• 한국CDE학회논문집
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• 제2권1호
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• pp.1-10
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• 1997

Finding the optimum route of ship's pipes is complicated and time-consuming process. Experience of designers is the main tool in this process. To reduce design man-hours and human errors a design expert system shell and a geometric modeler is used to automate the design process. In this paper, a framework of the intelligent CAD system for pipe auto-routing is suggested, which consists of general-purpose expert system shell and a geometric modeler. The design expert system and the geometric modeling kernel have been integrated. The CADDS5 of Computervision is used as the overall CAD environment. The Nexpert Object of Neuron Data is used as the expert system shell. The CADDS5 ISSM is used as the interface that creates and modifies geometric models of pipes. Existing algorithms for the routing problem have been analyzed. Most of them are to solve the 2-D circuit routing problems. Ship piping system, specially within the engine room, is a complicated, large scale 3-D routing problem. Methods of expert system have been used to find the route of ship pipes on the main deck.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.367-372
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• 2000

Accuracy of a machined component is determined by the relative motion between the cutting tool and the workpiece. One of the important factors which affects the accuracy of this relative motion is the geometric error of machine tools. In this study, geometric error is modeled using form shaping motion of machine tool, where a form shaping function is derived from the homogeneous transformation matrix. Geometric errors are measured by laser interferometer. After that, the local positioning error can be estimated from the form shaping model and geometric error data base. From this information, we can remodel the part by shifting the design surface to the amount of positional error. By generating tool path to the redesigned surface, we can reduce the machining error.

• 한국CDE학회논문집
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• 제9권1호
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• pp.19-26
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• 2004

It is not possible to exchange parametric information of CAD models based on the current version of STEP (Standard for the Exchange of Product model data). The designer intents are lost during the transfer of CAD models. To resolve this problem, the macro-parametric approach had been proposed. To enable this approach, a set of standard modeling commands has been defined. Errors or missing elements of the standard modeling commands can be discovered by implementing macro-parametric translators. But there is a limit to discover problems only by using translators. This paper proposes a method to verify the standard modeling commands by implementing a geometric modeler. First, each argument of a modeling command is verified. Second, the set of the standard modeling commands is applied to geometric modeling of commercially available product parts. For the geometric modeling, nine test models have been selected.

• Communications for Statistical Applications and Methods
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• 제21권2호
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• pp.147-160
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• 2014

In this paper, we introduce the exponentiated Weibull-geometric (EWG) distribution which generalizes two-parameter exponentiated Weibull (EW) distribution introduced by Mudholkar et al. (1995). This proposed distribution is obtained by compounding the exponentiated Weibull with geometric distribution. We derive its cumulative distribution function (CDF), hazard function and the density of the order statistics and calculate expressions for its moments and the moments of the order statistics. The hazard function of the EWG distribution can be decreasing, increasing or bathtub-shaped among others. Also, we give expressions for the Renyi and Shannon entropies. The maximum likelihood estimation is obtained by using EM-algorithm (Dempster et al., 1977; McLachlan and Krishnan, 1997). We can obtain the Bayesian estimation by using Gibbs sampler with Metropolis-Hastings algorithm. Also, we give application with real data set to show the flexibility of the EWG distribution. Finally, summary and discussion are mentioned.

• 대한조선학회논문집
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• 제40권6호
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• pp.30-36
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• 2003

To improve survivability of damaged ship, assessment of stability and structural safety, and behavior analysis in wave is required. Prediction of sinking time, damage stability and structural strength considering progressive flooding and dynamic force in wave is very important. To do it, a geometric model which can be express damaged ship is prepared. This paper described the geometric modeler for survivability assessment of damaged ship. The modeler is developed based on 3-D geometric modeling kernel, ACIS. The hull form and compartment definition is available fundamentally. And requirement for modeler contains data generation and interface for hydrostatic calculation, behavior analysis, and longitudinal strength analysis and so on. To easy access modeling system by conventional user such as crew, user interface is developing.

• 아동학회지
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• 제20권3호
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• pp.325-337
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• 1999

In this intervention study, an experimental group of kindergarten children participated in paper folding activities 2 times per week for 10 weeks while the control group did ordinary art activities. Subjects were 43 five-year-old children enrolled in N and D public kindergartens in Hwa-soon Chonnam province. Data were analyzed with a two-sample t-test. The ability to draw and to manipulate geometric figures increased significantly in the experimental group but there was no difference between the two groups in the discrimination of geometric figures.

• 한국측량학회지
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• 제27권5호
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• pp.585-597
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• 2009

본 연구는 항공다중센서시스템으로부터 동시에 취득되는 항공영상과 라이다데이터 사이에 존재하는 기하학적 불일치를 제거하는 정합 방법의 개발을 목표로 한다. 제안된 방법은 크게 정합요소의 추출, 정합요소간의 상호일치성 수립, 영상외부표정요소의 조정계산으로 구성된다. 정합요소로써 라이다데이터로부터 평면패치와 교면에지를 항공영상으로부터 객체점과 연결에지를 추출한다. 추출된 정합요소를 수평 및 수직요소로 구분하여 상호일치성을 수립한다. 이를 광속조정번에 확률제약조건으로 적용하며 외부표정요소를 정밀하게 조정한다. 제안된 방법을 실측 데이터에 적용한 결과에 따르면 외부표정요소 중에 자세변수에 대한 의미 있는 조정이 이루어졌으며, 조정에 사용된 대상객체에 존재하던 최대 2m 정도의 기하학적 불일치가 조정 후에 약 2cm 정도로 크게 감소된 것으로 분석되었다. 본 연구의 결과는 특히 도시지역의 고품질의 3차원 공간정보를 생성하기 위한 데이터 융합에 크게 기여할 것으로 판단된다.

• 한국측량학회지
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• 제27권2호
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• pp.213-223
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• 2009

지오이드 모델개발에 있어서 GPS/leveling 자료는 중력지오이드의 검증이나 합성지오이드의 계산에 있어서 매우 중요한 역할을 한다. 본 연구에서는 우리나라 GPS/leveling 자료의 배점밀도를 개선하기 위하여 산악지역을 포함하는 연구대상지역에서 직접 GPS측량을 실시하고, 이를 처리하여 산정된 기하학적 지오이드 고의 정확도를 분석하였다. 이를 위해 경북지역 내의 1등 및 2등 수준노선을 대상으로 총 211개소의 GPS/leveling 자료를 취득하고, 기선해석 및 망조정을 통해 198개소의 GPS/leveling 자료를 결정하였다. 이 198개소의 자료에 의한 기하학적 지오이드고는 EGM2008 모델에 의한 지오이드고와의 교차분석을 통해 그 정확도를 분석하였다. 그 결과 정규분포에 따른 과대오차 소거 후 190개소 자료에 대한 정확도는 -0.185$\pm$ 0.079m로 나타났고, 이를 이용하여 수준점 등급, 기선길이, 그리고 표고에 따른 정확도를 분석하였다.

• 한국의상디자인학회지
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• 제16권1호
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• pp.53-64
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• 2014

The main objective of this research was to understand the characteristics of printed geometric patterns through the statistical & qualitative analysis of fashion appeared in contemporary female collections 2011 S/S to 2013 A/W. Data collection of 294 was done through review of 'pr$\hat{e}$t-$\grave{a}$-porter Collections' of three major fashion cities; Paris, Milan and NY. Statistical analysis of frequency was conducted. Also qualitative interpretation of natural print design' characteristics were completed. The main findings were as followed; 1,636 of the total 15,852 designs were printed patterns in 12 Collections and the occurrence rate of printed geometric patterns in three collections were 8.6% in Milan, 9.2% in Paris and 12.9% in N.Y. Most geometric patterns were the types of compact or medium density in a front patterns with a variety of sizes and mainly applied to the one piece dress or two piece clothing item combination styles. Formative Characteristics of printed geometric patterns were classified into four types. First, a variety of thicknesses and shapes, such as a line or a rectangle shape to take advantage of the types of the typical geometric pattern. Second types were using the motifs which inspired by geometric shapes such as point, circle star and other special geometric shapes and arranging them regularly with various sizes and density. The third was repeated particular motifs which based on complex and sophisticated mathematical formulas. Fourth were the specific diagram types of bold and free shapes or dividing the flat and arranging them without rules, or the combination type of various geometric motifs.

• 한국지리정보학회지
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• 제7권4호
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• pp.15-23
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• 2004

원격탐사 자료를 효율적으로 사용하기 위해서 위성영상의 기하학적인 왜곡을 제거하는 작업은 반드시 필요하다. 이러한 기하보정을 위해서는 기하보정 된 위성영상, 수치지도, GPS 측량 및 기타 방법에 의해 획득되어진 지상기준점을 필요로 한다. 지금까지의 지상기준점을 이용한 기하보정 방법은 수동적으로 이루어 졌으며, 많은 시간과 노력을 필요로 하였다. 본 논문에서는 GCP Chip 데이터베이스를 이용하여 온라인 상에서 자동으로 기하보정 하는 방법을 제안하였다. 제안된 온라인 자동기하보정 시스템은 영상을 입력하는 부분, 지상기준점 영상을 조정하는 부분, 선택된 지상기준점을 수정 및 갱신하는 부분, 그리고 기하보정 결과를 저장하는 네 가지 부분으로 이루어져 있다. 결론적으로 이러한 온라인 자동 기하보정 시스템을 이용하여 기존의 수동적인 기하보정방법 보다 시간 및 노력을 줄일 수 있으며, 랜셋 영상의 활용에 기여할 것이다.