191 research outputs found

    A neural networks-based in-process adaptive surface roughness control (NN-IASRC) system in end-milling operations

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    In this research, the neural networks-based in-process adaptive surface roughness control (NN-IASRC) system employing multiple cutting tools was successfully developed for end-milling operations. The dynamometer sensor was used to monitor the uncontrolled cutting tool conditions to increase the accuracy of the surface roughness control. An empirical approach was applied to discover the proper cutting force signals, the average resultant peak force in XY plane ( Fap) and the absolute average force in the Z direction (Faz). These two forces were employed to represent the uncontrollable cutting tool conditions for surface roughness control. A statistical method was employed to verify that the cutting tools could influence the surface roughness, and obtain the correlation between surface roughness and the cutting force signals for the preparation of constructing the NN-IASRC system.;A neural networks theorem was successfully applied to build the NN-IASRC system. The neural networks associated with sensing technology were applied as a decision-making technique to control the surface roughness for a wide range of machining parameters. The NN-IASRC system consisted of two subsystems. One was the in-process neural networks based surface roughness prediction (INN-SRP) system, which was employed to predict the surface roughness. The other was the neural networks based adaptive machining parameters control (NN-APMC) system, which was utilized to adjust the adaptive degree of feed rate when the quality of predicted surface roughness did not fit the desired one. The accuracy of the INN-SRP system was 93%, and 100% for the NN-IASRC system. The high accuracy of results within a wide range of machining parameters indicates that the system can be practically applied in industry

    USULAN STRATEGI PERUSAHAAN MANUFAKTUR SEPEDA MELALUI IMPLEMENTASI QUANTITATIVE STRATEGIC PLANNING MATRIX

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    Brand competition in the children's bicycle industry at this time is increasingly fierce. PT X Manufacturing (PT X), which produces tricycles for children, has experienced a decline in sales and has not reached its sales target for the past three years. This study proposes strategies regarding brand awareness, perceivedquality, and internal and the company's external environment. These can be the company's strengths, weaknesses, opportunities, and threats. The hybrid method used in this study consists of the EFE matrix, IFE matrix, IE matrix, SWOT matrix, and QSPM. Data collection techniques used interviews, observations,and questionnaires. The results showed that PT X was located in the V-quadrant in the IE matrix. A suitable strategy was a hold and maintain strategy consisting of market penetration and product development strategies. Seven alternative strategies were formed through the SWOT matrix, and priority strategies weredetermined using the QSPM method. The priority strategy was utilizing online media to increase marketing and public awareness of product brands. This strategy was chosen as a priority because it has the highest value of 5.936

    Evaluasi Aktivitas LST Pada Institusi Pendidikan Tinggi Berdasarkan Persepsi Mahasiswa

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    Institusi pendidikan tinggi perlu berperan aktif dalam isu keberlanjutan untuk mencapai Tujuan Pembangunan Berkelanjutan (TPB). Studi ini bertujuan untuk mengetahui persepsi mahasiswa terhadap kegiatan universitas terkait LST. Penelitian ini dilakukan pada sebuah universitas swasta di Indonesia yang telah melaksanakan berbagai aktivitas terkait isu lingkungan, sosial dan tata kelola (LST) untuk mendukung pencapaian TPB. Hal ini telah dibuktikan dengan terbitnya Laporan Keberlanjutan dan partisipasi universitas tersebut dalam UI GreenMetrics. Metode yang diterapkan adalah penyebaran kuesioner kepada responden mahasiswa, dan mahasiswa memberikan respon pada skala Likert 1-5. Hasil menunjukkan bahwa bidang sosial dan tata kelola mendapatkan persepsi baik dari mahasiswa dengan skor persepsi 4, sedangkan bidang lingkungan mendapat skor kurang dari 4. Pendalaman lebih lanjut menunjukkan bahwa universitas masih perlu melakukan perbaikan atas kegiatan penghematan energi, pengelolaan bangunan dan promosi transportasi ramah lingkungan. Hasil studi ini dapat dipakai oleh universitas untuk meningkatkan aspek-aspek yang masih kurang dan mempertahankan aktivitas yang telah baik dari persepsi mahasiswa

    Search for High-Mass Resonances Decaying to τν in pp Collisions at √s=13 TeV with the ATLAS Detector

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    A search for high-mass resonances decaying to τν using proton-proton collisions at √s=13 TeV produced by the Large Hadron Collider is presented. Only τ-lepton decays with hadrons in the final state are considered. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 36.1 fb−1. No statistically significant excess above the standard model expectation is observed; model-independent upper limits are set on the visible τν production cross section. Heavy W′ bosons with masses less than 3.7 TeV in the sequential standard model and masses less than 2.2–3.8 TeV depending on the coupling in the nonuniversal G(221) model are excluded at the 95% credibility level

    Search for the direct production of charginos and neutralinos in final states with tau leptons in √s=13 TeV collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with at least two hadronically decaying tau leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of 36.1 fb−1, recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13TeV.Nosignificant deviation from the expected Standard Model background is observed. Limits are derived in scenarios of ˜χ+1 ˜χ−1 pair production and of ˜χ±1 ˜χ02 and ˜χ+1 ˜χ−1 production in simplified models where the neutralinos and charginos decay solely via intermediate left-handed staus and tau sneutrinos, and the mass of the ˜ τL state is set to be halfway between the masses of the ˜χ±1 and the ˜χ01. Chargino masses up to 630 GeV are excluded at 95% confidence level in the scenario of direct production of ˜χ+1 ˜χ−1 for a massless ˜χ01. Common ˜χ±1 and ˜χ02 masses up to 760 GeV are excluded in the case of production of ˜χ±1 ˜χ02 and ˜χ+1 ˜χ−1 assuming a massless ˜χ01. Exclusion limits for additional benchmark scenarios with large and small mass-splitting between the ˜χ±1 and the ˜χ01 are also studied by varying the ˜ τL mass between the masses of the ˜χ±1 and the ˜χ01

    Measurement of differential cross sections and W + /W − cross-section ratios for W boson production in association with jets at √s =8 TeV with the ATLAS detector

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    This paper presents a measurement of the W boson production cross section and the W + /W − cross-section ratio, both in association with jets, in proton--proton collisions at s √ =8 TeV with the ATLAS experiment at the Large Hadron Collider. The measurement is performed in final states containing one electron and missing transverse momentum using data corresponding to an integrated luminosity of 20.2 fb −1 . Differential cross sections for events with one or two jets are presented for a range of observables, including jet transverse momenta and rapidities, the scalar sum of transverse momenta of the visible particles and the missing transverse momentum in the event, and the transverse momentum of the W boson. For a subset of the observables, the differential cross sections of positively and negatively charged W bosons are measured separately. In the cross-section ratio of W + /W − the dominant systematic uncertainties cancel out, improving the measurement precision by up to a factor of nine. The observables and ratios selected for this paper provide valuable input for the up quark, down quark, and gluon parton distribution functions of the proto

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
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