• Title/Summary/Keyword: W-function

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Work Function Change of W(123) Plane Due to Hydrogen and Deuterium Adsorption at 78K (78K에서 수소 혹은 중수소 흡착으로 인한 W(123)면의 일함수 변화)

  • 박노길;김기석;김성수;정광호;황정남;최대선
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.78-82
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    • 1992
  • The changes in work function due to hydrogen and deuterium adsorption on W(123) plane are measured by means of Field Emission Method. In the case of hydrogen or deuterium adsorption, work function of W(123) plane at 78 K increase and after a maxium value, it decrease and saturated as increasing coverage. After annealing the tungsten emission tip at 200 K, the coverage corresponding to maximum change in work function was shifted toward low coverage and the effect of work function by terraces or steps of which orientation is [ O l l ] was observed.

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A Study on the Optimum Parameter Estimation of Software Reliability (소프트웨어 신뢰도의 적정 파라미터 도출 기법에 관한 연구)

  • Che, Gyu-Shik;Moon, Myong-Ho
    • Journal of Information Technology Applications and Management
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    • v.13 no.4
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    • pp.1-12
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    • 2006
  • Many software reliability growth models(SRGM) have been proposed since the software reliability issue was raised in 1972. The technology to estimate and grow the reliability of developing S/W to target value during testing phase were developed using them. Most of these propositions assumed the S/W debugging testing efforts be constant or even did not consider them. A few papers were presented as the software reliability evaluation considering the testing effort was important afterwards. The testing effort forms which have been presented by this kind of papers were exponential, Rayleigh, Weibull, or logistic functions, and one of these 4 types was used as a testing effort function depending on the S/W developing circumstances. I propose the methology to evaluate the SRGM using least square estimator and maximum likelihood estimator for those 4 functions, and then examine parameters applying actual data adopted from real field test of developing S/W.

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The Lambert W Function in the Design of Minimum Mean Square-Error Quantizers for a Laplacian Source (램버트 W 함수를 사용한 라플라스 신호의 최소 평균제곱오차 양자화)

  • 송현정;나상신
    • Proceedings of the IEEK Conference
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    • 2001.06a
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    • pp.333-336
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    • 2001
  • This paper reports that the Lambert W function applies to a non-iterative design of minimum mean square-error scalar quantizers for a Laplacian source. The contribution of the paper is in the reduction of the time needed for the design and the increased accuracy in resulting quantization points and thresholds, because the algorithm is non-iterative and the Lambert W function can be evaluated as accurately as desired.

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The solar cell modeling using Lambert W-function (Lambert W 함수를 이용한 태양전지 모델링)

  • Bae, Jong-Guk;Kang, Gi-Hwan;Kim, Kyung-Soo;Yu, Gwon-Jong;Ahn, Hyung-Geun;Han, Deuk-Young
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.278-281
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    • 2011
  • This system can predict the maximum output about all illumination levels so that the PV system designer can design the system having the best efficiency. For the output prediction exact about the solar cell, that is the device the basis most in the PV system, the basis has to be in order to try this way. The solution based on Lambert W-function are presented to express the transcendental current-voltage characteristic containing parasitic power consuming parameters like series and shunt resistances. A simple and efficient method for the extraction of a single current-voltage (I-V) curve under the constant illumination level is proposed. With the help of the Lambert W function, the explicit analytic expression for I is obtained. And the explicit analytic expression for V is obtained. This analytic expression is directly used to fit the experimental data and extract the device parameters. The I-V curve of the solar cell was expressed through the modeling using Lambert W-function and the numerical formula where there is the difficulty could be logarithmically expressed This method expresses with the I-V curve through the modeling using Lambert W-function which adds other loss ingredients to the equation2 as to the research afterward. And the solar cell goes as small and this I-V curve can predict the power penalty in the system unit.

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ANALYSIS ON THE AVAILABILITY OF COMS GS

  • Park, Durk-Jong;Lim, Hyun-Su;Ahn, Sang-Il
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.212-215
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    • 2006
  • This paper describes several reliability models to estimate COMS ground segment availability and shows assessed availability according to GS function. Due to a back-up concept among three ground center, SOC will have all H/W and S/W module to be installed in MSC and KOSC site. Therefore, all configurations and availability parameters for H/W and S/W modules in MSC and KOSC are assumed as equal with those in SOC, if related modules have same function. Prior to access availability over COMS GS function, Availability related to fundamental configuration such as series, parallel, partial operation, and module combined H/W and S/W is described. Consequently, all functions are expected to operate with more than 99% of availability.

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Measurement of Changes in Work Function on MgO Protective Layer after H2-plasma Treatment (수소 Plasma 처리 후의 MgO 보호막에 대한 일함수 변화 측정)

  • Jeong, Jae-Cheon;Rhee, Seuk-Joo;Cho, Jae-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.7
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    • pp.611-614
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    • 2007
  • The changes in the work $function({\Phi}_w)$ in the MgO protective layers after $plasma(Ar,\;H_2)$ treatment have been studied using ${\Upsilon}-focused$ ion beam $({\Upsilon}-FIB)$ system. The ${\Phi}_w$ was determined as follows: Ar-plasma $treatment({\Phi}_w=4.52eV)$, $H_2-plasma$ $treatment({\Phi}_w=5.65eV)$, and non-plasma $treatment({\Phi}_w=4.64eV)$. The results indicated that the H-plasma could not make any effective physical etching due to the small masses of hydrogen atoms and molecules while the hydration of H-plasma could grow some contaminating materials on the surface of MgO.

COEFFICIENT ESTIMATES FOR FUNCTIONS ASSOCIATED WITH VERTICAL STRIP DOMAIN

  • Bulut, Serap
    • Communications of the Korean Mathematical Society
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    • v.37 no.2
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    • pp.537-549
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    • 2022
  • In this paper, we consider a convex univalent function fα,β which maps the open unit disc 𝕌 onto the vertical strip domain Ωα,β = {w ∈ ℂ : α < ℜ < (w) < β} and introduce new subclasses of both close-to-convex and bi-close-to-convex functions with respect to an odd starlike function associated with Ωα,β. Also, we investigate the Fekete-Szegö type coefficient bounds for functions belonging to these classes.

W-function for the Improvement of the Network in Manufacturing Process (제조공정 Network의 개선을 위한 W-함수)

  • 이상도;박기주
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.12 no.20
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    • pp.71-76
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    • 1989
  • In this paper, GERT network in modeled to improve the network of manufacturing process with feedback loop. A lot of Information on the GERT network can be derived from the equivalent W-function and MGF(moment generating function) using Mason's rule. These equations are used in calculating the variations of the performance measure and in improving the system performance. System improvement in manufacturing process is achieved by increasing the equivalent probabilities of each branches and by decreasing the expected equivalent time.

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STABILITY OF THE BERGMAN KERNEL FUNCTION ON PSEUDOCONVEX DOMAINS IN $C^n$

  • Cho, Hong-Rae
    • Communications of the Korean Mathematical Society
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    • v.10 no.2
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    • pp.349-355
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    • 1995
  • Let $D \subset C^n$ be a smoothly bounded pseudoconvex domain and let ${\bar{D}_r}_r$ be a family of smooth perturbations of $\bar{D}$ such that $\bar{D} \subset \bar{D}_r$. Let $K_D(z, w)$ be the Bergman kernel function on $D \times D$. Then $lim_{r \to 0} K_{D_r}(z, w) = K_D(z, w)$ locally uniformally on $D \times D$.

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A Study On the Design of MyData API G/W (마이데이터 API G/W 설계 연구)

  • Sehjoon Dokko;Changwon Choi
    • Journal of Internet of Things and Convergence
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    • v.9 no.2
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    • pp.47-54
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    • 2023
  • The MyData service makes anyone possible to apply the personal information for the personal credit management or the financial management by proactive managing his/her own information. The MyData means that the anyone is able to control or manage the its own information by changing from the company-oriented or the organization-oriented information to his/her own information. It is mandatory to develop the API G/W which transforms the different user format to the standard format to support the MyData service. This study is to design the API G/W for the MyData service and the designed API G/W supports the 4 major functions - Validation function, Throttling function, Authentication&Authorization function, Mediation function. The designed API G/W make it possible to support the safely and efficient MyData service by serving the various queries with the different formats.