• International Journal of Aerospace System Engineering
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• v.6 no.2
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• pp.11-16
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• 2019

A system analysis program has been developed for a gas generator cycle liquid rocket engine of 30 ton class. Numerical models have been proposed for a combustor, a turbopump, a gas generator and pressure drop through a regenerative cooling system. Numerical algorithm has been validated by comparing with the published data of MC-1. The major source of error is not the numerical algorithm but the imperfect performance models of subsystems. So the precision of the program can be improved by revising the performance models using experimental data. The sea level specific impulse and vacuum specific impulse have been demonstrated for a 30 ton class gas generator engine. The optimal condition of combustor pressure and mixture ratio for specific impulse which is a typical characteristic of a gas generator cycle engine has been illustrated.

• Journal of IKEEE
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• v.17 no.2
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• pp.129-134
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• 2013

For the conventional power metal-oxide semiconductor field-effect transistor (MOSFET) device structure, there exists a tradeoff relationship between specific on-resistance ($R_{ON.SP}$) and breakdown voltage ($V_{BR}$). In order to overcome the tradeoff relationship, a uniform super-junction (SJ) trench metal-oxide semiconductor field-effect transistor (TMOSFET) structure is studied and designed. The structure modeling considering doping concentrations is performed, and the distributions at breakdown voltages and the electric fields in a SJ TMOSFET are analyzed. The simulations are successfully optimized by the using of the SILVACO TCAD 2D device simulator, Atlas. In this paper, the specific on-resistance of the SJ TMOSFET is successfully obtained 0.96 $m{\Omega}{\cdot}cm^2$, which is of lesser value than the required one of 1.2 $m{\Omega}{\cdot}cm^2$ at the class of 100 V and 100 A for BLDC motor.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.19-22
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• 2003

Class area is a portion of memory where the constants, fields, and codes of the classes loaded into the Java virtual machine are kept. Knowing the site of the class area is very important especially for embedded Java system with limited memory resources. This paper induces a formula which makes it possible estimate the size of the area. The formula needs some constant values specific to target JVM implementation. We also show that these values can be found using some simple probe classes. An experimental result is included in this paper to confirm the correctness of our approach.

• Radiation Oncology Journal
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• v.23 no.2
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• pp.116-122
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• 2005

Purpose: Histone deacetylase inhibitors (HDIs) are emerging as potentially useful components of anticancer therapy and their radiosensitizing effects have become evident. Specific HDAS are now available that preferentially inhibit specific HDAC classes; TSA inhibits Class I and II HDACs, and SK7041 inhibits Class I HDACs. Materials and methods: We tested the differential radiosensitization induced by two different classes of HDIs in HeLa cells. We next tested the hypothesis that p53 expression in cancer cells may influence the susceptibility to HDIs by using pharmacologic modification of the p53 status under an isogenic background. Results: It is interesting that p53 expression in the HeLa cells clearly increased the degree of radio-sensitization by TSA compared to that of the class I specific inhibitor SK7041. This suggests that p53 may, in part, be responsible for the mechanistic role for the greater radiosensitization induced by Class I & II inhibitors compared to that of the class I specific inhibitors. Thus, these studies are useful in distinguishing between events mediated solely by the Class I HDACS versus those events involving the other classes of HDACS as well. Conclusion: The anticancer efficacy of targeting Class I and II HDACS, in conjunction with radiation therapy, may be further enhanced by the restoration of p53 expression.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.2
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• pp.75-92
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• 2013

The vascular plants of Thuja orientalis community in Seokmun-bong, Danyang were listed 222 taxa (4.5% of all 4,881 taxa of vascular plants); 67 families, 150 genera, 163 species, 2 subspecies, 43 varieties and 14 forms. Limestone plants, 29 taxa; Asplenium rutamuraria, Celtis koraiensis, Goodyera coreana, etc. So, Based on the legal protection species, endangered wild plants II, were recorded; Thalictrum coreanum (EN) and rare plants, 8 taxa; Thuja orientalis (LC), Exochorda serratifolia var. serratifolia (LC), Diarthron linifolium (EN), Bupleurum falcatum (VU), Lithospermum erythrorhizon (LC), Dracocephalum argunense (EN), Polygonatum robustum (EN), etc. and endemic plants, 3 taxa; Populus tomentiglandulosa (Planted plant), Thalictrum actaefolium var. brevistylum, Asperula lasiantha, etc. Based on the list of specific plants, 29 taxa; Thalictrum coreanum in class V, 7 taxa (Neillia uyekii for. uyekii, Prunus sibirica, Abelia coreana, etc.) in class IV, 8 taxa (Spiraea trichocarpa, Polygala tatarinowi, Asparagus oligoclonos, etc.) in class III, 2 taxa (Potentilla dickinsii var. dickinsii, Weigela florida) in class II, 11 taxa (Morus cathayana, Buxus microphylla var. koreana, Zizyphus jujuba var. jujuba, etc.) in class I. Based on the list of naturalized plants, 10 taxa (Robinia pseudoacacia, Oenothera biennis, Festuca arundinacea, etc.), naturalization rate (NR) was 4.5% of all 222 taxa of vascular plants and urbanization index (UI) was 3.1% of all 321 taxa of naturalized plants.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.3
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• pp.59-75
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• 2006

The vascular plants of this site was listed 360 taxa; 86 families, 229 genera, 311 species, 42 varieties and 7 forms. Specific plant species by floral region were total 40 taxa; 2 taxa(Crypsinus hastatus, Prunus yedoensis) in class V, Patrinia rupestris in class IV, 6 taxa(Elymus mollis, Carex laticeps, Poncirus trifoliata, Melia azedarach var. japonica, Koelreuteria paniculata, Crepiastrum lanceolatum) in class III, Cirsium schantarense in class II, 30 taxa(Lygodium japonicum, Pteris multifida, Phacelurus latifolius, Asparagus cochinchinensis, Ficus erecta, Machilus thunbergii, Zanthoxylum planispinum, Euphorbia esula, Mallotus japonicus, Cayratia japonica, Camellia japonica, Glehnia littoralis, Lysimachia fortunei, Messerschmidia sibirica, Ixeris repens etc.) in class I. The naturalized plants in this site were 14 families, 34 genera, 41 species, 1 varieties, 42 taxa and naturalization rate was 20.3% of all 207 taxa vascular plants. Based on the list of the rare plants by the Forest Research Institute, 2 taxa were recorded in the studied areas; Phacelurus latifolius, Crypsinus hastatus and based on the list of Korean endemic plants, 7 taxa were recorded; Populus tomentiglandulosa, Filipendula glaberrima, Prunus yedoensis, Forsythia koreana, Paulownia coreana, Weigela subsessilis, Carpinus coreana. So, wild plants disturbing ecosystem like Solanum carolinense and Ambrosia artemisiifolia var. elatior have been increasing, it needs continuing control and conservation measures on the plant ecosystem.

• The Journal of the Acoustical Society of Korea
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• v.27 no.6
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• pp.303-308
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• 2008

The purpose of the present study is to investigate that word frequency has significant influence on noun definitions in Korean. The experimental group was 80 students from Elementary school, Middle school, High school and University. They rated familiarity and wrote definitions for nouns. Noun definitions were analyzed with semantic categories such as "use/purpose," "description," "association/relation," "partial explanation," "explanation," "error," "partial explanation-attribute," "partial explanation-specific class," "partial explanation-nonspecific class," "explanation-specific class," "explanation-nonspecific class." As a result, they showed familiarity for high-frequency nouns. "EXPL" categories that use class terms or critical attributes were used more frequently in definitions of high-frequency nouns compared with low-frequency nouns. They increased with age and errors decreased with age. Word frequency had a significant influence on noun definitions.

• IMMUNE NETWORK
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• v.16 no.4
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• pp.233-241
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• 2016

DCs, like the sensory neurons, express vanilloid receptor 1 (VR1). Here we demonstrate that the VR1 agonists, capsaicin (CP) and resiniferatoxin (RTX), enhance antiviral CTL responses by increasing MHC class I-restricted viral antigen presentation in dendritic cells (DCs). Bone marrow-derived DCs (BM-DCs) were infected with a recombinant vaccinia virus (VV) expressing OVA (VV-OVA), and then treated with CP or RTX. Both CP and RTX increased MHC class I-restricted presentation of virus-encoded endogenous OVA in BM-DCs. Oral administration of CP or RTX significantly increased MHC class I-restricted OVA presentation by splenic and lymph node DCs in VV-OVA-infected mice, as assessed by directly measuring OVA peptide SIINFEKL-K^b complexes on the cell surface and by performing functional assays using OVA-specific CD8 T cells. Accordingly, oral administration of CP or RTX elicited potent OVA-specific CTL activity in VV-OVA-infected mice. The results from this study demonstrate that VR1 agonists enhance anti-viral CTL responses, as well as a neuro-immune connection in anti-viral immune responses.

• Korean Journal of Food Science and Technology
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• v.6 no.1
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• pp.12-16
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• 1974

The amino acid pattern of embryo and endosperm of brown rice different in specific gravity was investigated using Jinheung (local leading temperate variety) and IR667-Suweon 213 (high-yielding newly bred tropical variety). 1. Embryo of IR667 (higher protein rice) showed lower protein, and lower lysine or essential amino acid per protein than that of Jinheung (lower protein rice). 2. In both embryo and endosperm nitrogen recovery as amino acids was highest in middle class of specific gravity and lowest in low class indicating that abundancy of non-protein nitrogen in low class and decomposition of amino acids by starch in high specific gravity class. 3. In both embryo and endosperm IR667 showed abundancy in order of glutamic acid, aspartic acid while Jinheung showed glutamic acid, arginine, suggesting varietal difference in nitrogen metabolism. 4. In both IR667 and Jinheung least amino acid was histidine and next leucine in embryo but histidine and next threonine in endosperm, suggesting organ difference in nitrogen metabolism.

• Journal of Radiation Protection and Research
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• v.44 no.1
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• pp.32-42
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• 2019

Background: There have been much efforts to develop the proper and realistic machine Quality Assurance (QA) reflecting on real Volumetric Modulated Arc Therapy (VMAT) plan. In this work we propose and test a special VMAT plan of plan-class specific (pcsr) QA, as a machine QA so that it might be a good solution to supplement weak point of present machine QA to make it more realistic for VMAT treatment. Materials and Methods: We divided human body into 5 treatment sites: brain, head and neck, chest, abdomen, and pelvis. One plan for each treatment site was selected from real VMAT cases and contours were mapped into the computational human phantom where the same plan as real VMAT plan was created and called plan-class specific reference (pcsr) QA plan. We delivered this pcsr QA plan on a daily basis over the full research period and tracked how much MLC movement and dosimetric error occurred in regular delivery. Several real patients under treatments were also tracked to test the usefulness of pcsr QA through comparisons between them. We used dynalog file viewer (DFV) and Dynalog file to analyze position and speed of individual MLC leaf. The gamma pass rate from portal dosimetry for different gamma criteria was analyzed to evaluate analyze dosimetric accuracy. Results and Discussion: The maxRMS of MLC position error for all plans were all within the tolerance limit of < 0.35 cm and the positional variation of maxPEs for both pcsr and real plans were observed very stable over the research session. Daily variations of maxRMS of MLC speed error and gamma pass rate for real VMAT plans were observed very comparable to those in their pcsr plans in good acceptable fluctuation. Conclusion: We believe that the newly proposed pcsr QA would be useful and helpful to predict the mid-term quality of real VMAT treatment delivery.