• Title/Summary/Keyword: E Field Distribution

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A Study on Restructuring of the Marine Products Value Chain and the Development of E-commerce Trading Systems in the Ubiquitous Environment (유비쿼터스 환경에서의 해양수산물 유통 가치사슬 혁신 및 전자상거래 시스템 구축에 관한 연구)

  • Pak, Myong-Sop;Kim, Jong-Uk;Lee, Won-Jun;Park, Sang-Cheol
    • Journal of Information Technology Services
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    • v.5 no.2
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    • pp.125-136
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    • 2006
  • In general, the distribution structure of marine products is very vulnerable to the uncertainties in the process from the production to the sale, and a lot of difficulty is thus inevitable in the supply control. Such a distribution structure is a very critical issue in securing the suability of marine products through systematic quality and hygiene control of marine products, and it is thus time to discuss the method to innovate and restructuring the distribution structure of marine products. From this point of view, this study approached the flow from production to consumption in view of SCM(supply chain management) beyond the partial discussion conducted so far for the distribution structure in the field of marine products. Further, this study suggested the establishment of electronic commerce systems with a traceability system built in RFID for marine products as an alternative of redesigning distribution infrastructure in the ubiquitous environment. From the results, we assured that such an electronic commerce system would be a new measure to improve the structure currently causing inefficiency and excessive distribution cost for the distribution structure of marine products.

Analysis and probabilistic modeling of wind characteristics of an arch bridge using structural health monitoring data during typhoons

  • Ye, X.W.;Xi, P.S.;Su, Y.H.;Chen, B.
    • Structural Engineering and Mechanics
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    • v.63 no.6
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    • pp.809-824
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    • 2017
  • The accurate evaluation of wind characteristics and wind-induced structural responses during a typhoon is of significant importance for bridge design and safety assessment. This paper presents an expectation maximization (EM) algorithm-based angular-linear approach for probabilistic modeling of field-measured wind characteristics. The proposed method has been applied to model the wind speed and direction data during typhoons recorded by the structural health monitoring (SHM) system instrumented on the arch Jiubao Bridge located in Hangzhou, China. In the summer of 2015, three typhoons, i.e., Typhoon Chan-hom, Typhoon Soudelor and Typhoon Goni, made landfall in the east of China and then struck the Jiubao Bridge. By analyzing the wind monitoring data such as the wind speed and direction measured by three anemometers during typhoons, the wind characteristics during typhoons are derived, including the average wind speed and direction, turbulence intensity, gust factor, turbulence integral scale, and power spectral density (PSD). An EM algorithm-based angular-linear modeling approach is proposed for modeling the joint distribution of the wind speed and direction. For the marginal distribution of the wind speed, the finite mixture of two-parameter Weibull distribution is employed, and the finite mixture of von Mises distribution is used to represent the wind direction. The parameters of each distribution model are estimated by use of the EM algorithm, and the optimal model is determined by the values of $R^2$ statistic and the Akaike's information criterion (AIC). The results indicate that the stochastic properties of the wind field around the bridge site during typhoons are effectively characterized by the proposed EM algorithm-based angular-linear modeling approach. The formulated joint distribution of the wind speed and direction can serve as a solid foundation for the purpose of accurately evaluating the typhoon-induced fatigue damage of long-span bridges.

Linear Instability and Saturation Characteristics of Magnetosonic Waves along the Magnetic Field Line

  • Min, Kyungguk;Liu, Kaijun
    • Journal of Astronomy and Space Sciences
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    • v.37 no.2
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    • pp.85-94
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    • 2020
  • Equatorial noise, also known magnetosonic waves (MSWs), are one of the frequently observed plasma waves in Earth's inner magnetosphere. Observations have shown that wave amplitudes maximize at the magnetic equator with a narrow extent in their latitudinal distribution. It has been understood that waves are generated from an equatorial source region and confined within a few degrees magnetic latitude. The present study investigates whether the MSW instability and saturation amplitudes maximize at the equator, given an energetic proton ring-like distribution derived from an observed wave event, and using linear instability analysis and particle-in-cell simulations with the plasma conditions at different latitudes along the dipole magnetic field line. The results show that waves initially grow fastest (i.e., with the largest growth rate) at high latitude (20°-25°), but consistent with observations, their saturation amplitudes maximize within ±10° latitude. On the other hand, the slope of the saturation amplitudes versus latitude revealed in the present study is not as steep as what the previous statistical observation results suggest. This may be indicative of some other factors not considered in the present analyses at play, such as background magnetic field and plasma inhomogeneities and the propagation effect.

Analysis of the stress disribution around flaws and the interaction effects between fatigue cracks by finite element method (유한요소법에 의한 결함 주위의 응력분포와 피로크랙의 간섭효과)

  • Song, S.H.;Kim, J.B.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.2
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    • pp.154-161
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    • 1995
  • In order to analysis of the stress distribution around flaws and the interaction effects between fatigue cracks, stress around micro hole was analyzed by Finite Element Method(F.E.M.) and micro hole specimens were tested using rotary bending fatigue machine and twisting fatigue machine to identify stress effects for fatigue cracks initiating from micro holes and interaction effects between micro holes. The results are as follows : Interaction effects of .sigma. $_{y}$for the micro hole side is larger than the large micro hole side when the interval between micro holes is near. Stress concentration factor increase as the diameter of micro hole becomes smaller. But, stress field of micro hole is smaller than that of large micro hole at h .leq. r (h:depth of micro hole, r:radius of micro hole) and that of large hole is larger than that of small micro hole at h >r expect the small range from micro hole.e.

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The Trapped Field Decay of YBCO Superconductor Composite with Times (시간 경과에 따른 YBCO 초전도 복합체의 포획 자기장 감쇄)

  • Lee, M.S.;Jang, G.E.;Jun, B.H.;Ha, D.W.;Son, M.H.;Han, Y.H.;Park, B.J.
    • Progress in Superconductivity
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    • v.12 no.2
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    • pp.82-87
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    • 2011
  • We studied the trapped field properties of bulk Y-Ba-Cu-O superconductors by applying 3 T of the permanent or $Nb_3Ti$ superconducting magnet. The 28 mm circular type of YBCO bulk superconductor was prepared and then hole at the center of bulk, parallel to the c-axis, was mechanically drilled. Typical size of hole in YBCO bulk was 10 mm in diameter. In order to examine the trapped field variation in terms of different impregnated materials, a hole in YBCO bulk was filled with resin and indium respectively. The trapped field decay due to flux flow was determined in terms of time. Our preliminary result indicates the trapped field value measured on the YBCO without hole after 30 minute by applying 3 T, was 6,500 G, which is much higher than that, 4,500 G, measured on YBCO with hole. Also, we confirmed that the tendency of a trapped field decrement with time was almost the same regardless of the impregnated materials in YBCO.

Uncertainty Avoidance, Individualism and the Readiness of Business-to-Consumer E-commerce

  • XU, Jun;CHENG, Chen
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.791-801
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    • 2021
  • This study aims to test whether and to what extend national culture affects the readiness of business-to-consumer (B2C) e-commerce across the world. We regress two sets of data at national level: (1) the ratings of two main dimensions of Hofstede's national culture framework, uncertainty avoidance and individualism, and (2) UTCTAD B2C e-commerce index value. A sample of 83 countries was tested in this study. Several control variables at national level are included in our regression model. We find that these two cultural dimensions have an effect on the readiness of B2C e-commerce in various ways. We find that countries with high individualism score have high index value of B2C e-commerce development. We discuss the implications of these findings for B2C e-commerce developing strategies. We then call for designing relative policies with full consideration on national culture to promote the development of B2C e-commerce. In addition, we identify the limitations of the study and propose recommendations for future research. This study is the first one to use UNCTAD data on B2C e-commerce to explore the relationships between two dimensions of Hofstede's national culture and the readiness of B2C e-commerce and adds to the knowledge of literature in this research field.

IRAS OBSERVATIONS OF DARK GLOBULES

  • Lee, H.M.;Hong, S.S.;Kwon, S.M.
    • Journal of The Korean Astronomical Society
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    • v.24 no.1
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    • pp.55-70
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    • 1991
  • Infrared emission maps are constructed at 12.5, 25, 60, and $100{\mu}m$ for dark globules B5, B34, B133, B134, B361, L134 and L1523 by using Infrared Astronomical Satellite data base. These clouds are selected on the basis of their appearance in Palomar print as dark obscuring objects with angular sizes in the range of 3 to 30 arcminutes. The short wavelength(12.5 and $25{\mu}m$) maps show the embedded infrared sources. We found many such sources only in B5, B361 and B34 regions, Diffuse component at 12.5 and $25{\mu}m$, possibly arising from the stochastically heated very small dust grains(a < $0.01{\mu}m$) by interstellar radiation field, is found in B361 and L1523 regions. Such emission is characterized by the limb brightening, and it is confirmed in L1523 and in B361. Infrared emissions at the long wavelengths(60 and $100{\mu}m$) are due to colder dusts with temperature less than 20 K. The distribution of color index determined by the ratio 60 to $100{\mu}m$ intensities shows monotonic decrease of dust temperature toward the center. The black body temperature determined from these ratios is found to lie between 16 and 23 K. Such temperature is possible for small(i.e., $a\;{\lesssim}\;0.01{\mu}m$) graphite grains if the grains are mainly heated by interstellar radiation field. Thus IRAS 100 and $60{\mu}m$ emissions are arising mainly from small grains in the colud. The distribution of such dust grains implied from the emissivity distributions at 100 and $60{\mu}m$ resembles that of isothermal sphere. This contrasts to earlier findings of much steeper distribution of dusts contributing visible extinction. These dust grains are mainly larger ones(i.e., $a{\simeq}0.1{\mu}m$). Therefore we conclude that the average grain size increase, toward the cloud center.

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Electric field distribution and discharge characteristics in accordance with various ITO electrode structures in AC-PDP

  • Cho, Seok-H.;Oh, P.Y.;Kim, J.H.;Hong, Y.J.;Kwon, G.C.;Cho, G.S.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.396-399
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    • 2008
  • In this study, the electric field distributions have been investigated by simulation in accordance with the various shapes of ITO-electrodes. Also we have measured the density of excited Xe atoms in the 1s5 state in discharge cell, where the gap distance of 60 um, gas pressure of 400 Torr, Xe contents of 7%, and sustaining voltage of 200 V are kept in this experiment. The maximum density of excited Xe atoms in the 1s5 state in a discharge cell for the fish-boned, T shaped and squared ITO electrodes have been measured to be $3.01\;{\times}\;10^{13}\;cm^{-3}$, $2.66\;{\times}\;10^{13}\;cm^{-3}$ and $2.06\;{\times}\;10^{13}\;cm^{-3}$, respectively. It is shown that the electric field distribution with different ITO Electrodes is essential factor for these maximum density of excited Xe atoms in discharge cell.

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Calculation and field measurement of earth pressure in shield tunnels under the action of composite foundation

  • Chi Zhang;Shi-ju Ma;Yuan-cheng Guo;Ming-yu Li;Babak Safaei
    • Geomechanics and Engineering
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    • v.34 no.1
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    • pp.17-27
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    • 2023
  • Taking a subway shield tunnel in a certain section of Zhengzhou Metro Line 5 as an example, the field tests of shield cutting cement-soil monopile composite foundation were carried out. The load and internal force of the tunnel lining under the action of composite foundation were tested on-site and the distribution characteristics and variation laws of earth pressure around the tunnel under the load holding state of the composite foundation were analyzed. Five different load combinations (i.e., overburden load theory + q0, Terzaghi's theory + q0, Bierbaumer's theory + q0, Xie's theory + q0, and the proposed method (the combination of compound weight method and Terzaghi's theory) + q0) were used to calculate the internal force of the tunnel structure and the obtained results were compared with the measured internal force results. The action mode of earth pressure on the tunnel lining structure was evaluated. Research results show that the earth pressure obtained by the calculation method proposed in this paper was more consistent with the measured value and the deviation between the two was within 5%. The distribution of the calculated internal force of the tunnel structure was more in line with the distribution law of field test data and the deviation between the calculated and measured values was small. This effectively verified the rationality and applicability of the proposed calculation method. Research results provided references for the design and evaluation of shield tunnels under the action of composite foundations.

A Study on the Advanced Foreign′s Third Parth Logistics Trend & View at Global Logistics Times (글러벌 물류시대 선진외국의 제3자 물류동향과 전망)

  • 박영태
    • Proceedings of the Korean DIstribution Association Conference
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    • 2001.11b
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    • pp.91-122
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    • 2001
  • This paper's object is to study the Advanced Foreign's Third Party Logistics Trend & View at Global Logistics Times. So, I analysed the Advanced Foreign U.S. & EU and the results are as follows: First, a growth in the number of outsourcing relationships has contributed to the development of more flexible organizations, based on core competencies and mutually beneficial longer-term relationships. So, the development of logistics relationships has brought mixed results. Across many industries, logistics outsourcing is a rapidly expanding source of cost savings, competitive advantage, and customer service improvements. Thus, it appears that Third Party Logistics(TPL) concepts could be useful in meeting the goals of the 1ogistics function. Second, the field of logistics and supply chain management is becoming strategically important. At the same time, it is becoming increasingly complex because of the rapid advances in management methods, e-commerce, technology, and enabling information systems. However, Third Party Logistics provider, many a times, lack broad set of skills, integrating technologies, strategies and global reach. So, Fourth Party Logistics(4PL) is the next significant evolution in supply chain outsourcing. 4PL delivers a comprehensive supply chain solution, and delivers value through the ability to impact the entire supply chain. The 4PL industry is likely to grow as more companies use e-commerce at Global Logistics Times.

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