• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.106-106
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• 2003

Choline serves critical roles in the CNS both as a precursor of neurotransmitter and as an essential component of membrane phospholipids. The long-term maintenance of brain choline concentration is dependent on choline transport across the blood-brain barrier (BBB), And, we examined to elucidate the characteristics of transport of choline across the BBB using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) in vitro. The ［$^3$H］choline in TR - BBB was increased by time dependently, but independent on Na$\^$＋/, and the transport process is saturable with Michaelis-Menten constrant, Km of about 26 ${\mu}$M. The uptake of ［$^3$H］choline is susceptible for inhibition by various organic cationic compounds including hemicholinium-3, tetraethylammonium chloride (TEA) and $\ell$-carnitine. Also, we investigated the relationship of transport of choline and cationic drugs. The uptake of ［$^3$H］choline is inhibited by antioxidant, a-phenyl-n-tert-butyl nitrone (PBN) with IC$\sub$50/ of 1.2 mM. and by Alzheimer's disease therapeutics, such as acetyl $\ell$-carnitine, tacrine and donepezil. Also, choline uptake presented competitive inhibition with PBN, donepezil and acetyl $\ell$-carnitine in Lineweaver-Burk plot. In conclusion, TR-BBB cells express a saturable transport system for uptake of choline, and several cationic drugs may be transported into the brain by BBB choline transporter.

• Fire Science and Engineering
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• v.30 no.6
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• pp.84-91
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• 2016

In case of fire, vertically and intensively loaded rack warehouses are faced with a severe status due to the rapid increase in fires. In this regard, there have been trials to prevent fires from spreading by applying fire extinguishing systems, such as ESFR and In-Rack Sprinklers, vertical and horizontal barriers, etc.; however, it is difficult to calculate and design proper fire extinguishing systems caused by various composition conditions, such as the size and loading density of the rack, types of loading commodities, etc. Therefore, in this study, a standard rack was manufactured, incorporating a rack warehouse in Korea by site investigations, surveys, etc. In addition, a full scale fire test was executed to check the fire characteristics depending on the conditions of the ignition points. As a result, the extracted fire spread speed is expected to be utilized as a reference for performance comparisons of the fire extinguishing systems to be developed and applied in the future.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.59-65
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• 2020

Lately the VR (Virtual Reality) game genre is becoming increasingly more popular and it has been cementing its place in the market as its own independent game genre. The key advantage of VR is that it lowers the barrier between player and the virtual world, thus creating an immersive experience. The suggested method develops a game that allows the player to experience what it is like to be visually impaired using the unique characteristics of VR. A distinctive feature of this game is that the character is provided only a limited range of sight, which is created using silhouette outlines. This restrictive visual field is then grafted onto VR and the player can indirectly experience blindness in a highly immersive manner. The silhouette outline along with the particle system is created using Oculus Rift, a headset highly used in VR game development, and Unity 3D game engine. We will also explain in detail regarding the removal of borders between the objects.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.4835-4855
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• 2015

TV white space (TVWS) is showing promise to become the first widespread practical application of cognitive technology. In fact, regulators worldwide are beginning to allow access to the TV band for secondary users, on the provision that they access the geolocation database. Device-to-device (D2D) can improve the spectrum efficiency, but large-scale D2D communications that underlie TVWS may generate undesirable interference to TV receivers and cause severe mutual interference. In this paper, we use an established geolocation database to investigate the power allocation problem, in order to maximize the total sum throughput of D2D links in TVWS while guaranteeing the quality-of-service (QoS) requirement for both D2D links and TV receivers. Firstly, we formulate an optimization problem based on the system model, which is nonconvex and intractable. Secondly, we use an effective approach to convert the original problem into a series of convex problems and we solve these problems using interior point methods that have polynomial computational complexity. Additionally, we propose an iterative algorithm based on the barrier method to locate the optimal solution. Simulation results show that the proposed algorithm has strong performance with high approximation accuracy for both small and large dimensional problems, and it is superior to both the active set algorithm and genetic algorithm.

• Journal of the Korean housing association
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• v.19 no.2
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• pp.19-30
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• 2008

The purpose of the study is to provide basic data to be useful for living environment of National Rental Housing, through comparative analysis of residential conditions, community consciousness of residents, characteristics of 3 complexes, whose residents have lived more than 3 years, different in area and size. Deungchon 11 Complex in Seoul, Eui-wang Naeson Complex, and Incheon Samsan 4 Complex are chosen for the investigation and the survey and 242 copies of the questionnaire are analyzed for the final result. Analyzing the contents of the survey results are as follows those deriving conclusions and suggestions. 1) Housing and construction standards are required to reconsider for enhancing of community consciousness and housing satisfaction of residents of National Rental Housing. 2) Spending on residential move, and minimize the unnecessary expense of low-income housing need to do to promote stability. 3) Facilities and equipments for residents are needed considering barrier-free design which introduces universal design. 4) Welfare facilities such as culture space and after-school classroom for teenagers are needed. 5) By using the broadcast media actively pro-mote, various layers are encouraged moving into National Rental Housing, through the concept of housing opportunities for change. 6) In short-term, community space are need remodeling and various activity programs are developed to induce activation of community facilities. In long-term, users considering a community facility plan, actively promoting activities, methods and operating system support for the government in the continuing policy and management is needed, when the National Rental Housing are planned to build. Therefore, the organic aspects such as the development and operation of the community program as well as the physical aspects such as the community space and facilities for the active community of the National Rental Housing are constantly considered in the follow-up studies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.1
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• pp.44-47
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• 2012

The $TiO_2/Si_3N_4/Ag/Si_3N_4/TiO_2$ multi layered structure was designed for the possible application of transparent electrodes in PDP (Plasma Display Panel). Multi layered film was deposited on a glass substrate at room temperature by DC/RF magnetron sputtering system and EMP (Essential Macleod Program) was adopted to optimize the optical characteristics of film. During the deposition process, the Ag layer in $TiO_2/Ag/TiO_2$ became heavily oxidized and the filter characteristic was degraded easily. In thus study, Si3N4 layer was used as a diffusion buffer layer between $TiO_2$ and Ag. in order to prevent the oxidation of Ag layer in $TiO_2/Si_3N_4/Ag/Si_3N_4/TiO_2$ structure. It was confirmed that $Si_3N_4$ layer is one of candidate materials acting as diffusin barrier between $TiO_2/Ag/TiO_2$.

• Ocean and Polar Research
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• v.36 no.2
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• pp.87-101
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• 2014

Recently, more attention has been paid to the geomorphological changes in the Nakdong River Estuary, because those changes are caused by artificial activities including weirs, reclamation and construction. In order to analyze quantitatively the recent geomorphological variability in the Nakdong River Estuary, we surveyed the depth and elevation of submarine topography near Jinwoodo and Sinjado from March 2007 to February 2012. A statistical method (based on Digital Shoreline Analysis System) and an Empirical Orthogonal Functions method were used to evaluate the morphological changes. According to the statistical variables (DCE, NDC, EPR, LRR), the highest amount and rate of accumulation were recorded around the Gadeokdo whereas the greatest amount of erosion appeared around the coast off the eastern part of Sinjado. In particular, a dynamic variation of morphology was clearly observed in the vicinity of the sub-tidal channel located between Jinwoodo and Sinjado, which seems to be attributable to channel migration. As a result of the EOF method, the first mode (48.7%) is most closely related to the pattern of morphological variability that might be associated with the westerly movement of sediment by longshore current. The spatial variability of the second mode (16.6%) was high in the shoreface of Sinjado, showing a 4-year periodicity of temporal variability. The strong correlation (coefficient 0.73) between the time coefficient and suspended sediment discharge from Nakdong River emphasizes the role of sediment discharge to deposition in this area. The spatial variability of the third mode (11.3%) was distributed mainly around the coast off the eastern part of Sinjado, which is related to the movement of the coastline of Sinjado. Based on the last 5 year's data, our results suggest that the study area is characterized on the whole by a depositional pattern, but the extent of sedimentation is different locally.

• Clinical and Experimental Pediatrics
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• v.56 no.9
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• pp.369-376
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• 2013

A complex interplay between genetic and environmental factors partially contributes to the development of allergic diseases by affecting development during prenatal and early life. To explain the dramatic increase in the prevalence of allergic diseases, the hygiene hypothesis proposed that early exposure to infection prevented allergic diseases. The hygiene hypothesis has changed to the microbial hypothesis, in which exposure to microbes is closely linked to the development of the early immune system and allergic diseases. The intestinal flora may contribute to allergic disease through its substantial effect on mucosal immunity. Based on findings that exposure to microbial flora early in life can change the Th1/Th2 balance, thus favoring a Th1 cell response, probiotics may be beneficial in preventing allergic diseases. However, evidence from clinical and basic research to prove the efficacy of probiotics in preventing allergy is lacking. To date, studies have yielded inconsistent findings on the usefulness of probiotics in allergic diseases. It is difficult to demonstrate an exact effect of probiotics on asthma, allergic rhinitis, and food allergy because of study limitations, such as different first supplementation period, duration, different strains, short follow-up period, and host factors. However, many studies have demonstrated a significant clinical improvement in atopic dermatitis with the use of probiotics. An accurate understanding of the development of human immunity, intestinal barrier function, intestinal microbiota, and systemic immunity is required to comprehend the effects of probiotics on allergic diseases.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.13
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• pp.1013-1032
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• 2000

At present, the scale of Electronic Commerce through internet has been rapidly increasing due to the development of information & communication technology, and aggregated to 2.4 billion dollar in America last year (1998). The market scale of worldwide electronic commerce is also presumed to be about 130 billion dollar in 2000, and to occupy more than 20% of the whole world trade in world 2020. Since the right of trademark, despite of being effective only in registered nations on the principle of territorialism, is unified on the cyber space of internet without domestic barrier or local limitation which make it easier to conduct the distribution of information rapidly through the address-internet domain name, those are very important that the systematic dispute-solving plan on problems such as decision of its Act and international jurisdiction to be established, in an effort to prevent the newly emerging dispute instances such as trademark infringement and improper competitiveness. In addition, it is natural that on the threshold of the electronic commerce age which formed with an unified area without the worldwide specific regulation, each country including us makes haste with the enactment of "electronic commerce Act" aiming at coming into force in 1999, in keeping with getting through "non-tariff law on electronic commerce" by U. S. parliament on May, 1998. In view of the properties of electronic commerce transactions through internet, there are the large curtailment of distributive channel, surmounting of restrictions on transaction area, space and time and the easy feedback with consumer and the cheap-required capital, from which the problems may arise - registration of trademark, the trademark infringement of domain name and the protection of prestigious trademark. Therefore, it is necessary to take the counter-measure, with a view of reviewing the infringement of trademark and domain name and the instances of each national precedent and to preventing the disputes. The improvement of the persistent system should be needed to propel the harmonious protection of those holding trademark right's credit and demanders' expectant profit by way of the righteous use of trademark.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.160-160
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• 2010

Organic electronic devices require a passivation layer to ensure sufficient lifetime. Specifically, flexible organic electronic devices need a barrier layer that transmits less than $10^{-6}\;g/m^2/day$ of water and $10^{-5}\;g/m^2/day$ of oxygen. To increase the lifetime of organic electronic device, therefore, it is indispensable to protect the organic materials from water and oxygen. Severe groups have reported on multi-layerd barriers consisting inorganic thin films deposited by plasma enhenced chemical deposition (PECVD) or sputtering. However, it is difficult to control the formation of granular-type morphology and microscopic pinholes in PECVD and sputtering. On the contrary, atomic layer deoposition (ALD) is free of pinhole, highly uniform, conformal films and show good step coverage. In this study, the passivation layer was deposited using single-process PEALD. The passivation layer, in our case, was a bilayer system consisting of $Al_2O_3$ films and a $TiO_2$ buffer layer on a poly (ether sulfon) (PES) substrate. Because the deposition temperature and plasma power have a significant effect on the properties of the passivation layer, the characteristics of the $Al_2O_3$ films were investigated in terms of density under different deposition temperatures and plasma powers. The effect of the $TiO_2$ buffer layer also was also addressed. In addition, the water vapor transmission rate (WVTR) and organic light-emitting diode (OLEDs) lifetime were measured after forming a bilayer composed of $Al_2O_3/TiO_2$ on a PES substrate.