scholarly journals Harvester Evaluation Using Real-Time Kinematic GNSS and Hiring Service Model

2021 ◽  
Vol 3 (2) ◽  
pp. 363-382
Author(s):  
Md. Kamrul Hasan ◽  
Takashi S. T. Tanaka ◽  
Md. Rostom Ali ◽  
Chayan Kumer Saha ◽  
Md. Monjurul Alam
Keyword(s):  
Developing Countries ◽  
Real Time ◽  
Economic Performance ◽  
Net Present Value ◽  
Satellite System ◽  
Cost Ratio ◽  
Great Opportunity ◽  
Real Time Kinematic ◽  
Combine Harvesters ◽  
Asian Developing Countries

To reduce human drudgery and the risk of labor shortages in the Asian developing countries, the appropriate introduction of agricultural machinery, especially combine harvesters, is an urgent task. Custom hiring services (CHSs) are expected to contribute to making paddy harvesters prevalent in developing countries; however, the economic performance has been rarely quantified. The study was carried out to precisely evaluate the machine performance attributes of medium and large combine harvesters using the real-time kinematic (RTK) global navigation satellite system (GNSS) and to estimate the economic performance of CHSs of paddy harvesters in Japan, as a typical case of Asian countries. The financial profitability was evaluated by four major indicators: net present value, benefit–cost ratio, internal rate of return, and payback period. The financial indicators showed that both types of harvester could be considered financially viable. Thus, the investment in combine harvesters can be highly profitable for CHS business by a local service provider and custom-hire entrepreneur, providing a great opportunity to use a combine harvester without initial investment by general farmers. The findings demonstrated the high feasibility of CHSs of paddy harvesters in Japan, while they highlighted that further study is needed to estimate the feasibility of CHS in the other Asian developing countries.

scholarly journals High-Accuracy Real-Time Kinematic Positioning with Multiple Rover Receivers Sharing Common Clock

2021 ◽  
Vol 13 (4) ◽  
pp. 823
Author(s):  
Lin Zhao ◽  
Jiachang Jiang ◽  
Liang Li ◽  
Chun Jia ◽  
Jianhua Cheng
Keyword(s):  
Real Time ◽  
Ambiguity Resolution ◽  
Temporal Stability ◽  
Estimation Method ◽  
Satellite System ◽  
Integer Ambiguity ◽  
Dual Frequency ◽  
Kinematic Positioning ◽  
Real Time Kinematic ◽  
Satellite Visibility

Since the traditional real-time kinematic positioning method is limited by the reduced satellite visibility from the deprived navigational environments, we, therefore, propose an improved RTK method with multiple rover receivers sharing a common clock. The proposed method can enhance observational redundancy by blending the observations from each rover receiver together so that the model strength will be improved. Integer ambiguity resolution of the proposed method is challenged in the presence of several inter-receiver biases (IRB). The IRB including inter-receiver code bias (IRCB) and inter-receiver phase bias (IRPB) is calibrated by the pre-estimation method because of their temporal stability. Multiple BeiDou Navigation Satellite System (BDS) dual-frequency datasets are collected to test the proposed method. The experimental results have shown that the IRCB and IRPB under the common clock mode are sufficiently stable for the ambiguity resolution. Compared with the traditional method, the ambiguity resolution success rate and positioning accuracy of the proposed method can be improved by 19.5% and 46.4% in the restricted satellite visibility environments.

APLICAÇÃO DE GEOTECNOLOGIAS NA ANÁLISE DE VIABILIDADE TÉCNICA E ECONÔMICA DO PROJETO DE IMPLANTAÇÃO DO IFMA - CAMPUS ITAQUI-BACANGA.

2021 ◽  
Vol 14 (2) ◽  
pp. 105
Author(s):  
Maelckson Bruno Barros Gomes ◽  
André Luis Silva Santos
Keyword(s):  
Real Time ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Real Time Kinematic ◽  
Global Navigation ◽  
Global Navigation Satellite

<p class="04CorpodoTexto">Este artigo tem por objetivo aplicar geotecnologias para obtenção de informações planialtimétricas a fim de avaliar a viabilidade de implantação do campus Centro Histórico/Itaqui-Bacanga do IFMA. Considerando que para realização de levantamento por métodos tradicionais é recomendado que seja realizado o destocamento e a limpeza do terreno previamente, avaliou-se a realização do levantamento planialtimétrico a partir de um par de receptores <em>Global Navigation Satellite System</em> (GNSS) pelo método <em>Real Time Kinematic</em> (RTK) pós processado e também a partir da realização de levantamento fotogramétrico, utilizando aeronave remotamente pilotada (ARP), popularmente conhecida como drone. Esta análise permitiu demonstrar que o aerolevantamento com a ARP pode ser aplicado na concepção inicial de um projeto de engenharia, conforme classificação do Tribunal de Contas da União (TCU) para níveis de precisão, pois obteve-se uma diferença orçamentária de 19% entre os projetos elaborados a partir das duas geotecnologias.</p><div> </div>

Impact of remittances on economic performance in consideration of institutional quality

2020 ◽  
Vol 47 (3) ◽  
pp. 479-507
Author(s):  
Surya Nepal ◽  
Sae Woon Park ◽  
Sunhae Lee
Keyword(s):  
Economic Growth ◽  
Developing Countries ◽  
South Asia ◽  
Central Asia ◽  
Financial Development ◽  
Economic Performance ◽  
Institutional Quality ◽  
Content Type ◽  
The Impact ◽  
Asian Developing Countries

PurposeThe purpose of this paper is to empirically assess the impact of remittances on the economic performance of the 16 Asian developing countries, taking account of their institutional qualities.Design/methodology/approachA panel of 16 Asian developing countries (Central Asia, South Asia, and ASEAN) over the period of 2002–2016 is employed in the analysis. To assess the impact of remittances on economic performance in consideration of institutional quality, OLS estimates as well as GMM are used.FindingsThe effect of remittances on economic growth is statistically significant. In addition, they also impact economic growth when they interact with institutional or financial development variables. For the long-run growth process of Central Asian, South Asian, and ASEAN countries, a sound and smooth institutional framework appears to be indispensable. Also, it was found that more fragile economies tend to achieve bigger growth than less fragile economies, as this kind of growth is triggered by more remittances flowing into fragile economies. However, the impact of remittances on growth does not depend on the level of ICT. FDI and financial development have positive impact on growth.Research limitations/implicationsThere are limitations to this research as well. Due to the unavailability of data, several countries had to be removed from this study. The cost of sending money might be an important variable for this study. However, the data on this variable from reliable sources are almost impossible to gather. Therefore, this variable is also not included in this research. The savings from remittances when intermediated through formal financial channels will, in fact, produce a positive allocation and distribution of resources that may eventually become an important source of growth. However, one precondition for larger and greater growth is that remittances need to be well and properly utilized by the financial sector. Therefore, quality institutions should be formed first, which can facilitate investment activities and make the flow of remittances more convenient.Originality/valueThis paper exclusively considers the case of Asian developing countries (Central Asia, South Asia, and ASEAN) to assess the impact of remittances on the economic performance of these countries, with special consideration of the interaction effects of remittances and institutional quality in these emerging Asian economies. The previous studies on the effect of remittances on growth do not conform to one concrete conclusion. This study is undertaken in a bid to get the best possible result on the impact of remittances on the growth of the selected countries, majority of which attract substantial chunk of remittances into their economies.

A Model for Combined GPS and BDS Real-Time Kinematic Positioning using one Common Reference Ambiguity

2018 ◽  
Vol 71 (4) ◽  
pp. 1011-1024 ◽  
Author(s):  
Rui Tu ◽  
Jinhai Liu ◽  
Rui Zhang ◽  
Pengfei Zhang ◽  
Xiaochun Lu
Keyword(s):  
Real Time ◽  
Global Positioning System ◽  
Carrier Phase ◽  
Satellite System ◽  
Phase System ◽  
Combined Model ◽  
Common Reference ◽  
Beidou Navigation Satellite System ◽  
Real Time Kinematic ◽  
Global Positioning

This paper proposes a model for combined Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) Real-Time Kinematic (RTK) positioning. The approach uses only one common reference ambiguity, for example, that of GPS L1, and estimates the pseudo-range and carrier phase system and frequency biases. The validations show that these biases are stable during a continuous reference ambiguity period and can be easily estimated, and the other estimated double-differenced ambiguities, such as those of GPS L2, BDS L1, and BDS L2, are not affected. Therefore, our approach solves the problems of a frequently changing reference satellite. In addition, because all the carrier phase observations use the same reference ambiguity, a relationship is established between the different systems and frequencies, and the strength of the combined model is thus increased.

scholarly journals Comparative economic performance of traditional and modernised fishmeal units in Veraval, Gujarat

2017 ◽  
Vol 64 ◽  
Author(s):  
V. Chandrasekar ◽  
P. Jeyanthi ◽  
Nikitha Gopal
Keyword(s):  
Economic Performance ◽  
Agricultural Sector ◽  
Net Present Value ◽  
Fish Meal ◽  
Modern Method ◽  
Raw Material ◽  
Cost Ratio ◽  
Benefit Cost Ratio ◽  
Benefit Cost

Fish meal is an important feed ingredient produced from trash and low value fishes and is widely used in the poultry, aquafeed and agricultural sector. In addition to traditional sun dried product, modern fish meal is produced by modern fish meal plants. This paper presents a comparison of economic performance of fish meal units adopting the traditional and modern methods of fish meal production in Veraval, Gujarat. The study was conducted among 12 fish meal plants operating in Veraval. In the traditional method, the raw material is sourced from and nearby places within the state which is sun dried and then ground to produce fish meal. In modern fish meal units, through a mechanised production line, raw fish is steam-cooked, dried and finally ground to produce fish meal. Quality of the fish meal produced in the modernised units was found to be superior as compared to traditional fish meal. While sun dried fish meal fetches `20-30 kg-1, the fish meal produced in modern units is sold at `50-70 kg-1. Even though the initial investment and operational cost, which includes raw material, labour and other overheads is more in the modern method, the price realisation is almost double per unit of the product and the quality of the fish meal is also better than the traditionally produced one. The benefit cost ratio and net present value for modern method was also estimated to be higher.

scholarly journals Technical and economic performance of combined harvester in farmers’ field

2015 ◽  
Vol 40 (2) ◽  
pp. 291-304 ◽  
Author(s):  
MA Hossain ◽  
MA Hoque ◽  
MA Wohab ◽  
MA M Miah ◽  
MS Hassan
Keyword(s):  
Economic Performance ◽  
Field Tests ◽  
Spare Parts ◽  
Primary Data ◽  
Cost Ratio ◽  
Benefit Cost Ratio ◽  
Technical Performance ◽  
Combine Harvester ◽  
Combine Harvesters ◽  
Benefit Cost

Labour scarcity, harvesting loss, timely harvesting and harvesting cost are crucial in rice and wheat harvesting in Bangladesh. Combine harvester is a newly introduced harvesting machine in Bangladesh. This study was undertaken to evaluate the technical and economic performance of combine harvester available in farmers? field and farmer?s perception regarding the use of combine. Field tests of two new (CLASS andDaedong) and two refresh (Kukje and Anower) combine harvesters were conducted for harvesting rice and wheat in the farners? field of Jessore, Pabna,Dinajpurand Thakurgaon districts during 2011-12. Primary data were collected from 30 adopter and 30 non-adopter farmers from each district of Bogra, Rangpur, Dinajpur and Thakurgaon through direct interviewingduring 2012-13. Information was also collected from different combine harvester traders available in Bangladesh. Average time, cost and grain saving by combine harvester over manual methods were 97.50, 35.00 and 2.75%, respectively. Benefit cost ratio of CLASS, Daedong, Kukje and Anower combine harvesters were found to be 2.68, 2.11, 2.29 and 2.70, respectively. The payback periods of refresh combine harvesters were lower than the new combine harvester. There were some mechanical problems observed in refresh combine harvesters during field operations. New harvester was observed almost trouble free and popular to the famers. Scarcity of spare parts and mechanic service were the main problems for repair and maintenance of the combine harvesters in farm level. Considering the technical performance of combine harvester and demand of the farmers, new combine harvester may be introduced in commercial basis in Bangladesh.Bangladesh J. Agril. Res. 40(2): 291-304 June 2015

scholarly journals Construcción de la superficie hidrográfica de referencia vertical para las bahías de Buenaventura y Málaga, Pacífico colombiano

2018 ◽  
pp. 53-69 ◽  
Author(s):  
Merly Constanza Álvarez Machuca ◽  
Diego Armando Pulido Nossa ◽  
Leidy Janeth Solano Trullo ◽  
Fernando Oviedo Barrero
Keyword(s):  
Real Time ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Geodetic System ◽  
Real Time Kinematic ◽  
Global Navigation ◽  
Global Navigation Satellite

El presente artículo define la ruta metodológica usada en el proyecto “Red Hidrográfica de Referencia Vertical para los principales puertos marítimos Colombianos”, durante la generación del marco vertical de referencia denominado “Superficie Hidrográfica de Referencia Vertical (SHRV2016)” para las bahías de Buenaventura y Málaga en el Pacífico Colombiano, a partir de tres componentes principales: la determinación matemática de datums verticales asociados a registros históricos de nivel de agua, el establecimiento de una red de vértices geodésicos de primer orden, y la medición de alturas en la superficie del mar con referencia al elipsoide WGS84 (World Geodetic System), empleando receptores del sistema GNSS (Global Navigation Satellite System) en modo diferencial RTK (Real Time kinematic). Los puntos de referencia en tierra fueron utilizados para dar el control vertical de precisión hacia los datums en el agua, y a su vez para la instalación de receptores base GNSS encargados de enviar las correcciones diferenciales en tiempo real durante la medición de alturas en la superficie del mar; Estas mediciones junto a la densificación de datums verticales calculados para la zona, constituyeron la base en la elaboración de la SHRV2016, modelo que con una resolución espacial de 500 metros, refiere al elipsoide WGS84 los datums verticales de nivel de agua, y que además de estandarizar las mediciones que realizan los diferentes usuarios en las aguas jurisdiccionales relativas a un datum vertical; permite aprovechar las ventajas de la tecnología GNSS para realizar la medición y corrección de nivel de agua en tiempo real con el menor grado de incertidumbre posible durante la ejecución de levantamientos hidrográficos, optimizando tiempo, calidad y recursos, especialmente en lugares como las Bahías de Buenaventura y Málaga, donde el régimen de marea hace compleja la actividad de corrección debido a la variabilidad en rango y fase propia del sector, lo cual obliga a instalar múltiples estaciones mareográficas, realizar tareas de topografía y geodesia en lugares de difícil acceso, y esperar al termino del levantamiento hidrográfico para incluir los registros de las estaciones en la corrección final de las profundidades. En un mediano plazo, las SHRV permitirán la generación de un modelo completo de referencia de los datums de marea hacia el elipsoide, que abarque completamente los litorales y regiones insulares del país, hasta los límites del mar territorial, gracias a la combinación con datos de altimetría satelital e instrumentos de observación mar adentro como boyas GPS, que permitan la correcta fusión con los modelos generados a nivel local en cada una de las bahías y puertos.

scholarly journals Análise comparativa entre métodos de determinação de desníveis: Nivelamento geométrico e posicionamento em tempo real (RTK)

2019 ◽  
Vol 3 (1) ◽  
pp. 75
Author(s):  
Zuleide Alves Ferreira ◽  
Jonathas Pereira Rabêlo ◽  
Lucas Elias Oliveira Borges ◽  
Matheus Gabriel Barbosa Cunha Gomes ◽  
Gustavo Marra Carrilho de Castro
Keyword(s):  
Real Time ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Real Time Kinematic ◽  
Global Navigation ◽  
Global Navigation Satellite

<p class="SitioNovoResumo">A altitude de um local consiste na distância vertical entre determinado ponto na superfície terrestre e o nível médio dos mares, podendo ser determinada por diversos métodos. Devido ao uso crescente de novas tecnologias relacionadas ao Sistema de Navegação Global por Satélite (<em>Global Navigation Satellite System - GNSS</em>) na determinação da posição geográfica, inclusive para a determinação de altitudes, este trabalho tem como principal objetivo comparar dados obtidos através de nivelamento geométrico e de posicionamento em tempo real (<em>Real Time Kinematic - RTK</em>). O trabalho de campo foi realizado na cidade de Palmas – TO, onde para o levantamento executado pelo método RTK foram utilizados dois pares de receptores GNSS modelo Hiper II da fabricante Topcon, e para o nivelamento geométrico, foi utilizado um nível digital modelo Sprinter 250M da fabricante Leica Geosystems. Após o nivelamento e contranivelamento dos pontos, foi identificado erro altimétrico de 4 milímetros. Comparando-se os resultados obtidos, foi possível verificar que a média das diferenças entre as altitudes obtidas pelos dois métodos foi de 10 milímetros, sendo o desvio padrão dessas diferenças igual a 5 milímetros, caracterizando a amplitude amostral entre altitudes de apenas 21 milímetros. Deste modo, os resultados demonstram que a determinação da altitude pelo posicionamento em tempo real (RTK) apresentou precisão satisfatória atendendo adequadamente à maioria das necessidades da topografia, constatando-se rapidez e eficiência do método RTK também para determinação de desníveis.</p><p class="SitioNovoResumo"><strong>Palavras-chave</strong>: Altitude ortométrica. Nível digital. Topografia. GNSS.</p>

scholarly journals Assessment of Centre National d’Études Spatiales Real-Time Ionosphere Maps in Instantaneous Precise Real-Time Kinematic Positioning over Medium and Long Baselines

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2293 ◽  
Author(s):  
Dariusz Tomaszewski ◽  
Paweł Wielgosz ◽  
Jacek Rapiński ◽  
Anna Krypiak-Gregorczyk ◽  
Rafał Kaźmierczak ◽  
...  
Keyword(s):  
Real Time ◽  
A Priori ◽  
Satellite Orbit ◽  
Satellite System ◽  
Ionospheric Delay ◽  
Reference Station ◽  
Atmospheric Effects ◽  
International Gnss Service ◽  
Real Time Kinematic ◽  
Global Navigation Satellite

Precise real-time kinematic (RTK) Global Navigation Satellite System (GNSS) positioning requires fixing integer ambiguities after a short initialization time. Originally, it was assumed that it was only possible at a relatively short distance from a reference station (<10 km), because otherwise the atmospheric effects prevent effective ambiguity fixing. Nowadays, through the use of VRS, MAC, or FKP corrections, the distances to the closest reference station have been increased to around 35 km. However, the baselines resolved in real time are not as far as in the case of static positioning. Further extension of the baseline requires the use of an ionosphere-weighted model with ionospheric delay corrections available in real time. This solution is now possible thanks to the Radio Technical Commission for Maritime (RTCM) stream of SSR corrections from, for example, Centre National d’Études Spatiales (CNES), the first analysis center to provide it in the context of the International GNSS Service. Then, ionospheric delays are treated as pseudo-observations that have a priori values from the CLK RTCM stream. Additionally, satellite orbit and clock errors are properly considered using space-state representation (SSR) real-time radial, along-track, and cross-track corrections. The following paper presents the initial results of such RTK positioning. Measurements were performed in various field conditions reflecting realistic scenarios that could have been experienced by actual RTK users. We have shown that the assumed methodology was suitable for single-epoch RTK positioning with up to 82 km baseline in solar minimum (30 March 2019) mid and high latitude (Olsztyn, Poland) conditions. We also confirmed that it is possible to obtain a rover position at the level of a few centimeters of precision. Finally, the possibility of using other newer experimental IGS RT Global Ionospheric Maps (GIMs), from Chinese Academy of Sciences (CAS) and Universitat Politècnica de Catalunya (UPC) among CNES, is discussed in terms of their recent performance in the ionospheric delay domain.

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