bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a flyback high-efficiency switching power supply
Authors: Jing Zhao , Shuang Wang Xiao , Jun Rao Xue , Ya Zhang Lu
Published: January 2021

Switching power supplies are widely used in automotive, aviation, and DC speed control fields. Its biggest requirement is stable output and high efficiency. It is usually realized by resonant converters, but its control circuit is complex and the output ripple is large. In this paper, a new type of flyback switching power supply is designed using a flyback conversion circuit and a single-tube self-excited conversion circuit. Experiments have shown that the designed switching power supply improves the efficiency and reliability of the power supply while obtaining a small ripple, continuously adjustable, and stable DC voltage.
Parameters Optimization Model and Solution Method Based on 3D Manufacturable Units
Authors: Tao Zhenming , Zhang Zhixiong , Luo Zirong , Tang Li , He Lijun
Published: January 2021

At present, the lightweight design methods for SLM (Selective Laser Melting) process cannot meet the performance requirements while maintaining the consistency of the appearance of parts, and there are some defects in material cost and processing efficiency. In order to improve these defects, this paper proposed a lightweight reconstruction parameters optimization model based on 3D manufacturable units, and finite element simulation and Matlab calculation were used to solve the model to obtain the optimal structural parameters. Finally, the reconstruction design of typical parts was taken as an example to verify the feasibility of the model and the solution method.
Study on Dry-Ice Particle Jet Polishing Process of 316L Stainless Steel Electrode
Authors: Yang Weiying , Feng Xu , Xing Yingjie , Pan Weihao , Song Jinlong
Published: January 2021

Dry-ice particle jet technique has the advantages of rapid sublimation, easy drying, and without residues after striking onto the surface, which has been applied in the field of optical coating and the polishing and cleaning of integrated circuit. However, the process mechanism of this technique on stainless steel is not clear and the application research is not in-depth, which restricts the development and application of dry-ice particle jet technique in electrode polishing. In this work, the influence of the processing parameters such as spraying pressure, spraying angle, spraying distance, and spraying time on the micro-morphology and roughness of the stainless steel electrode surface was studied by single factor experiments. In addition, the characterization methods for the surface roughness, surface defects, surface micro-morphology, surface micro-unevenness, and surface chemical composition of the stainless steel electrodes were developed. Comprehensive characterization technology of the electrode surface was established.
Analysis and Optimization on Vibration Characteristics of Twin Screw Pump
Authors: Zhong Yan , Zhou Pu , Fu Dongliang , Lu Zhen
Published: January 2021

Based on double screw pump as the research object, the vibration of twin screw pump under different outlet conditions and different technological parameters were tested. The vibration characters of the pump under various technological parameters were analyzed from the experimental point of view. The key parameters influencing the vibration characteristic of twin screw pump were found out and corresponding optimization measures were taken. By using the numerical method of fluid mechanics, the three-dimensional flow field inside the pump chamber was analyzed, and the internal working mechanistic and influencing factors were discussed. Local optimization was carried out to reduce the influence of fluid excitation force on structure vibration. The research results of this paper can provide necessary practical basis for the optimization of vibration and noise reduction of twin screw pump.
Research on The Wireless Communication Scheme of Substation Full Coverage
Authors: Zhang Hongmei , Zhang Ji , Zheng Ziyao , Li Liangyu , Zhang Yan
Published: January 2021

In order to meet the mobility and Broadband communication requirements of smart substation, this paper proposes a wireless communication scheme based on Wireless-Fidelity network for substation all-domain coverage, and makes an in-depth analysis of network performance. In this way, a communication scheme suitable for specific electric power application scenarios can be created, which can effectively improve the basic support capacity of information communication.
Research on Clustering Management of Power Distribution Internet of Things Based on Trusted Blockchain
Authors: Sun Yue , Chen Wei , Chen Leran , Li Min
Published: January 2021

Since the topological structure of power distribution Internet of Things is getting more and more complicated, and the amount of new services, such as remote dynamic monitoring and two-way real-time interaction, has been increasing, it is urgent and necessary to study the clustering management technology of power distribution Internet of Things combined with its running scenarios, security requirements and dynamic access characteristics. In this paper, a clustering security management scheme of power distribution Internet of Things based on trusted blockchain is proposed. The clustering management and data communication of power distribution Internet of Things are conducted based on trusted blockchain, which can improve the security of data interaction.
Engineering geological evaluation of landslide in a certain area
Authors: Xu Jiangtao , Yang Zhenwei , Sun Chengyong
Published: January 2021

Based on the analysis of the surrounding environmental conditions and the basic characteristics of the potential landslide, the stability of the potential landslide is analyzed, calculated and evaluated. Based on the analysis, the development trend and hazard assessment of potential landslide are obtained, and the prevention scheme is put forward, which plays a certain role in preventing landslide disaster.
Application of Magnetization Treatment in Flotation
Authors: Kong Yaran , Li Fengjiu , Jia Qingmei , Li Guofeng
Published: January 2021

With the decrease of mineral resources reserves, the characteristics of “poor, fine and miscellaneous” of mineral resources are becoming more and more obvious. People pay more and more attention to the environmental protection. A simple, green and efficient separation process magnetization flotation has been paid more and more attention by mineral processing workers. Based on the analysis and summary of the development process and advantages of magnetic flotation, the application status of magnetic flotation at home and abroad in the processing of ferrous metal ore, non-ferrous metal ore, rare metal ore, precious metal ore, non-metallic ore, coal, etc. Compared with conventional flotation, it is found that the cost of magnetic flotation is lower than that of conventional flotation. Combining theoretical analysis, computer simulation, experiment and advanced detection methods, the mechanism, influencing factors, process and equipment of magnetic flotation are the development trend in the future.
Effect of the Surface Roughness on Cross Sectional Properties of 1×3 Polymer Optical Fiber-based Splitter
Authors: Ab-Rahman Mohammad Syuhaimi , Guna Hadi , Arsad Norhana
Published: January 2021

This research focuses on the fabrication of 1×3 low-cost splitter based on polymer optical fiber (POF) and the characterization of the surface roughness on cross-sectional properties of the device. Due to the unique features and advantages of POF such as flexibility, low-cost material, and easy to install, POF is also resistant to high temperature and immune to electromagnetic noise (EMI). Thus, fabrication method to produce a 1×3 POF splitter using a low-cost fusion technique has been studied. A fabricated prototype will go through a characterization process by observing the performance of POF varied by the surface roughness of the devices. Two main parameters, such as excess loss and power efficiency percentage are obtained to observe the surface roughness on the fabricated device. The experimental results reveal that surface roughness is not giving a significant impact on the efficiency of the device. However, when it linked to a twisting ratio parameter, surface roughness shows predictable curves on the power efficiency of the low-cost POF splitter.
Fluid structure coupling simulation analysis of vibration assisted 3D bioprinting extruder
Authors: Li Bicong , Lin Sheng
Published: January 2021

Aiming at the problem of high wall shear stress at the nozzle of micro extrusion biological 3D printing technology, this paper proposes a method of reducing the viscosity of biological ink through vibration, so as to reduce the shear stress and improve printing efficiency and cell vitality. The 3D bioprinting extrusion device is taken as the research object, and the influence of vibration parameters on the printing process is studied on by fluid structure coupling simulation of the extrusion device.
Study on Ergonomic Digital Evaluation System for the Naval Shipborne Command Cabin Based on Extended JACK
Authors: Wu Jinchun , Xue Chengqi , Du Xiaoxi , Tong Mu , Miao Xinyue
Published: January 2021

The naval ship command cabin(NSCC) is an important part and the nerve centre of the whole ship. In order to achieve better evaluation and design improvements of the human-machine interface(HMI) of the naval shipborne command cabin in the design phase, we preliminarily expounded the ergonomic digital evaluation system of the NSCC based on extended JACK. The NSCC human-machine interface evaluation index system was constructed by using the improved Delphi method, and the quantitative and qualitative evaluation method was studied. The ergonomic digital evaluation system for the naval shipborne command cabin was developed by extending the JACK software, in which the mannequin module, human-machine interface design module, evaluation module and design standards module were integrated. Finally, the feasibility and applicability of the proposed ergonomic digital evaluation system were verified by an illustrated example.
Home intelligent integrated wardrobe
Authors: Zhang Yu , Miao Fengyi , Xing Shengbo , Wang Zhentong , Xiong Xinhong
Published: January 2021

With the development of Internet of Things technology, smart homes are increasingly entering the lives of the people. More and more families have put forward ironing, drying, disinfection and intelligent requirements for household wardrobes. However, most household wardrobes currently only have storage functions, which cannot meet people’s needs. Based on the above background, the project team designed a home smart integrated wardrobe. The household intelligent integrated wardrobe can be applied to most families. It has the characteristics of low price, rich functions, and convenient use. The home intelligent integrated wardrobe is conducive to improving people’s living standards and has good application prospects.
Design of deicing device for wind turbine blade based on microwave and ultrasonic wave
Authors: Luo Ruiliang , Chen Xu , Guo Jinyu
Published: January 2021

Nowadays, wind turbine deicing has become a hot research topic. The traditional deicing method of blade has many problems, such as high energy consumption, low efficiency and low effect. In order to solve the above problems, the project team designed a wind turbine blade deicing device based on microwave and ultrasonic wave. During the operation, two deicing methods, namely microwave thermal energy, ultrasonic cavitation effect and thermal effect, were used to deice in stages to achieve the purpose of high efficiency and energy saving. The whole device is composed of walking system, microwave system and ultrasonic system, and the operation of the device is realized by the electrical control part. Compared with the existing deicing methods, the device can achieve the purpose of low energy consumption and high efficiency Deicing; in addition, the device has the advantages of flexible mechanism for control, less pressure on wind turbine blades, and low cost.
Design and Development of Intelligent Fire-fighting Robot Based on STM32
Authors: Wu Changzhong , Ge Fan , Shang Guangchao , Zhao Mingpeng , Wang Guitao , Guo Hengshuai , Wu Liang
Published: January 2021

With the rapid growth of economy, fires occur frequently in various dangerous places. According to the investigation, in the ancient tragic fire cases, the number of intelligent mobile fire-fighting equipment is very small, and ordinary fire extinguishers and fire-fighting trains can’t put out the fire in time and quickly. As a kind of robot, intelligent fire-fighting robot plays an increasingly important role in fire-fighting and rescue. In this paper, the design of fire robot is studied. Intelligent fire-fighting robot is mainly composed of fire-fighting movement system, fire-fighting water spray system, fire-fighting control system and other components. All parts cooperate with each other and work together to complete the fire-fighting task.
Evaluation of Oil Paper Insulation State of Traction Transformer
Authors: Liu Jiyong , Liu Yang , Yao Qi , Zhang Hao , Tian Xingjun
Published: January 2021

The improved grey target theory is applied to study the aging state of oil paper insulation of traction transformer. Firstly, the data are measured by the recovery voltage method and the related parameters are identified based on the ED equivalent circuit model, and the extracted parameters are used as the characteristic quantity to evaluate the oil paper insulation state. Secondly, according to the different influence of each characteristic quantity on the aging state of oil paper insulation, the combination algorithm of improved AHP and entropy weight method is used to allocate the weight of each characteristic quantity. Thirdly the paper insulation evaluation model of traction transformer is established. Finally, the data of several traction transformers are collected and the classification calculation of oil paper insulation state is carried out. The example shows that the method can effectively and reasonably evaluate the aging state of oil paper insulation of traction transformer, which can provide reference for condition based maintenance of traction transformer.
Research on the Design of Electrical Control System of Production Machinery
Authors: Liu Yangliu
Published: January 2021

The principles of feasibility, rationality, compatibility and reliability should be followed in the design of electrical control system of production machinery. The design should meet the design requirements on the basis of repeated simulation tests. The electrical control system design of production machinery mainly includes the schematic design and technological design of electrical control. This paper analyzes the basic methods and design points of schematic design and technological design to provide references for related researchers.
Research on the critical equipment parameter control technology of slim cigarette rod forming
Authors: Zhang Tao , Zou Quan , Zhao Yunchuan , Pan Wen , Hu Qun , Yang Lei , Wu Jiacan , He Xufeng , Xu Yan Qun , Pu Qian , Wang Haijuan , Zou Juan , Feng Hongtao
Published: January 2021

In order to obtain the optimal control of the parameters of the critical equipment for the formation of a slim cigarette rod. In this study, the loose-end rate and weight stability are taken as the measurement indicators. According to the five factors that affect the control parameters of the critical equipment of tobacco forming, the “Uniform Design Method” is used to set up different control parameter combinations. The stepwise function is used to analyze the quadratic polynomial stepwise regression analysis, and the control parameter model is established and verified and optimized. The results show that the negative pressure of the suction chamber is 90Mbar, the proportion coefficient of the needle roller is 78%, the thickness of the block above the cleaver disc (the rail of the suction) is 2.5mm, the gap between the wire pressing wheel and the rail of the cigarette gun is 4.3mm, and the height of the cigarette tongue outlet is 4.3mm. The optimal range of the forming parameters of the cigarette rod can be obtained, which can effectively reduce the loose-end rate of the slim cigarette rod and improve the stability of the cigarette weight.
TiC nano-coating and their tribological properties were deposited by doal-ion beam sputtering on the tool surface
Authors: Zhongyu Dou , Zhangfaguang  , Guoyinglu  , Chenshaobo
Published: January 2021

By using the method of doal-ion beam sputtering deposition, N element is injected with ions to assist sputtering deposition of TiC to prepare the TiC nano-coating with high binding strength. SEM, XRD, dynamic ultra-micro hardness tester, friction and wear testing machine were used to characterize and analyze TiC properties. The results show that the TiC coating prepared by double ion beam sputtering deposition has high hardness, high bonding strength, good friction and wear performance, and improves tool service life.
Design and Research on the Hinged Cover of the Fuselage of Civil Aircraft
Authors: Gou Pengpo
Published: January 2021

Due to the complexity of aircraft interior system, some systems need to design components installed in the fuselage, which will open in the fuselage on the formation, at the same time as the aircraft aerodynamic design requirements, the system must be in the form of the opening cover is closed, so in the design of the fuselage flap design system is particularly important. This paper mainly introduces a hinged cover in common design points and design points of cap shape.
Error analysis of new 3UPS_UP parallel mechanism
Authors: Chen Yu , Li Kaiming
Published: January 2021

A new mechanism based on composite ball hinge is introduced. Since the structure of composite ball hinge is inconvenient to consider the attitude of moving platform, the ball center is set as the reference point to simplify the kinematics solution. The Jacobian matrix and error analysis model are derived. The effect of the bar length error and the initial position error of the moving platform are analyzed emphatically, and the distribution law of different plane errors is basically consistent, and the bar length error direction has certain influence on the position error. Through simulation analysis and numerical calculation, the rules are analyzed, which lays a foundation for improving the mechanism performance and further research.
Study on Moving Strategy of Internal Mechanical On-Line Balancing System
Authors: Zhou Huimin , Wang Zhan
Published: January 2021

Mechanical balancing system driven by the motor can cause wrong adjustment and long balancing time in the controlling process, which will result in lower accuracy of rotation. In order to solve this problem and achieve more efficient online dynamic balance, the optimal moving path of the built-in mass block of balancing device can be determined by us. Four kinds of moving paths for mass block are designed by using for balancing to make experimental verification of spindle dynamic balance movement. By comparing experimental results of balance accuracy and balance efficiency, the optimal dynamic balancing strategy is determined. The results show that the designed moving strategy is reasonable, and the moving optimized path can carry out more accurate control precision and shorter adjustment time to achieve the expected effect. The better control strategy of dynamic balance lays the foundation for the high-precision operation of the spindle system.
The effect of spot size on quality factor of Laser Doppler Velocimeter
Authors: Xi Chongbin , Nie Xiaoming , Huang Rong , Zhou Jian
Published: January 2021

Quality factor is an important evaluation index of Laser Doppler Velocimeter (LDV). In order to study the effect of spot size on quality factor, the effects of signal light intensity and transit time on the quality factor are discussed theoretically. In addition, the distribution of quality factor of LDV was measured and examined. Theoretical analysis and experimental results demonstrate that: Due to the symmetry of Gaussian beam, the distribution of quality factor is symmetric. Furthermore, the light intensity of Doppler signal at the waist spot of Gaussian beam is the largest while the transit time of moving particles diminishes due to the decrease of spot diameter, causing spectrum leakage. Under the influence of both Doppler signal intensity and transit time, the distribution of quality factor appears concave phenomenon.
Effect of cut tobacco size and distribution on critical cigarette quality characteristics of “slim cigarette” processing technology
Authors: Zou Quan , Zhang Tao , Zhao Yunchuan , Chen Ran , Yang Lei , Hu Qun , Wu Jia Can , Xu Yan Qun , Pu Qian , Zhao Mei Wei , Qiu Ye , Feng Hongtao
Published: January 2021

To further improve the stability of quality control on the processing technology of slim cigarettes in the process of cigarette manufacturing. In this study, based on the blending formula of product A, the cut tobacco screened out by different sieves was rolled according to different proportions. The cigarette structure, physical properties, tobacco loss from cigarette-end, dust content, and density of tobacco rod were systematically evaluated. The results showed that the proportion of medium and short cut tobacco (1.0 mm ∼ 3.35 mm) ≥ 62%, and the whole cut tobacco ratio in the cigarette was less than 40%, which could effectively improve the fluctuation of slim cigarette physical properties and the distribution stability of cut tobacco in tobacco rod.
Finite element analysis of belt conveyor bracket
Authors: Zhang Ming-Yuan , Zhu Hai-Dong , Zhang Wei
Published: January 2021

As an important part of the belt conveyor, the triangle bracket supports the roller and carries its load. Its stability and service life directly affect the function of the conveyor, so that the conveyor system can work stably and efficiently. Due to the characteristics of the belt conveyor, such as long transportation distance and large conveying volume, there are many problems in the actual working condition of the triangle. For example, the triangle bracket bears too much load, resulting in deformation and damage of the bracket structure. Working time is too long, the yield limit of the support is reduced, and the structure of the support is seriously failed, which leads to the shutdown of the conveying system and huge economic loss of the enterprise. There are many problems in the actual production of triangle bracket, so it is necessary to analyze and study triangle bracket to solve these problems. This project takes the triangle support of a belt conveyor as an example, establishes a three-dimensional solid model of the support, conducts finite element analysis on the triangle support model with ABAQUS software, analyzes the stress-strain displacement of the triangle support under the load, and optimizes the triangle support according to the finite element analysis results.
Finite Element Analysis of Misalignment and Contact State on the Interface of Bearing Bore Under Preload Condition
Authors: Meng Zhaohang , Ma Wei , Zhou Ping , Zhang Zhenyu , Ding Ze
Published: January 2021

The split bearing bores of diesel engine are generally bored after tightening bolts to install crankcase and cylinder block. Machining accuracy significantly affects the contact state during sliding bearing operation, thereby reducing the service life of bearing. For effectively suppressing misalignment of interface caused by deformation of bearing bore, this paper presents finite element model and experimental measurement. The theoretical analysis and numerical calculation of interface are carried out in this paper. The finite element models of bearing bore and interface between crankcase and cylinder block are established to quantitatively analyze the deformation characteristic and contact state. The results indicate that the contact pressure of interface increases gradually with increase of the pre-tightening torque. The sliding distance of interface is positively correlated with the contact pressure of interface. Furthermore, the direction and value of the principal stress are calculated by measuring the strain of nodes around the bearing bore. Differential forces on both sides of bearing bore lead to joint surface sliding. Finite element simulation results are compared with experimental results to verify the finite element model.
Simulation Analysis of Stress Corrosion of H62 Copper Alloy
Authors: Dazhao Yu , Tong Zhang , Wentao Niu
Published: January 2021

H62 copper alloy is a commonly used material in engineering, and stress cracking of copper alloys has always been concerned. In this paper, a two-dimensional model of H62 copper alloy was established by COMSOL electrochemical module, and the stress corrosion of H62 copper alloy was analyzed by using measured engineering stress-strain curve. The results show that the tensile stress has a serious effect on the stress corrosion, and the excessive tensile stress will lead to the fracture failure of the contact.
Reuse of cold drink packaging based on sustainable theory
Authors: Jun Han , Chen Derun
Published: January 2021

In today’s society, product packaging is increasing, and more and more kinds of materials are used, and different kinds of materials also have many difficulties in the later product recycling. Each link is closely related to the environment. From the designer’s point of view, it is very important to consider the abandonment of products from the early stage of design. How to make the cold drink packaging play its residual value is to apply the sustainable theory to solve the problem.
Microstructure and mechanical properties of AlNiCuCoX high-entropy Alloy
Authors: Wei Shanjun , Huang Zhuofang , Li Anmin , Wang Yongqi , Lu Ben , Li Qiusheng
Published: January 2021

AlNiCuCoX (X=Cr, CrTi, CrFe, FeTi and CrFeTi) series high-entropy alloys were prepared by vacuum arc furnace. The microstructures and properties of the alloys were analyzed. The results show that the microstructures of AlNiCuCoX alloys are composed of FCC solid solution and BCC solid solution, and the number of phases formed in the alloys is far lower than that predicted by equilibrium phase law. AlNiCuCoCrTi shows chrysanthemum like microstructure, while AlNiCuCoFeTi and AlNiCuCoCrFeTi alloys shows petal-like, chrysanthemum like and reticular (intercrystalline) white microstructure. The principal element is the key factor affecting the solidification mode (hypoeutectic, eutectic and hypereutectic solidification) of AlNiCuCoX series alloys. If the interdendritic phase is not considered, AlNiCuCoCr and AlNiCuCoCrFe high-entropy alloys are solidified in the end-solid solution solidification mode. When Ti is added, the alloy is solidified in the hypoeutectic solidification mode, and the equilibrium microstructure is composed of primary phase and eutectic. The microhardness of the most alloys increased with the increase of the number of principal elements, and the hardness of AlNiCuCoCrFeTi alloys is the highest (548HV). The compressive strength and strain of most AlNiCuCoX alloys are low (especially AlNiCuCoCrFeTi alloy). Both AlNiCuCoCr and AlNiCuCoCrFe alloys have better comprehensive mechanical properties.
Research on the application of microwave expanded fine-cut heavily rolled stems
Authors: Zou Quan , Feng Hongtao , Zhang Tao , Hu Qun , He Xufeng , Wu Jiacan , Pu Qian , Zhao Meiwei , Qiu Ye , Yang Lei
Published: January 2021

In order to improve the adaptability of slim cigarettes blended with cut stems. In this study, we have developed the microwave expanded fine-cut heavily rolled stems. By setting the different proportions of cut stems, compared with the traditional pneumatically dried cut stems, we analyzed the application characteristics of the microwave expanded fine-cut heavily rolled stems into the slim cigarette from the aspects of blending uniformity, physical characteristics of cigarette, mainstream smoke, sensory quality. The results showed that: the microwave expanded fine-cut heavily rolled stems is conducive to the Blending Uniformity, the draw resistance stability is better than that of the traditional pneumatically dried cut stems, the adaptability in slim tobacco is better than that of the traditional pneumatically dried cut stems, the stability of tar and CO release is improved, and the overall sensory quality of the microwave expanded fine-cut heavily rolled stems is better in sensory evaluation. This study supports the application of the microwave expanded fine-cut heavily rolled stems in the slim cigarettes.
Vision / inertial integrated navigation method for quadcopter based on EKF state observer
Authors: Xu Haibo , Li Peixuan , Wen Litao , Wang Zewei
Published: January 2021

Quadrotor UAVs are widely used in the field of power line inspections because of their advantages such as high accuracy, strong adaptability, and strong obstacle surmounting capabilities. However, in practical applications, the autonomous navigation of the UAV still has problems such as poor anti-interference ability, insufficient accuracy and still dominated by manual control. Visual navigation is difficult to obtain sufficient information or to track feature points when there is insufficient lighting, sparse features, and large maneuver. These problems can reduce the accuracy of visual navigation. The position estimation error directly obtained by integrating the IMU data of the inertial navigation unit will gradually increase with time. A vision / inertial integrated navigation method for a quadcopter UAV based on loosely coupled extended Kalman filter algorithm is proposed in this paper. Design state observer for UAV based on extended Kalman filter. The visual/inertial integrated navigation algorithm is simulated in gazebo. Finally, an experimental platform is set up to verify the vision / inertial integrated navigation algorithm experimentally. The overall position calculation error meets the positioning accuracy requirements during power line inspections.
Hesitant Fuzzy MP Filters of R0-Algebras
Authors: Man Jiang
Published: January 2021

In this paper, we introduce the notion of hesitant fuzzy( correlation) MP filters, some properties and equivalent conditions are investigated. The relationships between hesitant fuzzy MP filter and hesitant fuzzy correlation MP filter is disscussed. Finally, we prove the invariance between the image and the original image of hesitant fuzzy correlation filter is studied under the premise of homomorphism.
Dispersive Model for Undular Hydraulic Jump Behind a Weir
Authors: Magdalena I , Sutjianto F J , Andrew  , Sani A , Anastasia R
Published: January 2021

In this paper, we investigate a suitable weir design which yields in an undular jump phenomenon using both hydrostatic and non-hydrostatic models. We solved the hydrostatic model using numerical and analytical methods. After that, we validated the output from both methods using the experimental data. In order to simulate the undular jump better, modification towards the hydrostatic model is needed. Hence, for the non-hydrostatic model, we consider the existence of hydrodynamic pressure and solved the model numerically. The outcome of this paper can be beneficial for hydraulic structures design and the management of water resources.
The Locating Chromatic Number of some Modified Path with Cycle having Locating Number Four
Authors: Damayanti M , Asmiati  , Fitriani  , Ansori M , Faradilla A
Published: January 2021

The locating-chromatic number was introduced by Chartrand in 2002. The locating-chromatic number of a graph is a combined concept between the coloring and partition dimension of a graph. The locating chromatic number of a graph G is defined as the cardinality of minimum color classes. In this paper, we discuss about the locating chromatic number of three types modified path with cycle having locating chromatic number four.
A Two-Dimensional Map Derived From An Ordinary Difference Equation of mKdV and Its Properties
Authors: Yuliani E , Zakaria L , Asmiati
Published: January 2021

The discrete modified Korteweg–de Vries (mKdV) is a class of discrete integrable systems that may be distinguished as integrable partial difference equations (PΔE) and integrable ordinary difference equations (OΔE). By considering traveling wave solutions, the OΔE mKdV can be obtained from PΔE mKdV. Meanwhile, a mapping can be constructed from an OΔE mKdV. In this paper, we will focus on producing a new map using a process (replacement), the interchange of a single parameter, and an integral and investigate its properties.
Characteristics of Bayes Estimator in the Geometric Distribution with Prior Beta
Authors: Susilo T , Widiarti  , Kurniasari D , Aziz D
Published: January 2021

This study aims to examine the unbiased, minimum variance (efficient), and consistent characteristics of Bayes estimator in the Geometric distribution with prior Beta. Based on the results of simulation studies it is found that the Bayes estimator in the Geometric distribution with prior Beta are symptotically unbiased estimator for values θ < 0,5 and is biased for others, are efficient for the number of samples sizes large and values θ ≤ 0,6 and not efficient for others and consistent when value θ ≤ 0,5 and inconsistent for other.
Real time epidemic modeling using Richards model: application for the Covid-19 outbreak in East Kalimantan, Indonesia
Authors: Huda M N , Sifriyani  , Fitriani
Published: January 2021

The coronavirus pandemic has spread to all provinces in Indonesia within a few months. Coronavirus has entered East Kalimantan province in early March 2020. The number of people confirmed as COVID-19 increased dramatically after March. In this paper, we propose a simple mathematical model to predict coronavirus cases in East Kalimantan province. We applied the Richards growth model to the active case and probable case (PDP case) curves. We used the initial parameter values obtained from China’s Jiangsu province. This means that the strategy for handling coronavirus in East Kalimantan province is assumed to be the same as in China’s Jiangsu province. We have presented the final prediction for the coronavirus pandemic over a range of periods.
Determining the Noetherian Property of Generalized Power Series Modules by Using X-Sub-Exact Sequence
Authors: Faisol A , Ftriani  , Sifriyani
Published: January 2021

The Noetherian property of the generalized power series module can determine in several ways. This paper uses the sub-exact sequence of modules over a ring R to determine this property. This investigation not only determines the Noetherian property of the generalized power series module but also the Noetherian property of its submodule. Furthermore, we give a construction of R[[S]]-homomorphism between the generalized power series modules.
A Structural Equation Modeling of Factors Affecting Student Motivation in Thesis Preparation
Authors: Setiawan E , Pratiwi A , Herawati N , Nisa K , Faisol A
Published: January 2021

Structural equation modelling is a multivariate statistical analysis technique that is used to analyse structural relationships. This technique is the combination of factor analysis and multiple regression analysis, and it is used to analyse the structural relationship between measured variables and latent constructs. The purpose of this study is to use structural equation modelling to better understand student motivation in thesis preparation and its causal determinants. The study creates a plausible structural equation model (SEM) and tests it. The data used were students’ responses of a questionnaire survey about the student motivation in thesis preparation. Based on the results of the study, it was found that the relationship between lecturer and student and the environmental conditions have significant influence to student motivation in thesis preparation.
Implementation protein sequence segmentation in AAC and DC as protein descriptors for improving a classification performance of acetylation prediction
Authors: Rizqiana A , Faisal M R , Lumbanraja F R
Published: January 2021

Post-Translational Modification (PTM) identification is carried out to determine the position of the PTM in protein. Acetylation in the lysine protein is one of the many types of PTM that play an important role in biological processes. In existing research, identification of lysine acetylation was developed by computational methods, using several available protein descriptors along with classification methods. Research on protein classification usually only uses the length of the protein sequence to describe the state of the whole protein, not its local state. Knowing the local state of the protein sequence will have a good effect on the classification results. To find out the situation, the protein sequence segmentation approach is done by adjacent and overlapped segments. Adjacent and overlapped segments divide the length of the protein into several segments, then numerical features will be calculated, so that information about the protein is also obtained locally. Calculation of numerical features using the Amino Acid Composition and Dipeptide Composition descriptors, then the data is classified with Support Vector Machine. The experimental results show that protein segmentation increases the performance of protein classification by 0.7-2.5%. Segmentation using adjacent and overlapped segments provides improved performance. In this research, it was found that protein segmentation affected the performance of protein classification, especially in overlapped segments.
Implementation of Fuzzy-based Model for Prediction of Thalassemia Diseases
Authors: Susanto E. R. , Syarif A. , Muludi K , Perdani R. R. W. , Wantoro A.
Published: January 2021

Thalassemia is known as one of the blood disorder diseases that is inherited by parents. There are several types of Thalassemia, namely as Thalassemia major, minor, and intermedia. Among them, Thalassemia major is the most dangerous and needs more attention. Generally, it can be detected since the child is one year old. Late detection of this disease can have adverse consequences and various complications. This study aims to develop a new model for the prediction of thalassemia for children. The model adopts a fuzzy-based rule. The novelty in this article is that our model has 4 outputs, namely thalassemia major, intermedia, minor and not thalassemia. In the previous article it only had 3 outputs. In this study, we intend to implement a model that we developed using a fuzzy-based approach to classify thalassemia diseases based on CBC data. This article describes how to build a model and implement it in software. We compare the test results with the opinion of pediatricians regarding thalassemia. The final results of testing 4 CBC data show that our proposed model has successfully identified the type of thalassemia.
eDonation Android Application for Used Goods Donation using Location-based Service
Authors: Pribadi R I A , Pambudi A , Ardiansyah
Published: January 2021

Used goods/secondhand can be found anywhere during the buying cycle. Used goods are also can be reused and even still have value. Used goods such as books, clothes, bags, shoes that are still suitable for use, can also be donated to others needy. In the current technological development, many donations have been made online. This can provide donors and social institutions in raising donations. But the donations consist only of money and are not goods. In overcoming this, the eDonation apps can help donors in donating their used goods. This application also helps social institutions in raising broader donations. By utilizing location-based services, donors can find out the location of social institutions in the vicinity, so donors can choose the location of the nearest social institution that receives donations in the form of used goods that are suitable for use.
The Diversity and the Abundance ofCorn Planthopper(Hemiptera: Delphacidae)inLampung Province
Authors: Hasibuan R , Fitriana Y , Ratih S , Wibowo L , Aeny T N , Susilo FX , Swibawa I G , Lumbanraja F R
Published: January 2021

The outbreak of delphacid planthoppers has been detected across corn-growing regions in South Lampung. Survey study was conducted in three corn fields in Natar District, South Lampung Regency. In each study site, five corn plants were randomly sampled. In each sampled plant, one leaf with maximum number of planthoppers was selected for population recording. Based on the morphological identification results, there were two types of corn planthoppers attacking corn fields during sampling periods: the white bellied-planthopper, Stenocranus pacivicus Kirkaldy and Peregrinus maidis Ashmead. During sampling periods, S. pacivicus was most abundant species, while, the Peregrinus planthopper was almost undetectable. There was similar trend peak of density S. pacificus brachypters & nymph and macropters among the three corn fields. The maximum number of S. pacificus brachypters & nymph 412.38 ±23.12 individuals’ leaf−1 was recorded at 70 days after planting (DAP). While the S. pacificus macropters reached the highest population number 43.81 ± 5,76 individuals leaf−1. Extended feeding activity by planthoppers caused the chlorosis and necrosis of the leaf, reduced plant vigor, and stunting, resulting hopperburn symptoms. The results of this study confirm that the explosion of delphacid planthopper sand corn hopperburn are real and become a threat for corn production in Lampung Province.
Characterization Of morfology structure flower from variation cultivars of pisang kepok (Musa paradisiaca L.)
Authors: Ernawiati E , Pratami G D , Setyaningrum E , Ulhaq S S D
Published: January 2021

Banana is a fruit that is very popular in the community because it is easy to find and available in various types, besides is the price is very affordable, bananas also have a fairly complete nutritional value. One type of banana that is widely used by the community is pisang kepok. Pisang kepok has more diverse cultivars than other types of bananas. These cultivars have different morphological structures, one of which is the flower. Flowers have a role in the breeding of a plant. This study aims to determine the differences in the morphological structure of flowers among the pisang kepok cultivars with each other. The research was carried out in two stages. Frst, field sampling in residential area of Bandar Lampung City, Pesawaran Regency and South Lampung Regency. Second, morphological characterization based on the parameters determined conducted in the Biology Department of the FMIPA Unila Laboratory. The results obtained were cultivar of pisang kepok which had been observed to have almost the same morphological structure except in kepok batu The specific character of pisang kepok batu can be seen in the character of the color of pollen sacs, compound tepal pigmentation, free tepal color, free tepal apex shape and pistil shape.
Isolation and identification entomopathogen fungi as candidate of bioinsecticide from flies and cockroaches’ (Insect vector’s disease)
Authors: Rosa E , Ekowati C.N , Handayani T T , Widiastuti E L
Published: January 2021

Chemical insecticide has been used for many years to eradicate insects as disease vector, in which causing negative effects not only to those of target insects but also to the environment both in the short and long term. Therefore, it is necessary to determine an alternative biological control of this insect by using natural insecticide (bioinsecticide), such as using fungi as entomopathogen. As microorganism, fungi, contain of bioactive compound with their toxicity could kill the target insect from larvae to adults, called entomopathogen fungi. This entomopathogen fungi are presumably eco-friendly and able to produce toxic compound which can kill target insect such as cyclopeptida destruxin A, B, C, D and desmethyldestruxin B. Two of the fungi which known to be entomopathogenic are Metarhizium anisopliae and Beauveria bassiana. Yet, there should be more others, therefore it is necessary to explore and isolate any potential bio-insecticide of entomopatogen fungi for disease vectors such as from flies (Musca domestica) and cockroach (Periplaneta americana). This study found three isolated fungi from flies (L1, L2, L3). They were Geotrichum sp., Penicillium sp., and Aspergillus sp. Three isolated fungi from cockroach (K1, K2, K3) were also found, they were identified as Aspergillus sp., except for K3 Penicillium sp.
Micropropagation of Red Ginger (Zingiber officinale Rosc. Var. Rubrum) Using Several Types of Cytokinins
Authors: Karyanti  , Sukarnih T , Rudiyana Y , Hanifah N F , Sa’adah N , Dasumiati
Published: January 2021

One of the medicinal plants that is widely cultivated is the red ginger (Zingiber officinale Rosc. Var. Rubrum). The plant contains an active compound gingerol that is used as an ingredient for various treatments such as cough and flu. To meet the demand of medicinal and industrial raw materials, quality ginger seeds are needed. One alternative to producing seeds is to use tissue culture technology. This study aimed to obtain the best type and concentration of cytokinins in increasing the multiplication of red ginger shoots in vitro. This study used a factorial Completely Randomized Design (CRD) with 2 factors, namely the type of cytokinins (BAP, thidiazuron, zeatin, kinetin, and 2ip) and cytokinin concentrations (0, 0.1, and 1 ppm). The results showed that 1 ppm thidiazuron treatment produced the highest number of shoots and the highest shoot length in the first subculture. The responses in the second subculture showed that shoots from thidiazuron, 2ip, and BAP treatment media produced the highest number of shoots, roots, and leaves compared to kinetin and zeatin. Multiplication continued until the sixth subculture, and the best multiplication was found on shoots from 2ip treatment.
Growth and Estimation of Potential Carbon Absorption by Transplantation Branching Coral Reefs on Mahitam and Pahawang Islands of Pesawaran Regency, Lampung Province
Authors: Widiastuti E L , Dani S K D , Tugiyono  , Yudha I G , Susanto G N
Published: January 2021

This study aims to determine the growth and survival and carbon uptake of transplanted coral reefs in Mahitam and Pahawang Islands. Mahitam Island transplants were carried out using iron media and Pahawang Island using concrete media. Growth and survival measurements for 24 months were carried out 3 times from the start of planting. In addition, measurements of water quality were also carried out at that location. The amount of carbon in coral reefs was measured using spectrophotometry, where samples of coral reefs were dried first then mashed and dissolved using a solution of H2SO4 and K2Cr2O7 1N. The results showed that the branching coral transplanted for 24 months had an average growth of 17.21 cm on Mahitam Island and 19.97 cm on Pahawang Island. The coral survival was higher on Mahitam Island compared to Pahawang Island with a percentage of 92.14 % and 88.24 %. The organic carbon (C) content of the transplanted coral reefs on Mahitam Island was 1.11 % and on Pahawang Island was 1.01 %. In conclusion, the transplanting of branched coral reefs at Mahitam and Pahawang Islands was said to be successful with high growth and viability. As well as the transplanted coral reefs at the research location can store carbon (C).
Isolation and properties of ammonia-oxidizing bacteria from mangrove sediment, hanura lampung beach
Authors: Putri R , Sumardi  , Irawan B , Agustrina R , Tugiyono
Published: January 2021

Mangrove forest area is an area that has good water quality. In the sediments of mangrove forests, there are many types of microbes capable of bioremediating inorganic contaminants such as ammonia and the heavy metal mercury. Isolation of bacteria was carried out using specific nitrification media to obtain ammonia-oxidizing bacteria. The sensitivity test for heavy metal mercury was carried out in the laboratory with 9 combinations of concentrations. The results of bacterial isolation from mangrove forest sediments at Hanura Beach, Lampung, obtained four isolates of ammonia-oxidizing bacteria (A1, A1P, A3, and A3P). The sensitivity test for heavy metal mercury showed that the four isolates obtained were able to survive the addition of heavy metal mercury by 0.003 g / L.