• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.341-345
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• 1996

This paper presents the dynamics and the teal-time control of a horizontally rotating inverted pendulum. The dynamic equations representing three degrees of freedom rigid body motion of the pendulum are derived, and the state feedback controller is applied to the motion control of the pendulum. A 32 bit counter board with 16 bit hardware communication ability is developed to improve the real-time control performance and is applied to a horizontally rotating inverted pendulum. The simulation and experimental studies are conducted to evaluate the performance of the developed pendulum system and the timing in the real-time control is analyzed.

• 대한교통학회지
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• 제14권2호
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• pp.89-118
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• 1996

The development and implementation of a real-time, traffic adaptive control scheme based on fuzzy logic through Video Image Detector systems (VIDs) is presented. Through VIDs based image processing, fuzzy logic can be used for a real-time traffic adaptive signal control scheme. Fuzzy control logic allows linguistic and inexact traffic data to be manipulated as a useful tool in designing signal timing plans. The fuzzy logic has the ability to comprehend linguistic instructions and to generate control strategy based on a priori verbal communication. The implementation of fuzzy logic controller for a traffic network is introduced. Comparisons are made between implementations of the fuzzy logic controller and the actuated controller in an isolated intersection. The results obtained from the application of the fuzzy logic controller are also compared with those corresponding to a pretimed controller for the coordinated intersections. Simulation results from the comparisons indicate the performance of the system is between under the fuzzy logic controller. Integration of the aforementioned schemes into and ATMS framework will lead to real-time adjustment of the traffic control signals, resulting in significant reduction in traffic congestion.

• 대한교통학회지
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• 제21권2호
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• pp.83-94
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• 2003

서울을 비롯한 대도시에서는 최근, 신호교차로를 포함하는 도시 가로망에 기존의 고정식 신호체계를 대신하여 첨단신호체계를 도입하여 운영하고 있다. 이러한 신호시스템의 장점은 변화하는 교통상황에 따라 최적의 신호현시를 제공한다는 것이다. 그러나 이러한 신호체계가 큰 효과를 기대할 수 있음에도 불구하고 현재까지 이러한 시스템과 기존의 신호 시스템을 비교한 연구는 거의 없는 실정이다. 가장 큰 이유는 실시간으로 교통상황에 대응하는 이러한 신호시스템을 평가하는 것이 매우 어려운 일이기 때문이다. 본 연구의 목적은 독립교차로, 교통축, 네트워크 단위에서의 기존의 전자신호와 첨단신호체계의 효율성을 비교 평가할 수 있는 미시적 시뮬레이터를 개발하는 것이다. 이러한 시뮬레이터의 개발은 교통운영체계에 대한 보다 정밀한 분석을 가능하게 할 것으로 판단된다. 그리고 본 연구에서는 개발된 시뮬레이터를 이용하여 현재 서울의 강남지역에서 운영되고 있는 신신호 시스템의 각종 알고리즘에 대한 평가를 수행하였다.

• 천문학회지
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• 제55권4호
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• pp.111-121
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• 2022

Based on the light an exoplanet blocks from its host star as it passes in front of it during a transit, the mid-transit time can be determined. Periodic variations in mid-transit times can indicate another planet's gravitational influence. We investigate 83 transits of TrES-1 b as observed from 6-inch telescopes in the MicroObservatory robotic telescope network. The EXOTIC data reduction pipeline is used to process these transits, fit transit models to light curves, and calculate transit midpoints. This paper details the methodology for analyzing transit timing variations (TTVs) and using transit measurements to maintain ephemerides. The application of Lomb-Scargle period analysis for studying the plausibility of TTVs is explained. The analysis of the resultant TTVs from 46 transits from MicroObservatory and 47 transits from archival data in the Exoplanet Transit Database indicated the possible existence of other planets affecting the orbit of TrES-1 and improved the precision of the ephemeris by one order of magnitude. We now estimate the ephemeris to be (2 455 489.66026 BJD_TDB ± 0.00044 d) + (3.0300689 ± 0.0000007) d × epoch. This analysis also demonstrates the role of small telescopes in making precise midtransit time measurements, which can be used to help maintain ephemerides and perform TTV analysis. The maintenance of ephemerides allows for an increased ability to optimize telescope time on large ground-based telescopes and space telescope missions.

• Journal of Positioning, Navigation, and Timing
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• 제13권3호
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• pp.355-363
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• 2024

Time synchronization is crucial for ensuring the reliable operation of modern economic and social infrastructures. Techniques such as Global Navigation Satellite System (GNSS)-based methods and Two-Way Satellite Time and Frequency Transfer (TWSTFT) play key roles in precise time comparison and synchronization. TWSTFT, in particular, is recognized for its ability to achieve sub-nanosecond accuracy in time transfer, making it indispensable in fields such as satellite navigation. This paper proposes a comprehensive performance evaluation method for TWSTFT modems, emphasizing pre-validation in controlled environments to mitigate operational challenges. Using the proposed evaluation method, the study presents the standard deviation of RTT according to C/N₀ and compares it with the datasheet of a commercial TWSTFT modem. Through this approach, the aim of this study is to enhance the reliability and accuracy of TWSTFT-based time synchronization across diverse applications.

• 대한소아치과학회지
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• 제38권2호
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• pp.155-160
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• 2011

최근 들어, 수복 치료 등을 이용한 질병의 직접적인 치료보다는 예방 치료에 대한 중요성이 강조되면서, 그 동안 사용되었던 화학적인 약물을 통한 예방 치료 이외에도 유산균등을 이용한 probiotics에 대한관심이 높아지고 있다. 여러 논문에서 Lactobacillus와 Bifidobateria들이 DMFS와 S. mutans를 감소한다고 보고하고 있다. 하지만, 이러한 미생물들의 접종 시기와 접종 농도에 대한 언급은 부족하다. 따라서 본 실험에서는 probiotics의 대표적인 균인, L. rhamnosus GG를 이용하여 예방 효과를 보기 위한 적정 농도를 재정립하고, 접종시기를 고찰하였다. S. mutans 배지에 $1{\times}10^6$ CFU이상 농도의 L. rhamnosus를 접종하였을 때 S. mutans count가 현저하게 감소하는 것을 볼 수 있었다. 접종 순서는 L. rhamnosus와 S. mutans를 동시에 접종하거나 L. rhamnosus를 S. mutans 보다 선행하여 접종하였을 때가, S. mutans를 L. rhamnosus 보다 선행하여 접종하였을 때에 비교하여 S. mutans count를 더 감소시켰다. 이 실험의 결과로 보아 probiotics의 접종 시기는 probiotics을 임상에 적용할 때 반드시 고려되어야 하겠다.

• 패션비즈니스
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• 제18권4호
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• pp.153-167
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• 2014

In this study, changes in the timing of puberty physicality and mentality and beauty characteristics of high school students were characterized for high school students and the general high school population in order to distinguish between interest and beauty and beauty products and beauty behavior for comparative analysis. First, for beauty characteristics of high school students and the general high school population, differences in beauty action and beauty characteristics of high school students were higher than this beauty behavior. Secondly, for the high school students and high school beauty characteristics of general high school population for beauty and beauty products, the difference between interest and multi-functional beauty products that characterize high school students has beauty and beauty products with multi-functional beauty products interest being high. Third, high school students and high school beauty characterize the general high school population of beauty is different from behaviors on its factors with common factors including the psychological gratification 'for reasons of appearance management looks for reasons that do not' have time to manage the response. Two groups of factors that characterize the differences in appearance and beauty as areason to manage high school students interested in the 'style' order, high school students do not manage reasons for lack of interest in the 'general' as a response. Beauty characteristics of high school students in the beauty, beauty products, and products demonstrated a multi-functional information gathering with lots of attention, and much ability can have an active beauty behavior. The general high school population lacks the ability to gather information in accordance with interested beauty behavior being passive. The two groups and beauty behavior patterns of consumption could see that a difference occurred.

• 한국공간정보시스템학회 논문지
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• 제3권1호
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• pp.109-116
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• 2001

ITS산업은 정보경제의 일반적 특징이라고 할 수 있는 네트워크 외부성과 정보의 양방향성을 갖고있는 동시에, 정보의 적시성과 지역성, 자연 독점성, 공공성, 시스템 통합성 등 ITS만의 독특한 특징을 갖고 있기도 하다. 이런 특성들로 인해 ITS산업은 구(舊) 경제와는 다른 기업전략과 산업정책을 필요로 한다. 네트워크 외부성에 비추어 볼 때, ITS산업에 속하는 기업들은 개방과 공유 또는 전략적 제휴 등을 통해 경쟁사들과 시장을 나누어 가지는 전략이 효과적이며, 시장의 성숙을 위해서는 표준화를 조기에 이룩해야 한다. 자연 독점적 성격과 공공성 및 수익성의 병존이라는 특징에 비추어 ITS산업은 시스템별로 공공성 및 수익성 정도를 검토한 후, 이에 근거하여 공급주체와 자금조달주체를 결정하는 것이 바람직하다. 본 연구는 정보경제에서 ITS산업의 특성과 이러한 특성이 기업전략과 산업정책에 미치는 영향에 대해 분석하여 보았다.

• Journal of Preventive Medicine and Public Health
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• 제55권4호
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• pp.334-341
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• 2022

Objectives: This study was conducted to develop the Mobility to Participation Assessment Scale for Stroke (MPASS) and assess its content validity, internal consistency, inter-rater and intra-rater reliability, and convergent validity in people with stroke living in the community. Methods: The MPASS was developed using published data on mobility-related activity and participation timing in elderly individuals, and then reviewed by community physical therapists. Content validity was established by reaching a consensus of experienced physical therapists in a focus group. The MPASS was scored for 32 participants with stroke (mean age 61.75±4.92 years) by 3 individual testers. Reliability was examined using the intraclass correlation coefficient (ICC), internal consistency using the Cronbach alpha coefficient (α), and convergent validity using the Pearson correlation coefficient (r) to compare the MPASS to the Modified Rivermead Mobility Index as a referent test of mobility. Results: The MPASS consists of 8 items, and its scoring system provides information on the ability of people with stroke to reach a movement level enabling them to live in society, including interactions with other people and safe living in the community. The interrater and intra-rater reliability were excellent (ICC, 0.948; 95% confidence interval [CI], 0.893 to 0.982 and ICC, 0.967; 95% CI, 0.933 to 0.989, respectively). Internal consistency was good (α=0.877). The convergent validity was moderate (r=0.646; p<0.001). Conclusions: The newly developed MPASS showed acceptable construct validity and high reliability. The MPASS is suitable for use in people with stroke, especially those who have been discharged and live in the community with the ability to initiate sitting.

• 벤처창업연구
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• 제13권2호
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• pp.39-50
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• 2018

본 연구는 아산나눔재산의 AER사례를 중심으로 스타트업의 성공요인을 ERIS모델을 기반으로 창업단계, 상업화단계, 정착단계로 구분하여 분석하고 결과를 도출하였다. 사례분석 결과, 스타트업의 ERIS모델별 성공요인으로 창업단계에는 창업가의 창업 이력 및 경력, 분야경험 및 전문지식, 신속한 판단력과 문제해결이며, 구성원의 역량 및 팀웍, 네트워크, 정부의 창업지원 등이다. 상업화단계에는 사업화 및 투자자금 확보, 타이밍, 차별화전략, 해외진출, 고객의견 수용 등이며, 성장(성숙)단계에는 신제품 출시 및 다각화, 조직문화의 수립 등이었다. 본 연구는 이러한 분석결과를 바탕으로 각 단계별 성공요인 및 시사점을 도출하고 향후 연구방향을 모색하였다.