• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.193-194
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• 1998

Recently, evaluation of brain transport of taurine which is possible to effect on Alzheimer's disease has investigated in rats. Also, internal carotid artery perfusion (ICAP) method is very useful for measuring of blood-brain barrier (BBB) permeability in rats. But ICAP has difficulties to evaluate of BBB permeability in mice especially. In the present study examines neuropharmaceutials permeability through the BBB in mice by common carotid artery perfusion (CCAP) method that modify ICAP method and require simple surgery. The external carotid artery (ECA) is cannulated with coagulating pterygopalatine artery (PPA) on ICAP method, while CCA is cannulated without coagulating PPA on CCAP method. The CCAP method require 4-5 fold higher infusion rate than ICAP method because an additional factor of 2 must be incorporated to adjust for fluid loss to the extracerebral circulation.

• 한국지진공학회논문집
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• 제4권4호
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• pp.63-71
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• 2000

대부분의 경우 지반을 통해 전달되는 진동을 줄이기 위해 사용되는 방진벽의 차진효율은 지반 위 한 점에서의 진폭저감계수로 표현되고 있다. 그러나 한 점에서의 진동차단 효율은 일정 지역의 평균값과 많은 차이를 보이고 있어, 일정 단지의 진동환경 개선에 요구되는 경우, 한 점에서의 값만으로 차진효율을 표현하는 것은 적합하지 않다. 이를 위해 본 논문에서는 단지 내 진동환경 개선의 판단방법을 제시하고, 방진벽의 기하학적 규모가 방진벽의 진동차단 효율에 미치는 영향을 경계요소법을 이용하여 구하였다. 해석결과에 의하면 강성 방진벽의 경우, 단면적인 방진벽의 차진성능에 큰 영향을 미치는 것으로 나타났다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.537-542
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• 2000

When visual intrusion Is an Important factor, it is desirable to find alternative methods of Improving the insertion loss of a noise barrier without Increasing the height. Therefore, the primary object of the work attenuate the noise due to railway by small interference device installed at noise barrier edge. In this paper the performance of noise barriers with attached interference device, in terms of shape, absorptive material and split panel, we examined using the boundary element approach. Also, the scale models are mounted in an anechoic chamber and the frequency of the sound sources are appropriately scaled to simulate full scale site conditions. Lastly, experimental measurements of the designs are executed for a range of frequencies and receiver positions, and are compared with the results of numerical modeling.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.426.2-426.2
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• 2016

Numerous of researches are being conducted to improve the efficiency of $Cu_2ZnSnSe_4$ (CZTSe)-based photovoltaic devices, which is one of the most promising candidates for low cost and environment-friendly solar cells. In this work, we concentrate on the back contact of the devices. A proper thickness of $MoSe_2$ in back contact structure is believed to enhance adhesion and ohmic contact between Mo back contact and absorber layer. Nevertheless, too thick $MoSe_2$ layers that are grown during high-temperature selenization process can impede the current collection, thus resulting in low cell performance. By applying molybdenum nitride as a barrier in back contact structure, we were able to control the thickness of $MoSe_2$ layer, which resulted in lower series resistance and higher fill factor of CZTSe devices. The phase transformation of Mo-N binary system was systematically studied by changing $N_2$ concentration during the sputtering process. With a proper phase of Mo-N fabricated by using an adequate partial pressure of $N_2$, the efficiency of CZTSe solar cells as high as 8.31% was achieved while the average efficiency was improved by about 2% with respect to that of the referent cells where no barrier layer was employed.

• Journal of Korean Neurosurgical Society
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• 제50권4호
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• pp.288-292
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• 2011

Objective : Matrix metalloproteinases (MMPs), especially MMP-2 and MMP-9 have been known to play an important role in secondary inflammatory reaction after spinal cord injury (SCI). The aim of this study was to investigate the expression and activity of MMP-2 and MMP-9 and to determine their relationship with disruption of endothelial blood-barrier after photochemically induced SCI in rats. Methods : Female Sprague-Dawley rats, weighing between 250 and 300 g (aged 8 weeks) received focal spinal cord ischemia by photothrombosis using Rose Bengal. Expressions and activities of MMP-2 and MMP-9 were assessed by Western blot and gelatin zymography at various times from 6 h to 7 days. Endothelial blood-barrier integrity was assessed indirectly using spinal cord water content. Results : Zymography and Western blot analysis demonstrated rapid up-regulation of MMP-9 protein levels in spinal cord after ischemic onset. Expressions and activities of MMP-9 showed a significant increased at 6 h after the photothrombotic ischemic event, and reached a maximum level at 24 h after the insult. By contrast, activated MMP-2 was not detected at any time point in either the experimental or the control groups. When compared with the control group, a significant increase in spinal cord water content was detected in rats at 24 h after photothrombotic SCI. Conclusion : Early up-regulation of MMP-9 might be correlated with increased water content in the spinal cord at 24 h after SCI in rats. Results of this study suggest that MMP-9 is the key factor involved in disruption of the endothelial blood-barrier of the spinal cord and subsequent secondary damage after photothrombotic SCI in rats.

• 한국소음진동공학회논문집
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• 제14권2호
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• pp.164-171
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• 2004

Active control techniques have been used in wide areas of noise and nitration control engineering and a noise barrier is one of them. Omoto's work in 1993 would be one of the fundamental and systematic studies on the actively controlled noise barrier, in which he used equal number of control sources and error sensors. The error sensors were placed uniformly along the top edge of the noise barrier with equal distance apart and the control sources were placed in the exactly same way some distance apart from the error sensors. Since then, a couple of studies were made on the secondary sources'arrangement rather than the optimality of secondary source positions. Shao's results showed that arc shaped arrangement for secondary sources is better than the straight line one, and later work of Yang showed that the more important factor is the average distance between the primary source and secondary sources. However, since these studies were all executed with a simple uniform distribution of the secondary sources along the straight line or arc, it is difficult to conclude which arrangement is superior In order for the fare comparison. the optimality of the source positions in each arrangement must be given in prior. The primary goal of this study is focused on this aspect and some major factors were investigated and compared. The computer simulation results showed that the arc shaped arrangement is marginally better than the straight line one, and more importantly slightly tuned position can greatly improve the performance of the control system.

• IMMUNE NETWORK
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• 제7권2호
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• pp.87-94
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• 2007

Background: Chronic rhino-sinusitis and persistent allergic rhinitis is often cited as risk factor for developing adenoid hypertrophy or adenoiditis, but this relationship has not been studied extensively. In this study, we evaluated the mucosal barrier, squamous changes of ciliated epithelium, IgA secretion and BCL-6 expression in adenoids, and adenoid size. Methods: Six children with allergic rhinitis and sinusitis, nine children with only allergic rhinitis, nine children with only sinusitis and six children without any history of allergic rhinitis and sinusitis were enrolled. H-E stain of adenoid for squamous metaplasia, immunohistochemical study of adenoid for IgA and BCL-6, cytokeratin stain for evaluation of mucosal barrier and lateral view X-ray for adenoid size were performed. ANOVA test was used in the analysis and data showing p value of less than 0.05 were considered significant. Results: The number of ciliated cells had tendency to be decreased and squamous metaplasia had tendency to be increased in three experimental groups (p>0.05). Deterioration of mucosal barrier had tendency to be detected in three experimental groups than control group (p>0.05). BCL-6 had tendency to be increased and IgA secretion had tendency to be decreased in three experimental groups (p>0.05). There is no difference in adenoid size between three experimental groups and control group. Conclusion: Despite the expectation that adenoid would be affectecd by allergic rhinitis and rhino-sinusitis, we found no evidence for influence of adenoid immunity.

• 벤처창업연구
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• 제10권5호
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• pp.185-196
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• 2015

기존 산학협력의 연구에서, 산학협력의 연계(LINK)는 경로의존성에 의해 향후 지속적인 상호협력을 통해 다양한 채널의 폭을 가진다. 다양한 상호채널의 폭을 통해 산학협력의 연계(LINK)는 더욱 더 강력해지나, 반면 거래관련 장벽이 늘어나게 된다. 즉, 대학과 기업 간 링크(university-industry linkages) 관계를 다루는 문헌은 많이 검토되어져 왔지만, 상대적으로 이들 간에 존재하는 장벽과 그 장벽을 줄일 수 있는 요인에 대한 연구는 그리 많이 다뤄지고 있지 않다. 산학협력 정책의 중요성을 감안할 때, 산학협력의 장애물에 대한 연구의 부족은 효과적인 정책을 설계하는데 심각한 장애요인이 될 것이다. 본 논문은 산학협력의 상호채널의 폭과 산학협력의 장벽에 대해 기존의 문헌을 조사하고, 대학행정의 POB(Positive Organization Behavior)을 통해 산학협력의 장벽을 낮출 수 있는지를 분석해보고 이를 통해 정책점시사점을 제시해보고자 한다.

• 한국재료학회지
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• 제28권5호
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• pp.268-272
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• 2018

An $Al_2O_3/AlN$ bilayer deposited on GaN by atomic layer deposition (ALD) is employed to prepare $Al_2O_3/AlN/GaN$ metal-insulator-semiconductor (MIS) diodes, and their interfacial properties are investigated using X-ray photoelectron spectroscopy (XPS) with sputter etch treatment and current-voltage (I-V) measurements. XPS analyses reveal that the native oxides on the GaN surface are reduced significantly during the early ALD stage, indicating that AlN deposition effectively clelans up the GaN surface. In addition, the suppression of Al-OH bonds is observed through the ALD process. This result may be related to the improved device performance because Al-OH bonds act as interface defects. Finally, temperature dependent I-V analyses show that the barrier height increases and the ideality factor decreases with an increase in temperature, which is associated with the barrier inhomogeneity. A Modified Richardson plot produces the Richardson constant of $A^{**}$ as $30.45Acm^{-2}K^{-2}$, which is similar to the theoretical value of $26.4Acm^{-2}K^{-2}$ for n-GaN. This indicates that the barrier inhomogeneity appropriately explains the forward current transport across the $Au/Al_2O_3/AlN/GaN$ interface.

• 한국항만경제학회지
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• 제28권1호
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• pp.203-227
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• 2012

본 연구는 부산항 신항을 이용하는 고객을 대상으로 항만 서비스품질 차원(항만 내적 서비스 품질, 항만 외적 서비스품질, 항만 상호작용품질), 신뢰, 만족 및 충성도 간에 미치는 영향을 조사하기 위해 기존 연구에 근거하여 모델을 제안하였다. 특히 만족과 충성도 간의 관계에 전환장벽의 조절효과를 제안하였다. 분석에는 317부를 이용하였고, 측정모델의 타당성을 검증하기 위해 확인요인분석을 실시하였고, 가설을 검증하기 위해 AMOS 통계분석 방법을 이용하였다. 본 연구의 결과, 항만 서비스품질 차원은 항만 고객신뢰와 항만 고객만족에 정의 영향을, 항만 고객만족은 항만 고객신뢰에 정의 영향을, 항만 고객만족과 항만 고객신뢰는 항만 고객충성도에 정의 영향을 미쳤다. 그리고 항만 고객만족과 항만 고객충성도 간의 관계에서 전환장벽은 조절효과를 가졌다. 마지막으로 이러한 조사결과를 바탕으로 시사점과 미래연구방향을 제시하였다.