• The Journal of Engineering Geology
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• v.13 no.4
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• pp.405-418
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• 2003

Measurements of volumetric water content and saturation of porous media are very important factors in understanding the physical characteristics of soil, groundwater recharge by rainfall, pollutant movement, and slope failure. To measure such physical parameters, a permittivity method using electromagnetic wave is applied and use is made of the special permittivity response of understand to water and ethanol. In particular, the estimation is required because permittivity is influenced by the nature of the underground environment. In this study, we carried out experiments on the relative dependency of soil density, temperature and salinity of standard sand and granitic weathered soil using FDR-V system (Frequency domain reflectometry with vector network analyzer) within a frequency range of 1 - 18 GHz. The results of the study showed that the dielectric constants of standard sand and granitic weathered soil increased with increased volumetric water content of soil. However, the dependency of soil density was found to be a little low. Changes of dielectric constant with temperature appeared definitely in the real part of 1 GHz. That is, the dielectric constant of real part at 1 GHz of water and standard sand increased with the rise of temperature. However, ethanol showed decreased tendency. The study also showed that dielectric constant increased with increase in salinity at imaginary part of 1 GHz. It could be concluded from this study FDR-V system can adequately measure the physical properties of soil and the degree of salinity concentration of porous media within 1 GHz frequency range using dielectric constant.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.33-42
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• 2020

Emission factors for ammonia and particulate matters (PMs) from livestock buildings are of increasing importance in view of the environmental protection. While the existing emission factors were determined based on the emission inventory of other countries, in situ measurement of emission factors is required to construct an accurate emission inventory for Korea. This study is to report measurements of ammonia and PMs emissions from mechanically-ventilated pig houses, which are common types of pig barns in Korea. Ventilation rates and concentrations of ammonia and PMs were measured at the ventilation outlets of a weaner unit, a growing pig unit and a fattening pig unit to calculated the emission factors. The PMs emission was characterized with different aerodynamic diameters (PM_2.5, PM₁₀, and total suspended particulates (TSP)). The measured ammonia emission factors for weaners, growing pigs and fattening pigs were 0.225, 0.869 and 1.679 kg animal^-1 yr^-1, respectively, showing linear increase with pigs' age. The PMs emission factors for three growing stages were 0.023, 0.237 and 0.241 kg animal^-1 yr^-1, respectively for TSP, 0.017, 0.072 and 0.223 kg animal^-1 yr^-1, respectively for PM₁₀, and 0.011, 0.016 and 0.151 kg animal^-1 yr^-1, respectively for PM_2.5. PMs emissions were increased with pigs' age due to increasing feed supply and animal movement. The measured emission factors were smaller than those of the existing emission inventory indicating that the existing ones overestimate the emissions from pig buildings and also suggesting that long-term in situ monitoring at various livestock buildings is required to construct the accurate emission inventory.

• Korean Institute of Interior Design Journal
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• v.25 no.2
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• pp.21-29
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• 2016

This study has estimated the traits of conscious eye moving with the objects of the halls of subway stations. For that estimation, the observation data from eye-tracking were matched with the experiment images, while an independent program was produced and utilized for the analysis of the eye moving in the selected sections, which could provide the ground for clarifying the traits of space-users' eye moving. The outcomes can be defines as the followings. First, The application of the independently produced program provides the method for coding the great amount of observation data, which cut down a lot of analysis time for finding out the traits of conscious eye moving. Accordingly, the inclusion of eye's intentionality in the method for extracting the characteristics of eye moving enabled the features of entrance and exit of particular objects with the course of observing time to be organized. Second, The examination of eye moving at each area surrounding the object factors showed that [out]${\rightarrow}$[in], which the line of sight is from the surround area to the objects, characteristically moved from the left-top (Area I) of the selected object to the object while [in]${\rightarrow}$[out], which is from the inside of the object to the outside, also moved to the left-top (Area I). Overall, there were much eye moving from the tops of right and left (Area I, II) to the object, but the eye moving to the outside was found to move to the left-top (Area I), the right-middle (Area IV) and the right-top (Area II). Third, In order to find if there was any intense eye-moving toward a particular factor, the dominant standards were presented for analysis, which showed that there was much eye-moving from the tops (Area I, II) to the sections of 1 and 2. While the eye-moving of [in] was [I $I{\rightarrow}A$](23.0%), [$I{\rightarrow}B$](16.1%) and [$II{\rightarrow}B$](13.8%), that of [out] was [$A{\rightarrow}I$](14.8%), [$B{\rightarrow}I$](13.6%), [$A{\rightarrow}II$](11.4%), [$B{\rightarrow}IV$](11.4%) and [$B{\rightarrow}II$](10.2%). Though the eye-moving toward objects took place in specific directions (areas), that (out) from the objects to the outside was found to be dispersed widely to different areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.2919-2924
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• 2011

The automatic drawer is used to absorb the movement shock and adjust its velocity when it opens and closes. The tube in shock-absorber is the cylindrical case which surrounds its parts and is made of acetal. The purpose of this study is to determine the quality stability of the tube in the shock-absorber in injection molding process. The tube which had been manufactured in the process with 4 cavity cooling unit was used. In this study, the analysis and test are carried out to determine its quality stability. Which are the quality analysis with numerical simulation and performance tests of the tube compared with one of foreign make. It is calculated that the injection press is 87.6 MPa and the deflections in X, Y, Z directions are ranged in 0.07~1.00 mm. When the researched tube is compared with the foreign made tube, the maximum bending compressive load is 231 kgf higher, average axial compressive load is 0.05 kgf higher, and the roughness(Ra) on the inner surface is $0.02\;{\mu}m$. lower. In the result, it is known that the quality of researched tube in injection mold process is stable and its performance is superior.

• The KIPS Transactions:PartC
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• v.18C no.3
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• pp.167-178
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• 2011

As the growth of ubiquitous services, various types of ad hoc networks have emerged. In particular, wireless sensor networks (WSN) and mobile ad hoc networks (MANET) are widely known ad hoc networks, but there are also other kinds of wireless ad hoc networks in which the characteristics of the aforementioned two network types are mixed together. This paper proposes a variant of the Low Energy Adaptive Cluster Hierarchy (LEACH) routing protocol modified to be suitable in such a combined network environment. That is, the proposed routing protocol provides node detection and route discovery/maintenance in a network with a large number of mobile sensor nodes, while preserving node mobility, network connectivity, and energy efficiency. The proposed routing protocol is implemented with a multi-hop multi-path algorithm, a topology reconfiguration technique using node movement estimation and vibration sensors, and an efficient path selection and data transmission technique for a great many moving nodes. In the experiments, the performance of the proposed protocol is demonstrated by comparing it to the conventional LEACH protocol.

• Journal of Soil and Groundwater Environment
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• v.10 no.4
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• pp.54-61
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• 2005

An aquifer thermal energy storage (ATES) system can be very cost-effective and renewable energy sources, depending on site-specific parameters and load characteristics. In order to develop the ATES system which has certain hydrogeological characteristics, understanding the thermohydraulic process of an aquifer is necessary for a proper design of an aquifer heat storage system under given conditions. The thermohydraulic transfer for heat storage was simulated according to two sets of simple pumping and waste water reinjection scenarios of groundwater heat pump system operation in a two-layered aquifer model. In the first set of the scenarios, the movement of the thermal front and groundwater level was simulated by changing the locations of injection and pumping wells in a seasonal cycle. However, in the second set the simulation was performed in the state of fixing the locations of pumping and injection wells. After 365 days simulation period, the shape of temperature distribution was highly dependent on the injected water temperature and the distance from the injection well. A small temperature change appeared on the surface compared to other simulated temperature distributions of 30 and 50 m depths. The porosity and groundwater flow characteristics of each layer sensitively affected the heat transfer. The groundwater levels and temperature changes in injection and pumping wells were monitored and the thermal interference between the wells was analyzed to test the effectiveness of the heat pump operation method applied.

• Korean Journal of Remote Sensing
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• v.19 no.4
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• pp.277-284
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• 2003

We present a GPS-derived regional ionosphere model, which estimates Total Electron Content (TEC) in a rectangular grid on the spherical shell over Korea. After dividing longitude and latitude over Korea with 1$^{\circ}$$\times$1$^{\circ}$ spatial resolution, the TEC at the vertex of the grid was estimated by the Kalman filter. The GPS data received from nine nationwide GPS stations, operated by Korea Astronomy Observatory (KAO), were used for this study. To reduce inherent noises, the pseudorange data were phase-leveled by a linear combination of pseudoranges and carrier phases. The solar-geomagnetic reference frame, which is less variable to the ionosphere movement due to the Sun and the geomagnetic field than an Earth-fixed frame, was used. During a quiet time of solar activity, the KAO's regional ionosphere map indicated 30-45 Total Electron Content Unit at the peak of the diurnal variation. In comparison with the Global ionosphere Map of the Center for Orbit Determination in Europe, RMS differences were at the level of 4-5 TECU for five days.

• Korean Journal of Remote Sensing
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• v.12 no.2
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• pp.169-198
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• 1996

The objectives of this investigation are : 1. To analyze spectral signature and the associated vegetation index for geometric illumination conditions inf1uenced by low solar elevation and high slope orientations in mountainous forest. 2. To assess the accuracy of the spectral angle mapper classification for the a winter land cover in comparison with the maximum likelihood classification. 3. To produce the image of water quality and water properties that could be used to estimate the water pollution sources and the tide-included by turbid water in estuarine and coastal areas. These objectives are to characterize environmental and ecological monitoring applications of the Nak-Dong River Basin by using Fuyo-1 OPS VNIR data acquired on December 26, 1992. The results of this paper are as follows : 1. The spectral digital numbers and vegetation indexes (NDVI and TVI) of mountainous forest are higher on the slope facing the sun than on the slope hidden the sun under low sun elevation condition. 2. The spectral angle mapper algorithm produces a more accurate land cover classification of areas with steep slope, various aspects and low solar elevation than the maximum likelihood classifier. 3. The maximum likelihood classification images can be used for identifying the location and movement of both freshwater and salt water, regardless of geometric illumination conditions. 4. The color-coded density sliced image of selected water bodies by using the near-infrared band 3 can provide distribution of the water quality of the Lower Nak-Dong River. 5. The color-coded normalized difference vegetation index image of the selected mountain forest is suitable to classify winter vegetation cover types, i.e., forest canopy densities for slope orientations.

• The Korean Journal of Archival Studies
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• no.3
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• pp.3-32
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• 2001

In this paper, local public archives is referred to the public archives of provincial governments and metropolitan city governments as defined in the public Records Management Act. Under the Act, as professional archives, the local public archives preserves records designated as permanent preservation which the local government and its sub-agencies created or received to conduct public business. The Act also allows local public archives to establish an appropriate basic plan to manage its holdings as well as to oversight its sub-agencies. The Act stipulates that the local public archives are to be established in all provinces and metropolitan cities. The local public archives shall preserve archival heritage safely and utilize use of the recorded information as defined in the Article one of the Act. The local archives shall respect the principle of provenance. It is expected that the local archives shall strengthen local archival promotion campaigns which necessarily reflect unique local circumstances. However, as the Act just recommended the establishment of local public archives not to force as a mandatory procedure, it resulted in a flow of some confusions and misinterpretations. Despite the act was proclaimed two years ago, the local public archives are not yet established, not to mention that no preparatory works are on the way. To establish the local public archives effectively which meet local residents needs and demands, provincial governments and metropolitan city governments should proceed a well-prepared preparatory works plan considering the steps to transform them into the local public archives when they establish agency records centers. The first step in this process is to reach at a common consensus on the functions and roles of the local public archives which accommodates local residents needs and demands. Secondly, by analyzing the functions of archives to be established, an estimation of needed human resources, facilities, equipments, organization, budget appropriation, and local rules should be performed. Otherwise, the establishment of decent local archives is a far remote future. One of the methods to proceed this project systematically is to establish a local research institute for the local archives and cultural studies which would be put under the local university authority while consulting with local governments, local civil organizations, local historical and cultural societies. It is very undesirable to stress too much upon administrative efficiency when concerned parties discuss the functions and roles of the local public archives. They must keep in mind that when the functions to collect and use historically valuable records are active then administrative efficiency can be raised as well as accountability. Collecting and arranging historically valuable records is a short-cut way to promote accountability and develop local political culture. The local public archives is a valuable community historical center and an effective medium to facilitate historical speaking and writing among local people, something more than a simple public archives. Then our campaign for the establishment of local public archives can be a meaningful political cultural movement.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.783-791
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• 2018

The biased estimation of low density rainfall network and radar rainfall has limited application to extreme rainfall in a small area. To improve this, more rainfall information needs to be produced. In this study, we analyzed the applicability of the vehicle rainfall sensor developed and used recently. The developed rainfall sensor was attached to the vehicle to observe the rainfall according to the movement of the vehicle. The analytical method used time series and average rainfall values for observations of rainfall sensors and nearby rainfall stations. The results show that the trend of observed values according to rainfall events shows a certain pattern. It is analyzed that it is caused by various causes such as the difference between the observation position of the rainfall sensor and the nearby rainfall station, the moving speed of the vehicle, and the rainfall observation method. This result shows the possibility of rainfall observation using a rainfall sensor for a vehicle, and it is possible to observe rainfall more precisely through experiments and improvement of rainfall sensors in various conditions in the future.