bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Seismic Performance of Wooden Column in Ancient Buildings under Secondary Loading
Authors: Han Xiaoli , Dai Jian , Qian Wei , Chang Lihong
Published: June 2022

In order to provide some scientific references for the restoration of ancient timber buildings, the wooden column was subjected to a secondary load through the quasi-static test. The seismic performance parameters of wooden column such as the damage of the wooden column, P-Δ hysteretic curve, P-Δ skeleton curve and stiffness degradation were analyzed. The test results showed that the wooden column could still maintain the lateral resistance capacity after the secondary load under the action of low reversed cyclic load. The hysteretic curve of the wooden column had a certain degree of a pinch effect, which indicated that the semi-rigid characteristic of the wooden column was reserved after the secondary loading. The lateral stiffness of the wooden column after the secondary load decreases with the increased of the lateral displacement. The lateral stiffness decreases with the increase of displacement. It showed that the wooden column still had good seismic behavior after secondary load.
Influence of Stochastic Aggregate on Ultrasound Propagation in Concrete
Authors: Zhang Lu , Jiang Zishi , Li Hongyu , Lu Yuchun , Zhang Ermao
Published: June 2022

The ultrasonic testing (UT) has been successfully utilized in many civil engineering fields (e.g. steel structures, RC structures, PC structures, highway, and railway) since the UT can provides an efficient and convenient on-site inspection of internal and external defects. However, many influential factors, such as aggregate, grading, mortar and cement porosity, may introduce various uncertainties to the UT measurement in the concrete due to its highly heterogeneities. Herein, the aggregate in concrete is one of the most influential factors of heterogeneities. To understand the influence of the aggregate on the mechanism of elastic wave propagation is essential to increase the detectability of UT in concrete. Meanwhile, it can provide the supportive evidence of detection, which can increase the reliability. In this paper, a two-dimensional concrete model with consideration of stochastic distribution of aggregate is established numerically. The influence of the quantity of concrete coarse/fine aggregate on ultrasonic attenuation is studied. It was found that the distributed condition of aggregate affects the propagation velocity and attenuation of ultrasonic wave in concrete. Therefore, the reliability of UT test depends on the UT frequency and aggregate.
Study of undisturbed soil test about slope angle of the expanded-plate affecting the failure mechanism of the NT-CEP pile under vertical tension
Authors: Chen Yang , Qian Yongmei , Hong Guang , Jin Yujie , Wang Ruozhu
Published: June 2022

In this paper, it is computer simulation studied that the influence of the slope angle of expanded-plate of the new-type concrete expanded-plate pile (the NT-CEP pile) to the uplift failure mechanism. The model piles of different slope angle are designed in undisturbed soil test, in which the effect about the bearing capacity of the NT-CEP pile and the failure behavior of the soil is analyzed, at the same time, the computer simulating analysis of finite element is assistant by the ANSYS software, to verify the test results. The innovation of this paper is mainly to test research methods, which improves and innovates the existing model test method and test equipment because of completing the test with undisturbed soil and ensuring the reliability of the test results. The research results of this paper will enrich and improve the design theory of the NT-CEP pile and play a necessary complement to the practical engineering application and a positive role in promoting the research and application of the NT-CEP pile.
Research on Blast Resistance of the Cylinder with Aluminium Foam under Internal Explosive Load
Authors: Li Xiangyu , Zhang Guodong , Liang Minzu , Tian Zhandong
Published: June 2022

Aluminium foam has an excellent performance in terms of impact resistance and energy absorption. The experimental and numerical investigations on the blast resistance of the cylinder with aluminium foam under internal explosive load are carried out in this thesis and the factors influencing the blast resistance are analyzed. First, experiments were carried out under internal explosive load with different relative densities and explosion loads, and the defections of inner and outer layers were obtained. Second, based on the voronoi technique, a 2D finite element model of sandwich cylinders with a core of aluminium foam was constructed, the effectiveness of the model was then confirmed by conflicting results from simulations and experiments. Finally, the finite element model was used to analyze the effects of characteristic cell size and explosive load, which were reflected in the energy absorption and deflection of the outer layer. The test results show that the simulation results agree well with the experimental results. The characteristic cell size has little influence on energy absorption. In the case of homogeneous cores, the energy absorption per unit of mass decreases linearly with increasing relative density and the deflections of outer layers increase slightly.
Seismic Capacity Evaluation of Existing Residential Buildings Based on Big Data
Authors: Miao Shuang , Haifen Jin
Published: June 2022

Based on big data, the seismic capacity of existing residential buildings is evaluated in this paper. More than 60 representative large and medium cities in China are selected. Key indexes of buildings are extracted by investigating the Internet data, government statistics and business data, and the logical relationship between the indexes is clarified. Then the dynamic analysis model based on probability theory is applied for seismic disaster prediction. Considering changes of seismic fortification level and proportions of different ages of residential buildings, a new evaluation method based on big data is presented to obtain the seismic capacity index of a city. It will provide data support for the reinforcement and reconstruction of existing residential buildings.
Braking performance test of portable underground light trackless special rubber tyred vehicle Development of equipment
Authors: Zhang Chunying
Published: June 2022

The braking system of trackless rubber tyred vehicles used underground in China is mostly composed of parking brake and service brake. The parking brake can effectively prevent the vehicle from sliding after the driver leaves. The service brake mainly reduces the speed or stops during driving. China’s relevant standards require the parking braking system of underground trackless rubber tyred vehicles to be inspected regularly to provide safety guarantee for underground operation. At present, the underground trackless rubber tyred vehicles can only be operated by driving them to the fixed Laboratory of the test center regularly (once a year). It is necessary to inspect the vehicle’s braking system and check whether the vehicle’s braking system is normal, Operation and production can only be carried out when it is determined that the vehicle is in good condition. The current inspection methods are not only related to the work efficiency of vehicle inspection, but also affect the safety of operators and production. In view of the above situation, the development of a set of advanced portable detection equipment for braking performance test of underground light trackless special rubber tyred vehicle is very necessary to improve vehicle inspection efficiency and ensure scientific detection.
Effect of concrete under continuous load on demoulding time during construction
Authors: Yang Weihan , Ma Ruowen , Xu Binghong , Cao Honghui , Zhang Mengmeng
Published: June 2022

Based on the current construction progress of each floor of the building, under the action of continuous construction load, the concrete strength at this time is only about 80% of that at the same age without load. It is suggested that when the test block maintained under the same conditions reaches 85% of the design strength, the whole structure is not easy to crack, which is not safe.
Comparative Analysis of German Dgnb and Chinese Green Building Evaluation Standards
Authors: Cao Chenyuan
Published: June 2022

With the concept of sustainable development being promoted all over the world, green building, as one of the necessary ways to achieve sustainable development, has been carried out by more and more countries, and a series of evaluation standards related to green building have been introduced. This paper makes a brief introduction and comparative analysis of some typical green building evaluation codes in the world. On the basis of the German DGNB algorithm on the full life cycle cost of green buildings, combined with the actual situation of China, this paper puts forward the algorithm of the full life cycle cost of green buildings suitable for China, and carries out analysis and verification, so as to provide reference for improving the evaluation criterion of green buildings in China.
Exploring Temporal Patterns of Urban Management Cases Based on Functional Principal Component Data Analysis
Authors: Cao Xinyue , Liu Fan
Published: June 2022

This paper indentifies temporal patterns of urban management cases (UMCs) to facilitate relevant administrations finding UMCs from passive to active in a timely and effective way by employing functional principal component analysis (FPCA). Finally, this work obtains temporal patterns of UMCs which are different variability modes of case time series globally, providing practical decision making supports to build up precaution against cases and efficiency quality of related administrations. Furthermore, this work will contribute to the development of Smart City with social harmony greatly. Besides, the study also enriches research in related fields and has a specific academic value.
Fire Characteristics Analysis of On-fire Intercity Train in the Tunnel under Open Side Door
Authors: Chen Zheng , Guo Chun , Zhao Wei
Published: June 2022

In order to explore the fire characteristics of high-speed intercity trains running in the tunnel when the side door of the carriage is opened in case of emergency, this paper simulates the fire intercity trains in the tunnel based on PyroSim fire simulation software, and studies the fire temperature and smoke distribution characteristics in the carriage of intercity trains at different running speeds and obtained: With the increase of train speed, the temperature and smoke concentration in the carriage gradually decrease, when the speed exceeds 140km/h, the temperature influence range and smoke concentration distribution are roughly the same. When the speed exceeds 80km/h, the concentration of combustion products began to decrease and reached the lowest at 200km/h. According to the distribution of train temperature and smoke and products concentration obtained by numerical simulation, it is suggested that the speed of intercity train with fire should maintain its original speed when the side door of the train is opened.
Application of network security situational awareness in power information system security
Authors: Qi Lizhong , Zhao Chunhui , Yu Gao , Xue Jiarui
Published: June 2022

The increasingly complex network environment leads to more and more intense network attacks. Traditional firewall and intrusion detection technology cannot guarantee the network security of power information system, so network space situation awareness becomes the most important in the field of network security. Big data technology can be used to better understand the operation of the network, and different types of data for rapid analysis. Build a security situation awareness system framework that integrates data collection, data processing, data storage, data analysis and data presentation to filter out harmful data and ensure network security. In this paper, the basic concept and system framework of network security situational awareness are briefly introduced. Firstly, Flume and Kafka are used to obtain log or network attack information, and MapReduce and Storm technologies are used for batch or real-time analysis to achieve the perception of network security. Then, the analytic hierarchy process (AHP) is used to determine the index weight, extract the characteristics of the network situation, and complete the evaluation of the network security situation by analyzing and constructing the decision matrix. The system has the characteristics of high availability, scalability and easy deployment, which can better support the perception and prediction of various network security threats.
Optimal Design of Multi-Objective Parameters for Interference Fit of Motor Fan Pedestal based on ANSYS
Authors: Feng Yuan , Miao Jie , Zheng Libo , Wang Xingru
Published: June 2022

The motor fan is an important part of the motor, mainly responsible for the function of heat dissipation. The fan and the rotating shaft are connected by interference fit together. Under the working state, the fan not only bears the action of centrifugal force, but also the action of interference force, and the quality of its mechanical properties has a great influence on the life of the motor. In this paper, ANSYS Workbench is used to optimize the design of the interference fit between the fan base and the rotating shaft of the motor. The technology of finite element analysis is used to design the different structural parameter values, and to simulate and calculate the structural stress under various working conditions, when the criteria of the design are met, a satisfactory result is obtained to guide the design and development.
Failure Analysis of the Metal Hose Puncture and Leakage in a Natural Gas Reinjection Station
Authors: Song Enpeng , Jin Quan , Cai Ke , Liu Yangqin
Published: June 2022

The metal hose in the pump room of an oilfield natural gas reinjection station has multiple punctures and leaks. In order to analyze the reasons for the failures, a macro inspection, hydrostatic pressure and blasting test were carried out on a new hose of the same specification. Phase organization analysis, macro inspection, physical and chemical inspection, scanning electron microscopy (SEM), energy spectrum analysis, metallographic analysis and composition analysis of the conveying medium were carried out on the two failed hoses. The results show that the hydrostatic pressure test of the same batch of the new hoses of this specification meets the requirements of the standard, however the burst pressure does not meet the requirements of the standard. The failure is caused by the welding quality problems at the joint connection, welding defects such as weld bead, incomplete penetration and welding slag. The existence of deformation-induced martensite is found in the metallographic structure of the failed hose corrugated tube. There is tensile stress in the service environment, and a high content of corrosive medium Cl- in the conveying medium. Under the action of internal stress, the internal corrosive medium causes corrugation, the tube undergoes stress corrosion, thus initiating corrosion cracks and propagating along the grain boundaries, leading to the cracks and failure accidents.
Prediction of RBPs from sequence by means of genetic algorithm and nu-SVR
Authors: Li Wenjun , Yang Peng , Yanyan Ge
Published: June 2022

Post-transcriptional regulation occurs at every moment in human’s body, so it makes the identification of RNA-binding proteins (RBPs) very important, because the RBPs are indispensable accessories to post-transcriptional regulation. Although many computational methods have been developed to replace the high-costly experimental methods, most of them run slowly and the result not well enough. Based on above factors, in this study, we propose a new method namely GASVR-RBP. Firstly, we extract features from protein sequences based on physicochemical properties and Pre-in-One web server, after the feature vector space constructed, we trained eight classifiers on 9857 protein sequences with the combination of genetic algorithm (GA) and nu-SVR, and by employing the ensemble strategy, we obtained an improved performance in three test set, the accuracy are 89.3%, 84.3% and 88.8%, which higher than Naive Bayes (NB) and Random Forest (RF). These results show that our method is effective for RBPs prediction.
A simplified and stable lattice Boltzmann shallow water model
Authors: Maquignon Nicolas , Smaoui Hassan , Sergent Philippe , Bader Bruno
Published: June 2022

In this article, a simplified and stable (S&S) lattice Boltzmann shallow water (LBMSW) model is introduced. In past articles, several types of LBMSW models based on different collision operators were studied, such as BGK-SRT, raw moments MRT, central moments MRT, or cumulants MRT, and allowed to reach interesting performances in terms of numerical stability, accuracy and execution time. But no simplified and stable model for LBMSW have been published yet, such as those for gaseous cases. In this article, such a method is introduced for shallow water problems and numerical performances are studied. For numerical performances evaluation, dam break and circular dam break benchmarks using S&S will be presented and compared to other methods.
Investigation of the Blockage Correction to Improve the Accuracy of Taylor’s Low-Speed Wind Tunnel
Authors: Al-Obaidi A S M , Madivaanan Ganesh
Published: June 2022

Placing a test model in the wind tunnel test section creates an interaction between the flow and the model and walls of the test section. This interaction affects the accuracy of data reading of the wind tunnel. One of the significant factors is the blockage which affects the drag and lift coefficients, causing inaccurate readings. This paper considered streamlined and blunted shapes of different sizes to investigate and assess the effect of the shape and size of the test model on the reading accuracy. Wind tunnel tests were conducted with the three different sizes for each shape to determine the aerodynamic coefficients of the models. Different correction methods were applied to find the correction coefficient. CFD simulations were performed using ANSYS Fluent software. A comparison of numerical and experimental results was carried out to determine the most suitable blockage correction method for the chosen models. It is found that a blockage ratio of less than 16% has the least blockage effect. The blockage correction of drag reduction for these models is very minimal, less than 1%. Correction coefficients for both shapes were derived to correct the blockage effect created by models with a blockage ratio of 16% or higher.
Novel adjustable platform for camera mount
Authors: Chen P S M , Tien D T K , Chung E C Y
Published: June 2022

Pan-tilt mechanisms are often used as adjustable camera mounts which can be automated if required. However, existing motorized pan-tilt mechanisms are unsuitable for heavy cameras. In this study, a novel mechanism from patent MY-175792-A was adapted as a camera mount to assess its suitability as a motorized support for heavy cameras. Unlike a ball head or pan-tilt mechanism, this adjustable platform tended to change its centre of rotation as it pitched. To ensure that its stability was not compromised, various lengths of cameras were mounted on it to study changes in the centre of gravity of the system as it was pitched and yawed to different angles. This study was conducted entirely through simulation. To facilitate a seamless pan-tilt motion, the force required to slide the active joint was determined through the analysis of static equilibrium. In addition, the required torque to yaw the mount was determined through motion analysis using SolidWorks. The design proved viable as a platform for heavy cameras. It also tended to provide a natural zooming and elevating effect for its pitch motion. Its structure was stable despite simulating the longest available TV camera being pitched and yawed on it to any angle.
Desiccant-based air dehumidifier and cooling system
Authors: Al-Obaidi A S M , Peterson S , Hui K J L N
Published: June 2022

Air conditioning system plays a vital role in providing convenient environment for human. Many studies conducted on the efficiencies of the air conditioners operating under vapor compression cycle (VCC), however, only few recent studies conducted to analyse the indoor humidity efficiencies. In this research, silica gel, zeolite, and molecular sieve as solid desiccants were experimented to observe their adsorption ability to identify the suitable desiccant material for dehumidification for air conditioner. It was noted that silica gel adsorbs 48% of water during the experiment making it to be the best adsorbent. The highest water adsorption capability by silica gel motivated this research to conduct numerical method to analyse its performance in the desiccant wheel system. The density, thermal conductivity, and specific heat capacity of silica gel used at the desiccant channel region on the geometry. The numerical results showed that the suitable regeneration temperature to reactivate silica gel is 35 °C with thermal effectiveness of 0.375. Silica gel has dehumidification efficiency of 85% and moisture removal capacity of 2.571×10−4 g/s. This system can be a potential trademark for HVAC industries to innovate pollutant-free systems because SDCS does not release any harmful coolants such as chlorofluorocarbon and hydrochlorofluorocarbon to environment.
Evaluation of Pupillary Distance (PD) Measurement using Smartphone-based Pupilometer
Authors: Husna H N , Fitriani N
Published: June 2022

Measurement of the pupillary distance (PD) is one of the important steps of the spectacles-making process. PD measurement can be done using the PD Ruler, Auto-refractometer, and smartphones’ apps. The study aims to evaluate PD measurement apps (Pupil Distance Meter Pro from Vistech Project, PD Pupil Distance for Eye Glasses and VR Headset from Glassify Me, and The Ultimate PD Rule) and compared them with Auto-refractometer as the gold standard. A total of 39 students (age 19-22) were involved in this study. The result of this study indicated that there was no difference between the measurement of the PD using the Glassify me app and the Auto-refractometer (p = 0.48). However, there was a mean difference of 0.2 mm between them. It could be concluded that the Glassify me app has the best accuracy compared to other apps (p value 0.48). This app was recommended to be used as an alternative to PD measurement.
Electroencephalography Signal Power Spectral Density from Measurements in Room with and Without Faraday Cage: A Comparative Study
Authors: Suwandi G R F , Khotimah S N , Suprijadi
Published: June 2022

Electroencephalography (EEG) is a method for recording the brain’s electrical activity through electrodes placed on the scalp’s surface. This EEG has its problem, namely signal interference from outside the system or artifacts. Ways to eliminate this signal interference can be made in various ways, including handling signal sources outside the system or removing interference signals during the EEG signal processing process. One way is to isolate the measurement room from signal interference using a Faraday cage. In this study, we will compare the results of EEG signal processing in the form of power spectral density (PSD) from measurements in a room without a Faraday cage and a room with a Faraday cage. We find that the average value of the change in PSD from the measurement results in the two rooms had a level of difference that varied between 0.71%-66%. The location of the electrodes that have a high difference value is the frontal and parietal areas.
Statistical analysis of quantitative electrocardiographic signals with standard limb leads: Influences of gel use, subject positions, and electrodes configurations
Authors: Khotimah S N , Wahyuni F S , Haryanto F
Published: June 2022

An electrocardiogram records the heart’s electrical activity that provides helpful information on the cardio electrophysiological process. One cycle of cardiac contraction and relaxation produces the basic waves that consist of a P wave (atrial depolarization), a QRS complex (ventricular depolarization), and a T wave (ventricular repolarization). In this study, the quantitative electrocardiographic signals from six adult females aged 19 to 22 years in a relaxed state were measured using Cobra4 Electrophysiology with standard limb leads. Six conditions of the experiments were carried out for each subject to investigate the influence of gel use, subject positions, and electrodes configurations on electrocardiographic signals parameters: amplitude, duration, RRinterval, and correlation coefficient between two signals. It was obtained that the gel did not significantly influence the results for subjects when sitting but marginally influenced some electrocardiographic parameters for some individual subjects in lying positions. The subject positions influenced marginally for RRinterval. Electrode configurations are found to be related to the positive or negative deflection of the resulting electrocardiographic signals. All the measurements showed that two data sets of the ECG signals have a strong correlation for each subject in each condition.
Radiobiological Analysis of Radioiodine Absorption in Thyroid Cancer Therapy
Authors: Sudarso Y P D , Widita R
Published: June 2022

Thyroid cancer therapy using I-131 has already used widely to help ablate thyroid remnants, but many patients still not convinced whether this therapy really ablate thyroid or not and their distribution in the body, also about the effect of metabolic process on decreasing the exposure rate of the body so that patient can go home early. By exposure rate of the body and urine of the patient, will be determined the uptake percentage, absorbed dose, absorption rate, and washing out percentage that helped to determine the probability of radioiodine absorption in thyroid compared to other organs and effect of metabolic process on decreasing the body exposure rate of the patient. This research will be focused to prove that this therapy indeed being absorbed more in thyroid rather in other organs and by increasing the metabolic activity, the exposure rate of the patient will decrease faster which means that the treatment going faster and reduce the queue of this therapy.
Refining the Regional Aftershocks Catalog of the Ambon Earthquake Mw 6.5 on 26 September 2019 using manual picking and a non-linear algorithm: Preliminary Result
Authors: Kamaruddin B , Sahara D P , Halauwet Y
Published: June 2022

A destructive earthquake with magnitude Mw 6.5 occurred in Ambon, Indonesia, on 26 September 2019. This earthquake generated an aftershock sequence. In this study, we determined the location of the aftershock sequence using a non-linear algorithm from the Non-Linear Location (NonLinLoc) program. The catalog and waveform data were collected using 11 seismographs from BMKG regional network located around the Maluku archipelago. The data was recorded between 26 September and 18 October 2019. We have manually picked the P-and-S wave phase by using Seisgram2K software. In our preliminary result, we have located about 1,300 events of aftershock sequence with about 8,500 phases of P and S waves. Overall, the location of the focus depth of the aftershock sequence is dominantly distributed in between 5 - 25 km. Approximately ~70% of the distribution of aftershock locations show a North-South (N-S) oriented pattern from west Seram to Ambon Islands. Meanwhile, about ~20% of the aftershock’s locations are distributed around Ambon Island. Our ongoing and future study is to determine accurate hypocentre location derived from double-difference hypocenter relocation with waveform cross-correlation.
Gravity Forward and Inversion Modelling in Improving the Geology Model of the Flank Volcanic Structure
Authors: Laesanpura Agus , Telaumbanua Benyamin Oozatulo , Rahadinata Toni , Ekawati Gestin Mey , Sugianto Asep
Published: June 2022

Cross-sections of volcanic structures are generally constructed using existing surface rock data. The detailed subsurface is not accessible because of a limited approach; as a result, precision is less accurate. Geophysical data obtained from surface gravity measurements will improve this phenomenon based on the response of density variation through forward and inverse modelling. The joint interpretation will make it possible to improve the subsurface model and to apply it in volcano deposits that experience a throw. Gravity data acquisition is 200 points over an area of 16 × 14 square kilometres. An anomaly study will focus on near-surface phenomena, where modelling shows that inversion needs to be enhanced by mesh refinement. In addition, forward modelling renders the model more realistic. The results show, the fault reaches a half km. It is not seen in the geology section, and the density variation shows 0.3 grams/cc. This density change is interpreted for the pyroclastic in the depression segment. Fumaroles may interpret as the water percolating pathway from the peak through the flank structure. The meteoric water flows inside the volcanic deposits and the fault plane is the ends of the meteoric water reaching the outside.
Focal Mechanism Inversion on the Aftershock Sequence of the 25 October, 2010 Mw 7.8 Mentawai Earthquake: A Preliminary Result
Authors: Daniarsyad Gatut , Afnimar
Published: June 2022

An Mw 7.8 tsunami earthquake ruptured the shallow part of the Mentawai megathrust on 25 October 2010 and generated a large tsunami that hit the Mentawai Islands. The earthquake continued a partial rupture sequence of the 2007 Mw 8.5 and 7.9 Bengkulu earthquake and the 2008 Mw 7.2 North Pagai earthquake. The aftershock activity gives the opportunity to investigate the geometry of the subduction interface, which is critical to understanding the propagation and termination of a large earthquake. However, it is necessary to have a precise location and mechanism of the aftershock distribution to clearly image the fault geometry. In this preliminary study, we have applied the Cut-and-Paste (CAP) focal mechanism inversion method to 20 aftershocks (M ≥ 4.9) of the 2010 Mentawai earthquake. The seismic waveforms recorded by the BMKG broadband seismic network on the regional distance were used in the inversion. They successfully obtained ten focal mechanisms more than that provided in the GCMT catalog. The result exhibits a distinctly different thrust and normal faulting aftershocks activity. The thrust faulting aftershocks are mainly distributed in the downdip of the Mentawai 2010 mainshock rupture, indicating the stresses that have not been released during the mainshock. In the shallow region near the trench, the aftershocks are dominated by a normal faulting mechanism which shows the tensile stress caused by the bending of the subducting plate.
Love Wave Group Velocity Extraction Using Ambient Noise Tomography in West Java, Indonesia
Authors: Luthfiyani N , Rosalia S , Yudistira T , Widiyantoro S , Puspito A N T
Published: June 2022

West Java, Indonesia, is located in the northern part of the subduction zone between the Australian and Eurasian plates, with a complex tectonic setting and high seismicity level. In 2016, Institut Teknologi Bandung (ITB) and Australia National University (ANU) deployed 85 temporary seismometers to investigate this area. We constructed the shallow crust profile by applying the Ambient Noise Tomography (ANT) method to improve our knowledge of the tectonic condition in West Java. In this research, we used the north-south (NS) and east-west (EW) components to extract the Love waves Green’s function. We first rotated the NS and EW daily data series to obtain the transverse component. We then pre-processed the transverse daily data and applied cross-correlation to all station pair data. The daily cross-correlated data is stacked to obtain the Love waves Green’s function. The Green’s function in this study is clearly seen in the 1-25 s period band. The obtained Green’s function will be analyzed further to get the Love waves group velocity which then will be inverted to obtain the shear wave velocity (Vs) profile beneath the study area.
Evaluation of Atmospheric Correction Methods of Sentinel-2 for Monitoring Paddy Rice Growth in Cianjur and Klaten Regency
Authors: Muchsin F , Supriyatna  , Harmoko A , Prasasti I
Published: June 2022

Atmospheric correction is a critical pre-processing step required in quantitative remote sensing applications such as extraction of biophysical variables and multi-temporal analysis. The objective of this study was to evaluate surface reflectance of atmospheric correction methods base on scene-based empirical namely Dark Object Subtraction (DOS) and the radiative transfer methods namely the Second Simulation of Satellite Signal in the Solar Spectrum (6S). We applied these methods to Sentinel-2 images above rice fields in Cianjur and Klaten Regency, and compared surface reflectance from atmospheric correction methods with ground measured reflectance base on spectral response and vegetation indices (NDVI, EVI, SAVI and MSAVI). For that purpose, generative phase of rice growth was analysed by using statistical analysis. The result showed that the 6S method has better accuracy than DOS and varies on each bands.
Automatic Hyperbola Detection and Apex Extraction Using Convolutional Neural Network on GPR Data
Authors: Dewantara Daffa , Parnadi Wahyudi W.
Published: June 2022

Ground Penetrating Radar (GPR) is a non-destructive geophysical method used for subsurface mapping. It is frequently used for detecting buried cylindrical objects such as underground pipes and cables. Buried cylindrical objects show a hyperbolic signal pattern on a radargram. The typical shape of the hyperbolic reflections depends on the depth and material of the buried objects and the surrounding materials. In many cases, detecting buried cylindrical objects is quite a time-consuming task, thus limiting further interpretation procedures. In this paper, we propose a new method for automating hyperbola detection and apex extraction on radargram. Our work consists of two modules that take radargram as input in a form of images. In the first module, we used the Faster-RCNN to extract the hyperbola segments as a set of rectangular boundary boxes. The network was trained using synthetic radargram data simulated by the gprMax software. The second module is to estimate the coordinates of the hyperbola apex using an image processing technique. We had correctly detected all hyperbola on the simulated radargram from the test set. For the test on field radargram, the framework is capable of processing radargram that is similar to the simulated radargram data. The problem with the second module occurs on interference hyperbola as the searching window is disturbed by the noise. Apart from those problems, by using these two modules, the detection of buried cylindrical objects using GPR can be automated with a minimal amount of time.
Development of azimuthal resistivity survey data processing program with graphical user interface for anisotropic coefficient quantification
Authors: Atmaodi Berith , Parnadi Wahyudi W.
Published: June 2022

The physical properties of underground material are anisotropic. This applies to all physical properties including resistivity. Anisotropic property is quantified by the anisotropic coefficient. The anisotropy of physical properties can be shown by 2D and or 3D modeling, but it is not always economically efficient for small-scale studies, while 1D modeling is not capable of showing the anisotropy effect. One of the many geophysical methods developed to learn about anisotropic properties under the earth is the azimuthal resistivity survey (ARS) which is the improvement of the vertical electrical sounding (VES) method. Measurement is carried out in one dimension with various electrode spacing and azimuth of electrode lines. The result of this measurement is VES data for various azimuths. ARS data is then plotted with a polar plot to show the anisotropy of physical properties below the surface. The anisotropic coefficient calculation is carried out by performing the one-dimension inversion of the measurement data for every azimuth, for a user-defined number and constant thickness of the layer. The result is then used to calculate the variation of the anisotropic coefficient value against depth. The algorithm used to create the polar plot and VES data inversion are then combined into one program based on Python programming language. This program is equipped with a graphical user interface (GUI) to make the program more user-friendly. The program is tested with synthetic data and successfully imaged the anisotropic coefficient variation against depth for the synthetic data.
A Preliminary Result of Seismic Hazard Analysis in Eastern Part of Bali Island, Indonesia
Authors: Priambodo Imam Catur , Zulfakriza  , Solikhin Akhmad , Cipta Athanasius , Martanto  , Ardianto
Published: June 2022

Bali Island is one of the main tourist destinations in Indonesia. However, Bali Island is also prone to earthquakes, as evidenced by several historical destructive earthquakes, especially in the eastern part of Bali. A probabilistic seismic hazard modeling is undertaken to analyse the earthquake hazard, as well as studying the contribution of local geological conditions to earthquake ground motion. We use seismic waveforms retrieved from 23 temporary seismic stations across the eastern part of Bali Island from December 2018 to June 2019 and 5 permanent seismic stations around Mount Agung and Batur. The recording data were processed using the Horizontal to Vertical Spectral Ratio (HVSR) method. Our preliminary result shows local geological conditions for each station, represented by the value of the average shear-wave velocity on rocks to a depth of 30 meters (Vs30) and the total thickness of sediments above the bedrock (basin depth). These initial results will then be developed as site parameter input for probabilistic seismic hazard analysis in the eastern part of Bali.
Features Engineering and Features Extraction of Volcano-Tectonic (VT) Earthquake
Authors: Martanto Martanto , Nugraha Andri Dian , Sahara David P. , Syahbana Devy Kamil , Rahsetyo Puput P. , Priambodo Imam C. , Ardianto Ardianto
Published: June 2022

A volcano-Tectonic earthquake, commonly referred to as VT, is an earthquake caused by magma intrusion that increases the pressure below the volcano’s surface. The accumulation of stress that continuously affects the elasticity of rocks causes fractures when the elasticity limit of rocks is exceeded. VT is one of the earthquakes used as a parameter to decide the level of volcanic activity. To understand the characteristics of VT, it is necessary to do features engineering, which is a process of extracting features so that the characteristics of VT are obtained. The data used in this study was the VT earthquake when Agung was in crisis in 2017. The extraction process is conducted by performing statistics calculations in temporal and spectral domains. The waveform of VT is univariate time series data, and to perform the extraction of features, this study uses changes in amplitude value to the time taken from the waveform. Features that were successfully extracted from this study are as many as 48 features. The result of the extraction of these features can be used as input parameters in performing auto-classification of VT using machine learning.
Velocity Dispersion Attribute in Carbonate Reservoir
Authors: Erlangga M P , Sukmono S , Triyoso W , Sanny T A , Sigalingging A S , Wijaksono E
Published: June 2022

Detection of the presence of saturated hydrocarbons in pores or rock fractures is a major problem in the field of exploration geophysics which is interesting to study. Some of the fluid saturation indicators were originally derived from the Zoepprit equation. However, the indicator that is derived from the linearization of the reflection coefficient is not influenced by frequency. In fact, frequency is a physical quantity that is very sensitive to the presence of fluid in a pore or rock fracture. Seismic waves will experience attenuation and dispersion when propagating through a porous medium or gas-saturated fractures. Therefore, we need an indicator whose value is influenced by changes in the frequency of seismic waves. This indicator is an attribute of the velocity dispersion. In previous studies, the velocity dispersion attribute was used to detect the fluid content of gas in sandstone. Based on this research, it turns out that it shows effective results in mapping the presence of saturated gas zones in the carbonate pores. In the end, the results of this study will be able to map the presence of saturated gas zones in carbonate reservoir.
Design of Real-Time Object Detection in Mobile Robot for Volcano Monitoring Application
Authors: Evita M , Mustikawati S T , Djamal M
Published: June 2022

Indonesia is one of the countries located at the ring of fire which should be monitored to predict the eruption earlier and set the risk zones around with no human involvement especially while eruption taking place. Therefore, in this research, it is used a 4 wheeled mobile robot called PRAWIRA for this purpose. The robot should have the ability to avoid the obstacles in front of it in this area. It has been designed a real-time object detection system for volcano monitoring application using deep learning from the YOLOv5s model for 4 objects (trees, persons, stones, and stairs). It was used 484 images for the dataset after the pre-train process was conducted with several steps: object identification; dataset downloading (Google Chrome Extension and Open Images v6); image labeling (LabeImg); augmentation process (flip, blur, and rotation); and data training for varies epochs and batches by Jupyter Notebook GPU. The preliminary result for this research was presented in the mean average precision (mAP) of YOLOv5s (the smallest version). The first variation (batch = 16, epochs = 100) resulted in mAP_0.5 = 17.9% and mAP_0.5:0.95 = 7.27% with 0.262 hours of training time. The second (batch = 16, epochs = 500) resulted in mAP_0.5 = 25.7% and mAP_0.5:0.95 = 12.3% with 1.296 hours of training time, while the third (batch = 80, epochs = 100) resulted in mAP_0.5 = 17.7% and mAP_0.5:0.95 = 5.63% with 0.232 hours of training time. Furthermore, the last variation (batch = 80, epochs = 500) resulted in mAP_0.5 = 19.5% and mAP_0.5:0.95 = 8.92% with 1.085 hours of training time. Therefore, the second variation is the best result for the model with 14.8 MB of size. Moreover, interfaces for the best model were displayed to show the result of the training.
Design of Micro Power Energy Harvesting by Using High-Powered Engine Noise (Case Study: Generator Set ITK)
Authors: Hariyanto M F , Mayantasari M , Robiandi F
Published: June 2022

Study on design of micro power energy harvesting using high-power engine noise was aimed to compare the output voltage generated between random noise and stable noise and also determined the piezoelectric circuit variation which produced by ITK’s generator set noise. The noise energy harvester consisted of a quarter wavelength resonator box, three fins, and 3 ceramics piezoelectric. Function generator used to produce a stable wave and the ITK’s engine used to generate random wave. The first experimental result showed that piezoelectric average output voltage from noise engine was higher than noise from function generator when the circuit variation was 1 piezoelectric, parallel circuit, and 3 parallel-series piezoelectric and the opposite, series circuits generated average output voltage was the lowest. The pattern of piezolectric average output voltage which was generated from noise engine source fluctuates, didn’t as stable as noise function generator. This research also got the result that three series piezoelectric generated average output voltage higher than the others with the value of 201,07 mV when SPL and f respectively was 103,5 dB and 223,62 Hz. A higher output would be generated by increase the number of piezoelectric and arranged them into series circuit.
Surface Functional Groups Effect on the Absorption Spectrum of Carbon Dots: Initial TD-DFT Study
Authors: Umami Reza , Permatasari Fitri Aulia , Sundari Citra Deliana Dewi , Muttaqien Fahdzi , Iskandar Ferry
Published: June 2022

Carbon dots (CDs) have attracted considerable interest due to their remarkable performance, low cost and ease of preparation, and wide range of potential applications. Surface engineering, including modifying the surface functional group and subsequent chemical modification, is preferable to achieve the requirement of the specific application. Oxygen and Nitrogen-based surface functional groups are two common functionalizations on CDs that are subsequently generated during the synthetic process. In this study, we elucidate the optical properties of oxygen and nitrogen-functionalized CDs using time-dependent density functional theory (TD-DFT). Both considered functional groups, the carbon-oxygen double bond (-C=O) and amino groups (-NH2), are quite favourable to tailor the optical properties of CDs, especially in enhancing its absorption spectrum. Moreover, the carbonyl (-C=O) and amino (-NH2) functional groups effectively serve a new absorption peak in the first near-infrared window (650-900 nm). Our results suggest the potential application of the amino and carbonyl functionalized CDs as a photothermal agent in photothermal cancer therapy.
Rietveld study on the effect of pelletizing and sintering towards the structural evolution of Li1.3Al0.3Ti1.7(PO4)3
Authors: Sohib Ahmad , Karunawan Jotti , Sundari Citra Deliana Dewi , Floweri Octia , Iskandar Ferry
Published: June 2022

Lithium aluminium titanium phosphate, Li1.3Al0.3Ti1.7(PO4)3 (LATP), is a highly potential material for solid electrolyte (SE) in an all-solid-state battery (ASSB) thanks to its superior ionic conductivity. The crystallinity of the material plays an important role in determining the ionic conductivity, ensuring the excellent performance of ASSB. To be applied in the ASSB, LATP should be pressed into a disc and then sintered at a high temperature to obtain the dense disk. This research aims to investigate the effect of pelletizing and sintering on the crystallinity of LATP. LATP powder was synthesized via a sol-gel method and mechanically pressed into pellets and sintered. Morphology and structural features of the LATP samples (powder and pelletized samples) were characterized using a scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The results demonstrated that the particle size of LATP in the pelletized samples was larger than the powder one. This morphology possibly contributed to the lower internal resistance of LATP and, therefore, its higher ionic conductivity. Rietveld refinement analysis showed that the crystalline properties of LATP changed after pelletizing and sintering treatment. This research demonstrated the importance of well consideration of pelletizing and sintering process to achieve high ionic conductivity of LATP.