• Journal of the Korean GEO-environmental Society
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• v.5 no.3
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• pp.5-15
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• 2004

SIP has been widely used as a low noise and vibration piling method in Korea. But the quality control of SIP was not properly settled down and field workers did not fully understand the principle of SIP method. So not a less troubles were raised at construction site and bearing capacity was not fully mobilized. To settle these problems, Korea National Housing Corporation amended the construction and load test criteria of SIP in 2002. After load tests on the SIPs installed in field according to the new criteria, we found that the bearing capacity in field vs the design load ratio increased and bearing characteristics was enhanced than that installed by the former criteria. To consider the enhanced bearing characteristics in the pile design and determine the adequate design criteria, this paper analyzed the accuracy of design criterion which were commonly used in Korea comparing with the load test results. Analysis result shows that Meyerhof criteria(1976) properly simulates the bearing capacity of SIP installed by the new construction and load test criteria.

• Journal of the Korean Society for Advanced Composite Structures
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• v.3 no.2
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• pp.11-18
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• 2012

This study proposes flexural failure design criteria of continuous slabs enhanced by a hybrid system of fiber reinforced polymer (FRP) and ultra high performance concrete (UHPC). The proposed hybrid retrofit system is designed to be placed at the top surface of the slabs for flexural strengthening of the sections in both positive and negative moment zones. The enhancing mechanisms of the proposed system for both positive and negative moment regions are presented. The neutral axis of the enhanced sections in positive moment zone at flexural failure is enforced to be in UHPC overlay for preventing the compression in FRP. From this condition, a relationship between design parameters of FRP and UHPC is established. Although the capacity of the proposed retrofit system to enhance flexural strength and ductility is confirmed through experiments of one-way RC slabs having two continuous spans, the retrofitted slabs failed in shear. To prevent this shear failure, a design criteria of flexural failure is proposed.

• Journal of the Korean Solar Energy Society
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• v.34 no.3
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• pp.89-97
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• 2014

Recently design standard for energy-saving in apartment buildings has been consolidated gradually on the basis of evaluation and certification standards of energy efficiency of buildings, the energy-saving policy of building at home and abroad. Performance criteria for thennal insulation as well as fenestration has been progressively enhanced, and performance criteria for ventilation and airtightness of the building have also been re-developed. Therefore, heating and cooling load characteristics of the apartment building can be changed. For the design of the upcoming heating and cooling equipment in apartment buildings, it is necessary to evaluate the heating and cooling load characteristics according to the design strategies for energy saving in apartment buildings. As a result, in this study, it is intended to use as a resource for analyzing the impact that the adoption of energy-saving design variables for each of the apartment buildings, to predict the heating and cooling load characteristics in the apartment building.

• Smart Structures and Systems
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• v.4 no.5
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• pp.655-666
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• 2008

In the past 20 years, seismic isolation has see a variety of applications in design of structures to mitigate seismic hazard. In particular, isolation has been seen as a means of achieving enhanced seismic performance objectives, such as those for hospitals, critical emergency response facilities, mass electronic data storage centers, and similar buildings whose functionality following a major seismic event is either critical to the public welfare or the financial solvency of an organization. While achieving these enhanced performance objectives is a natural (and oftentimes requisite) application of seismic isolation, little attention has been given to the extension of current design practice to isolated buildings which may have more conventional performance objectives. The development of a rational design methodology for isolated buildings requires thorough investigation of the behavior of isolated structures subjected to seismic input of various recurrence intervals, and which are designed to remain elastic only under frequent events. This paper summarizes these investigations, and proposed a consistent probabilistic framework within which any combination of performance objectives may be met. Analytical simulations are presented, the results are summarized. The intent of this work is to allow a building owner to make informed decisions regarding tradeoffs between superstructure performance (drifts, accelerations) and isolation system performance. Within this framework, it is possible to realize the benefits of designing isolated buildings for which the design criteria allows consideration of multiple performance goals.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.94-101
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• 2018

With the development of industrial technology and science, production and manufacturing facilities have been enhanced and improved, and the importance of the safety of workers has also been regulated and limited by various safety management methods. As a way to secure the safety of the workers from the production facility, the fail-safe and fool-proof methods are now being applied. Any possible insecure behavior and unsafe conditions can be removed by adopting the standards and specifications that are now secure the safety of workers and equipment. This research analyzes EN ISO 13849-1 international and European standards during CE certification. In order to secure acceptable reduced risks, the risk assessment process of ISO 12100 and the processes for reducing its risk are applied. In the current ISO 13849-1 standard, the criteria for the required performance level PLr (Required Performance Level) for the applicable risk and safety functions through the risk assessment are subjective and not subdivided. Therefore, the evaluation criteria are likely to cause judge's judgement error due to qualitative judgement. This research focuses on evaluation and acceptable performance level setting for the safety circuit of the equipment. We propose an objective and specific evaluation criteria to secure safety, and the proposed evaluation criteria are applied to the case study of the safety circuit for the equipment. In order to secure the safety of the entire safety circuit, the improvement of the MTTFd and DC level related to the SRP/CS (Safety-Related Parts of Control Systems)' lifetime is required for the future research.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.363-368
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• 2022

For taller buildings with unconventional architecture, refined structural systems or in geographical areas with high wind conditions, performance-based design can be seen as an enhanced design process and is either a supplement to, or alternative to a prescriptive code-based design. The ultimate goal of Performance-Based Wind Design (PBWD) is to result in a building that better addresses key goals of performance over the buildings full life cycle. Major innovations around the use of a PBWD approach include nonlinear dynamic analysis for wind design, limited inelasticity in the main wind force resisting system elements, and system-based performance criteria. This paper discusses potential considerations and benefits made when using a performance-based approach, in addition to the general practicality of use, for the structural design on a few key tall buildings.

• Structural Engineering and Mechanics
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• v.25 no.2
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• pp.239-268
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• 2007

This paper deals with optimal stacking sequence design of laminate composite structures. The stacking sequence optimisation of laminate composites is formulated as a combinatorial problem and is solved using Simulated Annealing (SA), an algorithm devised based on inspiration of physical process of annealing of solids. The combinatorial constraints are handled using a correction strategy. The SA algorithm is strengthened by embedding Tabu search in order to prevent recycling of recently visited solutions and the resulting algorithm is referred to as tabu embedded simulated Annealing (TSA) algorithm. Computational performance of the proposed TSA algorithm is enhanced through cache-fetch implementation. Numerical experiments have been conducted by considering rectangular composite panels and composite cylindrical shell with different ply numbers and orientations. Numerical studies indicate that the TSA algorithm is quite effective in providing practical designs for lay-up sequence optimisation of laminate composites. The effect of various neighbourhood search algorithms on the convergence characteristics of TSA algorithm is investigated. The sensitiveness of the proposed optimisation algorithm for various parameter settings in simulated annealing is explored through parametric studies. Later, the TSA algorithm is employed for multi-criteria optimisation of hybrid composite cylinders for simultaneously optimising cost as well as weight with constraint on buckling load. The two objectives are initially considered individually and later collectively to solve as a multi-criteria optimisation problem. Finally, the computational efficiency of the TSA based stacking sequence optimisation algorithm has been compared with the genetic algorithm and found to be superior in performance.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.6
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• pp.525-532
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• 2012

The recently constructed buildings are ensuring seismic safety with enhanced design criteria. But, the buildings unapplied enhanced design criteria are very weak. In this study, steel grid shear wall is proposed as a solution of seismic retrofit to ensure safety of the existing buildings for the earthquake. And the structural performance experiments were carried out under axial force and cyclic lateral loads. The two specimens were made of a reference RC frame and steel grid shear wall in-filled RC frame. The test setup configured with two dynamic actuators, for the axial force with a 500kN capacity actuator and for the cyclic lateral load applied with the 2,000kN actuator. Compared with control specimen, the strength, stiffness, ductility, energy dissipation capacity of the seismic retrofit structures is evaluated.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.539-550
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• 1998

A computerized layout system based on a constraint satisfaction problem (CSP) technique was developed to treat both facility layout and instrument panel layout problems. This layout system attempts to allocate various facilities under multiple layout criteria including qualitative design objectives. Since most of the design objectives can be understood as constraints which the layout solution must satisfy to improve the goodness of the solution, a CSP technique was employed to solve the multi-constraints layout problem. The effectiveness of the system was evaluated by the comparison with the well-known facility layout program, CORELAP. Furthermore, the proposed system can also be applied to the instrument panel layout problem successfully. Several user-centered guidelines were well reflected on the solution obtained. CONSLAY, the prototype layout system being developed in the research, greatly enhanced the interactions with the designer so as to deal with the problem-dependent nature of the layout problem and to properly reflect the domain-specific knowledge of the designer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.2
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• pp.286-297
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• 2016

This study proposes criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration. The optimal design of the stator and rotor can be enhanced using both a response surface method and finite element method. In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor. Finally, this study verifies that the proposed motor can efficiently replace interior permanent magnet synchronous motor in many industries.