bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementation of Image Resampling Algorithm Based on Compressed Sensing
Authors: Li Denghui , Wang Yanhong
Published: January 2021

In this paper, the sampling rate of traditional signal reconstruction should be more than 2 times the maximum frequency of the original signal in order to ensure the non-distortion reconstruction of the signal. The theoretical knowledge of compressed sensing is deeply analysed, and the image signal is reconstructed by block compression sensing method. Experiments show that the sampling rate is more higher, and the reconstruction error is more smaller, but the processing complexity is more higher; conversely, the lower the sampling rate, the lower the processing complexity, the greater the reconstruction error.
Research on Image Recognition Algorithm Technology for Power Line detection
Authors: Wang Dong , Zhu Tuofu , Xie Aoyu , Fang Nian , Liu Hongliang
Published: January 2021

Based on the analysis of power line features in aerial images, this paper proposes a power line detection algorithm for aerial images based on adjustable direction filtering. The thesis first performs directional filtering on the image and calculates its directional energy function and ridge energy function, then combines the image local and global information to fit the line segments in the image, and finally verifies the reliability and real-time performance of the algorithm through experimental methods. The calculation of this algorithm is about half of the ED Lines algorithm. Experimental results show that the algorithm can detect power lines in aerial images better, and the algorithm is not complicated, which is suitable for real-time detection of power lines.
A New Neural Network with Genetic Algorithm in Searching Nonlinear Function Extremum
Authors: Qu Huiyan , Cheng Sining
Published: January 2021

In order to more accurate for nonlinear function extreme, this paper used improved particle swarm optimization neural network combining with genetic algorithm method to solve the problem. In view of the particle swarm optimization algorithm is easy to appear “premature” faults, introducing the adaptive threshold, initializing particles if they were under the constraint conditions, making particles jump out to the optimal value of the position in previous search. Through the experiment, contrasts to the genetic neural network algorithm and traditional BP neural network, this method is faster in convergence and has the smallest prediction error. Finally, combining with genetic algorithm, calculating the extreme value of nonlinear function by using the above three kinds of neural network trained forecast as an individual output fitness value. The adaptive particle swarm optimization neural network proves the most close to the theoretical calculation. It shows that the method is effective.
Effects of Thinning on Growth and Regeneration of Cyclobalanopsis glauca Secondary Forest
Authors: Shi Zhenwei
Published: January 2021

Based on the problems of poor productivity and natural regeneration of Cyclobalanopsis glauca secondary forest in hilly areas in southeast Hunan Province, experiments of thinning were carried out to analyze the effects on stand growth and regeneration of different thinning intensities and to provide guidance for managing secondary forests. Cyclobalanopsis glauca secondary forest was selected for research object, then experimental design was arranged with a randomized block by thinning intensity such as control(un-thinning), light thinning (10%), moderate thinning (20%) and heavy thinning (30%). Tree measuring factor and number of naturally regenerated seedlings were investigated for researching the responses to thinning treatment. Results showed that there were significant differences of mean DBH and current annual increment of DBH in terms of the four thinning treatments, and the larger the thinning intensity, the higher the DHB increment. The maximum mean height (10.1m) happened in stand of heavy thinning. However, significant differences existed in the current annual increment of height among the four thinning treatments. Stand volume was 93.27, 91.49, and 91.90 m3 hm−2 respectively in stand of heavy thinning, moderate thinning, light thinning, and were all lower than that of the control, but current annual increment of volume was 5.65, 4.43 and 3.75 m3 hm−2 yr−1, respectively and higher than that of the control. The Simpson index of shrub layer and herb layer of heavy thinning stand was 0.45 and 0.80, Shannon-Wiener index was 1.03 and 2.03, respectively. There were significant differences of naturally regenerated seedlings according to four thinning treatments only for seedlings of 5∼30 cm level, but there were no significant differences for seedlings of 30∼50 and 50∼150 cm level. The growing space and nutritional condition of retained trees after thinning were effectively improved, stand DBH and height increased with the increasing thinning intensity. However, stand volume was not significantly different among four thinning treatments. Besides, thinning at appropriate intensities could increase the biodiversity in shrub layer and herb layer, quantities of naturally regenerated seedlings also increased with the increasing thinning intensity. Heavy thinning (30%) was the best one among four thinning treatments for silvicultural interventions on Cyclobalanopsis glauca secondary forest.
Tebei calcium oyster powder may enhance rice output, decrease rice heavy metal concentration and reduce soil acidity
Authors: Huang Dongfeng , Luo Tao
Published: January 2021

The influences of several doses of Tebei calcium oyster powder on rice output, heavy metal concentration and basic soil fertility characteristics were studied by field plot experiment. Outcomes indicated that the use of several doses of Tebei calcium oyster powder could raise the dry matter output of rice by 5.24%∼20.65%, reduce the Cd and Pb concentration of rice by 7.80%∼53.67% and 12.63%∼60.10%, raise the pH value of soil by 4.1%∼24.5%, decrease the exchangeable acid (potential acid) by 1.0%∼53.8%, and decrease the concentration of Influenceive Cd and Pb by 64.22%∼77.98% and 4.65%∼22.59%, respectively.
Front Obstacle Detection System based on YOLOv3
Authors: Wang Chao , Huang Yiyang , Shi Bowen
Published: January 2021

The task of front obstacle detection in unmanned driving is to allow the model to accurately detect types and corresponding position of each object. Complex true driving environment, multiple types of objects within range of visibility and multiple examples are challenges for detection. Particularly in unmanned driving field, not only the detection precision shall be pursued, but also the detection speed shall be guaranteed. This paper puts forward the front obstacle detection method based on YOLOv3. It establishes a Tensor Flow+Keras framework on GPU server cluster, designs and realizes YOLOv3, and realizes calibration and classification of front obstacles through training and optimization of the model on the data set. This method supports over 10 object types. Experimental results show validation set Loss (VAL Loss) reaches 21.206, mAP reaches 78.64, and detection speed reaches 30 FPS. The study provides theoretical basis for obstacles detection of automated vehicle in complex environment.
Study on the optimization of pile group foundation under oblique load
Authors: Dong Bin , Wang Liang , Liu Wenting , Han Aiguo , Tang Yang , Yuan Lei
Published: January 2021

With the development of economy and science and technology in China, pile group foundation is widely used in various constructions to meet the complex engineering conditions. Pile foundation is often affected by inclined load (i.e. horizontal load and vertical load). The behavior of pile under inclined load is much more complex than that under single load. In engineering, the vertical component and the horizontal component of the pile top are often calculated separately, and then modified. This method is only suitable for small deformation, which is different from the actual situation. In this paper, taking the four pile foundation as an example, through the rotation of the cushion cap (the column does not rotate) and the column eccentricity, the force of the foundation pile can be relatively uniform. At the same time, the design calculation of the group pile foundation under the oblique load can be approximately equivalent to the design calculation of the group pile foundation under the single vertical load. When the force distribution on the pile top is relatively uniform under the same inclined load, the eccentricity of the column has a linear relationship with the depth of the cap. Through ABAQUS numerical simulation analysis, the correctness of the above understanding is verified.
Metal Material Resistant to Hydrochloric Acid Corrosion
Authors: Fan Ruicheng , Zhang Weiqi , Wang Yongwang , Chen Dong , Zhang Yunfeng
Published: January 2021

Hydrochloric acid, especially when contains a certain amount of FeCl3 (or oxidizing salt such as copper chloride), is highly corrosive to chemical equipment, which will lead to problems of malignant destruction and failure. Therefore, the correct and rational selection of material is essential for the production and use of hydrochloric acid. In this paper, from the corrosion characteristics of hydrochloric acid and the factors affecting the selection of hydrochloric acid resistant materials, the metal materials resistant to hydrochloric acid corrosion are reviewed, which provides a scientific basis for material selection of alumina extraction from fly ash by acid method and other similar working conditions.
Design of a kind of Steel Cable Bridge for Belt Conveyor
Authors: Zhou Qi , Li Chenxi , Liu Hongwei , Ma Ming , Zhang Rui , Zhang Zhao
Published: January 2021

Steel cable bridge is a kind of flexible suspension bridge with steel wire rope as the main stress components. It has the advantages of low construction cost, short engineering period, reliable structure, simple construction, etc., and has been widely used in driving and walking passages. In this paper, a 110m steel cable bridge supporting the belt conveyor is as an example, the finite element software Midas/civil is used to establish a spatial calculation model, and the cable force and displacement are calculated and analyzed. The results and calculation process can provide theoretical basis and practical experience for the design of steel cable bridge for belt conveyor.
Research on PMSM Speed Control System Based on Adaptive Fuzzy Control
Authors: Liu Shengjian , Wang Jianmin , Zheng Zhiyuan
Published: January 2021

PMSM servo system has nonlinear, parameter time-varying, load disturbance and other issues. In the face of these problems, traditional PI control strategies often fail to achieve ideal parameter tracking and load immunity, showing a large degree of limitations. Aiming at this kind of problem, this paper designs a fuzzy PI control method combining PI control and fuzzy control, and uses the vector rotation control method of current speed double closed loop to drive the permanent magnet synchronous motor for control. Finally, the traditional PI control system and fuzzy PI control system simulation model are built in Matlab/Simulink environment. The simulations were carried out in three cases of high speed, medium speed and low speed, and the speed and current waveforms of the two control methods were observed. The simulation results show that the fuzzy PI control system can increase the response rate, reduce the overshoot of the speed and reduce the current fluctuation in the full speed range. The robustness of the system is improved, the adaptability of the system to load changes is enhanced, and the correctness of the theoretical analysis is verified.
Experimental investigation of axial Solid concentration distribution in fluidized bed
Authors: Gao Shun , Lu Yuanchun , Duan Jihai
Published: January 2021

The axial solid concentration distributions were measured by using pressure inspection instrument in a glass bead fluidized bed. Set 1-3 belong to single size distribution and Set 4-5 have wide size distribution, respectively. The change trend of axial solid concentration distributions were investigated under different superficial gas velocities, particle size and particle density. The results showed that, with increasing superficial gas velocity, the solid concentrations in dense region decreased, but increased in dilute region. The glass bead particles whose particle size and particle density were smaller had good fluidization quality. It was also found that the joining of fine particles can significantly change the flow characteristics of the fluidized solid particles.
Flow Analysis and Optimization of the Air channel of Drying Chamber Based on CFD
Authors: Li Ming , Liu Jianqiao , Niu Hongwei , Jiang Yan
Published: January 2021

According to the structure of the air channel in the drying chamber of an automobile factory, a model of the original structure of the drying chamber was established. The air flow of this structure is analyzed based on the CFD simulation, and the velocity at specific points of the car shell being dried is also analyzed. The results show that the original drying chamber structure is optimized, the air flow is uniform in the drying air chamber and short circuit of air between inlet and outlet in the drying chamber is decreased.
Multi-objective Planning of the Economic Operation of Microgrid Considering the Energy Loss and the Start-up Cost of Conventional Units
Authors: Ke Xue , Yin Yiheng , Xu Zecheng
Published: January 2021

The fluctuation of load and new energy will have an important impact on the operation mode of microgrid. In order to balance the economy and reliability of microgrid, a chance constrained model of microgrid is established firstly. Based on the reliability cost, the operation cost of microgrid under different confidence levels is calculated, and a reasonable confidence level of rotating reserve is obtained. This paper analyzes the impact of energy storage charge and discharge loss and conventional unit start-up cost on the economic operation of the isolated micro grid; for the grid connected micro grid, the economy of its own operation and the effect of auxiliary large grid peak load shedding are taken as the objective function, and the multi-objective programming method proposed in this paper is used to solve the problem. The example analysis shows that the multi-objective programming method in this paper, by combining with particle swarm optimization algorithm, can optimize the weight of different objectives reasonably, which can not only help the large power grid to cut peak and fill valley, but also realize the economy of microgrid operation.
Analysis of Pt Ferroresonance based on Excitation Characteristic and Self-Excitation Mechanism
Authors: Zhang Yu , Xie Shijun , Jiang Nanxi , Zhao Zhirong , Luo Donghui , Wang Naihui , Li Jian
Published: January 2021

PT ferroresonance occurred frequently in distribution network, which seriously threatened the safety of personnel and equipment of substation, and seriously affected the power supply reliability of distribution network. In order to reveal the real cause of PT ferro resonance, to propose the solutions. In order to solve the problem of PT resonance and provide theoretical basis for PT resonance prevention and control, this paper carried out the analysis of PT resonance mechanism, PT excitation characteristics and PT frequency division resonance self-mechanism.
Analysis of Frequency Response Characteristics for CVT Over-voltage Monitoring Device under Different Load Conditions
Authors: Zhu Jingfeng , Chen Shaoqing , Su Tao , Zhao Jingwei , Liang Wei
Published: January 2021

The accurate measurement of over-voltage is very important to ensure the safety and stability of power grid. Therefore, the frequency response characteristics of the over-voltage monitoring device employing capacitive voltage transformer (CVT) under different load conditions are tested and analysed in this paper, and the effect of load change on the frequency response characteristics without and with interior low-voltage capacitor is studied. The results show that: for the case without interior low-voltage capacitor, when the secondary side of CVT is no-load or rated load, the frequency characteristics are roughly the same, but when the load is heavy, the frequency characteristics are greatly different from the situation under rated load. When there is an interior low-voltage capacitor, the presence of the interior low-voltage capacitor has almost no effect on the frequency characteristics of CVT under different load conditions, and there is also little effect on the frequency characteristics of the interior low-voltage capacitor high-voltage side under rated load and no-load conditions.
A partition design for a rotary shelf system based on ABC classification
Authors: Liu Yong , Tang Wei , Ma Yunfeng , Xie Qi
Published: January 2021

On the basis of the traditional ABC classification method, this paper determines another standard to subdivide the goods, that is, hierarchical ABC classification method. The calculation shows that, based on the hierarchical ABC classification method, the efficiency of multi-layer horizontal rotating shelves is increased by 26.94% and vertical shelves by 37.25%. The partition design scheme is helpful to optimize the operation efficiency of the rotating shelf warehousing system and verifies the validity and rationality of the partition design.
Accuracy Assessment of Detecting Cracks on Concrete Wall at Different Distances using Unmanned Autonomous Vehicle (UAV) Images
Authors: Norashikin Bohari Sharifah , Uzzairah Amran Ain , Ain Mohd Zaki Nurul , Safwan Suhaimi Muhammad , Rauf Abdul Rasam Abdul
Published: January 2021

Distance plays an essential role in detcrmining crack detection. Without proper or fixed value of length, the time taken to capture the image of a crack may increase. It is essential to know the capability of Unmanned Autonomous Vehicle (UAV) to capture images for detecting cracks at different distances as it may be useful for building inspection, especially as it shortens the time taken to inspect cracks on buildings. This paper aims to analyze the accuracy of the UAV image in detecting cracks at different distance measurements qualitatively and quantitatively. The observed UAV images of the concrete wall starting from 1m until 6m distances were obtained. The images were processed using Agisoft software, while the edge detection algorithm of the Digimizer software was used for the crack width detection process. It was found that in detecting cracks at different distances, the hairline crack was visible at 3 meters, the narrow crack at 5 meters, and the medium crack at 6 meters. The relationship between distance and size of crack allows for a better understanding on how distance affects the detection of the crack which may be useful for building inspections or in the engineering sector.
A Comparative Flight Altitude Using Multi-Rotor UAV for Oil Palm Tree Counting
Authors: Talib Noorfatekah , Shafizal Mohd Saad Mohamad , Aminah Anshah Siti , Md Saad Nurhafiza , Diana Ghazali Mimi , Amsyar Abdullah Mohd , Jafni Hazwan Wan Mohd Jailani Wan
Published: January 2021

Unmanned Aerial Vehicle (UAV) is a new platform used in various applications such as landslide monitoring, agriculture, mapping, traffic control, mining, and others. In the photogrammetry survey, the use of UAV is cheaper and more effective for 3-dimensional modelling compared with traditional photogrammetry and Light Detection and Ranging (LIDAR). The ability of UAV to acquire data at a different altitude below the cloud coverage and easy to control has made it one of the most popular platforms in surveying applications. The objective of this paper is to count the numbers of the oil palm tree and define the most suitable flight attitude for tree counting based on the different UAV processing software. The study area is located at Felda Laka Temin in Chuping, Perlis. The comparison of flight altitude is 100m and 200m processed in Agisoft PhotoScan and Pix4D Mapper software. The analysis has been done with errors in Standard Deviation and Root Mean Square Error (RMSE) of Ground Control Point (GCP) which are generated using two different software.
Soil Suitability Assessment for Harumanis Mango Cultivation in UiTM Arau, Perlis
Authors: Nasron N , Ghazali N S , Shahidin N M , Mohamad A A , Pugi S A , Razi N M
Published: January 2021

Perlis is one of the largest mango producers in Malaysia cultivating Sala, Harumanis, Thong Dam, Thong Dam Burma, and Melele. Among those types, Harumanis is the most popular and loved by many because of its aroma, texture, and sweetness. The production of quality Harumanis mango depends on the intensive care that is needed by the plant itself such as soil suitability, and climatic factors; such as weather and temperature. The soil suitability is an important role as a nutrient source by plant in maximizing plant growth. The extremely hot and prolonged weather conditions in December 2015 due to El Nino phenomenon are influencing a production of Harumanis products in Perlis on 2016. This phenomenon is effect on a soil moisture content rate for the plant growth. The aim of this study is to determine the soil suitability for the Harumanis mango cultivation in UiTM Arau, Perlis using Analytic Hierarchy Process (AHP) method. Three objectives were performed to achieve the aims which are identifying bulk density, soil pH, and organic matter content value using Inverse Distance Weight (IDW) interpolation method, determining criteria weight of parameter using AHP method, and determining soil suitability for Harumanis mango cultivation in UiTM Arau, Perlis. IDW interpolation method was done by using ArcGIS 10.5, and this method used for assuming value of the whole study area that unmeasured. AHP also applied to determine the soil suitability area for Harumanis mango cultivation. The highest weight value is representing criterion that have relative important and tendency in determining the suitability Harumanis mango cultivation. The results of this study show that 40,551 m2 represent 65% of the total area of the study area is highly suitable soil for Harumanis cultivation. The percentage value is obtained based on a combination of weight criteria between bulk density, soil pH, and organic matter content, where the weight value of bulk density has the relative importance and the highest tendency to determine the soil suitability for Harumanis mango cultivation in UiTM Arau, Perlis.
Effect of Erosion and Accretion on Beach Profile in Kuala Terengganu Coastal Areas
Authors: Haron Narashid Rohayu , Arif Zakaria Muhammad , Amri Mohd Fazly , Faiz Pa’suya Muhammad , Talib Noorfatekah , Helmy Ariffin Effi
Published: January 2021

Coastal erosion and accretion are long-term process that may cause changes in shoreline and beach profiles. Due to erosion and accretion effects, most of the coastal areas in Malaysia are suffering from destruction of property especially at the coastal areas in east coast of Peninsular Malaysia. This study was conducted to determine the effects of erosion and accretion on beach profiles at four (4) coastal areas in Kuala Terengganu using remote sensing and GPS observation methods. The objectives include to derive the coastal erosion and accretion rate, to measure coastal elevation for beach slope angle calculation, and to determine the relationship between beach slope angle with coastal erosion and accretion. The erosion and accretion rate was derived from SPOT-5 satellite image and unmanned aerial vehicles (UAV). In order to obtain the beach profile, the elevation with 50m offset for every chainage, and 5m offset for each cross-section point were carried out using real-time kinetic (RTK) observation methods. It was found that the highest and lowest erosion and accretion rates were 170.29 m²/year and 57.53 m²/year, respectively. The beach profile became steeper with the beach slope values of 11.004° and 7.652° at high and low erosion areas, respectively. The relationships between beach slope angle and coastal erosion/accretion were found as 0.12 and 0.86 respectively. The findings showed that steeper beach profiles influenced the high rate values of erosion and accretion. For more accurate findings, further studies on the factors affecting the erosion and accretion such as monsoon seasonal changes and morphological impact are necessary to support the reliable decision-making process for sustainable coastal management.
Assessment of Pleiades Satellite Image for Mangrove Family Classification
Authors: Aminah Anshah Siti , Nizam Rosli Sharul , Omar Hamdan , Talib Noorfatekah , Md Saad Nurhafiza , Diana Ghazali Mimi
Published: January 2021

Remote sensing technology is the most common method used in monitoring conservation and restoration at mangrove areas. This study aims to classify the mangrove family at Bagan Datuk, Perak, using object-based image analysis techniques based on Pleiades’ image with 0.63m spatial resolution obtained from the Malaysian Remote Sensing Agency (ARSM). The segmentation was done by choosing a suitable scale and merge level. Two classifiers namely support vector machine (SVM) and k-nearest neighbor (KNN) were used to classify the mangrove family. The mangrove family map was produced from the higher accuracy of the classification. The results show that the overall accuracy of SVM is 63.81% (kappa = 0.55) while KNN is 59.83% (kappa = 0.50). In conclusion, SVM outperformed K-NN for mangrove family classification.
Urban building detection using object-based image analysis (OBIA) and machine learning (ML) algorithms
Authors: Norman Masayu , Mohd Shahar Hanani , Mohamad Zuraihan , Rahim Ashnita , Amri Mohd Fazly , Zulhaidi Mohd Shafri Helmi
Published: January 2021

The information on building features especially in the urban area is very important to support urban management and development. Nevertheless, the automated and transferable detection of building features is still challenging because of variations of the spatial and spectral characteristics to support urban building classification using remote sensing techniques. Most previous studies utilized high-resolution images to discriminate buildings from other land use in the urban area and indeed it involves a high cost to achieve that purpose. Consequently, this study utilized a medium resolution remote sensing image, Sentinel-2B with a 10-meter spatial resolution to classified the building in Selangor, Malaysia. In order to obtain a good classification accuracy, the suitable segmentation parameters (scale, shape and compactness) and features selection for building detection have been determined. Machine learning (ML) algorithms, namely Support Vector Machine (SVM) and Decision Tree (DT) classifiers have been applied to categorized five different classes which are water, forest, green area, building, and road. The result from these two classifiers was then have been compared and it is obviously showing that the SVM classifier is able to produce 20% better accuracy compared to the DT classifier, with 93% and kappa is 0.92. Thus, by enhancing the classification techniques in OBIA, building extraction accuracy using ML algorithms for medium resolution images can be improved and the expenses can be reduced as well.
A Three Decades Urban Growth Monitoring in Hadejia, Nigeria Using Remote Sensing and Geospatial Techniques
Authors: Gambo Jibrin , Ahmed Yusuf Yusuf , Zulhaidi bin Mohd Shafri Helmi , Salihu Lay Usman , Ahmed Abubakar
Published: January 2021

Overpopulation growth and urban center crowd became a global phenomenon which mainly cause urban growth in both developed and developing countries cities including Nigeria. Understanding the extent and pattern of such growth required spatial information as well as earth observation data that will be analyse on a temporal dimension. Remote sensing data and geospatial approach together with other auxiliary’s data were used to detect and monitor the spatio-temporal growth pattern and extent in the three decades of Hadejia town. The aim of this research is to understand how Hadejia town are spatial expand in terms of size and population between the years 1984-2019. Nevertheless, the spatio-temporal analysis over the three decades of 1984, 1999 and 2019 have been made. The research was carried out via remote sensing and geospatial method, satellite data were acquired across the region; atmospheric corrected using QUAC in Envi software; and also produced landuse landcover map. However, the research utilized object based image analysis (OBIA) for image classification and then built-up area were extracted in order to evaluate the urban expansion. The results indicate that the overall urban expansion occurred in between 1999 – 2019 with expansion of 566 hectares. Most of the changes happens along town major highway especial along interstate routes. The city has experienced an extreme growth geographically at East- Northern part due to plain terrain than Southern part because of present of river Hadejia.
Planted Forest Fire Burn Area and Impact Assessment Using Sentinel-2: Case Study of the University of Ilorin Teak Plantation
Authors: Idrees Mohammed O. , Babalola Folaranmi D , Omar Dahir M. , Yusuf Abdul-Ganiyu , Babalola Ayo
Published: January 2021

This paper presents a comprehensive assessment of the locations, extent and the impact of forest fire in University of Ilorin Teak Plantation using pre- and post-fire Sentinel-2 level 1C products. First, the pre-fire image was classified into three classes: vegetation area, bare soil and water body, using supervised classification (Maximum Likelihood method) to distinguish between vegetation and non-vegetation areas. Then, from the post-fire image, the burn areas were detected and extracted using Normalized Burnt Ratio. With the burn area polygon, impact of the fire on the planted forest was determined by isolating the vegetation class within the classified map so estimating the number of teak trees affected through extrapolation of the burn area and the tree spacing grid of 3m. The classification result shows that vegetation land cover type accounted for about 419.7 ha (66 %) of the total area while bare soil and water body take 204.3 ha (32 %) and 12.9 ha (2 %), respectively. Also, the resulting classified map produced overall classification accuracy of 95 %. Impact assessment result reveals that a total number of 49156 tree stands were affected by the fire within burnt area of 54.8 ha (8.6%). Analysis of the estimation success rate using one of the burn areas as validation site yielded approximation in excess of 3% with 17621 counted and 18222 estimated. Planted forest management and planning has many phases; so, it is necessary to understand the current and future condition of what is being manage. The fire burn map derived from this study will assist the University teak plantation management team update its current management strategy to protect it from continuous exposure to fire. From fire management perspective, the list of planning activities that require future assessments include pruning preferences, replanting, commercial thinning, spacing of planted trees, and perimeter buffering.
Least Square Modification of Stokes Formulae with Additive Corrections Estimator for Klang Valley Geoid Modeling
Authors: Kieh Ming Tang , Mat Amin Zulkarnaini , Hassan Md Din Ami
Published: January 2021

Klang Valley is a fast-growing area and its development shall be equivalent with precise measurements for a precise vertical reference. Thus, existing vertical reference with 3 centimetres (cm) is inadequate and processed with complicated remove-compute-restore (RCR) procedure. Apart from this, areas such as Klang Valley should better than one (1) centimetre level vertical reference. Meanwhile processing method for vertical reference should be simplified and easy tasking. Because of that, methodology for this study is by employing the least squares modification of Stokes formula with additive corrections (KTH). This approach fully uses anomalies rather than residuals which it is more complicated. At the same time, the additive corrections estimator introduced combining the direct and indirect computations method. Datasets used in this study were refined rigorously prior to the gridding scheme in cross validation, free air anomalies, as well as anomaly correction. The KTHKVGM2020 gravimetric and geometric geoid models are evaluated from the reference position using GNSS levelling. It found that KTHKVGM2020 Geoid model is better than one (1) centimetre for Klang Valley area with efficiency processing method. Therefore, the study is an essential in future to develop high-precision geoid model with efficient methods particular for urban and rapidly developing areas.
Effectiveness of lowering saturation on residual shear strength of sand stabilized with fly-ash
Authors: Simatupang M
Published: January 2021

The established cementitious compounds as the pozzolanic reaction product could significantly ameliorate the peak shear strength of stabilized sand with fly ash. However, the enhancement of its residual shear strength has not been known well. In this research, the effects of fly ash percentages, curing times, and saturations, on various compositions, on the shear strength of stabilized sand were observed through direct shear strength tests. The residual shear strength of stabilized sand with fly ash was compared with that of bare sand. The research found that stabilized sand’s shear strength increased with fly ash and curing time and decreased with saturation, both at peak and residual state. There is a significant improvement in the residual friction angle, even in a small fly ash percentage, by reducing saturation during the specimen preparation. The useful effect of fly ash bonding remained in the friction angle after the shearing occurrence, showing that the sand stabilization approach with fly ash was effective during and after shearing.
Landslide vulnerability assessment using gis and remote sensing techniques: a case study from Garut – Tasikmalaya road
Authors: Banuzaki A S , Ayu A K
Published: January 2021

Road constructions, especially in mountainous topographical features, have been noted responsible for the significant increase of landslide occurrences. In the Garut – Tasikmalaya Road, numerous landslides have been recorded causing enormous losses. This road has a very important role as the main transportation connector between two regencies in West Java; those are Garut and Tasikmalaya Regency. To deal and control such problems, spatial distributions of landslide vulnerability need to be analyzed. The aim of this study was to assess the widespread landslide vulnerability zones along the Garut – Tasikmalaya Road. The landslide triggering factors, i.e. topographic slope, land use, lithology, distance to geological structure and distance to stream, were spatially evaluated and integrated using Analytical Hierarchy Process (AHP) and simple numerical rating method to determine the landslide vulnerability zones. The data of landslide triggering factors were derived from remote sensing data and processed using GIS technology. The data integration produced landslide vulnerability map along the Garut – Tasikmalaya Road, which delineates the research area into three zones of landslide vulnerability (high, moderate, and low). The landslide vulnerability map was validated using landslide inventory. The high vulnerability zones of landslide, that will affect the Garut – Tasikmalaya Road, are mainly located in the Salawu District.
Flood risk mapping of the Sukamahi Dam failure with overtopping scenario
Authors: Prakoso W G , Rahman B , Purwanti H , Irawan P
Published: January 2021

Sukamahi dam at Cisukabirus river, part of the upper Ciliwung watershed, located at Bogor regency. Sukamahi dam was designed for flood reduction purposes, especially for the downstream region, e.g., City of Bogor, Bogor regency, City of Depok, and Jakarta. Sukamahi dam will give flood reduction 13.53 m3/s with probability exceeded 2 %, and time to concentration (tc) for peak discharge (Qp) at least 4 hours longer than existing condition. Despite providing the benefits of flood control, the construction of dams also has the potential to increase the risk, i. E if a dam fails due to overtopping. Based on the Sukamahi dam flood failure scenario, dam failure has the potential to occur if the bottom outlet ( tunnel) and spillway fail when flood discharge with a 1000 year return period or more occur. Modeling of Sukamahi dam failure using 2 D HEC-RAS with unsteady flow analysis from sta 0 + 000 to STA 8 + 500 produces a map of inundation area of 36.89 Ha. The flood flow velocity is reaching 8.43 m/sec with a maximum flood flow depth of 69.72 m.
Development of smoothed particle hydrodynamics (SPH) method to model the interaction of sand and water during liquefaction with bingham fluid model adaptation
Authors: Mahardima H , Bahsan E , Marthanty R R D R
Published: January 2021

Smoothed Particle Hydrodynamics (SPH) is a mesh-free numerical method that models the movement of particles in the Langrangian method. SPH method treats the domain as discrete particles instead of continuous entities, making it more accurate to model phenomenons that have a big deformation. The purpose of this research is to analyze the interaction between soil and water particles, based on the particle movements, density, pressure, internal forces, and external forces. This research continues the previous research of interaction between fluid-fluid particles in SPH by applying the Bingham fluid model to one type of fluid to represent coarse-grained soil particles. In the future, we hope this research can be further developed into a liquefaction prediction model by quantifying the main factors of liquefaction, such as the amplitude of shear strain, effective stress reduction, and excess pore water pressure.
Forced vibration test of pedestrian steel bridge using eccentric mass shaker
Authors: Rastandi J I , Pramesti K , Orientilize M
Published: January 2021

The dynamic test has been performed on Jembatan Teksas, Universitas Indonesia. The purpose of the test was to obtain the dynamic parameters, which are the natural frequencies, the mode shapes, and the damping ratio. The test was conducted by applied forced excitation using an eccentric mass shaker. The dynamic responses were recorded using accelerometers and vibrometer during forced vibration state and a free vibration state. A comparison study was conducted through the 3D finite element analysis using SAP2000. The test could obtain five mode shapes of the bridge and the damping ratio. Close results were found between FE analysis and the test result. The average damping ratio obtained was 1.72% which was within the range of welding steel structures according to reference. Compared to the test conducted in 2011 and 2013, the bridge is in good condition which is indicated by its natural frequency where the current test decrease less than 2%.
The different effect of cyclic loading protocol on spun pile performance
Authors: Orientilize M , Prakoso W A , Swastinitya A P
Published: January 2021

Numerical study to investigate the effect of various loading protocol to seismic performance of spun pile connection has been performed using OpenSees. Six loading protocols adopted in FEMA P440 were applied to three specimens. The study started with validation of FE model, and the model can closely simulate the experiment conducted by another researcher. The loading was presented in the form of a drift ratio, a number of cycles, and the rate of loading. It is found that different types of loading protocols affect seismic performance in terms of stiffness and strength degradation. Among six loading protocols, TP-01, as adopted in ACI 437.1R-07, give moderate results. Significant stiffness degradation was observed on hollow spun pile compare to those with concrete infill. It is found that the presence of concrete infill improves the strength of the spun pile connection by 45%. Increase the strength of concrete infill slightly improve the performance of spun pile.
The dynamic test of simple span precast prestressed concrete bridge with elastomeric bearing support
Authors: Rastandi J I , Putra Irwan Ade , Orientilize M
Published: January 2021

The dynamic test of an elevated freeway bridge in Surabaya has been conducted. Eccentric mass shaker succeeded to apply an excitement to the bridge and hence the dynamic parameters such as the mode shape, the natural frequency and the damping ratio were obtained. The two main mode shapes from the test were the first vertical mode and the first longitudinal mode. The average damping ratio attained is within the range of damping ratio of prestresses concrete where the average is 2.12% whereas the range is between 2-3%. The test results are closely represented by a 3D FE model using SAP2000 without modelling the whole foundation. The deviation of the natural frequency compared to the test results is 8.50%. The elastomeric bearing effectively reduces the acceleration from upper to the bottom structure by 54.62% and 60.22% obtained from two measurements.
Geological and geotechnical review of gas and mudflow area as mitigation efforts in the risk of failure on Toll Road Project, Banten
Authors: Sabbah A B , Kusumawardani R , Mayasari R , Kurniadhi R
Published: January 2021

The toll project in Banten shows that there is an area of gas burst at one of the locations. The embankment road passes through the gas burst. The geoelectric results that there is a silt/sandy soil layer and rock on the surface (10-20m), the second layer is soft silt to silt (20-40m), and then a rock layer. The second layer has gaps towards the first layer from the bottom layer, which is identified carrying gas and water, which is passed through the gaps to the surface. The seismic refraction also results that there are basins with gaps through the top and bottom of soil layers. The layer which indicates the gas and water carrier line is volcanic, sandy, forming a layer that has undergone deformation and partly a water-bearing layer (sand). The result of LEMIGAS explained that the gas bursts are also not methane that comes from the humus decomposition. The gas bursts are originated from depth and related to petroleum activity. The CO2 content is up to 97.87%, which is poisonous. However, the burst area is open, and the morphology is flat and does not form a cup, this gas spreads out so that the impact is not too pronounced.
Development of the smoothed particle hydrodynamics (SPH) method for modeling movement of fluid layer interaction between impermeable soil layers with boundary conditions sloping surface
Authors: Wicaksana Y , Bahsan E , Rika R R D
Published: January 2021

Liquefaction usually occurs on a saturated sand deposit when the pore water pressure increases during the earthquake, and the water level will rise that could even burst out above the liquefied layer. If there is a relatively impermeable soil layer above the liquefied one, then the water could be trapped between the liquefied soil and other layers on the top. This research tries to develop a numerical model to simulate the phenomenon using the Smoothed Particle Hydrodynamics (SPH) method. SPH is a numerical method based on particle interactions that initially developed to solve the problems in astrophysics. Two sets of particles are assigned to behave like water and impermeable soil, where the thin layer of water is placed between two layers of soil. The model is built using the Fortran programming language developed in the previous research to simulate the impermeable layer’s behavior by controlling the stiffness coefficient and coefficient of damping. The soil and water layers are aligned at specific angles to simulate the field’s sloping surface condition. The simulation results are presented in graphical animation using Gnuplot and visually checked that the particle’s movement could represent the field’s actual movements.
Analysis of liquefaction potential in Lolu Village, Palu using SPT method and laboratory test of grain size distribution
Authors: Rahayu W , Nurizkatilah  , Bahsan E
Published: January 2021

Liquefaction is known to be a natural phenomenon where granular soil material from its solid to liquid form. One of its impacts is from an earthquake that occurred in Palu in September 2018. This research will conduct an analysis based on field test data of Standard Penetration Test (SPT) and laboratory test data of Grain Size Distribution. Samples were taken from five different boreholes. The analysis will use the Idriss and Boulanger method, referring to the soil safety factor’s value to evaluate the liquefaction potential. For grain size analysis, evaluation of liquefaction potential is carried out referencing liquefaction based on grain grading of Tsuchida, the coefficient of uniformity, and the curvature of the liquefied soil. The results showed that liquefaction potential was found from 1 m depth to 20 m with N-SPT value ranging from 3 – 54 blows. On the other hand, analysis using a grain distribution test showed that soil at the location is dominated by sandy soil with fine-grained contents that can experience liquefaction.
Analysis of thermal comfort with predicted mean vote (PMV) index using artificial neural network
Authors: Dyvia H A , Arif C
Published: January 2021

The thermal comfort standard can be accessed with a predicted mean vote (PMV) index that has six variables: air temperature, air velocity, relative humidity, mean radiant temperature, clothing insulation, and metabolism rate. Calculation of the thermal comfort of a room issued with a PMV index is quite complicated, considering the determination of the effect parameters can take a long time because it has a non-linear relationship. The purpose of this study is to analyze the sensitivity parameters that affect thermal comfort and to develop an artificial neural network model to predict the thermal comfort of the PMV index with two different input scenarios. Sensitivity analysis of thermal comfort uses the rank Spearman method, whereas the modeling of artificial neural networks uses the backpropagation method using a total of 784 data as data training and testing. Based on the results of sensitivity analysis shows metabolism rate and clothing insulation have a significant effect on the sensitivity of thermal comfort. Prediction of thermal comfort with the PMV index using an artificial neural network is very effective and has higher accuracy. The results are proven by validating the two model scenarios with an R2 value of 0.99 and low RMSE value.
Evaluation of urban landscape visual quality based on social media trends in Bogor City
Authors: Afiyanita Hana , Kaswanto
Published: January 2021

The urban landscape provides various benefits, including landscape aesthetics. This visual value can be measured by the community in many ways, so landscape managers can interpret their preferences of the landscape, which makes this research essential. This study aims to evaluate the visual quality of the urban landscape of Bogor City by analyzing community preferences through social media. This research uses one of the most used social media platforms, Instagram. Instagram is a platform that is specifically used for uploading and discovering visual contents, such as photos and videos. This can be a tool to analyze the community’s preferences and has become a new approach in the field of landscape. This study uses a descriptive method by data scraping and questionnaires. The scraped data is spatialized to compare the movements of trends that occurred in 2018 and 2019, and the questionnaires are handed out to conduct the visual quality assessment of Bogor City. The output produced in this study is a recommendation of urban landscape management based on social media trends, such as optimizing the 4.0 era by using social media as a process in decision making, and by taking the community preferences as a base in landscape planning.