비분산 적외선 분광법을 이용한 Co₂농도 고속 분석기의 Sampling Module 특성에 관한 실험적 연구

김우석,손덕영,박영무,유재석,이종화,Kim, Woo-Seok,Shon, Deok-Young,Park, Young-Moo,Yoo, Jae-Suk,Lee, Jong-Hwa 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.3

A fast response analyzer for measuring carbon dioxide concentration has been developed for transient characteristic and researches tested on internal combustion engine. The analyzer uses the well known NDIR(Non-Dispersive Infrared) method with miniaturized detection system, giving a time constant of approximately 30 microsecond, and sampling module consists of capillary tube. Since the transit time and the time constant of the sampling system depend on the sampling conditions, it is necessary to investigate the characteristics of sampling system before applied to exhaust gas measurement in engine. A unique method was designed to study the influence of the diameter of transfer sample line and operating conditions of the FRNDIR on transit time and time constant. A database of transit time and time constant was built up for different measured and simulated pressure conditions. The database can be used for correcting eventual $CO_2$ concentration measurement.

현수교 풍진동에 관한 2D 간단해석 및 변수연구

김우석,이재하,Kim, Woo Seok,Lee, Jaeha 한국전산구조공학회 2013 한국전산구조공학회논문집 Vol.26 No.6

본 연구에서는 풍진동에 대한 현수교의 거동을 예측하기 위하여 바닥판의 비틀림강성을 고려하여 Mckenna and Tuama 모델(2001)을 개선한 2D 간단해석 방법을 제안하였다. 기존의 모델은 풍속이 증가할수록, 진동수가 낮아질수록 비정상적인 값을 나타내고, 비틀림모드의 공진현상을 묘사할 수 없었다. 이에 본 연구에서는 비틀림강성을 고려하여 풍속에 따른, 진동수에 따른 비틀림진동을 분석하였다. 해석결과 진동 초기의 수직모드는 점차 비틀림모드로 전이되며 수직모드는 안정적으로 진동하는 것을 확인하였다. 또한 비틀림강성 효과를 고려하여 해석을 수행한 결과 수직모드는 시간이 경과함에 따라 안정화되는 모습을 보이나 비틀림 진폭은 일정시간(약 200초) 이후 나타나기 시작하여 비틀림각을 지속적으로 유지하였으며 맥놀이 주기는 풍속이 증가하면서 점차 감소하였다. 비틀림 강성에 따라 서로 다른 풍하중의 풍속과 진동수에 비틀림모드의 공진현상을 나타내므로 실제 설계에는 반드시 이러한 영향이 고려되어야 할 것이다. In this paper, 2D simple analyses were performed in order to predict the large torsional oscillations in a suspension bridge based on Makenna and Tuama model(2001). The existing model(Makenna and Tuama, 2001) has shown unrealistic results as the wind speed increases and frequency decreases. Furthermore, resonance could not be simulated by the existing model. Therefore, in this study, new model was proposed with a consideration of the torsional resistance. The vertical and rotational behaviors of the deck in the suspension bridge were analyzed. Analysis results showed that at first vertical oscillations were observed and it was gradually transformed to the rotation oscillations. With the consideration of the torsional resistance, it was shown that vertical behavior were stabilized as time passed. However, the rotational behavior was not stabilized and was kept until the end of analysis. Beat periods decreased while the wind speed increased. The resonance of the rotational mode was dependent to the rotational resistance. Obtained results could be applied for the design of the suspension bridge under the wind load.

일체식 교대 교량의 대횡변위를 위한 교대와 H형 말뚝 연결부의 개발

김우석,이재하,박대효,Kim, Woo Seok,Lee, Jaeha,Park, Taehyo 한국전산구조공학회 2013 한국전산구조공학회논문집 Vol.26 No.4

본 논문에서는 일체식 교대 교량의 장대화 및 내진성능 향상을 위해 가장 중요한 역할을 하는 교대-H형 강말뚝 연결부의 성능을 향상시키기 위하여 기존의 연결부의 균열형상을 파악하고, 이를 기반으로 새로운 형태의 연결부를 제안하기 위하여 철근을 활용하여 강성을 증가시키는 방법과 강말뚝의 형상을 개선하여 연성을 개선시키는 방법을 모색하였다. 먼저, 기존 연결부의 성능을 향상시키기 위하여 연결부 주변에 PennDOT에 규정된 철근상세와 나선철근의 배치와 HSS 튜브를 사용하였으나, PennDOT의 철근 상세와 HSS 튜브는 연결부의 성능을 향상시키지 못 했으나, 나선철근은 균열을 효과적으로 차단시키는 것을 확인할 수 있었다. 하지만, 철근의 구속효과로 인해 강말뚝의 저항력이 변위에 선형적으로 비례하여 증가하므로 교량의 상부구조에 축력을 발생시키는 효과를 가져왔다. 따라서, 강말뚝의 형상을 개선하기 위하여 콘크리트 교대에 매입된 부분의 플랜지를 제거하는 방법과 콘크리트 외부에서 플랜지의 폭을 축소시키는 형태를 검토하였다. 두 가지 방안 모두 균열을 억제하는데 효과적인 방법이었으나, 플랜지를 제거하는 쪽의 연결부가 더욱 효과적이었다. Abutment-to-pile connection in an integral abutment bridge is vulnerable to lateral displacement induced by thermal movement of the superstructure. However, previous researches have merely focused on the connection. In order to improve the performance of the connection, new abutment-to-pile connection designs were proposed based on quasi-static nonlinear finite element model. The reinforcement detail specified in PennDOT DM4 and HSS tube were barely effective in controlling crack growing but spiral rebar effectively performed to delay crack growth as well as absorbing energy capacity. However, it was found that delaying cracking and strengthening the connection also caused the high lateral load in superstructures. Consequently, shape of HP pile were modified to introduce plastic hinge of the HP pile for reducing the lateral load in superstructures. Connections with modified HP pile significantly prevented crack propagations under the lateral displacement.

청안탕과 침시술이 여드름 환자에 미치는 효과

김우석,조순금,김민범,박지현,성미경,조혜린,유형천,Kim, Woo-Seok,Cho, Soon-Keum,Kim, Min-Beom,Park, Ji-Hyun,Sung, Mi-Kyoung,Cho, Hye-Rin,Ryu, Hyung-Cheon 대한한방안이비인후피부과학회 2015 한방안이비인후피부과학회지 Vol.28 No.4

Objectives : We performed a retrospective study to verify the effects of Chungan-tang and acupuncture in acne patients.Methods : This study included patients with facial acne who visited to six branch of clinics in 2014. They were evaluated by Korean Acne Grading System (KAGS) before and after treatment.Results : The average grade of KAGS was 4.02±1.120 at before treatment and 1.30±0.867 at after treatment. 64 patients were classified as three groups by treatment period and KAGS grade significantly decreased in all groups. Six skin symptoms such as heat, blush, dryness, itch, prick, pain also significantly improved.Conclusions : This results may provide that Korean medical treatments including Chungan-tang and acupuncture have effects on improving acne.

국가균형발전정책의 변화를 위한 소고

김우석 ( Kim¸ Woo Seok ),김형진 ( Kim¸ Hyeong Jin ) 한국거버넌스학회 2020 한국거버넌스학회보 Vol.27 No.3

본 연구의 목적은 국가균형발전특별법에 의거하여 추진되고 있는 국가균형발전사업과 그 재원인 국가 균형발전특별회계를 면밀히 살펴보고, 국가균형발전사업의 계획·실행·평가·환류에도 불구하고 더욱 심화되고 있는 경제와 인구의 지역간 불균형에 대한 상세한 소고를 통해 대규모 국가균형발전사업의 필요성과 추진방향을 제시하고자 한다. 수도권과 비수도권 사이의 경제와 인구의 불균형이 나날이 심해지고 있는 상황에서 이를 해결하기 위한 대규모 국가균형발전사업이 요구되고 있는 현실이다. 재정분권을 통해 국가균형발전특별회계의 상당 부분이 중앙정부에서 지방정부로 이양되는 만큼 국가균형발전프로젝트는 단순히 지역별 적정예산 안분으로 끝나서는 안되며, 국가적 차원에서 지역의 경제와 인구를 고려하여 보다 장기적이고 거시적인 관점에서 균형발전을 달성하기 위한 대규모 국가균형발전사업의 추진방향 재정립이 요구된다. The purpose of this study is to suggest the necessity and direction of large-scale national balanced development projects. To do this, look closely at the national balanced development project, which is being promoted under the National Balanced Development Special Act, and the special account for national balanced development. Then make detailed comments on the imbalance between regions of the economy and the population that is getting worse despite the planning, implementation, assessment, and feedback of the national balanced development project. As the economic and population imbalance between the metropolitan area and the non-metropolitan area is increasing day by day, a large-scale national balanced development project is needed to solve this. The current large-scale national balanced development project should not simply end with an appropriate budget division for each region, as a significant portion of the special account for national balanced development is transferred from the central government to local government through fiscal decentralization. In order to achieve balanced development in a true sense from a longer-term and macroscopic perspective at the national level, considering the regional economy and population, it is necessary to re-establish the direction of large-scale national balanced project.

제주도에서 분리한 미생물의 수질정화 성능 평가에 관한 연구

김우석 ( Woo Suk Kim ),박준석 ( Jun Seok Park ),서대석 ( Dae Seuk Seo ),김봉균 ( Bong Kyun Kim ),손승욱 ( Seung Wook Son ),박재로 ( Jae Roh Park ) 한국수처리학회 2016 한국수처리학회지 Vol.24 No.4

In this study, we collected samples from rivers in Jeju Island and other places where the self-purification capacity of rivers had been recovered by utilizing effective microorganisms(EM). And then after separating microorganisms from among the samples, we evaluated each microorganism’s water purification. In addition, we performed DNA sequencing by means of the 16S rRNA gene (16S rDNA) sequencing method for the identification of microorganisms capable of improving water quality and sought to register gene sequence information in GenBank at the National Center for Biotechnology Information (NCBI). According to the COD experiment results, C1, B4 and C6 showed the average removal efficiency of 21.3, 23.4 and 38.6% respectively. According to the T-N experiment results, the respective strains of B4, B6, M3 and C1 showed the average removal efficiency of 26.8, 34.9, 28.3 and 23.3% respectively. According to the T-P experiment results, the respective strains of B4, B6, C1 and C4 showed the average removal efficiency of 15.0, 19.4, 15.1 and 9.1% respectively. By examining the present study, it is judged that the strain of B6 has the best water purification performance. As a result of its identification, the strain of B6 showed 99.66% similarity to the strain of Bacillus subtilis. Moreover, the gene sequence information was registered in GenBank at NCBI in the USA, thereby being assigned the accession number of ‘KU672511’.

초음파 속도법을 활용한 강교 부식 손상탐지법 개발

김우석 ( Woo-seok Kim ),문성모 ( Seong-mo Mun ),김철민 ( Cheol-min Kim ),이강문 ( Kang-moon Lee ),임석빈 ( Seok-been Im ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 논문집 Vol.25 No.6

본 연구는 강교량의 폐합부재 등 시각적으로 탐지하기 어려운 부위의 강재에 대한 손상을 탐지하기 위한 방법을 개발하기 위한 목적으로 시작되었다. 본 연구에서는 초음파 속도법을 활용하여 강재의 두께를 추정하는 방법에 대한 정확도를 향상시키기 위한 알고리즘을 개발 및 적용하였다. 또한 정적인 스캐닝과 연속 스캐닝의 비교를 실시하였고, 실용적인 범위의 정확도에서는 차이가 없는 것으로 나타났다. 강재 부재 내에 물이 고여 있는 상황을 고려하여 물이 있을 경우에 대한 물 높이 추정 알고리즘을 제안하였고, 이를 통해 측정한 결과 물의 높이가 강재 부재보다 두꺼울 경우에는 적절한 추정이 가능했으나, 작을 경우에는 물의 존재 유무만을 판단할 수 있었다. This study was intended to develop an inspection method to detect defects in closed-cell steel members in steel girder bridges. The ultrasonic pulse velocity method was selected as a rapid and effective method to identify thickness changes of steel specimens caused by corrsion. This study developed an algorithm to expedite the process and improve the accuracy in the prediction of steel plate thickness. Also, both static and continuous scanning methods were compared to each other to identify the difference in accuracy, but the results revealed that both methods produce almost the same results. This study also provided the idea to calculate the height of water contained in the closed-cell steel member and results of laboratory experimental results. The water heights which is thicker than the steel plate thickness were detectable and predicted using the idea suggested by this study, but the water heights lower than the steel plate thickness were not possible. However, the results showed whether the steel member contains water or not.

풍하중을 받는 현수교의 2D 간단해석

김우석(Kim, Woo Seok),정찬(Jeoung, Chan),박수봉(Song, Jae Joon),이재하(Lee, Jaeha),박대효(Park, Taehyo) 한국콘크리트학회 2014 한국콘크리트학회 학술대회 논문집 Vol.2014 No.5

ACF혼입율에 따른 시멘트 페이스트 강도특성에 관한 실험적 연구

김우석(Kim, Woo Suk),이형주(Lee, Hyung Joo),김승기(Kim, Seung Ki),서대석(Seo, Dae Sok),김봉균(Kim, Bong Kyun),박준석(Park, Jun Seok) 한국콘크리트학회 2014 한국콘크리트학회 학술대회 논문집 Vol.2014 No.5

매립시설 증설에 따른 비탈면 안정성 검토 연구

김우석(Kim, Woo-Seok),황성필(Hwang, Sung-Pil),정재형(Jeoung, Jae-Hyeung) 한국지반환경공학회 2022 한국지반환경공학회 학술발표회논문집 Vol.2022 No.9