• Korean Journal of Heritage: History & Science
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• v.48 no.2
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• pp.120-141
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• 2015

This paper is a preliminary study of architectural characteristics of Jangdae (general's podium), which shows one of the technical changes in fortification of Joseon Dynasty. As a facility for commands of generals and training for officers and men, it was located inside a fortress. Although it is not certain when the first Jangdae was built, the number of them dramatically increased around 18th century. Since the top priority function of the Jangdae was the prospect, it was installed at the hilly spot with open architecture. In addition, the open structure of Eupseong fortress towers on the riverside banks could simultaneously offer the functions as viewing around and Jangdae. Since Jangdae was also a place for military drills and reviews of soldiers, a wide podium was positioned at the front to muster the soldiers. This feature was standardized in the space organization of Jangdae in Joseon, and a mere podium was installed unless the topographic restrictions allows enough space. On the other hand, as a place for a commander, the hierarchy of the Jangdae was revealed through a variety of architectural characteristics. The hierarchy was assigned to the commander's space through the altitude difference, and diverse ornaments were added to show a sense of class. The floor plan of the Jangdae building can be largely categorized into rectangle and square, and the typical sizes of the former are $5{\times}4$ Kans (traditional measuring unit between two columns) and $3{\times}2$ Kans. Out of these two types, buildings of $5{\times}4$ Kans were found in flat land and eupseong fortresses with large space, and the relatively smaller ones of $3{\times}2$ Kans in mountain fortresses. All buildings of square floor plan had $3{\times}3$ Kans style, and the center Kan was twice wider than the side Kan to make the central space wide. It seems that the purpose was to secure the interior space of the upper story because the center Kan accounts for the floor area of the upper story. Some Jangdae's had internal story to form overhead space. The multi-roofed tower style with eaves attached to the upper and lower story is found exclusively in Jangdae. The buildings shows the Onkanmulim style which extends Naejinju (inner column) of the lower story to be the Byeonju (outer column) of the upper story, and the log-framed floor in the upper floor was structured by inserting the Changbang (connecting beam) between the Naejinju's and joining the log frames. In addition, the towers in eupseong fortresses had log-framed floor in the upper floor by setting up the high Nuhaju (column underneath a roof) and joining Cheongbang to the upper part of the column while it cannot be regarded as multi-roofed because only the upper part has a roof.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.4
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• pp.1-10
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• 2023

In the seismic design of structures, seismic forces are calculated based on structural models and analysis. In order to accurately address the dynamic characteristics of the actual structure in the structural model, calibration based on actual measurements is required. In this study, a 4-story frame test specimen was manufactured to simulate frame building, accelerometers were attached at each floor, and 1-axis shaking table test was performed. The natural period of the specimen was similar to that of the actual 4 story frame building, and the columns were designed to behave with double-curvature having the infinite stiffness of the horizontal members. To investigate the effects seismic waves characteristics, historical and artificial excitations with various frequencies and acceleration magnitudes were applied. The natural frequencies, damping ratios, and mode shapes were obtained using frequency response functions obtained from dynamic response signals, and the mode vector deviations according to the input seismic waves were verified using the Mode assurance criterion (MAC). In addition, the damping ratios obtained from the vibration tests were applied to the structural model, and the method with refined dynamic characteristics was validated by comparing the analysis results with the experimental data.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.1
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• pp.39-48
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• 2011

In this present study, a response modification factor for a lightweight steel panel-modular system which is not clarified in a current building code was proposed. As a component of the response modification factor, an over-strength factor and a ductility factor were drawn from the nonlinear static analysis curves of the systems modeled on the basis of the performance tests. The final response modification factor was then computed by modifying the previous response modification factor with a MDOF (Multi-Degree-Of-Freedom) base shear modification factor considering the MDOF dynamic behaviors. As a result of computation for the structures designed as a dual frame system, ranging from 2-story to 5-story, the value of 4 was estimated as a final response modification factor for a seismic design, considering the value of 5 as an upper limit of the number of stories.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.11
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• pp.113-123
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• 2018

First of all, the multi-story Housing applying resident's participation in europe was classified by the menu selection method, the two-step supply method and the cooperative method. And then I analyzed flexible unit plan of cases for deriving the planning methode and the characteristics of flexibility. First, I analyzed the area and form of the unit plan, structure and Installation, fixed and variable elements to derive the planning method. The area of units are distributed from a minimum of $35m^2$ to a maximum of $150m^2$, and many of the unit planes have a narrow front and a deep depth. The structure is a long-span wall-structure or a skeleton structure, and is designed without any columns and bearing walls in the interior space for flexibility in spatial composition. The vertical shafts are located in the center of the unit in a box-form or in the corner at the unit dividing wall for free placement of interior wall. Fixed elements are framework and facility systems. Most of the future residents in the two-steps supply method and the cooperative method were able to freely design the internal space within the zoning concept proposed by the architect and change the location of the facade element within module system proposed by the architect. Second, the characteristics of the flexibility applied to the unit plan were divided in integrated flexibility, functional flexibility, construction flexibility, and supply flexibility. The integrated flexibility enables residents to give the variable space combination based on the complex structure of the inner space for providing various living experiences. Regarding functional flexibility, the three-dimensional spatial structure with neutral space has multi-functionality according to the needs of residents and easily accepts mixing of hybrid programs such as work and residence. Constructive flexibility allows residents to create identity by freely planning interior space and changing the size or location of facade components in a determined system of architects. Finally, various types of size and space composition are proposed and realized in the whole building applying menu selection method, so that flexibility in the offer can accommodate and integrate various types of living.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.41-52
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• 2011

This study was carried out to investigate the effect of energy saving and sound insulation of building materials mixed with charcoal. To investigate the functionality of building based on the difference of construction materials, three different experimental buildings were constructed. They were buildings built with the conventional construction materials (A), the charcoal construction materials (B), and the charcoal-sericite construction materials (C). The study showed that energy consumption could be reduced approximately 9.5% and 14.5% by replacing A with B and C, respectively. Especially, it is revealed that the lower outdoor temperature was, the higher energy saving effect was. Also, after shutoff the boiler switch the decrease rate of room temperature of the one using B was lower than those of others using A and C so that the room temperature at the building using B was higher by $3.5{\sim}4.2^{\circ}C$ in the 1 meter air above the ground and by $4.4{\sim}5.4^{\circ}C$ on the floor surface after 12 hours passed. In the building noise test the heavy-and light-weight impact sound of the plate, represented by criterion of noise between floors in multi-story building, tended to decrease in the test sample containing charcoal.

• Smart Structures and Systems
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• v.15 no.2
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• pp.409-424
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• 2015

Structural nonlinearity is a common phenomenon encountered in engineering structures under severe dynamic loading. It is necessary to localize and identify structural nonlinearities using structural dynamic measurements for damage detection and performance evaluation of structures. However, identification of nonlinear structural systems is a difficult task, especially when proper mathematical models for structural nonlinear behaviors are not available. In prior studies on nonparametric identification of nonlinear structures, the locations of structural nonlinearities are usually assumed known and all structural responses are measured. In this paper, an identification algorithm is proposed for locating and identifying model-free structural nonlinearities and systems using incomplete measurements of structural responses. First, equivalent linear structural systems are established and identified by the extended Kalman filter (EKF). The locations of structural nonlinearities are identified. Then, the model-free structural nonlinear restoring forces are approximated by power series polynomial models. The unscented Kalman filter (UKF) is utilized to identify structural nonlinear restoring forces and structural systems. Both numerical simulation examples and experimental test of a multi-story shear building with a MR damper are used to validate the proposed algorithm.

• The KIPS Transactions:PartB
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• v.19B no.3
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• pp.177-182
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• 2012

We propose effective motion and observation models for the position of a WiFi-equipped smartphone user in large indoor environments. Three component motion models provide better proposal distribution of the pedestrian's motion. Our Gaussian interpolation-based observation model can generate likelihoods at locations for which no calibration data is available. These models being incorporated into the particle filter framework, our WiFi fingerprint-based localization algorithm can track the position of a smartphone user accurately in large indoor environments. Experiments carried with an Android smartphone in a multi-story building illustrate the performance of our WiFi localization algorithm.

• Steel and Composite Structures
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• v.21 no.4
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• pp.805-827
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• 2016

A new type of precast CFST column to RC beam braced frame is proposed in this paper. A series of shake table tests were conducted to excite a one-third scale six-story model for investigating the global seismic performance of this type of structure against earthquake actions. Particular emphasis was given to its dynamic property, global seismic responses and failure path. Correspondingly, a numerical model built on the basis of fiber-beam-element model, multi-layer shell model and element-deactivation method was developed to simulate the seismic performance of the prototype structure. Numerical results were compared with the measured values from shake table tests to verify the validity and reliability of the numerical model. The results demonstrated that the proposed novel precast CFST column to RC beam braced frame performs excellently under strong earthquake excitations; the "strong CFST column-weak RC beam" and "strong connection-weak member" anti-seismic design principles can be easily achieved; the maximum deflections of precast CFSTC-RCB braced frame satisfied the deflection limitations proposed in national code; the numerical model can properly simulate the dynamic property and responses of the precast CFSTC-RCB braced frame that are highly concerned in engineering practice.

• Journal of Korean Association for Spatial Structures
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• v.10 no.1
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• pp.75-84
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• 2010

According to the available study and experimental data about the long term behavior of CFT(Concrete Filled Tube) columns, the creep and of concrete in CFT columns are smaller than those of RC columns because of the confinement effect of outer steel columns. In this study, the uncertainties associated with assumed values for concrete properties such as strength, creep coefficients, and service load have been considered and analyzed for the prediction of time-dependent column shortening of CFT column. The CFT column shortening analysis using Monte Carlo method is proposed and an of a 37 story tall building with CFT columns is studied for illustration. According to the results obtained by the probability analysis with multi parameters, the effect of variation coefficient for 3 parameters is investigated considering confidence interval.

• Earthquakes and Structures
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• v.6 no.5
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• pp.561-580
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• 2014

After strong earthquakes conventional frames used worldwide in multi - story steel buildings (e.g. moment resisting frames) are not well positioned according to reparability. Two innovative systems for seismic resistant steel frames incorporated with dissipative fuses were developed within the European Research Program "FUSEIS" (Vayas et al. 2013). The first, FUSEIS1, resembles a vertical Vierendeel beam and is composed of two closely spaced strong columns rigidly connected to multiple beams. In the second system, FUSEIS2, a discontinuity is introduced in the composite beams of a moment resisting frame and the dissipative devices are steel plates connecting the two parts. The FUSEIS system is able to dissipate energy by means of inelastic deformations in the fuses and combines ductility and architectural transparency with stiffness. In case of strong earthquakes damage concentrates only in the fuses which behave as self-centering systems able to return the structure to its initial undeformed shape. Repair work after such an event is limited only to replacing the fuses. Experimental and numerical investigations were performed to study the response of the fuses system. Code relevant design rules for the seismic design of frames with dissipative FUSEIS and practical recommendations on the selection of the appropriate fuses as a function of the most important parameters and member verifications have been formulated and are included in a Design Guide. This article presents the design and performance of building frames with FUSEIS 1-1 based on models calibrated on the experimental results.