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The purpose of this study is to investigate whether question and keyword‐format queries are more successfully processed by search engines encouraging answers to searching and keyword‐format querying, respectively. This study aims to investigate whether web user characteristics and choice of search engine affects the relevancy scores and precision of the results.

The results of two search engines, Google and AskJeeves, were compared for question and keyword‐format queries. It was observed that AskJeeves was slightly more successful in processing question‐format queries, but this finding was not statistically supported. However, Google provided results on keyword‐format queries and the entire set of queries, which were statistically superior to those of AskJeeves.

Analysis of variance (ANOVA) showed that the age of web user is not as affective on the relevancy score and precision of results as other factors. Interactions of the main factors were also affective on the relevancy scores and precision, meaning that the different combinations of various factors cause a synergy in terms of relevancy scores and precision.

This was a preliminary work on the effect of user characteristics on comprehension and evaluation of search query results. Future work includes expanding this study to include more web user characteristics, more levels of the web user characteristics, and inclusion of more search engines.

The findings of this study provide statistical proof for the relationship between the characteristics of web users, choice of search engine and the relevancy scores and precision of search results.

AT the present time turbojet aircraft types which are capable of level flight Mach numbers well into the supersonic range are appearing in increasing numbers. Yet, while this represents in a sense a new phase in the evolution of piloted aircraft, from the point of view of the propulsion engineer it is rather the end of an era, in that hitherto the turbojet engines employed have been essentially subsonic engines suitably strengthened. Henceforth we may expect to see the use of engines specifically designed for the appropriate range of Mach number, and it is the purpose of this article to review some of the implications of this change of outlook in so far as they affect the prediction of engine performance.

The literature of the evaluation of Internet search engines is reviewed. Although there have been many studies, there has been little consistency in the way such studies have been carried out. This problem is exacerbated by the fact that recall is virtually impossible to calculate in the fast changing Internet environment, and therefore the traditional Cranfield type of evaluation is not usually possible. A variety of alternative evaluation methods has been suggested to overcome this difficulty. The authors recommend that a standardised set of tools is developed for the evaluation of web search engines so that, in future, comparisons can be made between search engines more effectively, and that variations in performance of any given search engine over time can be tracked. The paper itself does not provide such a standard set of tools, but it investigates the issues and makes preliminary recommendations of the types of tools needed.

The purpose of this paper is to outline the potential usage of ceramic engines in combination with other technologies as a possible propulsion contender for future aerospace applications.

The possibility of enabling novel propulsion systems in aerospace engineering is examined through a multilateral review study concerning ceramic engines and a proposed design approach. In view of the benefits and challenges of employing ceramic engines as possible candidates for the sustainable solutions of the future, a fundamental design proposal is presented for a conceptual generic unmanned air vehicle (GUAV).

The findings of this article identify a number of useful scenarios for future ceramic engine applications and considerations.

It is imperative to emphasize that this conceptual article solely sheds light on a limited number of key ideas associated with ceramic engines and their possible applications. Thus, many new areas may emerge and impact the application of ceramic engines in light of more in‐depth conceptual studies.

Implications of ceramic engine utilization in aeronautical applications may result in enhanced performance characteristics and less operational costs. Further implications could possibly be extended to various naval/automotive applications and new configurations of transportation vehicles.

The paper aims to generate an interest amongst younger individuals and environmental aware enthusiasts to consider ceramic engines for transportation applications to a greater extent than before.

The implementation of this particular conceptual design results in a synergistic ceramic engine combination with a hybrid airship design in novel aeronautical applications.

THE requirement for a ‘big twin’ had been recognised at an early stage in Europe, and in the interests of securing a suitable home market on which to launch the project, a consortium comprising manufacturers from Germany, France and the U.K. was established at the initiative of the three governments to develop and produce such an aircraft. The formation of this group brought together considerable resources and experience, particularly relevant experience being found in the Caravelle and Trident.

THE fact that the anti‐knock rating of aviation fuels in octane numbers presents difficulties, especially above 80 octane, has led us to develop a more suitable test method for aviation fuels, which might be called the “Allowable Boost Ratio ” method.

Implementing lean management (LM) provides universities with a variety of benefits and utilities. The purpose of this study is to systematically analyze the existing literature on the implementation of LM in universities.

A systematic literature review is undertaken to identify, select and evaluate the literature. A total of 68 articles were identified in Web of Science and Scopus, analyzed and synthesized from the first article published on the topic (2003) to mid-2020.

Literature analysis and evaluation have enabled us to offer a novel literature classification based around four research lines that summarize the empirical evidence on LM implementation in universities, namely, lean applied to academic management processes; lean applied to administrative management processes; factors that facilitate lean implementation and results obtained with lean. Finally, the gaps and challenges for future research into LM in universities are presented.

This study provides a characterization of the research carried out into LM implementation in universities, which facilitates the work of both scholars wishing either to begin or to dig deeper into this sphere and university professionals and managers pursuing the best outcomes from LM.

The types of innovation considered to be Schumpeterian can be very broad. What is an innovation? According to The Advanced Learner's Dictionary (Hornby, Gatenby, & Wakefield, 1973, p. 545), an innovation is “something new that is introduced.” This covers both inventions and their introduction. Thus, introducing methods to a new market can certainly be a form of Schumpeterian innovation. Schumpeter, however, distinguished innovations (innovators) from inventions (inventors) (Swedberg, 1991, p. 173). He considered innovations as the prime movers in the capitalist process. Johannessen, Olsen, and Lumpkin (2001) dwell on six measures of the “newness” of an innovation based on his interpretation of Schumpeter and others, but glossed over the distinction between innovations and inventions. What, then, was Schumpeter's original formulation?

THE current discussions to define a multi‐role aircraft for the mid 1970s have been notable for dissension of opinion on the choice between one engine or two. This remarkably basic choice has been with us since pioneer days — Lindbergh's acid comment on the value of two engines was ‘twice the trouble’, while the very fact that there are many aircraft in use of both layouts indicates that there has not been a clear case for choosing cither. Not, that is, until very recently, when statistics on the loss rate of both single and twin‐engined aircraft have confirmed that a definite margin does exist. This is the key to the whole choice between two engines or one, for it is necessary to compare not only the initial costs, but also the maintenance and operating costs, replacement of lost aircraft, and pilot training costs to achieve a realistic comparison on an overall cost basis. As with most cost‐effective arguments a strong danger exists of losing sight of primary objectives in a welter of tenuously related facts. The objectives in the choice between two engines and one is simple; which configuration fulfills an operational requirement at the least overall cost.

The purpose of this paper is to propose a solution of the engine bypass ratio choice problem of a very light jet (VLJ) class aircraft using the multiple objective optimization (MOO) method.

The work focuses on the choice of one of the most essential parameters of the jet engine, that is its bypass ratio. The work presents the methodology of optimal designing using the multitask character of the matter which is based on the mathematical model of optimization in the concept of the set theory. To make an optimal choice of the chosen parameter, a complete computational model of an aircraftwas made (aerodynamic, power unit, performance and cost) and then the method that allows to choose the bypass ratio was selected, regardingmultiple estimating criteria of the obtained solutions. The presented method can be used at the concept design state for determining the chosen and most important technical parameters of the aircraft.

The way to design a competing aircraft is to choose its design parameters, including the power unit, by using the advanced methods of MOO. The main aim of the work was to demonstrate a method of selecting chosen parameters of the transport aircraft at the preliminary design stage. The work focuses on the choice of bypass ratio of the jet engine of the VLJ. The method could be helpful at the preliminary design stage of a new aircraft to selection of other design parameters.

The exemplary calculations were made for 50 different transport tasks to take into account different performance conditions of the aircraft. The presented method can be used at the concept design state for determining the chosen and most important technical parameters of the aircraft.

The work shows a practical possibility to implement the proposed method. The presented method could be helpful at the preliminary design stage of a new aircraft to select its design parameters. The results of the analyses are a separate point for further research and studies.

The work shows a practical possibility to implement the proposed approach for design problems at early stages of product development.