• Journal of information and communication convergence engineering
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• 제21권1호
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• pp.17-23
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• 2023

Recently, several high-performance instance segmentation models have used the Mask R-CNN model as a baseline, which reached a historical peak in instance segmentation in 2017. There are numerous derived models using the Mask R-CNN model, and if the performance of Mask R-CNN is improved, the performance of the derived models is also anticipated to improve. The Mask R-CNN uses interpolation to adjust the image size, and the input differs depending on the interpolation method. Therefore, in this study, the performance change of Mask R-CNN was compared when various interpolation methods were applied to the transform layer to improve the performance of Mask R-CNN. To train and evaluate the models, this study utilized the PennFudan and Balloon datasets and the AP metric was used to evaluate model performance. As a result of the experiment, the derived Mask R-CNN model showed the best performance when bicubic interpolation was used in the transform layer.

• 한국정밀공학회지
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• 제16권8호
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• pp.138-148
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• 1999

Thermal deformations of tension mask under localized heating are analyzed using finite element method and electron beam landing shifts are predicted by the analysis results. In CRT, electron beam landing shifts due to thermal deformations of the tension mask make the color purity of screen worse. In order to get the final results of thermal deformations, firstly the tension processes of the mask and following welding processes between the tensional mask and rail must be analyzed sequentially. And then, nonlinear transient thermo-elastic finite element analysis is performed on every part inside CRT including tension mask, wherein thermal radiation is a main heat transfer mechanism. Because the tension mask has numerous slits, the effective thermal conductivity and effective and effective elastic modulus is calculated, and the tension mask is modeled as a shell without slits. From the displacement results of tension mask, electron beam landing shifts is calculated directly. Experiments are performed to confirm our analysis results. Temperature distributions and beam landing shifts of tension mask are measured and the results are in good agreement with those of analyses.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.23-29
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• 2009

Blob detection is an essential ingredient process in some computer applications such as intelligent visual surveillance. However, previous blob detection algorithms are still computationally heavy so that supporting real-time multi-channel intelligent visual surveillance in a workstation or even one-channel real-time visual surveillance in a embedded system using them turns out prohibitively difficult. In this paper, we propose a fast and precise blob detection algorithm for visual surveillance. Blob detection in visual surveillance goes through several processing steps: foreground mask extraction, foreground mask correction, and connected component labeling. Foreground mask correction necessary for a precise detection is usually accomplished using morphological operations like opening and closing. Morphological operations are computationally expensive and moreover, they are difficult to run in parallel with connected component labeling routine since they need much different processing from what connected component labeling does. In this paper, we first develop a fast and precise foreground mask correction method utilizing on neighbor pixel checking which is also employed in connected component labeling so that the developed foreground mask correction method can be incorporated into connected component labeling routine. Through experiments, it is verified that our proposed blob detection algorithm based on the foreground mask correction method developed in this paper shows better processing speed and more precise blob detection.

• 한국인터넷방송통신학회논문지
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• 제8권1호
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• pp.25-30
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• 2008

본 논문에서는 인물 이미지를 GIF로 변환 할 시에 색상의 손실을 최대한 줄이기 위한 알고리듬을 제안한다. 손실을 줄이는 방법으로는 Octree Quantization과 살색 검출 mask를 이용한다. 인물이미지의 경우, 살색정보가 이미지의 중요한 부분을 차지하고 있으므로, 살색 영역을 검출 할 수 있는 mask를 생성하여 살색영역과 그 밖의 영역을 분리하고, 분리된 영역별로 Color Quantization을 한다. 제안된 알고리듬을 통하여 24비트 이미지를 GIF로 변환한 결과, 일반적으로 많이 사용하는 이미지 포맷변환 툴을 사용하여 변환한 영상보다 살색 정보의 손실이 최소화됨으로써, 인물이미지의 GIF 변환에 있어 좋은 성능을 보여 준다는 것을 확인할 수 있다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.460-465
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• 2002

The nonlinear vibration of the CRT shadow mask is analyzed in consideration of the V-shaped tension distribution and the effect of wire impact damping. The reduced order FEM model of the shadow mask is obtained from dynamic condensation for the mass and stiffness matrices. Damping wire is modeled using the lumped parameter method to effectively describe its contact interactions with the shadow mask. The nonlinear contact-impact model is composed of spring and damper elements, of which parameters are determined from the Hertzian contact theory and the restitution coefficient, respectively. The analysis model of the shadow mask with damping wires is experimentally verified through impact tests of shadow masks performed in a vacuum chamber. Using the validated analysis model of the shadow mask with damping wires, the‘design of experiments’technique is applied to search fur the optimal damping wire configuration so that the vibration attenuation of the shadow mask is maximized.

• 대한기계학회논문집
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• 제17권10호
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• pp.2574-2581
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• 1993

A Shadow mask in C. R. T. (Cathod Ray Tube) undergoes a temperature increase due to impinging electron beams emitted from guns, and thermal deformation from such temperature rise may cause the electron beams to island on the panel, and thus give rise to depolarization. Hence the analysis of temperature distribution for a shadow mask is an important procedure for designing the shadow mask. In this paper, we are concerned with nonlinear finite element analysis of the temperature distribution on a shadow mask. First of all, we replace shadow mask, containing numerous apertures of a slit type, by an orthotropic shell without apertures, and calculate the apparent thermal conductivities. Because of thermal radiation, which is one of the major heat transfer mechanism for shadow masks, the resulting finite element equation is nonlinear and solved by the Newton method. Finally numerical examples are illustrated for a 21" FST(Full Square Tube) shadow mask, and followed by discussion.sion.

• 전기의세계
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• 제28권11호
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• pp.37-44
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• 1979

This paper deals with the computer program of finding the minimal sum-of-products for a switching function by using the MASK method derived from the characteristics of the Boolean algebra. The approach differs from the previous procedures in that all the prime implicants are determined only by the bit operation and the minimal sum-of-products are obtained by the modified Petrick method in this work. The important features are the relatively small amount of the run time and the less memory capacity to solve a problem, as compared to the previous computer programs.

• 제어로봇시스템학회논문지
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• 제14권4호
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• pp.348-352
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• 2008

Deformation of the shadow mask is one of the problems encountered during the deposition of organic materials for manufacturing large size organic light emitting diode (OLED). The larger the glass substrate, the larger the shadow mask becomes. As the size of the shadow mask increases, its deformation becomes more severe, thereby making it difficult to deposit organic materials in a precise pattern on a substrate. In this paper, a new method for reducing drooping of the shadow mask for large size OLED vapor depositions is proposed. The proposed shadow mask with cross stripe wires has higher stiffness than the pure shadow mask, which results in reducing drooping of the shadow mask. A commercial FEM program, ANSYS, is used for the evaluation of the proposed shadow mask. The analysis showed that the shadow mask with cross stripe wires have an effect on reducing drooping about 18.6% or more.

• 한국응급구조학회지
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• 제22권1호
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• pp.73-82
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• 2018

Purpose: The purpose of this study was to compare the tidal volumes and airway pressures of 3 mask-sealing methods (one hand C-E, two hands C-E, and one hand O-E) for ventilation treatment. Methods: The study subjects were 45 paramedic students. Tidal volume was measured for the three sealing methods by setting a ventilator, connecting it to the masks for 2 minutes, and using Respi-trainer software. Results: Regarding general characteristics, the group of men, in upper grades, and with practical training experience and experience and experience in the implementation of bag-valve-mask ventilation provided higher tidal volumes. Regarding physical characteristics, larger hands and greater grip strength correlated with higher tidal volume. Two hands C-E generated the highest tidal volume of $483.78{\pm}34.14mL$, one hand O-E generated $449.59{\pm}51.09mL$ and one hand C-E generated $394.31{\pm}68.95mL$. Conclusion: Means of tidal volumes were statistically significantly different based on mask sealing methods (p<.001). Two hand C-E was performed by the two-persons task and was suggested as the most effective method. For the one-person task, one hand O-E was the more effective method compared to the previous one hand C-E.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.251-256
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• 1993

In KACC'91 and '92 conference, we proposed a method of automatically detecting the shape of the faulty holes in a shadow mask by use of CCD ca.mera and image data processing technic. In this method, two adjoining test areas from one image data. of the shadow mask are taken and comparing the shape of holes in these two areas, we can detect the faults in the shadow mask. In this paper, a method is described by use of spatial filtering of effectively finding the faulty holes from the difference image data between the two tested image data. The main role of the filter is to remove sampling errors occurring at the edge of the holes. And the second role is not only to find the existence of faulty holes but also exactly express the shape of faulty holes. Computer simulations and actual experiments with shadow masks have shown that this method of fault detection is very effective for practical use.