• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.41-49
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• 2017

This paper will describe lunar lava tubes' five analyzed fields, such as geology, geomorphology, internal configuration, stability, communication and habitats requirements. This research gets through qualitative and qualitative data analysis as following results. A huge size and configuration differences between lunar lava tubes and earth one on geology and landform environments. Exo-genetics activities, such as meteorites, radiation, and sudden temperature bigger affect than Endo-genetic activities, such as effusion and earthquake of the lunar lava tubes. Landform and internal configuration of the lunar lava tubes due to the huge cave perilous landform that gravity difference have a technical limitation from internal approach and data obtain of the huge skylights and sinuous rilles. Stability of the lunar lava tubes deals with geology and landform. It was obvious geo-structural stability elements results generated on low rate of collapsed halls(skylights), low gravity, and relatively thick covers. In terms of the communication capability on the external and internal lunar lava tubes cordless communication techniques will overcome limitations of the sun-power generates supporting communication systems. Through this research it realized obvious differs between potential habitats possibility by accumulative theories by scholars and techniques of the lunar lava tubes. Especially, it is a favorable expectation throughout overcoming attempt on zero gravity, cosmo radiation, lunar dust of the exo-genetic limitations to the steep escarpment of skylights to approach and achieve techniques by the civil engineering, networking and GIS techniques as the endo-genetic environment treatment.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.415-422
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• 2013

The contents development for the Internet and cyber tour has been attempted in a number of areas. 3D topography of the spatial environment, land planning and land information contents as a 3D tour of the future ubiquitous city safe for tourism due to the implementation of information made available major area. Domestic service, and in urban areas of the country where land and precise spatial information in order to shoot satellites and aircraft in the area you want to mount the camera on a variety of photo images taken by conducting 3D spatial that is required is able to obtain the information. Geo spatial information in a variety of direct or indirect acquisition of the initial spatial data into a database for accurate collection, storage, editing, manipulation and application technology changes in the future by establishing a database of 3D spatial by securing content organization ubiquitous tourist to take advantage of new tourism industry was greatly. As a result of this study for future tourism using geo spatial information and analysis of 3D modeling by intelligent land information indirectly, with quite a few stereo site experience and a variety of tourist spatial acquisition and utilization of information could prove.

• Journal of Korea Water Resources Association
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• v.53 no.10
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• pp.871-876
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• 2020

Understanding the wave characteristics near the outlet of coastal power plants for cooling water in the vicinity of the dredged areas is critically important for the construction and operation of the plants. By Employing the eigenfunction expansion method, in this study, we analyzed the reflection of monochromatic water waves over (1) shear currents near the outlet and (2) multi-arrayed trenches representing dredged areas. We firstly optimized the number of grids expressing shear currents and the number of evanescent modes based on a convergence test. We then analyzed the sensitivity of the reflection coefficients depending on (1) magnitude of shear currents, (2) width of shear currents, (3) a distance between adjacent trenches, and (4) a number of trenches. The results showed that the reflection coefficient was more sensitive to the number of trenches and the distance between trenches than the velocity of shear currents and the width of shear currents. We also found that even the effect of shear currents is relatively small, the effect is not negligible in a relative water depth from shallow to near shallow water waves (0.01 < kh ≦ 0.70).

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.169-183
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• 2015

As a basic work for river restoration, analysis on fluvial geomorphological characteristics is made using past and present data to understand close-to-nature geomorphic status. The Miho and the Naesung Rivers are targets of this study. Fluvial geomorphic variables including valley-floor width, sinuosity, bankfull width, channel gradient, bed material size, bankfull discharge and unit stream power are evaluated with dominant processes. Though common sand-bed rivers with similar catchment area, the Miho and the Naesung Rivers are different in terms of valley-floor width, channel shape variables and dominant processes related with longitudinal location. In addition, analyses on interrelationship among the geomorphological variables are carried. Bankfull width is shown to be proportional to bankfull discharge, as is in a rough agreement with the previous studies. Relationship of bankfull discharge and channel gradient shows meandering and braiding are prevalent in the Miho River, whereas the most of the sub-reaches of the Naesung River fall to braiding. Relationship of channel gradient with width-depth ratio indicates dune-ripple processes are dominant in the Miho River, while the Naesung River shows longitudinal diversity from braiding in the downstream sub-reaches to riffle-pool and plane-bed along the upper ones. Analyses based on the past data on a river in a close-to-nature status are thought to be rather reasonable in comparison with those on the same river in a engineered condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.271-279
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• 2019

In extreme environment regions, unmanned rovers equipped with various sensors and devices are being developed for long-term exploration on behalf of humans. On the other hand, due to the harsh weather conditions and rough terrain, the rover camera has limited visible distance and field of view. Therefore, the rover cameras should be located for safe navigation and efficient terrain mapping. In this regard, to minimize the cost and time to manufacture the camera system on a rover, the simulation method using the rover design is presented to optimize the camera locations on the rover efficiently. In the simulation, a simulated terrain was taken from cameras with different locations and angles. The visible distance and overlapped extent of camera images, and terrain data accuracy calculated from the simulation were compared to determine the optimal locations of the rover's cameras. The simulated results will be used to manufacture a rover and camera system. In addition, self and system calibrations will be conducted to calculate the accurate position of the camera system on the rover.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.78-85
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• 2012

This paper proposes an efficient algorithm to develop a 3D terrain tools which is essential in the development of 3D computer games. In particular, this paper proposes a cross detection technique to improve picking speed. In other words, this paper proposes a more efficient cross detection technique consisting of a ray and a parallelogram than a cross detection technique consisting of a ray and a triangle. So, we can confirm the faster picking speed. This paper uses a picking example among DirectX SDK samples to test it. In addition, this paper compares the number of function calls for cross detection using the existing techniques and the proposed technique. As a result, in this paper the proposed technique has fallen off to about a 50 percent than the existing techniques. And if it is calculated by times, in this paper the proposed technique was reduced to 1 to 2 seconds than the existing techniques. Additionally, in this paper 3D terrain tools are provide more improved algorithms for features such as texture splatting, height map control, object arrangement and realistic water effect. So, 3D terrain tools is available efficient in the development of real 3d computer games.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.6
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• pp.487-496
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• 2017

Ground moving target indicator(GMTI) using syntheticaperture radar(SAR) used for finding moving targets on wide background clutter in short time is one of good ways to monitor a traffic situation or an enemy's threat. Although displaced phase center antenna (DPCA) is a real time method with low computational complexity, there have been few studies about its performance against various ground clutters. Thus, we need to analyze GMTI performance for various ground clutters in order to design a suitable DPCA detector. In this paper, simulation results show that the conventional DPCA detector produces different performance in terms of detection rate and false alarm rate. In particular, the false alarm rate of heterogeneous or extremely heterogeneous clutter from urban area is higher than one of homogeneous clutter from natural area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.445-450
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• 2008

Recently, environmental and ecological approaches is in progress in urban stream, especially the guarantee of instream flow becomes very important. In this paper, it is suggested that water volume estimation method utilizing the topographical shape data obtained by field investigation and satellite image to manage the urban stream efficiently. The data obtained at Gap River is the study area are analysed and those results are as belows. First, surveying to investigate topographic shape characteristics of urban stream is carried out. In details, the gradient characteristics from water surface to bottom in case of sand area and in case of grass area are 0.013 and 0.065 respectively. In conclusion, the gradient characteristic of grass area is five times bigger than that of sand area. Besides, IKONOS image is classified by spectrum analysis and Minimum Distance Method and the sand area extraction method by the generalization method as Median filter is suggested to calculate water volume. Finally, mapping process on the sand area extracted from the topographical shape field data in river and satellite images is carried out by the GIS spatial analysis. And on the assumption that the water level was 1m at that time when satellite image was taken, the water volume was $225,258m^3$. It is clarified that the effect of water volume improvement was about 10.5% in comparison with water volume that had no consideration on the gradient characteristics of sand-bar.

• Journal of the Korean association of regional geographers
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• v.6 no.2
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• pp.71-82
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• 2000

The purpose of this paper is to clarify geomorphic features and development on the boulder stream of granitoid in Korea. Considering the purpose and the method of this paper, three boulder streams are selected : Biseulsan(Mt. Biseul) boulder stream (Daegu city), Maneosan (Mt. Maneo) boulder stream(Gyeongnam province), Geumjeongsan(Mt. Geumjeong) boulder stream (Busan city). The boulder streams mentioned above are bigger in scale and more typical in shape than any other ones in the Korean Peninsula. The main results are summarized as follows. 1. The following are the main features of the boulder streams morphology : the mean gradient is $3{\sim}25^{\circ}$, the longer axes of the component boulders within the deposits averaged about 2m in length, the shapes of the component boulders may be both subangular and subrounded features. 2. The formation of the component boulders is associated with deep weathering of granitoid under warm humid conditions, and the downward movement of boulders occurred by solifluction and frost creep under periglacial conditions. 3. The geomorphic development stage of the boulder streams may be classified into four stages. These boulder streams come under fossil landform stage, the 4th stage ; evidence provided by lichens and weathering features indicate inactive or fossil landform. 4. In generally, boulder streams are well developed on shallow valley floors.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.1
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• pp.52-61
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• 2004

Korea Water Resources Corporation carried out LiDAR survey to construct detailed terrain data for flood mapping and it is expected that much money is required in flood mapping of all over the country. Therefore, it is desirable to use NGIS digital map to construct preliminary modelling data for selection of flood mapping area. And the analysis of DEM error with respect to scale of digital map is necessary for the sake of applying digital map as the input data of flood mapping. We compared DEM from digital map with DEM from LiDAR survey. Especially we analyzed DEM error characteristics that is occurred with respect to the interpolation method that is used to construct DEM from TIN of digital map. As a result of analysis, digital map(1:1,000) showed smaller error than digital map(1:5,000) and DEM applying linear interpolation showed smaller error than DEM applying quintic interpolation. Especially, variation of DEM error by cell resolution was evaluated as very slight because urban district was composed of gentle slope.