• 펄프종이기술
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• 제46권3호
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• pp.50-57
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• 2014

In this study, we investigated the physical properties of kraft pulps made from rice husk, peanut husk and garlic stems. These agricultural byproducts were collected individually, and then various pulps were manufactured from them by controlling active alkali, sulfidity, reaction time and the liquor ratio in the kraft pulping process in order to analyze the applicability of these agricultural byproducts as raw materials for kraft pulps. After kraft pulping, we measured yield, flake content, fiber length, fiber width and freeness of pulps, and the fiber shapes of the pulps were observed by using an optical microscope. When the higher active alkali, longer reaction time and lower liquor ratio were applied in kraft pulping process, reject content decreased and fiber yield increased. The pulp from garlic stems had the longest fiber length and that from rice husk showed the highest intial freeness. All of the pulps from agricultural byproducts showed higher initial freeness, shorter fiber length and the similar fiber width compared to OCC, BCTMP and hardwood BKP. The fibers of the pulps made from agricultural byproducts showed a similar shape to those of commercial pulps. It was concluded that these agricultural byproducts had a potential as raw materials to produce an alternative pulp to the commercial pulps.

• 영재교육연구
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• 제16권1호
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• pp.61-79
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• 2006

국내의 정보영재 교육과정을 살펴보면 프로그래밍 언어, 운영체제 혹은 컴퓨터 구조 등으로 편성되어 있다. 이들 교육과정의 운영 형태는 고등사고력 신장에 초점을 맞추기 보다는 다분히 기능 중심의 교육이 주류를 이루고 있다. 정보 영재는 이와 같은 교육 프로그램에 대해 불만을 가지고 있는 것으로 분석되었다(60명 중 58명, 96,67%). 이와 같은 불만은 정보영재 전문 교육기관에서 운영되고 있는 교육과정이 정보 관련 일반 교육 기관에서 운영되고 있는 교육과정과 크게 차별화되지 못하고 있는 이유 때문이다. 본 연구는 이러한 점에 착안하여 프로그래밍 언어를 게임이나 체험을 통하여 학습 할 수 있도록 대안적인 교재를 개발하였다. 본 연구는 대안적인 교재가 정보영재의 프로그래밍 언어 영역의 학업 성취를 향상시킨 것으로 결론 내렸으며, 이와 같은 연구 결과는 향후 정보영재를 위한 교재 개발의 새로운 방향을 제시할 것으로 기대하였다.

• 한국표면공학회지
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• 제34권5호
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• pp.403-408
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• 2001

In this work, the cyclic perfluorinated ether (c-C$_4$F$_{8}$O) with very high destructive removal efficiency (DRE) than other alternative gases, such as $C_3$F$_{8}$, c-C$_4$F$_{8}$ and NF$_3$ was used as an alternative process chemical. The plasma cleaning of silicon nitride using gas mixtures of c-C$_4$F$_{8}$O/O$_2$ and c-C$_4$F$_{8}$O/O$_2$+ $N_2$ was investigated in order to evaluate the effects of adding $N_2$ to c-C$_4$F$_{8}$O/O$_2$ on the global warming effects. Under optimum condition, the emitted net perfluorocompounds (PFCs) during cleaning of silicon nitride were quantified and then the effects of additive $N_2$ by obtaining the destructive removal efficiency (DRE) and the million metric tons of carbon equivalent (MMT-CE) were calculated. DRE and MMTCE were obtained by evaluating the volumetric emission using. Fourier transform-infrared spectroscopy (FT-IR). During the cleaning using c-C$_4$F$_{8}$O/O$_2$+$N_2$, DRE values as high as (equation omitted) 98% were obtained and MMTCE values were reduced by as high as 70% compared to the case of $C_2$F$_{6}$O$_2$. Recombination characteristics were indirectly investigated by combining the measurements of species in the chamber using optical emission spectroscopy (OES), before and after the cleaning, in order to understand any correlation between plasma and emission characteristics as well as cleaning rate of silicon nitride.silicon nitride.

• 소성∙가공
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• 제28권6호
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• pp.361-367
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• 2019

Microstructure evolution and tensile properties of Al-8mass%Mg alloy casting billet by biaxial alternative forging were investigated in this study. An alternative forging system tailored in this study was used to allow continuous strain accumulations on the alloy workpiece. A finite element (FE) simulation results revealed that the strain was mainly concentrated in the core and that the shear bands developed into a form with an X shape in the cross-section of workpiece after the alternative forging using octangular rod shaped dies. With increasing the forging passes, it was observed that the Al-8mass%Mg alloy workpieces were significantly deformed, and cracks began to form and propagate on the both ends of the forged workpieces after five passes at room temperature. In as-forged microstructures taken by microscopes, twins, clustering of dislocations, and fine subgrains were found. Tensile strengths of the forged specimens showed significant increases depending on the number of forging passes, and a trade-off relationship was observed between the elongation and strength. At room temperature and 100℃ the workpieces showed similar behaviors in microstructural evolution and tensile properties depending on forging passes, while the increase range in strength was reduced at 200℃.

• 대한한방내과학회지
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• 제30권4호
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• pp.732-745
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• 2009

Objectives : This study analyzed the contents of research papers of complementary and alternative medicine (CAM) concerning chronic obstructive pulmonary disease (COPD) published in PubMed during the last 5 years. This study was conducted to help clinical studies for treating COPD with Oriental medicine. Materials and Methods : We inspected 31 theses and scrutinized their objectives, periods, participants, materials and methods, methods of assessment, results and Jadad score. Results : The treatments in the studies were supplements, physical training, acupuncture, acu-TENS, Bojungikgi-tang (Buzhongyiqi-tang), counseling, breathing training, osteopathic manipulative treatment, reflexology, and distractive auditory stimuli. The aims of treatment were improvement of exercise capacity, lung function, quality of life, oxidative status, nutrient status, systemic inflammation, and cessation of smoking. The median for treatment period of study was 8 weeks, the median number of participants was 35 and the differences between mean $FEV_1$ from groups were less than 10% in 22 studies. The methods of assessment were lung function test, exercise capacity test, muscle strength test, questionnaire of QoL, laboratory studies, and measurement of nutrient state. The mean of Jadad score was $2.4\;{\pm}\;1.03$, and 24 treatment were assessed as effective. Conclusion : Recent CAM studies of COPD have focused on various topics in alternative and complementary medicine, and it is necessary to provide objective studies for treatment of this disease with Oriental medicines.

• 대한한방부인과학회지
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• 제22권1호
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• pp.243-262
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• 2009

Purpose: In recent, there have been a lot of studies exploring effective methods to relieve pains and sufferings of women delivered of child. The ultimate purpose of the study is to investigate the developmental trends of the complementary alternative medicine(CAM, hereafter), which has increasingly obtained the approval of the women and therefore established the academic foundations in effect. Methods: Systematic analysis with diverse written materials concerning the complementary alternative medicine was carried out. For the analysis, materials related with the issue of the study were searched at the Pubmed, the Korea Education & Research Information Service. Results: 1. One of the results of interest is the verification of the fact in that diverse complementary therapies are nowadays substantially applied to the many situations of delivery and childbirth. 2. The results showed clearly that CAM has several prominent influences on the whole process of the delivery: from the reduce of the pains and the time for delivery, to increasement of the satisfactional level of the mother. 3. According to the results, the emphasis of CAM is mainly placed not just on the relieving of pains and sufferings of the mothers, but on empowering them to face them with self-confidence. 4. The results of the study suggest strongly that the professionals should provide mothers with useful information and methods to help them to get through the pains during the delivery period. Conclusion: The result of the study is to suggest persuasively that more systematic attention should be paid to the researches exploring effectiveness and stability and safety of CAM.

• Structural Engineering and Mechanics
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• 제5권4호
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• pp.399-414
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• 1997

This paper presents an investigation into the seismic response characteristics of a proposed ligh-weight pedestrian cable-stayed bridge made entirely from Glass Fiber Reinforced Plastics(GFRP). The study employs three dimensional finite element models to study and compare the dynamic characteristics and the seismic response of the GFRP bridge to a conventional Steel-Concrete (SC) cable-stayed bridge alternative. The two bridges were subjected to three synthetic earthquakes that differ in the frequency content characteristics. The performance of the GFRP bridge was compared to that of the SC bridge by normalizing the live load and the seismic internal forces with respect to the dead load internal forces. The normalized seismically induced internal forces were compared to the normalized live load internal forces for each design alternative. The study shows that the design alternatives have different dynamic characteristics. The light GFRP alternative has more flexible deck motion in the lateral direction than the heavier SC alternative. While the SC alternative has more vertical deck modes than the GFRP alternative, it has less lateral deck modes than the GFRP alternative in the studied frequency range. The GFRP towers are more flexible in the lateral direction than the SC towers. The GFRP bridge tower attracted less normalized base shear force than the SC bridge towers. However, earthquakes, with peak acceleration of only 0.1 g, and with a variety of frequency content could induce high enough seismic internal forces at the tower bases of the GFRP cable-stayed bridge to govern the structural design of such bridge. Careful seismic analysis, design, and detailing of the tower connections are required to achieve satisfactory seismic performance of GFRP long span bridges.

• 한국비블리아학회지
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• 제31권3호
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• pp.191-211
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• 2020

본 연구는 시각장애인들의 독서보조기기를 이용한 정보접근에서 발생하는 한계와 문제점 등을 확인하고, 이를 기반으로 독서보조기기를 이용한 대체자료 이용 활성화 방안을 제안하는데 주된 목적을 두고 있다. 이를 위해 시각장애인 성인을 대상으로 설문조사를 수행하였으며, 설문 분석 결과를 통해 독서보조기기의 이용을 활성화하는데 있어서의 제한요인을 여섯 가지 측면으로 도출하였다. 도출한 제한요인을 중심으로 독서보조기기 이용 활성화를 위한 방안을 정책적, 운영적 측면으로 구분하여 제안하였다. 정책적 측면에서는 저가의 독서보조기기 개발, 독서보조기기 지원 정책에 대한 인지도 제고, 독서보조기기 적용성 향상을 위한 웹 표준 지침 준수 방안을 제안하였으며, 운영적 측면에서는 시각 이외에 청각 활용 기능의 보강, 독서보조기기 활용 관련 정보서비스 확충, 독서보조기기의 휴대성 강화 등을 제안하였다.

• 한국식품영양학회지
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• 제28권4호
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• pp.643-649
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• 2015

This study was performed to determine the optimal month of harvest between May and July for wild peach (Prunus davidiana) by comparison of functional materials. The general composition, amino acid and vitamin (A, C, and E) content, and antioxidant activity were determined. With respect to the general composition of wild peach according to the month of harvest, wild peach harvested in May (HMP) and July (HJP) contained mostly carbohydrate, the contents of which amounted to 77.37 g/100 g and 77.92 g/100 g, respectively. The total amino acid content of HMP and HJP were 675.29 mg% and 573.25 mg%, respectively. Regarding the vitamin contents, vitamin A (retinol), E (${\alpha}-tocopherol$) and C in HMP were higher than those in HJP. The total polyphenol content of HMP (218.37 mg TAE/g) was higher than that of HJP (71.45 mg TAE/g). The total flavonoid content of HMP (64.95 mg RE/g) was also higher than that of HJP (32.67 mg RE/g). Moreover, the DPPH and ABTS radical scavenging activities ($IC_{50}$) were higher in HMP ($137.18{\mu}g/mL$ and $157.15{\mu}g/mL$) than those in HJP ($160.10 {\mu}g/mL$ and $186.01 {\mu}g/mL$), meaning that the former produces better antioxidant effects. It can be concluded that wild peach harvested in May contained higher functional materials such as vitamins and amino acids and had a higher antioxidant effect, than wild peach harvested in july.

• 대한기계학회논문집A
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• 제21권9호
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• pp.1441-1451
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• 1997

This paper addresses method which can be used for analyzing thermal stresses of a functionally graded material(FGM) using semi-analytical approach. FGM is a nonhomogeneous material whose composition changes continuously from a metal surface to a ceramic surface. An infinite one dimensional FGM plate is considered. The temperature distribution in the FGM is obtained by approximate Green's function solution. To expedite the convergence of the solutions, alternative Green's function solution is derived and shows good agreement with results from finite difference method. Thermal stresses are calculated using temperature distribution of the plate.