• 한국도서관정보학회지
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• 제22권
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• pp.205-244
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• 1995

Originally the concept of the traditional resource sharing has been discussed in the context of bibliographic materials, and has been labor-intensive and high-cost activities. The technology has had a great impact on such pattern of the resource sharing, and has expanded the limited scope of the traditional concept into the sharing of library information in the levels of local, regional and national systems, and expertise, materials, facilities, equipments and personnels of the library system. While the traditional circulation service as a basic method to share library materials by users can provide the resource to a single person at a time, the electronic resource can be shared, by multi-users at a time anytime anywhere. The maximization of the electronic resource sharing requires that publishing process should be fundamentally changed and articles, books, chapters, speech manuscripts, music scores, maps, sound, and other formats of materials should be prepared in machine readable format. This study examined the positive effects of the technology on the resource sharing, but not investigate the concrete and complex problems as to the cost, guidelines, detailed procedures, design details, and intellectual properties and protection involved in the resource sharing. Some findings extracted from the study can be summarized as follows; (1) ILL will lose its meaning as a method to share the materials if they are all in the electronic format and the phrase 'networked information resource' becomes omnipresent. (2) The technology keeps on changing the concept of resource sharing. Today, the scope of resource sharing not only encompasses the sharing of the primary and secondary materials but also the sharing of the processings(eg. cataloging), expertise, user education, special facilities, and the integrated automated library systems. (3) The sharing of the networked resource will be a method to provide better services for library users in the low cost. (4) The a n.0, pplication of the technology to the resource sharing should be focus on the method which allows an end-users to do the direct access to the needed materials, and to be delivered the primary document as soon as possible.

• 농업과학연구
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• 제46권4호
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• pp.991-997
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• 2019

This study was conducted to investigate the laying period performance of two crossbred Korean native chicken (KNC) grand parent stock (GPS) layer during 20 to 40 weeks. A total of 351 20-week-old KNC GPS were allocated in a completely randomized design to give 4 birds per each cage. The chickens were fed commercial diets [i.e., week 20 - 32, crude protein (CP) 18.0% and metabolizable energy (ME) 2,850 kcal/kg; week 32 - 40, CP 17.0% and ME 2,800 kcal/kg)] and fresh water during the whole experiment period ad libitum basis. Body weight, age of sexual maturity, egg weight, hen-day egg production (HDP) and feed conversion ratio (FCR) were measured during the experiment period (week 20 - 40). The results show no significant difference in the Body weight, age of sexual maturity, egg weight, and hen-day egg production (HDP) except for egg weight. 1B had a higher egg weight on week 36 only. We expect that the reason why most factors showed no significant difference is the lack of nutrients caused by limited feeding which follows the standard feeding system for the grand-parent stock. These results provide basic information for laying data in 2-way crossbred Korean native chickens.

• 치위생과학회지
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• 제18권1호
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• pp.42-49
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• 2018

The computer-aided design/computer-aided manufacturing (CAD/CAM) system was introduced to shorten the production time of all-ceramic restorations and the number of patient visits. Among these types of ceramic for dental CAD/CAM, they have been processed into inlay, onlay, and crown shapes using leucite-reinforced glass-ceramics to improve strength. The purpose of this study was to observe the mechanical properties and microstructure of leucite-reinforced glass-ceramics for dental CAD/CAM. Two types of leucite-reinforced glass-ceramic blocks (IPS Empress CAD, Rosetta BM) were prepared with diameter of 13 mm and thickness of 1 mm. Biaxial flexural testing was conducted using a piston-on-three-ball method at a crosshead speed of 0.5 mm/min. Weibull statistics were used for the analysis of biaxial flexural strength. Fracture toughness was obtained using an indentation fracture method. Specimens were observed by field emission scanning electron microscopy to examine the microstructure of the leucite crystalline phase after acid etching with 0.5% hydrofluoric acid aqueous solution for 1 minute. The results of strength testing showed that IPS Empress CAD had a mean value of $158.1{\pm}8.6MPa$ and Rosetta BM of $172.3{\pm}8.3MPa$. The fracture toughness results showed that IPS Empress CAD had a mean value of $1.28{\pm}0.19MPa{\cdot}m^{1/2}$ and Rosetta BM of $1.38{\pm}0.12MPa{\cdot}m^{1/2}$. The Rosetta BM sample exhibited higher strength and fracture toughness. Moreover, the crystalline phase size and ratio were increased in the Rosetta BM sample. The above results are expected to elucidate the basic mechanical properties and crystal structure characteristics of IPS Empress CAD and Rosetta BM. Additionally, they will help develop leucite-reinforced glass-ceramic materials for CAD/CAM.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.455-465
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• 2006

In this study, the effect of scour was evaluated by regional and geotechnical characteristics and back data were accumulate for the design against scour through the local erosion characteristics evaluation of the Inchon coast. The erosion characteristics for the undisturbed soil samples collected near the main locations at the Incheon 2nd bridge, the Hwangyeong bridge, and a coast road in Songdo, are determined quantitatively through the scour rate tests. On the basic soil properties test, the bed around the Inchon coast chiefly consists of fined grained soils, and the soil samples were classified as silty clay(ML) or clay(CL) under the Unified Soil Classification System. On the scour rate test, the critical shear stress increases when the undrained shear strength increases as of the general trend of fine grained soils, and the average scour rate for the maximum velocity by 100 year flood is 173mm/hr at the Incheon 2nd bridge, 67mm/hr at the Hwangyeong bridge and 10mm/hr at a coast road in Songdo, respectively. Comparing to the scour rate of coarse grained soil, that of the bed around the Inchon coast is turned out to be very low. Therefore, the relative ability of the bed around the Inchon coast to resist erosion is assumed to be very high.

• Journal of Positioning, Navigation, and Timing
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• 제7권1호
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• pp.37-42
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• 2018

This paper proposed a microstrip antenna that can perform jamming of satellite signals from the GPS L5, GLONASS G3, BDS B2 frequency bands (1164 - 1217 MHz) that are employed mainly for military purposes among the GNSS frequencies using unmanned aircrafts over the enemy's sky in time of emergency. The single element in the proposed antenna can be easily mounted to unmanned aircrafts. This study analyzed the characteristics of miniaturization and beam of radiating elements by applying the image theories and perturbation effect to satisfy the uniform level at ${\pm}45^{\circ}$ of beam steering goal due to the phase delay after antenna array. The designed microstrip antenna had a miniaturized radiating element area (x-y plane), which was reduced by 76.3% compared to that of basic microstrip antenna, and its beam width was $190^{\circ}$ in the E-plane and $140^{\circ}$ in the H plane. In addition, the simulation was conducted to determine the characteristics due to the phase delay by arranging the designed single microstrip antenna by $1{\times}4$ array and the results showed that beam steering of ${\pm}45^{\circ}$ is possible in the H-plane on the basis of $0^{\circ}$. Thus, the proposed antenna was verified to be effective in satellite signal jamming in the air as it was attached to the lower end of unmanned aircrafts.

• 한국의류산업학회지
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• 제14권3호
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• pp.423-429
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• 2012

This study investigated purchasing practice and size satisfaction to offer basic data to establish a marketing strategy and produce down-aging clothes for females in their 40s-50s. For the data analysis, crosstabs, factor analysis, and one-way ANOVA were used. The results were as follows; first, middle-aged women were observed to purchase down-aging clothes "to look younger" and not purchase clothes "due to the lack of right sizes." For women who answered to 'not purchase clothes', they also acknowledged that they intended to purchase down-aging clothes in the future if the right size is available. Second, people in their early 40s significantly considered perceptual qualities such as fashion and brand names while people in their late 50s placed the most importance in practicality and wearability. For body shapes, people with overweight body types were found to significantly consider physical performance, practicality, and wearability. Third, the examination of purchase satisfaction levels by age groups showed that younger age groups had high satisfaction level for wear functionality related items that included size and activity however, the late 50s group had the lowest satisfaction level. Middle-aged women purchased clothes to look younger however, they simultaneously wear clothes that are plain and conservative or respectable and graceful. Therefore, the development of products reflect the analysis of designs that can help create a more youthful appearance and women's preferred styles are needed in addition to the establishment of a differentiated sizing system for middle-aged female consumers in the incorporation of the characteristics of middle-aged women's body parts.

• 대한토목학회논문집
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• 제33권4호
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• pp.1693-1705
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• 2013

국내의 수로교는 쌀문화로 상징되는 농업용수를 공급하는 교량으로서 수로교를 개보수하기 위해서는 기본설계를 실시하는 것이 바람직하나 현재 생략되고 있는 실정이므로 이에 소요되는 공사비를 산정할 필요가 있다. 이 연구에서는 2003년 이후 교체한 RC구조 수로교에 대한 실적자료를 기초로 개략공사비 산정 회귀분석(RA) 모델과 사례기반추론(CBR) 모델을 개발하였다. RA 모델의 경우 단순회귀 모델이 다중회귀 모델보다 오차율이 낮았다. CBR 모델의 경우 유전 알고리즘을 이용하였으며 영향요인의 가중치, 편차, 순위조건을 최적화 대상으로 하였고 특히 영향요인 가중치의 범위를 제한하여 수로교 개보수 공사비의 예측 정확도를 제고하였다. RA 모델과 CBR 모델 사이의 오차율은 통계적 차이를 보이지 않았다. 본 논문에서 제시된 수로교 개보수 개략공사비 산정방법은 개보수사업의 시행에 따른 신속한 의사결정을 하는데 활용될 수 있을 것으로 기대된다.

• Journal of Advanced Marine Engineering and Technology
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• 제36권4호
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• pp.423-429
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• 2012

밀러 사이클은 저배기 및 고효율 달성으로 Tier II 규제뿐만 아니라 $CO_2$ 저감을 동시에 달성할 수 있는 기술로 알려져 있다. 그러나 이를 위해서는 충분한 흡입공기량이 확보되어야 하며 흡기계통은 공기저항을 최소화할 수 있는 형상으로 개선되어야 한다. 본 연구에서 흡기계통 설계 및 사이클 해석에 활용하기 위한 기초 자료 확보를 위해 흡기밸브의 유량계수를 측정하였다. 유량계수 측정에는 정상유동장치를 이용하였다. 중속 박용기관에 사용되는 포핏 밸브를 대상으로 실험을 수행한 결과, 흡기밸브 유량계수는 밸브양정의 증가에 따라 약 0.62까지 지속적으로 증가하는 경향이며 행정/보어 비와는 무관한 흡기밸브 고유의 특성이 있음을 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제19권12호
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• pp.369-384
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• 2014

우리나라 영재교육은 2002년 시작된 이후 이제 교육지원체계가 확립되었고, 양적 측면에서 충분한 성장을 이루었다. 반면에 교육의 질적인 측면에서는 미흡한 점이 있다는 보고가 많다. 즉, 대부분의 영재교육이 선행학습에 의한 단순 지식확대 위주로 이루어진다는 것이다. 영재 교육의 질을 높이기 위해서는 간학문적 원리와 현상을 문제해결에 적용할 수 있는 비판적 사고력 및 창의력 배양 교육이 되어야 한다. 이 연구에서는 통합교육 개념에 근거하여 AND/OR/XOR 등의 기본 논리 연산이 컴퓨터의 세포 역할을 하게 되는 과정을 탐구하는 융합형 교수 학습 자료를 설계하고 개발하였다. 설문 조사 결과 기존의 다른 학습 주제보다 학생들의 만족도(유익성, 이해도, 흥미도)가 크게 높은 것으로 평가되어 설계 취지에 부합된 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제47권2호
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• pp.204-211
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• 2015

Probabilistic safety assessment (PSA) has had a significant role in quantitative decision-making by finding design and operational vulnerabilities and evaluating cost-benefit in improving such weak points. In particular, it has been widely used as the core methodology for risk-informed applications (RIAs). Even though the nature of PSA seeks realistic results, there are still "conservative" aspects. One of the sources for the conservatism is the assumptions of safety analysis and the estimation of failure frequency. Surveillance, diagnosis, and prognosis (SDP), utilizing massive databases and information technology, is worth highlighting in terms of its capability for alleviating the conservatism in conventional PSA. This article provides enabling techniques to solidify a method to provide time- and condition-dependent risks by integrating a conventional PSA model with condition monitoring and prognostics techniques. We will discuss how to integrate the results with frequency of initiating events (IEs) and probability of basic events (BEs). Two illustrative examples will be introduced: (1) how the failure probability of a passive system can be evaluated under different plant conditions and (2) how the IE frequency for a steam generator tube rupture (SGTR) can be updated in terms of operating time. We expect that the proposed model can take a role of annunciator to show the variation of core damage frequency (CDF) depending on operational conditions.