Modeling, identification and analysis of tractor and single axle towed implement system

Increased and sustained agricultural productivity is a key to meet the globally increasing demands for food and energy. Automation of agricultural machinery is one of the ways to improve the efficiency and productivity of various field operations. Because a field implement performs most of these operations, accurate implement guidance is needed to reduce production cost, increase yield, and improve sustainability. Model-based guidance controller design and virtual prototyping techniques can be used in automatic guidance controller development to improve the accuracy and robustness of the guidance controller while reducing the development time and cost. Hence, development and analysis of accurate tractor and implement system models are needed to support automatic tractor and implement guidance controller development. Real-time vehicle model simulation capability allows engineers and users to intuitively interact with the realistic virtual prototypes and to evaluate the performance of physical hardware. As the model complexity is increased to improve the model accuracy and/or fidelity, the computational need will also increases thus increasing the challenge to meet real-time constraints. In this regard, it is important to minimize the computational load to a Virtual Reality (VR)-based real-time dynamics model simulation system. In this dissertation, various strategies were investigated to reduce the computational burden on the dynamics model simulation so that real-time simulation could be achieved for increasingly complex models. A distributed architecture was developed for a virtual reality-based off-road vehicle real-time simulator to distribute the overall computational load of the system across multiple machines. Multi-rate model simulation was also used to simulate various system dynamics with different integration time steps so that the computational power can be distributed more intelligently. It is also important to study the trade-off between the model accuracy/fidelity and model complexity. Three different tractor-and-single-axle-towed-implement system models with varying degrees of fidelity, namely a kinematic model, a dynamic model, and a dynamic model with tire relaxation length, were developed, and the simulated transient and steady state responses were compared at various forward velocities and input frequencies. Both open and closed loop system characteristics were studied. Field experiments were also carried out to characterize the input-output relationship of the tractor-implement steering system. The responses from all three models were similar at lower forward velocities and with low frequency steering inputs (\u3c 0.2 Hz). However, when the system was operated at higher forward velocities or with higher frequency steering inputs, the responses from the three models varied substantially. In this case, the dynamic model with tire relaxation length best represented the experimental system responses. The system model contained various uncertain or varying parameters. It was important to understand and quantify the effect of parameter variation on system responses. Sensitivity analysis was used to identify the effect of variation in tire cornering stiffness, tire relaxation length, and implement inertial parameters on simulated system responses. Overall, the system was most sensitive to the tire cornering stiffness and least sensitive to the implement inertial parameters. In general, the uncertainty in the input parameters and the output variables were related in a non-linear fashion. At 4.5 m/s forward velocity, a 10% uncertainty in cornering stiffness caused a 2% average output uncertainty whereas a 50% uncertainty in cornering stiffness caused a 20% output uncertainty. Finally, a parameter identification method was used to estimate the uncertain model parameters from measured field data. The accuracy of the model responses improved substantially when the model was simulated with the estimated parameters. It was concluded that a dynamic model with tire relaxation length will represent a tractor and single axle towed implement system with reasonable accuracy. The study also helped improve the understanding of the relative importance of various model parameters, which will help to more judiciously allocate resources for estimating system parameters. Moreover, the analysis indicated that various vehicle parameters can be estimated with reasonable accuracy using a dynamic model, experimental data, and a parameter estimation method. The work will provide a framework for off-road vehicle and implement simulation through which engineers and scientists can determine to which parameters the system is most sensitive and how a model would perform with estimated model parameters

Optimization and cost analysis of lignocellulosic biomass feedstocks supply chains for biorefineries

This study estimated the biomass harvest and transport cost considering single pass biomass harvest with bulk and bale collections of biomass. Lignocellulosic biomass feedstocks costs were estimated using both corn stover and switchgrass as part of the feedstock supply chain. Harvest and transport cost for multi-pass biomass harvest operations using multiple feedstocks were analyzed and the optimal number of machines for all unit operations were estimated for each supply chain. This dissertation calculated and compared the biomass harvest and transport cost for single pass biomass harvest with bulk and bale collections of biomass. The objective of the research was to find the optimal number of machines, and least cost biomass harvest and transportation costs based on the harvest window, machine capacity, farm sizes and yield of the biomass. The least cost model was developed using the mixed integer non-linear programming model developed in General Algebraic Modeling System. The cost of harvest and transport using the bulk stover collection method was estimated about $25 Mg-1 ($23 ton-1) considering a transport distance of 3.2 km (2 miles) for primary storage from the field with the harvestable stover yield of 4.4 Mg ha-1 (2 ton ac-1) for the farm size of 2,000 ha. (5,000 ac.) Biomass feedstocks cost at the gate of biorefinery was estimated for multi-pass harvest systems with multi-feedstocks. Corn stover was considered a by-product of grain production and switchgrass as a single product. Planting and establishment cost was also considered along with harvest and transport cost for switchgrass. The cost of switchgrass varied from $75 Mg-1 to$97 Mg-1 ($68 ton-1 to$88 ton-1) and cost of corn stover varied from $75 Mg-1 to$97 Mg-1 ($20 ton-1 to$25 ton-1) respectively with the farm sizes variation from 400 ha to 2,000 ha (1,000 ac to 5,000 ac)

Growth and Development of a Malaysian Dipterocarp Forest After Harvest

The success of the Selective Management System (SMS) in managing" the hill dipterocarp forests of Peninsular Malaysia depends, among others, on the types of trees in the residual stand and the ability of these trees to grow and form the next crop. Specific information on growth and development of the residual stand is urgently required to evaluate the management system and its suitability in different forest types. In this study, data are analysed from logged over stands in the Lebir Forest Reserve, Peninsular Malaysia, which has been subjected to three harvesting intensities (HIs). The data consists of nine measurements covering a 14-year (1978-1991) period collected from nine permanent sample plots of size 200X200 m design under the systematic line sampling method. The plots were harvested first in 1977. Stocking, basal area and dbh growth of most species groups and HIs trees over 5 cm and over 15 cm dbh after harvest were significantly different (p<0.01) between the hill and lowland forests. The 5-15 cm dbh trees constituted more than 70 % of the total stocking and 20 % of total basal area. The stocking by dbh classes followed an inverse J-shape curve. The residual stand was dominated by non-dipterocarps. The potentially marketable (PM) and non-marketable species together accounted for more than 60% of total stocking and 58 % of total basal area in the both forests

Effects of Deforestation on Tree Diversity and Livelihoods of Local Community A Case Study from Nepal

The objectives of this study were to assess the status and trend of deforestation in the Shiwalik region of the central Nepal, and to explore the most significant effects of community forestry on tree diversity and livelihood of the local community. Two sites, heavily deforested in the past and one being presently owned by the government, the other managed by the local community for about 15 years, were compared with respect to tree and tree seedlings diversity and livelihood capitals. To analyze the diversity indices Hills diversity numbers, Shannon\u27s index and Importance value percentage were measured, whereas livelihood parameters were compared using the livelihood capitals model. The participatory approach was adopted to collect socio-economic data of the study sites. Community forestry helped increase the number of tree species as well as individuals. However, the study failed to state that the protection of forest from deforestation for a short period of time changed the diversity indices. Nevertheless, by protection the trend of an increased number of tree species coming as seedlings was obvious. Hence, the hypothesis that deforestation changes the tree diversity was proved. The study revealed that community forestry increased tree and wild animals, decreased soil erosion and checked the flooding in gullies and flow of debris. In the Government owned forest, soil erosion was rampant and had led to the decrease in agriculture productivity of the study area. The study also supported the fact that the protection of forest from deforestation by local people positively increased the majority of livelihood parameters. Thus, the hypothesis that the protection of forest from deforestation will have positive effects on livelihood of local people was accepted.\u2

Students’ perceptions of the Sub-Divisional Library, Kalimpong

This paper is an attempt to understand and evaluate the use of Sub-Divisional Library by the students of various Government, Government Sponsored and Private Schools of Kalimpong, West Bengal with respect to their demographical detail, purpose and frequency of using library, meeting required information by the libraries, difficulty in getting information, library collections and staffs, and their overall satisfaction to the services provided by the library. Hence a survey of 81 students of various schools across the tiny hilly station Kalimpong was conducted through structured questionnaire and out of which 73 questionnaires were duly obtained with a response rate of 90.12%. The results call for building functional and sound sub-divisional library to attract more students for its optimal utility and in meeting the information needs of students which ultimately augment the image of public librarianship in the expanse. The findings are valuable insights for anyone seeking to know more about the library usage and perceptions of school students towards the public library services

Students’ perceptions of the Sub-Divisional Library, Kalimpong

This paper is an attempt to understand and evaluate the use of Sub-Divisional Library by the students of various Government, Government Sponsored and Private Schools of Kalimpong, West Bengal with respect to their demographical detail, purpose and frequency of using library, meeting required information by the libraries, difficulty in getting information, library collections and staffs, and their overall satisfaction to the services provided by the library. Hence a survey of 81 students of various schools across the tiny hilly station Kalimpong was conducted through structured questionnaire and out of which 73 questionnaires were duly obtained with a response rate of 90.12%. The results call for building functional and sound sub-divisional library to attract more students for its optimal utility and in meeting the information needs of students which ultimately augment the image of public librarianship in the expanse. The findings are valuable insights for anyone seeking to know more about the library usage and perceptions of school students towards the public library services

Effects of Orchard Characteristics and Operator Performance on Harvesting Rate of a Mechanical Sweet Cherry Harvester

A model was developed to simulate sweet cherry harvesting with a mirrored-pair mechanical harvest system that removes fruit by transferring vibrational energy to tree limbs through an impactor. Six orchard characteristic variables (ST – tree spacing; SR – row spacing; NT – number of trees per row; NR – number of rows; NTB – number of branches per tree; and WTF – total weight of fruit per tree) and three harvester/operator characteristic variables (vH – forward speed of harvester, tIP – time to position impactor on actuation point, and tPS – shaking time per actuation point) were the main inputs to the model. Total harvest time (tTH) and harvesting rate were the two output variables of the model. Harvesting rate was evaluated with three different measures: time rate of area coverage (RAC), time rate of tree coverage (RTC), and time rate of fruit removal by weight (RFR). The model was validated with field data, showing very close predictions with modeling efficiencies of 99%, 86%, 82% and 84% respectively for tTH, RAC, RTC, and RFR. Local sensitivity analysis was conducted varying the input variables in five different levels in order to observe their effect on the output variables. A global sensitivity analysis was also performed to identify input variables with significant effects on the output variables. Data from a complete factorial experiment with three levels of input variables in 19,683 combinations was used to perform the global sensitivity analysis. . It was revealed that ST and SR only affected RAC by defining the unit area occupied by a single tree. NT and NR only affected tTH by determining the number of trees to be harvested, but had no effect on harvesting rate. NTB greatly affected harvesting time and all measures of harvesting rate, and was identified as the most important variable. WTF only affected RFR by determining how much fruit is removed in a single shaking event. Of the harvester/operator variables, tIP affected all the outputs the most whereas vH affected none. Except for RAC, which was least affected by SR, tPS had the least effect amid all the significant input variables. These results provide explanation for achieving different harvesting rates in different orchard settings, and can be used to optimize orchard characteristics and adjust operator behaviors for improved performance in mechanical sweet cherry harvesting

An empirical study on Public Libraries of Kalimpong

This paper is an attempt to examine the present status and position of Government and Government sponsored public libraries in the Kalimpong district of West Bengal in terms of their establishments, membership patterns, physical facilities, staff strength, their collections, organizations, services and computer facilities etc. A total of 30 structured questionnaires were distributed among the Public Libraries across this hilly area and all the questionnaires were duly obtained with a response rate of 100%. Based on the findings the study suggests some recommendations for building functional and sound public libraries for providing effective and efficient library services to the hill community

Evaluation of the effectiveness of countermeasures to enhance pedestrian safety

Pedestrian safety is a major concern in the United States because over 4,700 pedestrians are killed and 70,000 are injured annually. Nevada has one of the highest pedestrian fatality rates in the United States. Thus, there is a need to enhance pedestrian safety using existing and new strategies and to evaluate the effectiveness of these strategies. The objective of this research is to evaluate the effectiveness of various countermeasures to improve pedestrian safety. The countermeasures evaluated in this research include: (1) an in-pavement flashing light system, (2) pedestrian countdown signals, (3) turning traffic must yield to pedestrians signs, (4) a portable speed trailer, (5) in-roadway knockdown signs, (6) a high visibility crosswalk, (7) warning signs for motorists, (8) regulatory signs, and (9) advance yield markings; A before-and-after analysis was used to evaluate the selected strategies. Measures of effectiveness (MOEs) were used to evaluate the impacts of these countermeasures, including pedestrians\u27 and motorists\u27 behaviors. Data were collected immediately prior to the installation of each countermeasure and a few weeks after the installation of each countermeasure. Data were collected during both AM and PM peak periods. The data obtained from the two study periods (before installation and after installation) for each MOE were evaluated using statistical tools; Results from the analyses of the data show that the in-pavement flashing light system is an effective strategy to increase motorists\u27 yielding and to reduce average vehicle speeds at a location with low traffic and pedestrian volumes. The pedestrian countdown signal helps to improve pedestrians\u27 crossing behaviors. The observed mean vehicular speeds were higher when the pedestrian countdown timer was displayed on the pedestrian signal head than with the traditional pedestrian WALK phase. The installation of the sign turning traffic must yield to pedestrians increased motorists yielding behavior when they executed turning maneuvers on either red or green phases. The average vehicle speed was reduced upstream and downstream of the location of the portable speed trailer. The high visibility crosswalk, warning signs for motorists, regulatory signs for motorists, and advance yield markings at a mid-block location showed positive safety benefits in motorists\u27 and pedestrians\u27 behaviors; The MOEs used to evaluate countermeasures indicate improvements in both motorists\u27 and pedestrians\u27 behaviors. In most cases, these changed behaviors are positive and statistically significant. Even though these deployed strategies and their influence on pedestrians\u27 and drivers\u27 were effective in prevailing weather conditions and the geographic location of the Las Vegas metropolitan area, these findings are of value to other regions with similar traffic and pedestrian characteristics

Evaluation of Naked Barley Landraces for Agro-morphological Traits

Naked barley (Hordeum vulgare var. nudum L.) is a traditional, culturally important, climate-resilient winter cereal crop of Nepal. Evaluation of the naked barely genotypes for yield and disease is fundamental for their efficient utilization in plant breeding schemes and effective conservation programs. Therefore, to identify high yielding and yellow rust resistant landraces of naked barley for hilly and mountainous agro-ecosystem, twenty naked barley landraces collected from different locations of Nepal, were evaluated in randomized complete block design (RCBD) with three replications during winter season of 2016 and 2017 at Khumaltar, Lalitpur, Nepal. Combined analysis of variances revealed that NGRC04902 (3.46 t/ha), NGRC00886 (3.28 t/ha), NGRC02309 (3.21 t/ha) and NGRC06026 (3.10 t/ha) were the high yielding landraces and statistically at par with the released variety 'Solu Uwa' (3.15 t/ha). The landraces namely NGRC00837 (ACI Value: 1.86) was found resistant to yellow rust diseases. Landraces NGRC06034 (131.7 days) and NGRC02363 (130.8 days) were found early maturing and NGRC02306 (94.36 cm) was found dwarf landraces among tested genotypes. These landraces having higher yield and better resistance to yellow rust need to be deployed to farmers' field to diversify the varietal options and used in resistant breeding program to improve the productivity of naked barley for Nepalese farmers