• 대한산업공학회지
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• 제24권2호
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• pp.211-221
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• 1998

It is very important to have a satisfactory measurement system, since it is useless to try to improve the manufacturing process without an adequate measurement system. Therefore, evaluation of the measurement system is the first step for the quality improvement of the manufacturing process. To estimate the measurement error we must conduct a controlled gage repeatability and reproducibility(gage R&R) study. Many manufacturers use a gage or instrument to measure multiple dimensions for the overall quality of the manufactured parts. In this case, it is necessary to estimate the gage R&R for multiple dimensions. When a gage measures a large number of dimensions of a part, it is very time-consuming and costly to measure all the dimensions. In this paper we propose the use of the principal component analysis method to identify a few principal components out of the original multivariate measurement capability to explain most of the measurement system variation pattern.

• 대한조선학회지
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• 제24권2호
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• pp.20-28
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• 1987

In general, preliminary hull form design is performed by changing a parent hull form using a computer to satisfy given requirements, e.g., principal dimensions, displacement, $L_{CB}$, and etc. Principal dimensions, $C_b,\;L_{CB}$ and midship sections are the only parameters to be modified in the traditional hull form variation methods available for preliminary design. In this paper, a method is presented in which local cross sections as well as principal dimensions and midship sections are modified according to design requirements. The method gives hydrostatic curves of modified hull form simultaneously. An optimization technique to satisfy the constraints of hydrostatic characteristics such as maximizing KM as a design requirement is also considered.

• 한국해양공학회지
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• 제38권2호
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• pp.43-52
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• 2024

Investigating ship motion under real conditions is vital for evaluating the seakeeping performance, particularly in the design process stage. This study examined the influence of the principal particulars of a trawler on its seakeeping performance. The wave conditions in the Bering Sea are investigated using available data. The length-to-beam (L/B) and beam-to-draft (B/T) ratios of the ship are changed by 10% for the numerical simulation. The response amplitude operator (RAO) motion, root mean square (RMS) value and sensitivity analysis are calculated to evaluate the influence of the trawler dimensions on ship motions. The peak RAO motion affected the ship motions noticeably because of the resonance at the natural frequency. The L/B and B/T ratios are important geometric parameters of a ship that significantly influence its RMS motion, particularly in the case of roll and pitch. The change in the B/T ratio has a good seakeeping performance based on a comparison of the roll and pitch with the seakeeping criteria. The present results provide insights into the seakeeping performance of ships due to the influence of the principal dimensions in the design stage.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 춘계학술대회 논문집
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• pp.220-226
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• 2000

In this paper, a primitive study of yacht is carried out and an attempt to design a typical yacht is pursuited. General characteristics and types of a yacht is examined and the 1st step to design process is outlined. A model ship of an environmental adaptive yacht is presented and principal dimensions of the yacht is decided.

• Communications for Statistical Applications and Methods
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• 제9권2호
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• pp.543-553
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• 2002

Principal component analysis is applied to reduce p-dimensions into q-dimensions ( $q {\leq} p$). Any partition of a collection of data points with p and q variables generated by the application of six hierarchical clustering methods is re-classified by discriminant analysis. From the application of discriminant analysis through each hierarchical clustering method, correct classification ratios are obtained. The results illustrate which method is more reasonable in exploratory data analysis.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2001년도 봄 학술발표논문집 Vol.28 No.1 (B)
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• pp.529-531
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• 2001

We present an expectation-maximization algorithm for principal component analysis via orthogonalization. The algorithm finds actual principal components, whereas previously proposed EM algorithms can only find principal subspace. New algorithm is simple and more efficient thant probabilistic PCA specially in noiseless cases. Conventional PCA needs computation of inverse of the covariance matrices, which makes the algorithm prohibitively expensive when the dimensions of data space is large. This EM algorithm is very powerful for high dimensional data when only a few principal components are needed.

• 대한조선학회지
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• 제25권4호
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• pp.28-38
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• 1988

본 논문은 선박저항 추정을 위한 통계해석 방법을 기술하고 있다. 조파저항계수 추정식은 조파저항이론을 이용하여 선체주요치수와 횡단면적계수들로부터 유도하였으며, 그 회귀계수들은 저항시험 결과들을 회귀 분석하여 얻었다. 형상영향계수 추정식은 선체주요지수, 횡단면적와 저항시험결과들로부터 순수하게 회귀분석하여 얻었다. 또한 선체주요지수는 바꾸지 않고 횡단면적곡선만을 변화시켜 조파저항을 최소로 해주는 방법을 제시하였다. 이 방법들은 산적화물선의 저항성능 추정에 적용하였다. 그리고 조파저항이 최소가 되는 수정선형을 도출해 냈으며, 이로인한 유효동력의 절감효과를 저항시험을 통해 확인하였다.

• 한국항해항만학회지
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• 제42권3호
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• pp.177-186
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• 2018

보트의 초기설계단계에서 설계자는 주요치수 결정을 위해 많은 정보를 필요로 하며, 그러한 정보의 대부분은 해당 보트와 유사한 실적선 자료들을 많은 시간에 걸쳐 조사 및 분석함으로써 얻을 수 있다. 또한, 결정된 주요치수는 설계과정(기본/상세설계) 전반에 걸쳐 영향을 미치게 되고, 이는 결국 보트의 안정성과 성능으로 직결된다. 따라서 본 연구에서는 700여 척의 실적선 자료를 이용하여 보트 초기설계시스템(설계지원플랫폼)을 개발하고, 50피트급 고속보트를 대상으로 이를 활용하여 설계자가 초기설계단계에서도 주요치수를 편리하고 합리적으로 도출 및 결정할 수 있음을 확인하였다.

• 한국해양공학회지
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• 제24권4호
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• pp.47-52
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• 2010

In this paper, the shapes of windsurfing boards are proposed for the promotion of their public utilization. Initially, we investigated the principal dimensions of 1,500 windsurfing boards that were produced in the last six years to categorize the characteristics of the boards. Then, model tests were performed in a circulating water channel to determine the resistance characteristics and the flow phenomena, including the wetness of the decks. After analyzing the principal dimensions and the results of the tests of existing windsurfing boards, we proposed four public board shapes that resulted from changing the shapes of the nose and rail and protecting the deck of free-ride boards from wetness. Finally, we predicted the performance of the four proposed windsurfing boards.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.703-708
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• 2009

The present paper describes the application of an improved impression transfer vector method (Sakurai et al., 2007) to transform the three basic dimensions (Evaluation, Activity, and Potency) of higher-order impression. First, a set of shapes and surface textures of faces was represented by multi-dimensional vectors. Second, the variation among faces was coded in reduced parameters derived by applying principal component analysis. Third, a facial attribute along a given impression dimension was analyzed to select discriminative parameters from among principal components with higher sensitivity to impressions, and obtain an impression transfer vector. Finally, the parametric coordinates were changed by adding or subtracting the impression transfer vector and the image was manipulated so that its facial appearance clearly exhibits the transformed impression. A psychological rating experiment confirmed that the impression transfer vector modulated three dimensions of higher-order impression. We discussed the versatility of the impression transfer vector method.