• 한국정밀공학회지
• /
• 제22권12호
• /
• pp.87-92
• /
• 2005

In microcellular injection molding, gas supply system is needed. But, that device is very expensive to attach to the injection molding machines. So, new method is needed and gas-pellets MCPs is one of the solutions. In gas-pellets MCPs, there will be strange characteristics. In this paper, some characteristics are described on the view point of saturation pressure and saturation time.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
• /
• pp.1972-1975
• /
• 2003

Video segmentation is an essential part in region-based video coding and any other fields of the video processing. Among lots of methods proposed so far, the watershed method in which the region growing is performed for the gradient image can produce well-partitioned regions globally without any influence on local noise and extracts accurate boundaries. But, it generates a great number of small regions, which we call over segmentation problem. Therefore we proposes image segmentation improvement by selective application structuring element of mathematical morphology.

• 한국항해학회지
• /
• 제20권4호
• /
• pp.99-109
• /
• 1996

Though median filter is used for removing noise and smoothing image. But, the result of it has distortion around edge. And then, this paper proposes new noise removing algorithm by recursive morphological processing. Basic operation is same each other, but there is some different processing method between recursive morphology and general morphology theory. This recursive morphological filter can be viewed as the weighted order static filter, and then it has a weighted SE(structuring element). Especially using this algorithm to remove the 10% gaussian noise, this paper confirmed that PSNR is improved about 0.642~1.5757 db reserving edge well better than the results of the traditional median filter.

• 한국정밀공학회지
• /
• 제23권2호
• /
• pp.154-163
• /
• 2006

Tooth morphology is the most important scientific aspect of dental medicine in regards to the treatment and study of teeth attrition relating to the absence of teeth due to dental caries or the occlusion of teeth due to external force. Most of the studies have focused on the external morphology in cutting teeth regardless of sex and age. However, the importance of internal morphology in the treatment of damaged teeth has been increased. Therefore, this study established the measurement criteria for the morphology of the mandibular first premolar which had never been presented, in order to investigate the external and internal morphologies of mandibular first premolars, and introduced a non-destructive method such as a microcomputed tomogrphy. Mandibular first premolars in superlative state were taken from molars of middle aged males and females and used as specimens for this study. Criteria relating to the internal and external morphology measurements were established to quantify the length of the teeth in identical state. Two dimensional image data for the selected mandibular first premolar were obtained by taking the image of each O.022mm section, which is perpendicular to the vertical direction using the microcomputed tomography. The Vworks program was applied to measure the length of each morphological part according to the set measurement criteria. These measured data were compared with the data presented by G. V. Black and the internal and external morphologies of the teeth of middle aged Koreans were also compared according to gender. In addition, the methodology for measurement of the mandibular first premolar was presented and according to this, the standardized mandibular first premolars of middle aged Korean males and females were made by using a rapid prototyping system.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제31권3호
• /
• pp.267-275
• /
• 2004

인공생명기법의 대표적인 응용분야 중 하나인 개체 생성을 위하여 크게 방향성 그래프와 L-system의 두 가지 방법이 사용되고 있다. 두 가지 방법 모두 각기 좋은 특성이 있지만 L-system은 사용자에 의해 내부적인 파라메터로 정의되기 때문에 전체적인 실제 모양을 구조적으로 정의하기 어렵다. 본 논문에서는 이런 단점을 극복하고자 실제 모양을 표현하는데 적절한 구조적 방향성 그래프를 도입하여 꽃을 구조적으로 표현함으로써 실제 개체와 유사한 모양을 생성하고, 이를 대화형 유전자 알고리즘에 적용하여 사용자가 생성하고자 하는 실제 모양의 자연스러운 꽃을 자동으로 생성하게 하였다. 실험결과 감성적인 평가로 자연스러운 모양의 꽃이 생성됨을 알 수 있었다.

• 한국재료학회지
• /
• 제24권12호
• /
• pp.700-703
• /
• 2014

Calcium phosphate minerals are biologically important because of their application in the fields of orthopaedics and dentistry. Herein we have tried to synthesize calcium phosphate minerals from biowaste clam shells. A simple microwave method was used to synthesize a mixture of calcium phosphate minerals such as hydroxyapatite, tri-calcium phosphate, and monetite. The microwave induces vibration of the dipole ions in the reagent. The heating and rearrangement of ions and atoms occurs during the process. The phases obtained in the final powder were ascertained by X-ray diffraction; the morphology of each sample was checked using a scanning electron microscope. We were able to obtain a mixture of calcium phosphate minerals using the microwave method; the calcined powder showed a brick like morphology, which is different from the rod shape morphology of the hydroxyapatite obtained using the hydrothermal process.

• Geomechanics and Engineering
• /
• 제11권4호
• /
• pp.515-530
• /
• 2016

In this paper, five different quantitative parameters were proposed for the characterization of the primary roughness which is the component of surface morphology that prevails during large strike-slip faults of more than 50 m. These parameters are mostly the anisotropic properties of rock surface morphology at various scales: (i) coefficient ($k_a$) and degree (${\delta}_a$) of apparent structural anisotropy of surface; (ii) coefficient ($k_r$) and degree (${\delta}_r$) of real structural anisotropy of surface; (iii) surface anisotropy function P(${\varphi}$); and (iv) degree of surface waviness ($W_s$). The coefficient and degree of apparent structural anisotropy allow qualifying the anisotropy/isotropy of a discontinuity according to a classification into four classes: anisotropic, moderately anisotropic/isotropic and isotropic. The coefficient and degree of real structural anisotropy of surface captures directly the actual surface anisotropy using geostatistical method. The anisotropy function predicts directional geometric properties of a surface of discontinuity from measurements in two orthogonal directions. These predicted data may subsequently be used to highlight the anisotropy/isotropy of the surface (radar plot). The degree of surface waviness allows qualifying the undulation of anisotropic surfaces. The proposed quantitative parameters allows their application at both lab and field scales.

• Corrosion Science and Technology
• /
• 제17권3호
• /
• pp.123-128
• /
• 2018

The fabrication of a controlled surface is of great interest because it can be applied to various engineering facilities due to the various properties of the surface, such as self-cleaning, anti-bio-fouling, anti-icing, anti-corrosion, and anti-sticking. Controlled surfaces with micro/nano structures were fabricated using an ion beam focused onto a polypropylene (PP) surface with a fluoridation process. We developed a facile method of fabricating hydrophobic surfaces through ion beam treatment with argon and oxygen ions. The fabrication of low surface energy materials can replace the current expensive and complex manufacturing process. The contact angles (CAs) of the sample surface were $106^{\circ}$ and $108^{\circ}$ degrees using argon and oxygen ions, respectively. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy were used to determine the chemical composition of the surface. The morphology change of the surfaces was observed by scanning electron microscopy (SEM). The change of the surface morphology using the ion beam was shown to be very effective and provide enhanced optical properties. It is therefore expected that the prepared surface with wear and corrosion resistance might have a considerable potential in large scale industrial applications.

• 대한치과교정학회지
• /
• 제23권4호
• /
• pp.543-564
• /
• 1993

A cephalometric study was undertaken to reveal significant differences of craniofacial morphology of operated congenital cleft lip and palate subjects and control subjects. The material for this study consisted of 73 subjects with operated congenital cleft lip and palate subjects(53 males, 20 females) and 110 control subjects (7 males, 34 females) ranging from 3 to 14 years old. Each group was divided into four age groups (3-5, 6-8, 9-11, 12-14 year) and analyzed by Cohen's method and Burstone's method. The following conclusions were obtained ; 1. In Wit's appraisal, there was no difference the cleft lip and palate subjects and the control subjects. 2. In the cleft lip and palate subjects, they had smaller and more retrusive maxilla than the control subjects in both sexes. 3. In the cleft lip and palate subjects, they had more retrusive mandible than the control subjects in both sexes. 4. In the cleft lip and palate subjects, they had more concave profile than the control subjects.

• 한국세라믹학회지
• /
• 제45권3호
• /
• pp.161-166
• /
• 2008

The multi-films of a metallic film and a transparent conducting oxide (TCO, indium-tin oxide, ITO) film were formed on the stainless steel 316 and 304 plates by a sputtering method and an E-beam method and then the external metallic region of the stainless steel bipolar plates was converted into the metal nitride films through an annealing process. The multi-film formed on the stainless steel bipolar plates showed the XRD patterns of the typical indium-tin oxide, the metallic phase and the metal substrate and the external nitride film. The XRD pattern of the thin film on the bipolar plates modified showed two metal nitride phases of CrN and $Cr_2N$ compound. Surface microstructural morphology of the multi-film deposited bipolar plates was observed by AFM and FE-SEM. The metal nitride film formed on the stainless steel bipolar plates represented a microstructural morphology of fine columnar grains with 10 nm diameter and 60nm length in FE-SEM images. The electrical resistivity of the stainless steel bipolar plates modified was evaluated.