A Multi-Robot Task Assignment Framework for Search and Rescue with Heterogeneous Teams

In post-disaster scenarios, efficient search and rescue operations involve collaborative efforts between robots and humans. Existing planning approaches focus on specific aspects but overlook crucial elements like information gathering, task assignment, and planning. Furthermore, previous methods considering robot capabilities and victim requirements suffer from time complexity due to repetitive planning steps. To overcome these challenges, we introduce a comprehensive framework__the Multi-Stage Multi-Robot Task Assignment. This framework integrates scouting, task assignment, and path-planning stages, optimizing task allocation based on robot capabilities, victim requirements, and past robot performance. Our iterative approach ensures objective fulfillment within problem constraints. Evaluation across four maps, comparing with a state-of-the-art baseline, demonstrates our algorithm's superiority with a remarkable 97 percent performance increase. Our code is open-sourced to enable result replication.Comment: The 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2023 Advances in Multi-Agent Learning - Coordination, Perception, and Control Workshop

Influence of Team Interactions on Multi-Robot Cooperation: A Relational Network Perspective

Relational networks within a team play a critical role in the performance of many real-world multi-robot systems. To successfully accomplish tasks that require cooperation and coordination, different agents (e.g., robots) necessitate different priorities based on their positioning within the team. Yet, many of the existing multi-robot cooperation algorithms regard agents as interchangeable and lack a mechanism to guide the type of cooperation strategy the agents should exhibit. To account for the team structure in cooperative tasks, we propose a novel algorithm that uses a relational network comprising inter-agent relationships to prioritize certain agents over others. Through appropriate design of the team's relational network, we can guide the cooperation strategy, resulting in the emergence of new behaviors that accomplish the specified task. We conducted six experiments in a multi-robot setting with a cooperative task. Our results demonstrate that the proposed method can effectively influence the type of solution that the algorithm converges to by specifying the relationships between the agents, making it a promising approach for tasks that require cooperation among agents with a specified team structure.Comment: Accepted to Multi-Robot and Multi-Agent Systems (IEEE MRS 2023

Design and Evaluation of a Bioinspired Tendon-Driven 3D-Printed Robotic Eye with Active Vision Capabilities

The field of robotics has seen significant advancements in recent years, particularly in the development of humanoid robots. One area of research that has yet to be fully explored is the design of robotic eyes. In this paper, we propose a computer-aided 3D design scheme for a robotic eye that incorporates realistic appearance, natural movements, and efficient actuation. The proposed design utilizes a tendon-driven actuation mechanism, which offers a broad range of motion capabilities. The use of the minimum number of servos for actuation, one for each agonist-antagonist pair of muscles, makes the proposed design highly efficient. Compared to existing ones in the same class, our designed robotic eye comprises aesthetic and realistic features. We evaluate the robot's performance using a vision-based controller, which demonstrates the effectiveness of the proposed design in achieving natural movement, and efficient actuation. The experiment code, toolbox, and printable 3D sketches of our design have been open-sourced

COVID-19 Pandemic: What Can the West Learn From the East?

Differences in public health approaches to control the coronavirus disease 2019 (COVID-19) pandemic could largely explain substantial variations in epidemiological indicators (such as incidence and mortality) between the West and the East. COVID-19 revealed vulnerabilities of most western countries’ healthcare systems in their response to the ongoing public health crisis. Hence, western countries can possibly learn from practices from several East Asian countries regarding infrastructures, epidemiological surveillance and control strategies to mitigate the public health impact of the pandemic. In this paper, we discuss that the lack of rapid and timely community-centered approaches, and most importantly weak public health infrastructures, might have resulted in a high number of infected cases and fatalities in many western countries

HIV prevalence and risk behaviours among people who inject drugs in Iran: the 2010 National Surveillance Survey

Objectives To assess the prevalence of HIV and related risk behaviours among people who inject drugs (PWID) in Iran. Methods We conducted a national cross-sectional bio-behavioural surveillance survey between March and July 2010, interviewing male PWID from a geographically dispersed sample through a facility-based sampling method. Results We recruited 2480, and tested 2290 PWID. The overall prevalence of HIV was 15.2% (95% CI 9.7% to 23.1%). Among those who had injected drugs over the last month, 36.9% had used a non-sterile needle, and 12.6% had practiced shared injection. Over the past 12 months preceding the interview, 30.4% had sold sex for money, drugs, goods or a favour. In the multivariate analysis, the prevalence of HIV had a positive association with age, while having above high school education, and permanent job were protective. Conclusions Unsafe injection, and sexual risk behaviours are still frequent and the prevalence of HIV among PWID remains high. Intensified efforts are needed to prevent the further spread of HIV among Iranian PWID and their sexual partners

HIV prevalence and related risk behaviours among female sex workers in Iran: results of the national biobehavioural survey, 2010

Objectives To determine the prevalence of HIV and related behavioural risks among Iranian female sex workers (FSW) via the first national biobehavioural surveillance survey. Methods In 2010, 1005 FSW were approached and 872 recruited using facility-based sampling from 21 sites in 14 cities in Iran. We collected dried blood samples and conducted face-to-face interviews using a standardised questionnaire. Data were weighted based on the response rate and adjusted for the clustering effect of the sampling site. Adjustment was performed by weighting based on the sampling fraction of each site using a prior estimate of its total size of the FSW population. Results The prevalence of HIV infection (95% CI) was 4.5% (2.4 to 8.3) overall, 4.8% (2.2 to 9.8) among those who had reported a history of drug use and 11.2% (5.4 to 21.5) among those who had a history of injection drug use. The frequencies of condom use in the last sexual act with paying clients and non-paying partners were 57.1% and 36.3%, respectively. Any drug use was reported by 73.8% of participants, and among this subgroup, 20.5% had a history of injection drug use. Conclusions The prevalence of HIV was considerable among FSW particularly those who had a history of drug injection. A combination of prevention efforts addressing unsafe sex and injection are needed to prevent further transmission of HIV infection

Treatment outcomes in persons with severe haemophilia B in the Nordic region : The B-NORD study

Introduction Data on outcome in persons with haemophilia B (PwHB) are limited and mainly extrapolated from studies of haemophilia A (HA). Aim To characterize treatment outcomes in persons with severe HB in the Nordic region, with a focus on joint health, compared with matched controls with HA. Methods PwHB attending haemophilia centres in Denmark, Finland, Norway and Sweden were enrolled and matched with controls with HA. Joint assessment using Haemophilia Joint Health Score (HJHS) and ultrasound according to Haemophilia Early Arthropathy Detection protocol (HEAD-US) was conducted. Adherence was evaluated using the Validated Haemophilia Regimen Treatment Adherence Scale (VERITAS). Results Seventy-nine males with HB, with median age of 30 years (range 1-75), were enrolled. Eleven patients (14%) had a history of or current inhibitor. Twenty-nine PwHB (37%) reported joint bleeds during the prior year, and 35% had previously undergone joint surgery. Ninety-five per cent were on prophylaxis, and 70% used recombinant concentrates, with a median factor consumption of 3,900 IU/kg/year for standard half-life products. Only two patients had a VERITAS score corresponding to 'non-adherence'. Joint health, assessed with HJHS, showed a significant lower score among PwHB compared with HA controls, explained by a difference in the 18-49 age group, without observed differences in older or younger subgroups. The HEAD-US scores were overall low. Conclusion The Nordic cohort of PwHB is well treated by prophylaxis, but the goal of zero bleeds for all is not reached. Our findings suggest that patients with severe HB suffer from a milder arthropathy than patients with severe HA.Peer reviewe

Sources of academic stress among Iranian adolescents: a multilevel study from Qazvin City, Iran

Background: Academic stress can cause mental and physical problems and affect adolescents’ healthy development. This study aimed to estimate academic stress and explore its sources at the individual- and school levels among school-going adolescents in the city of Qazvin, Iran. Results: This cross-sectional study used a stratified cluster sampling to recruit 1724 students aged 12–19 years from 53 schools in Qazvin City. Data were collected using a validated self-administered questionnaire. The mean academic stress score was 45.7 (95% CI 45.2, 46.3). The stress level was statistically higher among older 47.5 (95% CI 46.7, 48.3) than younger 44.1 (95% CI 43.4, 44.9) adolescents. The main academic stressors included: future uncertainty 69.7 (95% CI 68.8, 70.7), academic competition 58.5 (95% CI 57.3, 59.6), and interaction with teachers 56.1 (95% CI 55.3, 56.9). Gender, educational period, school type, family socioeconomic status, and father’s education were associated with academic stress. Conclusions: We conducted a multilevel study using a random sample of male and female students in the city of Qazvin, Iran. Results indicated moderate levels of stress among Iranian adolescents. The academic stress was associated with several individual and school-level variables. Students and their families and teachers need education on stress prevention methods and coping mechanisms. Future research should focus on developing and testing multilevel policies and interventions to improve students’ mental health and academic performance. Keywords: Academic stress, Adolescence, Students, Multilevel analysis, Ira

Sources of academic stress among Iranian adolescents: a multilevel study from Qazvin City, Iran

Background: Academic stress can cause mental and physical problems and affect adolescents’ healthy development. This study aimed to estimate academic stress and explore its sources at the individual- and school levels among school-going adolescents in the city of Qazvin, Iran. Results: This cross-sectional study used a stratified cluster sampling to recruit 1724 students aged 12–19 years from 53 schools in Qazvin City. Data were collected using a validated self-administered questionnaire. The mean academic stress score was 45.7 (95% CI 45.2, 46.3). The stress level was statistically higher among older 47.5 (95% CI 46.7, 48.3) than younger 44.1 (95% CI 43.4, 44.9) adolescents. The main academic stressors included: future uncertainty 69.7 (95% CI 68.8, 70.7), academic competition 58.5 (95% CI 57.3, 59.6), and interaction with teachers 56.1 (95% CI 55.3, 56.9). Gender, educational period, school type, family socioeconomic status, and father’s education were associated with academic stress. Conclusions: We conducted a multilevel study using a random sample of male and female students in the city of Qazvin, Iran. Results indicated moderate levels of stress among Iranian adolescents. The academic stress was associated with several individual and school-level variables. Students and their families and teachers need education on stress prevention methods and coping mechanisms. Future research should focus on developing and testing multilevel policies and interventions to improve students’ mental health and academic performance. Keywords: Academic stress, Adolescence, Students, Multilevel analysis, Ira

Comparison of propagation efficiency of sobaity (Sparidentex hasta) fish rearing with fish capture from the sea in circular spawning tank

This project was conducted in imam Khomeini mariculture research state from October 2010 to June 2013 to compare reproductive performance between wild and domesticated Sobaity seabream broodstocks. In 3 years wild broodstocks did not spawn in 5 and 10 fiberglass and concrete tanks but domesticated broodstocks spontaneously spawned from February to March. In the first year domesticated broodstock in ratio of 3 females to 6 males allotted in 10 mt concrete tanks in triplicate. the about 2776000 eggs produced from 9 females and 18 males but further heavy mortality occurred because of winter shock syndrome and suppression of immunity system. Mean temperature, salinity and PH in incubation period was 16.5˚C (range between16-18˚C), 45ppt, 8.5 respectively. Mean floating eggs and hatch percent was 15.5% and 8.9% and about 19000 larvae produced. In the second year domesticated broodstock in ratio of 9 females to 23 males allotted in 5 mt fiberglass tanks in triplicate .about 17540000 eggs acquired from 27 female and 69 male broodstocks. Mean temperature, salinity and PH in culture period was 24.8 ˚C(range between20-28.3˚C), 47.5 ppt, 8.4 respectively. Mean floating eggs and hatch percent was 58.94% and 84% and about 8640000 larvae produced and stocking density was 10-30 larvae per liter. After 61 days mean production and survival were 503.3 (range between 140-1220) larvae per cubic meter and 5.3% (range between 0.47–12.2 %) respectively. Final mean weight of fry was 2.6 gr. In the third year domesticated broodstock in ratio of 3 females to 6 males allotted in 5 mt fiberglass tanks in triplicate. about 6570000 eggs acquired from 9 female and 18 male brood stocks. Mean temperature, salinity and pH in culture period was 23.9˚C(range between 19.5-28.4˚C), 45, 7.6 respectively. Mean floating eggs and hatch percent was 54.7% and 81.6% and about 2889800 larvae produced and stocking density was 10-30 larvae per liter. At the end of 87 and 89 days of husbandry the mean production and survival were 359 (range from 300 to 397) larvae per cubic meter and 2.7% (range between 1.32–3.8 %) respectively. Final mean weight of fry was 3.5 gram and Larvaeculture in the last 2 years carried out in 5 cubic meters fiberglass tanks. It seems to domesticated broodstocks because of spontaneous spawning, long spawning period, more brood stocks and possibility of reusing them in the next year are very economical for propagation than wild broodstocks