• 한국구조물진단유지관리공학회 논문집
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• 제19권3호
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• pp.48-54
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• 2015

본 연구에서는 수평변위와 횡력의 저감을 위해서 빌딩외부의 빌딩간 변형차이와 단면2차 모멘트의 최대화를 이용하여 다수의 빌딩으로 구성된 빌딩시스템의 빌딩간 협업제어 방식의 횡력분배 및 변위감소를 제안하였다. 제안된 복합빌딩 시스템의 안전설계를 위한 방안으로 케이블 파단시의 연속붕괴방지를 위한 연결부 정착판의 추가배치와 대공간구조 자체의 질량과 강성 및 공간을 활용한 동조질량감쇠장치의 설계에 대하여 제안하였다. 도심지 인구집중과 지가상승의 필연적 결과에 대한 해결방안으로 제안된 초고밀도 복합빌딩 시스템의 설계 최적화를 위하여, 3차원 빌딩구조시스템의 2축 대칭조건과 경계조건을 이용하여 2차원 모델을 구성하고 1차부정정구조를 이루는 2차원 모델의 중요설계변수를 검토하였다. 제안된 복합빌딩구조 시스템은 인구밀도와 지가가 상승하는 도심내 최대밀도구역에서 토지이용의 효율성을 극대화시키고, 새로운 빌딩 또는 기존빌딩구조의 안전성을 증대할 것으로 기대한다.

• KSBB Journal
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• 제28권4호
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• pp.260-268
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• 2013

Transgenic plant cell cultures are an attractive expression system for the production of industrial and pharmaceutical proteins because of their advantages in safety and low production cost. Human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) was produced and secreted when sugar was depleted in culture medium by transgenic rice cell lines (Oryza sativa L.) using RAmy3D promoter. Due to the production of the target protein by sugar depletion, concomitant occurrence of cell death is inevitable. For that reason, inhibition of cell death for enhancing productivity was necessary for the production period without energy sources. Supplementation of 0.1 mM sodium nitroprusside improved cell viability by 1.4-fold and maximum hCTLA4Ig production by 1.3-fold compared to those of control. Addition of 1 and 10 mM glutathione, N-acetylcysteine (NAC), and nicotinamide inhibited apoptotic-like programmed cell death by decreasing the activity of reactive oxygen species. Production hCTLA4Ig was enhanced 1.4-, 1.25-, and 1.15-fold with 10 mM NAC, 1 mM NAC, and 1 mM glutathione, respectively. In addition, it was found that the supplementation of NAC enhanced the cell viability.

• 전력전자학회논문지
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• 제19권1호
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• pp.91-97
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• 2014

Recently, the LED(Light Emitting Diode) is expected to replace conventional lamps including incandescent, halogen and fluorescent lamps for some general illumination application, due to some obvious features such as high luminous efficiency, safety, long life, environment-friendly characteristics and so on. To drive the LED, a single stage PFC(Power Factor Correction) flyback converter has been adopted to satisfy the isolation, PFC and low cost. The conventional flyback LED driver has the serious disadvantage of high 120Hz output current ripple caused by the PFC operation. To overcome this drawback, a new PFC flyback with low 120Hz output current ripple is proposed in this paper. It is composed of 2 power stages, the DCM(Discontinuous Conduction Mode) flyback converter for PFC and BCM(Boundary Conduction Mode) boost converter for tightly regulated LED current. Since the link capacitor is located in the secondary side, its voltage stress is small. Moreover, since the driver is composed of 2 power stages, small output filter and link capacitor can be used. Especially, since the flyback is operated at DCM, the PFC can be automatically obtained and thus, an additional PFC IC is not necessary. Therefore, only one control IC for BCM boost converter is required. To confirm the validity of the proposed converter, theoretical analysis and experimental results from a prototype of 24W LED driver are presented.

• 한국강구조학회 논문집
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• 제23권2호
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• pp.159-167
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• 2011

최근 강구조물의 건설이 지속적으로 증가되고 있고, 이에 따른 모니터링 시스템의 중요성이 더욱 부각되고 있는 실정이다. 강구조물의 노화로 인한 피로균열 및 부식은 강구조물의 수명저하에 가장 큰 요인이 된다. 구조물이 큰 교량의 경우에는 사람의 접근이 어렵고, 균열 측정 방법 또한 시간이 오래 걸리며, 많은 비용이 소비된다. 따라서, 초기에 균열을 발견하고 보수, 보강 작업을 수행함으로써 비용을 절감할 수 있는 모니터링 시스템의 개발이 절실히 요구된다. 본 연구에서는 강부재의 전위차법(EPDM : Electric Potential Drop Method)에 의한 모니터링 기법에 의해 쉽게 관찰되지 않는 피로균열의 발생 및 진전 상황을 추적하고 또한 잔여수명을 예측하였다.

• Osong Public Health and Research Perspectives
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• 제9권6호
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• pp.314-324
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• 2018

Objectives: The aim of this study was to analyze research and development projects in mental health services in Korea, using priority evaluation of mental health promotion policies to determine direction of the service. Methods: An online survey was conducted that targeted experts in the mental health service regarding promotion of mental health in Korea in 2016. The survey was based on 32 policy projects that resulted from 12 strategies according to 4 policy objectives. Results: Analysis of 32 mental health projects were assessed regarding the possibility of technology development success, magnitude of the ripple effect, and necessity of a national response. It was observed that 3 policy projects relevant to suicide, had a high relative priority. This was followed by policies for improvement of health insurance and the medical benefit cost system, and policies for reinforcement of crisis psychological support such as those for disaster victims. Conclusion: The prioritization of mental health services should place an emphasis on promotion of a healthy mental lifestyle, rehabilitation support for patients with serious mental illness, and reinforcement of social safety networks for suicide prevention.

• 한국항공우주학회지
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• 제49권10호
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• pp.871-877
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• 2021

항공기 결함은 항공기 운영 및 조종사의 생명과 직결된 중요한 사항으로 항공기 조종 중 발생하는 임무 소프트웨어의 결함은 조종사 임무수행 및 안전에 심각한 영향을 미친다. 항공기 개발을 주관하는 단체나 소프트웨어 결함을 개발 초기에 식별하고 제거하기 위해 프로세스를 강화하고 많은 공수와 시간을 할애하고 있지만 임무 소프트웨어의 특성상 타 항전 장비와 강한 기능적 결합도(Coupling) 및 높은 복잡도(Complexity)를 가지고 있어 기존 시험 방법을 통한 소프트웨어 결함 식별 및 제거에 제약이 따른다. 본 연구는 임무 컴퓨터 연동 장비의 통신 데이터 중 피드백 데이터의 기댓값 검증을 자동화하는 도구를 개발하여 데이터 무결성 검증을 통한 임무 소프트웨어 건전성 확보 및 시험 비용 감소 효과를 분석한다.

• Advances in Computational Design
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• 제4권1호
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• pp.53-72
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• 2019

Safety measures for tower cranes are extremely important among the seismic countermeasures at high-rise building construction sites. In particular, the collapse of a tower crane from a high position is a very serious catastrophe. An example of such an accident due to an earthquake is the case of the Taipei 101 Building (the author was the project director), which occurred on March 31, 2002. Failure of the bolted joints of the tower-crane mast was the direct cause of the collapse. Therefore, it is necessary to design for this eventuality and to take the necessary measures on construction sites. This can only be done by understanding the precise dynamic behavior of mast joints during an earthquake. Consequently, we created a new hybrid-element model (using beam, shell, and solid elements) that not only expressed the detailed behavior of the site joints of a tower-crane mast during an earthquake but also suppressed any increase in the total calculation time and revealed its behavior through computer simulations. Using the proposed structural model and simulation method, effective information for designing safe joints during earthquakes can be provided by considering workability (control of the bolt pretension axial force and other factors) and less construction cost. Notably, this analysis showed that the joint behavior of the initial pretension axial force of a bolt is considerably reduced after the axial force of the bolt exceeds the yield strength. A maximum decrease of 50% in the initial pretension axial force under the El Centro N-S Wave ($v_{max}=100cm/s$) was observed. Furthermore, this method can be applied to analyze the seismic responses of general temporary structures in construction sites.

• 방사성폐기물학회지
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• 제19권4호
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• pp.459-467
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• 2021

In the majority of countries, the upper limit of buffer temperature in a repository is set to below 100℃ due to the possible illitization. This smectite-to-illite transformation is expected to be detrimental to the swelling functions of the buffer. However, if the upper limit is increased while preventing illitization, the disposal density and cost-effectiveness for the repository will dramatically increase. Thus, understanding the characteristics and creating a database related to the buffer under the elevated temperature conditions is crucial. In this study, a strategy to investigate the bentonite found in Korea under the elevated temperatures from a mineral transformation and radionuclides retardation perspective was proposed. Certain long-term hydrothermal reactions generated the bentonite samples that were utilized for the investigation of their mineral transformation and radionuclide retardation characteristics. The bentonite samples are expected to be studied using in-situ synchrotron-based X-Ray Diffraction (XRD) technique to determine the smectite-to-illite transformation. Simultaneously, the 'high-temperature and high-pressure mineral alteration measurement system' based on the Diamond Anvil Cell (DAC) will control and provide the elevated temperature and pressure conditions during the measurements. The kinetic models, including the Huang and Cuadros model, are expected to predict the time and manner in which the illitization will become detrimental to the performance and safety of the repository. The sorption reactions planned for the bentonite samples to evaluate the effects on retardation will provide the information required to expand the current knowledge of repository optimization.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.187-196
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• 2022

In this paper, we propose an example of designing and constructing a roof-type solar power plant structure equipped with a Pseudo-BIPV (Building-Integrated Photovoltaic) shape suitable for use as a roof of a small warehouse with a sandwich-type panel structure. As the characteristics of the roof-type solar power generation facility to be installed in the small warehouse proposed in this study, the shape of the roof is not a general A type, but a right-angled triangle shape with the slope is designed to face south. We chose a structure in which an inverter for one power plant and a control facility are linked by grouping several roofs of buildings. In addition, the height of the roof structure is less than 20 cm from the floor, and it has a shape similar to that of the BIPV, so it is building-friendly because it is almost in close contact with the roof. At the same time, the roof creates a reflective light source due to the white color. By linking this roof with a double-sided solar panel, we designed it to obtain both the advantage of the roof-friendliness and the advantage of efficiency improvement for the electric power generation based on the double-sided panel. Compared to the existing solar power generation facilities using A-shaped cross-sectional modules, the power generation efficiency of roofs in this case is increased by more than 11%, which we can confirm, through the comparison analysis of monitoring data between power plants in the same area. Therefore, if the roof-type solar structure suitable for the small warehouse we have presented in this paper is used, the facilities of electric power generation is eco-friendly. Further it is easier to obtain facility certification compared to the BIPV, and improved capacity of the power generation can be secured at low material cost. It is believed that the roof-type solar power generation facility we proposed can be usefully used for warehouse or factory-based smart housing. Sensor devices for monitoring, CCTV monitoring, or safety and environment management, operating in connection with the solar power generation facilities, are linked with the Internet of Things (IoT) solution, so they can be monitored and controlled remotely.

• 대한핵의학회지
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• 제13권1_2호
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• pp.7-14
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• 1979

Radionuclide cardiac angiography has distinct advantages in safety, patient comfort, cost and ease of performance. This method offers diagnostic accuracy equivalent to that of cardiac catheterization. By this method the qualitative and quantitative diagnosis of the cardiac shunts are available. Also for it is repeatable with ease and more physiologic, it has application in following pre- and post-operative shunt patients. We performed the radionuclide cardiac angiographies in 147 cases of heart diseases and 26 cases of normal group. 1. The detection of left-to-right shunt was possible in 22 of 24 patients, and 2 patients were not diagnosed due to small shunt amount. (Qp/Qs<1.3) In 21 patients of right-to-left shunt, all were diagnosed by radionuclide cardiac angiography. 2. With the pulmonary time-activity curve, $C_2/C_1$ ratio was calculated. In normal control group, a range of $C_2/C_1$ ratios of $21{\sim}38%$ was established with a mean value of $28.6{\pm}4.6%$. In patients with left-to-right shunts determined by catheterization data, the range of $C_2/C_1$ ratio was $33{\sim}90%$, with a mean value of $67.8{\pm}12.2%$. 3. In 8 cases of left-to-right shunt, $Q_p/Q_s$ ratios determined by radionuclide cardiac angiography were compaired with those of cardiac catheterization. The correlation coefficient was 0.907. (P<0.001) 4. Postoperative radionuclide cardiac angiographies were done in 21 cases. 3 of 13 patients with left-to-right shunts were found to have residual shunts. 8 patients with right-to-left shunts were confirmed to have no residual shunt.