• Title/Summary/Keyword: Observational Research

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New Observational Design and Construction Method in Tunnels and Its Application to Very Large Cross Section Tunnel (터널의 신 정보화 설계시공법과 극대단면 터널에의 적용)

  • Hwang Jae-Yun
    • Journal of the Korean Geotechnical Society
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    • v.20 no.7
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    • pp.5-14
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    • 2004
  • The observational design and construction method in tunnels is becoming important recently. In many tunnels, enormous cost and time are consumed to cope with the failing or sliding of rock blocks, which could not be predicted because of the complexity of rock discontinuities. It is difficult to estimate the properties of rock masses before the construction. In this paper, a new observational design and construction method in tunnels are proposed, and then applied to the example of the very large cross section tunnel based on actual discontinuity information observed in situ. The items examined in developing a program for the new observational design and construction method are the following ones: generality, precision, high speed, and friendly usability. At the very large cross section tunnel, 7 key blocks were judged to be unstable because they could not be supported by standard supports. Supplementary supports were installed to these 7 key blocks before the excavation. It is possible to detect key blocks all along the tunnel exactly by using the numerical analysis program developed for the new observational design and construction method in the very large cross section tunnel. This computer simulation method with user-friendly interfaces can calculate not only the stability of key blocks but also the design of supplementary supports.

A Similarity-based Inference System for Identifying Insects in the Ubiquitous Environments (유비쿼터스 환경에서의 유사도 기반 곤충 종 추론검색시스템)

  • Jun, Eung-Sup;Chang, Yong-Sik;Kwon, Young-Dae;Kim, Yong-Nam
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.3
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    • pp.175-187
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    • 2011
  • Since insects play important roles in existence of plants and other animals in the natural environment, they are considered as necessary biological resources from the perspectives of those biodiversity conservation and national utilization strategy. For the conservation and utilization of insect species, an observational learning environment is needed for non-experts such as citizens and students to take interest in insects in the natural ecosystem. The insect identification is a main factor for the observational learning. A current time-consuming search method by insect classification is inefficient because it needs much time for the non-experts who lack insect knowledge to identify insect species. To solve this problem, we proposed an smart phone-based insect identification inference system that helps the non-experts identify insect species from observational characteristics in the natural environment. This system is based on the similarity between the observational information by an observer and the biological insect characteristics. For this system, we classified the observational characteristics of insects into 27 elements according to order, family, and species, and proposed similarity indexes to search similar insects. In addition, we developed an insect identification inference prototype system to show this study's viability and performed comparison experimentation between our system and a general insect classification search method. As the results, we showed that our system is more effective in identifying insect species and it can be more efficient in search time.

DEEP SPACE NETWORK MEASUREMENT MODEL DEVELOPMENT FOR INTERPLANETARY MISSION (행성간 탐사를 위한 심우주 추적망 관측모델 개발)

  • Kim, Hae-Yeon;Park, Eun-Seo;Song, Young-Joo;Yoo, Sung-Moon;Rho, Kyung-Min;Park, Sang-Young;Choi, Kyu-Hong;Yoon, Jae-Cheol;Yim, Jo-Ryeong;Choi, Jun-Min;Kim, Byung-Kyo
    • Journal of Astronomy and Space Sciences
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    • v.21 no.4
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    • pp.361-370
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    • 2004
  • The DSN(Deep Space Network) measurement model for interplanetary navigations which is essential for precise orbit determination has been developed. The DSN measurement model produces fictitious DSN observables such as range, doppler and angular data, containing the potential observational errors in geometric data obtained from orbit propagator. So the important part of this research is to model observational errors in DSN observation and to characterize the errors. The modeled observational errors include the range delay effect caused by troposphere, ionosphere, antenna offset, and angular refraction effect caused by troposphere. Non-modeled errors are justified as the parameters. All of these results from developed models show about $10\%$ errors compared to the JPL's reference results, that are within acceptable error range.

A Prospective Observational Study of Herbal Medicines on Depressive Disorder (우울장애 한약치료에 대한 전향적 관찰연구)

  • Kim, Ju Yeon;Kim, Hwan;Lee, Ji-Yoon;Jung, Jin-Hyeong;Yang, Changsop;Lee, Mi-Young;Jung, In Chul
    • Journal of Oriental Neuropsychiatry
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    • v.31 no.2
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    • pp.63-76
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    • 2020
  • Objectives: The purpose of this study was to verify the clinical effects of herbal medicines on patients with depressive disorder. Methods: A prospective observational study on patients with depressive disorder was conducted. The patients were treated with herbal medicines for eight weeks. The Korean Hamilton Depression Rating Scale (K-HDRS) was evaluated as the primary outcome and the Korean Beck's Depression Inventory (K-BDI), Instrument on Pattern Identification for Depression, Korean Symptom Checklist-95 (KSCL-95), Insomnia Severity Index (ISI), Korean State-Trait Anxiety Inventory (STAI-K), Korean State-Trait Anger Expression Inventory (STAXI-K), EuroQol five-dimensional Questionnaire (EQ-5D), Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Heart Rate Variability (HRV) were measured as the secondary outcome. Adverse events were assessed for safety. Results: A total of 35 participants were observed for 12 weeks. The K-HDRS improved significantly in four, eight, and 12 weeks and the K-BDI showed significant differences in four, and eight weeks. There were no significant improvements in other evaluation scales. Gyejibongnyeong-hwan was the most frequently and continuously prescribed, showing significant improvements of K-HDRS after eight weeks of treatment. Conclusions: In our observational study, herbal medicine was effective for relieving the depression of patients with depressive disorder and Gyejibongnyeong-hwan showed the most significant effectiveness.

Standardization of Metadata for Urban Meteorological Observations (도시기상 관측을 위한 메타데이터의 표준화)

  • Song, Yunyoung;Chae, Jung-Hoon;Choi, Min-Hyeok;Park, Moon-Soo;Choi, Young Jean
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.6
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    • pp.600-618
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    • 2014
  • The metadata for urban meteorological observation is standardized through comparison with those established at the World Meteorological Organization and the Korea Meteorological Administration to understand the surrounding environment around the sites exactly and maintain the networks and sites efficiently. It categorizes into metadata for an observational network and observational sites. The latter is again divided into the metadata for station general information, local scale information, micro scale information, and visual information in order to explain urban environment in detail. The metadata also contains the static information such as urban structure, surface cover, metabolism, communication, building density, roof type, moisture/heat sources, and traffic as well as the update information on the environment change, maintenance, replacement, and/or calibration of sensors. The standardized metadata for urban meteorological observation is applied to the Weather Information Service Engine (WISE) integrated meteorological sensor network and sites installed at Incheon area. It will be very useful for site manager as well as researchers in fields of urban meteorology, radiation, surface energy balance, anthropogenic heat, turbulence, heat storage, and boundary layer processes.

Agrometeorological Observation Environment and Periodic Report of Korea Meteorological Administration: Current Status and Suggestions (기상청의 농업기상 관측환경과 정기보고서: 현황 및 제언)

  • Choi, Sung-Won;Lee, Seung-Jae;Kim, Joon;Lee, Byong-Lyol;Kim, Kyu-Rang;Choi, Byoung-Choel
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.2
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    • pp.144-155
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    • 2015
  • Since the relocation project of equipment in 2011, the overall circumstances of KMA's agrometeorological observation have been significantly improved. Some concerns, however, emerged as a result of the evaluation of observational circumstances in terms of quality assurance after the field surveys on all stations. In order to improve the situation, we suggest: (1) establishment of clear management responsibilities, (2) enhancement of mutual cooperation system between relevant organizations, (3) detailed records of the changes in the observational circumstances, (4) standardization of equipment and sensors, (5) installation of unified information boards, (6) transfer of inappropriate facilities to an adjacent cropland and (7) setup of automated evaporation pan. In order to effectively utilize the high-quality data obtained through improvement of observational circumstances and an elaborate quality control, it is recommended to publish and disseminate regular reports on agrometeorological observations. To produce such a report on a trial basis, we have investigated different types of regular reports issued by domestic and foreign organizations, publication periods, geographical scope, main contents and amount. Based on our current situation, it would be beneficial to learn from the cases of Germany and Canada, which summarize mainly the distinctive agrometeorological phenomena occurred over the past years across the country.

An Analysis of Observational Environments for Solar Radiation Stations of Korea Meteorological Administration using the Digital Elevation Model and Solar Radiation Model (수치표고모델과 태양복사모델을 이용한 기상청 일사 관측소 관측환경 분석)

  • Jee, Joon-Bum;Zo, Il-Sung;Kim, Bu-Yo;Lee, Kyu-Tae
    • Journal of the Korean earth science society
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    • v.40 no.2
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    • pp.119-134
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    • 2019
  • In order to analyze the observational environment of solar radiation stations operated by the Korea Meteorological Administration (KMA), we used the digital elevation model (DEM) and the solar radiation model to calculate a topographical shading, sky view factor (SVF) and solar radiation by surrounding terrain. The sky line and SVF were calculated using high resolution DEM around 25 km of the solar stations. We analyzed the topographic effect by analyzing overlapped solar map with sky line. Particularly, Incheon station has low SVF whereas Cheongsong and Chupungryong station have high SVF. In order to validation the contribution of topographic effect, the solar radiation calculated using GWNU solar radiation model according to the sky line and SVF under the same meteorological conditions. As a result, direct, diffuse and global solar radiation were decreased by 12.0, 5.6, and 4.7% compared to plane surface on Cheongsong station. The 6 stations were decreased amount of mean daily solar radiation to the annual solar radiation. Among 42 stations, eight stations were analyzed as the urgent transfer stations or moving equipment quickly and more than half of stations (24) were required to review the observational environment. Since the DEM data do not include artifacts and vegetation around the station, the stations need a detail survey of observational environment.

A step-by-step guide to Propensity Score Matching method using R program in dental research (치의학 연구에서 R program을 이용한 성향점수매칭의 단계적 안내)

  • An, Hwayoen;Lim, Hoi-Jeong
    • The Journal of the Korean dental association
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    • v.58 no.3
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    • pp.152-168
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    • 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.

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