Characterization of optical communication in a leader-follower unmanned underwater vehicle formation

As part of the research to development an optical communication design of a leader-follower formation between unmanned underwater vehicles (UUVs), this paper presents light field characterization and design configuration of the hardware required to allow the use of distance detection between UUVs. The study specifically is targeting communication between remotely operated vehicles (ROVs). As an initial step in this study, the light field produced from a light source mounted on the leader UUV was empirically characterized and modeled. Based on the light field measurements, a photo-detector array for the follower UUV was designed. Evaluation of the communication algorithms to monitor the UUV’s motion was conducted through underwater experiments in the Ocean Engineering Laboratory at the University of New Hampshire. The optimal spectral range was determined based on the calculation of the diffuse attenuation coefficients by using two different light sources and a spectrometer. The range between the leader and the follower vehicles for a specific water type was determined. In addition, the array design and the communication algorithms were modified according to the results from the light field

Pose Detection and control of multiple unmanned underwater vehicles using optical feedback

This paper proposes pose detection and control algorithms in order to control the relative pose between two Unmanned Underwater Vehicles (UUVs) using optical feedback. The leader UUV is configured to have a light source at its crest which acts as a guiding beacon for the follower UUV which has a detector array at its bow. Pose detection algorithms are developed based on a classifier, such as the Spectral Angle Mapper (SAM), and chosen image parameters. An archive look-up table is constructed for varying combinations of 5-degree-of-freedom (DOF) motion (i.e., translation along all three coordinate axes as well as pitch and yaw rotations). Leader and follower vehicles are simulated for a case in which the leader is directed to specific waypoints in horizontal plane and the follower is required to maintain a fixed distance from the leader UUV. Proportional-Derivative (PD) control (without loss of generality) is applied to maintain stability of the UUVs to show proof of concept. Preliminary results indicate that the follower UUV is able to maintain its fixed distance relative to the leader UUV to within a reasonable accuracy

QoS-aware Traffic Management in Software Defined Networking

Software defined networking (SDN) provides effective traffic management solution by separating control and data planes, global centralization control, and being programmable. And, the traditional shortest path routing cannot provide effective traffic engineering because it only aware shortest path. The constraint-aware routing is more efficient than the traditional shortest path routing, however, it needed to estimate constraints such as link capacity, delay, jitter, and so on and it cannot guarantee the future traffic demands. This paper proposed QoS-aware traffic management method in SDN to guarantee the QoS-aware traffic by selecting the optimal path based on the estimated constraints. First, the proposed traffic management method categorized traffic classes: QoS-aware traffic and non QoS-aware traffic classes. Then, the proposed method estimated the QoS parameters and calculated the optimal path based on the estimated parameters. Finally, the QoS-aware traffic routed with the optimal path and non QoS-aware traffic simply routed through the shortest path. The proposed method is validated by using network emulator, Mininet and SDN controller, ONOS. The experiment results of throughput and packet loss show that our proposed method outperformed the other two traffic management methods

Fabrication and characterization of planar hall devices

Master'sMASTER OF ENGINEERIN

Alcohol consumption among adult males in urban area of Thanlyin Township, Yangon Region, Myanmar

Background: Alcohol consumption is a major cause of morbidity and mortality worldwide. It is frequently related to health and behavioural problems as well as socio-economic hardship. Therefore, this study was conducted to determine the prevalence and risk factors of alcohol consumption among adult males residing in urban area of Thanlyin Township, Yangon Region.Methods: A cross-sectional study was conducted among 380 adult males. Multi-stage random sampling was applied. Data entry and analysis was done using Stata 11.0 statistical package.Results: The prevalence of current alcohol drinking, ex-drinking and never drinking were 20.5%, 9.0% and 70.5%, respectively. There was a significant decreasing trend of alcohol consumption across the levels of age-group. Age, education status and practicing other health-risk behaviours such as smoking and betel chewing were detected as significant risk factors of alcohol consumption. Ever smokers and ever betel chewers were about 4 times more likely to be ever alcohol user compared to their counterparts even if age and education level were adjusted. By controlling smoking and betel chewing habits, 79.2% and 76.6% of existing prevalence of alcohol consumption among respondents would be reduced, respectively.Conclusions: There is an urgent need to curb the habit of alcohol consumption among adult males living in urban area, especially young adults. Alcohol and tobacco control policies in Myanmar should be strengthened or reinforced. Tobacco control program also needs to be intensified. Health education and health promotion activities should be enhanced in order to reduce alcohol consumption in the country.

Assessing Patient-centered Care: One Approach to Health Disparities Education

Patient-centered care has been described as one approach to cultural competency education that could reduce racial and ethnic health disparities by preparing providers to deliver care that is respectful and responsive to the preferences of each patient. In order to evaluate the effectiveness of a curriculum in teaching patient-centered care (PCC) behaviors to medical students, we drew on the work of Kleinman, Eisenberg, and Good to develop a scale that could be embedded across cases in an objective structured clinical examination (OSCE). To compare the reliability, validity, and feasibility of an embedded patient-centered care scale with the use of a single culturally challenging case in measuring students′ use of PCC behaviors as part of a comprehensive OSCE. A total of 322 students from two California medical schools participated in the OSCE as beginning seniors. Cronbach’s alpha was used to assess the internal consistency of each approach. Construct validity was addressed by establishing convergent and divergent validity using the cultural challenge case total score and OSCE component scores. Feasibility assessment considered cost and training needs for the standardized patients (SPs). Medical students demonstrated a moderate level of patient-centered skill (mean = 63%, SD = 11%). The PCC Scale demonstrated an acceptable level of internal consistency (alpha = 0.68) over the single case scale (alpha = 0.60). Both convergent and divergent validities were established through low to moderate correlation coefficients. The insertion of PCC items across multiple cases in a comprehensive OSCE can provide a reliable estimate of students′ use of PCC behaviors without incurring extra costs associated with implementing a special cross-cultural OSCE. This approach is particularly feasible when an OSCE is already part of the standard assessment of clinical skills. Reliability may be increased with an additional investment in SP training