• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.181-184
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• 2003

Low Energy High flux Plasma Source인 Stationary Plasma thruster (SPT)를 이용하여 폴리이미드의 표면개질 후 접촉각과 표면에너지의 변화를 조사하고 접착력과의 관계를 조사하였다. 이온에너지는 180 eV - 200 eV, 이온전류 밀도는 수백 ${\mu}A/cm^2$, 이온선량은 $5\times10^{15}/cm^2$부터, $10\times^{18}/cm^2$로 $Ar^+,\;N_2^+,\;O_2^+$를 이온 주입시켰다. 표면 처리된 폴리이미드에 대한 접촉각 변화는 dual contact anglemeter로 증류수와 에틸렌글리콜을 이용하여 측정하였고, 표면에너지의 변화량을 구하였다. 접촉각의 변화는 아르곤 이온의 경우는 최저 $35^{\circ}$, 질소와 산소의 경우 $1\times10^{17}/cm^2$에서 각각 $14^{\circ},\;10^{\circ}$정도의 전촉각을 보였으며, $5\times10^{17}/cm^2$이상에서는 측정하기 불가능하였다. 산소 이온빔으로 처리된 PI의 표면을 x-ray photoelectron spectroscopy를 통하여 측정하여본 결과, 친수성기가 많이 형성되었음을 확인할 수 있었다. 접촉각 측정으르부터 PI의 표변에너지는 42.1 mN/m에서 아르곤 이온빔의 처리 시 65.2 mN/m로 산소 이온빔의 처리 시 81.2 mN/m로 각각 1.5배, 1.9배 정도 증대하였다. 산소 이온빔으로 처리된 PI 표면위에 스퍼터링으로 300 nm 정도의 clad layer 형성 후 $20{\mu}m$ 정도의 구리 전기 도금막을 형성하여, peel 강도를 측정한 결과 0.79 kg/cm의 강도를 얻을 수 있었다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.4
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• pp.696-700
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• 1987

Guide modes in a graded index multinmode optical fiber are turned into clad modes when the optical fiber was bended into a perpendicular direction to its optical axes by microbending forces, which causes the loss of the guiding optical power. The theories reported on this microbending power loss can be applied to calculation of the transmission power loss only when the beding period equals to the mode coupling length. In this paper, we obtained the general expression of the optical power transmission loss in a graded index multimode fiber bended periodically. This can be applied to the calculation of the power loss of the periodically microbended fiber with an arbitrary bending shape and period. Also, by using the beam theory in mechanics, we could derive the expression of the displacement of the optical fiber caused by the external force which bends the fiber into a periodic trapezoidal shape. Experiments were carried out to determine the dependence of the power loss on the period of the microbending forces. Experimnetal results were in good agreement (in the same order of the magnitude) with theoritical values derived in our work within the bending period region of 2mm-10mm.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.464-465
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• 2008

Concrete poles(CP) are popular supports for distribution lines. Various types of grounding electrode, such as copper-clad rods, have been used to maintain CP's ground resistance under the required value. The buried part of CP can also have structural grounding effect because of its iron reinforcing rods inside CPs. In this paper, we measured the total ground current injected into CP ground while measuring the ground current splitting to the metal electrode as well as the total injecting current. By this, it was able to measure the ground current splitting to CP structure. Based on the measured results, interrelationship between ground resistance of metal electrodes and current split factor to CP structure was analyzed.

• Journal of the Korean Home Economics Association
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• v.41 no.11
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• pp.35-48
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• 2003

The purpose of this study is to investigate ideal body image and clothing style through the analysis of models portrayed in fragrance advertisement that is the representative goods showing the fashion brand image. For this study, 120 perfume advertisements appeared in GQ and Vogue magazines issued in 2002 were selected. The models' characteristics portrayed in advertisement are categorized with role relationship, race, body exposure and clothing styles. The results are as follows. 1. Fragrance advertisements most commonly depict a single model portraying narcissism, and later then most common are advertisements both male and female model in a sexual relationship. 2. The analysis of models' race shows racism toward Asian models and Afro- American models. White models are main characters in fragrance advertisements more often than other races, and in mixed-ethnic ads, whites typically outnumbered minorities. This shows currently aesthetic stereotypes, that is, white ideology still exists. 3. The results of models' body exposure are showing nudism with partially clad or nude. This shows the eroticism of male and female. 4. The highest portion of clothing style appeared in fragrance advertisement were casual wear for male model and dressy formal wear for female models, which respects current fashion trends.

• Journal of the Korean Society of Costume
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• v.62 no.1
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• pp.29-48
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• 2012

From ancient to modern days, Koreans have preferred and even worshiped white clothes to the extent that they are called "the white-clad race", and the color black has seldom been used for women's clothes. In western countries too, it was only after Chanel that black color came to represent feminine beauty. Black clothes were introduced in Korea after the opening of its ports to foreign countries in 1876 and have mainly been worn as a practical clolor for winter coats and school uniforms. The traditional preference for white and other bright colors continued well into the 1980s. However, the industrialization and urbanization caused by economic development and the influx of western cultures and ideas in the 1980s brought about the westernization of Korean aesthetic consciousness and resulted in the phenomenon of modern Korean women's preference for black fashion that became conspicuous from 1991. With the introduction of western fashion after the opening of the country in 1876, the spiritual values contained in preference for white clothes have been substituted by materialistic values as people accepted the practical beauty of black fashion, and the inclination toward intrinsic natural beauty intrinsic in the aesthetic senses that preferred white clothes has been replaced by the preference for modern, elegant and sensual beauties of black fashion whose preference has begun in the 1990s.

• Architectural research
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• v.8 no.2
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• pp.17-26
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• 2006

This paper attempts to identify the term "tectonics" comprehensively by collecting and categorizing existing definitions of tectonics within the architectural area rather than to stress the concept of tectonics of each specific theorist. Although no consensus of opinion on the concept of tectonics exists, architectural tectonics was closely related to the following terms in three categories: 1. $techn\acute{e}$, technique, and technology; 2. construction and structure; and 3. stereotomics. Based on its etymology, system, and material construct, the notion of tectonics common in these three categories signifies "the art of framing construction," in which linear elements are connected with joints and clad or infilled with lightweight material. Thus, the art of framing construction, as a common concept of tectonics, reveals the following characteristics: First, tectonics is based on framing construction in contrast to piling-up construction as the etymology of tectonics signifies the art of carpentry. Then, the term tectonics, dealing as it does with a higher level of construction rather than the mechanical level of structure, incorporates the poetic aspect of techne as well as the rational aspect of technology. Third, Owing to the organic, double system of tectonic frame and incrusting or infilling materials, the tectonic body becomes both the ornament and the structure simultaneously. As the art of framing construction is based on material construction rather than structural or ornamental form, this paper proposes that one can view tectonics as a term that conveys the meaning of the actual material effect on space.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.105-112
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• 2002

In recent years, the integrity of reactor Pressure Vessel(RPV) under pressurized thermal shock (PTS) accident has been treated as one of the most critical issues. Under PTS condition, the combination of thermal and mechanical stress by steep temperature gradient and internal pressure causes considerably high tensile stress at the inside of RPV wall. As a result, cracks on inner surface of RPV may experience elastic-plastic behavior which can be characterized by J-integral. In such a case, however, J-integral may possibly lose its vapidity due to the constraint effect. The degree of constraint effect is influenced by the loading mode, crack geometry and material properties. In this paper, in order to investigate the effect of clad thickness and crack geometry on constraint effect, three dimensional finite element analyses were performed for various surface cracks. Total of 27 crack geometries were analyzed and results were presented by a two-parameter characterization based on the J-integral and the f-stress.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.286-291
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• 2000

The reactor pressure vessel is usually cladded with stainless steel to prevent corrosion and radiation embrittlement, and number of subclad cracks have been found during an in-service-inspection. Therefore assessment for subclad cracks should be made for normal operating conditions and faulted conditions such as PTS. Thus, in order to find the optimum fracture assessment procedures for subclad cracks under a pressurized thermal shock condition, in this paper, three different analyses were performed, ASME Sec. XI code analysis, an LEFM(Liner elastic fracture mechanics) analysis and an EPFM(Elastic plastic fracture mechanics) analysis. The stress intensity factor and the Maximum $RT_{NDT}$ were used for characterizing. Analysis based on ASME Sec. XI code does not completely consider the actual stress distribution of the crack surface, so the resulting Maximum allowable $RT_{NDTS}$ can be non-conservative, especially for deep cracks. LEFM analysis, which does not consider elastic-plastic behavior of the clad material, is much more non-conservative than EPFM analysis. Therefore, It is necessary to perform EPFM analysis for the assessment of subclad cracks under PTS.

• Design & Manufacturing
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• v.2 no.1
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• pp.15-19
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• 2008

While recent industrial structure is various, it is small quantity batch production structure, and products requiring of various functions are increasing. In order to improve the quality of the sheared surface in cutting of inner structure bonded sheet metal the cut-off operation is mainly investigated, which is the typical shearing process in sheet metal forming technology. The sandwich sheet metals considered have inner structure which is constructed in the form of crimped expanded metal and woven metal. The inner structure is bonded between solid sheet by resistance welding or adhesive bonding. The shearing process is visualized by the computer vision system installed in front of the cut-off die and the sheared surface is measured and quantitatively compared with the help of the optical microscope after cut-off operation. From test results we found that the influence of sheared position can be observed and explained clearly and this result can be utilized to get the better sheared surface.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.369-370
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• 2006

During demonstrations of a process conditioning spent nuclear fuels, it is necessary to transport and handle Spent fuel road cuts from Post Irradiation Examination facility to Slitting device in The hot cell. the spent fuel pellets which are highly radioactive materials are separated with its clad and are fed into the next conditioning process. For this, a spent fuel rod, 3.5 m long, is cut by 25 cm long which is suitable length for the decladding process. These rod-cuts are packed into the capsule and are moved to the ACPF(Advanced spent nuclear fuel Conditioning Process Facility). In the ACPF, Once the capsule is unloaded in the ACPF, Capsule is taken out one-by-one and installed on the decladding device. In these processes, the crushed spent fuel pellet can be scattered inside the facilities and thus it contaminate the hot cell. In this paper, we developed the specially designed transportation and storage device for spent nuclear fuel capsules.