• Transactions on Electrical and Electronic Materials
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• 제4권2호
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• pp.35-39
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• 2003

This paper is contents on the orthorhombic crystalline calcined by the solid phase method with LiMnO$_2$ thin film structured as the result which an average pore diameter of power was 132.3${\AA}$ in porosity analysis. Voltage ranges are able to get the properties of charge and discharge for experimental results of LiMnO$_2$ thin film were 2.2V 4.3V. The current density and scan speed were 0. 1㎃/$\textrm{cm}^2$ and 0.2㎷/sec respectively. Properties of the charge and discharge are obtained by optimum experiment condition parameters. Li dense ratio of the LiMnO$_2$ thin film that discharged capacities were 87㎃h/g have been 96.9［ppm］ at 670.784［nm］ wavelength. The dense ratio of Mn analyzed to 837［ppm］ at 257.610［nm］ wavelength. It can be estimated the quality of the LiMnO$_2$ thin film as that the wrong LiMnO$_2$ thin film pulled up from cell of electrolyte and became dry it at 800$^{\circ}C$. The results of SEM and XRD were the same as that of original researchers.

• 천문학회보
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• 제42권1호
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• pp.55.3-55.3
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• 2017

The L1641 cloud in Orion is an active site of star formation. We mapped a square region of 60 arcmin by 60 arcmin in the continuum emission from 0.89 mm to 2.0 mm wavelength using MUSIC mounted on the Caltech Submillimeter Observatory 10.4 m telescope. Eight sources were detected in at least two wavelength bands, and all the detected emission comes from thermal dust continuum radiation of dense cloud cores. Their spectral energy distributions were characterized. The dust emissivity spectral index is beta = 1.3 on average, within the range of typical cores in nearby star-forming regions. Two cores, V380 Ori NE and HH 34 MMS, have unusually low emissivity index of beta = 0.3. These cores may contain millimeter-sized dust grains, which suggests that the lifetime of some dense cores can be much longer than the free-fall timescale.

• 한국통신학회논문지
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• 제34권6B호
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• pp.568-574
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• 2009

128 채널 고밀도 파장다중화 광신호들을 위한 320km 광전송 링크가 시뮬레이션으로 계산되고 실험으로 구현되었다. 이 링크에서 사용된 광섬유 증폭기은 분산형 라만 증폭기와 C 대역과 L 대역을 함께 증폭시킬 수 있는 이중 대역 EDFA가 함께 고려되어 컴퓨터 시뮬레이션을 통해 링크의 특성이 계산되었다. 여기서 계산된 값을 구현할 수 있도록 증폭기의 구조가 최적화되고 이 구조가 모듈로 제작되었다. 제작된 증폭기를 사용하여 구현된 링크에서 측정된 320km 거리에서의 광신호잡음비는 각 대역에서 평균 25dB였고 이는 처음 링크 계산 시에 의도된 값과 잘 일치하였다.

• 한국통신학회논문지
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• 제29권5A호
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• pp.484-491
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• 2004

L-band EDFA는 작은 평균밀도 반전율에서 동작하기 때문에 C-b란d에서 상대적으로 높은 흡수율로 인해 펌프 효과를 가지게 된다. 본 논문에서는 980nm의 펌프 입력 광 파워, C-band 펌프 파장 및 입력 광 파워에 따라 펌프 효과에 대해 논하고자 한다. 즉, C-band 펌프광의 흡수 또는 후방 자연방출광의 흡수라는 두 가지 다른 메카니즘을 통해 펌프 효과를 야기 시키게 된다. 또한 동일한 소 신호 이득 조건 하에서 L-band 신호 입력 광에 의한 포화 특성 (포화 광출력, 잡음지수에 있어서 장파장의 C-band 펌프가 양호한 것으로 나타난다. 전광 고정이득 L-band EDFA에서 C-band발진의 효과를 검토한 결과 L-band발진에 비해서 개선된 특성은 없는 것으로 나타난다.

• 한국통신학회논문지
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• 제27권7C호
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• pp.641-652
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• 2002

본 논문에서는 대용량의 데이터를 처리하기 위한 시간분할 및 파장분할 방식을 혼합한 구조를 갖는 대용량 광 교환기 ESCIMONET(Easily SCalable Interconnected Multiwavelength Optical NETwork)의 구조 및 동작과 특징에 대해 소개하였다. ESCIMONET은 n 개의 파장만을 이용하여 n$^3$의 가입자를 수용할 수 있어 스위칭 용량의 효율성이 매우 뛰어난 시스템이며, 시스템 손실 또한 기존의 구조에 비해 적어 손실 보상을 위해 삽입하는 광 증폭기의 개수를 최소화 할 수 있다. 또한 본 논문에서는 ESCIMONET에서 사용된 버퍼의 처리율(Throughput)을 분석하여 전체 스위칭 시스템의 처리율을 분석하였고, 버퍼의 평균 대기 시간을 계산하여 광 교환기 ESCIMONET의 성능을 평가하였다.

• 천문학회보
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• 제37권2호
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• pp.210.2-210.2
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• 2012

Using Fresnel reflection and Hapke BRDF model with Apollo 10084 soil sample's scattering properties, we constructed a real scale optical lunar model and used it to simulate lunar apparent albedo and moonshine. For Fresnel reflection, the refractive index of $1.68{\pm}0.5$ was used. For Hapke BRDF parameters from BUGs BRDF measurement, the single scattering with w=0.33, hot spot width h=0.017, average phase angle ${\zeta}$=-0.086 and Legendre polynomial coefficients b=0.308, c=0.425 in wavelength 700nm with two types of Henyey-Greenstein phase function was applied. The computation model includes the Sun as a Lambertian scattering sphere, emitting 1.5078 W/m2 at 700nm in wavelength. The Sun and Moon models were then imported into the IRT based radiative transfer computation. The trial simulation of the irradiance levels of moonshine lights shows that they agree well with the ROLO measurement data. We then estimate the lunar apparent albedo to 0.11. The results are to be compared with the measurement data.

• Journal of the Optical Society of Korea
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• 제17권6호
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• pp.538-542
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• 2013

We propose a simple model to elucidate the dispersion behavior of spiraling modes on silver nanowire by finding correspondence parameters and building a simple equivalent relationship with the planar insulator-metal-insulator geometry. The characteristics approximated for the proposed structure are compared with the results from an exact solution obtained by solving Maxwell's equation in cylindrical coordinates. The effective refractive index for our proposed equivalent model is in good agreement with that for the exact solution in the 400-2000 nm wavelength range. In particular, when the radius of the silver nanowire is 100 nm, the calculated index shows typical improvements; the average percentage error for the real part of the effective refractive index is reduced to only 5% for the $0^{th}$ order mode (11.9% in previous results) and 1.5% for the $1^{st}$ order mode (24.8% in previous results) in the 400-800 nm wavelength range. This equivalent model approach is expected to provide further insight into understanding the important behavior of nanowire waveguides.

• ETRI Journal
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• 제43권5호
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• pp.799-811
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• 2021

This paper considers a challenging problem: to simultaneously optimize the cost and the quality of service in opaque wavelength division multiplexing (WDM) networks. An optimization problem is proposed that takes the information including network topology, traffic between end nodes, and the target level of congestion at each link/ node in WDM networks. The outputs of this problem include routing, link channel capacities, and the optimum number of switch ports locally added/dropped at all switch nodes. The total network cost is reduced to maintain a minimum congestion level on all links, which provides an efficient trade-off solution for the network design problem. The optimal information is utilized for dynamic traffic in WDM networks, which is shown to achieve the desired performance with the guaranteed quality of service in different networks. It was found that for an average link blocking probability equal to 0.015, the proposed model achieves a net channel gain in terms of wavelength channels (𝛾_w) equal to 35.72 %, 39.09 %, and 36.93 % compared to shortest path first routing and 𝛾_w equal to 29.41 %, 37.35 %, and 27.47 % compared to alternate routing in three different networks.

• 대한기계학회논문집B
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• 제24권6호
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• pp.753-759
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• 2000

Photoelectric charging is a very efficient way of charging small particles. This method can be applied to combustion measurement, electrostatic precipitator, metal separation and control of micro-contamination. To understand the photoelectric charging mechanism, particle charging of silver by exposure to ultraviolet is investigated in this study. Average charges and charge distributions are measured at various conditions, using two differential mobility analyzers, a condensation nucleus counter, and an aerosol electrometer. The silver particles are generated in a spark discharge aerosol generator. After that process, the generated particles are charged in the photoelectric charger using low-pressure mercury lamp that emits ultraviolet having wavelength 253.7 nm. The results show that ultra-fine particles are highly charged by the photoelectric charging. The average charges linearly increase with increasing particle size and the charge distribution change with particle size. These results are discussed by comparison with previous experiments and proposed equations. It is assumed that the coefficient of electron emission probability is affected by initial charge. The results also show that the charge distribution of a particle is dependent on initial charge. Single changed particle, uncharged particle and neutralized particle are compared. The differences of charge distribution in each case increase with increasing particle size.

• 한국정보통신학회논문지
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• 제10권3호
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• pp.579-585
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• 2006

본 논문에서는 스펙트럼 분할된 WDM시스템의 성능해석시, 광전치 증폭기를 사용하여 일반적인 핀(PIN) 다이오드를 채용한 수신기를 통해 얻을 수 있는 수신감도를 개선하는 방법에 대해 해석하였다. 또한 온-오프키잉(OOK: On Off Keying)과 주파수 천이키잉(FSK: Frequency Shift Keying) 전송을 이용하여 표준에러 확률을 유지하기 위해 필요로 하는 비트당 광자의 수를 계산한 후 수신기에서 광신호와 전기신호의 다양한 대역폭 비가 변화하는 경우에 대하여 위의 값을 다시 도출함으로써 수신감도를 해석하였다.