The rotary type dust remover is a device in which the rake assembly filters and processes clumps in the water while rotating and repeating movements along the track. It is installed in the pump suction part of the drainage pump station and the rainwater pump station to protect the pump to ensure smooth drainage. Since the rake assembly plays a key role in filtering out complications while passing through the water, stainless steel is applied to all components constituting it, and damage or failure due to deformation causes a crisis in case of heavy rain. This is because the existing rake assembly is excellent in rigidity, but all components are assembled by welding, which takes a lot of time for repair and replacement. In this study, shape design for rakes and assemblies of the rotary type dust remover, structural analysis to secure reliability, and demonstration tests were conducted through prototype production. Through this, it is intended to help prevent the stiffness of the joint of the rotary type dust remover from deteriorating, reduce time and cost, and efficient operation.

By developing molds and facilities to horizontally mold the functional part of the dry-cast concrete block, We intend to develop molds and a series of facilities to horizontally mold the functional part of the dry-cast concrete block to increase production per cycle while maintaining existing production methods and major facilities. In order to do so, CAE analysis is first required to develop molds and facilities for horizontally molding the functional part of the drycast concrete block in the horizontal direction. The procedure will be carried out by reviewing the validity of boundary conditions and physical properties, 3D modeling, grid generation, construction of analysis models, model validity, analysis according to frequency changes, and analysis according to physical properties. First, through the comparison of two-point support, three-point support, and two-point and three-point support in the constraint conditions, We would like to compare it with the actual molded product in the horizontal direction.

By developing molds and facilities to horizontally mold the functional part of the dry-cast concrete block, We intend to develop molds and a series of facilities to horizontally mold the functional part of the dry-cast concrete block to increase production per cycle while maintaining existing production methods and major facilities. In order to do so, CAE analysis is first required to develop molds and facilities for horizontally molding the functional part of the drycast concrete block in the horizontal direction. The procedure will be carried out by reviewing the validity of boundary conditions and physical properties, 3D modeling, grid generation, construction of analysis models, model validity, analysis according to frequency changes, and analysis according to physical properties. First, through the comparison of two-point support, three-point support, and two-point and three-point support in the constraint conditions, We would like to compare it with the actual molded product in the horizontal direction. But first of all, it is considered three-point support in the constraint conditions in this paper.

In this study, when manufacturing a rectangular plate with a pinhole, the following conclusions were obtained as a result of analyzing the shape characteristics of the unit cell that fills the interior of the plate and the effect of changes in the size of the pinhole on the stress concentration coefficient. 1. The stress value generated in the case of the completely empty model was 13.9 MPa, which is an 18.8% increase in stress compared to the stress value 11.7 MPa generated in the fully filled model. However, since the weight of the empty model is 43.6% lower than that of the filled model, it is believed to be very advantageous in terms of cost. 2. The stress concentration coefficient value is lowest for the solid model and highest for the hollow model at the same d/H value. In other words, you can see that the values are changing within the boxes of the solid model and hollow model. However, the grid matching model is closest to the solid model and the filling rate is as low as 33.4-9.1%, showing the most stable strength when filling empty space.

This study analyzes the aerodynamic and structural characteristics of an H-Darrieus vertical-axis wind turbine (VAWT) under varying inlet velocities using transient analysis. The k-ε turbulence model and six-DOF were applied to simulate urban environments in the flow analysis, while the structural analysis considered blade momentum of inertia and RPM conditions. The numerical results showed that the drag and lift forces increased by 60% and 53% respectively from the nominal wind speed to the cut-off wind speed conditions. Structural analysis indicated that the maximum Von-Mises stress in the blade did not exceed the yield strength of 69 MPa of PC-ABS, ensuring structural stability. However, the connecting rod exceeded the yield strength of SPCC 270 MPa, suggesting potential failure due to repeated rotational loads. This study confirms that materials with a yield strength of more than 1,100 MPa required for connecting rods to ensure reliable operation at high wind speed. These findings provide important insights for the design of robust VAWTs suitable for extreme environments.

국제경영 환경에서 지속 가능한 발전 목표가 널리 수용됨에 따라, 기업의 ESG(환경/Environment, 사회/Social, 거버넌스/Governance) 성과는 글로벌 시장에서 다국적기업의 성공을 결정하는 핵심 지표 중 하나로 자리 잡고 있다. 본 연구는 제도이론에 근거하여 신흥시장 다국적기업의 ESG 성과가 국제화 속도에 어떻게 영향을 미치는가 를 탐구하였다. 이와 더불어 본 연구는 ESG 성과와 국제화 속도 간 관계에 대해 최고경영자의 해외 경험과 기업 의 소유구조, 즉 국유기업 여부가 어떠한 조절 효과를 미치는지에 대해서 검증하였다. 2010년부터 2022년까지 중국 A주 시장에 상장된 1,648개 기업의 8,329개 표본을 분석한 결과, 신흥시장 다국적기업의 ESG 성과는 국 제화 속도에 긍정적인 영향을 미치는 것으로 나타났다. 조절 효과의 분석 결과, 다국적기업 최고경영자의 해외 경 험은 이러한 관계를 약화시키는 것으로 나타났는데, 이는 높은 해외 경험을 가진 최고경영자의 경우, 국제화 속도 를 결정하는 데 있어 ESG 성과에 대한 의존도를 줄이는 한편, 보다 신중한 국제화 전략을 취하기 때문으로 해석 할 수 있다. 또한 신흥시장 다국적기업이 국유기업일 경우에, 민간기업에 비해 ESG 성과와 국제화 속도 간의 긍정 적인 관계가 약화되는 것으로 나타났는데, 이는 국유기업이 ESG 성과를 통해 빠른 국제화 속도를 추진할 때 정당 성 확보의 어려움에 직면할 수 있음을 시사한다. 본 연구의 결과는 다국적기업의 ESG 전략 및 성과가 글로벌 시장 에서 정당성을 강화하고 국제화 전략의 중요한 요인이 될 수 있음을 강조하는 동시에, 그 효과가 최고경영자의 특 성과 기업의 소유구조에 따라 달라질 수 있음을 보여준다. 이러한 결과는 신흥시장 다국적기업이 ESG 전략을 효 과적으로 활용하기 위해서는 경영진의 리더십과 소유구조를 함께 고려한 종합적인 접근이 필요함을 시사한다.

In this paper, the design feasibility of the high-temperature rotation test jig for the operating state of gas turbine blades was confirmed through thermal structural analysis and modal analysis. The structural analysis model was composed of assembled blade, disc, cover, and shaft. Here, the disc was designed to be assembled with two types of blade. First, thermal analysis was performed by applying the blade surface temperature of 800°C. Next, structural analysis was performed at 3600 RPM, the normal operating condition, and 4320 RPM, the overspeed operation condition. Lastly, modal analysis was performed to examine the natural frequency and deformation of the jig. The FE analysis showed that the temperature decreased from the blade to disc dovetail. Additionally, both the blade and disc showed structural stability as the maximum stress was below the yield strength. Also, the first natural frequency was 636.35Hz and 639.43Hz at 3600RPM and 4320RPM, respectively, satisfying gas turbine design standards and guidelines. Ultimately, the designed test jig was confirmed to be capable of high temperature and rotation testing of various blades.

Proper Orthogonal Decomposition (POD) is applied to analyze the coherent structure of three-dimensional cylinder wake flow. The flow field data, such as velocity and pressure as functions of time, was obtained by the incompressible CFD analysis. The resulting CFD data was then used to determine eigenvalues, POD modes, and time coefficients through POD process. The flow field was approximately reconstructed using some of lower POD modes. The three-dimensional field reconstructed using the low-order model was found to be in good agreement with the original. This verifies that low-dimensional modeling of complex flow fields is fully possible.

본 연구는 강릉 소나무 친환경벌채지 산림식생(벌채지, 산림영향권, 군상잔존구, 수림대, 대조구)을 대상으로 산림군집구조를 구명하고 조림학적 갱신 정보를 제공하고자 수행되었다. 2020년 7월 75개소의 방형구를 Braun-Blanquet 방법으로 식생조사를 실시한 후 중요치, 종다양도, 군락유사도, DCA를 분석하였다. 그 결과, 벌채지와 산림영향권에서 큰기름새의 중요치가 높은 것으로 나타났다. 종다양도는 대조구가 1.733로 가장 높게 나타났고, 벌채지가 1.237로 가장 낮게 나타났다. 군락유사도는 벌채지와 산림영향권이 0.706로 가장 높게 나타났고, 벌채지와 대조구가 0.452로 가장 낮게 나타났으며, Sørensen의 유사계수와 더불어 조사위치별 거리를 정량적으로 확인해 보고자 DCA분석을 실시한 결과 군락유사도와 유사한 결과를 나타내었다. 본 연구는 단기적인 연구결과이므로 추후 장기적인 모니터링을 통해 변화되는 친환경벌채지 산림식생에 대한 지속적인 식생 정보의 축적을 통해, 산림영향권이 포함된 친환경벌채지 산림식생의 회복과정에 대한 연구가 필요할 것으로 판단된다.

국화도는 화성시 동쪽에 위치한 섬으로 지질학적으로는 경기육괴의 서부 가장자리에 속하나 최근 한반도 지체구 조구의 재정립에 따라 홍성-임진강대에 포함된다. 최근 보고된 국화도 일원의 분포 암석들에 대한 지질구조 및 연대측정 결과를 기초로 분포 암석 및 변형구조의 특성을 논의하고 학술적으로 가치 있는 다양한 지질유산을 보고하고자 한다. 국화도의 암상은 석영, 방해석, 장석으로 구성된 밝은색의 저변성 변성사질암과 규암, 각섬석-흑운모-사장석-티타나이트로 구성된 어두운색의 각섬암과 변성니질암, 그리고 석회질 편암 혹은 석회질 규산염암과 같이 3개 단위층으로 구분된다. 이들 암체는 후기 트라이아스기의 섬장암에 의해 관입되었다. 단위층들의 경계는 뚜렷한 호층구조와 함께 엽리 방향에 평행하며 습곡작용에 의하여 반복되어 산출한다. 저변성 변성사질암에는 사층리, 점이층리, 대칭연흔이 관찰되어 이 지역 의 퇴적환경이 조간대 혹은 호수환경을 지시한다. 단위층들의 퇴적시기(후기 데본기-전기 펜실베이니아아기)와 섬장암의 U-Pb 저어콘 연령(232 Ma)으로부터 국화도에 일원에 발생한 최소 2회의 강한 습곡작용의 시기는 펜실베이니아아기-후 기 트라이아스기로 판단된다. 국화도 대부분의 노두에서는 등사(isoclinal) 및 밀착(tight) 습곡이 횡와 내지 수직습곡의 형태로 관찰되며 이들 습곡의 날개부에는 전단에 의한 비대칭 습곡과 부딘구조가 발달한다. 또한 이들 단위층과 습곡구 조를 절단하는 충상단층도 발달한다. 따라서 국화도는 한반도 중서부지역의 변성 및 변형작용의 특징이 잘 보존된 지질 유산이 풍부한 지역으로 학술적 가치와 함께 학생과 교사들의 지질학습장으로 활용성도 뛰어난 명소이다.

As global greenhouse gas reduction regulations are strengthened and the demand for eco-friendly energy increases, renewable energies, including offshore wind power, are growing rapidly. Unlike onshore wind power generation, offshore wind power is located in the ocean. As a result, the offshore wind power substructure is exposed to low temperatures, corrosion, and continuous fatigue loads. Therefore, selecting appropriate materials and welding techniques is crucial for durability. In this study, FCAW welding was performed on S355ML steel (EN10025) for offshore wind power applications. After the welding process, the mechanical properties of the welded joint were evaluated through tensile, low-temperature impact, and hardness tests to assess the welding condition. The study revealed that the tensile and yield strength of the welded joint were superior to those of the base material. Additionally, the impact strength at low temperatures was confirmed to exceed the standard.

본 연구는 지리산국립공원 내 설산습지의 식물상 및 식생 구조를 조사한 것으로, 향후 변화 추적을 위한 기초자료를 제공하고, 나아가 관리 및 보존 방안을 제안하고자 수행되었다. 관속식물 조사 결과, 68과 138속 170종, 3아종, 20변종, 4품종으로 총 197분류군이 확인되었다. 주요 종으로는 특산식물인 키버들과 매미꽃 등 6종, 희귀식물인 물들메나무 등 3종, 그리고 식물구계학적 특정식물 5등급에 해당하는 문수조릿대 등이 포함되었다. 습지선호도에 따른 분류 결과, 전체 197종 중 습지식물은 28종(14.2%)으로 확인되었다. 목본층에서는 버드나무가 우점하였으나 초본층은 수위에 따라 식생 구성이 달랐다. 수위가 지표면보다 높은 영역에서는 절대습지식물과 임의습지식물이, 수위가 지표면과 일치 하는 영역에서는 임의습지식물과 양생식물이, 수위가 지표면 아래인 영역에서는 절대육상식물의 세력이 우세하였다. 석축의 상태와 지표수 유입량은 습지의 현재 상태 유지를 결정하는 핵심 변수로 작용하였다. 따라서 방치된 계단식 논 습지의 보전을 위해서는 석축, 수로, 지형 등 물리적 환경과 동식물에 대한 지속적인 모니터링 결과를 기반으로 한 체계적인 관리가 필수적인 것으로 판단되었다.

This study attempted to examine the relationship between traditional architecture and its corresponding modern architecture by using the dynamic characteristics of text linguistics. The study assumed that past and present buildings, which maintain some kind of relationship, were a single text, and explored its internal structure that generated continuous textuality. As a case study, the buildings by Wang Shu and Kuma Kengo was reinterpreted using the techniques of cohesive structure to analyze their continuity with each tradition. The results showed that both architects used a variety of strategies to inherit tradition, but there were also differences in applying expressive and semantic aspects. Wang Shu attempted a modern reinterpretation of its architectural expressions at various levels, while Kuma actively borrowed traditional materials, structures, and patterns allowing various alteration in their meanings. We found that some concepts of text linguistics could be applicable as a meaningful perspective for analyzing and evaluating modern architecture that inherits tradition. We hope that our approach will develop into a comprehensive methodology for architectural analysis through more diverse attempts in the future.

According to literature, Chengdu was built in the ancient Shu period, and Chengdu experienced nearly 3,000 years of history in this region. After the city was founded in the Qin Dynasty, there were never any natural disasters such as floods in Chengdu for more than 2,000 years. Although there were no natural disasters, due to its central location in the southwest of China, wars were frequent. Thus, how to effectively suppress the rebellion in the southwest and how to rebuild the city after the wars became the top attention of the governments of Chengdu in the successive dynasties. At the beginning of the Qing Dynasty, the government followed the Yuan and Ming systems, and the layout and architectural style of the city was similar to the previous dynasties. With the gradual recovery of the economy, Chengdu became a military center in southwest China and a military base was built in the city. Since then, Chengdu has gradually broken the original city style. Therefore, in this study, through archeological and literature sources, we analyzed the spatial structural evolution of Chengdu city in the historical background, focusing on the urban space and major building structures of Chengdu during the Qing Dynasty, which was relatively rich in information.

본 연구는 강원 평창군에 위치한 발왕산 산림유전자원보호구역의 관속식물상 및 식생구조를 파악하기 위하여 2023 년 3월부터 9월까지 총 5차례에 걸쳐 현지조사를 수행한 후, 67개소의 식생 자료를 대상으로 이원지표종분석법 (TWINSPAN) 을 통하여 산림식생 유형을 구분하고 평균상대중요치, 종다양성, CCA를 통해 그 생태적 특성을 분석하 였다. 발왕산 산림유전자원보호구역의 관속식물상은 81과 186속 283종 7아종 28변종 2품종으로 총 320분류군이 확인 되었다. 특산식물은 숲개별꽃, 진범 등 총 13분류군, 희귀식물은 가시오갈피 (EN) , 바늘까치밥나무 (VU) 등 총 5분류군 이 확인되었다. 식물구계학적 특정식물종은 총 118분류군이 조사되었으며, 귀화식물은 하수오, 미국가막사리 등 총 11분류군으로 귀화율은 3.4%로 나타났다. 식생유형은 복장나무-난티나무군락, 분비나무-사스래나무군락, 전나무-단풍 취군락, 소나무군락, 신갈나무전형군락 등 총 5개의 유형으로 구분되었다. 종다양도는 2.222로 VT2가 다른 식생단위에 비하여 상대적으로 높게 나타났으며, 풍부도, 균재도에서도 가장 높은 것으로 나타났다. CCA 분석 결과, 식생의 분포에 영향을 미치는 환경요인으로 해발고도, 종다양도, 암석노출도와 관계가 있는 것으로 나타났다. 보호구역 내 공간분포 특성을 파악하기 위하여 현존상관식생도를 작성한 결과, 신갈나무군락, 복장나무-난티나무군락, 신갈나무-피나무군락, 물푸레나무-층층나무군락, 아고산침활혼효림, 소나무-신갈나무군락, 소나무군락, 전나무군락 등 총 8개의 군락으로 구분되었다.

이 연구는 다목적 선박(MPV)의 공기역학적 구조물 설계, 분석 및 향상을 통해 그린 워터 압력에 의한 구조적 안전을 보장하고, 탈탄소화 및 에너지 효율성에 이바지하는 방법을 기술하였다. 유한 요소 분석(FEA)을 통한 초기 평가에서 좌굴 발생에 대한 잠재적인 취약점 이 있음을 확인하였다. 이러한 문제를 해결하기 위해 보강재(Carling stiffener)와 두께 증가를 통하여 응력을 재분배하고 국부적인 좌굴 발생의 위험을 최소화하였다. 보강 후 분석 결과, 한국선급(KR)의 안전 기준인 항복 강도, 미국 선급(ABS) 좌굴 강도 및 노르웨이 표준(NORSOK) 변 위 기준을 모두 충족하는 것이 확인되었다. 결과적으로 고유치 좌굴 해석 결과가 안전 기준을 초과하고 최대 변위가 허용 한계 내에 있는 등 중요한 개선이 이루어졌다. 이러한 개선은 극한의 해양 조건에서 운영 신뢰성을 보장할 수 있다. 이 연구는 공기역학적 항력 감소와 구조적 안전성의 이중적인 이점을 강조하며, 국제 해사 기구(IMO)의 2050 탈탄소화 목표에 부합하는 연료 효율성 및 온실가스 배출 감소에 이바지할 수 있다. 연구 결과는 다양한 선박 유형에 걸쳐 항력 감소 기술을 확장하기 위한 기초 자료를 제공하며, 지속 가능하고 탄력적인 해양 운영을 위한 대안을 제시하였다. 향후 연구는 구조적 안전 평가를 가속할 수 있는 단순화된 모델링 기술 개발에 집중할 것이다.

To analyze the effect of fire in electric-vehicle battery on concrete cement structure. A scenario evaluation was conducted for fire occurrence due to external influences on lithium battery cells used in electric vehicles. Visual inspection was conducted at each stage of the battery fire, and the fire duration and temperature were measured. The battery temperature rise curve and temperature during fire have been examined previously. The stability of a cement structure was evaluated via X-ray diffraction and SEM analyses of the reaction-product changes with respect to temperature. The battery temperature rise curve shows that the battery begins to change at 200 °C–300 °C. However, the general stage of battery damage cannot be readily confirmed from the literature. The current experiment and literature review indicate that battery fire can cause the fire temperature to increase beyond 1000 °C within a few seconds. The reaction product changes structurally in cement from 300 °C or higher. Many voids are generated owing to the decomposition of Ca(OH)2 and C-S-H gel. The temperature of an electric-vehicle fire increases rapidly to 1000 °C or higher within a few seconds. High temperatures change the reaction products in cement structures, thus creating internal voids and cracks and reducing the stability of the structure; therefore, the appropriate countermeasures must be identified.

Piloti-type buildings are widely constructed in urban areas of South Korea. Due to stiffness irregularities, piloti-type buildings are vulnerable to lateral loads such as earthquakes. Although seismic retrofitting is necessary for piloti-type buildings, many of these structures are privately owned, and the extensive number of buildings creates significant challenges in terms of cost and time for regional seismic performance evaluation. This study proposes a methodology for determining the seismic performance of multiple piloti-type buildings within a region by utilizing structural parameters. Information on piloti-type buildings is classified into public building data and exterior building data, which are integrated to define structural parameters for estimating the first natural period of the buildings. Linear regression analysis was performed to develop a regression equation correlating structural parameters with the natural period. Additionally, the natural period and structural parameters are used to perform another linear regression analysis to estimate the yield and ultimate points of the capacity curve. The capacity curves derived from the regression equations facilitate seismic performance evaluation based on structural parameters.

The primary purpose of this study is to develop system modules of school buildings and the seismic loss function of the system modules for regional loss assessment of school buildings. System modules of school buildings were developed through statistical analysis of school facilities in Korea. The structural system of school buildings with non-seismic details is defined as reinforced concrete with partially masonry walls (RCPM), and 27 system modules of RCPM were developed considering the number of stories, spans, and the age of the building. System modules were designed to assess the structural behavior by applying the shear spring model and the shear failure of the columns of the school building. Probabilistic seismic demand models for each component of system modules were derived through nonlinear dynamic analysis to determine the relationship between seismic intensity, drift ratio, and peak floor acceleration of system modules. The seismic loss function was defined as the total damage ratio, which is the ratio of replacement cost to repair cost to evaluate the seismic loss quantitatively. The system module-based seismic loss well predicted the observed data. It will be possible to help many stakeholders make risk-informed decisions for a region through the regional loss assessment of school buildings in Korea.

In this study, a layout was designed to adjust the location of the LPG fuel tank by combining a Z-Spring and an Airbag in an LPG 1-ton truck air suspension assembly, and a structural analysis based on the finite element method was performed considering the load conditions of extreme situations based on the weight taken into account. The study was performed under a total load condition of 2.1 tons per axle with a safety factor of 2, and it was confirmed that the maximum stress value occurring in each part is within the yield strength value of the material. Through these results, it was confirmed that the designed LPG 1-ton truck air suspension assembly is a system with secured structural stability.