• 제목/요약/키워드: Eroding

검색결과 46건 처리시간 0.027초

환경친화형 친수호안(親水護岸)블록 수리특성 (Hydraulic Characteristics of water affinity sea-wall block)

  • 한재명;오영민
    • 한국해안해양공학회지
    • /
    • 제19권2호
    • /
    • pp.179-182
    • /
    • 2007
  • 본 연구에서는 연안침식방지와 친수공간을 제공하기 위한 목적으로 새로 개발된 환경친화형 친수호안블록의 성능을 검증하기 위하여 반사율과 안정성을 대상으로 수리모형실험을 실시하였다. 실험 결과 블록의 현장적용 가능성이 있음을 확인하였다.

Plasma Uniformity Analysis of Inductively Coupled Plasma Assisted Magnetron Sputtering by a 2D Voltage Probe Array

  • Joo, Junghoon
    • Applied Science and Convergence Technology
    • /
    • 제23권4호
    • /
    • pp.161-168
    • /
    • 2014
  • A real-time monitoring of immersed antenna type inductively coupled plasma (ICP) was done with a homemade 2 dimensional voltage probe array to check the uniformity of the plasma. Measured voltage values with a high impedance voltmeter are close to the floating potential of the plasma. As the substrate carrier was moving into a magnetron sputtering plasma diffusive from a $125mm{\times}625mm$ size cathode, measured results showed reliably separation of plasma into the upper and lower empty space over the carrier. Infra red thermal imaging camera was used to observe the cross corner effect in situ without eroding a target to the end of the usage. 3 dimensional particle trace model was used to analyze the magnetron discharge's behavior.

평판에 충동하는 사각봉의 소성응력해석 (An Analysis of Plastic Stress in Square Bar Impacting Plate)

  • 김기선;조재웅;최두석
    • 한국자동차공학회논문집
    • /
    • 제12권5호
    • /
    • pp.198-204
    • /
    • 2004
  • Dynamic fracture is investigated in plate applied by impacting bar. Numerical simulations of the experiments are made by using a finite element method(FEM) code, LS-DYNA. The eroding surface-to-surface contact allows between impacting bar and impacted plate. The occurrence of hourglass deformations in an analysis can invalidate results and hourglass energy is minimized to obtain the good accuracy of result. Total, internal and kinetic energies, von Mises plastic stress and X,Y,Z velocities of impacting bar are analyzed in this study.

공급사슬관점에서 수출기업의 글로벌 무역관리 전략 (Global Trade Management Strategies for Export Companies from the Supply Chain Management Perspective)

  • 양정호
    • 무역상무연구
    • /
    • 제35권
    • /
    • pp.179-219
    • /
    • 2007
  • Cross-border supply chains undergone complexity in the global trade process, unpredictability and continually evolving regulations and information requirements. Under these circumstances, longer lead time inhibiting quick response to market demands, unanticipated supply chain costs eroding product cost savings, compliance and documentation errors causing delays and fines are challenging global trade companies when they execute global business. These problems are mainly caused by unautomated, unintegrated process which lead to longer and more unpredictable lead times, slower cash flow, cost overruns, and ultimately lower profits and less satisfied customers. Complex and unpredictable global trade environment requires global trade companies of global trade management functions to automate and control this complex environment for driving out cost, time and risk from their business. Global trade management allows cost savings, supply chain efficiencies and improved compliance through improving global supply chain visibility, facilitating cash flow by supply chain financing, enhancing supply chain security and risk management.

  • PDF

토양의 침식과 보존에 관한 이론적 분석 4. 삼림토양의 침식과 유실기구 (The Theoretical Analyses of the Soil Erosion and Conservation 4. Erosion and Leaching Mechanism of the Forest Soils)

  • 장남기
    • 아시안잔디학회지
    • /
    • 제10권1호
    • /
    • pp.49-59
    • /
    • 1996
  • This report is researched on the cause and mechanism of soil erosion in comparison among Kwangnung, Mt. Kaya, Mt. Chili, and Mt. Soorak by physical and chemical analyses of their for- est soils. Clay, silt, and fine sand of Mt. Soorak are far less than those of Mt. Chili, Mt. Kaya, and Kwangnung area while coarse sand is very high level. The clay ratio of soil at Mt. Soorak is the most high level in comparison with that of other area. Denudation at Mt. Soorak, therefore, is cause of erosion by the result of transportation of soil particles. The eroding velocity increase for larger particle size and stronger cohesion between soil particles. Very fine sand, silt, and clay can be present in suspension near the bottom and the size of the particles in suspension depends upon the velocity of the current near the bottom and the roughness of the bottom. Key words: Theoretical analyses, Soil erosion and conservation, Forest soils.

  • PDF

A Numerical Study of the High-Velocity Impact Response of a Composite Laminate Using LS-DYNA

  • Ahn, Jeoung-Hee;Nguyen, Khanh-Hung;Park, Yong-Bin;Kweon, Jin-Hwe;Choi, Jin-Ho
    • International Journal of Aeronautical and Space Sciences
    • /
    • 제11권3호
    • /
    • pp.221-226
    • /
    • 2010
  • The failure of a Kevlar29/Phenolic composite plate under high-velocity impact from an fragment simulation projectile was investigated using the nonlinear explicit finite element code, LS-DYNA. The composite laminate and the impactor were idealized by solid elements, and the interface between the laminas was modeled as a tiebreak type in LS-DYNA. The interaction between the impactor and laminate was simulated using a surface-to-surface eroding contact algorithm. When the stress level meets the given failure criteria, the layer in the element is eroded. Numerical results were verified through existing test results and showed good agreement.

장시간 연소 텅스텐/이트리아 노즐목 삽입재의 내열성능 평가 (Thermal Performance Evaluations of Tungsten/Yttria as Nozzle Throat Insert Material for Long Duration Firing)

  • 강윤구;박종호
    • 한국항공우주학회지
    • /
    • 제38권2호
    • /
    • pp.200-205
    • /
    • 2010
  • 고온고압, 장시간 연소조건하에서 일정한 추력을 유지하는 로켓 추진기관 개발을 위해 W/$Y_2O_3$ 노즐목 삽입재를 평가하였다. 연소시간 증가에 따른 내열성능 변화를 검토하였으며, 비삭마 소재로 범용되고 있는 CIT의 내열성능과 비교하였다. 연소시간이 증가함에 따라 삭마율은 감소하는 경향을 보였으며, W/$Y_2O_3$의 삭마율은 CIT의 약 55 %이었다. 노즐목 삽입재의 육안검사와 미세조직검사에서 연소시간의 증가로 인한 특이 현상은 발견되지 않았으며, 진공 열처리는 균열 방지에 효과가 있음을 확인하였다.

Multiple myeloma presenting with a maxillary lesion as the first sign

  • Ramaiah, Kiran Kumar Kotagudda;Joshi, Vajendra;Thayi, Shilpa Ravishankar;Sathyanarayana, Pathalapate;Patil, Prashant;Ahmed, Zaheer
    • Imaging Science in Dentistry
    • /
    • 제45권1호
    • /
    • pp.55-60
    • /
    • 2015
  • Multiple myeloma is a clonal neoplastic proliferation of terminally differentiated B-lymphocytes involving the skeletal system in a multifocal fashion. Its oral manifestations are less common in the maxilla than in the mandible due to the lower amount of hemopoietic bone marrow in the maxilla. We report the case of a 50-year-old man who presented with a mass in the left maxillary alveolar region with tooth mobility. The mass had become enlarged after the teeth were extracted 15 days previously. Radiographs demonstrated multiple punched-out radiolucent lesions in the skull and pelvic region. Computed tomography images showed a soft tissue density mass in the left maxilla, eroding the floor and walls of the maxillary sinus. Although several analytical techniques were used to characterize the lesion, it was finally confirmed as multiple myeloma through immunohistochemistry.

장시간 연소용 초소형 저삭마 목삽입재 선정을 위한 내열성능 평가 (Thermal Performance Evaluations on High-Erosion Resistance Materials for Very Small Nozzle Throat Inserts)

  • 강윤구;박종호
    • 한국항공우주학회지
    • /
    • 제37권12호
    • /
    • pp.1245-1251
    • /
    • 2009
  • 고온/고압, 장시간 연소조건에서 비삭마에 가까운 삭마 특성을 갖는 초소형 목삽입재 선정을 위한 연구를 수행하였다. 평가 소재로서 C/SiC, CIT, W/$Y_2O_3$를 선정하였으며, 연소시간 20초의 내열성능평가모타로 시험하였다. 시험 결과 W/$Y_2O_3$가 가장 우수하였으나, 균열이 발생하였다. 본 연구를 통하여 각 소재들의 열반응 특성 및 내열 성능을 이해할 수 있었으며, W/$Y_2O_3$의 적용가능성을 확인하였다.

A Study on the User Acceptance of O2O Services : Mediating Effect of Customer Attitude

  • CHUNG, Ji Bok;NAM, Sung Jip
    • 동아시아경상학회지
    • /
    • 제8권3호
    • /
    • pp.15-24
    • /
    • 2020
  • Purpose - New technologies allow service providers to integrate all the customer information within and between contact channels so that they can offer individualized services. The availability of new mobile devices enables retailers to interact with customers through countless channels (Rigby, 2011). The objective of this research is to examine customers' attitudes toward O2O (on-line to off-line) services and their intention to use based on the Technology Acceptance Model (TAM). Research design, data, and methodology - Utilizing the TAM model, the mediating effect of the users' attitudes toward O2O services on the relationship among perceived ease of use, perceived usefulness, perceived risks and intention to use are to be investigated. Results - The result shows that the perceived ease of use, perceived usefulness, perceived risks have a significant effect on customers' attitudes toward O2O services. It is also revealed that the attitude toward O2O services has a mediating effect among perceived ease of use, perceived usefulness, perceived risks and intention to use. Conclusions - The boundary between on-line and off-line is eroding and various services based on the O2O platform are growing. The results of this study and managerial implications can be applied to O2O platform operators or enterprises planning to sharp on their competitiveness edge through offering variations of service channels.