• Korean Journal of Materials Research
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• v.30 no.3
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• pp.117-122
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• 2020

The effects of fast neutron irradiation on the electrical and optical properties of Li (3 at%) doped ZnSnO (ZTO) thin films fabricated using a sol-gel process are investigated. From the results of Li-ZTO TFT characteristics according to change of neutron irradiation time, the saturation mobility is found to increase and threshold voltage values shift to a negative direction from 1,000 s neutron irradiation time. X-ray photoelectron spectroscopy analysis of the O 1s core level shows that the relative area of oxygen vacancies is almost unchanged with different irradiation times. From the results of band alignment, it is confirmed that, due to the increase of electron carrier concentration, the Fermi level (E_F) of the sample irradiated for 1,000 s is located at the position closest to the conduction band minimum. The increase in electron concentration is considered by looking at the shallow band edge state under the conduction band edge formed by fast neutron irradiation of more than 1,000 s.

• Journal of the Korean Ceramic Society
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• v.55 no.1
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• pp.80-84
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• 2018

In this study, to improve the dispersity of $Fe_3O_4$ nanoparticles, dispersion properties were considered with various types of functionalization of $Fe_3O_4$ nanoparticles. Due to its high surface area, the electrically neutral state of its surfaces, and its magnetic momentum, $Fe_3O_4$ nanoparticles are easily aggregated in solution. In order to prevent aggregation, $Fe_3O_4$ nanoparticles were functionalized with carboxyl and amine groups in the form of a polymer compound. Carboxyl and amine groups were attached to the surface of $Fe_3O_4$ nanoparticles and the absolute value of the zeta potential was found to be enhanced by nearly 40 eV. Furthermore, the morphology and the magnetic property were analyzed for the application of $Fe_3O_4$ nanoparticles as a magnetic fluid.

• The Korea Journal of Herbology
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• v.25 no.2
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• pp.71-79
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• 2010

Objectives : In this study, the neuroprotective effects of modified Boyanghwano-Tang (mBHT) and the major medicinal plants, Astragali Radix(AR) and Salviae Miltiorrhizae Radix(SMR) were investigated in transient middle cerebral artery occlusion (tMCAO)-induced ischemic stroke of rats. Methods : mBHT(400 mg/kg) and AR(154 mg/kg) or SMR(62 mg/kg) water extract orally injected in rats after 90 min occlusion of MCA and then allow reperfusion to 24 h. Brain infarction was measured by TTC staining and the expressions of NOS isoforms and apoptotic molecules were determined in ischemic brain by Western blot. Results : The results showed that mBHT has stronger neuropreotective property through inhibitions of the PARP cleaved and caspase-3 activation in ischemic rats, and could reduced infarction volumes comparison of those of AR or SMR, respectively. While, AR extract has an angiogenic property through increasing the expressions of eNOS and VEGF, and SMR extract has a strong anti-inflammatory effects through inhibition of iNOS expression in ischemic brains. Conclusions : These results suggest that mBHT has multifactorial therapeutic advantages through anti-apoptosis, anti-inflammation and angiogenesis for ischemic stroke based on a synergistic combination of ingradients rather than monotherapy.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.72-79
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• 2018

Hybrid F2HX surfactants bearing a sulfate moiety and both hydrocarbon and fluorocarbon chains were prepared by the reaction of alkyl glycidyl ethers with fluoro-alcohol, and subsequent sulfation. The fluorocarbon number in F2HX was fixed at the shortest number possible (i.e., 2), while the hydrocarbon number (X) in the second chain was varied between 2, 4, 6, and 8. Their surface-active properties and emulsion stabilities were systematically estimated as a function of the X. Among them, F2H8 exhibited the optimal surfactant performance, which was comparable to previously reported surfactants and it was successfully applied in the emulsion polymerization of vinylidene fluoride.

• Genomics & Informatics
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• v.19 no.1
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• pp.7.1-7.13
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• 2021

Levodopa (L-DOPA) therapy is normally practised to treat motor pattern associated with Parkinson disease (PD). Additionally, several inhibitory drugs such as Entacapone and Opicapone are also cosupplemented to protect peripheral inactivation of exogenous L-DOPA (~80%) that occurs due to metabolic activity of the enzyme catechol-O-methyltransferase (COMT). Although, both Entacapone and Opicapone have U.S. Food and Drug Administration approval but regular use of these drugs is associated with high risk of side effects. Thus, authors have focused on in silico discovery of phytochemicals and evaluation of their effectiveness against human soluble COMT using virtual screening, molecular docking, drug-like property prediction, generation of pharmacophoric property, and molecular dynamics simulation. Overall, study proposed, nine phytochemicals (withaphysalin D, withaphysalin N, withaferin A, withacnistin, withaphysalin C, withaphysalin O, withanolide B, withasomnine, and withaphysalin F) of plant Withania somnifera have strong binding efficiency against human COMT in comparison to both of the drugs i.e., Opicapone and Entacapone, thus may be used as putative bioenhancer in L-DOPA therapy. The present study needs further experimental validation to be used as an adjuvant in PD treatment.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.3
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• pp.147-156
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• 2022

In this paper, we propose Time-Division-Multiplexing Tertiary Offset Carrier (TDMTOC), a novel GNSS modulation based on Tertiary Offset Carrier (TOC) modulation. The TDMTOC modulation multiplexes two three-level signals (i.e., -1, 0, and 1) while crossing over time, and is a type of TOC modulation designed specifically for signal multiplexing. The proposed modulation generates TDMTOC subcarriers of two different phases by simply combining two Binary Offset Carrier (BOC) subcarriers by addition or subtraction. TDMTOC has better correlation and spectral properties than conventional BPSK, BOC, and MBOC modulation techniques, and has good power and spectral efficiency since it can multiplex signals without power loss similar to time division multiplexing. To prove this, we introduce the multiplexing process of TDMTOC, and compare TDMTOC with Binary Phase Shift Keying (BPSK), BOC, Composite BOC (CBOC), and Time Multiplexed BOC (TMBOC) that are currently serviced in GNSS by simulations of various aspects. Through the simulation results, we prove that TDMTOC has better correlation property than modulations currently used in GNSS, less intersystem interference due to its wide spectrum property, and robustness in multipath and noise channel environments.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.563-570
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• 2019

Red tide has caused massive fish kills in Korean coastal waters with devastating economic loss in the aquaculture industry since 1995. Remote sensing technique has shown to be effective for the detection of red tide in wide areas, where the absorption property of red tide water plays a central role in understanding the red tide reflectance. This study analyzed the optical absorption property of sea waters dominated by the dinoflagellate specie of Alexandirum affine, off the Tongyeong area in August, 2017. Water samples collected from 20 stations in the ship-based campaign were measured for absorption by pigment, suspended solid, and dissolved organic matter, with the corresponding water quality variables such as chlorophyll concentration and total suspended solid. The analysis showed that Alexandrium-dominated water exhibits strong absorption in the spectral range below 400 nm unlike that of diatom-dominated waters, and greater fluctuations in the range of 400 nm - 500 nm. The packaging effect in pigment absorption was stronger in Alexandrium-dominated waters, and the exponent in the absorption by detritus and gelbstoff is disparate for diatom and Alexandrium. In the model for the detritus and gelbstoff absorption (a_dg(λ)=a_dg(λ₀)e^-s(λ-λ₀)), the optimal exponent coefficient(s) for the Alexandrium was close to 0.01 rather than to 0.015, which was commonly use for modelling diatom waters.

• MALSORI
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• no.27_28
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• pp.27-56
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• 1994

Processes involving the change of vowel height are natural enough to be found in many languages. It is essential to have a better feature specification for vowel height to grasp these processes properly, Standard Phonology adopts the binary feature system, and vowel height is represented by the two features, i.e., [\pm high] and [\pm low]. This has its own merits. But it is defective because it is misleading when we count the number of features used in a rule to compare the naturalness of rules. This feature system also cannot represent more than three degrees of height, We wi31 discard the binary features for vowel height. We consider to adopt the multivalued feature [n high] for the property of height. However, this feature cannot avoid the arbitrariness resulting from the number values denoting vowel height. It is not easy to expect whether the number in question is the largest or not It also is impossible to decide whether a larger number denotes a higher vowel or a lower vowel. Furthermore this feature specification requires an ad hoc condition such as n > 3 or n \geq 2, whenever we want to refer to a natural class including more than one degree of height The altelnative might be Particle Phonology, or Dependency Phonology. These might be apt for multivalued vowel height systems, as their supporters argue. However, the feature specification of Particle Phonology will be discarded because it does not observe strictly the assumption that the number of the particle a is decisive in representing the height. One a in a representation can denote variant degrees of height such as [e], [I], [a], [a ] and [e ]. This also means that we cannot represent natural classes in terms of the number of the particle a, Dependency Phonology also has problems in specifying a degree of vowel height by the dependency relations between the elements. There is no unique element to represent vowel height since every property has to be defined in terms of the dependency relations between two or more elements, As a result it is difficult to formulate a rule for vowel height change, especially when the phenomenon involves a chain of vowel shifts. Therefore, we suggest a new feature specification for vowel height (see Chapter 3). This specification resorts to a single feature H and a few >'s which refer exclusively to the degree of the tongue height when a vowel is pronounced. It can cope with more than three degrees of height because it is fundamentally a multivalued scalar feature. This feature also obviates the ad hoc condition for a natural class while the [n high] type of multivalued feature suffers from it. Also this feature specification conforms to our expection that the notation should become simpler as the generality of the class increases, in that the fewer angled brackets are used, the more vowels are included, Incidentally, it has also to be noted that, by adopting a single feature for vowel height, it is possible to formulate a simpler version of rules involving the changes of vowel height especially when they involve vowel shifts found in many languages.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.179-183
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• 2016

Background: As an important detecting device, TLD is a widely used in the radiation monitoring. It is essential for us to study the property of detecting element. The aim of this study is to calculate the thermo-luminescence efficiency of TL elements. Materials and Methods: A batch of thermo-luminescence elements were irradiated by the filtered X-ray beams of average energies in the range 40-200 kVp, 662 keV $^{137}Cs$ gamma rays and then the amounts of lights were measured by the TL reader. The deposition energies in elements were calculated by theory formula and Monte Carlo simulation. The unit absorbed dose in elements by photons with different energies corresponding to the amounts of lights was calculated, which is called the thermo luminescent efficiency (${\eta}^{(E)}$). Because of the amounts of lights can be calculated by the absorbed dose in elements multiply ${\eta}^{(E)}$, the ${\eta}^{(E)}$ can be calculated by the experimental data (the amounts of lights) divided by absorbed dose. Results and Discussion: The deviation of simulation results compared with theoretical calculation results were less than 5%, so the absorbed dose in elements was calculated by simulation results in here. The change range of ${\eta}^{(E)}$ value, relative to 662 keV $^{137}Cs$ gamma rays, is about 30% in the energy range of 33 keV to 662 keV, is in accordance by the comparison with relevant foreign literatures. Conclusion: The ${\eta}^{(E)}$ values can be used for updating the amounts of lights that are got by the direct ratio assumed relations with deposition energy in TL elements, which can largely reduce the error of calculation results of the amounts of lights. These data can be used for the design of individual dosimeter which used TLD-2000 thermo-luminescence elements, also have a certain reference value for manufacturer to improve the energy-response performance of TL elements by formulation adjustment.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.1-10
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• 2002

Metadata is data about data that is used to mange data itself. As applications based on DBMS are increased, it is suggested that metadata model and metadata interchange model to manage metadata in DBMS. but metadata which is in the form of XML (eXtensible Markup Language) document is generally stored into RDBMS. Therefore In this paper, as for the method to store metadata of RDBMS into OODBMS, we design metadata model, metadata interchange model and implement new repository system. The metadata of RDBMS is translated into in the form of XML Document and integrated into XML Data Server on OODBMS, eXcelon and executes retrieval metadata information about RDBMS by XQL(XML Query Language). So It is possible to searchm edit a metadata. The metadata of XML documents stored in eXcelon is easily made to be printed in web browser by applying a XSL (extensible StyleSheets Language). So we can have a detail information about property of metadata in DBMS.