87 research outputs found

    Mitigating supply chain uncertainty and risk through logistics innovation capability

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    This paper aims to develop a framework for mitigating supply chain uncertainty and risk by adopting logistics innovation capability. Due to the increased globalised supply chain operations, logistics and transport industries now face more supply chain uncertainties and risks than ever. Managing these supply chain uncertainties and risks is a priority task to logistics and transport managers. Based on resource based review, logistics innovation capability provides valuable insight into mitigating supply chain uncertainty and risk. This paper focuses on the relationship between logistics innovation capability and supply chain uncertainty and risk. This would illustrate the potential solutions for mitigating supply chain uncertainty and risk systematically. In addition to make a contribution for development supply chain uncertainty and risk management strategy

    Lazada's last mile: Where no e-commerce company in Vietnam had gone before

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    Aim/Purpose: This case study examines the last-mile logistics model as implemented by Lazada Vietnam, as well as the logistics challenges in the local business environment that led the e-commerce company to dually employ the inventory/retail model and the marketplace model for delivering orders to online customers in Vietnam in search of the way to perfect their last-mile logistics. Background: For electronic commerce companies aiming to be successful in customer service, what academics and practitioners refer to as 'last-mile logistics' is the one moment of truth, when deliveries have to be planned tactically and exactly, so that orders are delivered to customers at the right time, right place, right quantity, right quality, and ultimately at the right cost. When deciphering this type of supply chain, i.e., one that is e-commerce- driven, last-mile logistics is the one segment of the product flow that directly interacts with the ultimate customer, but many times is the one segment that is the most problematic and less efficient to implement well. Lazada Group, a German e-commerce company, discovered the serious complications of 'last-mile logistics' when they first entered Vietnam in 2013

    ProtoDESI: First On-Sky Technology Demonstration for the Dark Energy Spectroscopic Instrument

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    The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the universe using the baryon acoustic oscillations technique. The spectra of 35 million galaxies and quasars over 14,000 square degrees will be measured during a 5-year survey. A new prime focus corrector for the Mayall telescope at Kitt Peak National Observatory will deliver light to 5,000 individually targeted fiber-fed robotic positioners. The fibers in turn feed ten broadband multi-object spectrographs. We describe the ProtoDESI experiment, that was installed and commissioned on the 4-m Mayall telescope from August 14 to September 30, 2016. ProtoDESI was an on-sky technology demonstration with the goal to reduce technical risks associated with aligning optical fibers with targets using robotic fiber positioners and maintaining the stability required to operate DESI. The ProtoDESI prime focus instrument, consisting of three fiber positioners, illuminated fiducials, and a guide camera, was installed behind the existing Mosaic corrector on the Mayall telescope. A Fiber View Camera was mounted in the Cassegrain cage of the telescope and provided feedback metrology for positioning the fibers. ProtoDESI also provided a platform for early integration of hardware with the DESI Instrument Control System that controls the subsystems, provides communication with the Telescope Control System, and collects instrument telemetry data. Lacking a spectrograph, ProtoDESI monitored the output of the fibers using a Fiber Photometry Camera mounted on the prime focus instrument. ProtoDESI was successful in acquiring targets with the robotically positioned fibers and demonstrated that the DESI guiding requirements can be met.Comment: Accepted versio

    Preparation and characterization of carbon nanofluid by a plasma arc nanoparticles synthesis system

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    Heat dissipation from electrical appliances is a significant issue with contemporary electrical devices. One factor in the improvement of heat dissipation is the heat transfer performance of the working fluid. In this study, we used plasma arc technology to produce a nanofluid of carbon nanoparticles dispersed in distilled water. In a one-step synthesis, carbon was simultaneously heated and vaporized in the chamber, the carbon vapor and particles were then carried to a collector, where cooling furnished the desired carbon/water nanofluid. The particle size and shape were determined using the light-scattering size analyzer, SEM, and TEM. Crystal morphology was examined by XRD. Finally, the characterization include thermal conductivity, viscosity, density and electric conductivity were evaluated by suitable instruments under different temperatures. The thermal conductivity of carbon/water nanofluid increased by about 25% at 50°C compared to distilled water. The experimental results demonstrated excellent thermal conductivity and feasibility for manufacturing of carbon/water nanofluids

    Experimental and theoretical studies of nanofluid thermal conductivity enhancement: a review

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    Nanofluids, i.e., well-dispersed (metallic) nanoparticles at low- volume fractions in liquids, may enhance the mixture's thermal conductivity, knf, over the base-fluid values. Thus, they are potentially useful for advanced cooling of micro-systems. Focusing mainly on dilute suspensions of well-dispersed spherical nanoparticles in water or ethylene glycol, recent experimental observations, associated measurement techniques, and new theories as well as useful correlations have been reviewed

    Quais as principais características organizacionais das empresas dos diferentes segmentos da construção civil?

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    Resumo Neste artigo os autores se propõem a identificar os fatores que definem as principais características organizacionais de empresas do subsetor da construção civil, localizadas em Curitiba e região metropolitana, assim como verificar as diferenças existentes entre os cinco segmentos de atividade mais relevantes desse mercado: residencial, industrial e comercial, infraestrutura, serviços especializados e construção industrializada. Para tanto, foi desenvolvida uma pesquisa exploratória e de natureza quantitativa, em nível de mestrado. O método survey foi escolhido como procedimento principal para este estudo, permitindo a obtenção de dados primários por meio da aplicação de um questionário em um grupo de 118 empresas. Esse questionário procurou identificar o perfil da organização e as características organizacionais das empresas avaliadas. Os dados foram analisados com a aplicação de técnicas multivariadas de análise fatorial e análise discriminante. A análise fatorial evidenciou as estratégias de melhoria, o comportamento do indivíduo no trabalho, a estrutura de funcionamento, a dinâmica de crescimento, o estilo de gestão, as relações interpessoais e o posicionamento da empresa perante o mercado como fatores determinantes. A análise discriminante apontou significativa homogeneidade no desenvolvimento organizacional das empresas que representam os diferentes segmentos de atividade

    Overview of the DESI Legacy Imaging Surveys

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    The DESI Legacy Imaging Surveys (http://legacysurvey.org/) are a combination of three public projects (the Dark Energy Camera Legacy Survey, the Beijing–Arizona Sky Survey, and the Mayall z-band Legacy Survey) that will jointly image ≈14,000 deg2 of the extragalactic sky visible from the northern hemisphere in three optical bands (g, r, and z) using telescopes at the Kitt Peak National Observatory and the Cerro Tololo Inter-American Observatory. The combined survey footprint is split into two contiguous areas by the Galactic plane. The optical imaging is conducted using a unique strategy of dynamically adjusting the exposure times and pointing selection during observing that results in a survey of nearly uniform depth. In addition to calibrated images, the project is delivering a catalog, constructed by using a probabilistic inference-based approach to estimate source shapes and brightnesses. The catalog includes photometry from the grz optical bands and from four mid-infrared bands (at 3.4, 4.6, 12, and 22 μm) observed by the Wide-field Infrared Survey Explorer satellite during its full operational lifetime. The project plans two public data releases each year. All the software used to generate the catalogs is also released with the data. This paper provides an overview of the Legacy Surveys project

    Overview of the instrumentation for the Dark Energy Spectroscopic Instrument

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    The Dark Energy Spectroscopic Instrument (DESI) embarked on an ambitious 5 yr survey in 2021 May to explore the nature of dark energy with spectroscopic measurements of 40 million galaxies and quasars. DESI will determine precise redshifts and employ the baryon acoustic oscillation method to measure distances from the nearby universe to beyond redshift z > 3.5, and employ redshift space distortions to measure the growth of structure and probe potential modifications to general relativity. We describe the significant instrumentation we developed to conduct the DESI survey. This includes: a wide-field, 3.°2 diameter prime-focus corrector; a focal plane system with 5020 fiber positioners on the 0.812 m diameter, aspheric focal surface; 10 continuous, high-efficiency fiber cable bundles that connect the focal plane to the spectrographs; and 10 identical spectrographs. Each spectrograph employs a pair of dichroics to split the light into three channels that together record the light from 360–980 nm with a spectral resolution that ranges from 2000–5000. We describe the science requirements, their connection to the technical requirements, the management of the project, and interfaces between subsystems. DESI was installed at the 4 m Mayall Telescope at Kitt Peak National Observatory and has achieved all of its performance goals. Some performance highlights include an rms positioner accuracy of better than 0.″1 and a median signal-to-noise ratio of 7 of the [O ii] doublet at 8 × 10−17 erg s−1 cm−2 in 1000 s for galaxies at z = 1.4–1.6. We conclude with additional highlights from the on-sky validation and commissioning, key successes, and lessons learned

    Improving logistics performance for One Belt One Road: A conceptual framework for Supply Chain Risk Management in Chinese third party logistics providers

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    Chinese government recently launched one belt one road to reform and speed up the development of Chinese economic in the world. One Belt One Road (OBOR) strategy heavily relied on the traditional logistical trade routes including terrestrial and oceanic Silk Road. Logistics performance may play a vital role for implementing the One Belt One Road plan. Especially, third party logistics providers as supporting members to carry out value-adding supply chain activities in one belt one road. According to literature review, supply chain risk is an issue to obstruct the development of logistics performance. The purpose of this paper is to present a conceptual framework for managing supply chain risks and improving logistics performance under the OBOR initiative in Chinese third party logistics service providers. There are very few studies on risk management in the OBOR initiative. We focus on the innovation, customer response and flexibility in the third-party logistics providers. This would provide a guide for both academics and practitioners to manage supply chain risks and improve logistics performance and enlighten them to pay attention to supply chain risk management in the Chinese third party logistics sector. In addition, this contributes to the supply chain and logistics management in One Belt One Road literature
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