• The KIPS Transactions:PartB
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• v.11B no.5
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• pp.563-572
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• 2004

Sentence ion is a simplification of a sentence preserving its communicative function. It accomplishes sentence revision and concept ion simultaneously. Sentence revision is a method that resolves the discrepancy between human's thoughts and its expressed semantic in sentences. Concept ion is an expression of general ideas acquired from the common elements of concepts. Sentence ion selects the main constituents of given sentences and describes the upper concepts of them with detecting their semantic information. This enables sen fence revision and concept ion simultaneously. In this paper, a syntactic parser LGPI+ and an ontology OfN are utilized for sentence ion. Sentence abstracter SABOT makes use of LGPI+ and OfN. SABOT processes the result of parsing and selects the candidate words for sentence ion. This paper computes the sentence recall of the main sentences and the topic hit ratio of the selected sentences with the text understanding system using sentence ion. The sources are 58 paragraphs in 23 stories. As a result of it, the sentence recall is about .54 ～ 72% and the topic hit ratio is about 76 ～ 86%. This paper verified that sentence ion enables sentence revision that can select the topic sentences of a given text efficiently and concept ion that can improve the depth of text understanding.

• 연구논문집
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• s.30
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• pp.137-145
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• 2000

Since the concept of osseointegration was introduced, titanium and titanium-based alloy materials have been increasingly used for bone-anchored metal in oralmaxillofacial and orthopedic reconstruction. Successful osseointegration has been attributed to biocompatibility and surface condition of metal implant among other factors. Although titanium and titanium alloys have an excellent over the metal ion release and biocompatibility, considerable controversy has developed over the metal ion and wear debris in vivo and vitro. In this study, nitrogen ion implantation technique was used to improve the corrosion resistance and wear property of titanium materials, ultimately to enhance the tissue reaction to titanium implants As ion implantation energy was increased, projected range of nitrogen ion the Ti substrate was gradually increased. Under condition of constant ion energy. atomic concentration of nitrogen was also increased with ion doses. The friction in Hank's solution was increased with ion doses. The friction coefficient of ion implanted specimens in HanK's solution was increased from 0.39, 0.47 to 0.52, 0.65 respectively under high energy and ion dose conditions. As increasing ion energies and ion dose, amount of wear was reduced.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.842-848
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• 2008

In this study, we propose a novel micro-ion engine system. Single plasma source is used for both ion beam source and neutralizing electron source. By changing the electrical connection, either operation can be switched. This micro-ion engine system gives translation motion and attitude control to microspacecraft. The major objective of this study is verification of our concept. Small plasma source of 20 mm diameter was developed. Plasma was sustained by microwave power. Using this plasma source, ion beam extraction and electron emission was successively demonstrated.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.4
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• pp.51-58
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• 1985

A simple model for the impurity profile in an ion-implanted channel layer of an enhance-ment type IGFET is assumed and a simple expression for the threshold voltage is derived by the assumed impurity profile. In application, the concept of correction factor K is used and the value of threshold voltage is well agreed with experimental value. Also, 1-V character-istics curve is well agreed with experimental value. In addition, this program is packaged and is utilized.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.327-332
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• 2002

We made a human-sensitive motion interpretation to the interactive emotional robot, "Rai" of which the mechanism design was carried out and completed. Kinematic system of this emotional robot mainly consists of a body and a head. The body contains the total control units , the communicat ion modules and also two wheels and motors for main driving which make kinds of motions 1 ike the inverted pendulum. This robot system is designed under the concept on the human-friendly mot ion and react ion wi th humans around living room and office environments. Therefore, various scenarios are constructed in order to enable the emotional expressions at those places. Especially, we interpreted technically-possible motions while accommodating to the scenarios constructed. And we performed some experiments to make sere of the possibility of the motion interpretation.

• Progress in Medical Physics
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• v.31 no.1
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• pp.1-7
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• 2020

Hadron therapy, such as carbon and helium ions, is increasingly coming to the fore for the treatment of cancers. Such hadron therapy has several advantages over conventional radiotherapy using photons and electrons physically and clinically. These advantages are due to the different physical and biological characteristics of heavy ions including high linear energy transfer and Bragg peak, which lead to the reduced exit dose, lower normal tissue complication probability and the increased relative biological effectiveness (RBE). Despite the promising prospects on the carbon ion radiation therapy, it is in dispute with which bio-mathematical models to calculate the carbon ion RBE. The two most widely used models are local effect model and microdosimetric kinetic model, which are actively utilized in Europe and Japan respectively. Such selection on the RBE model is a crucial issue in that the dose prescription for planning differs according to the models. In this study, we aim to (i) introduce the concept of RBE, (ii) clarify the determinants of RBE, and (iii) compare the existing RBE models for carbon ion therapy.

• Corrosion Science and Technology
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• v.7 no.4
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• pp.212-218
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• 2008

Inorganic ion exchange compounds (IECs) including hydrotalcites and bentonite clays are a well known classes of layered mixed metal hydroxides or silicates that demonstrate ion exchange properties. These compounds have a range of applications from water purification to catalyst supports. The use of synthetic versions of these compounds as environmentally friendly additives to paints for storage and release of inhibitors is a new and emerging application. In this paper, the general concept of storage and release of inhibiting ions from IEC-based particulate pigments added to organic coatings is presented. The unique aspects of the IEC structure and the ion exchange phenomenon that form the basis of the storage and release characteristic are illustrated in two examples comprising an anion exchanging hydrotalcite compound and a cation exchanging bentonite compound. Examples of the levels of corrosion protection imparted by use of these types of pigments in organic coatings applied to aluminum alloy substrates is shown. How corrosion inhibition translates to corrosion protection during accelerated exposure testing by organic coatings containing these compounds is also presented.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.169-169
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• 2017

Due to key roles for the electrochemical stability and charge capacity the solid-electrolyte interphase (SEI) has been extensively studied in anodes of a Li-ion battery cell. There is, however, few of investigation for cathodes. Using first-principles based calculations we describe atomic-level process of the SEI layer formation at the interface of a carbonate electrolyte and $LiMn_2O_4$ spinel cathode. Furthermore, using beyond the conventional density functional theory (DFT+U) calculations we examine the work function of the cathode and frontier orbitals of the electrolyte. Based on the results we propose that proton transfer at the interface is an essential mechanism initiating the SEI layer formation in the $LiMn_2O_4$. Our results can guide a design concept for stable and high capacity Li-ion battery cell through screening an optimum electrolyte fine-tuned energy band alignment for a given cathode.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.293-302
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• 2002

The classical concept for iron uptake into mammalian cells has been the endocytosis of transferrin( $T_{f}$ )-bound F $e^{3+}$ via the $T_{f}$ - $T_{f}$ receptor cycle. In this case, we could not explain the uptake of F $e^{2＋}$ ion and the export of iron from endosome. Studies on iron transport revealed that other transport system exists in epithelial cells of the intestine. One of non- $T_{f}$ -receptor-mediated transport systems is Nramp2/DMT1/DCT1 which transports M $n^{＋＋}$, $Mg^{＋＋}$, Z $n^{＋＋}$, $Co^{＋＋}$, N $i^{＋＋}$ or C $u^{＋＋}$ ion as well as F $e^{+2}$ ion. DMT1 was cloned from intestines of iron-deficient rats and shown to be a hydrogen ion-coupled iron transporter and a protein regulated by absorbed dietary iron. DMT1 is founded in other cells such as cortical and hippocampal glial cells as well as endothelial cells in duodenum. Two F $e^{3+}$ ion bound to transferrin( $T_{f}$ ) are taken up via the $T_{f}$ - $T_{f}$ receptor cycle in the intestinal epithelial cell. F $e^{3+}$ in endosome was converted to F $e^{2＋}$ ion, and then exported to cytosol via DMT1. F $e^{2＋}$ ion is taken up into cytosol via DMT1. Several other transporters such as FET, FRE, CCC2, AFT1, SMF, FTR, ZER, ZIP, ZnT and CTR have been reported recently and dysfunction of the transporters are related with diseases containing Wilson's disease, Menkes disease and hemochromatosis. Evidences from several studies strongly suggest that DMT1 is the major transporter of iron in the intestine and functions critically in transport of other metal ions.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.269-269
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• 2012

A new ion source has been designed, fabricated, and installed at the NBTS (Neutral Beam Test Stand) at the KAERI (Korea Atomic Energy Research Institute) site. The goalis to provide a 100 keV, 2MW deuterium neutral beam injection as an auxiliary heating of KSTAR (Korea Super Tokamak Advanced Research). To cope with power demand, an ion current of 50 A is required considering the beam power loss and neutralization efficiency. The new ion source consists of a magnetic cusp bucket plasma generator and a set of tetrode accelerators with circular copper apertures. The plasma generator for the new ion source has the same design concept as the modified JAEA multi-cusp plasma generator for the KSTAR prototype ion source. The dimensions of the plasma generator are a cross section of $59{\times}25cm^2$ with a 32.5 cm depth. The anode has azimuthal arrays of Nd-Fe permanent magnets (3.4 kG at surface) in the bucket and an electron dump, which makes 9 cusp lines including the electron dump. The discharge properties were investigated preliminarily to enhance the efficiency of the beam extraction. The discharge of the new ion source was mainly controlled by a constant power mode of operation. The discharge of the plasma generator was initiated by the support of primary electrons emitted from the cathode, consisting of 12 tungsten filaments with a hair-pin type (diameter = 2.0 mm). The arc discharge of the new ion source was achieved easily up to an arc power of 80 kW (80 V/1000 A) with hydrogen gas. The 80 kW capacity seems sufficient for the arc power supply to attain the goal of arc efficiency (beam extracted current/discharge input power = 0.8 A/kW). The accelerator of the new ion source consists of four grids: plasma grid (G1), gradient grid (G2), suppressor grid (G3), and ground grid (G4). Each grid has 280 EA circular apertures. The performance tests of the new ion source accelerator were also finished including accelerator conditioning. A hydrogen ion beam was successfully extracted up to 100 keV /60 A. The optimum perveance is defined where the beam divergence is at a minimum was also investigated experimentally. The optimum hydrogen beam perveance is over $2.3{\mu}P$ at 60 keV, and the beam divergence angle is below $1.0^{\circ}$. Thus, the new ion source is expected to be capable of extracting more than a 5 MW deuterium ion beam power at 100 keV. This ion source can deliver ~2 MW of neutral beam power to KSTAR tokamak plasma for the 2012 campaign.