Broadcast diamond channel: Transmission strategies and bounds     

Zouhair Al-qudah  Ahmad Ababneh 《Journal of The Franklin Institute》2021,358(3):2178-2193

This paper proposes a new multiuser communication model in which a source with broadcast capabilities wants to transmit two different messages to two different destinations in the case that no direct links between the source and its destinations. In this channel model, two parallel half-duplex relays are used to extend the transmission. For this communication model, an outer bound to the achievable capacity is initially derived. Then, two distinctive transmission schemes are characterized such that the source can transmit to the two destinations. In each scheme, the transmission is split into two phases. Specifically, in the first phase, the source can broadcast different messages to the two relays. Then, in the second phase, the two relays can forward the source’s signals into their destinations. Based on the transmission on each scheme, the achievable rate region is characterized. Further, we derive the optimal duration of each phase. The theoretical analyses are followed by many numerical examples that compare between the different transmission techniques and also show the points at which the capacity is achieved.  相似文献   

Factors influencing Malaysian public attitudes to agro-biotechnology     

Amin L  Ahmad J  Jahi JM  Nor AR  Osman M  Mahadi NM 《Public understanding of science (Bristol, England)》2011,20(5):674-689

Despite considerable research in advanced countries on public perceptions of and attitudes to modern biotechnology, limited effort has been geared towards developing a structural model of public attitudes to modern biotechnology. The purpose of this paper is to identify the relevant factors influencing public attitudes towards genetically modified (GM) soybean, and to analyze the relationship between all the attitudinal factors. A survey was carried out on 1,017 respondents from various stakeholder groups in the Klang Valley region. Results of the survey have confirmed that attitudes towards complex issues such as biotechnology should be seen as a multifaceted process. The most important factors predicting support for GM soybean are the specific application-linked perceptions about the benefits, acceptance of risk and moral concern while risk and familiarity are significant predictors of benefit and risk acceptance. Attitudes towards GM soybean are also predicted by several general classes of attitude.  相似文献   

Combining Online Learning & Assessment in synchronization form     

Mohamed A. Amasha  Rania A. Abougalala  Ahmad J. Reeves  Salem Alkhalaf 《Education and Information Technologies》2018,23(6):2517-2529

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Teacher-center and school-based models of collegiality and professional development: Case studies of the teachers’ resource center and the Aga Khan school system in Karachi, Pakistan     

Mehrunnisa Ahmad Ali  Sheikh Abul Qasim  Rafiq Jaffer  Jeremy Greenland 《International Journal of Educational Research》1993,19(8)

Based on two recent teacher development efforts in Pakistan, this chapter examines efforts to promote teacher collegiality within these initiatives. The chapter first describes relevant contextual differences among schools in Karachi and summarizes the history of the two projects within this context. It then analyzes similarities and differences across these two projects in how they dealt with collegiality and professional development. While participants in both projects made progress in ameliorating extreme forms of teacher isolation and authoritarian relationships, they also discovered that balancing increased collegiality within a hierarchy of responsibilities and rewards is a difficult and elusive goal.  相似文献   

A dynamic systems analysis of classrooms: teacher experience and student motivation     

Ghafarpour  Hajar  Moinzadeh  Ahmad 《Learning Environments Research》2020,23(1):101-116

Learning Environments Research - In this study, classrooms were regarded as systems in which the teacher and students interact in context and behaviors of the teacher and students affect each other...  相似文献   

Academic promotion in Malaysian public universities: a critical look at issues and challenges     

Norzaini Azman  Ibrahim Che Omar  Aida Suraya Md Yunus  Ahmad Nurulazam Md Zain 《牛津教育评论》2016,42(1):71-88

The expansion and transformation of Malaysian universities have generated major changes in the nature of academic employment and the structure of academic promotion in higher education institutions. These changes have considerable implications, in particular for the policy and practice of academic promotion in the public universities. We argue that despite sharing one common grade and salary system, distinct and significant differences exist in the academic promotion systems of the public universities. Drawing on one recent study on the academic promotion process in Malaysian public universities to contextualise our discussion, this paper highlights the complexity in the promotion process in these institutions. It also discusses and articulates the attendant issues and challenging aspects of the academic promotion process. We argue that the interrelated issues and challenges, and certain academic practices and habits stemming from the pressure to gain a promotion are pervasive, and that they affect the academic value system and work culture. We conclude by asserting the importance of applying a consistent standard for promotion within a single salary system and that the academic promotion system in the public universities should ultimately affirm and communicate core academic values, and also aim at obtaining evidence of excellent accomplishments.  相似文献   

New insights on the utilization of ultrasonicated mustard seed cake: chemical composition and antagonistic potential for root-knot nematode,Meloidogyne javanica     

Nadeem  Hera  Malan  Pieter  Khan  Amir  Asif  Mohd  Ahmad Siddiqui  Mansoor  Tuhafeni Angombe  Simon  Ahmad  Faheem 《Journal of Zhejiang University. Science. B》2021,22(7):563-574

This study focused, for the first time, on the effect of ultrasonic features on the extraction efficiency of secondary metabolites in mustard seed cake(MSC). The nematostatic potential of sonicated seed cake was examined against the second-stage juveniles(J2 s) of root-knot nematode, Meloidogyne javanica. The results show that a 35 ppm(parts per million) concentration of a sonicated extract(SE) sample of MSC caused 65% J2 s mortality at 18 h exposure period in vitro. It also significantly suppressed the root-knot index(RKI=0.94) in tomato roots. The lethal concentration values for SE were 51.76, 29.79, and 13.34 ppm,respectively, at 6, 12, and 18 h of the exposure period, and the lethal concentration values for the non-sonicated extract(NSE)sample were 116.95, 76.38, and 55.59 ppm, respectively, at similar exposure time. Sinapine and gluconapin were identified as the major compounds in ultrasonic-assisted MSC. Because of the high extraction efficiency of metabolites in the SE, all treatments of SE were shown to be antagonistic to J2 s. Thus, this study of ultrasonication activity-based profiling of MSC may help generate target-based compounds at a scale relevant to the control of disease caused by nematodes in economic crops.  相似文献   

Malaysian university students' attitudes to academic dishonesty and business ethics     

Zauwiyah Ahmad  Maimun Simun  Junaini Mohammad 《Asia Pacific Journal of Education》2008,28(2):149-160

Academic dishonesty is believed to have predictive ability for subsequent behaviours in the workplace. This study adds to the literature by investigating Malaysian business students' attitudes to academic dishonesty and their attitudes to ethics issues in business. This study also explores the association between these two constructs. The form of academic dishonesty being investigated here is related to assignments, quizzes, and examinations. Employing data collected from 153 business students from different academic years, this exploratory study concludes that business students may have found that some level of dishonesty is acceptable in some academic settings as well as in business settings. The study's outcomes highlight the possibility of using students' attitudes to academic dishonesty to explain their attitudes to ethics in business contexts. The findings of this study, to a certain extent, indicate that years spent in business education might contribute to such unfavourable attitudes. This exploratory study also draws attention to several issues related to the teaching of ethics within business education.  相似文献   

Contemporary trends in traditional Chinese Islamic education     

Clyde Ahmad Winters 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1984,30(4):475-479

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Ramadan Fasting and the Propensity for Learning: Is There a Cause for Concern?     

Nur Adilah Masismadi  Marcus J.C. Lee  Ahmad Munir Che Muhamed  Michael Y.H. Chia 《Clearing house (Menasha, Wis.)》2017,90(3):77-85

The literature indicates that glucose deprivation, dehydration, decreased sleep quality and quantity, and mood changes, independently and adversely can influence cognitive functions and therefore learning. The Ramadan fast is an annual religious act undertaken by Muslims where individuals refrain from consuming food and fluid during daylight hours, daily over 30 days. Alteration in eating times and sleep–wake cycles lead to a disruption in the body's daily circadian rhythm resulting in sleep perturbations and mood swings. Consequently, Ramadan fasting is linked to daytime lower glucose concentration, dehydration, decreased sleep quality and quantity, mood swings and elevated subjective feelings of fatigue and malaise. This review highlights how Ramadan fasting potentially poses learning difficulties as a result of the independent and/or combined effects of these factors.  相似文献