bluuebunny/crossref_metadata_2025 huggingface dataset:
The quality of goat milk due to the level of Lactobacillus plantarum and different heating temperature
Authors: Yurliasni  , Novita C I , Hanum Z , Wajizah S , Munandar R
Published: February 2021

A research has been conducted on the utilization of Lactobacillus plantarum and different heating temperatures on the quality of fermented goat milk The characteristic of milk which is easily damaged requires an effort of good management, one of them is through the technology of heating and fermentation. The research was done through completely randomized factorial design in which there were two treatment given, including a1 = pasteurization (temperature of 72° C for 15 seconds), a2 = sterilization (temperature of 121° C for 1 second), and level of Lactobacillus plantarum (factor B), b1
(L. plantarum 2.5%), b2
(L. plantarum 5%), and b3 (L. plantarum 7.5%). Parameters measured were the level of protein, pH value, and the total of lactic acid bacteria. Data obtained were then processed statistically using analysis of variance (ANOVA). If there is significant difference, then it will be continued by Duncan's Multiple Range Test. The result showed that the heating temperature did not give any effect on the level of protein of the fermented milk with different levels of starter Lactobacillus plantarum. However, the protein level of milk pasteurized was higher than the protein level of milk sterilized. Furthermore, the treatment significantly affected (P<0.05) on pH value at the range of 4.017 – 4.197 and it obtained that there was interaction between the two treatment factors. The multiple result also showed that the heating temperature significantly affected (P<0.01) the total of lactic acid bacteria, while the level of Lacttobacillus plantarum significantly affected (P<.0.05) the total of lactic acid bacteria. It can be concluded that the temperature and level of L. plantarum affected the pH and total lactic acid bacteria of fermented goat milk
The conservation activities and land use changes in the upstream Bedadung watershed
Authors: Petrina J M , Alfarisy F K , Andriyani I , Suciati L P
Published: February 2021

Bedadung watershed is one of the largest watersheds in Jember Regency. The Bedadung watershed in upstream area is generally hilly with steep slopes, so it is prone to landslides and potential to erosion. The upstream area is a protected forest that functions as a water catchment area, turning into plantation and production forest to become the target of logging and deforestation. Conservation activities in the upstream watershed area is essential in the management of water resources. Natural resource management activities in the upstream area significantly affect the success of efforts to provide water and control water resources downstream damage. This study aimed to identify conservation activities in the upstream Bedadung watershed and the impact of changes in upstream land use on environmental damage. The conservation activities in the Jompo, Antrokan, Rempangan, and Rembangan Sub-watersheds is coffe plantation, cover crop, forestry, terrace, restoration, bush, grassland. The highest increase in land change in the four sub-watersged was irrigated land / field, while the decrease was non-irrigated land. The results of comparisons between the 2001 RBI map with the 2015 Landsat Image show an 8% forest loss and 7% increase in irrigated fields.
Risk analysis of Jernang plant (Daemonorops draco) in Aceh Province
Authors: Moulana R , Nilda C , Yusriana  , Gunawan V
Published: February 2021

Jernang is a non-timber forest product (NTFP) which has started to be traded and become a high-value commodity. Jernang is a type of rattan that produces a resin known as “dragon's blood” which has many benefits such as dye raw materials in the ceramics, marble, wood, paper and pharmaceutical industries. Aceh province is one potential area for Jernang development. Supply chain is a complex system that has elements that are orderly, interrelated, dynamic, have specific goals and are probabilistic. In the Jernang supply chain there are risks that can cause losses and failures in production. Failure in production does not only occur at the end process but can also occur at the beginning or when the production process is being carried out. Through the Failure Modes and Effect Analysis (FMEA) method, it is expected that each form of failure can be identified in the production process. The results identified indicate that nineteen risk factors at the producer level. Based on the calculation of Risk Priority Number (RPN), the risk of decreasing production results is the most important risk. As such, this risk is the first priority that must be addressed.
Modification and performance improvement of chopper palm frond (AE03-Type)
Authors: Bulan R , Yunus Y , Mustaqimah  , Sitorus A
Published: February 2021

A chopper machine has been developed to chop oil palm frond (OPF) for cattle feed in Aceh province. This paper reports the results of the modification of the third generation chopper machine named AE03-type. The purpose of this study is to improve the performance of the chopper machine for OPF through the process of modifying the chopper blade. Modifications made are designing a chopper blade with a plate thickness of 6 mm, a length of 15.5 cm and a width of 4 cm arranged in a spiral around a solid shaft with a diameter of 1 inch with a length of 100 cm, as many as 36 pieces. The parameters measured to show the performance of the chopper machine are dimension average of chopped, the percentage of chopped OPF, chopping efficiency, and capacity of the machine. Three variations of rotation speed are tested on the engine, which is 800 rpm, 1200 rpm, and 1600 rpm, respectively. The results show that modifying the chopper knife can improve the performance of the chopper machine. The best rotation speed for this chopper machine is 1200 rpm with length and width of chopped, OPF percentage of chopped, chopping efficiency, and capacity of the machines are 27.5 mm, 1.5 mm, 86.45%, 98.37%, and 147.85 kg/h, respectively. The size of the chopped is following the dimensions of feed for cattle feed needs, especially those in Aceh Province.
Rapid assessment of climate change issues in Indonesia strategic environmental assessment (SEA)-KLHS
Authors: Umam A H
Published: February 2021

Strategic Environmental Assessment (SEA) or KLHS is becoming increasingly popular in Indonesia following the promulgation of government regulation No. 46 of 2016, concerning the procedures of its organization. The SEA, which was at first voluntary, is now mandatory before the integration into a regional spatial and a medium-term development plan. Therefore, this study aims to evaluate the extent to which climate change issues are addressed in the Strategic Environmental Assessment. Furthermore, several SEA documents that are very limited in Indonesia and only obtain on the internet were evaluated. The document consists of the Medium-Term Development Plan, Spatial Planning, and SEA in the mineral and energy sector. In addition, the study adopted a set of evaluation criteria used by Nadruz and Gallardo (2015) [1], which is a modification of the framework developed by Wende et al. (2012) [2]. The results showed that climate change issues in the SEA are still very diverse and not evenly distributed from various existing documents. Some SEA of the province medium-term development plan makes the issue very important while other documents do not. The SEA document of the mining sector contains 18 climate change criteria. Conversely, the spatial planning document contains 12-22 criteria, and the SEA for medium-term development plan contains 12-22 as well. From this study, it can be concluded that the issue of climate change still varies greatly in Indonesian SEA, and it is therefore not significant.
The quality assessment on fermented virgin coconut oil treated under microwave heating
Authors: Khathir R , Hartuti S , Fadillah N
Published: February 2021

The study aimed to evaluate the quality of fermented virgin coconut oil (FVCO) treated under microwave heating. The FVCO was produced by local farmer from Aceh Besar District, the province of Aceh, Indonesia. A home microwave oven Samsung ME731K at frequency of 2,450MHz was used to heat 100ml of FVCO for 10 minutes. The experimental was designed by the variation of microwave power at 4 levels i.e. 0, 300, 450, and 600W. The parameters assessed were temperature, moisture, free fatty acid (FFA), and peroxide value (PV). The data was analysed by using analysis of variance (ANOVA). Results showed that the quality of FVCO still could not be improved yet where most of parameters observed did not meet the quality standard of VCO. However, the challenge of using microwave heating to improve the FVCO quality is quite big since the treatment had significantly influenced the FVCO temperature. Further study is highly recommended to treat the FVCO under microwave heating with the improvement in the procedure of observation.
A mini review on characteristic of depik fish (Rasbora tawarensis) and its processed products
Authors: Rahmi F , Susanti Z , Nilda C , Muzaifa M
Published: February 2021

Depikfish (Rasbora tawarensis) is a tpical endemic freshwater fish of Laut Tawar Lake in Central Aceh, Aceh Province. This lake has become the pride of the Gayo community as a source of clean water for various needs, a source of livelihood for residents and a tourist destination. Laut Tawar Lake anddepikfish have become the trademark of the city of Takengon, Central Aceh. However, it is unfortunate that due to several reasons such as environmental degradation, introduction of foreign fish, destructive fishing techniques, pollution and climate change globally,depikfish population is currently decreasing drastically. Evendepikfish has been appointed as a fish with a threatened status. Studies on the existence ofdepikfish as local food, form of presentation and nutrition are still rarely carried out. This article tries to review the existence ofdepikfish and its processed products through several existing studies including classification, distribution, morphological and genetic characteristics ofdepikfish as well as processing and characteristics of processed products.
Efficiency analysis of red chili farming in Pidie Jaya Aceh
Authors: Yusmaini  , Usman M , Safrida  , Kasimin S
Published: February 2021

The application of production management is very important in farming, this is reflected in the farming of red chili as one of the contributing commodities to inflation in Indonesia. chili is a commodity that has the most fluctuating price movements, where the price indicator is a reference for a farmer in planting red chili, therefore a farmer must be able to determine the time and carry out production management, one of which is the efficiency of production factors where this efficiency ultimately affects the the amount of income received by farmers. The purpose of this study is to determine what factors affect production, factors that have been economically efficient and factors that affect income in the red chili farming in Pidie Jaya Regency. This study uses Cobb Douglas efficiency analysis and income analysis. The factors that influence the production of red chilli farming in Bandar Baru and Trienggadeng Districts in Pidie Jaya Regency consist of seeds, compost, NPK, urea, KCL, TSP, pesticides and labor where the magnitude of the influence of the variable reaches 94.9%. The efficiency of production factors, namely compost, and KCL are not efficient, so it needs to reduce production factors, while seeds, NPK, urea, TSP, pesticides and labor are not efficient so need the addition of production factors. The influence of the factors of the amount of production, the selling price of red chili and production costs to the income of the farming of red chili in the District of Bandar Baru and the District of Trienggadeng in the District of Pidie Jaya that is equal to 91.90%.
Making briquette as fuel from rice husk waste and glutinous rice flour
Authors: Ramadhini M , Saputra D S , Setiawan H , Nur J , Asmaidi
Published: February 2021

Briquette is fuel energy produced from organic materials or agricultural waste (biomass) that is underutilized such as rice husk waste. In this research, briquettes will be made from a mixture of rice husk waste, sticky rice glue and PVAc glue. The purpose of this research is to see the temperature and length of burning of charcoal briquettes. This research uses conventional experimental methods. Based on the results of the study, sample 1 had a mixed composition of 100 gr rice husk waste, 15 gr glutinous rice flour, 5 gr PVAc glue, and 110 ml hot water, then a maximum temperature of 335.4°c was obtained and with a burning time of 19.18 minutes, whereas at sample 2 has a composition of mixed ingredients namely 90 gr rice husk waste, 25 gr glutinous rice flour, 5 gr PVAc glue, 110 ml hot water, then a maximum temperature of 353.6°c is obtained with a burning time of 17.54 minutes, whereas in sample 3 with a mixture of ingredients 110 gr rice husk waste, 5 gr glutinous rice flour, 5 gr PVAc glue, 110 ml hot water, then a maximum temperature of 427.1°c is obtained with a burning time of 27.46 minutes. Of the 3 sample specimens that obtained good temperature values were sample 3 with a maximum temperature of 427.1°c and a burning time of 27.48 minutes.
Modernization readiness analysis of Belitang irrigation system at region level using analytic hierarchy process (AHP) method
Authors: Imron F , Murtiningrum
Published: February 2021

Irrigation system management in the Belitang Irrigation System has some constraint that can be overcome by conducting irrigation modernization. Before implementing irrigation modernization, an irrigation system should be assessed to determine the level of irrigation modernization readiness stated by the readiness index of irrigation modernization (IKMI). The assessment of irrigation pillars was carried out in three regions including Belitang I, Belitang II and Belitang III. This study aimed to analyze the readiness of irrigation modernization in the Belitang Irrigation System and to determine the order of irrigation modernization development in three regions. Data was collected using 2 methods, namely walk through survey for irrigation infrastructure pillars and interviews for 4 other pillars including water availability, system management, institution and human resources. The assessment data was recapitulated and processed to obtain the IKMI. Then, decision making for the order of irrigation modernization development was conducted by using the analytic hierarchy process (AHP) method. The result of determining the IKMI was 69.05, so Belitang Irrigation System was categorized as less ready for modernization. This showed that the irrigation modernization needs to be postponed and the irrigation system is improved for 1-2 years. Furthermore, the results of the AHP analysis showed that the order of order of irrigation system development and improvement for irrigation modernization started from the Region of Belitang III, then Belitang I and Belitang II.
Potential of ciplukan extract (Physalis angulata L.) and patchouli waste (pogostemon patchouli pellet) as alternative sources of phytogenic feed additive
Authors: Daud M , Yaman M A , Usman Y , Aqmarina Y
Published: February 2021

This study aims to examine the potential of ciplukan and patchouli oil refining waste as alternative sources of phytogenic feed additive to replace the Antibiotic Growth Promotor (AGP) in livestock. The research was carried out by using the method of extraction and identification of phytogenic components of ciplukan and patchouli waste as well as in vitro for antibacterial and antioxidant tests of ciplukan leaf extract and patchouli waste. The variables observed were percentage yield, nutritional content, phytochemicals, phytogenic compounds, antibacterial inhibition and antioxidant content of ciplukan leaf extract and patchouli waste. Data analysis was carried out descriptively and tabulated according to the research variables. The results showed that the extraction using 96% ethanol solvent produced different yields, the highest yield was found in ciplukan, namely 9.75% and patchouli waste of 1.02% by weight of fresh ingredients. The nutritional content of ciplukan and patchouli waste respectively contains crude protein 27.79 and 14.19%, crude fiber 7.08 and 17.09%, fat 3.43 and 3.85%, BETN 27.46 and 40.87%, and the antioxidant content tends to be higher in ciplukan, namely 75.70% and 73.53% patchouli waste. Based on the results of the phytochemical test, patchouli waste extract contains bioactive substances in the form of alkaloids, flavonoids, phenols, tannins, saponins, steroids and terpenoids as well as essential oils, while the ciplukan extract does not contain terpenoids and essential oils. The results of the antibacterial test showed that patchouli waste extract had the largest inhibition zone against Escherichia coli and Salmonella bacteria compared to the ciplukan extract with an average diameter of 12.50 and 8.50 mm. Conclusion patchouli waste extract has the potential to be used as an alternative source of phytogenic feed additive because it contains phytogenic bioactive substances and can act as antibacterial.
Horticulture constraints in Aceh toward agricultural era 4.0
Authors: Kasimin S , Zakiah  , Mujiburrahmad  , Fadhliani Z
Published: February 2021

This study aims to: (1) present the characteristics of leading horticultural farming in Aceh, (2) compare the conditions of existing traits with those that should live in entering digital agribusiness, (3) identify the constraints in agribusiness to enter digital era, and (4) find the solution of the constraints. Descriptive analysis, tabulation, and comparison are used as the analytical tools in this study. The results show that leading horticultural agribusiness in Aceh have problems in adapting digital era because today’s agribusiness characteristics still outperform. Constraints are attributed to the internal factors of those who plays essential roles in agribusiness. Those factors are: older age of agribusiness actors, low educational attainment, unfamiliar with digital technology, and limited access to land and capital. This study find that government acts, such as improving social assistance, mentoring and coaching, are crucially needed to support agribusiness actors competing in digital era.
The construction of digital twin for reliability of liquid level volatile products
Authors: Yang DeZhen , Chen Jize , Ren Yi , Sun Bo , Feng Qiang , Qian Cheng
Published: February 2021

Due to the lack of air tightness and environmental stress, the liquid level volatile products will gradually volatilize, which will affect the performance and reliability of products. Due to the small volume, complex working environment, strong acidity of electrolyte and various electric environments, it is difficult to monitor the liquid level in real time, so it is impossible to predict the remaining life of such products. In view of this, this paper proposes a scheme to estimate the liquid level information and predict the remaining life of volatile liquid level products through reliability digital twin. First, a set of test device is designed to control the environmental factors of liquid level volatile products in real time and collect the information of liquid level height. Then, according to the product working environment and liquid level data collected by the test device in real time, a general mathematical model of liquid level volatile of products is fitted. According to the model, the twin mapping of this kind of products in virtual space can be built, which can make them have liquid level volatile products surplus life prediction ability. Finally, the digital twin real-time collects the actual use data of the product, and continuously evolves the remaining life prediction model of the product through learning, so as to improve the prediction accuracy and better guarantee the reliable use of the product.
Quality Big Data Analysis and Management Based on Product Satisfaction Index
Authors: Sun Y F , Lu A P , Zhuo L , Li G , Jia J , Liu W , Hu C J
Published: February 2021

The core idea of quality work is to create enduring quality by providing users with reliable, easy-to-use, and surprising products. In the Internet+ era, user demand for quality has changed with the times. Customers are no longer satisfied with the requirements of basic quality functions, and more in pursuit of ease of use, pleasure and even identity. Even if the product has "satisfied with the specifications" in quality, users are still dissatisfied and express their dissatisfaction through the Internet. If we can use the Internet, big data, artificial intelligence and other technologies to collect and analyze user expectations or dissatisfaction with product quality and find improvement directions, then quality management will see great progress. Based on this, we can create a new type of quality big data analysis and management system, which we can call the Product Satisfaction Index (PSI) management system. Through the analysis and transformation of PSI, the customer’s textual expectations are turned into numerical quantifiable indicators. Through the management of PSI indicators, quality big data mining and analysis are performed to improve the product to meet customer expectations. In advancing the product satisfaction index (PSI) indicator management system, we should fully implement the definition of PSI indicators, strategic position, data analysis methods, closed-loop management models, review and continuous improvement, and data platforms. Visualize customer needs, analyze the matching between product characteristics and customer needs, and promote continuous improvement of PSI indicators through closed-loop management. The new PSI index management method opens up new ideas and methods for quality performance management, and helps build high-quality development and create customer satisfaction.
Application on Damage Types Recognition of Civil Aeroengine Based on SVM Optimized by DMPSO
Authors: Bo Zheng , Xin Ma , Xiaoqiang Zhang , Huiying Gao , Jianhao Huang , Guoqing Chen
Published: February 2021

In order to recognize the damage types of aeroengine automatically and Reliably, enhance the support capability of aeroengine maintenance, the feature extraction method based on color moments and gray level co-occurrence matrix (GLCM) is proposed to construct the feature database of the aeroengine damage images. The support vector machine (SVM) is utilized as intelligent classifier for damages recognition. Meanwhile, a double-mutations particles swarm optimization (DMPSO) algorithm is designed to optimize the kernel parameter and penalty factor for guaranteeing the recognition performance of SVM. Finally, the feature databases are constructed by different feature methods according to actual four damage types of a certain aeroengine, and then the proposed SVM optimized by DMPSO is used to compare with back propagation (BP) network, extreme learning machine (ELM) network, and k-nearest neighborhood (k-NN). The recognition results have proven the proposed feature extraction method is more suitable for aeroengine damage recognition. Meanwhile, the comparison results have demonstrated the optimized SVM always has better and stable recognition output.
Reliability Evaluation of Li / SOCl2 Battery for Smart Electricity Meter Based on Remaining Capacity
Authors: Ye Xuerong , Sun Qisen , Li Haoxiang , Li Wenwen , Liu Li , Zhai Guofu
Published: February 2021

The life and reliability of the battery are the keys to ensuring smart electricity meters function properly during a power outage. This paper aims to study the capacity prediction and reliability evaluation methods of lithium thionyl chloride batteries for smart electricity meters based on capacity degradation model. The mechanism of capacity attenuation of backup lithium battery of smart electricity meters is introduced. An accelerated aging test method is proposed to study the influence of storage time, working condition, and temperature on capacity degradation. A semi data-driven model is used to describe the capacity degradation. According to the mathematical model, battery life under different storage conditions in the working environment of smart meters can be calculated.
An incipient consistency identification scheme of failure mechanism based on improved grey theory
Authors: Ye X R , Hu Y F , Si S , Feng R , Liu S R , Zhai G F
Published: February 2021

Accelerated degradation test (ADT) is an effective technique to quantitatively evaluate the life characteristics of high-reliability and long-life products. And the consistency of failure mechanism under different accelerated stress levels is the premise of ADT. In order to identify the consistency of failure mechanism as early as possible and improve the identification accuracy, an incipient consistency identification method of failure mechanism based on improved grey theory is proposed in this paper. Firstly, we reconstruct the background value through the calculation of the integral in the interval. Then the new information priority principle is introduced to improve the construction of initial values in the conventional grey theory. Subsequently, combined with the equal dimension model, the integrated scheme is employed to analyze the enhancement testing data of a resistor in a switching power supply to identify the mutation point of failure mechanism. Compared with the conventional GM (1,1) model, the proposed method has smaller residual, and another identification based on degradation model is also constructed to verify the feasibility and creditability of the proposed method.
Consistent robust design of bistable crystal cover relay
Authors: Huimin Liang , Xuqing Zhu , Jie Deng , Wei Tang , Hao Chen
Published: February 2021

Bistable crystal cover relays are widely used in aerospace and other electronic systems due to their outstanding resistance to mechanical environment. However, the bistable crystal cover relays have a complicated structure and are difficult to design and debug. There are still quality problems in this kind of relay such as low electromagnetic efficiency, small commissioning margin and large product dispersion. This paper aims at solving the problems of poor anti-interference of output characteristics caused by the imperfection of the reliability design. The finite element model of the electromagnetic system of the relay was established by using FLUX software and the electromagnetic characteristics of the relay were simulated and analyzed firstly. By comparing with the actual measurement, verified the correctness of the simulation results and guaranteed the accurate calculation of the experimental research. On the basis, this paper adopts the robust design method proposed by Taguchi Genichi to optimize the product parameters and tolerances of the relays. At present, the research conclusion is applied to the improvement of a certain type of aerospace electromagnetic relay. This paper provides necessary research means and basis for the robustness design of aerospace electromagnetic relay. The related methods and technologies can also be applied to the design of other electrical products.
Research on safety analysis and assessment control of dangerous materials transportation
Authors: Zhao Yong-Tao , Wang Yi-Dong , Li Ya-Fei
Published: February 2021

Aiming at the safety problems of flammable and explosive dangerous materials in the transport task profile, the types and characteristics of the transport environment were analysed. By using the method of fault tree safety analysis, the risk sources of the transport task profile were systematically identified, the basic events and risk factors that cause safety accidents were determined. And the risk factors were evaluated, the safety risk level was divided, and the control measures of transportation risk were put forward.
Full Scale Dent Rebound Testing of X65 Steel Linepipe
Authors: Sha Shengyi , Jia Guangming , Yan Bingchuan , Chen Pengchao , Pang Shengmin , Feng Qingshan
Published: February 2021

Dents in buried pipelines can be formed due to a number of causes: third party machinery strikes, rock strikes during backfilling, pipe resting on rock, and amongst others. Dents in pipelines would not only affect short and/or long-term integrity, but would also have a potential impact on the pass capacity of in-line inspection and cleaning tools when the size of the dent is large enough. Rebound for an originally constrained dent can decrease the dent depth and improve the pass capacity of in-line inspection and cleaning tools. In order to estimate the rebound capacity of dents especially in spiral weld pipelines, a full-scale dent rebound testing program of X65 steel pipeline was designed and performed. The full scale testing was conducted on the parent material and the spiral welds. Hemispherical and pyramidal indenters were used to generate dents to different depths. Strains around the denting area during formation of the dent and changes in depths due to rebounding after removing indenter were measured. Following each rebound test, the dent profile was portrayed with a 3D laser scanner and the maximum equivalent strain was then calculated. With the information obtained from the above measurements, detailed analyses were performed and a numerical model was developed. In this paper, the approach used for the study is described first. The results and findings are then presented. The effectiveness of the developed numerical model for dent integrity management is demonstrated.
Isolation Forest Wrapper Approach for Feature Selection in Software Defect Prediction
Authors: Ding Zhiguo
Published: February 2021

Software defect prediction is one of the hot research topics in the software engineering application. The performance of predictor largely depends on the quality of dataset used for learning the predictor. High dimensionality is a noteworthy characteristic of software defect dataset, which has some side-effect on the predictor building using data mining or machine learning algorithm. Feature selection, being an effective measure of dimensionality reduction, uses the optimal feature subset to represent the entire feature space and alleviate the dimensionality curse problem. In this paper, a wrapper feature selection approach applying genetic algorithm as a search strategy to find the optimal feature subset is firstly introduced. Secondly, an improved isolation forest based defect prediction method is proposed. The exploring experiments on 5 real NASA software defect datasets demonstrate the proposed method can improve the defect prediction performance to some extent and proves the positive effect of feature selection in SDP application.
Process design and optimization Of Two-Stage Axial Micro Turbine Air motor
Authors: Liu J , Guo Z P , Yuan Q , He X X , Miao S j
Published: February 2021

Based on the general machining center, a high-efficiency, mass-produced micro-turbine processing technology and a process scheme for improving metal removal rate are proposed to improve and optimize the metal removal rate of micro-machining. Taking the two-stage axial micro turbine air motor as the research object, the machining route of clamping the nozzle rotor is developed, and the metal removal rates of the turbine with the expandable surface when using the rounded end mill and the ball end mill are compared by the single factor analysis method. In the three processes of rough milling blade passage, finish milling blade and finish milling wheel hub, the metal removal rate of the rounded end mill is 2.96 times, 10 times and 2 times higher than the ball end mill, respectively. The Swarf finishing strategy of Powermill software is used to processing the side and bottom of the blade both roughly and accurately, and the suitable cutting parameters and side edge machining parameters are obtained. The surface roughness Ra of the side and bottom surfaces of the blade is tested to be 0.4-0.8μm using a surface roughness measuring instrument SJ-410. With the trigger type probe of the model Omp60, the dimensional tolerance of the blade is within 0.015 mm, and the coaxiality is from 0.002 to 0.003mm. The two-stage axial-type micro turbine air motor is assembled by the hot-packing method, and the torque and rotor speed are tested by a special platform. The results show that when the compressed air inlet pressure is 300KPa, the designed maximum speed of 100000rpm is satisfied, which meets the design requirement of the turbine motor and verifies that the numerical control machining process plan is feasible. Besides, the side edge machining of the blade using the cylindrical milling cutter is efficient to improve the metal removal rate. It also lays a foundation for the mass production of the two-stage axial-type micro turbine air motor.
Accuracy Degradation Model and Residual Accuracy Life Prediction of CNC Machine Tools Based on Wiener Process
Authors: Li Shilin , Ran Yan , Zhang Genbao , Zhang Dingfei
Published: February 2021

In order to predict the accuracy residual life of CNC machine tools, an accuracy degradation model and accuracy residual life prediction method of CNC machine tools based on accuracy degradation data are proposed. Considering the non-linear and uncertainties in the process of accuracy degradation, an accuracy degradation model of CNC machine tools was established based on the nonlinear Wiener process; The accuracy failure is judged when the measured accuracy value exceeds the failure threshold for the first time. An accuracy residual life prediction model based on Inverse Gaussian distribution is established, and the accuracy residual life is calculated as a probability density function. To solve the problem of lack of historical data and prior information for a single CNC machine tool, particle filter is used to recursively update the posterior values of the model parameters based on the current observation data to achieve continuous optimization of the residual life prediction results; Finally, the correctness and effectiveness of the accuracy degradation model and the prediction method of the accuracy residual life are verified through the example analysis of the accuracy degradation experimental data of CNC machine tool.
Reliability evaluation of command information system under different attack modes
Authors: Jia Guohui , Zhou Jie , Li Junyi
Published: February 2021

Based on the basic structure of the typical command information system network, the model has been divided into physical layer and information layer. According to the whole network efficiency and reliability, five functional characteristics quantity are selected as the reliability evaluation indexes when the system is attacked randomly or deliberately. With the model we established, reliability changes of the constructed system are compared of different attack modes. The results provide evidence that the system reliability change obviously in different attack modes which should be special focused in practical application.
Study on environmental adaptability of 2A12-T6 aluminum alloy in typical atmosphere environments
Authors: Wu S , Su Y , Zhu Y Q , Shu C , Luo L Z , Zhong Y , Chen Y
Published: February 2021

The environmental adaptability of 2A12-T6 aluminium alloy exposed in marine, cold and plateau atmosphere environments has been investigated by corrosion morphology observation, weight loss test and mechanical properties test. the results showed that compared with cold and plateau atmosphere environment, 2A12-T6 aluminum alloy presented higher corrosion susceptibility in marine atmosphere environment; Cross-section morphologies analysis manifested that 2A12-T6 aluminum alloy suffered pitting attack in marine atmosphere environments, and the corrosion is very slight in the cold and plateau atmospheric environment; The corrosion weight loss of 2A12-T6 aluminum alloy in the three environments shows a trend of increasing, which conforms to the power function, Moreover, the corrosion weight loss of 2A12-T6 aluminum alloy in marine atmospheric environment was far greater than that in cold and plateau atmospheric environment; The mechanical properties of 2A12-T6 aluminum alloy exposed to three kinds of environments showed an upward trend under the effect of natural aging at the initial stage, then decreased under the corrosion action of marine atmosphere with the extension of exposure time, and remained basically unchanged in cold and plateau atmosphere.
Satellite Dynamic Fault Analysis Method Based on AltaRica Logic Modeling
Authors: Wang H , Li Y , Wang Z , Wu J
Published: February 2021

Modern spacecraft has developed into a complex system integrated multi-task, multi-specialty and multi-information. The cross-linking and coupling between different systems have exposed more and more logic sequence fault caused by non-software and hardware failures. It is difficult to comprehensively and accurately analyze the logical sequence faults of complex systems by using traditional fault tree analysis (FTA), failure mode and effect analysis (FMEA) and other manual methods. Furthermore, the reliability and safety of the spacecraft cannot be effectively guaranteed. In this paper, the dynamic fault analysis of the spacecraft was carried out based on the method of AltaRica logic modeling. The satellite power supply and distribution (PSD) subsystem was taken as an example. A dynamic model of charge and discharge between the solar array, the storage battery and the bus was established. Logical events and sequences of the bus power supply fault was calculated. The results show that this method can effectively complete the dynamic modeling and fault analysis of the spacecraft system, and it has higher analysis capability and efficiency than traditional methods.
Neural network-based probability forecasting method of aviation safety
Authors: Zheqi Zhu , Bo Ren , Xiaofeng Zhang , Hang Zeng , Tao Xue , Qingge Chen
Published: February 2021

Aviation safety forecasting is of great significance for accident prevention. At present, aviation safety forecasting is mainly deterministic forecasting, ignoring the impact of various uncertainties on forecasting. In this paper, on the basis of deterministic forecasting, the forecasting of aviation safety probability is carried out based on the uncertainty of neural network point forecasting value. The uncertainty of aviation safety forecasting is described by three ideas: the numerical statistical characteristics of point forecasting value, the probability density fitting of point forecasting value and the distribution of error. The interval forecasting result is obtained, which can better understand the uncertainty and risk of forecasting quantity. Taking the aviation safety data of civil aviation from 1993 to 2008 as an example, the results show that this method can provide the most possible range of aviation safety forecasting under certain uncertainty level, and is more conducive to the modeling of aviation safety uncertainty.
Attack and Defense Strategy for Infection Network System with Two Early Warning Mechanism
Authors: Wang Jiaheng , Chen Die , Chen Fu
Published: February 2021

As the progress of IoT technology, Cyber-Physical System gradually becomes the basic pillar of people’s daily life. Contrary to its convenience, Cyber-Physical System could be easily broken by attackers and these attacks infect the system and affect more systems, thus interfering with people’s normal work and life. In this context, this paper establishes a system defense model for the propagable network with the warning mechanism as the core. The system defense model includes warning components, which trigger the first and second warning mechanisms, and components protection and camouflage components. After deducing the reliability of the defense model system, this paper considers the influence of different parameters about the system reliability and analyzes the relationship between warning components, camouflage components, and systemreliability. Based on the different parameters that affect the system reliability, this paper proposes the optimal defense deployment strategy under the attack optimal strategy and obtains the basic principles of the deployment of defense measures through numerical analysis. Finally, the simulation experiments of different systems prove the rationality and correctness of the proposed model.
Research on Fault Prognosis Methods Based on Data-driven:A Survey
Authors: Yuan Li , Zhuojian Wang , Zhe LI , Zihan Jiang
Published: February 2021

Fault prognosis technology, as the key to realize autonomy support and carry out condition-based maintenance (CBM), has been fully developed and researched in recent years. In this paper, the existing fault prediction methods are briefly summarized and studied, and focused on the data-driven prediction method. In the light of the scale of data, all kinds of prediction methods are divided into small sample-based and large sample-based fault prediction methods. The basic principles, advantages and disadvantages of each type of typical analytical methods are summarized, and finally, we put forward the research prospect the development direction of future data-driven fault prediction.
Reliability Life Estimation Considered fault Correlation of Aerial Bearing
Authors: Song C , Bian Z , Ding S N
Published: February 2021

The purpose of this paper is to study the reliability life calculation model of aerial rolling bearing considered the correlation of failure model. By mean of collecting relevant experiment data of vibration signal and temperature signal in the life test of the aerial rolling bearings, and analyse time domain and frequency domain, we can analyse the main failure modes and mechanism (e.g. wear, fatigue). The characteristic parameters that characterize the healthy state of aerial rolling bearings obviously are extracted further. Considering that the bearings expose multiple failure modes in the working process in most case, bearing fault diagnosis method is based on fuzzy theory. It is used to clarify the failure mechanism of different failure modes and the degradation rule of performance characteristic parameters. It’s very essential that establish the clear relationships between performance degradation and symptomatic set. According to the fault diagnosis results, each of failure modes is established the performance degradation model respectively. Considering the correlation between multiple different failure modes, Copula theory is introduced to analyse the correlation between multiple failure modes. Base on Copula theory, it’s obtained the life distribution model of aerial bearing based on multiple failure modes. Life distribution model are verified by subsequent experiments, which show that life distribution model of aerial rolling bearing in this paper, is feasible and necessary.
Dynamic Reliability and Reliability-Based Sensitivity of Transmission System in Shearer
Authors: Zhou D , Gao Y M , Pan E S
Published: February 2021

Transmission system in shearer, such as traction unit and cutting arm, is the essential mechanism in the mining process, which supports the whole shearer and shock vibration. Considering various uncertainties, the evolving process is established to describe the dynamic system response with uncertain factors. Considering the parametric randomness and material strength. the failure domain is regarded as the dynamic extreme value of transmission system response exceeding the threshold in operation. According to the saddle-point approximation method, the dynamic extreme distribution is investigated to measure the safe probability and parametric sensitivity of transmission system in shearer. The dynamic reliability and reliability-based sensitivity are analysed to evaluate the evolving process of transmission system in shearer. According to the transmission model of traction unit, the influence degree of each parameter’s fluctuation can be quantified based on the indices of dynamic mean-value reliability-based sensitivity and standard deviation reliability-based sensitivity. The crude Monte Carlo simulation is taken as the benchmark to validate the reasonability.
A Design Method of UAV Flight Protection Area Based on the Statistical Analysis of Flight Path Deviation
Authors: Xin MA , Xin HUANG , Li LU , Xia LI
Published: February 2021

According to the design specification of International Civil Aviation Organization(ICAO) document No. 8168, by referring to the flight record data of UAV and using the statistical and analysis method of flight line deviation limit data, the limit data is obtained, and according to the definition of collision probability model in flight programming specification, the design method of flight protection area for UAV is obtained based on flight path deviation limit data. A simulation experiment was established based on the computational simulation. The calculation results showed that: the design of UAV flight protection area is mainly determined by navigation accuracy, positioning mode, flight link and other factors, and the weight is different. By improving the accuracy and changing the flight link, the scope of UAV flight protection area can be effectively reduced. In the future, the joint operation of manned aircraft and UAV in the hollow and low-altitude airspace provides the basis for airspace planning, which further ensures flight safety and improves operational efficiency.
Deformation Inspection and Safety Assessment Method of Buried Flexible Pipeline in Service
Authors: Xinmin Zhu , Shaokong Feng , Tao Huang , Feng Shang , Lufei Yang
Published: February 2021

The working performance of buried flexible pipelines is connected with the pipe- soil interaction; the weak stiffness of backfill leads to large long-term pipeline deformation and even structural failure. Spangler’s formula is a theory for macroscopic evaluation of pipeline deformation, which cannot reflect the deformation state of various parts around the pipe from a microscopic view. A large number of engineering practices have shown that when the macro radial deformation of the flexible pipe is not large, it is also possible that the local geometric size of the pipeline may change suddenly in the microscopic view. Combining with a diversion project, a laser scanning and piecewise elliptic curve fitting combined method was proposed to measure the empty pipeline deformation in this paper. The deformation pattern of the flexible pipeline was analysis. And then, the analysis results were verified by the elastic wave test and material test data. Based on the deformation inspections, the internal force and related reliability of pipe structure were calculated. Finally, the structural safety of each pipe was assessed to guide the replacement, repair and reinforcement of pipeline.
Research on fatigue crack propagation of metal structure of casting crane based on XFEM
Authors: Chen G L , Cheng J M , Jin H
Published: February 2021

Aiming to solve the crack problem at the connection between the metal diaphragm of the casting crane and the lower cover plate and web, a three-dimensional model of solid-shell coupling of a single main beam is established according to the design drawing of the casting crane, and the crack propagation was simulated using the expansion finite element method (XFEM). The results show that during the crack propagation process at the joint between the diaphragm and the web, the magnitude of the equivalent stress intensity factor ΔKeff
is not much different from the magnitude of the type I crack stress intensity factor ΔKI
during crack growth at the junction of diaphragm and web weld. The amplitudes of Type II and Type III stress intensity are smaller than those of Type I and equivalent stress intensity factors. In the process of fatigue cracking of the weld between the diaphragm and the web, the type I cracks dominate the role, and the type II and III cracking models have little effect on the connection between the diaphragm and the web.