• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.357-360
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• 2005

Soil loss is widely recognized as a threat to farm livelihoods and ecosystem integrity worldwide. Soil loss prediction models can help address long-range land management planning under natural and agricultural conditions. Even though it is hard to find a model that considers all forms of erosion, some models were developed specifically to aid conservation planners in identifying areas where introducing soil conservation measures will have the most impact on reducing soil loss. Revised Universal Soil Loss Equation (RUSLE) computes the average annual erosion expected on hillslopes by multiplying several factors together: rainfall erosivity (R), soil erodibility (K), slope length and steepness (LS), cover management (C), and support practice (P). The value of these factors is determined from field and laboratory experiments. This study calculated soil erosion using GIS-based RUSLE model in Imha basin and examined soil erosion source area using SPOT 5 high-resolution satellite image and land cover map. As a result of analysis, dry field showed high-density soil erosion area and we could easily investigate source area using satellite image. Also we could examine the suitability of soil erosion area applying field survey method in common areas (dry field & orchard area) that are difficult to confirm soil erosion source area using satellite image.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.993-999
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• 2011

In WSN, at the initial stage, sensor nodes are randomly deployed over the region of interest, and self-configure the clustered networks by grouping a bunch of sensor nodes and selecting a cluster header among them. Specially, in WSN environment, in which the administrator's intervention is restricted, the self-configuration capability is essential to establish a power-conservative WSN which provides broad sensing coverage and communication coverage. In this paper, we propose a communication coverage-aware cluster head election algorithm for Herearchical WSNs which consists of communication coverage-aware of the Base station is the cluster head node is elected and a clustering.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.162-165
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• 2004

The authors' previous study found an interannual covariability between actual evapotranspiration (ET) and the Normalized Difference Vegetation Index (NDVI) over northern Asia. This result suggested that vegetation controls interannual variation in ET. In this prior study, NDVI data from the Pathfinder AVHRR Land (PAL) dataset were analyzed. However, studies of NDVI interannual change are subject to uncertainty, because NDVI data often contain errors associated with sensor- and atmosphere-related effects. This study is aimed toward reducing this uncertainty by employing NDVI dataset, from the Global Inventory Monitoring and Modeling Studies (GIMMS) group, in addition to PAL. The analysis was carried out for the northern Asia region from 1982 to 2000. 19-year interannual change in PAL-NDVI and GIMMS-NDVI were both compared with interannual change in model-assimilated ET. Although the correlation coefficient between GIMMS-NDVI and ET is slightly less than for PAL-NDVI and ET, for both NDVI datasets the annual maximum correlation with ET occurs in June, which is near the central period of the growing season. A significant positive correlation between GIMMS-NDVI and ET was observed over most of the vegetated land area in June as well as PAL-NDVI and ET. These results reinforce the authors' prior research that indicates the control of interannual change in ET is dominated by interannual change in vegetation activity.

• Proceedings of the KSRS Conference
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• v.2
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• pp.1001-1002
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• 2006

Special problem emphasized by specialists in the field of analyzing the heat interchanges in the system ocean-atmosphere (SOA) is a necessity of determination of the near-surface atmospheric temperature, which can be only indirectly connected with characteristics of the SOA natural microwave radiation measured from satellites. That is why, the following dilemma is not obvious, but interesting and promised: what is better - to use the satellite methods for retrieving the partial parameters of the SOA or for analysis its state as a whole. To our opinion, this task is similar to the idea recognized by specialists engaged in the heat infrared region (8-12 mcm) of electromagnetic spectrum and its applications, where an intensity of natural infrared radiation (effective radiation) is used as the inherent property (the attribute) of the SOA heat balance. Here we studied important aspects of this problem: a) what medium initiates a heat transfer in the SOA and disturbs its heat balance - the ocean or the atmosphere b) what SOA parameters directly influence on its natural microwave radiation intensity (brightness temperature) measured from satellites? We relate these processes mainly to the synoptic range of time scales enriched by various events in the SOA interface such as the mid-latitude and tropical cyclones.

• Proceedings of the KSRS Conference
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• v.1
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• pp.463-466
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• 2006

During Mid October of 2005 a mass mortality of the corals occurred surrounding Con Dao Islands (South Vietnam) where is the recognized as one of the most famous marine parks of Vietnam. Results from the field survey in October 2005 showed that the mass mortality of corals and benthos focused only on the North-West of the islands whereas there was almost no death recorded in the South - East parts. Based on field data it was assumed that an overlap between high water temperature ($>30^{\circ}C$) and low salinity (<25%o) during short term was the impact causing the situation. In this paper, we try to explain this phenomenon based on the hydrographical view together with analyzing ocean colour images. A coral bleaching warning system also is proposed for Condao site.

• Proceedings of the KSRS Conference
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• v.2
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• pp.725-727
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• 2006

The development of GIS and Location-Based Services requires a high-level database that will be able to allow real-time access to moving objects for spatial and temporal operations. MODB.MM is able to meet these requirements quite adequately, providing operations with the abilities of acquiring, storing, and querying large-scale moving objects. It enables a dynamic and diverse query mechanism, including searches by region, trajectory, and temporal location of a large number of moving objects that may change their locations with time variation. Furthermore, MODB.MM is designed to allow for performance upon main memory and the system supports the migration on out-of-date data from main memory to disk. We define the particular query for truncation of moving objects data and design two migration methods so as to operate the main memory moving objects database system and file-based location storage system with.

• Proceedings of the KSRS Conference
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• v.1
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• pp.301-304
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• 2006

For the purpose of investigating the contributions of various gases to climate change, the thermal radiation associated with greenhouse gases are extracted from AIRS (Atmospheric Infrared Sounder) infrared radiances over the tropical pacific region. AIRS instrument which was launched on the EOS-Aqua satellite in May 2002 covers the spectral range from 650 cm-1 to 2700 cm-1 with a spectral resolution of between 0.4 cm-1 and 1 cm-1. In order to extract the thermal radiation absorbed by individual gases, the interfering background radiances at the top of the atmosphere are simulated using the radiative transfer code MODTRAN (MODerate spectral resolution atmospheric TRANsmittance). The simulations incorporated the temperature and water vapor profiles taken from NCEP (National Centers for Environmental Prediction) reanalyses. The differences between the simulated background radiance and AIRS-measured radiance result in the absorption of upward longwave radiation by atmospheric gases (i.e. greenhouse effect). The extracted absorption bands of individual gases will allow us to quantify the radiative forcing of individual greenhouse gases and thus those data will be useful for climate change studies and for the validation of radiative transfer codes used in general circulation models.

• Proceedings of the KSRS Conference
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• v.2
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• pp.852-855
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• 2006

There is an increasing need to use data from different sensors in order to maximize the chances of obtaining a cloud-free image and to meet timely requirements for information. However, the use of data from multiple sensor systems is depending on comprehensive relationships between sensors of different types. Indeed, a study of inter-sensor relationships is well advanced in the effective use of remotely sensed data from multiple sensors. This paper was concerned with relationships between sensors of different types for vegetation indices (VI). The study was conducted using IKONOS and Landsat-7 ETM+ images. IKONOS and Landsat-7 ETM+ image of the same or about the same dates were acquired. The Landsat-7 ETM+ images were resampled in order to make them coincide with the pixel sizes of IKONOS. Inter-relationships of vegetation indices between images were performed using at-satellite reflectance obtained by converting image digital number (DN). All images were applied to topographic normalization method in order to reduce topographic effect in digital imagery. Also, Inter-sensor model equations between two sensors were developed and applied to other study region. In the result, the relational equations can be used to compute or interpret VI of one sensor using the VI of another sensor.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.49-54
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• 2007

고분해능복사계(AVHRR) 자료로부터 산출한 아시아지역 지면피복 분류자료들 (United States Geological Survey: USGS, International Geosphere Biosphere Programme: IGBP, University of Maryland: UMd)의 분류특성을 분석하였으며 이를 근거로 하여 이 지역에 대한 지면피복의 분류를 시도하였다. 서로 다른 지면피복 분류 자료들의 비교를 위하여 지도 투영법을 일치시켰으며 지면피복 정의가 유사한 유형들만 비교하였다. 세 지면피복 자료에서 분류가 모두 일치하는 비율은 33.57%이고 3 자료 중 두 자료에서 분류가 일치하는 비율은 49.69%로 나타났다. 전체적으로 나대지(사막)， 도시 및 혼합림과 같이 식생의 생물리적 특성이 뚜렷한 유형들에서는 분류의 일치율이 높게 나타났다. 반면에 농지， 낙엽활엽수림， 및 낙엽침엽수렴과 같이 식생의 생물리적 특성이 유사한 유형에서는 일치율이 낮게 나타났다. 분류에 사용된 기본 입력자료수， 지면피복 유형수，분류기법 및 입력 자료의 전처리 수준 등이 지면피복 분류 결과에 차이를 유발한 것으로 판단된다. 지면피복 자료들의 비교결과와 각 유형별 식생지수의 평균 계절변동 특성을 이용하여 이 지역에 대한 지면피복 분류자료를 보완하였다.

• Journal of Welding and Joining
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• v.18 no.3
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• pp.60-67
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• 2000

In this study, we constructed a preview-sensing visual sensor system for weld seam tracking in GMA welding. The visual sensor consists of a CCD camera, a diode laser system with a cylindrical lens and a band-pass-filter to overcome the degrading of image due to spatters and/or arc light. To obtain weld joint position and edge points accurately from the captured image, we compared Hough transform method with central difference method. As a result, we present Hough transform method can more accurately extract the points and it can be applied to real time weld seam tracking. Image processing is carried out to extract straight lines that express laser stripe. After extracting the lines, weld joint position and edge points is determined by intersecting points of the lines. Although a spatter trace is in the image, it is possible to recognize the position of weld joint. Weld seam tracking was precisely implemented with adopting Hough transform method, and it is possible to track the weld seam in the case of offset angle is in the region of $\pm15^{\circ}$.