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A Comparative Study of Two Tree-Based Models for Predicting Flyrock Velocity at Open Pit Bench Mining

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Open Journal of Applied Sciences 2024年第2期14卷 267-287页

作者： Ezatullah Rawnaq Bassir Esmatyar Akihiro Hamanaka Takashi Sasaoka Hideki shimada Department of Earth Resources Engineering Kyushu University Fukuoka Japan Department of Mining and Mineral Engineering Suleyman Demirel University Isparta Türkiye

Blasting is a cost-effective technique to break hard rock volumes by using explosives in the mining and civil engineering realms. Moreover, although blasting is a designed process and plays an indispensable role in these industries, it can also have multiple adverse environmental impacts. One such effect is flyrock, which poses risks to nearby machinery, and residential structures, and can even lead to injuries or fatalities. To optimize blasting efficiency as well as restrict side effects, prediction of the blast aftereffects is vital. Therefore, the present work focuses on using two machine learning methods to predict the velocity of flyrock in the open pit mine. To address this issue, a comprehensive dataset was gathered from the open pit mine. Then, Decision Tree and Random Forest algorithms were employed to predict flyrock velocity. The Random Forest model demonstrated superior performance compared to the Decision Tree model. Nonetheless, the performance of the Decision Tree model was deemed satisfactory, as evidenced by its coefficient of determination value of 0.83, mean squared error (MSE) of 4.2, and mean absolute percentage error (MAPE) of 5.6%. Considering these metrics, it is reasonable to conclude that tree-based algorithms can be effective in predicting flyrock velocity.

关键词： Flyrock Machine Learning Bench Blasting Coefficient of Determination

The Fundamentals Underlying the Computations of Acceleration for General Dynamic Applications:Issues and Noteworthy Perspectives

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Computer Modeling in Engineering & Sciences 2015年第2期104卷 133-158页

作者： M.shimada A.Hoitink k.k.Tamma Department of Mechanical Engineering University of Minnesota111 Church St.SEMinneapolisMN55455USA.

To-date,with the exception of the Newmark method and the midpoint rule,most computational algorithms under the umbrella of LMS methods,which are predominantly employed in research and commercial software fail to properly evaluate acceleration computations accurately for conducting the numerical dynamic ***,this is not trivial and a sound theoretical basis of the fundamental underlying issues is described in *** this paper,we provide a resolution and point-out several noteworthy perspectives to address the proper evaluation of acceleration computations for structural dynamics applications with focus on the class of LMS methods as an illustration.

关键词： acceleration trivial illustration

Rational double points on Enriques surfaces

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Science China Mathematics 2021年第4期64卷 665-690页

作者： Ichiro shimada Department of Mathematics Graduate School of ScienceHiroshima UniversityHigashi-Hiroshima 739-8526Japan

We classify,up to some lattice-theoretic equivalence,all possible configurations of rational double points that can appear on a surface whose minimal resolution is a complex Enriques surface.

关键词： Enriques surface rational double points hyperbolic lattice

A Conceptual Design Study for the Error Field Correction Coil Power Supply in JT-60SA

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Plasma Science and Technology 2013年第3期15卷 257-260页

作者： M.MATSUkAWA k.shimada k.YAMAUCHI E.GAIO A.FERRO L.NOVELLO Japan Atomic Energy Agency 801-1 MukoyamaNakaIbaraki 311-0193Japan Consorzio RFX-EURATOM ENEA Association C.so Stati Uniti 435127 PadovaItaly Fusion for Energy Boltzmannstr 2 Garching 85748Germany

This paper describes a conceptual design study for the circuit configuration of the Error Field Correction Coil （EFCC） power supply （PS） to maximize the expected performance with reasonable cost in JT-60SA. The EFCC consists of eighteen sector coils installed inside the vacuum vessel, six in the toroidal direction and three in the poloidal direction, each one rated for 30 kA-turn. As a result, star point connection is proposed for each group of six EFCC coils installed cyclically in the toroidal direction for decoupling with poloidal field coils. In addition~ a six phase inverter which is capable of controlling each phase current was chosen as PS topology to ensure higher flexibility of operation with reasonable cost.

关键词： JT-60SA error field correction coil power supply inverter multi-phase

Dynkin diagrams of rank 20 on supersingular k3 surfaces

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Science China Mathematics 2015年第3期58卷 543-552页

作者： shimada Ichiro ZHANG De-Qi Department of Mathematics Graduate School of Science Hiroshima University Department of Mathematics National University of Singapore

We classify normal supersingular k 3 surfaces Y with total Milnor number 20 in characteristic p,where p is an odd prime that does not divide the discriminant of the Dynkin type of the rational double points on *** pap... 详细信息

关键词： supersingular k3 surface supersingular k3 surface normal k3 surface

Hand-holding and releasing between the anion and cation to change their macroscopic behavior in water

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Green Energy & Environment 2019年第2期4卷 127-130页

作者： kosuke kuroda Yumiko shimada kenji Takahashi Faculty of Biological Science and Technology Institute of Science and Engineering Kanazawa University

Despite the similarity of ionic liquid and zwitterion, their some properties such as conductivity and hydrophobicity are different. Here we developed a novel phosphonium salt having a dynamic covalent bond between anion and cation, enabling reversible structural shift between free ion pair and zwitterion. With the phosphonium salt, control of the macroscopic phase behavior in aqueous solution, i.e. forming mono-or biphasic systems, upon exposure to an acid or base was reversibly achieved, based on the structural shift of the phosphonium salt. CO_2/N_2 bubbling reversibly changed the phase behavior as well as acid/base, leading to green separation systems.

关键词： Ionic liquid Zwitterion Phase separation Dynamic covalent bond

A Fine-Grained Runtime Power/Performance Optimization Method for Processors with Adaptive Pipeline Depth

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Journal of Computer Science & Technology 2011年第2期26卷 292-301页

作者：姚骏 Shinobu Miwa Hajime shimada Shinji Tomita Graduate School of Information Science Nara Institute of Science and Technology School of Engineering Tokyo University of Agriculture and Technology Graduate School of Informatics Kyoto University Institute for Integrated Cell-Material Sciences Kyoto University

Recently, a method known as pipeline stage unification （PSU） has been proposed to alleviate the increasing energy consumption problem in modern microprocessors. PSU achieves a high energy efficiency by employing a changeable pipeline depth and its working scheme is eligible for a fine control method. In this paper, we propose a dynamic method to study fine-grained program interval behaviors based on some easy-to-get runtime processor metrics. Using this method to determine the proper PSU configurations during the program execution, we are able to achieve an averaged 13.5% energydelay-product （EDP） reduction for SPEC CPU2000 integer benchmarks, compared to the baseline processor. This value is only 0.14% larger than the theoretically idealized controlling. Our hardware synthesis result indicates that the proposed method can largely decrease the hardware overhead in both area and delay costs, as compared to a previous program study method which is based on working set signatures.

关键词： dynamic optimization energy saving fine-grained pipeline stage unification workload analysis

Selective excitation of two-wave structure depending on crystal orientation under shock compression

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Science China(Physics,Mechanics & Astronomy) 2020年第11期63卷 59-71页

作者： QiLin Xiong Takahiro shimada Takayuki kitamura ZhenHuan Li Department of Mechanics Huazhong University of Science&TechnologyWuhan 430074China Hubei key Laboratory of Engineering Structural Analysis and Safety Assessment Wuhan 430074China Department of Mechanical Engineering and Science Kyoto UniversityKyoto 615-8540Japan

Single crystals subjected to shock compression exhibit responses with distinct two-wave structures for certain crystal ***,little is known to date regarding how the shock response depends on crystal orientation,and especially why the two-wave structure depends on the crystal *** this work,molecular dynamics simulations of shock compressions in copper single crystals are performed to investigate the orientation dependence of shock responses and the corresponding deformation *** copper single crystals with[001],[011],[012],and[123]crystal orientations along the depth direction are ***[011],[012],and[123]crystal orientations of copper single crystals show distinct two-wave structures in their shock responses,while such a two-wave structure in the shock response is not seen for those orientations having a[001]crystal *** potential causes are analyzed by considering the propagation velocities of both elastic and plastic *** develop a technique for identifying twin structures in face-centered cubic crystals and this technique can effectively identify the twin *** morphology of shock-induced defects(e.g.,dislocations and twins)shows the significant dependence of crystal orientation and the mechanisms behind these are discussed in ***,the Johnson-Cook constitutive model describing dynamic deformations at high temperatures and high strain rates is used to analyze the relationships between the shock responses and microscopic *** predictions of the Johnson-Cook constitutive model are consistent with the results of the molecular dynamics simulations.

关键词： orientation-dependent two-wave structure shock compression copper molecular dynamics

Model Analysis of Radar Echo Split Observed in an Artificial Cloud Seeding Experiment

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Journal of Meteorological Research 2016年第3期30卷 386-400页

作者： MASAkI shimada kIkURO Tomine kOJI Nishiyama Department of Earth and Ocean Sciences National Defense Academy Faculty of Engineering Kyushu University

An artificial cloud seeding experiment was performed over the Japan Sea in winter to show how massive seeding could be effective to mitigate heavy snowfall *** results showed that 20 min after cloud seeding,a portion of the radar echo beneath the seeding track was weakened to divide the radar echo into two *** order to analyze the results,a numerical simulation was conducted by using the Weather Research and Forecasting model verion *** this simulation,the seeding effects were represented as phenomena capable of changing rain particles by accreting cloud ice and snow to form graupel particles and by changing cloud liquid water to snow *** graupel particles fell rapidly,thus temporarily intensifying the rainfall,which subsequently ***,the weakened radar echo in the field experiment is deemed to have been caused by the increase in rapidly falling graupel particles.

关键词： heavy snowfall artificial cloud seeding numerical experiment