TDRSS), with a second satellite hop through a domestic satellite and a fiber-optic link at JSC. Static and dynamic test signals were used to test codec performance as were various types of subjective- test scenes with detail and motion. Included in the subjective material was IMAX film shot in space and transferred directly to high-definition video at 30 frames/second. Static tests highlighted the effects of the 54 MHz sampling rate in the codec. Color reproduction tests showed very little color error, even when transcoding externally from GBR signals. Dynamic test signals characterized the DCT and motion-compensation algorithm. Frame-by-frame analysis showed a small reduction in horizontal resolution, small color errors in fine detail, and reduced horizontal and vertical resolution immediately following transitions, where the effect was almost entirely masked by the transitions. Subjective codec performance on moving images at nominal TDRSS bit-error-rates (BER) was extremely good. The codec designers have done a very good job of leaving out information that is not perceived while including almost

  7. Annual Enrollment Report Number of Students Studying Journalism and Mass Communication at All-time High.

    Science.gov (United States)

    Becker, Lee B.; Vlad, Tudor; Huh, Jisu; Prine, Joelle

    2001-01-01

    Finds that journalism and mass communication programs appear to be entering another period of rapid enrollment growth, swept up by overall increases in enrollments at United States universities. Finds that only about four in ten of the journalism and mass communication programs report enrollments by race, suggesting many administrators are not…

  8. High-Efficiency K-Band Space Traveling-Wave Tube Amplifier for Near-Earth High Data Rate Communications

    Science.gov (United States)

    Simons, Rainee N.; Force, Dale A.; Spitsen, Paul C.; Menninger, William L.; Robbins, Neal R.; Dibb, Daniel R.; Todd, Phillip C.

    2010-01-01

    The RF performance of a new K-Band helix conduction cooled traveling-wave tube amplifier (TWTA), is presented in this paper. A total of three such units were manufactured, tested and delivered. The first unit is currently flying onboard NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft and has flawlessly completed over 2000 orbits around the Moon. The second unit is a proto-flight model. The third unit will fly onboard NASA's International Space Station (ISS) as a very compact and lightweight transmitter package for the Communications, Navigation and Networking Reconfigurable Testbed (CoNNeCT), which is scheduled for launch in 2011. These TWTAs were characterized over the frequencies 25.5 to 25.8 GHz. The saturated RF output power is greater than 40 W and the saturated RF gain is greater than 46 dB. The saturated AM-to-PM conversion is 3.5 /dB and the small signal gain ripple is 0.46 dB peak-to-peak. The overall efficiency of the TWTA, including that of the electronic power conditioner (EPC) is as high as 45%.

  9. Secure Communications in High Speed Fiber Optical Networks Using Code Division Multiple Access (CDMA) Transmission

    Energy Technology Data Exchange (ETDEWEB)

    Han, I; Bond, S; Welty, R; Du, Y; Yoo, S; Reinhardt, C; Behymer, E; Sperry, V; Kobayashi, N

    2004-02-12

    This project is focused on the development of advanced components and system technologies for secure data transmission on high-speed fiber optic data systems. This work capitalizes on (1) a strong relationship with outstanding faculty at the University of California-Davis who are experts in high speed fiber-optic networks, (2) the realization that code division multiple access (CDMA) is emerging as a bandwidth enhancing technique for fiber optic networks, (3) the realization that CDMA of sufficient complexity forms the basis for almost unbreakable one-time key transmissions, (4) our concepts for superior components for implementing CDMA, (5) our expertise in semiconductor device processing and (6) our Center for Nano and Microtechnology, which is where the majority of the experimental work was done. Here we present a novel device concept, which will push the limits of current technology, and will simultaneously solve system implementation issues by investigating new state-of-the-art fiber technologies. This will enable the development of secure communication systems for the transmission and reception of messages on deployed commercial fiber optic networks, through the CDMA phase encoding of broad bandwidth pulses. CDMA technology has been developed as a multiplexing technology, much like wavelength division multiplexing (WDM) or time division multiplexing (TDM), to increase the potential number of users on a given communication link. A novel application of the techniques created for CDMA is to generate secure communication through physical layer encoding. Physical layer encoding devices are developed which utilize semiconductor waveguides with fast carrier response times to phase encode spectral components of a secure signal. Current commercial technology, most commonly a spatial light modulator, allows phase codes to be changed at rates of only 10's of Hertz ({approx}25ms response). The use of fast (picosecond to nanosecond) carrier dynamics of semiconductors

  10. High-Sensitivity Phased Arrays for Radio Astronomy and Satellite Communications

    Science.gov (United States)

    Diao, Junming

    Radio astronomy is used to study stars, galaxies, black holes and gas clouds radiation at radio frequencies. Detecting extremely weak signals from deep space radio sources requires high sensitive feed system associated with large dish antennas. The key figure of merit is survey speed, or the time required to map a region of the sky to a given source flux density. Survey speed is proportional to the frequency bandwidth, the field of view or observable region of the sky, and the squared sensitivity, where sensitivity is related to reflector aperture efficiency and system noise temperature. Compared to the traditional single feed, phased array feeds with significantly expanded field of view are considered as the next generation feed for radio telescope. This dissertation outlines the design, analysis and measurement of high sensitivity L-band and mm-wave phased array feeds for the 100-meter Green Bank Telescope. Theoretical works for radio astronomy includes design guideline for high sensitivity phased array feed, fundamental frequency bandwidth limit, array antenna loss influenced by mutual coupling and beamformer coefficients and possibility of superdirectivity for radio telescopes and other antennas. These study are helpful to understand and guide the design of a phased array feed system. In the absence of dish antennas, sparse phased arrays with aperiodic structure have been developed for satellite communications. A compromise between the peak side lobe level, array element density, directivity and design complexity is studied. We have found that the array peak side lobe level can be reduced by enhancing the array element direction at the main lobe direction, increasing the array element density and enlarging the array size. A Poynting streamline approach develops to understand the properties of a receiving antenna and the mutual coupling effects between array elements. This method has been successfully used to generate effective area shape for many types of

  11. Design of High Gain and Broadband Antennas at 60 GHz for Underground Communications Systems

    Directory of Open Access Journals (Sweden)

    Yacouba Coulibaly

    2012-01-01

    Full Text Available A new broadband and high gain dielectric resonator antenna for millimeter wave is presented. The investigated antenna configuration consists of a periodic square ring frequency selective surfaces on a superstrate, an aperture-coupled scheme feed, an intermediate substrate, and a cylindrical dielectric resonator. This antenna is designed to cover the ISM frequency band at 60 GHz (57 GHz–64 GHz. It was numerically designed using CST microwave Studio simulation software package. Another prototype with a plain dielectric superstrate is also studied for comparison purposes. A bandwidth of 13.56% at the centered frequency of 61.34 GHz and a gain of 11 dB over the entire ISM band have been achieved. A maximum gain of 14.26 dB is obtained at 60 GHz. This is an enhancement of 9 dB compared to a single DRA. HFSS is used to validate our antenna designs. Good agreement between the results of the two softwares is obtained. With these performances, these antennas promise to be useful in the design of future wireless underground communication systems operating in the unlicensed 60 GHz frequency band.

  12. MIMO Underwater Acoustic Communications in Ports and Shallow Waters at Very High Frequency

    Directory of Open Access Journals (Sweden)

    Gaultier Real

    2013-10-01

    Full Text Available Hermes is a Single-Input Single-Output (SISO underwater acoustic modem that achieves very high-bit rate digital communications in ports and shallow waters. Here, the authors study the capability of Hermes to support Multiple-Input-Multiple-Output (MIMO technology. A least-square channel estimation algorithm is used to evaluate multiple MIMO channel impulse responses at the receiver end. A deconvolution routine is used to separate the messages coming from different sources. This paper covers the performance of both the channel estimation and the MIMO deconvolution processes using either simulated data or field data. The MIMO equalization performance is measured by comparing three relative root mean-squared errors (RMSE, obtained by calculations between the source signal (a pseudo-noise sequence and the corresponding received MIMO signal at various stages of the deconvolution process; prior to any interference removal, at the output of the Linear Equalization (LE process and at the output of an interference cancellation process with complete a priori knowledge of the transmitted signal. Using the simulated data, the RMSE using LE is −20.5 dB (where 0 dB corresponds to 100% of relative error while the lower bound value is −33.4 dB. Using experimental data, the LE performance is −3.3 dB and the lower bound RMSE value is −27 dB.

  13. Low latency, high bandwidth data communications between compute nodes in a parallel computer

    Science.gov (United States)

    Archer, Charles J.; Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

    2010-11-02

    Methods, parallel computers, and computer program products are disclosed for low latency, high bandwidth data communications between compute nodes in a parallel computer. Embodiments include receiving, by an origin direct memory access (`DMA`) engine of an origin compute node, data for transfer to a target compute node; sending, by the origin DMA engine of the origin compute node to a target DMA engine on the target compute node, a request to send (`RTS`) message; transferring, by the origin DMA engine, a predetermined portion of the data to the target compute node using memory FIFO operation; determining, by the origin DMA engine whether an acknowledgement of the RTS message has been received from the target DMA engine; if the an acknowledgement of the RTS message has not been received, transferring, by the origin DMA engine, another predetermined portion of the data to the target compute node using a memory FIFO operation; and if the acknowledgement of the RTS message has been received by the origin DMA engine, transferring, by the origin DMA engine, any remaining portion of the data to the target compute node using a direct put operation.

  14. High-efficiency atomic entanglement concentration for quantum communication network assisted by cavity QED

    Science.gov (United States)

    Wang, Guan-Yu; Li, Tao; Deng, Fu-Guo

    2015-04-01

    Quantum entanglement is the key resource in quantum information processing, especially in quantum communication network. However, affected by the environment noise, the maximally entangled states usually collapse into nonmaximally entangled ones or even mixed states. Here we present two high-efficiency schemes to complete the entanglement concentration of nonlocal two-atom systems. Our first scheme is used to concentrate the nonlocal atomic systems in the partially entangled states with known parameters, and it has the optimal success probability. The second scheme is used to concentrate the entanglement of the nonlocal two-atom systems in the partially entangled states with unknown parameters. Compared with the other schemes for the entanglement concentration of atomic systems, our two protocols are more efficient and practical. They require only an ancillary single photon to judge whether they succeed or not, and they work in a heralded way with detection inefficiency and absence of sophisticated single-photon detectors in practical applications. Moreover, they are insensitive to both the cavity decay and atomic spontaneous emission.

  15. High-dose insulin inhibits gap junction intercellular communication in vascular smooth muscle cells.

    Science.gov (United States)

    Bian, Ou; Zhang, Haishan; Guan, Qigang; Sun, Yingxian; Zeng, Dingyin

    2015-07-01

    Gap junction intercellular communication (GJIC) is important in mediating intercellular substance and signal transmission. Connexin (Cx)43 is a major component involved in GJIC in vascular tissue and its abnormal expression is closely associated with various vascular diseases. Insulin resistance is the central component of metabolic syndrome, and high doses of insulin can affect vascular function through multiple pathways, resulting in cardiovascular disease. However, the effects of insulin on GJIC function and connexin (Cx)43 expression in vascular smooth muscle cells (VSMCs) remain unclear. Following treatment of VSMCs with different doses of insulin, a fluorescence recovery after photobleaching (FRAP) assay was performed to evaluate GJIC function in treated VSMCs. The results showed that high‑dose insulin suppressed GJIC function. Western blot assays further demonstrated that high‑dose insulin induced the phosphorylation of Cx43 at s368 and downregulated the expression of Cx43. H2O2 release assays demonstrated that high‑dose insulin treatment significantly elevated the cellular H2O2 level. In addition, compared with cells treated with high‑dose insulin, pretreatment with catalase significantly restored the cellular GJIC function, decreased the phosphorylation level of Cx43 at s368, and enhanced Cx43 expression. In conclusion, these data indicate that high‑dose insulin inhibits cellular GJIC function through the oxidative stress‑activated signaling pathway. This phenomenon may also constitute a potential mechanism underlying the pathogenesis of insulin resistance and its complications.

  16. COOPERATIVE DIRECTIONAL INTER-CELL HANDOVER SCHEME IN HIGH ALTITUDE PLATFORM COMMUNICATIONS SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Li Shufeng; Wang Lijie; David Grace; Ma Dongtang

    2011-01-01

    A novel Cooperative Directional inter-cell Handover Scheme (CDHS) for High Altitude Platform (HAP) communications systems is proposed,in which the handover target cell and the two cells adjacent to this handover target cell work cooperatively to exploit the traffic fluctuation to improve handover performance.Users in the overlap area of the overloaded handover target cell will be forced to handover directionally before their optimal handover boundary in order to free up resources for the handover calls which would otherwise be dropped due to the shortage of resources and queue time out.Simulation results show that the handover call dropping probability is greatly reduced (at least 60%) compared with the general queue handover scheme,with little performancereduction to the call blocking probability,and the Not in the Best Cell (NBC) average time is only increased moderately.Moreover,an optimal cell radius can be achieved for a specific platform speed by minimizing the unified system performance,which is the linear combination of the handover call dropping probability and the NBC average time.

  17. A secure communication method for a high-power information signal based on chaotic masking

    Institute of Scientific and Technical Information of China (English)

    李建芬; 李农

    2002-01-01

    In this paper, we present a secure communication method for a high-power information signal based on chaoticmasking. In the transmitter, an adaptive controller is adopted to pick up the change of the information signal, andto inject the controller's error into the transmitting system. At the same time, the information is directly added tothe chaotic signal in transmission to drive the receiving system. In the receiver, another adaptive controller is usedto maintain chaotic synchronization of the transmitting and receiving systems and to recover the information signal.Since the synchronization error is independent from the information signal, the power of the information signal can beequivalent to that of the chaotic signal, and the frequency of the information signal can be set within the range of theprincipal frequencies of the chaotic signal. The results of theoretical analysis and numerical simulation show that thepresented method not only enhances the degree of security of low-dimensional chaotic systems but also significantlyimproves the signal-to-noise ratio at the receiving end.

  18. Communication Requirements and Interconnect Optimization forHigh-End Scientific Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kamil, Shoaib; Oliker, Leonid; Pinar, Ali; Shalf, John

    2007-11-12

    The path towards realizing peta-scale computing isincreasingly dependent on building supercomputers with unprecedentednumbers of processors. To prevent the interconnect from dominating theoverall cost of these ultra-scale systems, there is a critical need forhigh-performance network solutions whose costs scale linearly with systemsize. This work makes several unique contributions towards attaining thatgoal. First, we conduct one of the broadest studies to date of high-endapplication communication requirements, whose computational methodsinclude: finite-difference, lattice-bolzmann, particle in cell, sparselinear algebra, particle mesh ewald, and FFT-based solvers. Toefficiently collect this data, we use the IPM (Integrated PerformanceMonitoring) profiling layer to gather detailed messaging statistics withminimal impact to code performance. Using the derived communicationcharacterizations, we next present fit-trees interconnects, a novelapproach for designing network infrastructure at a fraction of thecomponent cost of traditional fat-tree solutions. Finally, we propose theHybrid Flexibly Assignable Switch Topology (HFAST) infrastructure, whichuses both passive (circuit) and active (packet) commodity switchcomponents to dynamically reconfigure interconnects to suit thetopological requirements of scientific applications. Overall ourexploration leads to a promising directions for practically addressingthe interconnect requirements of future peta-scale systems.

  19. High-Frequency Wireless Communications System: 2.45-GHz Front-End Circuit and System Integration

    Science.gov (United States)

    Chen, M.-H.; Huang, M.-C.; Ting, Y.-C.; Chen, H.-H.; Li, T.-L.

    2010-01-01

    In this article, a course on high-frequency wireless communications systems is presented. With the 145-MHz baseband subsystem available from a prerequisite course, the present course emphasizes the design and implementation of the 2.45-GHz front-end subsystem as well as system integration issues. In this curriculum, the 2.45-GHz front-end…

  20. Insights on Inspirational Education for "High-Risk" Youth Informed by Participatory Action Research (PAR) on Youth Engagement: Short Communication

    Science.gov (United States)

    Iwasaki, Yoshitaka; Hopper, Tristan; Whelan, Patricia

    2017-01-01

    This short communication provides our insights into how or in what ways educators can more effectively support aspiration of at-risk/high-risk youth toward meaningful education. These are informed by the key learnings from our ongoing youth engagement research. Those insights emphasize the importance of "meaningful engagement of youth"…

  1. High-Frequency Wireless Communications System: 2.45-GHz Front-End Circuit and System Integration

    Science.gov (United States)

    Chen, M.-H.; Huang, M.-C.; Ting, Y.-C.; Chen, H.-H.; Li, T.-L.

    2010-01-01

    In this article, a course on high-frequency wireless communications systems is presented. With the 145-MHz baseband subsystem available from a prerequisite course, the present course emphasizes the design and implementation of the 2.45-GHz front-end subsystem as well as system integration issues. In this curriculum, the 2.45-GHz front-end…

  2. Nurse-led care interventions for high blood pressure control: Implications for non-communicable disease programs in Uganda

    Directory of Open Access Journals (Sweden)

    Godfrey Katende

    2016-01-01

    Conclusion: Nurses play a significant role in the control of high blood pressure when they employ effective evidence based strategies in identification, prevention and management of hypertension. Adapting effective evidence based strategies in identification, prevention and management of non-communicable diseases could improve patient outcomes in Uganda.

  3. ULTRA-HIGH BW OPTICAL COMMUNICATION USING OXYGEN PLASMA ASSISTED InP BASED HYBRID Si LASER

    Directory of Open Access Journals (Sweden)

    PRATTAY BIN ABDUL WAHAB

    2010-12-01

    Full Text Available This paper demonstrates the development of a hybrid integration platform to build major electrically driven photonic active devices: silicon evanescent DFB lasers, silicon evanescent amplifiers, silicon evanescent waveguide photo-detectors or pre-amplified photo-detectors on a single silicon platform consisting of III-V gain layers with passive waveguide for board to board and for chip to chip optical communication for tera scale computing. The structural description proposed here may push forward the manufacturing of photonic ICs tomake high speed communicational imaginings to reality and to start a new era.

  4. High Prevalence of Chronic Non-Communicable Conditions Among Adult Refugees: Implications for Practice and Policy

    Science.gov (United States)

    Yun, Katherine; Hebrank, Kelly; Graber, Lauren K.; Sullivan, Mary-Christine; Chen, Isabel; Gupta, Jhumka

    2013-01-01

    The global rise in non-communicable disease (NCD) suggests that US-based refugees are increasingly affected by chronic conditions. However, health services have focused on the detection of infectious disease, with relatively limited data on chronic NCDs. Using data from a retrospective medical record review of a refugee health program in the urban Northeast (n = 180), we examined the prevalence of chronic NCDs and NCD risk factors among adult refugees who had recently arrived in the US, with attention to region of origin and family composition. Family composition was included because low-income adults without dependent children are at high risk of becoming uninsured. We found that half of the adult refugees in this sample had at least one chronic NCD (51.1%), and 9.5% had three or more NCDs. Behavioral health diagnoses were most common (15.0%), followed by hypertension (13.3%). Half of adults were overweight or obese (54.6%). Chronic NCDs were somewhat more common among adults from Iraq, but this difference was not significant (56.8 vs. 44.6%). Chronic NCDs were common among adults with and without dependent children (61.4 vs. 44.6%, respectively), and these two groups did not significantly differ in their likelihood of having a chronic NCD after adjustment for age and gender (AOR = 0.78, 95% CI = 0.39, 1.55). This study suggests that chronic NCDs are common among adult refugees in the US, including refugees at high risk for uninsurance. We propose that refugee health services accommodate screening and treatment for chronic NCDs and NCD risk factors, and that insurance outreach and enrollment programs target recently arrived refugees. PMID:22382428

  5. Transportable optical ground station for high-speed free-space laser communication

    Science.gov (United States)

    Shrestha, Amita; Brechtelsbauer, Martin

    2012-10-01

    Near real-time data downlinks from aircrafts, satellites and high altitude platforms via high-speed laser commu- nication links is an important research topic at the Institute of Communications and Navigation of the German Aerospace Center (DLR). Ground stations for such scenarios are usually fixed at a certain location. With a mo- tivation to provide a ground station that is quickly and easily deployed anywhere in the world, a transportable optical ground station (TOGS) has been developed. TOGS features a pneumatically deployable Cassegrain-type telescope with main mirror diameter of 60 cm, including optical tracking and receiving system. For calibration of position and attitude, multiple sensors like dual-antenna GPS and inclination sensors have been installed. In order to realize these systems, robust software that operates and controls them is essential. The software is platform independent and is aimed to be used on both mobile and ground terminals. It includes implementa- tion of accurate pointing, acquisition and tracking algorithms, hardware drivers, and user interfaces. Important modules of the software are GPS tracking, optical tracking, star- and satellite tracking, and calibration of the TOGS itself. Recently, a first successful data-downlink from an aircraft to TOGS using GPS tracking has been performed. To streamline the software development and testing process, some simulation environments like mount simulator, aircraft path simulator, tracking camera simulator and tracking error analysis tool have also been developed. This paper presents the overall hardware/software structure of the TOGS, and gives results of the tracking accuracy improvement techniques like GPS extrapolation and optical tracking.

  6. Data Relay Board with Protocol for High-Speed, Free-Space Optical Communications

    Science.gov (United States)

    Wright, Malcolm; Clare, Loren; Gould, Gary; Pedyash, Maxim

    2004-01-01

    In a free-space optical communication system, the mitigation of transient outages through the incorporation of error-control methods is of particular concern, the outages being caused by scintillation fades and obscurants. The focus of this innovative technology is the development of a data relay system for a reliable high-data-rate free-spacebased optical-transport network. The data relay boards will establish the link, maintain synchronous connection, group the data into frames, and provide for automatic retransmission (ARQ) of lost or erred frames. A certain Quality of Service (QoS) can then be ensured, compatible with the required data rate. The protocol to be used by the data relay system is based on the draft CCSDS standard data-link protocol Proximity-1, selected by orbiters to multiple lander assets in the Mars network, for example. In addition to providing data-link protocol capabilities for the free-space optical link and buffering the data, the data relay system will interface directly with user applications over Gigabit Ethernet and/or with highspeed storage resources via Fibre Channel. The hardware implementation is built on a network-processor-based architecture. This technology combines the power of a hardware switch capable of data switching and packet routing at Gbps rates, with the flexibility of a software- driven processor that can host highly adaptive and reconfigurable protocols used, for example, in wireless local-area networks (LANs). The system will be implemented in a modular multi-board fashion. The main hardware elements of the data relay system are the new data relay board developed by Rockwell Scientific, a COTS Gigabit Ethernet board for user interface, and a COTS Fibre Channel board that connects to local storage. The boards reside in a cPCI back plane, and can be housed in a VME-type enclosure.

  7. Highly Sensitive Photon Counting Detectors for Deep Space Optical Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new type of a photon-counting photodetector is proposed to advance the state-of the-art in deep space optical communications technology. The proposed detector...

  8. FY 2000 Blue Book: High Performance Computing and Communications: Information Technology Frontiers for a New Millennium

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — As we near the dawn of a new millennium, advances made possible by computing, information, and communications research and development R and D ? once barely...

  9. C-Band SATCOM Range Communications System for ELVs using ESAs and High Dynamics Modem Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Improving safety while increasing the pace of space launches requires improved communications capability. An increasing volume of real-time data from numerous...

  10. Global communication schemes for the numerical solution of high-dimensional PDEs

    DEFF Research Database (Denmark)

    Hupp, Philipp; Heene, Mario; Jacob, Riko;

    2016-01-01

    rounds or the total communication volume. Experiments on two different supercomputers show that either of the schemes outperforms the other depending on the size of the problem. Furthermore, we present a communication model based on the system’s latency and bandwidth and validate the model...... with the experiments. The model can be used to predict the runtime of the reduce/broadcast step for dimensionalities that are yet out of scope on current supercomputers....

  11. Microwave photonics technologies supporting high capacity and flexible wireless communications systems

    DEFF Research Database (Denmark)

    Lu, Xiaofeng; Tatarczak, Anna; Rommel, Simon;

    2015-01-01

    Emerging 5G wireless systems require technologies for increased capacity, guarantee robustness, low latency and flexibility. We review a number of approaches to provide the above based on microwave photonics and hybrid optical fiber-wireless communication techniques.......Emerging 5G wireless systems require technologies for increased capacity, guarantee robustness, low latency and flexibility. We review a number of approaches to provide the above based on microwave photonics and hybrid optical fiber-wireless communication techniques....

  12. Health care using high-bandwidth communication to overcome distance and time barriers for the Department of Defense

    Science.gov (United States)

    Mun, Seong K.; Freedman, Matthew T.; Gelish, Anthony; de Treville, Robert E.; Sheehy, Monet R.; Hansen, Mark; Hill, Mac; Zacharia, Elisabeth; Sullivan, Michael J.; Sebera, C. Wayne

    1993-01-01

    Image management and communications (IMAC) network, also known as picture archiving and communication system (PACS) consists of (1) digital image acquisition, (2) image review station (3) image storage device(s), image reading workstation, and (4) communication capability. When these subsystems are integrated over a high speed communication technology, possibilities are numerous in improving the timeliness and quality of diagnostic services within a hospital or at remote clinical sites. Teleradiology system uses basically the same hardware configuration together with a long distance communication capability. Functional characteristics of components are highlighted. Many medical imaging systems are already in digital form. These digital images constitute approximately 30% of the total volume of images produced in a radiology department. The remaining 70% of images include conventional x-ray films of the chest, skeleton, abdomen, and GI tract. Unless one develops a method of handling these conventional film images, global improvement in productivity in image management and radiology service throughout a hospital cannot be achieved. Currently, there are two method of producing digital information representing these conventional analog images for IMAC: film digitizers that scan the conventional films, and computed radiography (CR) that captures x-ray images using storage phosphor plate that is subsequently scanned by a laser beam.

  13. Outage Analysis of Train-to-Train Communication Model over Nakagami-m Channel in High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Pengyu Liu

    2013-01-01

    Full Text Available This paper analyzes the end-to-end outage performance of high-speed-railway train-to-train communication model in high-speed railway over independent identical and nonidentical Nakagami-m channels. The train-to-train communication is inter-train communication without an aid of infrastructure (for base station. Source train uses trains on other rail tracks as relays to transmit signals to destination train on the same track. The mechanism of such communication among trains can be divided into three cases based on occurrence of possible-occurrence relay trains. We first present a new closed form for the sum of squared independent Nakagami-m variates and then derive an expression for the outage probability of the identical and non-identical Nakagami-m channels in three cases. In particular, the problem is improved by the proposed formulation that statistic for sum of squared Nakagami-m variates with identical m tends to be infinite. Numerical analysis indicates that the derived analytic results are reasonable and the outage performance is better over Nakagami-m channel in high-speed railway scenarios.

  14. Evaluation of Heart Rate Assessment Timing, Communication, Accuracy, and Clinical Decision-Making during High Fidelity Simulation of Neonatal Resuscitation

    Directory of Open Access Journals (Sweden)

    Win Boon

    2014-01-01

    Full Text Available Objective. Accurate heart rate (HR determination during neonatal resuscitation (NR informs subsequent NR actions. This study’s objective was to evaluate HR determination timeliness, communication, and accuracy during high fidelity NR simulations that house officers completed during neonatal intensive care unit (NICU rotations. Methods. In 2010, house officers in NICU rotations completed high fidelity NR simulation. We reviewed 80 house officers’ videotaped performance on their initial high fidelity simulation session, prior to training and performance debriefing. We calculated the proportion of cases congruent with NR guidelines, using chi square analysis to evaluate performance across HR ranges relevant to NR decision-making: <60, 60–99, and ≥100 beats per minute (bpm. Results. 87% used umbilical cord palpation, 57% initiated HR assessment within 30 seconds, 70% were accurate, and 74% were communicated appropriately. HR determination accuracy varied significantly across HR ranges, with 87%, 57%, and 68% for HR <60, 60–99, and ≥100 bpm, respectively (P<0.001. Conclusions. Timeliness, communication, and accuracy of house officers’ HR determination are suboptimal, particularly for HR 60–100 bpm, which might lead to inappropriate decision-making and NR care. Training implications include emphasizing more accurate HR determination methods, better communication, and improved HR interpretation during NR.

  15. Inner experience in the scanner: Can high fidelity apprehensions of inner experience be integrated with fMRI?

    Directory of Open Access Journals (Sweden)

    Simone eKühn

    2014-12-01

    Full Text Available To provide full accounts of human experience and behavior, research in cognitive neuroscience must be linked to inner experience, but introspective reports of inner experience have often been found to be unreliable. The present case study aimed at providing proof of principle that introspection using one method, Descriptive Experience Sampling (DES, can be reliably integrated with fMRI. A participant was trained in the DES method, followed by nine sessions of sampling within an MRI scanner. During moments where the DES interview revealed ongoing inner speaking, fMRI data reliably showed activation in classic speech processing areas including left inferior frontal gyrus. Further, the fMRI data validated the participant’s DES observations of the experiential distinction between inner speaking and innerly hearing her own voice. These results highlight the precision and validity of the DES method as a technique of exploring inner experience and the utility of combining such methods with fMRI.

  16. A hybrid MAC protocol design for energy-efficient very-high-throughput millimeter wave, wireless sensor communication networks

    Science.gov (United States)

    Jian, Wei; Estevez, Claudio; Chowdhury, Arshad; Jia, Zhensheng; Wang, Jianxin; Yu, Jianguo; Chang, Gee-Kung

    2010-12-01

    This paper presents an energy-efficient Medium Access Control (MAC) protocol for very-high-throughput millimeter-wave (mm-wave) wireless sensor communication networks (VHT-MSCNs) based on hybrid multiple access techniques of frequency division multiplexing access (FDMA) and time division multiplexing access (TDMA). An energy-efficient Superframe for wireless sensor communication network employing directional mm-wave wireless access technologies is proposed for systems that require very high throughput, such as high definition video signals, for sensing, processing, transmitting, and actuating functions. Energy consumption modeling for each network element and comparisons among various multi-access technologies in term of power and MAC layer operations are investigated for evaluating the energy-efficient improvement of proposed MAC protocol.

  17. Reading, Writing, and Presenting Original Scientific Research: A Nine-Week Course in Scientific Communication for High School Students

    Directory of Open Access Journals (Sweden)

    Elizabeth Sarah Danka

    2015-08-01

    Full Text Available High school students are not often given opportunities to communicate scientific findings to their peers, the general public, and/or people in the scientific community, and therefore they do not develop scientific communication skills. We present a nine-week course that can be used to teach high school students, who may have no previous experience, how to read and write primary scientific articles and how to discuss scientific findings with a broad audience. Various forms of this course have been taught for the past 10 years as part of an intensive summer research program for rising high school seniors that is coordinated by the Young Scientist Program at Washington University in St. Louis. The format presented here includes assessments for efficacy through both rubric-based methods and student self-assessment surveys.

  18. ASPECTS OF THE COMMUNICATION IN THE EDUCATIONAL SYSTEM. CASE STUDY, HIGH SCHOOL SECTOR

    Directory of Open Access Journals (Sweden)

    Andrei Radu IOVA

    2013-01-01

    Full Text Available The pupil-teacher communication and the teacher communication skills seem to be key concepts to reach the objectives of the educational act. Recent studies highlight the link between the teacher communication skills, their efficiency, and the fact that these skills could play a more important role for the education that the teaching staff training, his intelligence level and teaching methods. The research goal was the investigation of the aspects specific to the educational communication, that constitute facilitator factors and barriers in the learning process and in the relation teacher-pupil. The quantitative analysis was based on a questionnaire for pupils and teachers, that aimed the investigation of the respondents perception on what it is a good teacher in order to identify those skills that make the difference, from the pupils point of view, and also from the teachers point of view, between a competent teacher and an ineffective one. The research used a double approach, quantitative and qualitative one. The quantitative study allowed the inclusion of a number of 151 subjects and the survey of some dimensions of teacherpupil communication. The qualitative research used a number of 47 subjects, but it allowed the consolidation of the approached topics. The results obtained were interpreted based on the differences that appear in the pupils and teaching staff opinions, but also through the investigation of those dimensions that make the difference, in the case of a model teaching staff, between the pupils and teachers perceptions.

  19. A Comparison of Online (High Tech) and Traditional (High Touch) Learning in Business Communication Courses in Silicon Valley

    Science.gov (United States)

    Fortune, Mary F.; Shifflett, Bethany; Sibley, Robert E.

    2006-01-01

    In this study, the authors explored differences in perceptions of skill development and the value of face-to-face interaction between students taking a business communication course offered online and in the traditional, on-campus classroom environment. They hypothesized that there would be no statistically significant difference in face-to-face…

  20. Institutional Barriers to Research on Sensitive Topics: Case of Sex Communication Research Among University Students

    Directory of Open Access Journals (Sweden)

    Carey M. Noland

    2012-11-01

    Full Text Available When conducting research on sensitive topics, it is challenging to use new methods of data collection given the apprehensions of Institutional Review Boards (IRBs. This is especially worrying because sensitive topics of research often require novel approaches. In this article a brief personal history of navigating the IRB process for conducting sex communication research is presented, along with data from a survey that tested the assumptions long held by many IRBs. Results support some of the assumptions IRBs hold about sex communication research, but do not support some other assumptions.

  1. The Orbital Experience: Building Community through Communication and Connections in High School Spanish Classes

    Science.gov (United States)

    Gomez, Diane W.; Gujarati, Joan; Heckendorn, Rick

    2012-01-01

    This article highlights the Orbital Experience (OE), a unique experience that explores the affective domains of second language acquisition, including communication in the target language, making interdisciplinary connections, and fostering a community of learners. Through Orbitals, students serve as experts by researching a topic of interest,…

  2. A Transceiver for High-Speed Global On-Chip Data Communication

    NARCIS (Netherlands)

    Schinkel, Daniël; Mensink, Eisse; Klumperink, Eric; Tuijl, van Ed; Nauta, Bram

    2005-01-01

    Global on-chip data communication is becoming a concern as the gap between transistor speed and interconnect bandwidth increases with CMOS process scaling. In this paper we show how a special form of equalization, pulse-width pre-emphasis, can significantly increase the data rate for a given length

  3. Missouri Assessment Program (MAP), Spring 1999: High School Communication Arts, Released Items, Grade 11.

    Science.gov (United States)

    Missouri State Dept. of Elementary and Secondary Education, Jefferson City.

    This document deals with testing in communication arts for 11th graders in Missouri public schools. The document contains the following items from the Test Booklet: "Two Words" (Isabel Allende) (Session 1, Items 5, 6, and 7); "Gumshoes Turn to Internet for Spadework" (Nicole Gaouette) (Session 1, Item 5); a writing prompt; and a writer's…

  4. Missouri Assessment Program (MAP), Spring 1999: High School Communication Arts, Released Items, Grade 11.

    Science.gov (United States)

    Missouri State Dept. of Elementary and Secondary Education, Jefferson City.

    This document deals with testing in communication arts for 11th graders in Missouri public schools. The document contains the following items from the Test Booklet: "Two Words" (Isabel Allende) (Session 1, Items 5, 6, and 7); "Gumshoes Turn to Internet for Spadework" (Nicole Gaouette) (Session 1, Item 5); a writing prompt; and…

  5. A Highly Secure Identity-Based Authenticated Key-Exchange Protocol for Satellite Communication

    NARCIS (Netherlands)

    Zhong Yantao, [No Value; Ma Jianfeng, [No Value

    2010-01-01

    In recent years, significant improvements have been made to the techniques used for analyzing satellite communication and attacking satellite systems. In 2003, a research team at Los Alamos National Laboratory, USA, demonstrated the ease with which civilian global positioning system (GPS) spoofing a

  6. A Highly Secure Identity-Based Authenticated Key-Exchange Protocol for Satellite Communication

    NARCIS (Netherlands)

    Zhong Yantao, [No Value; Ma Jianfeng, [No Value

    2010-01-01

    In recent years, significant improvements have been made to the techniques used for analyzing satellite communication and attacking satellite systems. In 2003, a research team at Los Alamos National Laboratory, USA, demonstrated the ease with which civilian global positioning system (GPS) spoofing a

  7. Shallow-water acoustic communication with high bit rate BPSK signals

    NARCIS (Netherlands)

    Gijzen, M.B. van; Walree, P.A. van

    2000-01-01

    BPSK signals have been defined for transmission through a shallow-water acoustic communication channel. The signals were accompanied by two displaced carriers to facilitate carrier recovery. To correct for the adverse effects of time spreading, a pseudo-random learning sequence was transmitted ahead

  8. Emotional Communication in Families of Conduct Problem Children with High versus Low Callous-Unemotional Traits

    Science.gov (United States)

    Pasalich, Dave S.; Dadds, Mark R.; Vincent, Lucy C.; Cooper, Francesca A.; Hawes, David J.; Brennan, John

    2012-01-01

    This study examined relationships between parent-child emotional communication and callous-unemotional (CU) traits and conduct problems. References to negative and positive emotions made by clinic-referred boys (3-9 years) and their parents were coded from direct observations of family interactions involving the discussion of shared emotional…

  9. Female and male communication in co-operative problem solving in high school science

    NARCIS (Netherlands)

    Harskamp, Egbert; Dhig, Ning; Tremante, A; Welsch, F; Malpica, F

    2007-01-01

    Empirical evidence is presented that males working in mixed-gender dyads on science problems do better than their female partners. This is not the case when males and females work in same gender dyads. There is a difference in communication style in mixed gender dyads in comparison with same gender

  10. A Health Communication Intervention to Reduce High-Risk Drinking among College Students

    Science.gov (United States)

    Glassman, Tavis; Haughton, Noela; Wohlwend, Jennifer; Roberts, Stephen; Jordan, Timothy; Yingling, Faith; Blavos, Alexis

    2013-01-01

    This investigation examined the effect of a health communication intervention on the alcohol consumption patterns of first-year college students. Researchers employed a quasi-experimental design consisting of students in three residence halls at two Midwestern universities. Between-group comparisons revealed students receiving the intervention…

  11. A Health Communication Intervention to Reduce High-Risk Drinking among College Students

    Science.gov (United States)

    Glassman, Tavis; Haughton, Noela; Wohlwend, Jennifer; Roberts, Stephen; Jordan, Timothy; Yingling, Faith; Blavos, Alexis

    2013-01-01

    This investigation examined the effect of a health communication intervention on the alcohol consumption patterns of first-year college students. Researchers employed a quasi-experimental design consisting of students in three residence halls at two Midwestern universities. Between-group comparisons revealed students receiving the intervention…

  12. A Study of Quality of Service Communication for High-Speed Packet-Switching Computer Sub-Networks

    Science.gov (United States)

    Cui, Zhenqian

    1999-01-01

    In this thesis, we analyze various factors that affect quality of service (QoS) communication in high-speed, packet-switching sub-networks. We hypothesize that sub-network-wide bandwidth reservation and guaranteed CPU processing power at endpoint systems for handling data traffic are indispensable to achieving hard end-to-end quality of service. Different bandwidth reservation strategies, traffic characterization schemes, and scheduling algorithms affect the network resources and CPU usage as well as the extent that QoS can be achieved. In order to analyze those factors, we design and implement a communication layer. Our experimental analysis supports our research hypothesis. The Resource ReSerVation Protocol (RSVP) is designed to realize resource reservation. Our analysis of RSVP shows that using RSVP solely is insufficient to provide hard end-to-end quality of service in a high-speed sub-network. Analysis of the IEEE 802.lp protocol also supports the research hypothesis.

  13. Recent advances in high-capacity free-space optical and radio-frequency communications using orbital angular momentum multiplexing

    Science.gov (United States)

    Willner, Alan E.; Ren, Yongxiong; Xie, Guodong; Yan, Yan; Li, Long; Zhao, Zhe; Wang, Jian; Tur, Moshe; Molisch, Andreas F.; Ashrafi, Solyman

    2017-02-01

    There is a continuing growth in the demand for data bandwidth, and the multiplexing of multiple independent data streams has the potential to provide the needed data capacity. One technique uses the spatial domain of an electromagnetic (EM) wave, and space division multiplexing (SDM) has become increasingly important for increased transmission capacity and spectral efficiency of a communication system. A subset of SDM is mode division multiplexing (MDM), in which multiple orthogonal beams each on a different mode can be multiplexed. A potential modal basis set to achieve MDM is to use orbital angular momentum (OAM) of EM waves. In such a system, multiple OAM beams each carrying an independent data stream are multiplexed at the transmitter, propagate through a common medium and are demultiplexed at the receiver. As a result, the total capacity and spectral efficiency of the communication system can be multiplied by a factor equal to the number of transmitted OAM modes. Over the past few years, progress has been made in understanding the advantages and limitations of using multiplexed OAM beams for communication systems. In this review paper, we highlight recent advances in the use of OAM multiplexing for high-capacity free-space optical and millimetre-wave communications. We discuss different technical challenges (e.g. atmospheric turbulence and crosstalk) as well as potential techniques to mitigate such degrading effects. This article is part of the themed issue 'Optical orbital angular momentum'.

  14. Risky Business: The Science and Art of Radiation Risk Communication in the High Risk Context of Space Travel

    Science.gov (United States)

    Elgart, Shona Robin; Shavers, Mark; Huff, Janice; Patel, Zarana; Semones, Edward

    2016-01-01

    Successfully communicating the complex risks associated with radiation exposure is a difficult undertaking; communicating those risks within the high-risk context of space travel is uniquely challenging. Since the potential risks of space radiation exposure are not expected to be realized until much later in life, it is hard to draw comparisons between other spaceflight risks such as hypoxia and microgravity-induced bone loss. Additionally, unlike other spaceflight risks, there is currently no established mechanism to mitigate the risks of incurred radiation exposure such as carcinogenesis. Despite these challenges, it is the duty of the Space Radiation Analysis Group (SRAG) at NASA's Johnson Space Center to provide astronauts with the appropriate information to effectively convey the risks associated with exposure to the space radiation environment. To this end, astronauts and their flight surgeons are provided with an annual radiation risk report documenting the astronaut's individual radiation exposures from space travel, medical, and internal radiological procedures throughout the astronaut's career. In an effort to improve this communication and education tool, this paper critically reviews the current report style and explores alternative report styles to define best methods to appropriately communicate risk to astronauts, flight surgeons, and management.

  15. Recent advances in high-capacity free-space optical and radio-frequency communications using orbital angular momentum multiplexing.

    Science.gov (United States)

    Willner, Alan E; Ren, Yongxiong; Xie, Guodong; Yan, Yan; Li, Long; Zhao, Zhe; Wang, Jian; Tur, Moshe; Molisch, Andreas F; Ashrafi, Solyman

    2017-02-28

    There is a continuing growth in the demand for data bandwidth, and the multiplexing of multiple independent data streams has the potential to provide the needed data capacity. One technique uses the spatial domain of an electromagnetic (EM) wave, and space division multiplexing (SDM) has become increasingly important for increased transmission capacity and spectral efficiency of a communication system. A subset of SDM is mode division multiplexing (MDM), in which multiple orthogonal beams each on a different mode can be multiplexed. A potential modal basis set to achieve MDM is to use orbital angular momentum (OAM) of EM waves. In such a system, multiple OAM beams each carrying an independent data stream are multiplexed at the transmitter, propagate through a common medium and are demultiplexed at the receiver. As a result, the total capacity and spectral efficiency of the communication system can be multiplied by a factor equal to the number of transmitted OAM modes. Over the past few years, progress has been made in understanding the advantages and limitations of using multiplexed OAM beams for communication systems. In this review paper, we highlight recent advances in the use of OAM multiplexing for high-capacity free-space optical and millimetre-wave communications. We discuss different technical challenges (e.g. atmospheric turbulence and crosstalk) as well as potential techniques to mitigate such degrading effects.This article is part of the themed issue 'Optical orbital angular momentum'. © 2017 The Author(s).

  16. The use of virtual characters to assess and train non-verbal communication in high-functioning autism.

    Science.gov (United States)

    Georgescu, Alexandra Livia; Kuzmanovic, Bojana; Roth, Daniel; Bente, Gary; Vogeley, Kai

    2014-01-01

    High-functioning autism (HFA) is a neurodevelopmental disorder, which is characterized by life-long socio-communicative impairments on the one hand and preserved verbal and general learning and memory abilities on the other. One of the areas where particular difficulties are observable is the understanding of non-verbal communication cues. Thus, investigating the underlying psychological processes and neural mechanisms of non-verbal communication in HFA allows a better understanding of this disorder, and potentially enables the development of more efficient forms of psychotherapy and trainings. However, the research on non-verbal information processing in HFA faces several methodological challenges. The use of virtual characters (VCs) helps to overcome such challenges by enabling an ecologically valid experience of social presence, and by providing an experimental platform that can be systematically and fully controlled. To make this field of research accessible to a broader audience, we elaborate in the first part of the review the validity of using VCs in non-verbal behavior research on HFA, and we review current relevant paradigms and findings from social-cognitive neuroscience. In the second part, we argue for the use of VCs as either agents or avatars in the context of "transformed social interactions." This allows for the implementation of real-time social interaction in virtual experimental settings, which represents a more sensitive measure of socio-communicative impairments in HFA. Finally, we argue that VCs and environments are a valuable assistive, educational and therapeutic tool for HFA.

  17. Reflection: a critical proficiency essential to the effective development of a high competence in communication.

    Science.gov (United States)

    Adams, Cindy L; Nestel, Debra; Wolf, Peter

    2006-01-01

    Reflection, or the ability to step back from an experience and consider it critically, in an analytical, non-subjective manner, is an essential aspect of problem solving and decision making, and also of effective communication with clients and colleagues. Reflective practice has been described as the essence of professionalism and is therefore a core professional skill; rarely, however, has it been explicitly taught in veterinary curricula, and it has only a recent history in undergraduate human medical curricula. We describe here two preliminary case studies, one in a veterinary medical education context and the other within a human medical education framework, as examples of approaches to assessing a student's ability for ''reflection.'' The case studies also illustrate some of the key principles. Both of the case studies described had as their end goal the enhancement of communication skills through critical reflection. At Monash University, Australia, the majority of students were assessed as being at a level of ''reflection in development.'' The students in the Ontario Veterinary College case study showed moderately good use of self-awareness and critical reflection as a basis for modifying and integrating communication skills into practice. While both preliminary case studies point to the fact that students recognize the importance of communication and value the opportunity to practice it, few students in either case study identified the importance of reflection for lifelong learning and professional competence. Opportunities to complete critical reflection exercises in other parts of curricula and outside of communication would likely reinforce its importance as a generic skill. Ongoing scholarly approaches to teaching, learning, and evaluating reflection and self-awareness are needed.

  18. Open MR imaging of the unstable shoulder in the apprehension test position: description and evaluation of an alternative MR examination position

    Energy Technology Data Exchange (ETDEWEB)

    Wintzell, G.; Larsson, S. [Uppsala Univ. Hospital (Sweden). Dept. of Orthopaedics; Haglund-Aakerlind, Y. [Dept. of Orthopaedics, Karolinska Hospital, Stockholm (Sweden); Larsson, H. [Dept. of Radiology, Nacka-Soeder Hospital, Stockholm (Sweden); Zyto, K. [Dept. of Orthopaedics, Nacka-Soeder Hospital, Stockholm (Sweden)

    1999-07-01

    The aim of this study was to describe and evaluate an alternative MR assessment procedure for analysis of unstable shoulders. Twelve patients with unilateral recurrent anterior shoulder dislocation had both shoulders examined. Magnetic resonance imaging was performed with an open-MR system in the apprehension position with the shoulder in 90 of abduction and maximum tolerable external rotation. Contrast enhancement was achieved with intravenous gadolinium. Correlations were made to the findings at operation. In 10 of 12 unstable shoulders the inferior glenohumeral ligament labral complex (IGHLLC) was detached from the glenoid as seen on MR and later verified during surgery. In one shoulder MR was unable to show a capsulolabral detachment that was verified at surgery, whereas in one shoulder both MR and surgical assessment revealed no soft tissue detachment (accuracy 92 %). A Hill-Sachs lesion was visualized and verified in all unstable shoulders, whereas the stable controls revealed normal IGHLLC and no Hill-Sachs lesion. Open-MRI evaluation of the shoulder in the apprehension test position may become a useful tool for the evaluation of anterior shoulder instability. (orig.)

  19. Communicating climate science to high school students in the Arctic: Adventure Learning @ Greenland

    Science.gov (United States)

    Hougham, R. J.; Miller, B.; Cox, C. J.

    2012-12-01

    Adventure Learning @ Greenland (AL@GL) engaged high school students in atmospheric research in the Arctic and in local environments to enhance climate literacy. The overarching objective for this project was to support climate literacy in high school students, specifically the concept of energy exchange between the Earth, atmosphere, and space. The goal then is to produce a model of education and outreach for remote STEM research that can be used to meaningfully engage K-12 and public communities. Over the course of the program experience, students conducted scientific inquiry associated with their place that supported a more focused science content at a field location. Approximately 45 students participated in the hybrid learning environments as part of this project at multiple locations in Idaho, USA, and Greenland. In Greenland, the Summit Camp research station located on the Greenland Ice Sheet was the primary location. The AL@GL project provided a compelling opportunity to engage students in an inquiry-based curriculum alongside a cutting-edge geophysical experiment at Summit: the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS) experiment. ICECAPS measures parameters that are closely tied to those identified in student misconceptions. Thus, ICECAPS science and the AL@ approach combined to create a learning environment that was practical, rich, and engaging. Students participating in this project were diverse, rural, and traditionally underrepresented. Groups included: students participating in a field school at Kangerlussuaq, Greenland and Summit Station as members of the JSEP; students at MOSS will were part of the Upward Bound Math Science (UBMS) and HOIST (Helping Orient Indian Students and Teachers) project. These project serve high school students who are first college generation and from low-income families. JSEP is an international group of students from the United States, Greenland, and Denmark

  20. Optimised dispersion management and modulation formats for high speed optical communication systems

    DEFF Research Database (Denmark)

    Tokle, Torger

    2004-01-01

    This thesis studies dispersion management and modulation formats for optical communication systems using per channel bit rates at and above 10 Gbit/s. Novel modulation formats—including recently proposed multilevel phase modulation—are investigated and demonstrated at bit rates up to 80 Gbit/s. New...... system performance. Differential phase shift keying (DPSK) has recently been showed to be a promising modulation format for optical communication. We study DPSK with focus on differential quadrature phase shift keying (DQPSK). In a 12.5 Gbit/s WDM system, we demonstrate the suitability of DQPSK for ultra......-channel system, the optimum pulse width is very narrow. We find that a pulse width equal to 5% of the bit slot results in optimum performance for the system studied here. These narrow RZ pulses offer good receiver sensitivity and excellent tolerance to the nonlinear effect self phase modulation (SPM). However...

  1. The TEDxLSU Student Creative Communications Team: Integrating High-Impact Practices to Increase Engagement, Facilitate Deep Learning, and Advance Communication Skills

    Science.gov (United States)

    Burdette, Rebecca; Galeucia, Annemarie; Liggett, Sarah; Thompson, Melissa

    2016-01-01

    This article provides background on Louisiana State University's Communication across the Curriculum (CxC) program and details the history and logistics of its experiential learning and community outreach event--TEDxLSU. In particular, the authors provide details on the Student Creative Communications Team (SCCT) which conceptualizes, plans, and…

  2. High-Speed Optical Wide-Area Data-Communication Network

    Science.gov (United States)

    Monacos, Steve P.

    1994-01-01

    Proposed fiber-optic wide-area network (WAN) for digital communication balances input and output flows of data with its internal capacity by routing traffic via dynamically interconnected routing planes. Data transmitted optically through network by wavelength-division multiplexing in synchronous or asynchronous packets. WAN implemented with currently available technology. Network is multiple-ring cyclic shuffle exchange network ensuring traffic reaches its destination with minimum number of hops.

  3. RF/optical shared aperture for high availability wideband communication RF/FSO links

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2014-04-29

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  4. RF/optical shared aperture for high availability wideband communication RF/FSO links

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2015-03-24

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  5. High-Speed Optical Wide-Area Data-Communication Network

    Science.gov (United States)

    Monacos, Steve P.

    1994-01-01

    Proposed fiber-optic wide-area network (WAN) for digital communication balances input and output flows of data with its internal capacity by routing traffic via dynamically interconnected routing planes. Data transmitted optically through network by wavelength-division multiplexing in synchronous or asynchronous packets. WAN implemented with currently available technology. Network is multiple-ring cyclic shuffle exchange network ensuring traffic reaches its destination with minimum number of hops.

  6. Low-Noise Free-Running High-Rate Photon-Counting for Space Communication and Ranging

    Science.gov (United States)

    Lu, Wei; Krainak, Michael A.; Yang, Guan; Sun, Xiaoli; Merritt, Scott

    2016-01-01

    We present performance data for low-noise free-running high-rate photon counting method for space optical communication and ranging. NASA GSFC is testing the performance of two types of novel photon-counting detectors 1) a 2x8 mercury cadmium telluride (HgCdTe) avalanche array made by DRS Inc., and a 2) a commercial 2880-element silicon avalanche photodiode (APD) array. We successfully measured real-time communication performance using both the 2 detected-photon threshold and logic AND-gate coincidence methods. Use of these methods allows mitigation of dark count, after-pulsing and background noise effects without using other method of Time Gating The HgCdTe APD array routinely demonstrated very high photon detection efficiencies (50) at near infrared wavelength. The commercial silicon APD array exhibited a fast output with rise times of 300 ps and pulse widths of 600 ps. On-chip individually filtered signals from the entire array were multiplexed onto a single fast output. NASA GSFC has tested both detectors for their potential application for space communications and ranging. We developed and compare their performances using both the 2 detected photon threshold and coincidence methods.

  7. Human activity under high pressure: A case study on fluctuation scaling of air traffic controller's communication behaviors

    Science.gov (United States)

    Wang, Yanjun; Zhang, Qiqian; Zhu, Chenping; Hu, Minghua; Duong, Vu

    2016-01-01

    Recent human dynamics research has unmasked astonishing statistical characteristics such as scaling behaviors in human daily activities. However, less is known about the general mechanism that governs the task-specific activities. In particular, whether scaling law exists in human activities under high pressure remains an open question. In air traffic management system, safety is the most important factor to be concerned by air traffic controllers who always work under high pressure, which provides a unique platform to study human activity. Here we extend fluctuation scaling method to study air traffic controller's communication activity by investigating two empirical communication datasets. Taken the number of controlled flights as the size-like parameter, we show that the relationships between the average communication activity and its standard deviation in both datasets can be well described by Taylor's power law, with scaling exponent α ≈ 0.77 ± 0.01 for the real operational data and α ≈ 0.54 ± 0.01 for the real-time training data. The difference between the exponents suggests that human dynamics under pressure is more likely dominated by the exogenous force. Our findings may lead to further understanding of human behavior.

  8. Implementation of Communicative Approach

    Science.gov (United States)

    Jabeen, Shazi Shah

    2014-01-01

    In the contemporary age of high professional requirements such as excellent communicative skills, the need for successful learning of communicative skills of English language suggests communicative ability to be the goal of language teaching. In other words, to teach English language using communicative approach becomes essential. Studies to…

  9. Design and Experimental Investigation for Improving the High Frequency Radio Communication Links between Benghazi-Libya and Sfax-Tunisia.

    Directory of Open Access Journals (Sweden)

    Mohamed Yousef Ahmed Abou-Hussein

    2014-02-01

    Full Text Available In this study, we have experimentally planned to replicate the positive results of the application of ionospheric prediction method to design and improve the high frequency (HF radio communication links between Benghazi-Libya and Sfax-Tunisia. The central radio propagation laboratory (CRPL method of ionospheric prediction of the National Bureau of Standards (NBS in U.S.A was used in the calculations of the optimal working frequencies for reliable HF radio communication links between Benghazi-Libya and Sfax-Tunisia. The results were drawn in the form of curves by using the computer. The computer was used to measure the received signal level variation of a frequency 17.500 Megahertz (MHz, which was transmitted with a power of 100 Kilowatt (KW from the Tunis Republic Broadcasting station in SFAX city, directed to the east region. The measurements were taken during daytime's for winter (December, January& February and summer (June, July & August seasons.

  10. Study of dual-directional high rate secure communication systems using chaotic multiple-quantum-well lasers

    Institute of Scientific and Technical Information of China (English)

    Yan Sen-Lin

    2007-01-01

    A scheme of synchronized injection multi-quantum-well (MQW) laser system using optical coupling-feedback is presented for performing chaotic dual-directional secure communication. The performance characterization of chaos masking is investigated theoretically, the equation of synchronization demodulation is deduced and its root is also given. Chaos masking encoding with a rate of 5 Gbit/s and a modulation frequency of 1 GHz, chaos modulation with a rate of 0.2 Gbit/s and a modulation frequency of 0.2 GHz and chaos shifting key with a rate of 0.2 Gbit/s are numerically simulated, separately. The ratio of the signal to the absolute synchronous error and the time for achieving synchronous demodulation are analysed in detail. The results illustrate that the system has stronger privacy and good performances so that it can be applied in chaotic dual-directional high rate secure communications.

  11. Technology and Communications Coursework: Facilitating the Progression of Students with Learning Disabilities through High School Science and Math Coursework.

    Science.gov (United States)

    Shifrer, Dara; Callahan, Rebecca

    2010-09-01

    Students identified with learning disabilities experience markedly lower levels of science and mathematics achievement than students who are not identified with a learning disability. Seemingly compounding their disadvantage, students with learning disabilities also complete more credits in non-core coursework-traditionally considered non-academic coursework-than students who are not identified with a learning disability. The Education Longitudinal Study of 2002, a large national dataset with both regular and special education high school students, is utilized to determine whether credit accumulation in certain types of non-core coursework, such as Technology and Communications courses, is associated with improved science and math course-taking outcomes for students with learning disabilities. Results show that credit accumulation in Technology and Communications coursework uniquely benefits the science course-taking, and comparably benefits the math course-taking, of students identified with learning disabilities in contrast to students who are not identified with a learning disability.

  12. A dual communicator and dual grid-resolution algorithm for petascale simulations of turbulent mixing at high Schmidt number

    Science.gov (United States)

    Clay, M. P.; Buaria, D.; Gotoh, T.; Yeung, P. K.

    2017-10-01

    A new dual-communicator algorithm with very favorable performance characteristics has been developed for direct numerical simulation (DNS) of turbulent mixing of a passive scalar governed by an advection-diffusion equation. We focus on the regime of high Schmidt number (S c), where because of low molecular diffusivity the grid-resolution requirements for the scalar field are stricter than those for the velocity field by a factor √{ S c }. Computational throughput is improved by simulating the velocity field on a coarse grid of Nv3 points with a Fourier pseudo-spectral (FPS) method, while the passive scalar is simulated on a fine grid of Nθ3 points with a combined compact finite difference (CCD) scheme which computes first and second derivatives at eighth-order accuracy. A static three-dimensional domain decomposition and a parallel solution algorithm for the CCD scheme are used to avoid the heavy communication cost of memory transposes. A kernel is used to evaluate several approaches to optimize the performance of the CCD routines, which account for 60% of the overall simulation cost. On the petascale supercomputer Blue Waters at the University of Illinois, Urbana-Champaign, scalability is improved substantially with a hybrid MPI-OpenMP approach in which a dedicated thread per NUMA domain overlaps communication calls with computational tasks performed by a separate team of threads spawned using OpenMP nested parallelism. At a target production problem size of 81923 (0.5 trillion) grid points on 262,144 cores, CCD timings are reduced by 34% compared to a pure-MPI implementation. Timings for 163843 (4 trillion) grid points on 524,288 cores encouragingly maintain scalability greater than 90%, although the wall clock time is too high for production runs at this size. Performance monitoring with CrayPat for problem sizes up to 40963 shows that the CCD routines can achieve nearly 6% of the peak flop rate. The new DNS code is built upon two existing FPS and CCD codes

  13. Management of dispersion, nonlinearity and polarization-dependent effects in high-speed reconfigurable WDM fiber optic communication systems

    Science.gov (United States)

    Luo, Ting

    As optical communications approach more data bandwidth, longer transmission distance, and more reconfigurability, dispersion, nonlinearity and polarization-dependent effects are becoming key issues for future all-optical fiber optic systems and networks. For ≥10 Gbit/s optical fiber transmission systems, it is critical that chromatic dispersion and polarization-mode-dispersion be well monitored and compensated using some type of dispersion monitoring and compensation. On the other hand, dispersive and nonlinear effects in optical fiber systems can also be beneficial and have applications on pulse management, all-optical signal processing and network function, which will be essential for high bite-rate optical networks and replacing the expensive optical-electrical-optical (O/E/O) conversion. In this Ph.D. dissertation, we present a detailed research on dispersion, nonlinearity, and polarization-dependent effects in high-speed optical communication systems. We have demonstrated: (i) A dynamic channel-spacing tunable multi-wavelength Erbium-doped fiber laser; (ii) Chromatic-dispersion-insensitive PMD monitoring by tracking the radio-frequency extracted from the vestigial-sideband; (iii) A method for simultaneous chromatic and polarization-mode dispersions monitoring by adding a frequency-shifted carrier; (iv) Polarization-insensitive optical parametric amplification by depolarizing the pump; (v) All optical chromatic dispersion monitoring potential for ultra-high speed (>40 Gbit/s) optical systems using cross-phase modulation in a highly nonlinear fiber; (vi) A novel fiber-based autocorrelator using polarimetric four-wave mixing effect and a tunable differential-group-delay element; (vii) A simple all-fiber-based autocorrelator by measuring the degree-of-polarization; and (viii) Reduction of pattern dependent data distortion in a stimulated Brillouin scattering based slow light element. These techniques will play key roles in future high-speed dynamic WDM optical

  14. High efficiency, long life traveling wave tubes for future communications satellites

    Science.gov (United States)

    Dayton, J. A., Jr.

    1988-01-01

    Electron beam devices, primarily traveling wave tubes (TWTs), have been used as the power amplifiers in almost all space communications and data transmission systems. Based on the technology that is presently available and the expected success of current research efforts, it is reasonable to predict the development of a new class of microwave TWTs with efficiencies in excess of 60 percent and lifetimes of at least ten years. Because of this rapid advance of technology, the TWT is expected to remain the dominant device for power amplifiers in space.

  15. A high-speed Schottky detector for ultra-wideband communications

    DEFF Research Database (Denmark)

    Valdecasa, Guillermo Silva; Cimoli, Bruno; Blanco Granja, Ángel;

    2017-01-01

    of the detector performance. The designed circuit is reviewed and measurements are provided for a manufactured prototype. The detector can successfully demodulate 2.5 Gbps video signals around a 7 GHz carrier. The bitrate to carrier frequency ratio of 35.7% is the highest reported for detectors at UWB frequencies......This letter reviews the design procedure of a high‐speed Schottky video detector for high‐data‐rate communications within the ultra‐wideband (UWB) frequencies. The classic design approach for video detectors is extended with a mixer‐like analysis, which results in a more detailed assessment...

  16. Music regulators in two string quartet ensembles: a comparison of communicative behaviours between low- and high-stress performance conditions

    Directory of Open Access Journals (Sweden)

    Michele Biasutti

    2016-08-01

    Full Text Available In ensemble performances, group members use particular bodily behaviours as a sort of language to supplement the lack of verbal communication. This research study focuses on music regulators, which are defined as signs to other group members for coordinating performance. The following two music regulators are considered: body gestures for articulating attacks (a set of movements externally directed that are used to signal entrances in performance and eye contacts. These regulators are recurring observable behaviors that play an important role in nonverbal communication among ensemble members. To understand how these regulators are used by chamber musicians, video recordings of members of two string quartet ensemble performances (Quartet Ensemble A performing Bartók and Quartet Ensemble B performing Haydn were analysed under two conditions: a low stress performance (LSP, undertaken in a rehearsal setting, and a high stress performance (HSP during a live concert. The results provide evidence for more emphasis in gestures for articulating attacks (i.e. the perceived strength of a performed attack-type body gestures during HSP than LSP. . Conversely, no significant differences were found for the frequency of eye contact between HSP and LSP. Moreover, there was variability in eye contacts during HSP and LSP, showing that these behaviours are less standardised and may change according to idiosyncratic performing conditions. Educational implications are discussed for improving interpersonal communication skills during ensemble performance.

  17. High-dimensional structured light coding/decoding for free-space optical communications free of obstructions.

    Science.gov (United States)

    Du, Jing; Wang, Jian

    2015-11-01

    Bessel beams carrying orbital angular momentum (OAM) with helical phase fronts exp(ilφ)(l=0;±1;±2;…), where φ is the azimuthal angle and l corresponds to the topological number, are orthogonal with each other. This feature of Bessel beams provides a new dimension to code/decode data information on the OAM state of light, and the theoretical infinity of topological number enables possible high-dimensional structured light coding/decoding for free-space optical communications. Moreover, Bessel beams are nondiffracting beams having the ability to recover by themselves in the face of obstructions, which is important for free-space optical communications relying on line-of-sight operation. By utilizing the OAM and nondiffracting characteristics of Bessel beams, we experimentally demonstrate 12 m distance obstruction-free optical m-ary coding/decoding using visible Bessel beams in a free-space optical communication system. We also study the bit error rate (BER) performance of hexadecimal and 32-ary coding/decoding based on Bessel beams with different topological numbers. After receiving 500 symbols at the receiver side, a zero BER of hexadecimal coding/decoding is observed when the obstruction is placed along the propagation path of light.

  18. Music Regulators in Two String Quartets: A Comparison of Communicative Behaviors between Low- and High-Stress Performance Conditions

    Science.gov (United States)

    Biasutti, Michele; Concina, Eleonora; Wasley, David; Williamon, Aaron

    2016-01-01

    In ensemble performances, group members use particular bodily behaviors as a sort of “language” to supplement the lack of verbal communication. This article focuses on music regulators, which are defined as signs to other group members for coordinating performance. The following two music regulators are considered: body gestures for articulating attacks (a set of movements externally directed that are used to signal entrances in performance) and eye contact. These regulators are recurring observable behaviors that play an important role in non-verbal communication among ensemble members. To understand how they are used by chamber musicians, video recordings of two string quartet performances (Quartet A performing Bartók and Quartet B performing Haydn) were analyzed under two conditions: a low stress performance (LSP), undertaken in a rehearsal setting, and a high stress performance (HSP) during a public recital. The results provide evidence for more emphasis in gestures for articulating attacks (i.e., the perceived strength of a performed attack-type body gesture) during HSP than LSP. Conversely, no significant differences were found for the frequency of eye contact between HSP and LSP. Moreover, there was variability in eye contact during HSP and LSP, showing that these behaviors are less standardized and may change according to idiosyncratic performance conditions. Educational implications are discussed for improving interpersonal communication skills during ensemble performance. PMID:27610089

  19. Music Regulators in Two String Quartets: A Comparison of Communicative Behaviors between Low- and High-Stress Performance Conditions.

    Science.gov (United States)

    Biasutti, Michele; Concina, Eleonora; Wasley, David; Williamon, Aaron

    2016-01-01

    In ensemble performances, group members use particular bodily behaviors as a sort of "language" to supplement the lack of verbal communication. This article focuses on music regulators, which are defined as signs to other group members for coordinating performance. The following two music regulators are considered: body gestures for articulating attacks (a set of movements externally directed that are used to signal entrances in performance) and eye contact. These regulators are recurring observable behaviors that play an important role in non-verbal communication among ensemble members. To understand how they are used by chamber musicians, video recordings of two string quartet performances (Quartet A performing Bartók and Quartet B performing Haydn) were analyzed under two conditions: a low stress performance (LSP), undertaken in a rehearsal setting, and a high stress performance (HSP) during a public recital. The results provide evidence for more emphasis in gestures for articulating attacks (i.e., the perceived strength of a performed attack-type body gesture) during HSP than LSP. Conversely, no significant differences were found for the frequency of eye contact between HSP and LSP. Moreover, there was variability in eye contact during HSP and LSP, showing that these behaviors are less standardized and may change according to idiosyncratic performance conditions. Educational implications are discussed for improving interpersonal communication skills during ensemble performance.

  20. Chemical communication of antibiotic resistance by a highly resistant subpopulation of bacterial cells.

    Directory of Open Access Journals (Sweden)

    Omar M El-Halfawy

    Full Text Available The overall antibiotic resistance of a bacterial population results from the combination of a wide range of susceptibilities displayed by subsets of bacterial cells. Bacterial heteroresistance to antibiotics has been documented for several opportunistic Gram-negative bacteria, but the mechanism of heteroresistance is unclear. We use Burkholderia cenocepacia as a model opportunistic bacterium to investigate the implications of heterogeneity in the response to the antimicrobial peptide polymyxin B (PmB and also other bactericidal antibiotics. Here, we report that B. cenocepacia is heteroresistant to PmB. Population analysis profiling also identified B. cenocepacia subpopulations arising from a seemingly homogenous culture that are resistant to higher levels of polymyxin B than the rest of the cells in the culture, and can protect the more sensitive cells from killing, as well as sensitive bacteria from other species, such as Pseudomonas aeruginosa and Escherichia coli. Communication of resistance depended on upregulation of putrescine synthesis and YceI, a widely conserved low-molecular weight secreted protein. Deletion of genes for the synthesis of putrescine and YceI abrogate protection, while pharmacologic inhibition of putrescine synthesis reduced resistance to polymyxin B. Polyamines and YceI were also required for heteroresistance of B. cenocepacia to various bactericidal antibiotics. We propose that putrescine and YceI resemble "danger" infochemicals whose increased production by a bacterial subpopulation, becoming more resistant to bactericidal antibiotics, communicates higher level of resistance to more sensitive members of the population of the same or different species.

  1. Novel NoC Topology Construction for High-Performance Communications

    Directory of Open Access Journals (Sweden)

    P. Ezhumalai

    2011-01-01

    Full Text Available Different intellectual property (IP cores, including processor and memory, are interconnected to build a typical system-on-chip (SoC architecture. Larger SoC designs dictate the data communication to happen over the global interconnects. Network-on-Chip(NoC architectures have been proposed as a scalable solution to the global communication challenges in nanoscale systems-on-chip (SoC design. We proposed an idea on building customizing synthesis network—on-chip with the better flow partitioning and also considered power and area reduction as compared to the already presented regular topologies. Hence to improve the performance of SoC, first, we did a performance study of regular interconnect topologies MESH, TORUS, BFT and EBFT, we observed that the overall latency and throughput of the EBFT is better compared to other topologies, The next best in case of latency and throughput is BFT. Experimental results on a variety of NoC benchmarks showed that our synthesis results were achieved reduction in power consumption and average hop count over custom topology implementation.

  2. The Effectiveness of a Program Based on the Combination of Relevance and Confidence Motivational Strategies in Developing EFL Argumentative Writing Skills and Overcoming Writing Apprehension among Students Teachers at Faculty of Education

    Science.gov (United States)

    Ahmed Helwa, Hasnaa Sabry Abdel-Hamid

    2014-01-01

    The aim of this research is to investigate the effectiveness of a program based on the combination of relevance and confidence motivational strategies in developing EFL argumentative writing skills and overcoming writing apprehension among students teachers at Faculty of Education. The design of the research is a mixed research methodology. It…

  3. Indirect MR arthrography of anterior shoulder instability in the ABER and the apprehension test positions: a prospective comparative study of two different shoulder positions during MRI using intravenous gadodiamide contrast for enhancement of the joint fluid

    Energy Technology Data Exchange (ETDEWEB)

    Wintzell, G.; Larsson, S. [Uppsala University Hospital (Sweden). Dept. of Orthopaedics; Larsson, H. [Nacka-Soeder Hospital, Stockholm (Sweden). Dept. of Radiology

    1998-09-01

    The value of MRI for the evaluation of anterior shoulder instability can be enhanced by shoulder positions that stress the stabilising structures. The ABER position is one that has been described in combination with intra-articular gadopentetate dimeglumine arthrography. We believe that MRI in the Apprehension test position with 90 abduction and maximal tolerable external rotation provides maximum tension on the anterior stabilising structures and with this technique it is sufficient to use indirect gadodiamide arthrography following intravenous injection of the contrast medium. The purpose of this study was to make a prospective comparative evaluation of the ABER and Apprehension test positions when using indirect arthrography with intravenous gadodiamide administration in shoulders with anterior instability. Results. Both the ABER and the Apprehension test position were useful techniques in detecting capsulolabral pathology and Hill-Sachs lesions. The Apprehension test position produced significantly better gadodiamide-enhanced joint fluid in the region of pathology in both the capsulolabral lesion and the Hill-Sachs lesion. It also visualised the size of the Hill-Sachs lesion significantly better than did the ABER position. (orig.)

  4. The Use of Virtual Characters to Assess and Train Non-Verbal Communication in High-Functioning Autism

    Science.gov (United States)

    Georgescu, Alexandra Livia; Kuzmanovic, Bojana; Roth, Daniel; Bente, Gary; Vogeley, Kai

    2014-01-01

    High-functioning autism (HFA) is a neurodevelopmental disorder, which is characterized by life-long socio-communicative impairments on the one hand and preserved verbal and general learning and memory abilities on the other. One of the areas where particular difficulties are observable is the understanding of non-verbal communication cues. Thus, investigating the underlying psychological processes and neural mechanisms of non-verbal communication in HFA allows a better understanding of this disorder, and potentially enables the development of more efficient forms of psychotherapy and trainings. However, the research on non-verbal information processing in HFA faces several methodological challenges. The use of virtual characters (VCs) helps to overcome such challenges by enabling an ecologically valid experience of social presence, and by providing an experimental platform that can be systematically and fully controlled. To make this field of research accessible to a broader audience, we elaborate in the first part of the review the validity of using VCs in non-verbal behavior research on HFA, and we review current relevant paradigms and findings from social-cognitive neuroscience. In the second part, we argue for the use of VCs as either agents or avatars in the context of “transformed social interactions.” This allows for the implementation of real-time social interaction in virtual experimental settings, which represents a more sensitive measure of socio-communicative impairments in HFA. Finally, we argue that VCs and environments are a valuable assistive, educational and therapeutic tool for HFA. PMID:25360098

  5. An evaluation of multiple-schedule variations to reduce high-rate requests in the picture exchange communication system.

    Science.gov (United States)

    Landa, Robin; Hanley, Gregory P

    2016-06-01

    Using procedures similar to those of Tiger, Hanley, and Heal (2006), we compared two multiple-schedule variations (S+/S- and S+ only) to treat high-rate requests for edible items in the Picture Exchange Communication System (PECS). Two individuals with autism participated, after they showed persistent requests for edible items after PECS training. Stimulus control was achieved only with the multiple schedule that involved presentation of a discriminative stimulus during reinforcement components and its removal during extinction components (S+ only). Discriminated requests were maintained for the 1 participant who experienced schedule thinning. © 2016 Society for the Experimental Analysis of Behavior.

  6. Cognitive radio networks efficient resource allocation in cooperative sensing, cellular communications, high-speed vehicles, and smart grid

    CERN Document Server

    Jiang, Tao; Cao, Yang

    2015-01-01

    PrefaceAcknowledgmentsAbout the AuthorsIntroductionCognitive Radio-Based NetworksOpportunistic Spectrum Access NetworksCognitive Radio Networks with Cooperative SensingCognitive Radio Networks for Cellular CommunicationsCognitive Radio Networks for High-Speed VehiclesCognitive Radio Networks for a Smart GridContent and OrganizationTransmission Slot Allocation in an Opportunistic Spectrum Access NetworkSingle-User Single-Channel System ModelProbabilistic Slot Allocation SchemeOptimal Probabilistic Slot AllocationBaseline PerformanceExponential DistributionHyper-Erlang DistributionPerformance An

  7. Analytical Estimation of Carrier Phase Recovery Approaches in Long-Haul High-Speed Optical Communication Systems

    CERN Document Server

    Xu, Tianhua

    2016-01-01

    The analytical study on the carrier phase estimation (CPE) approaches, involving a one-tap normalized least-mean-square (NLMS) algorithm, a block-wise average (BWA) algorithm, and a Viterbi-Viterbi (VV) algorithm has been investigated in the long-haul high-speed n-level phase shift keying (n-PSK) coherent optical fiber communication systems. The close-form predictions for the bit-error-rate (BER) performance have been derived and analyzed by considering both the intrinsic laser phase noise and the equalization enhanced phase noise (EEPN).

  8. High-Rate Communications Outage Recorder Operations for Optimal Payload and Science Telemetry Management Onboard the International Space Station

    Science.gov (United States)

    Shell, Michael T.; McElyea, Richard M. (Technical Monitor)

    2002-01-01

    All International Space Station (ISS) Ku-band telemetry transmits through the High-Rate Communications Outage Recorder (HCOR). The HCOR provides the recording and playback capability for all payload, science, and International Partner data streams transmitting through NASA's Ku-band antenna system. The HCOR is a solid-state memory recorder that provides recording capability to record all eight ISS high-rate data during ISS Loss-of-Signal periods. NASA payloads in the Destiny module are prime users of the HCOR; however, NASDA and ESA will also utilize the HCOR for data capture and playback of their high data rate links from the Kibo and Columbus modules. Marshall Space Flight Center's Payload Operations Integration Center manages the HCOR for nominal functions, including system configurations and playback operations. The purpose of this paper is to present the nominal operations plan for the HCOR and the plans for handling contingency operations affecting payload operations. In addition, the paper will address HCOR operation limitations and the expected effects on payload operations. The HCOR is manifested for ISS delivery on flight 9A with the HCOR backup manifested on flight 11A. The HCOR replaces the Medium-Rate Communications Outage Recorder (MCOR), which has supported payloads since flight 5A.1.

  9. Long-range high-speed visible light communication system over 100-m outdoor transmission utilizing receiver diversity technology

    Science.gov (United States)

    Wang, Yiguang; Huang, Xingxing; Shi, Jianyang; Wang, Yuan-quan; Chi, Nan

    2016-05-01

    Visible light communication (VLC) has no doubt become a promising candidate for future wireless communications due to the increasing trends in the usage of light-emitting diodes (LEDs). In addition to indoor high-speed wireless access and positioning applications, VLC usage in outdoor scenarios, such as vehicle networks and intelligent transportation systems, are also attracting significant interest. However, the complex outdoor environment and ambient noise are the key challenges for long-range high-speed VLC outdoor applications. To improve system performance and transmission distance, we propose to use receiver diversity technology in an outdoor VLC system. Maximal ratio combining-based receiver diversity technology is utilized in two receivers to achieve the maximal signal-to-noise ratio. A 400-Mb/s VLC transmission using a phosphor-based white LED and a 1-Gb/s wavelength division multiplexing VLC transmission using a red-green-blue LED are both successfully achieved over a 100-m outdoor distance with the bit error rate below the 7% forward error correction limit of 3.8×10-3. To the best of our knowledge, this is the highest data rate at 100-m outdoor VLC transmission ever achieved. The experimental results clearly prove the benefit and feasibility of receiver diversity technology for long-range high-speed outdoor VLC systems.

  10. Inhibition of intercellular communication by condensates of high and low tar cigarettes

    DEFF Research Database (Denmark)

    Vang, Ole; Wallin, Håkan; Autrup, Herman

    1995-01-01

    Inhibition of gap junctional intercellular communication (GJIC) is a predictive short term test for tumor promoting activity. A new metabolic cooperation assay has been developed, which takes the cytochrome P-450 metabolism into account. In this assay the inhibitory activity of tobacco smoke cond...... that compounds in the CSC act strongly synergistically. Furthermore, CSC and CSC fractions synergistically inhibit GJIC with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate, indicating different mechanisms of action....... no effect. The effect was only marginally greater in cells expressing different cytochrome P-450 enzymes, indicating that the active substances are not metabolized by these enzymes. The activities of CSC fractions were considerably lower than the activities in the unfractionated CSC. This may indicate...

  11. A Study of an Optical Lunar Surface Communications Network with High Bandwidth Direct to Earth Link

    Science.gov (United States)

    Wilson, K.; Biswas, A.; Schoolcraft, J.

    2011-01-01

    Analyzed optical DTE (direct to earth) and lunar relay satellite link analyses, greater than 200 Mbps downlink to 1-m Earth receiver and greater than 1 Mbps uplink achieved with mobile 5-cm lunar transceiver, greater than 1Gbps downlink and greater than 10 Mpbs uplink achieved with 10-cm stationary lunar transceiver, MITLL (MIT Lincoln Laboratory) 2013 LLCD (Lunar Laser Communications Demonstration) plans to demonstrate 622 Mbps downlink with 20 Mbps uplink between lunar orbiter and ground station; Identified top five technology challenges to deploying lunar optical network, Performed preliminary experiments on two of challenges: (i) lunar dust removal and (ii)DTN over optical carrier, Exploring opportunities to evaluate DTN (delay-tolerant networking) over optical link in a multi-node network e.g. Desert RATS.

  12. Results of innovative communication processes on productivity gains in a high technology environment

    Science.gov (United States)

    Kelly, B. J.

    1985-01-01

    The technology which resulted in performance breakthroughs at engineering and management services is discussed. As a result of the innovative approaches of communicating productivity concepts to the employees, specific outcomes can now be pinpointed at all levels of the organization such as: (1) employee-headed program; (2) performance feedback processes; and (3) an investigative approach to creating leadership. The Lockheed Corporation began the innovative trend in 1974 when they became the first company to introduce quality circles in America. Although some of Lockheed-EMSCO's processes may sound different from traditional improvement processes, the context out of which those to be presented evolved has sustained more than 10 years of positive results through employee involvement activities.

  13. Photonic Integrated Circuits for Cost-Effective, High Port Density, and Higher Capacity Optical Communications Systems

    Science.gov (United States)

    Chiappa, Pierangelo

    Bandwidth-hungry services, such as higher speed Internet, voice over IP (VoIP), and IPTV, allow people to exchange and store huge amounts of data among worldwide locations. In the age of global communications, domestic users, companies, and organizations around the world generate new contents making bandwidth needs grow exponentially, along with the need for new services. These bandwidth and connectivity demands represent a concern for operators who require innovative technologies to be ready for scaling. To respond efficiently to these demands, Alcatel-Lucent is fast moving toward photonic integration circuits technologies as the key to address best performances at the lowest "bit per second" cost. This article describes Alcatel-Lucent's contribution in strategic directions or achievements, as well as possible new developments.

  14. A good performance watermarking LDPC code used in high-speed optical fiber communication system

    Science.gov (United States)

    Zhang, Wenbo; Li, Chao; Zhang, Xiaoguang; Xi, Lixia; Tang, Xianfeng; He, Wenxue

    2015-07-01

    A watermarking LDPC code, which is a strategy designed to improve the performance of the traditional LDPC code, was introduced. By inserting some pre-defined watermarking bits into original LDPC code, we can obtain a more correct estimation about the noise level in the fiber channel. Then we use them to modify the probability distribution function (PDF) used in the initial process of belief propagation (BP) decoding algorithm. This algorithm was tested in a 128 Gb/s PDM-DQPSK optical communication system and results showed that the watermarking LDPC code had a better tolerances to polarization mode dispersion (PMD) and nonlinearity than that of traditional LDPC code. Also, by losing about 2.4% of redundancy for watermarking bits, the decoding efficiency of the watermarking LDPC code is about twice of the traditional one.

  15. High-capacity quantum secure direct communication using hyper-entanglement of photonic qubits

    Science.gov (United States)

    Cai, Jiarui; Pan, Ziwen; Wang, Tie-Jun; Wang, Sihai; Wang, Chuan

    2016-11-01

    Hyper-entanglement is a system constituted by photons entangled in multiple degrees of freedom (DOF), being considered as a promising way of increasing channel capacity and guaranteeing powerful eavesdropping safeguard. In this work, we propose a coding scheme based on a 3-particle hyper-entanglement of polarization and orbital angular momentum (OAM) system and its application as a quantum secure direct communication (QSDC) protocol. The OAM values are specially encoded by Fibonacci sequence and the polarization carries information by defined unitary operations. The internal relations of the secret message enhances security due to principle of quantum mechanics and Fibonacci sequence. We also discuss the coding capacity and security property along with some simulation results to show its superiority and extensibility.

  16. A Study of High-context and Low-context Communication——A Case Study of Chinese and American Everyday Communications

    Institute of Scientific and Technical Information of China (English)

    陈晓远

    2008-01-01

    The paper attempts to use case study to help people know the differences between China,the high-context cuhure and the us,the low-context culture.The aim is to find out the different ways members of the culture group behaye in everyday communications,which embodies and is embodied by low context or high context and to smooth intercultural communications.

  17. The ALMA high speed optical communication link is here: an essential component for reliable present and future operations

    Science.gov (United States)

    Filippi, G.; Ibsen, J.; Jaque, S.; Liello, F.; Ovando, N.; Astudillo, A.; Parra, J.; Saldias, Christian

    2016-07-01

    Announced in 2012, started in 2013 and completed in 2015, the ALMA high bandwidth communication system has become a key factor to achieve the operational and scientific goals of ALMA. This paper summarizes the technical, organizational, and operational goals of the ALMA Optical Link Project, focused in the creation and operation of an effective and sustainable communication infrastructure to connect the ALMA Operations Support Facility and Array Operations Site, both located in the Atacama Desert in the Northern region of Chile, with the point of presence of REUNA in Antofagasta, about 400km away, and from there to the Santiago Central Office in the Chilean capital through the optical infrastructure created by the EC-funded EVALSO project and now an integral part of the REUNA backbone. This new infrastructure completed in 2014 and now operated on behalf of ALMA by REUNA, the Chilean National Research and Education Network, uses state of the art technologies, like dark fiber from newly built cables and DWDM transmission, allowing extending the reach of high capacity communication to the remote region where the Observatory is located. The paper also reports on the results obtained during the first year and a half testing and operation period, where different operational set ups have been experienced for data transfer, remote collaboration, etc. Finally, the authors will present a forward look of the impact of it to both the future scientific development of the Chajnantor Plateau, where many installations area are (and will be) located, as well as the potential Chilean scientific backbone long term development.

  18. Determining Change in Students' Writing Apprehension Scores in a Writing Intensive Course: A Pre-Test, Post-Test Design

    Science.gov (United States)

    Fischer, Laura M.; Meyers, Courtney

    2017-01-01

    Writing skills are one of the most important skills college graduates need to possess; however, college graduates struggle to complete written communications proficiently in the workforce. Previous researchers have explained that college instructors must understand the students' fears with writing in order to create effective writing curriculum.…

  19. Ultrabroad linewidth orange-emitting nanowires LED for high CRI laser-based white lighting and gigahertz communications.

    Science.gov (United States)

    Janjua, Bilal; Ng, Tien Khee; Zhao, Chao; Oubei, Hassan Makine; Shen, Chao; Prabaswara, Aditya; Alias, Mohd Sharizal; Alhamoud, Abdullah Ali; Alatawi, Abdullah Awaad; Albadri, Abdulrahman M; Alyamani, Ahmed Y; El-Desouki, Munir M; Ooi, Boon S

    2016-08-22

    Group-III-nitride laser diode (LD)-based solid-state lighting device has been demonstrated to be droop-free compared to light-emitting diodes (LEDs), and highly energy-efficient compared to that of the traditional incandescent and fluorescent white light systems. The YAG:Ce3+ phosphor used in LD-based solid-state lighting, however, is associated with rapid degradation issue. An alternate phosphor/LD architecture, which is capable of sustaining high temperature, high power density, while still intensity- and bandwidth-tunable for high color-quality remained unexplored. In this paper, we present for the first time, the proof-of-concept of the generation of high-quality white light using an InGaN-based orange nanowires (NWs) LED grown on silicon, in conjunction with a blue LD, and in place of the compound-phosphor. By changing the relative intensities of the ultrabroad linewidth orange and narrow-linewidth blue components, our LED/LD device architecture achieved correlated color temperature (CCT) ranging from 3000 K to above 6000K with color rendering index (CRI) values reaching 83.1, a value unsurpassed by the YAG-phosphor/blue-LD counterpart. The white-light wireless communications was implemented using the blue LD through on-off keying (OOK) modulation to obtain a data rate of 1.06 Gbps. We therefore achieved the best of both worlds when orange-emitting NWs LED are utilized as "active-phosphor", while blue LD is used for both color mixing and optical wireless communications.

  20. Ultrabroad linewidth orange-emitting nanowires LED for high CRI laser-based white lighting and gigahertz communications

    KAUST Repository

    Janjua, Bilal

    2016-08-10

    Group-III-nitride laser diode (LD)-based solid-state lighting device has been demonstrated to be droop-free compared to light-emitting diodes (LEDs), and highly energy-efficient compared to that of the traditional incandescent and fluorescent white light systems. The YAG:Ce3+ phosphor used in LD-based solid-state lighting, however, is associated with rapid degradation issue. An alternate phosphor/LD architecture, which is capable of sustaining high temperature, high power density, while still intensity- and bandwidth-tunable for high color-quality remained unexplored. In this paper, we present for the first time, the proof-of-concept of the generation of high-quality white light using an InGaN-based orange nanowires (NWs) LED grown on silicon, in conjunction with a blue LD, and in place of the compound-phosphor. By changing the relative intensities of the ultrabroad linewidth orange and narrow-linewidth blue components, our LED/LD device architecture achieved correlated color temperature (CCT) ranging from 3000 K to above 6000K with color rendering index (CRI) values reaching 83.1, a value unsurpassed by the YAG-phosphor/blue-LD counterpart. The white-light wireless communications was implemented using the blue LD through on-off keying (OOK) modulation to obtain a data rate of 1.06 Gbps. We therefore achieved the best of both worlds when orange-emitting NWs LED are utilized as “active-phosphor”, while blue LD is used for both color mixing and optical wireless communications.

  1. Adolescent-parent communication on sexual and reproductive health issues among high school students in Dire Dawa, Eastern Ethiopia: a cross sectional study.

    Science.gov (United States)

    Ayalew, Mulatuwa; Mengistie, Bezatu; Semahegn, Agumasie

    2014-11-07

    Sexual and reproductive health communications are most likely promoting healthy sexual development and reduce sexual risks. Communication is the principal means for parents to transmit sexual values, beliefs, expectations and knowledge to their adolescents. However, there is a paucity of evidence about adolescent parent communication in Ethiopia. This study aimed to determine adolescent-parent communication on sexual and reproductive health issues and associated factors among high school students in Dire Dawa, Eastern Ethiopia. Institution based cross sectional study was conducted among high school students in Dire Dawa administrative council from February to March 2011. Simple random sampling technique was used to select 695 students from 9-12 grades. Qualitative data were collected through focus group discussion separately for female and male parents. Data were entered in Epi info version 3.5.1 and analyzed by SPSS version 16.1. Logistic regression with OR and 95% confidence interval was used to identify the independent predictors of adolescent parent communication. Thirty seven percent of students had ever discussed on at least two sexual and reproductive health topics with their parents. Of which, majority of student preferred to discuss with their peers than parent. Condom use during first intercourse was associated with having communication about sexual and reproductive health [AOR=1.9, 95% CI: 1.0, 3.8]. Cultural taboo, shame and lack of communication skill were reasons that hinder communication between parent and adolescent about sexual matters. Communication on sexual and reproductive health issue between adolescent and their parent was low. School based education is important to improve adolescent parent communication about sexual and reproductive health issues.

  2. Knowledge of communicable and noncommunicable diseases among Karen ethnic high school students in rural Thasongyang, the far northwest of Thailand

    Directory of Open Access Journals (Sweden)

    Lorga T

    2013-07-01

    Full Text Available Thaworn Lorga,1 Myo Nyein Aung,1,2 Prissana Naunboonruang,1 Piyatida Junlapeeya,1 Apiradee Payaprom31Boromarajonani College of Nursing Nakhon Lampang (BCNLP, Lampang, Thailand; 2Department of Public Health, Graduate School of Medicine, Juntendo University, Tokyo, Japan; 3Thasongyang Hospital, Thasongyang, Tak, ThailandBackground: The double burden of communicable and noncommunicable diseases (NCD is an increasing trend in low- and-middle income developing countries. Rural and minority populations are underserved and likely to be affected severely by these burdens. Knowledge among young people could provide immunity to such diseases within a community in the long term. In this study we aimed to assess the knowledge of several highly prevalent NCDs (diabetes, hypertension, and chronic obstructive pulmonary disease [COPD] and several highly incident communicable diseases (malaria and diarrheal diseases among Karen high school students in a rural district in far northwest of Thailand. The aim of the study is to explore information for devising life-course health education that will be strategically based in schools.Method: A cross-sectional survey approved by the ethics committee of Boromarajonani College of Nursing Nakhon Lampang (BCNLP, Lampang, Thailand was conducted in Thasongyang, Tak province, from September 2011 to January 2012. Questionnaires for assessing knowledge regarding diabetes, hypertension, COPD, malaria, and diarrheal diseases were delivered to all 457 Karen high school students attending Thasongyang high school. A total of 371 students returned the questionnaires. Experts' validation and split-half reliability assessment was applied to the instrument.Results: Students' main sources of health information were their teachers (62%, health care workers (60%, television (59%, and parents (54%. Familial risk factors of diabetes and hypertension were not known to more than two thirds of the students. Except obesity and physical

  3. Design and development of high linearity millimeter wave traveling-wave tube for satellite communications

    Institute of Scientific and Technical Information of China (English)

    何俊; 黄明光; 李现霞; 李海强; 赵磊; 赵建东; 李跃; 赵石雷

    2015-01-01

    The linearity of the traveling-wave tube is a very important characteristic for a modern communication system. To improve the linearity of the traveling-wave tube at no expense of the saturated output power and overall efficiency, a modified pitch profile combined with a small adjustment of operating parameters is proposed. The optimal design of the helix circuit is evaluated theoretically by a large signal analysis, and the experimental test is also carried out to make a comparison of performance between the novel and original designed traveling-wave tubes. The experiments show that the saturated output powers and efficiencies of these two tubes are close to each other, while the linearity of the traveling-wave tube is obviously improved. The total phase shift and AM/PM conversion at saturation of the novel tube, averaged over the operating band, are only 30.6◦/dB and 2.5◦/dB, respectively, which are 20.1◦/dB and 1.6◦/dB lower than those of the original tube, respectively. Moreover, the third-order intermodulation of the novel tube is up to 2.2 dBc lower than that of the original tube.

  4. High-capacity millimetre-wave communications with orbital angular momentum multiplexing.

    Science.gov (United States)

    Yan, Yan; Xie, Guodong; Lavery, Martin P J; Huang, Hao; Ahmed, Nisar; Bao, Changjing; Ren, Yongxiong; Cao, Yinwen; Li, Long; Zhao, Zhe; Molisch, Andreas F; Tur, Moshe; Padgett, Miles J; Willner, Alan E

    2014-09-16

    One property of electromagnetic waves that has been recently explored is the ability to multiplex multiple beams, such that each beam has a unique helical phase front. The amount of phase front 'twisting' indicates the orbital angular momentum state number, and beams with different orbital angular momentum are orthogonal. Such orbital angular momentum based multiplexing can potentially increase the system capacity and spectral efficiency of millimetre-wave wireless communication links with a single aperture pair by transmitting multiple coaxial data streams. Here we demonstrate a 32-Gbit s(-1) millimetre-wave link over 2.5 metres with a spectral efficiency of ~16 bit s(-1) Hz(-1) using four independent orbital-angular momentum beams on each of two polarizations. All eight orbital angular momentum channels are recovered with bit-error rates below 3.8 × 10(-3). In addition, we demonstrate a millimetre-wave orbital angular momentum mode demultiplexer to demultiplex four orbital angular momentum channels with crosstalk less than -12.5 dB and show an 8-Gbit s(-1) link containing two orbital angular momentum beams on each of two polarizations.

  5. Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications

    Science.gov (United States)

    Ren, Yongxiong; Li, Long; Wang, Zhe; Kamali, Seyedeh Mahsa; Arbabi, Ehsan; Arbabi, Amir; Zhao, Zhe; Xie, Guodong; Cao, Yinwen; Ahmed, Nisar; Yan, Yan; Liu, Cong; Willner, Asher J.; Ashrafi, Solyman; Tur, Moshe; Faraon, Andrei; Willner, Alan E.

    2016-09-01

    To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we show up to a 40-Gbit/s link by multiplexing and transmitting four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one at 520 nm for 1-Gbit/s/beam; we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the 40-Gbit/s link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the 4-Gbit/s link, a green laser diode is directly modulated. Finally, we show that inter-channel crosstalk induced by thermal gradients can be mitigated using multi-channel equalisation processing.

  6. Thermal stability enhanced ZDSF proposal for ultra high-speed long haul communication systems

    Science.gov (United States)

    Makouei, S.; Makouei, F.

    2017-04-01

    In this article, thermal stability enhanced triangular graded-index single-mode zero-dispersion shifted fiber (ZDSF) is designed and the effect of temperature variation on its characteristics is investigated. The zero-dispersion wavelength (λZD) adjustment is accomplished through minimization of the broadening factor at the wavelength of 1.55 μm. The simulation results admit that the dispersion and its slope at 1.55 μm are 0.0051 ps/km/nm and 0.038 ps/km/nm2, respectively. This small slope of the structure results in the bit rate of 133 Gb/s in the 100 km distance. In addition, compared to the bell-shaped electrical mode distribution structures, the proposed structure holds an extended effective area (Aeff), which leads to elimination of the nonlinear effects. The λZD in the designed fiber exhibits a lower thermal coefficient compared to the reports previously presented which provides a better stability. This satisfactory feature is the direct result of small dispersion slope in the introduced structure. Furthermore, a temperature compensation system based on tensile strain induction, for the first time to the best of our knowledge, is proposed that preserves the effective refractive index (neff) profile versus wavelength not only in λZD but also in all communication bands of S+C+L. This accomplishment compensates the temperature impact on parameters such as dispersion and zero-dispersion wavelength.

  7. Compressive sensing based Bayesian sparse channel estimation for OFDM communication systems: high performance and low complexity.

    Science.gov (United States)

    Gui, Guan; Xu, Li; Shan, Lin; Adachi, Fumiyuki

    2014-01-01

    In orthogonal frequency division modulation (OFDM) communication systems, channel state information (CSI) is required at receiver due to the fact that frequency-selective fading channel leads to disgusting intersymbol interference (ISI) over data transmission. Broadband channel model is often described by very few dominant channel taps and they can be probed by compressive sensing based sparse channel estimation (SCE) methods, for example, orthogonal matching pursuit algorithm, which can take the advantage of sparse structure effectively in the channel as for prior information. However, these developed methods are vulnerable to both noise interference and column coherence of training signal matrix. In other words, the primary objective of these conventional methods is to catch the dominant channel taps without a report of posterior channel uncertainty. To improve the estimation performance, we proposed a compressive sensing based Bayesian sparse channel estimation (BSCE) method which cannot only exploit the channel sparsity but also mitigate the unexpected channel uncertainty without scarifying any computational complexity. The proposed method can reveal potential ambiguity among multiple channel estimators that are ambiguous due to observation noise or correlation interference among columns in the training matrix. Computer simulations show that proposed method can improve the estimation performance when comparing with conventional SCE methods.

  8. Submarine Optical Fiber Cable Systems for High Speed Growth Developments in Optical Communication Networks

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-07-01

    Full Text Available Optical Submarine Cable systems play a principal role in international telecommunications, thanks to their superiority over satellite systems in terms of stability, latency and upgradability. The business of constructing and then maintaining and selling capacity over submarine fiber optic cables is fascinating, and is absolutely fundamental to modern day communications. The sector has its own unique challenges due to the extraordinarily rapid pace of development in transmission technologies as well as the timescales and levels of investment required to build new systems. In the present paper, ultimate optical transmission of ultra multi channels huge submarine cables under different depth conditions has been investigated over wide range of the affecting parameters. The double impact of both temperature and pressure is also analyzed. We have employed multiplexing technique namely UW-WDM to be merged number of 10000 transmitted channels on the same submarine optical transmission links respectively. Based on experimental data, both the deep ocean water temperature and pressure are tailored as functions of the water depth. The product of the transmitted bit rate and the repeater spacing is processed over wide ranges of the affecting parameters. As well as we have taken into account the estimation of the total cost planning and transmission data rate capacity of the submarine fiber cable system for this multiplexing technique under study.

  9. Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications

    CERN Document Server

    Ren, Yongxiong; Wang, Zhe; Kamali, Seyedeh Mahsa; Arbabi, Ehsan; Arbabi, Amir; Zhao, Zhe; Xie, Guodong; Cao, Yinwen; Ahmed, Nisar; Yan, Yan; Liu, Cong; Willner, Asher J; Ashrafi, Solyman; Tur, Moshe; Faraon, Andrei; Willner, Alan E

    2016-01-01

    To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we multiplex and transmit four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one at 520 nm for 1-Gbit/s/beam, we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the higher-rate link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the lower rates, a green laser diode is directly modulated. Finally, we s...

  10. Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications

    Science.gov (United States)

    Ren, Yongxiong; Li, Long; Wang, Zhe; Kamali, Seyedeh Mahsa; Arbabi, Ehsan; Arbabi, Amir; Zhao, Zhe; Xie, Guodong; Cao, Yinwen; Ahmed, Nisar; Yan, Yan; Liu, Cong; Willner, Asher J.; Ashrafi, Solyman; Tur, Moshe; Faraon, Andrei; Willner, Alan E.

    2016-01-01

    To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we show up to a 40-Gbit/s link by multiplexing and transmitting four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one at 520 nm for 1-Gbit/s/beam; we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the 40-Gbit/s link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the 4-Gbit/s link, a green laser diode is directly modulated. Finally, we show that inter-channel crosstalk induced by thermal gradients can be mitigated using multi-channel equalisation processing. PMID:27615808

  11. Camp Campus: College Preparation for Adolescents and Young Adults with High-Functioning Autism, Asperger Syndrome, and Other Social Communication Disorders

    Science.gov (United States)

    Retherford, Kristine S.; Schreiber, Linda R.

    2015-01-01

    Camp Campus is a 1-week campus experience for juniors or seniors in high school or high school graduates who are diagnosed with high-functioning autism, Asperger syndrome, or a related social communication disorder and who plan to attend college. Participants experience campus life by partaking of campus services, living and dining on campus,…

  12. Camp Campus: College Preparation for Adolescents and Young Adults with High-Functioning Autism, Asperger Syndrome, and Other Social Communication Disorders

    Science.gov (United States)

    Retherford, Kristine S.; Schreiber, Linda R.

    2015-01-01

    Camp Campus is a 1-week campus experience for juniors or seniors in high school or high school graduates who are diagnosed with high-functioning autism, Asperger syndrome, or a related social communication disorder and who plan to attend college. Participants experience campus life by partaking of campus services, living and dining on campus,…

  13. Communicating the Benefits of a Full Sequence of High School Science Courses

    Science.gov (United States)

    Nicholas, Catherine Marie

    2014-01-01

    High school students are generally uninformed about the benefits of enrolling in a full sequence of science courses, therefore only about a third of our nation's high school graduates have completed the science sequence of Biology, Chemistry and Physics. The lack of students completing a full sequence of science courses contributes to the deficit…

  14. Characterization and Analysis of Integrated Silicon Photonic Detectors for High-Speed Communications

    Science.gov (United States)

    2015-03-26

    devices. This document describes the characterization and analysis of inte- grated photodiodes for digital and analog applications. The photodiode is...50 LCR inductance , capacitance, and resistance . . . . . . . . . . . . . . . . . . . . . . . 52 TE transverse electric...application for the high-bandwidth capability of integrated pho- tonic systems, could be used for analog antenna remoting. By up-converting to a high

  15. THE ROLE AND DISTRIBUTION OF WRITTEN INFORMAL COMMUNICATION IN THEORETICAL HIGH ENERGY PHYSICS.

    Science.gov (United States)

    LIBBEY, MILES A.; ZALTMAN, GERALD

    THIS STUDY OF "PREPRINT" DISTRIBUTION IN THEORECTICAL HIGH ENERGY PHYSICS USED A QUESTIONNAIRE CIRCULATED TO ALL KNOWN HIGH ENERGY THEORISTS. A SECOND QUESTIONNAIRE WAS SENT TO A REPRESENTATIVE SAMPLE OF "PREPRINT LIBRARIANS" AT VARIOUS INSTITUTIONS IN THE U.S. AND ABROAD. BASED ON THIS DATA, THE STUDY CONCLUDED THAT AN EXPERIMENT WITH CENTRALIZED…

  16. The Horse That Drank: Electronic Communication and the High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    O' Connell, Heath B

    2000-08-15

    High energy physicists submit their papers to electronic archives, have them published in electronic journals and indexed in online databases. Despite this system now having been in place basically in its entirety since the middle of the 1990's, other fields have been slow to follow. What makes high energy physics special (and what doesn't)?

  17. Optimization Techniques for Source Follower Based Track-and-Hold Circuit for High Speed Wireless Communication

    Directory of Open Access Journals (Sweden)

    Manoj Kumar

    2011-03-01

    Full Text Available Since the current demand for high need for track and hold amplifiers (T&H operating at RF frequencies. A circuit is the key element in any modern wide band data acquisition system. Applications like a cable or a broad variety of different radio standards require high processing speeds with high resolution. The track-and-hold (T&H circuit is a fundamental block for analog allows most dynamic errors of A/D converters to be reduced, especially those showing up when using high frequency input signals. Having a wide band and precise acquisition system today’s trend towards multi-standard flexible radios, with as much signal processing as possible in digital domain. This work investigates effect of various design schemes and circuit topology for track and-hold circuit to achieve acceptable linearly, high slew rate, low power consumption and low noise

  18. Free-space optical communications with peak and average constraints: High SNR capacity approximation

    KAUST Repository

    Chaaban, Anas

    2015-09-07

    The capacity of the intensity-modulation direct-detection (IM-DD) free-space optical channel with both average and peak intensity constraints is studied. A new capacity lower bound is derived by using a truncated-Gaussian input distribution. Numerical evaluation shows that this capacity lower bound is nearly tight at high signal-to-noise ratio (SNR), while it is shown analytically that the gap to capacity upper bounds is a small constant at high SNR. In particular, the gap to the high-SNR asymptotic capacity of the channel under either a peak or an average constraint is small. This leads to a simple approximation of the high SNR capacity. Additionally, a new capacity upper bound is derived using sphere-packing arguments. This bound is tight at high SNR for a channel with a dominant peak constraint.

  19. A Framework to Improve Surgeon Communication in High-Stakes Surgical Decisions: Best Case/Worst Case.

    Science.gov (United States)

    Taylor, Lauren J; Nabozny, Michael J; Steffens, Nicole M; Tucholka, Jennifer L; Brasel, Karen J; Johnson, Sara K; Zelenski, Amy; Rathouz, Paul J; Zhao, Qianqian; Kwekkeboom, Kristine L; Campbell, Toby C; Schwarze, Margaret L

    2017-06-01

    Although many older adults prefer to avoid burdensome interventions with limited ability to preserve their functional status, aggressive treatments, including surgery, are common near the end of life. Shared decision making is critical to achieve value-concordant treatment decisions and minimize unwanted care. However, communication in the acute inpatient setting is challenging. To evaluate the proof of concept of an intervention to teach surgeons to use the Best Case/Worst Case framework as a strategy to change surgeon communication and promote shared decision making during high-stakes surgical decisions. Our prospective pre-post study was conducted from June 2014 to August 2015, and data were analyzed using a mixed methods approach. The data were drawn from decision-making conversations between 32 older inpatients with an acute nonemergent surgical problem, 30 family members, and 25 surgeons at 1 tertiary care hospital in Madison, Wisconsin. A 2-hour training session to teach each study-enrolled surgeon to use the Best Case/Worst Case communication framework. We scored conversation transcripts using OPTION 5, an observer measure of shared decision making, and used qualitative content analysis to characterize patterns in conversation structure, description of outcomes, and deliberation over treatment alternatives. The study participants were patients aged 68 to 95 years (n = 32), 44% of whom had 5 or more comorbid conditions; family members of patients (n = 30); and surgeons (n = 17). The median OPTION 5 score improved from 41 preintervention (interquartile range, 26-66) to 74 after Best Case/Worst Case training (interquartile range, 60-81). Before training, surgeons described the patient's problem in conjunction with an operative solution, directed deliberation over options, listed discrete procedural risks, and did not integrate preferences into a treatment recommendation. After training, surgeons using Best Case/Worst Case clearly presented a choice between

  20. Ka-Band Parabolic Deployable Antenna (KaPDA) Enabling High Speed Data Communication for CubeSats

    Science.gov (United States)

    Sauder, Jonathan F.; Chahat, Nacer; Hodges, Richard; Thomson, Mark W.; Rahmat-Samii, Yahya

    2015-01-01

    CubeSats are at a very exciting point as their mission capabilities and launch opportunities are increasing. But as instruments become more advanced and operational distances between CubeSats and earth increase communication data rate becomes a mission-limiting factor. Improving data rate has become critical enough for NASA to sponsor the Cube Quest Centennial Challenge when: one of the key metrics is transmitting as much data as possible from the moon and beyond Currently, many CubeSats communicate on UHF bands and those that have high data rate abilities use S-band or X-band patch antennas. The CubeSat Aneas, which was launched in September 2012, pushed the envelope with a half-meter S-band dish which could achieve 100x the data rate of patch antennas. A half-meter parabolic antenna operating at Ka-band would increase data rates by over 100x that of the AMOS antenM and 10,000 that of X-band patch antennas.

  1. Parent-nursing student communication practice: role-play and learning outcomes.

    Science.gov (United States)

    Fisher, Mark J; Taylor, Erin A; High, Patricia L

    2012-02-01

    Parents accompanying their child's hospitalization can experience stress associated with the child's illness, treatments, and major alterations in family life. Nurses often serve as the primary communicator and cultural broker because of their constant presence at the child's bedside. Nursing students may not have essential parent-nurse communication competencies. In an innovative method of teaching nursing students about communicating with parents, 64 undergraduate nursing students participated in a parent-led postconference with a nursing instructor. The parents provided background and led role-play activities and debriefing sessions with students. Feedback provided by students before and after the parent session included requests for additional parents' experiences, appreciation and exceeded expectations of hands-on experience, recognized value of information provided, and the recommendation that all students attend. We demonstrate that empathy is a teachable skill, nursing students are apprehensive about communicating with parents, and nursing students do not understand how much families rely on nurses. Copyright 2012, SLACK Incorporated.

  2. High Efficiency and Power Laser Transmitter for Deep Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this program, Freedom Photonics will design an innovative compact, diode laser pumped solid state laser to achieve specifications listed by the program. High...

  3. Fluorescent Molecules as Transceiver Nanoantennas: The First Practical and High-Rate Information Transfer over a Nanoscale Communication Channel based on FRET

    OpenAIRE

    Murat Kuscu; Alper Kiraz; Akan, Ozgur B.

    2015-01-01

    Fluorescent Molecules as Transceiver Nanoantennas: The First Practical and High-Rate Information Transfer over a Nanoscale Communication Channel based on FRET Murat Kuscu1, Alper Kiraz2 & Ozgur B. Akan1 1Next-generation andWireless Communications Laboratory (NWCL), Department of Electrical and Electronics Engineering, Koc University, Istanbul, 34450, Turkey, 2Optofluidics and Nano-Optics Research Laboratory, Department of Physics, Koc University, Istanbul, 34450, Turke...

  4. Optimum Location and System Engineering of High Power, High Frequency Transmitter-Receiver in Combat Vehicles (Short Communication

    Directory of Open Access Journals (Sweden)

    S. Sathyamurthy

    2010-04-01

    Full Text Available This paper discusses the procedure adapted after carrying out several iterations for selecting an ideal location to introduce a high power high frequency (HF transmitter-receiver in a tactical combat vehicle from electromagnetic compatibility view. This radio set contributes for very high field strength to neighbouring electronic devices and other very high frequency (VHF Tx-Rx situated in the same vehicular platform. An integrated approach was followed in deciding the optimum solution to locate the HF radio set. Leakage from HF radio set is to be minimised within the vehicle to reduce the field coupling level to neighbouring equipment. Radiation from HF antenna was maximised by careful installation of antenna, outside the vehicle environment to ensure optimum radiation of intended signal. Voltage standing wave ratio (VSWR measurement was carried out to verify this. Four different locations experimented have been reported in this paper. The vehicle penetration loss (VPL can reveal the amount of leakage from external field generated by antennas to field inside the turret. The HF, being a congested operating spectrum, due care was taken in electromagnetic interference control of HF-VHF radios and other tank electronic subsystems. High RF power of HF transmitter and very high sensitivity of HF receiver could affect systems either way. Hence, electromagnetic compatibility (EMC measures and optimum location of HF radio set are important from MIL-STD461 C, MIL6051-D/MIL-STD464A point of view.Defence Science Journal, 2010, 60(3, pp.302-306, DOI:http://dx.doi.org/10.14429/dsj.60.357

  5. [Leadership and communication].

    Science.gov (United States)

    Henninger, Michael; Barth, Christina

    2009-01-01

    Medical leadership requires specific communication skills in order to meet professional demands. Communicative behaviour is usually highly automated and not necessarily conscious. Managerial communication competes against elaborated but not role-specific behaviour patterns, especially in critical situations. Accordingly, competent medical leadership requires the awareness of individual communication habits as well as the knowledge and ability to use conversation techniques suitable for a specific situational context. The training of leadership-related communication techniques requires the de-automation of existing skills and a problem-oriented construction and re-automation of new communication techniques.

  6. Optimization Techniques for Source Follower Based Track-and-Hold Circuit for High Speed Wireless Communication

    Directory of Open Access Journals (Sweden)

    Manoj Kumar

    2011-03-01

    Full Text Available Since the current demand for highneedfor track and hold amplifiers (T&H operating at RF frequencies. Acircuit is the key element in any modern wideband data acquisition system. Applications like a cableor a broad variety of different radio standards require high processing speeds with high resolution. Thetrack-and-hold (T&H circuit is a fundamental block for analogallows most dynamic errors of A/D converters to be reduced, especially those showing up when usinghigh frequency input signals. Having a wideband and precise acquisition systemtoday’s trend towards multi-standard flexible radios, with as much signal processing as possible indigital domain. This work investigates effect of various design schemes and circuit topology for trackand-hold circuit to achieve acceptable linearly, high slew rate, low power consumption and low noise

  7. High cycle fatigue crack propagation resistance and fracture toughness in ship steels (Short Communication

    Directory of Open Access Journals (Sweden)

    R.S. Tripathi

    2001-04-01

    Full Text Available In this paper, two grades of steel, viz., plain carbon steel and low alloy steel used in naval ships have been selected for studies on high cycle fatigue, crack propagation, stress intensity and crack opening displacement (COD. Specimen for high cycle fatigue was prepared as per IS: 1608. High cycle fatigue was carried out up to 50,000 cycles at 1000 kgfto 2000 kgfloads. Up to 2000 kgfloads, both the materials were observed within elastic zones. A number of paran1eters, including stress, strain and strain range, which indicate elastic behaviour of steels, have been considered. Low alloy steel specimen was prepared as per ASTM standard: E-399 and subjected to 5,00,000 cycles. Crack propagation, COD, stress intensity, load-cycle variations, load-COD relation, and other related paran1eters have been studied using a modem universal testing machine with state-of-the-art technology

  8. High-power AlGaAs channeled substrate planar diode lasers for spaceborne communications

    Science.gov (United States)

    Connolly, J. C.; Goldstein, B.; Pultz, G. N.; Slavin, S. E.; Carlin, D. B.; Ettenberg, M.

    1988-01-01

    A high power channeled substrate planar AlGaAs diode laser with an emission wavelength of 8600 to 8800 A was developed. The optoelectronic behavior (power current, single spatial and spectral behavior, far field characteristics, modulation, and astigmatism properties) and results of computer modeling studies on the performance of the laser are discussed. Lifetest data on these devices at high output power levels is also included. In addition, a new type of channeled substrate planar laser utilizing a Bragg grating to stabilize the longitudinal mode was demonstrated. The fabrication procedures and optoelectronic properties of this new diode laser are described.

  9. High-speed narrowband PLC - High-performance Access Powerline Communication structures in smart grid; High-Speed Narrowband PLC. Leistungsfaehige Access-Powerline-Kommunikationsstrukturen im Smart Grid

    Energy Technology Data Exchange (ETDEWEB)

    Offner, Georg [devolo AG, Aachen (Germany)

    2012-07-01

    The smart grid provides a stable operation of a decentralized power system which is fed more and more by small providers by means of solar technology and wind power technology. Furthermore, commercial and private clients profit from the smart grid, as they may capture information about their current consumption in real time or can obtain these data from the Internet. The author of the contribution under consideration presents new approaches to access powerline communications that enable efficient communication between IPv6 based household meter and network station. The contribution under consideration describes the technologies used as well as practical experiences and initial results from field tests. Here insights from the integration of G3-PLC are in the foreground.

  10. Relative impact of meteor scatter and other long-distance high-latitude propagation modes on VHF communication systems

    Science.gov (United States)

    Cannon, Paul S.; Weitzen, Jay A.; Ostergaard, Jens; Rasmussen, John E.

    1996-09-01

    We have analyzed the duty cycle, due to ionospheric propagation, of very high frequency sounding signals for both polar cap and auroral paths. We find that at 35 and 45 MHz the propagation is often sustained by sporadic E layers and other nonmeteoric modes rather than by meteor scatter. At the higher frequencies of 65 and 85 MHz we find that the path is generally dominated by meteor scatter modes. These results have important ramifications for frequency reuse and security in meteor burst communications systems and for the development of extended frequency range HF systems (above 30 MHz) with a capability to operate on any available propagation mode. The diurnal, seasonal, and geomagnetic variations of the nonmeteoric duty cycle have been examined. A polar cap path model is presented for the nonmeteoric duty cycle as a function of geomagnetic activity.

  11. Do gender-specific and high-resolution three dimensional body charts facilitate the communication of pain for women?

    DEFF Research Database (Denmark)

    Egsgaard, Line Lindhardt; Christensen, Trine Søby; Petersen, Ida Munk

    2016-01-01

    BACKGROUND: Chronic pain is more prevalent among women; however, the majority of standardized pain drawings are often collected using male-like androgynous body representations. OBJECTIVE: The purpose of this study was to assess whether gender-specific and high-resolution three-dimensional (3D......) body charts facilitate the communication of pain for women. METHODS: Using mixed-methods and a cross-over design, female patients with chronic pain were asked to provide detailed drawings of their current pain on masculine and feminine two-dimensional (2D) body schemas (N=41, Part I) or on female 2D...... enabled a more accurate expression of their pain due to the detailed contours of the musculature and bone structure, however, patients also reported the 3D body chart was too human and believed that skin-like appearance limited 'deep pain' expressions. CONCLUSIONS: Providing gender-specific body charts...

  12. Resource Allo cation in High Energy-Effi cient Co op erative Sp ectrum Sharing Communication Networks

    Institute of Scientific and Technical Information of China (English)

    LIU Dandan; HUANG Cong; WANG Wenbo; GUO Wenbin

    2016-01-01

    High energy-efficient wireless communica-tion has become hot due to global low-carbon economy. The systems total transmitting power can be saved by resource allocation in cooperative spectrum sharing net-works. In cooperative spectrum sharing, the secondary user relays the primary users traffic, as a return, the sec-ondary user is admitted to access the licensed spectrum for its own data transmission. An optimal power and time al-location are presented to minimize the overall energy con-sum ption with the users service quality guaranteed in co-operative spectrum sharing. We formulated it as a convex problem and achieve its optimal power and time allocation in closed form. We analyze the performance of two different transmission protocols for the single relay channel.

  13. Communication, Coordination, Cooperation.

    Science.gov (United States)

    Rose, Nancy Oft; Wiper, Kathie Tippens

    Speech communication teachers at both secondary and postsecondary school levels must cooperate to improve oral communication education. Despite the importance of oral communication skills, speech courses are rarely required in high school. Teachers must tell school boards, higher education boards, and faculties of the importance of speaking and…

  14. Communication, Coordination, Cooperation.

    Science.gov (United States)

    Rose, Nancy Oft; Wiper, Kathie Tippens

    Speech communication teachers at both secondary and postsecondary school levels must cooperate to improve oral communication education. Despite the importance of oral communication skills, speech courses are rarely required in high school. Teachers must tell school boards, higher education boards, and faculties of the importance of speaking and…

  15. Career Field Experience: A Look at On-site Usage by High School Communication Class.

    Science.gov (United States)

    Kaye, Thomas

    The career field experience program at a midwestern high school places broadcasting students on location for observation of the profession and optional job training or work. In addition to radio and television stations, field locations include advertising agencies with production studios, corporate production facilities, recording studios, cable…

  16. Review on High Gain Conical Horn Antenna for Short-Range Communications

    Directory of Open Access Journals (Sweden)

    Priyanka Bhagwat

    2013-11-01

    Full Text Available Horn antennas are very popular at UHF (300 MHz-3 GHz and higher frequencies ( as high as 140 GHz. Horn antennas often have a directional radiation pattern with a high antenna gain, which can range up to 25 dB in some cases, with 10-20 dB being typical. Horn antennas have a wide impedance bandwidth, implying that the input impedance is slowly varying over a wide frequency range. The bandwidth for practical horn antennas can be of the order of 20:1 (for instance, operating from 1 GHz-20 GHz, with a 10:1 bandwidth being common. The gain of horn antennas often increases as the frequency of operation is increased. This is because the size of the horn aperture is measured in wavelengths; at higher frequencies the horn antenna is "electrically larger" because high frequency has a smaller wavelength. Horn antennas have very little loss, so the directivity of a horn is roughly equal to its gain. In this paper, we will present review about conical horn antenna which uses hybrid technique and provides high gain at frequencies ranging 3GHz keeping its size within limits. Also, literature survey will demostrate other reference papers will includes horn antennas using different techniques and used for various applications.

  17. Low-Power, High-Speed Transceivers for Network-on-Chip Communication

    NARCIS (Netherlands)

    Schinkel, Daniel; Mensink, E.; Klumperink, Eric A.M.; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

    Networks on chips (NoCs) are becoming popular as they provide a solution for the interconnection problems on large integrated circuits (ICs). But even in a NoC, link-power can become unacceptably high and data rates are limited when conventional data transceivers are used. In this paper, we present

  18. The 9th Beijing Chitec,Platform for International High & New Technology Communication

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The 9th China Beijing International High-tech Expo The 9th Chitec, Co-organized by The Ministry of Science and Technology, The Ministry of Commerce, The Ministry of Education, The Ministry of Information Industry, China Council for the Promotion of International Trade, State Intellectual Property office and Beijing Government, was held in Beijing from May 22 to May 27.

  19. Low-Power, High-Speed Transceivers for Network-on-Chip Communication

    NARCIS (Netherlands)

    Schinkel, Daniel; Mensink, E.; Klumperink, Eric A.M.; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

    2009-01-01

    Networks on chips (NoCs) are becoming popular as they provide a solution for the interconnection problems on large integrated circuits (ICs). But even in a NoC, link-power can become unacceptably high and data rates are limited when conventional data transceivers are used. In this paper, we present

  20. Cross-polarisation discrimination-induced interference in dual-polarised high-capacity satellite communication systems

    Directory of Open Access Journals (Sweden)

    Abdulkareem Sarki Karasuwa

    2016-05-01

    Full Text Available The design of spectrally-efficient, high-throughput satellite (HTS systems with capacity approaching one terabit per second requires operating at Ka-band frequencies and above, where there are several gigahertz of allocated radio spectrum, using multiple spot beams with dual orthogonal polarisation mode. At these high frequencies, rain attenuation poses a major obstacle to the design of high-availability satellite links which are needed for the realisation of ubiquitous broadband multimedia communication services including high-speed Internet access at rural and remote locations. Furthermore, depolarisation-induced interference in such systems could have a performance-limiting impact if a co-channel cross-polar signal combines with system noise to drive the carrier-to-noise-plus-interference ratio (CNIR below an acceptable threshold. This paper employs real measurement data to investigate the impact of depolarisation-induced interference on dual-polarised HTS systems for temperate and tropical climatic regions. Scenarios that cause significant system performance degradation are analysed, including the effects of signal frequency, antenna size, and regional rainfall rate. The impact of depolarisation on system performance is quantified by the reductions in the CNIR and link availability of a dual-polarised system when compared with those of a similarly-dimensioned single-polarised system.

  1. Towards a Seamless Future Generation Network for High Speed Wireless Communications

    Directory of Open Access Journals (Sweden)

    Kelvin O. O. Anoh

    2013-10-01

    Full Text Available The MIMO technology towards achieving future generation broadband networks design criteria is presented. Typical next generation scenarios are investigated. The MIMO technology is integrated with the OFDM technology for effective space, time and frequency diversity exploitations for high speed outdoor environment. Two different OFDM design kernels (fast Fourier transform (FFT and wavelet packet transform (WPT are used at the baseband for OFDM system travelling at terrestrial high speed for 800MHz and 2.6GHz operating frequencies. Results show that the wavelet kernel for designing OFDM systems can withstand doubly selective channel fading for mobiles speeds up to 280Km/hr at the expense of the traditional OFDM design kernel, the fast Fourier transform.

  2. Promoting Physical Activity With Group Pictures. Affiliation-Based Visual Communication for High-Risk Populations.

    Science.gov (United States)

    Reifegerste, Doreen; Rossmann, Constanze

    2017-02-01

    Past research in social and health psychology has shown that affiliation motivation is associated with health behavior, especially for high-risk populations, suggesting that targeting this motivation could be a promising strategy to promote physical activity. However, the effects that affiliation appeals (e.g., pictures depicting companionship during physical activities) and accompanying slogans have on motivating physical activity have been largely unexplored. Hence, our two studies experimentally tested the effects of exposure to affiliation-based pictures for overweight or less active people, as well as the moderating effect of affiliation motivation. The results of these two studies give some indication that group pictures (with or without an accompanying slogan) can be an effective strategy to improve high-risk populations' attitudes, self-efficacy, and intentions to engage in physical activity. Affiliation motivation as a personality trait did not interact with these effects, but was positively associated with attitudes, independent of the group picture effect.

  3. The 9th Beijing Chitec,Platform for International High & New Technology Communication

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

      The 9th China Beijing International High-tech Expo The 9th Chitec, Co-organized by The Ministry of Science and Technology, The Ministry of Commerce, The Ministry of Education, The Ministry of Information Industry, China Council for the Promotion of International Trade, State Intellectual Property office and Beijing Government, was held in Beijing from May 22 to May 27.……

  4. High speed nonlinear optical components for next-generation optical communications

    OpenAIRE

    Cleary, Ciaran Sean

    2013-01-01

    Electronic signal processing systems currently employed at core internet routers require huge amounts of power to operate and they may be unable to continue to satisfy consumer demand for more bandwidth without an inordinate increase in cost, size and/or energy consumption. Optical signal processing techniques may be deployed in next-generation optical networks for simple tasks such as wavelength conversion, demultiplexing and format conversion at high speed (≥100Gb.s-1) to alleviate the pres...

  5. Design of high speed serializer for interchip data communications with phase frequency detector

    Directory of Open Access Journals (Sweden)

    Vinod Kumar Nirala

    2016-05-01

    Full Text Available The part of project work presented in this report deals with high speed inter-chip serial data transfer. Serializer used for parallel to serial conversion is of not only high speed but also power efficient. The utilization of CMOS based serializer as well as CML (current mode logic based serializer at proper places helps in reducing the power requirement without compromising the adequate speed. Tree structure is adopted for the realization of higher order serializer(8:1. The basic building block is 2:1 serializer. The high frequency clock is generated with the help of delay locked loop (DLL based clock multiplier unit (CMU. Pre-charge type phase frequency detector (PFD is used to obtain better phase resolution which is necessary for enhancing the jitter performance of the transmitter. DLL generates 8 phases which are combined by a logic block to produce a clock of frequency 4 times input frequency of DLL. To obtain different other frequencies divider is utilized.

  6. SHORT COMMUNICATION: Metal carbide-carbon peritectic systems as high-temperature fixed points in thermometry

    Science.gov (United States)

    Yamada, Y.; Wang, Y.; Sasajima, N.

    2006-10-01

    WC-C, Cr3C2-C and Mn7C3-C peritectic systems were investigated for their potential of serving as high-temperature reference points in thermometry. Mixtures of high-purity graphite powder with W, Cr and Mn powder of 99.99%, 99.9% and 99.95% purity by mass, respectively, were placed in graphite blackbody crucibles and melting/freezing plateaus were observed by means of a radiation thermometer. The observed melting temperatures were 2749 °C (WC-C), 1826 °C (Cr3C2-C) and 1331 °C (Mn7C3-C), with a repeatability—in each case—of 0.02 K. The melting range for WC-C and Cr3C2-C peritectics was roughly 0.1 K. WC-C showed a flat freezing plateau that agreed with the melting plateau within the repeatability. The three fixed points are possible candidates, like the metal (carbide)-carbon eutectic fixed points, in the realization of an improved high-temperature scale above the copper point.

  7. Least Reliable Bits Coding (LRBC) for high data rate satellite communications

    Science.gov (United States)

    Vanderaar, Mark; Wagner, Paul; Budinger, James

    1992-02-01

    An analysis and discussion of a bandwidth efficient multi-level/multi-stage block coded modulation technique called Least Reliable Bits Coding (LRBC) is presented. LRBC uses simple multi-level component codes that provide increased error protection on increasingly unreliable modulated bits in order to maintain an overall high code rate that increases spectral efficiency. Further, soft-decision multi-stage decoding is used to make decisions on unprotected bits through corrections made on more protected bits. Using analytical expressions and tight performance bounds it is shown that LRBC can achieve increased spectral efficiency and maintain equivalent or better power efficiency compared to that of Binary Phase Shift Keying (BPSK). Bit error rates (BER) vs. channel bit energy with Additive White Gaussian Noise (AWGN) are given for a set of LRB Reed-Solomon (RS) encoded 8PSK modulation formats with an ensemble rate of 8/9. All formats exhibit a spectral efficiency of 2.67 = (log2(8))(8/9) information bps/Hz. Bit by bit coded and uncoded error probabilities with soft-decision information are determined. These are traded with with code rate to determine parameters that achieve good performance. The relative simplicity of Galois field algebra vs. the Viterbi algorithm and the availability of high speed commercial Very Large Scale Integration (VLSI) for block codes indicates that LRBC using block codes is a desirable method for high data rate implementations.

  8. "To speak or not to speak - that is the question". Oral communication skills in a broader profile of literacy: A high school teacher's quest for communicative competence in his chemistry classroom

    Science.gov (United States)

    Tuleja, Elizabeth A.

    The goal of any school is to help its students become literate. Broadly speaking, to be literate means to be well informed and educated. More specifically, literacy---or the ability to read and write---is encouraged through the language arts, which is usually characterized by activities that focus primarily on reading and writing skills. While reading and writing are absolutely essential to the academic success of any student, the aspect of speaking skills---or effective communication skills---is often considered ancillary instruction, something to do "if there is enough time," since speaking is assumed to be an innate skill. This research focused on the place of oral communication skills in a broader profile for literacy and its place in every course across the curriculum. The research for this study took place over a nine month period and focused on documenting what one high school science teacher called, "reading, writing, research and recitation" in his 10th and 11 th grade chemistry class. His objective was to teach his chemistry students about the significance of developing oral communication competencies (specifically presentation skills), in the content course of chemistry. Through a descriptive, interpretive, and naturalistic study, I sought to better understand three questions. First, how did this particular teacher integrate oral communication skills into the content area of science? Second, how did the students react to this process and what did they learn from it. Third, what happened when an intervention took place whereby an experienced instructor in the field of communication education partnered with this science teacher in order to help integrate oral communication competencies into the curriculum? The focus of this research was to understand the process that this teacher went through as he attempted to integrate oral speech skills into the curriculum, as well as what the students did with this information while they developed their oral

  9. Investigation and Demonstration of High Speed Full-Optical Hybrid FSO/Fiber Communication System under Light Sand Storm Condition

    KAUST Repository

    Esmail, Maged Abdullah

    2016-12-19

    In contrast to traditional free space optical (FSO) systems, the new generation is aimed to be transparent to optical fiber where protocols, high signal bandwidths, and high data rates over fiber are all maintained. In this paper, we experimentally demonstrate a high speed outdoor full-optical FSO communication system over 100 m link. We first describe the design of our transmitter, which consists of a comb generator and a flexible multiformat transmitter. Our measurements are performed in arid desert area under a light dust storm. In this environment, we use a 12 subcarrier comb generator, each of which is modulated by a quadrature-amplitude modulation (QAM) signal. We achieved a 1.08 Tbps error free data rate with 3.6 b/s/Hz spectral efficiency. We place long optical fiber rolls in the transmitter side and the receiver side to mimic real FSO deployments. Furthermore, we investigated the effect of receiver misalignment in outdoor conditions and the effect of background noise. We find that full-optical FSO system is sensitive to the misalignment effect. However, the background noise has negligible effect. Finally, we find that solar heating of the transceiver causes collimator deviation, which requires using a cooling unit or auto tracking system.

  10. High Capacity Phase/Amplitude Modulated Optical Communication Systems and Nonlinear Inter-Channel Impairments

    Science.gov (United States)

    Tavassoli, Vahid

    This thesis studies and mathematically models nonlinear interactions among channels of modern high bit rate (amplitude/) phase modulated optical systems. First, phase modulated analogue systems are studied and a differential receiving method is suggested with experimental validation. The main focus of the rest of the thesis is on digital advanced modulation format systems. Cross-talk due to fiber Kerr nonlinearity in two-format hybrid systems as well as 16-QAM systems is mathematically modelled and verified by simulation for different system parameters. A comparative study of differential receivers and coherent receivers is also given for hybrid systems. The model is based on mathematically proven assumptions and provides an intuitive analytical understanding of nonlinear cross-talk in such systems.

  11. The High-efficiency LED Driver for Visible Light Communication Applications

    Science.gov (United States)

    Gong, Cihun-Siyong Alex; Lee, Yu-Chen; Lai, Jyun-Liang; Yu, Chueh-Hao; Huang, Li Ren; Yang, Chia-Yen

    2016-08-01

    This paper presents a LED driver for VLC. The main purpose is to solve the low data rate problem used to be in switching type LED driver. The GaN power device is proposed to replace the traditional silicon power device of switching LED driver for the purpose of increasing switching frequency of converter, thereby increasing the bandwidth of data transmission. To achieve high efficiency, the diode-connected GaN power transistor is utilized to replace the traditional ultrafast recovery diode used to be in switching type LED driver. This work has been experimentally evaluated on 350-mA output current. The results demonstrate that it supports the data of PWM dimming level encoded in the PPM scheme for VLC application. The experimental results also show that system’s efficiency of 80.8% can be achieved at 1-Mb/s data rate.

  12. Identification of Abiotic Stress Responsive Genes from Indian High Altitude Lepidium latifolium L. (Short Communication

    Directory of Open Access Journals (Sweden)

    Sanjay Mohan Gupta

    2012-09-01

    Full Text Available Abiotic stresses are major environmental factors that periodically account for significant loss in crop productivity. In order to improve the abiotic stress tolerance in vegetable crops through transgenic approaches, authors isolated and cloned six up-regulated, LlaDREB1b (JN214345, LlaGPAT (JN398166, LlaNAC (FJ423495, LlaCIPK (FJ423496, LlaPR5 (GQ853409 and LlaIPK (FJ487575 and two down-regulated LlaRan (JN214347 and LlaDRT (JN214346 abiotic stress responsive genes from Indian high altitude Lepidium latifolium L. plant that that may be used for abiotic stress-tolerance engineering upon functional validation.Defence Science Journal, 2012, 62(5, pp.315-318, DOI:http://dx.doi.org/10.14429/dsj.62.1495

  13. Communication: Virial coefficients and demixing in highly asymmetric binary additive hard-sphere mixtures.

    Science.gov (United States)

    López de Haro, Mariano; Tejero, Carlos F; Santos, Andrés

    2013-04-28

    The problem of demixing in a binary fluid mixture of highly asymmetric additive hard spheres is revisited. A comparison is presented between the results derived previously using truncated virial expansions for three finite size ratios with those that one obtains with the same approach in the extreme case in which one of the components consists of point particles. Since this latter system is known not to exhibit fluid-fluid segregation, the similarity observed for the behavior of the critical constants arising in the truncated series in all instances, while not being conclusive, may cast serious doubts as to the actual existence of a demixing fluid-fluid transition in disparate-sized binary additive hard-sphere mixtures.

  14. Communication: Disorder-suppressed vibrational relaxation in vapor-deposited high-density amorphous ice

    Science.gov (United States)

    Shalit, Andrey; Perakis, Fivos; Hamm, Peter

    2014-04-01

    We apply two-dimensional infrared spectroscopy to differentiate between the two polyamorphous forms of glassy water, low-density (LDA) and high-density (HDA) amorphous ices, that were obtained by slow vapor deposition at 80 and 11 K, respectively. Both the vibrational lifetime and the bandwidth of the 1-2 transition of the isolated OD stretch vibration of HDO in H2O exhibit characteristic differences when comparing hexagonal (Ih), LDA, and HDA ices, which we attribute to the different local structures - in particular the presence of interstitial waters in HDA ice - that cause different delocalization lengths of intermolecular phonon degrees of freedom. Moreover, temperature dependent measurements show that the vibrational lifetime closely follows the structural transition between HDA and LDA phases.

  15. High-performance two-axis gimbal system for free space laser communications onboard unmanned aircraft systems

    Science.gov (United States)

    Locke, Michael; Czarnomski, Mariusz; Qadir, Ashraf; Setness, Brock; Baer, Nicolai; Meyer, Jennifer; Semke, William H.

    2011-03-01

    A custom designed and manufactured gimbal with a wide field-of-view and fast response time is developed. This enhanced custom design is a 24 volt system with integrated motor controllers and drivers which offers a full 180o fieldof- view in both azimuth and elevation; this provides a more continuous tracking capability as well as increased velocities of up to 479° per second. The addition of active high-frequency vibration control, to complement the passive vibration isolation system, is also in development. The ultimate goal of this research is to achieve affordable, reliable, and secure air-to-air laser communications between two separate remotely piloted aircraft. As a proof-of-concept, the practical implementation of an air-to-ground laserbased video communications payload system flown by a small Unmanned Aerial Vehicle (UAV) will be demonstrated. A numerical tracking algorithm has been written, tested, and used to aim the airborne laser transmitter at a stationary ground-based receiver with known GPS coordinates; however, further refinement of the tracking capabilities is dependent on an improved gimbal design for precision pointing of the airborne laser transmitter. The current gimbal pointing system is a two-axis, commercial-off-the-shelf component, which is limited in both range and velocity. The current design is capable of 360o of pan and 78o of tilt at a velocity of 60o per second. The control algorithm used for aiming the gimbal is executed on a PC-104 format embedded computer onboard the payload to accurately track a stationary ground-based receiver. This algorithm autonomously calculates a line-of-sight vector in real-time by using the UAV autopilot's Differential Global Positioning System (DGPS) which provides latitude, longitude, and altitude and Inertial Measurement Unit (IMU) which provides the roll, pitch, and yaw data, along with the known Global Positioning System (GPS) location of the ground-based photodiode array receiver.

  16. A High Performance System With Explicit Incorporation of ATC Regulations to Generate Contingency Plans for UAVs with Lost Communication Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a comprehensive and systematic contingency plan generation framework to deal with lost communication in UAVs. ATC regulations are explicitly incorporated...

  17. Review of Millimeter-Wave Integrated Circuits With Low Power Consumption for High Speed Wireless Communications

    Science.gov (United States)

    Ellinger, Frank; Fritsche, David; Tretter, Gregor; Leufker, Jan Dirk; Yodprasit, Uroschanit; Carta, C.

    2017-01-01

    In this paper we review high-speed radio-frequency integrated circuits operating up to 210 GHz and present selected state-of-the-art circuits with leading-edge performance, which we have designed at our chair. The following components are discussed employing bipolar complementary metal oxide semiconductors (BiCMOS) technologies: a 200 GHz amplifier with 17 dB gain and around 9 dB noise figure consuming only 18 mW, a 200 GHz down mixer with 5.5 dB conversion gain and 40 mW power consumption, a 190 GHz receiver with 47 dB conversion gain and 11 dB noise figure and a 60 GHz power amplifier with 24.5 dBm output power and 12.9 % power added efficiency (PAE). Moreover, we report on a single-core flash CMOS analogue-to-digital converter (ADC) with 3 bit resolution and a speed of 24 GS/s. Finally, we discuss a 60 GHz on-off keying (OOK) BiCMOS transceiver chip set. The wireless transmission of data with 5 Gb/s at 42 cm distance between transmitter and receiver was verified by experiments. The complete transceiver consumes 396 mW.

  18. Satellite Communication.

    Science.gov (United States)

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  19. Communication System and Method

    Science.gov (United States)

    Sanders, Adam M. (Inventor); Strawser, Philip A. (Inventor)

    2014-01-01

    A communication system for communicating over high-latency, low bandwidth networks includes a communications processor configured to receive a collection of data from a local system, and a transceiver in communication with the communications processor. The transceiver is configured to transmit and receive data over a network according to a plurality of communication parameters. The communications processor is configured to divide the collection of data into a plurality of data streams; assign a priority level to each of the respective data streams, where the priority level reflects the criticality of the respective data stream; and modify a communication parameter of at least one of the plurality of data streams according to the priority of the at least one data stream.

  20. Optical communications and a comparison of optical technologies for a high data rate return link from Mars

    Science.gov (United States)

    Spence, Rodney L.

    1993-01-01

    The important principles of direct- and heterodyne-detection optical free-space communications are reviewed. Signal-to-noise-ratio (SNR) and bit-error-rate (BER) expressions are derived for both the direct-detection and heterodyne-detection optical receivers. For the heterodyne system, performance degradation resulting from received-signal and local oscillator-beam misalignment and laser phase noise is analyzed. Determination of interfering background power from local and extended background sources is discussed. The BER performance of direct- and heterodyne-detection optical links in the presence of Rayleigh-distributed random pointing and tracking errors is described. Finally, several optical systems employing Nd:YAG, GaAs, and CO2 laser sources are evaluated and compared to assess their feasibility in providing high-data-rate (10- to 1000-Mbps) Mars-to-Earth communications. It is shown that the root mean square (rms) pointing and tracking accuracy is a critical factor in defining the system transmitting laser-power requirements and telescope size and that, for a given rms error, there is an optimum telescope aperture size that minimizes the required power. The results of the analysis conducted indicate that, barring the achievement of extremely small rms pointing and tracking errors (less than 0.2 microrad), the two most promising types of optical systems are those that use an Nd:YAG laser (lambda = 1.064 microns) and high-order pulse position modulator (PPM) and direct detection, and those that use a CO2 laser (lambda = 10.6 microns) and phase shifting keying homodyne modulation and coherent detection. For example, for a PPM order of M = 64 and an rms pointing accuracy of 0.4 microrad, an Nd:YAG system can be used to implement a 100-Mbps Mars link with a 40-cm transmitting telescope, a 20-W laser, and a 10-m receiving photon bucket. Under the same conditions, a CO2 system would require 3-m transmitting and receiving telescopes and a 32-W laser to implement such