Station Distance Research Articles

Hydrogen station location optimization based on multiple data sources

A hydrogen station is one that fills or stores the hydrogen, which is critical to the commercial development of hydrogen energy and fuel cell vehicle industry. Therefore, its location planning becomes an important issue. Similar to the electric vehicle (EV) charging station's planning, several factors are considered including the location, the demand of the fuel, the driving distance, etc. In this paper, multiple data sources are applied to the site selection model, including the existing petrol-refueling station network data, geographic information system (GIS) data, population data and regional economic data. Based on the operation of the genetic algorithm, combined with the idea of the greedy algorithm and the annealing algorithm, we propose a multi-algorithm hybrid solution, which not only can avoid local optimal, but also can converge quickly. On the basis of the site selection scheme of the hydrogen station in California, we have optimized the location scheme in Beijing. Finally, we present the feasibility proposals for hydrogen station location in Beijing, including the appropriate number of hydrogen stations in different regions, the reasonable coverage distance of hydrogen stations, etc. Due to the huge development prospects for hydrogen energy and the urgent need to reduce the construction cost of hydrogen stations in China, this research can quickly optimize the location of the hydrogen station and further explore potential mathematical relationships, which has certain social significance and economic benefits.

Water resource selection of large mammals for water resources planning

Iran is one of the driest countries in the world and shortage of water is one of the main concerns for wildlife conservation in this country. We have studied eight mammal species at Bafgh protected area at the center of Iran. We have investigated the physic-chemical parameters (salinity, chlorine, bicarbonate, carbonate, calcium, sodium, potassium, magnesium, total dissolved solids, dissolved oxygen, water temperature, electrical conductivity, and pH) and geo-ecological characteristics (altitude, slope, distance of settlements in rural area, distance of road, distance of stream, distance of protection station, distance of mine, distance of human-made construction, percent coverage of Phragmites australis, percent coverage of Pistacia atlantica, percent coverage of Peganum harmala, percent coverage of Punica granatum) of water bodies and their relationships with big mammals’ visiting frequencies from these water bodies. We have developed species–environment relationships using a backward-selected logistic regression. A separate model has been developed for each species, because we expected that different species may respond differently to environmental parameters. Our results showed that slope, elevation, and distance of settlement, road, protection station, mine, and human-made construction are the most important variables in the selection of water sources for the studied species. Our results also indicated that natural water resources in summer had the highest importance for Panthera pardus, Ovis orientalis, Vulpes vulpes, Felis silvestris, and Capra aegagrus, while during the season the artificial water resource showed the highest priority for Caracal caracal, Gazella bennettii, and Canis aureus. Therefore, it is suggested that protected area managers pay more attention to natural water bodies to be sure that wildlife does not face water shortage in critical seasons.

On Scaling of Earthquake Rise‐Time Estimates

AbstractThe scaling behavior of rise times Tr determined within earthquake source inversions that used strong‐motion data is determined using estimates as accumulated in the SRCMOD database. The Tr versus M0 trend derived from this data set is close to logTr=1/3logM0+ const; this agrees with the assumption of self‐similarity of earthquake ruptures. No biasing effect of station distance on Tr was found. The result was compared to recent scaling estimates based on mass teleseismic inversions. Absolute levels of teleseismic and local inversions match well; the slope of the trend of teleseismic estimates is somewhat more gradual. The absolute levels of Tr versus M0 trends recovered from finite source inversions may need reduction when used to predict parameters of near‐source ground motion. The observed scaling behavior of Tr is incompatible with the assumption that Tr defines the second corner frequency of the source spectrum.

Performance of Network-Based RTK GNSS for the Cadastral Survey in Thailand

In Thailand, a network of GNSS Continuously Operating Reference Station (CORS) has been operating as a Network-based Real Time Kinematic (NRTK) GNSS positioning solutions since 2008. The Department of Lands designs a Thai-NRTK system mainly for GNSS cadastral survey using the Virtual Reference Station (VRS) as its positioning concept. The current Thai-NRTK consists of 114 GNSS CORSs covering only some parts of Thailand. The CORS spacing ranges from 25.1 km to198.6 km. According to previous studies, the performance of NRTK-GPS positioning determination in Thailand is strongly depending on the dimension of the triangular CORS locations; known as a “loop”. This research aims to examine the horizontal position performance of this Thai-NRTK GNSS positioning solutions as a quality indicator for GNSS cadastral surveying. The test was carried out with quite a large number of test samples (total of 2,122 points) and where every loop is separated into 4 test groups with differing the station distances starting from the loop spacing of: 30 km to 50 km, 50 km to 70 km, 70 km to 90 km and 90 km to 110 km, respectively. The positioning performance test is conducted in two main folds; namely, positioning accuracy and time to resolve its solutions. On positioning accuracy, the test results show that the spacing of every tested loop achieves the accuracy in accordance with the cadastral surveying requirements. This proves that the Thai-NRTK GNSS positioning network and technique is well-designed and suitable for cadastral positioning within its coverage areas. On time to resolve fixed solution, the test results indicate that the ‘time to first fixed’ and the ‘rate of the horizontal position jump’ increase with longer loop distance; whereby only loop length of 30 km to 50 km has 100% success ‘rate of ambiguity-fixing’ solutions; therefore, in order to achieve a high reliable performance positioning from the Thai-NRTK GNSS solutions for cadastral survey in Thailand, it is recommended that the reference stations shall be kept within 50 km.

Quantifying location uncertainties in seismicity catalogues: application to the Pyrenees

Linearised least-square inversions are commonly used to locate small-magnitude earthquakes, as they are fast and simple to implement. These methods are based on minimising the root-mean-square (RMS) of travel time residuals to find the best-fitting location coordinates and origin time. There are two well-known problems that affect location estimates: (1) the linearisation of the inverse problem causes dependence on the initial guess; (2) regularisation produces solutions that depend on the chosen damping coefficient and biased uncertainty estimates. In this work, we propose a method to quantify unbiased uncertainties with a series of synthetic tests. We first generate travel times for events from all possible coordinates on a 3D grid and then locate each synthetic event by using HYPOCENTER software (this can be applied to any location method). We show that the uncertainties estimated from the standard linearised inversion are strongly underestimated, and we propose another method to compute uncertainties. We produce a 3D error map, where at each grid point we plot the location error, defined as the distance between the event at the given grid point and its inverted location. Moreover, we show how this error map varies with the quantity and quality of the data, and with user-defined parameters such as maximum event–station distance or station corrections. We also provide a methodology to tune the seismic location parameters and calculate the corresponding uncertainties for users who are using similar earthquake location software. Finally, we present an application to the Pyrenean region.

MCRO-ECP: Mutation Chemical Reaction Optimization based Energy Efficient Clustering Protocol for Wireless Sensor Networks

Wireless sensor networks encounter energy saving as a major issue as the sensor nodes having no rechargeable batteries and also the resources are limited. Clustering of sensors play a pivotal role in energy saving of the deployed sensor nodes. However, in the cluster based wireless sensor network, the cluster heads tend to consume more energy for additional functions such as reception of data, aggregation and transmission of the received data to the base station. So, careful selection of cluster head and formation of cluster plays vital role in energy conservation and enhancement of lifetime of the wireless sensor networks. This study proposes a new mutation chemical reaction optimization (MCRO) which is an algorithm based energy efficient clustering protocol termed as MCRO-ECP, for wireless sensor networks. The proposed protocol is extensively developed with effective methods such as potential energy function and molecular structure encoding for cluster head selection and cluster formation. While developing potential functions for energy conservation, the following parameters are taken into account: neighbor node distance, base station distance, ratio of energy, intra-cluster distance, and CH node degree to make the MCRO-ECP protocol to be potential energy conserver. The proposed protocol is studied extensively and tested elaborately on NS2.35 Simulator under various senarios like varying the number of sensor nodes and CHs. A comparative study between the simulation results derived from the proposed MCRO-ECP protocol and the results of the already existing protocol, shows that MCRO-ECP protocol produces significantly better results in energy conservation, increase network life time, packets received by the BS and the convergence rate.

A Prototype Earthquake Early Warning System for Northern India

ABSTRACT Part of North-Western Himalaya particularly Uttarakhand has been identified by several eminent seismologists as gap area where large size earthquake (greater than magnitude 7) is expected. The region has witnessed two earthquakes having a magnitude greater than 6 in last 25 years (March 28, 1999 Chamoli earthquake and October 20, 1991 Uttarkashi earthquake) both having an epicenter in Gharwal region of Uttarakhand. Several studies have shown that a future large earthquake in central Himalayas can generate severe ground motion in the National capital region of Delhi, which is about 300 km from this expected source. Several densely populated cities and villages having total population of several millions are located between Delhi and Uttarakhand. These towns/cities will be severely affected by a large earthquake having an epicenter in this region. Using advancements in communication technology and real-time seismology, a project to have an earthquake early warning system for Northern India is under progress at Indian Institute of Technology, Roorkee. In this project, a dense network of 84 accelerometers has been installed covering an area of about 100 × 40 km in Garhwal region. This network has an average station to station distance of less than 10 km and all the sensors are streaming data, which is being processed in real time at central server stationed at Roorkee. This paper describes details of the network, sensors, present status of development, performance of instrumentation during recent events, and processing details.

A Sub-Regional Extraction Method of Common Mode Components from IGS and CMONOC Stations in China

There is always a need to extract more accurate regional common mode component (CMC) series from coordinate time series of Global Positioning System (GPS) stations, which would be of great benefit to describe the deformation features of the Earth’s surface with more reliability. For this purpose, this paper combines all 11 International Global Navigation Satellite System (GNSS) Service (IGS) stations in China with over 70 stations selected from the Crustal Movement Observation Network of China (CMONOC) to compute CMC series of IGS stations by using a principal component analysis (PCA) method under cases of one whole region and eight sub-regions. The comparison results show that the percentage of first-order principal component (PC1) in North, East and Up components increase by 10.8%, 16.1% and 25.1%, respectively, after dividing the whole China region into eight sub-regions. Meanwhile, Root Mean Square (RMS) reduction rates of residual series that have removed CMC also improve obviously after partitioning. In addition, we compute displacements of these IGS stations caused by environmental loadings (including atmospheric pressure loading, non-tidal oceanic loading and hydrological loading) to analyze their contributions to the non-linear variation in GPS coordinate time series. The comparison result shows that the method we raise, PCA filtering in sub-regions, performs better than the environmental loading corrections (ELCs) in improving the signal-to-noise ratio (SNR) of GPS coordinate time series. This paper raises new criteria for selecting appropriate CMONOC stations around IGS stations when computing sub-regional CMC, involving three criteria of interstation distance, geology and self-condition of stations themselves. According to experiments, these criteria are implemental and effective in selecting suitable stations, by which to extract sub-regional CMC with higher accuracy.

Improving GNSS Zenith Wet Delay Interpolation by Utilizing Tropospheric Gradients: Experiments with a Dense Station Network in Central Europe in the Warm Season

The Benchmark data set collected within the European COST Action ES1206 has aimed to support the development and validation of advanced Global Navigation Satellite System (GNSS) tropospheric products, in particular high-resolution zenith delays and tropospheric gradients. In this work we utilize this unique data set to show that the interpolation of GNSS Zenith Wet Delays (ZWDs) can be improved by utilizing tropospheric gradients. To do this we first prove the concept with simulated observations, that is, zenith delays and tropospheric gradients derived from a Numerical Weather Model. We show how tropospheric gradients can be converted to ZWD gradients. Then the ZWD gradients together with the ZWDs at selected reference stations are used in an inverse distance weighting interpolation scheme to estimate the ZWD at some target station. For a station configuration with an average station distance of 50 km in Germany and a period of two months (May and June 2013), we find an improvement of 20% in interpolated ZWDs when tropospheric gradients are taken into account. Next, we replace the simulated by real observations, that is, zenith delays and tropospheric gradients from a Precise Point Positioning (PPP) solution provided with the G-Nut/Tefnut analysis software. Here we find an improvement of 10% in interpolated ZWDs when tropospheric gradients are taken into account.

Delivering More Homes: Radical Action to Unblock the System

The planning system has become too complex and the revisions to the National Planning Policy Framework risk exacerbating the situation. The principle of a clear general presumption in favour of sustainable development that has equal weight to other considerations, including the Development Plan, must be reintroduced. The Planning Inspectorate appears to be under extreme pressure; increased involvement of outside specialists and a sitting mediation service would help to resolve the problems and speed up decisions. All Green Belt boundaries should be reviewed, starting with those areas that do not have an adequate land supply for the next ten years to meet known population requirements. An early release of Green Belt would help to meet the urgent need for housing in and around Birmingham, Manchester, and London. The most sustainable areas will be within walking distance of railway or underground stations. The government should introduce legislation to enable the setting up of Special Purpose Vehicles (SPVs) as an appropriate delivery mechanism for new integrated and sustainable communities with a mix of housing types and tenures, for example, homes for sale, private rental, housing association accommodation and more specialised types, such as sheltered accommodation for the elderly. The Government Property Unit in the Cabinet Office needs to up its game and accelerate progress with its Government Estate Strategy, notably in respect of the One Public Estate programme which appears to have made lamentable progress as far as land sales are concerned. Given the slow progress so far made on public land disposals, consideration should be given to allowing a private sector body permission to apply to acquire public sector land under the Compensation Code and serve a Disposal Order to achieve such a transfer. This might prove particularly relevant where this relates to land where a local authority has already granted planning permission. There is a strong case to use land promotion partners where additional expertise and funding is judged necessary to unlock sites for development. Promoters can supply ‘shovel-ready’ sites into the land market, speeding up the delivery of new homes.

Research on Lateral Positioning Algorithm of Fixed Radiation Source by Mobile Single Station

Wireless communication and satellite navigation technology to promote passive positioning technology has become a hot topic in the field of electronic countermeasures. The passive positioning technology can determine the position of the radiation source under the condition that it does not generate radiation, and has the characteristics of long distance of action and strong anti-interference ability. In this paper, the theory of passive lateral positioning is discussed. In the three-dimensional space, a new algorithm for moving the single station to the lateral positioning and geometric combination of fixed radiation source is established, and the error analysis and simulation are carried out. The distance of the observation station is 300km, Δβ = 0.06°, Δε = 0.01°, r = 30m, and can be calculated. That is, when the distance between the measurement target and the ground observation station is 300km, the system space positioning error is up to 320m. When the distance between the measurement target and the ground observation station is 100km, the system space positioning error is up to 115m. Therefore, the positioning accuracy of the calculation method can reach 0.12% of the distance. The experimental verification and result analysis show that the algorithm has good applicability in the field of lateral positioning of fixed radiation sources.

Reversible ground motion-to-intensity conversion equations based on the EMS-98 scale

The relation between observed macroseismic intensities and recorded ground motion parameters is a matter of interest in earthquake engineering, and it has been widely discussed in literature in the past. Several relationships already exist, correlating macroseismic intensity and peak ground motion parameters (i.e. PGA, PGV or PGD, respectively peak ground acceleration, velocity and displacement). However, most of these formulations are based on Mercalli-Cancani-Sieberg (MCS) scale, developed using regional databases and difficult to be applied at large scale. In this research, new formulations are proposed that correlate European Macroseismic Scale (EMS-98) with ground shaking parameters (PGMs), Arias intensity and Housner intensity. An initial PGM/EMS-98 intensity dataset was assembled for this scope, collecting 610 data pairs of observations, from 35 different Italian seismic events derived from the Parametric Catalogue of Italian Earthquakes (CPTI15) and the Italian Accelerometric Archive (ITACA), subsequently filtered considering only tectonic events and data pairs with site – station distances lower than 3 km. The resulting final dataset of 220 data pairs from 22 earthquakes was thus used to obtain regression relationships, finally compared with existing models based on the Modified Mercalli (MM) scale and MCS scale.

Ranging Precision Analysis of Stonex X300 3D Laser Scannerd

This paper takes Stonex X300 3D laser scanners as a design scheme, tests ranging nominal and ranging precision of instrument and compares between calculating solution of Stonex X300 3D laser scanners and the measured distance of Leica TS30 total station. Experiment result shows ranging precision of 3D laser scanners is given on the basis of certain distances while ranging nominal is given on the basis of certain experiment conditions. In the process of collecting data in field surveying, it cannot completely reach its calibration value due to conditional limitation and ranging error in certain distance easily reaches nominal value. However, in terms of total station-scaled 3D laser scanners, it cannot reach too high differentiating ability. The farther the distance, the more difficult the discovery of target point. Ranging precision testing method in this paper has better reliability to be implemented and also has practical value for precision research in 3D terrain laser scanners.

Modeling snow depth extremes in Austria

Maps of extreme snow depths are important for structural design and general risk assessment in mountainous countries like Austria. The smooth modeling approach is commonly accepted to provide more accurate margins than max-stable processes. In contrast, max-stable models allow for risk estimation due to explicitly available spatial extremal dependencies, in particular when anisotropy is accounted for. However, the difference in return levels is unclear, when modeled smoothly or with max-stable processes. The objective of this study is twofold: first, to investigate that question and to provide snow depth return level maps for Austria; and second, to investigate spatial dependencies of extreme snow depths in Austria in detail and to find a suitable model for risk estimation. Therefore, a model selection procedure was used to define a marginal model for the GEV parameters. This model was fitted to 210 snow depth series comprising a length of 42 years using the smooth model approach and different max-stable models allowing for anisotropy. Despite relatively clear advantages for the Extremal-t max-stable process based on two scores compared to the smooth model as well as the Brown–Resnick, Geometric Gaussian and Schlather processes, the difference in 100-year snow depth return levels is too small, to decide which approach works better. Spatial dependencies of snow depth extremes between the regions north and south of the Austrian Alps are almost independent. Dependencies are stronger in the south for small distances between station pairs up to 120 km and become stronger in the north for larger distances. For risk modeling the Austrian Alps could be separated into regions north and south of the Alps. Fitting an anisotropic Extremal-t max-stable process to either side of the Alps can improve modeling of joint exceedance probabilities compared to one single model for the whole of Austria, especially for small station distances.

Potential of Cost-Efficient Single Frequency GNSS Receivers for Water Vapor Monitoring

Dual-frequency Global Navigation Satellite Systems (GNSSs) enable the estimation of Zenith Tropospheric Delay (ZTD) which can be converted to Precipitable Water Vapor (PWV). The density of existing GNSS monitoring networks is insufficient to capture small-scale water vapor variations that are especially important for extreme weather forecasting. A densification with geodetic-grade dual-frequency receivers is not economically feasible. Cost-efficient single-frequency receivers offer a possible alternative. This paper studies the feasibility of using low-cost receivers to increase the density of GNSS networks for retrieval of PWV. We processed one year of GNSS data from an IGS station and two co-located single-frequency stations. Additionally, in another experiment, the Radio Frequency (RF) signal from a geodetic-grade dual-frequency antenna was split to a geodetic receiver and two low-cost receivers. To process the single-frequency observations in Precise Point Positioning (PPP) mode, we apply the Satellite-specific Epoch-differenced Ionospheric Delay (SEID) model using two different reference network configurations of 50–80 km and 200–300 km mean station distances, respectively. Our research setup can distinguish between the antenna, ionospheric interpolation, and software-related impacts on the quality of PWV retrievals. The study shows that single-frequency GNSS receivers can achieve a quality similar to that of geodetic receivers in terms of RMSE for ZTD estimations. We demonstrate that modeling of the ionosphere and the antenna type are the main sources influencing the ZTD precision.

Mapping of buried faults using the 2D modelling of far-field controlled source radiomagnetotelluric data

Controlled source radiomagnetotellurics (CSRMT) is a relatively new geophysical method for near-surface applications. A rectangular signal with base frequencies between 0.1 and 150 kHz is injected through a grounded electric dipole which is used as a transmitter. Electric and magnetic field components are observed at these frequencies and at their subharmonics, usually in the far-field zone so that apparent resistivities and impedance phases can be obtained in a broad frequency range between 1 and 1000 kHz. Inline or broadside configuration can be used for measurements. Similar to the controlled source audiomagnetotelluric method, tensor measurements are also possible when locating two transmitters perpendicular to each other. A scalar CSRMT survey was carried out on the buried faults in the Vuoksa region, 110 km north of St. Petersburg to test the applicability of this method to the mapping of near-surface faults. A 700 m electric dipole with base frequencies of 0.5, 11.3, 30 and 105 kHz was used as a transmitter. Smooth apparent resistivity and phase values as a function of frequency from 1 kHz to 1 MHz were observed in the far-field zone for the inline configuration at 57 stations using a station distance of 20 m. Electric fields observed in the direction of the transmitter were perpendicular to the assumed strike direction of the buried faults so that they could be associated with the TM mode. The observed apparent resistivity and phase TM mode data were interpreted using the 2D inversion algorithm, and a good data fitting could be obtained. The resistivity structure beneath the survey area (down to a depth of 80 m) could be derived and the buried faults could be mapped successfully. In addition to the CSRMT observations, a conventional radiomagnetotelluric (RMT) survey was also carried out on the same profile. An excellent correlation of the observed RMT and CSRMT transfer functions and 2D conductivity models was achieved.

Subway Service Down Again? Assessing the Effects of Subway Service Interruptions on Local Surface Transit Performance

Cities around the world are keen to offer modern urban transit systems that connect various locations in an efficient and reliable manner with the highest degrees of riders’ experience. These systems may consist of various modes such as buses, streetcars (or trams), and rapid transit systems (e.g., subways). In both research and practice, the quality of transit service has traditionally been measured and investigated on a mode-by-mode basis. Therefore, it is rare to find studies that investigate the impacts of poor performance or breakdown of one transit mode on other functioning modes in multimodal integrated transit systems. This research aims at understanding the impact of subway service interruptions on the speed performance of surface transit in Toronto, Ontario. To do that, a detailed data set of subway service interruptions collected in 2013 by the Toronto Transit Commission (TTC), the public transit provider in the City of Toronto, was used. In addition, another data set was obtained from the TTC’s automatic vehicle location system for 51 bus and streetcar routes that are within a short walking distance of some subway stations. Using two statistical models, the paper results indicate that subway service interruptions have a statistically significant negative impact on bus and streetcar service operations in terms of slower speeds, with more immediate and intense impacts on streetcar service.

A hybrid DEA-based K-means and invasive weed optimization for facility location problem

In this paper, instead of the classical approach to the multi-criteria location selection problem, a new approach was presented based on selecting a portfolio of locations. First, the indices affecting the selection of maintenance stations were collected. The K-means model was used for clustering the maintenance stations. The optimal number of clusters was calculated through the Silhouette index. The efficiency of each cluster of stations was determined using the Charnes, Cooper and Rhodes input-oriented data envelopment analysis model. A bi-objective zero one programming model was used to select a Pareto optimal combination of rank and distance of stations. The Pareto solutions for the presented bi-objective model were determined using the invasive weed optimization method. Although the proposed methodology is meant for the selection of repair and maintenance stations in an oil refinery Company, it can be used in multi-criteria decision-making problems.

Accumulation of some heavy metals in the prevailing plants (Alhagi mourorum and Suaeda vermiculata) near the thermal power plant in Al-Nasiriyah city south of Iraq

The present study aims to investigate the effect of Thermal power plant emissions upon two species of plant Alhagi mourorum and Suaeda vermiculata which growth in the region close to Thermal power plant. triplicater samples were collected seasonllys from autumn 2016 up to summer 2017 one time from each season. three station were selected in the study area to execute this study meters. The first station distances 400 meters from the thermal power station, The second station is located 800 meters from the thermal power plant . While, the third station distances 1200 meters from the thermal power plant . Three stations were with prevailing wind direction (north wind) , while control station situated far from the thermal power plant about 12 km. the concentratios of heavy metals Cd, Cu, Pb and Zn were estimate in root and shoot systems for both plants, their concentration in root system more higher than their concentrations in shoot system. its concluded from the present study that thermal electric power station emissions affected upon the plants which growth in the surrounding region with thermal power plant.

An Improved LEACH Routing Algorithm for Wireless Sensor Network

Optimization of energy consumption is major concern for the design and planning of wireless sensor networks (WSNs). Recent research has demonstrated that organizing nodes in clusters has higher energy efficiency. LEACH is the most popular routing protocol for cluster-based in WSNs, and FCM algorithm is used for the optimum number of the clusters and their location. Aiming at the shortcomings of LEACH and FCM-LEACH, which including inaccurate cluster centers, unreasonable clustering and sole data transmission mode. This paper proposes a new energy efficient routing algorithm (NF-LEACH). In the new algorithm, There are many factors have considered to prolong the network life cycle that they are the degree of membership, residual energy, base station distance and data transmission mode. Finally, the comparison among LEACH, FCM-LEACH, and NF-LEACH has been done. The results show that the NF-LEACH has the longest lifetime and the most evenly distributed amongst three algorithms.