• Atmosphere
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• v.29 no.4
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• pp.439-450
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• 2019

Present weather plays an important role not only for atmospheric sciences but also for public welfare and road safety. While the widely used state-of-the-art visibility and present weather sensor yields present weather, a single type of measurement is far from perfect to replace long history of human-eye based observation. Truly automatic present weather observation enables us to increase spatial resolution by an order of magnitude with existing facilities in Korea. 8 years of human-eyed present weather records in 19 sites over Korea are compared with visibility sensors and auxiliary measurements, such as humidity of AWS. As clear condition agrees with high probability, next best categories follow fog, rain, snow, mist, haze and drizzle in comparison with human-eyed observation. Fog, mist and haze are often confused due to nature of machine sensing visibility. Such ambiguous weather conditions are improved with empirically induced criteria in combination with visibility and humidity. Differences between instrument manufacturers are also found indicating nonstandard present weather decision. Analysis shows manufacturer dependent present weather differences are induced by manufacturer's own algorithms, not by visibility measurement. Accuracies of present weather for haze, mist, and fog are all improved by 61.5%, 44.9%, and 26.9% respectively. The result shows that automatic present weather sensing is feasible for operational purpose with minimal human interactions if appropriate algorithm is applied. Further study is ongoing for impact of different sensing types between manufacturers for both visibility and present weather data.

• Journal of the Korea Society of Computer and Information
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• v.21 no.2
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• pp.79-88
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• 2016

In this paper, we propose an efficient automatic observation system for cloud amount and height observations. Observation system consists of clouds observations machinery, operational programs, cloud amount extraction program, cloud height extraction program, expert support programs. The experiment was conducted at the Daegwallyeong and Busan, through experimental observation confirmed the usefulness of the proposed system.

• Atmosphere
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• v.30 no.2
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• pp.103-113
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• 2020

In this study, we analyzed and developed the monitoring system in order to confirm the effect of observations on forecast sensitivity on ensemble-based data assimilation. For this purpose, we developed the Ensemble Forecast Sensitivity to observation (EFSO) monitoring system based on Local Ensemble Transform Kalman Filter (LETKF) system coupled with Korean Integrated Model (KIM). We calculated 24 h error variance of each of observations and then classified as beneficial or detrimental effects. In details, the relative rankings were according to their magnitude and analyzed the forecast sensitivity by region for north, south hemisphere and tropics. We performed cycle experiment in order to confirm the EFSO result whether reliable or not. According to the evaluation of the EFSO monitoring, GPSRO was classified as detrimental observation during the specified period and reanalyzed by data-denial experiment. Data-denial experiment means that we detect detrimental observation using the EFSO and then repeat the analysis and forecast without using the detrimental observations. The accuracy of forecast in the denial of detrimental GPSRO observation is better than that in the default experiment using all of the GPSRO observation. It means that forecast skill score can be improved by not assimilating observation classified as detrimental one by the EFSO monitoring system.

• Atmosphere
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• v.33 no.1
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• pp.33-47
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• 2023

In this study, for the application of observation errors to the Korean Integrated Model (KIM) to utilize the Constellation Observing System for Meteorology, Ionosphere & Climate-2 (COSMIC-2) new satellites, the observation errors were diagnosed based on the Desroziers method using the cost function in the process of variational data assimilation. We calculated observation errors for all observational species being utilized for KIM and compared with their relative values. The observation error of the calculated the Global Navigation Satellite System Radio Occultation (GNSS RO) was about six times smaller than that of other satellites. In order to balance with other satellites, we conducted two experiments in which the GNSS RO data expanded by about twice the observation error. The performance of the analysis field was significantly improved in the tropics, where the COSMIC-2 data are more available, and in the Southern Hemisphere, where the influence of GNSS RO data is significantly greater. In particular, the prediction performance of the Southern Hemisphere was improved by doubling the observation error in global region, rather than doubling the COSMIC-2 data only in areas with high density, which seems to have been balanced with other observations.

• Korean Institute of Interior Design Journal
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• v.18 no.5
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• pp.128-136
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• 2009

This study analyzed and defines the property of visual perception throughout the revision of the observation time of the original space and the rotating space. The conclusions of this study are as fellows: First, based on the existing theory and experiment, the study obtained the basis which decides the sector data originating fixation-gaze after staring the specific sector over 300ms time. It will become the turning point hereafter for our research to fix the time in this way. Second, in analyzing the minute data, the study built a revision method of the observation time by analyzing the meanings and the reasons of the revision of the original data. Third, according to the difference of revision quantity, female testee have more increases in the amount of data than male testee from the original screen. On the other hand, the opposite tendency appears from the previous data. This shows there is a difference in the observation properly by sex. Last, we could grasp Information about the property of the observation time throughout eyeball fixations, and the revision and analysis of the 'controlled observation data'. These data can be used in design element arrangement of interior space, hereafter.

• Journal of Astronomy and Space Sciences
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• v.23 no.3
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• pp.269-288
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• 2006

We revised the OTFTOOL which was developed in Five College Radio Astronomy Observatory (FCRAO) for the On-The-Fly (OTF) observation. Besides the improvement of data resampling function of conventional OTFTOOL, we added a new SELF referencing mode and data pre-reduction function. Since OTF observation data have a large redundancy, we can choose and use only good quality samples excluding bad samples. Sorting out the bad samples is based on the floating level, rms level, antenna trajectory, elevation, $T_{sys}$, and number of samples. And, spikes are also removed. Referencing method can be chosen between CLASSICAL mode in which the references are taken from the OFFs observation and ELLIPSOIDAL mode in which the references are taken from the inner source free region (this is named as SELF reference). Baseline is subtracted with the source free channel windows and the baseline order chosen by the user. Passing through these procedures, the raw OTF data will be an FITS datacube. The revised-OTFTOOL maximizes the advantages of OTF observation by sorting out the bad samples in the earliest stage. And the new self-referencing method, the ELLIPSOIDAL mode, is very powerful to reduce the data. Moreover since it is possible to see the datacube at once without moving them into other data reduction programs, it is very useful and convenient to check whether the data resampling works well or not. We expect that the revised-OTFTOOL can be applied to the facilities of the OTF observation like SRAO, NRAO, and FCRAO.

• Korean Journal of Occupational Health Nursing
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• v.9 no.1
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• pp.56-61
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• 2000

This study was done in an attempt to reveal those factors interfering with the observation study. Three trained research assistants collected data by observing the two occupational health nurses working in the small scale enterprises on the 3rd and 10th of February, 1999. The first observation was performed on the 3rd of February without observation guidance. Guidance was given during the second observation on the 10th of February. These data were compared between reporters in nursing services of 'Workplace visiting', 'Health counselling' and 'Blood pressure checking' according to nursing time and frequency. These areas were chosen because these activities were regarded as clearly identifiable by observers in contrast to the other performances. The data showed inconsistency between reporters. However, they were reduced when reporters observed nurses with guidance, although there were still minor differences between data in time and frequency. Discussions were carried out to find possible reasons for these differences. The causes were mainly attributed to the difficulty in workplace conditions to observe, the work specificity of nurses visiting each workplace and the delicate situation between nurses and observers when reporters were travelling in the nurse's car. Therefore, the results suggest that the observation method applied to the nursing service research at small-scale enterprises should be more concerned about the selection of appropriate workplace and operational definition of nursing activity in order to more precisely measure nurses' attitudes.

• Korean Institute of Interior Design Journal
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• v.20 no.4
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• pp.101-108
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• 2011

When observing an object in a space, a part of it is remembered into our perception in the time for paying attention or conscious observation and it reaches to our visual understanding. In this study, it examined characteristics by each subject through the process of visual understanding by changes in such observation time. The results from this study are summarized as belows: First, through analysis of the observation data focused on the distance between the observed points, it was able to apply those visual theories organized before to the analysis of characteristics of the time for understanding by each subject. Second, there showed big differences in the time for visual understanding by each subject according to changes in the observation time so that it was found that there were big differences according to the characteristics of subject's intention or purpose of the observation of a space. Third, as the number of continuous observation gives an important clue in judgement of how well the space was understood, it was able to compare and organize the mutual characteristics of the time the attention was concentrated, the time observed intentionally and the time understood visually. Fourth, it was found that the shorter subjects gave the intentional observation in observing a space, the longer they spent the time for paying attention, while the less they could understand it visually.

• The Journal of Korean Physical Therapy
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• v.32 no.2
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• pp.65-69
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• 2020

Purpose: This study examined the effects of action-observation training using the Y-Balance on the balance ability of young adults. Methods: Thirty-four healthy adults were randomized into an action-observation group (n=17) or a control group (n=17). All subjects performed the Y-Balance test before and after watching the video. The action observation group watched a video of someone performing a Y-Balance test, and the control group watched a video of scenery unrelated to the training. The subjects were measured through a Y-Balance test for both the length of the legs extended in three directions and the Y-balance composite score. Results: A significant difference in the Y-balance composite score was observed between the two groups. A part of the direction of the extended leg in the action observation group was increased significantly (posteromedial direction of the right leg, posterolateral direction of the right leg, posteromedial direction of left leg) compared to the control group. Conclusion: These results suggest that action observation training only could help improve balance.

• Journal of The Korean Association For Science Education
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• v.30 no.1
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• pp.157-169
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• 2010

Scientific observation has been recognized as one of the fundamental aspects in scientific inquiry. However, more detailed discussions and practical guides for teachers' and students' understanding about the nature of scientific observation have not been conducted. Therefore, based on literature reviews, we described the nature of theory-laden scientific observation as 11 detailed statements. Using theses statements, we investigated science teachers' and students' recognition of each statement. According to results, certain aspects of theory-laden scientific observation were determined as important aspects to be considered for science teachers' in-service programs or for students' learning activities in understanding the nature of science.