• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.357-365
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• 2004

Effect of artificial circulation on amelioration of water quality in Yeoncho Lake was analyzed using summer data between 1991-2002. Two sites, intake tower area where aeration systems are concentrated in and near the inlet of reservoir were selected for comparison in this study. Summer averages between may and september Showed that aeration system might be beneficial in the improvement of water quality of BOD5, COD, and TN while Chl-a concentration and transparency did show opposite pattems. Wilcoxon's singed rank test for matched pair indicated slight increase of BOD5 and COD concentrations in the vicinity of intake tower while other variables did not show any significant differences from data of inlet of reservoir. During the study, it was found that the following subjects need to be investigated for more detailed analysis. 1) Dynamic pollutant loading from outside and inside the lake, 2) Biological, Chemical and Physical lake data when aeration systems are in and not in operation and 3) Radius of influence of aeration system.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.637-639
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• 2021

인공지능 기반의 생활폐기물의 인식 및 선별에서, 선별 정확도의 저하는 인식 대상의 형태적 다양성과 학습데이터 부족 및 불균등성에 기인한다. 본 연구에서는 비전 인공지능 기반의 효과적인 폐기물 선별을 위한 인식 시스템 및 감독학습 기반의 인공지능 학습 기법을 제안한다. 생활폐기물 중 순환자원적 가치가 높은 CAN, PET, 그리고 이와 형상적으로 유사한 폐기물에 대해 본 연구에서 제안된 시스템에서 물체원형 및 훼손된 형태의 총 18 종 이미지 데이터를 대상으로, 감독학습기반의 인공지능 모델 제작에서 최적의 데이터 레이블링을 위한 분류체계를 제시한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.476-476
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• 2021

도시화로 인한 불투수율 증가는 자연 물순환을 왜곡시켜 표면 유출량 증가, 침투량 감소, 증발량 감소 등을 야기한다. 뿐만 아니라 도시화로 인한 인구밀도 집중은 배출오염물질의 평균 농도와 물 사용량을 증가시켜 인공 물순환의 왜곡을 초래한다. 왜곡된 물순환의 회복을 위해 건전한 도시 물순환의 정의를 정립하는 것은 필수적이다. 본 연구는 물순환과 관련된 문헌조사와 평가 분석 방법을 검토하여, 건전한 도시 물순환을 지속가능성, 공평성, 안전성, 효율성 측면에서 시간, 공간, 이해관계자들이 균형을 이루는 것에 초점을 맞추고자 한다. 과거와 현재 상태, 그리고 미래 기후변화시나리오 적용 시 어떤 변화가 있으며, 이에 따른 물순환 관리체계가 확보될 수 있는 모습, 공간적 측면에서 물의 수평적·수직적 이동이 치우침이 없는 모습, 수요자 입장에서 가뭄이나 홍수로 인한 재산·인명 피해가 최소화된 모습, 공급자 입장에서 수량·수질 관리체계가 확보된 모습을 각각 지속가능성, 공평성, 안전성, 효율성으로 정의 내렸다. 도시 물순환의 적절한 상태를 제안하기 위해서 도시 물순환의 지표로 증발산율, 지표수유출률, 지하수유출률, 침투율로 선정하였다. 앞서 언급한 네 가지 측면(지속가능성, 안전성, 공평성, 효율성)에서의 모습과 네 개의 지표 상태를 비교하여 균형 잡힌 도시 물순환의 상태를 제안하고자 한다. 정의에 제시된 네 가지 측면에 대한 하위 항목은 WAMIS, KOSTAT 등을 통해 조사하고 국내 주요 도시와 서울대학교 관악캠퍼스 내에서 분석하고자 한다. 본 연구를 통해 도시 정책 설립 및 이해관계자들에게 수문학적 관점에서 건전한 도시화의 방향을 줄 수 있을 것이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.174-179
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• 2006

본 연구에서는 지하철 노선, 지하수 양수량 및 상수도 누수량 등 도시유역에서 물순환에 큰 영향을 미치는 인공적 요소들을 분포형 수문모형에 반영하여 물순환을 모의하였다. 분포형 수문모형으로는 일본토목연구소에서 개발된 WEP 모형을 사용하였다. 입력자료 구축시 지하철 노선을 따라서 제1투수층, 제1난투수층, 제2투수층의 투수계수를 낮게 설정하여 지하철 노선의 영향을 반영하였으며, 지하철역 및 구별 지하수 양수량, 상수도 누수량을 모형의 입력자료로 구축하였다. 모의결과를 서울시 지하수관측공의 실측 자료와 비교하여 양호한 결과를 얻을 수 있었으며, 유역 스케일에서의 지하수위 분포양상을 모의할 수 있었다. 지하철 노선, 지하수 양수량, 상수도 누수량 등을 고려, 미고려시를 별도로 모의하여 각각 요소가 물순환에 미치는 개별적 종합적 영향에 대해 평가하였다.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.326-329
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• 1997

Coronary artery bypass grafting(CABG) without cardiopulmonary bypass(CPB) is now an accepted technique of myocardial revascularization in selective cases of coronary arterial occlusive disease. The lesion was total(100%) occlusion of proximal right coronary artery(RCA) without any evidence of dis,Base in the rest of coronary arteries. Percutaneous transluminal angioplasty(PTCA) was tried but unsuccessful. We herein report a case of successful CABG to right coronary artery without CPB on a patient with complete occlusion of RCA and symptomatic wit minimal activity.

• Journal of Industrial Convergence
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• v.20 no.4
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• pp.23-30
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• 2022

Recently, with the development of artificial intelligence (AI) and deep learning, the importance of conversational artificial intelligence chatbots is being highlighted. In addition, chatbot research is being conducted in various fields. To build a chatbot, it is developed using an open source platform or a commercial platform for ease of development. These chatbot platforms mainly use RNN and application algorithms. The RNN algorithm has the advantages of fast learning speed, ease of monitoring and verification, and good inference performance. In this paper, a method for improving the inference performance of RNNs and applied algorithms was studied. The proposed method used the word group expansion learning technique of key words for each sentence when RNN and applied algorithm were applied. As a result of this study, the RNN, GRU, and LSTM three algorithms with a cyclic structure achieved a minimum of 0.37% and a maximum of 1.25% inference performance improvement. The research results obtained through this study can accelerate the adoption of artificial intelligence chatbots in related industries. In addition, it can contribute to utilizing various RNN application algorithms. In future research, it will be necessary to study the effect of various activation functions on the performance improvement of artificial neural network algorithms.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.1
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• pp.34-42
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• 2015

The paper investigates environmental hazards and characteristics of the artificial lightweight aggregate manufactured by using dyestuff sludge from dyeing industrial complex. The dyestuff sludge used in this study is chemically treated with Ti and Fe salt for the purpose of recycling. The artificial lightweight aggregate is manufactured through 3 step; 1) Selecting the optimum moisture content by evaluating plasticity from the mixing ratio of the clay and sludge, 2) shaping round type based on the optimum mixing ratio, 3) drying and Sintering process. Based on KS F 2534 "Lightweight Aggregate for Structural concrete", the particle size, fineness modulus, the density, absorption, unit volume weight, stability and environmental hazards of the manufactured lightweight aggregate are evaluated. Experimental results show that the particle size and fineness modulus is out of the range. However, it is observed that other physical properties are within criteria. In addition, it is confirmed that the problem of the particle size and fineness modulus could be solved in the manufacturing process.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.198-203
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• 2020

In this paper, we propose an artificial water level prediction system for small river flood prediction. River level prediction can be a measure to reduce flood damage. However, it is difficult to build a flood model in river because of the inherent nature of the river or rainfall that affects river flooding. In general, the downstream water level is affected by the water level at adjacent upstream. Therefore, in this study, we constructed an artificial intelligence model using Recurrent Neural Network(LSTM) that predicts the water level of downstream with the water level of two upstream points. The proposed artificial intelligence system designed a water level meter and built a server using Nodejs. The proposed neural network hardware system can predict the water level every 6 hours in the real river.

• 순환기질환의공학회:학술대회논문집
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• 2006.10a
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• pp.44-45
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• 2006

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.1-12
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• 2005

The primary responsibility of a perfusionist is to operate the heart-lung bypass machine during open heart surgery, which is vital for the successful operative outcome. However, despite the perfusionist's crucial role on the cardiac surgical team, no relevant studies have not yet been conducted in our country. In this regard, this study was performed about the current status of perfusionists in Korea with comparative analysis on the certification and education system of perfusionists in foreign countries. Material and Method: We analyzed the demographic data on the Korean perfusionists conducted in 1994 and 2003, with comparison of recent data on the perfusionists of the nineteen foreign countries. Result and Conclusion: Although all agree that professionalism and responsibility of the perfusionist are essential in conducting a cardiac procedure and bringing about successful outcome, the formally approved training and certification system for perfusionists have not yet been established in Korea. Adequate measures should be done as soon as possible in order to try to obtain the adequate recognition of the profession.