• Structural Monitoring and Maintenance
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• 제2권1호
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• pp.1-18
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• 2015

Traditionally, it is not easy to carry out tests to identify modal parameters from existing railway bridges because of the testing conditions and complicated nature of civil structures. A six year (2007-2012) research program was conducted to monitor a group of 25 railway bridges. One of the tasks was to devise guidelines for identifying their modal parameters. This paper presents the experience acquired from such identification. The modal analysis of four representative bridges of this group is reported, which include B5, B15, B20 and B58A, crossing the Caraj$\acute{a}$s railway in northern Brazil using three different excitations sources: drop weight, free vibration after train passage, and ambient conditions. To extract the dynamic parameters from the recorded data, Stochastic Subspace Identification and Frequency Domain Decomposition methods were used. Finite-element models were constructed to facilitate the dynamic measurements. The results show good agreement between the measured and computed natural frequencies and mode shapes. The findings provide some guidelines on methods of excitation, record length of time, methods of modal analysis including the use of projected channel and harmonic detection, helping researchers and maintenance teams obtain good dynamic characteristics from measurement data.

• Asian Pacific Journal of Cancer Prevention
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• 제15권15호
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• pp.6211-6217
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• 2014

Previous genome-wide association studies (GWAS) have implicated several single nucleotide polymorphisms (SNPs) in the AT-rich interactive domain 5B (ARID5B) gene with childhood acute lymphoblastic leukemia (ALL). However, replicated studies reported some inconsistent results in different populations. Using meta-analysis, we here aimed to clarify the nature of the genetic risks contributed by the two polymorphisms (rs10994982, rs7089424) for developing childhood ALL. Through searches of PubMed, EMBASE, and manually searching relevant references, a total of 14 articles with 16 independent studies were included. Odds ratios (ORs) with 95% confidence intervals (95%CI) were calculated to assess the associations. Both SNPs rs10994982 and rs7089424 showed significant associations with childhood ALL risk in all genetic models after Bonferroni correction. Furthermore, subtype analyses of B-lineage ALL provided strong evidence that SNP rs10994982 is highly associated with the risk of developing B-hyperdiploid ALL. These results indicate that SNPs rs10994982 and rs7089424 are indeed significantly associated with increased risk of childhood ALL.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.1079-1084
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• 2002

Systems engineering technology development program for Korea next-generation high-speed railway(KNHR) system in progress is a national large-scale system development program that is not only a large-size and complex but also multi-disciplinary in nature. Using the RDD-IOO, a systems engineering tool, the KNHR program can establish requirements traceability and development process management in the course of development. This paper presents the results from a computer-aided systems engineering application to KNHR system technology development project over the three years of activities. The traceability among the system design database in the vertical direction of SE process, as the results of the first year and the second year research was accomplished. The database in both the requirement management domain and the project management domain was developed and set up the traceability between them in the horizontal direction of the SE process in the V model as the results of the third year research. Therefore, KNHR design database was built to support the life-cycle management of the system as well as to reuse the knowledge in future programs. In the following development phase, this database will be utilized to accomplish the test and integration activities providing a baseline database. The outcome of the study contributes to the establishment of the model-based systems engineering approach as a best practice in the accumulation and advancement of systems engineering technology for railway system development.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.503-510
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• 2015

The iLOV protein belongs to a family of blue-light photoreceptor proteins containing a light-oxygen-voltage sensing domain with a noncovalently bound flavin mononucleotide (FMN) as its chromophore. Owing to advantages such as its small size, oxygen-independent nature, and pH stability, iLOV is an ideal candidate over other reporter fluorescent proteins such as GFP and DsRed. Here, for the first time, we describe the feasibility of applying LOV domain-based fluorescent iLOV as a metal sensor by measuring the fluorescence quenching of a protein with respect to the concentration of metal ions. In the present study, we demonstrated the inherent copper sensing property of the iLOV protein and identified the possible amino acids responsible for metal binding. The fluorescence quenching upon exposure to Cu²⁺ was highly sensitive and exhibited reversibility upon the addition of the metal chelator EDTA. The copper binding constant was found to be 4.72 ± 0.84 µM. In addition, Cu²⁺-bound iLOV showed high fluorescence quenching at near physiological pH. Further computational analysis yielded a better insight into understanding the possible amino acids responsible for Cu²⁺ binding with the iLOV protein.

• 전력전자학회논문지
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• 제14권3호
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• pp.188-196
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• 2009

슈퍼커패시터는 전력밀도가 높고 사이클 수명이 길며 깨끗한 특성으로 인해 신재생에너지원의 동특성 보상 및 배터리의 동작시간이나 수명연장을 목적으로 널리 사용되고 있다. 본 논문에서는 개선된 슈퍼커패시터의 동특성 모델을 전기화학적 임피던스 분광법(Electrochemical Impedance Spectroscopy)을 이용하여 개발한다. 개발된 모델은 슈퍼커패시터의 정확한 동적 행동을 예측하거나 특정 충전상태(State-Of-Charge)에서의 정확한 정전용량 값을 계산하는데 사용될 수 있다. 주파수영역에서 개발된 모델은 Matlab/Simulink 시뮬레이션을 위하여 시간영역으로 등가 변환된다. 시뮬레이션 결과는 실험 결과와 일치하였으며, 이를 통해 개발된 모델의 유용함과 정확성을 증명하였다.

• 한국환경교육학회지:환경교육
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• 제8권1호
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• pp.81-97
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• 1995

This study is to consider the result of the Field Trip Contest(FTC) and get a suggestion as a way of environmental education at school level in field. FTC was executed with selected students(3/1team) of 5th grade nationwide at Nam-Han mountain fortress in the suburbs of Seoul in Oct., 1994. The outcome of FTC was very high with the score of 1.38/2.0, and the quality of the program was generally high with the score of 1.09/2.0. Among areas of the outcome domain, accomplishment of the objectives of FTC was very high(1.55), execution of the policy of FTC was generally high(1.27), and operation and promotion of FTC was generally high(1.16). And in the Program of FTC domain, meaning of execution was very high(1.57), possibility of accomplishment was not high(0.03), validity of the content was generally high(1.18), appropriateness of activity scope was generally high(1.15), possibility of application into school system was generally high(1.22), and extending effect to education was generally high(0.9). Participants responded they got a great experience of inquiry for protecting nature during the activity of FTC and teachers accompanying found a good possibility to do in own school province.

• Wind and Structures
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• 제32권2호
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• pp.89-104
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• 2021

Non-synoptic winds generated by tornadoes, downbursts or gust fronts exhibit significant non-stationarity and can cause significant wind load effect on flexible structures such as long-span bridges. However, conventional assumptions on stationarity used to evaluate the structural wind-induced vibration are inadequate. In this paper, an efficient frequency domain scheme based on fast CQC method, which can predict non-stationary buffeting random responses of long-span bridges, is presented, and then this approach is applied to evaluate the buffeting response of a long-span suspension bridge located in a complex mountainous wind environment as an example. In this study, the data-driven method based on one available measured wind speed sample is firstly presented to establish non-stationary wind models, including time-varying mean wind speed, time-varying intensity envelope function and uniformly modulated fluctuating spectrum. Then, a linear time-variant (LTV) system based on the proposed scheme can be generally applied to calculate the non-stationary buffeting responses. The effectiveness and accuracy of the proposed scheme are verified through Monte Carlo time domain simulation implemented in ANSYS platform. Also, the transient effect nature of the bridge responses is further illustrated by comparison of the non-stationary, quasistationary and steady-state cases. Finally, buffeting response analysis with traditional stationary treatment (10 min constant mean plus stationary wind fluctuation) is performed to illustrate the importance of the non-stationary characteristics embedded in original wind speed samples.

• Nuclear Engineering and Technology
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• 제56권8호
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• pp.3385-3396
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• 2024

Copper canisters are commonly employed to contain HLW for the long-term, making it crucial to understand how corrosion affects the canister. This study conducted a comparative analysis of two widely used calculation methods for modeling canister corrosion within a 3-D DGR domain. The first method, termed transport-limited corrosion, assumes an immediate sulfide-copper reaction and has been traditionally used due to its conservative nature. The second method, known as the potential-limited corrosion, considers coupled redox reactions at the canister surface and computes corrosion rates through anodic current density. From the results, we found that the edge of the canister geometry and the omission of electrochemical kinetics impose critical limitations with the transport-limited corrosion method. These limitations include the singularity problem, excessive sensitivity to the curvature of the canister's edge, and an inability to evaluate the distribution of corrosion rate over the canister surface as a function of the sulfide concentration. On the other hand, the potential-limited corrosion method avoided the limitations found in the other method. Since the factors relating to these limitations are critical to the design and optimization of the copper disposal canister, careful consideration when selecting appropriate calculation methods for corrosion will be required.

• 한국지구과학회지
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• 제28권4호
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• pp.393-404
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• 2007

본 연구의 목적은 우리나라 10학년 과학 교과서 지구 분야에 등장하는 과학적 모델을 분류해 보는 것이었다. 과학적 모델을 표상 매체, 표상 방법, 모델의 가동성이라는 세 가지 차원에서 검토할 수 있도록 개발된 분류틀을 이용하여 11종 교과서의 지구과학 관련 단원을 분석하였다. 연구의 결과, 과학 교과서들은 지구과학의 세부 영역의 본성이 반영된 영역-특이적인 모델들을 수록하고 있는 것을 알 수 있었다. 즉, '지구의 변동' 단원은 접근이 용이하지 않은 지구의 내부 구조나 판들의 운동을 표상하는 모상 모델을 많이 포함하고 있었는데, 이들은 대부분 평면적 그림 모델과 정적 모델에 속하였다. '대기와 해양' 단원에서는 일기도나 해수의 온도와 염분을 나타낸 등치선도 등을 포함한 기호모델과 도해적 모델이 많이 등장하였다. '태양계와 은하' 단원에서는 규모가 큰 천체나 그들의 운동을 표상하는 모상 모델이나 유비 모델의 비율이 상대적으로 높게 나타났다. 이러한 분석 결과가 지구과학 교육과 관련 연구에 시사하는 바를 논의하였다.

• 기록학연구
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• 제32호
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• pp.45-78
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• 2012

2004년도에 발생했던 대통령 탄핵사건의 의미는 다양한 맥락에서 해석될 수 있겠지만 그 명분에 해당하는 성격은 무엇보다도 국내의 탄핵제도에 의한 헌법재판 사건이었다. 본 논문은 이러한 "공적 활동으로서의 탄핵사건"이라는 성격을 중심으로 사건에 관한 이해와 관련된 기록들의 현황을 비교분석하는 내용을 담고 있다. 이러한 목적에 따라 먼저 공적활동으로서 탄핵사건을 이해하기 위한 탄핵사건 분석을 시도하였으며 그 결과를 바탕으로 공공영역에 존재하는 탄핵사건 기록현황을 직접방문, 전화면담, 정보공개청구의 방법으로 조사 분석한 내용을 기술하였다. 공적활동으로서 탄핵사건은 국내의 탄핵제도의 규범 아래 탄핵소추를 담당하는 국회와 탄핵심판을 담당하는 헌법재판소가 헌법 등에 명시된 고유한 권한을 중심으로 진행하는 활동으로 이해할 수 있다. 또한 피소추자인 대통령과 탄핵소추에 의해 생성된 대통령권한대행체제 그리고 탄핵의 결정적 사유를 제공한 중앙선거관리위원회 역시 공적 활동의 주요한 주체로서 식별되었다. 또한, 공공영역의 경우 법적인 요건에 해당하는 기록들이 잘 생산되어 현재 보존 관리되고 있음을 확인하였다. 하지만 탄핵사건 기록이 주로 표면적인 처리과정과 명시적 활동의 결과에 관한 것들이 주를 이룸으로써 업무와 관련되어 내용적으로 철저하게 생산되었다고 보기는 어려웠다고 평가하였다. 특히, 활동의 맥락을 보여주는 기록들의 부재를 확인할 수 있었다.