• Earthquakes and Structures
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• v.13 no.4
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• pp.377-386
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• 2017

Earthquake-induced pounding damages to building structures were repeatedly observed in many previous major earthquakes. Extensive researches have been carried out in this field. Previous studies mainly focused on the regular shaped buildings and each building was normally simplified as a single-degree-of-freedom (SDOF) system or a multi-degree-of-freedom (MDOF) system by assuming the masses of the building lumped at the floor levels. The researches on the pounding responses between irregular asymmetric buildings are rare. For the asymmetric buildings subjected to earthquake loading, torsional vibration modes of the structures are excited, which in turn may significantly change the structural responses. Moreover, contact element was normally used to consider the pounding phenomenon in previous studies, which may result in inaccurate estimations of the structural responses since this method is based on the point-to-point pounding assumption with the predetermined pounding locations. In reality, poundings may take place between any locations. In other words, the pounding locations cannot be predefined. To more realistically consider the arbitrary poundings between asymmetric structures, detailed three-dimensional (3D) finite element models (FEM) and arbitrary pounding algorithm are necessary. This paper carries out numerical simulations on the pounding responses between a symmetric rectangular-shaped building and an asymmetric L-shaped building by using the explicit finite element code LS-DYNA. The detailed 3D FEMs are developed and arbitrary 3D pounding locations between these two buildings under bi-directional earthquake ground motions are investigated. Special attention is paid to the relative locations of two adjacent buildings. The influences of the left-and-right, fore-and-aft relative locations and separation gap between the two buildings on the pounding responses are systematically investigated.

• Wind and Structures
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• v.23 no.3
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• pp.211-229
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• 2016

In recent years, the frequency and duration of supply interruption in electric power transmission system due to flashover increase yearly in China. Flashover is usually associated with inadequate electric clearance and often takes place in extreme weathers, such as downbursts, typhoons and hurricanes. The present study focuses on the wind-induced oscillation of conductor during the process when a downburst is passing by or across a specified transmission line. Based on a revised analytical model recently developed for stationary downburst, transient three-dimensional wind fields of moving downbursts are successfully simulated. In the simulations, the downbursts travel along various motion paths according to the certain initial locations and directions of motion assumed in advance. Then, an eight-span section, extracted from a practical 500 kV ultra-high-voltage transmission line, is chosen. After performing a non-linear transient analysis, the transient displacements of the conductors could be obtained. Also, an extensive study on suspension insulator strings' rotation angles is conducted, and the electric clearances at different strings could be compared directly. The results show that both the variation trends of the transient responses and the corresponding peak values vary seriously with the motion paths of downburst. Accordingly, the location of the specified string, which is in the most disadvantageous situation along the studied line section, is picked out. And a representative motion path is concluded for reference in the calculation of each string's oscillation for the precaution of wind-induced flashover under downburst.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.51-59
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• 2010

Apartment complex, buildings, markets and department stores have inner parking lots which can accept many cars but drivers waste lots of times to find the empty parking spaces in crowding parking lots. In this paper, we proposed the inner parking information support system based on microprocessor which can decrease roaming times to find vacant parking spot in confusing parking lots through notice monitor and provide SMS to make it easy to find parked place. Proposed system consist with RFID system for detecting access of cars, microprocessor system for processing data of checking existence of cars on parking spots and communicating with server, and server system which processes information of cars' in and out, guides empty parking spots and parked location to drivers. Suggested system is realized by handmade model parking lot size of 8 cars, and we confirmed practicality by providing information using parking notice monitor and single message service.

• International Journal of High-Rise Buildings
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• v.10 no.4
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• pp.265-283
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• 2021

To ensure that fire induced collapse of a building is prevented it is important to understand the sequence of events that can lead to this event. In this paper, the initiation of collapse mechanisms of generic a multi-storey steel frame subjected to vertical and horizontal travelling fires are analysed computationally by tracking the formation of plastic hinges in the frame and generation of fire induced loads. Both uniform and travelling fires are considered. In total 58 different cases are analysed using finite element software LS-DYNA. For the frame examined with a simple and generic structural arrangement and higher applied fire protection to the columns, the results indicate that collapse mechanisms for singe floor and multiple floor fires can be each split into two main groups. For single floor fires (taking place in the upper floors of the frame (Group S1)), collapse is initiated by the pull-in of external columns when heated beams in end bays go into catenary action. For single floor fires occurring on the lower floors(Group S2), failure is initiated (i.e. ultimate strain of the material is exceeded) after the local beam collapse. Failure in both groups for single floor fires is governed by the generation of high loads due to restrained thermal expansion and the loss of material strength. For multiple floor fires with a low number of fire floors (1 to 3) - Group M1, failure is dominated by the loss of material strength and collapse is mainly initiated by the pull-in of external columns. For the cases with a larger number of fire floors (5 to 10) - Group M2, failure is dominated by thermal expansion and collapse is mainly initiated by swaying of the frame to the side of fire origin. The results show that for the investigated frame initiation of collapse mechanisms are affected by the fire type, the number of fire floors, and the location of the fire floor. The findings of this study could be of use to designers of buildings when developing fire protection strategies for steel framed buildings where the potential for a multifloor fire exists.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.31-37
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• 2021

Recently, in the market of home appliances, the technical differentiation of products using convergence technology has been receiving a lot of response to satisfy consumer demand. However, air-conditioner products are an area that requires research and development in the early stages of convergence technology. In this paper, it is developed that a non-contact bio-signal(respiration, movement) collection technology using IR-UWB(Impulse-Radio Ultra Wideband) technology, which controls the air-conditioner direction according to the user's location and also monitors sleep to provide an optimal sleep environment. In addition, emotional lighting and ASMR are developed to provide a comfortable and emotional place of life. Finally, based on the developed convergence technology, we develop intelligent smart air-conditioning services for the convenience of daily life and a comfortable resting space.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.411-416
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• 2018

It is generally not preferable to install a turnout on a sharp curves but it is not desirable for the safety of a train. However, in a mountainous area or a depot where a sufficient space can not be secured to secure a straight line. In this study, in order to analyze the cause of train derailment accident that occurred in the place where turnout is installed in a sharp curves, we performed derailment analysis using line data and accident vehicle data measured at the location where the accident occurred. This derailment coefficient maximum turnout at the start of the track and derailment curve analysis showed that even big enough to cause a derailment as 1.37 in size, which was found to be consistent with the actual site survey results derailment occurred.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.25-32
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• 2019

The urban river has played an important role in biodiversity by providing various waterside areas in urban areas that are difficult for organisms to live in. The river is also used as a resting place and experience space for citizens. In particular, Yeouido Saetgang is the first ecological park in Korea, and it is located in the heart of downtown Seoul, making it highly valuable for its location and ecological value. However, water quality issues have continuously been raised since the construction project of Yeouido Saetgang river. So it is necessary to investigate the environment state and analyze the causes of the environment deterioration. In this study, the causes of the river stagnation and water quality deterioration in Yeouido Saetgang river were analyzed. For this, river surveys and aerial photo analysis were used to analyze the causes of difficulties in natural water circulation. Also, the results of monitoring water quality showed that the averaged level of BOD and T-P in dry season is III and IV, respectively, while that of BOD and T-P are V~VI in rainy season. In addition, through the drainage analysis of sewer network, small drainages that affect the water quality in Saetgang river was selected and discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.243-250
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• 2018

This paper designs and implements a smart care system for the senior citizen who lives alone. Recently, as the level of living has increased due to the rapid improvement of medicine, living standard and environment, the proportion of the elderly population is increasing. In addition, the proportion of the elderly living alone, which is increasing with the aging society, suggests that the provision of services such as the elder care system and emergency notification is becoming an important issue. However, since the existing emergency notification technology analyzes fixed CCTV images, it is difficult to monitor in the blind spot of CCTV and to move to a place where the camera is not installed. There is a problem that it can not be performed. Therefore, in this paper, we design and develop a smart care system that utilizes robot and object tracking technology that can move in real time to overcome these shortcomings. This enables real-time monitoring regardless of the location, and prompts for assistance in case of an emergency, so that it can provide convenience to cares and assistants.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.8
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• pp.77-86
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• 2018

The purpose of this study is to examine the condition of the architectural location and the history of Yeongbojeong and investigate the motivation which formed the YuSik space and the poetical circles of it. And another purpose of the study is to discover how Yeongbojeong, located in a military camp in Western coast, displayed the poetic scenery so to be the poetic summer house among so many Nujeongs in Joseon. Yeongbojeong is currently located in Soseong-ri, Ocheon-myeon, Boryeong City, Chungnam. Yeongbojeong has the biggest size among all the summer houses in the country with 24 architectural rooms. And Yeongbojeong is not only the summer house in which people could simply see its scenery, but beyond the poetic space of Joseon, it was the unique poetic summer house which enables poets and calligraphers to enjoy imaginary freedom. The time range of the study was from the building of Yeongbojeong in 1504 to its demolish in 1901, and its space range was taken focused on the particular scenery which was seen from around Yeongbojeong. To investigate the architectural aspect of Yeongbojeong, the existing records about the summer houses, "OcheonGoonJi" and the landscape paintings etc. were referred. The travel records and poems in the work collection of the famous poets who explored Yeongbojeong were referred to examine the formation of the Yeongbojeong poetical circles. The result of the study shows the process that Yeongbojeong had become the famous national place with scenery and how it became the most visited YuSik space. And this study figured out the full account of Yeongbojeong poetical circles which had been formed by so many poets of the country for 4 hundred years.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.11
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• pp.145-156
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• 2018

Urban campus, one of the main urban facilities, is the representative place that is struggling with 'gridlock'. Due to privatization of space among different departments and space shortages, gridlock has been occurring as a result. The urban campus trying to solve this problem by changing the quality of space, especially the structure of the shared space, which is expected to be the solution to the grid lock problem. The main purpose of this study is to investigate the structural change in the university's shared space based on paradigm transition. The theoretical consideration is to analyze the spatial characteristics of university shared space that appear at different stages through a new perspective that compares the gridlock phenomenon and the shared paradigm. The framework of the analysis of the shared space, which has recently been restructured, is classified into the spatial characteristics of collaborative space, the creative space, and the common/complex space. In addition, these spatial characteristics are again analyzed through the division of legislative facility classification, management governance subject, area, building location and layout, exposure to the outside as well as the analysis of student and staff entry and exit, sharing structure of site and space, and the classification of program characteristics. The results are as follows: The restructured space is systemized so that the management governance of each space would be connected to each other to share information and space. Furthermore, the spatial boundary between colleges or between campus spaces are not only physically, but categorically clear. The restructured space has semi (or in-between)-spatial characteristics such as the intersection in inside and outside of the pedestrian's circulation and the mixture of programs. This study could serve as principal references in presenting the systematic analysis of directions of the shared spatial structure for the urban campus where new educational space is required due to the changes in the university system.