• 대한전기학회논문지:시스템및제어부문D
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• 제54권12호
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• pp.716-722
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• 2005

In this paper, we propose the audio watermarking algorithm based on the critical band of HAS(human auditory system) without audibly affecting the quality of the watermarked audio and implement the detecting algorithm on the BSS(broadcast synchronizing system) for testing the proposed algorithm. According to the audio quality test, the SNR(signal to noise ratio) of the watermarked audio objectively is 66dB above. In the robustness test, the proposed algorithm can detect the watermark more than $90\%$ from various compression(MP3, AAC), A/D and D/A conversions, sampling rate conversions and especially asynchronizing attacks. The BSS automatically switches the programs between the key station and the local station in broadcasting system. The result of reliability test of implemented system by using the real broadcasting audio has no false positive error during 30 days. Because of detecting once processing per 0.5 second, we can judge that the false positive error does not occur.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권9호
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• pp.520-525
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• 2003

A robust controller for large space structures(LSS) is studied from passivity point of view. While velocity sensors are commonly used for proportional-derivative (PD) control law to stabilize large space structures, if the structure can be controlled without velocity measurements, it is desirable against the failure of velocity sensors and for the cost reduction of the sensing system. In a recent result a dynamic output feedback control law has been provided using only displacement measurements. This paper presents a passivity-based controller design method and provides an alternative stability analysis tool for the previous displacement feedback robust control law. The closed-loop system can be viewed as a feedback interconnection of a passivated large space structure (LSS) and a strictly positive real (SPR) system.

• Journal of Mechanical Science and Technology
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• 제18권7호
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• pp.1150-1158
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• 2004

In this paper, we present an adaptive observer for nonlinear systems that include unknown constant parameters and are not necessarily observable. Sufficient conditions are given for a nonlinear system to be transformed by state-space change of coordinates into an adaptive observer canonical form. Once a nonlinear system is transformed into the proposed adaptive observer canonical form, an adaptive observer can be designed under the assumption that a certain system is strictly positive real. An illustrative example is included to show the effectiveness of the proposed method.

• 무역학회지
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• 제45권6호
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• pp.113-130
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• 2020

This study analyzes the effect of misalignment exchange rate on economic performance asymmetrically. The results show that the over valuation of the real effective exchange rate of won has a significant positive relationship with economic performance. The under valuation of the real effective exchange rate of won has a positive effect on economic performance, but it is not significant. This is due to the high ratio of re-exports of intermediate goods despite Korea being an export-oriented country. In Japan, the undervaluation of the exchange rate has a negative impact on economic performance.

• 한국경영과학회지
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• 제29권4호
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• pp.159-173
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• 2004

Instant Messenger is a communication tool which allows instant real-time connection between parties through Internet Compared to the most popular Internet communication tool. email. the messenger allows people to check network presence of other parties and to connect in real time among multiple parties. Mostly due to the convenience it provides. use of instant messengers has increased tremendously not only for personal purpose but also for business purpose. However. firms are agonizing about the real impact of instant messenger usage among employees. whether the impact is positive or negative in terms of the productivity, Applying the theory of reasoned action (TRA) and technology acceptance model (TAM). this study sets UP perceived ease of use. perceived usefulness and cultural orientation of individuals as antecedents of adoption and use of the messenger application, Also. the impacts of messenger usage are measured as task productivity and intimacy among colleagues. This study presents several findings about the instant messenger, First. perceived ease of use. and usefulness play important roles in raising the adoption level of instant messenger. Also. culture propensity also maintains strong influence towards the actual usage of the messenger. Among cultural variables. innovativeness, supportiveness and outcome orientation reveal strong positive impacts on adoption and use of the messenger. On the dependent side. use of instant messenger seems to have a strong direct impact on task productivity as well as indirect impact through intimacy. Implications are discussed.

• 한국건설관리학회논문집
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• 제18권1호
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• pp.90-99
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• 2017

본 연구는 서울의 상업용 부동산인 오피스 빌딩 및 소매용 부동산 자산을 대상으로 체계적 위험과 자본환원율 간의 관계를 실증분석함으로써 시장의 효율성과 CAPM의 적용여부를 검증하는 것을 목적으로 한다. 이를 위하여 본 연구에서는 투자의 위험을 수반하는 자본자산의 기대수익률 결정이론인 자본자산가격결정모형(CAPM)을 토대로 서울의 3대 오피스 빌딩 시장인 강남권, 여의도 마포권, 도심권 그리고 기타권역과 소매용 부동산의 3대 시장인 강남권, 신촌 마포권, 도심권 그리고 기타 권역에 대하여, 시장포트폴리오인 증권시장선과 권역별 초과자본환원율로 산정된 증권특성선을 비교 및 분석하였으며 그 결과, 오피스 빌딩 시장에서 GBD 권역을 제외한 나머지 권역들(YBD 권역, CBD 권역 그리고 기타 권역), 소매용 부동산 시장에서는 SBD 권역 및 CBD 권역에서 체계적 위험이 증가할수록 분기초과자본환원율이 감소하여 시장이 효율적이지 않음을 알 수 있었다. 이와 함께, 오피스 빌딩 시장의 4개 권역(강남권의 GBD 권역, 마포 여의도권의 YBD 권역, 도심권의 CBD 권역, 그리고 기타 권역)과 소매용 부동산 시장의 4개 권역(강남권의 GBD 권역, 마포 신촌권의 SBD권역, 도심권의 CBD 권역, 그리고 기타 권역) 모두에서 CAPM이 성립하지 않음도 확인할 수 있었다.

• The Journal of Asian Finance, Economics and Business
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• 제6권3호
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• pp.163-172
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• 2019

The paper aims to investigate the impact of the gap between domestic and international gold price on money demand in Vietnam, an emerging economy in the Asian region. We use a quarterly database collected from the first quarter of 2004 to the fourth quarter of 2016. The time-series database includes 52 observations. The money demand is represented by M2; Domestic income is the Gross domestic product at the constant prices of 1994; Inflation rate is calculated by the Customer Price Index from the General Statistics Office of Vietnam. The result confirms the existence of a long-term cointegration relationship between the money demand and the gap between domestic and international gold price as well as some variables including domestic income, inflation, and real exchange rate. The regression results also show that the gap between domestic and international gold price has a positive impact on money demand in the Vietnamese economy. Besides, the domestic income and international gold price have positive impacts on money demand while the inflation and real exchange rate are negatively related in the long run. This proves that the gap between the domestic and international gold price really has a positive impact on money demand in Vietnam during the study period.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.583-593
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• 2021

The objective of this paper is to investigate the impact of economic growth (per capita real GDP), the square of per capita real GDP, energy use, financial development (FD), and foreign direct investment (FDI) on ecological footprint (EF) in the case of Malaysia over the period 1971-2014, by employing the ARDL approach. The long-run results revealed that economic growth has a significant positive impact on the ecological footprint and it implies that the economic growth deteriorates the environmental quality in Malaysia. Conversely, the square of GDP showed a negative and significant impact on the EF in the long run. As the coefficient of GDP in our study is positive and statistically significant while the coefficient of squared GDP is negatively significant, thus, this study supports the presence of the environmental Kuznets curve (EKC) hypothesis in the case of Malaysia. Furthermore, the result indicates that FDI has a positive and significant impact on the EF in the long run, which means a rise in FDI will enhance the environmental pollution level. Thus, it confirms the pollution haven hypothesis. Hence, it suggests that Malaysia imposes stricter environmental policies. Further, FDI and FD are causing GDP in Malaysia, but through increasing EF.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.103-112
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• 2021

The labor force plays an important role in attracting foreign direct investment (FDI) both in developed and developing countries. In countries where there are appropriate policies for training human resources and maintaining the health of human resources, such countries have a competitive advantage and can attract FDI inflows, besides having a workforce to meet the needs of foreign investors. The purpose of this paper is to analyze the effect of the labor force and several other factors on FDI attraction in Vietnam. The empirical model is employed to perform regression and correlation on the impact of the labor force, real gross domestic product, inflation, index of business freedom, and index of investment freedom on Vietnam's FDI attraction by using a secondary time series data set during the period 1995-2018. The empirical results found that both labor force and inflation have a positive influence on FDI at a 5% significance level; index of business freedom has a positive impact on FDI at a 10% significance level, and real gross domestic product and index of investment freedom have a positive impact on FDI at a 1% significance level. From these results, this study proposes several important policy implications for Vietnam in attracting FDI in the future.

• 무역학회지
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• 제47권5호
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• pp.75-93
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• 2022

Purchasing Power Parity (hereafter, PPP) means the purchasing power of two currencies is the same when one is converted into the other one. According to previous studies on PPP, as the volatility of the real exchange rate is smaller, PPP may be more likely to hold. Since New Zealand adopted the inflation targeting policy in December 1989, many countries started to adopt it as their monetary policy frame. Previous studies on inflation targeting found that inflation targeting policy has positive effects on not only achieving price stability but also reducing the volatility of nominal/ real exchange rates. Therefore, in this study, I explored whether inflation targeting policy has positive effects on purchasing power parity subject to 19 OECD countries, applying an Exponential Smooth Transition Autoregressive (ESTAR) model during the sample periods, from 1974:Q1 to 2019:Q4. Based on the ESTAR estimate results, I found limited favorable evidence of PPP for only two countries- England and Switzerland- among 9 inflation targeters, compared to non-inflation targeters, and also I found that favorable evidence of PPP only for these two countries among 9 inflation targeters during post-inflation targeting, but not during pre-inflation targeting. These findings imply that the positive effects of inflation targeting on PPP may be questionable unlike Ding and Kim (2012) and Kim (2014)'s study.