• 한국체육학회지인문사회과학편
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• v.57 no.6
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• pp.263-272
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• 2018

This study examined the association of gait variability and physical fitness with frailty status in older women. In a cross-sectional design, 168 elderly women, aged 65 years and older (75.07±5.40 years), measured body composition, gait parameters gait variability, physical fitness variables, MMSE-DS and CES-D. Subjects were classified as robust, pre-frail, and frailty based on the Fried et al.(2001) criteria for frailty weight loss, exhaustion, low hand-grip strength, low gait speed, and physical inactivity. Logistic regression analyses were used to determine the odds ratio (ORs) and 95% confidence interval (CI) of frailty status for having gait variability and physical fitness levels. Compared to the robust group (OR=1), the frailty group had significantly higher ORs of having terminal double limb stance (OR=1.48, 95% CI=0.10-2.21, p=.049), step cadence (OR=2.06, 95%CI=1.20-3.43, p=.009) variability, and significantly lower ORs of having upper-strength (OR=0.49, 95%CI=0.31-0.77, p=.002) even after adjusting for age, education, comorbidity, K-IADL, MMSE-KC and CES-D score. The finding of this study suggested that terminal double limb stance, step cadence and upper body muscular strength were independent predictors of frailty.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.323-324
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• 2007

• 전기의세계
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• v.41 no.5
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• pp.5-13
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• 1992

이 글에서, 우리는 앰블러 메카니즘 그리고 집적보행 시스템의 성분에 대해 집중적으로 논의했고, 보행 실험을 문서화 했다. 거슬러 올라가서 연구는 교통기관과 항해 문제점들에 초점을 맞추었다. 현재, 우리는 광범위한 시험들-점점 더 모험적인 지형위로의 보행-을 앰블러와 집적 보행 시스템의 능력을 실증하기 위해 수행하고 있다. 미래 보행 실험들을 앰블러의 이동성과 자율성에 보다 더 도전할 것이다. 집적 시스템이 믿을 수 있는 설비로 성숙함에 따라, 우리는 머리위의 기증기를 제거할 것이다. 이것은 앰블러가 더 거친 실재 코스(더큰 높이 변동)에 대처하게 할 것이며, 그리고 앰블러가 실외로 이동하도록 한다. 앰블러가 더 긴 범위의 코스을 횡단한다면, 밧줄은 그때 줄여지게 될 것이다. 1991년 12월에 대한 목적은, 밤에, 앰블러가 모래, 바위들, 철도 연결선, 자갈, 그리고 톱밥으로 구성되어 진 100m의 실외 코스를 횡단할 것이라는 것이다. 동시에, 증가하고 있는 강조점즐은 수행하고 있고, 발전하고 있는 임무의 배경에서, 조작 문제들에 놓이게 될 것이다. 이 목적으로 이동성과 조작을 조합하는 것ㅇ과 연관된 문제점들을 나타내기 위해 표본획득 툴과 감지기들이 앰블러에 부착되어질 것이다. 1991년 12월의 또 다른 목적은 실내 표본 임무를 실증하는 것이다. 예를들면, 동 떨어진 조작자에 의해 지시되어 지는 부분적으로 묻힌 바위를 수집하는 것이다.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.109-118
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• 2013

The purpose of this study was to determine the effects of line dance programme on the balance ability during walking to reveal the exercise intervention for fall prevention. A 12-week line dance programme was applied to 18 elderly females who aged more than 65 years in the community. Balance ability during walking was evaluated by the range of center of pressure(cop), the velocity of cop, and free torque that calculated on the basis of ground reaction force data. The range and velocity of cop in the anterio-posterior were significantly reduced after performing(p<.01, p<.05, respectively), but change in those of cop in the medio-lateral and free torque were not found. It was demonstrates that 12-week line dance programme allows more effective in anterio-posterior stability of walking. It was suggested that the effect of fall prevention exercise should be studied more associate with fall frequency as future study.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.49-58
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• 2008

The purpose of this study was to identify effects of walking speed and a cognitive task during treadmill walking on gait variability. Experiments consisted of 5 different walking speeds(80%, 90%, 100%, 110% and 120% of preferred walking speed) with/without a cognitive task. 3D motion analysis system was used to measure subject's kinematic data. Temporal/spatial variables were selected for this study; stride time, stance time, swing time, step time, double support time, stride length, step length and step width. Two parameters were used to compare stride-to-stride variability with/without cognitive task. One is the coefficient of variance which is used to describe the amount of variability. The other is the detrended fluctuation analysis which is used to infer self-similarity from fluctuation of aspects. Results showed that cognitive task may influence stride-to-stride variability during treadmill walking. Further study is necessary to clarify this result.

• KDI Journal of Economic Policy
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• v.22 no.1_2
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• pp.363-417
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• 2000

우리 경제는 외환위기를 계기로 단기금융시장을 포함한 국내 자본시장이 전면 개방된 동시에 외환거래 역시 대폭 자유화됨에 따라 실물부문은 물론 금융부문에 있어서도 완전한 개방경제체제로 전환하였다. 이러한 전면적인 자본시장 개방은 국내외 자본시장의 통합을 촉진하는 동시에 환율, 금리, 물가 등 거시 금융변수간의 상충관계(trade-off)에 변화를 초래함으로써 거시경제정책 환경도 크게 변호시킬 것으로 기대된다. 본고에서는 국내외 금리 및 주가간의 동조화 현상에 초점을 맞추어 자본시장 개방에 따른 국내외 자본시장 통합 효과를 살펴본 후, 자본시장 개방이 환율변동패턴의 통계적 특성에 어떠한 영향을 미쳤는지를 분석하였다. 특히 외환위기를 계기로 국내 자본시장이 제도적으로 완전 개방된 점을 고려하여 위기 이전과 이후에 자본시장 통합도와 환율 변동패턴에 어떠한 변화가 발생하였는지를 실증분석하였다. 금리에 대한 실증분석 결과는 외환위기 이후 금리재정거래(金利裁定去來)(interest parity)가 국내금리변화에 미치는 영향이 크게 확대되고 있음을 나타내고 있다. 주가에 대한 실증분석의 경우에도 미국과 국내주가 간의 동조화 현상이 외환위기 이후 심화되고 있으며, 국내 주식시장이 효율적 시장가설(efficient market hypothesis)을 지지하는 방향으로 변화하고 있음을 나타내고 있다. 환율의 경우에도 외환위기 이후 환율변동패턴에 임의보행(random walk)적 특성이 보다 강화된 것으로 나타나고 있어 외환시장의 효율성이 제고되었음을 시사하고 있다.

• International Area Studies Review
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• v.21 no.4
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• pp.159-172
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• 2017

In a typical trend-cycle decomposition of GDP, the trend component is usually assumed to follow a random walk process. This paper considers an ARIMA trend and assesses the validity of the ARIMA trend model. I construct univariate and bivariate unobserved-components(UC) models, allowing the ARIMA trend. Estimation results using U.S. data are favorable to the ARIMA trend models. I, also, compare the forecasting performance of the UC models. Dynamic pseudo-out-of-sample forecasting exercises are implemented with recursive estimations. I find that the bivariate model outperforms the univariate model, the smoothed estimates of trend and cycle components deliver smaller forecasting errors compared to the filtered estimates, and, most importantly, allowing for the ARIMA trend can lead to statistically significant gains in forecast accuracy, providing support for the ARIMA trend model. It is worthy of notice that trend shocks play the main source of the output fluctuation if the ARIMA trend is allowed in the UC model.

• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.323-331
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• 2006

The purpose of this study was to investigate the effect of performing a cognitive task during treadmill walking on the stride rate variability. Ten university students(age $24.0{\pm}0.25$, height $172{\pm}3.1cm$, weight $66{\pm}5.3kg$) were participated in dual task experiments which consist of both walking alone and walking with a cognitive task. Two-back task was selected for the cognitive task since it did not have learning effect during the experimental procedure.3D motion analysis system was used to measure subject's position data by changing walking speed with 4.8, 5.6, 6.4, 6.8, and 7.2 km/hr. Stride rate was calculated by the time between heel contact and heel contact. Accuracy rate of a cognitive task during walking, coefficient of variance, allometric scaling methods and Fano factor were used to estimated the stride rate variability. As the walking speed increased, accuracy rate decreased and the logarithmic value of Fano factor increased which showed the statistical difference. Thus it can be concluded that the gait control mechanism is distracted by the secondary attention focus which is the cognitive task ie. two-back task. Further study is needed to clarify this by increasing the number of subject and experiment time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.420-426
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• 2018

The purpose of this paper is to examine the business cycle in the Jeju region and what differences exist in relation to the nation as a whole, to calculate the relative importance between the random walk stochastic trend and cyclical factor, and to find out its causes and implications. Results of empirical analysis found that the characteristics of the business cycle in the Jeju region were as follows: First, the Jeju region, which is likely to have a growth component of the economy such as technological development and the accumulation of capital, was projected to have a possibility of high growth due to a greater proportion of the stochastic trend factor(46.8%) than the entire country(27.8%). Secondly, employment fluctuation in Jeju, which varies from 0.007 to 0.058 depending on the model, was lowest compared to the fluctuation of other indicators. The employment market in Jeju remained firm, showing that it is not smooth enough to create new jobs despite the production growth in industry. Third, the tourism industry was acting as a stabilizing factor, whereas the mining and manufacturing production was the opposite of tourism industry. This implies that the mining and manufacturing production was based on a weak foundation.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.951_952
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• 2009

기존의 소듐이나 메탈할라이드 램프는 수명이 짧아 잦은 유지보수가 필요하다. 8~12m정도의 도로조명은 유지보수 중에 사고가 발생할거나 교통의 흐름에 불편을 가져와 이에 대한 대책이 필요하다. LED조명장치는 반도체 특유의 장수명으로 유지보수의 문제에 솔루션을 가지고 있다. 또한 기존의 조명시스템은 단색으로 색온도의 제어가 어려워 기능성조명장치의 구현이 거의 이루어지고 있지 않지만 반도체조명 장치인 LED조명은 다양한 LED칩을 적절히 배치하고 활용함으로서 색온도를 가변시켜 우천시나 안개시에 운전자의 주의를 환기시킬 수 있어 도로안전을 확보할 수 있다. 본 논문에서는 백색LED와 오렌지LED를 혼색하여 우천시나 안개시, 즉, 습도의 변동상황에서 색온도를 가변시켜 운전자나 보행자의 시인성을 확보하고 통행의 주의를 환기시켜 기능성조명으로서의 역할을 부여하는 LED가로등조명장치를 구현하여 이에 대한 성능을 실험하였다.