J. Cunha, F. Nogueira, R. Branco, J. Costa, P. Prates, F. Berto, F. Antunes
This paper presents a methodology to predict the fatigue lifetime in notched geometries subjected to multiaxial loading on the basis of the cumulated strain energy density. The modus operandi consists of defining an energy-based fatigue master curve that relates the cumulated strain energy density with the number of cycles to failure using standard cylindrical specimens tested under low-cycle fatigue conditions. After that, an elastic-plastic finite-element model representative of the material behaviour, notched geometry and multiaxial loading scenario is developed and used to account for the strain energy density at the crack initiation site. This energy is then averaged using the Theory of Critical Distances and inserted into the energy- based fatigue master curve to estimate the lifetime expectancy. Overall, the comparison between the experimental and predicted fatigue lives has shown a very good agreement. Keywords: Multiaxial fatigue, Fatigue life prediction, Strain energy density
{"title":"A Mixed Experimental-numerical Energy-based Approach for Fatigue Life Assessment in Notched Samples under Multiaxial Loading","authors":"J. Cunha, F. Nogueira, R. Branco, J. Costa, P. Prates, F. Berto, F. Antunes","doi":"10.18502/keg.v5i6.7107","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7107","url":null,"abstract":"This paper presents a methodology to predict the fatigue lifetime in notched geometries subjected to multiaxial loading on the basis of the cumulated strain energy density. The modus operandi consists of defining an energy-based fatigue master curve that relates the cumulated strain energy density with the number of cycles to failure using standard cylindrical specimens tested under low-cycle fatigue conditions. After that, an elastic-plastic finite-element model representative of the material behaviour, notched geometry and multiaxial loading scenario is developed and used to account for the strain energy density at the crack initiation site. This energy is then averaged using the Theory of Critical Distances and inserted into the energy- based fatigue master curve to estimate the lifetime expectancy. Overall, the comparison between the experimental and predicted fatigue lives has shown a very good agreement. \u0000Keywords: Multiaxial fatigue, Fatigue life prediction, Strain energy density","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127667657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also crucially important. Laboratory measurements are presented for several performance aspects of Wi-Fi IEEE 802.11a54 Mbps WPA2 point-to-point and four node point-to-multipoint links. Our study contributes to performance evaluation of this technology under WPA2 encryption, using available equipment (HP V-M200 access points and Linksys WPC600N adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet length, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to corresponding results for Open links. Conclusions are drawn about the comparative performance of the links. Keywords: Wi-Fi, WLAN, IEEE 802.11a, Wireless network laboratory performance, Multi-Node WPA2 links
{"title":"Performance Investigations of IEEE 802.11 a54 Mbps WPA2 Laboratory Links","authors":"J. P. Carvalho, H. Veiga, C. Pacheco, A. Reis","doi":"10.18502/keg.v5i6.7031","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7031","url":null,"abstract":"The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also crucially important. Laboratory measurements are presented for several performance aspects of Wi-Fi IEEE 802.11a54 Mbps WPA2 point-to-point and four node point-to-multipoint links. Our study contributes to performance evaluation of this technology under WPA2 encryption, using available equipment (HP V-M200 access points and Linksys WPC600N adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet length, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to corresponding results for Open links. Conclusions are drawn about the comparative performance of the links. \u0000Keywords: Wi-Fi, WLAN, IEEE 802.11a, Wireless network laboratory performance, Multi-Node WPA2 links","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115983279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. C. Duarte, A. Veloso, A. Ramos, D. Ferreira, M. P. Simões
The irrigation patterns in two peach orchards, located in the central eastern region of Portugal, called “Beira Interior”, and the effect of different amounts of irrigation on the total production and fruit quality were evaluated. The experiment was conducted in 2016, in two different orchards, and included three treatments correspondent to three different flow rates per tree: 8, 12 and 16 l/hour. The water balance, which included the water supplied by rain and irrigation and the crop evapotranspiration, was developed. At harvest, crop production, pulp firmness and percentage of the total soluble solids were evaluated. There were no significant differences between treatments in the average production per tree. However, in one of the orchards production increased with the volume of irrigation. In the same orchard, fruit firmness decreased with the increasing water supply. Total soluble solids had decreased with the increasing water supply in both orchards, probably as a consequence of the dilution effect due, directly, to the water incorporated in the fruits, or, indirectly, to the larger fruits produced by the trees that were irrigated more. In general, the treatments used in this study as well as in the farmers’ practices, the supplied water was in deficit, but the farmers tend empirically to follow closely the evolution of evapotranspiration. Keywords: Deficit irrigation, Peach tree, Production, Total soluble solids, Fruit firmness
{"title":"Deficit Irrigation in Peach Orchards under Water Scarcity Conditions","authors":"A. C. Duarte, A. Veloso, A. Ramos, D. Ferreira, M. P. Simões","doi":"10.18502/keg.v5i6.7092","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7092","url":null,"abstract":"The irrigation patterns in two peach orchards, located in the central eastern region of Portugal, called “Beira Interior”, and the effect of different amounts of irrigation on the total production and fruit quality were evaluated. The experiment was conducted in 2016, in two different orchards, and included three treatments correspondent to three different flow rates per tree: 8, 12 and 16 l/hour. The water balance, which included the water supplied by rain and irrigation and the crop evapotranspiration, was developed. At harvest, crop production, pulp firmness and percentage of the total soluble solids were evaluated. There were no significant differences between treatments in the average production per tree. However, in one of the orchards production increased with the volume of irrigation. In the same orchard, fruit firmness decreased with the increasing water supply. Total soluble solids had decreased with the increasing water supply in both orchards, probably as a consequence of the dilution effect due, directly, to the water incorporated in the fruits, or, indirectly, to the larger fruits produced by the trees that were irrigated more. In general, the treatments used in this study as well as in the farmers’ practices, the supplied water was in deficit, but the farmers tend empirically to follow closely the evolution of evapotranspiration. \u0000Keywords: Deficit irrigation, Peach tree, Production, Total soluble solids, Fruit firmness","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125304251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, technological advances related with the so-called intelligent materials have been exploited for problem solving in many engineering fields. In this regard, shape memory alloys (SMA) seem suitable for medical and engineering applications and many others. These alloys have the ability to return to the original form after an apparently plastic deformation by applying heat and the also ability to perform phase changes with voltage variations under a specific temperature. These properties allow the development of a hysteretic loop with energy dissipation, which can be used as a damping element in a vibratory system. In this paper, a MATLAB algorithm was developed to create an interface with the Ansys® APDLTM software that simulate the dynamic behavior of a SMA. The software is capable to obtain the cyclical behavior of a vibratory mechanical system based on the energy dissipation properties of the SMA. The results show that the free vibration of a mass-damper (alloy) system presents the energy dissipation related in magnitude with the area of the hysteresis loop until the deformation caused by the motion which does not correspond to a voltage required to initiate the (direct) phase transformation of the material, thus reducing the displacement to a constant level. Keywords: SMA, ANSYS APDLTM, Matlab
{"title":"Matlab® Algorithm to Simulate the Dynamic Behavior of an NiTi Alloy through Ansys® APDLTM Models","authors":"J. Hilário, M. Braz-César, C. Andrade, A. Borges","doi":"10.18502/keg.v5i6.7024","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7024","url":null,"abstract":"In recent years, technological advances related with the so-called intelligent materials have been exploited for problem solving in many engineering fields. In this regard, shape memory alloys (SMA) seem suitable for medical and engineering applications and many others. These alloys have the ability to return to the original form after an apparently plastic deformation by applying heat and the also ability to perform phase changes with voltage variations under a specific temperature. These properties allow the development of a hysteretic loop with energy dissipation, which can be used as a damping element in a vibratory system. In this paper, a MATLAB algorithm was developed to create an interface with the Ansys® APDLTM software that simulate the dynamic behavior of a SMA. The software is capable to obtain the cyclical behavior of a vibratory mechanical system based on the energy dissipation properties of the SMA. The results show that the free vibration of a mass-damper (alloy) system presents the energy dissipation related in magnitude with the area of the hysteresis loop until the deformation caused by the motion which does not correspond to a voltage required to initiate the (direct) phase transformation of the material, thus reducing the displacement to a constant level. \u0000Keywords: SMA, ANSYS APDLTM, Matlab","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117235966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plug-In hybrid vehicles have a complex propulsion system management, trying to manage the conventional and electric motorization in the most energy efficient way according to the driving dynamics, topography and battery charge state. In this sense, the aim of this work is to analyze the energy performance of plug-in hybrid vehicles, based on road tests, under real conditions of use, focusing on the management system of the two energy sources present, varying the level of battery charge at the start of the test to visualize the impact of this change. To complement the analysis and in order to better understand the operation of the management system, a methodology for applying the VSP parameter is used, which allows the load state to be approximated according to the vehicle’s operating mode, alternating between the three modes according to the conditions at the time in question, prioritizing the electric motor when the state of charge of the battery is maximum. These results confirm the fact that plug-in hybrid vehicles allow better electricity management due to the diversity of external or internal charging sources, which makes this type of vehicle more efficient and versatile than conventional hybrids, allowing a reduction in fossil fuel consumption and consequently a reduction in the emission of pollutant gases, making this type of vehicle a very competitive alternative in the transport sector in view of the current challenges due to the goals present in the current European regulations. Keywords: Plug-in hybrid vehicles, Energy assessment, Climatization systems, Load support, State of charge
{"title":"Energy Assessment of a Plug-in Hybrid Vehicle Propulsion Management System","authors":"Miguel Campino, N. Henriques, Gonçalo O. Duarte","doi":"10.18502/keg.v5i6.7103","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7103","url":null,"abstract":"Plug-In hybrid vehicles have a complex propulsion system management, trying to manage the conventional and electric motorization in the most energy efficient way according to the driving dynamics, topography and battery charge state. In this sense, the aim of this work is to analyze the energy performance of plug-in hybrid vehicles, based on road tests, under real conditions of use, focusing on the management system of the two energy sources present, varying the level of battery charge at the start of the test to visualize the impact of this change. To complement the analysis and in order to better understand the operation of the management system, a methodology for applying the VSP parameter is used, which allows the load state to be approximated according to the vehicle’s operating mode, alternating between the three modes according to the conditions at the time in question, prioritizing the electric motor when the state of charge of the battery is maximum. These results confirm the fact that plug-in hybrid vehicles allow better electricity management due to the diversity of external or internal charging sources, which makes this type of vehicle more efficient and versatile than conventional hybrids, allowing a reduction in fossil fuel consumption and consequently a reduction in the emission of pollutant gases, making this type of vehicle a very competitive alternative in the transport sector in view of the current challenges due to the goals present in the current European regulations. \u0000Keywords: Plug-in hybrid vehicles, Energy assessment, Climatization systems, Load support, State of charge","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130661032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Santiago Zazo Del dedo, H. Macian-Sorribes, C. Fael, Ana-María Garía-Martín, José-Luis Molina, M. Pulido‐Velazquez
Currently, noticeable changes in traditional hydrological patterns are being observed on the short and medium-term. These modifications are adding a growing variability on water resources behaviour, especially evident in its availability. Consequently, for a better understanding/knowledge of temporal alterations, it is crucial to develop new analytical strategies which are capable of capturing these modifications on its temporal behaviour. This challenge is here addressed via a purely stochastic methodology on annual runoff time series. This is performed through the propagation of temporal dependence strength over the time, by means of Causality, supported by Causal Reasoning (Bayes’ theorem), via the relative percentage of runoff change that a time-step produces on the following ones. The result is a dependence mitigation graph, whose analysis of its symmetry provides an innovative qualitative approach to assess time-dependency from a dynamic and continuous perspective against the classical, static and punctual result that a correlogram offers. This was evaluated/applied to four Spanish unregulated river sub-basins; firstly on two Douro/Duero River Basin exemplary case studies (the largest river basin at Iberian Peninsula) with a clearly opposite temporal behaviour, and subsequently applied to two watersheds belonging to Jucar River Basin (Iberian Peninsula Mediterranean side), characterised by suffering regular drought conditions. Keywords: Causal reasoning, Theorem of Bayes, Temporal dependence propagation, Runoff time series, Water resources management
{"title":"Qualitative Approach for Assessing Runoff Temporal Dependence Through Geometrical Symmetry","authors":"Santiago Zazo Del dedo, H. Macian-Sorribes, C. Fael, Ana-María Garía-Martín, José-Luis Molina, M. Pulido‐Velazquez","doi":"10.18502/keg.v5i6.7106","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7106","url":null,"abstract":"Currently, noticeable changes in traditional hydrological patterns are being observed on the short and medium-term. These modifications are adding a growing variability on water resources behaviour, especially evident in its availability. Consequently, for a better understanding/knowledge of temporal alterations, it is crucial to develop new analytical strategies which are capable of capturing these modifications on its temporal behaviour. This challenge is here addressed via a purely stochastic methodology on annual runoff time series. This is performed through the propagation of temporal dependence strength over the time, by means of Causality, supported by Causal Reasoning (Bayes’ theorem), via the relative percentage of runoff change that a time-step produces on the following ones. The result is a dependence mitigation graph, whose analysis of its symmetry provides an innovative qualitative approach to assess time-dependency from a dynamic and continuous perspective against the classical, static and punctual result that a correlogram offers. This was evaluated/applied to four Spanish unregulated river sub-basins; firstly on two Douro/Duero River Basin exemplary case studies (the largest river basin at Iberian Peninsula) with a clearly opposite temporal behaviour, and subsequently applied to two watersheds belonging to Jucar River Basin (Iberian Peninsula Mediterranean side), characterised by suffering regular drought conditions. \u0000Keywords: Causal reasoning, Theorem of Bayes, Temporal dependence propagation, Runoff time series, Water resources management","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115812104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Planning the development of transport systems, as well as assessing the effects of investment activities in the field of spatial development requires the use of appropriate IT tools enabling an objective assessment of investment intentions. In the field of transport analysis, one such tool is a transport demand model. Reproduction of transport-related processes is the main role of such transport demand model. This applies to both the transport of people and goods, and includes both residential travel and visitors travelling to and within the study area. The description of the process of creation and implementation of transport demands is usually based on the assumptions in the field of places of generation and absorption of travel - i.e. sources and destinations of travel. The generalization of the mathematical description of this phenomenon introduced the concept of transport zones, which are separated homogeneous areas of the study area, as sources and destinations of trips. Practice in the construction and use of transport models indicates that the problem of defining transport zones requires further investigation. Increasingly extensive transport infrastructure data collected in open databases (such as OpenStreets) are encouraging a change in the approach to the problems of constructing transport zones. The current solutions are characterized by a high level of generalization of sources and destinations rather than detailed transport analysis. This article presents the author’s method of dividing the study areas into transport zones based on a uniform hexagonal system, explaining the basic assumptions and evaluating the pros and cons of this proposed system. Keywords: Transport, Demand models, Algorithms
{"title":"Hexagonal Zones in Transport Demand Models","authors":"J. Chmielewski, J. Kempa","doi":"10.18502/keg.v5i6.7025","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7025","url":null,"abstract":"Planning the development of transport systems, as well as assessing the effects of investment activities in the field of spatial development requires the use of appropriate IT tools enabling an objective assessment of investment intentions. In the field of transport analysis, one such tool is a transport demand model. Reproduction of transport-related processes is the main role of such transport demand model. This applies to both the transport of people and goods, and includes both residential travel and visitors travelling to and within the study area. The description of the process of creation and implementation of transport demands is usually based on the assumptions in the field of places of generation and absorption of travel - i.e. sources and destinations of travel. The generalization of the mathematical description of this phenomenon introduced the concept of transport zones, which are separated homogeneous areas of the study area, as sources and destinations of trips. Practice in the construction and use of transport models indicates that the problem of defining transport zones requires further investigation. Increasingly extensive transport infrastructure data collected in open databases (such as OpenStreets) are encouraging a change in the approach to the problems of constructing transport zones. The current solutions are characterized by a high level of generalization of sources and destinations rather than detailed transport analysis. This article presents the author’s method of dividing the study areas into transport zones based on a uniform hexagonal system, explaining the basic assumptions and evaluating the pros and cons of this proposed system. \u0000Keywords: Transport, Demand models, Algorithms","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124621254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hausmannian buildings architecture spreads throughout the city of Paris. These buildings were constructed in the 19th century, being presently centenarians. However, they present several pathologies which prevent their adequate use, moreover, an update regarding users security, sound, thermal and fire requirements is, among others, urgently needed. Additionally, there is presently, in Paris, an increasing demand for hotel rooms. For those previous reasons, Hausmannian buildings are presently submitted to heavy operations related to rehabilitation, strengthening, use change and conservation. In this paper, rehabilitation and strengthening works presently carried out in those buildings are described. This description is the result of a technical survey on several Hausmannian building construction sites which occurred between 2015 and 2018. The knowledge from this study should be very useful for the development of sustainable rehabilitation and strengthening techniques and guidelines, aiming to preserve this important building heritage or similar ones existing in other countries. Keywords: Hausmannian buildings, Rehabilitation, Strengthening, Sustainability
{"title":"Hausmannian Buildings Rehabilitation and Strengthening","authors":"R. Cardoso, A. Paiva","doi":"10.18502/keg.v5i6.7018","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7018","url":null,"abstract":"Hausmannian buildings architecture spreads throughout the city of Paris. These buildings were constructed in the 19th century, being presently centenarians. However, they present several pathologies which prevent their adequate use, moreover, an update regarding users security, sound, thermal and fire requirements is, among others, urgently needed. Additionally, there is presently, in Paris, an increasing demand for hotel rooms. For those previous reasons, Hausmannian buildings are presently submitted to heavy operations related to rehabilitation, strengthening, use change and conservation. In this paper, rehabilitation and strengthening works presently carried out in those buildings are described. This description is the result of a technical survey on several Hausmannian building construction sites which occurred between 2015 and 2018. The knowledge from this study should be very useful for the development of sustainable rehabilitation and strengthening techniques and guidelines, aiming to preserve this important building heritage or similar ones existing in other countries. \u0000Keywords: Hausmannian buildings, Rehabilitation, Strengthening, Sustainability","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123960404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work presents the coder and decoder of block 3B4B with auxiliary channel. The coder 3B4B converts an input 3 bits word in an output 4 bits word. It transmits an equal number of 1’s and 0’s to provide a DC constant component. It increases the transitions number, improves the system quality and security. The objective is also to improve the system potentialities with an auxiliary channel to monitor the communication (alarm). The main channel is real, but the auxiliary channel is fictitious. Keywords: Block codes, Digital systems, Transmission lines
{"title":"Coder and Decoder of Block 3B4B with Auxiliary Channel","authors":"A. Reis, J. F. Rocha, A. Gameiro, J. P. Carvalho","doi":"10.18502/keg.v5i6.7086","DOIUrl":"https://doi.org/10.18502/keg.v5i6.7086","url":null,"abstract":"This work presents the coder and decoder of block 3B4B with auxiliary channel. The coder 3B4B converts an input 3 bits word in an output 4 bits word. It transmits an equal number of 1’s and 0’s to provide a DC constant component. It increases the transitions number, improves the system quality and security. The objective is also to improve the system potentialities with an auxiliary channel to monitor the communication (alarm). The main channel is real, but the auxiliary channel is fictitious. \u0000Keywords: Block codes, Digital systems, Transmission lines","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128675012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In urban areas it is difficult to access natural terrain due to strong human intervention. Therefore, any exposure of the natural terrain is considered an important source of geological and geotechnical data collection. The Geographic Information Systems (GIS) has been responsible to provide great development in geotechnical cartography, particularly in urban environment, using geographic databases and new analysis tools. Our goal is to create a geographical database that will allow and/or improve the elaboration of geotechnical thematic maps, using cartographic data of open platforms combined with free and open source GIS software. In the presented study our focus was related with the identification of the granite alteration degree...Through the geographical database, along with the geological map of the study area, the areas related to the degree of granite alteration were identified and delimited. The data were collected through “Street View” which results from the integration of a specific module in the GIS software (QGIS). The obtained data were validated by direct observation and were photographically recorded. This approach proved to be an effective method, with no significant differences when compared with direct observations. The methods’ limitations are the quality of some “Street View” images, and the existent subjectivity related to the observer in the identification of the degree of alteration of the rocky massif. Its advantage is to reduce the data collection’s time and the possibility of comparing the same place at different time points.
{"title":"Elaboration of Geotechnical Thematic Maps in Urban Areas","authors":"A. Monteiro, L. Pais, C. Rodrigues","doi":"10.18502/keg.v5i5.6908","DOIUrl":"https://doi.org/10.18502/keg.v5i5.6908","url":null,"abstract":"In urban areas it is difficult to access natural terrain due to strong human intervention. Therefore, any exposure of the natural terrain is considered an important source of geological and geotechnical data collection. The Geographic Information Systems (GIS) has been responsible to provide great development in geotechnical cartography, particularly in urban environment, using geographic databases and new analysis tools. Our goal is to create a geographical database that will allow and/or improve the elaboration of geotechnical thematic maps, using cartographic data of open platforms combined with free and open source GIS software. In the presented study our focus was related with the identification of the granite alteration degree...Through the geographical database, along with the geological map of the study area, the areas related to the degree of granite alteration were identified and delimited. The data were collected through “Street View” which results from the integration of a specific module in the GIS software (QGIS). The obtained data were validated by direct observation and were photographically recorded. This approach proved to be an effective method, with no significant differences when compared with direct observations. The methods’ limitations are the quality of some “Street View” images, and the existent subjectivity related to the observer in the identification of the degree of alteration of the rocky massif. Its advantage is to reduce the data collection’s time and the possibility of comparing the same place at different time points.","PeriodicalId":106635,"journal":{"name":"KnE Engineering","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128332127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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