Rajaplaneerimine multi-robot süsteemile jagatud lasti transportimisel

Shared payload transportation has emerged as one of the key real-world applications that warrants the deployment of multiple robots. The key motivation stems from the fact that actuation and sensing abilities of multiple robots can be pooled together to transport objects that are either too big or heavy to be handled by a single robot. This thesis proposes algorithmic and software frameworks to achieve precise multi-robot coordination for object transportation. On the algorithmic side, a trajectory optimization formulation is developed which generates collision-free and smooth trajectories for the robots transporting the object. State-of-the art Gradient Descent variants are utilized for obtaining the solution. On the software side, a trajectory planner (local planner) is developed and integrated to Robot Operating System (ROS). The local planner is responsible for calculating individual velocities for any number of robots forming a rigid geometric in-plane constellation. Extensive simulation as well as real-world experiments are performed to demonstrate the validity of the developed solutions. It is demonstrated that how the proposed trajectory optimization approach outperforms off-the-shelf planners with respect to metrics like smoothness and collision avoidance. In estonian: Ühise lasti transportimine mitme roboti poolt on kujunenud üheks rakendusvaldkonnaks, kus mitme roboti samaaegne kasutamine on õigustatud. Mitme roboti andureid ja ajameid on eriti kasulik kasutada transportimaks objekte, mis on ühe roboti jaoks kas liiga suured ja/või rasked. Käesolev lõputöö pakub välja algoritmilise ja tarkvaralise raamistiku, mis võimaldab täpselt koordineerida mitme roboti koostööd ühise lasti liigutamisel. Välja on töötatud trajektooride optimeerimise algoritm, mis genereerib kokkupõrkevabad ja sujuvad ühist objekti kandvate robotite trajektoorid. Selleks on kasutatud nüüdisaegset gradientlaskumise (ingl Gradient Descent) meetodit. Tarkvara poolelt on loodud trajektoori planeerija (lokaalne planeerija) ja see on integreeritud arendusplatvormil ROS (Robot Operating System). Lokaalne planeerija arvutab individuaalsed kiirused igale robotile, mis moodustavad ühise jäiga tasapinnalise kujundi, kusjuures robotite arv kujundis ei ole piiratud. Väljatöötatud lahenduse toimimist on kontrollitud ulatuslike simulatsioonide abil aga ka viies läbi praktilisi katseid. Väljapakutud trajektoori optimeerimise lahendus ületab olemasolevaid planeerijaidd nii trajektoori sujuvuse kui ka kokkupõrgete vältimise võime osas

A Vibrotactile Display Design, evaluation and Fabrication

Vision and audition are the two best understood modalities which humans use to interact with the outside world. These modalities can provide highly precise spatial and temporal information. Thus, the field of human-computer interface design has focused much of their study and design on these modalities. On the other hand, the sense of touch has been largely ignored despite the fact that it is an essential part of human ability to interact with the environment. We are interested to identify key findings on how to use tactile technology effectively to design and fabricate a tactile interface. We intend to design a wearable tactile interface which can assist Unmanned Aerial Vehicles (UAV) operators in supervisory control and monitoring tasks. Tactile displays are usually comprised of vibratory stimulators which are arranged in specific formation based on the application of the display. Quantitative properties of a vibrating tactor which was used as the vibratory stimulator in our tactile interface were investigated and evaluated in this study. We executed a series of experiments to investigate the intensity of vibrations that the vibrating tactor can generate when it is being activated through different electrical signals. Driving signals were different in terms of waveform, frequency and amplitude. By applying the outcomes of our experiments, and using the available guidelines for the design of tactile displays, we proposed some methods for displaying flight dynamics (Roll, Pitch and Yaw) of a UAV through a tactile display which is structured in form of a vest. Due to the relative infancy of this branch of information presentation, and also the lack of thorough discussion within the scientific community we need to execute further experiments to evaluate the performance of the suggested tactile display

Laser-plasma source parameters for Kr, Gd, and Tb ions at 6.6 nm

There is increasing interest in extreme-ultraviolet (EUV) laser-based lamps for sub-10-nm lithography operating in the region of 6.6 nm. A collisional-radiative model is developed as a post-processor of a hydrodynamic code to investigate emission from resonance lines in Kr, Gd, and Tb ions under conditions typical for mass-limited EUV sources. The analysis reveals that maximum conversion efficiencies of Kr occur at 5 x 10(10) W/cm(2), while for Gd and Tb it was similar or equal to 0.9%/2 pi sr for laser intensities of (2-5) x 10(12) W/cm(2)

Investigating the skills of integrating Internet tools in teaching by math teachers of secondary schools in Ahvaz first educational district

Background and Objectives: Today Internet has a substantial effect on all aspects of human life and has influenced every individual and social aspects. According to studies, more than 82 percent of Iran's population use Internet by the year 2019. Internet as an attractive and pervasive medium has a deep effect on economic, financial, administrative sectors as well as social, cultural, and scientific communications; and somehow has changed people’s lifestyle. This effect has been such that today a concept called digital citizenship is mentioned instead of the traditional concept of citizenship. Since instruction and learning are an important area of human life, reducing the increasing costs of instruction and improving students’ learning and teachers’ teaching have become a main challenge of educational systems, and officials and mangers therefore seek to solve such a problem. Generally, technologies as a new solution open promising windows for educational system administrators. From the advent and development of the Internet as a powerful and interactive tool, it has been at the center of attention of the administrators. The unique nature of the Internet and the fundamental differences with previous media have also attracted the attention of many teachers and professors. Internet provides numerous tools and facilities and could be a desired environment for overcoming challenges. These tools and facilities could be applied in different phases and parts of teaching. Some are appropriate for presenting materials, some for gaining and directing students’ attention, some for doing various practices, and some for doing cooperative and group projects. Therefore, researchers recently have studied how to use Internet tools for various purposes of teaching and learning. Investigating teachers' abilities and capabilities for using Internet tools in teaching and learning has become a main question for researchers. Therefore, the purpose of this study was to investigate the skills of math teachers of secondary schools in Ahvaz to integrate Internet tools in their teaching. Methods: The research method was descriptive survey in which a researcher-made questionnaire was designed. Developed questionnaire consisted of 41 Likert type questions which were divided into 5 categories. 10 questions were related to presenting the material, 9 questions to gaining attention and motivating learners, 13 questions related to designing and developing practices, 4 questions related to providing optimal feedback to learners and finally 5 questions related to facilitating cooperative learning. Reliability of the questionnaire was assessed by alpha coefficient and found to be 0.872. Then expert views were used for assessing the validity of the questionnaire. Statistical population was Ahvaz math teachers and based on the size of the population, all 67 teachers (37 males and 30 females) were selected from high-school teachers. Then the required data was gathered by the questionnaire.  Findings: The results this study indicate that the teachers' skills in using the Internet tools are almost poor. In other words, teachers' skills for presenting the materials (1.62), for gaining attention and motivating learners (1.55), developing practices (1.79), providing optimal feedback to learners (1.72), and for facilitating cooperative learning environment (1.23) were all lower than the assumed mean of the study. Conclusion: Theskills of teachers in integrating Internet tools into teaching including presenting the materials, gaining attention and motivating, developing practices, providing optimal feedback to learners, and for facilitating cooperative learning environment are all poor and need to be improved.   ===================================================================================== COPYRIGHTS  ©2021 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

E- Governance Development Model Towards Anti-Corruption in Iran

Extended Abstract Abstract The Corruption Perceptions Index (CPI) published by Transparency International over recent years sheds light on Iran's unfavorable ranking. The present research develops an Electronic government (e-Government) model that emphasizes countering corruption in Iran. It prioritizes the critical parameters in countering corruption to establish the comprehensive structure of e-Government. Thus, this study is developmental and applied in terms of its goals. It draws on the Exploratory sequential mixed methodology and follows a descriptive correlational research design. The statistical population in the qualitative section consists of experts, whereas the quantitative part studies the relevant staff and university professors. The qualitative phase relies on judgment sampling, with the quantitative phase utilizing cluster sampling and semi-structured interviews. The quantitative and fuzzy Delphi phase employs questionnaires with closed-ended questions. Reliability was calculated through the retest reliability method and was verified using Cronbach's alpha coefficient. Theme analysis and the Fuzzy Delphi method were used to analyze the data. Findings suggest that Information Technology (IT), network accessibility, regulations, C2G, B2G, and G2G services, and human capital constitute critical priorities in establishing an e-Government to counter corruption.  IntroductionOne of the important factors that can prevent the efforts of the government from achieving its goals is corruption. Corruption is an act that ignores the public interest in favor of some special interests (Arayankalam et al., 2021). Transparency International's 2021 report on the Corruption Perceptions Index indicates that Iran's ranking has dropped by one step and ranked 150 out of 180 countries under review, and this is the result of the influence of corruption in the governing body, which weakens the effectiveness of the legislative, executive and judicial branches. has made it necessary to deal with this social problem as a result. E-government refers to the use of information and communication technology (ICT) and the Internet to increase access and provide all aspects of government services and operations for the benefit of citizens, businesses, employees and other stakeholders and is widely recognized in the fight against corruption. (Nam, 2018;). However, there is considerable ambiguity in existing research on the impact of e-government on corruption.Materials and Methods This research is based on the objective, applied-developmental, based on method of mixed type (quantitative-qualitative), sequential-exploratory, and in terms of the data analysis method, descriptive-correlation. In the qualitative part, the statistical community is organizational and academic experts in the field of E-government and organizational behavior, and in the quantitative part, it is the relevant employees and some university professors. Sampling in the qualitative stage was by judgmental method and 9 organizational experts and 4 academic experts were selected in the quantitative stage 60 people were selected by cluster method and according to Karjesi and Morgan table. The method of collecting theoretical data is archival and field statistical data. The qualitative data collection tool (theme analysis stage) was a semi-structured interview and the Fuzzy and quantitative Delphi stage was a questionnaire with closed questions. The validity of the qualitative data measurement tool was checked by the Newman validation method and the validity of the quantitative data was checked by the form and construct validity method and confirmed. To calculate the reliability of the qualitative part, the retest reliability method was used to measure the reliability in the quantitative part, the Alpha Cronbach coefficient was used and confirmed. To analyze the data in the qualitative part, the theme analysis method was used and in the second stage, the Fuzzy Delphi method was used. Quantitative part data was also analyzed by structural equation modeling method with the help of Smart PLS3 software.Discussion and Results    Theme analysis method was used to identify the indicators, components, factors affecting the reduction of corruption, and G2B, G2C, G2G services, human resources training, network access, information technology infrastructure, organizational rules, general rules and work process were included as independent variables. were examined and the significant coefficients of all 9 parameters were extracted above 2.58. To check the quality of the structural model in general, the GOF index was used and the value of 0.5325 was obtained, which confirms the appropriate quality of the qualitative model. The current research was conducted to developing the E-government model for anti-corruption in Iran. The results showed that the model includes service components, communication infrastructure and access to the network, laws and regulations, and human capital, while the coefficients of the result were significant at 99.9%

Measuring urban social sustainability:Scale development and validation

Despite the significant role of social sustainability in the sustainable development agenda, there is a lack of research to clearly define and fully operationalise the concept of urban social sustainability. The aim of this study is to contribute to the existing literature by developing a comprehensive measurement scale to assess urban social sustainability at the neighbourhood level. We argue that urban social sustainability is a multidimensional concept that incorporates six main dimensions of social interaction, sense of place, social participation, safety, social equity and neighbourhood satisfaction. Failure to consider each of these dimensions may lead to an incomplete picture of social sustainability. Validity, reliability and dimensionality of the urban social sustainability scale are examined using factor analysis. We also illustrate the application of the urban social sustainability scale by investigating the influence of quality of design, as one of the least studied factors of urban form, on different dimensions of social sustainability. The paper uses data collected from the household questionnaire survey in a sample of 251 respondents from five case study neighbourhoods of Dunedin city, New Zealand. This study provides new evidence on the significance of improving neighbourhood quality of design and its positive and significant relationship with different dimensions of social sustainability and the overall social sustainability

Bond and Development Length in Concrete Beams with Exposed Reinforcement

Corrosion of steel reinforcement in Ontario bridges is causing severe soffit spalling in many situations. These spalled areas are often located within the lap splices and curtailment zones of the primary reinforcement. This can lead to inadequate bar development lengths and the possibility of failures. In order to better predict the residual strength of these deteriorated bridges, a test program was designed, which involved mid-sized concrete beam specimens, with partially de-bonded reinforcement. The de-bonding was simulated in various beam locations, with various de-bonding patterns. The test program consisted of thirteen beams; ten under-reinforced and three over-reinforced. All beams had dimensions of 2100×150×100 mm. The span between simple supports was 1900 mm with a single point load applied at the midspan. Rebar strains and displacement at the midspan were recorded. The goal of this experimental study was to determine the correlation between the spatial location and surface area of de-bonding with the strength of the beams. This was achieved by testing beam specimens with different combinations of de-bonding patterns with respect to location and area. Four beams had de-bonded reinforcement in the flexural zones, seven were de-bonded in the anchorage and flexural zones, and two were fully bonded. In a previous study, a so-called “modified area concept” was developed for rapid assessment of the remaining capacity of heavily spalled girders. This concept was integrated in a computer program, which assesses girder capacity, given a graphical spalling survey and a structural drawing of the girder. The developed program can be easily adapted for full bridge analysis, and to evaluate the effects of reinforcement cross section loss and bond deterioration. The research presented in the current thesis investigates several of the assumptions made in this previous study. The current thesis includes the rationale for the design of the experimental program. In addition, the test results are presented and analyzed. By analyzing the failure modes, failure loads, and crack patterns, along with the load-displacement, load-stiffness, and load-strain behaviour of the various beams, it is concluded that: 1) reinforced concrete beams can carry a significant portion of their original capacity after losing cover over a significant portion of their flexural reinforcement, 2) predictions of the beam capacities and failure modes using the modified area concept are reasonably accurate and conservative in most cases, and 3) the flexural stiffness of the beams was seen to decrease with an increase in the length of the exposed area, in most cases. Recommended areas of future research are identified, including: 1) tests of beams with splices in the flexural reinforcing along the span, 2) field investigation of the concrete strength in regions of the soffit immediately adjacent to the spalled regions, and 3) the development of a correction factor to account for the effects of violating the plane sections assumption.1 yea

Urban sustainability Compact versus dispersed form in terms of social interaction and patterns of movement

Available from British Library Document Supply Centre-DSC:DXN033886 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Spectroscopic Studies of Laser-Based Far-Ultraviolet Plasma Light Source

A series of experiments is described which were conducted to measure the absolute spectral irradiances of laser plasmas created from metal targets over the wavelength region of 123–164 nm by two separate 1.0 μm lasers, i.e., using 100 Hz, 10 ns, 2–20 kHz, 60–100 ns full-width-at-half-maximum pulses. A maximum radiation conversion efficiency of ≈3%/2πsr is measured over a wavelength region from ≈125 to 160 nm. A developed collisional-radiative solver and radiation-hydrodynamics simulations in comparison to the spectra detected by the Seya–Namioka-type monochromator reveal the strong broadband experimental radiations which mainly originate from bound–bound transitions of low-ionized charges superimposed on a strong continuum from a dense plasma with an electron temperature of less than 10 eV