• Journal of Energy Engineering
• /
• v.23 no.1
• /
• pp.40-45
• /
• 2014

The ventilation frequency of 0.5 times in residential facilities is applied mandatorily to the housing facilities containing more than 100 house units to improve the indoor air quality and create comfortable interior conditions and pleasantness for residents. The Building Energy Efficiency Rating system requires the implementation of leakage test based on ventilation frequency with the test results being reflected in the efficiency ratings, thereby stimulating the precise construction of the fittings in the periphery of windows and savings of energy that can be lost due to the infiltration air. The inspection results of the Building Energy Efficiency Rating at the site showed that the ventilation frequency was in the range between 0.63 and 0.71 and that the difference was found to have a significant effect on the amount of energy reduction. It is urgent to conduct the study on highly leakage-proof buildings and construction methods, along with the expansion of mandatory leakage-proof diagnosis of non-residential buildings, considering the mandatory ventilation frequency below 0.6 for passive houses under the European standards and the target set by Korea to introduce the passive house, the rigorous standard for energy efficiency in buildings and mitigating their ecological footprint, by 2017 and achieve the zero house by 2025.

• Korean Chemical Engineering Research
• /
• v.52 no.5
• /
• pp.667-671
• /
• 2014

In this study, we suggest a facile method to control conditions of single component independently when preparing consisting two-component metal oxides nanofiber by simply dispersing nanoparticles in precursor solution. The well dispersed $SiO_2$ nanoparticles in $TiO_2$ nanofibers were successfully synthesized through a simple electrospinning process. The as-synthesized nanodfibers were investigated via FE-SEM, XRD and EDS for structural studies, furthermore, the analysis of UV-VIS and photocatalytic activity were carried out for demonstrate the effect of $SiO_2$ nanoparticles dispersed in $TiO_2$ nanofibers. As a result, $TiO_2$ nanofibres dispersed with $SiO_2$ nanoparticles have enhanced photocatalytic activity than that of $TiO_2$ nanofibres only. In this strategy, the introduction of $SiO_2$ nanoparticles in $TiO_2$ nanofibers were attribute to enlarge absorption in the visible region (380~440 nm). Additionally, $Br{\o}nsted$ acid sites generated in each metal oxide of Ti and Si increase OH radicals efficiently as well as it limit recombination loss by holding photogenerated electrons for high efficient photocatalytic activity.

• Geophysics and Geophysical Exploration
• /
• v.11 no.4
• /
• pp.350-360
• /
• 2008

Electrical resistivity is one of physical property of the earth and measured by electrical resistivity survey, electrical resistivity logging and laboratory test. Recently, electrical resistivity is widely used in determination of rock quality in support pattern design of road and railway tunnel construction sites. To get more reliable rock quality data from electrical resistivity, it needs a lot of test and study on correlation of resistivity and rock quality. Firstly, we did rock property test in laboratory, such as P wave velocity, Young's modulus, uniaxial compressive strength (UCS) and electrical resistivity. We correlate each test results and we found out that electrical resistivity has highly related to P wave velocity, Young's modulus and UCS. Next, we accomplished electrical resistivity survey in field site and carried out electrical resistivity logging at in-situ area. We also performed rock classification, such as RQD, RMR and Q-system and we correlate electrical resistivity to RMR data. We found out that electrical resistivity logging data are highly correlate to RMR. Also we found out that electrical resistivity survey data are lower than electrical resistivity logging data when there are faults or fractures. And it cause electrical resistivity survey data to lowly correlate to RMR.

• Tunnel and Underground Space
• /
• v.19 no.6
• /
• pp.490-497
• /
• 2009

The horizontal and vertical response spectra using the observed ground motion from the recent 5 macro earthquakes were analysed and then were compared to both the seismic design response spectra(Reg Guide 1.60), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings(1997). 74 horizontal and 89 vertical observed ground motions, without considering soil types, were used for normalization with respect to the peak acceleration value of each ground motion. The results showed that the horizontal MPOSD(Mean Plus One Sigma Standard Deviation) response spectra revealed much higher values for the whole frequency bands above 1 Hz than Reg. Guide(1.60). For the vertical response spectra, the results showed slightly higher than just between 7 and 8 Hz frequency band. The results were also compared to the Korean Standard Response Spectrum for the 3 different soil types and showed that the horizontal MPOSD response spectra revealed much higher values for the whole periods below 2 second(0.5 Hz) than those of SE soil type. The vertical response spectra showed similar to the values of the Korean Standard Response Spectrum of SD soil type. These spectral values dependent on frequency could be related to characteristics of the domestic crustal attenuation and the effect of each site amplification. However, through the qualitative improvements and quantitative enhancement of the observed ground motions, the conservation of horizontal seismic design response spectrum should be considered more significantly for the whole frequency bands above the 1 Hz.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.4D
• /
• pp.397-406
• /
• 2012

Contributed acceptance system is causing problems with the usefulness and follow-up services and the like, other than the origin purpose which needs to be operated as rational adjustment method between the public interest and the private. Accordingly, this study has examine the problems by analyzing the present condition of practical public facilities and has the purpose on drawing the improvements by conducting consciousness survey from in substance users. The problems drawn from the analysis and the survey are location and position of the public facilities by reason of making public facilities at leftover land, the awareness and use as in-site facilities, creating street facilities without considering the use and safety of the users, follow-up service issues and the usefulness issues by creation without considering the surrounding conditions. The proposal of improvements for efficient operation by each problems are devising plans by considering location and position of the facilities for utilization and usefulness, secondly the necessity of the public relations for the improvements of the utilization of public facilities. thirdly, conducting the legal obligation by installing direction boards for its awareness of public facilities and delegating operation of facilities to public corporations such as SH, LH and inhabitants for efficient follow-up services, lastly, establishing the public facility map service which could figure out the surrounding conditions of public facilities to utilize for the contributed acceptance.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.4 no.3
• /
• pp.13-20
• /
• 2001

The purpose of this study is development of the management and guide system for convenient use of new address guide system for systematic management and use of spatial information gained by mapping of numerical map of building and road to large basic new address, survey and input of main gate, decision of the road session, naming and input of road name, grant of numbering of all houses and buildings, new address guide, real life geographical information and added information service on web site in Jecheon-si city area. In this study, the development and establishment of new address management and guide system in local cities are designed by making full use of GIS function of client server based system. A guide system is designed the same database as management system, and it is transformed into Web GIS environment and developed in order to add the various functions of life GIS as well as new address guide. In the result, the effectiveness of new address system and guide of Jecheon-si city could be highly increased owing to not only citizens' easy access but also easy availability of various informations necessary in life by developed its system.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.5
• /
• pp.1609-1623
• /
• 2014

A number of studies have been conducted recently regarding the development of automation systems for the construction sector. Much of this attention has focused on earthwork because it is highly dependent on construction machines and is regarded as being basic for the construction of buildings and civil works. For example, technologies are being developed in order to enable earthwork planning based on construction site models that are constructed by automatic systems and to enable construction equipment to perform the work based on the plan and the environment. There are many problems that need to be solved in order to enable the use of automatic earthwork systems in construction sites. For example, technologies are needed for enabling collaborations between similar and different kinds of construction equipment. This study aims to develop a construction system that imitates collaborative systems and decision-making methods that are used by humans. The proposed system relies on the multi-agent concept from the field of artificial intelligence. In order to develop a multi-agent-based system, configurations and functions are proposed for the agents and a framework for collaboration and arbitration between agents is presented. Furthermore, methods are introduced for preventing duplicate work and minimizing interference effects during the collaboration process. Methods are also presented for performing advance planning for the excavators and compactors that are involved in the construction. The current study suggests a theoretical framework and evaluates the results using virtual simulations. However, in the future, an empirical study will be conducted in order to apply these concepts to actual construction sites through the development of a physical system.

• Journal of Digital Convergence
• /
• v.14 no.5
• /
• pp.273-281
• /
• 2016

The issue about the safety management of gas related work has been studied toward a direction to utilize IoT system recently. For this purpose, the matters of user's demand has been deduced through the literature survey, field survey, and professional consultation, by studying the characteristics of worker, work, and work site. In summary, these are the demands for mobile App, 1)a clear arrangement of contents, 2)a design with high readability, 3)a design with low death, 4) securing of user's accessibility, 5)an effective information transmission plan in the work section where it is impossible to operate the mobile device, 6)an activation of alarm function at the section of high working error, 7)a fast two-way transmission and receipt of safety inspection matter needed at work, 8)a selection of images and contents that can guide the situation to the worker in case of accident, 9)an alarm function for the degree of danger in an area of worker's location. Based on these, a basic design of safety application for gas related work has been proposed, that can secure the user accessibility.

• Journal of Korean Society for Atmospheric Environment
• /
• v.31 no.3
• /
• pp.255-268
• /
• 2015

Single particle soot photometer (SP2) is an advanced instrument capable of real-time measurement of concentration, coating thickness, and size distribution of individual BC particle using laser-induced incandescence. So far, there have been insufficient studies examining the real-time characteristics of BC in Korea. In this study, we examined temporal variations in BC concentration and mass size distribution of BC in volume equivalence diameter at a background site of Aewol, Jeju in May. Average concentration and mass median diameter (MMD) of BC particles measured during the study period (06~ 16 May 2013) were $0.69{\pm}0.48{\mu}g/m^3$ and $196{\pm}17nm$, respectively. The BC concentration measured in Aewol was very similar to that observed in the spring of 2012 in Baengnyeong island, and showed diurnal profiles similar to those in other background areas. MMD of BC ranged from 172 to 222 nm. It was found that the mass size distribution of BC varied depending on the location (ground-based), season, types of air masses, and altitude (aircraft-based).

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.1
• /
• pp.187-192
• /
• 2015

In general, design of urban intersections are fundamentally different from rural intersections, but current urban intersection design has been appled to rural standards. This study has suggested the design standard for urban intersection grades based on the existing literature, field investigating and comparative analysis. Moreover, this study analyzes and compares the differences between urban and rural intersections, and intersections have been derived by appropriate design standards after reviewing the domestic and international grades design criteria. Site survey was performed to validate the derived design criteria by analyzing statistically to establish the design standards. Results were produced for the intersection portion grade standards by comparing the number of instructions which produced appropriate slope degree from 2.5% to 3% in normal condition and slope can be extended to 5% in some critical cases. In-situ investigation was performed to validate the produced data where slope was found from 0.0~8.6%. Additional data of accident analysis were also collected for the validation of the suggested data and correlation analysis was performed using the SPSS tool. Data were analyzed statistically using 95% significance level for vehicle-to-vehicle collided, head-on collision accident rates, where accident rates significantly correlated with the grade. Therefore, appropriate grade at the intersection should be designed and applied in order to reduce the number of accidents at the intersection. Finally, appropriate grades for urban intersections are suggested from 1-3% for normal cases and grades could extend up to 5% for unavoidable cases where extra care must be taken when designing.