건설현장에서 조적, 미장, 방수, 타일 등 습식공사는 대부분의 작업들이 인력에 의해 공사가 이루어지고 있다. 공사를 위해 다뤄지는 자재들도 인력에 의해 운반 및 시공되 는 경우가 많아 작업자들은 여러 가지 안전사고의 위험에 노출된다. 안전한 작업환경 을 만들기 위해서는 작업공정을 단순화 하고 사용하는 자재와 장비도 경량화하여야 한다. 특히 벽돌과 콘크리트 블록 쌓기와 같은 조적공사시 사용하는 철근콘크리트 인 방보는 중량이 무겁고, 현장에서 제작시 시간도 많이 소요된다. 따라서 이번 연구를 통하여 무거운 콘크리트 인방보 대신 벽돌을 압축재로 사용할 수 있는 합성구조 인방 보 형상을 연구함으로써 가볍고 경제적인 강재인방보 구조형상을 제시하고자 한다.

When we excavate an underground to build basement, the ground anchors are needed to prevent collapse of neighboring ground, subsidence and movement. Ground anchor construction required shore sheet piles, wales and struts as to maintain secure excavation. Existing box-type bracket using head part of ground anchor can not be possibly adjustable to the boring angle because the brackets are manufactured with unified angle in a factory. Also, box-type brackets have imperfection and instability caused by inequable force. In this study, a new bracket system is proposed. The bracket's side plate is reinforced and the angle of boring can be controlled. To investigate the structural performance of presented brackets, FEM analysis has been performed by using ANSYS commercial program. As a result, this bracket shows sufficient stability for all angle case and the strength is increased about 24% than existing bracket.

본 연구에서는 텅스텐합금강의 상부구조와 폴리에틸렌소재로 구성된 하부구조의 인공관절이 하중을 받았을때의 인공관절의 하중분포와 인공관절의 설치를 위한 지지구멍에 가해지는 응력분포에 대하여 유한요소해석을 통하여 결과값을 도출하였으며, 실물을 이용한 다음 실험을 위한 기초자료를 얻을 수 있었다. 이를 통하여 나온 해석결과의 하중분포는 텅스텐합금의 상부구조가 모서리 끝부분부터 하중이 집중되어 크랙이 발생하며 이는 의학계에 보고된 인공관절파손에 의한 조직괴사사례와 그 거동이 일치 하였다.

Estimation approaches for casual relation model with high-order factors have strict restrictions or limits. In the case of ML (Maximum Likelihood), a strong assumption which data must show a normal distribution is required and factors of exponentiation is impossible due to the uncertainty of factors. To overcome this limitation many PLS (Partial Least Squares) approaches are introduced to estimate the structural equation model including high-order factors. However, it is possible to yield biased estimates if there are some differences in the number of measurement variables connected to each latent variable. In addition, any approach does not exist to deal with general cases not having any measurement variable of high-order factors. This study compare several approaches including the repeated measures approach which are used to estimate the casual relation model including high-order factors by using PLS (Partial Least Squares), and suggest the best estimation approach. In other words, the study proposes the best approach through the research on the existing studies related to the casual relation model including high-order factors by using PLS and approach comparison using a virtual model.

The research is a correlational study to look for causes and factors relating to the design of written documents (professional reading materials) and identify those relationships that are useful for communication designers. The research specifically targeted the relationships between perception and reader’s past experiences and appearance of the written documents. A preliminary survey, such as interviews, discussions, questionnaires and brainstorming sessions are conducted to establish the observable attributes related to perception which are reader’s interests, importance of information and written documents complexity. Finally, the research used Structural Equation Model (SEM) to identify significant differences and analyze strong and weak correlations between these attributes. In general, the results of the study shows that the attribute appearances of a written documents with excellent visualizations for information display shows a strong correlation with interests while the attributes importance is weakly correlated with the complexity of the documents.

In automobiles, the main source contributing to the resulting car interior noise is the combustion engine, including gearbox, driveline, intake and exhaust system, wind, tire. Interior noise of a vehicle is usually caused by the vibration of the vehicle’s body transmitted from engine und driveline through the mounting system. The vibration and sound radiation is extremely complex. The final result of interest is in any case the sound pressure in the driver’s ear canals. The transferpath are separated into structure-borne and air-borne path. In oder to estimate the contribution of these components to car interior noise, the total sound pressure in car interior is estimated by using Transferpathanalysis method. In dies paper, experimental simulation has been carried out to analyze transfer characteristics for car interior noise transferred from sound source of the engine and driveline. The results from this study could be applicable for optimal design of noise reduction system in car.

The wheel is an active area of automobile component design and development. The wheel must be durable enough to tolerate significant loads and harsh environment. Temporary tire substituted for spare tire is made in a half band wheel size. Therefore this temporary tire is carried out lightweight and fuel saving of automobile. In this research, structural analysis and fatigue analysis of the temporary steel wheel are carried out using ANSYS 3D-modeling. The model is verified by the equivalent(von-Mises) stress analysis obtained from the ANSYS static structural analysis. Fatigue analysis is performed at the equivalent stress considering the automobile load and moment. Finally, this temporary wheel can be used temporary but not continuously.

This study presents a structural safety analysis method for a plant annunciator panel under the seismic effect. Seismic qualification analysis for the nuclear plant annunciator panel is carried out to confirm the structural integrity and the results are represented by required response spectra. For the numerical analysis, finite element method is adopted. Mode combinations are also used to obtain the reliability of the spectrum analysis. The analysis results shows that the nuclear plant annunciator panel is designed as a dynamically rigid assembly, without any resonance frequency blow 33Hz. The calculated stress of the nuclear plant annunciator panel is much less than yield stress of used steel.

The circular hollow section is usually used for member of main frame to carry the external load in single layer lattice dome. But, the H-shaped section may be used for member of main frame since it is convenient for attaching roof panels. Single layer lattice domes have various buckling characteristics, such as the overall buckling, the member buckling, and nodal buckling. The purpose of this study is to compare buckling characteristics of single-layer lattice domes in which the H-shaped steel section as the existing domestically-produced structural steel is used as main frames to those of domes in which a circular hollow section is used as main frames.

Accumulation of more than 20,000,000 vehicles since the establishment of the quality of life and economic development needs several parking lots and cause crack problem in Korea. Related structures in large cities due to the lack of parking garage attached to secure underground parking structures are actively being built, and the basement parking lot will continue to increase more stories and the trend is expected to be larger. But so far, construction of the underground parking structure is related to a number of problems, including cracks in the structure. Therefore, in this study, repair, reinforcement and a few non-economic losses in the current design criteria are presented. The review of the structure used to current design criteria is to minimize crack and maximize usability.

The seismic damage of non-structural components, such as communication facilities, causes direct economic losses as well as indirect losses which result from social chaos occurring with downtime of communication and financial management network systems. The current Korean seismic code, KBC2009, prescribes the design criteria and requirements of non-structural components based on their elastic response. However, it is difficult for KBC to reflect the dynamic characteristics of structures where non-structural components exist. In this study, both linear and nonlinear time history analyses of structures with various analysis parameters were carried out and floor acceleration spectra obtained from analyses were compared with both ground acceleration spectra used for input records of the analyses and the design floor acceleration spectrum proposed by National Radio Research Agency. Also, this study investigates to find out the influence of structural dynamic characteristics on the floor acceleration spectra. The analysis results show that the acceleration amplification is observed due to the resonance phenomenon and such amplification increases with the increase of building heights and with the decrease of structure’s energy dissipation capacities.

Recently, most of moving parts at automobile engine are required to be lighter and compacter and have high performances such as strength and endurance, etc. In particular, the crankshaft is subject to complex loadings such as shear, bending, and torsional loads as well as inertia and torsional vibration. To investigate critical area and optimize the shape of crankshaft at intial design stage, it is necessary to consider the dynamic effect of crankshaft. This paper carried out structural analysis of engine crankshaft by using multi-body dynamics and multi-axial fatigue analysis

최근 환경오염 문제에 대한 심각성이 대두되며 전 세계적으로 환경부하 저감을 위해 다양한 노력을 쏟고 있다. 특히 환경 저해 산업의 하나인 건설분야에서는 CO2배출량과 에너지 소비량을 줄이기 위해 활발한 연구를 진행해 왔다. 그러나 건설분야의 기존 연구들은 대부분 CO2배출량이 가장 큰 사용 및 유지관리 단계에만 집중하고 있으며, 설계단계에 대한 연구는 2D의 철근콘크리트 부재 및 구조물에 대해서만 실행되었을 정도로 초기단계이다. 사실, LCA적 관점에서 친환경적 건설산업을 이루기 위해서는 건물의 초기설계 단계에서부터 CO2배출량을 저감시키기 위한 방향으로 설계를 유도할 수 있어야 하며, 구조 엔지니어로서 환경성을 고려한 설계안을 제시할 수 있어야 한다. 그러므로 본 연구에서는 매입형 합성기둥(SRC)을 대상으로 CO2최적화 기법을 제시하였으며, 이를 통해 얻은 여러 설계단면을 이용하여 SRC기둥의 CO2배출량에 영향을 미치는 3가지 요소(① 강재 크기, ② 콘크리트 압축강도, ③ 작용 하중 크기)에 대한 영향관계를 분석하였다.

In animals, structural coloration is the production of color by microscopically structured surfaces of many birds as well as many butterfly wings and beetles wing cases. This structural coloration is caused by interference effects rather than by pigments. It has been known that the colors are produced when a material is scored with fine parallel lines, formed of one or more parallel thin layers, or otherwise composed of microstructures on the scale of the colour’s wavelength. Current research is performed using light and scanning electron microscopes to examine the fine structural characteristics of scales in the three species of iridescent butterflies Papilio maackii, Charaxes tiridates and Anaea glaucone. It has been revealed that the structural coloration of these butterflies is responsible for the blues and greens of the scales of wings. In addition, the reflected color depends on the viewing angle, which in turn controls the apparent spacing of the structures responsible for specific color patterns of the wing scales.

Insects possess two distinct acetylcholinesterases (AChE1 vs. AChE2), which are encoded by two paralogous loci originated from duplication. Kinetic analyses of several insect AChEs revealed that both AChE1 and AChE2 retain common catalytic properties of AChE but subtle kinetic differences also exist between these two AChEs. To understand how selection pressure has shaped the protein structure of AChEs and affected their function during evolution, we measured and compared the nucleotide diversity (Pi) and amino acid site-specific selection pressure between AChE1 and AChE2 from various insects. Highly conserved were the majority of the amino acid residues involved in forming the essential domains, including peripheral anionic site (PAS), and little differences were revealed between AChE1 and AChE2, suggesting the presence of strong purifying selection pressure over these essential residues. Interestingly, the EF-hand like motif was mostly found in the AChE1 lineage but not in AChE2. In addition, a unique amino acid difference in the PAS (D72 vs. Y72) was highly conserved between AChE1 and AChE2. Three-dimensional modeling of insect AChEs by particularly focusing on the PAS revealed that a subtle but consistent structural alteration in the active site topology was caused by the PAS amino acid substitution. Taken together, despite the long evolutionary history and low overall sequence similarity, both insect AChE1 and AChE2 still share a extremely high degree of structural and functional conservation, indicative of a strong purifying selection pressure. Nevertheless, only a small change in the PAS, appears to be associated with a local but significant alteration of AChE2 structure, which in turn drives the functional differentiation of AChE.

Silk fibroin (SF) and silk sericin (SS) have been studied as a biomaterial due their useful properties including good blood compatibility and good cell activities. However, previous studies, silkworm variety has not been considered although it can affect structure and properties of silk fibroin and sericin. Therefore, in the present study, structure and properties of silk fibroins and sericins obtained from different silkworm variety were examined. Most of regenerated SF solutions from different silkworm varieties displayed Newtonian fluid behaviors and their viscosities were different depending on the silkworm variety. N74 showed the highest viscosity among the SF samples. Molecular weight (MW) distribution and mechanical properties of regenerated SF showed similar result to viscosity result. SS did not show significant difference in MW distribution and viscosity result depending on the silkworm variety.

In this study, silk sericin solutions and films were prepared with different solvents: formic acid and water. Also, silk sericin film from aqueous solution was prepared at different casting temperature. Regardless of solvent type, silk sericin solutions showed a shear thinning implying highly molecular entangled state of silk sericin. Silk sericin aqueous solution showed a higher turbidity than that of formic acid solution. Silk sericin aqueous solution showed shorter gelation time than formic acid. FTIR results showed β-sheet crystallization of silk sericin was affected by casting solvent and temperature. Silk sericin film from aqueous solution showed more β-sheet conformation as the casting temperature was decreased. Silk sericin film from formic acid showed higher crystallinity index than silk sericin films cast from aqueous solution. XRD diffraction measurement showed similar results to those of FTIR. In case of mechanical properties, tensile strength of sericin film from formic acid was higher than sericin films from aqueous solution.

본 논문에서는 건물의 횡방향 구조반응을 평가하기 위한 변형률 기반의 모니터링 기법이 제시되고, 이에 대한 기초 연구로써, 구조해석을 통해 제안된 기법을 검증한다. 광섬유 격자 센서(fiber Bragg grating, FBG)는 일반 변형률 센서와 비교하여 내구성이 뛰어날 뿐 아니라 높은 샘플링 수와 여러 지점을 동시에 계측할 수 있는 장점이 있다. 이러한 특성 때문에 FBG 센서는 구조 모니터링을 위해 많은 센서가 요구되는 건물의 모니터링에 적합하다. 본 연구에서 FBG 센서는 수직 부재의 변형률을 계측하며, 이는 해당 부재의 곡률을 평가한다. 이러한 곡률은 횡변위와 횡가속도를 평가하는데 사용된다. 추가적으로 횡방향 가속도는 frequency domain decomposition(FDD) 기법을 이용하여 구조물의 고유진동수와 모드형상을 추정하는데 사용된다. 9층 철골모멘트 골조 예제의 적용을 통해, 제시된 기법이 건물의 다양한 횡방향 구조 반응과 동적 특성을 평가하는데 적절함을 확인하였다.

광역방제기의 송풍팬은 방제성능을 좌우하는 핵심 부품으로서 구조적으로 안전성이 확보되어야 한다. 따라서, 대풍량 축류식 송풍기의 알루미늄 축류팬의 안전한 운용을 위해, 축류팬 블레이드에 대해 3차원 전산유동해석과 구조상호해석을 실행하여 축류팬의 요구수명을 만족할 수 있는 개선된 축류팬을 제시하고자 하였다. 이에 제1 보에서는 유동해석과 구조해석을 통하여 기존의 일체형 모델의 안전성을 검토하였는데, 그 결과 축류팬의 기계적 강도가 다소 미흡하여 무한수명을 보장할 수 없음이 판단되어 개선 설계가 절실히 요구되었다. 제2 보의 개선된 설계에서는 축류팬의 각 블레이드를 허브에 조립하여 응력을 분산시킴으로써 등가응력 수준을 반감시킬 수 있었다. 개선모델의 경우 유동저항에 의한 압력분포와 원심력으로부터 예측된 최대 등가응력(74.21MPa)이 소재 항복강도의 1/2 이하로 저감되었고, 내구수명해석을 통해 알루미늄 합금 소재의 무한 피로한도를 보장할 수 있을 것으로 예상되었다. 또한 제1 모드 고유 진동수가 105.62 Hz로서 공진현상은 발생하지 않을 것으로 예상되어 안전한 설계임을 확인할 수 있었다.