• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.402-402
• /
• 2020

대청호는 1998년 조류경보제 도입 이후 1999년과 2014년을 제외하고 매년 조류 경보가 발령되었으며 2001년 조류 경보 '대발생'이 발령된 후 2017년 가장 높은 조류 발생 수치를 기록하였다. 상시 조류 발생 지역인 대청호 내 녹조를 제어하기 위해 비점오염원 발생원을 기준으로 우선관리지역을 선정하고, 각 지역의 특성을 반영한 관리대책을 제안하였다. 우선관리지역 선정을 위해 대청호 유역 내 오염총량 소유역을 기준으로 각 소유역의 농업 비점오염원의 발생부하량을 산정하고 유출을 고려한 가중치를 추가하였다. 본 연구에서는 농업 비점오염원을 크게 토지계 비점오염원과 축산계 비점오염원으로 분류하였으며, 토지계 농업비점오염원은 논, 밭, 과수원 지역으로 정의하였다. 발생부하량의 산정은 오염총량관리 기술지침(2019, 국립환경과학원)을 기준으로 하였으며, 토지계 발생부하량 산정을 위한 토지계 정보원으로 환경부에서 제작 및 배포하는 세분류 토지피복도를 축산계 발생부하량 산정을 위한 축산 두수는 2017년 기준 전국오염원조사 내 축산두수를 이용하였다. 토지계 비점오염원의 하천까지 유출을 반영하기 위해 각 소유역별 평균 경사도를 가중치로 이용하였으며, 축산계 비점오염원은 오염물질이 발생한 후 하천까지의 평균 유출 정도를 확인하여 가중치로 반영하였다. 실제 하천에 미치는 영향이 높은 지역에 대한 우선적인 관리를 위해 하천수 수질측정망에서 측정한 수질 데이터와의 비교를 통하여 최종 우선관리지역을 보청A03, 보청A05, 금본F14, 금본F22 소유역으로 선정하였다. 각 소유역에 대한 수질 관리목표를 확인하였으며, 지역의 특성을 분석하여 토지계 및 축산계 비점오염원에 대한 적절한 관리대책을 제안하였다. 본 연구에서 사용한 수질 측정망 데이터가 각 소유역보다 적게 분포하여 소유역에서 발생한 비점오염물질이 하천에 미치는 영향을 직접 파악하는데 한계가 있었다. 또한, 축산계의 경우 발생한 비점오염물질이 모두 하천으로 유입되지 않으며, 축산계 비점오염원의 배출경로를 파악하는데 어려움이 있다는 한계를 가진다. 본 연구의 한계를 바탕으로 농림축산식품부 및 축협 등에서 구축하는 사육두수의 데이터를 이용하는 방법론 등의 추가적인 연구가 필요할 것으로 보인다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.5D
• /
• pp.831-838
• /
• 2006

An experimental/analytic study has been conducted to understand the adverse effects of low vehicle speed, high axle load and high tire pressure on the performance of asphalt pavements. Of 33 asphalt sections at KHC test road, two sections having different base layer thickness (180 mm versus 280 mm) are adopted for rollover tests. During the test, a standard three-axle dump truck maintains a steady state condition as moving along the wheel path of a passing lane, and lateral offsets and real travel speed are measured with a laser-based wandering system. Test results suggest that vehicle speed affects both longitudinal and transverse strains at the bottom of asphalt layer (290 mm and 390 mm below the surface), and even slightly influences the measured vertical stresses at the top of subbase and subgrade due to the dynamic effect of rolling vehicle. Since the anisotropic nature of asphalt-aggregate mixtures, the difference between longitudinal and transverse strains appears prominent throughout the measurements. As the thickness of asphalt pavement increases, the measured lateral strains become larger than its corresponding longitudinal strains. Over the limited testing conditions, it is concluded that higher axle weight and higher tire pressures induce more strains and vertical stresses, leading to a premature deterioration of pavements. Finally, a layered elastic analysis overestimates the maximum strains measured under the 1st axle load, while underestimating the maximum vertical stress in both pavement sections.

• Membrane Journal
• /
• v.33 no.6
• /
• pp.352-361
• /
• 2023

Steam methane reforming is currently the most widely used technology for producing hydrogen, a clean fuel. Hydrogen produced by steam methane reforming contains impurities such as carbon monoxide, and it is essential to undergo an appropriate post-purification step for commercial usage, such as fuel cells. Recently, membrane separation technology has been gaining great attention as an effective purification method; in this study, we evaluated the feasibility of using commercial polysulfone membranes for biogas upgrading to separate and recover hydrogen from a hydrogen/carbon monoxide gas mixture. Initially, we examined the physicochemical properties of the commercial membrane used. We then conducted performance evaluations of the commercial membrane module under various conditions using mixed gas, considering factors such as stage-cut and operating pressure. Finally, based on the evaluation results, we carried out simulations for process design. The maximum H₂ permeability and H₂/CO separation factor for the commercial membrane process were recorded at 361 GPU and 20.6, respectively. Additionally, the CO removal efficiency reached up to 94%, and the produced hydrogen concentration achieved a maximum of 99.1%.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.6
• /
• pp.637-645
• /
• 2023

This study was conducted to confirm the meaning and essence of the interpersonal caring experience of nursing students who participated in an enneagram-based care intervention program. The subjects of the study were nine second-year students in the Department of Nursing at a university located in the region, and data were collected from April 25 to August 26, 2022, through interview records, statements, and reflection journals. The collected data were analyzed using Colaizzi's phenomenological method. Results, It appeared in three categories and 10 topic groups 'Recognition through sharing and listening', 'Acceptance through comfort and forgiveness', 'Praise and giving hope through participation and companionship in daily life', While writing a person care reflection journal, you can realize the meaning of care through critical reflection, understand the essence of the person care experience, and confirm the vivid person care experience, and develop the ability to care for people through in-depth reflection on personal experiences, feelings, and deep understanding. As this improved and internalized care, confidence in one's own ability to care increased. Therefore, it is believed that the experience of caring for people based on the Enneagram can be confirmed, the results can be used for learning, and it will be used as educational material to perform people care, contributing to the development of people care education.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.5
• /
• pp.113-119
• /
• 2023

Most infrastructure structures were completed during periods of economic growth. The number of infrastructure structures reaching their lifespan is increasing, and the proportion of old structures is gradually increasing. The functions and performance of these structures at the time of design may deteriorate and may even lead to safety accidents. To prevent this repercussion, accurate inspection and appropriate repair are requisite. To this end, demand is increasing for computer vision and deep learning technology to accurately detect even minute cracks. However, deep learning algorithms require a large number of training data. In particular, label images indicating the location of cracks in the image are required. To secure a large number of those label images, a lot of labor and time are consumed. To reduce these costs as well as increase detection accuracy, this study proposed a learning structure based on mean teacher method. This learning structure was trained on a dataset of 900 labeled image dataset and 3000 unlabeled image dataset. The crack detection network model was evaluated on over 300 labeled image dataset, and the detection accuracy recorded a mean intersection over union of 89.23% and an F1 score of 89.12%. Through this experiment, it was confirmed that detection performance was improved compared to supervised learning. It is expected that this proposed method will be used in the future to reduce the cost required to secure label images.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.33 no.6
• /
• pp.255-260
• /
• 2023

As demanding the detection of explosive molecules, it is required to develop rapidly and precisely responsive sensors with ultra-high sensitivity. Since two-dimensional semiconductors have an atomically thin body nature where mobile carriers accumulate, the abrupt modulation carrier in the thin body channel can be expected. To investigate the effectiveness of WSe₂ semiconductor materials as a detection material for TNT (Trinitrotoluene) explosives, WSe₂ was synthesized using thermal chemical vapor deposition, and afterward, WSe₂ FETs (Field Effect Transistors) were fabricated using standard photo-lithograph processes. Raman Spectrum and FT-IR (Fourier-transform infrared) spectroscopy reveal that the adsorption of TNT molecules induces the structural transition of WSe₂ crystalline. The electrical properties before and after adsorption of TNT molecules on the WSe₂ surface were compared; as -50 V was applied as the back gate bias, 0.02 μA was recorded in the bare state, and the drain current increased to 0.41 μA with a dropping 0.6% (w/v) TNT while maintaining the p-type behavior. Afterward, the electrical characteristics were additionally evaluated by comparing the carrier mobility, hysteresis, and on/off ratio. Consequently, the present report provides the milestone for developing ultra-sensitive sensors with rapid response and high precision.

• Korean Association of Arts Management
• /
• no.50
• /
• pp.5-31
• /
• 2019

The main purpose of this study was to use Deep Learning based Topic Modeling and Semantic Network Analysis to examine research trend of arts management-related papers in korea. For this purpose, research subjects such as 'The Journal of Cultural Policy', 'The Journal of Cultural Economics', 'The Journal of Culture Industry', 'The Journal of Arts Management', and 'The Journal of Human Content', which are the registered journal of the National Research Foundation of Korea directly or indirectly related to arts management field. From 1988 to 2017, a total of 2,110 domestic journals' signature, abstract, and keyword were analyzed. We tried Big Data analysis such as Topic Modeling and Semantic Network Analysis to examine changes in trends in arts management. The analysis program used open software R and standard statistical software SPSS. Based on the results of the analysis, the implications and limitations of the study and suggestions for future research were discussed. And the potential for development of convergent research such as Arts & Artificial Intelligence and Arts & Big Data.

• Journal of The Korean Association For Science Education
• /
• v.26 no.2
• /
• pp.200-211
• /
• 2006

The purpose of this study was to analyze Korean middle school student achievement in environmental science based on the TIMSS 2003 (Trends in International Mathematics and Science Study), a student comparison of 46 participating nations. Korea ranked the fourth with a mean score of 554 in environmental science. However, all 3 environment science topics assessed in TIMSS are not included in the Korean science curriculum through 8th grade, even though they are included in most other participating nations' curricula. The average percent correct of items was analyzed according to the main topic, the item type and the cognitive domain. Items that showed differences between the average percent correct of Korea and the international average as well as differences between the average percent correct of boys and girls were further analyzed. Results revealed that Korean students performed better than the international average, especially in 'use and conservation of natural resources', multiple-choice items, and items requiring 'factual knowledge'. Also, male students demonstrated significantly higher achievement than female students. On the other hand, Korean students showed relatively lower achievement in constructed-response items, items that contained content they had not learned in science lessons and items requiring descriptions of the uses and effect of science and technology. Moreover, Korean student lacked understanding about acid rain, global warming, and ozone layer destruction. Korean female students showed relatively lower environmental conceptions and lower performance on items requiring data analysis than Korean male students. On the basis of these results, this study suggested that topics of environmental science be included in the science curriculum and taught in the science classroom to help middle school students more fully comprehend environmental issues.

• Journal of the Korea Society of Computer and Information
• /
• v.29 no.7
• /
• pp.41-51
• /
• 2024

In this paper, we explore the enhancement of target detection accuracy in the guided weapon using deep learning object detection on infrared (IR) images. Due to the characteristics of IR images being influenced by factors such as time and temperature, it's crucial to ensure a consistent representation of object features in various environments when training the model. A simple way to address this is by emphasizing the features of target objects and reducing noise within the infrared images through appropriate pre-processing techniques. However, in previous studies, there has not been sufficient discussion on pre-processing methods in learning deep learning models based on infrared images. In this paper, we aim to investigate the impact of image pre-processing techniques on infrared image-based training for object detection. To achieve this, we analyze the pre-processing results on infrared images that utilized global or local information from the video and the image. In addition, in order to confirm the impact of images converted by each pre-processing technique on object detector training, we learn the YOLOX target detector for images processed by various pre-processing methods and analyze them. In particular, the results of the experiments using the CLAHE (Contrast Limited Adaptive Histogram Equalization) shows the highest detection accuracy with a mean average precision (mAP) of 81.9%.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.2
• /
• pp.27-33
• /
• 2024

In this article, this study examines the issue of "Physician-assisted Suicide" and how Ramon Sampedro asserts his right to a dignified death through litigation. Ramon, the protagonist of the movie <The Sea Inside> is a patient, severely paralyzed man who has spent more than 26 years in bed. The only thing he can do is verbally ask his family for help. Ramon can no longer support this worthless existence, so he pursues death with dignity. Ramon files a lawsuit to authorize death with dignity within a legal framework, but is denied on the grounds that life is a duty. Ramon eventually fulfills his desire for death with dignity with the help of his friends. Ramon sets up a camera to document the process of his death and introduces the cyanide, which is used in assisted dying, by inhaling cyanide in front of the camera and dying quietly. Although Ramon is not a terminally ill patient, who can blame him for practicing death with dignity as he chooses to do so. We will need to work to build social consensus and legislate for death with dignity for seriously ill patients like Ramon.