Visual Tracking of Human Hand and Head Movements and Its Applications

Tracking of human body movements is an important problem in computer vision with applications in visual surveillance and human-computer interaction. Tracking of a single hand moving in space is addressed and a set of applications in human computer interaction are presented. In this approach, a disparity map and motion fields extracted from a stereo camera set are modelled using a robust estimation method. Then, the absolute position and orientation of the hand in space are estimated and the central region of the hand is tracked over time. Virtual drawing in space, a virtual marble game, and 3D object construction are shown as the applications of the single hand tracking. Algorithms are presented for tracking the hands and head of a person or several interacting people viewed by a set of cameras in 3D. The problem is first defined as a general multiple object tracking problem in a multiple sensor environment and a two layered solution is proposed. The proposed solution includes a low level particle filtering layer to track individual targets in parallel, and a finite state machine to analyze the interactions between the targets and apply application specific heuristics. A set of activity recognition experiments in visual surveillance show the usefulness of the system. The recognized activities involve interactions between the hands and head of people and objects. A color analysis scheme and a technique for combining information from different cameras are presented. They are used to detect carried objects and exchanges between the hands

Multiwalled Carbon Nanotubes and Nitric Oxide Modulate the Germination and Early Seedling Growth of Barley under Drought and Salinity

To evaluate the impacts of various concentrations of multiwalled carbon nanotubes (0, 500, 1000 and 2000 mg L-1) and sodium nitroprusside (0 and 100 μM as nitric oxide (NO) donor) on seed germination and early seedling growth of barley, two separate factorial experiments were conducted based on a randomized complete block design under polyethylene glycol-simulated drought stress and NaCl salinity stress conditions. Based on the results, a concentration-dependent declining trend was observed in barley germination indices upon seed exposure to polyethylene glycol (PEG) and NaCl suspensions. Employing multiwalled carbon nanotubes (MWCNTs) particularly 1000 and 500 mg L-1 and sodium nitroprusside (SNP) alleviated the adverse impacts of drought and salinity stresses. However, applied MWCNTs and SNP together were more efficient than suspension alone. The combined application of MWCNTs with SNP increased germination percentage, germination rate, root length, shoot length, vigor index and decreased mean germination time of barley. Similarly, the amount of moisture content and uniformity of seed germination were obviously increased by MWCNTs and SNP under drought and salinity. In contrast, MWCNTs at 2000 mg L-1 had an inhibitory impact on barley seed germination, while use of SNP moderated adverse effects of MWCNTs. Generally, it can be concluded that appropriate concentration of MWCNTs is beneficial in improving drought and NaCl salinity tolerance of barley by boosting seed water absorption and increasing the moisture content of seedlings

Assessment of check dams’ role in flood hazard mapping in a semi-arid environment

This study aimed to examine flood hazard zoning and assess the role of check dams as effective hydraulic structures in reducing flood hazards. To this end, factors associated with topographic, hydrologic and human characteristics were used to develop indices for flood mapping and assessment. These indices and their components were weighed for flood hazard zoning using two methods: (i) a multi-criterion decision-making model in fuzzy logic and (ii) entropy weight. After preparing the flood hazard map by using the above indices and methods, the characteristics of the change‐point were used to assess the role of the check dams in reducing flood risk. The method was used in the Ilanlu catchment, located in the northwest of Hamadan province, Iran, where it is prone to frequent flood events. The results showed that the area of ‘very low’, ‘low’ and ‘moderate’ flood hazard zones increased from about 2.2% to 7.3%, 8.6% to 19.6% and 22.7% to 31.2% after the construction of check dams, respectively. Moreover, the area of ‘high’ and ‘very high’ flood hazard zones decreased from 39.8% to 29.6%, and 26.7% to 12.2%, respectively

18 JOURNAL OF MULTIMEDIA, VOL. 1, NO. 7, NOVEMBER/DECEMBER 2006 Employing the Hand as an Interface Device

Abstract — We propose algorithms and applications for using the hand as an interface device in virtual and physical spaces. In virtual drawing, by tracking the hand in 3-D and estimating a virtual plane in space, the intended drawing of user is recognized. In a virtual marble game, the instantaneous orientation of the hand is simulated to render a graphical scene of the game board. Real-time visual feedback allows the user to navigate a virtual ball in a maze. In 3-D model construction, the system tracks the hand motion in space while the user is traversing edges of a physical object. The object is then rendered virtually by the computer. These applications involve estimating the 3-D absolute position and/or orientation of the hand in space. We propose parametric modelling of the central region of the hand to extract this information. A stereo camera is used to first build a preliminary disparity map of the hand. Then, the best fitting plane to the disparity points is computed using robust estimation. The 3-D hand plane is calculated based on the disparity plane and the position and orientation parameters of the hand. Tracking the hand region over a sequence of frames and coping with noise using robust modelling of the hand motion enables estimating the trajectory of the hand in space. The algorithms are real-time and experiments are presented to demonstrate the proposed applications of using the hand as an interface device

Assessment of drainage network analysis methods to rank sediment yield hotspots

This paper aims to test different methods used for assessing the indices of sediment yield to identify hotspots and rank sediment yield hotspots. This process includes the assessment of the Entropy Weighting (EW), Fractal Dimension (FD), Slope Length (SL) gradient, and Sediment Connectivity (SC) methods. The indices at different sub-catchment levels were applied in the Ilanlu catchment (Iran) and organized based on five different levels of sediment hazard classes. To assess the performance of sediment hazard mapping, the superimposing methods were used and assessed by the Erosion Potential Model (EPM). The superimposing method showed that 8, 10, 4 and 9 sub-catchments based on the degree of susceptibility obtain the highest results considering the results of FD, EW, SL and SC with an output of EPM model, respectively. The results show that EW and SC can achieve greater performance than FD and SL methods in identifying sediment production hotspots

Application of multi-criteria decision making and GIS for check dam layout in the Ilanlu basin, northwest of Hamadan Province, Iran

Monitoring and managing floods and sediments are considered major challenges in the sustainable management of watersheds. Hence, an effective layout of the hydraulic structures across channels is considered as a measure to overcome these two challenges. This study was carried out in the Illanlu catchment in the northwest of Hamadan Province, Iran. A set of effective indices were identified and developed using the Geographic Information System (GIS) and fuzzy logic to model optimal location of sites for construction of the check dams. Based on the ability to construct the check dams e.g. access road and environmental constraints, the map was classified from very high to very low construction ability. In the study area, 26% of the catchment area was located in the very high and high classes, predominantly in the upstream sub-catchments, 13% in the very low class, and 62% in moderate and low ability ranges. Finally, by using superimposing method and the receiver operating characteristic (ROC) curve the accuracy of developed spatial model estimated to be 70% and 73.5%, respectively

Impact of roof rain water harvesting of runoff capture and household consumption

In recent years, the occurrence of floods is one of the most important challenges facing in Hamadan city. In the absence/inefficiency of urban drainage systems, rainwater harvesting (RWH) systems as low-impact development (LID) methods can be considered as a measure to reduce the floods. In this study, three scenarios concerning the RWH from the roof surfaces are studied to evaluate the type of the harvested water on reducing flooding. In the first scenario, which indicates the current situation in the studied area, it is indicated that there is no harvest of the roof surfaces in the studied area. The second scenario is about the use of water harvested from the roof surfaces for household purposes. The third scenario also refers to the use of harvested water for irrigation of gardens. The simulation results of these three scenarios using the Soil Conservation Service (SCS) method in the Hydrologic Modeling System (HEC-HMS) model reveal that if the second scenario is implemented, the runoff volume decreases from 28 to 12% for the return period from 2 to 100 years. However, in the third scenario, this reduction in runoff volume will be 48 and 27% for return periods of 2 to 100 years, respectively. Therefore, the results of this study indicate that the use of harvested water can also affect the reduction on runoff volume