Operator workload analysis on coconut tree climbing using portable coconut climbing equipment

Recently, the work of climbing coconuts, especially in Aceh Province Indonesia still uses traditional methods, namely by climbing coconut trees directly. Traditional climbing is very high risk because it can fall which threatens the safety of life. Besides that, this job is also a heavy work category because it requires a lot of energy to do it. Therefore, the analysis of operator workload on climbing coconut trees using portable coconut climbing equipment is expected to be useful for developing tool designs and methods for climbing coconuts that are safer, more comfortable and more effective. The calculation of the operator’s workload is based on heart rate measurements, where three operators have their heart rate data taken during coconut tree climbing activities, either manually or using portable climbing tools. The workloads analyzed are qualitative and quantitative workloads. The results of the workload analysis indicate that climbing is traditionally classified as a “medium” job with an average IRHR value of 1.45, while using portable climbing equipment is classified as heavy work with an IRHR value of 1.54 The traditional climbing energy consumption rate is 3.29 kcal/hour.kg-ow (kilocalories per hour per operator’s weight), while using a portable climbing equipment is 3.82 kcal/hour.kg-ow. The high level of operator workload is largely determined by the operator’s habits in doing climbing as well as skills that must be trained in operating the tool. However, in terms of operator safety, the use of portable equipment has a higher level of security because there are footrests and handrails as well as seat belts.

Ergonomics study on pivot-type trailer operation for two-wheel tractor on sloping land

The operation of the pivot type trailer on a two-wheeled tractor on flat land shows that it is more ergonomic than conventional trailers, but for testing on sloping land it has never been tested. Therefore, this study aims to analyze ergonomics, especially the operator’s workload on the operation of a pivot-type trailer on a two-wheel tractor on a sloping land. The calculation of the operator’s workload is based on heart rate measurements, where three operators have their heart rate data taken during the activity of operating a two-wheeled tractor in pulling a trailer. The workloads analyzed are qualitative and quantitative workloads. The results showed that the operation of conventional trailers for land slopes of 0°, 10°, and 30° respectively showed IRHR values of 1.23, 1.24, and 1.31 or the level of work “light”, “light”, and “light”. While using a pivot type trailer, the IRHR values are 1.20, 1.27, and 1.55 or the work levels are “light”, “light”, and “medium”. The average energy consumption rate of operating a conventional trailer is 2.54 kcal/hour.kg-bb (kilocalories per hour per operator’s weight), while using a pivot type trailer 2.60 kcal/hour.kg-bb. The high level of operator workload is largely determined by the skill of the operator in operating the trailer, which requires training in its operation. This causes the operator’s workload to operate on pivot type trailers higher than conventional trailers. However, from the aspect of operator comfort and safety, pivot-type trailers are superior, especially when turning.

Research on the Output Characteristics of Emerging Market Entities Serving the Development of New Energy

The power emerging market entities connected to the grid in a decentralized manner can increase the local new energy consumption rate. Under the background of accelerating the development of new energy, it is urgent to clarify the output characteristics of emerging market entities such as wind power, photovoltaics, energy storage, and electric vehicles to adapt to the development of distributed energy and the progress of power market reform. Major emerging entities contribute to mathematical analysis, promote the transaction design of emerging entities, and promote the rapid and healthy development of new energy.

EVALUATION OF PERFORMANCE INDICATORS OF SELECTED WATER COMPANIES IN VIETNAM

Performance indicators of water supply company can provide important information of its service quality and business efficiency, and be intelligent basis for decision making process. The authors have analyzed key performance indicators of 19 selected municipal water supply systems in Vietnam, including operation and design capacities, treated water quality, unit investment cost, water tariff, non-revenue water (NRW) ratio, and energy consumption rate. The average NRW of the 19 systems was 12.6% which was lower than country-wide value of 21%. The energy consumption rate of selected systems was ranging from 0.16 to 0.5KWh/m3, in average 0.3KWh/m3, which was also lower than country average of 0.35KWh/m3, whereas the rate of energy consumption in municipal water systems in China, USA, Australia, Chile, Canada was ranging from 0.1 to 1.33KWh/m3, depending on ground elevation, transfer distance, influent water quality, and applied technologies for water treatment and transportation. The selected water systems have applied improved treatment technologies such as mechanized coagulation-flocculation, lamella settling tank, dual media sand filter, combined contact clarifier with lamella plates, etc. The average treated water turbidity was ≤0.5NTU. The domestic water tariff of the selected systems was within the country range, from USD0.2 to 0.4/m3. Further, the authors have indicated correlation between selected performance indicators, such as energy consumption rate and non-revenue water ratio. The analytical results shown performance indicators of top water companies in Vietnam were in fairly good position compared to others, but improvements were still needed. Reduction of NRW ratio and keeping it at a low value are other challenges requiring water utility efforts.

Simulation of Heavy Haul Train Energy Consumption With Locomotive Adhesion Model

Conventional train energy calculation models cannot consider locomotive wheel-rail adhesions, traction adhesion control and locomotive dynamics. This paper developed an advanced model to fill this research gap. The model uses a 3D locomotive model with a fully detailed wheel-rail contact model. The locomotive model was integrated into a Longitudinal Train Dynamics model with the consideration of locomotive adhesion control. Energy consumption simulations using a conventional model (1D model) and the new model were conducted and compared. The 3D model reports less energy consumption than the 1D model. Maximum difference in energy consumption rate between the 3D model and the 1D model was 12.5%.

Eco-Driving Optimal Controller for Autonomy Tracking of Two-Wheel Electric Vehicles

The eco-driving profiles are algorithms able to use additional information in order to create recommendations or limitation over the driver capabilities. They increase the autonomy of the vehicle but currently their usage is not related to the autonomy required by the driver. For this reason, in this paper, the eco-driving challenge is translated into two-layer optimal controller designed for pure electric vehicles. This controller is oriented to ensure that the energy available is enough to complete a demanded trip, adding speed limits to control the energy consumption rate. The mechanical and electrical models required are exposed and analyzed. The cost function is optimized to correspond to the needs of each trip according to driver behavior, vehicle, and traject information. The optimal controller proposed in this paper is a nonlinear model predictive controller (NMPC) associated with a nonlinear unidimensional optimization. The combination of both algorithms allows increasing around 50% the autonomy with a limitation of the 30% of the speed and acceleration capabilities. Also, the algorithm is able to ensure a final autonomy with a 1.25% of error in the presence of sensor and actuator noise.

Primary energy consumption for insulating

In this article a mathematical model for thermal protection level analysis is developed. It is based on the consumption rate of primary energy. It allows to calculate the relevant thickness of the selected insulation material under any climatic and economic conditions with any constant layers of building envelope taken from structural considerations. The key factors influencing the model are also evaluated. The main factors to influence the energy model are the region degree-days and the energy consumption rate for the production, transportation and installation of the insulation material. The following results were reached: this approach requires the data, which sometimes has no public access, provides us with an objective assessment criteria when comparing the level of building thermal protection in different countries.

An Online Charging Scheme for Wireless Rechargeable Sensor Networks Based on a Radical Basis Function

The node energy consumption rate is not dynamically estimated in the online charging schemes of most wireless rechargeable sensor networks, and the charging response of the charging-needed node is fairly poor, which results in nodes easily generating energy holes. Aiming at this problem, an energy hole avoidance online charging scheme (EHAOCS) based on a radical basis function (RBF) neural network, named RBF-EHAOCS, is proposed. The scheme uses the RBF neural network to predict the dynamic energy consumption rate during the charging process, estimates the optimal threshold value of the node charging request on this basis, and then determines the next charging node per the selected conditions: the minimum energy hole rate and the shortest charging latency time. The simulation results show that the proposed method has a lower node energy hole rate and smaller charging node charging latency than two other existing online charging schemes.