• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.285-291
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• 1998

During recent years, the durability of concrete structures has been considered in concret practice and material research. To preserve the brittleness of concrete as well as energy absorption and impact resistance, amount of fiber usage has greatly increased in the field of public works. Ultra fine powder, silica fume, mixed into concrete, it reduce void of concrete structure. Especially, there's a great effect for strength improvement of concrete by initial pozzolanic reactions. For these reasons, if silica fume mixed into concrete, it decrease the total void by microfilter effect . Pozzolan reaction, between cement particle and silica powder, can elaborate the micro structure of matrix. And so, in this paper, we deal SFRC for the purpose of efficiently using of industrial by-products(silica fume). Also we performed the test for durability such as freeze-thaw resistance and accelerated carbonation of SFRC using silica fume.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 1999년도 추계학술대회
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• pp.147-155
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• 1999

This paper discusses an optimal burn-in procedure to minimize total costs based on the assumption that the failure rate pattern follows a bimodal mixed Weibull distribution. The procedure will consider warranty period as a factor of the total expected burn-in cost. A cost model is formulated to find the optimal burn-in time that minimizes the expected burn-in cost. Conditional reliability for warranty period will be discussed. An illustrative example is included to show how to use the cost model in practice.

• 한국응급구조학회지
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• 제25권2호
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• pp.55-69
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• 2021

Purpose: This study aimed to develop 360° virtual reality videos and common videos for cardiac arrest recognition. Methods: A sequential mixed methods study was conducted, using qualitative interviews (with a total of seven experts) and a quantitative survey. Results: First, the cardiac arrest situation should be developed within 2-3 minutes after witnessing the patient collapse, for each of the four cardiac arrest videos about apnea, gasping, seizure, gasping, and seizure. Second, the education program should be designed so that the education on cardiac arrest recognition can proceed before CPR practice begins. Conclusion: 360° virtual reality videos and common videos for cardiac arrest recognition can play an important role in the education of the general public about cardiac arrest experience.

• 대한지역사회영양학회지
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• 제4권4호
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• pp.489-495
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• 1999

This study was conducted to investigate the weaning practice of 198 infants in Taejon city in October, 1998. Information on infant feeding and weaning practices were obtained by interviewing mothers in gynecologist and pediatric clinics located in Taejon. The results obtained were as follows : In the survey 37.4% of the infants were breast-feeding, while 31.3% of them were bottle-feeding and 29.3% of them were mixed-feeding. The reason for bottled-feeding was due either to the lack of breast-milk secretion or motner’s job. The educational level of the mother and maternal job affected the feeding methods before weaning. Lower rates of breast-feeding were found among mothers witn a lover level of education. The breast-feeding rate was lower in full-time and part-time job worker groups than in housewife. There was no significant difference in the feeding methods according to family income. Among the subjects, 71.5% of infants began to be weaned within 7 months. The onset of weaning was delayed in the full-time worker group. There was no significant difference in the onset time of weaning according to feeding method, the educational level of the mother, and family income. 60.6% of infants received fruit juice and 29.6% of them received cereals for first-given-supplementary food. ‘For baby’s nutritional status’ was the most common motivation for the onset of weaning. Commercially prepared foods were used more than home-made food for supplementary food.

• Journal of Nutrition and Health
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• 제27권3호
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• pp.272-280
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• 1994

The weaning practice of infants from 5 to 12 months of age in the area of Chunchon, Kangwon-do was studied. Subjects were divided into 2 groups depending on residential area, monthly family income and mother's educational level. Parents of group 1 (n=90) received higher education and more monthly family income than those of group 2(n=32). The family income was significantly higher in group 1 than in group 2. Mother's educational level has been markedly improved over 10 years, which affected the feeding methods before weaning in both groups(P<0.05). Group 1 appeared to be bottle-fed. Bottle-and mixed-feeding were mainly due to lack of breast milk. 95.6% of group 1 and 71.9% of group 2 started weaning before the age of 6 months and only 16.4% were completely finished regardless of the groups. Commercially prepared foods were used more than home-made for first given-supplementary food. 82.2% of group 1 received fruits and 84.4% of group 2 cookies/crackers as their main supplementary foods. As the motivation of onset of weaning, 'for baby's health and nutritional status' was the most common. These results demonstrate that there are distinct differences between these 2 groups in 1) the feeding methods prior to weaning, 2) time of onset of weaning, and 3) main supplementary foods, influenced by mother's educational level, economic purchasing power, or subjects birth order.

• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.117-127
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• 2007

Many real world control systems usually track several control objectives, simultaneously. At the moment, it is desirable to meet all specified goals using the controllers with simple structures like as proportional-integral (PI) and proportional-integral-derivative (PID) which are very useful in industry applications. Since in practice, these controllers are commonly tuned based on classical or trial-and-error approaches, they are incapable of obtaining good dynamical performance to capture all design objectives and specifications. This paper addresses a new method to bridge the gap between the power of optimal multiobjective control and PI/PID industrial controls. First the PI/PID control problem is reduced to a static output feedback control synthesis through the mixed $H_2/H_{\infty}$ control technique, and then the control parameters are easily carried out using an iterative linear matrix inequalities (ILMI) algorithm. Numerical examples on load-frequency control (LFC) and power system stabilizer (PSS) designs are given to illustrate the proposed methodology. The results are compared with genetic algorithm (GA) based multiobjective control and LMI based full order mixed $H_2/H_{\infty}$ control designs.

• 식품보건융합연구
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• 제5권4호
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• pp.13-17
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• 2019

Amiodarone hydrochloride is an antiarrhythmic agent which has low aqueous solubility and presents bioavailability problem. These properties are a challenge for the pharmaceutical industry. Inclusion of lipophilic compound in the hydrophobic core of micelles, i.e. self-assembled structures based on surfactants in aqueous solution, is one way of increasing the solubility. Intravenous formulation of amiodarone hydrochloride with polysorbate 80 as a detergent and benzyl alcohol as a co-solvent is used in medical practice. This paper aimed to study the effect of polysorbate 80 and benzyl alcohol on the water solubility of amiodarone hydrochloride. Formation of mixed micelles consisting of nonionic surfactant polysorbate 80 and cationic amiodarone with chloride counterion was investigated by fluorescence spectroscopy. Benzyl alcohol was found to decrease the stability of the mixed micelles and lead to crystallization of amiodarone hydrochloride. The greatest amounts of crystals formed at 4℃ for 30 days in the model drug solutions with polysorbate 80 concentrations of 100.1 mg/mL and 97.9 mg/mL. A change of the polysorbate 80 concentration and avoidance the use of benzyl alcohol are recommended to improve the stability of the parenteral dosage form. These results can open new perspectives in the optimization of amiodarone intravenous formulations.

• 정보관리학회지
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• 제26권1호
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• pp.351-370
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• 2009

본 연구는 근거중심 문헌정보실무의 개념과 연구방법 및 동향을 분석하여 국내 적용가능성을 살펴보기 위한 기초연구로 수행되었다. 근거중심 문헌정보실무는 실무에서 문제해결과 업무수행 향상을 위해 신뢰성 있는 연구 결과의 활용을 촉진함으로써 연구와 실무 간에 근본적으로 존재하는 격차를 줄이기 위한 운동이다. 근거중심 문헌정보실무는 초기에 의학도서관을 중심으로 수행되었으나 점차로 대학, 전문, 학교도서관으로 확대되었으며 연구 주제 또한 이용자연구, 평가에 한정되었던 것이 경영, 장서, 서비스 등 도서관 서비스 전분야로 확대되고 있다. 근거중심 문헌정보실무의 수행은 특정한 문제해결을 위한 다양한 연구 결과의 검색, 선정, 평가, 활용의 과정이 이루어진다. 또한 가장 높은 수준의 연구결과인 비평적 리뷰의 생산과정을 정형화함으로써 기존 연구의 체계적인 평가를 수행함과 동시에 새로운 연구통합 방법을 제시하고 있다.

• 한국조경학회지
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• 제38권5_2호
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• pp.135-143
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• 2010

The 21st century is currently undergoing an era of urban regeneration. The purpose of this research is to secure and expand the green infrastructure with zoning regulation in the context of urban regeneration. This objective also seeks a way of urban regeneration through the use of existing large parks by employing park-based mixed use districts around the periphery of large urban parks and green spaces. This research examines the limits, problems of existing single- and mixed-use zoning districts for securing of green infrastructure by book review. This research finally advocates introducing a another type of urban mixed-use districts, namely park-based mixed use district and its characteristics and functions, by using landscape ecology and landscape urbanism as a theoretical basis. The results of this research suggested that large parks and green spaces should be considered as one of patch in landscape ecology. This research also discusses the possibility that, as patches have ecotones with greater biodiversity in the peripheral areas of it, the green infrastructure can be constructed around the periphery of large urban large parks and green spaces by introducing cultural ecotone of nature's convergence with the city. As a result, the green infrastructure and high density of land use and using behaviour can be increased. Park-based mixed use districts encourage the convergence of parks and the city, with the park being used as the main function; residential, commercial, business and cultural uses etc. are partial functions. In order for the park-based mixed use districts to be designated, the size of large urban parks and green spaces, as well as location, city function and condition of the peripheral areas all need to be considered. The necessity to examine the designated width of the park-based mixed use districts and the form of the peripheral area was also discussed. This research, which is based on investigative research results, suggests that further in-depth and comprehensive analysis of the actual condition of urban large parks and peripheral areas needs to be completed. Specialists and other interested parties, analysis and investigation on related plans and designs are also needed for the institutional practice.

• 한국수산과학회지
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• 제1권2호
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• pp.129-133
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• 1968

The writer reviewed the cutting method of webbing practiced in major countries. Cutting rhythm Bar cutting to Point Cutting) should be chosen to approach as straight as possible, therefore the knot cuttings or the side cuttings should be 1, if possile. According to calculation, an arbitrary solution to a mixed cutting was undertaken, while another cutting method, of calculation 5 and 6, was taken by a prepared table. In no case, it was consequently possible to use an unmixed cutting rhythm. Sometimes, the cutting calculated from approximate value differs from desired result, tut this defference should not be taken too significant in practice.