• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.2
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• pp.45-58
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• 1999

Digital map is utilized for an effective display of the distributions of the hydrogeological variables such as water table height(hydraulic head) and log-transmissivity(lnT) in north Pohang, KyungBug. Specifically the geostatistical method kriging is used to construct the distributions in an unconfined aquifer from a finite set of measured data. The experimental variograms for both the head and lnT suggest spherical models with nugget of 0 and range of 6km. The kriged results by using these variograms show that the head decreases primarily from the west to the east with a large peak in the north-western part and lnT is at the maximum level in the central part with outwardly decreasing trend. The constructed delineation is also used to calculate the flow field in the region. Finite differences with second order consistency are used to calculate the fluxes in the east(x) and north(y) across a vertical cross-section of unit width and height equal to the thickness of the wet zone in the aquifer. It is demonstrated that the flow is dominantly in the east with diverging trend on the eastern hillside of the water table peak. A few convergent spots also appear.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.178-183
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• 2008

The goal of this study is finding flow-map in conversation what is going on user and embodied conversational agent by analysing that conversation. Specifically, this study not only find elements of conversation, but also draw out patterns of conversation can be exist for dialogue ability between user and Embodied conversational agent. To do this, we collect data through in-depth one to one interview, and then we analysis collected data to try to find out element of user-agent conversation based on qualitative research refer to the theory of conversation analytics and type of conversation. As a result, six flow map is deducted Especially, the irregular conversation is hard to find in human-human conversation, and the frequency is the most in data. In addition, when elements of interruption came out, be hostile to partner or correct the press conversation. This study can have positive effect to embodied conversation agent developer, user and service offerer because this study find the type of conversation through analysis that between embodied conversational agent and user.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.10
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• pp.1443-1449
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• 2013

Automatic detection of vehicles in front is an integral component of many advanced driver-assistance system, such as collision mitigation, automatic cruise control, and automatic head-lamp dimming. Regardless day and night, tail-lights play an important role in vehicle detecting and status recognizing of driving in front. However, some drivers do not know the status of the tail-lights of vehicles. Thus, it is required for drivers to inform status of tail-lights automatically. In this paper, a recognition method of status of tail-lights based on video processing and recognition technology is proposed. Background estimation, optical flow and Euclidean distance is used to detect vehicles entering tollgate. Then saliency map is used to detect tail-lights and recognize their status in the Lab color coordinates. As results of experiments of using tollgate videos, it is shown that the proposed method can be used to inform status of tail-lights.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.1
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• pp.14-22
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• 2008

The forest soil sediment disasters occurred in Jinbu-myeon Pyeongchang county were investigated characteristics by the aerial photograph analysis. After digitizing from aerial photographs, forest soil sediment disaster sites were classified into 695 collapsed sites, 305 flowed sites and 199 sediment sites. DEM (Digital Elevation Model) were generated from 1 : 5,000 digital topographic map. Factors of geography, hydrology, biology, and geology were analyzed using DEM, geologic map, and forest stand map with aerial photographs by GIS spatial analysis technique. The forest soil sediment disasters were mainly occurred from southeastern slope to southwestern slope. In collapsed sit es, the average slope degree is $28.9^{\circ}$, the average flow length is 163.5m, the average area of drainage basin is 897$m^2$. In case of flowed sites, the average slope degree, flow length, the area of drainage basin and confluence order is $27.0^{\circ}$, 175m, 2,500$m^2$ and 1, respectively. In sediment sites, the average slope, flow length, the area of drainage basin and confluence order is $12.5^{\circ}$, 2,50m, 25,000$m^2$ and 4, respectively. Also the forest soil sediment disasters were occurred most of collapsed sites in the afforest land after felling and igneous rocks composed of granite.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.5-18
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• 2019

In this study, it was conducted a broad-area landslide analysis for the entire area of Kyungsangbuk-do Province based on spatially-distributed wetness index and root reinforcement infinity slope stability theory. Specifically, digital map, soil map and forest map were used to extract topological and geological parameters, and to build spatially-distributed database at $10m{\times}10m$ resolution. Infinity flow direction method was used for rain catchment area to produce spatially-distributed wetness index. The safety level that indicates risk of a broad-area landslide was classified into four groups. The result showed that areas with a high estimated risk of a landslide coincided with areas that recently went through an actual landslide, including Bonghwa and Gimcheon, and unstable areas were clustered around mountainous areas. A comparison between the estimation result and the records of actual landslide showed that the analysis model is effective for estimating a risk of a broad-area landslide based on accumulation of reasonable parameters.

• Journal of Power System Engineering
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• v.19 no.1
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• pp.19-23
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• 2015

The swirling flow fields of a gun-type gas burner(GTGB) without a combustion chamber were measured by a straight-type five-hole pressure probe(FHPP) under the cold flow condition. The three kinds of velocity components and the static pressure were calculated by using a non-nulling calibration method covering the velocity reduction performance of the effective flow attack angle of ${\pm}80^{\circ}$. As a result, the velocity and static pressure measured by a FHPP comparatively shows the better performance on the swirling flow of a GTGB than those measured by X-probe.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.265-268
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• 2004

In this present study, mechanical properties of the Zr-Ti-Cu-Ni-Be bulk metallic glass are characterized by compression test over a wide range of temperatures and strain rates. Three different types of deformation behavior have been identified as a result, viz., Newtonian viscous flow, non-Newtonian flow and brittle fracture without plastic deformation. A transition state theory is applicable fur the flow stress - strain rate curve that contains the transition from Newtonian to non-Newtonian flow. Based on the relationship between viscosity and strain rate within undercooled liquid state, we can easily obtain the experimental deformation map and suggest the boundaries among different deformation behavior of this alloy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.371-379
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• 2000

A noise prediction method of axial flow fan is developed by incorporating through-flow method and vortex shedding noise model. Fan noise is assumed to be generated due to the pressure fluctuation induced by wake vortices of fan blades and radiate as diploe distribution. The wake vortices are analyzed by combining Karman vortex street model and through-flow analysis results, and the vortex-induced fluctuating pressure on blade surface is calculated by thin airfoil theory. The predicted sound pressure levels and directivity patterns of fan noise by the present method are favorably compared with fan noise test data. Furthermore, the present method is shown to be very useful for predicting the aero-acoustic performance map of the fan operated at off-design point.

• Journal of The Geomorphological Association of Korea
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• v.26 no.3
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• pp.53-67
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• 2019

The purpose of this study is to identify the quality of landslide susceptibility in a landslide-prone area (Jinbu-myeon, Gangwon-do, South Korea) by spatial prediction modeling approach and compare the results obtained. For this goal, a landslide inventory map was prepared mainly based on past historical information and aerial photographs analysis (Daum Map, 2008), as well as some field observation. Altogether, 550 landslides were counted at the whole study area. Among them, 182 landslides are debris flow and each group of landslides was constructed in the inventory map separately. Then, the landslide inventory was randomly selected through Excel; 50% landslide was used for model analysis and the remaining 50% was used for validation purpose. Total 12 contributing factors, such as slope, aspect, curvature, topographic wetness index (TWI), elevation, forest type, forest timber diameter, forest crown density, geology, landuse, soil depth, and soil drainage were used in the analysis. Moreover, to find out the co-relation between landslide causative factors and incidents landslide, pixels were divided into several classes and frequency ratio for individual class was extracted. Eventually, six landslide susceptibility maps were constructed using the Bayesian Predictive Discriminant (BPD), Empirical Likelihood Ratio (ELR), and Linear Regression Method (LRM) models based on different category dada. Finally, in the cross validation process, landslide susceptibility map was plotted with a receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) and tried to extract success rate curve. The result showed that Bayesian, likelihood and linear models were of 85.52%, 85.23%, and 83.49% accuracy respectively for total data. Subsequently, in the category of debris flow landslide, results are little better compare with total data and its contained 86.33%, 85.53% and 84.17% accuracy. It means all three models were reasonable methods for landslide susceptibility analysis. The models have proved to produce reliable predictions for regional spatial planning or land-use planning.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.2
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• pp.199-206
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• 2004

The heat transfer enhancement by pulsating flow in a plate heat exchanger has been experimentally investigated in this study. The effect of the pulsating flow, such as pulsating frequency and flow rate on the heat transfer as well as pressure drop in a plate heat exchanger has been studied in detail. Reynolds number in cold side of a plate heat exchanger is varied 100∼530 while that of hot side is fixed at 620. The pulsating frequency is considered in the range of 5∼30 Hz. The results of the pulsating flow are also compared with those of steady flow. It is found that the average heat transfer rate as well as pressure drop is increased as flow rate is increased for both steady flow and pulsating flow cases. When pulsating flow is applied to the plate heat exchanger, heat transfer could be substantially increased in particular ranges of pulsating frequency or Strouhal number; St=0.36∼0.60 and pressure drop is also increased, compared with those of steady flow. However, in the region of low pulsating frequency or high pulsating frequency, heat transfer enhancement is in meager. Heat transfer enhancement map is suggested based on Strouhal number and Reynolds number of pulsating flow.