• 펄프종이기술
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• 제42권2호
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• pp.82-87
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• 2010

The Hanji dyed with persimmon juice were useful goods in the past, but they are not widely used nowadays despite of their many strong points such as antibacterial and water-resistant properties. The object of this study is to provide useful data for developing new products by using them. We dyed traditional Korean hand-made papers (Hanji) with colorants extracted from fruits of Diospyros kaki and investigated the effect of various dyeing factors (mordant, mordanting method, pH of dyeing solution, light exposure time etc.) on optical and mechanical properties of the dyed Hanji. Changing mordant affected the color of dyed Hanji. The dyed Hanji after-mordanted with Cu mordant had the highest K/S value and showed the deepest yellow and red shade. The best mordanting method was an after-mordanting. The K/S value of dyed Hanji increased with decreasing pH of dyeing solution. The tensile index and size degree values of the Hanji were increased after dyeing.

• Journal of Construction Engineering and Project Management
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• 제1권2호
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• pp.11-17
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• 2011

Recent demands from construction industry have emphasized the capability for graduates to have improved skills both technical and non-technical such as problem solving, interpersonal communication. To satisfy these demands, problem-based learning that is an instructional method characterized by the use of real world problem has been adopted and has proven its effectiveness various disciplines. However, in spite of the importance of field senses and dealing with real problem, construction engineering education has generally focused on traditional lecture-oriented course. In order to improve limitations of current construction education and to satisfy recent demands from construction industry, this paper proposes a new educational approach that is Failure-Based Learning for using combination of the procedural characteristics of the problem-based learning theory in construction technology education utilizing failure information that has the educational value in the construction area by reinterpreting characteristics of construction industry and construction failure information. The major results of this study are summarized as follows. 1) Educational effect of problem-based learning methodology and limitation of application in construction area 2) The educational value of the information on construction failure and limitation in application of the information in construction sector 3) Anticipated effect from application of the failure-based learning 4) Development and application of the failure-based learning conceptual model.

• 한국가스학회지
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• 제10권1호
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• pp.1-6
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• 2006

압력설비를 안전하고 효율적으로 사용하기 위하여 본 연구에서는 API-581 절차에 의한 위험기반검사에서 취성파괴에 의한 사고발생 가능성을 정량적으로 해석하였다. 그 결과, 낮은 온도/낮은 인성파괴와 뜨임취성에서는 A 충격곡선이고. 낮은 온도와 열처리 전인 상태에서 기술종속계수(TMSF)가 큰 값을 나타내었고, $855^{\circ}F$ 취성에서는 위험도가 무시할 수 있었으나, 시그마상 취성에서는 낮은 온도의 고 시그마인 경우에 TMSF가 큰 값을 나타내어 사고발생 가능성이 매우 높았다.

• 품질경영학회지
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• 제45권3호
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• pp.583-594
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• 2017

Purpose: The purpose of this study is how personal information protection risks affect the intention to use domestic smart banking services. VAM(Value based Adoption Model) model is validated as a theoretical background, selecting ease of use, usefulness and perceived security as a benefit factor, and considers perceived cost, technical complexity, and risk of personal information leakage as a sacrifice factor. Methods: The method of this study used questionnaire survey to collect 365 data on suer's perception on smart banking services, and also performed a structural equation modeling method using by AMOS 23. Results: The result of this paper shows that all hypothesis are accepted statistically significant except 1 hypothesis. Conclusion: This research is concluded that perceived value is affected on statistically positive impact on ease of use, usefulness and perceived security, and negative impact on perceived cost and risk of personal information violation, not statistically technical complexity.

• 펄프종이기술
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• 제31권2호
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• pp.50-57
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• 1999

This study was carried out to compare a conventional alkaline flotation deinking conditions with neutral deinking conditions with and without enzyme addition with respect to the ink removal efficiency and theflotation deinking filtrate quality such as chemical oxygen demand, cationic demand, suspended solids. Based on ink removal rate the neutral deinking condition without enzyme was better than the alkaline deinking condition, and the neutral deinking with enzyme addition turned out to be the best. The brightness of the deinked pulp was found to be the same trend as the ink removal rate. Flotation reject rate for the neutral deinking condition without enzyme was higher than that of the alkaline deinking condition, but that of the neutral deinking condition with enzyme was lower than that of the alkaline and the neutral deinking condition without enzyme. On the freeness of the deinked pulp, the neutral deinking condition with enzyme had the highest value and the alkaline deinking condition had the lowest value among the conditions tested. On the filtrate of the flotation stage, the cationic polymer demand of the neutral deinking condition with enzyme was much lower than the other conditions. Suspended solids and chemical exygen demand for the neutral flotation deinking filtrate was lower than those of the alkaline flotation deinking filtrate.

• 펄프종이기술
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• 제43권3호
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• pp.88-97
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• 2011

We carried out cationization of Dak pulp (paper mulberry bast fiber pulp) which is raw material of Hanji (Traditional Korean Paper) using a (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride to improve dyeability during a dyeing of Hanji with Gardenia (Gardenia jasminoides) and smoke tree (Cotinus coggygria). Fiber specific charge densities were determined using polyelectrolyte titration method and K/S values of dyed Hanji was calculated by Kubelka-Munk equation. As the result, fiber specific charge density increased with degree of cationization. Colors of Hanji dyed with Gardenia did not vary significantly with degree of cationization, but cationized Hanji dyed with smoke tree showed a large increase of a* value and reddish yellow color. After-mordanting did not decrease K/S value of dyes with cationized Hanji. K/S values of dyed Hanji decreased with increasing dyeing temperature. For smoke tree, the cationization impair lightfastness of dyed Hanji without mordant. After-mordanting with copper acetate or iron chloride improved lightfastness of dyed Hanji.

• 펄프종이기술
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• 제29권4호
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• pp.53-63
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• 1997

Most cellulose resources come from the higher plants, but bacteria also synthesize same cellulose as in plants. Many scientists have been widely studied on the bacterial cellulose, the process development, manufacturing, even marketing of cellulose fibers. The bacterial celluloses are very different in its physical and morphological structures. These fibers have many unique properties that are potentially and commercially beneficial. The fine fibers can produce a smooth paper with enchanced its strength property. But there gave been few reports on the mechanical properties of the processing of bacterial cellulose into structural materials. This study were performed to elucidate the mechanical properties of sheets prepared from bacterial cellulose. Also reinforcing effect of bacterial cellulose on the conventional pulp paper as well as surface structures by scanning electron microscopy were discussed. Paper made from bacterial cellulose is 10 times much stronger than ordinary chemical pulp sheet, and the mixing of bacterial cellulose has a remarkable reinforcing effect on the papers. Mechanical strengthes were increased with the increase of bacterial cellulose content in the sheet. This strength increase corresponds to the increasing water retention value and sheet density with the increase of bacterial cellulose content. Scanning electron micrographs were shown that fine microfibrills of bacterial celluloses covered on the surfaces of hardwood pulp fibers, and enhanced sheet strength by its intimate fiber bonding.

• 펄프종이기술
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• 제47권6호
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• pp.57-65
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• 2015

Microfibrillated cellulose (MFC) or Nanofibrillated cellulose (NFC) has been used to reduce the use of raw pulp and to improve paper strength. The problem of MFC preparation is high manufacturing cost. In this study, it was carried out to prepare MFC after enzyme beating and estimated properties of MFC. Endo-D was the best beating efficiency among three type of endo-glucanase. As the grinder pass number increased, the viscosity and the fines of MFC suspension increased while the crystallinity and the porosity of MFC sheet decreased. Also enzyme beating MFC was higher value in the crystallinity and lower value in the viscosity than non-enzyme MFC. In addition, the aspect ratio of MFC was the highest at 5 pass. MFC addition improved the handsheet strength and the air permeability but worsened the drainage.

• 펄프종이기술
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• 제47권6호
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• pp.139-146
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• 2015

We manufactured natural dyed Korean traditional paper (Hanji) for cultural properties conservation and storage with goldthread (Coptis chinensis) and silver nitrate ($AgNO_3$). Goldthread and silver nitrate are known to be an excellent antimicrobial activity. The effect of content of goldthread and silver nitrate on properties of dyed Hanji was investigated. Color strength of dyed Hanji decreased with increasing content of silver nitrate. After-mordanting with 3% silver nitrate improved lightfastness of dyed Hanji. Tannic acid treatment increased K/S value of dyed Hanji. As the amount of the increase in goldthread content was reduced silver nitrate content. Sim-mordanting method was used for simplifying manufacture process. Silver nitrate sim-mordanting method increased K/S value of goldthread than after-mordanting method.

• 한국전자파학회논문지
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• 제26권6호
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• pp.581-588
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• 2015

본 논문에서는 함정의 RCS(Radar Cross Section) 기준치 설정은 함정의 생존성, 기술적 건조 가능성, 운용성 등 여러가지 측면이 고려되어 결정될 수 있다. 본 연구는 수상함의 RCS 기준치 및 설계 목표치를 설정하기 위하여 수상함에 위협이 되는 대함유도탄, 연안레이다, 항공기 등의 기본 성능을 조사하고, 조사결과를 토대로 현재의 국내 기술수준에서 가능한 RCS 목표치/기준치 설정을 위한 절차를 제시하였다. RCS 기준은 가급적 낮게 설정하는 것이 생존성 측면에서 좋겠지만, 함정의 고유 기능에 대한 영향, 기술적인 한계, 비용 등을 감안하지 않을 수 없기 때문에, 이 연구에서는 구체적인 숫자의 제시보다는 기준에 필요한 요소를 분석하고, 생존성을 보장할 수 있는 RCS 범위를 제시함으로써 기준치 설정 절차를 제시하였다.