367 research outputs found
Using Evolutionary Algorithms for the Scheduling of Aircrew on Airborne Early Warning and Control System
Equipped with an advanced radar and other electronic systems mounted on its body, Airborne Early Warning and Control System (AWACS) enables the airspace to be monitored from medium to long distances and facilitates effective control of friendly aircraft. To operate the complex equipment and fulfill its critical functions, AWACS has a specialised flight and mission crew, all of whom are extensively trained in their respective roles. For mission accomplishment and effective use of resources, tasks should be scheduled, and individuals should be assigned to missions appropriately. In this paper, we implemented evolutionary algorithms for scheduling aircrew on AWACS and propose a novel approach using Genetic Algorithms (GA) with a special encoding strategy and modified genetic operations tailored to the problem. The objective is to assign aircrew to various AWACS tasks such as flights, simulator sessions, ground training classes and other squadron duties while aiming to maximise combat readiness and minimise operational costs. The presented approach is applied to several test instances consisting notional weekly schedules of Turkish Boeing 737 AEW&C Peace Eagle AWACS Base, generated similar to real-world examples. To test the algorithm and evaluate solution performance, experiments have been conducted on a novel scheduling software called AWACS Crew Scheduling (ACS), developed as a test bed. Computational results reveal that presented GA approach proves to be quite successful in solving the AWACS Crew Scheduling Problem and exhibits superior performance when compared to manual methods
AN APPLICATION TO ERROR AND UNCERTAINTY ANALYSIS IN INDUSTRIAL TYPE DRYER EXPERIMENTS
In this study, information is given about the driers commonly used in the industry and the experimental errors anduncertainties that will be encountered in the experiments using these driers are tried to be explained by using the dataobtained from the experiments carried out in an 8 chambers hot oil heated stenter, which is a conveyor type convectiondryer. The fabric used in the experiments is the Thessaloniki type fabric, containing 67% cotton and 37% polyester. Theexperiments were carried out at a drying air temperature of 160 ºC and a fabric advance rate of 23 m/h (0.383 m/s). Thus,the example of error analysis in such experimental studies is provided and criteria that may cause an error for drying systemsare discussed. As a result of the uncertainty analysis, the largest uncertainty in the system occurred in temperaturemeasurements at ±0.367 - ±0.568 ºC values and the error rate for the whole system was found to be 4.08%. In terms ofconducting the experiments in real production conditions and the materials and methods used in the experiments, this studyis thought to will be help researchers that working on drying systems in their experimental studies
INVESTIGATION OF EFFICIENCY OF R717 REFRIGERANT SINGLE STAGE COOLING SYSTEM AND R717/R744 REFRIGERANT CASCADE COOLING SYSTEM
This study is an adaptation of ammonia cascade cooling systems using carbon dioxide on ice cream production machinesand includes thermodynamic analysis of R717/R744 cascade refrigeration system with R717 refrigerant single-stagerefrigeration system and investigation of its efficiency. As a result of the analyses, the COP value of the single-stage systemwas 3.67, the Carnot efficiency was 0.57, the second law efficiency was 0.19 and the power required to operate thecompressor was 27.55 kW. In the cascade cooling system, the COP value was 4.46, the Carnot efficiency 0.59 and thecompressor power 22.7 kW in the high-temperature part, while the COP value was measured as 14.65, the Carnot efficiency0.58 and the compressor power 6.4 kW in the low-temperature part. For the whole cascade system, the COP 3.24 and thesecond law efficiency were found to be 0.43. When the results were compared, it was concluded that although the COPvalue of the cascade cooling system was 0.43 points lower than the single-stage ammonia system, when our country'sclimate conditions and the thermophysical properties carbon dioxide gas were considered together, one of the most suitabledesigns was the cascade cooling system
Göstergebilimin Serüveni
Linguistic philosophy has become one of the most popular study fields that has overstepped the borders of philosophy in the twentieth century. 1960s are the years of vehement discussions between existentialism, structuralism and Marxism. In these years, the studies of natural languages primarily expanded to cover artificial language studies as well. As a consequence of the influence of these studies, semiotics, trying to resolve and define all of the meaningful systems, has emerged. While Ferdinand de Saussure was forming semiology with his Linguistic studies in Europe on these dates, Charles Sanders Peirce was dealing with determining the principles of semiotics that was going to be used as a framework in order to define the relationships between signs in America. On the other hand, Roland Barthes was accepted as the founder of semiotics with his sign theory in the second half of the 1960s. This paper aims at describing how semiotics has emerged as a result of debates in the language philosophy by examining the first philosophical texts and current discussions.Dil felsefesi, yirminci yüzyılda felsefenin de sınırlarını aşan en gözde çalışma alanlarından biri haline gelmiştir. Özellikle 1960’lı yıllar varoluşçuluk, yapısalcılık ve marksizm arasındaki hararetli tartışmaların yaşandığı yıllardır. Bu yıllarda öncelikle doğal dillere ilişkin yapılan çalışmalar yapay dil çalışmalarını da içine alacak şekilde genişlemiştir. Bu çalışmaların etkisiyle bütün anlamlı dizgeleri çözümlemeye ve betimlemeye çalışan göstergebilim ortaya çıkmıştır. Bu tarihlerde Avrupa da Ferdinand de Saussure Dilbilim çalışmalarıyla göstergebilimi (Semiology) hazırlarken ondan habersiz bir şekilde Amerika da Charles Sanders Peirce göstergeler arasındaki ilişkileri tanımlamak için bir çerçeve olarak kullanılacak göstergebilim (semiotic)’in ilkelerini belirlemekle meşguldür. 1960’ların ikinci yarısında ise Roland Barthes geliştirdiği gösterge kuramıyla müstakil bir göstergebilimin kurucusu olarak kabul görmüştür. Bu çalışmadaki amacımız göstergebilimin ilk felsefi metinlerden günümüze gelen dil felsefesi içerisindeki tartışmaların sonucunda nasıl ortaya çıktığını betimlemektir
Constructing the quantum Hall system on the Grassmannians Gr(2)(C-N)
In this talk, we give the formulation of Quantum Hall Effects (QHEs) on the complex Grassmann manifolds Gr2(CN). We set up the Landau problem in Gr2(CN), solve it using group theoretical techniques and provide the energy spectrum and the eigenstates in terms of the SU(N) Wigner D-functions for charged particles on Gr2(CN) under the influence of abelian and non-abelian background magnetic monopoles or a combination of these thereof. For the simplest case of Gr2(C4) we provide explicit constructions of the single and many- particle wavefunctions by introducing the Plucker coordinates and show by calculating the two-point correlation function that the lowest Landau level (LLL) at filling factor v = 1 forms an incompressible fluid. Finally, we heuristically identify a relation between the U(1) Hall effect on Gr2(C4) and the Hall effect on the odd sphere S5, which is yet to be investigated in detail, by appealing to the already known analogous relations between the Hall effects on CP3 and CP7 and those on the spheres S4 and S8, respectively. The talk is given by S. Kürkçüoğlu at the Group 30 meeting at Ghent University, Ghent, Belgium in July 2014 and based on the article by F.Ballı, A.Behtash, S. Kürkçüoğlu, G.Ünal [1]
Effectiveness of Bobath therapy on balance in cerebral palsy
Purpose: Weakness on balance control is one of the most common problems for children with cerebral palsy. Present study aimed to investigate the effectiveness of 8 week-Bobath therapy on balance in children with diparetic or hemiparetic cerebral palsy.Materials and Methods: A total of 15 cerebral palsy diagnosed children (8 diparesis, 7 hemiparesis) aged 5-14 years, were included in this study. Children could walk independently or by using a walking aid. The demographic data were saved for each case. Gross Motor Function Classification System and Gross Motor Function Measure were used to determine level of motor function. 1 Minute Walking Test, 10-meter Walking Test, Pediatric Balance Scale for balance ability and Functional Independence Measure for children (WeeFIM) for assessing of independence in activities of daily living were used. Bobath therapy were applied to children one 60-minute session, 2 days a week and 8 weeks in total. All evaluations were performed before treatment and repeated after treatment program.Results: After 8-week Bobath therapy, the results showed that improvement in motor function, level of functional independence and balance scores were statistically significant.Conclusion: Bobath therapy improves functional motor ability, independence level on daily living activities, and also balance ability in children with cerebral palsy
World Equity Markets and COVID-19: Immediate Response and Recovery Prospects
Following the spread of the COVID-19 pandemic, most global equity markets experienced
significant falls. Recognizing the severe economic impacts of the pandemic, from mid-March,
many governments announced unprecedented economic rescue packages, which appear to
restore investors’ confidence, given the recoveries in most stock markets. However, the recovery
performance significantly varies across countries. This paper provides an empirical
analysis of how much of the recovery performance observed in equity markets can be explained
by the size and types of rescue packages declared by countries. We find that among
different types, fiscal stimulus supports seem to be a stronger predictor of equity market recovery
performance. We also find that the severity of the outbreak, reliance more on natural
resource and tourism revenues are negatively correlated with countries’ stock market recovery
performance
Depression and anxiety in child and adolescents with follow-up celiac disease and in their families
Background/Aims: Earlier research has indicated a positive association between Celiac disease and some mental disorders in both adults and children. The aim of this study was to explore the diet compliance and depression and anxiety levels of pediatric celiac children and their families after a gluten-free diet.
Materials and Methods: A total of 30 celiac pediatric patients (17 children [57%] and 13 adolescents [43%]) were enrolled in the study, and 20 healthy controls (11 children [55%] and 9 adolescents [45%]) were studied as controls. Depression was assessed with the Children's Depression Inventory (CDI) form, and anxiety was assessed with the Screen for Child Anxiety Related Disorders (SCARED) form. Diet compliance was measured with a diet compliance form, and the families were asked to complete the Beck Depression Measurement (BDI) form for depression and the State-Trait Anxiety Inventory I-II (STAI-I and STAI-II) forms for anxiety.
Results: There was no significant difference in depression and anxiety between pediatric celiac patients consuming a gluten-free diet and the healthy control group. We observed no difference in depression and anxiety in the Celiac CD group patients. Diet compliance was 73.3% in the study group.
Conclusion: The depression and anxiety levels of pediatric celiac patients and their parents did not differ from those in the healthy group
4E analysis of an underfloor heating system integrated to the geothermal heat pump for greenhouse heating
In this study, 4E (energy, exergy, exergoeconomic, and exergoenvironmental) analysis of an underfloor heating system integrated with the geothermal heat pump of a greenhouse with a usage area of 90 m(2) has been made. When the results of the 4E analysis applied to the system and its elements were examined, the energy efficiency of the heating system in the winter months has been determined to be 77.85% and the exergy efficiency 30.61%. According to the results of exergoeconomic analysis, the levelized energy cost of the system has been determined as 0.894 /h, and the exergoeconomic factor value as 51.12%. According to the results of the exergoenvironmental analysis, the part-based environmental impact of the system was 0.0910 mPts/s, the environmental impact value due to exergy was 0.1823 mPts/s, and the exergoenvironmental factor value was 37.77%. In addition, the equivalent CO2 emission value that will occur if the heating requirement of the greenhouse is met with a natural gas boiler instead of a geothermal heat pump was investigated and a comparison was made between the two systems. Accordingly, it has been determined that the emission of 909.75 kg equivalent carbon dioxide to the environment will be prevented in the 4-month period, which is considered the heating season, by using the heat pump. As a result, the examined heating system has been evaluated as the effective system for heating the greenhouse, reducing energy consumption, and reducing emissions that cause environmental pollution
Evaluatıon of some parameters affectıng embroıdery qualıty
Vezenje je ukrašavanje tekstila koji može biti raznih oblika uzoraka (organskih, anorganskih ili geometrijskih motiva) i različitih tekstura. U području tekstila i odjeće vezenje je značajna radna faza jer direktno utječe na izgled i troškove, kako vizualno tako i s obzirom na dizajn i proces izrade. U radu je prikazano općenito vezenje, te parametri koji utječu na kvalitetu veza i vezenja tekstila i odjeće. Određeni parametri su vrednovani u odnosu na standardne tipove vezenja. Za kvalitetu veza razmatrane su i podloge za vez. Podloge od netkanog tekstila, taljive podloge veza koje se termički otklanjaju, odnosno tale ili vodotopive podloge mogu biti prikladne za vezenje velikih površina za koje nije poželjno da budu debele i teške. Podloge, koje se ne mogu potpuno ukloniti s vezene površine, mogu se upotrebljavati za male površine vezenja kao kod vezenja logotipova.Embroidery is an important work step in Textile and Apparel sector, because it affects directly the appearance and the costs of both visually and the design and application process. This study offers generally information on embroidery first. Factors influencing the quality of embroidery applied to textiles and garments have been identified and these factors have been evaluated practically with a standard embroidery type. As a result, heat and water-soluble interlinings may be suitable for embroidery with large areas that are undesirable to be thick and heavy. Interlinings that cannot be completely removed from the embroidered area can be used for small embroidered areas such as the brand logo
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