对小地区失业统计差额比的推定

本文对韩国国内行政区域如市郡区等小地区的失业统计共同差额比进行推定的方法有联合推定量,Woolf推定量和Mantel-Haenszel推定量等。对这个推定量的可信度是通过偏差和平均平方误差的概念来进行比较的。从对京畿地区经济活动人口调查情况看,这个地区内的24个市郡单位行政自治地区的男、女失业率差额比的偏差及平均平方误差是通过本次研究提出的推定程序来推定的。这些推定数的稳定性和效率性可以通过相对偏差和相对平均误差平方根来评价。Woolf推定量或Mantel-Haenszel推定量比联合推定量更为稳定,从其效率性来看三者很相似。     

Application of signal processing techniques to the detection of tip vortex cavitation noise in marine propeller

The tip vortex cavitation and its relevant noise has been the subject of extensive researches up to now. In most cases of experimental approaches, the accurate and objective decision of cavitation inception is primary, which is the main topic of this paper. Although the conventional power spectrum is normally adopted as a signal processing tool for the analysis of cavitation noise, a faithful exploration cannot be made especially for the cavitation inception. Alternatively, the periodic occurrence of bursting noise induced from tip vortex cavitation gives a diagnostic proof that the repeating frequency of the bursting contents can be exploited as an indication of the inception. This study, hence, employed the Short-Time Fourier Transform (STFT) analysis and the Detection of Envelope Modulation On Noise (DEMON) spectrum analysis, both which are appropriate for finding such a repeating frequency. Through the acoustical measurement in a water tunnel, the two signal processing techniques show a satisfactory result in detecting the inception of tip vortex cavitation.     

EXPERIMENTAL ESTIMATION OF A SCALING EXPONENT FOR TIP VORTEX CAVITATION VIA ITS INCEPTION TEST IN FULL- ANDMODEL-SHIP

Tip vortex cavitation noise of marine propeller became primary concerns to reduce hazardous environmental impacts from commercial ship or to keep the underwater surveillance of naval ships. The investigations of the tip vortex and its induced noise are normally conducted through the model test in a water cavitation tunnel. However the Reynolds number of model-test is much smaller than that of the full-scale, which subsequently results in the difference of tip vortex cavitation inception. Hence, the scaling law between model-and full-scales needs to be identified prior to the prediction and assessment of propeller noise in full scale. From previous researches, it is generally known that the incipient caivtation number of tip vortex can be represented as a power of the Reynolds number. However, the power exponent for scaling, which is the main focus of this research, has not been clearly studied yet. This paper deals with the estimation of scaling exponent based on tip vortex cavitation inception test in both full-and model-scale ships. Acoustical measurements as well as several kind of signal processing technique for an inception criterion suggest the scaling exponent as 0.30. The scaling value proposed in this study shows slight difference to the one of most recent research. Besides, extrapolation of model-ship noise measurement using the proposed one predicts the full-scale noise measurement with an acceptable discrepancy.     

感知购物环境对旅游者购物行为的影响机制研究——旅游者购物情绪的媒介作用

在相关研究的基础上,本文运用结构方程建模方法建立了感知购物环境对旅游者购物行为的全影响和间接影响模型,通过对两个模型的对比分析,发现了感知购物环境影响旅游者购物行为的路径机制,即感知购物环境对旅游者购物行为的影响是通过改变旅游者的购物情绪而实现的,旅游者购物情绪在环境→情绪→行为这一路径中起到非常重要的媒介作用。最后,本文提出了管理建议。     

Disappearing Dividends: Implications for the Dividend–Price Ratio and Return Predictability

The conventional dividend–price ratio is highly persistent, and the literature reports mixed evidence on its role in predicting stock returns. We argue that the decreasing number of firms with a traditional dividend‐payout policy is responsible for these results, and develop a model in which the long‐run relationship between the dividends and stock price is time varying. An adjusted dividend–price ratio that accounts for the time‐varying long‐run relationship is considerably less persistent. Furthermore, the predictive regression model that employs the adjusted dividend–price ratio as a regressor outperforms the random‐walk model. These results are robust with respect to the firm size.     

Explaining Financial Management Behavior for Koreans Living in the United States

Using a cross‐cultural conceptualization with a targeted sample of Americans and Koreans, it was noted that Koreans exhibited more responsible financial management behavior than Americans after controlling for locus of control, financial knowledge, and income interactions. Overall, financial knowledge was positively related to responsible financial behavior. No direct effects on financial management behavior were noted for locus of control or household income. Locus of control was found to mediate the effect of financial knowledge on financial behavior for Koreans. Being Korean did moderate between financial knowledge and financial behavior.     

MEASURING PRICE ELASTICITY OF SECTORIAL IMPORTS

Previous published studies have estimated the long‐run cointegrating relationship to infer the price elasticity of imports, but a stable long‐run cointegrating relationship might not be detected in the data, especially in the case of sectoral data. This paper develops a method to estimate the price elasticity of imports based on a vector autoregression model, which can be applied when a stable long‐run cointegration relationship does not exist. The methods developed in past studies and our method are applied to Korean sectoral imports data to illustrate the usefulness of our method.     

EFFECTS OF TAXES AND BENEFITS ON INCOME DISTRIBUTION IN KOREA

This paper examines the redistributive effects of Korea's fiscal policies, including consumption taxes and in‐kind benefits. Using the Household Income and Expenditure Survey of 2007, we find that taxes and transfers reduce income inequality in Korea by 13.8 percent. Contrary to the popular belief that direct taxes are the key tool for redistribution, in‐kind benefits, direct taxes, and social security contributions all decrease the Gini coefficient by 6.7, 4.7, and 2.9 percentage points, respectively. The redistributive effect of consumption taxes is small and negative (?0.5 percentage point). Policy simulations indicate that education spending financed by the personal income tax has a positive redistributive effect and that the lower 70 percent of households enjoy positive net benefits. Spending targeting the poor has a strong redistributive effect, which implies low popularity because the majority of households face net losses.     

Financial Integration in Emerging Asia: Challenges and Prospects

Using both quantity‐ and price‐based measures of financial integration, the paper shows an increasing degree of financial openness and integration in emerging Asia. Assessing the impact of a regional shock relative to a global shock on local equity and bond markets, the findings suggest that the region's equity markets are integrated more globally than regionally, although the degrees of both regional and global integration have increased significantly since the 1997/1998 Asian financial crisis. However, emerging Asia's local currency bond markets remain generally segmented, being neither regionally nor globally integrated. There are potential benefits from increased regional integration of financial markets. Financial integration at the regional level allows for the region's economies to benefit from allocation efficiency and risk diversification. Policymakers in the region must strike the right balance between maximizing the net benefits from regional and global financial openness, and minimizing the potential costs of financial contagion and crisis.     

EXPLOITING UNCERTAINTY—INVESTMENT OPPORTUNITIES AS REAL OPTIONS: A NEW WAY OF THINKING IN ENGINEERING ECONOMICS

A new trend in corporate planning is to exploit uncertainty by taking investment opportunities as real options. This options approach is to complement the conventional net present value (NPV) criterion in evaluating risky investments. In this paper, we take a broad look at the real options approach to various engineering economic decision problems, laying out how it provides an immediate and important perspective on value creation in an uncertain world. Unlike financial options, real options analysisdeals with investments in real assets, which is one of the primary interest areas in engineering economics. For that reason, we believe that any advancement in the real options decision framework will benefit the field of engineering economics.