• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.127-130
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• 2003

In this paper, a hypothesis in order that the impulse response of a stable linear system does not change sign is suggested. For fixed zeros of the systems, the problem of synthesizing such a system is reduced to the problem of finding a proper denominator polynomial so that the step response of the overall system will not overshoot. The hypothesis is associated with the generalized time constant by Kim[5]. Under the hypothesis, we propose several methods that allow to compose a continuous time LTI systems achieving non-negative impulse response.

• Environmental and Resource Economics Review
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• v.14 no.2
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• pp.291-336
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• 2005

This paper investigates how oil price changes have an impact on the Korean manufacturing production activities. For this investigation, we use a structural VAR motel to estimate impulse response functions of industrial production, producer price and export price to an oil price increase over manufacturing industries. It finds that in most manufacturing industries, an oil price increase leads to decreases in industrial productions and domestic prices except energy intensive industries, but to increases in industrial export prices except non-metallic (26), computers and offic machinery (30), electronic components, radio, television and communication (32) industries. This result explains that an oil price increase makes negative impacts on the manufacturing production activities not only through demand slowdown in the domestic markets but also through supply contraction in the export markets.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2243-2250
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• 2006

When a patient is positioned at insulated bed and practitioner is positioned at insulated floor, that condition could be a cause of lessening effect in acupuncture practice. We investigated how Ground connection and Insulation could influence on the electrical meridian potential between practitioner and patient during acupuncture practice. We treated 30 normal healthy subjects with acupuncture and measured changes in the electrical potential between the stomach meridian points ST-39 and ST-37 in response to light touch after insertion of a needle at ST-36. At first, we stimulated non-insulated needle and measured electrical potentials for non ground, patient ground only, practitioner ground only, all ground respectively. Then we used insulated needles and measured same as above. Non-insulated all ground subject elicited positive mean potential $44.6{\pm}19.2{\mu}V$ and showed $181.4{\pm}59.7{\mu}V$ peak to peak potential. Practitioner ground only showed negative mean potential of $51.5{\pm}9.3{\mu}V$ and $367.4{\pm}27.8{\mu}V$ of peak to peak potential. Patient ground only revealed no mean potential of $2.9{\pm}1.3{\mu}V$, $16.4{\pm}11.9{\mu}V$ of peak to peak potential. All ground showed no mean potential of $1.6{\pm}0.7{\mu}V$, $3.3{\pm}1.9{\mu}V$ of peak to peak potential. In case of Insulated condition, there elicited no mean potential. Non ground and Practitioner only showed weak value of peak to peak potential as $7.8{\pm}2.6{\mu}V$ and $8.4{\pm}2.5{\mu}V$ each. But patient only and all ground showed no potential as $4.7{\pm}2.2{\mu}V$, $3.4{\pm}2.2{\mu}V$, respectively. Therefore, Ground connection modulate the energy transfer course between practitioner and patient. Insulation block energy transfer but static electrical impulse between practitioner and patient.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.51-57
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• 2021

If a company's actions to save or avoid taxes are judged to be tax evasion rather than legal tax action by the tax authorities, the company will not only pay tax but also non-tax costs such as damage to corporate image and stock price decline due to a series of tax evasion-related news articles. Therefore, this study measures the frequency of occurrence of tax evasion controversial keywords in internet news portal as a factor to measure the severity of the case, and analyzes the effect of the frequency of occurrence on corporate value. In the Korean stock market, we crawl related articles from internet news portal by using keywords that are controversial for tax evasion targeting top companies based on market capitalization, and generate a time series of the frequency of occurrence of keywords about tax evasion by company and analyze the effect of frequency of appearance on book value versus market capitalization. Through panel regression and impulse response analysis, it is analyzed that the frequency of appearance has a negative effect on the market capitalization and the effect gradually decreases until 12 months. This study examines whether the tax evasion issue affects the corporate value of Korean companies and suggests that it is necessary to take these influences into account when entrepreneurs set up tax-planning schemes.