Hands on Wheel Classification Based on Depth Images and Neural Networks

This paper describes a system to automatically observe if the driver has his hands on the wheel, which is important to know that he can intervene if necessary. To accomplish this an artificial neural network is used, which utilizes depth information captured by a camera in the roof module of the car. This means that the driver and the steering wheel are viewed from above. The created classification system is described. It is designed to require as little computational effort as possible, since the target application is on an embedded system in the car. A dataset is presented and the effect of a class imbalance that is incorporated in it is studied. Furthermore, it is examined which part, i.e. the depth or the intensity image, of the available data is important to achieve the best possible performance. Finally, by examining a learning curve, an experiment is made to find out whether the recording of further training data would be reasonable.

Cooling Benefits of an Extensive Green Roof and Sensitivity Analysis of Its Parameters in Subtropical Areas

The present study aims to further demonstrate the cooling benefits of an extensive green roof (EGR) and fill the gap existing in the literature in terms of a sensitivity analysis of an EGR, especially in subtropical areas. First, onsite measurements were performed. The results indicated that the peak air temperatures in the chamber with the EGR were 4.0 °C and 1.9 °C lower, respectively, compared to those in the chamber with a bare roof on sunny and rainy days. Moreover, the EGR decreased the daily electricity consumption from air conditioning by up to 16.7% on sunny days and 6.7% on cloudy days. Second, the measured values were employed to validate the green roof module (GRM) in EnergyPlus. The results demonstrated that the GRM yielded accurate results in quantifying the cooling benefits of the EGR. Finally, we selected 16 factors of the EGR, each with four levels, to perform the sensitivity analysis. Range and variance analyses revealed that the factors that most significantly impacted the EGR performance were the R-value of roof construction, substrate (soil) thickness, the thermal conductivity of dry substrate, the leaf area index, leaf emissivity, and the solar absorptance of the substrate. These factors contributed 90.8% to the performance index.

Effect of Fertilizer Rate on Plant Growth and Leachate Nutrient Content during Production of Sedum-vegetated Green Roof Modules

With the increasing popularity of green roofs, efficient green roof plant production is required to adequately supply the industry. Applying fertilizer at an appropriate rate can provide sufficient plant nutrition for efficient plant growth without excess nutrient leaching into the environment. This study compared rates of controlled-release fertilizer (CRF) applied to green roof modules at the plant production stage to determine an optimum CRF rate for encouraging plant growth and vegetative coverage while minimizing the amount and concentration of leached nutrients. After sedum cuttings were rooted in green roof modules on 29 Aug. 2011, CRF was applied at 5, 10, 15, 20, 25, 30, and 35 g·m−2 nitrogen (N) and modules were compared with an unfertilized control. Plant growth, vegetative coverage, and overall appearance requirements were met after fertilization at 20 g·m−2 N. Modules fertilized at less than 20 g·m−2 N did not reach the target proportion coverage during the study. When fertilized at 20 g·m−2 N, green roof modules reached the target proportion coverage after 240 days of growth. Differences in leachate volumes were observed among treatments 35 days after fertilization and fertilization at 20 g·m−2 N minimized leaching of most nutrients. Therefore, with the green roof module system used in this study, an application of 20 g·m−2 N for green roof module or sedum cutting production is an optimum CRF rate for plant growth and vegetative coverage while minimizing negative environmental impacts.

Experimental Study of the Thermal Insulation Property of Sedum Linear Roof Module in Real Weather Condition in Guangzhou, China

In this paper, four typical building roof modules, i.e., sedum linear module, lightweight planting soil module, water-retaining board module and XPS module, were experimentally investigated by using the guarded hot box under real weather condition in Guangzhou, China. The testing results were compared and analyzed regarding to three main properties of the roof module, i.e., the top and bottom surface temperatures of the modules, air temperature inside the inner box of the guarded hot box and temperature attenuation characteristics for the thermal insulation of the modules. It was found that the sedum linear module performed well in the thermal insulation property under the typical summer weather condition. The analysis results could be used to assist in the application of the green roof module, and contribute to the energy conservation of the buildings.

Plant Nutrition Requirements for an Installed Sedum-Vegetated Green Roof Module System: Effects of Fertilizer Rate and Type on Plant Growth and Leachate Nutrient Content

The objectives of this study were to compare fertilizer rates and types to identify an optimum rate to maintain green roof vegetative coverage and encourage plant growth (i.e., plant performance) while minimizing the amount and concentration of nutrients leached from a green roof module system. Sedum-vegetated modules with no added fertilizer (control) were compared with modules fertilized with 5, 7.5, 10, 15, 20, 30, and 60 g·m−2 nitrogen (N) of 16N–2.6P–10K POLYON® Homogenous NPK plus Minors, 5–6 month controlled-release fertilizer (CRF), 5 g·m−2 N of a 2.9N–2.2P–2.3K fly-larvae processed chicken manure fertilizer (5-Sus), or 5 g·m−2 N of 4N–4P–4K Gaia Green All Purpose organic fertilizer (5-OR). The total amount and concentration of aluminum (Al), calcium (Ca), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), sodium (Na), NH4+, nickel (Ni), NO3–, phosphorus (P), lead (Pb), sulfur (S), and zinc (Zn) in leachate as well as plant overall appearance, winter injury, vegetative coverage, shoot height, bloom duration, and leaf color of green roof modules were evaluated between July 2011 and Aug. 2012. A CRF fertilizer rate of 15 g·m−2 N maximized vegetative coverage and overall plant appearance while maintaining leachate quality within Ontario and Canadian guidelines for most of the measured elements. The amount of Zn in the CRF appeared to be higher than plant demand and the high amount and concentration of P in leachate was likely the result of release from the growing substrate. The 5-Sus fertilizer resulted in increased coverage the first spring and increased greenness soon after application compared with the same rate of CRF. Overall, 15 g·m−2 N of CRF was the best treatment based on vegetative coverage and plant growth in sedum-vegetated green roof modules.