• Proceedings of the KSR Conference
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• 2001.05a
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• pp.393-400
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• 2001

State of the art and current issues related with the RC and PSC structure system for the German magnetic levitation train were investigated. The German magnetic levitation train adopted a new kind of a structure to enable high-speed transportation, which allows the use of the space over a ground. The loading from Transrapid is light-weight compared with a regular train due to load distribution to a supporting structure. Therefore, Transrapid is considered an economical and efficient transportation system, and is also an environmentaly-sustainable structure, In this paper, the structural design and construction technology specific to a magnetic levitation train were discussed, and structural considerations related with an actual operation of the train were pointed out. In addition, the future research area of a magnetic levitation train was proposed.

• Journal of the Korea Society for Simulation
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• v.11 no.2
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• pp.55-66
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• 2002

VHDL has been. widely used in modeling and simulation of hardware designs. However, complex relationship between components of the designs makes the VHDL modeling problem very difficult. Furthermore, after the initial creation of VHDL models, they evolve into many versions over their lifetime. To cope with such difficulties, this paper proposes a new methodology for the management of VHDL models supporting versions. Its conceptual bases are system entity structure and relational database. Within the methodology, a family of hierarchical structures of a design is organized in the form of VHDL model structure. It is, in turn, represented in the form of relational tables. Once the model structure is built in such a way, a specific simulation model which meets design objective is pruned from the model structure. The details of VHDL codes are systematically synthesized by combining it with the primitive models in a model base. These algorithms are also defined in terms of relational algebraic operations.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.73-79
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• 2009

In this paper, the structural analysis and optimization of the door supporting rail structure in the header box located at the top of the aluminum passenger safety door(PSD) at the subway station, which opens and closes regularly, is performed. In case the simple fixed boundary condition is used for the bolt fixture on the supporting rail where the glass door is moving, excessive stresses are obtained. Therefore, more realistic finite element modeling of the bolts is used at the bolt fixture in the whole structure in order to obtain the more physically acceptable FEM results. As a result, fatigue life of twenty years of the structure is obtained to satisfy the design object. Also the optimal design of cross section of the rail part is performed using the response surface method and 15% of weight of the supporting rail part on the door is reduced.

• Structural Engineering and Mechanics
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• v.40 no.6
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• pp.763-782
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• 2011

Results from nonlinear time-history analyses of wall-frame structural models indicate that the condition of vulnerable foundations -for which uplifting and reaching the bearing capacity of the supporting soil can occur before yielding at the base of the shear walls- may not be necessarily detrimental to the drift response of buildings under strong ground motions. Analyses also show that a soil-foundation system can inherently have deformation capacity well in excess of the demand and thus act as a source of energy dissipation that protects the structural integrity of the shear walls.

• Language and Information
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• v.19 no.1
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• pp.1-18
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• 2015

Korean marks case for subjects and objects, but it is well known that case-markers can be dropped in certain contexts. Kwon and Zribi-Hertz (2008) establishes the phenomenon of Korean case drop on a single factor of f(ocus)-structure visibility and claims that both subject and object case drop can fall under a single linguistic generalization of information structure. However, the supporting data is not empirically substantiated and the tenability of the f-structure analysis is still under question. In this paper, an experiment was conducted to show that the specific claims of Kwon and Zribi-Hertz's analysis that places exclusive importance on information structure cannot be adequately supported by empirical evidence. In addition, the present study examines H. Lee's (2006a, 2006c) multi-factor analysis of object case drop and investigates whether this approach can subsume both subject and object case drop under a unified analysis. The present findings indicate that the multi-factor analysis that involves the interaction of independent factors (Focus, Animacy, and Definiteness) is also compatible with subject case drop, and that judgments on case drop are not categorical but form gradient statistical preferences.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1231-1239
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• 2015

We developed a robot that has four limbs, each of which has the same kinematic structure and has 6 degrees of freedom. The robot is 600mm high and weighs 4.3kg. The robot can perform walking and manipulating task by using the four limbs selectively. The robot has three walking patterns. The first one is biped walking, which uses two rear limbs as legs and two front limbs as arms. The second one is biped walking with supporting arms, which is basically biped walking but uses two arms as supporting legs for increasing stability of the robot. The last one is quadruped walking, which uses all the four limbs as legs. When a task for the robot is given, the robot approaches the task point by selecting an appropriate walking pattern among three walking patterns and performs the task. The robot has many degrees of freedom and is a redundant system for a three dimensional task. We propose a redundancy resolution method, in which the robot’s translational move to the task point is modeled as a prismatic joint and optimal solutions are obtained by optimizing some performance criteria. Several simulations are performed for the validity of the proposed method.

• Applied Microscopy
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• v.32 no.1
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• pp.17-30
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• 2002

The retinae of Todarodes pacificus and Octopus minor are divided into four layers that are an outer segment, a rod base region, an inner segment, and a plexiform layer, respectively. The retina of Octopus minor is about $20{\mu}m$ thicker ($400{\sim}420{\mu}m$) than that of Todarodes pacificus ($385{\sim}400{\mu}m$). A retina is composed of visual cells and supporting cells. The microvilli of length $0.6{\sim}0.7{\mu}m$ are packed densely on top of the supporting cells of Octopus minor while they are not found in Todarodes pacificus. The visual cells and supporting cells have pigment granules that exclude light. In case of Todarodes pacificus, the pigment granules of the visual cell are larger ($2.0{\times}0.5{\mu}m$) than those of the supporting cell ($1.0{\times}0.3{\mu}m$). But, the sizes of both cells are similar in Octopus minor. In the upper portion of a visual cell, microvilli shaped like a comb are forming a rhabdome (diameter, 60 nm) of a hexagonal structure. The rhabdome consists of 4 rhabdomere and the total area of a rhabdom of Octopus minor is larger than that of Todarodes pacificus. The synaptosome constructing a plexiform layer in Todarodes pacificus are divided into two types, each of which possess electron dense-core vesicles and electron lucent vesicles, respectively. Octopus minor also has two types of synaptosomes but each type comprises a mixture of electron dense vesicles and electron lucent vesicles, and electron lucent vesicles only, respectively, which is different from the case of Todarodes pacificus.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.812-818
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• 2001

The drop type impact test and finite element analysis are established for examining the buckling behavior of a square tube under the lateral impact load. Based on these results, the effects by the boundary conditions for supporting the structure are reviewed, which are as follows. One is pinned condition by screw; the other is fixed by welding. The critical impact force and acceleration by test are nearly same between two cases. However, the critical impact velocity of the pinned condition is higher than that of the fixed case. Therefore, the dynamic buckling behavior of a pinned structure is better than the fixed condition in view of critical impact velocity. These test and analysis results will be adaptable for predicting the dynamic structural integrity of a tube structure not only the axial impact event but the lateral impact event.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2268-2276
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• 2021

Spent nuclear fuel, which can degrade during long-term storage, must be transported intact in normal transport conditions. In this regard, many studies, including those involving Multi-Modal Transportation Test (MMTT) campaigns, have been conducted. In order to transport the spent fuel safely, a tie-down structure for supporting and transporting a cask containing the spent fuel is essential. To ensure its structural integrity, a method for finding an optimum conceptual design for the tie-down structure is presented. An optimized transportation test model of a tie-down structure for the KORAD-21 metal cask is derived based on the proposed optimization approach, and the transportation test model is manufactured by redesigning the optimized model to enable its producibility. The topology optimization approach presented in this paper can be used to obtain optimum conceptual designs of tie-down structures developed in the future.

• Korean Journal of Computational Design and Engineering
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• v.8 no.2
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• pp.90-100
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• 2003

Engineering change (EC) objects are the data structure and related operations that can support applications for EC procedures or processes. Their functionalities include controlling management data, specifying related product structure, and archiving a history of product structure changes for EC management. In this paper we introduce a systematic approach to support the propagation of changes between different product structure views using the history of structure changes in EC objects. The change propagations supported by EC objects enable designers to maintain the consistency of multiple product structure views for engineering, manufacturing or even customer support applications. This paper also includes EC examples and experimental implementations for the proposed EC objects.