• Journal of the Korean Chemical Society
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• v.40 no.7
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• pp.526-530
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• 1996

3-(N-Alkylamino)-4,5-dihydro-1,2,5-thiadiazole 1,1-dioxides have been prepared by the treatment of 3-imino-1,2,5-thiadiazolidine 1,1-dioxides with alkylamines. The selected spectral properties of these heterocycles are detailed, as well as an X-ray crystallographic structure of a representative member of these compounds. 3-(N-Benzylamino)-4,5-dihydro-4-(4'-methoxyphenyl)-1,2,5-thiadiazole 1,1-dioxide crystallyzes in space group $P2_1a$, monoclinic, with $a=22.512(3)(1)\AA$, $b=9.831(2)\AA$, $c=7.194(4)\AA$, $\beta=96.65(2)$, and Z=4.

• YAKHAK HOEJI
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• v.55 no.4
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• pp.338-344
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• 2011

This study aimed to identify the changes in the list of drugs covered by national health insurance(NHI) after the introduction of positive list system (PLS) in Korea in December, 2006. Six-year (pre-policy:2004-2006, post-policy:2007-2009) lists of the NHI reimbursable drugs filed from Health Insurance Review and Assessment Service (HIRA) were analyzed. The total number of listed drugs as well as drug ingredients, and the average number of listed drugs per manufacturer decreased annually after the introduction of PLS. More than 8,000 drugs were delisted in the year 2007 right after the policy change. Prescription-only drugs occupied more than 85% of NHI listed drugs. The percentage of oral type of listed drugs has been increased to more than 60% after the policy change. Korean pharmaceutical manufacturers occupied more than 90% of listed drugs than multinational firms. The gap between Korean and foreign manufacturer in terms of the average number of newly listed drugs per manufacturer in each year has decreased two years after the PLS (Korean 7.7 vs. foreign 6.3 in 2009) as the price negotiation power of foreign firms has increased. The total number of listed drugs is expected to decrease in the future as the Korean government makes an effort to delist the unnecessary drugs that do not show cost-effectiveness.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.4
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• pp.683-690
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• 2018

In this paper, a new signal processing technique is proposed for calibrating gain, phase, delay offsets in array antenna based anti-jamming minimum variance distortionless response (MVDR) global-positioning-system (GPS) receivers. The proposed technique estimates gain, phase and delay offsets across the antennas, and compensates for the offsets based on the estimates. A pilot signal with good correlation characteristics is used for accurate estimation of the gain, phase and delay offsets. Based on the cross-correlation, the delay offset is first estimated and then gain/phase offsets are estimated. For fine delay offset estimation and compensation, an interpolation technique is used, and specifically, the discrete Fourier transform (DFT) is employed for the interpolation technique to reduce the computational complexity. The proposed technique is verified through computer simulation using MATLAB. According to the simulation results, the proposed technique can reduce the gain, phaes and delay offset to 0.01 dB, 0.05 degree, and 0.5 ns, respectively.

• Explosives and Blasting
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• v.32 no.3
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• pp.1-9
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• 2014

Since the rock fragmentation from a bench blasting can affect the subsequent processes including loading, hauling and crushing, its control is essential for the assessment of blasting efficiency as well as production cost. In this study, the delay time could be precisely controlled by using electronic detonators. The rock fragmentations resulted from the blastings with different delay times of 1, 2, 3, 4, 5, 7 and 10ms per each meter of burden were measured from full scale field tests in a limestone mine. The results showed that the optimum delay time for minimum fragmentation was approximately 6ms/m. From the analysis of fragmentation size distribution, it was possible to find that delay time can be a parameter on rock fragmentation and thus it would be possible to control rock fragmentation by adjusting delay time.

• The Korean Journal of Pharmacology
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• v.22 no.2
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• pp.135-143
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• 1986

This study was designed to investigate the role of calcium in the function of an isolated perfused rabbit kidney and its effect on the diuretic action of furosemide. The administrations of hydralazine and verapamil produced remarkable diuretic actions mainly by decreasing renal resistance. The administration of furosemide in combination with hydralazine or verapamil produced remarkable diuretic action and there was no difference between the two groups. The administration of quinidine produced a diuretic action in spite of vasoconstriction and potentiated the diuretic action of furosemide. In the calcium-free perfusion medium, the administration of calcium produced a marked diuretic action in spite of vasoconstriction and potentiated significantly the diuretic action of furosemide. The administration of quinidine did not alter renal function and the diuretic action of furosemide, but the combined administration of quinidine and calcium showed antidiuretic effect due to excessive vasoconstriction in the calcium-free perfusion medium. Although the administration of verapamil produced a slight diuretic action in the calcium-free perfusion medium, verapamil did not alter the diuretic action of calcium as well as the diuretic actions of furosemide alone and in combination with calcium. The results of this experiment show that calcium, verapamil and quinidine produced diuretic actions and calcium potentiates the diuretic action of furosemide.

• Explosives and Blasting
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• v.40 no.1
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• pp.29-38
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• 2022

Electronic detonators are now widely used in various construction sites and quarry mines. Including the sites where safety-thing is located nearby, Cases of using electronic detonators are increasing to maximize operational efficiency by improving blast fragmentation or reducing the cost of secondary blasting. This case study is about applying for electronic detonators on zone 00 construction site, which is the part of urban area metropolitan express rail A line project. Although the project was initially planned to utilize non-electric detonators, Electronic detonators are considered as the solution not only for safe and fast excavation, but also to minimize civil complaint and the damage of safety-thing. By applying electronic detonators, we were able to satisfy environmental regulations standards and prevent nearby safety-thing from getting damaged.

• Journal of Ocean Engineering and Technology
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• v.35 no.6
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• pp.446-456
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• 2021

To build an environment facility of a large-scale ocean basin, various detailed reviews are required, but it is difficult to find data that introduces the related research or construction processes on the environment facility. The current generator facility for offshore structure safety evaluation tests should be implemented by rotating the water of the basin. However, when the water in the large basin rotates, relatively large flow irregularities may occur and the uniformity may not be adequate. In this paper, design and review were conducted to satisfy the performance goals of the DOEB through computational numerical analysis on the shape of the waterway and the flow straightening devices to form the current in the large tank. Based on this, the head loss, which decreases the flow rate when the large tank water rotates through the water channel, was estimated and used as the pump capacity (impeller) design data. The impeller of the DOEB current generator was designed through computational numerical analysis (CFD) based on the lift surface theory from the axial-type impeller shape for satisfying the head loss of the waterway and maximum current velocity. In order to confirm the performance of the designed impeller system, the flow rate and flow velocity performance were checked through factory test operation. And, after installing DOEB, the current flow rate and velocity performance were reviewed compare with the original design target values. Finally, by measuring the current velocity of the test area in DOEB formed through the current generator, the spatial current distribution characteristics in the test area were analyzed. Through the analysis of the current distribution characteristics of the DOEB test area, it was confirmed that the realization of the maximum current velocity and the average flow velocity distribution, the main performance goals in the waterway design process, were satisfied.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.9
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• pp.391-398
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• 2022

As non face-to-face classes carry on discussion about learner's attention continues. To improve learning effect learner's attention is important whether non face-to-face classes or face-to-face classes. In this study a mobile application prototype inducing learner attention is developed taking account of learner emotion that is one of the factors affecting learner attention. When learner selects one of the four emotions displayed in the application, it shows the activity inducing the learner's attention related to the selected emotion. In order to evaluate the usability of the developed application, 32 middle and high school students are asked to run the application and then conduct a survey using 5 point Likert scale. The survey result indicates that there is a possibility that the developed application in this study induces learner attention as showing that the result point of 'I can pay attention' and 'I feel psychological stable' is respectively 3.56 and the result point of 'I feel useless thought disappear' is 3.6.

• International Journal of Stem Cells
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• v.16 no.3
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• pp.269-280
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• 2023

Background and Objectives: The colonic epithelial layer is a complex structure consisting of multiple cell types that regulate various aspects of colonic physiology, yet the mechanisms underlying epithelial cell differentiation during development remain unclear. Organoids have emerged as a promising model for investigating organogenesis, but achieving organ-like cell configurations within colonic organoids is challenging. Here, we investigated the biological significance of peripheral neurons in the formation of colonic organoids. Methods and Results: Colonic organoids were co-cultured with human embryonic stem cell (hESC)-derived peripheral neurons, resulting in the morphological maturation of columnar epithelial cells, as well as the presence of enterochromaffin cells. Substance P released from immature peripheral neurons played a critical role in the development of colonic epithelial cells. These findings highlight the vital role of inter-organ interactions in organoid development and provide insights into colonic epithelial cell differentiation mechanisms. Conclusions: Our results suggest that the peripheral nervous system may have a significant role in the development of colonic epithelial cells, which could have important implications for future studies of organogenesis and disease modeling.

• Explosives and Blasting
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• v.28 no.2
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• pp.99-107
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• 2010

Domestic explosive demolition techniques have been developed and applied for low-rise structures up to now. However, the demand for the development of those techniques that can be applied economically, safely and environment-friendly rapidly increases because the old high-rise RC rahmen structures that were built since around 1970s are now required to rebuild. As a result, element technologies of explosive demolition for low-rise structures were applied to take advantage of technology in high-rise structures that performed application testing at Chungang Department demolition field in Daejeon city. It could judge elements technology establishment for high-rise structure demolition and field application and suggest the improvements when the problems occurred to develop High-rise building demolition techniques for method of protection a field test and the dust reduction test. The water cannon test was applied to reduce the dust site and the drilling tests are performed to select the best components for explosives demolition elements techniques of the reliability. This paper shows that we have the ability to remove a high-rise building using environmentally friendly safe and economical explosives demolition method. It would contribute to prevent a foreign company from entering the domestic market and should contribute to acquire competitiveness of domestic demolition industry.