• Title/Summary/Keyword: short-range ordering

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Exploratory Study on the Efficient Operation of Parcel Delivery Network with the Growth of Online Shopping Industries (온라인 쇼핑의 성장에 따른 택배물류 네트워크의 효율적 운영에 관한 탐색적 연구)

  • Lim, Hyunwoo;Lim, Jong Won;Yi, Hansuk
    • Asia Marketing Journal
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    • v.9 no.2
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    • pp.97-129
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    • 2007
  • The critical link between consumer-based internet ordering and the delivery of the product to the consumer is a key success factor in online shopping. Market areas of online shopping company implies the range of space where products ordered from online shopping can be physically delivered to customers distributed over space with reasonable shipping cost and lead time through the physical distribution network. The average rate of growth in online shopping is 36% per year in Korea for the last 5 years. But there are no maps available that describe sales/delivery density of online shopping, few researches are focused on the short-term/long-term adaptation to demand increase by online shopping. In this paper (1) Maps of trade area are described indicating the sales/delivery density around the nation. (2) Empirical researches suggested that short-term adaptation to demand increase resulted in price reduction and service in enhancement of service quality in local transportation. But the long-term adaptation on the parts of parcel delivery industry are to be investigated in future researches.

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Spatial Distributions of Alloying Elements Obtained from Atom Probe Tomography of the Amorphous Ribbon Fe75C11Si2B8Cr4

  • Shin, Jinkyung;Yi, Seonghoon;Pradeep, Konda Gokuldoss;Choi, Pyuck-Pa;Raabe, Dierk
    • Korean Journal of Materials Research
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    • v.23 no.3
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    • pp.190-193
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    • 2013
  • Spatial distributions of alloying elements of an Fe-based amorphous ribbon with a nominal composition of $Fe_{75}C_{11}Si_2B_8Cr_4$ were analyzed through the atom probe tomography method. The amorphous ribbon was prepared through the melt spinning method. The macroscopic amorphous natures were confirmed using an X-ray diffractometer (XRD) and a differential scanning calorimeter (DSC). Atom Probe (Cameca LEAP 3000X HR) analyses were carried out in pulsed voltage mode at a specimen base temperature of about 60 K, a pulse to base voltage ratio of 15 %, and a pulse frequency of 200 kHz. The target detection rate was set to 5 ions per 1000 pulses. Based on a statistical analyses of the data obtained from the volume of $59{\times}59{\times}33nm^3$, homogeneous distributions of alloying elements in nano-scales were concluded. Even with high carbon and strong carbide forming element contents, nano-scale segregation zones of alloying elements were not detected within the Fe-based amorphous ribbon. However, the existence of small sub-nanometer scale clusters due to short range ordering cannot be completely excluded.

Effect of cold working on the thermal expansion and mechanical properties of Fe-29%-Ni-17%Co low thermal expansion alloy (Fe-29%Ni-17%Co 저열팽창성 합금의 기계적 및 열팽창 특성에 미치는 냉간 가공의 영향)

  • Lee, Kee-Ahn;Kim, Song-Yi;NamKung, Jung;Kim, Mun-Chul
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.355-356
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    • 2009
  • The change of thermal expansion and mechanical behaviors by cold working has been investigated in Fe-29%Ni-17%Co low thermal expansion Kovar alloy. Fe-29%Ni-17%Co alloy was cold rolled gradually and prepared to plates having reduction ratio of 0%, 20%, 40%, 60%, and 80%. Annealing effect on the properties was also studied. Thermal expansion was measured from $25^{\circ}C$ to $600^{\circ}C$ with a heating rate of $5^{\circ}C$/min by using vacuum differential dilatometer. It was found that thermal expansion coefficient ($\alpha_{30{\sim}400}$) slightly decreased (reduction ration of 20%) and then remarkably increased (above reduction ration of 40%) with increasing reduction ratio of cold rolling. Thermal expansion coefficient ($\alpha_{30{\sim}400}$) was sharply decreased after annealing heat-treatment. Yield and tensile strengths were continuously increased and elongation was decreased by cold roiling. Microstructural observation and X-ray diffraction analysis results showed that the $\alpha$ phase significantly increased as the reduction ratio increased. The slight decrease of thermal expansion coefficient bellow reduction ration of 20% could be explained by the destroying short-range ordering and the decreasing of grain size. The significant increase of thermal expansion coefficient with cold rolling mainly attributed to the appearance of $\alpha$ phase. The correlation between the microstructural cause and invar phenomena for the low thermal expansion behavior was also discussed.

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