• Economic and Environmental Geology
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• v.31 no.4
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• pp.325-338
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• 1998

105 oriented samples (19 matrix samples, 86 cobble samples) were collected from the Silla Coglomerate Formation in Jinju and Goryeong areas to clarify the regional remagnetization of Cretaceous Kyongsang supergroup. Both the alternating field and thermal demagnetizations were conducted for the collected samples. The characteristic remanent magnetizations of these samples divided into three types in the Silla Conglomerate Formation: The ingredient magnetic minerals are magnetite, hematite, or both magnetite and hematite in a specimen. The characteristic remanent directions of cobble samples did not clustered to any direction. And the characteristic remanent directions of interbedded sandstones in the Silla Conglomerate Formation is $D/I=20.6^{\circ}/54.5^{\circ}$ (${\alpha}_{95}=11.1^{\circ}$, k=48.8) after tilting correction, agree with previous paleomagnetic studies on the Hayang group. These results implied that conglomerate test was passed indicating no regional remagnetization in the studied area after deposition of the Silla Conglomerate Formation.

• Korean Journal of Geomatics
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• v.3 no.2
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• pp.99-106
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• 2004

In order to meet the users' demand, who needs faster and more accurate data in geographic information, it is necessary to obtain and process the data more effectively. Now more effective data obtainments about geographic information is possible through the development of integration technology, which is applied to the field of geographic information, as well as through the development of hardware and software engineering. With the fast and precise correction and update, the development of integrate technology can bring the reduction of the time and money. To obtain fast and precise geographic information using Aerial Photogrammetry method, it is necessary to develop Airborne GPS/INS integration system, which makes GCP to the minimum. For this reason, this study has tried to develop a system which could unite and process both GPS and INS data. For this matter, code-processing module for DGPS and OTF initializaion module, which can decide integer ambiguity even in motion, have been developed. And also, continuous kinematic carrier-processing module has been developed to calculate the location at the moment of filming. In addition, this study suggests a possibility of using a module, which can unite GPS and INS, using Kalman filtering, and also shows the INS navigation theory.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.607-620
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• 1998

The influence of transportation on air quality has been elevating in urban area. Air pollutants from automobiles cause primary and secondary air pollution, and need to be tightly controlled. In this study, the effect of automobile air pollutants on highway vicinity area was evaluated by the comparison of field measurement. and target was for modeling using CALINE3, NO2 was the target for this work. It was found that the concentration predicted by CALINE3 is overestimated at low wind speed and input data of wind speed requires correction. Based on the measured data, the wind speed was modified by effective wind speed equation [Ue=U+0.24·EXP(-pxU)], and there after the accuracy of CALINE3 calculation was improved neighborhood area of highway. It was also observed that weather conditions and traffic volume affect the concentration of air pollution. Finally, the NO2 effect of automobile air pollutants on the vicinity area of highway proved to be up to 400∼600m from the highway.

• Steel and Composite Structures
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• v.15 no.4
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• pp.399-423
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• 2013

In the present study, the thermal buckling behavior of functionally graded sandwich plates is studied using a new hyperbolic displacement model. Unlike any other theory, the theory is variationally consistent and gives four governing equations. Number of unknown functions involved in displacement field is only four, as against five in case of other shear deformation theories. This present model takes into account the parabolic distribution of transverse shear stresses and satisfies the condition of zero shear stresses on the top and bottom surfaces without using shear correction factor. Material properties and thermal expansion coefficient of the sandwich plate faces are assumed to be graded in the thickness direction according to a simple power-law distribution in terms of the volume fractions of the constituents. The core layer is still homogeneous and made of an isotropic material. The thermal loads are assumed as uniform, linear and non-linear temperature rises across the thickness direction. The results reveal that the volume fraction index, loading type and functionally graded layers thickness have significant influence on the thermal buckling of functionally graded sandwich plates.

• Structural Engineering and Mechanics
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• v.64 no.6
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• pp.737-749
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• 2017

A new quasi-3D higher shear deformation theory (quasi-3D HSDT) for functionally graded plates is proposed in this article. The theory considers both shear deformation and thickness-stretching influences by a hyperbolic distribution of all displacements within the thickness, and respects the stress-free boundary conditions on the upper and lower surfaces of the plate without using any shear correction factor. The highlight of the proposed theory is that it uses undetermined integral terms in displacement field and involves a smaller number of variables and governing equations than the conventional quasi-3D theories, but its solutions compare well with 3D and quasi-3D solutions. Equations of motion are obtained from the Hamilton principle. Analytical solutions for buckling and dynamic problems are deduced for simply supported plates. Numerical results are presented to prove the accuracy of the proposed theory.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.985-996
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• 2000

In the coastal zone, to draw up short and medium range weather forecasts, mesoscale pluviogenic systems coming from the sea have to be observed in real time. These observations use remote sensing. However, satellite remote sensing is not sufficient to describe pluviogenic systems; reference to radar long distance observations is indispensable. This paper deals with the corrections, which must be made to long distance radar data if the rainfall field is to be both accurately and quantitatively defined. The error due to vertical variation in the reflectivity factor can be corrected from estimation of the mean profiles or by a climatic adjustment method. Atten-uation in the propagation can be corrected by an iterative polarimetric method. These various correc-tions permit the distance validity limits of radar data to be extended.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.1
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• pp.1-7
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• 2002

As the existing noise measuring device was affected the flow-field and structural vibration directly, new experimental device was required. Two Hydrophone Boxes are designed and their performances are investigated. The noise level of the KRISO cavitation tunnel is compared with those of the other cavitation tunnels which have been designed for the noise study. The present experimental results show the possibility of the full-scale prediction for propeller cavitation noise and the improvement of the measurement performance at the range of low-frequency.

• Journal of Broadcast Engineering
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• v.6 no.2
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• pp.160-168
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• 2001

In this paper, we propose a new practical motion model that can exploit the general properties of camera motion in constructing a panorama. accounting for panning. tilting, and evert the change in focal length of the camera. We also present an efficient algorithm to handle moving objects or noose in the scene based on outliers rejection. Spatial and temporal statistical properties of motion field are exploited to detect the outliers. The proposed algorithm removes moving objects or noise from the panoramic Image so that mode clear and complete view of the background Image can be obtained. This method does not require assumptions or a priors knowledge of the scene. The entire process is fully automatic as this method does not require any manual correction in the process of constructing a Panorama. The proposed algorithm is tested on the broadcasting images of soccer games. Oun simulation result shows that this method is superior to conventional image mosaicing algorithms.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.176-176
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• 2011

전 세계적으로 국지성 집중호우의 발생이 증가하고 있다(건설교통부, 2007 ; 김광섭과 김종필, 2008). 특히, 국내의 경우 급속한 도시화에 의한 기상 변화의 영향으로 서울 및 중소도시 지역에 집중호우의 발생이 크게 증가하였고, 산악지역에 발생한 강도 높은 집중호우로 인하여 돌발홍수의 발생 또한 급증하고 있다. 이처럼 집중호우는 단시간에 큰 강우강도를 동반하여 돌발홍수를 유발할 뿐만 아니라 잦은 발생으로 인하여 막대한 재산 손실과 인명 피해를 초래하고 있다(유철상 등, 2007a). 현실적으로 이러한 이상호우에 의한 피해를 원천적으로 방지하는 것은 불가능하다. 그러나 어느 정도(accuracy) 이상의 강우예측이 전제된다면 피해의 규모를 크게 줄일 수 있는 것이 또한 사실이다(유철상 등, 2007b). 집중호우로 인한 피해의 주범은 수 시간이내에 발생하는 돌발홍수로서 이에 대한 피해를 최소화하기 위해서는 정확한 초단기예측 강우가 절실한 상황이다. 이에 본 연구에서는 초단기예측 강우의 보정을 목적으로 G/R 비를 예측하였다. 먼저, 강우의 임계치와 누적시간에 따른 G/R 비의 특성변화를 검토하여 G/R 비 산정방법을 개선하였다. 초단기예측 강우로 캐나다 McGill 대학교에서 개발된 MAPLE 예측강우를 사용하였으며, 이를 보정하기 위하여 칼만 필터를 이용하여 G/R 비를 실시간으로 예측하였다. 이러한 분석은 레이더 자료의 품질이 가장 양호할 것으로 판단되는 내륙지역을 대상으로 하였다. 결과적으로 강우의 임계치와 누적시간의 고려를 통해 안정화된 G/R 비의 산정이 가능하였으며, 이를 이용함으로서 예측 G/R 비의 정확성이 보다 향상되었다.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.373-378
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• 2006

The western coast of South Korea is famous for its large and broad tidal lands. Nevertheless, land reclamation, which has been conducted on a large scale, such as Sihwa embankment construction project has accelerated coastal environmental changes in the embankment inland. For monitoring of environmental change, vegetation change detecting of the embankment inland were carried out and field survey data compared with Landsat TM, ETM+, IKONOS, and EOC satellite remotely sensed data. In order to utilize multi-temporal remotely sensed images effectively, all data set with pixel size were analyzed by same geometric correction method. To detect the tidal land vegetation change, the spectral characteristics and spatial resolution of Landsat TM and ETM+ images were analyzed by SMA(spectral mixture analysis). We obtained the 78.96% classification accuracy and Kappa index 0.2376 using March 2000 Landsat data. The SMA(spectral mixture analysis) results were considered with comparing of vegetation seasonal change detection method.