Light, when constructed in terms of the elementary quanta of light, may be viewed in particle‐like or wave‐like terms. The elementary quanta of light, when placed in motion…
Abstract
Light, when constructed in terms of the elementary quanta of light, may be viewed in particle‐like or wave‐like terms. The elementary quanta of light, when placed in motion through space/time at a speed of a constancy of c forms a light path through the space or reference frame viewed. The light path formed is curved, as space/time is curved. The curvilinear light path formed is a function of the gravitational potential within the viewed frame of reference. The linear description of this light path, termed the geodesic (Riemannian), does not describe the curvilinear light path, but rather the chord of the curvilinear path described by the inscribed arc. This linear description of the light path is the manner in which we describe the coordinate system involved, and is the same manner in which we determine the “speed of light”. The arc length of the light path, compared to the lesser value as described by the chord length, allows for a displacement to be determined, if both measures are applied to a linear measure. A displacement of linear coordinates then occurs, with this displacement a result of the gravitational potential occurring within the frame viewed. This displacement, derived via observation and predictions of the quantum model, resolves Maxwell as well as Newton. The theory concludes that the Special Theory of Relativity, suitably modified to account for gravitational displacement within one particular frame, derives a precise relative model of gravitation within the special frame. This model satisfies Newton, as the model arrives at an exact description of the three‐body problem.
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Liang Zhang, Changzhu Wei, Yin Diao and Naigang Cui
This paper aims to investigate the problem of on-line orbit planning and guidance for an advanced upper stage.
Abstract
Purpose
This paper aims to investigate the problem of on-line orbit planning and guidance for an advanced upper stage.
Design/methodology/approach
The double impulse optimal transfer orbit is planned by the Lambert algorithm and the improved particle swarm optimization (IPSO) method, which can reduce the total velocity increment of the transfer orbit. More specially, a simplified formula is developed to obtain the working time of the main engine for two phases of flight based on the theorem of impulse. Subsequently, the true anomalies of the start position and the end position for both two phases are planned by the Newton iterative algorithm and the Kepler equation. Finally, the first phase of flight is guided by a novel iterative guidance (NIG) law based on the true anomaly update with respect to the geometrical relationship. Also, a completely analytical powered explicit guidance (APEG) law is presented to realize orbital injection for the second phase of flight.
Findings
Simulations including Monte Carlo and three typical orbit transfer missions are carried out to demonstrate the efficiency of the proposed scheme.
Originality/value
A novel on-line orbit planning algorithm is developed based on the Lambert problem, IPSO optimization method and Newton iterative algorithm. The NIG and APEG are presented to realize the designed transfer orbit for the first and second phases of flight. Both two guidance laws achieve higher orbit injection accuracies than traditional guidance laws.
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Abstract
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Ewa McGrail, J. Patrick McGrail and Alicja Rieger
To explore the potential of conversations with an authentic audience through blogging for enriching in young writers the understanding of the communicative function of writing…
Abstract
Purpose
To explore the potential of conversations with an authentic audience through blogging for enriching in young writers the understanding of the communicative function of writing, specifically language and vocabulary use.
Design/methodology/approach
We situate our work in the language acquisition model of language learning, in which learners develop linguistic competence in the process of speaking and using language (Krashen, 1988; Tomasello, 2005). We also believe that language learning benefits from formal instruction (Krashen, 1988). As such, in our work, we likened engaging in blogging to learning a language (here, more broadly conceived as learning to write) through both natural communication (acquisition) and prescription (instruction), and we looked at these forms of learning in our study.
We were interested in the communicative function of language learning (Halliday, 1973; 1975; Penrod, 2005) among young blog writers, because we see language learning as socially constructed through interaction with other speakers of a language (Tomasello, 2005; Vygotsky, 1978).
Findings
The readers and commenters in this study supported young writers in their language study by modeling good writing and effective language use in their communication with these writers. Young writers also benefited from direct instruction through interactions with adults beyond classroom teachers, in our case some of the readers and commenters.
Practical implications
Blogging can extend conversations to audiences far beyond the classroom and make writing a more authentic endeavor for young writers. Teachers should take advantage of such a powerful tool in their writing classrooms to support their students’ language study and vocabulary development.
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Kenneth A. Leithwood, Paul T. Begley and J. Bradley Cousins
Growing appreciation for the potential impact of principals ontheir schools has stimulated a significant body of research concerningthe principalship. While many aspects of the…
Abstract
Growing appreciation for the potential impact of principals on their schools has stimulated a significant body of research concerning the principalship. While many aspects of the principalship have been the object of study, it is often difficult to determine the relationship among these studies and how these studies, as a whole, contribute to a better understanding of the principalship. It is also difficult to judge which aspects of the principalship would provide the most productive focus for subsequent research. The review reported in this article addressed both sets of difficulties by analysing a total of 135 empirical studies conducted between 1974 and 1988; 60 of these studies were reported between 1985 and 1988 and received more attention than the earlier 75. Results of the analysis identify aspects of the principalship about which much is known, approaches to research which appear to have exhausted their usefulness and areas in which further study seems likely to be of most value. One major conclusion from the analysis is that we know most about effective principal practices and least about how such practices develop.
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David Sorrell and Gavin T.L. Brown
The purpose of this paper is to explore the explicit teaching of information text schema with vocabulary instruction to primary-aged students in Hong Kong international education.
Abstract
Purpose
The purpose of this paper is to explore the explicit teaching of information text schema with vocabulary instruction to primary-aged students in Hong Kong international education.
Design/methodology/approach
Data were collected through three quasi-experimental studies with different age groups and participants. Each study divided participants into two randomly assigned groups, either informational texts (IT) or vocabulary building (VB). Impact was evaluated with gain scores on a standardized reading comprehension test and researcher-designed cloze tests of fiction and nonfiction passages.
Findings
The explicit teaching of IT can benefit student reading comprehension from an early age, particularly to first language (L1) English students and possibly second language (L2) English learners. School reading programmes should include opportunities for students to experience IT (nonfiction) and fiction materials, and build their vocabulary through incidental learning and explicit teaching. For IT, they should be exposed to: layout – e.g., headings, sub-headings, glossary, and index; and content – photographs and specific/technical vocabulary. For fiction-based texts and VB, the following themes should be covered by younger aged students: antonyms, synonyms, and affixes.
Research limitations/implications
Several limitations apply to this study which will need to be addressed in future studies. These include: the random sampling of students from the overall student population was not an option, given the necessity of voluntary participation and avoiding disruption to school routines. This study used meta-analysis to aggregate results across multiple comparisons largely because of the extremely small samples available. The data show large standard errors as a consequence of small numbers of participants. Hence, the current results, notwithstanding the power of meta-analysis, need to be validated with much larger samples in future studies.
Originality/value
This paper suggests that greater comprehension and cloze performance among L1 students was found due to the teaching of IT compared to vocabulary training, with the reverse result for L2 English learners.
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Muhammad Waleed Shehzad, Md. Kamrul Hasan, Rida Ahmed, Shazma Razzaq and Shehzad Ahmed
Grit is a novel, rather an important psychological variable that has been associated with performance in the English as a second or foreign language (ESL/EFL) context. However…
Abstract
Purpose
Grit is a novel, rather an important psychological variable that has been associated with performance in the English as a second or foreign language (ESL/EFL) context. However, there is a dearth of research on the relationship of grit and pronunciation performance among EFL learners. Consequently, the current study sought to establish the association between grit and the pronunciation performance of Saudi EFL learners by employing pronunciation self-efficacy beliefs as a mediating variable.
Design/methodology/approach
A quantitative correlational research design was deployed in this research. Data were collected from 350 Saudi university EFL learners using questionnaires and a pronunciation test.
Findings
Findings indicated that both the dimensions of grit (i.e. perseverance of effort and consistency of interest) showed a significant and positive association with the learners' pronunciation self-efficacy beliefs. Also, the pronunciation self-efficacy beliefs showed a significant and positive association with the pronunciation performance. Lastly, findings indicated that pronunciation self-efficacy beliefs mediated the association between girt (i.e. perseverance of effort and consistency of interest) and pronunciation performance.
Originality/value
The study’s findings have implications for the EFL classroom. By incorporating grit and self-efficacy beliefs into students, teachers can enhance their students' English pronunciation performance.
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In October, 1908, a report was issued by the Medical Officer of Health for the City of London relating to the unsatisfactory manner in which soda water was manufactured at that…
Abstract
In October, 1908, a report was issued by the Medical Officer of Health for the City of London relating to the unsatisfactory manner in which soda water was manufactured at that time in the London district, and to the means that had been used after official enquiry to better the methods of manufacture. The circumstances were referred to in this Journal for November, 1908. It will be remembered that at the time reputable members of the trade readily agreed that they should be bound by certain regulations. These regulations had been drawn up by the Medical Officer of Health for the City of London and related to inspection of premises and examination of plant, water, and materials. As a proof that they had complied with the regulations a certificate was issued to each firm by their trade society, “The London Bottle Exchange and Mineral Water Trade Protection Society, Limited.” This certificate was submitted to and passed by the Medical Officer of Health for the City of London before issue. The arrangement, though good in conception, appears to be faulty in design, and it is desirable, therefore, to offer some criticism.
E.A. De Souza Neto, Djordje Perić and D.R.J. Owen
This work addresses the computational aspects of a model forelastoplastic damage at finite strains. The model is a modification of apreviously established model for large strain…
Abstract
This work addresses the computational aspects of a model for elastoplastic damage at finite strains. The model is a modification of a previously established model for large strain elastoplasticity described by Perić et al. which is here extended to include isotropic damage and kinematic hardening. Within the computational scheme, the constitutive equations are numerically integrated by an algorithm based on operator split methodology (elastic predictor—plastic corrector). The Newton—Raphson method is used to solve the discretized evolution equations in the plastic corrector stage. A numerical assessment of accuracy and stability of the integration algorithm is carried out based on iso‐error maps. To improve the stability of the local N—R scheme, the standard elastic predictor is replaced by improvedinitial estimates ensuring convergence for large increments. Several possibilities are explored and their effect on the stability of the N—R scheme is investigated. The finite element method is used in the approximation of the incremental equilibrium problem and the resulting equations are solved by the standard Newton—Raphson procedure. Two numerical examples are presented. The results are compared with those obtained by the original elastoplastic model.