• Journal of the Korean GEO-environmental Society
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• v.14 no.12
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• pp.5-12
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• 2013

In this study, weathered granite model tests were performed to investigate the variation of volumetric water content and matric suction by the adsorption and desorption processes of artificial rainfall. It has been compared with numerical analysis in unsaturated condition. As the results, the behaviors of volumetric water content and matric suction were distinguished by the seepage distance separated into higher, middle and lower area, and the drainage layer located at the bottom of the experimental device. In the adsorption process, the instantaneously large change of matric suction and water content were related to the increase of permeability in soil. However, in the desorption process, the change of matric suction and water content were gradually small because of the decrease of permeability. The volumetric water content and matric suction showed the difference according to the seepage distance, however the typical characteristic curves were made by the adsorption and desorption processes.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1069-1079
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• 2019

The purpose of this study is to grasp the value of consumption and the propensity to consume of participants in Golf and to clarify the relationship between Golf's behavior and consumption behavior. For example, the functional value, social value, Repetitive behaviors and other person's recommendation behaviors, which are the sub-factors of resource consumption, planning purchase, impulse purchase, show-off consumption, consciousness and consumption behavior of others, which are subordinate factors of emotional value. The final validated sample was 241 copies and the statistical program used to solve the purpose of this study with this material utilized PASW 18.0. PASW 18.0 was used to analyze the frequency, Analysis, reliability analysis, and multiple regression analysis, the following results were obtained. First, it was found that the value of consumption had a significant effect on the propensity to consume. It was found that the propensity to consume had a significant effect on the behavior of consumers.

• Fire Science and Engineering
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• v.29 no.6
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• pp.98-108
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• 2015

An integrated command system is critical for the safety of firefighters and effective work in the headquarters of a special disaster areas such as natural disaster or large man-made hazard. The integrated command system requires environmental information such as temperature, humidity, and $CO_2$ levels, as well as personal physical information such as pulse and air respirator levels. An Analog to Digital Converter (ADC) chip converts sensed information into digital signals, and a Micro Controller Unit (MCU) transmits the digital signals to a transmission board using serial communication through a Serial Peripheral Interface (SPI). The digital signals are saved in a transmission board and transmitted to the integrated command system by a Radio Frequency (RF) unit. The location of fire-fighters in a building are determined using a gyro sensor and an inertial sensor. The collected information is applied to the integrated command system for firefighter safety and to ensure that they can effectively carry out their duties. Tthis study theoretically and experimentally investigated the technologies of RF transmission, indoor position, and an integrated command system that supports decision making using the transmitted information.

• Journal of Wetlands Research
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• v.12 no.2
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• pp.1-12
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• 2010

This study examined geological characteristics of a wetland in Mountain Geumjeong in Busan Metropolitan City. Field survey and laboratory tests were performed to identify topographic features, geological and structural geological characteristics, rock strength along the distance from the wetland, soil profile in the wetland, and chemical property of the wetland soil. The bedrock of the wetland consists of hornblende granite. Hornblende granite and rhyolitic rock around the wetland have the joints with strikes of N-S, E-W, and NE-SW directions and with higher dips greater than $60^{\circ}$. Lower rock strength and higher weathering grades take place towards the wetlands. According to X-ray diffraction analysis of wetland soil samples, kaolinite, montmorillonite, and gibbsite appear which demonstrate weathered products of feldspars in the hornblende granite. The soil profile in the wetland comprises O, A, B, and C horizons from the land surface. The contents of the organic matters decrease from shallow parts to deeper parts of the soil profile. In addition, $K^+$ and $Na^+$ originating from the weathering of feldspars are dominant components among inorganic ions in the wetland soil.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.2
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• pp.78-88
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• 2005

The combustion characteristics of End-Burning hybrid combustor using different types of injector system are numerically investigated to visualize the temperature fields in the combustion chamber The basic characteristics of combustion with different O/F ratio is also analyzed in order to capture the main behavior of diffusion flame inside the swirl induced hybrid combustion chamber It was found that the arrangement of oxidizer injectors give strong effect on the temperature field dominating mixing between fuel and oxidizer. The results show that among five different oxidizer injectors arrangement, the counter flow injector has the highest mixing efficiency. However, the observed high wall temperature presence near the oxidizer injectors remains to be solved.

• Journal of the Korean Geotechnical Society
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• v.39 no.3
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• pp.17-27
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• 2023

In order to accurately determine soil characteristics, it is necessary to collect undisturbed samples, and it is important to collect these samples with minimal disturbance. In this study, a sampler that minimizes sample disturbance was developed by attaching a catcher to the tip, and its applicability was reviewed through in situ sampling, X-ray CT, and laboratory tests. Results confirmed that horizontal cracks are likely to occur when using the Shelby tube sampler, whereas these cracks can be suppressed when using the newly developed sampler. Moreover, consolidation and shear test results showed that the samples collected using the newly developed sampler showed higher maximum shear strength compared to those collected using the Shelby tube sampler.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2C
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• pp.89-98
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• 2006

In this study, the iron and aluminium electrode was put in marine clay which was taken from south coast in Korea to increase the undrained shear strength by inducing the densification and cementation between clay particles and precipitation which was developed by electrode decomposition. For raising the cementation rate and reducing treatment time, high electric current( 2.5A) was applied in each electrode at semi-pilot scale soil box with marine clay. After the tests, the undrained shear strength was measured at designated points using cone penetration test device and sampling was conducted simultaneously in order to measure water content, pH and electric conductivity which would be the key for configuring the cementation effects indirectly. The iron electrode decomposition test results show that the water content adjacent to anode section decreased in 35% and increased in 13% at cathode section. The measured shear strength however, was increased considerably comparing to initial shear strength because of cementation effect between iron ions and soil particles. In case of aluminium electrode decomposition test, the distribution of measured shear strength and degree of improvement were more homogeneous than iron electrode decomposition test.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.6
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• pp.37-44
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• 2019

This study was conducted to identify the distribution characteristics of small village wetlands in Geumsan County, an inland mountain zone, and comparing with Seocheon County, a coastal plain area with different ecological environment characteristics. Using Arc-GIS (v10.1) the village wetland code was extracted to derive the possible location of the village wetland, and the final distribution of the village was obtained by performing indoor judging work based on satellite images, aerial photographs, topographical maps, Korea Land Information System (KLIS), land use level, land cover degree (division), and land use status by local surveying and indoor analyzing. Although Geumsan County (576.66km2) is more than 60% larger than Seocheon County (358.04km2), 607 villages in Geumsan County and 570 villages in Seocheon County are capable of making similar levels of 106.5% of wetlands, but only a fraction of those in Seocheon County were found to be 67.6%. The density of the village wetlands was much lower than that of Seocheon County, a coastal plain area, because there were many mountainous areas in Geumsan County, and most of the wetlands temporarily created for water supply were removed during the analysis phase of the Jeongsa Image, so the actual wetlands of the village were judged to be only two-thirds different from those of Seocheon County.

• The Journal of Engineering Geology
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• v.15 no.1
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• pp.29-39
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• 2005

For detecting a ground contamination survey, soil sampling method have been used a drilling or coring technique in general. However these methods are very difficult to systematically real-time monitoring of variation of contamination degree in field. ]'n this research frequency Domain Reflectometry (FDR) system was suggested and carried out to experimental approaches for determination of oil contamination on surface and underground. Experimental method using FDR method was discussed with feasibility of measurement in the laboratory column test. It is determined to degree of oil contamination due to response of dielectric constant re-lated with volumetric water content(θ/sub w/) and volumetric oil content( θ/sub al/ ) of saturated and unsaturated soil media. And physical properties such as effective porosity and oil residual ratio of saturated soil media were also measured through real-time monitoring works using installed FDR measurement sensors, which are defected characteristics of oil movement in the saturated soil media under the soil column tests. In the results of these experiments, a range of effective porosity was estimated to about 0.35 compared with initial porosity 0.40 of manufactured saturated soil media, which is also calculated to about 87.5% to the ratio of initial porosity to effective porosity. Finally oil residual ratio which is compared with volumetric water content and volumetric oil content was calculated about 62.5%.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.973-978
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• 2010

The emission of volatile organic compounds (VOCs) from building materials is one of great concerns due to maintain airtight condition of a building to reduce energy consumption, and it causes the deterioration of indoor air quality. Therefore, the emission characterization of VOCs from building materials is necessary to improve indoor air quality. Emission characteristics of VOCs from a plywood flooring that is one of the most commonly used materials in an under-heating system, and from an adhesive that is generally used to stick a plywood flooring to a concrete floor were investigated using an emission chamber test in this study. It was found that the VOCs emission factor was dependent upon and proportional to indoor temperature, and the emission characteristics were closely related to the existing places and conditions of VOCs sources inside the building materials. Maximum emission factors of hexane and toluene from building materials were generally observed at the beginning, however, only that of toluene from a plywood flooring was shown after 6 hours from the beginning. It could be considered that the existing place and condition of toluene source inside a plywood flooring could influence on the VOCs emission. From this study, bake-out time more than 72 hours could be recommended before moving in to avoid the exposure to high concentration of VOCs emitted from an under-heating system.