• Asian-Australasian Journal of Animal Sciences
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• v.15 no.3
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• pp.421-426
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• 2002

The pyruvate dehydrogenase complex (PDC), a member of $\alpha$-keto acid dehydrogenase complex, catalyzes the oxidative decarboxylation of pyruvate with the formation of $CO_2$, acetyl-CoA, NADH, and $H^+$. This complex contains multiple copies of three catalytic components including pyruvate dehydrogenase (E1), dihydrolipoamide acetyltransferase (E2), and dihydrolipoamide dehydrogenase (E3). Two regulatory components (E1-kinase and phospho-E1 phosphatase) and functionally less-understood protein (protein X, E3BP) are also involved in the formation of the complex. In this study, we have partially cloned the gene for E3BP in human. Nine putative clones were isolated by human genomic library screening with 1.35 kb fragment of E3BP cDNA as a probe. For investigation of cloned genes, Southern blot analysis and the construction of the restriction map were performed. One of the isolated clones, E3BP741, has a 3 kb-SacI fragment, which contains 200 bp region matched with E3BP cDNA sequences. The matched DNA sequence encodes the carboxyl-terminal portion of lipoyl-bearing domain and hinge region of human E3BP. Differences between yeast E3BP and mammalian E3BP coupled with the remarkable similarity between mammalian E2 and mammalian E3BP were confirmed from the comparison of the nucleotide sequence and the deduced amino acid sequence in the cloned E3BP. Cloning of human E3BP gene and analysis of the gene structure will facilitate the understanding of the role(s) of E3BP in mammalian PDC.

• Wind and Structures
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• v.25 no.1
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• pp.79-100
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• 2017

The use of wind energy resources is developing rapidly in recent decades. There is an increasing number of wind farms in high wind-velocity areas such as the Pacific Rim regions. Wind turbine towers are vulnerable to tropical cyclones and tower failures have been reported in an increasing number in these regions. Existing post-disaster failure case studies were mostly performed through forensic investigations and there are few numerical studies that address the collapse mode simulation of wind turbine towers under strong wind loads. In this paper, the wind-induced failure analysis of a conventional 65 m hub high 1.5-MW wind turbine was carried out by means of nonlinear response time-history analyses in a detailed finite element model of the structure. The wind loading was generated based on the wind field parameters adapted from the cyclone boundary layer flow. The analysis results indicate that this particular tower fails due to the formation of a full-section plastic hinge at locations that are consistent with those reported from field investigations, which suggests the validity of the proposed numerical analysis in the assessment of the performance of wind-farms under cyclonic winds. Furthermore, the numerical simulation allows to distinguish different failure stages before the dynamic collapse occurs in the proposed wind turbine tower, opening the door to future research on the control of these intermediate collapse phases.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.1
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• pp.132-138
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• 2011

A micromachined silicon accelerometer capable of surviving and detecting very high accelerations(up to 200,000 times the gravitational acceleration) is necessary for a high impact accelerometer for earth-penetration weapons applications. We adopted as a reference model a piezoresistive type silicon micromachined high-shock accelerometer with a bonded hinge structure and performed structural analyses such as stress, modal, and transient dynamic responses and sensor sensitivity simulation for the selected device using piezoresistive-structural coupled-field analysis. In addition, structural optimization was introduced to improve the performances of the accelerometer against the initial design of the reference model. The design objective here was to maximize the sensor sensitivity subject to a set of design constraints on the impact endurance of the structure, dynamic characteristics, the fundamental frequency and the transverse sensitivities by changing the dimensions of the width, sensing beams, and hinges which have significant effects on the performances. Through the optimization, we could increase the sensor sensitivity by more than 70% from the initial value of $0.267{\mu}V/G$ satisfying all the imposed design constraints. The suggested simulation and optimization have been proved very successful to design high impact microaccelerometers and therefore can be easily applied to develop and improve other piezoresistive type sensors and actuators.

• Knowledge Management Research
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• v.10 no.3
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• pp.51-80
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• 2009

The purpose of this study is to empirically analyze the impact that occurs when Korean organizations make practical use of various information technology tools and systems in the knowledge management process, such as sharing, learning and creating knowledge. Such a process is usually made through online and offline knowledge management activities. This paper also verifies how the externalization of tacit knowledge, and the internalization of explicit knowledge via the Internet and offline socialization activities have altered the mechanisms of knowledge transfers inside organizations. For the research, a survey was conducted on the satisfaction and usability levels of information technology, and the impact of IT usage on the results of knowledge management activities and knowledge transfers. 622 Korean organizations were surveyed, including major listed firms and public organizations. The results were examined as an online/offline integration process using SECI's Model proposed by Nonaka (1994, 1995). The analysis shows that information technology satisfaction and the usage of information technology help accelerate the pace of the knowledge flow and amplify the volume of the knowledge transfer by boosting the externalization and internalization processes-also known as knowledge management activities. However. there is no distinct correlation between information technology and socialization, an offline knowledge transferal activity. In particular, the quality of knowledge-an end result of knowledge transfer-does not improve merely by the externalization of online knowledge and instead requires the internalization of knowledge processes. Above all, the research reveals that offline socialization processes vastly contribute to the improvement of knowledge quality. This paper suggests that in order to ensure a transfer of quality knowledge, an organization or a company should focus on the use of information technology rather than the satisfaction level of information technology, and that knowledge transfers via the Internet has limitations in creating high quality of knowledge. For an organization to ensure the transfer of high-quality knowledge, the organization should not entirely hinge the transfer of knowledge online, as it is essential to have an offline method-a form of socialization such as a 'community of practice.'

• Journal of Korean Society of Steel Construction
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• v.12 no.1 s.44
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• pp.55-63
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• 2000

This paper is a study on the behavior of Concrete-Filled Square Tubular(CFST) column to H-beam connections reinforced with external stiffeners and reinforcing bar. The cyclic loading tests of 5 test specimens were carried out. The main Parameters are as follows; 1)the length of the stiffener: 200mm, 250mm, 2)the diameter of reinforcing bar: HD16, 19. The results of the researches demonstrate that the increase of the stiffener length was more effective than the increase of the area of reinforcing bar in the point of both strength and stiffness. By reinforcing external stiffeners, stable hysteretic behavior was shown and plastic hinge was formed on the beam flange. Cold-formed tube sections should be used carefully to avoid the welding fracture at the round corners of section, and the proposed welding methods are suitable for this connections.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.6
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• pp.461-469
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• 2017

A segment of the wave board has been expressed as a submerged line segment in the two dimensional wave flume. The lower end of the line segment could be extended to the bottom of the wave flume and the other opposite upper end of the board could be extended to the free surface. It is assumed that the motion of the wave board could be defined by the sinusoidal motion in horizontal direction on either end of the wave board. When the amplitude of sinusoidal motion of the wave board on lower and upper end are equal, the wave board motion could express the horizontally oscillating submerged segment of piston type wave generator. The submerged segment of flap type wave generator also could be expressed by taking the motion amplitude differently for the either end of the board. The pivot point of the segment motion could play a role of hinge point of the flap type wave generator. Simplified analytic solution of oscillating submerged wave board segment in water of finite depth has been derived through the first order perturbation method at two dimensional domain. The case study of the analytic solution has been carried out and it is found out that the solution could be utilized for the design of wave generator with arbitrary shape by linear superposition.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.2
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• pp.87-94
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• 1998

Behavioral characteristics of shallow circular arches with dynamic loading and different end conditions are analysed. Geometric nonlinearity is modelled using Lagrangian description of the motion. The finite element analysis procedure is used to solve the dynamic equation of motion, and the Newmark method is adopted in the approximation of time integration. The behavior of arches is analysed using the buckling criterion and non-dimensional time, load and shape parameters which Humphreys suggested. But a new deflection-ratio formula including the effect of horizontal displacement plus vertical displacement is presented to apply for the non-symmetric buckling problems. Through the model analysis, it's confirmed that fix-ended arches have higher buckling stability than hinge-ended arches, and arches with the same shape parameter have the same deflection ratio at the same time parameter when loaded with the same parametric load.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.2
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• pp.15-26
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• 2010

The purpose of this study is to develop a precast concrete structural wall system that can assure reliable seismic performance. In previous studies, the connections of precast concrete structural walls have had some problems in their seismic performance. Therefore, this research proposes precast concrete structural walls which have an improved seismic performance. One is a hybrid precast concrete structural wall that is composed of a reinforced concrete component and a precast concrete component, and another is a precast concrete wall whose reinforcements have a partially reduced section and are partially unbonded from the surrounding concrete. To evaluate the seismic performance of the proposed precast concrete structural walls, the behavior of three specimens, including a reinforced concrete wall, were subjected to reversed cyclic combined flexure and shear. According to the test results, the proposed precast concrete structural walls have reliable seismic performance.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.5
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• pp.569-576
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• 2011

In this paper a new analysis procedure for evaluation of progressive collapse resisting capacity of a structure was proposed based on the nonlinear static analysis procedure. The proposed procedure produces analysis results identical to those obtained by the linear static analysis procedure specified in the GSA guidelines without iteration, therefore saving a lot of computation time and excluding the possibility of human errors during the procedure. To verify the validity of the proposed procedure, the two methods were applied to the analysis of a reinforced concrete moment frame and a steel braced frame subjected to loss of a first story column and the results were compared. According to the analysis results, the two methods produce identical results in the prediction of progressive collapse and the hinge formation. As iterative analysis is not required in the proposed method, significant amount of analysis time is saved in the proposed analysis procedure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.4
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• pp.309-318
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• 2013

Abutment-to-pile connection in an integral abutment bridge is vulnerable to lateral displacement induced by thermal movement of the superstructure. However, previous researches have merely focused on the connection. In order to improve the performance of the connection, new abutment-to-pile connection designs were proposed based on quasi-static nonlinear finite element model. The reinforcement detail specified in PennDOT DM4 and HSS tube were barely effective in controlling crack growing but spiral rebar effectively performed to delay crack growth as well as absorbing energy capacity. However, it was found that delaying cracking and strengthening the connection also caused the high lateral load in superstructures. Consequently, shape of HP pile were modified to introduce plastic hinge of the HP pile for reducing the lateral load in superstructures. Connections with modified HP pile significantly prevented crack propagations under the lateral displacement.