• Steel and Composite Structures
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• v.27 no.5
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• pp.613-622
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• 2018

The requirement to safe and economical buildings caused to the exploitation of nonlinear capacity structures and optimization of them. This requirement leads to forming seismic design method based on performance. In this study, concentrically braced frames (CBFs) have been optimized at the immediate occupancy (IO) and collapse prevention (CP) levels. Minimizing structural weight is taken as objective function subjected to performance constraints on inter-story drift ratios at various performance levels. In order to evaluate the seismic capacity of the CBFs, pushover analysis is conducted, and the process of optimization has been done by using Bee Algorithm. Results indicate that performance based design caused to have minimum structural weight and due to increase capacity of CBFs.

• Smart Structures and Systems
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• v.14 no.4
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• pp.541-558
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• 2014

This paper proposes a new design of shape memory alloy (SMA) wire actuated gripper for open mode operation. SMA can generate smooth muscle movements during actuation which make them potentially good contenders in designing grippers. The principle of the shape memory alloy gripper is to convert the linear displacement of the SMA wire actuator into the angular displacement of the gripping jaw. Steady state analysis is performed to design the wire diameter of the bias spring for a known SMA wire. The gripper is designed to open about an angle of $22.5^{\circ}$ when actuated using pulsating electric current from a constant current source. The safe operating power range of the gripper is determined and verified theoretically. Experimental evaluation for the uncontrolled gripper showed a rotation of $19.97^{\circ}$. Forced cooling techniques were employed to speed up the cooling process. The gripper is simple and robust in design (single movable jaw), easy to fabricate, low cost, and exhibits wide handling capabilities like longer object handling time and handling wide sizes of objects with minimum utilization of power since power is required only to grasp and release operations.

• Coupled systems mechanics
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• v.2 no.1
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• pp.111-126
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• 2013

The structural design requirements of an offshore platform subjected to wave induced forces and moments in the jacket can play a major role in the design of the offshore structures. For an economic and reliable design; good estimation of wave loadings are essential. A nonlinear response analysis of a fixed offshore platform under structural and wave loading is presented, the structure is discretized using the finite element method, wave plus current kinematics (velocity and acceleration fields) are generated using 5th order Stokes wave theory, the wave force acting on the member is calculated using Morison's equation. Hydrodynamic loading on horizontal and vertical tubular members and the dynamic response of fixed offshore structure together with the distribution of displacement, axial force and bending moment along the leg are investigated for regular and extreme conditions, where the structure should keep production capability in conditions of the 1-yr return period wave and must be able to survive the 100-yr return period storm conditions. The result of the study shows that the nonlinear response investigation is quite crucial for safe design and operation of offshore platform.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.3 s.18
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• pp.38-46
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• 2004

This paper deals with the development of simulation model for the horizontal launch at submarines in the preliminary design phase. The simulation model is composed of submarine motion model, cross flow force model in the bow of submarine, and weapon motion model In launch through torpedo tubes. Using submarine and weapon characteristics and simulation condition, it can simulate the exit velocity of weapon through torpedo tubes and reaction forces. It should be helpful for the analysis of the safe launch and design requirements in the preliminary design phase of a submarine or a weapon launched through torpedo tubes.

• Proceedings of the Korean Reliability Society Conference
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• 2004.07a
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• pp.262-267
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• 2004

In designing and evaluating a new product, the company needs to give thought to the entire spectrum of produceability, usability, and ultimate reliability, as well as safety of users. For each design review(DR) stage, a formal, systematic, documented review and evaluation of a product design is conducted to assure that the product is safe and reliable, that costs and materials have been optimized, and that the design complies with its specifications and requirements. This paper presents how to improve development process for product's safety and reliability. The process requires gathering the appropriate information, determining the limits of the product, estimating risk associated with the task-hazard combinations, and reducing risk according to a prioritized procedure.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.3
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• pp.137-144
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• 2000

Judging from the occasional occurrences of minor and major earthquakes in Korean peninsula, it is generally considered that Korean peninsula is not located in safe zone from earthquake any more. The worldwide damages from earthquake in public buildings such as bridges are also urging the necessity for an appropriate earthquake proof action. The elastomeric bearings have been used in seismic isolation design of bridges. and elastomeric bearings are quite ideal ones which allow movement and rotation in all directions without restraining superstruture. Within the limits of this study on dynamic behavior of the LBR for seismic isolation design, the reaearch results revealed that the Laminated Rubber Bearing(LRB) is useful in bridges for seismic isolation design. In addition, the relationship between the shape factor and compressive strength is linear. It was also found that the compressive strength gets higher as the shape factor increases.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2352-2354
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• 1999

The purpose of substation grounding system is to provide reference potential with power system and protect field workers from electrical shock resulted from unsymetrical power system faults. For this purpose, grounding grid should be designed to maintain max, touch voltage under safety criteria in fault conditions. It is difficult, however, to design a safe grounding grid at very resistive or narrow area. This paper describes an example of substation grounding grid design procedures in such areas with very severe design conditions. By using grounding conductors, which is located close to earth surface, earth surface potential could be controlled effectively, so that maximum touch voltages is to be maintained under safety criteria.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.41-55
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• 2015

This study is proposed a new hybrid mount having a moving-magnet type electromagnetic actuator to reduce the vibration transmitted from naval shipboard equipment to the structure of the ship's hull. Optimal design specifications are determined through experimental analysis. The detailed design of the hybrid mount is determined through several design steps with electromagnetic numerical analysis using Maxwell Software(S/W). The hybrid mount that combines a rubber mount and an electromagnetic actuator has a fail-safe function for shock resistance. The mount is fabricated and tested using a universal testing machine to evaluate the design specifications. Finally, numerical simulation of the hybrid mount is performed to confirm control performance and applicability.

• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.423-433
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• 2014

For the proper decision making and responsibility enhancement for an unexpected accident in large-scale facilities, it is important to train operators or first responders to minimize potential human errors and consequences resulted from them. Simulation technologies, including human-computer interaction and virtual reality, enables personnel to participate in simulated hazardous situations with a safe, interactive, repetitive way to perform these training activities. For the development of accident response training simulator, it is necessary to define components comprising the simulator and to integrate them for the given training purpose. In this paper, we analyze requirements of the training simulator, derive key components, and design the training simulator. Based on the design, we developed a prototype training simulator and verified the simulator through experiments.

• International Journal of High-Rise Buildings
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• v.1 no.4
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• pp.255-269
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• 2012

Tall buildings' implementation has often lacked urban design and architectural guidance. There are many examples of tall buildings that have been inappropriately located, designed, and built, and consequently dissatisfaction with high-rise development is wide-spread. This paper attempts to provide extensive urban and architectural guidelines in order to manage cityscape and to ensure safe and healthy living. Through recommendations on design and layout of tall buildings and open spaces the guidelines seek enhancing the visual experience, improving the microclimate conditions, and fostering active social life. These guidelines help in providing enjoyable urban experiences through the examination of spatial relationships, human scale, genius loci, perceptual characteristics, local identity, built heritage, economic activities, and social life.