• 한국측량학회지
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• 제17권4호
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• pp.421-429
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• 1999

21세기에는 전 세계인구의 70%가 도시에서 생활할 것으로 예상되며, 이러한 도시화는 도시관리를 위해 GIS와 더불어 건물 DEM과 정사투영영상에 대한 요구가 증대될 것이다. 건물 DEM을 생성하기 위해서는 건물의 형태를 나타내는 경계선을 검출해야 한다. 이를 위해서 일반적으로 자동과 반자동 건물 추출법을 사용한다. 그러나 자동 검출법을 항공사진에 직접 적용하면 지붕의 색깔이나 그림자 그리고 주변의 나무 등 때문에 정확한 건물 경계선을 추출하기 매우 어렵다. 이러한 문제점을 극복하기 위해 본 연구에서는 반자동 건물 추출법을 제시하였다. 건물 지붕의 색깔이 균일할 경우 지붕의 한 부분을 마우스로 클릭하여 건물경계를 찾도록 하였으며, 균일하지 않은 경우 건물의 모서리 부분을 클릭하여 건물 모서리점을 검출하도록 프로그램을 개발하였다. 건물 DEM은 영상정합에 의해 계산된 건물 높이와 건물 경계선을 이용하여 생성하였다.

• Korean Journal of Radiology
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• 제22권3호
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• pp.435-441
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• 2021

Objective: To evaluate the usefulness of the ventricular volume percentage quantified using three-dimensional (3D) brain computed tomography (CT) data for interpreting serial changes in hydrocephalus. Materials and Methods: Intracranial and ventricular volumes were quantified using the semiautomatic 3D threshold-based segmentation approach for 113 brain CT examinations (age at brain CT examination ≤ 18 years) in 38 patients with hydrocephalus. Changes in ventricular volume percentage were calculated using 75 serial brain CT pairs (time interval 173.6 ± 234.9 days) and compared with the conventional assessment of changes in hydrocephalus (increased, unchanged, or decreased). A cut-off value for the diagnosis of no change in hydrocephalus was calculated using receiver operating characteristic curve analysis. The reproducibility of the volumetric measurements was assessed using the intraclass correlation coefficient on a subset of 20 brain CT examinations. Results: Mean intracranial volume, ventricular volume, and ventricular volume percentage were 1284.6 ± 297.1 cm³, 249.0 ± 150.8 cm³, and 19.9 ± 12.8%, respectively. The volumetric measurements were highly reproducible (intraclass correlation coefficient = 1.0). Serial changes (0.8 ± 0.6%) in ventricular volume percentage in the unchanged group (n = 28) were significantly smaller than those in the increased and decreased groups (6.8 ± 4.3% and 5.6 ± 4.2%, respectively; p = 0.001 and p < 0.001, respectively; n = 11 and n = 36, respectively). The ventricular volume percentage was an excellent parameter for evaluating the degree of hydrocephalus (area under the receiver operating characteristic curve = 0.975; 95% confidence interval, 0.948-1.000; p < 0.001). With a cut-off value of 2.4%, the diagnosis of unchanged hydrocephalus could be made with 83.0% sensitivity and 100.0% specificity. Conclusion: The ventricular volume percentage quantified using 3D brain CT data is useful for interpreting serial changes in hydrocephalus.

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.791-797
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• 2007

This paper proposes a semiautomatic vertebra segmentation method that overcomes limitations of both manual segmentation requiring tedious user interactions and fully automatic segmentation that is sensitive to initial conditions. The proposed method extracts fence surfaces between vertebrae, and segments a vertebra using fence-limited region growing. A fence surface is generated by a deformable model utilizing valley information in a valley emphasized Gaussian image. Fence-limited region growing segments a vertebra using gray value homogeneity and fence surfaces acting as barriers. The proposed method has been applied to ten patient data sets, and produced promising results accurately and efficiently with minimal user interaction.

• Design & Manufacturing
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• 제6권1호
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• pp.18-23
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• 2012

HI-WORTH T-32, a non-powered plasma cutter, is a portable cutter that utilizes compressor-plasma inverter. With a special air-pressure piston, the cutter is semiautomatic. When they were produced by die casting dies, the bodies or housings of the cutter have defects about 100 percent of defect rate due to blisters and thermal deformation. Therefore, they are produced by mechanical machining, which leads to a hike in material and machining costs and to the loss of productivity. And companies are left with insignificant profit margins. Besides mechanical machining, this study proposes to modify defective mold and cut down defective rate and boost productivity.

• 한국안전학회지
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• 제13권2호
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• pp.65-75
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• 1998

The cases of welders illness by welding fume generated during arc welding are recently reported, which makes the legal regulation in the welding work place. Also, this situation makes the employers and welders be concerned about the welding fume seriously. At this point of time it is necessary that a standard testing method is developed as a fundamental tool for the evaluation of Fume Generation Rate(FGR) required for making progress in the development of low fume electrodes and welding process technology and also constructing the ventilation system in welding area. However, the current standard(KS D 0062) is only applicable to the manual covered electrode arc welding. In this study the evaluation procedure for the FGR is established by developing the fume collection chamber which can be applicable to semiautomatic and automatic arc welding as well as manual arc welding. This evaluation system and procedure can be used as a tool not only to develop the low fume welding electrode and welding process technology but also to construct the equipment controlling the welding workshop atmosphere.

• 산업경영시스템학회지
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• 제27권2호
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• pp.10-16
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• 2004

Data mining technique is the exploration and analysis, by automatic or semiautomatic means, of large quantities of data in order to discover meaningful patterns and rules. This paper uses a data mining technique for the prediction of defect types in manufacturing Process. The Purpose of this Paper is to model the recognition of defect type Patterns and Prediction of each defect type before it occurs in manufacturing process. The proposed model consists of data handling, defect type analysis, and defect type prediction stages. The performance measurement shows that it is higher in prediction accuracy than logistic regression model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.249-254
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• 1987

This paper presents a new method for generating smooth free-form surface by local correction. B-spline surface is used for its convenience of local correction, and the direction of surface correction is fixed to the average-surface-normal direction. The surface to be corrected is approximated into a uniform cubic B-spline surface. Then, the smoothness (curvature arrows, iso-parametric lines) of the approximated surface is displayed with B-spline control points. When a control point near the region that needs correction is selected, a new point 1 mm higher than the original control point in the direction of the average surface normal is displayed. And the surface is corrected by giving the amount of control point movement interactively. Since the direction of correction is given by the program and the amount of correction is selected by the user, the method is called semiautomatic. sufficiently smooth surface can be obtained by this method. Examples are given to illustrate the method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.17-19
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• 2007

This paper describe an interactive video object segmentation tool which can be used to generate MPEG-4 video object planes for multimedia broadcasting and enables content based functionalities. In order to apply these functionalities, each frame of video sequence should be represented in terms of video objects. Semiautomatic segmentation can be thought of as a user-assisted segmentation technique. A user can initially mark objects of interest around the real object boundaries. Then the user-guided and selected objects are continuously separated from the unselected areas though time evolution in the image sequences. We proposed method shows very promising result and this encourages the development of object based video editing system.

• 한국구조물진단유지관리공학회 논문집
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• 제6권3호
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• pp.185-192
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• 2002

Prototyping for field inspection safety assessment expert system of bridge structures is presented in this paper. Knowledgebase with production rules is constructed using the semiautomatic method on the basis of bridge inspection manuals and working reports of the related agency. Backward inference method is taken with the aids of external shells as a inference engine of knowledge-based systems. Implementation of the developed prototype system on MS Windows98 will shows inspiring aspects useful to guide and standardize the field works. In the case to be reinforced with abundant knowledge bases, this will be expected to be educate the practicing engineers.

• 대한수의학회지
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• 제26권2호
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• pp.245-249
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• 1986

The present study has been carried out to investigate the optimal condition on the blastogenesis of guinea pig lymphocytes. A microculture system in conjunction with a semiautomatic multiple sample harvester(SAMSH) was used to study the in vito optimal condition of guinea pig lymphocytes. Data were presented to show many variables that are Involved in studying the responses of guinea pig lymphocyte in a microculture system to the stimulation of Concanavalin A(Con A) and lipopolysaccharide (LPS). Analysis indicated that the conditions for optimal Con A as measured by incorporation of $^3H$-TdR include : (1) use of RPMI-1640 as culture medium, (2) use of $6{\mu}g$ of Con A, per culture, (3) use of $1{\times}10^6$ cells per culture. Conditions for optimal stimulation with LPS mitogen were similar to those used for Con A.