• International conference on construction engineering and project management
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• 2005.10a
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• pp.587-591
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• 2005

The case of laboratory-acquired SARS Corona virus infection in Taiwan has revealed a number of weaknesses in management, construction, and oversight of laboratories. Also, with the increased demands for bio-safety laboratory, there is an urgent need to develop a uniform and comprehensive guidance for architects and construction engineers in the preparation of design and construction. This research investigates the key elements for designers, engineers, and potential owners in biosafety laboratory design and construction. It defines key elements and determines major relationships and standards that should be adhered to when developing site layout. In addition to layout planning and design guidance of biosafety laboratory, this research also interviews the perspective of architects and survey the state-of-the-art technology in Taiwan. It represents the portraits by site investigation. The purpose of the research is to provide guideline of design and avoid potential future conflict to ensure the critical continuity of functions.

• Geomechanics and Engineering
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• v.38 no.4
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• pp.421-437
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• 2024

The soil nailing method entails the utilisation of nails to reinforce and stabilise a zone of soil mass. This is widely used for various applications due to its effective performance under various loading conditions. The seismic response of 6m high vertical soil-nailed cut in various site classes under dynamic excitations has been investigated in this study considering various lengths and inclinations of nails. The influence of frequency content of dynamic excitation on the response of structure has been assessed through finite element analysis using time history data of three different earthquakes. The seismic stability of the nailed cut in retaining soil in various sites under El Centro, Kobe and Trinidad earthquake ground motion is evaluated based on maximum acceleration response, maximum horizontal deformation, earth pressure distribution on the wall and maximum axial force mobilised in nails. The optimum nail inclination is identified as 15° and a minimum nail length ratio of 0.7 is essential for a stable vertical cut under dynamic excitations.

• Journal of Korea Foundry Society
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• v.31 no.6
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• pp.362-365
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• 2011

In the present work, the corrosion properties of Mg-xSn (x = 1, 3, 5, 7 and 9 wt.%) alloys have been investigated. Potentiodynamic polarization and immersion tests were carried out in 3.5% NaCl solution of pH 7.2 at room temperature to measure the corrosion properties of Mg-xSn (x = 1, 3, 5, 7 and 9 wt.%) alloys. With increase of the Sn contents, the volume fraction of the $Mg_2Sn$ phase was increased. The corrosion rate of Mg-xSn alloys was increased up to 7 wt.%Sn and decreased above 9 wt.%Sn. Initiation of galvanic site during immersion mainly occurred at Mg/$Mg_2Sn$ interface and propagation went into ${\alpha}$-Mg. For this reason, corrosion properties of Mg-xSn (added from 1 wt.%Sn to 7 wt.%Sn alloys) alloys are decreased because the galvanic site was increased with increasing Sn addition. In Mg-9wt.%Sn alloy, however, the corrosion site were changed from Mg/$Mg_2Sn$ interface to ${\alpha}$-Mg/$M_2Sng$ interface in lamellar structure. Preferentially corrosion of ${\alpha}$-Mg/$M_2Sn$ interface in lamellar structure impeded corrosion propagation went into ${\alpha}$-Mg.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.460-466
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• 2012

Perchlorate is used in a number of applications as an oxidizer in solid propellants, munitions and fireworks and is one of the endocrine disrupting chemicals, which interferes with iodide uptake into the thyroid gland. The purpose of this study was to investigate perchlorate occurrence and distribution with a results of analysis of 94 samples collected from military facilities in Korea from October 11 to October 23, 2011. Overall, among all of the 94 samples analyzed, perchlorate was detected in 6.4% of the total number of samples above $4{\mu}g/L$ (minimum reported limit) and the average concentration was $26.1{\mu}g/L$ and the maximum concentration was $107.7{\mu}g/L$ which was observed in surface water near manufacturing site of ammunition. By site classification, perchlorate was detected at one site in 4 manufacturing sites of ammunition and the maximum concentration was $107.7{\mu}g/L$ which was six times higher than that in guideline for perchlorate in Nakdong River and resulted from point source discharge. Perchlorate was detected at 3 sites in 78 measurements for shooting area and the maximum concentration was $12.4{\mu}g/L$ which was collected in dringking water and perchlorate in another sample was detected above MRL in shooting area was collected right away after shooting. These results showed that long term monitoring was needed considering weather conditions and shooting schedules.

• Earthquakes and Structures
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• v.8 no.6
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• pp.1363-1386
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• 2015

The October 23 2011 Van Earthquake is studied from an earthquake engineering point of view. Strong ground motion processing was performed to investigate features of the earthquake source, forward directivity effects during the rupture process as well as local site effects. Strong motion characteristics were investigated in terms of peak ground motion and spectral acceleration values. Directiviy effects were discussed in detail via elastic response spectra and wide band spectograms to see the high frequency energy distributions. Source parameters and slip distribution results of the earthquake which had been proposed by different researchers were summarized. Influence of the source parameters on structural response were shown by comparing elastic response spectra of Muradiye synthetic records which were performed by broadband strong motion simulations of the earthquake. It has been emphasized that characteristics of the earthquake rupture dynamics and their effects on structural design might be investigated from a multidisciplinary point of view. Seismotectonic calculations (e.g., slip pattern, rupture velocity) may be extended relating different engineering parameters (e.g., interstorey drifts, spectral accelerations) across different disciplines while using code based seismic design approaches. Current state of the art building codes still far from fully reflecting earthquake source related parameters into design rules. Some of those deficiencies and recent efforts to overcome these problems were also mentioned. Next generation ground motion prediction equations (GMPEs) may be incorporated with certain site categories for site effects. Likewise in the 2011 Van Earthquake, Reverse/Oblique earthquakes indicate that GMPEs need to be feasible to a wider range of magnitudes and distances in engineering practice. Due to the reverse faulting with large slip and dip angles, vertical displacements along with directivity and fault normal effects might significantly affect the engineering structures. Main reason of excessive damage in the town of Erciş can be attributed to these factors. Such effects should be considered in advance through the establishment of vertical design spectra and effects might be incorporated in the available GMPEs.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.1-6
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• 2020

Recently, ex-situ remediation technologies has been emerging to clean up contaminated soils mainly because the in-situ techniques have limited applicability and technical difficulties in relatively small contaminated sites. Accordingly, implementation of off-site treatment and disposal have been continuously increased in soil remediation and restoration projects in Korea. However, in many cases, reclaimed soil is still not properly recycled or reused. Therefore, there is an urgent need to document the current status of soil management practices in soil remediation projects in the nation. This study presents a survey of soil contamination status and remedial approaches in Korea based on soil cleanup projects completed in 2015 - 2019, and proposes the possible options of the recycling or reusing the reclaimed soils under compliance with related regulations. The results of the soil survey showed soil contamination was most severe in gas stations, industrial facilities, and military areas. The major types of pollution were related to the petroleum-contaminated site (TPH and BTEX) with 77.0% occurrence in all the contaminated sites. The reclaimed soils were mostly reused as a ground filling-up soils in industrial facilities (60.0%) and warehouses (37.0%).

• International conference on construction engineering and project management
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• 2022.06a
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• pp.563-570
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• 2022

Industrialized and modular construction is a growing construction technique that can transfer a large portion of the construction process to off-site fabrication yards. This method of construction often involves the fabrication, pre-assembly, and transportation of massive and long volumetric modules. The module weight keeps increasing as the modules become more complete (with infill) to minimize the work at the site and, as higher productivity can be achieved at the fabrication shop. Thus, a volumetric module delivery gets more challenging and risky. Despite its importance, past research paid relatively insufficient attention to the problem related to the lifting of heavy modules. This can be a complex and time-consuming problem with multiple lifting for transportation-and-installation operations both in fabrication yard and jobsite, and require complex crane operations (sometimes, more than one crane) due to crane load capacity and load balance/stability. This study investigates this problem by focusing on the structural perspective of lifting such long volumetric modules through simulation studies. Various scenarios of lifting a weighty module from the top using four lifting cables attached to crane hooks (either a single crane or double crane) are simulated in SAP software. The simulations account for various factors pertaining to structural indices, e.g., bending stress and deflection, to identify a proper method of module lifting from a structural point of view. The method can identify differences in structural indices allowing identification of structural efficiency and safety levels during lifting, which further allows the selection of the number of cranes and location of lifting points.

• Journal of Soil and Groundwater Environment
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• v.13 no.2
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• pp.21-29
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• 2008

Sorption and desorption processes play an important role in the transport and fate of organic contaminants in subsurface system. In this study, sorption and desorption characteristics of atrazine in 7 soils selected at the Gwangju area were investigated. Soil organic carbon contents ranged from 0.42 to 2.82%. Sorption and desorption experiments were performed in batch slurries. Sorption distribution coefficient ($K_d$) of atrazine were ranged from 0.48 to 3.26 l/kg and $K_d$ value increased with increasing organic carbon contents except of Kyongbang and Youngdong soils. Single desorption data were analyzed by the three-site desorption model including equilibrium, non-equilibrium and non-desorbable site. Non-desorbable site fractions of atrazine in all soils were enumerated and non-desorbable atrazine was observed in seriesdilution desorption experiment. Sorption/desorption hysteresis was also observed in the series-dilution desorption experiment.

• Journal of Advanced Navigation Technology
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• v.11 no.3
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• pp.259-265
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• 2007

Systematic components for implementing ubiquitous computing, for example, electronic devices, electric home appliances, and controllers, etc, are consist of not only circuits but also softwares expected to do some special system-controlling functions, and these softwares used to be called like as embedded software. Because embedded software is a core component controlling systems, the codes or control flows should be protected from being opened to the public or modified. Embedded software security can be divided into 2 parts: first is the unauthorized access to development site and embedded software, second is the unauthorized disclosure or modification. And this research is related to the first aspect of them.This paper proposes some security check requirements related to embedded software development site by analyzing the ALC_DVS.1 of the ISO/IEC 15408 and Base Practices (BPs) of the ISO/IEC 21827. By applying this research, we expect to protect unauthorized modification of embedded software indirectly.

• Journal of the Korean GEO-environmental Society
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• v.14 no.8
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• pp.45-51
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• 2013

In the construction site of underground buildings which have severe environment such as dust, noise, vibration, the technology of rescue the builders in the construction site when accident occurs by tracking the location of the builders and express the mission of supervisor smoothly. In this study, in order to acquire the location information of the builders in the construction site of underground buildings by using MEMS INS and air pressure sensor, we firstly performed the field test in construction site, analyzed the location and the elevation accuracy based on the detected results, and then verified its practicality and rationality after all. As a result, we could acquire worker's position-accuracy within 10m in horizontal direction and 4m in vertical direction. Therefore we could judge availability in construction fields of underground structure.