• 한국안전학회지
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• 제14권4호
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• pp.93-99
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• 1999

A try was carried out to reduce lead time of die manufacturing. That is to make manual machining and finishing work time shorter by improving CAD/CAM modeling methods, so called with "separate modeling" and "relief modeling". The manual machining and finishing manual work time were reduced adapting the novel CAD/CAM modeling methods. Ultimately we accomplished much reduction of the lead time of die manufacturing.f die manufacturing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.116.3-116
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• 2001

A diagnosis methodology for thickness quality in hot finishing mill is proposed based on multivariate statistical analysis. The thickness of hot strip is a key quality factor that is measured by x-ray thickness gauge. Currently, the thickness quality is guaranteed by upper and lower limit of thickness deviation from target thickness. But if any over-limit is occurred, there is no in-line method to identify the causes. In this paper, many parameters are extracted from the thickness deviation signal such as mean deviation(top, middle, tail), rms deviation(top, middle, tail) and peak deviation(top, middle, tail) as time domain parameters ...

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1877-1880
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• 2003

We were interest in Deburring using MAF(magnetic abrasive finishing) method. So Magnetic inductor was designed and manufactured to generate proper magnetic induction fer deburring the burr formed in drilling SM45C. We experienced according to the Rotational speed, table feed rate, grain size of powder and working gap are changed to investigate the effect on deburring. At this time we experienced in abrasive effect mainly.

• 한국염색가공학회지
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• 제31권4호
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• pp.341-353
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• 2019

Quercetin is one of flavonoids widely distributed in the plants and well known to have antioxidants, antiinflammatory, antimicrobial properties. In this study, alginate sponge containing quercetin-encapsulated nanocapsules was prepared by miniemulsion polymerization, dyring/crosslinking method and their bioactive characteristics were investigated. Alginate sponge containing quercetin-encapsulated nanocapsules were evaluated using a field emission scanning electron microscope(FE-SEM), a high performance liquid chromatography, cell viability, DPPH radical scavenging activity and antibacterial activity. The study indicates that alginate sponge containing quercetin-encapsulated nanocapsules had significant antioxidant, antiinflammatory and antibacterial activities. This study suggested that alginate sponge containing quercetin-encapsulated nanocapsules can be a potential candidate for medical materials.

• Fibers and Polymers
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• 제5권1호
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• pp.75-81
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• 2004

To obtain high molecular weight (HMW) poly(methyl methacrylate) (PMMA) with high conversion, methyl methacrylate (MMA) was polymerized in suspension using a room temperature initiator, 2,2'-azobis(2,4-dimethylvaleronitrile) (ADMVN), and the effects of polymerization conditions on the polymerization behavior of MMA and the molecular parameters of PMMA were investigated. On the whole, the experimental results well corresponded to the theoretically predicted tendencies. These effects could be explained by a kinetic order of ADMVN concentration calculated by an initial rate method and an activation energy difference of polymerization obtained from the Arrhenius plot. Suspension polymerization at 25℃ by adopting ADMVN proved to be successful in obtaining PMMA of HMW (number-average degree of polymerization (P/sub n/): 30,900-36,100) and of high yield (ultimate conversion of MMA into PMMA: 83-93 %) with diminishing heat generated during polymerization. The P/sub n/ and lightness were higher and polydispersity index was lower with PMMA polymerized at lower temperatures.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.9-10
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• 2011

Domestic construction industry suffered from the IMF and makes a great effort to improve in 'cost management', 'strengthening the competitiveness of the construction industry'. Therefore, the industry has become interested in improving the productivity of construction and ongoing research is being progressed in various angles. In such circumstances, the needs for a study of concepts and space of the actual construction work place is emerging. This study were utilized BIM to understand the types and causes of problems in space during the finishing work in construction and categorize importance and frequency of occurence through a survey of experts and AHP to analyze the realtive effects of importance then modeling to them to aware of issues and give direction for efficient management. This study is anylize the problem which is caused by same time process in finishing work progress of apartment applied by BIM. and categorize the type of work interference management in finishing work, and anylize by the type of occurence then predict the work interference management through in BIM 3D VIEW and suggest the solutions.

• 대한치과기공학회지
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• 제22권1호
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• pp.79-88
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• 2000

The objective of this finite element method study was to analyze the stress distribution induced in a maxillary central incisor Ni-Cr base metal coping ceramic crowns with various margin design. Margin designs of crown in this experiment were knife-edge metal margin on chamfer finishing line of tooth preparation(M1), butt metal margin on shoulder finishing line(M2), reinforced butt metal margin on shoulder finishing line(M3), beveled metal margin on bevelde shoulder finishing line(M4). Two- dimensional finite element models of crown designs were subjected to a simulated biting force of 100N which was forced over porcelain near the lingual incisal edge. Base on plane stress analysis, the maxium von Miss stresses(Mpa) in porcelain venner was 0.432, in metal coping was 0.579, in dentin abutment was 0.324 for M1 model, and M2 model revealed in porcelain was 0.556, in metal coping was 0.511, in dentin was 0.339, and M3 model revealed in porcelain was 0.556, in metal coping was 0.794, in dentin was 0.383 for M4 model. All values of each material in metal-ceramic crown were much below the critical failure values.

• 한국재료학회지
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• 제13권2호
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• pp.133-136
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• 2003

Sn-2.5Cu alloy layers were deposited on the Alloy 42 lead-frame substrates by the electroplating method, and their microstructures, adhesion strength, and electrical resistivity were measured to evaluate the applicability of Sn-Cu alloy as a surface finishing material of electronic parts. The Sn-2.5Cu layers were electroplated in the granular form, and composed of pure Sn and Cu$_{6}$Sn$_{5}$ intermetallic compound. Surfaces of the electroplated Sn-2.5Cu layers were rather rough and also the thickness variance was large. The adhesion strength of the Sn-2.5Cu electroplated layers was highly comparable to that of the electroplated Cu alloy layer and the electrical conductivity was about 10 times higher than the pure Sn. After the 20$0^{\circ}C$ 30 min. annealing of the electroplated Sn-2.5Cu layers, the surface roughness was reduced, and adhesion strength and conductivity were improved. These results showed the Sn-Cu alloys can be used as an excellent surface finishing material.ial.

• 대한화학회지
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• 제40권12호
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• pp.741-747
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• 1996

기능성색소로 응용되는 몇몇 squarylium 및 croconium계 색소를 합성한 후 이들이 특성에 관해 조사했다. Squarylium 색소의 경우 5위치에 니트로기의 도입에 의하여 대폭 심색이동이 관찰되었으며 IR 및 solvatochromism 특성으로부터 중심 4고리의 1, 3 위치에 indoline환이 결합된 형태이며 기저상태가 극성인 구조를 취하고 있음을 알 수 있었다. 또한 다단계반응에 의해 비대칭 squaryliunm계 색소를 합성하였다. 중심에 5고리를 가지는 croconium계 색소를 합성하였으며 이들은 770-780nm에 ${\lambda}_{max}$을 나타냈다. 이들 색소의 구조와 흡수스펙트럼의 관계를 PPP-MO를 상용하여 해석한 결과 실측치와 좋은 상관관계를 나타냈다.

• 대한화학회지
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• 제37권5호
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• pp.523-526
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• 1993

Photochromism을 나타내는 spiroxazine 색소의 흡수스펙트라 및 용매 효과에 관해 검토하였다. 그 결과 positive solvatochromism을 나타내었으며 이로부터 spiro 고리가 자외선 조사에 의해 개열되었을 때는 keto 형의 분자구조로 되어있음을 나타낸다는 것을 알 수 있었다. 색소골격내에 C 대신 N 원자가 존재하므로서 흡수극대치가 장파장측에 이동한다는 것을 ppp 분자궤도법(Pariser-Parr-Pople Molecular Orbital Method)을 사용해 정량적으로 해석하였다.