• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.159-163
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• 2005

A dynamic vibration absorber using the Zener's model has been taken into account with respect to frequency response characteristics. The concept of the tuned mass damper with a single degree of freedom has been well applied for many industrial fields, because many researchers have extensively studied various basic characteristics, performance and optimization methods for long time. The Zener's model has an additional spring, which is connected between a damper and a mass, while the tuned mass damper with a single degree of freedom consists of a mass, a spring and a damper connected in parallel. In previous works, the basic performance and characteristics of the Zoner's model as a dynamic vibration absorber have not been investigated. In this study, the frequency response characteristics according to the parameter change of the Zener's model have been described. In order to find the optimum value of several parameters, we use iterative scheme with three dimensional frequency response diagram by MATLAB programming. Present results shows the Zener's model can give more good damping performance than the simple tuned mass damper, and the numerical of optimization method should be developed for the efficient vibration absorbtion.

• Journal of Information Processing Systems
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• 제20권4호
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• pp.491-500
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• 2024

In hopes of resolving the issue of poor quality of information input for teaching spoken English online, the study creates an English teaching assistance model based on a recognition algorithm named dynamic time warping (DTW) and relies on automated voice recognition technology. In hopes of improving the algorithm's efficiency, the study modifies the speech signal's time-domain properties during the pre-processing stage and enhances the algorithm's performance in terms of computational effort and storage space. Finally, a simulation experiment is employed to evaluate the model application's efficacy. The study's revised DTW model, which achieves recognition rates of above 95% for all phonetic symbols and tops the list for cloudy consonant recognition with rates of 98.5%, 98.8%, and 98.7% throughout the three tests, respectively, is demonstrated by the study's findings. The enhanced model for DTW voice recognition also presents higher efficiency and requires less time for training and testing. The DTW model's KS value, which is the highest among the models analyzed in the KS value analysis, is 0.63. Among the comparative models, the model also presents the lowest curve position for both test functions. This shows that the upgraded DTW model features superior voice recognition capabilities, which could significantly improve online English education and lead to better teaching outcomes.

• 대한간호학회지
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• 제40권4호
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• pp.580-588
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• 2010

Purpose: The purpose of this study was to examine effects of decreased locomotor activity on mass, Type I and II fiber cross-sectional areas of ipsilateral and contralateral hindlimb muscles 21 days after establishing the Parkinson's disease rat model. Methods: The rat model was established by direct injection of 6-hydroxydopamine (6-OHDA, 50 ${mu}g$) into the left substantia nigra after stereotaxic surgery. Adult male Sprague-Dawley rats were assigned to one of two groups; the Parkinson's disease group (PD; n=17) and a sham group (S; n=8). Locomotor activity was assessed before and 21 days after the experiment. At 22 days after establishing the rat model, all rats were anesthetized and soleus and plantaris muscles were dissected from both ipsilateral and contralateral sides. The brain was dissected to identify dopaminergic neuronal death of substantia nigra in the PD group. Results: The PD group at 21 days after establishing the Parkinson's disease rat model showed significant decrease in locomotor activity compared with the S group. Weights and Type I and II fiber cross-sectional areas of the contralateral soleus muscle of the PD group were significantly lower than those of the S group. Conclusion: Contralateral soleus muscle atrophy occurs 21 days after establishing the Parkinson's disease rat model.

• 무역학회지
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• 제47권2호
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• pp.69-88
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• 2022

This paper aims to predict Busan's regional product and employment using the logistic regression models and machine learning models. The following are the main findings of the empirical analysis. First, the OLS regression model shows that the main industries such as electricity and electronics, machine and transport, and finance and insurance affect the Busan's income positively. Second, the binomial logistic regression models show that the Busan's strategic industries such as the future transport machinery, life-care, and smart marine industries contribute on the Busan's income in large order. Third, the multinomial logistic regression models show that the Korea's main industries such as the precise machinery, transport equipment, and machinery influence the Busan's economy positively. And Korea's exports and the depreciation can affect Busan's economy more positively at the higher employment level. Fourth, the voting ensemble model show the higher predictive power than artificial neural network model and support vector machine models. Furthermore, the gradient boosting model and the random forest show the higher predictive power than the voting model in large order.

• 한국농공학회지
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• 제35권2호
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• pp.57-64
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• 1993

A modified kinematic wave model of the overland flow in vegetated filter strips was developed. The model can predict both flow depth and hydraulic radius of the flow. Existing models can predict only mean flow depth. By using the hydraulic radius, erosion, deposition and flow's transport capacity can be more rationally computed. Spacing hydraulic radius was used to compute flow's hydraulic radius. Numerical solution of the model was accomplished by using both a second-order nonlinear scheme and a linear solution scheme. The nonlinear portion of the model ensures convergence and the linear portion of the model provides rapid computations. This second-order nonlinear scheme minimizes numerical computation errors that may be caused by linearization of a nonlinear model. This model can also be applied to golf courses, parks, no-till fields to route runoff and production and attenuation of many nonpoint source pollutants.

• 한국도서관정보학회지
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• 제34권3호
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• pp.317-343
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• 2003

최근에는 인쇄된 매체인 책과 함께 컴퓨터나 인터넷을 이용한 문학작품인 전자문학에 대한 관심이 높아지고 있으며, 이의 활용에 대해서는 다양한 측면에서 활발한 탐구가 있어왔다. 전자도서관을 이용한 효과적인 자료의 탐색, 전자문학 중심의 온라인 독서교육의 전개, 웹 문학의 교육적 활용 탐색 등의 연구가 있어왔고, 그것의 효과에 대해서 매우 긍정적이다. 이에 본 연구에서는 아동이 흥미를 갖고 있는 매체인 정을 기반으로 문학교육을 전개하는 방법을 탐색하고, 이를 구체화하여 모형으로 제시하였다.

• 대한안전경영과학회지
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• 제12권2호
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• pp.199-207
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• 2010

The purpose of this study is looking for the support policies and factors to stimulate the quality innovation movement. Kano's model proposed a two-dimensional model on quality based on customer perception and experience. And Timko developed the customer satisfaction coefficient for overcome the weak points of Kano's model. In this paper, new approach framework is proposed by integrated Kano's model and Timko's customer satisfaction coefficient. And it applied to confirm the various factors which was offered by government and major company's policies for small and medium enterprises.

• 한국항해항만학회지
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• 제37권6호
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• pp.567-574
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• 2013

Although Korea coastal area has the increasing potential marine accident due to frequent ship's encounter, increased vessel traffic and large vessel, there is no specific model to evaluate the navigating vessel's risk considering the domestic traffic situation. The maritime transport environmental assessment is necessary due to the amended maritime traffic law. However, marine safety diagnosis is now carried out by foreign model. In this paper, therefore, we suggest a domestic traffic model reflecting the characteristics of korea coastal area and navigator's risk as we named PARK(Potential Assessment of Risk) model. We can evaluate the subjective risk by establishing the model and model output into maritime risk exposure system. To evaluate this model's effectiveness, we used ship handling simulation and applied, analyzed collision accident which occurred in korea coastal area. And also, we applied integrated to an ECDIS program for monitoring traffic risk of vessels with real time based AIS data and apply to evaluate traffic risk in busan harbor waterway. As a result, we could evaluate busan harbor waterway risk effectively.

• 한국농공학회논문집
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• 제55권5호
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• pp.37-48
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• 2013

The objective of this study is to assess the impact of potential climate change on the hydrological components, especially on the streamflow, evapotranspiration and snowmelt, by using the Soil Water Assessment Tool (SWAT) for 17 Hanriver middle watersheds of South Korea. For future assessment, the SWAT model was calibrated in multiple sites using 4 years (2006-2009) and validated by using 2 years (2010-2011) daily observed data. For the model validation, the Nash-Sutcliffe model efficiency (NSE) for streamflow were 0.30-0.75. By applying the future scenarios predicted five future time periods Baseline (1992-2011), 2040s (2021-2040), 2060s (2041-2060), 2080s (2061-2080) and 2100s (2081-2100) to SWAT model, the 17 middle watersheds hydrological components of evapotranspiration, streamflow and snowmelt were evaluated. For the future precipitation and temperature of RCP 4.5 scenario increased 41.7 mm (2100s), $+3^{\circ}C$ conditions, the future streamflow showed +32.5 % (2040s), +24.8 % (2060s), +50.5 % (2080s) and +55.0 % (2100s). For the precipitation and temperature of RCP 8.5 scenario increased 63.9 mm (2100s), $+5.8^{\circ}C$ conditions, the future streamflow showed +35.5 % (2040s), +68.9 % (2060s), +58.0 % (2080s) and +63.6 % (2100s). To determine the impact on snowmelt for Hanriver middle watersheds, snowmelt parameters of SWAT model were determined through evaluating observed streamflow data during snowmelt periods (November-April). The results showed that average SMR (snowmelt / runoff) of 17 Hanriver middle watersheds was 62.0 % (Baseline). The annual average SMR were 42.0 % (2040s), 39.8 % (2060s), 29.4 % (2080s) and 27.9 % (2100s) by applying RCP 4.5 scenario. Also, the annual average SMR by applying RCP 8.5 scenario were 40.1 % (2040s), 29.4 % (2060s), 18.3 % (2080s) and 12.7 % (2100s).

• 한국수자원학회논문집
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• 제53권7호
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• pp.557-567
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• 2020

서울지역에 대해서 6개의 증발접시계수 산정모형들로부터 산정된 증발접시계수를 측정된 증발접시 증발량과 FAO Penman-Monteith 기준증발산량으로부터 산정된 증발접시계수와 비교함으로서 증발접시계수 산정모형들의 활용 적합성을 평가하였다. 적용된 6개의 모형은 Cuenca 모형, Snyder 모형, Pereira 등의 모형, Allen 등의 모형, Orang 모형, 그리고 Raghuwanshi와 Wallender 모형이다. 또한 산정된 증발접시계수를 이용하여 산정된 증발량을 관측된 증발량과 비교분석하였으며, 비교결과를 바탕으로 서울지역에 대해서 증발접시계수 산정모형을 개발하였다. 연구결과에 의하면 기존에 연구자들에 의해서 제안된 6개 증발접시계수 산정모형을 10 m, 15 m 그리고 20 m의 풍역대 거리로 설정하여 적용하는 경우 모든 풍역대 거리에서 Snyder에 의해서 제안된 증발접시계수가 가장 양호한 증발접시계수 산정값을 보였다. 반면에 Pereira 등의 모형으로부터 산정된 증발접시계수 값이 관측값과 가장 큰 차이를 보였다. 따라서 서울지역을 대상으로 Snyder모형을 수정한 증발접시계수 산정모형을 유도하였다. 본 연구에서 제시한 모형을 적용하는 경우 모든 풍역대 거리(10 m, 15 m, 20 m) 조건에서 산정된 월평균 증발량은 동일하게 92.1 mm이고 관측된 월평균 증발량은 91.9 mm로서 다른 모형들과 비교하여 가장 근사한 결과를 보였다.