• Journal of Bio-Environment Control
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• v.14 no.4
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• pp.254-262
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• 2005

This experiment was carried out to select the desirable welsh onion (Allium fistulosum L.) varieties for the year-round cultivation in water culture. Ten varieties were tested, of which five were Korean's and the other five were Japanese's. The germination percentage and germinative energy of most varieties we.e more than 90 percent. The fastest germination speed were 'Geumjanguedaepa', 'Gujopa' and 'Fuyune'. The best growth of the varieties were 'Geumjanguedaepa' and 'Tokyokuro' in spring, 'Geumjanguedaepa', 'Gujopa', 'Saesaeksisilpa' and 'Tokyokuro' in summer, 'Geumjanguedaepa', 'Gujopa' and 'Tokyokuro' in fall, and 'Geumjanguedaepa', 'Midorigawa' and 'Tokyokuro' in winter cultivation. Suitable varieties of growth fur all seasons were 'Geurnjanguedaepa' and 'Tokyokuro', though 'Gujopa' was good in summer and fall. In the view of nutritional content, nitrate content was significantly lower in 'Geumjanguedaepa', 'Tokyokuro' and 'Fuyune' than that in'Saesaeksisilpa' and 'Starziam'. Vitamin C content was higher in 'Aqua Green', 'Midorigawa' and 'Seoulbaekpa' than that of the others. Pyruvic acid content was the highest in 'Geumjanguedaepa' and 'Suckchanguedaepa'. Based on the above results, 'Geumjanguedaepa', 'Gujopa' and 'Tokyokuro' were selected as the most desirable young welsh onion varieties for the year-round water culture.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.750-756
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• 2010

This study was performed to investigate the role of phytohormones in the bulbing of garlic in order to assess the yield and quality. The effect on endogenous plant hormones such as gibberellin (GA) content was also examined during growth stage i.e. clove differentiation to bulbing in garlic. More than 18 gibberellins in garlic were identified with extensive gas chromatograph-mass spectrometry-selected ion monitoring (GC-MS-SIM) quantitative analysis. The results showed that GAs were biosynthesized by both non C-13 hydroxylation pathway (NCH) and early C-13 hydroxylation pathway (ECH) in garlic plant. It was also revealed that NCH pathway leading to synthesis of bioactive $GA_4$ was the more prominent GA biosynthesis pathway than ECH pathway in which bioactive $GA_1$ was synthesized. Total GAs level was gradually increased from clove differentiation to bulbing and later decreased, which portrays the active role of GA in differentiation. The biosynthesis ratio of bioactive $GA_4$ and $GA_1$ concentration was similar to that of total GAs content, which was closely related with bulb development in garlic.

• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.516-520
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• 2016

Concentrated liquid detergents have 2~3 times higher surfactant contents [35~45% (w/w)] compared to those of normal type detergents. In general, a single surfactant forms a lyotropic liquid crystal (LC) phase when the concentration is in the region of 30~60% (w/w). Whereas the concentrated liquid detergent at about 40% (w/w) concentration in a mixed surfactant system shows an opaque appearance of gel or LC. In order to meet consumer needs and preference for product appearance, we applied hydrotropes and various surfactants systems in concentrated liquid detergents to obtain an opaque gel-phase and also a clear transparent phase at even below zero $^{\circ}C$ temperature. The more effective hydrotropes for making concentrated liquid detergents are 1,6-hexanediol, adipic acid and dipropylene glycol (DPG) which have two hydrophilic groups in both terminated positions. In order to prepare an excellent concentrated liquid detergent, good hydrotropes alongside secondary type surfactants like LAS and SAS were used. The formation of LC phase of concentrated liquid detergents at about 40% (w/w) concentration could be prevented by the use of both hydrotropes and secondary type surfactants. The result indicate that concentrated detergents having excellent low temperature stability and controlled viscosity can be prepared.

• Journal of Radiation Protection and Research
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• v.38 no.1
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• pp.29-36
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• 2013

The aim of this study was to determine the correlation between exposure index (EI) and dose factors related to radiation dose optimization in digital radiography (DR) system. Two phantoms with built-in regional test object for quantitative assessment of images were used to produce image signals that acquired in chest radiography background. EI and entrane surface dose (ESD) increased proportionally with rise of radiation dose (kVp, mAs) in both DR and CR systems. Especially, DR detector was effective to form good contrast and hence, reached easily to improvement of image quality with minimal dose changes. It made operators possible to expect the accuracy of EI values deeply related to absorbed dose of the detector. The evaluation of images was obtained specially employed calculation of noise to signal ratio (NSR) and contrast to noise ratio (CNR). These measurements were performed for how exposure factors affect image quality. NSR was inversely proportional to kVp and mAs and low NSR represented high signal detection efficiency. Consequently, EI values was the measure of the amount of exposure received by the image receptor and it was proportional to exposure factors. Therefore the EI in a recommended range from manufacturer can offer optimal image quality. Also, continuous monitoring of EI values in the digital radiography can reduce the unnecessary patient dose and help the quality control of the system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.791-799
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• 2016

The purpose of this work is to analyse the impact of new accident risks on maritime safety in Korea. The new accident risks have been induced from new/rare or unprecedented events in world maritime transportation, as identified by 46 experts in the previous study. To measure the impact of these new accident risks on maritime safety in Korea, the statistical accident data reported by the Korean Maritime Safety Tribunals (KMST) has been used for calculation, and the concept of Risk Index (RI) = Frequency Index (FI) + Severity Index (SI)established in a Formal Safety Assessment (FSA) by the IMO has also been introduced. After calculating two kinds of weight for FI and SI from the statistical accident data, high ranked scenarios were identified and their relationships between new risks and these scenarios were analysed. The results from this analysis showed, the root cause of the top-ranked scenario to be "developing high technology", which leads to "shorten cargo handling time". These results differed from optimum RCOs such as "business competition" and "crewing problems" which were identified in the previous study.

• Journal of the Korean Society for Railway
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• v.17 no.2
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• pp.94-99
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• 2014

Recently, trends in new transportation system development have been primarily focused on sustainable and ecofriendly mobility solutions. The personal rapid transit (PRT) system has been considered a promising candidate in this category; its competitiveness is being improved through convergence with cutting-edge electric vehicle (EV) technologies. However, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. In this study, a design approach for a solar-power assisted PRT system is presented with small-scale demonstrations aimed at circumventing challenges facing its adoption, as well as helping speed the transition to electric-powered ground transportation. From the results, it is expected that flexible photovoltaic (PV) cells will be able to supply 11% of the power required by the service equipment installed in a prototype vehicle. In particular, flexible photovoltaic (PV) cells are advantageous in terms of cost, weight, and design considerations. Most importantly, the cells' flexibility and attach-ability are expected to give them great potential for extended application in various areas.

• Journal of the Korea Society for Simulation
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• v.15 no.4
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• pp.119-128
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• 2006

A turnout system which permits trains to pass from one track to another is a combination of the switch, the crossing, lead rails which are necessary to connect the switch and the crossing, two guard rails and a switch machine for operating the switch. A turnout is the sole moving part among the railway components and has complex configuration, so the safety has always been raised an issue. In Korea, it is planned to adopt the high speed tilting train, which operates at the maximum speed of 200km/h, at conventional lines by the year of 2010. However, for the application of the tilting train to conventional lines, it is prerequisite to establish a stable turnout system allowing the tilting train to pass through it without reducing speed. Therefore, the improved turnout system for the speed-up of conventional lines has been developed and the prototype of the turnout system has been constructed. In this study, simulation of noise and vibration around the improved turnout system was performed in order to predict the generation level of noise and vibration due to passing of the tilting train through the turnout system.

• Korean Journal of Medicinal Crop Science
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• v.5 no.4
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• pp.314-317
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• 1997

This study was carried out to determine the effect of various fertilizer levels on the growth and yield of Scutellaria baicalensis Georg cultivated after the barley in the southern coastal areas of Korea under the non-mulching condition by direct sowing culture. The flowering date of medium dressing plot $(N\;:\;P_2O_5\;:\;K_2O=9\;:\;13.5\;:\;9 kg/10a)$ and heavy dression plot $(N\;:\;P_2O_5\;:\;K_2O=12\;:\;18\;:\;12kg/l0a)$ were July 23. The flowering date of the medium and the heavy dressing plot was delayed by 3days compared with that of non-fertilizing plot. The growth characteristics such as stem length, diameter of main stem, number of branch per plant, main root length, main root thickness and dry weight of stem leaves were more increased at medium dressing plot than that of other fertilizer levels. The root dry weight of in Scutellaria baicalensis Georg cultivated after barley was highest at the fertilizing plot of N, $P_2O_5\;:\;K_2O$ = 9 : 13.5 : 9kg/10a. The dried-root yield was 178kg in medium dressing plot, 167kg in standard dressing pot, and 126kg in non-dressing plot. The dried-root yield of medium dressing plot was 7% and 41% higher than that of standard dressing pot and non-dressing control plot, respectively.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.14-22
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• 2006

the basic model of chemical reactor using glow discharge, we used cathode discharge cell with vacant cavity in the middle. Currently glow discharge is widely studied as a radiation source or atomization device in atomic spectroscopy and remarkable technological achievements are made through the graft with other analysis devices such as microanalysis and steel analysis.1 Additionally, as the characteristics of basic glow discharge and radiation have been reviewed many times, those results could be used in this experiment.2-3 In 1993, an article regarding the treatment of poisonous gas in the air using low temperature plasma was published. According to this article, if DC Glow Discharge is used under continuous atmospheric flow, poisonous gases such as SO2 and NO can be removed.4 Based on those findings, we designed highly efficient reactor where stable air plasma is composed and all air flow pass the negative glow area passing through the tube. It was observed that the cathode tube type glow discharge developed in this study would be economical, easy to use and could be used as radiation source as well.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.477-480
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• 2002

Si-O-C(-H) thin film with a tow dielectric constant were deposited on a P-type Si(100) substrate by an inductively coupled plasma chemical vapor deposition (ICPCVD). Bis-trimethylsilymethane (BTMSM, H$_{9}$C$_3$-Si-CH$_2$-Si-C$_3$H$_{9}$) and oxygen gas were used as Precursor. Hybrid type Si-O-C(-H) thin films with organic material have been generated many voids after annealing. Consequently, the Si-O-C(-H) films can be made a low dielectric material by the effect of void. The surface characterization of Si-O-C(-H) thin films were performed by SEM(scanning electron microscope). The characteristic analysis of Si-O-C(-H) thin films were performed by X-ray photoelectron spectroscopy (XPS).