• Title/Summary/Keyword: Reduced-Order Model

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Estimating an Optimal Scale of a Railway Station with Non-Passengers (철도 비승차 이용객을 고려한 역사 시설물별 적정규모 산정방안)

  • Oh, Tae ho;Lee, Seon ha;Kang, Hee up;Insigne, Maria Sharlene L.;Lee, Sang Jae
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.4
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    • pp.76-91
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    • 2017
  • The Area of a domestic railway station is designed based on the 4-step traffic demand forecasting model with the average daily passenger count as one of its parameter. However, nowadays, due to increasing rate of railway station's function, the non-passengers are increasing. In order to consider those non-passengers who aren't using trains, assumed volume are added to the average daily passenger count of station to estimate the area, but the criteria being applied has no concrete basis. Therefore, this study aimed to recalculate the increasing non-passenger rate based on actual survey data of station users in any type of railway station to obtain the optimum area. Subsequently, the the design area was performed through pedestrian simulation. According to the result of the simulation, it was found that the total space of the exciting railway stations can be reduced up to 45% and will still satisfy the level of service(LOS) requirement.

A Study on the Determination of Slip-up Time for Slip-Form System using Surface Wave Velocity (표면파 속도를 이용한 슬립폼 시스템 상승 시기 결정에 관한 연구)

  • Kim, Heeseok;Kim, Young Jin;Chin, Won Jong;Yoon, Hyejin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5D
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    • pp.483-492
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    • 2012
  • The early setting time of concrete is an important factor determining the slip up velocity of the slip-form system. Accordingly, need is for a technique evaluating the early setting time in order to secure the safety of the slip-form system and the construction quality of concrete. This paper intends to estimate the early setting time by evaluating the setting degree of concrete using surface wave velocity so as to determine the slip up time of the slip-form system. Penetration resistance test and compressive strength test are performed first to clarify the relationship between the early setting time of concrete and the compressive strength. Then, compressive strength test and ultrasonic wave test are conducted to examine the relation between the compressive strength and the surface wave velocity. Continuous wavelet transform is adopted to measure the surface wave velocity. Numerical analysis is carried out to demonstrate the appropriateness of the application of continuous wavelet transform. Based on these results, the propagation velocity of the surface wave required for the slip up of slip-form system is suggested. Finally, a reduced model test of the slip-form system is conducted to verify the feasibility of the proposed surface wave velocity for the determination of th slip up velocity.

A study of the Mori Radicis Cortex pre-treatment on transient ischemic brain injury in mice (상백피(桑白皮) 메탄올 추출물 전처치가 일과성 허혈에 의한 생쥐의 뇌 손상에 미치는 영향)

  • Chung, Byung-Woo;Lim, Jae-Yu;Lee, Se-Eun;Lee, Byoungho;Lim, Sehyun;Lim, Chiyeon;Cho, Suin
    • The Korea Journal of Herbology
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    • v.32 no.1
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    • pp.25-31
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    • 2017
  • Objectives : Mori Radicis Cortex (MRC), the root epidermis of Morus alba L., has been traditionally used to treat lung-related diseases in Korean Medicine. The common of MRC is Mulberry bark Morus bark, and it's pharmaceutical properties and taste are known as sweet and cold, and it promotes urination and reduce edema by reducing heat from the lungs and soothe asthma. In the present study, anti-apoptotic mechanism of MRC in middle cerebral artery occlusion (MCAO) model in mice. Methods : Two-hundred grams of MRC was extracted with methanol at room temperature for 5 days, and this was repeated one time. After filtration, the methanol was removed using vacuum evaporator, then stored at $-20^{\circ}C$ until use. C57BL/6 male mice were housed in an environment with controlled humidity, temperature, and light cycle. In order to determine beneficial effects of MRC on ischemia induced brain damage, infarct volume, neurological deficit scores, activities of several apoptosis-related proteins such as caspase-8, -9, Bcl-xL in MCAO-induced brains of mice were analyzed. Mice in MRC-treated groups were orally administered 30, 100, or 300 mg/kg of body weight for three consecutive days before commencing the MCAO procedure. Results : Pre-treatment of MRC significantly reduced infarct volume in MCAO subjected mice applied with 300 mg/kg of MRC methanol extract, and MRC effectively inhibited Bcl-xL reduction and caspase-9 activation caused by MCAO-induced brain damage. Conclusions : MRC showed neuro-protective effects by regulating apoptosis-related protein signals, and it can be a potential candidate for the therapy of ischemia-induced brain damage.

The Application of Science Education Lecture for Pre-Service Teacher Using Teaching-Learning Method Based on Flipped Learning (플립러닝 교수-학습 방법을 활용한 예비교사의 과학교육론 수업 적용)

  • Jeon, Young-ju;Yoon, Ma-byong
    • Journal of The Korean Association For Science Education
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    • v.36 no.3
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    • pp.499-507
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    • 2016
  • A flipped learning class was held in an attempt to overcome the limits of lecture-type classes in pre-service science teacher training and to provide a student-oriented education suitable for digital native generation. The principles of teaching-learning in flipped learning were applied to the general ADDIE model to design the class; learning materials were developed accordingly. The developed flipped learning materials and class design were verified for their validity using an expert panel's Delphi method and validity test, in which the validity was verified with 0.75 CVR. The developed flipped learning materials were applied to the theory of science education and the instructional effectiveness was analyzed. The results suggest that the students' motivation to study, interest, and confidence in learning increased; however, their satisfaction in class decreased by 30% as compared to the lecture-type class and their self-confidence in the improvement of their academic achievement was not sufficient. In order for a flipped learning class to be successful, the class should be small in size, which would ensure appropriate teacher-student communication and individualized learning; also, the students' burden of learning should be reduced and accessibility to video materials for pre-class learning should be reinforced.

Effects of Taegeuk Acupuncture on the Autonomic Nervous System by Analyzing Heart Rate Variability in 20's Soeumin (태극침법이 정신적 스트레스를 가한 20대 소음인 남성의 심박변이도에 미치는 영향)

  • Kim, Nam Sik;Kim, Jin Youp;Kwak, Sang Gyu;Shin, Im Hee;Nam, Sang Soo;Kim, Yong Suk
    • Journal of Acupuncture Research
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    • v.30 no.3
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    • pp.39-49
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    • 2013
  • Objectives : The purpose of this study is to assess the effect of Taegeuk acupuncture on reducing mental stress by analyzing heart rate variability in Soeumin. Methods : Six Soeumin-diagnosed men participated in this study. They were randomly divided into group A and group B. Each participant went through 4 sessions every week with 1 week of washout period in between each session. HRV was measured three times at every session; at baseline, after administering mentally stressful circumstances and after applying Soeumin Taegeuk acupuncture or Soyangin Taegeuk acupuncture. This study was designed as a crossover clinical trial. Group A participants were treated with two sets of Soeumin Taegeuk and Soyangin Taegeuk acupuncture treatment in respective order (i.e. Soeumin Taegeuk - Soyangin Taegeuk - Soeumin Taegeuk - Soyangin Taegeuk acupuncture treatment). Group B participants were treated with reverse-ordered acupuncture treatment (i.e. Soyangin Taegeuk - Soeumin Taegeuk - Soyangin Taegeuk - Soeumin Taegeuk acupuncture treatment ). Bayesian analysis was performed by using WinBUGS(Ver. 1.4.3) for comparison between Soeumin Taegeuk acupuncture and Soyangin Taegeuk acupuncture. Results : Overall, Soeumin Taegeuk acupuncture tends to reduce LF/HF ratio, LF, HF, LF(Norm) and increase HF(Norm) more than Soyangin Taegeuk acupuncture, but the difference was not statistically significant. In one participant, however, Soeumin Taegeuk acupuncture reduced LF/HF ratio, LF(Norm) and increased HF(Norm) more than Soyangin Taegeuk acupuncture, and the difference was stastatistically significant. Conclusions : This study suggests that Soeumin Taegeuk acupuncture might be an effective means of stabilizing mental stress-induced imbalance of autonomic nervous system for Soeumin.

Antimetastatic and Antitumor Effect of Ginsenoside Rh2 and ${\beta}-glucan$ in Mice (Ginseniside Rh2와 베타 글루칸의 암세포 전이억제효과)

  • Lee, Chang-Hwan;Won, Eun-Kyung;Sung, Hyun-Jea;Choung, Se-Young
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.4
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    • pp.856-859
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    • 2007
  • We have investigated the antimetastatic and antitumor effects of Ginsenoside Rh2 and ${\beta}-glucan$ unsing an experimental metastatic mouse model intravenously injected with B 16 melanoma F 10 cells. Animal groups are divided into six groups according to the dosage of drug administration and the kind of drugs. The groups are control, ${\beta}-glucan$ with 50, 100 and 200 mg/kg, Geinsenoside Rh2 50 mg/kg, and ${\beta}-glucan$ 50 mg/kg + Ginsenoside Rh2 50 mg/kg. Oral administration of various concentration of ${\beta}-glucan$( 50, 100, and 200 mg/kg) were reduced the lung- metastatics induced by metastatic B16 melanoma F 10 cells injection with a dose dependent manner in the syngenic mice. At same dosage group, Ginsenoside Rh2 (50 mg/kg) has more antimetastatic effect than the ${\beta}-glucan$(50 mg/kg). The highest antimetastatic effects was observed in the ${\beta}-glucan$ 50 mg/kg + Ginsenoside Rh2 50 mg/kg group and has a similar tendency in the anti-tumor effects, including decrease of the average tumor weight and increase of the average survival rate. There are no differences of the average tumor weights were apparent in the ${\beta}-glucan$ groups, however there were little decrease of the average tumor weight in Ginsenoside 50 mg/kg group and ${\beta}-glucan$ 50 mg/kg + Ginsenoside Rh2 50 mg/kg group than that of the control group. The rate of average survival rate in the ${\beta}-glucan$ 50 mg/kg + Ginsenoside Rh2 50 mg/kg group, ${\beta}-glucan$ 200 mg/kg, ${\beta}-glucan$ 100 mg/kg and ${\beta}-glucan$ 50 mg/kg, and Ginsenoside 50 mg/kg groups were highly in order. These data suggest that antimetastatic and antitumor effect of combination of Ginsenodide Rh2 and ${\beta}-glucan$ be the highest in this study.

Dynamic Analysis of Superstructures on Very Large Floating Structure with Semi-Rigid Connections (반강접 접합부를 적용한 초대형 부유식 구조물 상부구조체에 대한 동적해석)

  • Song Hwa-Cheol;Kim Woo-Nyon
    • Journal of Navigation and Port Research
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    • v.29 no.5 s.101
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    • pp.389-394
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    • 2005
  • The additional moment occurs because the superstructures of VLFS are influenced by wave loads instead of earthquake loads. In order to reduce the additional moment, this study used the semi-rigid connections which lie between fully rigid and pinned. If the semi-rigid connections are used for superstructures of VLFS, the moment of beams can be reduced and more economical construction will be possible. This study aims to show the effect of wave loads on structure and the efficiency of the semi-rigid connections due to wave loads by analyzing the time history responses. The dynamic behaviors of the rigid frame are compared with those of the semi-rigid frame considering of static loads, wave loads and combination loads for a four-bay, three-story frames. The semi-rigid connection type is a steel tubular column with square external-diaphragm connections and the time history analysis is used for the dynamic responses. The additional moment responses due to wave loads increase $33\%$ in the rigid frame, $26\%$ in the semi-rigid frame with the spring model.

A Study on Performance Characteristics of Horizontal Axis Tidal Turbine Considering Nose Shape, Angle of Inflow and Tower Structure (수평축 조류발전 터빈의 노즈 형상 및 유입각도, 타워 구조물의 영향을 고려한 터빈 성능특성 분석)

  • Heo, Man-Woong;Kim, Dong-Hwan;Yi, Jin-Hak
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.1
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    • pp.17-25
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    • 2020
  • In this study, three-dimensional fluid flow analyses have been performed in order to investigate the performance characteristics of a horizontal axis tidal turbine (HATT) by solving three-dimensional Reynolds-averaged Navier-Stokes equations utilizing the shear-stress-transport turbulence model. The computational domain for the flow analysis has been composed of hexahedral grids, and the grid dependency test has been carried out so as to determine the optimum grid size. Performance characteristics of the HATT have been investigated in consideration of the effects of hub nose geometry, inflow angle, and the tower. It has been found that the power output can be enhanced along with an increase of the ratio of the length to the diameter of the turbine nose, and the power of HATT has been reduced by approximately 10% when the primary fluid flow had an inflow angle of 15°. The power output of downstream HATT is found to be lower than that of the upstream HATT by about 1%.

Multi-Level Correlation LMS Algorithm for Digital On-Channel Repeater System in Digital TV Broadcasting System Environment (DTV 방송 시스템 환경에서 동일 채널 중계기를 위한 다중 레벨 상관 LMS 기법)

  • Lee, Je-Kyoung;Kim, Jeong-Gon
    • Journal of Broadcast Engineering
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    • v.15 no.1
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    • pp.63-75
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    • 2010
  • In this paper, the equalizer techniques that is able to adopt the digital on-channel repeater for 8VSB-based DTV system has been analyzed and we propose an effective equalizer structure which can reduce the error propagation phenomenon by the feedback signal and improve the receiver performance at the same time. In order to confirm the effective cancellation of the feedback signal, the multi-level Correlation LMS scheme is proposed through the analysis of conventional basic LMS based DFE and Correlation LMS algorithm and as compared with the conventional method, we can confirm the reduction of error propagation. When performing the computer simulation, as the Brazil channel model which is very popular for DTV broadcasting system is adopted, the result is drawn by comparing and analysing the equalizer algorithm. We have examine the symbol error rate which is in the range of 15~25dB of operation receipt SNR and MSE(Mean Square Error) in the DTV broadcasting system. As a result of comparing with the existing method, the signal-noise ratio which is necessary for maintain the bit error correction ability that the means of proposal is same is reduced by about 2~5dB, and in the rate of convergence through the MSE, we found the reduction of needed time.

Probabilistic Medium- and Long-Term Reservoir Inflow Forecasts (II) Use of GDAPS for Ensemble Reservoir Inflow Forecasts (확률론적 중장기 댐 유입량 예측 (II) 앙상블 댐 유입량 예측을 위한 GDAPS 활용)

  • Kim, Jin-Hoon;Bae, Deg-Hyo
    • Journal of Korea Water Resources Association
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    • v.39 no.3 s.164
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    • pp.275-288
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    • 2006
  • This study develops ESP (Ensemble Streamflow Prediction) system by using medium-term numerical weather prediction model which is GDAPS(T213) of KMA. The developed system forecasts medium- and long-range exceedance Probability for streamflow and RPSS evaluation scheme is used to analyze the accuracy of probability forecasts. It can be seen that the daily probability forecast results contain high uncertainties. A sensitivity analysis with respect to forecast time resolution shows that uncertainties decrease and accuracy generally improves as the forecast time step increase. Weekly ESP results by using the GDAPS output with a lead time of up to 28 days are more accurately predicted than traditional ESP results because conditional probabilities are stably distributed and uncertainties can be reduced. Therefore, it can be concluded that the developed system will be useful tool for medium- and long-term reservoir inflow forecasts in order to manage water resources.