• Journal of The Korean Association For Science Education
• /
• v.39 no.1
• /
• pp.129-141
• /
• 2019

As the number of minority students such as multicultural, North Korean defectors, and low-income groups increases, more research is needed in science education to help their learning. Due to the various growth backgrounds and learning environments of the underprivileged students, there is a big difference in the individual characteristics of the group rather than the whole group characteristics. In this study, we conducted about 50 hours of science lessons for seven students in the underprivileged class, categorized them by observing and interviewing the characteristics of their science learning. Seven underprivileged students showed five different learning patterns, these are 'I love science', 'I think I know science', 'I want to know science', 'I need to know science', and 'I don't know what I want'. Although the scientific activities they experienced were not all of an excellent educational quality, their interest in science learning has increased with their experience in science activities. It shows the need to provide more abundant science experience and educational opportunities for these minority students who can only experience science learning under the public educational system.

• Journal of the Society of Naval Architects of Korea
• /
• v.56 no.3
• /
• pp.281-289
• /
• 2019

In order to investigate the influence of thru holes near leading edge of model propeller on cavitation behavior, a model propeller with thru holes was manufactured and tested at Large Cavitation Tunnel (LCT). The pressure distribution around the thru hole on propeller blade was numerically calculated to help understand the local flow characteristics related to cavitation behavior. The model propeller is a five bladed propeller which has 2 blades with thru holes and 3 blades with smooth surface. The cavitation observation tests were conducted at angles of $0^{\circ}$ & $6^{\circ}$ using an inclined-shaft dynamometer in LCT. There are big difference on the suction side cavitation behavior each other due to the existence of thru hole. While the blades with thou holes start generation of the sheet cavitation from the leading edge on the suction side, the blades with smooth surface generate the cloud cavitation from the mid-chord. Cavitation on the blades with thru holes shows more similar behavior to those of the full-scale propeller of which the pipe line for air injection is closed. The numerical analysis result shows that the sharp pressure drop occurs around thru holes on the blade. Consequently, the thru hole around leading edge stimulates the cavitation occurrence and stabilizes the cavitation behavior. Based on these results, the effect of thru holes on propeller cavitation behavior behind a model ship should be studied in the future.

• Database Research
• /
• v.34 no.3
• /
• pp.58-68
• /
• 2018

Distributed computing helps to efficiently store and process large data on a cluster of multiple machines. The performance of distributed computing is greatly influenced depending on the state of the servers constituting the distributed system. In this paper, we propose a self-diagnosis system that collects log data in a distributed system, detects anomalies and visualizes the results in real time. First, we divide the self-diagnosis process into five stages: collecting, delivering, analyzing, storing, and visualizing stages. Next, we design a real-time self-diagnosis system that meets the goals of real-time, scalability, and high availability. The proposed system is based on Apache Flume, Apache Kafka, and Apache Storm, which are representative real-time distributed techniques. In addition, we use simple but effective moving average and 3-sigma based anomaly detection technique to minimize the delay of log data processing during the self-diagnosis process. Through the results of this paper, we can construct a distributed real-time self-diagnosis solution that can diagnose server status in real time in a complicated distributed system.

• Journal of Digital Convergence
• /
• v.19 no.1
• /
• pp.361-371
• /
• 2021

Communication education research has focused on the effects of instructor characteristics on learning. It is necessary to consider student characteristics as well to develop an effective teaching strategy. The current study tries to classify students into multiple distinct groups depending on their personality traits and communication characteristics and investigates differences in effects of teacher characteristics between those groups. A survey on unversity students was conducted to collect data. A cluster analysis was carried out to identify distint sub-groups of respondents by their personality traits and communication characteristics. The analysis yielded two distinct groups. The two groups were named stable-reticent group', and 'neurotic-talkative group' respectivley. Series of multiple regression were carried out in order to investigate differences in the effects of instructor characteristics. The analyses found different patterns of effects between the two sub-groups. The findings suggest that it is necessary to adopt different communication styles and teaching strategies depending on student types.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.34 no.8
• /
• pp.69-76
• /
• 2018

This study is basically about the changing appearance of the big pavilion, Yeongnamnu in Miryang city belonging to the government guesthouse of Joseon dynasty. And the purpose of this study confirms that even if the appearance of the building has not changed, the function of the building changes because the reason why people think about the building is also different. First, looked at the appearance of architecture and the function of architecture that changes with the times. In the course of the research, the changes of pavilion were traced by dividing it into five from Kory? dynasty which was first established to the present. Then, tried to find out the change patterns by analyzing important events related to buildings or places in each period. As a result, the following facts were confirmed. 1. Because of the Buddhist repression policy in Joseon Dynasty, the Yeongnamnu changed from the temple pavilion to the government pavilion. 2. Throughout the Joseon Dynasty, Yeongnamnu was the representative scenic of Miryang City. 3. In the late Joseon Dynasty, Yeongnamnu was famous as a place where a woman named Arang devoted her life in order to preserve his fidelity. 4. Since 1910, Yeongnamnu has become an important cultural asset, and space has been widely used as a venue for various public events. 5. From 1945 to 1999, Yeongnamnu was used mainly for the events of Arang Remembrance and Miryang Culture Festival. And the inner space of Yeongnamnu was rarely used because people thought preservation is important.

• Environmental and Resource Economics Review
• /
• v.29 no.4
• /
• pp.419-442
• /
• 2020

The majority of the natural gas demand in South Korea is mainly determined by the heating demand. Accordingly, there is a distinct seasonality in which the gas demand increases in winter and decreases in summer. Moreover, the degree of sensitiveness to temperature on gas demand has changed over time. This study firstly introduces changing temperature response function (TRF) to capture effects of changing seasonality. The temperature effect (TE), estimated by integrating temperature response function with daily temperature density, represents for the amount of gas demand change due to variation of temperature distribution. Also, this study presents an innovative way in forecasting daily temperature density by employing functional principal component analysis based on daily max/min temperature forecasts for the five big cities in Korea. The forecast errors of the temperature density and gas demand are decreased by 50% and 80% respectively if we use the proposed forecasted density rather than the average daily temperature density.

• Food Science and Industry
• /
• v.49 no.4
• /
• pp.40-63
• /
• 2016

John Glenn, America's first man to eat anything in the near-weightless environment of Earth orbit, found the task of eating fairly easy. With improved packaging came improved food quality and menus. By the time of the Apollo Program, the quality and variety of food increased even further. Apollo astronauts were the first to have hot water, which made rehydrating foods easier and improved the food's taste. Thermostabilized pouches were also introduced on Apollo. The task of eating in space got a big boost in Skylab. It also had a food freezer and refrigerator a convenience offered by no other vehicle before or since. Two different food systems will be used for future long-duration missions to other planets, one for traveling to and from the distant body and one for use on the surface of the moon or Mars. The transit food system will be similar to the space station food system with the exception that products with three-to five-year shelf lives will be needed. Thus, this part of the trip will be similar to what occurs aboard space missions now. The surface food system, be it lunar or planetary, will be quite different. It will be similar to a vegetarian diet that someone could cook on Earth. Once crew members arrive on the surface and establish living quarters, they can start growing crops. Once the crops are processed into edible ingredients, cooking will be done in the spacecraft's galley to make the food items. Disposal of used food packaging will be an issue since there will be no Progress vehicles to send off and incinerate into the Earth's atmosphere. Packaging materials will be used that have less mass but sufficient barrier properties for oxygen and water to maintain shelf life as those now in use.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.6
• /
• pp.1123-1130
• /
• 2020

This study aims to classify the severity in car crashes using five classification learning models. The dataset used in this study contains 21,013 vehicle crashes, obtained from Korea Expressway Corporation, between the year of 2015-2017 and the LightGBM(Light Gradient Boosting Model) performed well with the highest accuracy. LightGBM, the number of involved vehicles, type of accident, incident location, incident lane type, types of accidents, types of vehicles involved in accidents were shown as priority factors. Based on the results of this model, the establishment of a management strategy for response of highway traffic accident should be presented through a consistent prediction process of accident severity level. This study identifies applicability of Machine Learning Models for Predicting of the Severity of Car Traffic Accidents on a Highway and suggests that various machine learning techniques based on big data that can be used in the future.

• Journal of Korean Neurosurgical Society
• /
• v.65 no.4
• /
• pp.507-513
• /
• 2022

Objective : The goal of the following statewide age and gender-coordinated cohort study in Korea is to find out if there is a link between acute myocardial infarction (AMI) and Parkinson's disease (PD). Methods : Utilizing the National Health Insurance Sharing Service cohort, patient data were collected. Six thousand four hundred seventy-five individuals with PD were distinguished by utilizing the International Classification of Diseases 10 code G20 and have enrolled in the PD group. The number of participants decreased to 5259 after excluding 1039 patients who were hospitalized less than one time or who visited an outpatient clinic less than twice. Then, 26295 individuals were selected as part of the control group after case control matching was conducted through 1 : 5 age- and gender-coordinated matching. The Cox proportional hazard regression analysis and Kaplan-Meier method were utilized to analyze the likelihood of AMI in PD. Results : After controlling for age and gender, the hazard ratio of AMI in the PD group was 3.603 (95% confidence interval [CI], 2.837-4.577). After that, the following hazard ratio of AMI in the PD group was modified against for co-morbid medical disorders, resulting in 3.551 (95% CI, 2.795-4.511). According to a subgroup analysis, in males and females aged <65 and aged ≥65 and in the non-diabetes and diabetes, hypertension and non-hypertension, dyslipidemia and non-dyslipidemia subgroups, the AMI incidence rates were dramatically higher in the PD group compared to that of the control. Conclusion : Individuals with PD have a greater chance of AMI, according to this cross-national study.

• Nutrition Research and Practice
• /
• v.17 no.1
• /
• pp.62-72
• /
• 2023

BACKGROUND/OBJECTIVES: Many studies have revealed an association between fat mass and the obesity-related gene (FTO) and obesity. On the other hand, no meta-analysis was conducted with data from only Koreans. Therefore, this study performed a meta-analysis using Korean data to provide evidence for the association between FTO single nucleotide polymorphisms (SNPs) and the risk of obesity among Korean adults. SUBJECT/METHODS: Meta-analysis was finally conducted with data extracted from seven datasets of four studies performed on Korean adults after the screening passed. Five kinds of FTO SNPs (rs9939609, rs7193144, rs9940128, rs8050136, and rs9926289) were included, and the relationship between FTO SNPs and body mass index (BMI) was investigated using linear regression with an additive model adjusted for covariants, such as age, sex, and area. RESULTS: The minor alleles of FTO SNPs were associated with increased BMI (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.21-1.42). In sub-group analysis, FTO rs9939609 T>A was significantly associated with BMI (OR, 1.23; 95% CI, 1.06-1.42). The other FTO SNPs together were significantly associated with BMI (OR, 1.37; 95% CI, 1.25-1.49). The publication bias was not observed based on Egger's test. CONCLUSIONS: This meta-analysis showed that minor alleles in the FTO SNPs were significantly associated with an increased BMI among Korean adults. This meta-analysis is the first to demonstrate that minor alleles in the FTO SNPs contribute significantly to the increased risk of obesity among Korean adults using data from a Korean population.