• Title/Summary/Keyword: Infinite product

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GALOIS CORRESPONDENCES FOR SUBFACTORS RELATED TO NORMAL SUBGROUPS

  • Lee, Jung-Rye
    • Communications of the Korean Mathematical Society
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    • v.17 no.2
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    • pp.253-260
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    • 2002
  • For an outer action $\alpha$ of a finite group G on a factor M, it was proved that H is a, normal subgroup of G if and only if there exists a finite group F and an outer action $\beta$ of F on the crossed product algebra M $\times$$_{\alpha}$ G = (M $\times$$_{\alpha}$ F. We generalize this to infinite group actions. For an outer action $\alpha$ of a discrete group, we obtain a Galois correspondence for crossed product algebras related to normal subgroups. When $\alpha$ satisfies a certain condition, we also obtain a Galois correspondence for fixed point algebras. Furthermore, for a minimal action $\alpha$ of a compact group G and a closed normal subgroup H, we prove $M^{G}$ = ( $M^{H}$)$^{{beta}(G/H)}$for a minimal action $\beta$ of G/H on $M^{H}$.f G/H on $M^{H}$.TEX> H/.

Multiple Product Single Facility Stockout Avoidance Problem (SAP) and Weighted Stockout Problem (WSP)

  • Moon, Il-Kyeong
    • Journal of the Korean Operations Research and Management Science Society
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    • v.17 no.3
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    • pp.137-158
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    • 1992
  • We study the Multiple Product Single Facility Stockout Avoidance Problem (SAP). That is the problem of determining, given initial inventories, whether there is a multiple product single facility production schedule that avoids stockouts over a given time horizon. The optimization version of the SAP where stockouts are pnelized linearly is also studied. We call this problem the Weighted Stockout Problem (WSP). Both problems are NP-hard in the strong sense. We develop Mixed Integer Linear Programming (MIP) formulations for both the SAP and the WSP. In addition, several heuristic algorithms are presented and performances are tested using computational experiments. We show that there exist polynomial algorithms for some special cases of the SAP and the WSP. We also present a method to phase into a target cyclic schedule for infinite horizon problems. These can be used as a practical scheduling tool for temporarily overloaded facilities or to reschedule production after a disruption.

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Production-distribution Planning in Supply Chain Management Considering Processing Times and Capacity Using Simulation and Optimization Model (시간과 능력을 고려한 공급사슬 경영에서의 생산-분배 계획을 위한 시뮬레이션과 최적화모델의 적용)

  • Sook Han Kim;Young Hae Lee
    • Proceedings of the Korea Society for Simulation Conference
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    • 2000.11a
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    • pp.165-173
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    • 2000
  • Analytic models have been developed to solve integrated production-distribution problems in supply chain management (SCM). As one of major constraints in analytic models, capacity, which is the total operation time in this paper has mostly been known or disregarded assuming infinite capacity. Also, as major factors, machine processing time to fabricate or assemble a part or product at a certain machine center in production system and vehicle processing time to deliver a product to a customer by a certain vehicle in distribution system have been fixed and regarded as a static factor, But in the real systems significant differences exit between capacity and the required time to achieve the production-distribution plan and between processing time and consumed time to process a part or product. In this paper, capacity and processing times in the analytic model are considered as dynamic factors and adjusted by the results from independently developed simulation model, which includes general production-distribution characteristics. Through experiments, we obtain the more realistic solutions reflecting stochastic natures by performing the iterative analytic-simulation procedure.

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Finding and Analysis of Defective Elements of an LED Streetlight Lamp Based on the Product Liability (PL에 근거한 LED 가로등의 결함 요소 발굴 및 분석)

  • Kim, Hyang-Kon;Choi, Chung-Seog
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.4
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    • pp.632-632
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    • 2009
  • The purpose of this study is to present the range of defects mentioned in the Product Liability (PL) and to establish an objective basis and grounds for the analysis of accidents expected to happen by analyzing and presenting the external flame pattern and electrical characteristics of an LED streetlight lamp, a new lighting lamp. From the analysis of the cross-section of a cable carbonized by an external flame, it was observed that the wire's strand and insulation material had solidly adhered, and that greater voids were formed at the surface than at the center. Irregular carbide lumps were formed in the globe directly exposed to the flame, and the globe carbonized by the indirect flame showed characteristics that they had melted and flowed downward. It was found that the forward and backward resistances of the normal LED were approximately 1.74 [$M{\Omega}$] and 140 [$M{\Omega}$], respectively. The lamp burnt by the strong flame exhibited infinite forward and backward resistances and the LED did not emit light. The carbonized LED lamp was gray and exhibited fine delaminations. According to the Product Liability, a product defect signifies a simple product defect. Most of the defects were caused by the lack of stability, and the defect of the product itself occurred during the design and manufacture. The defects in warnings and markings include an insufficiency of handling manuals and warnings, expressive warranty violations, defective markings, etc. In order to prevent an accident resulting from a product, it is necessary to prepare safety warnings and documentation, establish clear-cut lines of liabilities, and subscribe insurances. However, it could be seen that important factors against the Product Liability were product improvement, response to compensation requests and law suits, credit restoration, etc.

SEQUENCE SPACES OF OPERATORS ON l2

  • Rakbud, Jitti;Ong, Sing-Cheong
    • Journal of the Korean Mathematical Society
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    • v.48 no.6
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    • pp.1125-1142
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    • 2011
  • In this paper, we define some new sequence spaces of infinite matrices regarded as operators on $l_2$ by using algebraic properties of such the matrices under the Schur product multiplication. Some of their basic properties as well as duality and preduality are discussed.

CONJUGACY SEPARABILITY OF CERTAIN GENERALIZED FREE PRODUCTS OF NILPOTENT GROUPS

  • Kim, Goansu;Tang, C.Y.
    • Journal of the Korean Mathematical Society
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    • v.50 no.4
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    • pp.813-828
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    • 2013
  • It is known that generalized free products of finitely generated nilpotent groups are conjugacy separable when the amalgamated subgroups are cyclic or central in both factor groups. However, those generalized free products may not be conjugacy separable when the amalgamated subgroup is a direct product of two infinite cycles. In this paper we show that generalized free products of finitely generated nilpotent groups are conjugacy separable when the amalgamated subgroup is ${\langle}h{\rangle}{\times}D$, where D is in the center of both factors.

Short Run Production Cusum IX Chart & MR Chart (짧은 생산 주기를 갖는 누적합 개별치 관리도와 이동범위 관리도)

  • 신숙현;나인성;조남호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.24 no.65
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    • pp.1-9
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    • 2001
  • Enterprises confronted the Environment of infinite competition should be prepared to abrupt variations of management environment and have the ability to be changed in short term. It has to be studied, the control method of products that correspond to molt-functionalization and reduced product life which is caused by high-quality and varied customers demands. As a process control method, we must be able not only to control varies characteristic in a control at once but also to detected special values quickly for high-quality. In this paper a control method referred above is presented.

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BOUNDS AND INEQUALITIES OF THE MODIFIED LOMMEL FUNCTIONS

  • Mondal, Saiful R.
    • Communications of the Korean Mathematical Society
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    • v.34 no.2
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    • pp.573-583
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    • 2019
  • This article studies the monotonicity, log-convexity of the modified Lommel functions by using its power series and infinite product representation. Some properties for the ratio of the modified Lommel functions with the Lommel function, sinh and cosh are also discussed. As a consequence, $Tur{\acute{a}}n$ type and reverse $Tur{\acute{a}}n$ type inequalities are given. A Rayleigh type function for the Lommel functions are derived and as an application, we obtain the Redheffer-type inequality.

Lean Startup and New Product Innovation - Focused on Idol TWICE Case - (린스타트업과 신제품 혁신 - 아이돌 가수 트와이스 사례를 중심으로 -)

  • Kim, Jung-Rae
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.5
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    • pp.47-57
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    • 2019
  • New product innovation is a key component of a company's survival and sustained growth. With the rapidly changing market environment and global infinite competition, The importance of innovative new product development is growing. In the domestic entertainment industry, Competition is intensifying, and many companies are focusing on developing innovative new products in order to secure continuous competitive advantage in the era of global infinite competition. The problem is that as the intensity of competition increases and the idol production system develops more and more, The costs of planning and marketing are increasing. The fair trade commission estimated the cost of creating an idol group to be about 1 billion won, and some large entertainment companies claim that the investment cost is about 20 ~ 3 billion won. Lean startup is attracting attention as an innovation framework for sustainable competitive advantage of companies. But, there are not many related studies in Korea despite the growing interest. In particular, Case studies that can help to establish specific strategies are limited. Therefore, this study analyzed the successful case of JYP Entertainment's idol singer TWICE who succeeded in new product innovation and suggested practical implications. Theoretically, This study extended the Lean startup to the entertainment industry and suggested practical implications as the basic data for establishing the innovation strategies for the idol singers of domestic entertainment companies.

A REMARK OF EISENSTEIN SERIES AND THETA SERIES

  • Kim, Dae-Yeoul;Koo, Ja-Kyung
    • Bulletin of the Korean Mathematical Society
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    • v.39 no.2
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    • pp.299-307
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    • 2002
  • As a by-product of [5], we produce algebraic integers of certain values of quotients of Eisenstein series. And we consider the relation of $\Theta_3(0,\tau)$ and $\Theta_3(0,\tau^n)$. That is,we show that $$\mid$\Theta_3(0,\tau^n)$\mid$=$\mid$\Theta_3(0,\tau)$\mid$,\bigtriangleup(0,\tau)=\bigtriangleup(0,\tau^n)$ and $J(\tau)=J(\tau^n)$ for some $\tau\in\eta$.