bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Numerical Simulation of the Vertical Water Entry Process of High Speed Projectile with Small Angle of Attack
Authors: Li Ruijie , Wang Rui , Yao Zhong , Sun Yanhu , Wang Jiawen 
Published: April 2021

Abstract
Based on the numerical simulation method, the high speed vertical water entry process of projectile moving at 1000m/s with small angle of attack is studied. By analyzing the cavity configuration and hydrodynamic characteristics of the process, the influences of the small entry angle on the water entry stability process are obtained. The simulation results indicate that the projectile’s ballistic can achieve relative stable state when the water entry angle is less than 0.5°, otherwise the water entry cavity can be pierced by tail fin. The pierced size tend to increase with the increased water entry angle as well as the projectile’s ballistic become unstable. In addition, the rotation of the projectile owing to pitching moment has little effect on cavity configuration and water entry stability.
A quantum-inspired particle swarm optimization for sizing optimization of truss structures
Authors: Xu Zhiqiang , Cui Yunxian , Li Baoliang 
Published: April 2021

Abstract
Particle swarm optimization (PSO) algorithm has some advantages such as simple principle, less model parameters. However, it has some flaws for dealing with sizing optimization of truss structures, such as low accuracy, slow astringency and poor population diversity in the later evolution stage. In order to overcome these shortcomings and deal with optimization problem of truss structures effectively, a new quantum-inspired particle swarm optimization (QPSO) algorithm with quantum angle encoding and a perturbation operator of the population is proposed in this paper. Then, QPSO is used for optimization of truss structures by means of penalty function method. In the end, two typical numerical tests for truss design are performed to calibrate and verified the proposed algorithm. The results of the QPSO compared with PSO and other optimization algorithms show that the proposed QPSO has a better performance in terms of both the optimum solutions and the convergence capability than PSO and is a powerful optimization technique for solving optimization problem of truss structures.
Research on Innovative Practice Links of Physical Education Course Based on Computer Big Data
Authors: Jiang Ren 
Published: April 2021

Abstract
The thesis uses literature research, information research methods, and logical reasoning methods. After in-depth research on the current situation of the development of school sports activities between classes, it is found that some schools still adopt the form of interclass exercises due to insufficient hardware or software facilities. The problem is that there is very little communication between schools, and the school itself has no position in the inter-class activities of sports. To fill this gap, we must not only strengthen policies, but also integrate with the rapid development of modern information. In the era of big data, the traditional physical education teaching model is being impacted and challenged. College students no longer like the passive “indoctrination” teaching model, but prefer to explore the autonomous learning method. How does the teaching of sports innovation practice adapt to the era of big data? Development is worth pondering, and it is of great significance to explore teaching models that are conducive to cultivating students’ autonomous learning ability and inquiry ability.
Two Types of Second Order Fractional Differential Equations
Authors: Yu Chii-Huei 
Published: April 2021

Abstract
In this paper, we make use of a new multiplication of fractional functions, variable separation method and chain rule for fractional derivatives, regarding the Jumarie type of modified Riemann-Liouville (R-L) fractional derivatives to solve two types of second order fractional differential equations. Moreover, some examples are proposed to illustrate our results.
Research on College English Teaching System Based on Computer Big Data
Authors: Zhu Weihua 
Published: April 2021

Abstract
With the development and maturity of computer and multimedia technology, computer-aided teaching represents advanced teaching ideas and teaching methods. Computer-aided learning systems can dynamically generate personalized teaching content and strategies through intelligent system inferences. The diagnosis mechanism is used to judge the learning level of students and provide a favorable basis for teachers to adjust teaching content. Based on the advancement of the current English teaching reform, the use of computer aid has become a trend in English teaching. It analyzes the current design requirements of computer aided English teaching systems and designs a teaching system based on C++ and Windows. The results prove that based on C++ and Windows, the design and realization of computer-assisted English teaching cannot increase the actual teaching efficiency by 20%, and can also play the value of computer-assisted English teaching, improve the level of English teaching by 12.0%. The conclusion shows that in the design of computer-assisted English teaching system, the design system based on C++ and Windows can effectively improve the quality of computer-assisted English teaching and have a positive impact..
A comprehensive index model for real estate convenience based on multi-source data
Authors: Hua Ling 
Published: April 2021

Abstract
The description information of the convenience of real estate is often qualitative and simple, and lacks comprehensive evaluation, so it is difficult to make horizontal comparison of the convenience of different real estate. Therefore, this paper proposes a comprehensive index model which uses multi-source data to measure the real estate convenience quantitatively. Based on the walking index, the model adds vector road network data, poi (point of interest) data and other multi-source data, and introduces the concept of walking score. Combined with the practical application of real estate, the model classifies the convenience facilities and calculates the walking distance between the convenience facilities and real estate quantitatively, so as to obtain a real number index to comprehensively measure the convenience of real estate. Finally, the experimental results based on Amap data prove the accuracy and effectiveness of the proposed model.
Arctic tundra shrubification: a review of mechanisms and impacts on ecosystem carbon balance
Authors: Mekonnen Zelalem A , Riley William J , Berner Logan T , Bouskill Nicholas J , Torn Margaret S , Iwahana Go , Breen Amy L , Myers-Smith Isla H , Criado Mariana García , Liu Yanlan , Euskirchen Eugénie S , Goetz Scott J , Mack Michelle C , Grant Robert F 
Published: April 2021

AbstractVegetation composition shifts, and in particular, shrub expansion across the Arctic tundra are some of the most important and widely observed responses of high-latitude ecosystems to rapid climate warming. These changes in vegetation potentially alter ecosystem carbon balances by affecting a complex set of soil–plant–atmosphere interactions. In this review, we synthesize the literature on (a) observed shrub expansion, (b) key climatic and environmental controls and mechanisms that affect shrub expansion, (c) impacts of shrub expansion on ecosystem carbon balance, and (d) research gaps and future directions to improve process representations in land models. A broad range of evidence, includingin-situobservations, warming experiments, and remotely sensed vegetation indices have shown increases in growth and abundance of woody plants, particularly tall deciduous shrubs, and advancing shrublines across the circumpolar Arctic. This recent shrub expansion is affected by several interacting factors including climate warming, accelerated nutrient cycling, changing disturbance regimes, and local variation in topography and hydrology. Under warmer conditions, tall deciduous shrubs can be more competitive than other plant functional types in tundra ecosystems because of their taller maximum canopy heights and often dense canopy structure. Competitive abilities of tall deciduous shrubs vs herbaceous plants are also controlled by variation in traits that affect carbon and nutrient investments and retention strategies in leaves, stems, and roots. Overall, shrub expansion may affect tundra carbon balances by enhancing ecosystem carbon uptake and altering ecosystem respiration, and through complex feedback mechanisms that affect snowpack dynamics, permafrost degradation, surface energy balance, and litter inputs. Observed and projected tall deciduous shrub expansion and the subsequent effects on surface energy and carbon balances may alter feedbacks to the climate system. Land models, including those integrated in Earth System Models, need to account for differences in plant traits that control competitive interactions to accurately predict decadal- to centennial-scale tundra vegetation and carbon dynamics.
Community Structure And Phytoplankton Abundance In Different Estuary In Coast Waters Lekok Pasuruan East Java
Authors: Herawati E. Y. , Darmawan A. , Azkiya M. 
Published: April 2021

Abstract
The quality of water in estuary is influenced by human activities around it which can affect the sustainability of the life of the organisms in these waters and other living things that use it. The aim is to analyze the abundance of phytoplankton and the quality of the waters of the river estuaries with different land uses for ponds, settlements and mangroves. This study was conducted by using survey method and carried out April - May 2020. The results of the abundance of phytoplankton in the coastal waters of Lekok as a whole are 3543 - 7692 cells / ml which are classified into mesotrophic waters. The phytoplankton with the highest abundance was dominated by Ceratium sp, indicating this species as an indicator of polluted waters. The results of water quality in Lekok coastal waters such as temperature, pH, salinity, DO and TOM are suitable for the life of phytoplankton organisms and in accordance with sea water quality standards. Water quality that exceeds the quality standard for nitrate, orthophosphate and TSS is due to the presence of nutrients or organic matter from human activities in different land uses that enter the waters and river estuaries.
Increasing Dissolved Oxygen in The Floating Net Cage Area of Jatiluhur Reservoir, Purwakarta
Authors: Zulkarnain R. , Adiyana K. , Waryanto  , Nugroho H. 
Published: April 2021

Abstract
Dissolved oxygen is one of the important parameters in fish farming in floating net cage in reservoirs or lakes. However, dissolved oxygen will decrease due to upwelling. In this study, an aerator trial was conducted in floating net cages in reservoir. The data obtained were analyzed descriptively and statistically. The results obtained show that the aerator can increase the level of dissolved oxygen in the floating net cage area with different magnitudes from 0.05 mg/L - 1.3 mg/L especially in especially at 4 and 5 m depths because output pipe length was 4 m for aeration.
Identification of Five Types Kampar River Fish With Genetic Approach
Authors: Fauzi M , Sumiarsih E , Hendrizal A 
Published: April 2021

Abstract
Fish identification in the mainland waters of Riau Province is generally carried out based on morphological characteristics. To identify fish species accurately in a short time, the DNA Barcoding method with a molecular approach is used. Five types of fish were taken from Kampar River and coded as MJ313, PJ36, SJ35, BJ33, and GJ41. The genes of these five fish were amplified, and PCR products were sequenced and analyzed using bioinformatics software. The editing of the sequencing results and the determination of the nucleotide composition were analyzed using Mega5 software. DNA sequences were aligned using the ClustalW software. The sequences obtained are then compared with GeneBank data using Basic Local Alignment Search Tools (BLAST). The results showed that the species with the code MJ313 and GJ41 were Channa striata, PJ36 were Osteochilus hasseltii, BJ33 were Mystus sp. Based on the sample examination, the species coded SJ35 cannot be determined because the marker band is low so that it is not visible. The results of the analysis on species coded SJ35 indicate that there is no COI report for species coded SJ35 on GeneBank.
Analysis of Water Quality in Layer Cage with Aquaponic System in PLTA Koto Panjang Container, Kampar District
Authors: Sumiarsih E 
Published: April 2021

Abstract
Aquaponies is one way to reduce water pollution produced by fish fanning, it can also be an alternative to reduce the amount of water used in the aquaculture system. Water quality is an important factor in fish fanning activities because it can affect the growth and development of fish cultivated in reservoir waters. The purpose of this study was to analyze the water quality of the KJA (floating net cages) layered with the aquaponic system tested in the waters of the Koto Panjang Hydroelectric Reservoir. Tins research was conducted in June - August 2020 at the Koto Panjang Hydroelectnc Reservoir. Measurement of water quality parameters is earned out directly at the research location. The analysis of the physical and chemical parameters of the waters is measured in the laboratory and the calculation of the water quality parameters refers to the APHA-AWWA and is compared with Government Regulation Number 82 of 2001 concerning Class II water quality standards. Based on the results of observations on water quality in layered cages with the aquaponies system, it is known that temperature parameters range from 31-33°C. pH ranges from 5-6. dissolved oxygen ranges from 9.38 - 9.65 mg / L. free carbon dioxide ranges from 9.14 - 11, 12 mg / L and brightness range from 148.9 to 156.2 cm. Meanwhile, nitrate parameters ranged from 0.03-0.04 mg L and phosphates ranged from 0.30 to 0.06 mg L. The water quality in the layered marine cage in the aquaponies system in the Koto Panjang Hydroelectric Reservoir has been able to reduce nitrate and phosphate content so that it can reduce the impact of organic pollution that occurs in the waters of the Koto Panjang Hydroelectric Reservoir.
The Use of SPOT 6 and RapidEye Imageries for Mangrove Mapping in the Kembung River, Bengkalis Island, Indonesia
Authors: Oktorini Y , Darlis V V , Wahidin N , Jhonnerie R 
Published: April 2021

Abstract
High-resolution satellite imageries believed to map the mangrove area well. Two satellite imageries with almost similar spatial resolution were expected to achieve this objective, including SPOT (Satellite Pour l’Observation de la Terre) 6 and a RapidEye. Two images covered the same area and acquired under the equivalent season at Kembung River, Bengkalis Island, Riau Province. A comparison was tested on several objectives. First, a comparison was conducted band by band through examining their statistical spectral analysis. RapidEye had a higher variance in all visible bands but low at NIR. Second, spectral separability using Jeffrey-Matusita distance was executed with three-band composites (SPOT 6/VNIR; RAPIDEYE/VNIR and RAPIDEYE/VNIR+RedEdge). SPOT 6 had better separability than RapidEye imageries compositions (VNIR+RedEdge and VNIR), with an overall accuracy of 79.9%, 75.3%, and 67.3%, respectively. Third, mangrove land cover classification. Three pixel-based classification rules were used, including a general classifier, maximum likelihood (ML), and two advanced classifiers, i.e., neural network (NN) and support vector machine (SVM). Results indicated that the use of SPOT 6 produced better overall accuracy than the other two image composition for each classifier. SVM was promising in the mangrove mapping algorithm compare to NN and ML.
The Effect of Administering Jeruju (Acanthus Ilicifolius) Leaf Extract on Blood Parameters of Tilapia (Oreochromis niloticus)
Authors: Rumondang  , Mulyani I , Sualang S M 
Published: April 2021

Abstract
This study was aimed to investigate the effect of various doses of jeruju leaf extract administered through feed on the blood parameters of tilapia, including erythrocyte count, leukocyte count, and differential leukocyte count and to determine the dose effectively affected the blood parameters of tilapia. Jeruju is a type of herbaceous plant or phytopharmaca which has the potential to enhance fish immunity. This plant is mostly found in coastal areas. The study was conducted from July to August 2018 in the Laboratory of Tanjung Balai Polytechnics (extract preparation), Blood Laboratory of Kisaran (blood examination) and Dusun IV in Pahang Village, Talawi Subdistrict, Batu Bara Regency (research location). The research method applied was the experimental method with Completely Randomized Design (CRD) consisted of four (4) treatments and six (6) replications, namely A (0 g/kg), B (8 g/kg), C (10 g/kg), and D (12 g/kg). The blood parameters of tilapia which included leukocyte count, erythrocyte count, and the percentage of lymphocytes, neutrophils, and monocytes were examined on the 0th, 7th and 14th day of the study. The administration of jeruju leaf extract resulted in a significant effect on leukocyte count, erythrocyte count, and lymphocyte percentage (P<0.05), but did not significantly affect the percentage of neutrophils and monocytes.
Fecundity and Eggs Diameter of Mullet Fish (Moolgarda perusii, Valenciennes, 1836) at Selotong Aquatic Langkat Regency, North Sumatera
Authors: Desrita  , Hutagalung S. , Onrizal  , Leiodonald R. 
Published: April 2021

Abstract
The aquatic area of the Selotong, Langkat Regency is an area with a good fisheries sector. Mullet fish is one of the caught fish in the Selotong. The purpose of this study was to determine the fecundity and the eggs’s diameter of Mullet fish (Moolgarda perusii). This research was conducted in July - September 2019 used gill net with 1.5 inch mesh size. Fecundity of Mullet fish (M. perusii) in GML III and IV ranges at 19.586 – 203.124 eggs with egg’s diameters ranging from 9,3-18,4 μm. Mullet fish (M. perusii) is a type of partial spawner.
Application of Principal Component Analysis to Characterize The Effect of Fishing Ground of Portunus pelagicus in Lancang Island Based on Environmental Parameters
Authors: Rahimah I. , Siregar E. S. Y. , Heriyanto T. , Siregar V. P. 
Published: April 2021

Abstract
Crab is a high economic value fishery commodity that is third after tuna and shrimp. crab production depends on natural fishing. In the use of crab resources, it is necessary to understand several factors. Quantitative ecological analysis can be use Principal Component Analysis. This analysis divides the parameter matrix into several components, then compiles the diversity of components collected from the largest at the turn of the main component. Spatial distribution of physical and chemical parameters is obtained by following the findings of catching the crab. This paper tries to understand the suggested environmental parameters for the success of crab life. Water quality sampling was taken on June 2015 (representing the eastern season), with an average range according to the following: SST 27.89°C - 29.39°C, TDS 28.05 - 29.60 g / L, TSS 0.004 - 0.161 mg / l, brightness 1.37 - 5.45 m, DO 5.09 - 9.17 mg / L, salinity 29.8 - 31.70 psu, phosphate 0.013 - 0.09 mg / L, nitrate 0,0009 - 0,5 mg / L, bathymetry 2.3 - 30 m. The fishing ground of crab is in grid B, C and D. On-grid B there are grids B1, B3, and B4. Then on-grid C there is on grid C3 and C4. On-grid D on the D6 grid. The results of the analysis of the correlation matrix of aquatic biophysical parameters show that the variance in the main components of the five main axes is 85.7%. Thus, the four main components can explain 85.7% of all information available on all parameters. The parameters that have the highest contribution are salinity, TSS, DO, brightness, nitrate, and sediment. The highest contribution indicates the influence of these parameters on the presence of crabs in the waters of Lancang Island and its surroundings.
Analysis of Production and Business Income of Gouramy (Osphronemus gouramy) Hatchery in Fifty Cities District West Sumatra Province
Authors: Hendrik  , Darwis A.N , Safputri M. A. 
Published: April 2021

Abstract
The research was carried out in Lima Puluh kota, West Sumatra Province, during March 2018. The purpose of this study was to analyze the efficiency use level of production factors, gouramy hatchery business farmer income, analysis of the BEP value of revenue, production and prices. The method used in this study was a survey method with a total sample of 36 farmers from a total of 126 farmers. Taking respondents using statified random sampling. Data analysis uses VPM / MFC ratio analysis, income analysis, and BEP analysis. The results showed that the use of urea fertilizer and feed production factors had exceeded the optimal conditions (efficiency value <1), while the production factors of the number of mother fish, manure, lime and labor were not optimal (efficiency value> 1). The average income is IDR 80,293,650 per year. The average BEP value of IDR 17,204,069, BEP production 9,271 tails, and BEP price of IDR 491, - / tail.
Sediment Distribution Model at Mesjid River Estuary in The Rupat Strait, Riau Province, Indonesia
Authors: Rifardi  , Mubarak  , Elizal  , Nurhuda A 
Published: April 2021

AbstractThe sediment transport model showing the sediment derived from the Mesjid River will be distributed to the Rupat Strait with different dispersion distances and concentrations depend on the tidal current pattern. The highest concentration of suspended sediment (0.0001 kg/m3- 0.0013 kg/m3) can be found at a distance of 3.3 km from the Mesjid River Estuary toward the Rupat Strait. Meanwhile, at a distance of 3.5 km from the estuary, the concentration have returned to normal or there is no longer any sediment derived from the Mesjid River. However, at a distance of 2.8 km to 3.3 km, or at the coordinates 101,372 - 101,376 North Latitude and 1,744 to 1,750 East Longitude, sediment deposition occurs with concentrations ranging from 0.00027 kg/m3to 0.00035 kg/m. Based on satellite images taken on August 2, 2006 and satellite images on January 5, 2020, sedimentation in the area has resulted in accretion with an area of ± 30,454 m2.
Determination of optimum animal feed raw material order allocation
Authors: Wahyuni D , Sembiring M T , Budiman I , Utari T , Silaen C D N 
Published: April 2021

Abstract
The availability of raw materials is the key to the implementation of production activities so that suppliers, who are able to supply according to the needs of the company, are needed. If the material that comes is not according to the specifications requested, even though the supplier changes so that the amount of material is still fulfilled, it still causes disruption to the smooth production process. The aim of this study is to assess the supplier’s performance to optimize allocated raw material. This research was conducted at an animal feed factory. The raw materials used include yellow corn and rice bran, obtained from several suppliers. The raw material that comes in part is rejected because it is not in accordance with the requested specifications, among others due to excessive water content, mushroom content and the content of corn cobs that exceed the established limit. In this study, carried out a performance analysis of suppliers referring to 23 supplier assessment criteria by Dickson and used 6 selected criteria, namely quality, delivery, history of supplier performance, claim and guarantee policies, prices and communication systems. The optimal amount of raw material orders from the results of goal programming is allocated to each supplier based on their performance.