• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.311-318
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• 2006

CFD simulation is a tool very useful to predict the generation and absorption of the contaminant from the construction materials for the single room condition. However, there is a limit in multi-room simulation for analyzing air movement and contaminant concentration at the condition that the door of each room was closed. A lot of network simulation tool were developed which can used to analyze the mass transfer and contaminant concentration as results in the multi-room condition. However, existing network simulation method was not able to analyze the change of the heating and cooling load with the ventilation as though the change of the indoor air-pollution density was predictable. In this study, new approach to predict heating/cooling load and indoor contaminant concentration will be reviewed. New indoor contaminant concentration module reviewed in this study wad coupled with existing ESP-r network simulation method. The validity of new approach will be analysed for comparison the results of simulation and field measurement results.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.385-385
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• 2012

Understanding the thermodynamics and structural transformation during the Metal-Insulator Transition (MIT) is critical to better understand the underlying physical origin of phase transition in the vanadiumdioxide ($VO_2$). Here, through the temperature-dependent in-situ high resolutiontransmission electron microscopy (HR-TEM), and systematic electrical transport study, we have shown that the tunable MIT transition of $VO_2$ nanowires is strongly affected by interplay between strain and domain nucleation by ion beam irradiation. Surprsingly, we have also observed that the $VO_2$ rutile (R) metallic phase could form directly in a strain-induced metastable monoclinic (M2) phase. These insights open the door toward more systematic approaches to synthesis for $VO_2$ nanostructures in desired phase and to use for applications including ultrafast optical switching, smart window, metamaterial, resistance RAM and synapse devices.

• Fire Science and Engineering
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• v.25 no.3
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• pp.8-13
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• 2011

The fire compartments which are composed of fire walls and fire doors for buildings are compulsorily required to minimize the fire damage in Korea. The performance standards of fire doors for compartments are regulated by the notification of the ministry of land, transport and maritime affairs and are mainly about the Integrity of the doors not insulation. In this study, we measured the radiant heat of six different kinds of fire doors in fire and analyzed the results and presented the reasons of the need to consider adding the radiant heat standard for fire doors to the notification.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.339-347
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• 2005

A type IP-2 transport package should prevent a loss or dispersal of the radioactive contents and a more than $20\%$ increase in the maximum radiation level at any external surface of the package when it were subjected to the drop test under the normal conditions of transport. If a shielding thickness of IP-2 transport package is thick, a bolted lid type may prevent a loss or dispersal of the radioactive contents than the door type of ISO containers which are generally used as a type IP-2 transport package. In this paper, to evaluate the effect of drop directions on the bolt tension and the coherence of a bolt, the drop tests of preliminary small model are tested and evaluated for seven directions before the drop test of a type IP-2 transport package with a bolted lid type under the normal conditions of transport. Seven drop directions which are a bottom-vertical drop, a lid-vortical drop. a horizontal drop and four corner drops have been carried out. Using a force sensor, the bolt tension during the drop impact is measured. The coherence of bolt is evaluated by the difference between the fastening torque of bolt before a drop test and the unfastening torque of bolt after a drop impact.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.727-736
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• 2021

Road tunnel lengths are increasing. Some 1,300 tunnels with 1,102 km in length had been increased till 2019 from 2010. There are 64 tunnels over 3,000 m in length, with their total length adding up to 276.7 km. Safety facilities in the event of a tunnel fire are critical so as to prevent large-scale casualties. Standards for installing disaster prevention facilities are being proposed based on the guidelines of the Ministry of Land, Infrastructure and Transport, but they may be limited to deep underground tunnels. This study was undertaken to provide guidelines for the spacing of evacuation connection passages and the widths of evacuation connection doors. Evacuation with various spacing and widths was simulated in regards to evacuation time, which is the measure of safety, using the evacuation analysis simulation software EXODUS Ver.6.3 and the fire/smoke analysis software SMARTFIRE Ver.4.1. Evacuation connection gates with widths of 0.9 m and 1.2 m, and spacings of 150 m to 250 m, were set to every 20 m. In addition, longitudinal slopes of 6 % and 0 % were considered. It was determined to be safe when the evacuation completion time was shorter than the delay diffusion time. According to the simulation results, all occupants could complete evacuation before smoke spread regardless of the width of the evacuation connection door when the longitudinal slope was 6 % and the interval of evacuation connection passage was 150 m. When the evacuation connection passage spacing was 200 m and the evacuation connection gate width was 1.2 m, all occupants could evacuate when the longitudinal slope was 0 %. Due to difference in evacuation speed according to the longitudinal slope, the evacuation time with a 6 % slope was 114 seconds shorter (with the 190 m connection passage) than with a 0 % slope. A shorter spacing of evacuation connection passages may reduce the evacuation time, but this is difficult to implement in practice because of economic and structural limitations. If the width of the evacuation junction is 1.2 m, occupants could evacuate faster than with a 0.9 m width. When the width of a connection door is 1.2 m with appropriate connection passage spacing, it might provide a means to increase economic efficiency and resolve structural limitations while securing evacuation safety.

• Korean Institute of Interior Design Journal
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• v.26 no.5
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• pp.143-151
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• 2017

This study aims to analyze the design of public libraries which act as anchors in culture-led urban regeneration. They have been built as city's symbols as well as catalysts to revitalize city centers and urban spaces since the 1990s. This study finds that the public libraries play roles in the urban development as cultural icons, multi-functional spaces, and public domain. This study examines the five examples of the libraries and finds their important design qualities as follow. First, public libraries are planned to symbolize local culture and history as cultural icons. The shapes of public libraries are expressed with sculptured cultural icons, while their facades are designed to signify cities' identities and images. Second, public libraries in culture-led urban regeneration have multi-functional spaces which provide diverse activities and experiences to visitors. The libraries often have galleries and theaters for cultural life, cafes and shops for daily uses, educational facilities, as well as public services, parking, and transport systems that connect to urban infrastructure. Third, the public libraries become the anchors of surrounding public spaces and cultural buildings. The libraries have the sequences of approach from entry plazas, transitional zones, and entrances to lobbies. Especially the transitional zones between the libraries and the cities that are covered with giant cantilevers expand the libraries' space and establish attractive urban spaces. Forth, the libraries employ nature and cityscapes in their design. The surfaces and openings of the libraries are adjusted to allow many attractive views to visitors. Fifth, the libraries have big lobby spaces which are the centers of the buildings as well as the public domain. The lobby spaces are designed as in-door spaces like out-doors with vertical and horizontal openness that allow the natural flows of light from ceilings, glass walls and vertical voids.

• Journal of the Korean Society of Safety
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• v.39 no.1
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• pp.55-61
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• 2024

In response to the COVID-19 pandemic, the logistics industry in Korea has rapidly been expanding, with offline demand concentrating on online platforms owing to the development of digital infrastructure. This has increased the workload of courier drivers considerably, along with labor intensity. A delivery driver died recently from overwork due to the continuous increase in delivery volume, which raises social concerns. Delivery drivers work long hours, (over 12 hours) and are greatly affected by weather conditions, such as snow, rain, heat waves, and cold waves. In addition, they lack a fixed workplace; perform atypical work handling workpieces of various sizes, weights, and shapes; and spend a large amount of time driving as part of their work. This work involves a high level of tension and requires attention and concentration. Despite the frequency of industrial accidents in the courier industry, studies on safety and health to quantitatively analyze and systematize the work of courier workers are very scarce. Therefore, to define the work process necessary for investigating the harmful factors in delivery service and the work analysis, this study conducted interviews and on-site surveys to analyze the unit work of the delivery service by targeting delivery workers. In other words, a framework of unit work for work analysis was presented to enable research and analysis by considering the aforementioned characteristics of the courier industry. The process was broadly divided into work, transport, storage, delay, and inspection. Work was divided into loading, sorting, unloading, and door subcategories, and transportation was divided into vehicle, cart, and walking subcategories as well as 10 small processes. Moreover, 22 unit works were again drawn by conducting field surveys and interviews. The risk of unit work derived from this study was ergonomically evaluated, and the ergonomic analysis revealed that uploading and transportation were the most dangerous. The results of this study could be used as basic data for preventing industrial accidents among courier workers, whose work has increased with the logistics volume and the development of the logistics industry.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.83-90
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• 2023

In a reefer container, temperature deviation occurs between the front of the loading part with the refrigerator and the rear of the loading part with the container door due to the external environment. In particular, this temperature deviation in the transport of fresh cargo has a great influence on the freshness of the cargo. In this study, we propose a method to minimize the temperature deviation by partially shielding the T-Floor to reduce the temperature deviation and evaluating the effect of the T-Floor shielding rate on the temperature change of the reefer container loading part. The subject of the experiment was a 40 feet smart reefer container, and the T-Floor shielding rates were set to 0%, 50%, 60%, 70%, and 80%. As a result of the experiment, it occurred differently in the temperature deviation of the reefer container loading part according to the shielding rate, and it was confirmed that the temperature deviation was the most uniform when the shielding rate was 60%. By minimizing the temperature deviation of the loading part, it is possible to prevent corruption and cold damage of cargo during transportation of fresh cargo by using the smart reefer container.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2183-2190
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• 2013

Container Security Device (ConTracer) which is suggested in this study is to monitor temperature, humidity, and impact inside of the container while the container is transported. ConTracer could also give information to users when a door of the container is opened over 2 inch within 1 second. Additionally, GPS/GLONASS based global position and status information about container are transmitted to a remote server using IoT (Internet of Things) based communication. In this research, we are looking into the development trend of global container security devices; and applying ConTracer to real freight transport from domestic to overseas using Global Roaming Service which is offered for domestic Mobile Communication Companies as well. As a result, we estimate the performance of ConTracer and verify it.

• Fire Science and Engineering
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• v.32 no.4
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• pp.7-16
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• 2018

In this study, the prediction performance of design fire curves (DF) was evaluated for gas fires in a compartment by using CFAST. The CFAST simulations adopted the 2-stage DF suggested by the previous study and the Quadratic and Exponential DF suggested by Ingason. It was found by comparing the simulation and experimental results that the overall prediction performance of the design fire cures for the spatially-averaged temperature and concentrations of $O_2$ and $CO_2$ was, from the most reasonable to the most inaccurate, 2-stage DF > Quadratic DF > Exponential DF. The CFAST simulation could not predict for the difference in the spatially-averaged temperature and concentrations of $O_2$ and $CO_2$ at door and inner side locations in a compartment. The CFAST simulations also showed a limitation in the prediction of the spatially-averaged temperature at lower layer and the concentration of CO.