• Title/Summary/Keyword: survey sampling

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A TBM data-based ground prediction using deep neural network (심층 신경망을 이용한 TBM 데이터 기반의 굴착 지반 예측 연구)

  • Kim, Tae-Hwan;Kwak, No-Sang;Kim, Taek Kon;Jung, Sabum;Ko, Tae Young
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.1
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    • pp.13-24
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    • 2021
  • Tunnel boring machine (TBM) is widely used for tunnel excavation in hard rock and soft ground. In the perspective of TBM-based tunneling, one of the main challenges is to drive the machine optimally according to varying geological conditions, which could significantly lead to saving highly expensive costs by reducing the total operation time. Generally, drilling investigations are conducted to survey the geological ground before the TBM tunneling. However, it is difficult to provide the precise ground information over the whole tunnel path to operators because it acquires insufficient samples around the path sparsely and irregularly. To overcome this issue, in this study, we proposed a geological type classification system using the TBM operating data recorded in a 5 s sampling rate. We first categorized the various geological conditions (here, we limit to granite) as three geological types (i.e., rock, soil, and mixed type). Then, we applied the preprocessing methods including outlier rejection, normalization, and extracting input features, etc. We adopted a deep neural network (DNN), which has 6 hidden layers, to classify the geological types based on TBM operating data. We evaluated the classification system using the 10-fold cross-validation. Average classification accuracy presents the 75.4% (here, the total number of data were 388,639 samples). Our experimental results still need to improve accuracy but show that geology information classification technique based on TBM operating data could be utilized in the real environment to complement the sparse ground information.

Survey of Emission Characteristics and Weather Factors for Application in Prediction Modeling for Phytoncide Weather Services (피톤치드 기상서비스 예측 모델링 적용을 위한 발생특성 및 기상인자 조사)

  • Kim, Byoung-Ug;Hyun, Geun-Woo;Choi, Jong-Han;Hong, Young-Kyun;Yi, Geon-Ho;Huh, In-Ryang;Choi, Seung-Bong
    • Journal of Environmental Health Sciences
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    • v.46 no.6
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    • pp.636-645
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    • 2020
  • Objectives: This study was performed to find phytoncide (monoterpene) emission characteristics and weather factors for application in prediction modeling for phytoncide weather services. Methods: From 2017 to 2019, one coniferous forest and one deciduous forest were selected to investigate the monthly emission characteristics and identify the correlation with weather factors. Research items were analyzed for 11 species known to be emitting the most monoterpenes. Results: Phytoncide (monoterpene) began to increase in April when trees were activated and continued to be released until November. The concentration range of monoterpene in deciduous forests was 0.0 to 427.4 ng/S㎥ and coniferous forests was 0.0 to 1,776.8 ng/S㎥. Phytoncide emission concentrations in deciduous forests were 20 to 90 percent of those in coniferous forests, and averaged 39 percent overall. The correlation between monoterpene and temperature was very close, with 0.835 for the broadleaf forest and 0.875 for the coniferous forest. Monoterpene and humidity were found to be 0.731 for the broadleaf forest and 0.681 for the coniferous forest, while wind speed showed a negative correlation of -0.482 and -0.424, respectively. Regression of temperature with phytoncide showed that the coefficient of determination (r2) was highly correlated with 0.75 for the broadleaf forest and 0.80 for the coniferous forest. Not only is phytoncide concentration affected by temperature, humidity, and wind speed, but also rainfall over the preceeding one to three days. Nearby rainfall on the day of sampling was found to have a direct effect on the physiological activities of the trees. Conclusions: Overall, if the values of monoterpene and temperature, humidity, and wind speed are used as basic factors, and rainfall from one to three days previous is replaced with complementary values, it is believed that the numerical analysis and modeling of daily and monthly phytoncide will be possible.

The Effects of the Online Learning Using Virtual Reality (VR) Geological Data: Focused on the Geo-Big Data Open Platform (가상현실(VR) 지질자료 개발을 통한 원격수업의 효과 분석: 지오빅데이터 오픈플랫폼 활용을 중심으로)

  • Yoon, Han Do;Kim, Hyoungbum;Kim, Heoungtae
    • Journal of the Korean Society of Earth Science Education
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    • v.15 no.1
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    • pp.47-61
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    • 2022
  • In this study, We developed VR (Virtual Reality) geological resources based on the Geo Big Data of the Big Data platform that provided by the Korea Institute of Geoscience and Mineral Material (KIGAM). So students selected the theme of lessons by using these resources and we operated Remote classes using the materials that developed as to Virtual Reality. Therefore, the geological theme maps provided by the Geo Big Data Open Platform were reconstructed and produced materials were created for Study about Real Korean geological outcrops grounded in Virtual Reality. And Topographic information data was used to produce class materials for Remote classes. Twenty students were selected by Random sampling, and data were collected by conducting a survey including interviews to confirm the change in students' perception of remote classes in virtual reality geological data development and the effect of the classes, so data were analyzed through inductive categorization. The results of this study are as follows. First, students showed positive responses in terms of interest, utilization, and knowledge utilization as taking remote classes for developing geological data in virtual reality geological data. This is the result of showing the adaptability of diverse and flexible learning getting away from a fixed framework by motivating and encouraging students and inducing cooperation for communication. Second, students recognized distance education in the development of Virtual Reality geological data as 'Realistic hands-on learning process', 'Immersive learning process by motivation', and 'Learning process of acquiring knowledge in the field of earth science'.

A Study of Servicescape Focused on Taekwondo Gym (태권도장의 서비스스케이프에 대한 연구)

  • Jang, Won-Yong;Choi, Kyoung-Ho;Cho, Won-Ho
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.4
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    • pp.207-216
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    • 2021
  • The purpose of this study was to empirically examine the servicesape focused on Taekwondo gym. More specifically, this study was to investigate the effect of servicescape on gym's image, parents' satisfaction and re-enroll intention. The 250 survey questionnaires were distributed among the trainee's parents of through convenience sampling. Due to the reliability of data, 18 samples were discarded and 232 samples were put to actual analysis. By using SPSS Ver. 21.0, data were analyzed for frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis and multiple regression analysis. The results of the study were as follows. First, the variables of servicescape which was ambient condition, cleanliness and comfort had positive effects on gym's image. Second, the servicescape which was consist of ambient condition, cleanliness, comfort and safety had significantly effects on parents' satisfaction. Third, servicescape which was consist of s ambient condition, cleanliness, comfort and safety had significantly effects on re-enroll intention. This study has a positive meaning in that it confirms the importance of the servicescape of the Taekwondo gym and presents the operation strategy through the servicescape.

Exploring Predictors of Preventive Behavior against COVID-19:Centered on Korean Collegians' Social Distancing (코로나19 예방행동 영향요인의 탐색: 우리나라 대학생의 사회적 거리두기를 중심으로)

  • Joo, Jihyuk
    • The Journal of the Korea Contents Association
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    • v.22 no.10
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    • pp.488-496
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    • 2022
  • For over two years, after COVID-19 was first reported in the last quarter of 2019, the world has suffered from the pandemic. The Korean government has taken an initiative and has implemented a variety of policies to protect people from COVID-19. These policies have resulted in some suffering and inconvenience for people. In this context, we aim to find out what factors influence Korean college students' intention to social distance. We surveyed with Google's online survey tool(Google Form) for 116 Korean college students using a convenient sampling from December 30, 2020, to January 8, 2021. We put perceived susceptibility, perceived severity, perceived health status, level of involvement, and trust in the policy as independent variables into a multiple regression equation using the stepwise method. We found that intention to social distance was predicted by perceived susceptibility, level of involvement, and trust in the policy in the final model. The findings mean that the more people perceive themselves susceptible to COVID-19, and the more they get involved with COVID-19, and the more they trust their governmental policies on COVID-19, the more they agree on social distancing.

Distribution Status and Extinction Threat Evaluation of Ladislabia taczanowskii (Cypriniformes, Cyprinidae), a Cold Water Fish in Korea (한국산 냉수성 어류 새미(잉어목, 잉어과)의 분포현황 및 멸종위협평가)

  • Choi, Kwang-Seek;Bae, Yang-Seop;Ko, Myeong-Hun
    • Korean Journal of Ichthyology
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    • v.34 no.1
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    • pp.34-43
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    • 2022
  • A distribution survey was conducted from March to August 2021 to evaluate the distribution status, habitat characteristics, and threat of extinction of the Korean cold-water fish Ladislabia taczanowskii Dybowski (Cypriniformes, Cyprinidae). Historical distribution reports were divided into 1997~2005, 2006~2012, 2013~2019, and distribution surveyed 169 sampling sites, and 1,040 individuals were collected from 72 sites. Areas where the habitat was confirmed were Namhan River (27 stations), Han River (17 stations), Bukhan River (16 stations), Samcheok Osipcheon (4 stations), Yeongokcheon (3 stations), Gangneung Namdaecheon (2 stations), Jeoncheon (1 station), Chucheon (2 stations). The main habitat of L. taczanowskii was upstream of the river with a high altitude of more than 300 m, 2~30 m water flow width, 0.3~1.5 m water depth, and high ratio (50~90%) boulder bottoms. The main reasons for the decline in population size were assumed as river works, construction of reservoirs and bridges, discharge of contaminated water into the river, the inflow of summer vacationers, and weir. Compared to our results there exists evidence that states a 36.1% reduction in occupancy within 10 years, in a small appearance range (7,820 km2) and occupancy area (288 km2), number of disconnected locations (19 locations), and a decline in habitat quality. Therefore, L. taczanowskii is now considered as Vulnerable (VU) based on the results (VU A2ac, Near meets B1b (i, ii, iii)+B2b (i, ii, iii)) of IUCN Red List categories and criteria. Lastly, the conservation plan of Ladislabia taczanowskii was discussed.

A study on the structural relationship between resource attraction, entertainment experience, love mark and attachment in tourist destination (관광목적지의 자원매력, 오락적 체험, 러브마크, 애착 간의 구조적 관계)

  • Seo, Gyeong-Do;Lee, Jung-Eun
    • Journal of Digital Convergence
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    • v.20 no.5
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    • pp.261-268
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    • 2022
  • This study tried to understand the meaning of resource attraction, entertainment experience, love mark, and attachment of tourist destinations. A theoretical study was conducted on each research concept to achieve the proposed research purpose. Based on this, an empirical study was conducted after deriving a questionnaire based on this, and a non-face-to-face survey was conducted nationwide using population-proportional sampling. The empirical study was confirmed through the statistical programs SPSS25.0 and AMOS25.0. The resource attractiveness of the tourist destination had a positive (+) relationship with the influence on the tourists' experience. The relationship between the experience and the love mark had a positive (+) relationship. A positive (+) relationship was also formed in the relationship between experience and attachment. However, the relationship between love mark and attachment did not form a significant relationship.Because it reflects regional characteristics, it is a useful material for local culture and history, so protection, preservation, and active program development are required. is needed.

A Exploratory Study on the Influential Factors of Resilience in Female High School Students (여고생의 회복탄력성 영향요인에 대한 탐색적 연구)

  • Hwang, Ran Hee
    • Journal of the Korea Convergence Society
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    • v.13 no.5
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    • pp.425-433
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    • 2022
  • This purpose of this study was to survey state-anxiety, depression and resilience in female high school students and to identify factors influencing resilience. Data were collected 177 female high school students. Data were analyzed using ANOVA, t-test, Scheffe's test, Stepwise Regression Analysis, Pearson's correlation coefficient. The mean score of state-anxiety was 39.56±11.37. There was statistically significant difference in state-anxiety on variable such as academic achievement, satisfaction of school life, parental rearing attitudes, satisfaction of family life. The mean score of depression was 7.53±8.52. There were statistically significant difference in depression on variables such as relationship with school fellow, satisfaction of school life, parental rearing attitudes, satisfaction of family life. The mean score of resilience was 98.36±17.76. There was statistically significant difference in resilience on variables such as academic achievement, parental rearing attitudes, Resilience was negatively correlated with state-anxiety. Resilience was negatively correlated with depression. Self-esteem was positively correlated with depression. Factor influencing resilience were state-anxiety, high academic achievement, which explained 49.6%. Findings provide useful information for further studies in female high school students. Further research with careful sampling will be needed to enhance the resilience of male and female high school students,

Analysis of Forest Fire Damage Areas Using Spectral Reflectance of the Vegetation (식생의 분광 반사특성을 이용한 산불 피해지 분석)

  • Choi, Seung-Pil;Kim, Dong-Hee;Ryutaro, Tateishi
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.2 s.36
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    • pp.89-94
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    • 2006
  • Forest damage is a worldwide issue and specially, a forest fire involves damage to itself and causes secondary damage such as a flood etc. However, actually, clear analysis on forest fire damage can be hardly conducted due to difficulty in approaching a forest fire and quite a long period of time for analysis. To overcome such difficulty, recently, forest fire damage has been actively investigated with satellite image data, but it is also difficult to obtain satellite image data fitted to the time a forest fire occurred. In addition, it is burdensome to verify accuracy of the obtained image. Therefore, this study was attempted to look into the damaged districts from forest fires by reference to spectroradiometric characteristics of the obtained vegetation with a spectroradiometer as preliminary work to use satellite image data. To begin with, the researcher analyzed the field survey data each measured 3 months and 6 months after occurrence of a forest fire by judging the extent of the damage through visual observation and using a spectroradiometer in order to investigate any potential errors arising out of one-time visual observation. Besides, in this study, groups showing possibilities that trees might be restored to life and wither to death could be classified on the sampling points where forest fire damage is minor.

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A Study on the Residents Consciousness in Emergency Planning Zone for Radioactive Disasters (방사능 재난에 대한 방사선비상계획구역내 주민의식조사)

  • Namhee Park
    • Journal of the Society of Disaster Information
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    • v.18 no.4
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    • pp.729-745
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    • 2022
  • Purpose: This study collects basic data on the awareness of evacuation methods and evacuation facilities in the event of a radiological disaster of residents living in the emergency planning zone. Method: The residents of emergency planning zone were sampled using a random sampling method. A 1:1 interview was conducted using a structured questionnaire, and statistical analysis was performed using the minitab program. Result: First, the survey subjects showed a relatively low and negative awareness of the local government's work on radioactive disasters. Second, in terms of resident safety education, they had little experience in education, but they felt it was necessary and wanted education on evacuation methods, action tips, and the location of relief centers. Third, the location of the relief centers related to radioactive disasters was not well known, and there were many responses that they did not receive any guidance, and that they would be with their families when using the relief centers. Satisfaction levels were generally low with regard to the relief facilities. Fourth, the necessary priorities in preparation for radioactive disasters were education and training for radioactive disasters, facility supplementation, and supply of protective chemicals. Conclusion: The residents of emergency planning zone perceived the policies and tasks of the government or local governments relatively negatively in preparation for the occurrence of radioactive disasters, and their satisfaction was low. Regarding the matters pointed out as a priority, the government and local governments should publicize and educate the residents of accurate information and policies on radioactive disasters.