본 연구는 Tuned Mass Damper(TMD)가 적용된 원자력 발전소 파이핑 시스템의 동적 응답 저감 효과를 평가하기 위해 수행되었다. ABAQUS를 활용하여 실제 크기의 파이핑 시스템 유한요소 모델을 개발하고, 실험 데이터를 통해 모델의 적합성을 검증하 였다. 이후, 확장된 수치해석을 통해 국부 손상 발생 시 TMD의 응답 저감 효과를 분석하였다. 연구 결과, TMD는 무손상 상태에서 가속도와 변위 응답을 각각 최대 20%와 30% 저감하는 효과를 보였으며, 특정 국부 손상(30%, 50%, 70%)에서도 저감 효과가 유지됨 을 확인하였다. 이는 국부 손상이 시스템의 주파수 특성에 미치는 영향이 제한적임을 시사한다. 그러나 손상의 위치와 응답 특성에 따라 저감 효과에는 차이가 있었으며, 최대 응답 위치에서 TMD의 효과가 보다 두드러졌다. 본 연구는 선형 해석에 초점을 맞췄으며, 향후 비선형 재료 특성과 다양한 지진 조건을 고려한 추가 연구가 필요함을 제안한다.

This study aims to identify crisis signs in small and medium enterprise (SME)-concentrated regions and establish measures to prevent economic recession and normalize regional economies through proactive responses. To achieve this, we investigated and analyzed the crisis status and outlook of companies located in Jeonbuk, their detailed management conditions, management issues by industry, difficulties in business operations, and policy demands. Out of 4,144 SMEs in Jeonbuk's concentrated areas, 270 companies responded to the survey. The results showed that 60% of the responding companies perceived their current management situation as being in a state of crisis. However, the outlook for the next quarter and the following year is expected to improve. Notably, compared to manufacturing companies, non-manufacturing firms responded that their crisis situation in the next quarter would not improve and expected the crisis to persist. In terms of detailed business conditions, regardless of the distinction between manufacturing and non-manufacturing sectors, all aspects of the survey, including domestic sales, export sales, operating profit, financial status, and the number of employees, indicated better prospects for the next quarter and the following year compared to the current quarter. The study's findings suggest that companies in SME-concentrated areas of Jeonbuk are relatively accurate in recognizing the crisis situation of their own businesses and operating markets. Additionally, the companies responded that crisis monitoring is necessary. Differences in difficulties faced by the manufacturing and non-manufacturing sectors imply the need for industry-specific financial support programs. Based on the survey results, we propose financial support projects tailored to the manufacturing and non-manufacturing sectors, considering the degree of market competition. For more precise research, future studies will involve extracting larger samples and conducting a detailed analysis by subdividing manufacturing sectors (e.g., food, metal) and non-manufacturing sectors (e.g., agriculture, design).

The dome structure is suitable as a roof for large spatial structures because it can maintain the shape without installing columns in the internal space. However, the structure characteristics of the lower and upper structures of the dome structure are different, and damage may occur when an earthquake occurs. Therefore, in this study, mid-story isolation system was applied to the ribbed dome and geodesic dome structures to analyze the seismic response of the lower and upper structures according to the dome shape. As a result of the analysis, the displacement of the ribbed dome increased, but the deformation of the ribbed dome and the response of the lower structure decreased, and the seismic response of the geodesic dome decreased overall. From this result, the effect of the isolator according to the shape of the dome structure was confirmed, and the mid-story isolation is considered effective in reducing the seismic response of the upper and lower structures.

The diagrid structural system has a braced frame that simultaneously resists lateral and vertical loads, and is being applied to many atypical high-rise buildings for aesthetic effects. In this study, a 60-story structure with twisted degrees of 0° to 180° was selected to determine seismic response control performance of twisted high-rise structures whether the diagrid system was applied and according to the reduction of braced frame material quantity. For this purpose, ‘Nor’ model without the diagrid system and the ‘DS’ model with the diagrid system, which was modeled by reducing braced frame member section to 700~400, were modeled. As a result, the 'DS' model showed an seismic response control effect in all Twisted models even when the quantity was reduced, and especially, the Twisted shape model was found to have an superior response control effect compared to the regular structure. In addition, the ‘600DS’ analysis model, which matched the ‘Nor’ model by 99.0% in quantity, showed an increase in seismic response control performance as the rotation angle increased.

Since atypical high-rise buildings are vulnerable to gravity loads and seismic loads, various structural systems must be applied to ensure the stability of the structure. In this study, the authors selected a 60-story twisted-shaped structure among atypical high-rise structures as an analytical model to investigate its structural behavior concerning the outrigger system. The structural analyses were performed varying the number of installed layers and the arrangement of the outrigger system, as well as the placement of the mega column, as design variables. The analysis revealed that the most effective position for the outrigger was 0.455H from the top layer, consistent with previous studies. Additionally, connecting outriggers and mega columns significantly reduced the displacement response of the model. From an economic standpoint, it is deemed efficient to connect and install outriggers and mega columns at the structure's ends.

본 논문의 목적은 한국이 직면한 뉴테러리즘 양상과 위협 요인을 분석해보고, 선제적으로 대응할 수 있는 과제에 대해 제시해 봄에 있다. 현재 한국은 포괄적 안보상황 하에서 대중과 다중이용시설 대상 무차별적 공격의 사전 차단 및 대량살상 등 전방위적으로 테러위협에 대응하고 있다. 이에 이 논문에서는 테러 수단의 첨단화 및 고도화되고 있는 뉴테러리즘에 대해 선제적으로 국가 및 국민적 인식을 강화하고 취약점 보완을 위해 법률적, 제도적 대응 방안을 제시했다. 또 포괄적 안보 상황을 반영하여 국내 테러 양상을 분석하고, 테러예방시스템 구축을 위한 통합방위법 및 테러방지법의 상호 연계성과 사법집행 강화를 위한 근거를 마련해야 한다. 특히 AI 기반의 테러예방 및 대응 시스템 등 4차 산업혁명의 신기술 적용을 토대로 테러위협을 선제적 으로 차단하고 이 같은 기술을 활용하는 대테러업무 담당자를 대상 으로 교육훈련을 강화할 수 있는 방안 역시 마련해야 한다.

In general, the design response spectrum in seismic design codes is based on the mean-plus-one-standard deviation response spectrum to secure high safety. In this study, response spectrum analysis was performed using seismic wave records adopted in domestic horizontal design spectrum development studies, while three response spectra were calculated by combining the mean and standard deviation of the spectra. Seismic wave spectral matching generated seismic wave sets matching each response spectrum. Then, seismic fragility was performed by setting three damage levels using a single-degree-of-freedom system. A correlation analysis was performed using a comparative analysis of the change in the response spectrum and the seismic fragility concerning the three response spectra. Finally, in the case of the response spectrum considering the mean and standard deviation, like the design response spectrum, the earthquake load was relatively high, indicating that conservative design or high safety can be secured.

The importance of Structural Health Monitoring (SHM) in the industry is increasing due to various loads, such as earthquakes and wind, having a significant impact on the performance of structures and equipment. Estimating responses is crucial for the effective health management of these assets. However, using numerous sensors in facilities and equipment for response estimation causes economic challenges. Additionally, it could require a response from locations where sensors cannot be attached. Digital twin technology has garnered significant attention in the industry to address these challenges. This paper constructs a digital twin system utilizing the Long Short-Term Memory (LSTM) model to estimate responses in a pipe system under simultaneous seismic load and arbitrary loads. The performance of the data-driven digital twin system was verified through a comparative analysis of experimental data, demonstrating that the constructed digital twin system successfully estimated the responses.

The timescale of safety assessment for a geological disposal system is considered up to hundreds of thousands of years when the radionuclides in spent nuclear fuel decay to levels comparable to natural radioactivity. During this long period, a variety of climate changes are expected to occur, including variations in temperature and precipitation as well as long-term sea level changes and glacial cycles. These climate changes can either directly affect water balance components or indirectly affect water balance by altering terrain and vegetation that have an impact on water balance. Water balance is a significant element of safety assessment, because it affects the radionuclide transport via groundwater flow, which in turn affects the radiological risk to humans and other biotas. Therefore, it is important to understand the hydrologic response to climate changes for proving the long-term safety of the disposal system. To this end, this study performed hydrological simulations using the SWAT (Soil and Water Assessment Tool) for several climate change scenarios. SWAT is the watershed-scale hydrological model developed by the USDA-ARS (United States Department of Agriculture - Agricultural Research Service) and has been widely used to quantify the water balance in a watershed. It calculates the hydrologic cycle based on the water balance equation with different physical processes for water balance components such as evapotranspiration, surface runoff, and groundwater recharge. This study assumed several climate change scenarios (e.g., variations in temperature and precipitation, sea level change, and formation of permafrost) and analyzed how the components of the water balance would respond under different scenarios and which scenarios would have the greatest impact on the water balance. These findings can provide valuable insights for future long-term safety assessments on the Korean Peninsula and can also be used as input data for the biosphere module of APro (Adaptive process-based total system performance assessment framework).

본 연구는 딥러닝을 위한 비선형 변환 접근법을 사용하여 Single-lap joint의 접착 영역을 조사하기 위한 진동 응답 기반 탐지 시스템 을 제시한다. 산업 혹은 공학 분야에서 분해가 쉽지 않은 구조 내에 보이지 않는 부분의 상태와 접착된 구조의 접착 부위 상태를 알기 어려운 문제가 있다. 이러한 문제를 해결하기 위해 본 연구는 비선형 변환을 이용하여 기준 시편의 진동 응답으로 다양한 시편의 접착 면적을 조사하는 탐지 방법을 제안한다. 이 연구에서는 CNN 기반 딥러닝으로 진동 특성을 파악하기 위해 비선형 변환을 적용한 주파 수 응답 함수를 사용했고 분류를 위해 가상의 스펙트로그램을 사용했다. 또한, 제시된 방법을 검증하기 위해 알루미늄, 탄소섬유복합 재 그리고 초고분자량 폴리에틸렌 시편에 대한 진동 실험, 분석적 해, 유한요소해석을 수행했다.

잎들깨 수경재배 시 적합한 고형배지를 선발하기 위하여 본 연구를 수행하였다. ‘남천’과 ‘소미랑’ 2품종에 대해 코이어 (chip:dust = 5:5), 펄라이트, 입상 암면, 원예용 상토(cocopeat: peatmoss:vermiculite:perlite:zeolite = 50:25:10:10:5) 등 4종의 배지에 따른 배지의 물리화학적 특성 및 생육반응을 분 석하였다. 배지 간의 EC와 pH의 차이는 보이지 않았으나, 용 기용수량 측정 결과 입상 암면이 가장 높고 원예용 상토와 코 이어가 적절한 수준을 유지하였다. 배지의 기상률은 코이어 와 펄라이트가 30% 이상으로 높은 경향을 보였으며 가비중은 코이어 배지를 제외한 모든 배지가 기준을 충족하였다. 잎의 크기는 품종 간에 배지에 따른 반응이 다르게 나타났는데 ‘남 천’ 품종은 원예용 상토에서 엽장, 엽폭이 가장 컸고 ‘소미랑’ 의 경우 코이어에서 재배하였을 때 가장 컸다. 엽중은 두 품종 모두 원예용 상토에서 재배한 것이 가장 높았고, 코이어와 펄 라이트에서 재배한 것이 상대적으로 낮았다. 총 생산량을 조 사한 결과 수량이 높은 원예용 상토 및 입상 암면과 수량이 낮 은 코이어, 펄라이트로 두 그룹으로 구분되는 형태를 보였으 며 그룹 간에 최대 28% 차이를 보였다. 따라서 근권에 충분한 수분 공급이 필요한 잎들깨를 수경재배하기 위해서는 보수력 이 좋은 원예용 상토와 입상 암면을 이용하는 것이 적합할 것 으로 판단한다.

In this study, a structural health monitoring system for cable-stayed bridges is developed. In the system, condition assessment of the structure is performed based on measured records from seismic accelerometers. Response indices are defined to monitor structural safety and serviceability and derived from the measured acceleration data. The derivation process of the indices is structured to follow the transformation from the raw data to the outcome. The process includes noise filtering, baseline correction, numerical integration, and calculation of relative differences. The system is packed as a condition assessment program, which consists of four major processes of the structural health evaluation: (i) format conversion of the raw data, (ii) noise filtering, (iii) generation of response indices, and (iv) condition evaluation. An example set of limit states is presented to evaluate the structural condition of the test-bed and cable-stayed bridge.

Second language (L2) peer response literature is defined in part by discourse research, yet there is scant research on text-specific comments, or comments that make explicit text references, thus resisting generic qualities. The purpose of this case study was to examine such peer response activities in an English writing course at a South Korean university. The data comprises two essay assignments with peer response conducted between two drafts – as accomplished during class time on the class learning management system (LMS) – as well as the subsequent revisions in second drafts. This paper expands on previous coding schemes accounting for area, nature and type commentary to account for a specificity dimension, and also links these categories to revision practices. While students entertained diverse commenting and revising options, popular practices included generic evaluating or revising local or surface-level concerns. This paper offers implications for modelling response activities as well as for how to better define specific and complex idea construction exhibited during response.

Seismic qualification of equipment including piping is performed by using floor response spectra (FRS) or in-structure response spectra (ISRS) as the earthquake input at the base of the equipment. The amplitude of the FRS may be noticeably reduced when obtained from coupling analysis because of interaction between the primary structure and the equipment. This paper introduces a method using a modal synthesis approach to generate the FRS in a coupled primary-secondary system that can avoid numerical instabilities or inaccuracies. The FRS were generated by considering the dynamic interaction that can occur at the interface between the supporting structure and the equipment. This study performed a numerical example analysis using a typical nuclear structure to investigate the coupling effect when generating the FRS. The study results show that the coupling analysis dominantly reduces the FRS and yields rational results. The modal synthesis approach is very practical to implement because it requires information on only a small number of dynamic characteristics of the primary and the secondary systems such as frequencies, modal participation factors, and mode shape ordinates at the locations where the FRS needs to be generated.

국내 방사능재난대응체계는 일본 후쿠시마 원전 사고와 최근의 국내 대형 재난 교훈 등을 바탕으로 개선돼 오고 있지만, 아직 방사능재난 특성과 후쿠시마 원전 사고 교훈을 완전히 반영하고 있지 못하다. 하나의 방사능재난대응체계에 복수의 국내법이 적용되면서, 실제 상황 시, 대응체계의 실효성을 훼손할 가능성이 있는 법 조항 간 불일치 사항이 존재하기도 한다. 이에 본 논문에서는 방사능재난대응 속성을 분석하고, 방사능재난대응체계 적절성 측면에서「재난 및 안전관리 기본법」과 「원자력시설 등의 방호 및 방사능 방재 대책법」에서 규정한 방사능재난대응체계, 후쿠시마 원전 사고 시 일본측의 방사능 재난 대응 활동을 분석하고, 이 분석결과를 토대로, 대응체계와 조직 측면에서 국내 방사능재난대응체계 실효성을 제고하기 위해 필요한 개선사항을 도출하여 제시하였다.