Vilnius Gediminas Technical University
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Application of fuzzy DEMATEL method for analyzing occupational risks on construction sites
No full textThe construction industry is known as a hazardous industry because of its complexity
and strategic nature. Therefore, it is important to know the main causes of occupational accidents
to prevent fatal occupational accidents in construction industry. At building construction sites,
workers performing tasks are continuously exposed to risks, not only emerging from their own
mistakes but also from the mistakes of their co-workers. A great deal of studies investigating
risks and preventing occupational hazards for the construction industry has been carried out in
the literature. The quantitative conventional methods mostly use either probabilistic techniques or
statistics, or both, but they have limitations dealing with the ambiguity and fuzziness in information.
In this study, to overcome these limitations, an applicable and improved approach, which helps
construction managers to propose preventive measures for accidents on construction sites, is proposed
to simplify the risk assessment. It is shown that the Fuzzy Decision Making Trial and Evaluation
Laboratory (DEMATEL) method can evaluate causal factors of occupational hazards by a cause–effect
diagram and improve certain safety measures on construction sites. In addition, sensitivity analysis
is conducted to verify the robustness of the results
MCDM assessment of a healthy and safe built environment according to sustainable development principles: a practical neighborhood approach in Vilnius
No full textUrbanization has a massive effect on the environment, both locally and globally. With
an ever-increasing scale of construction and manufacturing and misuse of energy resources come
poorer air quality, growing mortality rates and more rapid climate change. For these reasons,
a healthy and safe built environment is ever more in demand. Global debates focus on sustainable
development of the built environment; a rational approach to its analysis is multiple criteria decision
making (MCDM) methods. Alternative MCDM methods applied to the same problem often produce
different results. In the search for a more reliable tool, this study proposes that a system of MCDM
methods should be applied to a single problem. This article assesses 21 neighborhoods in Vilnius
in the context of a healthy and safe built environment in view of the principles of sustainable
development. MCDM methods were used for this purpose: entropy, Criterion Impact LOSs (CILOS)
and Integrated Determination of Objective Criteria Weights (IDOCRIW) methods were used to
determine the objective weights of the criteria, while expert judgement determined the subjective
weights. With the overall weights determined, the Vilnius neighborhoods were assessed through the
application of COmplex PRoportional ASsessment (COPRAS), Simple AdditiveWeighting (SAW),
Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Evaluation based on
Distance from Average Solution (EDAS) methods. The final results were then processed using the
rank average method, Borda count and Copeland’s method
Valstybės ekonominės politikos ir jos sprendimų inicijavimas bei įgyvendinimas: valstybės tarnybos vaidmuo
No full textŠiame teorinio pobūdžio straipsnyje yra nagrinėjami valstybės ekonominės politikos ir jos sprendimų inicijavimo, rengimo bei įgyvendinimo klausimai. Pagrindinis dėmesys yra teikiamas valstybės tarnybos veiklai inicijuojant, parengiant ir įgyvendinant valstybės ekonominės politikos sprendimus. Parodoma sąsaja tarp valstybės ekonominės politikos sprendimų ir valstybės tarnybos veiklos reiškinių. Detaliai aptariamos šiuolaikinės valstybės ekonominės politikos ir jos sprendimų inicijavimo, rengimo ir įgyvendinimo problemos. Apibūdinti šiuolaikinės valstybės ekonominės politikos prioritetai. Atskleistas globalizacijos, žiniomis grindžiamos visuomenės ir žinių ekonomikos kūrimo, Europos integracijos ir Europos Sąjungos raidos procesų poveikis šiuolaikinės valstybės ekonominės politikos sprendimams. Atskleistas valstybės tarnybos vaidmuo šiuolaikinės visuomenės gyvenime, detaliai parodomos valstybės tarnybos funkcijos inicijuojant, parengiant ir įgyvendinant valstybės ekonominės politikos sprendimus
Passive voice as a means of impersonal presentation of facts in English quality press
No full textThe current paper presents the analysis of passive constructions as means of impersonal presentation of facts in English quality press. The article gives the definition of the passive voice as a grammatical category and describes the use and purpose of impersonalization strategies. The data for the research were taken from The Financial Times (UK), the leading international English daily broadsheet newspaper, which has millions of both print and online subscribers worldwide. The articles on political, business, economic, and social issues were chosen on a random basis and scrutinized for passive constructions as a means of impersonal presentation of facts. 173 cases of impersonalization were chosen for the analysis. The most and least often used types of passive constructions were identified and compared. The results of the current study may be useful for editors, journalists, writers, as well as for further study of impersonalization strategies in the English language
Optimal shakedown of the thin-wall metal structures under strength and stiffness constraints
No full textClassical optimization problems of metal structures confined mainly with 1st class crosssections. But in practice it is common to use the cross-sections of higher classes. In this paper, a new mathematical model for described shakedown optimization problem for metal structures, which elements are designed from 1st to 4th class cross-sections, under variable quasi-static loads is presented. The features of limited plastic redistribution of forces in the structure with thin-walled elements there are taken into account. Authors assume the elastic-plastic flexural buckling in one plane without lateral torsional buckling behavior of members. Design formulae for Methods 1 and 2 for members are analyzed. Structures stiffness constrains are also incorporated in order to satisfy the limit serviceability state requirements. With the help of mathematical programming theory and extreme principles the structure optimization algorithm is developed and justified with the numerical experiment for the metal plane frames
The influence of commonly used plasticizing admixtures on the plasticizing effect of cement paste
No full textThe article aims to present a research into the impact of dosage and effectiveness of commonly used plasticizing admixtures. More specifically, it focuses on rheological properties of the cement pastes (yield stresses and plastic viscosities) of different testing times (from 0 min to 90 min after mixing). The following materials were used in the study: Portland cement CEM I 42.5 R, plasticizer P (ligno-sulphonates based), superplasticizer SP1 (modified acrylic polymer based), superplasticizer SP2 (polycarboxylate esters based) and water. Experiments were carried out using rotational rheometer Rheotest RN4.1 with coaxial cylinders. It was observed that larger dosage of SP1 (0.6–1.2 %) results in slower increase in plasticizing effects until the 90 min margin. In conclusion, from the start of mixing until the 90 min margin, the best plasticizing effect and its retention are achieved by superplasticizer SP2. Recommended SP2 dosage varies within the range of 0.6 % to 0.8 %
Stroke-affected upper extremity movement assessment via continuous relative phase analysis
No full textPaper presents the quantified assessment of stroke-affected upper extremity (UE) coordination via continuous relative phase (CRP) analysis. 14 post-stroke patients were divided into 3 groups based on the
severity of impairment according to Wolf Motor Function Test (WMFT). CRP was determined based on
UE kinematics parameters measured using inertial measurement units fixed on arm, forearm and hand
while subjects performed designated movement. UE movement cycles were analysed based on the metrics derived from phase planes, the phase angle and CRP plots, as well as the calculated range of motions
and CRP variability rates. It was found that CRP variability is associated with impairment level, i.e. it is
decreasing with a higher level of dysfunction. Therefore, the CRP might serve as measurable quantity
and could be valuable for supporting clinical assessment and quantifying impairment severity of UE
motor functions
Optimization of rigidly supported guyed masts
No full textA technique for simultaneous topology, shape, and sizing optimization of tall guyed masts is presented in this paper. The typical
scheme of telecommunication masts that are triangular in plan and supported by a certain number of guys’ levels is examined. The
objective function is the total mass of the mast, including the mass of the guys. The mast structure is optimized for self-weight
and wind loading that is evaluated according to Eurocodes. The nonlinear behaviour of the guyed mast is simplified idealizing
the nonlinear guys as approximate boundary conditions for the mast. A comparison of the simplified solution with the results
of nonlinear analysis with Ansys shows small discrepancies that are on the safe side. The constraints involve all strength, local
and global stability, and slenderness requirements. The optimization problem is solved using evolutionary algorithm with original
genome repair procedure. As an example, a typical 96 m guyed broadcasting antenna for mobile-phone networks was designed
employing the proposed optimization technique and taking up to 10 guys’ levels. It is shown that the optimal mast is supported by
3–5 guys’ levels. The optimal ranges of all remaining design variables were also obtained
Priešgaisrinės saugos praktinio mokymo tyrimas
No full textPati dažniausia ir pavojingiausia stichija, su kuria tenka susidurti žmonėms, – tai ugnis. Gaisras yra nekontroliuojamas degimo procesas, kurio metu plintanti ugnis, aukšta temperatūra ir dūmai sudaro pavojų pastate esantiems žmonėms ir palieka didelius socialinius ir ekonominius padarinius. Atsidūrus ekstremalioje situacijoje, ypač svarbios tampa automatinės (psichomotorinės) reakcijos. Tuo tikslu žmonės turi būti apmokyti, kokių veiksmų imtis, kilus gaisrui, kaip saugiai elgtis ir evakuotis iš pastatų. Net vienas žuvęs gaisre yra perdaug
Finite element investigation osteoporotic lumbar L1 vertebra buckling in a presence of torsional load
No full textIn this article, the human lumbar spine region, af-fected by osteoporosis, L4 vertebra modelling and stability analysis are presented. Tissue degradation problem was ex-amined. Spatial numerical model in SolidWorks computer program environment was done. Numerical experiment was done in finite element method in ANSYS Workbench envi-ronment. This article is also given with calculation results, when the compression force and the compression force with tension are applied. Model’s cases for loss of load bearing capacity are examined with simulating aging and osteopo-rosis effects, which occurs with aging of the tissue. Degra-dation of the tissue is modelled while applying expressions determined with empirical approach, which link depend-ency between mechanical properties and porous bone den-sity