• Applied Microscopy
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• 제48권4호
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• pp.81-86
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• 2018

The respiratory chain complex forms a supercomplex (SC) in the inner mitochondrial membrane. This complex facilitates the process of electron transfer to produce the proton gradient used to synthesize ATP. Understanding the precise structure of the SC is considered an important challenge. However, it has not yet been reported. The development of a Cryo-electron microscopy (EM) technique provides an effective way to obtain high-resolution micrographs to determine the high-resolution three-dimensional structure of biomolecules. In this brief review, the currently reported Cryo-EM structures of the mammalian respirasome have been described in order to establish a direction for further research in the respiratory system.

• Clinics in Shoulder and Elbow
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• 제18권3호
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• pp.152-158
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• 2015

Background: Acromioclavicular (AC) stability is maintained through a complex combination of soft-tissue restraints that include coracoclavicular (CC), AC ligament and overlying muscles. Among these structures, the role of the CC ligament has continued to be studied because of its importance on shoulder kinematics, especially after AC injury. This study was designed to determine the geometric change of conoid and trapezoid ligaments and resulting stresses on these ligaments according to various scapular motions. Methods: The scapuloclavicular (SC) complex was isolated from a fresh-frozen cadaver by removing all soft tissues except the AC and CC ligaments. The anatomically aligned SC complex was then scanned with a high-resolution computed tomography scanner into 0.6- mm slices. The Finite element model of the SC complex was obtained and used for calculating the stress on different parts of the CC ligaments with simulated movements of the scapula. Results: Average stress on the conoid ligament during anterior tilt, internal rotation, and scapular protraction was higher, whereas the stress on the trapezoid ligament was more prominent during posterior tilt, external rotation, and retraction. Conclusions: We conclude that CC ligament plays an integral role in regulating horizontal SC motion as well as complex motions indicated by increased stress over the ligament with an incremental scapular position change. The conoid ligament is the key structure restraining scapular protraction that might occur in high-grade AC dislocation. Hence in CC ligament reconstructions involving only single bundle, every attempt must be made to reconstruct conoid part of CC ligament as anatomically as possible.

• 대한건축학회논문집:구조계
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• 제34권6호
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• pp.11-18
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• 2018

Isogeometric concept is introduced to find out the optimum layout of plane structure under free vibration. Eigenvalue problem is formulated and numerically solved in order to obtain natural frequencies and mode shapes of plane structures. For the exact geometric expression of the structure, the Non-Uniform Rational B-spline Surface (NURBS) basis functions is employed and it is also used to define the material density functions. A node-wise design variables is adopted to deal with the updating of material density in topology optimization (TO). The definition of modal strain energy is employed to achieve the maximization of fundamental frequency through its minimization. The verification of the proposed TO technique is performed by a series of benchmark test for plane structures.

• 대한건축학회논문집:구조계
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• 제35권3호
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• pp.3-10
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• 2019

On November 15, 2017, an earthquake($M_L5.4$) occurred in Pohang. Pohang earthquake was the second largest earthquake since earthquake was observed in Korea, but structural damage caused by earthquake was biggest. Structural damage caused by Pohang earthquake was mainly caused by schools and pilotis, above all damage to pilotis was outstanding. This is because area where pilotis structures are concentrated is located near epicenter, and seismic performance of pilotis structures is not excellent compared with general structures. In this study, described results of damage investigation and analysis of damage causes through analysis of pilotis Structures on 131 buildings that were investigated immediately after Pohang earthquake. In addition, cause of damage was analyzed through analysis of seismic wave. Investigation site was selected to Jangseong-dong, where damage occurred in large numbers. Damage level was classified into A, B, and C level by measuring residual crack width and story drift of structural members.

• 한국강구조학회 논문집
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• 제21권5호
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• pp.471-481
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• 2009

본 연구는 SSC(Stiffened Steel Plate-Concrete) 구조와 NSC(Non-Stiffened Steel Plate-Concrete) 구조의 압축거동 특성을 비교 분석하여 SSC 구조의 구조적 성능 향상 효과를 파악하는데 그 목적이 있다. 여기서, SSC 구조는 강판에 리브(H형강)을 사용하여 선지지하고 스터드로 점지지하여 콘크리트와 일체화 시킨 구조이다. 한편 NSC 구조는 강판에 스터드로 점지지하여 콘크리트와 일체화 시킨 구조이다. 실험을 통해 다음과 같은 결과를 얻었다. SSC 구조가 NSC 구조에 비해 시험체의 강판좌굴 억제 및 급격한 콘크리트의 취성파괴를 방지하는 것으로 나타났다. 또한 SSC 구조가 NSC 구조에 비해 약 5%~28%정도 최대압축강도가 증가한 것으로 나타났다.

• 한국진공학회지
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• 제22권1호
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• pp.37-44
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• 2013

본 연구에서는 양자점(quantum dot, QD)에서의 전하트랩이 태양전지의 특성에 미치는 영향을 조사하기 위하여, GaAs 모체 태양전지(MSC)의 활성층에 InAs/GaAs QD을 삽입한 $p^+-QD-n/n^+$ 태양전지(QSC)를 제작하여 그 특성을 비교 조사하였다. Stranski-Krastanow (SK)와 준단층(quasi-monolayer, QML)의 2종류 QD를 도입하였으며, 표준 태양광(AM1.5)에서 얻은 전류-전압 곡선으로부터 태양전지의 특성인자(개방전압($V_{OC}$), 단락전류($I_{SC}$), 충만도(FF), 변환효율(CE))를 결정하였다. SK-QSC의 FF값은 80.0%로 MSC의 값(80.3%)과 비슷한 반면, $V_{OC}$와 $J_{SC}$는 각각 0.03 V와 $2.6mA/cm^2$만큼 감소하였다. $V_{OC}$ 및 $J_{SC}$ 감소 결과로 CE는 2.6% 저하되었는데, QD에 의한 전하트랩이 주요 원인으로 지적되었다. 전하트랩을 완화시키기 위한 구조로서 QML-QD 기반 태양전지를 본 연구에서 처음 시도하였으나, 예측과는 달리 부정적 결과를 보였다.

• Smart Structures and Systems
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• 제13권4호
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• pp.501-515
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• 2014

This paper presents a linear computational homogenization framework to evaluate the effective (or generalized) electromechanical coupling coefficient (EMCC) of adaptive structures with piezoelectric structural fiber (PSF) composite elements. The PSF consists of a silicon carbide (SiC) or carbon core fiber as reinforcement to a fragile piezo-ceramic shell. For the micro-scale analysis, a micromechanics model based on the variational asymptotic method for unit cell homogenization (VAMUCH) is used to evaluate the overall electromechanical properties of the PSF composites. At the macro-scale, a finite element (FE) analysis with the commercial FE code ABAQUS is performed to evaluate the effective EMCC for structures with the PSF composite patches. The EMCC is postprocessed from free-vibrations analysis under short-circuit (SC) and open-circuit (OC) electrodes of the patches. This linear two-scale computational framework may be useful for the optimal design of active structure multi-functional composites which can be used for multi-functional applications such as structural health monitoring, power harvest, vibration sensing and control, damping, and shape control through anisotropic actuation.

• 대한건축학회논문집:구조계
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• 제35권7호
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• pp.147-156
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• 2019

The purpose of this study is to consider structural issues and analyze construction sequences when constructing hanging floors supported by Mega truss. Since suspended structures were supported by the Mega truss, vertical load on suspended structures was needed to transfer from low to high. Deflection management of structures was the primary point under construction. The results of this study were as follows; The steel structures, which has relatively lighter self-weight, were constructed upwards after the base floor steel truss erection. Concrete Placing, which has relatively heavier self-weight, were performed in two phases to minimize structure's deflection. Slab was placed downwards from the top floor to lower floor whereas column was places upwards. Deflection measurements were carried out at every construction sequences.

• Wind and Structures
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• 제37권2호
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• pp.133-151
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• 2023

This paper first provides a wide overview about the design codes and standards covering the use of Computational Wind Engineering / Computational Fluid Dynamics (CWE/CFD) for wind-sensitive structures and built environment. Second, the paper sets out the basic assumptions and underlying concepts of the new Annex T "Simulations by Computational Fluid Dynamics (CFD/CWE)" of the revised version "Guide for the assessment of wind actions and effects on structures" issued by the Advisory Committee on Technical Recommendations for Constructions of the Italian National Research Council in February 2019 and drafted by the members of the Special Interest Group on Computational Wind Engineering of the Italian Association for Wind Engineering (ANIV-CWE). The same group is currently advising UNI CT021/SC1 in supporting the drafting of the new Annex K - "Derivation of design parameters from wind tunnel tests and numerical simulations" of the revised Eurocode 1: Actions on structures - Part 1-4: General actions - Wind actions. Finally, the paper outlines the subjects most open to development at the technical and applicative level.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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• pp.193-195
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• 2011

Nowadays, climatic environment change has become a major issue in the world. This causes major emissions of carbon dioxide industries steel industry, thermal power industry, cement industry is essential in the reduction of carbon dioxide, which is based on total carbon dioxide emissions account for most of the construction industry in an effort to minimize the environmental load is needed. accordingly, through case studies, It can be induce the selection to minimize environmental load by comparing the output of quantitative energy consumption and carbon dioxide emissions per constructional methods. As a result of this study, RC Structure was less environmental load than SC structure.