• Atmosphere
• /
• v.24 no.1
• /
• pp.17-27
• /
• 2014

In this study, the observational environment for sunshine duration at Seoul and Daegu Automated Synoptic Observing Systems (ASOSs) was analyzed using a numerical model. In order to analyze the effects of topography and buildings on observational environment for sunshine duration, the model domains including the elevated building and mountainous areas around Seoul and Daegu ASOSs were considered. Three dimensional topography and buildings used as input data for the numerical model were constructed using a geographic information system (GIS) data. Solar azimuth and altitude angles calculated for the analysis period (one-week for each season in 2008) in this study were validated against those by Korea Astronomy and Space Science Institute (KASI). The starting and ending times of sunshine duration observed at ASOSs largely differed from the respective sunrise and sunset times simply calculated using solar angles and information of ASOSs' latitude and longitude, because uneven topography and elevated buildings around ASOSs cut off sunshine duration right after the sunrise and right before the sunset. The model produced the sunshine indices for Seoul and Daegu ASOSs with the time interval of one minute and the period of one week for each season and we compared the hourly averaged indices with those observed at the ASOSs. One week of which the cloudiness is lowest for each season is selected for analysis. Not only the adjacent buildings but also distant buildings and mountain cut off sunshine duration right after the sunrise and right before the sunset. The buildings and topography cutting off sunshine duration were found for each analyzing date. It was suggested that, in order to evaluate the observational environment for sunshine duration, we need to consider even the information of topography and/or building far away from ASOSs. This study also showed that the analyzing method considering the GIS data is very useful for evaluation of observational environment for sunshine duration.

• Tunnel and Underground Space
• /
• v.15 no.1 s.54
• /
• pp.71-79
• /
• 2005

The stability of the intersection area of two tunnels is analyzed by observational method. The depth from ground surface to the intersected area is shallow and the geology around the area consists of soil and/or weathered rock. The tunnel is supported by reinforced protective umbrella method with 12 m long 3-layer steel-pipes and the intersected area is additionally reinforced with 6 m long rockbolts. The measured displacements are converged and mechanical stability of the intersected area of two tunnels is confirmed; tunnel arch settles to 6-7 mm at the crown and the sidewalls converges to about 5 mm. So based on the displacement measurements, the supporting system for the tunnel intersection proves to be effective to not only reduce the deformation of tunnels but also maintain the stability of tunnels.

• Nuclear Engineering and Technology
• /
• v.19 no.4
• /
• pp.233-241
• /
• 1987

Difficulties are encountered when the behavior of complex systems (i.e., fuel failure probability) that have unreliable deterministic models is predicted. For more realistic prediction of the behavior of complex systems with limited observational data, the present study was undertaken to devise an approach of combining predictions from the deterministic model and actual observational data. Predictions by this method of combining are inferred to be of higher reliability than separate predictions made by either model taken independently. A systematic method of hierarchical pattern discovery based on the method developed in the SPEAR was used for systematic search of weighting factors and pattern boundaries for the present method. A sample calculation was performed for prediction of CANDU fuel failures that had occurred due to power ramp during refuelling process. It was demonstrated by this sample calculation that there exists a region of feature space in which fuel failure probability from the PROFIT model nearly agree with that from observational data.

• Journal of Digital Convergence
• /
• v.10 no.9
• /
• pp.409-416
• /
• 2012

This study aimed to compare the effectiveness of action-observational training and task-oriented training on upper limb function and activities of daily living in patients with post-stroke hemiparesis. This study included 12 voluntary participants with post-stroke hemiparesis. Subjects were randomly assigned to either group 1 or group 2, with 6 in each group. Each subject completed the crossover experiment that comprised of action-observational training (A) and task-oriented training (B). The intervention sequence was A-B for the group 1 and B-A for the group 2. Each training was performed for 30 min a day, 5 times a week for 2 weeks (total experimental period of 4 weeks). Assessments were made using the Wolf Motor Function Test (WMFT) and Modified Barthel Index (MBI) thrice: at baseline, after 2 weeks of intervention, and after 4 weeks of intervention. The results showed that the WMFT and MBI scores significantly improved after the completion of each training (p<.05). Therefore, a determination of the superior training method was difficult. The effect sizes of both groups were greater when performed the action-observational training. The findings suggest that both the action-observational training and task-oriented training may be helpful in improving the upper limb function and activities of daily living for patients with post-stroke hemiparesis, and support the clinical feasibility of the action-observational training.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.2
• /
• pp.70.2-70.2
• /
• 2019

Recent observational works have reported spiral wave patterns (SWPs) in sunspots, but there is a lack of samples to derive the physical properties. In this presentation, we suggest the automatic method to detect the SWPs in observational data and present their statistical properties. From our method, we find more than 1000 SWPs observed by the Atmospheric Imaging Assembly onboard in the Solar Dynamic Observatory from 2013 to 2018. From our samples, more than half of the SWPs has the one spiral arm. The predominant oscillation period is 2 to 3 minutes. The rotating direction of the spiral arms does not depend on the latitude and the polarity of the sunspots. Our statistical results support the physical model suggested by Kang et al. (2019) that explain the generation of SWPs as the depth of the wave driving source and azimuthal modes in the straight vertical magnetic flux tube.

• The Journal of the Korean dental association
• /
• v.58 no.3
• /
• pp.152-168
• /
• 2020

The propensity score matching method is a statistical method used to reduce selection bias in observational studies and to show effects similar to random allocation. There are many observational studies in dentistry research, and differences in baseline covariates between the control and case groups affect the outcome. In order to reduce the bias due to confounding variables, the propensity scores are used by equating groups based on the baseline covariates. This method is effective, especially when there are many covariates or the sample size is small. In this paper, the propensity score matching method was explained in a simple way with a dental example by using R software. This simulated data were obtained from one of retrospective study. The control group and the case group were matched according to the propensity score and compared before and after treatment. The propensity score matching method could be an alternative to compensate for the disadvantage of the observation study by reducing the bias based on the covariates with the propensity score.

• Proceedings of the Korea Society of Design Studies Conference
• /
• 1998.04a
• /
• pp.6-7
• /
• 1998

• Proceedings of the Korean Society for Rock Mechanics Conference
• /
• 2008.03a
• /
• pp.185-201
• /
• 2008

• Geomechanics and Engineering
• /
• v.8 no.2
• /
• pp.153-171
• /
• 2015

The observational method in tunnel engineering allows the evaluation in real time of the actual conditions of the ground and to take measures if its behavior deviates considerably from predictions. However, it lacks a consistent and structured methodology to use the monitoring data to adapt the support system in real time. The definition of limit criteria above which adaptation is required are not defined and complex inverse analysis procedures (Rechea et al. 2008, Levasseur et al. 2010, Zentar et al. 2001, Lecampion et al. 2002, Finno and Calvello 2005, Goh 1999, Cui and Pan 2012, Deng et al. 2010, Mathew and Lehane 2013, Sharifzadeh et al. 2012, 2013) may be needed to consistently analyze the problem. In this paper a methodology for the real time adaptation of the support systems during tunneling is presented. In a first step limit criteria for displacements and stresses are proposed. The methodology uses graphics that are constructed during the project stage based on parametric calculations to assist in the process and when these graphics are not available, since it is not possible to predict every possible scenario, inverse analysis calculations are carried out. The methodology is applied to the "Bois de Peu" tunnel which is composed by two tubes with over 500 m long. High uncertainty levels existed concerning the heterogeneity of the soil and consequently in the geomechanical design parameters. The methodology was applied in four sections and the results focus on two of them. It is shown that the methodology has potential to be applied in real cases contributing for a consistent approach of a real time adaptation of the support system and highlight the importance of the existence of good quality and specific monitoring data to improve the inverse analysis procedure.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.29 no.4
• /
• pp.289-294
• /
• 2015

In order to make digital processing of facial color, standardization methods of photographing and observational requirements and gloss-detecting are done through preceding papers and actual experiences. Examiner's observational informations should be contained with original and temporary color, normalcy and deviation range and gloss. And these are interrelated with time, interior and exterior temperature, emotional state, so should be recorded too. Picturing procedure should be controlled in simple and practical but objective way. Just water cleansing, 15 to 20 minute resting, prohibiton of moisturizing of examinee are common for examiner. Temperature and moisture, width, light source requirement, brightness, polarizing filter of parlor and camera-to-object distance, posture of examinee are should be recorded. In addition, pre and post-revision of color and manifestation of color space after taking images are needed coping with construction of diagnostic database.