• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.4
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• pp.309-317
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• 2007

Cadastral control points in Korea are refered to various origins, for example an early separated small triangulation, a separated small triangulation, a separated control surveying origin and an unified origin. Cadastral map with early separated small triangulation origin have difficulties to connect with national GIS data by refered an unified origin. We determined transformation parameters from old origin to unified origin using 2D conformal transformation method. To evaluate of transformation accuracy, we compared with GPS field surveying results. And we experiment on coordinate transformations with unified results between the local geodetic datum and the new Korea geodetic datum.

• Journal of the Korean Data and Information Science Society
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• v.25 no.2
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• pp.403-410
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• 2014

Binary logistic regression analysis is a statistical technique that explains binary response variable by quantitative or qualitative explanatory variables. In the binary logistic regression model, the probability that the response variable equals, say 1, one of the binary values is to be explained as a transformation of linear combination of explanatory variables. This is one of big barriers that non-statisticians have to overcome in order to understand the model. In this study, an educational tool is developed that explains the need of the binary logistic regression analysis using Excel VBA. More precisely, this tool explains the problems related to modeling the probability of the response variable equal to 1 as a linear combination of explanatory variables and then shows how these problems can be solved through some transformations of the linear combination.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.48-56
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• 2004

This research focuses on the development of a fast datum transformation model to be used in GIS that utilizes real-time data transformation. Instance, when a GIS data constructed according to a datum is conformed to another datum, instead of transforming the axes of the original data, the data is transformed right before the results are reflected on the monitor. In this research, the prospects of calculating transformation parameters for every grid cells on the area based on two-dimensional conformal transformation model in order to decrease real-time datum transformation time while maintaining a high accuracy has been investigated. Research results showed that for a fixed area, the accuracies of the two-dimensional conformal transformation and the three-dimensional datum transformation, which requires more computing time, were almost equal and fast transformation speed, high accuracy real-time datum transformation is made feasible by implementing the grid-divided two-dimensional conformal transformation model.

• The Korean Journal of Applied Statistics
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• v.17 no.2
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• pp.347-357
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• 2004

It is very important to select a split variable in constructing the classification tree. The efficiency of a classification tree algorithm can be evaluated by the variable selection bias and the variable selection power. The C4.5 has largely biased variable selection due to the influence of many distinct values in variable selection and the QUEST has low variable selection power when a continuous predictor variable doesn't deviate from normal distribution. In this thesis, we propose the SRT algorithm which overcomes the drawback of the C4.5 and the QUEST. Simulations were performed to compare the SRT with the C4.5 and the QUEST. As a result, the SRT is characterized with low biased variable selection and robust variable selection power.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1799-1803
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• 2008

표면영상유속계는 하천 표면의 영상을 분석하여 유속을 산정하는 매우 실용적이며 간편한 장비이다. 그러나, 표면영상유속계를 이용하여 유량을 산정하고자 할 경우, 하천 표면의 평면 측량 자료와 하천의 단면 측량 자료가 반드시 필요하다. 이 때문에 표면영상유속계의 간편성과 유용성에도 불구하고, 이용자들이 쉽게 이용하기 어렵다는 그릇된 인식을 줄 수 있다. 만일 효율적이고 간편하게 하천의 단면을 추정할 수 있다면, 표면영상유속계를 마치 일반적인 프로펠러 유속계처럼 쉽게 이용할 수 있을 것이다. 이 연구는 일반적인 평면 측량없이, 두 대의 비디오 카메라로 이루어진 표면 영상 유속계를 이용하여 하천 평면을 계측하는 방법을 개발하는 것이다. 이를 통하여 표면 영상 분석 과정을 반자동화할 수 있게 된다. 두 대의 카메라를 이용한 평면 측량은 사진 측량 분야이나 컴퓨터 비전 분야에서 오랫 동안 연구되어 왔다. 이 기법을 표면영상유속계에 적용함으로써 간단하게 하천의 평면 좌표를 구할 수 있도록 하였다. 두 대의 카메라에 대해서는 직접 선형 변환법을 이용하여 내부 표정과 외부 표정을 수행하여 변환의 매개 변수들을 추정하였다. 추정된 변수들과 공간 전방 교회법을 이용하여 하천의 고정된 기준점들의 좌표를 측정한다. 측정된 좌표점들은 기울어진 영상을 연직으로 사영된 평면으로 변환하는 데 이용되며, 이 과정을 통하여 번거로운 하천의 평면 측량 과정을 생략할 수 있게 되었다. 온천천에 실제 적용하여 본 결과, 결과는 아직은 만족할 만한 정도는 아니나, 보다 정밀한 카메라의 보정 등을 통하여 보다 나은 결과를 도출할 수 있을 것으로 기대된다.

• Journal of Korea Multimedia Society
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• v.10 no.5
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• pp.687-697
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• 2007

Although the Java bytecode has numerous advantages, there are also shortcomings such as slow execution speed and difficulty in analysis. Therefore, in order for the Java class file to be effectively executed under the execution environment such as the network, it is necessary to convert it into optimized code. We implemented CTOC for transforming to optimized code. In Optimization, SSA Form that distinguish variable by assignment is used to determine value and type statically. Copy propagation, dead code elimination optimization is applied to SSA Form. However, existing SSA Form is related to variable than expression. Therefore, in this paper, to performing optimization to SSA Form expression, after performing copy propagation and dead code elimination, in addition to that, partial redundant expression elimination is performed

• The Korean Journal of Applied Statistics
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• v.20 no.2
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• pp.323-332
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• 2007

We present a new type of portmanteau test in the frequency domain which is derived from the discrete cosine transform(DCT). For the stationary time series, DCT coefficients are asymptotically independent and their variances are expressed by linear combinations of autocovariances. The covariance matrix of DCT coefficients for white noises is diagonal matrix whose diagonal elements is the variance of time series. A simple way to test the independence of time series is that we divide DCT coefficients into two or three parts and then compare sample variances. We also do this by testing the slope in the linear regression model of which the response variables are absolute values or squares of coefficients. Simulation results show that the proposed tests has much higher powers than Ljung-Box test in most cases of our experiments.

• Journal of Korea Spatial Information System Society
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• v.2 no.1 s.3
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• pp.57-62
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• 2000

Open GIS Consortium(OGC) provides with Simple Features Specification for OLE/COM which is a system object technology of interoperability and reusable capability. In this research, the Spatial Reference System(SRS) component is developed based on the OGC specification using ATL. The component presents 44 map projections and transformations between different geographic coordinate systems utilizing the seven parameter(Bursa Wolf) and Molodenski's methods, a user can set up all objects and its attributes comprising SRS and can create SRS and save its setting using predefined text, WellKnownText. The Spatial Reference System component can be easily implemented into the variety of GIS software so that it reduces the developing time for a system and defines new reference system without difficulty.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.563-573
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• 2000

In this paper, we propose three estimators of Kullback-Leibler Information functions using the data from accelerated life tesb. This acceleration model is assumed to be a tampered random variable model. Some asymptotic properties of proposed estimators are proved. Simulations are performed for comparing the small sample properties of the proposed estimators under use condition of accelerated life test.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.758-763
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• 2006

In various fields of basic science and engineering, in order to present signals and systems exactly and acquire useful information from spatial and timely changes, many researches have been processed. In these methods, the Fourier transform which represents signal as the combination of the frequency component has been applied to the most fields. But as transform not to consider time information, the Fourier transform has its limitations of application. To overcome this problem, a variety of methods including the wavelet transform have been proposed. As transform to represent signal by using the changing window, according to scale parameter in time-scale domain, the wavelet transform is capable of multiresolution analysis and defines various functions according to the application environments. In this paper, to detect features of signal we analyzed wavelet the spectrum by using the basis function of the fourier transform.