• Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.202-212
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• 2014

To survive in the current shipbuilding industry, it is of vital importance for shipyards to have the ship components' accuracy evaluated efficiently during most of the manufacturing steps. Evaluating components' accuracy by comparing each component's point cloud data scanned by laser scanners and the ship's design data formatted in CAD cannot be processed efficiently when (1) extract components from point cloud data include irregular obstacles endogenously, or when (2) registration of the two data sets have no clear direction setting. This paper presents reformative point cloud data processing methods to solve these problems. K-d tree construction of the point cloud data fastens a neighbor searching of each point. Region growing method performed on the neighbor points of the seed point extracts the continuous part of the component, while curved surface fitting and B-spline curved line fitting at the edge of the continuous part recognize the neighbor domains of the same component divided by obstacles' shadows. The ICP (Iterative Closest Point) algorithm conducts a registration of the two sets of data after the proper registration's direction is decided by principal component analysis. By experiments conducted at the shipyard, 200 curved shell plates are extracted from the scanned point cloud data, and registrations are conducted between them and the designed CAD data using the proposed methods for an accuracy evaluation. Results show that the methods proposed in this paper support the accuracy evaluation targeted point cloud data processing efficiently in practice.

• International Journal of CAD/CAM
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• v.8 no.1
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• pp.45-53
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• 2009

As the point sampling technology evolves rapidly, there has been increasing need in generating tool path from dense point set without creating intermediate models such as triangular meshes or surfaces. In this paper, we present a new tool path generation method from point set using Euclidean distance fields based on Algebraic Point Set Surfaces (APSS). Once an Euclidean distance field from the target shape is obtained, it is fairly easy to generate tool paths. In order to compute the distance from a point in the 3D space to the point set, we locally fit an algebraic sphere using moving least square method (MLS) for accurate and simple calculation. This process is repeated until it converges. The main advantages of our approach are : (1) tool paths are computed directly from point set without making triangular mesh or surfaces and their offsets, and (2) we do not have to worry about no local interference at concave region compared to the other methods using triangular mesh or surface model. Experimental results show that our approach can generate accurate enough tool paths from a point set in a robust manner and efficiently.

• Journal of the Korean Society of Safety
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• v.19 no.4 s.68
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• pp.69-73
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• 2004

The flash point is one of the most important combustible properties used to determine the potential for the fire and explosion hazards of industrial material and the fire point is the temperature of the flammable liquid at which there will be flaming combustion, sustained 5 seconds in response to the pilot flame. In this study, the flash point and fire point were measured to present raw data of the flammable risk assessment for alcohols, using Tag open-cup apparatus(ASTM D 1310-86). The measured values were compared with the calculated values based on 0.78 times stoichiometric concentration. The values calculated by the proposed equations were in good agreement with the measured values.

• Journal of Acupuncture Research
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• v.24 no.4
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• pp.25-33
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• 2007

Objective : The purpose of this study is to compare the effects of near acupuncture point needling and remote acupuncture point needling on treating ankle sprain of acute stage. Methods : From March 1st, 2007 to May 30th, 2007, the 50 patients who had visited Iksan oriental medical hospital, Wonkwang university with acute ankle sprain were divided into 2 groups ; one group took near acupunture point needling, and the other group took remote acupunture point needling. Both group had been treated with the same additional rest, ice, compression and elevation(RICE) therapy. To evaluating the efficiency of each treatment, Visual Analog Scale(VAS) and Ankle-Hindfoot Scale(AHS) were applied before 1st treatment and after 3rd treatment. Results : As a result of evaluation by using AHS, the score change comparison between the two groups had no significance after the treatment. As a result of evaluation by using VAS, treatment score of remote acupucture point needling was marked lower than score of near acupucture point needling. Conclusion : Remote acupucture point needling is more effective than near acupucture point needling in controlling the pain of acute ankle sprain.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.143-148
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• 2004

This paper presents the two modes for maximum power point tracking of the photovoltaic system. The method combines the merits of the two methods consisting of the open circuit method and the three point weight comparison method. The maximum point found by this method is exactly than by the open circuit method. By the simulation results, the actual maximum point can be found that is better than the Perturb and Observe (P&O) method or the three point weight method only one method, especially, in the case of non regular pattern of Power-Voltage (P-V) curve.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1821-1829
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• 2017

A point machine requires lots of time and attention in terms of maintenance, since it causes 40% of failures among the railway signaling devices. The senescence of the point machine critically matters to the overall turnout system. In this paper, we analyzed the aging characteristics of the point machine by using the switching current of the point machine. The analysis is done based on the switching current measurements of the point machines deployed in the Sehwa outdoor test site and the Korail Kyongbu line. It is expected that the analysis result can be utilized for real-time diagnosis in the aspect of the maintenance of the point machines and predicting abnormal operations.

• Elastomers and Composites
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• v.39 no.4
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• pp.318-323
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• 2004

Cloud-point and bubble-point curves for poly(ethylene-co-13.8 mol% octene) ($PEO_{13.8}$) and Poly(ethylene-co-15.3 mol% octene) ($PEO_{15.3}$) were determined up to $150^{\circ}C$ and 450 bar in hydrocarbons which have different molecular size and structure. Whereas ($PEO_{15.3}$+ n-pentane) system has cloud-point and bubble-point type transitions, ($PEO_{15.3}$+ n-propane) and ($PEO_{15.3}$+ n-butane) systems do only cloud-point type transition. In cyclo-pentane, -hexane, -heptane, and -octane, $PEO_{15.3}$ has a bubble-point transition. ($PEO_{13.8}$+ n-butane) mixture has a critical mixture concentration at 5 wt% PEO. (PEO + hydrocarbon) mixtures exhibit LCST type behavior. Solubility of PEO increases with hydrocarbon size due to increasing dispersion interaction which is favorable to dissolve PEO.

• Journal of Acupuncture Research
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• v.28 no.1
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• pp.85-92
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• 2011

Objectives : The purpose of this research was to compare remote and near acupuncture point needling with near acupuncture point needling acupuncture on posterior neck pain treatment. Methods : We divided 36 patients with posterior neck pain patient into two groups and treated Group A with near acupuncture and remote acupuncture point needling and Group B with near acupuncture point needling. The efficacy of treatment was measured by VAS scores and NDI scores of before and after 5 days to start treatment. Results : Both group A and B represented effective improvement in VAS and NDI of neck pain. And group A is more effective than B group statistically. Conclusions : It was suggested that near acupuncture and remote acupuncture point needling might have more effect compared with near acupuncture point needling acupuncture on posterior neck pain treatment.

• The Journal of Korea Robotics Society
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• v.10 no.1
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• pp.9-15
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• 2015

We present a robust power transmission lines detection method based on vanishing point estimation. Vanishing point estimation can be helpful to detect power transmission lines because parallel lines converge on the vanishing point in a projected 2D image. However, it is not easy to estimate the vanishing point correctly in an image with complex background. Thus, we first propose a vanishing point estimation method on power transmission lines by using a probabilistic voting procedure based on intersection points of line segments. In images obtained by our system, power transmission lines are located in a fan-shaped area centered on this estimated vanishing point, and therefore we select the line segments that converge to the estimated vanishing point as candidate line segments for power transmission lines only in this fan-shaped area. Finally, we detect the power transmission lines from these candidate line segments. Experimental results show that the proposed method is robust to noise and efficient to detect power transmission lines.

• Journal of Korean Society for Quality Management
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• v.17 no.2
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• pp.101-112
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• 1989

We investigate a procedure which detects the parameter change point in AR(1) by Bayesian Approach using Jeffrey prior, for example, coefficient change point, variance change point, coefficient and variance change point, etc. And we apply our procedure to the simulated data.