• Title/Summary/Keyword: Rogers

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ON THE INFINITE PRODUCTS DERIVED FROM THETA SERIES I

  • Kim, Dae-Yeoul;Koo, Ja-Kyung
    • Journal of the Korean Mathematical Society
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    • v.44 no.1
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    • pp.55-107
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    • 2007
  • Let k be an imaginary quadratic field, h the complex upper half plane, and let $\tau{\in}h{\cap}k,\;q=e^{{\pi}i\tau}$. In this article, we obtain algebraic numbers from the 130 identities of Rogers-Ramanujan continued fractions investigated in [28] and [29] by using Berndt's idea ([3]). Using this, we get special transcendental numbers. For example, $\frac{q^{1/8}}{1}+\frac{-q}{1+q}+\frac{-q^2}{1+q^2}+\cdots$ ([1]) is transcendental.

Foreign Direct Investment Projects of Korean Companies

  • Choi, Yeana;Yuce, Ayse
    • The Journal of Asian Finance, Economics and Business
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    • v.3 no.1
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    • pp.5-14
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    • 2016
  • This paper investigates announcement effects of the outward foreign direct investment (FDI) projects of the Korean multinational companies. Although the FDI is considered corporate activity that can provide various benefits beyond financial resources, the most previous research focused on macro analysis such as country-level and industry-level analysis instead of the firm-level study, which is required to decide the investment project from a management perspective. Thus, this study examines the relationship between the outward FDI activities of the Korean corporations and their financial performance to fill the gap in this area.

ON ROGERS-RAMANUJAN TYPE IDENTITIES FOR OVERPARTITIONS AND GENERALIZED LATTICE PATHS

  • Goyal, Megha
    • Bulletin of the Korean Mathematical Society
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    • v.55 no.2
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    • pp.449-467
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    • 2018
  • In this paper we introduce and study the lattice paths for which the horizontal step is allowed at height $h{\geq}0$, $h{\in}{\mathbb{Z}}$. By doing so these paths generalize the heavily studied weighted lattice paths that consist of horizontal steps allowed at height zero only. Six q-series identities of Rogers-Ramanujan type are studied combinatorially using these generalized lattice paths. The results are further extended by using (n + t)-color overpartitions. Finally, we will establish that there are certain equinumerous families of (n + t)-color overpartitions and the generalized lattice paths.

REMARKS FOR BASIC APPELL SERIES

  • Seo, Gyeong-Sig;Park, Joong-Soo
    • Honam Mathematical Journal
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    • v.31 no.4
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    • pp.463-478
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    • 2009
  • Let k be an imaginary quadratic field, ℌ the complex upper half plane, and let ${\tau}{\in}k{\cap}$ℌ, q = exp(${\pi}i{\tau}$). And let n, t be positive integers with $1{\leq}t{\leq}n-1$. Then $q^{{\frac{n}{12}}-{\frac{t}{2}}+{\frac{t^2}{2n}}}{\prod}^{\infty}_{m=1}(1-q^{nm-t})(1-q^{nm-(n-t)})$ is an algebraic number [10]. As a generalization of this result, we find several infinite series and products giving algebraic numbers using Ramanujan's $_{1{\psi}1}$ summation. These are also related to Rogers-Ramanujan continued fractions.

NEW BEST PROXIMITY POINT RESULTS FOR DIFFERENT TYPES OF NONSELF PROXIMAL CONTRACTIONS WITH AN APPLICATION

  • Khairul Habib Alam;Yumnam Rohen;S. Surendra Singh;Kshetrimayum Mangijaobi Devi;L. Bishwakumar
    • Nonlinear Functional Analysis and Applications
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    • v.29 no.2
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    • pp.581-596
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    • 2024
  • A new variety of non-self generalized proximal contraction, called Hardy-Rogers α+F-proximal contraction, is shown in this work. Also, with an example, we prove that such contractions satisfying some conditions must have a unique best proximity point. For some particular values of the constants, that we have used to generalize the proximal contraction, we conclude different α+F-proximal contraction results of the types Ćirić, Chatterjea, Reich, Kannan, and Banach with proof, that all such type of contractions must have unique best proximity point. We also apply our result to solve a functional equation.

Applications of Innovation Adoption and Diffusion Theory to Demand Estimation for Communications and Media Converging (DMB) Services (혁신채택 및 확산이론의 통신방송융합(위성DMB) 서비스 수요추정 응용)

  • Sawng Yeong-Wha;Han Hyun-Soo
    • Korean Management Science Review
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    • v.22 no.1
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    • pp.179-197
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    • 2005
  • This study examines market acceptance for DMB service, one of the touted new business models in Korea's next-generation mobile communications service market, using adoption end diffusion of innovation as the theoretical framework. Market acceptance for DMB service was assessed by predicting the demand for the service using the Bass model, and the demand variability over time was then analyzed by integrating the innovation adoption model proposed by Rogers (2003). In our estimation of the Bass model, we derived the coefficient of innovation and coefficient of imitation, using actual diffusion data from the mobile telephone service market. The maximum number of subscribers was estimated based on the result of a survey on satellite DMB service. Furthermore, to test the difference in diffusion pattern between mobile phone service and satellite DMB service, we reorganized the demand data along the diffusion timeline according to Rogers' innovation adoption model, using the responses by survey subjects concerning their respective projected time of adoption. The comparison of the two demand prediction models revealed that diffusion for both took place forming a classical S-curve. Concerning variability in demand for DMB service, our findings, much in agreement with Rogers' view, indicated that demand was highly variable over time and depending on the adopter group. In distinguishing adopters into different groups by time of adoption of innovation, we found that income and lifestyle (opinion leadership, novelty seeking tendency and independent decision-making) were variables with measurable impact. Among the managerial variables, price of reception device, contents type, subscription fees were the variables resulting in statistically significant differences. This study, as an attempt to measure the market acceptance for satellite DMB service, a leading next-generation mobile communications service product, stands out from related studies in that it estimates the nature and level of acceptance for specific customer categories, using theories of innovation adoption and diffusion and based on the result of a survey conducted through one-to-one interviews. The authors of this paper believe that the theoretical framework elaborated in this study and its findings can be fruitfully reused in future attempts to predict demand for new mobile communications service products.

A Study on the Reliability of Failure Diagnosis Methods of Oil Filled Transformer using Actual Dissolved Gas Concentration (유중가스농도를 이용한 유입식 변압기 고장진단 기법의 신뢰성에 관한 연구)

  • Park, Jin-Yeub;Chin, Soo-Hwan;Park, In-Kyoo
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.60 no.3
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    • pp.114-119
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    • 2011
  • Large Power transformer is a complex and critical component of power plant and consists of cellulosic paper, insulation oil, core, coil etc. Insulation materials of transformer and related equipment break down to liberate dissolved gas due to corona, partial discharge, pyrolysis or thermal decomposition. The dissolved gas kinds can be related to the type of electrical faults, and the rate of gas generation can indicate the severity of the fault. The identities of gases being generated are using very useful to decide the condition of transformation status. Therefore dissolved gas analysis is one of the best condition monitoring methods for power transformer. Also, on-line multi-gas analyzer has been developed and installed to monitor the condition of critical transformers. Rogers method, IEC method, key gas method and Duval Triangle method are used to failure diagnosis typically, and those methods are using the ratio or kinds of dissolved gas to evaluate the condition of transformer. This paper analyzes the reliability of transformer diagnostic methods considering actual dissolved gas concentration. Fault diagnosis is performed based on the dissolved gas of five transformers which experienced various fault respectively in the field, and the diagnosis result is compared with the actual off-line fault analysis. In this comparison result, Diagnostic methods using dissolved gas ratio like Rogers method, IEC method are sometimes fall outside the ratio code and no diagnosis but Duval triangle method and Key gas method is correct comparatively.