SNL-EFDC를 이용한 군산항 유사퇴적고 계산의 비교 연구

이동주 ( Dong-joo Lee ),송상현 ( Sang-hyun Song ) 한국환경기술학회 2015 한국환경기술학회지 Vol.16 No.4

본 논문은 Ziegler, Lick, and Jones에 의해 개발된 SEDZLJ라 부르는 유사역학 알고리즘이 계산되는 SNL-EFDC 모델을 이용하여 군산항의 퇴적고 계산에 관하여 연구하였다. SEDZLJ모듈은 SEDflume 이나 Annular flumes로부터 얻은 현장 침식률 및 침식 한계전단응력 자료를 직접 결합할 필요가 있다. 군산항에서는 SEDflume 자료를 구할 수 없기 때문에 Ryu와 Yim에 의한 Annular flumes 실험으로부터 얻은 현장 침식률 및 침식 한계전단응력 자료를 이용하였다. SNL-EFDC 모델이 군산항의 유사퇴적고를 계산하기 위해 적용되었고 관측된 부유사 농도와 퇴적고를 사용하여 검증되었다. 유사 퇴적고 계산에 대한 모델의 적용성은 NSEC가 0.72로 침식과 퇴적의 물리적 변화가 적절하게 재현됨이 입증되었다. 부가적으로 검증된 모델은 저면 활성층두께에 대한 매개변수 α값의 영향을 조사하기 위해 사용되었고, Lee와 Park에 의해 수행된 SEDTM을 이용한 유사이동 계산의 결과와 비교하기 위해 사용되었다. 그 결과, 매개변수 α값의 변화는 유사퇴적고 계산에 미미한 영향이 미치는 것으로 나타났다. SEDZLJ에 의한 결과를 SEDTM의 것과 비교할 때 SEDZLJ모듈이 군산항에서 SEDTM 보다 NSEC가 0.03향상 되어 토사이송 과정을 재현함이 확인되었다. This paper was studied on the sediment deposition height computation at Gunsan port using recently advanced SNL-EFDC model which the sediment dynamics algorithm was called as SEDZLJ developed by Ziegler, Lick and Jones. SEDZLJ module needs to directly incorporate site-specific erosion rate and critical shear stress data from SEDflume or Annularflumes. Here this model attempted to use site-specific erosion rate and critical shear stress data from Annular flumes experiment by Ryu and Yim instead of unavailable SEDflume data at Gunsan port. SNL-EFDC was applicated to calculate deposition height at Gunsan port and verified using observed values for suspended sediment concentration and sediment deposition height. The model applicability for sediment deposition height computation was evaluated as NSEC 0.72 and verified that it reproduced the physical variations of erosion and deposition. In addition, the verified model was used to investigate the effect of parameter “α” on the active bed layer thickness and used to compare with the result of sediment transport computation using SEDTM done by Lee and Park. As a result, it was found that the change of parameter “α” value has a negligible effect on sediment deposition height computation. As results of SEDZLJ are compared with those of SEDTM, it was identified that SEDZLJ module reproduces the sediment transport process more appropriately than SEDTM at Gunsan port with advanced NSEC 0.03.

전자기 및 광학 센서를 적용한 무기체계의 강수 운용규격 설정을 위한 한반도 강수량 분포에 관한 연구

이동주,김재하,Lee, Dong-Ju,Kim, Jai-Ha 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.2

When a weapon system is developed, climate elements such as temperature, rainfall, and so on have an effect on development costs and a developing period. Therefore, effects of environment and climate must be examined throughly before the design of weapon systems and be applied to their developments. And so, operational and storage requirements for weapon systems are determined and are applied to related tests through analyzing not only environmental factors such as vibration, shock, and so on, but also climate factors. In this paper, the distribution and the frequency of occurrence of rainfall were analyzed and were suggested as a good guide to determine standards of tests for weapon systems when it's raining.

하이브리드 환기시스템의 운영 및 제어방식

이동주,Lee Dong-Ju 대한설비공학회 2006 설비저널 Vol.35 No.5

겨울철에 흔한 정형외과적 손상

이동주,Lee, Dong-Ju 한국건강관리협회 2002 건강소식 Vol.26 No.12

광산수의 탈염을 위한 축전식 탈염기술의 적용

이동주,강문성,이상호,박진수,Lee, Dong-Ju,Kang, Moon-Sung,Lee, Sang-Ho,Park, Jin-Soo 한국전기화학회 2014 한국전기화학회지 Vol.17 No.1

본 연구에서 광산수의 재활용을 위해 축전식 탈염공정을 적용하였다. 이를 위해 이온교환폴리머를 코팅한 탄소 전극을 활용하였는데 본 성능을 관찰하기 위해 이온교환폴리머를 코팅하지 않은 탄소 전극으로 광산수의 탈염 운전을 수행하고 비교분석하였다. 또한, 광산수의 높은 농도가 축전식 탈염공정에 미치는 영향을 조사하기 위해 저농도의 기수(NaCl 200 ppm)를 활용한 운전 성능 비교 역시 수행하였다. 연구 결과 이온교환폴리머를 코팅한 탄소 전극을 활용한 광산수 탈염 효율 및 제거양 모두 그렇지 않은 전극에 비해 높았고 에너지 소모량은 더 적게 나타났다. 이는 높은 비패러데이 전류, 높은 염농도에 따른 낮은 용액 저항, 전극 기공 내에서의 이중층 중첩효과에 기인하는 것으로 판단되었다. 또한, 이온교환폴리머를 코팅한 전극을 활용한 기수 탈염 운전 결과 낮은 염농도에 따라 용액의 저항이 높아지고, 제거 대상의 염의 양이 낮아 광산수에 비해 매우 높은 효율을 보였으나, 제거양은 매우 낮음을 알 수 있었다. In this study, capacitive deionization (CDI) was introduced for desalination of mining water. Ion-exchange polymer coated carbon electrodes (IEE) were used in CDI to desalt mining water. The CDI performance using the IEE for desalination of mining water was carried out and then was compared with that using general carbon electrodes without ion-exchange polymer coating (GE). Moreover, to investigate the effect of the concentration of influent solutions on CDI performance, the CDI performance using the IEE for desalination of brackish water (NaCl 200 ppm) was also performed and analyzed. As a result, the higher salt removal efficiency, rate and the lower energy consumption in the CDI process using the IEE and mining water were obtained compared with those using the GE and mining water. It is mainly due to higher non-Faradaic current, low ohmic resistance of the influent, overlapping effect of electric double layers in micropore of the electrode. In addition, the CDI process using the IEE and brackish water shows much higher salt removal efficiency and lower salt removal rate than that using the IEE and mining water. This results from the lower concentration (i.e., higher ohmic resistance) and salt amount of the influent.

Ka-대역 추적 레이더용 전원공급기 개발

이동주,안세환,주지한,권준범,서미희,Lee, Dongju,An, Se-Hwan,Joo, Ji-Han,Kwon, Jun-Beom,Seo, Mihui 한국인터넷방송통신학회 2022 한국인터넷방송통신학회 논문지 Vol.22 No.5

밀리미터파 추적 레이더는 다양한 환경조건에서 운용하므로 입력전압의 큰 변동에도 안정적인 출력전원을 공급하는 전원공급기가 필요하며, 송수신기에 고품질의 전원공급을 위해 낮은 잡음레벨 특성을 가져야 한다. 본 논문에서는 Ka-대역 추적 레이더에 적용하기 위한 최대 출력 727 W급의 소형 전원공급기 설계 및 구현방안에 대해 기술한다. 전압안정도 및 효율 요구사항을 충족하기 위해 buck 타입의 DC-DC 컨버터의 윗면이 전원공급기의 커버와 맞닿게 배치하여 방열효율을 극대화하였다. 최대 부하 조건에서 시스템 효율 88.4 %, 전압정밀도 ±2 %, 잡음레벨은 전압값의 1 % 이내임을 확인하였다.

클린 디젤엔진용 워터펌프 유동해석

이동주,김태영,전문수,Lee, Dongju,Kim, Taeyoung,Chon, Mun Soo 한국교통대학교 융복합기술연구소 2014 융ㆍ복합기술연구소 논문집 Vol.4 No.2

Pressure distribution around rotating impeller blades in centrifugal pump has been main issue for design of efficient and high performance automotive water pump. In addition, pressure losses of inlet water pipes should be considered to reduce additional pressure drop and design high performance engine cooling system. In this paper, pressure distribution inside water pump and pressure drop between inlet and outlet of water pump are investigated numerically to design plastic water pump for clean diesel engine application. And the inlet geometry of water pump was considered to analysis the effect of inlet water pipe geometry on pressure distribution around impeller blades and outlet pressure. The prediction results are compared with experimental data to validate and determine optimal operation condition without water pump cavitation. Major design parameters such as blade angle, volute geometry, system pressure, and coolant flow rate are considered to confirm applying possibility of plastic blades to the clean diesel engine.

IEA 가입과 석유비축

이동주,Lee, Dong-Ju 대한석유협회 2001 석유와 에너지 Vol.2001 No.1

표준화 포럼 탐방 - 5G 포럼

이동주,Lee, Dong-Ju 한국정보통신기술협회 2018 TTA저널 Vol.2018 No.-

Factors Influencing Learning Satisfaction of Migrant Workers in Korea with E-learning-Based Occupational Safety and Health Education

이동주,Young Joo Lee 한국산업안전보건공단 산업안전보건연구원 2015 Safety and health at work Vol.6 No.3

Background: E-learning-based programs have recently been introduced to the occupational safety and health (OSH) education for migrant workers in Korea. The purpose of this study was to investigate how the factors related to migrant workers’ backgrounds and the instructional design affect the migrant workers’ satisfaction with e-learning-based OSH education. Methods: The data were collected from the surveys of 300 migrant workers who had participated in an OSH education program. Independent sample t test and one-way analysis of variance were conducted to examine differences in the degree of learning satisfaction using background variables. In addition, correlation analysis and multiple regression analysis were conducted to examine relationships between the instructional design variables and the degree of learning satisfaction. Results: There was no significant difference in the degree of learning satisfaction by gender, age, level of education, number of employees, or type of occupation, except for nationality. Among the instructional design variables, “learning content” (b ¼ 0.344, p < 0.001) affected the degree of learning satisfaction most significantly, followed by “motivation to learn” (b ¼ 0.293, p < 0.001), “interactions with learners and instructors” (b ¼ 0.149, p < 0.01), and “previous experience related to e-learning” (b ¼ 0.095, p < 0.05). “Learning environment” had no significant influence on the degree of learning satisfaction. Conclusion: E-learning-based OSH education for migrant workers may be an effective way to increase their safety knowledge and behavior if the accuracy, credibility, and novelty of learning content; strategies to promote learners’ motivation to learn; and interactions with learners and instructors are systematically applied during the development and implementation of e-learning programs.