• The Korean Journal of Physiology and Pharmacology
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• 제21권6호
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• pp.643-650
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• 2017

Vascular dementia (VaD) is a group of heterogeneous diseases with the common feature of cerebral hypoperfusion. To identify key factors contributing to VaD pathophysiology, we performed a detailed comparison of Wistar and Sprague-Dawley (SD) rats subjected to permanent bilateral common carotid artery occlusion (BCCAo). Eight-week old male Wistar and SD rats underwent BCCAo, followed by a reference memory test using a five-radial arm maze with tactile cues. Continuous monitoring of cerebral blood flow (CBF) was performed with a laser Doppler perfusion imaging (LDPI) system. A separate cohort of animals was sacrificed for evaluation of the brain vasculature and white matter damage after BCCAo. We found reference memory impairment in Wistar rats, but not in SD rats. Moreover, our LDPI system revealed that Wistar rats had significant hypoperfusion in the brain region supplied by the posterior cerebral artery (PCA). Furthermore, Wistar rats showed more profound CBF reduction in the forebrain region than did SD rats. Post-mortem analysis of brain vasculature demonstrated greater PCA plasticity at all time points after BCCAo in Wistar rats. Finally, we confirmed white matter rarefaction that was only observed in Wistar rats. Our studies show a comprehensive and dynamic CBF status after BCCAo in Wistar rats in addition to severe PCA dolichoectasia, which correlated well with white matter lesion and memory decline.

• 정보관리학회지
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• 제32권4호
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• pp.167-203
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• 2015

본 연구에서는 설문조사를 통해 공공도서관이 디지털통합적 지역사회 구축자로서의 역할에 어느 정도 기여하고 있는지를 파악하고자 하였다. 이를 위해 국가도서관통계시스템에 등록된 전국 공공도서관 935개 기관을 대상으로 설문을 수행하였다. 그 결과 첫째, 컴퓨터, 노트북, 스캐너, 태블릿 PC 등 장비 인프라, 인터넷 인프라 등은 비교적 높은 수준에 있는 것으로 파악되었다. 둘째, 이용자가 이용할 수 있는 전자책, 디지털 및 가상참고서비스, 도서관서비스 모바일 앱 등 서비스나 자원은 비교적 높은 수준이나 협업과 그룹작업을 지원하는 소프트웨어나 참여공간의 가용성 등은 상당히 낮게 나타났다. 셋째, 기술과 관련된 리터러시 훈련 비율은 22.4%에 지나지 않았고, 교육주제도 자원탐색 주제로 집중되어 있으며, 화상회의기술 사용법이나 클라우드 컴퓨팅 어플리케이션 교육 등 다소 미래지향적인 기술교육은 하지 않는 것으로 나타났다. 결론적으로 문화향유 공간 또는 창의적인 공간으로서의 도서관의 다양한 역할 변화를 모색해야 하는 이 시대의 흐름에 따라 기술 및 장비의 제공확대, 그리고 미래지향적 서비스 및 교육제공을 고려해야 할 것이다.

• 한국유체기계학회 논문집
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• 제17권1호
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• pp.35-40
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• 2014

A multi-objective optimization of a regenerative fan for enhancing the aerodynamic and aeroacoustic performance was carried out using an integrated fan design system, namely, Total FAN-Regen$^{(R)}$. The Total FAN-Regen$^{(R)}$ was developed for non-specialists to carry out a series of design process, viz., computational preliminary design, three-dimensional aerodynamic and aeroacoustic analyses, and design optimization, for a regenerative fan. An aerodynamic analysis of the regenerative fan was conducted by solving three-dimensional Reynolds-averaged Navier-Stokes equations using the shear stress transport turbulence model. And, an aeroacoustic analysis of the regenerative fan was implemented in a finite/infinite element method by solving the variational formulation of Lighthill's analogy based on the results of the unsteady flow analysis. An optimum shape obtained by Total FAN-Regen$^{(R)}$ shows the enhanced efficiency and decreased sound pressure level as much as 1.5 % and 20.0 dB, respectively, compared to those of the reference design. The performance test was carried out for an optimized regenerative fan to validate the performance of the numerically predicted optimal design.

• 한국환경과학회지
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• 제22권7호
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• pp.895-903
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• 2013

This study analyzed on characteristics of the ground-water capture zone in coastal areas and mid-mountainous area according to pumping rate. For this study, it targeted Jejudo island where is the volcanic island. To analyze, MODFLOW model and MODPATH model, which are the ground-water flow analysis models, were used. As a result of research, the following conclusions could be obtained. As a result of analyzing influence of a change in pumping time upon length of capture zone, the length of capture zone in coastal area was indicated to be greater in the changing ratio compared to the length of capture zone in mid-mountainous area. Next, in the coastal area, the pumping rate and the capture-zone length are changing similarly. However, in mid-mountainous area, the length of capture zone was indicated to grow when the pumping rate comes to exceed 1,500m3/day. As a result of analyzing influence of a change in pumping time upon capture area, the tendency of a change in the area was indicated similarly in coastal areas and mid-mountainous area. Especially, it could be known that the larger pumping rate leads to the more definite increase in tendency to a change in capture area. Based on this study, it was allowed to be possibly used in the suitable pumping rate in coastal areas and mid-mountainous area of the volcano island in the future. A follow-up research is judged to necessarily analyze the influence of tubular-well group upon capture zone by additionally analyzing a change in capture zone targeting the concentrated tubular well.

• Carbon letters
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• 제21권
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• pp.33-50
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• 2017

In this study, Fe-Ni bimetallic catalyst supported on kaolin is prepared by a wet impregnation method. The effects of mass of kaolin support, pre-calcination time, pre-calcination temperature and stirring speed on catalyst yields are examined. Then, the optimal supported Fe-Ni catalyst is utilised to produce multi-walled carbon nanotubes (MWCNTs) using catalytic chemical vapour deposition (CCVD) method. The catalysts and MWCNTs prepared using the optimal conditions are characterized using high resolution transmission electron microscope (HRTEM), high-resolution scanning electron microscope (HRSEM), electron diffraction spectrometer (EDS), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD). The XRD/EDS patterns of the prepared catalyst confirm the formation of a purely crystalline ternary oxide ($NiFe_2O_4$). The statistical analysis of the variance demonstrates that the combined effects of the reaction temperature and acetylene flow rate predominantly influenced the MWCNT yield. The $N_2$ adsorption (BET) and TGA analyses reveal high surface areas and thermally stable MWCNTs. The HRTEM/HRSEM micrographs confirm the formation of tangled MWCNTs with a particle size of less than 62 nm. The XRD patterns of the MWCNTs reveal the formation of a typical graphitized carbon. This study establishes the production of MWCNTs from a bi-metallic catalyst supported on kaolin.

• 한국한의학연구원논문집
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• 제15권2호
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• pp.119-124
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• 2009

The purpose of this study was investigation of quantitative analysis of marker substances in Paeonia lactiflora extracts by solid fermentation. High performance liquid chromatography (HPLC) for the determination of albiflorin and paeoniflorin in P. lactiflora extracts by solid fermentation, the separation method was performed on C18 column ($250\;mm\;{\times}\;4.6\;mm$, $5\;{\mu}m$, RS tech) using gradient solvent mixtures of water-acetonitrile with photodiode array detector (230nm). The flow rate was 1.0 ml/min. Retention time of albiflorin and paeoniflorin was about 28.88, 31.92 min and linearity of calibration was showed good result(r2 = 0.9998, 0.9996), respectively. Content of albiflorin was $0.090\;{\pm}\;0.03%$ in P. lactiflora extract(control), $0.102\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Paecilomyces japonica, $0.056\;{\pm}\;0.01%$ in P. lactiflora extract fermented with Ganoderma lucidum, $0.093\;{\pm}\;0.00%$ in P. lactiflora extract fermented with honey and $0.046\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Nuruk. Content of paeoniflorin was $4.506\;{\pm}\;0.13%$ in control, $2.599\;{\pm}\;0.04%$ in P. lactiflora extract fermented with Paecilomyces japonica, $1.222\;{\pm}\;0.03%$ in P. lactiflora extract fermented with Ganoderma lucidum, $2.750\;{\pm}\;0.05%$ in P. lactiflora extract fermented with honey and $0.847\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Nuruk, respectively. Content of the marker substances did not increase in all fermentation experiment group.

• 한국지역사회생활과학회지
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• 제16권2호
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• pp.51-59
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• 2005

The purpose of the present study is to seek measures to increase the quality of farmers lives by considering the results of a survey on the welfare demand for them when setting up policy. The results are as follows: First, though many concerns and policies to control the rural exodus have been exerted in terms of maintaining agricultural communities, which is one of critical components for the development of Korean agriculture and farming villages, the rural exodus became more and more serious. It is urgently required, therefore, for the Korean administration to correspond actively to the reasons why farmers depart their villages, such as bad prospects, low incomes or problems with their children's education. Second, as the number of females who take part in farming has increased, it is necessary to reform the rural educational environment. In addition, as the agricultural community develops, and other industries flow in, the greater the worries about crime, and consequently, it is necessary to equip a local safety system, share information on job opportunities, and provide educational opportunities. Third, since rural districts nay have financial difficulties because of old-aged and small-sized farmhouse, it is necessary to mainly support the welfare of the aged and lower-income farmers, considering the characteristics of each group and area. Fourth, over half of the farmers responded that they cannot bear to pay the national pension and health insurance premiums, and therefore it should be considered to reduce the pension and premium, or to readjust the insurance value appropriate to the level of the farmer's income. Fifth, despite a number of agricultural policies now in place, farmers desire a policy which can promise a prosperous vision for Korean agriculture and the facilities needed for education and health. It is necessary for the administration to set up policies that are characterized by locality with the view that farmers are not mere recipients, but participants in the policies.

• Wind and Structures
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• 제25권3호
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• pp.283-299
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• 2017

Two types of aerodynamic admittance function (AAF) that have been adopted in bridge aerodynamics are addressed. The first type is based on a group of supposed relations between flutter derivatives and AAFs. In so doing, the aero-elastic properties of a section could be used to determine AAFs. It is found that the supposed relations hold only for cases when the gust frequencies are within a very low range. Predominant frequencies of long-span bridges are, however, far away from this range. In this sense, the AAFs determined this way are of little practical significance. Another type of AAFs is based on the relation between the Theodorsen circulation function and the Sears function, which holds for thin airfoil theories. It is found, however, that an obvious illogicality exists in this methodology either. In this article, a viewpoint is put forward that AAFs of bluff bridge deck sections are inherently dependent on oncoming turbulent properties. This kind of dependence is investigated with a thin plate and a double-girder bluff section via computational fluid dynamics method. Two types of wind fluctuations are used for identification of AAFs. One is turbulent wind flow while the other is harmonic. The numerical results indicate that AAFs of the thin plate agree well with the Sears AAF, and show no obvious dependence on the oncoming wind fields. In contrast, for the case of bluff double-girder section, AAFs identified from the turbulent and harmonic flows of different amplitudes differ among each other, exhibiting obvious dependence on the oncoming wind field properties.

• 디지털융복합연구
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• 제15권4호
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• pp.35-42
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• 2017

정부는 공공부문 정보화사업의 체계적인 추진과 더불어 정보화사업에 대한 효율성을 강화하기 위하여 정보화사업을 추진하는 경우 반드시 정보화전략계획수립을 의무화하고 있다. 그러나 정보화계획수립 필요성이 높은 사업임에도 명확한 판단기준의 부재로 정보화계획수립 없이 사업이 진행됨으로써 정보화사업 추진의 타당성이 낮은 실정이다. 본 연구는 공공부문 정보화사업에서 정보화전략계획수립의 실효성을 담보하기 위해 정보화전략계획수립 의무화대상을 명확히 판단하기 위한 판단기준을 마련하고자하는데 그 목적이 있다. 이를 위해 본 연구에서는 델파이방법을 통해서 공공부문 정보화사업의 정보화전략계획수립 의무화를 결정하는 결정요인과 판단모델을 설정하였다. 또한, 설문조사를 통해 정보화전략계획수립 의무화 판단모델에서의 4가지 결정요인들에 대한 타당성과 각 결정요인별 세부적인 판단기준을 파악하였다. 최종적으로 전문가집단에 의한 FGI를 통해서 설문조사 결과를 분석하고 정보화전략계획수립 의무화 대상 판단기준(안)을 제시하였다. 한편, 본 연구결과는 정부차원에서 정보화전략계획수립 의무화에 대한 정책결정과 예산작성지침으로써의 활용될 수 있을 것이다.

• 멤브레인
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• 제26권5호
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• pp.365-371
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• 2016

메탄을 순도 95% 이상으로 분리, 회수하기 위하여 메탄에 대한 분리특성이 우수한 폴리설폰 중공사 분리막 모듈을 2단으로 연결하고 재순환 흐름을 이용하여 회수율을 90% 이상으로 유지할 수 있도록 공정을 설계하였다. 이렇게 설계된 2단 공정을 통한 메탄 분리 거동 특성을 이론적으로 예측하기 위하여 Compaq Visual Fortran 6.6 소프트웨어를 이용하여 수치 해석하였다. 개발한 프로그램을 사용하여 수치 해석을 수행한 결과 공정 변수에 따라 최종 메탄의 농도 변화에 미치는 영향을 고찰할 수 있었다. 공급 기체 압력과 분리막 길이와 공급측 메탄 농도 증가, 유량이 감소함에 따라 최종 생산물 내 메탄 농도 증가를 관찰할 수 있었으며, 메탄의 회수율은 감소함을 알 수 있었다.