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17 pages, 2502 KB  
Article
Development of a Reinforcement Learning-Based Intelligent Irrigation Decision-Making Model
by Xufeng Zhang, Xinrong Zheng, Zhanyi Gao, Yu Fan, Ke Zhou, Weixian Zhang and Xiaomin Chang
Agronomy 2025, 15(10), 2416; https://doi.org/10.3390/agronomy15102416 - 18 Oct 2025
Cited by 1 | Viewed by 736
Abstract
Originating from the practical demands of digital irrigation district construction, this study aims to provide support for precise irrigation management. This study developed a reinforcement learning-based intelligent irrigation decision-making model for districts employing traditional surface flood irrigation methods. Grounded in the theoretical framework [...] Read more.
Originating from the practical demands of digital irrigation district construction, this study aims to provide support for precise irrigation management. This study developed a reinforcement learning-based intelligent irrigation decision-making model for districts employing traditional surface flood irrigation methods. Grounded in the theoretical framework of water cycle processes within the Soil–Crop–Atmosphere Continuum (SPAC) system and incorporating district-specific irrigation management experience, the model achieves intelligent and precise irrigation decision-making through agent–environment interactive learning. Simulation results show that in the selected typical area of the irrigation district, during the 10-year validation period from 2014 to 2023, the model triggered a total of 22 irrigation events with an average annual irrigation volume of 251 mm. Among these, the model triggered irrigation 18 times during the winter wheat growing season and 4 times during the corn growing season. The intelligent irrigation decision-making model effectively captures the coupling relationship between crop water requirements during critical periods and the temporal distribution of precipitation, and achieves preset objectives through adaptive decisions such as peak-shifting preemptive irrigation in spring, limited irrigation under low-temperature conditions, no irrigation during non-irrigation periods, delayed irrigation during the rainy season, and timely irrigation during crop planting periods. These outcomes validate the model’s scientific rigor and operational adaptability, providing both a scientific water management tool for irrigation districts and a new technical pathway for the intelligent development of irrigation decision-making systems. Full article
(This article belongs to the Section Water Use and Irrigation)
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20 pages, 2374 KB  
Review
Serous Papillary Adenofibroma Cyst of the Ovary in a Young Woman: Case Report and Literature Review
by Laurențiu Augustus Barbu, Liliana Cercelaru, Valeriu Șurlin, Stelian-Stefaniță Mogoantă, Tiberiu Stefăniță Țenea Cojan, Nicolae-Dragoș Mărgăritescu, Ana-Maria Țenea Cojan, Mihai Popescu, Valentina Căluianu, Gabriel Florin Răzvan Mogoș and Liviu Vasile
Life 2025, 15(10), 1601; https://doi.org/10.3390/life15101601 - 14 Oct 2025
Cited by 1 | Viewed by 636
Abstract
Background: Serous papillary adenofibroma cyst (SPAC) of the ovary is a rare benign epithelial tumor that can mimic borderline or malignant ovarian neoplasms. Reports in young women are particularly scarce. Purpose: The aim of this study is to present a rare clinical case [...] Read more.
Background: Serous papillary adenofibroma cyst (SPAC) of the ovary is a rare benign epithelial tumor that can mimic borderline or malignant ovarian neoplasms. Reports in young women are particularly scarce. Purpose: The aim of this study is to present a rare clinical case of ovarian SPAC in a young woman and to review the existing literature, highlighting diagnostic challenges and implications for fertility-preserving management. Methods: We present a clinical case of ovarian SPAC in a 41-year-old woman and conducted a narrative literature review. The search was performed in PubMed, Scopus, and Web of Science to identify reports published between 2000 and 2025. Additional relevant articles were also identified through manual screening of reference lists from selected papers. Results: MRI revealed a well-encapsulated septated cystic lesion with solid nodular components and post-contrast enhancement. Tumor markers, including CA 19-9, were elevated. Laparoscopic surgery with intraoperative frozen section confirmed the diagnosis of SPAC, allowing fertility-preserving management. Histopathology established the final diagnosis. Conclusions: This case emphasizes the importance of considering SPAC in the differential diagnosis of complex adnexal masses. Early recognition and intraoperative frozen section can guide conservative surgical strategies, avoiding overtreatment and preserving reproductive potential in young patients. Full article
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23 pages, 5085 KB  
Article
Process Importance Identification for the SPAC System Under Different Water Conditions: A Case Study of Winter Wheat
by Lijun Wang, Liangsheng Shi and Jinmin Li
Agronomy 2025, 15(3), 753; https://doi.org/10.3390/agronomy15030753 - 20 Mar 2025
Viewed by 771
Abstract
Modeling the soil–plant–atmosphere continuum (SPAC) system requires multiple subprocesses and numerous parameters. Sensitivity analysis is effective to identify important model components and improve the modeling efficiency. However, most sensitivity analyses for SPAC models focus on parameter-level assessment, providing limited insights into process-level importance. [...] Read more.
Modeling the soil–plant–atmosphere continuum (SPAC) system requires multiple subprocesses and numerous parameters. Sensitivity analysis is effective to identify important model components and improve the modeling efficiency. However, most sensitivity analyses for SPAC models focus on parameter-level assessment, providing limited insights into process-level importance. To address this gap, this study proposes a process sensitivity analysis method that integrates the Bayesian network with variance-based sensitivity measures. Four subprocesses are demarcated based on the physical relationships between model components revealed by the network. Applied to a winter wheat SPAC system under different water conditions, the method effectively and reliably identifies critical processes. The results indicate that, under minimal water stress, the subprocesses of photosynthesis and dry matter partitioning primarily determine agricultural outputs. As the water supply decreases, the subprocesses of soil water movement and evapotranspiration gain increasing importance, becoming predominant under sever water stress. Throughout the crop season, the subprocess importance and its response to water stress are modulated by the crop phenology. Compared to conventional parameter sensitivity analysis, our method excels in synthesizing divergent parameter importance changes and identifying influential subprocesses, even without high-sensitivity parameters. This study provides new insights into adaptive SPAC modeling by dynamically simplifying unimportant subprocesses in response to environmental changes. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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23 pages, 14094 KB  
Article
Characterization of the Sedimentary Cover in the City of Aïn Témouchent, Northwest Algeria, Using Ambient Noise Measurements
by Ahmed Saadi, Fethi Semmane, Juan José Galiana-Merino, Abdelkrim Yelles-Chaouche, Abdelouahab Issaadi and Billel Melouk
Appl. Sci. 2025, 15(6), 2967; https://doi.org/10.3390/app15062967 - 10 Mar 2025
Viewed by 1680
Abstract
The city of Aïn Témouchent, located in northwest Algeria at the westernmost part of the Lower Cheliff Basin, has experienced several moderate earthquakes, the most significant of which occurred on 22 December 1999 (Mw 5.7, 25 fatalities, severe damage). In this study, ambient [...] Read more.
The city of Aïn Témouchent, located in northwest Algeria at the westernmost part of the Lower Cheliff Basin, has experienced several moderate earthquakes, the most significant of which occurred on 22 December 1999 (Mw 5.7, 25 fatalities, severe damage). In this study, ambient noise measurements from 62 sites were analyzed using the horizontal-to-vertical spectral ratio (HVSR) method to estimate fundamental frequency (f0) and amplitude (A0). The inversion of HVSR curves provided sedimentary layer thickness and shear wave velocity (Vs) estimates. Additionally, four spatial autocorrelation (SPAC) array measurements refined the Rayleigh wave dispersion curves, improving Vs profiles (150–1350 m/s) and sediment thickness estimates (up to 390 m in the industrial zone). Vs30 and vulnerability index maps were developed to classify soil types and assess liquefaction potential within the city. Full article
(This article belongs to the Special Issue Earthquake Engineering: Geological Impacts and Disaster Assessment)
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21 pages, 6474 KB  
Article
Characterization of Shallow Sedimentary Layers in the Oran Region Using Ambient Vibration Data
by Ahmed Saadi, Juan José Galiana-Merino, Fethi Semmane, Abdelkrim Yelles-Chaouche and Abdelouahab Issaadi
Appl. Sci. 2024, 14(16), 7364; https://doi.org/10.3390/app14167364 - 21 Aug 2024
Cited by 1 | Viewed by 1829
Abstract
This study investigates the structure of shear-wave velocities (Vs) in the shallow layers of the Oran region, north-west of Algeria, using non-invasive techniques based on ambient vibration arrays. The region has experienced several moderate earthquakes, including the historical Oran earthquake of 1790. Ambient [...] Read more.
This study investigates the structure of shear-wave velocities (Vs) in the shallow layers of the Oran region, north-west of Algeria, using non-invasive techniques based on ambient vibration arrays. The region has experienced several moderate earthquakes, including the historical Oran earthquake of 1790. Ambient vibration measurements were carried out at 15 sites throughout the study area. Two methods were used: spatial autocorrelation (SPAC) and frequency–wavenumber analysis (f-k), which allowed us to better constrain Rayleigh wave dispersion curves. The inversion of the dispersion curves derived from the f-k analysis allowed for estimating the shear-wave velocity profiles and the Vs30 value at the sites under study. The other important result of the present study is an empirical equation that has been proposed to predict Vs30 in the Oran region. The determination of near-surface shear-wave velocity profiles is an important step in the assessment of seismic hazard. This study has demonstrated the effectiveness of using ambient vibration array techniques to estimate the soil Vs structure. Full article
(This article belongs to the Special Issue Earthquake Engineering: Geological Impacts and Disaster Assessment)
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37 pages, 2956 KB  
Article
Business IT Alignment Impact on Corporate Sustainability
by Uroš Zabukovšek, Polona Tominc and Samo Bobek
Sustainability 2023, 15(16), 12519; https://doi.org/10.3390/su151612519 - 17 Aug 2023
Cited by 6 | Viewed by 5972
Abstract
Business–IT alignment (BITA) has become crucial for effective organisational management in today’s interconnected global economy. This article investigates the relationship between BITA and corporate sustainability, exploring how businesses can leverage BITA for sustainable growth and development. The study employs a case research approach [...] Read more.
Business–IT alignment (BITA) has become crucial for effective organisational management in today’s interconnected global economy. This article investigates the relationship between BITA and corporate sustainability, exploring how businesses can leverage BITA for sustainable growth and development. The study employs a case research approach in a multinational manufacturing organisation, utilising a mixed methods research (MMR) design. In the quantitative part of the research, the PLS-SEM technique was used to examine the influence of six BITA factors on employees’ self-perceived action competence for sustainability (SPACS). This study confirmed that all six BITA factors strongly influence all three SPACS factors. In the qualitative part of the research, semi-structured interviews were used to measure the BITA maturity level of the organisation and the influence of BITA factors on corporate sustainability. Based on quantitative and qualitative research results, it can be confirmed that BITA strongly influences corporate sustainability. Results also confirm that there is no universal approach to BITA and its influence on corporate sustainability. Organisations must focus on all factors of BITA equally to achieve better levels of BITA and ensure its influence on corporate sustainability. Full article
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18 pages, 362 KB  
Article
High-Dimensional Regression Adjustment Estimation for Average Treatment Effect with Highly Correlated Covariates
by Zeyu Diao, Lili Yue, Fanrong Zhao and Gaorong Li
Mathematics 2022, 10(24), 4715; https://doi.org/10.3390/math10244715 - 12 Dec 2022
Cited by 1 | Viewed by 1929
Abstract
Regression adjustment is often used to estimate average treatment effect (ATE) in randomized experiments. Recently, some penalty-based regression adjustment methods have been proposed to handle the high-dimensional problem. However, these existing high-dimensional regression adjustment methods may fail to achieve satisfactory performance when the [...] Read more.
Regression adjustment is often used to estimate average treatment effect (ATE) in randomized experiments. Recently, some penalty-based regression adjustment methods have been proposed to handle the high-dimensional problem. However, these existing high-dimensional regression adjustment methods may fail to achieve satisfactory performance when the covariates are highly correlated. In this paper, we propose a novel adjustment estimation method for ATE by combining the semi-standard partial covariance (SPAC) and regression adjustment methods. Under some regularity conditions, the asymptotic normality of our proposed SPAC adjustment ATE estimator is shown. Some simulation studies and an analysis of HER2 breast cancer data are carried out to illustrate the advantage of our proposed SPAC adjustment method in addressing the highly correlated problem of the Rubin causal model. Full article
(This article belongs to the Special Issue Computational Statistics and Data Analysis)
17 pages, 4755 KB  
Review
Revisiting Soil Water Potential: Towards a Better Understanding of Soil and Plant Interactions
by Yuanyuan Ma, Hu Liu, Yang Yu, Li Guo, Wenzhi Zhao and Omer Yetemen
Water 2022, 14(22), 3721; https://doi.org/10.3390/w14223721 - 17 Nov 2022
Cited by 12 | Viewed by 14031
Abstract
Soil water potential (SWP) is vital for controlling the various biological and non-biological processes occurring through and across the soil-plant-atmosphere continuum (SPAC). Although the dynamics and mechanisms of SWP have been investigated for several decades, they are not as widely explored in ecohydrology [...] Read more.
Soil water potential (SWP) is vital for controlling the various biological and non-biological processes occurring through and across the soil-plant-atmosphere continuum (SPAC). Although the dynamics and mechanisms of SWP have been investigated for several decades, they are not as widely explored in ecohydrology research as soil moisture, due at least partly to the limitation of field observation methods. This limitation restricts the understanding of the responses of plant physiology and ecological processes to the SWP gradient and the ecohydrological functions of SWP dynamics in different contexts. Hence, in this work, we first briefly revisit the origin and development of the concept of SWP and then analyze the comprehensive factors that influence SWP and the improvement of SWP observation techniques at field scales, as well as strategies for developing new sensors for soil water status. We also propose views of focusing on the response characteristics of plant lateral roots, rather than taproots, to SWP dynamics, and using hormone signaling research to evaluate plant response signals to water stress. We end by providing potential challenges and insights that remain in related research, such as the limitations of the SWP evaluation methods and the future development direction of SWP data collection, management, and analysis. We also emphasize directions for the application of SWP in controlling plant pathogens and promoting the efficiency of resource acquisition by plants. In short, these reflections revisit the unique role of SWP in eco-hydrological processes, provide an update on the development of SWP research, and support the assessment of plant drought vulnerability under current and future climatic conditions. Full article
(This article belongs to the Special Issue Advances in Studies on Ecohydrological Processes in the Arid Area)
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20 pages, 11182 KB  
Article
Vs30 Structure of Almeria City (SE Spain) Using SPAC and MASW Methods and Proxy Correlations
by Fernando López, Manuel Navarro, Pedro Martínez-Pagán, Antonio García-Jerez, Jaruselsky Pérez-Cuevas and Takahisa Enomoto
Geosciences 2022, 12(11), 403; https://doi.org/10.3390/geosciences12110403 - 31 Oct 2022
Cited by 5 | Viewed by 2919
Abstract
The topographic slope method is an innovative, fast and very low-cost technique for estimating the average S-wave velocity in the upper 30 m (Vs30) based on the relationship between this quantity and the slope of the ground, obtained using a Digital [...] Read more.
The topographic slope method is an innovative, fast and very low-cost technique for estimating the average S-wave velocity in the upper 30 m (Vs30) based on the relationship between this quantity and the slope of the ground, obtained using a Digital Elevation Model (DEM). The method is based on the good linear correlations log(Vs30)–log(slope) found experimentally, which, ideally, should be determined for each region. If measured Vs30 data are not available to carry out this fitting for the study area, correlations from other areas could be used, although the reliability of the estimated Vs30 results would be lower. In this article, Vs30 observations are made for the city of Almeria, using Spatial Autocorrelation Surveys (SPAC) and Multichannel Analysis of Surface Waves (MASW), obtaining two types of fitting: (a) linear relationship log(Vs30)–log(slope); and (b) considering additional dependence on geological units. The reliability, evaluated by Multiple R-Squared (MRS), varies between 79.2% in the first case and 87.0% in the second, lowering the mean absolute values of the residuals at the observation points in the first case from 40.0 m/s to 29.0 m/s. Using a more generic correlation obtained for other areas of the world, the mean absolute residuals increase to 74.7 m/s. Full article
(This article belongs to the Section Natural Hazards)
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19 pages, 6548 KB  
Article
Effect of Different Water Treatments in Soil-Plant-Atmosphere Continuum Based on Intelligent Weighing Systems
by Hairong Gao, Rui Guo, Kaili Shi, Huanfang Yue, Shaoying Zu, Zhiwei Li and Xin Zhang
Water 2022, 14(4), 673; https://doi.org/10.3390/w14040673 - 21 Feb 2022
Cited by 6 | Viewed by 3864
Abstract
In order to meet the needs of dynamic continuous monitoring of soil-plant-atmosphere continuum (SPAC), a new soil, plant, atmosphere analysis system has been established based on an intelligent weighing system (IWS). Four types of irrigation treatments (90%, 80%, 70%, and 60% of field [...] Read more.
In order to meet the needs of dynamic continuous monitoring of soil-plant-atmosphere continuum (SPAC), a new soil, plant, atmosphere analysis system has been established based on an intelligent weighing system (IWS). Four types of irrigation treatments (90%, 80%, 70%, and 60% of field capacity (FC)) were conducted on lettuce (Lactuca sativa var. ramosa Hort.) for two-season planting experiments. Regarding the soil, the relative system weight of IWS showed a significant linear correlation with the soil volumetric moisture content (SWC) (R2 = 0.64–0.94). When the SWC increased by 1.00%, the soil weight increased by 56–62 g. Regarding plants, the IWS also clearly reflected the changes in plant weight gain, transpiration rate, and stomatal conductance at different growth stages. After verification, the relative errors of the transpiration rate and stomatal conductance measured by the IWS were −9.60–22.30% and −7.20–22.20%, respectively. Regarding the atmospheric environment, the variation trend of the crop evapotranspiration (ETc) based on the IWS and the reference crop evapotranspiration (ET0) calculated with meteorological parameters were consistent. However, the numerical difference was in the uncertainty of the crop coefficient (Kc). The ETc of lettuce under the 80% FC treatment was the highest. Accordingly, a daily online measurement method for Kc was established. The Kc values of lettuce at different growth stages were 0.88, 1.22, and 2.43, respectively. The growth, yield, and water use efficiency (WUE) of crops under 80% FC treatment compared with other treatments significantly increased by 11.07–21.05%, 0.91–9.89%, and 2.16–15.80%, respectively. Therefore, the 80% FC was adopted as the irrigation low limit of potted lettuce. The experimental results provide a theoretical basis for further guiding crop irrigation. Full article
(This article belongs to the Special Issue Numerical Modeling of Water Flow, Nutrients and Sediment Transport)
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12 pages, 2273 KB  
Article
Point-of-Care Detection of Salivary Nitrite Based on the Surface Plasmon-Assisted Catalytic Coupling Reaction of Aromatic Amines
by Chen Zhao, Ruyi Shi, Jiale Wu, Xuan Luo and Xiangjiang Liu
Biosensors 2021, 11(7), 223; https://doi.org/10.3390/bios11070223 - 5 Jul 2021
Cited by 8 | Viewed by 4297
Abstract
Rapid quantification of nitrite (NO2) in food, drink and body fluids is of significant importance for both food safety and point-of-care (POA) applications. However, conventional nitrite analytical methods are complicated, constrained to sample content, and time-consuming. Inspired by a nitrite-triggered [...] Read more.
Rapid quantification of nitrite (NO2) in food, drink and body fluids is of significant importance for both food safety and point-of-care (POA) applications. However, conventional nitrite analytical methods are complicated, constrained to sample content, and time-consuming. Inspired by a nitrite-triggered surface plasmon-assisted catalysis (SPAC) reaction, a rapid point-of-care detection salivary nitrate was developed in this work. NO2 ions can trigger the rapid conversion of p-aminothiophenol (PATP) to p,p′-dimercaptozaobenzene (DMAB) on gold nanoparticles (GNPs) under light illumination, and the emerged new bands at ca. 1140, 1390, 1432 cm−1 originating from DMAB can be used to the quantification of nitrite. Meanwhile, to make the method entirely suitable for on-site fast screen or point-of-care application, the technique is needed to be further optimized. The calibration graph for nitrates was linear in the range of 1–100 µM with a correlation coefficient of 0.9579. The limit of detection was 1 µM. The facile method could lead to a further understanding of the progression and treatment of periodontitis and to guide professionals in planning on-site campaigns to effectively control periodontal diseases. Full article
(This article belongs to the Special Issue Nanomaterial-Based Biosensors for Food Analysis)
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12 pages, 2412 KB  
Article
A Novel Approach for the Simulation of Reference Evapotranspiration and Its Partitioning
by Pei Wang, Jingjing Ma, Juanjuan Ma, Haitao Sun and Qi Chen
Agriculture 2021, 11(5), 385; https://doi.org/10.3390/agriculture11050385 - 24 Apr 2021
Cited by 5 | Viewed by 3118
Abstract
To estimate the irrigation volume required for agriculture and improve water resources utilization efficiency, it is essential to obtain an estimate of reference evapotranspiration (ET0) and its components (e.g., reference transpiration, T0 and reference soil evaporation, E0). This [...] Read more.
To estimate the irrigation volume required for agriculture and improve water resources utilization efficiency, it is essential to obtain an estimate of reference evapotranspiration (ET0) and its components (e.g., reference transpiration, T0 and reference soil evaporation, E0). This study updated a soil-plant-atmosphere continuum (SPAC) evapotranspiration model and its associated components to obtain a reference-based SPAC model of reference evapotranspiration (R-SPAC), and it applied the model to an agricultural ecosystem. Model simulations of mean hourly ET0 were benchmarked against those of the Penman-Monteith method by the Food and Agriculture Organization (FAO-PM) throughout the growing season. The resulting good correlation obtained (R2 = 0.96, agreement index, I = 0.98, root-mean-square deviation (RMSD) = 0.05 mm h−1) validated the accuracy of the R-SPAC model. Sensitivity analysis was used to explore uncertainties and errors for ET0, T0, and E0 caused by input variables. The results showed that net radiation and shortwave radiation at the study site were the main drivers of ET0 for both the FAO-PM and R-SPAC models. The study showed that the proposed R-SPAC model can be used for predicting ET0 and for exploring interactions between climate, crop type, and soil in determining evapotranspiration under various future environment conditions. Full article
(This article belongs to the Section Agricultural Water Management)
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18 pages, 5705 KB  
Article
VS30 Seismic Microzoning Based on a Geomorphology Map: Experimental Case Study of Chiang Mai, Chiang Rai, and Lamphun, Thailand
by Patcharavadee Thamarux, Masashi Matsuoka, Nakhorn Poovarodom and Junko Iwahashi
ISPRS Int. J. Geo-Inf. 2019, 8(7), 309; https://doi.org/10.3390/ijgi8070309 - 18 Jul 2019
Cited by 9 | Viewed by 6223
Abstract
Thailand is not known to be an earthquake-prone country; however, in 2014, an unexpected moderate earthquake caused severe damage to infrastructure and resulted in public panic. This event caught public attention and raised awareness of national seismic disaster management. However, the expertise and [...] Read more.
Thailand is not known to be an earthquake-prone country; however, in 2014, an unexpected moderate earthquake caused severe damage to infrastructure and resulted in public panic. This event caught public attention and raised awareness of national seismic disaster management. However, the expertise and primary data required for implementation of seismic disaster management are insufficient, including data on soil character which are used in amplification analyses for further ground motion prediction evaluations. Therefore, in this study, soil characterization was performed to understand the seismic responses of soil rigidity. The final output is presented in a seismic microzoning map. A geomorphology map was selected as the base map for the analysis. The geomorphology units were assigned with a time-averaged shear wave velocity of 30 m (VS30), which was collected by the spatial autocorrelation (SPAC) method of microtremor array measurements. The VS30 values were obtained from the phase velocity of the Rayleigh wave corresponding to a 40 m wavelength (C(40)). From the point feature, the VS30 values were transformed into polygonal features based on the geomorphological characteristics. Additionally, the automated geomorphology classification was explored in this study. Then, the seismic microzones were compared with the locations of major damage from the 2014 records for validation. The results from this study include geomorphological classification and seismic microzoning. The results suggest that the geomorphology units obtained from a pixel-based classification can be recommended for use in seismic microzoning. For seismic microzoning, the results show mainly stiff soil and soft rocks in the study area, and these geomorphological units have relatively high amplifications. The results of this study provide a valuable base map for further disaster management analyses. Full article
(This article belongs to the Special Issue Geomatics and Geo-Information in Earthquake Studies)
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26 pages, 4453 KB  
Article
Distributed and Communication-Efficient Spatial Auto-Correlation Subsurface Imaging in Sensor Networks
by Maria Valero, Fangyu Li, Jose Clemente and Wenzhan Song
Sensors 2019, 19(11), 2427; https://doi.org/10.3390/s19112427 - 28 May 2019
Cited by 7 | Viewed by 4512
Abstract
A wireless seismic network can be effectively used as a tool for subsurface monitoring and imaging. By recording and analyzing ambient noise, a seismic network can image underground infrastructures and provide velocity variation information of the subsurface that can help to detect anomalies. [...] Read more.
A wireless seismic network can be effectively used as a tool for subsurface monitoring and imaging. By recording and analyzing ambient noise, a seismic network can image underground infrastructures and provide velocity variation information of the subsurface that can help to detect anomalies. By studying the variation in the noise cross-correlation function of the noise, it is possible to determine the subsurface seismic velocity and image underground infrastructures. Ambient noise imaging can be done in a decentralized fashion using Distributed Spatial Auto-Correlation (dSPAC). In dSPAC over sensor networks, the cross-correlation is the most intensive communication process since nodes need to communicate their data with neighbor nodes. In this paper, a new communication-reduced method for cross-correlation is presented to meet bandwidth and cost of communication constraints in networks while ambient noise imaging is performed using dSPAC method. By applying the proposed communication-reduced method, we show that energy and computational cost of the nodes is also preserved. Full article
(This article belongs to the Section Internet of Things)
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12 pages, 2695 KB  
Article
Estimation of Vs Structure of Krueng Aceh and its Suburb Basin of Aceh Province, Indonesia, Derived from Microtremor Measurements
by Asrillah Asrillah, Marwan Marwan, Umar Muksin, Rusydy Ibnu, Sasaki Takao, Furumoto Yoshinori, Minami Yuichiro and Hikime Chisa
Geosciences 2019, 9(4), 186; https://doi.org/10.3390/geosciences9040186 - 22 Apr 2019
Cited by 5 | Viewed by 4774
Abstract
The Aceh and Seulimeum Faults flank the Krueng Aceh Basin in Indonesia, and the shear-wave velocity (Vs) structure of the basin is not extensively available. Understanding the Vs structure is very important in order to figure out how the basin structures seemingly appear, [...] Read more.
The Aceh and Seulimeum Faults flank the Krueng Aceh Basin in Indonesia, and the shear-wave velocity (Vs) structure of the basin is not extensively available. Understanding the Vs structure is very important in order to figure out how the basin structures seemingly appear, and this can eventually be used to generate a microzonation map for other forthcoming studies. To provide this, Vs was measured over an area approximately covering Banda Aceh City and its surroundings, by setting two lines consisting of eight points projected in the NW–SE and SW–NE orientations. This research aims to facilitate the approximation of the Vs structure characteristics of the Krueng Aceh Basin using the microtremor array method (MAM). Triangular configurations were set by deploying four seismometers following an M-station geometry for three different array sizes (i.e., 3, 10, and 30 m in distance). The data were then processed by utilizing the spatial autocorrelation (SPAC) technique. The result shows that the Vs structure generally dips down from SE to NW, and it gradually declines from SW to NE. The combination of these Vs structures tends to be oblique toward the SW–NE direction. This form may be affected by the Aceh Segment Fault which is more active than the Seulimeum Segment Fault. The average maximum penetration depth and Vs are 603 m and 947.5 m/s in the SE–NW orientation, and 650 m and 958 m/s in the SW–NE direction. Generally, the thickness of the strata is greater in the upstream area compared to the downstream area. Their composition consists of alluvium (A) at the uppermost layer and diluvium (D) at the underlying layers. Then, all of the identified strata are aged from the Pleistocene to Tertiary Pleistocene (Tp). These characteristics of the strata could potentially cause surface damages as a result of site effect responses when an earthquake is occurring. Full article
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