bluuebunny/crossref_metadata_2025 huggingface dataset:
Probabilistic Selective Broadcast for energy-saving communications in Cognitive Ad Hoc Networks
Authors: Li Yueyue , Huang Zhong , Wen Guangjun , Ma Yugang
Published: June 2019

Cognitive radio, as a promising technology, plays an important role in ad hoc network communications, leading to more reasonable and orderly utilizations of wireless spectrum resources. It is not only an opportunity but also a challenge for wireless mobile communications. In cognitive radio ad hoc networks, the non-uniform channel arrays available for secondary users make difficult to the application of broadcasting technologies, concentrating on common channel selection and broadcast collision. In this paper, a probabilistic selective broadcast, called pSB, is proposed, aiming at economy and energy-saving distributed wireless communications. The protocol adopts an intelligent channel selection policy with a probabilistic forwarding strategy to alleviate collisions caused by redundant message exchanges. Consequently, the proposed pSB outperforms other methods in terms of higher message reach rates and fewer broadcast collisions evaluated by simulations under different parameter configurations.
The High Precision Capacitance Array in 16-bit SAR ADC
Authors: Li Yong-Kai , Qi Xu , Yang Ping , Cen Yuan-Jun , Li Da-Gang , Liao Zhi-Kai
Published: June 2019

In SAR ADC, the capacitance array is a very important unit, it will determine the conversion performance of the whole ADC. In normal semiconductor foundry, the matching precision of the linear capacitor is always about 10 bit, so it is not impossible to realize the 16-bit conversion precision in normal COMS foundry. This paper introduces a new design, for getting a smaller layout area, the main body frame of capacitor array uses the M+N+L bit sectional type; For getting the high matching precision performance, the lower bridging capacitor will be the normalized capacitor; For getting the high conversion precision, all the Upper-Bit in capacitance array will add a sub-calibrated capacitor array. So in this paper, it uses the circuit structure to realize the high precision capacitor array in 16-bit SAR ADC.
A mathematical model for reflection of electromagnetic wave
Authors: Ding Qiuyu
Published: June 2019

HF signal whose frequency is under MUF can propagate by reflect between the ionosphere and the earth, which can achieve a long distance communication. This paper is to solve the problem of HF propagation. We first describe the strength of reflection off the calm ocean. Then the numerical simulation ocean wave model is built and the geometry and energy characteristics of reflection wave off the turbulent ocean are determined by analytic geometry principle and Fresnel formula. We compare the strength of the two kinds of reflection waves by getting the total energy ratio between them. Finally, we take the energy loss of ionosphere into consideration and calculate the signal-to-noise ratio to determine the maximum number of hops.
Collision detection Based on OBB Simplified modeling
Authors: Zhang Rong , Liu Xiaogang , Wei Jianjun
Published: June 2019

This paper has analysed the most common algorithm of collision detection based on Oriented Bounding Box(OBB) simplified modeling. After that, in order to improve the efficiency of traditional collision detection algorithm in practical applications, an improved OBB collision detection algorithm is proposed.Moreover, a collision detection algorithm and the double robot coordinated motion model were built by matlab software, at the same time, a trajectory where two robots can collide with each other was built. In addition, the two algorithms were compered by changing the calculation accuracy in robot trajectory planning. Finally, the results show that the algorithm can greatly improve the efficiency of collision detection in dual robot systems.
Traditional Book Stores Industry Reforming Based on the New Management System
Authors: Luo Tianyi
Published: June 2019

The Book Stores industry has had its pages ruffled over the near half decade. Despite a strengthening domestic economy and rising per capita disposable income, the industry continues to experience decline. The business had negative annual growth since 2013, and there is no sign of stopping this trending. It is highly duo to two main factors, the change of consumer purchasing preference and external competitors rising.

When such a traditional business decided to embrace this new “Internet+” era by opening a new online store to reseize the market share, it needs to adopt a new management system containing technologies such as big data and cloud computing which have performed a significant role in this era. At the same time, to keep pace with the new requirements, both physical and online store needed a simple information management system and database to support their inventory and sales operations. This paper aims to set and design the database to support the operations of this industry.
Personalized employment recommendation method based on semantic matching of requirements
Authors: Wang Weihong , Feng Qian , Zhou Fuxiang , Cao Yuhui , Hongyan LV
Published: June 2019

Aiming at the lack of personalized recommendation method in existing employment application system, a personalized employment recommendation method based on semantic matching of requirements(PERM-SMR) was proposed in the paper.Firstly, the web crawler technology is used to collect the recruitment information and clean the data.Secondly, word2vec method was selected for corpus training to obtain the word vector model.Thirdly, we performed semantic analysis on the demand information of both sides, calculated the weight of the feature words in the text and generated text vector, and then carried out the requirement information matching and generated the recommendation list.Finally, it is verified by experiments that the PERM-SMR is more accurate and effective, and provides better employment guidance for graduates.
Morphology and Wear Resistance of HVOF Sprayed H13-WC/Ni Gradient Coating on H13 Steel Surface
Authors: Li Hongbo , Li Ban , Deng Chengxu , Wang Yijing
Published: June 2019

A H13-WC/Ni gradient coating was prepared by high velocity oxygen-fuel (HVOF) thermal spraying on the surface of H13 steel. The coating consists of multi-layer H13 and Ni/WC powders in different proportions with the reinforced particles of Ni/WC ratio increased by 15% (mass fraction) layer by layer. By observing the microstructures of sprayed powders and coatings and testing the thermal shock resistance and frictional wear behavior of the three coatings and matrix at 600°C, the results indicate a uniform, smooth and crack-free surface of the coating, and a good bonding between the coating and the matrix. The main mode of bonding is mechanical bonding. The average microhardness of the coating surface rises with the increasing of hard phase content, and the hardness of the section increases gradually from the matrix to the coating surface. Spot-like flaking can be observed on the H13 after thermal shock 10 times, cracks can be found on all three coatings after 15 times and cracks can be spotted on the gradient coating but falling off is not discovered after 55 times. It can be concluded that the H13 and Ni/WC coatings could improve the wear resistance of the matrix at high temperature, and the wear resistance of the gradient coating was better than that of the monolayer coating.
Structure Parameter Optimization of Welding Spot of Corrugated Plate Component
Authors: Zhang Xiang , Jia Wang , Qingzhong He , Manjiao Chen
Published: June 2019

A simple model is used to determine the research route of corrugated plate component with good fatigue life based on equivalent stress, and the simulation results are proved to be reasonable by physical test. It is found that the equivalent stress of corrugated plate component increases with the increase of horizontal distance between welding points during single-row welding, after the analysis of the simulation results. In all the arrangement forms, the number of welding points arranged in triangle arrangement is large, which has good connection effect on corrugated plate component and good structural stability. Therefore, it is better to connect corrugated plate component in a way of welding in row 3, with a distance of 2 mm from top to bottom, a distance of 10 mm from left and right sides of row 1 and row 3, and a distance of 37.2 mm from left and right sides of row 2. The fatigue life simulation result of corrugated plate component under the structural parameters is 7.89e6 times, and the actual fatigue life of physical test exceeded 3.0e7 times, meeting the working condition requirements.
Failure Analysis on Loosing Bar of An Elevator Brake
Authors: Ren Facai , Liang Xiao , Li Bo , Wu Xinghua
Published: June 2019

A failure analysis was performed on loosing bar of an elevator brake. The macroscopic morphology and metallographic microstructure of the elevator brake loosing bar were investigated based on the optical microscope and scanning electron microscope analysis. The results showed that the material of elevator brake loosing bar meets the technical standard of 45 steel. The abnormal peel wear was caused by the abnormal rotation between the loosing bar and magnetic ring.
Failure Analysis of An Elevator Brake Plunger
Authors: Ren Facai , Liang Xiao , Li Bo , Wu Xinghua
Published: June 2019

A failure analysis was performed on an elevator brake plunger. The macroscopic morphology and metallographic microstructure of the elevator brake plunger were investigated based on the optical microscope and scanning electron microscope analysis. The results showed that the material of elevator brake plunger doesn’t meet the technical standard of DT4.
Review on the Discoloration Treatment Technology of Paulownia Wood
Authors: Gao Weixia
Published: June 2019

This paper firstly introduces different views about discoloration of paulownia wood. Secondly, it summarizes treatment methods to prevent and remove stains on surface of paulownia wood. Finally, it analyzes the trend of paulownia wood discoloration treatment technology.
Effect of wheel polygonization on the axle box vibrating and bolt self-loosening of high-speed trains
Authors: Shan Wei , Wu Pingbo , Wu Xingwen , Zhang Fubing , Shi Huailong
Published: June 2019

The wheel polygonization has become a great concern for the high speed rail vehicle owing to its highly adverse effects in high speed condition. Such periodic distributed wear along the wheel can give rise to high magnitude of high frequency impact loads at the wheel/rail interface and further contribute to severe fluctuations in axle box acceleration and the self-loosening for axle box bolts. In this study, the wheel polygonization-induced axle box vibrations and bolt self-loosening are thus initially investigated through the field tests and the roller test rig. Subsequently, a coupled vehicle/track dynamic model integrating a typical high speed rail vehicle and a flexible slab track is formulated to identify the mechanism of bolt self-loosening in the presence of wheel polygonization. The results suggest that the wheel polygonization can result in high magnitude accelerations in the axle box, and excite some of vibration modes of the axle box and its end cover. The accelerations on the axle box end cover are much larger than those obtained on the axle box, which is also comparable to the experimental results. It is thus believed that the self-loosening of axle box end cover’s bolts is mainly attributed to the severe oscillations on the axle box due to the wheel polygonization.
Study on efficient and green reduction of graphene oxide by a one-step hydrothermal method
Authors: Zhi Maoyong , Liu Quanyi , Chen Hao , Feng Sihai , He Yuanhua
Published: June 2019

This work reports an efficient and green reduction method of graphene oxide (GO) by a one-step hydrothermal process. GO was prepared by the oxidation of graphite using a modified Hummers method. The reduced graphene oxide (rGO) were characterised and studied by means of UV-vis absorption spectra, Raman spectroscopy and transmission electron microscope (TEM) techniques. UV-vis absorption spectra revealed that GO was successfully reduced to rGO and the π-conjugated structure was restored. Raman spectroscopy suggested that rGO had a smaller average size of the in-plane sp2 domains and more sp2 domains than that of GO. Fourier transform infrared (FTIR) spectra demonstrated that most oxygen functionalities on the GO were removed after the reduction. TEM images further confirmed that there was no irreversible agglomeration of rGO layers. Furthermore, we proposed a possible mechanism for the reduction of GO with subcritical water under hydrothermal condition. This study provides a novel idea for developing environmentally friendly reduction methods of GO.
Research and Implementation of Modbus TCP Security Enhancement Protocol
Authors: Xuan Luo , Yongzhong Li
Published: June 2019

Considering the security problem of Modbus TCP protocol, such as the lack of authentication mechanism, the protection mechanism of data transmission and abuse of function code, a secure industrial control communication protocol(Modbus-S protocol) is designed based on the original Modbus TCP protocol, which uses symmetric key algorithm to ensure the confidentiality of data; the uniqueness of data is guaranteed by the synchronization mechanism based on hash algorithm; digital signature algorithm is used to ensure the verifiability and integrity of data; finally, “White List” filtering mechanism is used to manage function codes based on roles to effectively prevent abuse of function codes. Through the verification and analysis of experiment, Modbus-S can fully compensate for the design defects of Modbus TCP protocol. Compared with the existing methods, this method has higher security and can comprehensively improve the communication security of Modbus TCP protocol.
Simulation of Urban Rainstorm Waterlogging and Pipeline Network Drainage Process Based on SWMM
Authors: Zhang Sui , Zhe LI
Published: June 2019

Urban flood has already become weaknesses of flood control system in China. Flood and pipeline drainage calculation based on hydraulics model plays a key role in flood monitoring, warning and control management. On the basis of the topographic maps (high-precision DEM), underground drainage networks, land use and rainfall data in Enshi City, a SWMM-based urban flood model is constructed, which is applied to calculating rainstorm waterlogging and pipeline drainage process under the designed storm probability of 0.01, 0.02 and 0.05, and the designed storm period of 1 hour and 3 hours. The pipeline drainage peak flow of different pipeline type is also retrieved. And results suggest that SWMM is a reliable urban storm water model, which is suitable for urban storm flood simulation and pipeline network drainage analysis.
Design and Implementation of Control Unit for Medium and Short Wave Broadcast Exciter Based on STM32
Authors: Liu Xi , Lu Qibin
Published: June 2019

This paper designs a control unit of medium and short wave broadcast exciter based on STM32F107 microcontroller and Ethernet PHY device DP83848. It mainly designs and analyses the modules of human-computer interaction and Ethernet communication. The hardware and software design of the control unit is described in detail, and the remote control function is realized by building Web server with LWIP. The test results show that the programme has reliable performance, easy to use, low in cost, and has a good application prospect.
Integrative Landslide Emergency Monitoring Scheme Based on GB-INSAR Interferometry, Terrestrial Laser Scanning and UAV Photography
Authors: Zheng Xiangtian , Yang Xiaolin , Ma Haitao , Ren Guiwen , Yu Zhengxing , Yang Feng , Zhang Hao , Gao WenYuan
Published: June 2019

In this study, an integrated remote sensing scheme comprised of a Ground-based Interferometric Synthetic Aperture Radar (GB-InSAR), Terrestrial Laser Scanning (TLS) and an Unmanned Aerial Vehicle (UAV) is utilized for rockslide emergency monitoring. GB-InSAR, here proposed as surface deformation monitoring of residual dangerous rock mass, provides data support and decision basis for the study of secondary slope instability. TLS grasps the landslide body as point cloud, and the 3D modelling of the main hidden danger area of secondary sliding at the site. UAV obtained timely geographic information about disasters, investigated potential hazards and shared them in real time. A case study, based on the entrustment of China Ministry of Emergency Management (CMEM) and China Institute of Geological Environment Monitoring (CIGEM), deals with a rockslide locates at K18+350 Junhong Road (Beijing, China). First, acquired data are processed for early warning of hazard to ensure the safe transfer of personnel and property within 72 hours in villages and towns affected by dangerous rock masses. Second, the monitoring services ongoing on accurately measurement of each hidden risk spot in the spatial coordinates, elevation and dynamic change and influence range. The methodology has been proved effective in emergency management.
Error Performance of DPSK Satellite-to-Ground Laser Communication over Atmospheric Turbulence and Pointing Errors
Authors: Hao Shiqi , Wan Xiongfeng , Zhao Qingsong , Xu Chenlu
Published: June 2019

In satellite-to-ground laser communication, atmospheric turbulence will seriously deteriorate the system performance. The DPSK modulation technology is usually used to control the influence of atmospheric turbulence. The Meijer G-function is used to give the closed-form expression of the average bit error rate (ABER) of the system considering the combined influence of the atmospheric turbulence and the pointing errors, where the atmospheric turbulence channel is submitted to the Gamma-Gamma distribution and the pointing errors is submitted to the Beckman distribution. Through numerical simulation, the influence of system transmitting power, normalized beam width and zenith angle on the BER performance of the system is analyzed. The simulation results show that the ABER of the system decreases with the increase of the transmitting power, the error performance of the system considered the bias errors is obviously higher, and the error performance is also different when the azimuth and elevation normalized jitter deviation are not equal. The system performance will decline rapidly with the increase of the zenith angle. The BER of the system decrease firstly and then increase with the increase of the normalized beam width, and the optimal normalized beam width can be found to achieve the best performance.
Construction Exploration of Chongqing Environmental Supervision Information System under the Background of Environmental Protection Vertical Reform
Authors: Luxiao Wang , Xiaoyan Huang , Rong Jiang , Xiaoming Hu
Published: June 2019

According to the environmental protection vertical management reform requirement, the environmental supervision information system was designed based on the existing informational situation and the responsibility of Chongqing environmental supervision office. The system built the whole management process of collecting, screening, assigning, examining, checking, feedback, verification and canceling problems. The integrated environmental supervision information system established the vertical and horizontal data exchange channel among the ministry of environmental protection, Chongqing environmental protection bureaus and the municipal departments. It not only provided an information working platform for the supervision of environment supervision office, but also provided a good example for environmental supervision information construction.
Preliminary Discussion on the Application of Internet in Tobacco Monopoly Retail License Management
Authors: Yang Tian , Fan Xiangyu , Hongwei LU
Published: June 2019

It is expounded that the background and necessity of tobacco monopoly retail license online processing, is analyzed that the advantages and functions of Internet technology to solve tobacco monopoly retail license processing, and is put forward the development and application strategy: the construction of Wechat communication module of the application link of business households; establishing retail license processing module and carry out extensive publicity; establishing the feedback module of retail license handling, and promoting the interaction between government, enterprises and business households.
Cubic fitting method of wavelength shift of optical fiber grating temperature sensor and a temperature measuring device
Authors: Chengyou Wang , Yajun Deng , Peng Wei , Haijun Xue
Published: June 2019

The center wavelength movement of fiber grating reflecting is not strictly linear relationship with the measured temperature due to the influence of grating materials, fiber materials, packaging and other factors. This makes the fiber Bragg grating temperature sensor produce error. In order to improve the accuracy of temperature measurement, the more mature method is to use the conic fitting method to correct the error. This method has good temperature measurement accuracy in the medium-low temperature region (-20.0∼80.0°C). But the error of the medium-high temperature region (80.0∼140.0°C) increases gradually. In this paper, the cubic fitting method of wavelength shift is proposed and a temperature measuring device is developed by using this method. The method selects the center wavelength of the reflected light at the temperature of 0° as the reference wavelength and The measured temperature is fitted with the cubic polynomial of the shift Δλ between the reflected wavelength and the reference wavelength. The temperature measurement experiment shows that this method improves the temperature measurement accuracy of the medium-high temperature zone under the premise of calibration in the medium-low temperature zone.
The Principle and Application of Optical Fiber Sensing Technology: Three Kinds of Distributed Sensing and Fiber Bragg Grating
Authors: Yuan Gao
Published: June 2019

In modern society, optical fiber plays a significant role in ordinary people’s life. The development of optical fiber communication is so fast while the optical fiber sensing has gained huge achievements although fewer people know about that. In fact, optical fiber sensing technology has become increasingly popular due to its low price and the fact that this method overcomes the problems encountered with traditional sensor, such as in the high-intensity magnetic field. Meanwhile distributed sensing enables the all-day and all-spots monitoring. Based on different principles, distributed optical fiber sensing could be classified into three kinds, which are optical time-domain reflectometry based on Rayleigh scattering, Raman-optical time-domain reflectometry based on Raman Scattering and Brillouin-optical time-domain reflectometry based on Brillouin scattering. These three methods have their own benefits and applications because of their special structures. Fiber Bragg grating can be taken as one kind of optical fiber sensor as well as the grating locates inside the optical fiber. Relying on the diffraction effect, FBG can measure temperature, strain and even pressure sensitivity. The demodulation methods of FBG are various as well. There are about 8 different methods that can meet different requirements, each with its own benefits and defects.
Control of Powder Material Automatic Batching System based on PLC
Authors: Yang Xinjun , Kong Lingyu , Wang Ying , Xu Feng , Zhu Xiaqing
Published: June 2019

Aiming at the characteristics of powder material, such as easy to dust, easy to leakage, polluting the environment and harmful to human body, an automatic batching system for powder material is designed. The system adopts a quantitative weighing device with buoyancy weighing sensor as the core, feeding with electric vibration feeder and 16 small cups. Simatic S7-1200, the latest generation of Siemens PLC, is used to control the system. 2304HS42A1 motor of Hamderburg Company, Germany, is used to control the movement of the cup on the workbench. The software control scheme of the system is designed. Practice has proved that the system runs stably and has good performance, which is worth popularizing.
Study on Emission Characteristics of Hydrogen Direct-Injection Gasoline Engine
Authors: Liang Jinguang
Published: June 2019

Experiments have been carried out on a hydrogen direct-injection and gasoline port-injection engine at the conditions of locally rich hydrogen and lean-burn mode in order to study the effect of hydrogen fraction and air-fuel ratio on the engine’s emissions. The experiments results demonstrated that when the excess-air ratio was increased from 1 to 1.8, NOx and CO emissions were at least decreased by 91% and 95% respectively and HC emission was increased by 56%. Almost 23% reduction was observed in HC emission when hydrogen fraction changed from 3.9% to 10.5%, whereas the NOx emission has almost been tripled and CO emission is found to be less affected with hydrogen fraction.
A Multi-Channel Data Acquisition System for Capacitive Sensing
Authors: Li Jianke , Zhao Yanxia , Li Jianfeng , Hu Aihua , Wei Ruoyan , Zhang Changshui
Published: June 2019

Capacitive sensing can be applied to a variety of applications. A multi-channel data acquisition system for capacitive sensing was designed based on an FDC2214 with external L-C resonators. The FDC2214 was used for capacitance-to-digital converting by measuring the ratio of the resonator frequency to a reference frequency. Employing MSP430F5529 as host processor and the two-wire I2C serial bus interface connected with the FDC2214, the system implemented multi-channel data acquisition. As a test system, an 8-channel physical hardware device was provided. Experiments for gesture recognition had been done using the 8-channel capacitive sensing data acquisition system. The good experimental results verified the availability of the designed system.
Influence of Turning Parameters on Surface Integrity of D840 Wheel Material
Authors: Yu Lang , Quan Yanming , Liu Peijie , Wan Junjie
Published: June 2019

The machined surface integrity of heavy-haul freight wheel is one of the direct factors which affects the wheel’s service performance and life. Based on the wheel turning parameters, single-factor experiments on D840 wheel material under dry cutting condition were performed. The changing laws including the surface work hardening, surface microstructure, surface roughness, and surface morphology were analyzed via micro-hardness tester, metallographic microscope, SEM and surface profilometer under different cutting parameters. The results show that the surface hardness and the hardening layer increase with the increase of feed and cutting depth within a certain range of cutting parameters. The surface amorphous layer and fiber layer thicken with the increase of feed and cutting depth. The fibrosis of proeutectoid ferrite in the plastic deformation layer and the extrusion deformation of the flake pearlite are obvious. Meanwhile, pearlitic lamellar spacing decreases gradually. The surface roughness increases with the increase of feed, and cutting speed a cutting depth have less effect on roughness.
Preliminary Study on Teaching Reform of Automatic Welding Practice Based on K5 Teaching Method
Authors: Qin Song , Xiaoming Tian
Published: June 2019

With the continuous development of automation technology, the teaching of automation technology in colleges and universities currently plays an important role. For example, in the process of automated welding practice, students are required to complete the practical hands-on ability of automated welding technology through the orderly teaching, and master the relevant theories of automated welding technology.
Advanced Heat Treatment Equipment Technology And Product Development of Metal Materials
Authors: rile Ge
Published: June 2019

From the current analysis of steel materials in the field of heat treatment and offline heat treatment, the implementation of advanced heat treatment equipment and processes for automated metal materials in China has carried out numerous innovations. In order to improve the technical level of localized equipment and promote the continuous development of new industrialization processes, the use of green manufacturing processes to achieve heat treatment of steel and non-ferrous metals is the focus of current research. This paper focuses on the analysis of advanced heat treatment equipment, process and product development of metal materials, and proposes to adopt green manufacturing concept and carry out research and development on advanced heat treatment equipment and technology of metal materials. It is expected to have reference value for improving rolling technology and continuous rolling automation in China.
Development of Karmana-Problem Based Learning Modelto Train Problem Solving Skills and Concept Mastery of Biology Teacher Candidates
Authors: Karmana I W , Ibrahim M , Susantini E
Published: June 2019

Problem solving skills and concept mastery are the most essential skills in the 21st century. In relation to that, the purpose of this research is to develop a learning model, namely Karmana-Problem Based Learning (K-PBL) model to train the problem solving skills and concept mastery of biology teacher candidates. This is a research and development by using the Borg and Gall model design, which will produce a product, that is the K-PBL model is valid, practical, and effective. The validity of the model is assessed by validator, practicality is assessed using observation sheet of learning scenario and students activities,and the effectiveness is determined based on pre-test and post-test problem solving skills and biology concept mastery. The data technique analysis is descriptive-qualitative.The results of this resarch show that the developed learning model (K-PBL) is determined to be valid by the validator with a reliability score of 0,91 (reliable) with the syntax assessment: 1) Knowledge; 2) Advance organizer; 3) Review; 4) Management strategy; 5) Acting; 6) Note and presentation; and 7) Asessessment, including learning tools and instruments have been declared valid. Furthermore, the implementation of the learning model (try out) in biology education students of IKIP Mataram is declared to be practical because the percentage of learning implementation reaches 100% with reliability 0,97 (reliable), and the percentage of student activity also reach 100% with reliability 0,98 (reliable). In addition, the obstacles in learning that arise can be overcome. The model was also declared effective due to an increase in problem solving skills with a high grade 0.71 N-Gain score, concept mastery of the students achieve a high grade 0.73 N-Gain score with students responses to K-PBL model categorized positively (91,7%). It can be concluded the K-PBL model is valid, practical, and effective to train problem solving skills and concept mastery of biology teacher candidates.
The Effects of Using Multiple Representations on Prospective Teachers’ Conceptual Understanding of Intermolecular Forces
Authors: Widarti H R , Marfu’ah S , Parlan
Published: June 2019

Intermolecular force is one of study material in Organic Chemistry I course, which involves numerous representations. This study aimed to find out the effects of using multiple representations on prospective teacher’s conceptual understanding of intermolecular forces. The research method used in this study was a quasi-experiment. The research subjects were 56 second-semester chemistry education students batch 2017-2018 in Universitas Negeri Malang which enrolled in Organic Chemistry I course. The research subjects are grouped into two classes including experimental and control classes with 28 students each. The experimental class was taught with the multiple representations-based learning, while the control class was taught using an expository learning. The measuring instrument included 6 question items with three-tier test question type and a reliability of 0.639. The research result showed there was a positive effect on the use of multiple representations-based learning. This can be seen from the existence of a difference in experimental and control classes’ conceptual understanding. The conceptual understanding of intermolecular forces in the experimental class (mean 55.93) was higher compared to the control class (mean 36.96).
Socio-scientific Issues (SSI) in Chemistry Education: Enhancing Both Students’ Chemical Literacy & Transferable Skills
Authors: Rahayu S
Published: June 2019

Chemistry education has tasks to guide students to be future employment within the field of science and enginerring and also to provide societies with many opportunity for chemistry-related career. However, there are some challenges faced by chemistry education, such as lack of transferable skills of chemistry graduates, education reform on the need for scientifically literate citizens and for reducing the shortage in participation and interest of young people in science and engineering. One possible way to solve such challenges is that we could use socio-scientific issues (SSI) as a context to be integrated in a chemistry instruction. Through socio-scientific issues related chemistry, both scientific literacy and transferrable skills could be enhanced. This paper discuss potency socio-scientific issues in developing the skills and how to incorporate it in the instruction.
Interactive Task Development of The Area and Perimeter of Rectangle to Reduce The Anxiety of Secondary Students in Doing Mathematics Task
Authors: Nasution S H , Qohar A , Susiswo
Published: June 2019

This article discussed the interactive task development of the area and the perimeter of a rectangle to decrease the anxiety of secondary students in doing Mathematics task. The purpose of this development was producing an interactive task of rectangle area that was valid and effective to decrease the students’ anxiety in doing mathematics task. The development consists of three phases, they were: (1) Analysis phase, (2) design phase, and (3) development phase. The product that developed was validated and tested in a small scale with five trial subjects. The validator concluded that the validation product was valid. Furthermore, the trial result in small scale concluded that the product could decrease the anxiety of secondary students in doing Mathematics task.
Students’ Mathematical Thinking Process Involving Equal Signs
Authors: Tomé A O , Purwanto  , Sa’dijah C
Published: June 2019

The purpose of this research is to know the process of students’ mathematical thinking in solving mathematics problems involving equal sign. The method used in this research is descriptive qualitative using two stages such as testing and interviewing. This research was conducted at Sekolah Dasar Islam Surya Buana Malang and held at 5th grade involved 30 students, after having the test, will be continued the interview. The interviewed was conducting with two students who choosed based on the communication’s ability; so the students be able to explain the responding that has been given. Based on the result of this study most students understood that the equal sign as a symbol to obtain the results of a calculation. This result also shows that there are students who can understand equal sign as equality, however that understanding just limited to the equal sign with closed type, while in open type all students did not understand. It can be concluded that students more understand the equal sign as an operational symbol. This result is suggested to the teachers to introduce the meaning of equal sign to students especially relating to equality.
Students’ Thinking Interference in Understanding Functions
Authors: Hidayanto E , Budiono E
Published: June 2019

This paper aims to describe students’ thinking interference when studying function material. The study was conducted by analyzing the work results of 6 students of Mathematics Education Study Program FMIPA State University of Malang in the 6th semester about the function material. The results of the study show that students think interference when they understand the functions with verbally, symbolically, and diagrams.
Shadow Supervisor Strategy on Student with ADHD in Mathematics Learning Activity for Inclusive Secondary Class of Elementary School
Authors: Marlina R , Budiyono  , Usodo B
Published: June 2019

The purpose of this study is to describe and analyze the strategy of Shadow Supervisor in mathematics learning for student with Attention Deficit/Hyperactivity Disorder (ADHD) in inclusive secondary class of elementary school. Learning strategies include models, approaches, methods and learning techniques. This is a qualitative research (field research) with purposive sampling. The samples are special supervisor (shadow) and student with ADHD. The instruments used are observation and documentation. The results showed that for basic competence to sequence of numbers and stepping number (number pattern), a place value number system, addition and subtraction, time measurement (clock reading), and two-dimentional figure grouping, the learning model used was behavioristic. The approach is synthetic, spiral and intuitive in accordance with the basic competencies being taught. The learning method used were question and answer, drilling and exercises, games and stories, and assignment. Learning techniques used was vary according to the basic competence of learning materials.
Implementation of Creativity Problem Solving Model Using E-Learning in Applied Graph Theory Course
Authors: Wahyuningsih S , Satyananda D , Octoviana L T , Nurhakiki R
Published: June 2019

One of learning alternatives that can be applied to improve students’ activity and creativity is e-learning.. Implementation of e-learning for applied graph theory course used e-module for course material, e-portfolio for student assignments, and online-based tasks that can be accessed by other students, hence it is could be as a pioneer of wider implementation of online learning. In applied graph theory course, students needed to have direct experience in solving problems in related industries/institutions. From direct application experience in the field, students raise problems, model problems in the graph, and determine appropriate methods to solve the problem. Creative thinking process could be identified from students’ problem solving task by using Creative Problem Solving (CPS) model. There are four indicators of main step (understanding the challenge, generating ideas, preparing for action, and planning approach) and eight minor step indicators (constructing opportunities, exploring data, problem framing, generating ideas, developing solutions, building acceptance, appraising tasks, and designing process) in the recent version. Purpose of the paper is to analyze result of CPS model implementation, and to discuss student’s responses to the implementation. By implementing the CPS model through e-learning, it could be identified that student’ s creativity in real problem solving were good. The questionnaire indicated that the student response strongly agree with the implementation of this learning to develop creativity.
The Effect of the ELPSA Framework on Students’ Ability to Solve Function Problems
Authors: Nissa I C , Sanapiah  , Yuntawati
Published: June 2019

Mathematical functions are good to learn for solving problems in everyday life associated with the "input" and "output" processes. Mathematically, functions are expressed in terms of formulas. Students may be able to determine the functional value of a given function formula for an input value, but most students still have difficulties to do otherwise. The difficulties faced by students are related to the ability to transfer problem in context to mathematical problem. ELPSA (Experience, Language, Pictorial, Symbolic, Application) is a framework that views learning as an active process in which students build their own way of knowing (developing understanding) through both individual thinking and social interaction with others. This is an experimental research to measure the effect of mathematics teaching by using ELPSA framework on students’ ability to solve function problems. The samples of this study were the 8th grade of Aletheia Christian Junior High School at Mataram city, West Nusa Tenggara. This research used a quasi-experimental with non-equivalent control group design. Data were collected by giving a test and observations during the learning process taken place. Data were analyzed by using data analysis tools in Microsoft. Based on the results of statistical tests and observations of students’ performance during the mathematics learning process, then there was significant effect of the ELPSA framework on students’ ability to solve function problems. Furthermore, it is can be used as a reference for mathematics teachers to use ELPSA framework as an innovative strategy of teaching mathematics in improving students’ problem solving skills.
An Analysis of Students’ Creative Thinking Skill in Creating Open-Ended Mathematics Problems Through Semi-Structured Problem Posing
Authors: Titikusumawati E , Sa’dijah C , As’ari A R , Susanto H
Published: June 2019

This study aims to analyze how students of Mathematic Education study program in one of tertiary education providers in Salatiga Regency, Indonesia, creates open-ended problems via semi- structured problem posing. A qualitative descriptive method was employed to study a population of research subjects that had been selected through a stratified random sampling based on their academic ability level. As many as 30 students were categorized into Upper Level Academic ability (AA), Average Level Academic Skill (AS), and Lower Level Academic Skill (AB). Three students from each category: AA, AS, AB, were randomly selected as the research subjects. Their creative thinking skills were measured by the number of problems, strategies, and variations of open-ended problems and its solutions that had been created by students as representations of creative thinking aspects: fluency, flexibility, originality and elaboration. Results show that AB students had under developed creative thinking skills, while AS students began to develop their creative thinking skills, and AA students demonstrated their developed creative thinking skills.
Student Algebraic Reasoning to Solve Quadratic Equation Problem
Authors: Damayanti N W , Purwanto  , Parta I N , Chandra T D
Published: June 2019

The reasoning is closely related to students’ mathematical abilities. Reasoning becomes a key element in mathematics learning. The student’s reasoning habits need to be developed. Competence in algebra is important. Algebra is one branch of mathematics that an essentials role in mathematics education. Algebra was prerequisite for higher studies mathematics and science courses, and a lack of algebra skills have a chance results in poor performance in courses The purpose of this research is to describe students’ algebraic reasoning in solving quadratic equation problem. The method used in this research is descriptive qualitative. Research subjects were three students of class X. The results in the study showed that students use a different strategy in solving the problem of quadratic equations. This can make a description of the existing schema. There are also students who misunderstand the concept of understanding operations in algebra so that this can affect their reasoning process and makes their answer incorrect.
The Scaffolding Approach to Enhance Senior High School Student’s Statistical Literacy Ability
Authors: Murod R R , Priatna N , Martadiputra B A P
Published: June 2019

This research aimed to analyze the enhancement of senior high school student’s statistical literacy ability (SLA) through teaching with scaffolding and direct approach. This research used a quasi-experimental design with pre-test post-test control group. This research held in two classes from XI MIIA classes in a state high school in Bandung. In this study there are two groups: experimental and control group. The experimental group consists of 33 students who learn mathematics by scaffolding approach, while the control group consists of 34 students, learning mathematics by direct approach. The main result obtain are: (1) the enhancement of student’s SLA who learn mathematics using scaffolding approach higher than student who learn mathematics using direct approach viewed from the whole students and all student’s ability level based on statistical prior knowledge, (2) there is no significant interaction effect between teaching approaches and ability level based on statistical prior knowledge in enhancing student’s SLA. (3) the enhancement’s quality of student’s SLA who learn mathematics using scaffolding approach are in the medium category while student who learn mathematics using direct approach are in the low category viewed from the whole students and all student’s ability level based on statistical prior knowledge.
Science Learning for Students with Visually Impaired: A Literature Review
Authors: Ediyanto  , Kawai N
Published: June 2019

Science learning should be accessible for all learners including students with visually impaired (VI). Students with VI apparently have the same cognitive abilities range and can master higher-order science concept as well. The purpose of this study is to explain that students with VI can learn science well if there is the right learning support tool by in-depth literature review. This in-depth literature review uses the following steps: selection of the articles, analysis the studies and categorization of the articles. A total of seventeen journal articles from the year of 2009-2018 written in English on the topic of science learning for students with VI that divided based on how do the students with VI learn and teaching and learning science to students with VI. This literature was collected via the ERIC database and the Google Scholar website. Based on this literature reviews, students with VI can learn science well if there is a proper support tool for them to learn. If the teachers are able to apply the right learning model and are supported with good facilities such as orientation and movement, tactile and kinesthetic learning, auditory learning and accommodations, and assistive technology, it is possible that students with VI will be able to learn about science very well.
Growth Pattern The Second Generation of Marine Fish Larvae Mangrove Red Snapper Lutjanus argentimaculatus (Forsskål, 1775)
Authors: Melianawati R , Gunawan  , Slamet B
Published: June 2019

Mangrove red snapper Lutjanus argentimaculatus is a high economically value of snapper. Growth is important biological parameters during larvae stage. The growth of the second generation (F-2) of cultivated L. argentimaculatus is important to be evaluated as part of cultivation success. This study was conducted to determine the growth pattern of L. argentimaculatus F-2 during larval to juveniles stage. Larval rearing was done in hatchery. Larvae were fed zooplankton rotifers Brachionus rotundiformis and Artemia, also micro pelet as the artificial feed. Microscopic measurement on larval samples were performed periodically every 5 days from 5 to 40 days old larvae, by using 10 larval samples each time. The biological parameters of larvae were total length, standard length, dorsal spine length, ventral spine length, anal spine length and body weight. The results of this study indicated that the growth of mangrove red snapper larvae took place for 35-40 days to metamorphosis become juveniles. The growth pattern on all parameters was exponential. The larval total length has a positive correlation to its body weight with correlation value of 0.99. Larvae had certain characteric growth during metamorphosis stage. Mangrove red snapper L. argentimaculatus F-2 had a similar growth pattern with those of larvae F-1.