• Title/Summary/Keyword: Confined

Search Result 2,294, Processing Time 0.045 seconds

MBE Growth and Fabrication of Oxide-Confined VCSEL Array (산화막 구경 표면발광 레이저 어레이의 MBE 성장과 제작)

  • 김진숙;장기수;김종민;배성주;이용탁
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2003.02a
    • /
    • pp.144-145
    • /
    • 2003
  • VCSEL은 우수한 소자 특성과 표면 발광 구조가 갖는 여러 가지 장점들로 인하여 병렬 광연결과 근거리 광섬유 통신에서 이상적인 광원으로 인정받고 있다. 특히 산화막 구경을 갖는 VCSEL은 이득영역 근처에서 횡 방향으로 광학적, 전기적 제한을 가함으로써 낮은 문턱전류와 높은 전력변환 효율을 갖기 때문에 현재까지 많은 연구가 진행되어 왔다. 본 논문에서는 in-situ 광 반사법을 이용한 VCSEL의 MBE 성장과 1■10 산화막 구경 VCSEL 어레이의 제작공정, 그리고 발진특성에 대하여 논하고자 한다. (중략)

  • PDF

Railway logistics plan by analyzing origin & destination of possible mad goods by railway (철송가능 육송품목의 기종점 분석을 통한 철도물류 활성화방안)

  • Park, Eun-Kyung
    • Proceedings of the KSR Conference
    • /
    • 2009.05a
    • /
    • pp.1708-1727
    • /
    • 2009
  • Even though we usually analyze logistic market based on confined railway logistics, but this study would like to judge what is potential demand transferable to railway goods through accurate analysis of railway sharing rates by the analysis of origin and destination of each item in total freight transportation market. Accordingly, by analyzing each items transferable to railway, excluding items stuck to original market, this study wants to choose some major items which are expected to lasting demand and activate railway logistics plan by focusing on major items for marketing strategy.

  • PDF

Observation of Soft-Rot Wood Degradation Caused by Higher Ascomyceteous fungi

  • Lee, Yang-Soo
    • Mycobiology
    • /
    • v.28 no.1
    • /
    • pp.47-50
    • /
    • 2000
  • The capability of higher ascomyceteous fungi to cause typical soft-rot decay for wood under laboratory conditions is reviewed and discussed. Fungi tested were extremely active in the decomposition of timbers. Scanning electron micrographs illustrated typical soft-rot decay pattern of higher wood decay ascomycetes, with the exception of H. trugodes that caused white-rot decay. Most of the fungi tested could be grouped as soft-rot fungi that showed typical soft-rot type II. Hypha confined primarily to the resin canals in softwoods or vessel elements in hardwoods and spread tracheid to tracheid via pits of cell wall to cell wall with mechanical force.

  • PDF

Pityriasis Rosea in Pig: A Case Report (돼지의 장미비강진(薔薇秕糠疹) 일례(一例))

  • Kwon, Nam Suk;Park, Young Jun;Lee, Chung Gil
    • Korean Journal of Veterinary Research
    • /
    • v.19 no.2
    • /
    • pp.159-160
    • /
    • 1979
  • Pityriasis rosea in a 2-month old pig is described. Lesions were confined to the abdomen and groin. They consisted of raised, erythematous papules with distinct borders. Microscopic examination of the lesions revealed a nonspecific dermatitis with acanthosis, moderate infiltration of mononuclear cells and eosinophils in the upper dermis. The known occurrence of the disease will help differentiate the condition from other dermatoses.

  • PDF

On the Size of Quantum Dots with Bound Hydrogenic Impurity States

  • Sun, Ho-Sung
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.2
    • /
    • pp.315-318
    • /
    • 2009
  • Some particular bound state energies of an electron, under Coulomb potential field, confined in a two-dimensional circle and a three-dimensional sphere are analytically derived. The derivation shows that the electron cannot be bound in a negative energy state when the circle (or sphere) is smaller than a certain critical size. The critical size dependency on the strength of Coulomb potential and the angular momentum of the electron is also analytically derived. This system mimics quantum dots. Therefore the derivation provides new information on a minimum critical size of quantum dots with hydrogenic impurity.

Eelectro-optic Behavior of Opal-LC Photonic Crystals

  • Kang, Dae-Seung
    • Journal of Information Display
    • /
    • v.2 no.4
    • /
    • pp.19-22
    • /
    • 2001
  • In this paper, we describe the electro-optic effects of photonic crystals made of a synthetic opal filled with a nematic liquid crystal(LC). By applying an external electric field, a shift in the Bragg reflection peak position(stop band) and a field-induced change in its peak reflectivity are observed. These significant surface alignment effects of the opal-LC composite are discussed in a similar manner for Freederick-type transitions of LC within a confined geometry in the presence of external fields.

  • PDF

Effects of noe-economic factors on the cyclcal fluctuations of price level in Korea

  • Yoon, Suk-Bum
    • Journal of the Korean Statistical Society
    • /
    • v.3 no.1
    • /
    • pp.17-30
    • /
    • 1974
  • There are a number of studies on the peculiarities of inflation in underdeveloped economies. These studies are, however, confined to the cases of Latin American countries, and the essence of methodologies applied in the studies is basically estimations of linear parameters of an extended quantity equation with lagged variables. As it is generally observed, inflation in most of underdeveloped economies are, to some extent, affected by non-economic factors such as political instability, social disorder, abrupt institutional changes, etc. Sometimes, these factors underlying the basic movement of price level change are reflected in such variables as quantity of money supply, income velocity, gross national product.

  • PDF

Frequency Selective Recursive LP of Discrete Harmonic Spectra for Audio Cording

  • Nam, Seung-Hyon
    • The Journal of Engineering Research
    • /
    • v.5 no.1
    • /
    • pp.37-44
    • /
    • 2004
  • n this paper, an efficient LP method for discrete harmonic spectra is proposed and discussed. A new efficient LP method is a combination of recursive and frequency selective LP. While the recursive LP provides better spectral matching in spectral hill, frequency selective LP eliminates numerical instability and improves spectral matching when the harmonics are confined in the low frequency region. The proposed LP method is applied to the HILN coder. Simulation results using a verification model(VM) software for real audio signals show a definite trend of significant improvement.

  • PDF