Formation control of a group of micro aerial vehicles (MAVs)

Coordinated motion of Unmanned Aerial Vehicles (UAVs) has been a growing research interest in the last decade. In this paper we propose a coordination model that makes use of virtual springs and dampers to generate reference trajectories for a group of quadrotors. Virtual forces exerted on each vehicle are produced by using projected distances between the quadrotors. Several coordinated task scenarios are presented and the performance of the proposed method is verified by simulations

Death anxiety in outdoor-adventure recreation: study of demographic variables and experience

This study investigated the death anxiety (DA) scores of participants in outdoor-adventure recreational (OAR) activities, and the relationship of the DA scores to several demographic features and experience of DA. The study included 589 individuals with various leisure-time OAR experience levels (131 women, 458 men; Mage=29.79±9.64). Their sports included climbing (n=200), scuba diving (n=142), and paragliding (n=247). DA was measured by the Thorson-Powell Death Anxiety Scale. Overall, the DA scores were low, with no significant differences between OAR activities. However, the DA scores were affected by age and gender, and length of OAR experience. More specifically, the DA scores were highest for 18-28-year-old participants, women, and participants with 4-6 years of middle-level OAR experience. Previous negative DA experiences did not increase the DA scores

H.264 Baseline video encoder implementation and optimization on TMS320DM642 digital signal processor /

Digital video encoding plays an important role in many applications such as digital surveiance systems, video conference systems as wel as digital TV. In this thesis. a H.264 baseline encoder is implemented on Texas Instruments TMS320DM642 digital signal processor. The TMS320DM642 is a high-performance digital media processor with 2-level memory/cache hierarchy and very-long-instruction-word (VLIW) architecture. The proposed encoder system consists of almost al parts of standard H.264 baseline encoder except quarter-pel motion compensation and error resiliency tools such as Arbitrary Sice Ordering (ASO) and Flexible Macroblok Order (FMO). Instead of quarter-pel motion compensation, integer-pel motion estimation and compensation for both Luminance and Chrominance samples is implemented. The complete H.264 encoder system is verified to work on both computer and DM642 EVM (Evaluation Module) platform. Basicaly, the encoder takes the input of a QCIF video sequence (YUV) and converts it to the standard compressed H.264 AnnexB fie format. The encoder is fuly compliant with the standard H.264 JM Decoder. The reconstructed video, which is exactly the same with the output of the standard JM H.264 decoder, is being displayed on a TV screen. In addition, by making use of the TI development tools. performance of the complete encoder system is anayzed for real-time applications. Finaly, memory optimization, code optimizations and compier optimizations are applied to the encoder for higher performance. The proposed H.264 encoder is able to encode, display and store 26.7 QCIF frames per second

A new coordination framework for multi-UAV formation control

Unmanned Aerial Vehicles (UAVs) have become very popular in the last few decades. Nowadays these vehicles are used for both civilian and military applications which are dull, dirty and dangerous for humans. The remarkable advances in materials, electronics, sensors, actuators and batteries enable researchers to design more durable, capable, smart and cheaper UAVs. Consequently, a significant amount of research effort has been devoted to the design of UAVs with intelligent navigation and control systems. There are certain applications where a single UAV can not perform adequately. However, carrying out such tasks with a fleet of UAVs in some geometric pattern or formation can be more powerful and more efficient. This thesis focuses on a new coordination scheme that enables formation control of quadrotor type UAVs. Coordination of quadrotors is achieved using a virtual structure approach where orthogonal projections of quadrotors on a virtual plane are utilized to define coordination forces. This plane implies planar spring forces acting between the vehicles. Virtual springs are also augmented with dampers to suppress oscillatory motions. While the coordination among the aerial vehicles is achieved on a virtual plane, altitude control for each vehicle is designed independently. This increases maneuvering capability of each quadrotor along the vertical direction. Due to their robustness to the external disturbances such as wind gusts, integral backstepping controllers are designed to control attitude and position dynamics of individual quadrotors. Several coordinated task scenarios are presented and the performance of the proposed formation control technique is assessed by several simulations where three and five quadrotors are employed. Simulation results are quite promising

Effects of Some Hormone Applications on Germination and Morphological Characters of Endangered Plant Species Lilium artvinense L. Seeds

Lilies are economically important plants because of their large and attractive flowers. Thus, many wild species of lilies have been cultivated to produce Lilium bulbs or flowers. This work was conducted to analyse the effect of hormone applications on Lilium artvinense (Syn: Lilium ponticum K. Koch., Lilium ponticum var. artvinense (Miscz.) P. H. Davis and D. M. Hend., Lilium carniolicum var. artvinense (Miscz.) P. H. Davis and D. M. Hend and Lilium pyrenaicum var. artvinense (Miscz.) V.A. Matthews) seeds on germination percentage and seedlings morphological traits. In the research, 1000, 3000 and 5000 ppm doses of IAA, IBA, NAA and GA3 hormones were applied to L. artvinense seeds and approximately 180 days later, the number of roots, root length, offset stem height and diameter were assessed. As a result, while the control group except 5000 ppm NNA application achieved an increase in the percentage of germination (40%) of all the applications. Germination frequency up to 100% was obtained using 5000 ppm GA3. Effects of hormone applications on other key morphological characters (rooting percentage, root height, number of scions, scion height and width) are described in terms of growth rate between 1.27 and 2.44

48-60 aylık çocuklarda sembolik oyun ve bilişsel işlevler “Oyun ve Biliş”

Bu çalışmada okul öncesi eğitim kurumlarına devam eden çocukların sembolik oyun becerilerini değerlendirmek, etkili olabilecek etmenleri ortaya koymak, bilişsel işlevler ile sembolik oyun becerileri arasındaki ilişkiyi incelemek amaçlanmıştır. Araştırmada çalışma grubu anaokullarına devam eden 48-60 ay aralığındaki 100 çocuktan oluşmuştur. Çalışma kapsamında çocukların bilişsel işlevlerini değerlendirmek için “Bilişsel İşlevlerin Uygulanması Ölçeği” , sembolik oyun becerilerini değerlendirmek için “Sembolik Oyun Testi” kullanılmıştır. Araştırma sonuçlarında, sembolik oyun açısından kızlar lehine anlamlı bir sonuç çıktığı, yetişkin desteğinin çocukların ön test son test puanları arasında fark yarattığı ve bilişsel işlevlerin sembolik oyunun anlamlı bir yordayıcısı olduğu görülmüştür

A Bibliometric analysis of mountain research literature on journal of mountain research and development: Current situation and future directions

Academic studies on mountains have increased since the 1990s. The aim of this study is to examine the current situation and development of the international literature on mountainous areas. The Mountain Research and Development Journal was determined as a sample and formed the data set of 1574 articles published in the journal. Network analysis method was applied using VOSviewer v.1.6 program. To conduct the research, only the terms in the keywords were used as the unit of analysis. In this context, frequency, relationality, clustering and time trend analyses were performed, respectively. When the clustering of the most used concepts in the keywords of the articles published in the MRD journal according to the network analysis was examined, eight clusters were determined. It turned out that the most frequently used concept among these clusters was "climate change". When the time trend is examined according to the network analysis of the concepts, studies on the effects of climate change have gained importance, especially in the last 10 years. Where there are conceptual transformations in the studies carried out on mountain slopes in certain years, anthropic emphases have come to the forefront rather than natural conditions

Calculation of the time-varying mean velocity by different methods and determination of the turbulence intensities

The raw velocity data for both stream-wise and transversal directions in unsteady flows, which are formed by generating input hydrograph, are obtained by using a flow tracker. The same hydrograph is generated 15 times and the mean values are found by calculating the average of all hydrographs. The time varying mean is obtained by using FFT, moving average, wavelet and EMD methods. The best time varying mean is selected according to prescribed criteria. Then, the 15 time series are processed and the stream-wise and transversal turbulence intensities are obtained. The mean of the product of fluctuations is also determined. © 2010 Academic Journals.TÜBİTAK (project number 106M274

Attitudes toward Women Managers in Turkey and Pakistan

This paper examines managerial attitudes toward women managers in Turkey and Pakistan by using “Managerial Attitudes toward Women Executives Scale (MATWES)” and draws a cross-cultural comparison between these two countries’ respondents. Significant differences were found in several managerial attitudes between these two countries’ respondents, and both women and men in Turkey have a negative attitude toward women managers as compared to Pakistani respondents. In contrast to the early findings in the literature, women’s attitudes toward women managers in Turkey were more negative than that of men’s while Pakistani women have more favorable attitudes than Turkish women toward women managers. The last result of this study indicated that Pakistani men showed more positive attitudes toward women managers than Turkish men

Anadolu Çoban Köpeklerinde (Canis familiaris) Siliyer Cisim ve İridokorneal Açı Üzerine Morfolojik Bir Çalışma]

This study was carried out to determine morphological structures of Anatolian Shepherd dog eye to compare with other animals. This important sensory organ from five adult male dogs were investigated by light microscopic and scanning electron microscopic analyses. Anatolian Shepherd dog cornea is about 435 (center) to 501 (periphery) mu m thick. The dense pigmentation observed in the anterior and posterior iridal epithelium. The ciliary cleft of the iridocorneal angle was not large and well-developed. The ciliary processes, another component of the ciliary body, formed the conspicuous bundles. In conclusion, it is considered that the description of the morphological properties of both the iridocorneal region and the ciliary body would contribute to the interpretation of the functional correlation, thus to future experimental studies to be conducted in this field