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The article analyzes the separation of fats from paper waste packaging. The method is based on interaction with boiling water and greaseproof paper. The cooking process is considered the formation of emulsions according to different slots. The research data are presented and discussed obtained from the analysis of ready-made samples. 20 different fat-coated paper samples have been prapared for research. Ten of them have been selected for printing paper, and another dozen cartons. The half of the samples analyzed are covered with vegetable fat, the remaining samples are vegetable fat. It was found that the carton samples were less opposed to the separation of fat. During the experiment, it was determined that by cooking the cardboard samples coated with olive oil for 5 minutes, 30% of the total fat content was removed. The most effective samples of this type were heated for a long time. [ABSTRACT FROM AUTHOR]

Paper and prints on it are analyzed as composite materials. Printing, varnishing and lamination are described in terms of the formation of the composite material. The article discusses why and how the properties of a print should differ from the properties of paper. [ABSTRACT FROM AUTHOR]

Friction between different papers, inkjet and flexographic prints has been experimentally investigated. Flexographic prints have been made using an anilox roller, and inkjet prints have been produced covering paper with one and four toner layers. Static (SCOF) and kinetic (KCOF) friction coefficients between paper and paper, paper and prints, prints and prints have been determined. Friction properties have been discovered to be different in flexographic and laser prints. The dependence of SCOF and KCOF on pressure (both decrease) together with roughness measurements enables to conclude that the friction of prints is mainly governed by adhesion forces. [ABSTRACT FROM AUTHOR]

In the paper the folding quality in the printing house "BALTO" is investigated. The concept of quality, paper folding process, combined folding machine parameters and printing papers are described. In the paper the percent of folding defects is determined, the spoilage dependence on paper characteristics, folding machine settings and other factors are investigated. Results were presented as histograms and were analyzed using statistical methods. [ABSTRACT FROM AUTHOR]

The article discusses some inaccurate uses of pronominal forms, certain terms and one of the syntactical mistakes -- the expression of purpose. The article also provides the examples of mistakes found in welding papers. The use of nonpronominal forms in the denoted terms is one of typical morphological mistakes in treating the process of welding. Another problem is the inaccurate use and wrong formation of terminology. The article also focuses on the mistaken expression of purpose. [ABSTRACT FROM AUTHOR]

This paper examines the impact of business cycles on unemployment rates in EU countries. The relationship between changes in gross domestic product and changes in the unemployment rate is referred to in the academic literature as Okun’s law. This law is of particular importance and the relationship has been extensively investigated in the scientific literature, but there are not many studies that analyse the European Union countries. This paper examines the relationship between the unemployment rate and real GDP in the EU-27. The data used for the study cover the period 2007–2019. The results of a correlation regression analysis provide evidence of the inverse relationship between the unemployment rate and real GDP as established by theory. The results also show that the relationship between business cycles and unemployment varies from country to country: in Lithuania and the UK, there is a very strong inverse relationship between the unemployment rate and real GDP. In Lithuania, the coefficient was –0.9377, and a similar coefficient was found in the United Kingdom (-0.9337). [ABSTRACT FROM AUTHOR]

The release of dyes used in the textile industry into the natural environment causes unwanted negative effects due to the carcinogenic, mutagenic or even teratogenic properties of the dyes. Based on their chemical composition, dyes are divided into anionic, cationic and non-ionic dyes. In this work, the physical method of wastewater treatment - adsorption - was studied. This is a method in which various natural substances called sorbents are used. Materials used in the adsorption process should be nontoxic, environmentally friendly, cheap, and their use should not cause secondary pollution. The idea of using sorbents made from waste in experimental studies, which can even be used several times in the adsorption process, promotes the sustainable use of resources. The study compared different sorbents: aerogel, devulcanized rubber granules and sewage sludge. It was found that the highest values of adsorption efficiency were characterized by sewage sludge granules that were pyrolyzed at 500 °C. Using 500 °C pyrolysis sewage sludge, the adsorption efficiency reached 28.14-53.73%. Granules made from devulcanized car tire rubber had the lowest adsorption efficiency values: the adsorption efficiency value reached 12.92%. The adsorption efficiency values of the aerogel synthesized from paper waste ranged from 28.21 to 38.07%. [ABSTRACT FROM AUTHOR]

Network intrusion detection is a relevant cybersecurity research field. The growing number of intrusions requires more sophisticated methods to protect computer networks. Various machine learning algorithms are used to detect network intrusions and anomalies, but their accuracy is limited. In this research, we address the problem of improving network-level intrusion detection by applying hybrid machine-learning algorithms. The paper proposes three new hybrid machine learning methods and investigates their accuracy using two publicly available datasets CSE-CIC-IDS2018 and NSW-NB-15. In order to increase the accuracy of the classification models, hyperparameter optimization was performed. The iteration method and the Chi-square χ² test were used to identify significant features of the data set. Analyzing the research results, it was found that the highest network anomaly recognition accuracy of 99.34% was achieved by applying a hybrid algorithm consisting of a decision tree, naive Bayesian, and multilayer perceptron algorithms. Achieved result is 3.13% higher than the best accuracy achieved by individual machine learning algorithms. In order to comprehensively evaluate the studied machine learning algorithms and their suitability for detecting intrusions in a computer network, the algorithms were ranked using the SCR, DR, FR ranking methods. [ABSTRACT FROM AUTHOR]

This paper proposes a method for automated Lithuanian hands gestures data collection and for Lithuanian hands gestures classification. The dataset of 1100 samples was collected for 10 different classes of Lithuanian hands gesture. The features of hands gestures were extracted with CNN network. The classification was made with LSTM network. The trained LSTM network classified the Lithuanian hands gestures with 85% accuracy. [ABSTRACT FROM AUTHOR]

The approach to reduce the amplitude noise of a vertical channel of the sampling oscilloscope is presented in this paper. In general, the vertical channel of the sampling oscilloscope consists of a high-frequency sampling circuit and a relatively low-frequency sample transmission path along with a high bit resolution analogto- digital converter. The paper presents a method to improve the sensitivity of the vertical channel of a stroboscopic oscilloscope by extending the conventional channel architecture. The main vertical channel unit of the oscilloscope is a sampling device (sampler), which made of discrete elements and usually implemented using high frequency diodes. The sampler performs a transformation of the sample of the high-frequency signal under test into a low-frequency equivalent signal (otherwise called a balance impulse). In a conventional sampling device, this pulse is quantized once the amplitude is at its highest, thus achieving the best signal-to-noise ratio. The paper analyzes the operating parameters of the sampling device circuit and their influence on the output signal of the sampler. In this approach uses the fastest (15 MHz) high-resolution (18-bit) analog-to-digital converters currently on the market to reduce the amplitude noise of vertical channel based on conventional architecture. Our research has shown that it is possible to obtain an increase in the signal-tonoise ratio of almost 1.3 times. [ABSTRACT FROM AUTHOR]

In the article opportunities of changing paper CMR waybill into electronic are analysed, whereas the paper CMR waybill does not guarantee operational information exchange between participants of logistics chain components in road transport. Due to this reason use ofelectronic CMR waybill becomes more and more important. According to researches done by article authors, the article submitted the limitations of paper CMR waybill, benefits of electronic CMR waybill, concept model of implementing electronic CMR waybill and application possibilities of supply chain components. [ABSTRACT FROM AUTHOR]

The article experimentally investigates the properties of offset print friction and determines static and kinetic coefficients of friction. Conventional and UV inks have been found to increase the static friction coefficient and reduce the kinetic friction coefficient between paper and print. The roughness properties of two different types of paper and prints using conventional and UV inks have been examined and compared thus determining that conventional inks strongly increase the roughness of print surface and that the influence of UV inks depend on the type of paper. [ABSTRACT FROM AUTHOR]

The paper explores the concept of weather derivatives: what it is, what its features are, and in what areas they can be applied. It has been established that there can be several types of weather derivative instruments – options and swaps. The use of weather derivatives has also been found to be very broad and attractive for tourism, construction, agriculture and heating companies. Companies operating in Lithuania do not use weather derivatives, although they do provide insurance against the risks associated with adverse weather conditions. The paper is conducting a study to determine which heating companies should apply weather derivatives to improve their performance. The study is conducted using multi-criteria assessment methods – SAW and TOPSIS. The multi-criteria assessment showed that AB Šiaulių energija and UAB Varėnos šiluma could use the opportunity to apply weather derivatives in their activities. [ABSTRACT FROM AUTHOR]

This paper reviews effect of wax content to performance of bitumen and asphalt pavement. Negative influence of wax content is known from literature reviews, which effects elasticity of binder and causes sensitivity to low temperatures and increases cracking. There is lack information of methods to evaluate wax content in bitumen. This paper presents literature review of variety of wax types, separation wax as saturated hydrocarbons by studying fractional composition and methodology for determination of wax content in bitumen and negatively effect of crystallization. [ABSTRACT FROM AUTHOR]

Agricultural drainage and associated water management systems are designed to eliminate to an acceptable level the factors associated with excess water that limit crop growth. In order to eliminate excess water in cultivated areas, it is important to reduce the leaching of nitrogen compounds flowing together with drainage water, as well as to ensure the safe and sustainable use of plant protection products and fertilizers. One possible solution is to transform free drainage structures into controlled drainage systems. In such systems, it is possible to regulate the groundwater level according to the needs of the plants and reduce the leaching of nutrients with drainage water. This paper presents a comparative analysis of controlled and free drainage water pollution by nitrogen compounds. The research was carried out in Pasvalys district, where both types of drainage systems operate next to each other. [ABSTRACT FROM AUTHOR]

The printing industry today faces major challenges posed by increased competition, rapid technological development, shortage of specialists, declining product circulation, and more. An appropriate and effective business management system helps to reduce the risk of all these factors. This article presents a study aimed at investigating enterprise resource planning systems for printing industry and making suggestion for development opportunities. The object of research is the ERP system in printing industry. This paper presents an empirical study conducted using the survey method and uses two types of this method: a questionnaire survey and an interview. The research is summarized by qualitative and quantitative methods, based on the results of the research the ways of solving the problem are presented and the ERP improvement scheme is formed, the proposed knowledge management module is presented. These suggestions can help processes in companies and be more competitive in the market. This article highlights the importance of continuous improvement of business management systems. [ABSTRACT FROM AUTHOR]

The paper examines the possibilities of speculating in exchangetraded funds by using artificial intelligence. The main goal of the research is to create a support system for speculative decisionmaking for investors operating in exchange-traded funds market. The research will be based on the theoretical aspects of artificial intelligence and speculation of exchange-traded funds. The support system is developed on the basis of reinforcement learning, the methods of synthesis, concretization and generalization were used to create and detail the system, as well as the methods of mathematical-statistical analysis were used to process them. Successful application of the chosen methodology in the design of the support system has resulted in positive trade results. Successful research broadens the boundaries for usage of deep reinforcement learning, and provides a basis for further development of the support system for exchange-traded funds. The support system put in place will shorten the time between the occurrence of a trading signal and the decision of the investor, which will help to reduce the loss of potential profits. [ABSTRACT FROM AUTHOR]

In 2021, aviation industry companies are facing one of the biggest crisis during the last two decades. Due to that, affected aviation companies must adapt their business models and rearrange their business interactions. The article describes the impact of the crises on aviation companies and crises management to decrease damage to the business. The concept of the crises is discussed as well as its nature, typology, unique factors, and classification based on scientific literature. The article briefly covers the biggest crises the aviation industry suffered in the last decades. Business partnership management is discussed as one of the instruments to decrease the effect of the crisis, to manage and neutralize them. The paper provides insights into criteria for partner selection in the aviation industry and based on expert evaluationseeks to provide insights how aviation companies can choose and evaluate their business partners. [ABSTRACT FROM AUTHOR]

Even today, industrial companies are struggling on new product development and market launch. This article reviews the theoretical aspects of new product development and commercialization processes and the factors determining their success. Overviewed Baltic States cosmetics industry market and trends. The study focused on the success factors of new product development and market launch processes in the cosmetics industry. The aim was to identify and analyze the success factors of cosmetic product development and market launch processes and to provide a solution model. Identified factors prevailing in the development and launch of new products in the cosmetics industry sector and the connections between them. Investigated the influence of these factors on the success of new products in the market. The paper presents the results of a survey of companies in the Baltic cosmetics industry. Based on the results of the research, a model for the development and launch of new products for the cosmetics industry is presented. [ABSTRACT FROM AUTHOR]

High-tech industry stands out as progressive, inovative field of industry which continuously makes investments towards R&D development. High-tech industry also has distinguishing features such as rapid use of new science findings and constant investments to new equipment, which tends to quickly depreciate and is replaced. Also, high-tech industry companies typicaly cooperate with international organisations, research centers and universities. It is not unusual for high-tech industry companies to have a lot of patents and licences. It is difficult to implement business improvement models, which tend to increase competitive advantage by reducing production cost, increasing production speed and reducing delivery time in continiously evolving high-tech industry companies. In this paper the posibility to implement business improvement models in high-tech industry is analyzed. Additionaly, employee motivation and initiative, as factors of business model implementation success is analyzed. Finally, based on the research of scientific literature and empirical data of two high-tech industry companies a model for high-tech industry performance improvement is proposed, which also introduces tools to improve employee motivation and initiative. [ABSTRACT FROM AUTHOR]

This article examines the issue of establishing and developing start-up business. Possibilities of establishing a business in Lithuania, tendencies of promoting young and innovative companies and problems of long-term establishment in the market are reviewed. According to the tendencies and methods described in the scientific literature, a survey of Lithuanian small and medium business was conducted. The business environment and opportunities in the eyes of developers, the steps of business development and the obstacles encountered were examined. The paper presents the generalized results of the surveyed companies. Based on the problems identified during the study, the model is presented, as well as conclusions and suggestions on what essential mistakes should be avoided. [ABSTRACT FROM AUTHOR]

Port of Šventoji is a maritime facility in the settlement of Šventoji, located within the country Lithuania, near the seaside resort town of Palanga. In this paper five Port of Šventoji development alternatives are overviewed using a multi-criteria decisionmaking (MCDM) method. The results will be compared with the ones found in “Port of Šventoji reconstruction feasibility study” (liet. Šventosios jūrų uosto atstatymo galimybių studija). Criteria weights of the analysed alternatives are determined using the entropy method. Alternative analysis is carried out using the TOPSIS multicriteria method. [ABSTRACT FROM AUTHOR]

This paper describes the stability calculations of the most common road embankments slopes and their results using the modified Bishop method. By searching for the smallest possible effective angle of internal friction of the different slope steepness embankments, the possible different bases of the embankment, the weight of the embankment soil, the load caused by transport and the location of load application (shoulder) were evaluated. Analyzing the obtained calculation results, it was determined that at a slope of 1:2 (26.57°) steepness, to ensure slope stability, the calculated effective internal friction angle of the embankment soil should be φʹd ≥ 28.5°, and at a slope of 1:1.75 (29.74°) steepness – φʹd ≥ 29.8°. When the slope is 2:3 (33.69°) steepness, the stability of the slope cannot be guaranteed. [ABSTRACT FROM AUTHOR]

Most of the existing supply chain management methods and systems are being transferred to construction sphere regardless of the specifics of companies in the construction sector. Numerous complex factors such as ecological, social and economic are required for the continuous evaluation in the modern management of construction sector. The provided studies and the research to examine sustainable supply chain management in construction sector from a holistic perspective, concentrating on mostly longterm sustainable decision-making by the construction company rather than being centered only on the supply chain management for construction projects. This paper identifies a list of sustainability indicators for examining the supply chains of construction companies. Those indicators were categorized and assigned to one or a couple groups by reviewing their use in the previous literature agreeing to the reasoning to way better reflect the SSCM principle of their use in construction companies. The use of indicators can help develop strategies for the construction sector for sustainable policy makers and construction company managers. [ABSTRACT FROM AUTHOR]

The European building sector is facing a pressing issue of natural resources. Importing road building materials for the asphalt surfacing increases the cost of the asphalt mixture. The asphalt surfacing mixtures shall consist of a mixture of graded aggregates accounting for 80-90% of the total volume of the asphalt mixture, or 90-96% of the total weight of the asphalt mixture and binder: road bitumen or polymer modified bitumen. In the Republic of Lithuania, asphalt mixes are designed in accordance to the Design Regulations for Road Pavement Standardized Pavement Structures KP SDK 19 and accordance to the normative documents and their requirements for graded aggregates and binders. Road builders import graded aggregates to asphalt mixes from other countries, and this increases the cost of asphalt mixes. According to the scientific researches in the Lithuanian quarry Petrašiūnai II, using unique production technology is produced class I dolomite crushed stone, which mechanical, physical properties and designed asphalt mixtures can replace imported graded aggregates. The economic question remains as to the economic effect of the most commonly used asphalt mixtures in Lithuania AC 11 VS (asphalt mixture of asphalt pavement wearing course) and SMA 11 S (crushed and mastic asphalt) made from indigenous minerals compared to imported minerals. The aim of the paper is to perform the calculation and evaluation of the economic effect of asphalt mixtures AC 11 VS, SMA 11 S with different minerals and micro-aggregate. The paper identifies and analyses the properties of asphalt test mixtures, and identifies the locations of mineral suppliers in Lithuania. According to the economic impact assessment scheme, the economic effect of asphalt mixtures AC 11 VS, SMA 11 S with different minerals and micro-aggregate was calculated. According to the calculations made, the economic effect of producing asphalt mixtures AC 11 VS, SMA 11 S with class I dolomite chips is 13-14%. [ABSTRACT FROM AUTHOR]

Varnishing quality and the gloss of lithographic prints on different papers and cardboards were evaluated using expertise rating. It was found that varnishing quality and gloss increase with grammage do not depend on the varnish grade (two grades were tested) and is the same for the paper and cardboard of the same grammage.. [ABSTRACT FROM AUTHOR]

Mechanical properties of paper and flexographic prints made with different anilox rollers were investigated experimentally. Flexographic prints roughness, breaking force and folding resistance values were determined. The results showed that folding resistance is bigger for machine direction prints than for cross machine direction prints. Flexographic prints on cardboards folding resistance values are different for machine direction and cross machine direction. It was determined that roughness of flexographic prints increases with the amount of ink on anilox roller. Results were explained by the ink water influence. [ABSTRACT FROM AUTHOR]

The paper investigates the quality of a steel welded joint of a tire shredding knife. Defects occurring during restoration are analyzed. In order to determine the mechanical properties of the welded joint, the following tests and tests were carried out: visual inspection, magnetic particle tests, metal hardness tests and chemical analysis of the parent and weld metal. [ABSTRACT FROM AUTHOR]

This paper presents the analysis of Building Information Model usage in Facilities Management. The main Facility Management aspects and problems are analyzed and advantages and disadvantages of Building Information Model are evaluated, opinions about BIM development and use in facilities management. The effectiveness of BIM use in the Facilities Management is analyzed with the help of SWOT analysis. The guidelines to the Facility Management company for using BIM are created. [ABSTRACT FROM AUTHOR]

The high share of global energy costs to create an indoor climate has been of increasing interest to the global community for several decades and is increasingly the focus of policy. This paper analyses the energy performance gap between actual energy consumption and energy demand obtained during the dynamic energy simulation and building certification. To identify the energy performance gap, an existing office of energy efficiency class B was selected as a case study. The simulation program IDA Indoor Climate and Energy was used to create a dynamic energy model, based on the designed documentation and the actual indoor climate parameters recorded by the building management system. The results of the case study showed that the accuracy and reliability of the results presented by the dynamic energy model of the building directly depend on the assumptions. The correct values of the internal heat gains, indoor climate parameters, human behavior, air quality levels at different times of the day and season, HVAC system operation parameters and operation modes, specific fan powers of ventilation systems, the seasonal energy efficiency of cooling equipment and characteristics of sun protection measures have to be selected. [ABSTRACT FROM AUTHOR]

The installation of heat pumps in district heating (DH) systems is one of the most promising technologies to increase the efficiency of heat supply by using renewable energy sources and reducing heat carrier temperatures in the networks. The possibilities of installing heat pumps in DH systems are very wide, but most often the main purpose of their application is to increase the temperature of the supplied heat carrier at the heat substations of individual consumers or their groups. This paper describes a study that analyzed the possibilities of integrating an individual heat pump at a heat substation in a building to reduce the temperature of the heat carrier in the return line. The results of the study revealed the dependences of the reduction of the heat demand of the building from the DH network, the power of the heat pump, the coefficient of per [ABSTRACT FROM AUTHOR]

In this paper examines the possibilities of applying 3D printing in the manufacture of orthoses. Features of 3D printing of biocompatible materials are analyzed. In this work, mechanical bending tests of three printed samples were performed. Based on test results, PETG material is selected for 3D modeling and printing. Technological properties of 3D printing were summarized. Modeling and printing of the orthoses prototype, compared to traditional methods, takes less time, and uses lower material costs, does not require much physical effort, is well suited to the patient’s body anatomy, and has a variety of design options. [ABSTRACT FROM AUTHOR]

The article compares different materials of bone substitutes – bioceramics: hydroxyapatite (HA), tricalcium phosphate (CaP) and polymer: polylactide (PLA). In the paper determines which of the substitutes is mechanically similar to the natural bone. Universal testing machine for tensile, compression was used for research. The properties of the test substances were determined by a compression and hardness test. Comparative tests are conducted with HA, CaP, PLA which were kept for 3 weeks in physiological saline and with natural pig bone. The mechanical properties of PLA specimens produced by 3D printers have been found to be similar to natural bone. When held in saline, PLA does not change its properties and dissolves less quickly than tricalcium phosphate. [ABSTRACT FROM AUTHOR]

Building Information Modelling (BIM) is increasingly being implemented both in the World and in Lithuania. The benefits provided by BIM promise a much more efficient and smoother construction process and suggest that the construction market of the future will continue to develop based on the BIM methodology. However, both the implementation and development of BIM can face some challenges, obstacles and limitations for construction market participants that occur with the use of BIM and that can slow down the smooth implementation of a project. This paper examines the difficulties of BIM in the implementation and use phase. During the research, the literature sources were analysed describing the implementation of BIM in the development of residential and other projects. The advantages and challenges of BIM described by the authors were analysed, and the emerging problems were highlighted. The literature sources analysed and found BIM limitations were grouped according to the most frequently mentioned. [ABSTRACT FROM AUTHOR]

Heat pumps are becoming increasingly popular and are playing an important role in the heat and cooling supply chain of buildings sector. Although more than 160 years have passed since the manufacture of the first heat pump, this technology, designed to recover low-potential heat energy and its useful use, can be called an innovative and efficient energy transformer. Air-to-water and air-to-air heat pumps are becoming more popular today due to their installation cost compared to ground-to-water heat pumps. It has been noticed that recently air-to-air heat pumps are more often installed in modern air handling units. The main energy transformers in these air handling units are the air-to-air heat pump and recovery heat exchanger. In the scientific literature little attention is paid to the thermodynamic cycle of the combination of the air handling unit and the heat pump, as well as the search for new possibilities to change and control it, this is a potential direction that can increase the efficiency of the whole system. To study the control capabilities of the unit, an experimental stand of the heat pump built into the ventilation unit is needed; it would help validate the results of theoretical studies and investigate the possibilities of expanding the control. Therefore, this paper presents a review of the experimental stands of non-integrated heat pumps and integrated heat pumps in air handling unit. Based on this review, the basic requirements for the installation of an experimental stand of a heat pump built into an air handling unit are formulated and a conceptual scheme of this stand is drawn up. [ABSTRACT FROM AUTHOR]

The article discusses IoT based solutions to improve waste collection and monitoring in public waste containers. The paper examines whether the monitoring system used in the measurement process can be used to monitor the filling of containers. The system consists of a wireless module connected to an ultrasonic sensor. The data sent makes it possible to calculate the empty space in the waste containers. The values are obtained by measuring the distance from the top of the container to the surface of the waste. Low-power long-distance broadband network (LoRaWAN) transmitters were used for data transmission. The aim of the research: to test an inexpensive monitoring system and to describe a new system of sensors and transmitter modules. The system is characterized by extremely low power consumption and a wide range of sensors used. Measurements were performed in Vilnius. Containers of two types of sizes were analyzed, measurements were performed at five points of horizontal cross section of the containers. The study was performed at two different levels of container filling. The results show that an ultrasonic sensor can representatively measure waste filling depths at different levels of container filling. Based on the results, this sensor can be recommended in the intelligent waste management market. Such a system can provide the necessary data for optimizing waste collection processes in cities and avoid container overcrowding problems. [ABSTRACT FROM AUTHOR]

With the growth of energy-efficient building sector, ventilation systems are becoming increasingly important not only of fresh air supply but also in terms of energy consumption. The aim of this paper is to describe and analyse the operation of an air handling unit (AHU) with a heat pump using energy and exergy analyses under the variable environmental temperature (from –30 °C to 10 °C). The application of selected methods is illustrated in a case study of an AHU using environmental temperatures of Vilnius city during heating season (from the beginning of October to the end of April). An analytical method for determining distribution of the environmental (outdoor air) temperature is used. Energy and exergy analyses showed periods when the highest amounts of energy and exergy were consumed and the greatest exergy losses occurred. This allowed to reveal the component of the system with the highest exergy losses – the heat pump evaporator. Therefore, further research is needed for its design and application. At the end of the article, the seasonal indicators of the AHU with heat pump operation were calculated: coefficient of performance and exergy efficiency. The presented research procedure could be applied to the analysis of other energy systems and processes in them. [ABSTRACT FROM AUTHOR]

Intense competition in the mobile services market encourages these service providers to take measures to create, maintain and enhance consumer loyalty. In such a concentrated market, it becomes important for service providers to identify and enhance the factors determining customer loyalty and their expression, whereas maintaining existing users requires significantly less effort and financial, human and time resources than attracting new ones. This article deals with a case study of Lithuania’s mobile operators: UAB “Bitė Lietuva”, UAB “Tele2”, UAB “Telia” in the context of consumer loyalty. The paper raises the question of what factors influence mobile phone user loyalty and how these factors can be evaluated. The article presents theoretical analysis of factors determining consumer loyalty in the service sector. An expert evaluation and multi-criteria study reveals which loyalty factors have the strongest influence on customers of mobile operators when choosing a particular service provider in Lithuania. The relevance of this article has potential for a practical study of consumer loyalty factors in the future. In the future, the research may be continued on a larger scale, involving more companies in the telecommunications sector, choosing research methods that are suitable for a broader sample of research and formulating consumer loyalty enhancement solutions applicable exclusively to organizations in the industry. [ABSTRACT FROM AUTHOR]

The paper deals with the problem of transport enterprise technological development and its use as a tool for assurance the transport enterprise competitive and the quality of services. The ever-changing market for transport services poses challenges to meet the needs of users and providers. The growing and very fast processing of transport enterprise information provides an opportunity for new ways of communicating with the enterprise’s suppliers / consumers. The innovativeness of the production processes of the transport enterprise, its productivity and the quality of its production are completely dependent on the information transfer technologies used in the enterprise. Qualitative research identified technological development disruptions in transport companies. It has been defined, that transport enterprise needs to update and improve their technology constantly in order to succeed in the competitive market. [ABSTRACT FROM AUTHOR]

Digital oscilloscope’s structure has analog signal acquisition circuit, which transforms signal’s amplitude to fit ADC dynamic range. This circuit is commonly called oscilloscope’s vertical or front-end amplifier. Difficulty in designing front-end amplifiers in GHz range largely affects higher frequency range oscilloscope’s price. This work is focused on designing a front-end amplifier using discrete and openly sold components. We propose a design for attenuator, buffer, variable gain circuits. Amplifier’s prototype is designed. Main characteristics of the amplifier were measured. Measured bandwidth is 3 GHz. Amplifier’s gain and attenuation can support vertical scale sensitivity range from 10 mV/div to 1 V/div. Step response distortion is under 10 %. SMD and PTH relay model attenuators were evaluated. In this paper we review oscilloscope’s front-end purpose and structure. We review amplifiers design and provide the results of experimental measurements. [ABSTRACT FROM AUTHOR]

This paper reviews CMOS LC Voltage Controlled Oscillators (VCO) for wireless multi-standard transceivers and wireless communications. The main parameters, such as IC technology, phase noise, carrier frequency, supply voltage, tuning range, power dissipation, figure of merit (FOMT and FOMTT) were reviewed in this paper. These parameters were taken of 20 articles published in 2012-2016 years. Of the reviewed articles it can be said that most VCOs was designed in 180 nm (55%) and 65 nm (25%) CMOS IC technology. FOMTT quality function has been proposed for extended VCO quality assessment. FOMTT quality function additionally evaluates VCO IC technology, and the power supply. [ABSTRACT FROM AUTHOR]

The aging of the labor force is observed in most developed and developing countries. The employment rate of older employees has been increasing every year and it appears to be not changed in the nearest future. The aging workforce is a serious challenge for organizations due to the prevailing stereotypical approach that older employees are less motivated, demonstrate lower labor productivity, they have more difficulties adopting new information, technologies and the lower ability to adapt to innovations. The aim of the paper is to investigate the impact of the work characteristics on the involvement in the work, the influence of employee’s characteristics on the work engagement, the influence of age and related factors on the involvement in the work and the relationship between age and achievements. The research is based on the analysis and synthesis of scientific literature, investigating work engagement issues of older employees. The study enabled to reveal the diversity of the concepts and methodologies and to systematize prevailing issues. The paper integrates the main researches in the field of older employees' engagement and provides recommendations for future research. [ABSTRACT FROM AUTHOR]

The paper analyses the innovative internal blinds, which allow to use the solar energy, received through a window for a heating, more efficiently and to ensure a greater air velocity due to the convection. Blinds are constructed that one side is covered with material, which absorbs the solar energy and the other side is reflective. Thus, there is an ability to control an amount of absorbed solar radiation and air supply temperature between the window and the blinds. In addition, the construction of the air to provide locating elements. The elements for air deflection are additionally foreseen in the construction. Due to the natural circulation cold air falls between the blinds and the window, then warms up and rises to the top. The paper presents an empirical and theoretical assessment of an operation of the blinds. In addition, the analysis of the experimental researches of an air flow intensity and a dependency of temperature increase from external (climatic) conditions is performed. [ABSTRACT FROM AUTHOR]

This paper proposes an algorithm to reduce limitations in bandwidth measurements of sampling oscilloscopes then using a swept sine-wave measurement method. The traditional swept sine-wave method allows to measure only magnitude response. Phase response can be computed only if a sampler is a minimal phase circuit. In this paper alternative bandwidth measurement algorithm using the nose-to-nose method with measurements corrections for the non-idle properties of oscilloscope is described. Algorithm includes noise, time base distortions and jitter in measurement signals corrections methods. Proposed algorithm allows to measure phase and magnitude responses when only two similar oscilloscopes and the source of sync pulse are used. Algorithm performs as well as the swept sine-wave method in case when both samplers have the same frequency characteristics. [ABSTRACT FROM AUTHOR]

Cultural heritage buildings are an important origin of a country's cultural memory, originality, and attractiveness, which motivated cultural growth, economic development, and social employment. However, cultural heritage buildings threaten to decay regarding the contributing poor funding for cultural heritage buildings preservation and maintenance, increasing urbanization changes. The adaptive reuse of cultural heritage buildings is one of the reasons, helping to preserve heritage buildings. This paper submits qualitative and quantitative criteria and subcriteria for the adaptive reuse of cultural heritage buildings. The set of criteria consists of economic, social, environmental, cultural heritage and legal criterion. [ABSTRACT FROM AUTHOR]

One of the hardest task for a machine is creativity. Computational creativity defines creative task completion for a machine. Three main creative content generation methods are: exploratory, combinatorial and transformational. Video game content can be generated using procedural generation. Computational creativity, procedural generation, and application are explained in this paper. Procedural level generator is used as a base and additional features are built on top of it. The main goal of this research and modification is to increase application creative value, variety and expression. Additional functionality consists of tree and texture generation. [ABSTRACT FROM AUTHOR]

This paper analyzes an experimental heat pump used for heat recovery in a mechanical room ventilation system. The aim of the work is to examine the operation, control logic of the heat pump and evaluate the possibilities of its operation modes, cycle control by outdoor air temperature. A review of scientific literature and experimental tests of the heat pump were performed to achieve this goal. Tests were performed in three stages, after each stage, according to the results obtained the heat pump stand was improved and experimental modes were adjusted. During the experiment, the tendencies of the heat pump freon and air involved in the heat exchange parameters are analyzed with different combinations of expansion valve positions and compressor power. Knowing these experimental characteristics, the extent to which the combination of these two controls can be used to efficiently control of the heat pump according to the outside air temperature is assessed. Based on the results of the research the heat pump control algorithms (depending on the variable outdoor air temperature) are prepared. [ABSTRACT FROM AUTHOR]

Combating climate change and reducing greenhouse gas emissions are among the European Union's priorities today. Direct implementation of these priorities is sustainable buildings. This paper analyzes the energy supply of a health resort building with renewable energy sources in the context of the "BREEAM In-Use" sustainability assessment system. The criteria for the "BREEAM In-Use" scoring system are grouped according to the 3E criteria and recommendations are made for the weights of the 3E assessment system criteria. In accordance with the criteria grouping methodology in the article, in the context of 3E criteria, the maximum weight should reach the energy indicator (about 50%), the second most important one is the ecological criterion, and about 16% should only meet the economic criterion. [ABSTRACT FROM AUTHOR]

The paper presents an experimental study of the influence of heat transfer fluid (HTF) mass flow rate on phase change materials (PCM) behaviour. The experimental study was performed on a specially designed test bench. Research object - PCM based thermal energy storage unit which consists of a stainless steel tank with dual circuit tube-fin copper heat exchanger. The tank (storage volume) was filled with phase change material RT82. The experiment was carried out using three different mass flow rates of HTF: high - 0.25 kg/s, medium - 0.125 kg/s, low - 0.05 kg/s. The analysis showed that in the case of high and medium mass flow rates the melting/solidification process highly depends on the temperature of inlet HTF. Influence of mass flow rate is higher in the case of low mass flow rate. [ABSTRACT FROM AUTHOR]

Various countries apply different methodology for national critical infrastructure identification. MCDM method TOPSIS is extensively used in different areas of research such as logistics, health. The best alternative is based on all criteria, dependant on their significance. The paper presents the study of multiple criteria decision-making method TOPSIS application for identification of Lithuanian national critical infrastructure. The experiments demonstrate, that use of MCDM ensure better and more stable identification of critical infrastructure resulting in concentrating protection efforts and resources on the most important infrastructure nodes. [ABSTRACT FROM AUTHOR]