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The finite element model developed for a new-designed aircraft was used to solve some problems of structural dynamics. The key purpose of the task was to estimate the critical flutter velocities of the light airplane by performing numerical analysis with application of MSC Software.

Flutter analyses processed by Nastran require application of some complex aeroelastic model integrating two separate components – structural model and aerodynamic model. These sub-models are necessary for determining stiffness, mass and aerodynamic matrices, which are involved in the flutter equation. The aircraft structural model with its non-structural masses was developed in Patran. To determine the aerodynamic coefficient matrix, some simplified aerodynamic body-panel geometries were developed. The flutter equation was solved with the PK method.

The verified aircraft model was used to determine its normal modes in the range of 0-30 Hz. Then, some critical velocities of flutter were calculated within the range of operational velocities. As there is no certainty that the computed modes are in accordance with the natural ones, some parametric calculations are recommended. Modal frequencies depend on structural parameters that are quite difficult to identify. Adopting their values from the reasonable range, it is possible to assign the range of possible frequencies. The frequencies of rudder or elevator modes are dependent on their mass moments of inertia and rigidity of controls. The critical speeds of tail flutter were calculated for various combinations of stiffness or mass values.

The task described here is a preliminary calculational study of normal modes and flutter vibrations. It is necessary to prove the new airplane is free from flutter to fulfil the requirement considered in the type certification process.

The described approach takes into account the uncertainty of results caused by the indeterminacy of selected constructional parameters.

The purpose of this study was to analyze the possibility of using combat aircraft including decommissioned as a platform for launching and carrying space rockets with satellites (nano and microsatellites). Thus, an airborne-launcher-to-space-system may be attractive to countries without ground-based space rocket launch sites.

For considered launch-to-orbit system configurations, simulations of space rocket effects on aerodynamic characteristics were performed using computational fluid dynamics (CFD ANSYS Fluent) methods. In addition, experimental studies were performed in a wind tunnel to verify the numerical simulations. Discrete models of the aircraft structure were developed for analysis using finite element method (FEM). The analysis of simulated structural properties of the models was carried out to test its stiffness and mass characteristics important for solving the static and dynamic problems of the structure. The validation analyses of aircraft models were based on mass distribution estimation and matching the stiffness properties of the individual airframe structural assemblies.

The results of numerical analyses and tunnel tests indicate that the influence of carrier rockets on the change of aerodynamic and strength characteristics of the airframe is rather negligible. The aircraft can be used as launching platforms for space rockets. Simulations have indicated that the aircraft will successfully perform a mission of taking away and launching a rocket of at least about 1,000 kg total weight with a 10 kg space payload included.

The combat aircraft can be used as launch platforms for space rockets, and the air/rocket set can become the equivalent of responsive space assets for countries with small space budgets.

The work presents original results obtained by the authors during a preliminary design of a low-cost satellite launch system consisting of a carrier aircraft and a space rocket orbiter. The possibility of using decommissioned combat aircraft as air-launch-to-orbit platforms was taken into consideration. In the absence of aircraft design documentation, reverse engineering methods and techniques were used to develop aircraft geometry and airframe strength structure. Use of CFD, FEM and simulation methods to evaluate system capabilities was demonstrated. Numerical results from CFD simulations were finally verified in experimental tests.

The paper describes the application of two different vibration measurement methods for the identification of natural modes of the miniature unmanned aerial vehicle (UAV). The purpose of this study is to determine resonant frequencies and modes of mini-airplane within the specified range of frequency values.

Special measuring equipment was used including both contact and non-contact techniques. The measuring systems on equipment of the Institute of Aviation Technology in the Faculty of Mechatronics, Armament and Aerospace of Military University of Technology (Warsaw, PL) were used to conduct measurements. In traditional ground vibration testing (GVT) methods a large number of sensors should be attached to the aircraft. The weight of sensors and cables is negligible in relation to the mass of the large aircraft. However, for small and lightweight unmanned aerial vehicles, this could bring a significant mass component in relation to the total mass of the tested object.

The real mini-UAV construction was used to investigate its resonant modes in the range of frequencies between 0 and 50 Hz. After receiving the output values it is possible to perform some flutter calculations within the range of operational velocities. As there is no certainty that the computed modes are in accordance with those natural ones some parametric calculations are recommended. Modal frequencies depend on structural parameters which are quite difficult to identify. Adopting their values from the reasonable range it is possible to assign the range of possible frequencies. The frequencies of rudder or elevator modes are dependent on their mass moments of inertia and rigidity of controls. The critical speeds of tail flutter were calculated for various combinations of stiffness or mass values.

In this paper, some specific techniques of performing the GVT test were presented. Two different measuring methods were applied, i.e. the contact method and the non-contact method. Using the dedicated apparatus in relation to the mini-airplane, properly prepared in terms of mass distribution, rudders deflection stiffness and proper support, some resonant characteristics can be determined. The contact measuring system consists of a multi-channel analyzer, piezoelectric accelerometers, electrodynamic exciters, amplifiers, impedance heads and a computer with the Test.Lab Software. As the non-contact method, a laser scanning vibrometer was used. The principle of its operation is based on the separation of the emitted laser beam. The returning beam reflected from a vibrating object is captured by the camera and compared to the reference beam. Dedicated software analyzes collected data and on the basis of it creates animations of structural vibrational shapes and spectral plots within the investigated frequency range.

The object used for research is the mini-UAV Rybitwa – composite mini-plane with a classic aerodynamic layout manufactured in Institute of Aviation Technology Military University of Technology. In the work, both measurement methods and some sample results were presented. Results referenced to dynamic properties of the mini-UAV can be applied in the future for its finite element model tuning, what would be useful for the needs of some parametric analyzes in case of some UAV modifications because of its structural or equipment modifications.

This is an empirical study of family firm size, as measured by the number of employees, and the relationship of a firmʼs size to a variety of management activities, styles, and characteristics. A statistical analysis of data drawn from 159 American family businesses indicates significant differences by size with regard to the number of nonfamily members in top management, use of outside advisors, time spent engaged in strategic management, use of sophisticated methods of financial management, proportion of women family members involved in firm management, and level of conflict between family members. Implications are offered for family firm owner-managers, for those who assist such businesses, and for researchers in the field of family business.

In the literature of family business, certain management activities, styles and characteristics have been most frequently examined. Yet no prior research focusing on the relationship between these family businesses variables has been found. This is a survey‐research correlation study of 149 family businesses. Of the twelve variables studied, twenty of the sixty‐six correlations were found to be significant. Major findings are the consistent use of professional management activities, styles and characteristics in family businesses, and that using non‐family members within top management does not significantly increase the professionalism of management of such businesses.

The purpose of this paper is to investigate how family businesses change as they grow in size, and to compare differences between the USA and France.

The research design is survey research, statistically t‐testing 12 hypothesized differences between smaller and larger firms in the USA (n=159) and in France (n=116).

The research finds that both countries' larger firms have significantly (p < 0.05) more non‐family members within top management and make greater use of outside consultants, advisors, and professional services than smaller firms. However, family businesses in France had no other significant differences, while those in the USA had four. Larger US firms have a smaller percentage of women family members working in the firm and less conflict and disagreement between family members; they also spend more time in strategic management activities, and use more sophisticated methods of financing.

There are some variations between the two country samples.

Understanding whether and how family business management activities, styles and characteristics change with growth can help those who own and manage such businesses. It can also be of value to those who advise and assist family businesses, as well as researchers who study them.

This is the first study to analyze the effect of firm size on family business management and to conduct a cross‐national comparison.

The purpose of this paper is to compare first‐, second‐, and third‐generation family business managerial characteristics and practices in a combined sample from six countries (Croatia, Egypt, France, India, Kuwait, and the USA) with significant differences in cultures, economies, levels of entrepreneurial activity, and family business demographics.

The design was survey research with a sample of 593 businesses from six countries. To compare differences between the three generations, analysis of covariance was run for the 11 dependent variables, followed by post hoc Tukey honestly significant difference multiple comparisons tests to determine which of the three generations were significantly different.

As family businesses move from first to second to third generation, some managerial characteristics and practices remain the same while others change. Furthermore, only minor generational differences between the various countries were found, thus supporting commonality of family businesses in spite of the differing cultural, economic, and demographic variations.

The results lead to an improvement in our understanding of entrepreneurial behavior and managerial characteristics and practices between generations of family business in six very diverse economic and cultural settings.

Prior family business research has rarely focused specifically on comparisons of first‐, second‐, and third‐generation firms. No prior research combined family firm data from different countries. The analyses are more complex and mixed than the methodologies used in most of the limited previous research, raising questions and indicating a need for further research.

The purpose of this paper is to examine the family business literature on human resource management (HRM) activities within family-owned businesses to advance theory and practice.

This paper is a review of research on the formation, adaptation, and termination of the employment relationship within family businesses.

Important areas for future research are revealed. For example, little research investigates how family members are recruited, socialized, or how exit decisions are made. In contrast, significant attention has been given to role transitions during succession.

The paper focuses on managing employment relationships (e.g. recruitment, selection, etc.) within family businesses. The research revealed HRM activities within family businesses are often informal so aspects of the employment relationship may not be fully captured by extant research.

This review provides specific HRM suggestions for practitioners to consider. For example, this review highlights that training inside the family business can be as effective as training outside the family business.

This review is novel in applying an established HRM framework to family business research and focuses on HRM activities of family members as opposed to non-family employees. The paper offers considerations for families bringing next generation members into their businesses and preparing offspring to run them successfully.

The purpose of this research is to investigate differences in the perceived performance and competitiveness of “successful” family and non‐family‐owned firms in overseas markets.

This paper reports on findings from a postal survey and subsequent interviews involving managers of firms that are winners of the UK Queen's Award for Export.

Statistical analysis and follow‐up interviews establish that limited differences exist between high performing family and non‐family‐owned SMEs in respect of measures and sources of performance.

The data were based on a sample of firms judged to have been successful and therefore the usefulness of the sampling frame is questionable based on the criteria of the award's committee.

The findings indicate that small family‐owned businesses can be just as competitive in overseas markets as their non family‐owned counterparts, assuming that an effective strategy is employed. These can serve as useful role models.

Prior research has focused on general surveys and has not explicitly investigated differences between family and non‐family‐owned higher performing firms.

While family firms constitute a highly important component of most countries' economies, and in many countries a sizable portion of these family businesses are owned and managed by women, there has been minimal study of gender issues in family business ownership and management. The purpose of this paper is to fill this gap.

The research design was self‐reported survey research, which is the most commonly used methodology in family business research and for small business and entrepreneurship quantitative research.

In contrast to early (pre‐1980) gender comparisons in management and entrepreneurship, and in support of the majority of more recent studies, this investigation found no significant relationships between the gender of family business owner‐managers and ten management characteristic variables in a sample of 593 family businesses in six countries.

These findings add to the limited and currently inconclusive body of knowledge regarding gender issues specifically in family business, and more generally in entrepreneurship and management.