Comparison of the performances of absorption refrigeration cycles

This paper compares the performance of absorption refrigeration cycles that are used for refrigeration temperatures below 0°C. Since the most common vapor absorption refrigeration systems use ammonia-water solution with ammonia as the refrigerant and water as the absorbent, research has been devoted to improvement of the performance of ammonia-water absorption refrigeration systems in recent years. In this paper the performances of the ammonia-water and possible alternative cycles as ammonia-lithium nitrate, ammonia-sodium thiocyanate, monomethylamine-water, R22-DMEU, R32-DMEU, R124-DMEU, R152a-DMEU,R125-DMEU, R134a-DMEU, trifluoroethanol (TFE)-tetraethylenglycol dimethylether (TEGDME), methanol-TEGDME and R134a-DMAC are compared in respect of the coefficient of performance (COP) and circulation ratio (f). The highest COP and the lowest f, were found as a function of the generator, condenser, absorber and evaporating temperature

Is a comparison of results meaningful from the inexact replications of computational experiments?

The main objective of this paper is to correct the unreasonable and inaccurate criticism to our previous experiments using Teaching–Learning-Based Optimization algorithm and to quantify the amount of error that may arise due to incorrect counting of fitness evaluations. It is shown that inexact experiment replication should be avoided in comparisons between meta-heuristic algorithms whenever possible. Otherwise, an inexact replication and margin of error should be explicitly reported

CRLF2 gene rearrangements in Philadelphia-like acute lymphoblastic leukemia

Philadelphia-podobna akutna limfoblastna levkemija (Ph-podobna ALL) je oblika B-celične ALL, ki ima zelo podoben profil izraženih genov kot Ph-pozitivna ALL, vendar pa nima prisotnega značilnega kromosoma Ph. Na genski ravni gre za zelo heterogeno bolezen, pri kateri lahko pride do različnih sprememb, ki vodijo v deregulacijo citokinskih receptorjev in tirozinskih kinaz. Posledično predstavlja diagnostika te bolezni precejšen izziv in zahteva sistematičen večstopenjski pristop ter uporabo različnih metod. Najpogostejše genske spremembe pri tej obliki ALL so spremembe v genu CRLF2. Gen CRLF2 se nahaja v psevdoavtosomni regiji 1 na kratki ročici spolnih kromosomov in kodira citokinski receptor tipa I, ki je del receptorja za timusni stromalni limfopoetin. Aktivacija tega receptorja aktivira signalne poti, ki so vpletene v procese proliferacije in razvoja hematopoetskega sistema. Spremembe gena CRLF2 vodijo do nenadzorovane proliferacije in preživetja prekurzorskih celic B. Namen magistrske naloge je bil ugotoviti, kakšna je pogostost preureditev gena CRLF2 pri slovenskih bolnikih z B-ALL in ovrednotiti uporabnost preiskave FISH v odkrivanju bolnikov s Ph-podobno ALL. Preureditve gena CRLF2 na kratki ročici spolnih kromosomov smo zaznavali z dvobarvno razcepno fluorescenčno DNA-sondo Cytocell CRLF2 Breakapart Probe. Najprej smo določili pražni vrednosti za DNA-sondo, in sicer 3,8 % za translokacijo (največkrat nastane IGH-CRLF2) in za delecijo (nastane P2RY8-CRLF2) prav tako 3,8 %. Analizirali smo 49 vzorcev, pridobljenih iz kostnega mozga slovenskih bolnikov z B-ALL, ki niso imeli prisotnih drugih ponavljajočih se genskih nepravilnosti. Preureditve gena CRLF2 smo našli pri 4 preiskovancih, kar predstavlja 8,2 % (4/49) analiziranih vzorcev oz. 3 % (4/133) vseh slovenskih bolnikov z B-ALL med januarjem 2012 in junijem 2019. Pri 3 preiskovancih je bila prisotna translokacija, pri 1 pa delecija. Pri 1 preiskovancu s translokacijo smo določili tudi rahlo povišano izražanje proteina TSLPR (določeno s pretočno citometrijo). Preiskava FISH se je izkazala za uspešno pri odkrivanju bolnikov s Ph-podobno ALL, njena vpeljava v rutino pa je enostavna. Predlagamo preverjanje prisotnosti preureditev gena CRLF2 s kombinacijo pretočne citometrije in preiskave FISH ter uvedbo DNA-sonde CRLF2 v algoritem izbire DNA-sond pri bolnikih z B-ALL, pri čemer se bo preiskava s sondo CRLF2 izvedla, če bodo predhodno izključene vse druge ponavljajoče se genske spremembe.Philadelphia-like acute lymphoblastic leukemia (Ph-like ALL) is a type of B-cell ALL that has a similar gene expression profile to Ph-positive ALL, however, no Philadelphia chromosome is present. Genetically, this is a very heterogeneous disease. Several different alterations that lead to deregulation of cytokine receptors and tyrosine kinases can be found. This makes the diagnosis of Ph-like ALL challenging yet of vital importance for treatment selection. It requires a systematic approach and use of various methods. Alterations in the CRLF2 gene are the most common alterations in Ph-like ALL. CRLF2 gene is located in the pseudoautosomal region 1 on the short arms of chromosomes X and Y. It encodes a member of the type I cytokine receptor family, which is a part of the receptor for thymic stromal lymphopoietin. The activation of this receptor leads to the activation of several signaling pathways that control processes such as cell proliferation and development of the hematopoietic system. Alterations in the CRLF2 gene lead to uncontrolled proliferation and survival of B-cell progenitors. The purpose of this project was to determine the frequency of CRLF2 rearrangements in Slovenian patients with B-ALL and to evaluate the usefulness of FISH analysis in identification of Ph-like ALL patients. The rearrangements were detected using a fluorescently labeled DNA probe Cytocell CRLF2 Breakapart Probe which detects two CRLF2 rearrangements on the short arms of the sex chromosomes. We determined the cut-off value to be 3,8 % for the translocation (usually results in IGH-CRLF2) and 3,8 % for the deletion (results in P2RY8-CRLF2) as well. We analyzed 49 bone marrow samples from Slovenian B-ALL patients that did not have recurring genetic alterations. CRLF2 rearrangements were found in four samples which accounts for 8,2 % (4/49) of all analyzed samples and 3 % (4/133) of all Slovenian B-ALL patients (from January 2012 to June 2019). Three patients carried a translocation and one carried a deletion. One patient with the translocation also had a slightly higher CRLF2 gene expression (detected by flow cytometry). FISH analysis proved to be efficient in identification of Ph-like ALL patients and its introduction into routine diagnostics is simple. We suggest the use of both flow cytometry and FISH to identify patients with CRLF2 rearrangements. We also suggest an introduction of the CRLF2 DNA probe into the DNA probe choice algorithm for B-ALL patients. This probe should be used, if all other recurring alterations are ruled out

Magnetic water treatment for scale control in heating and alkaline conditions

Magnetic water treatment (MWT), an alternative solution for scale control, is discussed with emphasis on the construction of the magnetic devices and the mechanism of MWT influence on the scale formation. Two applications in high-temperature and high-pH conditions are presented. The treatment noticeably reduced the scale thickness on the heating spiral and removed preciously precipitated scale from hot tap-water outlet pipeon the walls in the zone with heated alkaline water, instead of hard scale, only thin, brittle coating was formed. The morphology analyses showed the acceleration of aragonite nucleation and raised formation of fine suspended particles

Gravitational Swarm Optimizer for Global Optimization

In this article, a new meta-heuristic method is proposed by combining particle swarm optimization (PSO) and gravitational search in a coherent way. The advantage of swarm intelligence and the idea of a force of attraction between two particles are employed collectively to propose an improved meta-heuristic method for constrained optimization problems. Excellent constraint handling is always required for the success of any constrained optimizer. In view of this, an improved constraint-handling method is proposed which was designed in alignment with the constitutional mechanism of the proposed algorithm. The design of the algorithm is analyzed in many ways and the theoretical convergence of the algorithm is also established in the article. The e�fficiency of the proposed technique was assessed by solving a set of 24 constrained problems and 15 unconstrained problems which have been proposed in IEEE-CEC sessions 2006 and 2015, respectively. The results are compared with 11 state-of-the-art algorithms for constrained problems and 6 state-of-the-art algorithms for unconstrained problems. A variety of ways are considered to examine the ability of the proposed algorithm in terms of its converging ability, success, and statistical behavior. The performance of the proposed constraint-handling method is judged by analyzing its ability to produce a feasible population. It was concluded that the proposed algorithm performs e�fficiently with good results as a constrained optimizer

Heat waves analysis and the heat load of agricultural workers during the heat waves in 2017 (using index WBGT)

Workers in agriculture are regularly exposed to heat stress during summer, which can affect reduced labour productivity and income losses. Air temperatures in Slovenia have been rising in recent decades, and climate change projections show that this trend will continue along with an increase in the number of days with heat stress risk. Changes in the number of heat waves in central and south-western Slovenia for the period 1961–2017 were analysed as well as the risk of the heat stress for workers during heat waves in the year 2017. The heat wave occurs if the temperature threshold for the average daily temperature is reached or exceeded on at least three consecutive days, with the threshold for the mild continental climate (Ljubljana) 24 °C and the mild Submediterranean climate (Bilje) 25 °C. The WBGT (Wet Bulb Globe Temperature) index, assessing the risk of heat stress, was calculated from relative humidity and air temperatures. At both locations, the number of days in heat waves increased as well as their intensity, average daily air temperatures were significantly higher than in the first half of the considered period. The time span, in which the heat waves occur, also extended, as until 1990 they did not appear in early June and late August, as in recent years. The calculated values of the WBGT show that for most days in the heat waves in 2017 in Ljubljana and Bilje, the WBGT 23 °C threshold was exceeded practically all day, which shows a high level of heat stress risk for physically intense work. In the case of exceeded WBGT reference values, employers or farmers themselves should take actions to reduce the risk of heat stress

Adapting Quality Assurance to Adaptive Systems: The Scenario Coevolution Paradigm

From formal and practical analysis, we identify new challenges that self-adaptive systems pose to the process of quality assurance. When tackling these, the effort spent on various tasks in the process of software engineering is naturally re-distributed. We claim that all steps related to testing need to become self-adaptive to match the capabilities of the self-adaptive system-under-test. Otherwise, the adaptive system's behavior might elude traditional variants of quality assurance. We thus propose the paradigm of scenario coevolution, which describes a pool of test cases and other constraints on system behavior that evolves in parallel to the (in part autonomous) development of behavior in the system-under-test. Scenario coevolution offers a simple structure for the organization of adaptive testing that allows for both human-controlled and autonomous intervention, supporting software engineering for adaptive systems on a procedural as well as technical level.Comment: 17 pages, published at ISOLA 201

Maintaining regularity and generalization in data using the minimum description length principle and genetic algorithm: case of grammatical inference

In this paper, a genetic algorithm with minimum description length (GAWMDL) is proposed for grammatical inference. The primary challenge of identifying a language of infinite cardinality from a finite set of examples should know when to generalize and specialize the training data. The minimum description length principle that has been incorporated addresses this issue is discussed in this paper. Previously, the e-GRIDS learning model was proposed, which enjoyed the merits of the minimum description length principle, but it is limited to positive examples only. The proposed GAWMDL, which incorporates a traditional genetic algorithm and has a powerful global exploration capability that can exploit an optimum offspring. This is an effective approach to handle a problem which has a large search space such the grammatical inference problem. The computational capability, the genetic algorithm poses is not questionable, but it still suffers from premature convergence mainly arising due to lack of population diversity. The proposed GAWMDL incorporates a bit mask oriented data structure that performs the reproduction operations, creating the mask, then Boolean based procedure is applied to create an offspring in a generative manner. The Boolean based procedure is capable of introducing diversity into the population, hence alleviating premature convergence. The proposed GAWMDL is applied in the context free as well as regular languages of varying complexities. The computational experiments show that the GAWMDL finds an optimal or close-to-optimal grammar. Two fold performance analysis have been performed. First, the GAWMDL has been evaluated against the elite mating pool genetic algorithm which was proposed to introduce diversity and to address premature convergence. GAWMDL is also tested against the improved tabular representation algorithm. In addition, the authors evaluate the performance of the GAWMDL against a genetic algorithm not using the minimum description length principle. Statistical tests demonstrate the superiority of the proposed algorithm. Overall, the proposed GAWMDL algorithm greatly improves the performance in three main aspects: maintains regularity of the data, alleviates premature convergence and is capable in grammatical inference from both positive and negative corpora

A self-adaptive multimeme memetic algorithm co-evolving utility scores to control genetic operators and their parameter settings

Memetic algorithms are a class of well-studied metaheuristics which combine evolutionary algorithms and local search techniques. A meme represents contagious piece of information in an adaptive information sharing system. The canonical memetic algorithm uses a fixed meme, denoting a hill climbing operator, to improve each solution in a population during the evolutionary search process. Given global parameters and multiple parametrised operators, adaptation often becomes a crucial constituent in the design of MAs. In this study, a self-adaptive self-configuring steady-state multimeme memetic algorithm (SSMMA) variant is proposed. Along with the individuals (solutions), SSMMA co-evolves memes, encoding the utility score for each algorithmic component choice and relevant parameter setting option. An individual uses tournament selection to decide which operator and parameter setting to employ at a given step. The performance of the proposed algorithm is evaluated on six combinatorial optimisation problems from a cross-domain heuristic search benchmark. The results indicate the success of SSMMA when compared to the static Mas as well as widely used self-adaptive Multimeme Memetic Algorithm from the scientific literature