Ключ. слова: барьеры Шоттки, высокотемпературный микромонтаж, электрические свойства приборов
Індекс рубрикатора НБУВ: З852.2-01

Рубрики:

Напівпровідникові діоди

Шифр НБУВ: Ж14479 Пошук видання у каталогах НБУВ 

This paper reports the results from a pilot study investigating the information needs and information seeking behavior of small business owners and entrepreneurs in Pittsburgh and the Greater Pittsburgh area and potential information services they mayprefer to receive. Twenty-one participants of a workshop co-organized by the Business Service Department of the Carnegie Library of Pittsburgh and a local organization (Service Corps of Retired Executives) responded to a detailed survey. Results show that this particular group of small business people occasionally searches for various types of information. When looking for business related information, they tend to ask their friends and relatives (27.84%), business consultants (23.2%) and colleagues (21.65%) rather than librarians (5.67%) for information about marketing, finance, management, customer services, taxes, employment laws, etc. They use telephone (44.19%) or go in person (36.58%) rather than using email (12.09%) or fax (5.58%) to contact information providers. Although books and magazines are their major information resources (55.02%), they prefer to locate information from homes (41.59%) to libraries (16.81%). They favor value-added information services. They are willing to pay for packaged information prepared by information professionals, advisement sessions with business consultants, and workshops and seminars covering small business topics. Implications and suggestions for the design of user-centered information services are discussed.

Представлен обзор основных теоретических исследований в области влияния компьютерных игр на развитие ребёнка, проанализировано отношение к компьютерным играм детей и их родителей, составлена типология компьютерных игр, предпочитаемых детьми младшего школьного возраста.

Надано огляд основних теоретичних досліджень у сфері впливу комп’ютерних ігор на розвиток дитини, проаналізовано відношення до комп’ютерних ігор дітей і їх батьків, складено типологію комп’ютерних ігор, яким віддається перевага дітей молодшого шкільного віку.

The article notes that the rapid development of information and computer technology has not bypassed the world of childhood. Modern child lives in a world different from the one in which his parents grew up, and the emergence of a new life in their game reality, makes a careful attention to this phenomenon. In modern psychological approaches there are many opinions about the dangers and benefits of the computer in the child’s life. However, scientists are unanimous in saying that the introduction into the daily lives of the children of the computer along with the use of rocks and a number of problems, including computer addiction, the impoverishment of the imagination of children as imaginative side of the coin is offered in an already structured and packaged as producers. The aim of the article is to analyze the specifics of the game the computer activity of younger schoolchildren. By author pilot study gives an idea about the presence or absence of the younger students play computer dependence on the regularity of visits and the time spent by them on computer games; to make representation with respect to gaming preferences younger students, and the attitudes of parents towards their children’s computer activities.

Наведено результати аналізу підходів до формування альтернативних варіантів транспортно-технологічних схем доставки вантажів. Запропоновано критерій визначення оптимальної транспортно-технологічної схеми доставки. Надано модель вибору оптимальної транспортно-технологічної схеми доставки тарно-штучних вантажів у міжміському сполученні.

Разработан алгоритм выбора интервала измерений и корректировки параметров объектов контроля и управления иерархических АСУ, укомплектованных разнообразными техническими средствами и средствами связи между компонентами. Допустимый по точности воспроизведения характеристик объектов интервал определяется на основе теоремы Котельникова. Алгоритм предлагается использовать как универсальную последовательность действий при реализации различных способов достижения оптимального управления. Показана возможность использования алгоритма при управлении динамическими объектами с прогнозирующими моделями.

Розроблено алгоритм вибору інтервалу вимірювань і коригування параметрів об'єктів контролю та управління ієрархічних АСУ, укомплектованих різноманітними технічними засобами і засобами зв'язку між компонентами. Допустимий за точністю відтворення характеристик об'єктів інтервал визначається на основі теореми Котельникова. Алгоритм пропонується використовувати як універсальну послідовність дій у процесі реалізації різних способів досягнення оптимального управління. Показано можливість використання алгоритму за умов управління динамічними об'єктами з прогнозувальними моделями.

The author presents an algorithm for selecting of measurements and adjusting interval of parameters of control and management objects of hierarchical ACS, packaged with a variety of technical equipment and means of communication between the components. The interval that is acceptable for fidelity of reproduction of characteristics of objects is determined using Kotelnikov theorem. The algorithm is proposed to be used as a universal sequence of actions in the implementation of the various ways to achieve optimal control. The paper shows the possibility of using the algorithm in the management of dynamic objects with predictive models.

Представлены результаты исследований и разработки выключателей и переключателей с использованием p—i—n-диодов сосредоточенного типа, обеспечивающих время переключения единицы наносекунд. С целью увеличения развязки в закрытом состоянии (потерь запирания) около 40 дБ в устройствах применено каскадное включение диодов в волноводную и микрополосковую линии передачи на электрической длине θ = π /2. Представлены результаты исследований по созданию коммутационных устройств коротковолновой части миллиметрового диапазона длин волн (f = 300 ГГц) с использованием продольно- и поперечно-распределенных p—i—n-структур.

Наведено результати досліджень і розробки вимикачів і перемикачів з використанням p–i-n–діодів скупченого типу, що забезпечують час перемикання на рівні одиниць наносекунд. З метою збільшення втрат запирання (приблизно 40 дБ) в пристроях застосовано каскадне включення діодів в хвилеводну і мікросмугову лінії передачі на електричній довжині θ = π /2. Подано результати досліджень зі створення комутаційних пристроїв короткохвильової частини міліметрового діапазону довжин хвиль (f = 300 ГГц) з використанням подовжно- і поперечно-розподілених p–i–n-структур.

The paper presents the results of research and development of concentrated type p—i—n-diodes switches providing the switching time units of nanoseconds. To increase lock losses of (~40 dB) the authors use a cascade connection of diodes into waveguide and microstrip transmission line of θ = π/2 electric length. Investigation results of creation of switching devices using longitudinally and transversely-distributed p—i—n-structures in the shortwave part of the millimeter wavelength range (f =300 GHz) are presented. When developing switching devices intended to control the level of microwave power in the millimeter wavelength range, a number of special features arise limiting the achievement of optimal parameters. The dimensions of the metal ceramic packaged p—i—n-diodes and the mounting elements of semiconductor structures become comparable with the wavelength. As a result, package cannot be considered in the calculations and in the design as the capacity of the concentrated type. In our case the diode package is considered in the form of radial line which is able to transform the input impedance of the transmission line to the terminals of the diode structures, and realize high-impedance state (parallel resonance) in the device circuit in the mode of microwave power transmission. Engineering calculations for the given parameters of the silicon mesostructures showed the possibility of creating high-speed devices for switching microwave power with good characteristics. For diode assembling industrial clockwork ruby jewels with high quality of surface finish, strength and appropriate dimensions are applied as dielectric bushings. Suffice it to say that in the frequency range of 150 GHz, we used the bushings with dimensions of external diameter D = 0.4 mm and a height of h = 0.15 mm. The switches created provide transient units of nanoseconds, isolation more than 40 dB at relative frequency bandwidth of 30-40%. Evaluating progress in the development of millimeter wavelength devices, itshould be noted that at frequencies greater than 200 GHz, the application of the concentrated type diodes is problematic. In this range it would seem to be promising to use bulk semiconductors. In this case surface-oriented p—i—n-structures can be applied as unified elements of the control devices in the shortwave part of the millimeter range, as well as in quasi-optical transmission lines.

Індекс рубрикатора НБУВ: Л645.2

Рубрики:

Капсулі-запальники та засоби займання гарматних зарядів

Шифр НБУВ: Ж69121 Пошук видання у каталогах НБУВ 

The British Retail Consortium Global Standard for Food Safety enjoys great popularity among food industry companies, the number of companies with the certified standard is rising every year. The packaging used for food packaging has a very large impact on the safety and quality of the packaged food. The purpose of the study was to indicate the requirements of the standard in relation to packaging, which should be implemented firstly by enterprises of the food industry. In the research part, the AHP analysis was conducted on the basis of the experts' recommendations. Decision matrixes for every criterion: hazard analysis concerning packaging, purchase procedure, packaging acceptance procedure were developed. A decision matrix for the main criterion as a result of criteria decision matrix was developed, global decision hierarchy was also developed. Research clearly showed that the most important activity (among the proposed) is hazard analysis, with a 0,517 weighted sum value. In many of the detailed requirements of the standard, hazard analysis and risk assessment (0,333 weighted sum value) are the basis for many activities, including establishing a purchasing procedure (0,163 weighted sum value), accepting packaging (0,297 weighted sum value), or many others. The relevance of this study is the identification of the hierarchy of importance of activities performed within the framework of ensuring the quality and safety of food packaging. A reasonable approach is presented. The AHP method allows indicating the sequence of activities during the implementation of the BRC standard, as evidenced by pilot studies carried out on the basis of procedures related to the safety of packaging. The standard sets up requirements for packaging in the form of packaging management procedure, in which it should be stated how the site operates with packaging. Moreover, there are requirements concerning hazard analysis in relation to packaging.