On the computational complexity of dynamic slicing problems for program schemas

This is the preprint version of the Article - Copyright @ 2011 Cambridge University PressGiven a program, a quotient can be obtained from it by deleting zero or more statements. The field of program slicing is concerned with computing a quotient of a program that preserves part of the behaviour of the original program. All program slicing algorithms take account of the structural properties of a program, such as control dependence and data dependence, rather than the semantics of its functions and predicates, and thus work, in effect, with program schemas. The dynamic slicing criterion of Korel and Laski requires only that program behaviour is preserved in cases where the original program follows a particular path, and that the slice/quotient follows this path. In this paper we formalise Korel and Laski's definition of a dynamic slice as applied to linear schemas, and also formulate a less restrictive definition in which the path through the original program need not be preserved by the slice. The less restrictive definition has the benefit of leading to smaller slices. For both definitions, we compute complexity bounds for the problems of establishing whether a given slice of a linear schema is a dynamic slice and whether a linear schema has a non-trivial dynamic slice, and prove that the latter problem is NP-hard in both cases. We also give an example to prove that minimal dynamic slices (whether or not they preserve the original path) need not be unique.This work was partly supported by the Engineering and Physical Sciences Research Council, UK, under grant EP/E002919/1

Decidability of strong equivalence for subschemas of a class of linear, free, near-liberal program schemas

The article attached is a preprint version of the final published article which can be accessed at the link below. The article title has been changed. For referencing purposes please use the published details. Copyright © 2010 Elsevier B.V. All rights reserved.A program schema defines a class of programs, all of which have identical statement structure, but whose functions and predicates may differ. A schema thus defines an entire class of programs according to how its symbols are interpreted. Two schemas are strongly equivalent if they always define the same function from initial states to final states for every interpretation. A subschema of a schema is obtained from a schema by deleting some of its statements. A schema S is liberal if there exists an initial state in the Herbrand domain such that the same term is not generated more than once along any executable path through S. In this paper, we introduce near-liberal schemas, in which this non-repeating condition applies only to terms not having the form g() for a constant function symbol g. Given a schema S that is linear (no function or predicate symbol occurs more than once in S) and a variable v, we compute a set of function and predicate symbols in S which is a subset of those defined by Weiser's slicing algorithm and prove that if for every while predicate q in S and every constant assignment w:=g(); lying in the body of q, no other assignment to w also lies in the body of q, our smaller symbol set defines a correct subschema of S with respect to the final value of v after execution. We also prove that if S is also free (every path through S is executable) and near-liberal, it is decidable which of its subschemas are strongly equivalent to S. For the class of pairs of schemas in which one schema is a subschema of the other, this generalises a recent result in which S was required to be linear, free and liberal.This work was supported by a grant from the Engineering and Physical Sciences Research Council, Grant EP/E002919/1

Characterizing minimal semantics-preserving slices of predicate-linear, free, liberal program schemas

This is a preprint version of the article - Copyright @ 2011 ElsevierA program schema defines a class of programs, all of which have identical statement structure, but whose functions and predicates may differ. A schema thus defines an entire class of programs according to how its symbols are interpreted. A subschema of a schema is obtained from a schema by deleting some of its statements. We prove that given a schema S which is predicate-linear, free and liberal, such that the true and false parts of every if predicate satisfy a simple additional condition, and a slicing criterion defined by the final value of a given variable after execution of any program defined by S, the minimal subschema of S which respects this slicing criterion contains all the function and predicate symbols ‘needed’ by the variable according to the data dependence and control dependence relations used in program slicing, which is the symbol set given by Weiser’s static slicing algorithm. Thus this algorithm gives predicate-minimal slices for classes of programs represented by schemas satisfying our set of conditions. We also give an example to show that the corresponding result with respect to the slicing criterion defined by termination behaviour is incorrect. This complements a result by the authors in which S was required to be function-linear, instead of predicate-linear.This work was supported by a grant from the Engineering and Physical Sciences Research Council, Grant EP/E002919/1

miRNA in Circulating Microvesicles as Biomarkers for Age-Related Cognitive Decline

Community dwelling older individuals from the North Florida region were examined for health status and a comprehensive neuropsychological battery, including the Montreal Cognitive Assessment (MoCA), was performed on each participant. A subpopulation (58 females and 39 males) met the criteria for age (60–89) and no evidence of mild cognitive impairment, with a MoCA score ≥23. Despite the stringent criteria for participation, MoCA scores were negatively correlated within the limited age range. Extracellular microvesicles were isolated from the plasma and samples were found to be positive for the exosome marker CD63, with an enrichment of particles within the size range for exosomes. miRNA was extracted and examined using next generation sequencing with a stringent criterion (average of ≥10 counts per million reads) resulting in 117 miRNA for subsequent analysis. Characterization of expression confirmed pervious work concerning the relative abundance and overall pattern of expression of miRNA in plasma. Correlation analysis indicated that most of the miRNAs (74 miRNAs) were positively correlated with age (p <0.01). Multiple regression was employed to identify the relationship of miRNA expression and MoCA score, accounting for age. MoCA scores were negatively correlated with 13 miRNAs. The pattern of expression for cognition-related miRNA did not match that previously described for Alzheimer’s disease. Enrichment analysis was employed to identify miRNA–gene interactions to reveal possible links to brain function

The use of energy potential of exhausted ventilation flow of iron enterprises with The purpose of generation of electrical energy

Бойко С. М. Використання енергетичного потенціалу відпрацьованого вентиляційного потоку залізорудних підприємств з метою генерації електричної енергії / С. М. Бойко, І. В. Носач, С. Я. Вишневський, А. В. Некрасов, Є. М. Касянов // Вісник Хмельницького національного університету. Сер.: Технічні науки. - 2018. - № 5. - С. 186-190. Режим доступу: http://journals.khnu.km.ua/vestnik/pdf/tech/pdfbase/2018/2018_5/jrn/pdf/29.pdfОдним із чотирьох заходів, запропонованих Міжнародною енергетичною агенцією для підвищення енергоефективності в країнах світу, є збільшення використання вітрової енергії в загальному обсязі виробництва електричної енергії [1]. Внаслідок природного зниження рівнів видобутку залізорудної сировини (ЗРС) на понад 1000–1500 м, тобто в бік запроектних показників, вже зараз необхідно збільшувати об’єми повітря для вентиляції. Існуюча перепроектована система вентиляції за нагнітально-всмоктувальним принципом дозволяє забезпечити необхідні обсяги, зменшити втрати і збільшити швидкість потоку повітря [2–4]. За таких умов можливим є використання частини енергії вітрових потоків для перетворення її в електричну [1] з метою використання для резервного живлення відповідальних споживачів. Безумовно, обсяги отриманої електроенергії не можуть бути значними через просторову обмеженість гірничих виробок. Разом з тим, підземні електроприймачі шахт, як правило, мають значні потужності й їх живлення від автономних джерел, зокрема вітроенергетичних установок (ВЕУ), є неможливим [5]. Особливо актуальними ці питання є для тимчасово законсервованих горизонтів шахт. Останні, як правило, відключені від централізованого електропостачання підземних підстанцій. Вітроенергетичний комплекс, встановлений в законсервованих виробках залізорудних шахт, здатний, перетворюючи частину енергії вентиляційних повітряних потоків у електричну енергію, забезпечувати аварійне резервне електропостачання освітлювальної мережі для виконання умов техніки безпеки [6]. Для досягнення належної енергоефективності ВЕУ в таких умовах необхідно враховувати низку додаткових вимог до них і, насамперед, до їх електромеханічної частини. Вони стосуються вибору типу та параметрів складових останньої, а також конструктивних особливостей приводного механізму електрогенератора [3–9]. Одной из четырех мер, предложенных Международным энергетическим агентством по повышению энергоэффективности в странах мира, является увеличение использования ветровой энергии в общем объеме производства электрической энергии [1]. В результате естественного снижения уровней добычи железорудного сырья (ЖРС) более чем на 1000–1500 м, то есть в сторону запроектных показателей, уже сейчас необходимо увеличивать объемы воздуха для вентиляции. Существующая перепроектированная система вентиляции по нагнетающе-всасывающему принципу позволяет обеспечить необходимые объемы, уменьшить потери и увеличить скорость потока воздуха [2–4]. При таких условиях возможно использование части энергии ветровых потоков для превращения ее в электрическую [1] с целью использования для резервного питания ответственных потребителей. Безусловно, объемы полученной электроэнергии не могут быть значительными из-за пространственной ограниченности горных выработок. Вместе с тем, подземные электроприемники шахт, как правило, имеют значительные мощности и их питание от автономных источников, в частности ветроэнергетических установок (ВЭУ), невозможно [5]. Особенно актуальны эти вопросы для временно законсервированных горизонтов шахт. Последние, как правило, отключены от централизованного электроснабжения подземных подстанций. Ветроэнергетический комплекс, установленный в законсервированных выработках железорудных шахт, способен, превращая часть энергии вентиляционных воздушных потоков в электрическую энергию, обеспечивать аварийное резервное электроснабжение осветительной сети для выполнения условий техники безопасности [6]. Для достижения надлежащей энергоэффективности ВЭУ в таких условиях необходимо учитывать ряд дополнительных требований к ним и прежде всего к их электромеханической части. Они касаются выбора типа и параметров составляющих последней, а также конструктивных особенностей приводного механизма электрогенератора [3-9]. One of the four measures proposed by the International Energy Agency for improving of energy efficiency in the countries of the world is increasing of the use of wind energy in the total electricity production [1]. Due to the natural decrease in the levels of iron ore (IOE) extraction by more than 1000-1500 m, that is towards the design indicators, it is now necessary to increase the volume of air for ventilation. The existing redesigned ventilation system according to the injection suction principle allows to provide the necessary volumes, reduce losses and increase the air flow rate [2–4]. Under such conditions, it is possible to use part of the energy of wind streams to convert it into electrical power [1] in order to use for backup power supply of responsible customers. Of course, the amount of generated electricity can not be significant due to the spatial limitation of mining work. At the same time, underground electrical collectors of mines, as a rule, have significant capacity and their nutrition from autonomous sources, in particular from wind power turbines (WPT), is impossible [5]. These issues are particularly relevant for temporarily preserved horizons of mines. The latter, as a rule, are disconnected from the centralized power supply of underground substations. The wind power complex installed in the preserved development of iron ore mines is capable providing an emergency back-up power supply to the lighting network to fulfill the safety conditions turning a part of the energy of ventilation air streams into electric energy [6]. In order to achieve the proper energy efficiency of the wind turbine in such conditions it is necessary to take into account a number of additional requirements to them and, first of all, to their electromechanical part. They concern the choice of the type and parameters of the components of the latter, as well as the design features of the drive mechanism of the generator [3–9]