• 한국항만경제학회지
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• 제34권4호
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• pp.181-190
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• 2018

본 연구는 2012년 1월부터 2018년 5월까지의 주별 건화물선 운임과 원자재 가격 자료를 사용하여 두 변수간의 비대칭적인 관계를 다음의 두 가지를 중심으로 실증 분석한다. 첫째, 원자재가격의 거시경제지표에 대한 비대칭성을 2단계 경계(threshold) 공적분 검정모형으로 추정한다. 둘째, 기존의 원자재가격 변화의 무역수지에 대한 비대칭관계 검정을 보다 고빈도 건화물선 운임지수로 우회해서 검정한다. 추정결과 기존의 선형 분석과 대조적으로 하한과 상한에 대한 각각의 경계값이 상이한 비대칭성을 갖는 것으로 드러났다. 이는 불규칙적인 수익률 변동을 유발하는 급격한 잔차의 변동 구간이 원자재 가격과 건화물선 운임간의 선형의 장기균형관계가 성립하지 않도록 함을 의미한다. 따라서 이상의 추정결과는 급격한 가격 변화를 분석에 고려하기 위해서는 불규칙(irregular)적인 변동성을 제어하는 무반응(band of inaction)구간을 모형에 포함하는 것이 필요함을 의미하며 기존의 원자재가격의 무역수지에 대한 비대칭성과 일치하는 실증분석 결과다.

• 대한치과교정학회지
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• 제35권3호
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• pp.163-173
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• 2005

본 연구는 안면비대칭 환자에서 경조직의 비대칭 정도와 연조직 비대칭 정도의 차이를 3차원적으로 밝히고자 시행되었다. 안면비대칭으로 보이는 성인 남녀 34명을 대상으로 두경부 전산단층사진을 촬영하고 3차원 입체영상으로 재구성한 후 기준평면에 대해 비대칭을 나타내는 5개의 계측항목을 경조직에 설정하고, 이에 대응하는 연조직 계측항목을 각각 설정한 후 3차원 계측을 시행하고 경조직과 연조직의 계측항목간 차이를 비교하였다. 이부편위측과 반대측간의 계측치 차이를 비교한 결과, 경조직과 연조직 모두에서 좌우측 계측치간에 통계적으로 유의한 차이가 관찰되었으며 경조직과 연조직의 비대칭 계측항목을 비교한 결과, 6개의 계측항목 모두에서 통계적으로 유의한 차이를 나타내었다. 이부편위를 나타내는 chin deviation, 하악지와 하악골체를 나타내는 frontal ramal inclination difference, frontal corpus inclination difference 항목은 경조직의 비대칭 정도에 비하여 연조직 비대칭 정도가 작게 나타난 반면, 입술경사를 나타내는 lip cheilion height difference, lip canting은 maxillary height difference, occlusal plane canting보다 크게 나타나 입술부위의 비대칭 정도는 하부 경조직의 비대칭 정도보다 큰 것으로 나타났다. 안면비대칭자에서 경조직과 연조직간 비대칭 정도 차이를 규명한 본 연구 결과는 안면비대칭 평가 시 경조직 외에 연조직 계측항목을 이용한 비대칭 분석도 필요함을 시사하였다.

• 재무관리연구
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• 제23권1호
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• pp.101-133
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• 2006

본 연구에서는 1992년 1월 3일부터 2003년 12월 30일까지의 표본기간동안 KOSPI 200 포트폴리오와 이에 대응하는 Non-KOSPI 200 포트폴리오를 구성하여 새로운 파생상품거래가 현물시장 변동성의 비대칭성에 어떤 영향을 미치는지를 검증하였다. 연구결과는 파생상품 도입이후 현물시장의 변동성 비대칭성이 대체적으로 완화되었음을 보여준다. GJR-GARCH 모형을 이용한 분석결과는 KOSPI 200과 Non-KOSPI 200을 비교할 때 새로운 파생상품 거래가 KOSPI 200 변동성의 비대칭 정토를 감소시키며, 파생상품거래의 효과는 제한적이나마 Non-KOSPI 200을 구성하는 종목들에게까지 영향을 미침을 보여준다. 음(-)의 수익률 충격에 의한 변동성과 양(+)의 수익률 충격에 의한 변동성의 비율인 변동성비율을 계산하여 분석한 결과는 KOSPI 200의 경우 주가지수옵션 도입 이후 및 외환위기 이후 변동성의 비대칭성이 크게 감소했으나 Non-KOSPI 200에서는 해당기간에 뚜렷한 효과가 나타나지 않는다. 특히, KOSPI 200에서 규제완화가 크게 이루어진 1999년 1월 이후기간에서 변동성비율이 현저히 낮아졌음을 확인할 수 있으며, 이는 변동성의 비대칭정도가 시장의 규제수준과 밀접한 관련이 있음을 시사한다. 또한 본 연구의 결과는 레버리지효과와 환율변동이 한국유가증권시장의 변동성 비대칭성을 설명하는 중요 요인이 될 수 있음을 보여주고 있다.

• Physical Therapy Rehabilitation Science
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• 제10권3호
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• pp.374-378
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• 2021

Objective: Bilateral movement training is an effective method for upper extremity rehabilitation of stroke. An approach to induce bilateral movement through functional electrical stimulation is attempted. The purpose of this study is to develop an EMG-triggered functional electrical stimulation device for upper extremity bilateral movement training in stroke patients and test its feasibility. Design: Feasibility and Pilot study design. Methods: We assessed muscle activation and kinematic data of the affected and unaffected upper extremities of a stroke patient during wrist flexion and extension with and without the device. Wireless EMG was used to evaluate muscle activity, and 12 3D infrared cameras were used to evaluate kinematic data. Results: We developed an EMG-triggered functional electrical stimulation device to enable bilateral arm training in stroke patients. A system for controlling functional electrical stimulation with signals received through a 2-channel EMG sensor was developed. The device consists of an EMG sensing unit, a functional electrical stimulation unit, and a control unit. There was asymmetry of movement between the two sides during wrist flexion and extension. With the device, the asymmetry was lowest at 60% of the threshold of the unaffected side. Conclusions: In this study, we developed an EMG-triggered FES device, and the pilot study result showed that the device reduces asymmetry.

• 대한물리의학회지
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• 제15권3호
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• pp.89-98
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• 2020

PURPOSE: This study investigated the effects of unilateral static stretching on the flexibility and symmetry of the lower leg, and temporal gait variables in gait asymmetry people. METHODS: Twenty gait asymmetry people were divided into a unilateral static stretching group (USG, n = 10) and control group (CON, n = 10). The USG performed unilateral static stretching for 60 minutes, three times a week, and eight weeks. The flexibility of the lower leg (SR), and symmetry (BR), and temporal gait variables (Step length; SL, gait speed; GS) were measured before, after four and eight weeks of unilateral static stretching. Moreover, SI (symmetry index; SI) was calculated from the measured SL value. Statistical analyses were conducted using one-way ANOVA and two-way ANOVA with repeated measures, a paired t-test, and multiple comparisons according to Scheffe. RESULTS: SR and BR in the dominant and non-dominant side, and GS were increased significantly at USG after eight-weeks compared to before unilateral static stretching (p < .05). The difference in BR in the dominant and non-dominant side, and step length (SI) decreased significantly at USG after eight-weeks compared to before unilateral static stretching (p < .05). CONCLUSION: Unilateral static stretching improves the flexibility and symmetry of the lower leg, and temporal gait variables in gait asymmetry people.

• Asia Marketing Journal
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• 제15권3호
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• pp.53-77
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• 2013

As advertising and promotions are categorized as operating expenses, managers tend to reduce marketing budget to improve their short term profitability. Gauging the value and accountability of marketing spending is therefore considered as a major research priority in marketing. To respond this call, recent studies have documented that financial market reacts positively to a firm's marketing activity or marketing related outcomes such as brand equity and customer satisfaction. However, prior studies focus on the relation of marketing variable and financial market variables. This study suggests a channel about how marketing activity increases firm valuation. Specifically, we propose that a firm's marketing activity increases the level of the firm's product market information and thereby the dispersion in financial analysts' earnings forecasts decreases. With less uncertainty about the firm's future prospect, the firm's managers and shareholders have less information asymmetry, which reduces the firm's cost of capital and thereby increases the valuation of the firm. To our knowledge, this is the first paper to examine how informational benefits can mediate the effect of marketing activity on firm value. To test whether marketing activity contributes to increase in firm value by mitigating information asymmetry, this study employs a longitudinal data which contains 12,824 firm-year observations with 2,337 distinct firms from 1981 to 2006. Firm value is measured by Tobin's Q and one-year-ahead buy-and-hold abnormal return (BHAR). Following prior literature, dispersion in analysts' earnings forecasts is used as a proxy for the information gap between management and shareholders. For model specification, to identify mediating effect, the three-step regression approach is adopted. All models are estimated using Markov chain Monte Carlo (MCMC) methods to test the statistical significance of the mediating effect. The analysis shows that marketing intensity has a significant negative relationship with dispersion in analysts' earnings forecasts. After including the mediator variable about analyst dispersion, the effect of marketing intensity on firm value drops from 1.199 (p < .01) to 1.130 (p < .01) in Tobin's Q model and the same effect drops from .192 (p < .01) to .188 (p < .01) in BHAR model. The results suggest that analysts' forecast dispersion partially accounts for the positive effect of marketing on firm valuation. Additionally, the same analysis was conducted with an alternative dependent variable (forecast accuracy) and a marketing metric (advertising intensity). The analysis supports the robustness of the main results. In sum, the results provide empirical evidence that marketing activity can increase shareholder value by mitigating problem of information asymmetry in the capital market. The findings have important implications for managers. First, managers should be cognizant of the role of marketing activity in providing information to the financial market as well as to the consumer market. Thus, managers should take into account investors' reaction when they design marketing communication messages for reducing the cost of capital. Second, this study shows a channel on how marketing creates shareholder value and highlights the accountability of marketing. In addition to the direct impact of marketing on firm value, an indirect channel by reducing information asymmetry should be considered. Potentially, marketing managers can justify their spending from the perspective of increasing long-term shareholder value.

• The Journal of Asian Finance, Economics and Business
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• 제6권1호
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• pp.21-31
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• 2019

This paper examines how corporate social responsibility is related to the degree of asymmetric information in the Korean financial market. Recent theory argues that there is a negative relationship between a firm's corporate social responsibility and its information asymmetry. To test this hypothesis, we use the environment, social and governance (ESG) score, published by the Korean Corporate Governance Service, to proxy a firm's management practices toward socially responsible activities. In the entire sample of the Korean firms, we find contrasting results; the ESG score shows negative relationships with the price impact measure but statistically insignificant relationships with the dispersion of analyst forecasts. However, the ESG score shows negative relationships with both measures when we exclude chaebol affiliates from the sample. These findings are robust when we examine environmental, social and corporate governance scores separately. This set of results argues for the extant theory, expecting a negative relationship between a firm's engagement in corporate social responsibility and asymmetric information. It further argues for the importance of firm characteristics in determining the influence of socially responsible activities.

• 응용통계연구
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• 제24권1호
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• pp.11-23
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• 2011

Robust unit root tests are developed for dynamic panels consisting of TAR processes. The test statistics are all based on diverse combinations of individual t-type tests for significance of TAR coefficients. Limiting null distributions are established. A Monte-Carlo experiment compares the proposed tests. The tests are applied to a panel data set of Canadian unemployment rates which show asymmetric features as well as having outliers.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.516-519
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• 2012

This study proposes a method of an equivalent bell model in order to tune the beat period of a Korean bell. In a Korean bell having a slight asymmetry, each circumferential mode splits into a mode pair which has a slight difference in frequency, and the interaction of the mode pair makes a beat in vibration and sound. An equivalent bell model which consists of an axi-symmetric bell and an equivalent point mass, has the same mode property as in a real bell. The equivalent bell model is constructed by the finite element analysis based upon the theory of a revolutionary shell Using the equivalent bell model, the beat period is predicted when the bell thickness is locally decreased to improve the beat property. The predicted result is verified by experiment on a test bell. The proposed method is useful to save the time required for tuning the beat period of a large bell.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권3호
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• pp.414-430
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• 2013

This paper shows the study of preswirl duct as an effective energy saving devices that have been devised and reviewed to support the propeller performance, especially for the ship of VLCC with large block coefficients. From the bare hull wake measurements, typical upper/lower asymmetry of hull wake at the propeller disk was found. The 2 kinds of pre-swirl duct, Unconventional half circular duct and Conventional circular pre-swirl duct have been designed and reviewed to recover the loss of propeller running in that condition. The general function of the pre-swirl duct was set to work against this asymmetry of wake and generate pre-swirled flow into the propeller against the propeller rotating direction. The optimum self propulsion tests with various angle configurations were carried out and the best configuration was decided. Accordingly, cavitation test was carried out with best configuration of unconventional half circular duct. The blade surface and tip vortex cavitation behaved smoother when the duct was mounted. The hull pressure amplitudes reflected this difference, so the hull pressure amplitude with duct was smaller than that of without duct.