• 한국산학기술학회논문지
• /
• 제17권5호
• /
• pp.612-618
• /
• 2016

본 연구의 목적은 청색광 차단 렌즈에서 발생하는 미광이 상의 질에 미치는 영향에 대하여 알아보는 것이다. 이상적인 안경 렌즈, 내부 반사가 없는 무반사 안경 렌즈, 내부 반사가 있는 무반사 안경 렌즈, 그리고 내부 반사가 있는 청색광 차단 렌즈를 설계하고 광도 분포 및 미광 분포를 도출하였다. 설계된 안경 렌즈는 굴절능 0.00 D, 굴절률 1.56, 반지름 155.16 mm 인 메니스커스 렌즈이다. 청색광 차단 렌즈의 피크는 430~440 nm 영역 사이에 있으며, 반사율은 5%, 10%, 15%, 20%이 되도록 설계하였다. 분석 결과에 따르면 청색광 차단 렌즈의 반사율이 증가함에 따라 중심부의 광도의 세기는 감소하고 중심-주변부와 주변부의 미광의 세기는 증가하였다. 이러한 현상은 청색광 차단 렌즈의 반사율이 증가할수록 심화되는 것으로 나타났다. 청색광 차단 렌즈의 반사율 증가는 중심-주변부 및 주변부의 미광을 증가시켜 상의 질을 떨어뜨리므로 청색광 차단 렌즈에서의 반사율은 청색광 차단율 및 시감 투과율을 고려하여 시각적으로 불편함이 없는 수준에서 조절할 필요가 있다.

• 한국분말재료학회지
• /
• 제22권1호
• /
• pp.6-9
• /
• 2015

In this study, the behavior of densification of copper powders during high-pressure torsion (HPT) at room temperature is investigated using the finite element method. The simulation results show that the center of the workpiece is the first to reach the true density of copper during the compressive stage because the pressure is higher at the center than the periphery. Subsequently, whole workpiece reaches true density after compression due to the high pressure. In addition, the effective strain is increased along the radius during torsional stage. After one rotation, the periphery shows that the effective strain is increased up to 25, which is extensive deformation. These high pressure and severe strain do not only play a key role in consolidation of copper powders but also make the matrix harder by grain refinement.

• 대한수의학회지
• /
• 제37권4호
• /
• pp.727-734
• /
• 1997

Hemolymph nodes of the Korean native cattle were observed gross anatomically and light microscopically in this study. Hemolymph nodes of the Korean native cattle were found mainly at the periphery of the thoracic and abdominal aortae although there were some other parts to observe these small organs. These organs were small in size and spherical or ovoid in shape, and color of them was dark red or gray in common with red band. The hemolymph nodes were surrounded by a relatively thick connective tissue capsules composed of dense collagen fibers with many scattered smooth muscle fibers and there was a hilus in each node. The parenchyma was divided into an outer cortex and an inner medulla. A few primary and secondary lymph nodules were observed in the cortex and there were diffuse lymphatic tissues among them. The medullary cords consisted of diffuse lymphatic tissues were separated by the medullary sinuses which filled with erythrocytes. The afferent and efferent lymph vessels were observed at the periphery of the capsule and the hilus area, respectively. The stroma of the hemolymph nodes was composed of reticular cells and fibers, and the meshwork of the stroma was filled with many lymphocytes and erythrocytes, and a few macrophages and megakaryocytes etc. These findings suggest that the hemolymph node of the Korean native cattle is involved in blood filtration and immune reaction.

• Restorative Dentistry and Endodontics
• /
• 제9권1호
• /
• pp.115-119
• /
• 1983

The purpose of this study was to compare the solubility of enamel and dentin to an etchant after fluoride application. Specimens were collected from extracted anterior and bicuspid and each tooth was cut into several pieces. These specimen were allocated in 7 group; 1%, 2%, 3% NaF, 1%, 8%, 20% $SnF_2$, and control group. Five specimens in each group was exposed to pre-determined fluoride solution for 3 minutes, and washed with running water. These specimens were etched by Hipol (commercial label) etchant for 30 seconds. Following are the findings obtained through S.E.M. 1. All specimens with acid etching revealed preferential removal of prism periphery leaving prism core. 2. Specimens treated with 1%, 2% NaF solution showed that the shape of prism tip was thin and sharp like a needle. The case of 3% NaF showed rather round shape at prism end. 3.1% of $SnF_2$ case showed similar findings with the control group but 8% and 20% $SnF_2$ case revealed needle shape at the prism and was less clear than NaF case. Preferential removal of prism periphery was partialy observed and un decalcified area is fused to prism forming reidge. 4. Dentine treated by fluoride compound in low concentration showed the orifice of dentinal tubule was clearly enlarged whereas in high concentration the orifice was not widened.

• ETRI Journal
• /
• 제32권5호
• /
• pp.729-739
• /
• 2010

Due to the rapid development of mobile devices equipped with cameras, instant translation of any text seen in any context is possible. Mobile devices can serve as a translation tool by recognizing the texts presented in the captured scenes. Images captured by cameras will embed more external or unwanted effects which need not to be considered in traditional optical character recognition (OCR). In this paper, we segment a text image captured by mobile devices into individual single characters to facilitate OCR kernel processing. Before proceeding with character segmentation, text detection and text line construction need to be performed in advance. A novel character segmentation method which integrates touched character filters is employed on text images captured by cameras. In addition, periphery features are extracted from the segmented images of touched characters and fed as inputs to support vector machines to calculate the confident values. In our experiment, the accuracy rate of the proposed character segmentation system is 94.90%, which demonstrates the effectiveness of the proposed method.

• The Korean Journal of Physiology and Pharmacology
• /
• 제6권4호
• /
• pp.173-181
• /
• 2002

The sinoatrial (SA) node is a complex and inhomogeneous tissue in terms of cell morphology and electrical activity. There are two models of the cellular organisation of the sinoatrial node: the gradient and mosaic models. According to the gradient model there is a gradual transition in morphology and electrical properties of SA node cells from the centre to the periphery of the SA node. In the mosaic model, there is a variable mix of atrial and sinoatrial node cells from the centre to the periphery. This review focuses on the cellular organisation of the rabbit sinoatrial node in terms of the expression of connexin (Cx40, Cx43 and Cx45), L-type $Ca^{2+}$ channel and $Na^+-Ca^{2+}$ exchanger proteins. These immunocytochemical data, together with morphological and electrophysiological data, obtained from the intact sinoatrial node and isolated sinoatrial node cells support the gradient model of the cellular organisation of the SA node. The complex organisation of the sinoatrial node is important for the normal functioning of the sinoatrial node: (i) it allows the sinoatrial node to drive the surrounding hyperpolarized atrial muscle without being suppressed by it; (ii) it helps the pacemaker activity of the sinoatrial node continue under a wide range of physiological and pathophysiological conditions; (iii) it helps protect the sinoatrial node from reentrant arrhythmias.

• 한국경제지리학회지
• /
• 제7권2호
• /
• pp.137-156
• /
• 2004

본 논문은 우리나라의 왜곡된 정치 현실과 경제적 상황을 가장 극명하게 나타내는 경기도 접경지역의 실태를 고찰하여 이 지역에 대한 종합적 지리학 연구의 기초 자료를 제공하는데 목적이 있다. 연구 결과 경기도 접경지역은 첫째, 군사시설보호법에 의한 규제로 주민들의 생활과 경제적 활동이 제한되어온 지역임을 알 수 있었다. 둘째, 수도권 과잉집중을 해결하기 위해 시행된 수도권정비계획법은 수도권 북부지역 및 접경지역의 개발에 또 하나의 제약조건이 되고 있다. 셋째, 경제관련 지표 분석 결과 경기접경지역은 이러한 규제들로 인해 낙후성을 면치 못하고 있음을 알 수 있었다.

• 한국전기전자재료학회논문지
• /
• 제15권7호
• /
• pp.627-633
• /
• 2002

Many isolated featureless domains were explicitly observed even at the air-water interface. We measured the surface pressure shift originating from the photo-isomerization of azobenzene units on the periphery of dendrimers. The maximum surface pressure was gradual1y increased and saturated by cyclic compression and decompression. By irradiation of 365 [nm] light, the surface pressure was increased, which was originated by the photo-isomerization process of the azobenzene group on the periphery from trans to cia form. The increase of the dipole moment ($\mu$), which may increase the interaction among Azo dendrimer molecules, made an important role on surface pressure shift. From the absorbance spectrum by UV irradiation and heat treatment, we can see that the absorbance in the UV region decreases with the increase of the UV irradiation time, but the peak at 350 m, characteristic of dendrimers in the LB monolayers, was not shifted until four irradiation cycles. This suggests that optical behavior and morphological change are affected by the functional group and the symmetric chain.

• Journal of Ginseng Research
• /
• 제16권1호
• /
• pp.37-43
• /
• 1992

Structural changes of the endosperm of Panax ginseng C.A. Meyer from fertilization to germination were investigated by light microscope. The endosperm of the ginseng seed is cellular type. Since endosperm cells adjacent embryo continuously breakdown and disappear with the elongation of embryo, the real of endosperm is gradually decreased. As the anatropous ovules of immature seed with green seed coat developes more and more, ovary cells adjacent ovary cavity become abundant by the periclinal division, their size is decreased, hypotrophy of cell wall discern, and they are gradually differentiated in seed coat. Though embryo responds strongly to basic dye at the stage of completion of endosperm formation, tissue of endosperm responds to acidic dye positively Cell wall of embryo and endosperm are composed of primary cell wall not lignified. Endosperm cells adjacent embryo begin to breakdown in the endosperm tissue of indehiscent seed before the beginning of the after-ripening. Dehiscent seed of which seed coat is opened through after-ripening represent the form as a seedling in the result of embryo developments with the formation of organs; radicle, cotyledon, plumule. Umbilifom layer represents strong positive response to the toluidine blue and the basic function. Umbiliform layer that endosperm cells breakdown and disappear is observed clearly at the periphery of the embryo cotylemon, while slightly at the periphery of the radicle.

• 한국생산제조학회지
• /
• 제20권6호
• /
• pp.679-684
• /
• 2011

Recently, STS 301L joints of side panels to frames for stainless steel rolling stock have been made out by using existing welding methods including Resistance Spot Welding, Laser Welding and Arc Welding. Most of the processes were jointed by spot welding because it is faster at welding and comparatively less expensive for investment in welding facilities than other methods. During spot welding, however, indentation of the metal surface was made due to pressure and melting property of welding. Moreover, since the melting metal was forced to periphery of the plate as indentation was made, sheet separation, which cracked apart between jointed sheets, was carried out. A slight deformation which resulted from sheet separation deteriorated the emotional quality of railway vehicles. This paper suggests that by processing conventional spot electrode tip appropriately, melting metal is able to push up around the processed part (Hollow Spot Electrode Tip) and prevent from being dislodged from first place to periphery. Consequently, sheet separation is remarkably decreased. Also, the emotional quality of appearance of stainless steel rolling stock is enhanced considerably.