• Journal of the Korean Wood Science and Technology
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• 제25권4호
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• pp.68-74
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• 1997

This research was studied dissolving pulp for rayon production, which is not KP, SP methods but steam explosion and oxygen alkali treatment. The variation of characterization in wood cellulose after steam explosion and oxygen alkali treatment this follows. In the oxygen alkali treatment of exploded pine wood, yield of dissolving pulp was lower than steam-exploded oak wood, and we have obtained dissolving pulp that high purity cellulose, but degree of polymerization was inclined to decrease less than 200. In the case of steam-exploded oak wood, degree of polymerization was higher than steam-exploded pine wood but purity of cellulose was lower than its.

• 한국의류학회지
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• 제20권4호
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• pp.682-689
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• 1996

A preparative method has been proposed for obtaining chitosan products which have a desired degree of deacetylation (DD, %) without much decrease in molecular weight. Deacetylation was prepared by two methods. The method I which was proposed by Domard etc. was that DMSO/thiophenol was used repeatedly only during the deacetylation, the method II was that DMSO/thiophenol was used after the alkali treatment. Then, effective deacetylation was performed by the method ll. To determine the degree of deacetylation, potentiometric titration method was adopted. According to the increase of DD, the viscosity average moleclar weght $(\overline{M\upsilon}$) and the DP of the chitosan products were decreased. The intensity of FT-lR peak appeared at $1655cm^{-1}, which was characteristic peak of amide I (Nacetyl secondary amide group), was gradually decreased with deacetylation. X-ray analysis showed that the lattice-spacing in the chitosan film increased with the degree of deacetylation, but the difference of the transparency of the chitosan products was not diverged significantly.

• 한국의류산업학회지
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• 제6권3호
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• pp.377-383
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• 2004

Photografting of styrene (St) on polypropylene (PP) nonwoven fabric using benzoin ethyl ether (BEE) as a photosensitizer was investigated. Inhibition of homopolymerization was achieved by adding various concentrations of $FeSO_4{\cdot}7H_2O$, $CuSO_4{\cdot}5H_2O$ and Mohr's salt. As St concentration was increased, the degree of grafting was increased as to a specific value and then decreased, and the effect of BEE concentration showed the same tendency. It was also found that the degree of grafting increased with reaction time and reaction temperature. Addition of the polyfunctional monomers and $H_2SO_4$ to the grafting system accelerated the photografting. The melting temperature, molecular weight, tensile strength and elongation were decreased with the increase in the degree of grafting.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.812-817
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• 1995

Endodontically treated teeth are usually restored for crown protection, aesthetics, and prevention of root canal recontamination. Restoration of these teeth, however, often requires intracanal posts. Various depths and techniques have been recommended for the preparation of post space. Therefore the purpose of this study was to evaluate the effect that pst preparation has on the coronal seal by linear dye penetration of root canals obturated by lateral condensation, vertical condensation, and thermafil techniques. Forty canals of roots of incisors and canines were cleaned and shaped with the use of a step-back technique. Thirty canals were obturated, 10 each with lateral, vertical, and thermafil techhniques. Five root canals were obturated without a root canal sealer and served as positive controls. Another five root canals were obturated, and their coronal half was sealed with sticky wax and served as negative controls. The apical 5 to 6mm of the filling materials were exposed to india ink for 48 hours. The depth of dye penetration was measured in all groups and statistically analyzed (ANOVA). The results were as follows. 1. The apical plugs in the thermafil groups had the highest degree of coronal dye leakage. 2. The group filled by vertical condensation technique had the lowest degree of coronal dye leakage. 3. No significant statistical difference was found in the amount of coronal dye leakage in canals filled by lateral condensation versus those filled by the veritcal condensation technique. 4. Significant statistical differences in coronal dye penetration were found between the canals filled by thermafil and those filled by the lateral or vertical condensation techniques (p<0.05).

• 한국콘텐츠학회논문지
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• 제19권10호
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• pp.472-486
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• 2019

본 연구는 중장년층의 노후준비도와 삶의 만족도의 영향관계를 분석하고, 노후준비도와 삶의 만족도 간의 영향관계에서 자기효능감의 매개효과를 검증하고자 수행되었다. 이를 위해 서울 경기지역의 중장년층을 대상으로 설문조사를 하였으며, SPSS 25.0을 활용하여 빈도분석, 상관관계 분석, 위계적 회귀분석 등을 실시하였다. 분석결과, 자기효능감, 사회적 노후준비, 신체적 노후준비, 경제적 노후준비, 학력 순으로 삶의 만족도에 유의미한 영향을 미치는 것으로 나타났으며, 인구학적 특성보다는 심리적 요인이 중장년층의 삶의 만족도에 더 큰 영향요인임을 확인하였다. 또한, 자기효능감은 노후준비도와 삶의 만족도의 영향관계에서 매개효과가 있는 것으로 나타났다. 이를 바탕으로 중장년층의 삶의 만족도를 올리기 위한 대안과 본 연구의 한계점 및 후속연구에 대해 논의 하였다.

• 한국콘텐츠학회논문지
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• 제15권8호
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• pp.313-325
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• 2015

본 연구는 산재경험 고령자의 경제적 노후준비에 영향을 미치는 요인을 앤더슨모형을 적용하여 분석하고, 과거 산재당시 종사상지위에 따라 정규직 근로자와 비정규직 근로자로 구분해 경제적 노후준비의 영향요인을 분석하고자 하였다. 이를 위해 산재보험패널조사(PSWCI)의 1차년도 자료를 이용하여 로지스틱 회귀분석을 실시하였다. 연구결과, 선행요인에서는 학력이 높고 정규직인 근로자가 비정규직인 여성 근로자에 비해 경제적 노후준비 가능성이 높게 나타났다. 자원요인에서는 정규직, 비정규직 근로자 모두 근로소득이 많을수록 노후준비 가능성이 높게 나타났으나, 국민연금 가입여부는 경제적 노후준비에 도움을 주지못하였다. 비정규직 근로자에게는 건강보험 가입이 경제적 노후준비에 영향을 미치고 있었다. 욕구요인에서는 정규직과 비정규직 근로자 모두 산업재해로 인한 통증이 일상 및 삶을 방해하는 정도가 높을수록 경제적 노후준비에 취약함을 확인하였다. 이러한 연구결과를 토대로 하여 정책적 함의를 제시하였다.

• 벤처창업연구
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• 제9권6호
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• pp.37-46
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• 2014

본 연구는 범국가적으로 일자리 창출을 위한 창업정책이 우선 국정과제로 대두된 오늘날 과연 창업자가 얼마나 잘 준비하여야지만 성과를 낼 수 있을까 하는 의문에서 출발하였다. 성과를 측정하는 기준은 목적에 따라 다르겠지만 일반적으로 기업의 성과는 기술적 성과와 경제적 성과로 구분할 수 있다. 본 연구에서는 연구대상 기업들의 업력이 주로 2~3년차의 초기 기술창업 기업임을 감안하여 우선 얼마나 기술적 성과를 거두고 있는지 중점 살펴보고자 한다. 기업성과에 영향을 미치는 수많은 변수 중에서 어떤 변수가 가장 큰 영향을 미칠 것인가에 대한 연구가 많이 이루어졌다고 할 것이나, 과연 어떤 변수가 기업의 성과를 확실하게 측정할 수 있는지에 대하여서는 회의적이다. 이에 본 연구는 창업준비정도를 기술창업자가 실제로 창업을 준비하는 기간인 창업준비기간과 창업하기 전 직무경력을 파악할 수 있는 동업종종사기간을 독립변수로 또 조절변수로는 정부나 지자체가 지원하는 각종 창업지원사업의 활용도를 파악할 수 있는 지원사업수혜금액을 가지고 기술적 성과에 대한 실증분석을 실시하였다. 검증 결과 기술창업자의 창업준비기간은 기술적 성과에 유의적인 정(正)(+)의 영향력을 발휘하는 것으로 확인되었으나 기술 창업자의 동업종 경력을 확인할 수 있는 동업종종사기간은 기술적 성과에 일반적인 기대와 달리 부(否)(-)의 영향력을 발휘하는 것으로, 또, 지원 사업수혜금액과 동업종종사기간 사이의 조절효과는 부(否)(-)의 유의성이 있는 것으로 창업준비기간과는 유의적인 조절효과가 없는 것으로 확인 되었다. 본 연구는 최근 청년들의 일자리 창출을 위해 범국가적으로 각종 정책이 수립 집행되는 현실에서 과연 창업정책 입안자들이 어떻게 정책적 고민을 해야 하는지와 창업예정자나 창업을 준비 중인 사람들이 어떻게 창업을 해야 할 것인가에 대한 미력하나마 방향을 제시하였다는 점에 의미를 두고자 한다.

• 대한지구과학교육학회지
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• 제4권3호
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• pp.297-304
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• 2011

The objective of the research which it sees to investigate and teachers elementary school preparation should have had what kind of line concept from astronomical field, to interpret. The research questions of this study were as follows. It tried to observe the result which investigates the line concept of teachers preparation in about conceptual gain and loss degree of the astronomical field which it comes to reveal from the research which it sees. The students where are not the scientific department of pedagogy and the scientific department of pedagogy were visible a relatively high gain and loss degree from the earth shape and phase change of month during one night. Also the part which it thinks rhinologically was many. When it presents the type, with afterwords it is same. First, The endurance rotates in about location change of month during various day, it revolves with the direction where also the month is the same type which does not know a fact, The students do not recognize well in about the shape of month changing everyday the type. The students does not understand the location which the month when it follows at time is accurate well the type was many. Second, when it tries to compare a scientific department of pedagogy 3 grade and a rhinologic department of pedagogy 3 grade, the gain and loss degree of most scientific department of pedagogy 3 grade is appearing highly.

• 대한치과보철학회지
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• 제30권4호
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• pp.508-525
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• 1992

The purpose of this study was to evaluate the effect of some resistance form designs on the bond strength of resin-retained prosthesis. Six sub-groups are designed in natural teeth group and resin teeth group . The framework designs in natural teeth group: 1) no groove preparation 2) groove at the center of distal surface 3) groove at the distobuccal line angle 4) 45 degree lateral load with no groove 5) 45 degree lateral load with center groove 6) splint two teeth with no groove. The framework designs in resin teeth group: 1) no groove preparation 2) groove at the center of distal surface 3) groove at the distobuccal line angle 4) metal covered the 1/2 of distal surface 5) metal covered the 1/2 of mesial surface 6) metal extended over the 114 of buccal surface. Specimens were treated electrolytic etching by Oxy-Etch and cemented with Panavia EX. Failure load was measured by Instron. Another 30 specimens were carried out fatigue tests by MTS 810 fatigue testing machine for 5000 cycles at different load level. The following results were obtained from this study. 1. The failure load was significantly increased by resistance forms. 2. The failure load was not increased by increase of total surface area bonded with teeth. The distal surface area played an important role in failure load. 3. In 45 degree lateral load group, the failure load was decreased significantly than that of in vertical load group. 4. Bond failure modes between static test and fatigue test exhibited no differences.

• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.205-213
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• 1993

The purpose of the study was to evaluate the degree of the marginal leakage of esthetic restorative materials on root caries restoration. 120 cavities were prepared to $90^{\circ}$ butt joint on all margins on the crown and root portion, and divided into 4 groups. The four groups of cavity were filled with Amalgam(Dongmuyung Dental Alloy Co., Ltd, KOREA), Silux$^{(R)}$(3M Co., USA)-Scotch Bond 2$^{(R)}$(3M Co., USA), Silux$^{(R)}$-All Bond$^{(R)}$(BISCO USA), and GC Fuji II$^{(R)}$(G-C Co., JAPAN) respectively. The apical margin of the preparation was finished to leave a flash of restorative material. The coronal margin of the preparation was finished not to leave a flash of restorative material. All specimens were sectioned longitudinally with Isomet Low speed saw(Buether Ltd, USA). The degree of dye penetration was evaluated as the parameter of marginal leakage under the stereoscope. The results were as follows. 1. At the enamel and dentin/cementum margins, the margin were finished to leave a flash of material showed less marginal leakage than that were finished not to leave a flash of material (P<0.001). 2. The enamel margins showed less marginal leakage than the dentin/cementum margins(P<0.001). 3. There was no significant difference in the degree of the marginal leakage between Silux$^{(R)}$-Scotch Bond 2$^{(R)}$ group and Silux$^{(R)}$-All Bond$^{(R)}$ group.