• Journal of the Korean earth science society
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• v.45 no.2
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• pp.111-120
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• 2024

Cloud coverage is a key factor in determining whether to proceed with observations. In the past, human judgment played an important role in weather evaluation for observations. However, the development of remote and robotic observation has diminished the role of human judgment. Moreover, it is not easy to evaluate weather conditions automatically because of the diverse cloud shapes and their rapid movement. In this paper, we present the development of a cloud monitoring program by applying a machine learning-based Python module "cloudynight" on all-sky camera images obtained at Miryang Arirang Astronomical Observatory (MAAO). The machine learning model was built by training 39,996 subregions divided from 1,212 images with altitude/azimuth angles and extracting 16 feature spaces. For our training model, the F1-score from the validation samples was 0.97, indicating good performance in identifying clouds in the all-sky image. As a result, this program calculates "Cloudiness" as the ratio of the number of total subregions to the number of subregions predicted to be covered by clouds. In the robotic observation, we set a policy that allows the telescope system to halt the observation when the "Cloudiness" exceeds 0.6 during the last 30 minutes. Following this policy, we found that there were no improper halts in the telescope system due to incorrect program decisions. We expect that robotic observation with the 0.7 m telescope at MAAO can be successfully operated using the cloud monitoring program.

• The Korean Journal of Applied Statistics
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• v.32 no.2
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• pp.173-185
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• 2019

Causal questions are prevalent in scientific research, for example, how effective a treatment was for preventing an infectious disease, how much a policy increased utility, or which advertisement would give the highest click rate for a given customer. Causal inference theory in statistics interprets those questions as inferring the effect of a given intervention (treatment or policy) in the data generating process. Causal inference has been used in medicine, public health, and economics; in addition, it has received recent attention as a tool for data-driven decision making processes. Many recent datasets are observational, rather than experimental, which makes the causal inference theory more complex. This review introduces key concepts and recent trends of statistical causal inference in observational studies. We first introduce the Neyman-Rubin's potential outcome framework to formularize from causal questions to average treatment effects as well as discuss popular methods to estimate treatment effects such as propensity score approaches and regression approaches. For recent trends, we briefly discuss (1) conditional (heterogeneous) treatment effects and machine learning-based approaches, (2) curse of dimensionality on the estimation of treatment effect and its remedies, and (3) Pearl's structural causal model to deal with more complex causal relationships and its connection to the Neyman-Rubin's potential outcome model.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.539-548
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• 2022

Objective : Although full-endoscopic lumbar interbody fusion (Endo-LIF) has been tried as the latest alternative technique to minimally invasive transforaminal lumbar interobody fusion (MIS-TLIF) since mid-2010, the evidence is still lacking. We compared the clinical outcome and safety of Endo-LIF to MIS-TLIF for lumbar degenerative disease. Methods : We systematically searched electronic databases, including PubMed, EMBASE, and Cochrane Library to find literature comparing Endo-LIF to MIS-TLIF. The results retrieved were last updated on December 11, 2020. The perioperative outcome included the operation time, blood loss, complication, and hospital stay. The clinical outcomes included Visual analog scale (VAS) of low back pain and leg pain and Oswestry disability index (ODI), and the radiological outcome included pseudoarthosis rate with 12-month minimum follow-up. Results : Four retrospective observational studies and one prospective observational study comprising 423 patients (183 Endo-LIF and 241 MIS-TLIF) were included, and the pooled data analysis revealed low heterogeneity between studies in our review. Baseline characteristics including age and sex were not different between the two groups. Operation time was significantly longer in Endo-LIF (mean difference [MD], 23.220 minutes; 95% confidence interval [CI], 10.669-35.771; p=0.001). However, Endo-LIF resulted in less perioperative blood loss (MD, -144.710 mL; 95% CI, 247.941-41.478; p=0.023). Although VAS back pain at final (MD, -0.120; p=0.586), leg pain within 2 weeks (MD, 0.005; p=0.293), VAS leg pain at final (MD, 0.099; p=0.099), ODI at final (MD, 0.141; p=0.093) were not different, VAS back pain within 2 weeks was more favorable in the Endo-LIF (MD, -1.538; 95% CI, -2.044 to -1.032; p<0.001). On the other hand, no statistically significant group difference in complication rate (relative risk [RR], 0.709; p=0.774), hospital stay (MD, -2.399; p=0.151), and pseudoarthrosis rate (RR, 1.284; p=0.736) were found. Conclusion : Relative to MIS-TLIF, immediate outcomes were favorable in Endo-LIF in terms of blood loss and immediate VAS back pain, although complication rate, mid-term clinical outcomes, and fusion rate were not different. However, the challenges for Endo-LIF include longer operation time which means a difficult learning curve and limited surgical indication which means patient selection bias. Larger-scale, well-designed study with long-term follow-up and randomized controlled trials are needed to confirm and update the results of this systematic review.

• Korean Journal of Health Education and Promotion
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• v.27 no.4
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• pp.165-175
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• 2010

Objectives: The purpose of this study is to evaluate the program theory of a lifestyle intervention program for the prevention and treatment of metabolic syndrome. Methods: The program evaluated is a tailored intervention for multiple health behavior associated with metabolic syndrome which is informed by theoretical constructs from the Intervention Mapping and Transtheoretical model. The program components include one-to-one health counseling, a self-management handbook, and a health diary. To evaluate program impact theory we examined the logic of program goals and objectives, intervention methods and strategies, and the theoretical constructs of program materials through document review and matrix building. Results: This evaluation has found that the intervention program applied social cognitive theory constructs to design intervention methods and strategies in addition to the Transtheoretical model: self-monitoring for goal setting and monitoring skill, outcome expectation for the benefits of health behavior change, and interaction with environment for observational learning through modeling. While the intervention addresses multiple determinants and behaviors, it is limited to an individual level and lacks social and environmental approaches. Following the Transtheoretical framework, the contents of the intervention materials were developed utilizing consciousness raising as a main strategy for earlier stages of change, and counterconditioning and stimulus control for later stages of change. Conclusion: Program theory evaluation can be a process of enhancing program validity. It would also be necessary for providing basis for efficient program implementation. When comparisons of program theory between similar programs are possible, program theory and validity will be strengthened when comparisons of program theories between similar programs are possible.

• Journal of Educational Research in Mathematics
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• v.27 no.4
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• pp.639-661
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• 2017

This article reviews several classroom observational frameworks and introduces one of them, Teaching for Robust Understanding of Mathematics (TRU Math) framework, in more detail. The TRU Math framework has unique features, especially of which it helps researchers and practitioners analyze lessons with a focus on opportunities to learn and on how students access to the learning opportunities in mathematics classrooms rather than focusing on teacher behaviors. In this article, using this TRU Math framework, a Korean high school mathematics lesson was analyzed. The analysis illustrates the aspects of good mathematics teaching according to the five dimensions that we theorized. It provides implications on how to better use the tool for both research and practice in Korean school culture and teacher professional development contexts.

• The Journal of Korean Academic Society of Nursing Education
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• v.17 no.2
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• pp.257-266
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• 2011

Purpose: The aim of this study was to elucidate the themes involved in a nursing experience of caring for extremely low birth weight infants (ELBWIs) in a neonatal intensive care unit (NICU). Methods: Interviews with 6 nurses in various positions and observations in a level III NICU were conducted. The transcribed interview contents and observational notes were reviewed to analyze the data and conceptualize major themes. Results: Three major themes were identified: the fears expressed by the nurses regarding taking care of ELBWIs, reasons for persistent fears, and overcoming fears and gaining intuition. Nurses were afraid of the following factors: the physical fragility of the infants; the possibility of developing disabilities in the future; and the rapid changes in infants' physical condition. These fears were reduced when nurses had developed intuition and confidence in taking care of ELBWIs through various situational experiences. Conclusion: NICU nurses may benefit from obtaining more opportunities to participate in various learning experiences with simulated nursing situations in a variety of patient groups. Applying knowledge and skills into various nursing situations in an integrative way may contribute to enhancing nurses' confidence in nursing practice.

• 한국정보교육학회:학술대회논문집
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• 2021.08a
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• pp.101-105
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• 2021

With the advent of the 4th industrial revolution era, many countries around the world are making efforts to prepare for a new future. In addition to changes in the industrial structure, efforts are being made to reflect new changes in the education system to cultivate human resources. As one of the important parts of change, software education is reflected as a core area of the curriculum and introduced as a future competency in order to cultivate human resources who can prepare for and lead the change into a computer-oriented intelligent information society. In this study, the purpose of this study was to examine the perceptions of pre-service teachers on software education, analyze the direction and thoughts they have about elementary school information education, and examine the necessity and direction of the subject. Based on the responses of preliminary teachers, it was suggested that project-based learning is necessary for how SW education is carried out in the school field, and they answered that the evaluation should be performed through observational evaluation. In addition, as a result of examining the perception of prospective teachers, it was possible to see the result that SW education is recognized as an important competency for preparing for the future society.

• Korean Journal of Optics and Photonics
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• v.28 no.6
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• pp.327-333
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• 2017

The purpose of this research was to analyze characteristics of verbal interactions of each homogeneous group in the learning of the 6th grade's 'Use of Lenses' Unit. For this research, six learning sessions were conducted in one 6th grade class composed of a high-academic-achievement group, an intermediate-academic-achievement group, and a low-academic-achievement group. All lessons were recorded, to analyze the verbal interactions of each group, and the transcribed data were analyzed using the verbal-interaction analytic framework. Results included: In the upper group, although opinions were presented more frequently, there were many negative verbal interactions in completing the tasks. The middle group was observed more specifically to accept peer opinions critically in their observational activities. The middle group's members were more active in presenting their opinions than listening to others' opinions. The lower group had difficulties in drawing conclusions because of a lack of ability to persuade peers or to respect the opinions of peers, even though the frequency of verbal interactions was higher than in other groups. Therefore, a homogeneous group structure is good for a simple activity involving a simple inquiry or an exchange of opinions, while a heterogeneous group structure is more effective in activities focused on understanding scientific concepts and knowledge.

• Journal of Korean Home Economics Education Association
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• v.33 no.1
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• pp.101-127
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• 2021

The purpose of this study is to design and develop a teaching-learning process plan for process-based assessment, focusing on the unit related to life design in middle school home economics(HE: Home Economics part of 「Technology and Home Economics」), to propose a feedback plan after implementing it, and to evaluate the plan through participatory observation and interviews. The student reflection journals, teacher's class journals, participatory observation journals, interviews, and performance tasks, were collected and analyzed to provide foundational date to be utilized for feedback to students, and class improvement. The research results are as follows: First, the developed teaching-learning process plan consists of a total of 8 sessions, i.e. 2 sessions for each of the four learning themes, under the practical question of "What should I do to live the life I want?" The portfolio was composed of five evaluation topics and for evaluation, oral presentation, observational evaluation, self-assessment, and peer evaluation were considered. Second, during the class, feedback from teachers, feedback from fellow students, feedback through results, and a plan to record them were provided. Third, from the analysis of collected data including observation journals and interviews, it was apparent that the students recognized the necessity of process-based assessment after the class, and students acknowledged that through the process-based evaluation in which they are evaluated on the efforts they made and provided with feedbacks, they participated more in class, and it lead them to experience a sense of growth and a feeling that they took a step forward into their future. Teachers suggested that the class through feedback was suitable for the unit and the capacity of the class, but the difficulty they experienced in giving feedback was presented as a disadvantage. For the process-based assessment, follow-up research is needed on various ways to provide feedback on-line and off-line through changes in the perception of assessment.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.41.1-41.1
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• 2018

We introduce a current status and future plans of Korea Microlensing Telescope Network (KMTNet) microlensing experiments, which include an observational strategy, pipeline, event-finder, and collaborations with Spitzer. The KMTNet experiments were initiated in 2015. From 2016, KMTNet observes 27 fields including 6 main fields and 21 subfields. In 2017, we have finished the DIA photometry for all 2016 and 2017 data. Thus, it is possible to do a real-time DIA photometry from 2018. The DIA photometric data is used for finding events from the KMTNet event-finder. The KMTNet event-finder has been improved relative to the previous version, which already found 857 events in 4 main fields of 2015. We have applied the improved version to all 2016 data. As a result, we find that 2597 events are found, and out of them, 265 are found in KMTNet-K2C9 overlapping fields. For increasing the detection efficiency of event-finder, we are working on filtering false events out by machine-learning method. In 2018, we plan to measure event detection efficiency of KMTNet by injecting fake events into the pipeline near the image level. Thanks to high-cadence observations, KMTNet found fruitful interesting events including exoplanets and brown dwarfs, which were not found by other groups. Masses of such exoplanets and brown dwarfs are measured from collaborations with Spitzer and other groups. Especially, KMTNet has been closely cooperating with Spitzer from 2015. Thus, KMTNet observes Spitzer fields. As a result, we could measure the microlens parallaxes for many events. Also, the automated KMTNet PySIS pipeline was developed before the 2017 Spitzer season and it played a very important role in selecting the Spitzer target. For the 2018 Spitzer season, we will improve the PySIS pipeline to obtain better photometric results.