Experimental Evaluation and Modeling of Physical Hardening in Asphalt Binders

The research described in this paper deals with the experimental evaluation and modeling of physical hardening in asphalt binders. The term physical hardening refers to a reversible phenomenon occurring at low temperatures that causes time-dependent changes in viscoelastic properties. The experimental approach, followed to quantitatively assess physical hardening, was based on flexural creep tests carried out by means of the Bending Beam Rheometer at various temperatures and conditioning times. The results obtained confirmed that hardening phenomena have a significant influence on the creep response of asphalt binders, to an extent that can be quantitatively assessed by referring to the appropriate rheological parameters and by applying the loading time–conditioning time superposition principle. The experimental data were fitted to a mechanical model proposed in the literature (composed of a single Kelvin–Voigt element) and thereafter to an improved model (with two Kelvin–Voigt elements in series). Both models were assessed in terms of their prediction accuracy. The improved model was found to better describe physical hardening effects in the case of both short- and long-term conditioning. Practical implications of the study were finally highlighted by referring to possible ranking criteria to be introduced in acceptance procedures for the comparative evaluation of asphalt binders.

Improving the accuracy of predicting the hazard of the earth’s surface failure formation during underground mining of mineral deposits

Purpose. Development of a new approach to improving the accuracy of predicting situations in which the earth’s surface failures occur as a result of undermining a rock mass during the development of mineral deposits. Methods. The critical situations, including the earth’s surface failures, are predicted on the basis of assessing the value of geoenergy and studying its change as large volumes of rock mass are involved in mining. Analytical solutions based on the fundamental laws of physics and mechanics of continuous media are used. The research is performed using methods of cause-and-effect analysis. Findings. Based on the cause-effect relationship, determined between the change in the value of the mass geoenergy and deformation processes on the daylight surface of the field, an effective method has been developed for ranking it according to the degree of hazard of failure formation with the simultaneous use of two criteria. One of the criteria is determined by the relative change in geoenergy during the system transition from the initial (stable) state to the current one, which becomes unstable under certain conditions. The second criterion is formed on the basis of the change in geoenergy during the transition from the current (possibly unstable) state to the final (stable) state. Originality. For the first time, when zoning the daylight surface of a field according to the degree of hazard of failure formation, two ranking criteria are used simultaneously, based on the assessment of geoenergy accumulated in a heterogeneous mass, when it is undermined in the conditions of triaxial compression. Practical implications. The territory ranking method, developed on the basis of the used criteria for hazard of failure formation, allows improving the quality of situational control, predicting risk situations and their development, as well as optimizing the short-term and long-term plans for the development of mining operations.

Maximum Drawdown, Recovery, and Momentum

We empirically test predictability on asset price using stock selection rules based on maximum drawdown and its consecutive recovery. In various equity markets, monthly momentum- and weekly contrarian-style portfolios constructed from these alternative selection criteria are superior not only in forecasting directions of asset prices but also in capturing cross-sectional return differentials. In monthly periods, the alternative portfolios ranked by maximum drawdown measures exhibit outperformance over other alternative momentum portfolios including traditional cumulative return-based momentum portfolios. In weekly time scales, recovery-related stock selection rules are the best ranking criteria for detecting mean-reversion. For the alternative portfolios and their ranking baskets, improved risk profiles in various reward-risk measures also imply more consistent prediction on the direction of assets in future. Moreover, turnover rates of these momentum/contrarian portfolios are also reduced with respect to the benchmark portfolios. In the Carhart four-factor analysis, higher factor-neutral intercepts for the alternative strategies are another evidence for the robust prediction by the alternative stock selection rules.

Comparative Evaluation of Translation Memory (TM) and Machine Translation (MT) Systems in Translation between Arabic and English

In general, advances in translation technology tools have enhanced translation quality significantly. Unfortunately, however, it seems that this is not the case for all language pairs. A concern arises when the users of translation tools want to work between different language families such as Arabic and English. The main problems facing Arabic<>English translation tools lie in Arabic’s characteristic free word order, richness of word inflection – including orthographic ambiguity – and optionality of diacritics, in addition to a lack of data resources. The aim of this study is to compare the performance of translation memory (TM) and machine translation (MT) systems in translating between Arabic and English.The research evaluates the two systems based on specific criteria relating to needs and expected results. The first part of the thesis evaluates the performance of a set of well-known TM systems when retrieving a segment of text that includes an Arabic linguistic feature. As it is widely known that TM matching metrics are based solely on the use of edit distance string measurements, it was expected that the aforementioned issues would lead to a low match percentage. The second part of the thesis evaluates multiple MT systems that use the mainstream neural machine translation (NMT) approach to translation quality. Due to a lack of training data resources and its rich morphology, it was anticipated that Arabic features would reduce the translation quality of this corpus-based approach. The systems’ output was evaluated using both automatic evaluation metrics including BLEU and hLEPOR, and TAUS human quality ranking criteria for adequacy and fluency.The study employed a black-box testing methodology to experimentally examine the TM systems through a test suite instrument and also to translate Arabic English sentences to collect the MT systems’ output. A translation threshold was used to evaluate the fuzzy matches of TM systems, while an online survey was used to collect participants’ responses to the quality of MT system’s output. The experiments’ input of both systems was extracted from Arabic<>English corpora, which was examined by means of quantitative data analysis. The results show that, when retrieving translations, the current TM matching metrics are unable to recognise Arabic features and score them appropriately. In terms of automatic translation, MT produced good results for adequacy, especially when translating from Arabic to English, but the systems’ output appeared to need post-editing for fluency. Moreover, when retrievingfrom Arabic, it was found that short sentences were handled much better by MT than by TM. The findings may be given as recommendations to software developers.

Multi-Objective Faculty Course Assignment Problem with Result and Feedback Based Uncertain Preferences

In this paper, a multi-objective faculty course allocation problem with result analysis and feedback analysis based on uncertain preferences mathematical model is presented. To deal with an uncertain model, three different ranking criteria are being used to develop: a) Expected value, b) Optimistic value, c) Dependent optimistic value criterion. These mathematical models are transformed into their corresponding deterministic forms using the basic concepts of uncertainty theory. The deterministic model of DOCM consists of fractional objectives which are converted into their linear form using Charnes and Cooper’s transformation. These deterministic formulations MOFCAP are converted into a single objective problem by using the fuzzy programming technique with linear and exponential membership functions. Further, the single objective problem for all the defined models is solved in the Lingo 18.0 software to derive the Pareto-optimal solution. The sensitivity of the models is also performed to examine the variation in the objective function due to the variation in parameters. Finally, a numerical example is given to exhibit the application and algorithm of the models.

Analysis of the criteria for evaluating judo judges for performance indicators in competitions

Purpose: with the help of a questionnaire, to analyze the criteria for evaluating judo judges for performance indicators at competitions. Material and methods. During the research the following methods were used: theoretical analysis and generalization of literature sources, Internet data, questionnaires, generalization of theoretical and practical experience of specialists in the field of martial arts, methods of mathematical statistics. A questionnaire survey of judo judges was conducted. The study involved 30 judo judges of the international category (3 men – 10 %) of the national category (15 people – 50 %) and the first category (12 people – 40 %). Results: the analysis of the conducted survey of judo judges on the basis of 50 evaluation criteria for the performance of judges in competitions revealed the main 11 criteria that are in the opinion of most experts the most effective. Thus, 11 criteria were distributed among specialists of international, national and first categories of judges as follows: in the first place - professional ethics and discipline 1,33; in second place - the appearance of 1,66; in third place - knowledge of the rules and the ability to use them 3,66; in fourth place - is the clarity of commands and gestures 4,66; in fifth place - moving on the tatami and choosing the correct position 5,00; in sixth place - interaction with judges 6,67; in seventh place - the ability to correctly and timely assess errors 7.66; in eighth place - the ability to accurately and timely assess technical actions 8,00; in ninth place - psychological stability 8,33; in tenth place - the reaction to the situation 8,66; on the eleventh place - the ability to use technical means 10,33. Conclusions. Thus, the survey of judges' categories from the 50 proposed criteria revealed 11 most practical criteria by which it is possible to evaluate the work of judges in competitions. As a result of the questionnaire survey, most experts put professional ethics and discipline in the first place; second place - appearance; third place - knowledge of the rules and the ability to use them. Keywords: judo, questionnaire, ranking, criteria, judges, professional ethics

A Ranking Framework for Higher Education Institutions

The use of league tables and rankings (LTRs) as a tool to rank or measure the performance of higher education institutions (HEIs) has grown in popularity. Research indicates that these ranking criteria are often discussed from the standpoint of governments, the HEI management, and the ranking institutions producing these LTR publications. The opinions of the students on the suitable ranking criteria used by ranking institutions are generally omitted. This chapter investigates the applicable criteria for ranking HEIs in South Africa, from the perspective of students. A survey was conducted to determine the most relevant university ranking criteria considered by university students. The results indicate that the students perceive resources and infrastructure, accreditation, international orientation, research output, faculty quality, and teaching and learning as the most relevant criteria for ranking HEIs. Managerial recommendations are provided for HEIs to address the ranking criteria rated important by students.