• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6A
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• pp.397-404
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• 2003

In this paper, we have analyzed the level of cross-modulation noise required for CDMA mobile station and proposed a guideline for optimum design. From the analysis, the level of cross-modulation noise is determined by the system's noise figure(NF) and VCO's phase noise and there is a trade-off relationships between them. In addition, we have determined the value of LNA's IIP3 and duplexer's isolation to satisfy the above level in designing the system. Therefore, this paper will give a guideline for a selection of components in designing cdma2000 mobile station.

• 연구논문집
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• s.22
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• pp.39-46
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• 1992

A dynamic design process was proposed for the design of the secondary suspension characteristics of a magnetically levitated vehicle(MAGLEV). It is based on a ride quality-secondary stroke trade-off. For the vertical vibration analysis, a magnetically levitated vehicle was simplified as 2 d.o.f. linear model, and FRA's class-6-track irregularities were considered as exciting disturbances. The optimum value of airspring stiffness and damping coefficient for the secondary suspension of a prototype MAGLEV was determined using this proposed design process.

• Journal of IKEEE
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• v.12 no.4
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• pp.255-262
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• 2008

In this paper, we proposed the novel IGBT with an additional n-type MOS structure to achieve the improved trade-off between turn-off and on-state voltage drop(Vce(sat)). These low on-resistance and the fast switching characteristics of the proposed IGBT are caused by an enhanced electron current injection efficiency which is caused by additional n-type MOS structure. In the simulation result, the proposed IGBT has the lower on state voltage of 2.65V and the shorter turn-off time of 4.5us than those of the conventional IGBT(3.33V, 5us).

• Journal of Global Scholars of Marketing Science
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• v.10
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• pp.71-89
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• 2002

The on-line market is sudden and it tilts the effort which various in order to reveal the difference point against the on-line consumer and the off-line consumer from under the environment which grows is. What reveals the on-line consumer and the difference point of off-line consumer two group from like this situation is a possibility of decreasing the place help which establishes a marketing strategy in the each retail trade sleeping field. The research which it sees to sleep it searched for the variable which shows the difference point of shopping orientation of the on-line consumer and off-line consumer two group and it attempted. From the research which it sees shopping propensity shopping it is joyful, it perceives dangerously, with price ceremony and convenient characteristic to classify, it analyzed. Analysis result shopping it is joyful it was rejected, classifies the perception against a danger and a price ceremony and convenient Royal favor two group with the consider variable which it appeared. The namely on-line consumer perceived against a danger lowly, it was sensitive to a price, it appeared with the fact that it pursues a convenient characteristic.

• Journal of IKEEE
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• v.14 no.1
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• pp.55-64
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• 2010

In this paper, we proposed the novel TIGBT with an additional p-type MOS structure to achieve the improved trade-off between turn-off and on-state voltage drop(Vce(sat)). These low on-resistance and the fast switching characteristics of the proposed TIGBT are caused by an enhanced electron current injection efficiency which is caused by additional p-type MOS structure. In the simulation result, the proposed TIGBT has the lower on state voltage of 1.67V and the shorter turn-off time of 3.1us than those of the conventional TIGBT(2.25V, 3.4us).

• Journal of Information Technology Services
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• v.15 no.2
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• pp.51-63
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• 2016

In this study, we conducted a comparative analysis of R&D investment efficiency and operational efficiency of IT firms using Data Envelopment Analysis (DEA). We categorized thirteen sample firms into two groups-IT manufacturing and IT service-after an extensive literature review on IT industry classification. We adopted an output-oriented two-stage DEA model suggested by Banker et al. (1984) with total asset and R&D investment as input variables. Then, we constructed investment efficiency and operational efficiency by using Return on Equity (ROE) and Return on Asset (ROA) as intervening variables and operating income and Earnings Per Share (EPS) as output variables. The outcome of the analysis is summarized as follows. First of all, IT manufacturing firms were more efficient (57% on average) than IT service firms. To be specific, IT service firms showed decreasing returns to scale (DRS) with diseconomy of scale. In contrast, IT service firms showed higher operational efficiency (81.5% on average) than IT manufacturing firms. Also, we conducted a Mann-Whitney U test to compare the output of IT service firms and IT manufacturing firms. Lastly, we found a negative correlation ($R^2$ = -.754) between R&D investment efficiency and operational efficiency which infers the trade-off between two constructs

• Asia pacific journal of information systems
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• v.18 no.3
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• pp.45-65
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• 2008

The rapid growth of the Internet has increased the amount of transmission of personally identifiable information. At the same time, with new Internet related technologies, organizations are trying to collect and access more personal information than before, which in turn makes individuals concern more about their information privacy. For their successful businesses, organizations have tried to alleviate these concerns in two ways: (1) by offering privacy policies that promise certain level of privacy protection; (2) by offering benefits such as financial gains or convenience. In this paper, we interpret these actions in the context of the information processing theory of motivation. This paper follows Hann et al.(2007)'s methods to analyze Internet users privacy concerns in Korea and tries to compare the findings. Our research objectives are as follows: First, we analyze privacy concern mitigation strategies in the framework of the expectancy theory of motivation. Subsequently, we show how the expectancy theory based framework is linked o the conjoint analysis. We empirically validate the predictions that the means to mitigate privacy concerns are associated with positive valences resulting in an increase in motivational score. In order to accommodate real-life contexts, we investigate these means in trade-off situation, where an organization may only be able to offer partially complete privacy protection and/or promotions and/or convenience, While privacy protection (secondary use, improper access) are associated with positive valences, we also find that financial gains can significantly increase the individuals' motivational score of a website in Korea. One important implication of this empirical analysis is that organizations may possess means to actively manage the privacy concerns of Internet users. Our findings show that privacy policies are valued by users in Korea just as in the US or Singapore. Hence, organizations can capitalize on this, by stating their privacy policy more prominently. Also organizations would better think of strategies or means that may increase online users' willingness to provide personal information. Since financial incentives also significantly increase the individuals' motivational score of website participation, we can quantify the value of website privacy protection in terms of monetary gains. We find that Korean Internet users value the total privacy protection (protection against errors, improper access, and secondary use of personal information) as worthy as KW 25,550, which is about US 28. Having done this conjoint analysis, we next adopt cluster analysis methodology. We identify two distinct segments of Korea's internet users-privacy guardians and information sellers, and convenience seekers. The immediate implication of our study is that firms with online presence must differentiate their services to serve these distinct segments to best meet the needs of segments with differing trade-offs between money and privacy concerns. Information sellers are distinguished from privacy guardians by prior experience of information provision, To the extent that businesses cannot observe an individual's prior experience, they must use indirect methods to induce segmentation by self-selection as suggested in classic economics literature of price discrimination, Businesses could use monetary rewards to attract information sellers to provide personal information. One step forward from the societal trends that emphasize the need of legal protection of information privacy, our study wants to encourage organizations and related authorities to have the viewpoints to consider both importance of privacy protection and the necessity of information trade for the growth of e-commerce.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.110-118
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• 2017

This study investigated empirically one of the controversial subjects in modern finance, in that there is an optimal level of capital structure for KOSPI-listed firms in the Korean capital market. Given the major theories on the capital structure, such as Myers' pecking order, trade-off, and agency cost ones, this study applied an analysis of covariance models in parametric and non-parametric statistical methods. In particular, two covariates to control for the possible effects of trade-off and agency cost, were employed separately in each corresponding model, while the other proxy for pecking order rationale was adopted in previous research [1] to conduct inter- and intra-industry analyses. Based on the outcomes obtained from the study, it was demonstrated empirically that there are optimal capital structures for firms in the sample industries at the inter-industry level, whereas statistical differences indicating non-existence of an optimal point, were revealed within the industry. Accordingly, these findings suggest a new vision to potential investors that firms in the domestic market may have financial opportunities to increase their value by gradually adjusting the leverage ratios in terms of the intra-industry perspective.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.5
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• pp.93-102
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• 2009

A prediction of streamflow based on multi-objective function is presented to check the performance of Probability Distributed Model(PDM) in Miho stream basin, Chungcheongbuk-do, Korea. PDM is a lumped conceptual rainfall runoff model which has been widely used for flood prevention activities in UK Environmental Agency. The Monte Carlo Analysis Toolkit(MCAT) is a numerical analysis tools based on population sampling, which allows evaluation of performance, identifiability, regional sensitivity and etc. PDM is calibrated for five model parameters by using MCAT. The results show that the performance of model parameters(cmax and k(q)) indicates high identifiability and the others obtain equifinality. In addition, the multi-objective function is applied to PDM for seeking suitable model parameters. The solution of the multi-objective function consists of the Pareto solution accounting to various trade-offs between the different objective functions considering properties of hydrograph. The result indicated the performance of model and simulated hydrograph are acceptable in terms on Nash Sutcliffe Effciency*(=0.035), FSB(=0.161), and FDBH(=0.809) to calibration periods, validation periods as well.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.633-636
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• 2005

An electro-optical camera system consists of many subsystems such as the optics, the detector, and the electronics and so on. They may create variations in the processed image that were not present original scene. The performance analysis of the electro-optical camera system is a mathematical construct that provides an optimum design through appropriate trade off analysis. The SNR(Signal to Noise Ratio) is one of the most important performance for the electro-optical camera system. The SNR analysis shown in this paper is performed based on the practical high resolution satellite camera design. For the purpose of the practical camera design, the analysis assumes that the defined radiance, which is calculated for the Korean peninsula, reached directly to the telescope entrance. In addition, the actual operation concept such as integration time and the normal operation altitude is assumed. This paper compares the SNR analysis results according to the various camera characteristics such as the optics, the detector, and the camera electronics. In detail, the optical characteristics can be split into the focal length, F#, transmittance, and so on. And the system responsivity, the quantum efficiency, the TDI stages, the quantization noise and the analogue noise can be used for the detector and the camera electronics characteristics. Finally this paper suggests the optimum design to apply the practical electro-optical system.