Time Series Anomaly Detection Using Contrastive Learning based One-Class Classification

이예슬,백준걸 대한산업공학회 2022 대한산업공학회 추계학술대회논문집 Vol.2022 No.11

Theoretical Analysis of Bending Stresses to Design a Sprocket for Transportation Part of a Chinese Cabbage Collector

이예슬,ALI MOHAMMOD,Md Nafiul Islam,Kamal Rasool,장보은,Md Shaha Nur Kabir,강태경,정선옥 한국농업기계학회 2020 바이오시스템공학 Vol.45 No.2

Purpose Force calculation, stress, and fatigue analysis are major issues in machine design to ensure the life expectancy of sprocket-gear power transmission systems. Therefore, this study aims to conduct a theoretical analysis of bending stresses to select the size and component materials for the power transmission part of a Chinese cabbage collector that is under development. Methods The three-dimensional models of a 14T sprocket gear for two steel materials, SCr420H and SM45C, were generated, employing commercial software. The bending stresses, deformations, and fatigue damages of the designed sprocket were determined by varying the face width and pressure angle of the sprocket teeth. The Lewis and American Gear Manufacturer Association (AGMA) equations were used to calculate the bending stresses. The calculated bending-stress values were compared with the stress values obtained from finite-element analysis (FEA). Results The maximum stress values on the gear teeth were 650.07, 826.23, and 840.77 MPa for a 20° pressure angle by using the Lewis, AGMA, and FEA methods, respectively. The simulated maximum stress value was higher than the yield strength of the SM45C steel and lower than the yield strength of the SCr420H steel. In addition, the maximum face width showed the minimum bending stress and fatigue damage for the selected material. Hence, considering the safety factor, the steel material SCr420H was selected with a 4.5-mm face width for designing the power transmission part of the Chinese cabbage collector. Conclusion The analysis of bending stresses presented in this research can guide the design of a sprocket for the efficient transfer of Chinese cabbages using the proposed Chinese cabbage collector.

Contrastive One Class Classification for Unsupervised Real-time Anomaly Detection

이예슬,송승환,박관용,구병모,백준걸 한국경영과학회 2023 한국경영과학회 학술대회논문집 Vol.2023 No.5

Comparison of rapid screening immunoassay and intradermal test for canine atopic dermatitis

이예슬,강지훈,정동인,진영배,이상래,양만표,강병택 충북대학교 동물의학연구소 2015 Journal of Biomedical and Translational Research Vol.16 No.3

The intradermal test (IDT) has been developed for confirming diagnosis of canine atopic dermatitis (CAD). Prior to performing IDT, rapid immunoassay (Allercept E-screen 2nd generation; ES2G) can detect allergen-specific immunoglobulin E (IgE) antibodies in canine serum. The objective of this study was to evaluate agreement between IDT and immunoassay in diagnosis of CAD in domestic atopic dogs. Forty dogs were diagnosed with CAD in accordance with Favrot’s criteria. Intradermal testing was performed using 39 selected allergens. ES2G detected IgE antibodies specific for three allergen groups, including indoor allergens, grasses and weeds, and trees. Among 19 dogs diagnosed by IDT, the highest positivity was observed in house dust mites, followed by molds, epidermis and inhalants, house dust, and weeds. A total of 28 atopic dogs were evaluated by rapid ES2G immunoassay. Indoor allergens showed the strongest positive reaction, followed by grasses/weeds and trees. IDT and ES2G were performed concurrently in 17 dogs. The results of ES2G showed slight agreement with those of IDT. Level of agreement was highest for indoor allergens, which showed a predictive positive value of 100% in ES2G. These results indicate that a rapid immunoassay may be valuable for predicting the results of IDT in atopic dogs sensitized to indoor allergens.

우리나라 정지위성 GK2A를 활용한 사회적 가치 창출: 비용 편익 분석을 중심으로

이예슬,최용상,이권민 사단법인 사회적기업학회 2019 사회적기업연구 Vol.12 No.3

This study conducts the cost-benefit analysis of social value through theGEO-KOMPSAT-2A satellite (GK2A). This study shows the importance ofevaluating social value of satellites and the possibility of diffusion of socialvalues through satellites. The social values of GK2A are estimated as thebenefits of ‘protection of property and infrastructure’ for reducing social costsand ‘added value’ and ‘private use by citizens’ in terms of increasing socialbenefits. As a result of the cost-benefit analysis, the net present value (NPV)and benefit/cost ratio (B/C), calculated as a present value of 19 years(2011~2029) cost and benefit with a discount rate of 4.5%, is 69.5 billion KRWand 1.12 respectively. During the development period, the GK2A continues togenerate costs. However, the benefit is steadily increasing after the operation. Eventually, the benefits for society are higher than costs in the long run. Sincethe operation of the GK2A has been started, the social value can be generatedby expanding the service to other countries, applying to weather services, andutilizing as the accumulated data. Therefore, it is necessary to develop adetailed index for measuring the social value of satellites and to respond to theinterests and needs of various stakeholders utilizing the satellite. 기후변화의 여파로 정확한 기상 정보에 대한 수요가 증가하고 있다. 이에 따라 민간 영역에서도 위성으로사회적 가치를 창출해내는 서비스가 확대되고 있으며, 위성을 활용한 사회적 가치 측정에 대한 필요성도높아지고 있다. 본 연구는 우리나라 고해상도 정지위성 천리안 위성 2A호(GK2A)의 사회적 가치를 비용 편익 분석 방법을 통해 측정해보았다. 본 연구는 유럽과 미국에서 실시된 저궤도 기상위성의 사회경제적 편익 및 사회적 가치 측정에 관한 선행연구의 분석틀을 바탕으로 GK2A 위성의 비용을 개발비용과 운용비용으로, 편익을 재산보호 및 인프라 비용 절감 편익, 국가경제 내 부가가치 창출 편익, 국민의 개인적 활용편익으로 산정하였다. GK2A의 사회적 가치를 2019년 현재 가치로 환산해 산출한 결과, 순현재가치(NetPresent Value; NPV)는 약 695억 원, 편익 비용 비율(Benefit/Cost Ratio; B/C)은 1.12로 나타났다. 이를통해, GK2A 위성의 개발 기간 동안에는 지속적으로 비용이 발생하나 위성의 현업 운영이 시작되는 2020년 이후로는 꾸준한 사회적 비용 감소와 사회적 편익 증가가 나타나 사회 전체적으로 편익이 비용보다 높게 발생하는 것을 추정해 볼 수 있었다. 이를 통해 위성을 통한 사회적 가치의 확산 가능성과 추후 위성데이터를 통한 서비스를 제공하게 되는 사회적기업 등 민간 영역에서의 가치 평가에 사회적 영향력이 고려되어야 하는 필요성을 제시하고자 하였다.

Novel Donor-Acceptor type copolymers enhanced intermolecular interaction

이예슬,김명종,김윤희 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.1

조리전공학생의 학습동기(ARCS)가 학습태도에 미치는 영향

이예슬,이봉선 한국의료정보교육협회 2023 보건의료생명과학논문지 Vol.11 No.1

This study established a hypothesis that cooking students' learning motivation (ARCS) will have a positive (+) effect on learning attitudes, and verified the research model and hypothesis established through empirical analysis. In order to conduct an empirical study, this study conducted a survey of students at specialized high schools and culinary high schools in Korea, and based on a total of 402 samples, the hypothesis was verified through a reliability, suitability, and validity review of the research model. Frequency analysis, correlation analysis, and regression analysis were conducted with the SPSS/WIN statistical program 22.0 to verify the hypothesis of the study. In this study, the learning motivation (ARCS) theory analyzed the correlation between learning attitudes for students majoring in cooking to provide basic data on effective teaching and learning methods to improve learning outcomes of cooking education.

Contrastive One Class Classification for Unsupervised Real-time Anomaly Detection

이예슬,송승환,박관용,구병모,백준걸 대한산업공학회 2023 대한산업공학회 춘계학술대회논문집 Vol.2023 No.5

내부정보유출 위험등급 판단을 위한 딥 러닝 모델 성능비교에 관한 연구

이예슬,김명호 한국IT정책경영학회 2018 한국IT정책경영학회 논문지 Vol.10 No.1

Recently, there has been an increase in the leakage of internal information in the companies. Most of the internal information leakage is caused by insiders. Companies are applying several security solutions to prevent this. However, there is still a lack of research on solutions applying deep learning to detection of data leakage with limitations in preventing leakage in advance. In this paper, a method to judge internal data leakage risk classification is proposed by applying various deep learning models. Security events are generated for each user by mapping the security log and user information obtained through the security device to determine the risk of internal information leakage. Training data based on the mapped data is generated, and applied to deep learning models such as MLP, LSTM, and GRU to compare the performance between models. In addition, the number of hidden nodes and the activation function are changed and their effects are examined. Experimental results showed that the model with softmax activation function applied to the GRU model without dropout showed the highest performance and 93% accuracy.

무용분야 진로에 관한 국내 연구동향 분석

이예슬,최윤소 학습자중심교과교육학회 2021 학습자중심교과교육연구 Vol.21 No.11

Objectives The purpose of this study was to analyze domestic research trends on the career of dance. Methods To achieve the goal of this study, all date was collected from the website of Research Information Sharing Service by searching three main key words ‘career of dance’, ‘jobs in the field of dance’, and ‘dance as an occupation’. Then, this study was conducted by using net-miner program to look at the result of frequency of words and topic modeling by each stage. Results The results of this study are as follow. First, ‘dancer as a occupation’ was shown very often in the first stage. In the second stage, two key words, ‘satisfaction on occupations’ and job exploration to increase job opportunities’ were frequently shown. A keyword ‘university students majoring dance’ was often shown in the third stage. Second, in the result of topic-modeling, a total of 4 topics(socio-psychological research, professional dance team, career education, promoting reviewer) were suggested in the first stage. In the second stage, a total of 5 topics(socio-psychological research, occupational philosophy on dancer, policies on career, career education, social system on changing career) were suggested and a total of 5 topics(career education, socio-psychological research, preparatory on career, job ability of dancer, promoting domestic economy) were shown in the third stage. Through the trends on career of dance, three key words ‘socio-psychological research’, ‘occupation as a pro dancer’, and ‘education on promoting career’ were shown in the research trends regardless of periods. Conclusions This result represents that these three research topics are important in career-related studies in the field of dance. 목적 본 연구는 무용 분야의 진로에 관한 연구주제를 시기별로 살펴보기 위한 목적으로 진행되었다. 방법 연구의 목적을 위하여 한국학술정보서비스에서 ‘무용 진로’, ‘무용 취업’, ‘무용 직업’을 검색한 후 자료를 수집하였다. 수집된자료는 정제과정을 거친 후 시기별로 구분하여 단어빈도분석과 토픽모델링을 실시하였다. 결과 그 결과 첫째, 단어 빈도분석 결과, 1기에는 직업무용수에 관한 단어가 자주 등장하였다. 2기에는 직업에 관한 만족도, 일자리활성화를 위한 직업 조사와 관련된 단어가 자주 등장하였으며, 3기에는 무용전공 대학생들에 관한 키워드가 다수 등장하였다. 둘째, 토픽모델링 결과 1기에는 ‘사회심리학적 연구’, ‘직업무용단’, ‘진로교육’, ‘비평가 활성화’ 토픽이 도출되었으며, 2기에는 ‘사회심리학적 연구’, ‘무용수 직업관’, ‘직업창출 정책’, ‘진로교육’, ‘직업전환제도’ 토픽이 도출되었다. 3기에는 ‘진로교육’, ‘사회심리학적 연구’, ‘진로준비활동’, ‘무용수 직업능력’, ‘내수경제 활성화’ 토픽이 도출되었다. 결론 이러한 토픽의 양상을 통해 진로와 관련된 사회심리학적 요인 연구, 전문무용수로서의 직업, 진로를 위한 교육의 연구주제들은시기에 구분 없이 꾸준히 등장하여 무용 분야의 진로 연구에서 그 중요성을 대변하고 있다