International Journal on Advanced Science, Engineering and Information Technology
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Structural Evaluation and Strengthening Strategy of the Law Faculty Hall Building in Andalas University, Padang, Indonesia
Get PDFThe Law Faculty Hall building is one of the composite steel-concrete building structures in Andalas University, Padang, Indonesia. This building was designed according to the old Indonesian seismic code (SNI 1726-2002). The building was first constructed in 2006. However, it cannot be completed in the year due to the lack of the university budget. In 2012, the revised seismic code (SNI 1726-2012) was published, so evaluating the building structure should be carried out according to the revised code. The building's analysis results based on SNI 1726-2012 show that the existing building could not carry the combination of loads acting on the building structure. Therefore, the building should be strengthened before continuing the construction to meet the new performance-based seismic design techniques' requirements. In this study, there are three strengthening methods recommended and analyzed: (a) Installment of inverted V-type steel bracing (IWF 200.100.5.5.8) to the structural frames; (b) Increase of the web thickness of the IWF beams; and (c) Addition of the longitudinal steel bar (4 D10) and shear reinforcement (Ø8-150mm) to the composite beams. The building performance is evaluated in terms of the structural elements' load-bearing capacity, story drifts, and lateral displacements. The results show that all the strengthening methods improve the building's structural capacity to resist the applied loads. Therefore, reinforcement bars to the composite beams were recommended as the best method to strengthen the building due to cost-effectiveness and ease installed
Segmented Network Architecture for Promoting High Availability in Fog Computing through Middleware
Get PDFThis paper proposes an architecture for deploying applications on a fog computing environment by adding another layer of fog nodes in a network segment that gains high software application availability. The conventional fog computing architecture would permanently shift the storage, applications, and data from cloud servers to fog nodes, thus reducing the dependency on the cloud. As a result, fog nodes are burdened with the task previously done by cloud servers and have become “mini cloud servers.†Instead of permanently shifting the tasks from cloud servers to fog nodes, the proposed architecture would only do the shifting, when necessary, like if an internet outage. Additionally, this research also introduced the middleware application that acts as a detector and replacement if service outage so that the availability of the services is not interrupted, especially during the internet outage, by adding another layer of fog node in a network segment. The computational process occurs between end-users and the fog nodes without having to rely on cloud servers. An experiment was conducted to test the performance of the proposed architecture. From the experiment, it can be concluded that the deployment of fog nodes in a segmented network is possible and able to increase the availability of data and services if an internet outage
Collective Action in Communities Exposed to Recurring Hazards: The Camp Fire, Butte County, California, November 8, 2018
Get PDFWildfires constitute an increased risk for California, with the frequency, size, and scale of extreme events and ensuing losses escalating year by year. This article presents a case study of the Camp Fire, Butte County, California, on November 8, 2018. The event exceeded the parameters of prior emergency planning and led to the loss of 85 lives, the deadliest wildfire in California’s history. The study’s objective is to identify gaps in the information flow within and among actors that led to this outcome and to propose more robust strategies that would enable communities to manage wildfire risk sustainably. Data were collected through documentary analysis of existing emergency plans, policies, and protocols; field site visits to the damaged area; attendance at the Paradise Town meeting; and semi-structured interviews with emergency officials who had responsibility for managing the event and residents of the damaged area. A unique combination of highly risky conditions compelled the urgent evacuation of the entire Town of Paradise when emergency personnel was committed to fire suppression in a neighboring community, leaving residents of Paradise to manage their evacuation. Communications failed; regional communities, not alerted, continued standard traffic patterns, creating a massive slowdown in evacuation from Paradise. Key insights from this study include: 1) the need to model wildfire as a regional event; 2) informed residents of communities at risk act collectively to protect the community as a whole; and 3) interaction of science, technology, and human organizations create an interdisciplinary science for managing wildfire
Teacher's Digital Competencies. A Systematic Review in the Latin-American Context
Get PDFCurrently, more than 290 million students in the world are not attending classes due to the pandemic caused by COVID-19. In this sense, many educational centers have adapted classroom teaching to a non-classroom setting in response to the crisis. However, the change of modality from face-to-face to virtual education cannot suppose only a decision in which it is intended to replace the first one using some computer tools as video conferences. With this preamble, the need to systematically map digital competencies in Latin American higher education teachers raises since there are no records of the status of teacher's digital competencies in this part of the world before the pandemic. Therefore, this work examines the scientific literature published in the Web of Science, Scopus, ACM, IEEE, and Science Direct databases from 2004 until 2019. The Kitchenham method applied for the systematic mapping allowed determining quantitative and qualitative results such as year of publication and documentary sources with the most significant number of papers. The main contribution of this research is the areas found of teachers' digital skills that are considered relevant in the Latin American context and its differences with other models. Finally, a discussion of the results and conclusions serves as a starting point for future research in other geographic areas and preliminary information to determine teachers' training needs to face the crisis
Characterization of Fire Severity in the Moroccan Rif Using Landsat-8 and Sentinel-2 Satellite Images
Get PDFForest ecosystems are exposed increasingly to a variety of human activities and accentuated by climate change. With its Mediterranean climate, Northern Morocco is very hot, which exposes forests to widespread fires. This work aims at the delineation of wildfires and the spectral characterization of burnt vegetation as well as the characterization of the fire severity in the North of Morocco by using Landsat-8, Sentinel-2 spectral data, and topographic data. The methods used include the derivation of wildfires spectral indices and the computation of topographic parameters (elevation, slope, exposure) from SRTM and PALSAR digital elevation models. Then, the Spectral Angle Mapper (SAM) classification was used to map forest fires' severity. Furthermore, we have compared the severity classes obtained from the SAM method applied to Landsat 8 and Sentinel 2 data, with different spectral indices specialized in detecting wildfires, on the one hand, and topographic data, on the other hand. Results showed that MIRBI and NBR indices allow a better characterization of burned areas than BAI index. For its part, SAM classification provides a fair characterization of the severity classes of burnt forests. It has also been shown that the MIRBI index and sun exposure are strongly correlated with severity classes. The obtained maps show the spatial heterogeneity of burns severity and how they interact with topography. These maps may help land resource managers and fire officials predict areas of potential fire hazards and study vegetation regrowth areas after fires
Identification of Micro-Earthquake Hypocenters using Geiger and Coupled Velocity-Hypocenters Methods
Get PDFThe accuracy location of hypocenter is needed to determine the subsurface character beneath a geothermal area. The study used 73 micro-earthquake events; each micro-earthquake event was classified based on the time difference between the P and S waves (ts-tp) that had values ≤ 3seconds, the magnitude of micro-earthquake ≤ 3SR and each micro-earthquake event was recorded at least by 3 observer stations. We inverted selected P and S travel times from 11-unit seismic stations on X geothermal area. The initial hypocenter location was determined using Geiger method. The result of the Geiger method's initial hypocenter location was then used as the input to determine the accurate hypocenter location in the following method, Coupled Velocity-Hypocenters method. Other parameters were also used on this second method, including hypocenter location, 1-D velocity model, origin time, vp/vs ratio, zshift and the station correction. The distribution of hypocenter locations of micro-earthquakes obtained using the second method was better than the results from Geiger method. This result is supported by the Coupled Velocity-Hypocenters average RMS error value, which was smaller, only 0.19 seconds, compared to the Geiger method, which had an average RMS error of 0.74 seconds. The hypocenter location of the relocation was more clustered in the reservoir area, precisely in the production well, and in the heat source area. The hypocenter location in the production well area indicates fluid flow through the fracture from the permeable zone
Treatment of Produce Water with a Combination of Electrocoagulation with Iron (Fe) Electrodes and Adsorption Using Silica and Activated Carbon
Get PDFProduction, the oil and gas industry, has a problem with an enormous volume of liquid waste, and 80% of the liquid waste produced is water, which is called produced water. This water differs from water because it contains dangerous chemicals and other elements in oil and gas. In this study, an adsorption process followed the electrocoagulation process using Iron electrodes with voltage variations of 3, 6, 9, and 12V using silica sand from bottom ash and active carbon from a coconut shell. It proposed the combination of these processes as an alternative method for treating produced water. It carries this combination method out in a continuous reactor series where sampling is done at the 30, 60, 90, 120, and 150 minutes. The results of the study show that the highest decrease in oil and grease (98.14%) from the initial content of 377 Mg/L becomes 7 Mg/L, COD (97.39%) from the initial content of 430.25 Mg/L to 11.24 Mg/L, TDS (91, 19%) from the initial content of 12670 Mg/L to 989 Mg/L, Ammonia (69.18%) from the initial content of 17.71 Mg/L to 5.46 Mg/L, Alkalinity (92.84%) of the initial content 317.86 Mg/L to 7 Mg/L, Total Hardness (93.74%) from the initial content of 201.84 Mg/L to 12.63. The best conditions are to get at 12V voltage for 150 minutes to reduce produced water to meet quality standards based on Minister of Environment Regulation no. 19 of 2010
Analyzing the Relationship between the Dow Jones Index and Oil Prices Using the ARIMAX Model
Get PDFThe values prediction of the Dow Jones index is essential in the global financial markets systems. The index provides a clear vision of what is happening in the market as a whole. Hence, it offers integrated information on that index to stipulate forecasts characterized as efficient for investors and shareholders. In this study, the ARIMAX model was used to predict the daily Dow Jones index values from 1/1/2020 to 1/ 5/2020 (the spread of COVID-19), considering Brent crude's effect daily prices as an external factor. The Dow Jones Index daily price prediction process went through several stages. The first stage is the time series stationary test phase through the Augmented Dickey-Fuller test. The second stage is achieving stationary by taking the first difference, passing through the stage of identifying the model, and determining the rank based on criteria (AIC), (BIC), (RMSE). The preference of the model was shown in ARIMA (0,1,2) for the Dow Jones index series. The ARIMA (1,1,0) model was shown for crude price Brent series and determining the order of the transfer function of the ARIMAX model. The comparison stage between the models ARIMA (0,1,2) and ARIMAX(3,1,1)(0,0,1) by residuals scatter plot and (Ljung-Box) test for each model. The results demonstrated the superiority of the ARIMAX model over the ARIMA model. The daily Dow Jones Index values were predicted based on corresponding Brent crude prices according to the ARIMAX (3,1,1) (0,0,1) model. The researchers did not find substantial differences in the index’s behavior, except for a slight decrease in the index's value
A Comparative Study on the Effect of Eccentric Viewing Training Using PC and VR Contents
Get PDFThe purpose of this study is to develop PC Eccentric Viewing Training (EVT) and VR EVT Content, to conduct experiments to verify the validity of contents first through non-disabled people, and to compare and analyze VR and PC contents. Both PC and VR contents were produced with UNITY. This content model assumes that reducing inaccurate saccades by eliminating eye movement helps improve reading accuracy. In addition, the two contents are implemented in the same way as VR and PC versions. The content consists of two steps, both PC and VR. The purpose of the content is to improve reading accuracy by improving the fixation stability of Preferred Retinal Locus (PRL) and reducing inaccurate Saccades. The experiment consisted of 12 persons (within maximum visual acuity less than 0.3), and they were assigned to the PC Content group and VR Content group. The experiment was conducted a total of 5 times, except for two weeks, which is the time to adapt PRL. The experimental results showed that the reading accuracy of the VR content group was higher. In addition, When comparing VR contents with PC contents, the group that conducted the training through PC contents showed a decrease in concentration as it progressed to 1-3 steps, and the score distribution also fell overall. In conclusion, the study compared VR and PC contents, and the effectiveness of contents was verified through experiments
Regulation of Nonlinear Chemical Processes with Variable Dead Time: a Generalized Proportional Integral Controller Proposal
Get PDFThis work shows the development and application of a Generalized Proportional Integral (GPI) Controller based on a First Order Plus Dead Time (FOPDT) approximation for an industrial chemical process. GPI control is a relatively recent advancement in automatic control. Nowadays, several enhancements with the GPI technique come from integral reconstructions of the system states. Chemical engineering processes present numerous challenging control problems, including nonlinear dynamic behavior. Â GPI can become a new option to consider in industrial applications since, along with the arrival of Industry 4.0, there are many improvements in computers and automation architecture to implement controller algorithms. The new controller's functionality shows significant accessibility of mathematical and logical potential. A comparison between the GPI and a PID controller is made under the same conditions to evaluate their performance. After carrying out some tests, the GPI shows better performance and a smoother controller action when applied to the mixing tank with a variable delay than the PID. Performance indexes as Integral Square Error (ISE) for evaluating the Output Variable and Control Effort Total Variation (TVu) for evaluating the control action are used to measure performance. Finally, designing an appropriate controller like the GPI that recognizes and incorporates nonlinearities is required for chemical processes. Simulations were developed using Simulink-MATLAB