• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.399-404
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• 2005

In this paper, An immunized PID(I-PID) controller based on cell mediated immune response is proposed to improve the control performance of the controller with PID scheme. And it is applied to the vibration of the building structure in the port with active damper systems. The immune system of organism in the real body regulates the antibody and T-cells to protect the attack from the foreign materials which are virus, germ cell, and other antigens. It has similar characteristics that are the adaptation and robustness to overcome disturbances and to control the plant of engineering application. At firstly, we build a model of the T-cell regulated immune response mechanism. We have also designed an I-PID controller focusing on the T-cell regulated immune response of biological immune system. Finally, we show that some computer simulations of the vibraton control for the building structure system with wind force excitation. These results for the proposed method also show that is has performance than other conventional controller design method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.138-146
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• 2014

Structural safety as well as variety and aesthetics of building facade are currently gathering more attention in building construction and stone curtain wall is widely used in exterior wall. However, two main problems are existed in curtain wall construction method. One is an uniformity of construction quality and the other is a repair work of stone panels. Also, the noise and vibration occurring in construction may be cause of civil complaint. Therefore, a new method is needed to overcome these problems. This paper presents a new stone curtain wall system using under cut anchor and secondary holes that was developed in this study. Additionally, structural performance evaluation was conducted to verify the constructability and structural safety for wind pressure and seismic load. Through the evaluation of this method, improved constructability and economic efficiency were verified.

• Journal of Korean Association for Spatial Structures
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• v.5 no.3 s.17
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• pp.75-82
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• 2005

The conceptual structural design consists of selecting structural material and form of the building, producing a preliminary dimensional layout. The information such as height of the building use, typical live load, wind velocity, design acceleration, maximum lateral deflection, span, story height is a important factor in conceptual design phase. In this case, the knowledge solutions for past similar problems cam be used in the process of defining and finding a solution to the design problems. In this paper, the conceptual structural design method using case-based reasoning which is intended to assist engineers in the conceptual phase of the structural design of tall buildings is introduced. Inductive retrieval method and nearest-neighbor retrieval method are used for selecting structural system and similar design case, respectively.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.4
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• pp.339-346
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• 2012

In this paper, equivalent models for active control devices are proposed so that building structures with such devices are analyzed using commercial structural analysis programs for the assessment of the structural members under active vibration control. Equivalent link models represent active control device with a virtual linear spring and dashpot, and equivalent force models are control force history acting at the installation point in structural models. Active controllers are designed based on the reduced-order models for a vertical cantilever model and a high-rise building model and corresponding equivalent models are determined from control gain matrices. Based on acceleration, displacement and member force responses, the effectiveness of the equivalent models is verified. As a result, proposed equivalent models, of which equivalent link model showed better performance, appear to enable detailed investigation of structural behavior to the extent of member force level.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.149-154
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• 2019

The structural system of domestic high-rise apartments can be divided into two parts; the core wall system, which is composed of walls concentrated in the center and the shear wall system, which comprises a great number of walls distributed in the plan. In order to analyze the lateral behavior of each system, buildings with typical domestic high-rise apartment plans were selected and nonlinear static analysis was performed to investigate the their collapse mechanism. From the force-displacement relation derived from nonlinear static analysis, response modification factor was evaluated by calculating the overstrengh and ductility factor, which are important in the seismic response. The ductility of core wall system is small, but as it is governed by wind load, its overstrength is greatly estimated, and its response modification factor is calculated by the overstrengh factor. Due to a large number of walls, shear wall system has a large ductility, making the response modification factor considerably large.

• Journal of the Korea Institute of Building Construction
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• v.21 no.1
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• pp.41-49
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• 2021

This study was to solve the lift problem of the existing unit curtain wall type by using the vertical material mullion as a rail in curtain wall, which is recently used as an external finishing material for high-rise buildings. It has been shown that the application of the curtain wall mullion's rail can be quantified even at 20m/sec wind speed through the Mock-Up test. Based on the sites selected for comparison of construction methods, it was analyzed that the construction period could be shortened by 48 days, or about 20 percent. It was analyzed that the number of construction workers could be reduced by about 33 percent from the previous nine to six. Based on these results, assuming the installation of curtain wall units of 10,000㎡, it is judged that construction cost can be reduced by 80% or more.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.291-299
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• 2021

Recently, due to environmental problems caused by densification and high rise of urban areas, interests in air flow is increasing and appropriate shape and layout design of buildings is required. Therefore, in this study, we intend to propose an experimental method that can observe the air flow around a building using thermochromic pigment. Thermochromic pigments have limitations in observing precise temperature changes due to the characteristic that the color changes only with respect to a specific temperature, but they have the advantages of easy configuration of experimental equipment and short time required for experiments. In this study, the air flow tendencies around a building was examined by performing CFD analysis for a simple model and then compared with the thermochromic experiment results in order to review the usefulness of the proposed experimental method. As a result of the experiment, it was possible to observe the formation of separated flow and vortex region generated by buildings using the charateristics of thermochromic pigment and it was confirmed that the proposed method can be useful for buildings design and urban city planning.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.69-72
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• 2022

This paper actually investigates the load on major large-scale buildings in the downtown area, examines the economic feasibility of installing PV and ESS in a microgrid target building, and evaluates whether an electric vehicle capable of V2G through two buildings is effective as an economical analysis program (HOMER) was analyzed using. It is economical to install a mixture of ESS rather than using the whole PV, and it is shown that if there is an electric vehicle using the V2G function of EV, there is an economic effect to replace the PV. So that Incentives and policies are needed to replace a large area of PV and utilize the existing parking lot to lead EV as a resource of the microgrid. Currently, P2X technology that stores power as ESS or converts it to other energy to control when surplus renewable energy occurs in large-capacity solar power plants and wind farms, etc. This is being applied, and efforts are being made to maintain the stability of the system through the management of surplus power, such as replacing thermal energy through a heat pump. Due to the increase in electric vehicles, which were recognized only as a means of transportation, technologies for using electric vehicles are developing. Accordingly, existing gas stations do not only supply traditional chemical fuels, but electricity, and super stations that also produce electricity have appeared. Super Station is a new concept power plant that can produce and store electricity using solar power, ESS, V2G, and P2G. To take advantage of this, research on an urban microgrid that forms an independent system by tying a large building and several buildings together and supplies power through a super station around the microgrid is in full swing.

• Earthquakes and Structures
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• v.23 no.6
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• pp.493-502
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• 2022

In recent decades, infrastructural development has exploded, particularly in the coastal region of Saudi Arabia. The rising demand of most consumed aggregate in construction can be effectively compensated by the alternative material like scoria which lavishly exists in the western region. Scoria is characterized as lightweight aggregate beneficially used to develop lightweight concrete (LWC) - a potential alternative of normal weight concrete (NWC) ensuring reduction in the structural element's size, increase in building height, comparatively lighter foundation, etc. Hence, the goal of this study is to incorporate scoria-based structural lightweight concrete and evaluate its impact on superstructure and foundation design beside contributing to the economy of construction. Fresh, mechanical, and rheological properties of the novel LWC have been investigated. The structural analyses employ the NWC as well as LWC based structures under seismic and wind loadings. The commercial finite element package - ETABS was employed to find out the change in structural responses and foundations. The cost estimation and SWOT analysis for superstructure and foundation have also been carried out. It was revealed that the developed LWC enabled a more flexible structural design. Notable reduction in the steel and concrete prices of LWC might be possible in the low-rise building. It is postulated that the cost-effective and eco-friendly LWC will promote the usage of scoria as an effective alternative in Saudi Arabia and GCC countries for structurally viable LWC construction.

• Geomechanics and Engineering
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• v.31 no.6
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• pp.573-582
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• 2022

The geometry of the gravity-type anchorage changes depends on various factors such as the installation location, ground type, and relationship with the upper structure. In particular, the anchorage geometry embedded in the ground is an important design factor because it affects the pull-out resistance of the anchorage. This study examined the effect of four parameters, related to anchorage geometry and embedded ground conditions, on the pull-out resistance in the gravity-type anchorage through two-dimensional finite element analysis, and presented a guide for major design variables. The four parameters include the 1) flight length of the stepped anchorage (m), 2) flight height of the stepped anchorage (n), 3) the anchorage heel height (b), and 4) the thickness of the soil (e). It was found that as the values of m increased and the values of n decreased, the pull-out resistance of the gravity-type anchorage increased. This trend is related to the size of the contact surface between the anchorage and the rock, and it was confirmed that the value of n, which has the largest change rate of the contact surface between the anchorage and the rock, has the greatest effect on the pull-out resistance of the anchorage. Additionally, the most effective design was achieved when the ratio of the step to the bottom of the anchorage (m) was greater than 0.7, and m was found to be an important factor in the pull-out resistance behavior of the anchorage.