• Journal of the Korea Institute of Building Construction
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• v.24 no.3
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• pp.343-354
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• 2024

This study reviewed the existing legal framework governing construction supervision practices and conducted a survey of expert groups to identify and propose strategies for facilitating the digital transformation of construction supervision processes, with the goal of enhancing the quality and safety of construction projects. The research underscored the necessity for digital transformation to improve quality, safety, and efficiency of construction supervision. Additionally, it highlighted the need for greater consistency and clarity in terminology related to construction supervision. The study also presented recommendations for improvement, which included: establishing a structured supervision checklist to ensure safety and compliance, establishing a specialized construction supervision corporations subject to qualification screening, and introducing evaluation criteria to encourage the adoption of digital transformation technologies in construction supervision. The findings of this study are intended to serve as the foundation for future policy and regulatory frameworks aimed at promoting the digital transformation of construction supervision practices.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.311-320
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• 2020

This study conducted a comparative analysis on domestic and foreign computer science curriculum, in order to introduce the data structure education as a core foundation of computer science. The findings show that the scope and level of data structure contents included in elementary school software education are poorer than those in U.S.A and England. To resolve such a problem, it selected some data structure education factors and a Delphi survey about the importance of contents and the fitness of education periods were administered to experts. Although they responded that 'text information', 'array', 'stack' and 'queue' for linear structures', and 'tree' for non-linear structures are important, their opinions were different in education periods by its factors. The generalization of the findings may be limited, given that the analysis was based on the survey of some experts, but this study has an implication, in that it provides important information for improving elementary school software curriculum for the introduction of data structures.

• Journal of the Korean Ceramic Society
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• v.50 no.3
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• pp.231-237
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• 2013

Thermodynamic modeling of the $Ni_{0.5}Zn_{0.4}Cu_{0.1}Fe_2O_4$ complex ferrite system has been adopted as a rational approach to establish routes to better synthesis conditions for pure phase $Ni_{0.5}Zn_{0.4}Cu_{0.1}Fe_2O_4$ complex ferrite. Quantitative analysis of the different reaction equilibria involved in the precipitation of $Ni_{0.5}Zn_{0.4}Cu_{0.1}Fe_2O_4$ from aqueous solutions has been used to determine the optimum synthesis conditions. The spinel ferrites, such as magnetite and substitutes for magnetite, with the general formula $MFe_2O_4$, where M= $Fe^{2+}$, $Co^{2+}$, and $Ni^{2+}$ are prepared by coprecipitation of $Fe^{3+}$ and $M^{2+}$ ions with a stoichiometry of $M^{2+}/Fe^{3+}$= 0.5. The average particle size of the as synthesized $Ni_{0.5}Zn_{0.4}Cu_{0.1}Fe_2O_4$, measured by transmission electron microscopy (TEM), is 14.2 nm, with a standard deviation of 3.5 nm the size when calculated using X-ray diffraction (XRD) is 16 nm. When $Ni_{0.5}Zn_{0.4}Cu_{0.1}Fe_2O_4$ ferrite is annealed at elevated temperature, larger grains are formed by the necking and mass transport between the $Ni_{0.5}Zn_{0.4}Cu_{0.1}Fe_2O_4$ ferrite nanoparticles. Thus, the grain sizes of the $Ni_{0.5}Zn_{0.4}Cu_{0.1}Fe_2O_4$ gradually increase as heat treatment temperature increases. Based on the results of Thermogravimetric Analysis (TGA) and Differential Scanning Calorimeter (DSC) analysis, it is found that the hydroxyl groups on the surface of the as synthesized ferrite nanoparticles finally decompose to $Ni_{0.5}Zn_{0.4}Cu_{0.1}Fe_2O_4$ crystal with heat treatment. The results of XRD and TEM confirmed the nanoscale dimensions and spinel structure of the samples.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.166-166
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• 2002

The response of environmental pollutants can be detected bioanalytically focusing on the source and matrices of concern. Cell culture bioassays are rapid and inexpensive, and thus have great potential for determination of environmental pollution. We have examined the estrogenic and dioxin-like activites of industrial wastewater using E-screen assay and EROD microbioassay. Influent and effluent wastewater were collected from four different industrial wastewater treatment plants, such as cosmetics, paints, textile producing and metal coating plant, and extracted using solid-phase extraction with Oasis＠HLB plus cartridge. Pollutants adsorbed to the cartridge were eluted with MTBE. MCF-7 cells were treated with extracts showed various estrogenic potential. The textile wastewater showed strong estrogenic activity and the others showed weak estrogenic activity, No effect was observed in the wastewater from paints producing plant. All extracts showed CYPIA inducing effects, indicating these samples contain dioxin-like chemicals. Bioanalytical results of effluents compared with influents could give us information about the incomplete wastewater treatment and biological potency caused by pollutants. [Supported by a Grant from the Korea Science and Engineering Foundation]

• Tribology and Lubricants
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• v.30 no.2
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• pp.116-123
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• 2014

The objective of this study is to model and simulate the nonlinear lubrication performance of the sliding part between the piston and cylinder wall in a hydrostatic swash-plate-type axial piston pump. A numerical algorithm is developed that facilitates simultaneous calculation of the rotating body motion and fluid film pressure to observe the fluid film geometry and power loss. It is assumed that solid asperity contact, so-called mixed lubrication in this study, invariably occurs in the swash-plate-type axial piston pump, which produces a higher lateral moment on the pistons than other types of hydrostatic machines. Two comparative mixed lubrication models, rigid and elastic, are used to determine the reaction force and sliding friction. The rigid model does not allow any elastic deformation in the partial lubrication area. The patch shapes, reactive forces, and virtual local elastic deformation in the partial lubrication area are obtained in the elastic contact model using a simple Hertz contact theory. The calculation results show that a higher reaction force and friction loss are obtained in the rigid model, indicating that solid deformation is a significant factor on the lubrication characteristics of the reciprocating piston part.

• Fire Science and Engineering
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• v.28 no.1
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• pp.58-63
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• 2014

This study was performed to propose measures to improve and secure safety in the scene activities of firefighters. First, the majority of firefighters thought that working environment and equipment in fire station were inadequate for perforeming work tasks safely. Second, influential factors threatening safe scene activities mainly arose externally such as insecure working conditions of firefighting or emergency scene. Third, improvement in working environments was pointed out as the most urgent issue to secure safety. Firefighters recognized the expansion of field workforce in system, personnel management and the foundation of hospitals for firefighters hospital in working environment, and the development and distribution of safe equipment and change and inspection of air respirator facepiece on regular basis in equipment as urgent issues to be improved.

• Journal of the Korea Safety Management & Science
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• v.21 no.1
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• pp.1-7
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• 2019

Along with industrial development, various architectural structures have become bigger and higher, leading to an expansion in the size and capacity of construction equipment. And with the development of public transportation, the use of subways as a means of transportation in the city center is increasing, so that vibrations and structural noises are emerging as a new environmental issue. Considering that architectural structures may be used from several decades to hundreds of years after the time of construction, they can be seen as semi-permanent. Due to changes in the vibration-proof polyurethane mats installed in the foundation of these structures, settling may occur and vibration reduction may become inadequate. Therefore, in view of service life, it is necessary to have a high-level standard of reliability and stability. In accordance with this, the Floating Floor System, which uses soft polyurethane foam and can be constructed within a relatively short period of time, has excellent vibration resistant characteristics. It is presented as a great alternative solution to the issue of vibrations caused by subways, railways and building structures. At present, vibration-proof polyurethane mats have been developed up to the same product level as in other advanced countries. However, in the construction of structure foundations, the physical properties of this product and its shape incur changes. If they are installed as such in the structure of a building, it may cause significant impact on stability, requiring that this cause be urgently identified and improved.

• Journal of Information Processing Systems
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• v.3 no.2
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• pp.43-53
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• 2007

The use of agent paradigm in today's applications is hampered by the security concerns of agents and hosts alike. The agents require the presence of a secure and trusted execution environment; while hosts aim at preventing the execution of potentially malicious code. In general, hosts support the migration of agents through the provision of an agent server and managing the activities of arriving agents on the host. Numerous studies have been conducted to address the security concerns present in the mobile agent paradigm with a strong focus on the theoretical aspect of the problem. Various proposals in Intrusion Detection Systems aim at securing hosts in traditional client-server execution environments. The use of such proposals to address the security of agent hosts is not desirable since migrating agents typically execute on hosts as a separate thread of the agent server process. Agent servers are open to the execution of virtually any migrating agent; thus the intent or tasks of such agents cannot be known a priori. It is also conceivable that migrating agents may wish to hide their intentions from agent servers. In light of these observations, this work attempts to bridge the gap from theory to practice by analyzing the security mechanisms available in Aglet. We lay the foundation for implementation of application specific protocols dotted with access control, secured communication and ability to detect tampering of agent data. As agents exists in a distributed environment, our proposal also introduces a novel security framework to address the security concerns of hosts through collaboration and pattern matching even in the presence of differing views of the system. The introduced framework has been implemented on the Aglet platform and evaluated in terms of accuracy, false positive, and false negative rates along with its performance strain on the system.

• World Technopolis Review
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• v.6 no.1
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• pp.5.1-5.12
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• 2017

The Republic of Korea developed a national project to construct a new administrative capital, Sejong city and to relocate administrative organizations of the central government for improvement of overpopulated capital, Seoul and regional balanced development. By the way, to relocate the central administrative organizations was not a sufficient condition for the sustainable development of the city. An industrial infrastructure development has been tried to attract universities, enterprises and research institutions in the region as a demand for internal growth power of the city was increased. In addtion, a basis for regional endogenous growth through projects to establish innovation system based on industry-academia cooperation was prepared as well. This paper reviews the major contents of the development plans for Tech-Valley project and looks into major introductory functions, characterization plans, strategies for fostering strategic industry, cooperation system of the inside and outside the region, and a strategy for building innovation platform. This case can be regarded as a significance of constructing technology infrastructure for the sustainable growth by preparing foundation for establishing innovation system and a cluster based on this system in the process of building and developing new city which did not have any industrial platform in the region.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.5
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• pp.315-323
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• 2015

Damage level of coastal structures has been scaled up according to increase of wave height and duration of the storm due to the abnormal global climate change. So, the design criteria for new breakwaters is being intensified and structural strengthening is also conducted for the existing breakwaters. Recently, interlocking concept has been much attention to enhance the structural stability of the conventional caisson structure designed individually to resist waves. The interlocking caisson breakwater may be survival even if unusual high wave occurs because the maximum wave force may be reduced by phase lags among the wave forces acting on each caisson. In this study, the dispersion characteristics of wave forces using interlocking system that connect the upper part of caisson with cable in the normal direction of breakwater was investigated. A simplified linear model was developed for computational efficiency, in which the foundation and connection cables were modelled as linear springs, and caisson structures were assumed to be rigid. From numerical experiments, it can be found that the higher wave forces are transmitted through the cable as the angle of incident wave is larger, and the larger the stiffness of the interlocking cable makes larger wave dispersion effect.