• The Journal of Information Systems
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• v.8 no.1
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• pp.65-92
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• 1999

As the information technology advances and the number of internet users increase, the electronic commerce has been discussed actively in the academic and industrial circles. Though the reference model is important as a guide to the study on electronic commerce at this time, current studies on the reference model are inclined to emphasize on the specified area, not on overall area. In this respect, this paper aims to provide the synthetic reference model - named the ECGR model(Electronic Commerce Generic Reference model) - and its application plans. First, for these purposes, several frameworks and reference models of electronic commerce are compared and analyzed from the various viewpoints. Second, several factors for the development of the reference model are proposed. Finally, the ECGR model is developed and its application plans are suggested. The ECGR model provides a conceptual and analytical apparatus to interpret the profound understanding of electronic commerce and presents the fundamental framework related to the electronic commerce projects. According to the expansion of electronic commerce and the development of related information technology, the ECGR model must be modified.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.2
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• pp.139-144
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• 2013

Negative bias temperature instability (NBTI) has become a major factor determining circuit reliability. The effect of the NBTI on the circuit performance depends on the duty cycle which represents the stress and recovery conditions of each device in a circuit. In this paper, we propose an analytical model to perform more accurate duty cycle estimation at the gate-level. The proposed model allows accurate (average error rate: 3%) computation of the duty cycle without the need for expensive transistor-level simulations Furthermore, our model estimates the waveforms at each node, allowing various aging effects to be applied for a reliable gate-level circuit aging analysis framework.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.120-128
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• 2011

Recent development of communication technology and evolution of telecommunications services, various needs of users are giving Telecom operators difficulties in discovering new services and its promotion strategies. In addition, at the launching of new services, if carriers does not consider complementary and substitution relationships with competing services or self-encroachment problem with the existing service profitability is reduced or lost in the current market. In this study, by analyzing usage pattern of telecommunications services respect to changes in supply and demand environment, the complementarity/substitutability analysis and systematic analytical framework is proposed. This study proposes approaches to establish mobile operators' business strategies and to identify new services demand.

• Journal of Communications and Networks
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• v.15 no.2
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• pp.222-227
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• 2013

This paper presents an analytical framework for dynamic spectrum allocation in cognitive radio networks. We propose a distributed queuing based Markovian model each for single channel and multiple channels access for a contending user. Knowledge about spectrum mobility is one of the most challenging problems in both these setups. To solve this, we consider probabilistic channel availability in case of licensed channel detection for single channel allocation, while variable data rates are considered using channel aggregation technique in the multiple channel access model. These models are designed for a centralized architecture to enable dynamic spectrum allocation and are compared on the basis of access latency and service duration.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.658-669
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• 2016

The tremendous increase in mobile data traffic coupled with fierce competition in wireless industry brings about spectrum scarcity and bandwidth fragmentation. This inevitably results in asymmetric-valued long term evolution (LTE) spectrum allocation that stems from different timing for twice improvement in capacity between competing operators, given spectrum allocations today. This motivates us to study the economic effects of asymmetric-valued LTE spectrum allocation. In this paper, we formulate the interactions between operators and users as a hierarchical dynamic game framework, where two spiteful operators simultaneously make spectrum acquisition decisions in the upper-level first-price sealed-bid auction game, and dynamic pricing decisions in the lower-level differential game, taking into account user subscription dynamics. Using backward induction, we derive the equilibrium of the entire game under mild conditions. Through analytical and numerical results, we verify our studies by comparing the latest result of LTE spectrum auction in South Korea, which serves as the benchmark of asymmetric-valued LTE spectrum auction designs.

• Industrial Engineering and Management Systems
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• v.1 no.1
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• pp.10-18
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• 2002

A more comprehensive analytical framework for examining the relative merits of alternative dispatching process policies for nurseries is developed in this paper. The efficiency of the dispatch process of plants in a nursery is analysed using a vehicle routing model. The problem then involves determining in what order each vehicle should visit its locations. The problem is NP-hard. Several heuristic techniques are used to solve a real life nursery sequencing problem. The results obtained by these heuristic techniques are compared with each other and the current sequencing of orders. The model with some minor alterations can be also used to minimise the dispatching and collecting process in different agricultural plants.

• Journal of the Korean Society for information Management
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• v.9 no.1
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• pp.1-23
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• 1992

The purpose of this study is to answer a question as to "How much does CD-ROM improve thefunction of library\ulcorner" and, then, to build up an analytical framework to analyze the above question.The hypothesis is statistically tested with the responses of 282(70.5%) librarians in the libraries whichare currently using CD-ROM. The hypothesis is positively or vigorously supported by four steps.Therefore, the researcher suggests strongly at a plan to utilize CD-ROM be forwarded to improvelibrary functions. library functions.

• Structural Engineering and Mechanics
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• v.59 no.1
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• pp.101-122
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• 2016

Elasticity solutions for bi-directional functionally graded beams subjected to arbitrary lateral loads are conducted, with emphasis on the end effects. The material is considered macroscopically isotropic, with Young's modulus varying exponentially in both axial and thickness directions, while Poisson's ratio remaining constant. In order to obtain an exact analysis of stress and displacement fields, the symplectic analysis based on Hamiltonian state space approach is employed. The capability of the symplectic framework for exact analysis of bi-directional functionally graded beams has been validated by comparing numerical results with corresponding ones in open literature. Numerical results are provided to demonstrate the influences of the material gradations on localized stress distributions. Thus, the material properties of the bi-directional functionally graded beam can be tailored for the potential practical purpose by choosing suitable graded indices.

• World Technopolis Review
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• v.7 no.2
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• pp.113-124
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• 2018

Since the term smart city was coined, theories and practices of smart cities have flourished. Regarding the theoretical aspect, user-driven innovation has been discussed in studies on the innovation ecosystems of smart cities. Smart cities have been built in various countries around the world in recent years, including in Japan, which has experienced the same global trends in smart cities since 2010. Four smart community projects run by the Agency for Natural Resources and Energy between 2010 and 2014 followed such trends. The present study addressed user-driven innovation using the quadruple helix model as an analytical framework for the four smart community projects, and the outcomes of the projects were evaluated. In conclusion, the smart community projects were evaluated as successful. However, it was revealed that these projects were not completely conducive to user-driven innovation.

• Structural Engineering and Mechanics
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• v.68 no.6
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• pp.701-711
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• 2018

Herein, the thermo-magneto-elastic wave dispersion answers of functionally graded (FG) double-nanobeam systems (DNBSs) are surveyed implementing a nonlocal strain gradient theory (NSGT). The kinematic relations are derived employing the classical beam theory. Also, scale influences are covered precisely in the framework of NSGT. Moreover, Mori-Tanaka homogenization model is introduced in order to obtain the effective material properties of FG nanobeams. Meanwhile, effects of external forces such as thermal and Lorentz forces are included in this research. Also, based upon the Hamilton's principle, the Euler-Lagrange equations are developed; afterwards, these equations are incorporated with those of NSGT to reach the nonlocal governing equations of FG-DNBSs. Furthermore, according to an analytical approach, the governing equations are solved to obtain the wave frequencies and phase velocities of FG-DNBSs. At the end, some illustrations are rendered to clarify the influences of a wide range of involved parameters.