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Šio darbo tikslas buvo susipažinti su terahercinių impulsų generavimo ir detektavimo būdais, įsisavinti įvairias terahercinių impulsų panaudojimo metodikas bei pritaikyti jas puslaidininkių medžiagų ir puslaidininkinių prietaisų tyrimui. Buvo tirtos trys medžiagų grupės: GaAsBi, GaAs nanovielutės ir Cu – In chalkogenidai. Tyrimui buvo naudojamos: THz – TDS, optinio žadinimo – THz zondavimo, optinio žadinimo – optinio zondavimo bei THz sužadinimo spektroskopijos metodikos. Pagrindiniai rezultatai aprašyti disertacijoje yra šie: GaAsBi bandinių atkaitinimas stipriai sumažino krūvininkų gyvavimo trukmes, kas yra naudinga THz komponentų gamyboj. Optinio praskaidrėjimo efektas ir pikosekundžių eilės krūvininkų gyvavimo trukmės GaAsBi epitaksiniuose sluoksniuose su 10% ir daugiau Bi atomų stebimas žadinant juos optine spinduliuote, kurios bangos ilgiai siekia iki 1600 nm. Šios GaAsBi bandinių savybės leidžia juos priakyti įsisotinančių sugėriklių veidrodžių gamyboje. Bandiniai su GaAs nanovielutėmis emituoja THz spinduliuotę kelis kartus geriau nei GaAs padėklas, dėl padidėjusios sugerties, kurią skatina paviršinių optinių plazmonų rezonansai GaAs nanovielutėse. THz emisijos efektyvumas iš Cu-In chalkogenidų sluoksnių stipriai priklauso nuo jų stechiometrijos ir viršutinio skaidraus kontakto parametrų, ir gali būti naudojamas saulės elementų, pagamintų šių sluoksnių pagrindu, vidinių elektrinių laukų tyrimui. The goal of this dissertation work was to develop pulsed terahertz radiation techniques and use them to study different properties of the semiconductor materials and semiconductor devices. Three groups of materials were investigated: GaAsBi, GaAs nanowires, copper-indium chalcogenide. The used techniques are THz-TDS, optical pump – THZ probe, optical pump – optical probe and THz excitation spectral measurements. The main results that were presented in this dissertation are the following: thermal annealing has resulted in the shortening of electron lifetime in GaAsBi to picosecond values, which is important achievement for the application of this material in THz range components. In GaAsBi layers with larger than 10% Bi content absorption bleaching recovering on the picosecond time scale and its saturation can be realized when the wavelengths of the optical signals are as long as 1600 nm. The results of these studies can be applied in the production of SESAM with bismide absorption layer. The samples with GaAs nanowires emit THz radiation several times better than the bulk GaAs substrates due to enhanced light absorption because of localized surface plasmon resonances in GaAs nanowires. THz emission efficiency from thin copper-indium chalcogenide layers strongly depends on their stoichiometry and on the parameters of the top transparent contact layers, thus it can be used for the mapping of built-in electric fields in solar cells made from these layers.

Виконана оцінка похибки визначення азимута самоорієнтовною безплатформною інерціальною навігаційною системою (БІНС) на лазерних гіроскопах при дії на неї випадкової хитавиці. Результати отримані без накладання будь-яких обмежень на сигнали лазерних гіроскопів, мають загальний характер, тому можуть бути поширені на БІНС, побудованих на інших типах гіроскопів: оптичних, волоконно- оптичних, динамічно-настроюваних, мікромеханічних та інших., Выполнена оценка погрешности определения азимута самоориентирующейся бесплатформенной инерциальной навигационной системой (БИНС) на лазерных гироскопах при действии на неё случайной качки. Результаты получены без наложения каких-либо ограничений на сигналы лазерных гироскопов, носят общий характер и могут быть распространены на БИНС, построенных на других типах гироскопов: оптических, волоконно-оптических, динамически-настраиваемых, микромеханических и т.п., The estimation of self-orienting strapdown navigation system (SINS) azimuth error of laser gyro influenced by random pitching has been done. Results are obtained without imposing any limitations on the signals of laser gyros, are generic and can be extended to SINS built on other types of gyroscopes: optical, fiber optic, dynamically configurable, micromechanical etc.

THz pulse emission from GaAs and GaAs-MnAs nanowire (NW) samples illuminated by femtosecond laser pulses has been studied. The amplitude of THz pulses emitted by nanowire samples was more than twice larger than that radiated from GaAs substrate. It was found that terahertz emissivity of NW samples rapidly decreases with increasing laser photon energy - behavior that could be explained by localized surface plasmon resonances in GaAs and GaAs-MnAs NWs. The plasmon enhanced absorption has been identified as a major factor for intense THz emission from our samples.

Наданий аналіз основних шляхів застосування навігаційної апаратури при типових варіантах ведення бойових дій., Представлен анализ основных путей применения навигационной аппаратуры при типовых вариантах ведения боевых действий общевойсковыми подразделениями., Analysis of the main ways to use navigation equipment in the conventional warfare of combined arms units is presented.

Part 2: Conceptualizing EIS; International audience; Enterprise resource planning (ERP) systems are rapidly becoming a de facto standard in business activity. While large and medium-sized companies have the luxury to afford proprietary ERP solutions, small companies are struggling with resource poverty which maybe makes them consider available open source ERP products which are free from licensing fee. However, there is little knowledge available on open source ERP adoption in small companies. In order to spread some light on the first phase of ERP adoption, an experiment on open source ERP deployment was conducted. The experiment aimed at investigating what knowledge is required to successfully deploy open source ERP systems. The experiment was based on a research framework, the Technology Acceptance Model 2 (TAM2), and considered usability testing and user training and education factors. The factors of Perceived Ease of Use (PEOU) and Perceived Usefulness (PU) were used to determine the ease of deployment process, and the usefulness of the open source ERP deployed in relation to the made effort. The findings suggest that user with advanced computer skills perceive open source ERP deployment process as easy, and the deployed open source ERP was seen as being useful to organizations business activities.

The development of Information and Communication Technologies has opened up a large pool of possibilities for any and every business actor. These possibilities have brought up new vulnerabilities as well. Information security has become an inherent part of any organization. Companies and organizations invest significant amount of resources in IT security solutions, usually omitting the weakest link of the defense - the people. The research intended to study and evaluate the information security awareness level of employees in a public organization which preferred to remain anonymous. This study is based on a mixed-methods approach. A survey was built up and performed, basing on the interview of the employees and the IT Security Chief. The interview intended to give a general picture of the attitude, knowledge and behavior the employees towards information security and its constituent aspects. The results of the survey show that the information security awareness at this particular organization has an average performance based on the grading scale determined by the management of the company. Generally speaking, half of the information security focus areas show underdeveloped sense of awareness among employees, whereas the other focus areas are close to perfect. In terms of information security, the research indicates that there is a gap between the employees' theoretical condition and their day to day be-havior. In other words, the theoretical and practical preparation of the employees does not provide an appropriate information security awareness behavior. Some of the reasons for unsecure behavior were complex and sophisticated security designs including passwords; another problem was inherent in the work design which imposed the use of multiple systems and applications in the daily work. In the end, the research suggests some recommendations for improvement, as well as practices to sustain a desirable level of information security awareness level. The overall information security awareness program required immediate improvements in order to boost the positive attitude and behavior of employees towards information security, as well as enrich the knowledge of information security in general.

The best cooled Schottky diode mixer receivers at mm and submm wavelengths use specially fabricated "cryogenic" diodes. Parameters of these diodes permit one to realize very low noise temperatures when cryocooled, the noise temperature of the UVA2P9-600 diode being less than 50 K at 20 K). Preliminary investigation at 20 K of the I-V characteristics of the available diodes has shown them possessing the noise temperature theoretical limit of about 110 K. This is considerably higher than the noise of the above-mentioned "cryogenic" diode UVA2P9-600. With the purpose of compensating this high level of Schottky diode noise, we have focused our efforts on the reduction of the mixer conversion loss. Our receiver design incorporates a full-height waveguide mixer mount employing no input guide impedance transformer, thus reducing the waveguide channel and backshort losses. The necessary input impedance transformation in this mixer mount is realized immediately at the Schottky diode location. The DSB receiver noise temperature with a full-height waveguide mixer at room temperature is 270 K. For cryogenic operation an overmoded waveguide and linear taper to rectangular waveguide are added to the receiver input circuit.

Though the low energy electrons (160-200 keV) do not penetrate deep into the material's surface the application of such beams can be effective enough in some technological processes, i.e. for processing the materials surface or for realizing processes in gases. For researching the low energy beams influence on materials, the authors created a special experimental installation based on a powerful electron gun with wide rectangular output window. A number of different polymer materials were processed in this installation.

Carrier dynamics in MBE-grown GaBixAs1−x layers was investigated by the optical pump-–THz probe technique. Rapid thermal annealing at temperatures up to 700 °C has a dual effect on the electron decay characteristics. For the GaBi0.04As0.96 layer it led only to a small change of the decay time, whereas for the layer with x = 0.06 this parameter decreased by two orders of magnitude and became shorter than 1 ps. It can be assumed that the recombination centers in GaBiAs are more likely to occur in the layers with a larger Bi composition, a bigger lattice mismatch with the substrate.

High-speed photographic waiting type GSFK camera is intended for the investigation of high-speed processes both in the reflected light and with shadow and interferometric devices. Connecting optical attachments are provided for this purpose. The camera operates in framing and streak modes. The registration is provided in the vi-sible range of spectrum in a waiting mode, i.e. no synchronization to the event is required.