• Journal of the Korean Data and Information Science Society
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• v.20 no.6
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• pp.1015-1027
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• 2009

Many problems of confounding and identifiability for polynomial models in an experimental design can be solved using methods of algebraic geometry. The theory of $Gr\ddot{o}bner$ basis is used to characterize the design. In addition, a fractional factorial design can be uniquely represented by a polynomial indicator function. $Gr\ddot{o}bner$ bases and indicator functions are powerful computational tools to deal with ideals of fractions based on each different theoretical aspects. The problem posed here is to give how to move from one representation to the other. For a given fractional factorial design, the indicator function can be computed from the generating equations in the $Gr\ddot{o}bner$ basis. The theory is tested using some fractional factorial designs aided by a modern computational algebra package CoCoA.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.57-64
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• 1999

To effectively identify near-surface faults with vertical slips from seismic refraction data, the GRM interpretation technique is tested and investigated in terms of various parameters through computer modeling. A characteristic change in shape of the velocity-analysis function near faults is noticed, and a new strategy of `Slope Variation Indicator (SVI)' is developed and tested in this study. The SVI is defined as a first horizontal derivative of the difference of velocity analysis functions for a large XY value and a small one, respectively. As the dip of refractor decreases and as the difference in XY value increases, the peak value of SVI increases and its duration decreases. Consequently, the SVI indicates accurately the location of buried fault in the test models. The SVI is believed to be an efficient tool in seismic refraction method to investigate location and distribution of shallowly buried faults.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.305-306
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• 2018

본 논문에서 하드웨어 위주의 교육에서 벗어나 알고리즘을 고민할 수 있는 콘텐츠를 개발하였다. 지시박스와 신호등을 이용한 간단한 알고리즘을 시작으로 조건문과 함수를 만들어서 코딩을 할 수 있는 복잡한 알고리즘까지 생각해 볼 수 있도록 한다. 각각의 알고리즘에서 조금씩 다른 상황들을 제시하여 익히도록 교육용 콘텐츠를 개발하였다.

• Journal of Korea Multimedia Society
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• v.9 no.9
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• pp.1150-1159
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• 2006

This paper proposed a curve progress control function of the area base instead of the existing edge indication function, in order to detect the brain ventricle area by utilizing a geodesic active contour model. The proposed curve progress control function is very effective in detecting the brain ventricle area and this function is based on the average brightness of the brain ventricle area which appears brighter in MRI images. Compared numerically by using various measures, the proposed method in this paper can detect brain ventricle areas better than the existing method. By examining images of normal and diseased brain's images by brain tumor, we compared the several brain ventricle detection algorithms with proposed method visually and verified the effectiveness of the proposed method.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.65-74
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• 1999

From refraction data along four seismic profiles near Eonyang which the Yangsan fault passes through, the Slope Variation Indicators (SVI) are computed and interpreted in terms of fault distribution. The average velocities of 2,250-2,870 m/s are estimated using velocity-analysis functions for the target boundary along those profiles. The average velocity for Line 1 is approximately 600 m/s lower than ones for the other lines. The SVI's with amplitude greater than or equal to 0.5 ms/m are turned out to be located near faults shown on the high-resolution reflection section, as closely as one station spacing (3 m). Large amplitude SVI's are densely distributed near National Road 35, and the fault having the largest vertical slip is indicated to be located approximately 930 m west of the inferred fault on the published geologic map.

• Korean Journal of Logic
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• v.16 no.3
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• pp.347-380
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• 2013

In this paper I will try to show how Wittgenstein criticized Frege's theory of meaning. Frege's theory of meaning can be compressed as sense-reference theory. Frege distinguishes between sense and reference on all the linguistic expressions. In particular, he regards that a sentence has sense and reference. This distinction was raised from, so to speak, the problem of identity sentences. Wittgenstein's "fundamental thought" of Tractatus Logico-Philosophicus is the key of his direct criticism of Frege's sense-reference theory. That is, it is an attack on Frege's thought that the reference of a sentence is a truth value and truth values are "objects themselves" (in Frege's meaning). According to Wittgenstein, such an object does not exist and according to his picture theory, the function of a name and that of a proposition are fundamentally different. By the way, Frege can reply justly to this criticism that it is insufficient. In short, Frege's 'sense' and 'reference' etc, are the technical terms. Hence Wittgenstein's decisive criticism of Frege's theory consists in accusing his theory of logical flaws. There is an another route to the sense and reference of a sentence which Frege introduces. In discourses of judgement stroke and content stroke in his Begriffsshrift and in those of horizontal stroke since his "Function and Concept", Frege deals with the sense and reference of a sentence. Wittgenstein criticize that the sense of a complex sentence such as ~p would by no means be determined by Frege's determination.

• Journal of KSNVE
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• v.8 no.4
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• pp.690-699
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• 1998

This paper discusses the techniques, procedures and the results of the ground vibration test(GVT) performed on the development aircraft and the simple procedure of FE model updating technique from the GVT results. The GVT was carried out using random excitation technique with MIMO(Multi-Input-Multi-Output) data acquistion method, and taking full advantage of poly-reference global parameter estimation technique to identify the vibration modes. In dynamic FE modeling, the aircraft was represented by beam elements and all dynamic analysis was performed using MSC/NASTRAN for this model. In updating procedure, the stiffness of the beam model was adjusted iteratively so as to get the natural frequencies and mode shapes close to the GVT results.

• The Journal of the Petrological Society of Korea
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• v.23 no.3
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• pp.249-259
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• 2014

Proxies for paleo-circulation are drawing much interest with the recognition that ocean circulation plays an important part in the redistribution of heat and climate change on orbital and millennial timescales. In this review, we will introduce how neodymium isotope ratios of the authigenic fraction of marine sediments can be used as a proxy for ocean circulation along with analytical methods and two case studies. The first case study shows how the North Atlantic Deep Water (NADW) has varied over the glacial-interglacial and stadial-interstadial periods. The second case study shows how the freshwater budget and water circulation within the Arctic Ocean can be reconstructed for the last glacial period.

• Journal of the Korean Geotechnical Society
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• v.28 no.11
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• pp.5-16
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• 2012

Since geologic data are often sampled at sparse locations, it is important not only to predict attribute values at unsampled locations, but also to assess the uncertainty attached to the prediction. In this paper, the assessment of the local uncertainty of prediction for the depth to weathered soil was performed by using the indicator kriging. A conditional cumulative distribution function (ccdf) was first modeled, and then E-type estimate was computed for the spatial distribution of the depth to the weathered soil. Also, optimal estimate of spatial distribution for the depth to weathered soil was determined by using ccdf and loss function. The design procedure and method considering the minimum expected loss presented in this paper can be used in the decision-making process for geotechnical engineering design.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.2
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• pp.110-125
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• 2010

We present a novel scheme for generating line drawings from 2D images, aiming to facilitate effective visual communication. In contrast to conventional edge detectors, our technique imitates the human line drawing process to generate lines effectively and intuitively. Our technique consists of three parts: line extraction, line rendering, and user guidance. In line extraction, we extract lines by estimating a likelihood function to effectively find the genuine shape boundaries. In line rendering, we consider the feature scale and the blurriness of lines with which the detail and the focus-level of lines are controlled. We also employ stroke textures to provide a variety of illustration styles. User guidance is allowed to modify the shapes and positions of lines interactively, where immediate response is provided by GPU implementation of most line extraction operations. Experimental results demonstrate that our technique generates various kinds of line drawings from 2D images enabled by the control over detail, focus, and style.