bluuebunny/crossref_metadata_2025 huggingface dataset:
Batik Context as PISA-like Problem to Assess Students’ Mathematical Literacy
Authors: Machromah Isnaeni Umi , Sari Christina Kartika , Zakiyyah
Published: February 2021

PISA is an international assessment of mathematics and science achievement that concern for the mathematical literacy. Students’ mathematical literacy, however, was still low in Indonesia. This study aims to develop PISA-like problem that valid, practical and has potential effect to assess mathematical literacy. This study was research and development that consisting of preliminary, development, and assessment stages. The subject of this research was students on grade 7th. The data was collected by observation, questionnaire, and test. This research result PISA-like problem involves three questions with Batik theme in quantity content. This PISAlike problem was declared valid, practical, and had a potential effect to assess mathematical literacy. This problem is valid based on judgment from experts concerning on the content, construct, and language aspects. This problem is practical based on the results of the test to small groups of students. Besides, this problem has potential effect on assessing students’ mathematical literacy.
Pattern Generalization Strategy From Concrete Operational Students
Authors: Fadiana Mu’jizatin , Amin S M , Lukito A , Yuliastuti R , Apriono D
Published: February 2021

Pattern generalization played an important role in the introduction of early algebra which became a bridge between arithmetic and algebra. However, there are still many students who have difficulty in generalizing patterns. The difficulty of students in generalizing patterns lies in the steps of producing general formulas. Students find it difficult to represent generalizations in the form of variables-n. In addition, students also find it difficult to justify the resulting generalization. This difficulty is experienced by concrete operational students. For this reason, this research aims to study students’ concrete operational thinking processes in generalizing patterns. The results of this study provide effective learning strategy solutions for concrete operational students in generalizing patterns. This research is a qualitative research with a case study approach to junior high school students. The results indicated that concrete operational students looked patterns represented in the form of geometric drawings globally without looking the structure of the images. Concrete operational students use two strategies in generalizing patterns, namely the guess and check strategy and the explicit visual strategy
Reflective thinking ability of junior high school students in relations and function problems
Authors: Hidayat Nurul , Usodo B , Saputro D R S
Published: February 2021

Reflective thinking is the ability of a person to select the knowledge he has to solve the problem at hand, starting from analyzing the problem, evaluating, to concluding. This study aims to describe the reflective thinking skills of students of class VIII C SMP N 1 Pundong in solving mathematical problems in the subject matter of relations and functions. This type of research is descriptive qualitative. The subjects of this study were 26 students taken using the purposive sampling method. The results of this study indicate that the percentage of achievement in the first indicator of reflective thinking describes a case based on mathematical concepts of 72.11%. The second indicator of reflective thinking to identify mathematical concepts or formulas involved in mathematical problems is 54.81%. The third indicator of reflective thinking draws an analogy from two similar cases of 24.04%. The fourth indicator of reflective thinking evaluates based on mathematical concepts was 38.46%. And the fifth indicator of reflective thinking makes conclusions using mathematical concepts by 42.31%. So that the average reflective thinking ability of students in class VIII C is 46.35% in the medium category.
Context-based tasks in mathematics textbooks for vocational high school students
Authors: Rejeki Sri , Meidina Rista Alfi , Hapsari Meytia Puspita , Setyaningsih Rini , Azura Raja Noor Farah
Published: February 2021

This study analyzes the context-based tasks in mathematics textbooks for grade ten and eleven vocational high school students in Indonesia. A vertical analysis was done based on the types of context, types of information, and cognitive demand types. This study is a descriptive qualitative study involving an external coder to ensure its validity and reliability. The data collection was conducted through text analysis and literature study. Whereas the data analysis used is content analysis. Based on the data analysis, it can be concluded that there are still little tasks with the relevant and essential context in the mathematics textbooks (10% for grade ten and 30% for grade eleven). Regarding vocational high school expertise, the tasks are relevant to vocational high school’s specific expertise. Regarding the types of information, tasks with matching categorized are dominant: 54% in grade ten and 88% in grade eleven. For the types of cognitive demand, grade ten is dominated with reproduction (54%), and grade eleven is dominated with connection (46%). Cohen’s Kappa coefficient on the types of context, types of information, and cognitive demand types in both mathematics books for vocational high school students grades ten and eleven are in a good or excellent category.
The effect of application of realistic mathematics education (RME) approach to mathematical reasoning ability based on mathematics self efficacy of junior high school students in Pekanbaru
Authors: Zubaidah Amir MZ , Urrohmah Athik , Andriani Lies
Published: February 2021

This research was purposed tofind the differences on mathematic reasoning ability between students using Realistic Mathematics Education (RME) approach and those taught by direct learning derived from their self-efficacy. This research was an experimental research with factorial experimental design. The samples of this research were 66 students on 8th grade students at SMPIT Az-Zuhra Islamic School Pekanbaru on the material number pattern. Sampling technique was cluster random sampling. Data were collected with reasoning ability test, questionnaire self-efficacy.The research findings were: there was a difference on mathematic reasoning ability between students taught by using RME approach and those with Direct learning, there was a difference on mathematic reasoning ability among students having high, medium, and low self-efficacy, and there was no interaction between learning approach and self-efficacy toward student mathematic reasoning ability.
Petri Net Model and Max-Plus Algebra in Outpatient Care at Solo Peduli Clinic, Surakarta
Authors: Haneefa Ghooda Phateena Taqie , Siswanto
Published: February 2021

Patients come to SoloPeduli Clinic to get medical treatment. Medical treatment at SoloPeduli Clinic is divided into two parts namely outpatient and inpatient health services. Patients generally do not know how long it will take for service from arrival to discharge at the clinic. The queue flow is called a system, while the patients queuing at each service are called states, the number of states cannot be limited as health services must be available 24 hours a day. This issue includes a Discrete Event System which can be modeled with a Petri Net. Petri Net is a mathematical model that can be used to describe certain events in a Discrete Event System. In this research, service flow is modeled using Petri Net which is then represented in the form of a matrix. Coverability Tree was created to define life and deadlock. Scheduling is modeled using Max-Plus Algebra. Service times will be randomly selected to facilitate scheduling and length of service time.
Geographically Weighted Logistic Regression (GWLR) with Adaptive Gaussian Weighting Function in Human Development Index (HDI) in The Province of Central Java
Authors: Nur Indah Manfaati , Al Haris M.
Published: February 2021

The Human Development Index (HDI) is an indicator to measure the success of quality human life. Efforts to calculate HDI to the district/city level are very important, so a better understanding of local conditions is needed with more adequate data support for all districts/cities in Indonesia. Modelling of HDI in Central Java with the factors suspected to influence it is done by Geographically Weighted Logistic Regression (GWLR) with the Adaptive Gaussian Kernel weighting function. The analysis result shows that the deviance value is 32.3992, where the value is greater than the value of χ2 (0.1.4) table, which is 7.77943. So, there is at least one independent variable that significantly affects of HDI in Central Java. GWLR Model Parameter Testing Results with Adaptive Gaussian Kernel weighting function obtained factors that influence HDI in Central Java Province is health facilities.
Bibliometric Analysis Related to Mathematical Research through Database Dimensions
Authors: Suharso Putut , Setyowati Lis , Arifah Mufida Nur
Published: February 2021

A bibliometric study of the publication of research results and mathematical thinking at this time is needed to see the development of progress and trends that are happening. The purpose of this study is to conduct bibliometric research in online scientific publications. The research method uses quantitative studies from electronic information sources through the Dimension database. Data obtained from 2015-2019 from research results published in leading international journals. Data is processed using the Vosviewer application to create predetermined formulas and produce visualizations. The results of this study have described the number of publications that have been made through international journals, the distribution of titles in international journals, the types of publications produced, and the level of productivity of authors from the name of the institution. The results of the research are then carried out an analysis related to the trends that occur related to education policy in Indonesia in the obligation and culture of writing in scientific publications.
Construction fuzzy logic with curve shoulder in inference system mamdani
Authors: Putri Salsabila Naura , Saputro D R S
Published: February 2021

Fuzzy Logic is a popular methodology and widely used at cybernetics in developing software programs. Fuzzy logic is a logic which the truth values of variables any real number between 0 and 1 both are inclusive with the truth value shown through the membership function (curve). It is used to deal with the concept of partial truth, where the truth value may range between completely true or completely false. In general, fuzzy logic provides an inference structure that capable to match human reasoning which called an inference system. Fuzzy inference system Mamdani is the process of decision making based on fuzzy sets, fuzzy rules and fuzzy logic with Mamdani method (min-max). On Mamdani method, the fuzzy sets are obtained by taking the minimum value of the rule, then use it to modify the fuzzy region and apply it to the output with the operator OR (union). This paper concerns fuzzy logic construction with curve shoulder in inference system Mamdani. The result shows five steps that used to construct inference system Mamdani which are fuzzification, operator fuzzy logic, implication, aggregation, and defuzzification.
Construction of Hyperplane, Supporting Hyperplane, and Separating Hyperplane on ℝ
n
and Its Application
Authors: Hariyanto Susilo , Sumanto Y.D. , Udjiani Titi , Sagala Yuri C
Published: February 2021

Hyperplane, supporting hyperplane and separating hyperplane have been defined well in inner product space. These definitions are expressed in very general concept of space, so in its understanding it requires understanding the specific inner product space. It is difficult, so in this paper the definitions will be explained in the ℝ
n
space or Euclidean space, beginning with constructing all possible hyperplanes of a given convex set. From all the hyperplane constructions, they will be classified as supporting hyperplane or separating hyperplane. This understanding will be generalized in the case of convex set with point and with other convex set. To clarify this discussion, it is completed with several examples of the construction of the hyperplane in ℝ
n
. In addition, this paper will give some examples of the application of hyperplane construction in ℝ
n
in computing the distance between point and a convex set. The application will also be further discussed in a more general problem, namely the distance between two disjoint convex sets.
Determination of neutron image quality of compact collimator facility for non-destructive testing
Authors: Chulapakorn T. , Wonglee S. , Pornroongruengchok W. , Liamsuwan T. , Kotayee S.
Published: February 2021

Neutron imaging, based on a digital-based detector system, was developed for non-destructive internal inspection at the Thai Research Reactor-1/Modification 1 (TRR-1/M1). Neutron activation analysis was employed to determine thermal-neutron flux at the imaging position. The facility provided flux of thermal neutrons at 2.5× 105 cm−2s−1. Several standard samples were used to evaluate the collimation ratio (L/D), resolution, and unsharpness for the current setup of neutron imaging. An analytical method was employed to determine image quality parameters to moderate neutron flux. The L/D ratio depends on the aperture size of the divergent collimator and can be amended by using appropriate sample shape, resulting in more accurate estimate of collimation parameters. Resolution and unsharpness for neutron tomography were 0.5 mm and 1 mm, respectively. Results suggested the possibility of evaluating image quality using samples with non-complex structure.
Volatile organic compounds as disease predictors in newborn infants: a systematic review
Authors: Course Christopher , Watkins W John , Müller Carsten T , Odd David , Kotecha Sailesh , Chakraborty Mallinath
Published: February 2021

Volatile organic compounds (VOCs) detected in human breath, urine, stool, sweat, saliva, and blood result from metabolic processes in the body during health or disease. Using sophisticated measurement systems, small amounts of these compounds can be detected in the above bodily fluids. Multiple studies in adults and children have shown the potential of these compounds to differentiate between healthy individuals and patients by detecting profiles of compounds in non-invasively collected samples. However, the detection of biomarkers in VOCs from neonates is particularly attractive due to the non-invasive nature of its approach, and its ability to track disease progress by longitudinal sampling. In this work we have reviewed the literature on the use of VOCs in neonates and identified areas for future work. Overview of VOCs and their usefulness as metabolic signatures. Detailed review of studies on VOCs in neonates Learn about potential uses of VOCs as derived from adult and paediatric studies. Examine current limitations and identify future work. Detailed studies on VOCs involving neonatal patients including sick preterm infants and term infants with specific morbidities are needed. These studies should collect longitudinal samples using non-invasive methods for the detection of potential biomarkers. Underlying metabolic processes need to be identified so that any therapeutic options can be clarified.
Organic fertilizer from agricultural waste: determination of phosphorus content using near infrared reflectance
Authors: Devianti D , Yusmanizar Y , Syakur S , Munawar A A , Yunus Y
Published: February 2021

Agricultural waste can be converted onto useful materials like compost or organic fertilizers. In a simply practice, those wastes were kept and mixed with additional composting materials to enrich the fertilizer nutrients and compositions. Generally, plants can growth optimally in sufficient media, that is soil. It requires adequate micro and macro nutrients like phosphorus (P). in order to determine P content and other nutrient properties, many methods have been widely used from which most of them are wet chemical analysis. The main aim of this present study is to employ the near infrared reflectance (NIRS) technique in determining P content of organic fertilizer. Spectra data were generated in wavenumbers 5000 – 10 000 cm−1 and the model were established using principal component regression (PCR) method. The results showed that P content of compost materials can be determined using NIRS with maximum correlation coefficient 0.99 and robustness index 4.14 respectively.
A comparative study on integration of courtyard in creating environmental sustainability space for eclectic buildings
Authors: Safar Farhana Binti , Raman Noor Azah Binti Abdul , Sulaiman Siti Nazwin Izani Binti
Published: February 2021

Buildings are categorised into various types such as residential, educational, assembly and etc. This paper is described one type of assembly building namely mosque and its elements. The mosque is comprising of several elements such as courtyard, prayer hall, arcades, minaret, dome, the ablution rooms and toilets. It should be designed to accommodate the worshipper to feel comfortable and humble in the presence of God while performing the ‘solah’. In tropical region, especially in Malaysia; the existence of the courtyard in traditional mosques is still questionable whether it has fully considered the environmental benefits or it is simply a trend adopted from the Middle East. Previous studies have found that the purpose of having a courtyard inside a mosque is either for spatial reasons or it may be negligible. Hence, this study is conducted to understand the courtyard in a specificity of architectural style and the effects on spatial organization in traditional mosque design. The observation methods are used at the fieldwork in selected traditional mosques. From the observation two types of building indicator of space and form are identified for better understanding of courtyard characteristics of selected traditional mosques.
Load current, dropped voltage and size considerations in LDR based light control system
Authors: Candra R A , Suherman S , Siregar Y
Published: February 2021

Energy consumptions are dominated by lighting and air conditioning. Automatic controlling is the solution as human awareness is unreliable. Lighting and air conditioning can be automatically controlled by employing light sensor as well as human existence sensor. Light bulb and street lighting have been widely equipped by light sensor such as the light dependence resistor (LDR). LDR sensor circuit can be made transformer less and transformer based. Transformer less LDR circuit can be integrated into light bulb while transformer based LDR circuit is designed as a standalone device. This paper examines power consumption, load current and circuit size of both LDR circuits. Experiments show that transformer less LDR circuit consumes higher power with limited load current. However, its size is smaller. On the other hand, transformer based LDR circuit consumes less power and provides larger load current. But the challenge is the transformer size to overpower the transformer less circuit.
Signal jammer reduces wireless fidelity network and global system in local environment
Authors: Yunan A , Satria E , Ilham D N , Anugreni F , Khairuman K , Sandra S
Published: February 2021

Cellular networks are a way of long distance communication without the use of cables, this system is a modern style of communication that was previously communication using a landline-based telephone. Cell phones (cellphones) or cell phones (cellphones) are electronic-based telecommunications devices that have the exact same basis as telephone telecommunications devices using cables or wireless wireless. The use of cellular or wireless phones is very useful, but in certain conditions their use can be limited because it can interfere with people around him such as the implementation of worship, examinations, meetings and so forth. To answer complaints about how to reduce cell phone and wireless signals, a tool that is able to deactivate GSM and Wi-fi cell phone signals at certain radii will use a jammer, a device that works by emitting full noise signals at 900 MHz frequency banks, 1800 MHz and 2700 MHz, so that the communication device cannot be used until the time limit and the distance of the radius that reaches the communication device. The results of this study have been successfully carried out by deactivating cell phone and wireless signals at a maximum distance of 7 meters from the jammer.
Performance test of vertical dryer hybrid for drying Tuna fish
Authors: Nurba D , Mustaqimah M , Fadhil R , Darmansyah D , Fajri M
Published: February 2021

Drying is the stage of processing tuna to extend the fish's shelf life until it is consumed. In general, fishers are drying the processed salted fish under direct sunlight. During the rainy season, conventional drying under the sun is impossible to inhibit the drying process; therefore, a mechanical dryer is needed. A greenhouse dehydrator (GHE) using a combination of solar and biomass energy is the right choice. The purpose of this study was to test the performance of the Vertical Dryer Hybrid to dry tuna. Drying is done by placing the tuna sample on four drying racks, then observing the moisture content, air humidity, solar irradiation, and the use of biomass energy. During 35 hours of observation, the GHE Vertical Dryer reduced the water content of tuna from 70.8% to 13.3% initial water content with average solar irradiation of 280.2 W / m2. The dryer's highest temperature during the drying process is 67°C, with an average of 46.7°C. The highest temperature in the environment is 37°C, with an average of 33.3°C. The highest RH in the dryer during the drying process is a 75% average of 43.8%, the highest RH in the environment is 79%, with 61.2%. The full use of bio-charcoal during drying is 5.5 kg, with the amount of energy obtained is 155.87 MJ, and the total solar energy obtained is 88.613 MJ with a total energy total of 244.49 MJ.
Threat of ecology aspect towards people’s cocoa plantations management sustainability at Aceh Timur Regency
Authors: Mulyani C , Iswahyudi  , Juanda B R
Published: February 2021

Cocoa plantations at Aceh Timur regency face many problems in its management. Currently, there is not yet existing condition data of cocoa plantations so that it becomes obstacles in management to achieve cocoa plantations sustainibilility. This research is aim to identify key factors of ecology aspect impact towards plantations management sustainability of people’s cocoa at Aceh Timur Regency. The method used in this study is to intergrate descriptive qualitative approach, quantitatif and analysis system Rap-kakaoatim approach constitutes modification of Multidimensional Scalling (MDS). MDS utilized to assess sustainability status indexs and key factors that give lack influence of sustainability in people’s cocoa plantations management. The analysis result shows that status people’s cocoa plantations management is lack of sustainability by ecology dimension and institutional, from the side of economy is adequate sustainability, and with socio cultural dimension is extremely sustainable. From ecology dimension, key factor that influence people’s cocoa plantations sustainability are cocoa plantations rejuvenation, shade plantations and HPT attack. Those three factors are able to give positive effect towards cocoa plantations production if its condition inclines however on the contrary it can decline cocoa plantation production if its existence decreases. To intensify sustainability indexs of ecology aspect can be carried out by insentive distribution to the farmers of cocoa and Field School Program PHT (SLPHT) for controlling HPT.
Utilization of waste from refined lemongrass for producing mosquito repellent
Authors: Rusnanda R , Ramadhini M , Putra W S , Asmaidi
Published: February 2021

Because of its geographical location, South Aceh Regency has many natural resources, one of which is fragrant lemongrass. As it is known, citronella is processed and produced into essential oils. In the production process, waste is produced in the form of solid waste and liquid waste. Usually, the waste is left and becomes a problem for the environment around the distillery. The purpose of this study was to make a mosquito repellent by utilizing citronella processing waste. This research is using the experimental method. This experimental method examines the effect of certain treatments on others under certain conditions. Three samples will be tested for combustion. The results of this study from each sample with a variable initial burning time. The first test kills mosquitoes. The durability of mosquito repellent is sample 3 is the best sample for making mosquito repellent from the use of citronella distillation waste seen from the burn test. The conclusion from this study, the waste produced by citronella distillation can be used as a basic ingredient in making mosquito repellent because there are active compounds contained in citronella waste capable of killing mosquitoes.
Filter impact based on inverter circuit performances
Authors: Hardisal  , Candra R A , Ilham D N , Suherman S , Yunan A , Saragi D P , Harahap R , Irwansyah
Published: February 2021

This paper examines filter component impact on inverter output. The inverter prototype was designed by using pulse width modulation (PWM) signal generated by EGS002 module, combined with DC voltage source, voltage regulator, MOSFET Bridge and low pass filter. As component assembled, the output voltage quality is determined by the choice of filter components. Experiment shows that the calculated values may not suitable as soldering and connection imperfection may change component values. As adjustments were performed, filter components of 12.63 H and 6.5uf generated the finest sinusoidal output of 30.8 Vpp with frequency of 50.05 Hz.
The application of different mulches and its effect on soybean yield
Authors: Hasanuddin  , Hafsah S , Nurahmi E , Hayati E , Migawati S W , Bobihoe J , Aryani D S
Published: February 2021

Mulching is known as a great suppressant, a modern agricultural practise. It modifies the soil microenvironment and maintains crop yield. This study was conducted in January to April 2019 to investigate the effectiveness of several plants for mulch in various doses on soybean crop and to evaluate their effect to soybean yield. This study employed Randomized Completely Block Design (RCBD) Factorial with two factors. The first factor was 3 different plants applied for soil mulching: mexican sunflower (Tithonia diversifolia), siam weed (Chromolaena odorata) and neem (Azadirachta indica). The second factor was 4 different doses of mulch: 0, 8, 16 and 24 tons ha−1. Variables observed were number of pods per plant, number of seeds per plant, seed weight per plant, and yield of dry seeds. The results indicated that the application of different mulches did not have effect on all variables observed. However, the application of 16 - 24 tons mulch ha−1 has improved the number of pods per plant and yield of dry seeds. There was no interaction between plant types for mulching and dose of mulch in all variables observed.
Off-site domestic wastewater management system in Banda Aceh, Indonesia: the problems and future solutions concept
Authors: Harahap J , Gunawan T , Suparayogi S , Widyastuti M
Published: February 2021

Currently, Banda Aceh has been dealing with several problems related to pollution caused by domestic wastewater. According to previous studies, shallow groundwater and surface water in Banda Aceh have been contaminated by domestic wastewater produced by the community. The settlement scale off-site system with communal-WWTP operating in several villages has not function optimally in treating domestic wastewater. The problem also caused by service coverage which is still very small (only 2.12% of the total population). Therefore, it is require an acceleration of service improvement, by developing urban scale off-site system with centralized-WWTP and a wider pipe line network system. Moreover, further investigations are needed to develop the concept of planning as a preliminary design in the management of urban scale off-site system. This paper aims to develop a concept of domestic wastewater management using an urban scale off-site system that considers environmental characteristics in Banda Aceh as an alternative to mitigate the occurrence of water body pollution by domestic wastewater.
Design of orange grading system based on real time image processing
Authors: Ifmalinda  , Andasuryani  , Putri I
Published: February 2021

Orange is one of preference agricultural products by consumers, because it has several benefits suchas vitamin C and antioxidants. The fruit is often used for gift when someone visits the relatives, thus the quality of orange is mostly detected by visual suchas size and skin color of the fruit. Determination of the quality is done manually because it takes faster. The manual grading has the weakness and less effisien, resulting several quality gradings and needs man power more. Using the man power tend to be subjective judgement. One of the ways to increase the productivity to determine the orange quality is that using grading methode using technology real time digital analysis mechanically. The aims of the resarch is to design of grading machine and grading program based on diameter and skin color of the orange that analysed by real time image processing. Based on the research result, this system can be applied on orange grading. The capacity of the manual grading is 1,276 fruit/hour,meanwhile capacity of the grading system is 712.87 fruit/hour. From the speed of the process and grading capacity, the manual methode is better instead of grading system using image processing. Meanwhile for the quality of the grading, Using the grading system based on the image processing can be said that it is suitable toward the standard. If using manual grading, it use the principle of habit, without really measure specifically and detail.
Effect of various drying methods on the physical characteristics of purple yam powder
Authors: Nugraheni N F , Karyadi J N W , Tarwaca S N , Indrasari Y P , Albyan R , Setiyadi I , Ayuni D
Published: February 2021

Purple yam (Dioscorea alata) is a type of plant that grown in almost all regions of Southeast Asia. In Indonesia, purple yam is one of the most popular types of sweet potatoes compared to other types of the genus Dioscorea. Purple yum is usually consumed directly as a side dish, or processed into a powder. One important process of making purple yam powder is drying. In this study, the characteristics of purple yam powder were evaluated from several drying methods, namely sunlight drying (SD), cabinet drying (CD), and pneumatic drying (PD). The pneumatic dryer used was self-made with a stainless steel plate (3 mm thickness) and has total dimension of 1600x 500x 2500 mm. The results showed that the CD sample had the lowest water content. The purple yam powder by CD and PD can produce brighter powder compared to that with SD method. From the FM test, the smallest FM value was obtained from CD sample. CD sample proven to be able to retain purple yam nutritive values after drying process.
Precision agriculture: automated irrigation system in tandem with solar panels for melon farming cultivation
Authors: Nasution I S , Munawar A A , Devianti  , Satriyo P , Gunawan H G , Yunus Y
Published: February 2021

This present study aimed to design and apply an automated irrigation system powered by solar panels for melon farming cultivation. It related to precision agriculture practices from which benefited as an environmental friendly approach. This study was performed by designing irrigation systems, constructing solar panels as a power source for generating pump used to irrigate melon orchard. The results showed that those combinations setup were benefited to reduce manual irrigation system which is normally conducted by human efforts. Further, it also acted as an environmental friendly practice since the system is attempted to utilize solar energy as main power source for irrigation pump. Based on obtained results, it may conclude that abundance energy in our earth can be used for precision agriculture practices with the aim to reduce environmental pollution and waste.
Fitting Method of Small Sample P-S-N Curve Based on Weibull Distribution
Authors: Huang T , An Z W , Ma Q , Han M Q
Published: February 2021

In order to obtain the probabilistic stress-fatigue life curve of materials with small samples, a small sample P-S-N curve fitting method is proposed. This method is based on the premise that Weibull distribution can be applied to fatigue test data the method first uses the sample mean fitting to obtain the median S-N curve. Secondly, constructs the random variable function based on the Weibull distribution characteristics, in addition, the sample median is used as the initial value of iteration to perform perturbation optimization to determine the shape parameter a and the scale parameter β of Weibull distribution. The fitting of P-S-N curve is realized. Taking the fatigue data of aluminum alloy 2425-T3 as an example, the results show that the intercept relative error and slope error are less than 0.5% by comparing the fitting results of the proposed method with those of the traditional method, and the intercept error between the proposed method and the traditional method is less than 1.5% and the slope error is small when designing three groups of small sample fitting schemes (7-7-7-7, 5-5-5, 3-3-3) at 3.0%. The proposed method can obtain high-precision P-S-N curve fitting results in the case of small samples, which have a certain significance for engineering applications.
Research on Multi-Agent Task Optimization and Scheduling Based on Improved Ant Colony Algorithm
Authors: Wang Y , Yang R R , Xu Y X , Li X , Shi J L
Published: February 2021

As a key problem of cloud computing, the performance of task scheduling strategy may seriously affect the efficiency and service quality of the system. With the purpose of achieving balanced task scheduling with optimal completion time, ant colony optimization (ACO) algorithm is adopted as task scheduling strategy in this paper. Considering the problem of premature convergence to local optimal solution of ACO, an improved Max-Min Ant System (MMAS) is introduced to find the global optimal solution. Based on the study of pheromone’s updating mechanism of MMAS, MMAS is applied as task scheduling strategy with reasonable mapping from the objective of shortest path to shortest completion time. The task scheduling strategy based on MMAS has been simulated from views of tasks’ number, size and load balance, and the results shows that MMAS task scheduling strategy is with a better performance on completion time and load balance than ACO based strategy.?
Study on the Development of I&C Equipment Performance Monitoring Program for Nuclear Power Plants
Authors: Qian Yugang , Zhou Shumin , Hu Jiacheng , Zhu Guixia , Hu Yuying
Published: February 2021

The equipment performance monitoring program is designed to provide guidance for monitoring the performance of equipment, with an aim to enable engineers to identify hidden hazards as early as possible and take corresponding corrective actions to achieve the purpose of equipment reliability management of nuclear power plant. The nuclear power plant realizes monitoring, control and protection of the whole plant through I&C equipment, by which to ensure the safe, reliable and economic operation of the nuclear power plant. In this paper, a set of performance monitoring program process special for I&C equipment of nuclear power plant is developed. And the RGL system (rod control system and rod position system) of a nuclear power plant is taken as an example to illustrate, analyze and summarize, which lays a foundation for nuclear power plant to carry out equipment reliability management.
Remaining Useful Life Prediction Using Deep Multi-scale Convolution Neural Networks
Authors: Ge Y , Liu J J , Ma J X
Published: February 2021

Accurate Remaining useful life (RUL) prediction is the premise of system prognostics and health management (PHM). In fact, it is often difficult to predict the accurate RUL because of the diversity of working condition and self-state between systems. In this paper, a data-driven method is proposed for RUL prediction using deep multi-scale convolution neural networks (DMSCNN), which is made up of four convolution layers. Two of the four convolution layers are multi-scale convolution layers, which are composed by three different scales convolutions connected by deep concatenation layer. After the four convolution layers, we add fully connected layer and regression layer to build a deep learning structure for predicting RUL. The IEEE PHM 2012 data challenge bearing dataset is employed to verify the proposed method. The experiments result show that the proposed DMSCNN has better performance and higher prediction accuracy than other methods. Additionally, the t-distributed stochastic neighbour embedding (t-SNE) dimension reduction method is used to reduce the computation. Experiments result demonstrate that the features processed by t-SNE have better distinguishability, and the prediction accuracy can be further improved by inputting the t-SNE features into the DMSCNN proposed in this paper for RUL prediction. This paper offers a new and effective approach for RUL prediction.
A Birnbaum Importance and regression analysis based heuristic algorithm for multi-type component assignment problem
Authors: Guan Zhiling , Shi Yida , Qiu Siqi
Published: February 2021

In this paper, a new kind of multi-type component assignment problem (MCAP) called the two types of component of component assignment problem (TCAP) is proposed. The problem is to assign two types of components to three types of positions in a system in order to obtain high system reliability. The number of each type of components equals the number of positions in the system where the components can be placed in. A new heuristic algorithm, called the REG-ZK method, based on Birnbaum Importance and regression analysis for solving the new MCAP, is illustrated in the paper. Comprehensive numerical experiments on small systems and large systems are conducted to evaluate the optimization effect of the method. Compared to the enumeration and randomization method, the REG-ZK method proves to be applicable and efficient with good optimization quality.
Research on computer application software monitoring data processing technology based on NLP
Authors: Wang J , Liu B J , He W , Xue J K , Han X Y
Published: February 2021

In the process of using computer application software, the system may fail because of software defects. During the operation of the computer system, the running state of the system is also monitored. This paper mainly studies the monitoring data processing technology of computer application software based on NLP and presents a software monitoring data processing scheme based on NLP. First, the data were preprocessed by word segmentation and data cleaning. Then the named entity recognition and extraction information are accomplished by fusing CRF and rule-based methods. It can provide effective data support for system failure prediction by characterizing the software monitoring data.
An efficient global reliability analysis method for turbine disc’s multi-failure modes considering importance distribution technology
Authors: Liu Yu , Liu Xi , Hu Dianyin , Wang Rongqiao
Published: February 2021

This paper presents an improved efficient global reliability analysis (EGRA) method for a turbine disc considering the importance distribution of multi-failure modes, such as low cycle fatigue (LCF) and creep-fatigue (CF). Failure mode effects and criticality analysis (FMECA) technology is firstly used to analyse the criticality and occurrence probability of each failure mode. Importance factor S is then proposed to quantify the importance of the corresponding failure mode. In order to improve the reliability analysis’s efficiency, expected feasibility function (EFF) criterion in sequential sampling method is selected through numerical experiments to generate the samples of random variables. Secondly, EGRA method is established by combining sampling method with Kriging model, in which the performance function is fitted using the key sampling points near both the failure boundaries and high uncertainty region. On the basis of EFF criterion, the composite EFF criterion applied to EGRA method is developed. This method avoids repeated analysis on non-significant failure modes, which further improves the reliability analysis’s efficiency for the multi-failure modes system. Through a binary nonlinear example, it is proved that the prediction accuracy is 99.8% compared with Monte Carlo method. Moreover, the computational time of reliability is reduced by half compared with EFF criterion, which proves the prediction efficiency of composite EFF criterion. Finally, the reliability analysis on a turbine disc is conducted using the improved EGRA method combining with the failure mode importance distribution technology. Results show that the fatigue life at 99.9% reliability is decreased by 7.4% after considering the importance of failure modes, indicating that the ignoration of failure modes’ importance would lead to a more dangerous prediction result.
Reliability analysis and optimization of production system for production scheduling
Authors: Duan Weiwei , Dai Wei , Wang Yue , Sun Jiahuan
Published: February 2021

Production planning and scheduling mainly solve the problems of multi-process, multi-resource scheduling and sequence optimization in the workshop. Existing production scheduling methods focus on how to minimize the production period, but production system reliability is seldom considered in the actual production scheduling strategy. Production system reliability is closely related to the state change of equipment in production system, the production stability and efficiency. Therefore, in order to ensure the reliability of the production system when planning production tasks, this paper proposes a new strategy for production scheduling. Firstly, the model of production system is conducted to analyses its reliability. Secondly, a reliability evaluation method is proposed by analysing the status of equipment in the production system. Moreover, the optimization goal of production system reliability is added to the original production scheduling goal. Finally, the optimization method is put forward and verified by an example.
Bayesian Inference for General Half-Normally Distributed Lifetime Products
Authors: Xin Hua , Liu Tingting , Liu Zhifang
Published: February 2021

The generalized half-normal (GHN) distribution has earned widely concerned in reliability analysis. Type-I hybrid censoring (HC-I) is one efficient scheme for saving test time and cost to collect lifetime information of reliable products. However, the HC-I scheme also induces a complicated likelihood function and makes the searching of maximum likelihood estimates of the model parameters difficulty. In this study, the maximum likelihood estimation and Bayesian estimation procedure are studied for the GHN distribution based on HC-I samples. The Markov chain Monte Carlo approach using the Metropolis-Hastings algorithm via Gibbs sampling is proposed to implement the Bayesian estimation procedure for obtaining the Bayes estimators of the model parameters. The Bayesian estimation procedure is more reliable than the ML estimation method due to the Bayesian estimation procedure does not use gradient methods to search the estimates of model parameters. Simulation results show that the proposed Bayesian estimation procedure perform well in terms of the bias and mean square error.
Research on solder joint stress damage evaluation method based on discrete SSI model
Authors: Rong K Y , Zhang S J , Li Y R Y , Wan B
Published: February 2021

Based on the discrete SSI(Stress-strength-interference) model, this paper establishes a stress damage evaluation method for the through-hole insertion process. First, based on the Monte Carlo sampling method, the mean value of solder joint stress was clarified, and a stress-strength interference model for through-hole insertion was established. Secondly, after calculating the shape of the solder joints of the through-holes, the simulated load input curve is determined and the stress simulation is performed to obtain the stress and strain simulation results. The stress and strain of the PCB board are measured through experiments. Finally, a random stress model of solder joints was established by Monte Carlo sampling, and a constant strength model of through-hole solder joints was established in combination with material strength. According to the stress strength interference model, the failure probability of process stress damage was calculated, and the stress damage evaluation of solder joints in through-hole insertion process was realized.
Quantitative analysis of a process industry’s operating status of based on DCS data set
Authors: Chen Qian , Sun Kai
Published: February 2021

The process industry represented by energy chemical enterprise is a typical distributed and complex electromechanical system. Its distributed control system (DCS) records overall operating status information of a process industry. It is a challenge to quantitative operating status through analyzing DCS data set. This paper proposed a novel method to calculate fault score of system’s operating status by classifying its DCS data set and forming a classifier matrix. Firstly, define a classifier matrix depends on the baseline of the DCS data. Secondly, calculate the classifier matrix to obtain the fault score. The higher fault score means the lower security of the system. Last but not least, a period of the system operating status trend could be observed by plotting the fault score. A case study of a real chemical plant is introduced to verify the validation of the method.
Application on the impact domain analysis of on-orbit maintenance in China Space Station
Authors: Lv Zhen , Zhang Hua , Zhao Zhi-Ming , Gong Kai-Xiang
Published: February 2021

On-orbit maintenance is an important means to extend the service life and improve the reliability of the space station. As an essential part of maintainability analysis, impact domain analysis of on-orbit maintenance can find out the deficiency of maintainability design in advance and reduce the risk brought by maintenance. In this paper, the analysis method of the impact domain of the space station on-orbit maintenance is studied, and the working idea of "stage by stage, full coverage, focusing on key points" is put forward to adapt to the development and needs of China Space Station. The process, object, content, and analysis emphasis of the impact domain analysis for different development phases and different kinds of products are determined. The engineering practice shows that reasonable maintenance process and optimal design can be determined by the analysis of the impact area of on-orbit maintenance, which lays the foundation for the good maintainability of China Space Station.
Fatigue test and analysis of Hi-Lock bolt lap joint structure
Authors: Wang L , Li J , Mu H J , Duan L , Lin W Q , Xie L Y
Published: February 2021

Hi-Lock bolt lap joint structure is widely used in aircraft, such as wings, tails and etc. During the service of an aircraft, the joints are subjected to variable loading, which may usually tend to fatigue failure. The single-shear lap joint with four Hi-Lock bolts is taken as the research object. The static tensile test and fatigue test of the Hi-lock bolt lap joint structure are conducted. The macroscopic and microscopic fracture analysis were carried out. It is found that the crack source is located on the joint surface of the two plates, which is on the longitudinal direction away from the edge of the hole, but not on the edge of the connection plate. The results also show that there is no significant difference between the effect of clearance and interference fit on the fatigue life of the lap joint structure under high load conditions.