• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1122-1129
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• 2009

Recently taping robot with smart recognition function have been studied in the coil manufacturing field. Due to the difficulty of 3D surface processing from the complicated working environment, it is not easy to accomplish smart tape attachment motion with non-contact sensor. To solve these problems the applicable surface recognition algorithm and a flexible sensing device has been recommended. In this research, the fusion method between 1D displacement and 3D laser scanner is applied for robust tape attachment about cold rolled coil. With these sensors we develop a two-step exploration and the smart algorithm for the awareness of non-aligned coil's information. In the proposed robot system for tape attachment, the problem is reduced to coil's radius searching with laser displacement sensor at first, and then position and orientation detection with 3D laser scanner. To get the movement at the robot's base frame, the hand-eye compensation between robot's end effector and sensing device should be also carried out respectively. In this paper, we examine the auto-coordinate transformation method in the calibration step for the real environment usage. From the experimental results, it was shown that the taping motion of robot had a robust under the non-aligned cold rolled coil.

• 한국강구조학회 논문집
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• 제20권3호
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• pp.445-454
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• 2008

철골모멘트접합부에 관한 이전의 연구에 의하면 RHS 기둥과 기존의 스캘럽을 가진 접합부실험체의 변형능력은 매우 열등했고, 보단부의 응력집중은 보에서 기둥으로 전달되는 모멘트의 전달효율에 영향을 받는다는 사실을 실험이나 해석적으로 밝혔다. 본 연구는 보강된 RBS 접합부와 용접수평스티프너를 사용한 효고현남부지진 이전에 지어진 모멘트 접합부를 내진보강하는데 주안점을 두었다. 이러한 내진보강은 시공성과 경제성을 고려하여 보의 하부플랜지에만 실시하였다. 접합부의 내진보강방법을 발견하고 이를 향상시키기 위해서 비선형유한요소해석을 통해서 다양한 변수를 바탕으로 한 파라메타 연구를 실시하였다.

• Earthquakes and Structures
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• 제10권4호
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• pp.867-891
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• 2016

This paper addresses numerically the behavior of steel structures under Fire-after-Earthquake (FAE) loading. The study is focused on a four-storey library building and takes into account the damage that is induced in structural members due to earthquake. The basic objective is the assessment of both the fire-behavior and the fire-resistance of the structure in the case where the structure is damaged due to earthquake. The combined FAE scenarios involve two different stages: during the first stage, the structure is subjected to the ground motion record, while in the second stage the fire occurs. Different time-acceleration records are examined, each scaled to multiple levels of the Peak Ground Acceleration (PGA) in order to represent more severe earthquakes with lower probability of occurrence. In order to study in a systematic manner the behavior of the structure for the various FAE scenarios, a two-dimensional beam finite element model is developed, using the non-linear finite element analysis code MSC-MARC. The fire resistance of the structure is determined using rotational limits based on the ductility of structural members that are subjected to fire. These limits are temperature dependent and take into account the level of the structural damage at the end of the earthquake and the effect of geometric initial imperfections of structural members.

• Structural Engineering and Mechanics
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• 제46권3호
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• pp.323-335
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• 2013

This work aims to study the effect of stiffener ties in the behavior of intermediate length open section Cold-Formed Steel (CFS) Columns under axial compression. A comparative study on the behaviour and strength of Cold Formed Steel Columns by changing the direction of projection of lips (i.e., inwards or outwards) are also done. In this work two types of sections were considered Type-I section with lip projecting outwards (hat) and Type-II section with lip projecting inwards (channel). The length of the columns is predicted by performing elastic buckling analysis using CUFSM software. The theoretical analysis is performed using DSM - S100;2007, AS/NZ: 4600-2005 and IS: 801-1975. The compression tests are carried out in a 400 kN loading frame with hinged-hinged end condition. The non-linear numerical analysis is performed using Finite Element software ANSYS 12.0 to simulate the experimental results. Extensive parametric study is carried out by varying the width and spacing of the stiffener ties. The results are compared; the effects of stiffener ties on behaviour and load carrying capacity on both types of columns are discussed.

• Steel and Composite Structures
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• 제18권6호
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• pp.1405-1421
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• 2015

Semi-rigid connections are the actual behavior of beam-to-column connections in steel frames. However, the behavior of semi-rigid connections is not taken into account for the simplicity in the conventional analysis and design of steel frames. A computer-based analysis and design has been studied for the three-dimensional steel frames with semi-rigid connections. The nonlinear analysis which includes the effects of the flexibility of connections is used for this study. It is designed according to the buckling and combined stress constraints under the present loading after the joint deformations and the member end forces of the space frame are determined by the stiffness matrix method. The semi-rigid connection type is limited to the top and bottom angles with a double web angle connection. The Frye-Morris polynomial model is used to describe the non-linear behavior of semi-rigid connections. Various design examples are presented to demonstrate the efficiency of the method. The results of design and analysis of unbraced semi-rigid frames are compared to the results of unbraced rigid frames under the same design requirements.

• Earthquakes and Structures
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• 제5권5호
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• pp.527-552
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• 2013

Development of flexural yielding and large rotation ductilities in the plastic hinge zones of frame members is synonymous with the spread of bar reinforcement yielding into the supporting anchorage. Yield penetration where it occurs, destroys interfacial bond between bar and concrete and reduces the strain development capacity of the reinforcement. This affects the plastic rotation capacity of the member by increasing the contribution of bar pullout. A side effect is increased strains in the compression zone within the plastic hinge region, which may be critical in displacement-based detailing procedures that are linked to concrete strains (e.g. in structural walls). To quantify the effects of yield penetration from first principles, closed form solutions of the field equations of bond over the anchorage are derived, considering bond plastification, cover debonding after bar yielding and spread of inelasticity in the anchorage. Strain development capacity is shown to be a totally different entity from stress development capacity and, in the framework of performance based design, bar slip and the length of debonding are calculated as functions of the bar strain at the loaded-end, to be used in calculations of pullout rotation at monolithic member connections. Analytical results are explored parametrically to lead to design charts for practical use of the paper's findings but also to identify the implications of the phenomena studied on the detailing requirements in the plastic hinge regions of flexural members including post-earthquake retrofits.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.28-33
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• 1998

A gene coding for ${\beta}$-xylosidase from thermophilic xylanolytic Bacillus sp. KK-1 was cloned into Escherichia coli using plasmid pBR322. Recombinant plasmid DNAs were isloated from E. coli clones which were capable of hydrolyzing 4-methylumbelliferyl-${\beta}$-D xylopyranoside. Restriction analysis showed the DNAs to share a common insert DNA. Xylo-oligosaccharides, including xylotriose, xylotetraose, xylopentaose, and xylobiose were hydrolyzed to form xylose as an end product by cell-free extracts of the E. coli clones, confirming that the cloned gene from strain KK-1 is ${\beta}$-xylosidase gene. The ${\beta}$-xylosidase gene of strain KK-1 designated as xylB was completely sequenced. The xylB gene consisted of an open reading frame of 1,602 nucleotides encoding a polypeptide of 533 amino acid residues, and a TGA stop codon. The 3' flanking region contained one stem-loop structure which may be involved in transcriptional termination. The deduced amino acid sequence of the KK-1 ${\beta}$-xylosidase was highly homologous to the ${\beta}$-xylosidases of Bacillus subtilis and Bacillus pumilus, but it showed no similarity to a thermostable ${\beta}$-xylosidase from Bacillus stearothermophilus.

• 한국강구조학회 논문집
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• 제15권4호통권65호
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• pp.457-466
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• 2003

본 연구의 목적은 실험적 방법을 통하여 P-${\Delta}$ 효과를 고려한 기둥항복형 강구조 골조의 안정성을 고찰하는데 있다. 이를 위하여 3개의 1층 1스팬 기둥항복형 강구조 비가새 골조에 대한 가력실험을 실시하였다. 실험의 변수로는 기둥의 강성과 축력비를 적용하였다. 실험결과 기둥의 강성 감소는 P-${\Delta}$효과를 증가시켜 골조의 안정성에 큰 영향을 미치는 것으로 나타났으며, 특히 보항복형 골조와 비교하여 최대내력 도달 이후의 내력자하 현상이 다소 급격하게 나타났다. 이것은 기둥의 강성이 낮은 기둥항복형 골조의 경우 P-${\Delta}$효과의 영향이 골조의 안정성에 미치는 영향이 증가되어 나타난 현상으로 사료된다.

• Nuclear Engineering and Technology
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• 제42권2호
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• pp.145-150
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• 2010

The paper is describing work being developed in the frame of a 5-year IAEA Coordinated Research Programme (CRP) started in late 2005. Participants gained knowledge of modelling methodologies and experience in the development and use of rather sophisticated simulation tools in support of site characterization and performance assessment calculations. These goals were achieved by a coordinated effort, in which the advantages and limitations of numerical models are examined and demonstrated through a comparative analysis of simplified, illustrative test cases. This knowledge and experience should help them address these issues in their own country's nuclear waste program. Coordination efforts during the first three years of the project aimed at enabling this transfer of expertise and maximizing the learning experience of the participants as a group. This was accomplished by identifying common interests of the participants (i.e., Process Modelling and Total System Performance Assessment methodology), and by defining complementary tasks that are solved by the members. Synthesis of all available results by comparative assessments is planned in the coming months. The project will be completed end of 2010. This paper is summarizing activities up to November 2009.

• 제어로봇시스템학회논문지
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• 제8권8호
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• pp.639-648
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• 2002

The stewart platform manipulator is a manipulator that has the closed-loop structure with an upper plate end-effector and a base frame. The stewart platform manipulator has the merit of high working accuracy and high stiffness compared with a serial manipulator. However, this is a complex structure, so controllability of the system is not so good. In this paper, we introduce a new robust motion control algorithm using partial state feedback for a class of nonlinear systems in the presence of modelling uncertainties and external disturbances. The major contribution of this work introduces the development and design of robust observer for the state and the perturbation, which is integrated into a variable structure controller(VSC) structure. The combination of controller/observer improves the control performance, because of the robust routine called sliding mode control with sliding perturbation observer(SMCSPO). Simulation and experiment are performed to apply to the manipulator. And their results show a high accuracy and a good performance.