• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.99-106
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• 2017

Recently, the condensation and mold problems of apartment buildings has been growing due to high insulation and high air-tightness performance for energy saving. Most of all, occupants in residential buildings has suffered from property damages due to the condensation and mold of built-in furniture. Condensation at built-in furniture were generally found in winter at the of furniture's back panels, adjacent surfaces of wall, floor and ceiling. The aim of paper is to analyze the characteristics of adjacent area around built-in furniture's condensation problem and the thermal environment around the built-in furniture in winter through the field measurements at apartment buildings. In this research, the thermal conditions and surface temperature around the built-in furniture were measured during winter season. In this research, we analyzed thermal conditions for built-in furniture which were applied and not applied auxiliary heating device. In results, it is important to consider increasing surface temperature for using heater and decreasing absolute humidity due to the occupants' behavior around built-in furniture for preventing condensation.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.156-158
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• 2007

Laser wave length can have evaporation effect by absorption because outer skin or tissue of focus is consisted of water almost though absorption of water occurs more than 90% almost in formation thickness of very thin floor Can operate outer skin, steam by floor and correct incision of formation is available. Suture surgical operation is avaliable to vein or lymph system and surgical operation region can dry and see as eye and radish bleeding surgical operation is avaliable Specially, stability of tube both end output about pulse by weight very, this research can cause various curative effect because can reduce bulk and control easily current wave style of medical laser using electric power conversion device of high frequency way. If introduce ZVS (Zero Voltage Switching) or ZVZCS (Zero Voltage and Zero Current Switching), is more profitable because can reduce switching damage Because electric power department of proposed medical laser can do stable soft-switching in wide subordinate extent introducing ZVZCS technique by the first help and control department composes microcontroller, output current waveform user have free form make. Result that experiment because design and manufacture, brought result that improve of 20% than existing equipment, and will be bought to get into superior result if supplement as systematic late.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.4
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• pp.386-394
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• 2012

Recent trends in the flexible manufacturing systems are morphing cell control for the shop-wide production operation system and providing the integrated operation and execution system together with vendor-specific FMC/FMS platform. In these requirements, the shop-floor level operation system plays a role of coordinating the control activity of each cell, and has to provide flexibility for the complexity of mixed operations of various cells. This paper suggests a system architecture for the mixed environments of multi-cells and job shop, its corresponding enabling technologies based on comparative studies with other related studies and commercialized systems. This approach includes a process definition model considering the integration with upper BOM-BOP and external service modules, and reconfigurable device-level interface which provides dynamic interconnections with machine tools and cell controllers. The function modules and their implementation results are also described to provide the feasibility of the proposed approaches as the flexible shop-floor operation system for the multi-cell environments.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.52-54
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• 2007

Laser wave length can have evaporation effect by absorption because outer skin or tissue of focus is consisted of water almost though absorption of water occurs more than 90% almost in formation thickness of very thin floor. Can operate outer skin, steam by floor and correct incision of formation is available. Suture surgical operation is available to vein or lymph system and surgical operation region can dry and see as eye and radish bleeding surgical operation is available. Specially, stability of tube both end output about pulse by weight very, this research can cause various curative effect because can reduce bulk and control easily current wave style of medical laser using electric power conversion device of high frequency way. If introduce ZVS (Zero Voltage Switching) or ZVZCS (Zero Voltage and Zero Current Switching), is more profitable because can reduce switching damage. Because electric power department of proposed medical laser can do stable soft-switching in wide subordinate extent introducing ZVZCS technique by the first help and control department composes microcontroller, output current waveform user have free form make. Result that experiment because design and manufacture, brought result that improve of 20% than existing equipment, and will be bought to get into superior result if supplement as systematic late.

• Journal of Korean Association for Spatial Structures
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• v.24 no.3
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• pp.61-68
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• 2024

High-rise buildings are equipped with TMD (Tuned Mass Damper), a vibration control device that ensure the stability and usability of the building. In this study, the seismic response control performance was evaluated by selecting the design variables of the TMD based on the installation location of the twisted irregular building. To this end, we selected analysis models of 60, 80, and 100 floors with a twist angle of 1 degree per floor, and performed time history analysis by applying historical seismic loads and resonant harmonic loads. The total mass ratio of TMDs was set to 1.0%, and the distributed installation locations of TMDs were selected through mode analysis. The analysis results showed that the top-floor displacement responses of all analysis models increased, but the maximum story drift ratio decreased. In order to secure the seismic response control performance by distributed installation of TMDs in twisted irregular buildings, it is judged that the mass ratio distribution of TMDs will act as a key variable.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.4 s.310
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• pp.35-44
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• 2006

The network induced transmission delay deteriorates the performance and stability of the real-time distributed control system on LonWorks over IP (LonWorks/IP) virtual device network (VDN). LonWorks/IP virtual device network is an integrated form of LonWorks device network and IP data network. The time delay in servo control on the LonWorks/IP-based VDN has highly stochastic nature. In the real-time distributed servo applications for predictive maintenance on the factory floor, timely response is essential.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.13-20
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• 2021

Recently, various piloti structures have been constructed in Korea to secure residential and parking spaces. However, these piloti structures have been constructed in the form of protruding columns without walls to secure parking spaces on the first floor. In this form, when an earthquake occurs, the column is relatively easily damaged compared to general structures, and such damage can lead to the collapse of the structure. Therefore, in this study, a study on securing the safety of the piloti structure using the MPS (Multi Performance System) seismic isolation device was conducted. Nonlinear dynamic analysis according to the presence or absence of MPS seismic isolation device was performed on the existing piloti structure, and analysis results were compared and analyzed. Finally, each seismic performance evaluation was performed and the superiority of the MPS seismic isolation device was verified.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.899-906
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• 2017

This paper proposes an inter-floor noise prevention system using an open-source controller. In the proposed system, Arduino which is a widely used open source controller analyzes sound signals and vibration signals with fast fourier transform. When the magnitude of the band-passed signal excesses the noise reference considering transmission loss of a panel or a wall, the system displays warning messages on an LCD module and a mobile device for users to be aware of the noise condition. In the experiment, the system has succeeded extracting and processing the band-passed signals between 130 Hz ~ 1040 Hz. When the magnitude of the extracted signal that is subtracted from the transmission loss exceeds 45 dB, the system has displayed the warning message on an LCD module and a mobile devicefor noise reduction.

• Journal of Environmental Health Sciences
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• v.35 no.5
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• pp.355-361
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• 2009

This study evaluated the bacterial concentrations and affecting factors at the laboratories of a university in Seoul, Korea. Thirty-three samples of total airborne bacteria (TAB) and eighteen samples of gram negative bacteria (GNB) were collected from both microbiology laboratories (7) and chemistry laboratories (6). GM (GSD) of TAB and GNB concentrations were 194 (2.52) $cfu/m^3$, 24 (4.1) $cfu/m^3$, respectively. TAB concentrations in the chemical laboratories (GM (GSD): 193 (2.0) $cfu/m^3$) were not significantly different from those in microbial laboratories (GM (GSD): 202 (2.7) $cfu/m^3$, (p>0.05)). GM (GSD) of TAB concentrationsat the top of sink, the center of laboratory, and the front of ventilation ventilation device within laboratories, 182 (3.2) $cfu/m^3$, 217 (2.2) $cfu/m^3$, 176 (2.4) $cfu/m^3$, respectively, were not significantly different (p=0.48). Related factors were measured such as temperature, relative humidity, floor of laboratory, number of persons and laboratory area. TAB concentrations were significantly related to temperature (r=0.36, p<0.05), and the floor of laboratory and temperature were also significantly related (r=0.49, p<0.001). However, other factors such as relative humidity, number of persons and laboratory area did not show any significant relationship with TAB concentrations (p>0.05). TAB concentrations were affected significantly by cleaning frequency (p<0.001) and floor of laboratory (p<0.05). There was also a significant difference (p<0.01) between TAB indoor concentrations and TAB outdoor concentrations. However, other factors such as general ventilation did not affect TAB concentrations (p>0.05) in this study.

• Structural Monitoring and Maintenance
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• v.8 no.4
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• pp.329-344
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• 2021

The use of structural control devices to minimize structural response to seismic/dynamic excitations has attracted increased attention in recent years. The use of magnetorheological (MR) dampers as a control device have captured the attention of researchers in this field due to its flexibility, adaptability, easy control, and low power requirement compared to other control devices. However, little attention has been paid to the effect of configuration and number of dampers installed in a structure on responses reduction. This study assesses the control of a five-story structure using one and two MR dampers at different stories to determine the optimal damper positions and configurations based on performance indices. This paper also addresses the fail-safe current value to be applied to the MR damper at each floor in the event of feedback or control failure. The model is mathematically simulated in SIMULINK/MATLAB environment. Linear control strategies for current at 0 A, 0.5 A, 1 A, 1.5 A, 2 A, and 2.5 A are implemented for MR dampers, and the response of the structure to these control strategies for different configurations of dampers is compared with the uncontrolled structure. Based on the performance indices, it was concluded that the dampers should be positioned starting from the ground floor, then the 2^nd floor followed by 1^st and rest of the floors sequentially. The failsafe value of current for MR dampers located in lower floors (G+1) should be kept at a higher value compared to dampers at top floors for effective passive control of multi-story structures.