Vilnius Gediminas Technical University
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Defining the Minimum Security Baseline in a Multiple Security Standards Environment by Graph Theory Techniques
Get PDFOne of the best ways to protect an organization’s assets is to implement security requirements defined by different standards or best practices. However, such an approach is complicated and requires specific skills and knowledge. In case an organization applies multiple security standards, several problems can arise related to overlapping or conflicting security requirements, increased expenses on security requirement implementation, and convenience of security requirement monitoring. To solve these issues, we propose using graph theory techniques. Graphs allow the presentation of security requirements of a standard as graph vertexes and edges between vertexes, and would show the relations between different requirements. A vertex cover algorithm is proposed for minimum security requirement identification, while graph isomorphism is proposed for comparing existing organization controls against a set of minimum requirements identified in the previous step
Design of an Oscillation-Based BIST System for Active Analog Integrated Filters in 0.18 µm CMOS
No full textIn this paper, an oscillation-based built-in self-test system for active an analog integrated circuit is presented. This built-in self-test system was used to detect catastrophic and parametric faults, introduced during chip manufacturing. As circuits under test (CUT), second-order Sallen-Key, Akerberg-Mossberg and Tow-Thomas biquad filters were designed. The proposed test hardware detects parametric and catastrophic faults on changeable limits. The influence of both oscillation and test hardware on fault detection limits were investigated and analyzed. The proposed oscillation based self-test system was designed and simulated in 0.18 µm complementary metal-oxide semiconductor (CMOS) technology. Due to the easiness of implementation and configuration for testing of different active analog filters, such self-test systems can be effectively used in modern integrated circuits, made of a large number of devices and circuits, such as the multi-standard transceivers used in the core hardware of software-defined radios. Using the proposed test strategy, the fault tolerance limits for catastrophic faults varied from 96% to 100% for all injected faults in different structures of low pass filters (LPF). The detection range of parametric faults of passive components’ nominal value, depending on the used structure of the filter, did not exceed –0.74% – 0.72% in case of Sallen-Key, –3.31% – 1.00% in case of Akerberg-Mossberg and –2.39% – 1.44% in case of Tow-Thomas LPF.This article belongs to the Section Microelectronics and OptoelectronicsThis research was funded by the European Regional Development Fund according to the supported
activity “Research Projects Implemented by World-class Researcher Groups” under Measure No. 01.2.2-LMT-K-718.
The APC was funded by Vilnius Gediminas technical university Faculty of Electronics
Research of Modified Atomizers and Their Application for Moistening of Air-Cleaning Device Charges
No full textThe size of sprayed droplets is a very important parameter that influences the operational efficiency of air-cleaning device charges. It is desirable for atomizers to spray droplets that are dispersed as much as technically and economically reasonable and possible. Fine dispersion spraying ensures effective moistening of the air-cleaning device charges, as well as an optimal consumption of water or other liquids. Three modifications of special atomizers were used for experimental analysis. The atomization of liquid and spraying in the special atomizer occurs when two frontal streams confront each other. Frontal streams are formed by an inner shield located in the special atomizer. The experiment was conducted using different spraying pressures, namely: 6 bar, 4 bar, 2 bar. The evaluation (performed using a microscope) of the size of sprayed droplets shows that the best (finest) spraying was by the special atomizer of modification 3. The depth of the channel of the inner shield is the parameter that has the biggest influence on the size of sprayed droplets. The special atomizer of modification 3 produces droplets with the following size distribution and rates: ≤0.05 mm—63.2 vol%; 0.2–0.6 mm—28.3 vol%; 0.6–1.0 mm—8.1 vol%; ≥1.0 mm—0.4 vol%.This article belongs to the Special Issue Green Technologies in Air Treatmen
Comparative Evaluation and Ranking of the European Countries Based on the Interdependence between Human Development and Internal Security Indicators
Get PDFNew solutions and techniques for developing country policies are used under real conditions. The present study aims to propose a new approach for evaluating and ranking the European countries by using the interrelation between two groups of criteria, associated with the Human Development Index (HDI) and the World Internal Security and Police Index (WISPI). HDI and its components rank countries by value and detail the values of the components of longevity, education and income per capita. WISPI focuses on the effective rendering of security services and the outcome of rendered services. The priority of criteria is determined in the descending order of their correlation values with other group criteria. The criteria weights are set simultaneously for both groups by applying the weight balancing method WEBIRA. The methodology based on minimising sum of squared differences of the weighted sums within groups is used. Finally, the generalised criteria measuring the level of the country are calculated using the SAW method. Cluster analysis of the countries was carried out and compared with MCDM results. The study revealed that WEBIRA ranking of countries is basically consistent with the results of cluster analysis. The proposed methodology can be applied to develop the management policy of the countries, as well as to their evaluation and ranking by using various indices, criteria and procedures. The results of this research can also be used to reveal national policy choices, to point out government policy priorities.This article belongs to the Special Issue Optimization for Decision Makin
Hybrid Group MCDM Model to Select the Most Effective Alternative of the Second Runway of the Airport
No full textSustainable and efficient development is one of the most critical challenges facing modern society if it wants to save the world for future generations. Airports are an integral part of human activity. They need to be adapted to meet current and future sustainable needs and provide useful services to the public, taking into account prospects and requirements. Many performance criteria need to be assessed to address issues that often conflict with each other and have different units of measurement. The importance of the criteria to evaluate the effectiveness of alternatives varies. Besides, the implementation of such decisions has different—not precisely described in advance—effects on the interests of different groups in society. Some criteria are defined using different scales. Stakeholders could only evaluate the implemented project alternatives for efficiency throughout the project life cycle. It is essential to find alternative assessment models and adapt them to the challenges. The use of hybrid group multi-criteria decision-making models is one of the most appropriate ways to model such problems. This article presents a real application of the original model to choose the best second runway alternative of the airport.This article belongs to the Special Issue Multi-Criteria Decision-Making Techniques for Improvement Sustainability Engineering Processe
The N-Grams Based Text Similarity Detection Approach Using Self-Organizing Maps and Similarity Measures
Get PDFIn the paper the word-level n-grams based approach is proposed to find similarity between texts. The approach is a combination of two separate and independent techniques: self-organizing map (SOM) and text similarity measures. SOM’s uniqueness is that the obtained results of data clustering, as well as dimensionality reduction, are presented in a visual form. The four measures have been evaluated: cosine, dice, extended Jaccard’s, and overlap. First of all, texts have to be converted to numerical expression. For that purpose, the text has been split into the word-level n-grams and after that, the bag of n-grams has been created. The n-grams’ frequencies are calculated and the frequency matrix of dataset is formed. Various filters are used to create a bag of n-grams: stemming algorithms, number and punctuation removers, stop words, etc. All experimental investigation has been made using a corpus of plagiarized short answers dataset.This article belongs to the Special Issue Advances in Deep Learnin
The analysis of gravimeter performance by applying the theory of covariance functions
No full textIn this paper, an analysis of the spread of random extraneous low-frequency (50 Hz) vibrations excited in a
gravimeter body is presented. Further, their influence on the gravimeter scale reference system is determined by applying
the theory of covariance function. The data on the measurement of strength of random extraneous vibrations in fixed points
excited in the gravimeter body were recorded on the time scale in the form of arrays using a three-axis accelerometer.
High-frequency (2 and 20 kHz) noise vibrations were also used to modulate the gravimeter scale data. While processing
the results of measuring the strength of random extraneous vibrations and the data arrays on the reference system, estimates
of autocovariance and cross-covariance functions by changing the quantisation interval on the time scale were calculated.
Software developed within the MATLAB 7 package was applied for the calculations
Assessment and modelling of urban bypasses’ influence on transport flows distribution in street network
Get PDFDisertacijoje nagrinėjama aplinkkelių ir greito eismo gatvių vietos parinkimo mieste problema. Pagrindinis darbo objektas – aplinkkelių ir greito eismo gatvių padėties poveikis transporto srautams gatvių tinkle. Panaudojant transporto srautų modeliavimą sukurta aplinkkelio ir greito eismo gatvės vietos parinkimo metodika, nereikalaujanti sudėtingo, daug laiko ir lėšų atimančio viso miesto transporto srautų modeliavimo. Metodika yra pritaikyta dviem didžiausiams Lietuvos miestams – Vilniui ir Kaunui. Darbo tikslas – sudaryti aplinkkelių ir greito eismo gatvių vietos parinkimo metodiką, panaudojant transporto srautų modeliavimą, ją pritaikyti praktikoje, ir siekti sumažinti miesto gyventojų patiriamas laiko sąnaudas susisiekimui.
Disertaciją sudaro įvadas, 3 skyriai, bendrosios išvados, literatūros sąrašas, publikacijų sąrašas ir 11 priedų.
Įvade trumpai aptariama tiriamoji problema, darbo aktualumas, aprašomas tyrimo objektas, formuluojamas darbo tikslas ir uždaviniai, aprašoma mokslinis darbo naujumas, ginamieji teiginiai. Įvado pabaigoje pristatomos autoriaus paskelbtos publikacijos disertacijos tema, pranešimai konferencijose ir pateikiama disertacijos struktūra.
Pirmame skyriuje pateikiama literatūros apžvalga nagrinėjama tematika. Atliekama mokslinių darbų analizė. Taip pat įvertinami Lietuvos Respublikos bei Europos Sąjungos dokumentai, formuojantys transporto politiką.
Antrajame skyriuje pristatomas sukurtas idealizuoto miesto transporto modelis. Darbo metu yra sumodeliuota 90 skirtingų aplinkkelių ir (ar) greito eismo gatvių įrengimo padėties variantų. Apibendrinus gautus modeliavimo rezultatus ir atlikus jų analizę, sudaryta miesto aplinkkelių ir greito eismo gatvių vietos parinkimo metodika.
Trečiajame skyriuje aptarti pagrindiniai transporto tyrimų būdai, – išsiskiriantys prieinamumu ir minimalia kaina bei užtikrinantys pakankamą aprėptį ir tikslumą. Išnagrinėtos dviejų didžiausių Lietuvos miestų, – Vilniaus ir Kauno, susisiekimo sistemos, nustatyti jų pagrindiniai parametrai bei pritaikyta aplinkkelių ir greito eismo gatvių vietos parinkimo metodika.
Disertacijos tema paskelbtos penkios mokslinės publikacijos, iš kurių keturios referuojamuose duomenų bazės Clarivate Analytics (ISI Web of Science) recenzuojamuose mokslo žurnaluose. Atliktų tyrimų rezultatai paskelbti dvejose Lietuvos ir vienoje užsienio konferencijose.Disertacij
Technologijų perdavimo proceso aukštojo mokslo institucijose efektyvumo vertinimas
Get PDFHigher education institutions (HEIs) play the key role as the link to encourage science and business partnerships within innovation systems worldwide. Notwithstanding one of the most important issue is to increase Lithuanian innovation potential. This dissertation analyses the problems of inefficient technology transfer (TT) and commercialization process, financial and human resource allocation at universities. The object of the research is the efficiency of technology transfer process (TTP) in higher education institutions. The analysis of technology transfer offices (TTOs) within the TTP allows the best model to be suggested for the evaluation of TTP as well as the improvement of TT results in the future perspective. This model is designed to assess the performance of the HEIs, to identify key indicators that demonstrate the efficiency of TTP, allowing to design future strategies to improve the efficiency of HEIs TTP financial and human capital.
The goal of the dissertation is to examine TT process, propose and empirically test the efficiency evaluation model of the technology transfer process at HEIs. It is important to assess how the institutional (TTO employees, tasks, PhD-share) and regional (industry concentration, startups, patent applications) factors of TTO influence TT performance and commercialization.
This research work resolves a few key tasks: 1. To conduct a theoretical analysis of the TTP (discussing the concept of the TTP and the key attributes, reviewing the foreign TT models, discussing factors encouraging the improvement of the TTP); 2. To perform a theoretical analysis of the efficiency of the TTP activities; 3. To create an original TTP efficiency evaluation model based on a comparative analysis of multicriteria research methods suitable to perform evaluation of TT activities of HEIs; 4. To conduct an empirical research and to validate the efficiency evaluation model of TTP using multicriteria research tools (FARE, TOPSIS, MULTIMOORA, COPRAS and DEA), to gather and aggregate the research data needed to evaluate the efficiency of the TTP, and to create a database for empirical research; 5. To analyse and discuss the research results of TTP, to formulate final conclusions to assess HEIs’ TTP efficiency, which would help to im-prove the performance of economic and other indicators through a more efficient allocation of financial and human resources.
Analysis of research results shows that the number of employees working in TTO correlates with the number of intellectual (inventions) products that are being developed during the research and development (R&D) process.Dissertatio
Analysis of the hybrid global path planning algorithm for different environments
No full textTo achieve the overall goal of realising an efficient and advantageous participation of autonomous ground vehicles in the
transport system as fast as possible, a lot of work is being done in different and specific research fields. One of the most important
research fields, which has a large impact on safe autonomous ground vehicle realisation, is the development of path planning
algorithms. Therefore, this work describes in detail the development and application of a hybrid path planning algorithm. The
described algorithm is based on classical and heuristic path planning approaches and can be applied in unstructured and structured
environments. The efficiency of the algorithm was investigated by applying the algorithm and executing theoretical and
experimental tests. The theoretical and experimental tests were executed while optimising different complexity paths. Results
analysis demonstrated that the described algorithm can generate a smooth, dynamically feasible and collision-free path