Hasil untuk "Engineering (General). Civil engineering (General)"

Yixian Chen, Sofie De Geeter, Jean Poesen et al.

Gully formation is a significant driver of soil erosion and land degradation worldwide and often leads to important downstream impacts. Nonetheless, our understanding of the global patterns and the factors controlling this process remains limited. Here, we present the first global assessment of gully density's spatial patterns. Using mapped observations from over 17,000 representative study sites worldwide, we trained random forest models that simulate both the susceptibility to gullying at a 1 km2 resolution and the corresponding gully head density (GHD). Through an interpretable machine learning framework, we demonstrate that global GHD patterns result from a combination of environmental factors with non-linear interactions, leading to significant regional variations in the dominant factors controlling GHD. We distinguish between gully hotspots driven primarily by natural factors such as topography, geomorphology, tectonics, pedology or climate and those where land use and land cover play a dominant role. Based on these insights, we identified critical global areas of gully erosion, i.e., hotspots where gully occurrence is likely highly sensitive to anthropogenic drivers. These include the Chinese Loess Plateau, the Ethiopian Highlands, and large parts of the Mediterranean and Sahel regions. Also desert regions are often characterized by high GHDs. However, in these cases, their occurrence is mainly driven by natural factors. The insights we provide are valuable to inform land management and targeted erosion mitigation strategies.

Renato Pereira, José Muralha, Luís Lamas

Este artigo explora a aplicação de métodos probabilísticos na análise da fiabilidade e no dimensionamento do reforço de taludes rochosos sujeitos a mecanismos de rotura planar. O estudo incide no caso de um maciço rochoso intersetado por uma família de descontinuidades paralela à face do talude. O volume com potencial de instabilização é idealizado como um modelo de blocos, para o qual se desenvolve uma formulação em sistemas de componentes. Como termo de comparação, analisa-se igualmente um modelo simplificado que considera o mesmo volume como um bloco único. Os resultados evidenciam a influência da inclinação do plano de deslizamento. Verifica-se que o modelo constituído por múltiplos blocos conduz a índices de fiabilidade inferiores. Contudo, a sua utilização para o dimensionamento probabilístico do reforço tem vantagens apenas para inclinações baixas do plano de deslizamento. A análise sugere ainda que o modelo de blocos múltiplos pode ser adequadamente representado por um modelo simplificado de dois blocos.

Yong Wang, Hongwen He, Yuankai Wu et al.

An effective energy management strategy (EMS) is essential to optimize the energy efficiency of electric vehicles (EVs). With the advent of advanced machine learning techniques, the focus on developing sophisticated EMS for EVs is increasing. Here, we introduce LearningEMS: a unified framework and open-source benchmark designed to facilitate rapid development and assessment of EMS. LearningEMS is distinguished by its ability to support a variety of EV configurations, including hybrid EVs, fuel cell EVs, and plug-in EVs, offering a general platform for the development of EMS. The framework enables detailed comparisons of several EMS algorithms, encompassing imitation learning, deep reinforcement learning (RL), offline RL, model predictive control, and dynamic programming. We rigorously evaluated these algorithms across multiple perspectives: energy efficiency, consistency, adaptability, and practicability. Furthermore, we discuss state, reward, and action settings for RL in EV energy management, introduce a policy extraction and reconstruction method for learning-based EMS deployment, and conduct hardware-in-the-loop experiments. In summary, we offer a unified and comprehensive framework that comes with three distinct EV platforms, over 10  000 km of EMS policy data set, ten state-of-the-art algorithms, and over 160 benchmark tasks, along with three learning libraries. Its flexible design allows easy expansion for additional tasks and applications. The open-source algorithms, models, data sets, and deployment processes foster additional research and innovation in EV and broader engineering domains.

Koki Toyoda, Shunsuke Kimura, Keiichiro Maki et al.

Effective gutta-percha/sealer removal is essential for predictable nonsurgical endodontic retreatment, but the effects of key operational parameters on nickel–titanium rotary removal instruments remain insufficiently understood. This study aimed to examine how varying downward loads and rotational speeds affect the removal efficiency and torque/force generation of the HyFlex Remover. Sixty transparent straight resin canals filled with gutta-percha and AH Plus sealer were prepared using the HyFlex Remover at two rotational speeds (400 and 800 rpm) and three downward loads (2, 3, and 4 N; <i>n</i> = 10/group). The removal rate, calculated using micro-computed tomography, as well as removal time, maximum force, maximum torque, and cumulative torque were recorded and evaluated using two-way analysis of variance with Bonferroni correction (α = 0.05). The removal rate was consistently higher at 400 rpm than at 800 rpm (<i>p</i> < 0.001), while removal time and cumulative torque were greater at 400 rpm (<i>p</i> < 0.001). Maximum torque differed only between the 800-2 N and 800-4 N groups (<i>p</i> = 0.006). Maximum force increased with higher loads (<i>p</i> < 0.001), and at 3 N and 4 N, it was lower at 400 rpm than at 800 rpm (3 N: <i>p</i> = 0.039, 4 N: <i>p</i> < 0.001). Overall, lower downward loads reduced torque but prolonged working time, whereas higher rotational speeds shortened both working time and torque but decreased the removal rate.

Ashraf abdallah, Bara&#039; Al-MISTAREHI, Amir SHTAYAT

Agriculture is a vital component of Egypt's economy; therefore, using Digital Elevation Models (DEMs) in agricultural planning in Egypt has significant benefits regarding water management, site appropriateness assessment, flood risk mitigation, and infrastructure construction. It is also essential for planners to make more informed decisions, optimize resource allocation, and support sustainable farming practices. This research paper investigates the accuracy of obtaining DEM data from four free global models (STRM30, ALOS30, COP30, and TanDEM-X90). The global DEM data has been compared to an actual GNSS-RTK DEM data surveyed onsite for two agricultural block areas in Aswan, the southern Government of Egypt. The two blocks are a part of a national project. For Block I and II, the RMSE of the Model STRM30 was 2.92 m and 3.59 m, respectively, indicating a poorer solution. Regarding accuracy, the ALOS30 model ranks third, reporting an RMSE of 2.58 m for block II and 3.30 m for block I. COP30 has an RMSE value of 1.06 m for blocks I and II and.91 m overall. TanDEM-X90 is the most accurate model in this investigation; block I provided an RMSE of 0.90 m with an SD of 0.58 m (SD95% = 0.38 m). After removing the anomalies, the model's stated RMSE for block II was 0.34 m, with an SD value of 0.62 m and 1.03 m. According to the classification using machine learning algorithms, with an accuracy of 84.7% for block I and 85% for block II, TanDEM-X90 is the best solution.

Syed Bustan Fatima Warsi, Biranchi Panda, Pankaj Biswas

3D Concrete Printing (3DCP) is a growing field of sustainable technology that offers an avenue for rapid industrialisation of the construction industry. Over the years, many non-structural elements have been fabricated by 3D printing, thus demonstrating significant advantages over traditional casting process, including freedom from the need of mold, realisation of complex geometries and reduction of material use etc. However, examples of 3D printed structural parts are still limited with addition of fibres into concrete mixes. The fibres can be incorporated in 3D printed concrete either before mixing or printing; or during the printing. The present study adopted systematic review methodology to recommend effective fibre addition method in terms of mechanical properties of the printed concrete composite. In this review work, an attempt has been made to summarise the effect of different fibres including their type, dosage, entrainment methods, while highlighting the technical challenges and approaches adopted in the past for increasing the fibre dosages, controlling their distribution and orientation. This may save a significant amount of time and resources for the industrial sector for 3D printing high strength fibre reinforced concrete structures.

Jinichi Sakaguchi, Keisuke Nakayama, Katsuaki Komai et al.

Carbon capture and storage due to photosynthesis activities has been proposed as a carbon sink to mitigate climate change. To enhance such mitigation, previous studies have shown that freshwater lakes should be included in the carbon sink, since they may capture as much carbon as coastal areas. In eutrophic freshwater lakes, there is uncertainty about whether the equilibrium equation can estimate the partial pressure of carbon dioxide (pCO2), owing to the presence of photosynthesis due to phytoplankton, and pH measurement error in freshwater fluid. Thus, this study investigated the applicability of the equilibrium equation and revealed the need to modify it. The modified equilibrium equation was successfully applied to reproduce pCO2 based on total alkalinity and pH through field observations. In addition, pCO2 at the water surface was lower than the atmospheric partial pressure of carbon dioxide due to photosynthesis by phytoplankton during strong stratification. The stratification effect on low pCO2 was verified by using the Net Ecosystem Production (NEP) model, and a submerged freshwater plants such as Potamogeton malaianus were found to have high potential for dissolved inorganic carbon (DIC) sequestration in a freshwater lake. These results should provide a starting point toward more sophisticated methods to investigate the effect of freshwater carbon on DIC uptake in freshwater stratified eutrophic lakes.

Iwa Pramudya, Deny Andesta, Hidayat Hidayat

Work accidents have the ability to cause the formation of every work activity. Aspects of work accidents can be caused by machines or aspects of worker negligence. The comfort of workers is highly dependent on the situation and the industrial area. One of the markers that need to be observed is occupational safety and health. So that the industry applies the K3 listed on PT Swadaya Graha which is currently still in a non-HIRARC condition as a basis for mitigation. The HIRARC procedure finds a procedure that starts to ensure the activity after which the source of the hazard is identified, risk assessment, and control over that exists and has the aim of remembering the level of risk associated with a place. From that case, the author thinks it is necessary to carry out an OHS risk assessment using the HIRARC procedure by carrying out research that aims to find out how to analyze the capabilities of hazards that can be carried out and their control on a cnc lathe machine at PT Swadaya Graha . The procedure used is the HIRARC (Hazard Identification Risk Assessment and Risk control) approach. The results of this research are that there are 5 work disaster hazard capabilities in the Ministry of CNC BUBUT. After that this research shows there is no. 1. extreme type of hazard. risk, and 1 high risk and 3 medium risk. The most common hazard abilities occur because of the lack of PPE and the undisciplined workers and not exploring work SOPs. Therefore, it is necessary to try socialization and continue to emphasize through daily safety briefings and safety signs.

Kseniia Bazilevych, Ievgen Meniailov, Dmytro Chumachenko

Предмет: використання математичного апарату нейронних мереж для наукового обгрунтування протиепідемічних заходів з метою зниження захворюваності при прийнятті ефективних управлінських рішень. Ціль: застосувати кластерний аналіз, на основі нейронної мережі, для вирішення задачі виділення зон розповсюдження захворюваності. Задачі: проаналізувати методи аналізу даних для вирішення задачі кластеризації; розробити нейромережевий метод кластеризації територій України за характером епідемічного процесу COVID-19; на основі розробленого методу реалізувати програмний додаток аналізу даних для виділення зон розповсюдження захворюваності на прикладі коронавірусу COVID-19. Методи: моделі та методи аналізу даних, моделі та методи теорії систем (на базі інформаційного підходу), методи машинного навчання, зокрема метод Adaptive Boosting (на основі методу градієнтного спуску), методи навчання нейронних мереж. Результати: були використані розподілені по областям України дані Центру громадського здоров’я МОЗ України про захворюваність на COVID-19, кількість лабораторно обстежених осіб, кількість проведених лабораторних досліджень методами ПЦР та ІФА, кількість проведених лабораторних досліджень IgA, IgM, IgG; в моделі використані дані з березня 2020 по грудень 2020, при моделюванні не враховані дані з тимчасово окупованих територій України; для кластерного аналізу побудована нейронна мережа з 60 вхідними нейронами, 100 прихованими нейронами з активаційною функцією Фермі та 4 вихідними нейронами; для програмної реалізації моделі використана мова програмування Python. Висновки: проведено аналіз методів побудови нейронних мереж; аналіз методів навчання нейронних мереж, у тому числі методу градієнтного спуску; всі теоретичні вiдомостi, описанi в цiй роботi, були використанi для реалiзації програмного продукту обробки даних тестування на COVID-19 в Україні; було проведено розбиття областей України на зони зараження вірусом COVID-19 та представлено карту цього розбиття.

Jingkai Xie, Yue-Ping Xu, Yuxue Guo et al.

Quantifying the contributions of climatic variables to runoff variance is still a great challenge to water resource management. This study adopted an extended Budyko framework to investigate the effects of terrestrial water storage changes (ΔS) on runoff variance across the source region of the Yellow River, China, during the period of 2003–2014. A new decomposition framework based on the extended Budyko framework was proposed to effectively quantify the contributions of different climatic variables including precipitation, PET and ΔS to runoff variance. The results demonstrated that the extended Budyko framework showed a better performance in presenting the water and energy balance than the original Budyko framework, especially at fine time scales. Meanwhile, the variance in runoff estimated by the new decomposition framework was close to that of runoff observations, indicating that this framework can effectively capture the variation in runoff during 2003–2014. It was also found that precipitation was the most important factor that contributed to runoff changes, while PET made a slightly smaller contribution compared to precipitation. Notably, the results also emphasized the important effects of ΔS on runoff variance at fine time scales, which was useful to better understand the interactions between atmospheric and hydrological processes for regions. HIGHLIGHTS A new decomposition framework was proposed to effectively quantify the contributions of different climatic variables to runoff variance.; Precipitation was the most important factor that contributed to runoff changes, while PET made a slightly smaller contribution compared to precipitation.; The important effects of ΔS on runoff variance at fine time scales can not be neglected.;

Tusar Kanti Roy

M. Nakhaei, M. Correia

Water-risk management is one of the most challenging issues in the conservation of earthen sites, because of the inherent weakness of earth to moisture, and also the severe damage after rainfall as a result of a combination of many factors in the deterioration processes. In Tchogha Zanbil World Heritage Site (WHS) in Iran, this problem causes more damage due to the heavy rains that impact the site in a short period of time. The property encompasses a vast area, which makes regular maintenance more difficult. Also, there are insufficient strategies for controlling water runoff on the structures. Archaeological studies have revealed an ancient system for managing surface water at this site which could be compatible and adaptable for further development of the current management system. This study aims to present sustainable approaches in managing water-risk in the Tchogha Zanbil WHS, by identifying the authenticity values, investigating the problems and challenges in the current water-management system, and more importantly, assessing ancient strategies for controlling water, based on archaeological evidence.

Donghwan Song, Adrian Matias Chung Baek, Jageon Koo et al.

Over the past decades, additive manufacturing has rapidly advanced due to its advantages in enabling diverse material usage and complex design production. Nevertheless, the technology has limitations in terms of quality, as printed products are sometimes different from their desired designs or are inconsistent due to defects. Warping deformation, a defect involving layer shrinkage induced by the thermal residual stress generated during manufacturing processes, is a major factor in lowering the quality and raising the cost of printed products. This study utilized a variety of thermal time series data and the K-nearest neighbors (KNN) algorithm with dynamic time warping (DTW) to detect and predict the warping deformation in the printed parts using fused deposition modeling (FDM) printers. Multivariate thermal time series data extracted from thermocouples were trained using DTW-based KNN to classify warping deformation. The results showed that the proposed approach can predict warping deformation with an accuracy of over 80% by only using thermal time series data corresponding to 20% of the whole printing process. Additionally, the classification accuracy exhibited the promising potential of the proposed approach in warping prediction and in actual manufacturing processes, so the additional time and cost resulting from defective processes can be reduced.

Alejandro Aroca Bavich, Daniel Martínez Llaneza, Iván Ossandon et al.

El proyecto de investigación asociado a esta publicación pretende el estudio y acercamiento a las Pymes radicadas en la región con el fin de determinar los rasgos sobresalientes que estas tienen en materia de gerenciamiento. Se buscó indagar sobre las Pymes para determinar concretamente si realizan Planeamiento Estratégico, si las políticas de Recurso Humanos se vinculan a dicho Planeamiento y si desde estas empresas se incorpora innovación tecnológica y de qué modo incorpora el avance tecnológico en su función de producción. A tales fines se llevó adelante una campaña de relevamiento mediante encuestas que permitió estudiar e inferir el comportamiento de las organizaciones empresariales al respecto de varios de estos aspectos, la presente publicación logra caracterizar las pymes en conceptos generales y da evidencia del avance e incorporación de las Tecnologíasde Información y Comunicación en las PyMEs, explicando los principales mecanismos de innovación en esta materia.

Nevena Dragičević, Barbara Karleuša, Nevenka Ožanić

This paper analyses the possibilities to derive drainage density map, a parameter used within Erosion Potential Method (EPM, Gavrilović), for the Dubračina catchment study area in better detail and precision. EPM method is used for erosion assessment in the karstic areas characterized by torrential rivers. In this paper, three different methodologies were used to derive drainage density map each using different assumptions and allowing different spatial variability. The third case of drainage density map provides most realistic spatial variance of the drainage density parameter with lower values along the edges of the catchment and higher values concentrated along the river and tributary intersections.

Walter Fuertes, Francisco Reyes, Paúl Valladares et al.

Cyber-attacks have increased in severity and complexity. That requires, that the CERT/CSIRT research and develops new security tools. Therefore, our study focuses on the design of an integral model based on Business Intelligence (BI), which provides reactive and proactive services in a CSIRT, in order to alert and reduce any suspicious or malicious activity on information systems and data networks. To achieve this purpose, a solution has been assembled, that generates information stores, being compiled from a continuous network transmission of several internal and external sources of an organization. However, it contemplates a data warehouse, which is focused like a correlator of logs, being formed by the information of feeds with diverse formats. Furthermore, it analyzed attack detection and port scanning, obtained from sensors such as Snort and Passive Vulnerability Scanner, which are stored in a database, where the logs have been generated by the systems. With such inputs, we designed and implemented BI systems using the phases of the Ralph Kimball methodology, ETL and OLAP processes. In addition, a software application has been implemented using the SCRUM methodology, which allowed to link the obtained logs to the BI system for visualization in dynamic dashboards, with the purpose of generating early alerts and constructing complex queries using the user interface through objects structures. The results demonstrate, that this solution has generated early warnings based on the level of criticality and level of sensitivity of malware and vulnerabilities as well as monitoring efficiency, increasing the level of security of member institutions.

Ali ÖZTÜRK, Beytullah BOZALİ, Salih TOSUN

Bu çalışmada, tristor kontrollü seri kompanzator( TSCS) ve statik var kompanzator (SVC) denetleyicilerinin güç sistemi gerilim kararlılığına olan etkileri incelenmiştir. İncelemeler 5 örnek olarak seçilen 5 baralı sistem üzerinde yapılmıştır. Sürekli güç akışı analizi yöntemi kullanılarak TSCS ve SVC’nin gerilim çökmeleri üzerindeki etkileri incelenmiştir. Hatların kararlılık indeksi değerleri ve yük baralarına ait voltaj kararlılık indeksi değerleri hesaplanmıştır. Bu index değerlerine göre güç sistemi Esnek alternatif akım cihazları iletim cihazları (FACTS) bağlantı noktaları belirlenmiştir.  FACTS cihazları bağlandıktan sonra simülasyon programı ile yük akışı çalışmaları yapılmıştır. Yapılan çalışma ile elde edilen sonuçlara göre güç sisteminin kararlılık sınır değerlerini iyileştirmede ve aktif güç kayıplarını azaltmada FACTS cihazlarının önemli bir etkiye sahip olduğu görülmüştür.

Gustavo Riente de Andrade, José Reynaldo Setti, Antônio Clóvis Pinto Ferraz

Neste trabalho foram identificadas na literatura e descritas as funções de atraso mais comumente usadas nos pacotes de modelagem de demanda por transporte, a saber: (1) BPR; (2) Conical; (3) Função de Akçelik; e (4) Logística. Em seguida, foi testada a compatibilidade entre essas quatro VDFs e os modelos atuais do HCM, calibrados para o ambiente rodoviário brasileiro. Como principais conclusões, tem-se que os melhores ajustes foram obtidos com o uso da função do BPR e logística. Por outro lado, as funções Conical e de Akçelik devem ser empregadas com cautela, pois tendem a subestimar o atraso em condições de fluxos de tráfego baixos a médios, comuns em rodovias rurais. Especificamente com relação às rodovias de pista simples, a função logística se mostrou interessante, devido a capacidade de refletir atrasos mais acentuados para baixos fluxos de tráfego, e produzir maiores atrasos em condições congestionadas, característica desejável em modelagem de demanda.

Miguel Herrera Suárez, Omar González Cueto, Elvis López Bravo et al.

Starting from the development that has reached the computational means in the last decades, the application of the numeric methods in the simulation of the interaction soil tillage-tool, has won in acceptance. As previous step, to the simulation of this phenomenon becomes necessary the definition of the models that predict with more accuracy the soil mechanical behavior. Taking into account these aspects the objective of present work is, to simulate the soil mechanical behavior in the soil-tillage tool interface by means of the finite element method. Starting from the employment of a model that is based on frictional approaches, with the inclusion of the adherence and the establishment of a tension of slip limit, as penalty to restrict the relative displacement between both surfaces. The models were implemented in the computational tool ABAQUS 6.4, starting from that which the soil-metal relative displacement was simulated. The results evidenced the validity of the model implemented to simulate the soil mechanical response in the soil-tool interface. The errors in the prediction of the soil stress oscillated from 1,45 to 5,45%, for the case of the soil vertical deformations it varied among 2,22 to 3,57%. 

Carlos E Alciaturi, Marcos E Escobar, Carlos De La Cruz et al.

Los métodos instrumentales de análisis químico hacen uso de las relaciones entre la señal obtenida y una propiedad del sistema estudiado (generalmente, una concentración). Los avances en electrónica y computación han hecho posible un rápido progreso en la adquisición de datos y en su transmisión y procesamiento. La aplicación de diversos métodos matemáticos al cálculo de concentraciones y otras propiedades a partir de datos instrumentales se conoce como quimiometría y es un área de intensa actividad, por sus amplias aplicaciones en la industria química, de procesos y en estudios ambientales. Uno de los métodos más usados en quimiometría es el método de mínimos cuadrados parciales, conocido por sus iniciales en inglés, PLS ("partial least squares"). Este método, relacionado con la regresión de componentes principales, PCR ("principal components regression") posee ventajas teóricas y computacionales que han llevado a innumerables aplicaciones. Se encuentran en Internet decenas de miles de referencias solamente para el PLS lineal. En este artículo, se explica los fundamentos del método y se muestra una aplicación a la predicción de propiedades de carbones minerales a partir de datos del infrarrojo medio, con el objetivo de desarrollar métodos de análisis rápidos y no destructivos para estos materiales.