Vilnius Gediminas Technical University
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Assessing Sustainable Mobility Measures Applying Multicriteria Decision Making Methods
No full textAn increasing number of recent discussions have focused on the need for designing transport systems in consonance with the importance of the environment, thus promoting investment in the growth of non-motorized transport infrastructure. Under such conditions, the demand for implementing the most effective infrastructure measures has a profoundly positive impact, and requires the least possible financial and human resources. The development of the concept of sustainable mobility puts emphasis on the integrated planning of transport systems, and pays major attention to the expansion of non-motorized and public transport, and different sharing systems, as well as to effective traffic management involving intelligent transport systems. The development of transport infrastructure requires massive investment, and hence the proper use of mobility measures is one of the most important objectives for the rational planning of sustainable transport systems. To achieve this established goal, this article examines a compiled set of mobility measures and identifies the significance of the preferred tools, which involve sustainable mobility experts. The paper also applies multicriteria decision making methods in assessing urban transport systems and their potential in terms of sustainable mobility. Multicriteria decision making methods have been successfully used for assessing the effectiveness of sustainable transport systems, and for comparing them between cities. The proposed universal evaluation model is applied to similar types of cities. The article explores the adaptability of the model by assessing big Lithuanian cities.This article belongs to the Special Issue SUMP for Cities’ Sustainable DevelopmentThis research was funded by Vilnius Gediminas Technical Universit
Improving the Results of the Earned Value Management Technique Using Artificial Neural Networks in Construction Projects
No full textThe cost, time and scope of a construction project are key parameters for its success. Thus, predicting these indices is indispensable. Correct and accurate prediction of cost throughout the progress of a project gives project managers the chance to identify projects that need revision in their schedules in order to result in the maximum benefit. The aim of this study is to minimize the shortcomings of the Earned Value Management (EVM) method using an Artificial Neural Network (ANN) and multiple regression analysis in order to predict project cost indices more precisely. A total of 50 road construction projects in Fars Province, Iran, were selected for analysis in this research. An ANN model was used to predict the projects’ cost performance indices, thereby creating a more accurate symmetry between the predicted and actual cost by considering factors that influence project success. The input data of the ANN model were analysed in MATLAB software. A multiple regression model was also used as another analytical tool to validate the outcome of the ANN. The results showed that the ANN model resulted in a lower Mean Squared Error (MSE) and a greater correlation coefficient than both the traditional EVM model and the multiple regression model.This article belongs to the Special Issue Symmetric and Asymmetric Data in Solution Model
Evaluating the Impact of Building Information Modeling (BIM) on Mass House Building Projects
No full textThis paper aims to identify and investigate the factors affecting the goals of mass-housing building projects due to the use of building information modeling (BIM). A descriptive-survey method was used to collect necessary data. Fifty respondents from the target sectors and experts in the field of modeling building information participated in self-selection survey. The tools of collecting data included three questionnaires regarding three phases of construction work: pre-construction, during construction and post-construction, which were developed based on the three indices of cost, time and quality. The face, content and construct validity of the questionnaires were confirmed after several rounds of testing. The reliability coefficient of the pre-construction, during the construction and post-construction questionnaires were 0.923, 0.917 and 0.876, respectively. The results show that the F-statistic is significant for the difference between the three groups (pre-construction, during construction and post-construction) at the 0.01 level. The results confirmed that BIM has a great influence on a project in terms of meeting time, cost and quality objectives through the whole life cycle of a construction project: during pre-construction, construction, and post-construction stages.This article belongs to the Special Issue Sustainable Development of Buildings: Design, Construction, Quality Inspection, Operation Managemen
An Assessment of Self-Purification in Streams
No full textThe territory of Lithuania is characterized by a prevailing moisture excess, therefore in order to timely remove excess water from arable lands, the drainage systems have long been installed. In order to drain excess water people used to dig trenches, to regulate (deepen or straighten) natural streams. The length of regulated streams has reached 46,000 km and they are deteriorated ecosystems. Investigations showed that the self-purification of streams from nitrates and phosphates is more effective in natural stretches than in stretches regulated for drainage purposes. Decrease in the average concentration of nitrates in natural and regulated stretches are 8.8 ± 5.0 and 3.0 ± 2.9 mg NO−3 L−1, respectively. The average coefficient of nitrate self-purification, at a confidence level of 95% in natural stream stretches is 0.50 ± 0.22, and in regulated is −0.15 ± 0.21 km−1, and this difference is essential. The change in the average concentration of phosphates in natural and regulated stretches is almost the same, 0.2 ± 0.1 and 0.2 ± 0.2 mg PO3−4 L−1, respectively. The average coefficient of phosphate self-purification, at a confidence level of 95%, in natural stream stretches is 0.28 ± 0.12, in regulated −0.14 ± 0.12 km−1, and this difference is not essential. In terms of the need for the renovation of drainage systems it is suggested that soft naturalization measures are first applied in the streams of Western (Samogitian) Highlands, Coastal Lowlands, and South-Eastern Highlands to improve their self-purification processes.This article belongs to the Special Issue A Systems Approach to River and River Basin Restoratio
The Peculiarities of Low-Cost Carrier Development in Europe
No full textLow-cost carriers (LCCs) have been growing by 11.4% in revenue passenger kilometers over 2017 and changed the airline industry radically. It drove down prices in the industry. Southwest Airlines (USA) designed the LCC blueprint model, and Ryanair copied it within Europe, followed by other airlines. This research aims to fulfill the gap in contemporary research upon LCC successfulness in Europe by a description of the current situation within Europe (2018 and January 2019) and the development issues it faced, which are mapped by the Ishikawa fishbone diagram. Furthermore, to rank the airlines on strength and vulnerability, The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) methodology was used for meeting LCC characteristics and airline success. By comparison of meeting the LCC characteristics and the rank of the successfulness, the results of the TOPSIS analysis showed that the airlines meeting the most LCCs characteristics are seemingly less vulnerable to the development issues that airlines are facing, as Wizz Air and Ryanair are meeting most characteristics and are the most successful. Concluded is that airlines meeting the most LCC characteristics are the least vulnerable to current issues. However, major disruptions can still form an issue and limit growth. This research can be useful for comparing and positioning airlines in the market, based on issues and operational choices.This article belongs to the Special Issue Innovation in Energy Security and Long-Term Energy Efficienc
E-mail-Based Phishing Attack Taxonomy
Get PDFThe amount of fraud on the Internet is increasing along with the availability and the popularity of the Internet around the world. One of the most common forms of Internet fraud is phishing. Phishing attacks seek to obtain a user’s personal or secret information. The variety of phishing attacks is very broad, and usage of novel, more sophisticated methods complicates its automated filtering. Therefore, it is important to form up-to-date and detailed phishing attack taxonomy, which could be used for both human education purposes as well as phishing attack discrete notation. In this paper, we propose an e-mail-based phishing attack taxonomy, which includes six phases of the attack. Each phase has at least one criterion for the attack categorization. Each category is described, and in some cases the categories have sub-classes to present the full variety of phishing attacks. The proposed taxonomy is compared to similar taxonomies. Our taxonomy outperforms other phishing attack taxonomies in numbers of phases, criteria and distinguished classes. Validation of the proposed taxonomy is achieved by adapting it as a phishing attack notation for an incident management system. Taxonomy usage for phishing attack notation increases the level of description of phishing attacks compared to free-form phishing attack descriptions.This article belongs to the Section Computing and Artificial Intelligenc
Cement Equivalence of Metakaolin for Workability, Cohesiveness, Strength and Sorptivity of Concrete
No full textA series of concrete mixes with metakaolin (MK) content ranging from 0 to 30% and water/cementitious materials (W/CM) ratio varying from 0.30 to 0.50 were produced for performance testing. The results showed that adding MK up to 20% as ordinary Portland cement (OPC) replacement best improved the 28-day and 70-day cube strengths, whereas adding MK up to 30% as OPC replacement always increased the cohesiveness and decreased the sorptivity, but impaired the workability. Moreover, the cement equivalent factor (CEF), i.e. the equivalent mass of OPC per mass of MK added, for each performance attribute, including workability and cohesiveness, was evaluated. Whilst the actual CEF of MK was generally higher at a higher W/CM ratio and lower at a higher MK content, overall, the average CEFs were found to be 1.98, 2.17, 3.83, 1.93, 2.12, and 4.70 for slump, flow, cohesiveness, 28-day cube strength, 70-day cube strength, and sorptivity coefficient, respectively. These CEF values indicated that the MK is a highly effective cementitious material for improving the cohesiveness, strength, and durability. Moreover, it has been demonstrated that the CEFs for workability and cohesiveness are useful parameters in aiding the mix design of MK concrete.This research was funded by National Natural Science Foundation of China (grant number 51678161), Research Project of Guangdong Provincial Education Department of China (grant number 2018GXJK197), Guangdong Provincial Education Department Educational Reformation Project (grant number 595 in year 2018), Research Centre of Green Building Materials and Modular Integrated Construction Technology of Guangdong Province of China (grant number ZCZX201803), Featured and Innovative Project for Colleges and Universities of Guangdong Province (grant number 2017KTSCX061) and Pearl River S&T Nova Program of Guangzhou City (grant number 201906010064
Įmonių bankroto grėsmės diagnostika
No full textSummary of doctoral dissertationSummary of doctoral dissertatio
Investigation of efficiency of gravel roads dust suppressants and evaluation in the road environment
No full textDisertacijoje nagrinėjamos žvyrkelių eksploatavimo metu atsiradusios dulkėtumo problemos bei žvyrkelių priežiūroje taikomos dulkėtumo mažinimo medžiagos. Pagrindinis tyrimo objektas yra žvyrkelių dulkėtumą mažinančių medžiagų sąveika su žvyrkeliais. Žvyrkeliai yra svarbi susisiekimo sektoriaus dalis. Dulkėtumo sumažinimas žvyrkeliuose yra svarbus pakelės augalijos augimui (dulkės užkemša augalų poras ir augimas yra stabdomas) ir greta gyvenančių žmonių sveikatai. Pagrindinis disertacijos tikslas – surasti efektyvią naudojamų tirpalų mišinio koncentraciją, kuo mažiau kenkiančią žvyrkelio aplinkai. Disertacijoje taip pat siekiama ištirti siūlomo mišinio poveikį pakelės augalijai bei chloridų kiekį žvyrkelio dangoje bei šalikelėse, sudarant skersinį profilį.
Darbe sprendžiami keli pagrindiniai uždaviniai: tiriamas žvyrkelių dulkėtumą mažinančių medžiagų efektyvumas ir poveikis kelio aplinkai. Uždaviniai suformuluoti, atsižvelgiant į analizuojamą problemą, ieškant informacijos užsienio šalyse, siejasi su atliktų tyrimų rezultatais ir jų modeliavimu.
Disertaciją sudaro įvadas, šeši skyriai, bendrosios išvados ir rekomendacijos, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir vienas priedas.
Įvadiniame skyriuje aptariama tiriamoji problema, darbo aktualumas, aprašomas tyrimų objektas, formuluojamas darbo tikslas bei uždaviniai, aprašoma tyrimų metodika, darbo mokslinis naujumas, darbo rezultatų praktinė reikšmė, ginamieji teiginiai. Įvado pabaigoje pristatomos disertacijos tema autoriaus paskelbtos publikacijos ir pranešimai konferencijose bei disertacijos struktūra.
Pirmasis skyrius skirtas literatūros šaltinių analizei. Jame analizuojama informacija apie dulkių dalelių atsiradimą ir dinamiką, dulkėtumą mažinančias medžiagas, jų naudojimą, bendruosius taikymo principus, veikimą, naudojamus kiekius, efektyvumą, poveikį aplinkai, pasaulio šalyse naudojamas medžiagas, kietųjų dalelių sklaidos modeliavimą. Skyriaus pabaigoje formuluojamos išvados ir uždaviniai. Antrajame skyriuje pateikiama kietųjų dalelių emisijos mažinimo laboratorinių tyrimų metodikos, rezultatų analizė, išvados. Trečiajame skyriuje pateikiamos eksperimentinio kelio ruožo aplinkoje tyrimų metodikos, rezultatų analizė, išvados. Ketvirtajame skyriuje pateikiamos žolinių augalų augimo užterštame dirvožemyje tyrimų metodikos, rezultatų analizė, išvados. Penktajame skyriuje pateikiama modeliavimo metodika, gautų modeliavimo rezultatų palyginimas su tyrimų metu gautais rezultatais, pateikiamos išvados. Šeštajame skyriuje aprašomas aplinkosauginis sprendimas.
Disertacijos tema paskelbti 7 straipsniai: du – žurnaluose, referuojamuose ISI Web of Science duomenų bazėje, vienas – konferencijų medžiagoje, referuojamoje ISI Proceedings duomenų bazėje, trys – recenzuojamose Lietuvos konferencijų medžiagose, vienas – nerecenzuojamoje Lietuvos konferencijos medžiagoje. Disertacijos tema perskaityti 2 pranešimai tarptautinėse ir 5 pranešimai konferencijose Lietuvoje.Daktaro disertacij