• Research in Plant Disease
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• v.27 no.1
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• pp.32-37
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• 2021

In May 2020, necrosis and necrotic ring patterns were observed on leaves of three of 140 Iris domestica plants in a demonstration garden in Wanju, Jeollabuk-do. Three symptomatic plants were found to be infected by tomato spotted wilt virus (TSWV). To analyze the whole genomic sequence of one TSWV isolate, 'Blackberry lily-kr1', L, M, and S genome segments were sequenced and analyzed by comparison of nucleotide sequences of the three segments with corresponding sequences of other TSWV isolates. 'Blackberry lily-kr1' isolate was most closely related to 'JJ' isolate (MF159046) or 'HJ' isolate (LC273305) in the L segment, and to 'JJ' isolate (MF159058 and KY021439) in the M and S segments, respectively. Phylogenetic analysis by Maximum likelihood method using MEGA X program with 'Blackberry lily-kr1' isolate showed high relationship with 'JJ' pepper isolate or 'HJ' Humulus japonicas isolate in the all three segment. Necrosis and double ring patterns on leaves were formed in the glasshouse after inoculation of healthy I. domestica plants with sap of 'Blackberry lily-kr1'-infected Nicotiana rustica plants. This result suggests that I. domestica plants showing necrotic ring patterns in the open field are caused by TSWV infection. This is the first report of TSWV infection of I. domestica in Korea.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.44-44
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• 2003

As a basic measurement tool in the areas of animal models of human disease, gene expression and therapy, and drug discovery and development, small animal PET imaging is being used increasingly. An ideal small animal PET should have high sensitivity and high and uniform resolution across the field of view to achieve high image quality. However, the combination of long narrow pixellated crystal array and small ring diameter of small animal PET leads to the degradation of spatial resolution for the source located at off center. This degradation of resolution can be improved by determining the depth of interaction (DOI) in the crystal and by taking into account the information in sorting the coincident events. Among a number of 001 identification schemes, dual layer phsowich detector has been widely investigated by many research groups due to its practicability and effectiveness on extracting DOI information. However, the effects of each crystal length composing dual layer phoswich detector on DOI measurements and image qualities were not fully characterized. In order to minimize the DOI effect, the length of each layer of phoswich detector should be optimized. The aim of this study was to perform simulations using a simulation tool, GATE to design the optimum lengths of crystals composing a dual layer phoswich detector. The simulated small PET system employed LSO front layer LuYAP back layer phoswich detector modules and the module consisted of 8${\times}$8 arrays of dual layer crystals with 2 mm ${\times}$ 2 mm sensitive area coupled to a Hamamatsu R7600 00 M64 PSPMT. Sensitivities and variation of radial resolutions were simulated by varying the length of LSO front layer from 0 to 10 mm while the total length (LSO + LuYAP) was fixed to 20 mm for 10 cm diameter ring scanner. The radial resolution uniformity was markedly improved by using DOI information. There existed the optimal lengths of crystal layers to minimize the variation of radial resolutions. In 10 cm ring scanner configuration, the radial resolution was kept below 3.4 mm over 8 cm FOV while the sensitivity was higher than 7.4% for LSO 5 mm : LuYAP 15 mm phoswich detector. In this study, the optimal length of dual layer phoswich detector was derived to achieve high and uniform radial resolution.

• Communications of Mathematical Education
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• v.25 no.2
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• pp.473-495
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• 2011

Across the secondary school, students deal with the algebraic conditions like as identity, inverse, commutative law, associative law and distributive law. The algebraic structures, group, ring and field, are determined by these algebraic conditions. But the conditioning of these algebraic structures are not mentioned at all, as well as the meaning of the algebraic structures. Thus, students is likely to be considered the algebraic conditions as productions from the number sets. In this study, we systematize didactically the meanings of algebraic conditions and algebraic structures, considering connections between the number systems and the solutions of the equation. Didactically systematizing is to construct the model for student's natural mental activity, that is, to construct the stream of experience through which students are considered mathematical concepts as productions from necessities and high probability. For this purpose, we develop the program for the gifted, which its objective is to teach the meanings of the number system and to grasp the algebraic structure conceptually that is guaranteed to solve equations. And we verify the effectiveness of this developed program using didactical experiment. Moreover, the program can be used in ordinary students by replacement the term 'algebraic structure' with the term such as identity, inverse, commutative law, associative law and distributive law, to teach their meaning.

• Bulletin of the Korean Chemical Society
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• v.22 no.9
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• pp.1023-1029
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• 2001

The positions of Kr atoms encapsulated in the molecular-dimensioned cavities of fully dehydrated zeolite A of unit-cell composition Cs3Na8HSi12Al12O48 (Cs3-A) have been determined. Cs3-A was exposed to 1025 atm of krypton gas at 400 $^{\circ}C$ for four days, followed by cooling at pressure to encapsulate Kr atoms. The resulting crystal structure of Cs3-A(6Kr) (a = $12.247(2)\AA$, R1 = 0.078, and R2 = 0.085) has been determined by single-crystal X-ray diffraction techniques in the cubic space group Pm3m at $21(1)^{\circ}C$ and 1 atm. In the crystal structure of Cs3-A(6Kr), six Kr atoms per unit cell are distributed over three crystallographically distinct positions: each unit cell contains one Kr atom at Kr(1) on a threefold axis in the sodalite unit, three at Kr(2) opposite four-rings in the large cavity, and two at Kr(3) on threefold axes in the large cavity. Relatively strong interactions of Kr atoms at Kr(1) and Kr(3) with Na+ ions of six-rings are observed: Na-Kr(1) = 3.6(1) $\AA$ and Na-Kr(3) = $3.08(5)\AA.$ In each sodalite unit, one Kr atom at Kr(1) was displaced $0.74\AA$ from the center of the sodalite unit toward a Na+ ion, where it can be polarized by the electrostatic field of the zeolite, avoiding the center of the sodalite unit which by symmetry has no electrostatic field. In each large cavity, five Kr atoms were found, forming a trigonal-bipyramid arrangement with three Kr(2) atoms at equatorial positions and two Kr(3) atoms at axial positions. With various reasonable distances and angles, the existence of Kr5 cluster was proposed (Kr(2)-Kr(3) = $4.78(6)\AA$ and Kr(2)-Kr(2) = $5.94(7)\AA$, Kr(2)-Kr(3)-Kr(2) = 76.9(3), Kr(3)-Kr(2)-Kr(3) = 88(1), and Kr(2)-Kr(2)-Kr(2) = $60^{\circ}).$ These arrangements of the encapsulated Kr atoms in the large cavity are stabilized by alternating dipoles induced on Kr(2) by four-ring oxygens and Kr(3) by six-ring Na+ ions, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.472-482
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• 2019

This paper describes the stabilization of underwater TAS winch system Deploy/Recover operation performance. TAS winch installed on the stern of submarine performs to deploy/recover sensor, towing cable and rope tail which is deployed from the stern and separated from submarine itself. Also TAS winch provides transmission path of power to the sensor and data transmitting/receiving path which data are acquired from underwater environment like sound, depth and temperature. At the step of TAS winch evaluation test, sporadic standstill and rotating speed oscillation phenomenon were occurred. Winch motor provides the available torque to deploy/recover TAS and root cause analysis to the winch motor was done to find exact reason to sporadic malfunction. When winch motor was disassembled, eccentricity of rotor, slip-ring and the other composition part for winch motor were found. These might cause magnetic field distortion. To make TAS winch system more stable and block magnetic field distortion, this paper suggests methods to enhance fixing status installed in winch motor. For reliable data acquisition for TAS winch operation, the deploy/recover function of the improved type of TAS winch was verified in LBTS making similar condition with sea status. At the end of stage, improved type of TAS winch was tested on some functions not only deploy/recover function, but sustainability of TAS operation on specific velocity, steering angle of submarine in the sea trial. Improved type of TAS winch was verified in accordance with design requirement. Also, validity of suggested methods were verified by the sea trial.

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.59-66
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• 2007

Three dimensional quantitative structure-activity relationships (3D-QSARs) on the fungicidal activity of N-phenyl-O-phenylthionocarbamate analogues against resistant and sensitive gray mold (Botrytis cinerea) (RBC & SBC) were studied quantitatively using CoMFA and CoMSIA methods. The correlation coefficient and predict- ability of optimized CoMFA model with the atom based fit alignment were better ($r^2$ & $q^2=CoMFA{\gg}CoMSIA$) than that of CoMSIA model. And statistical values of the models on the fungicidal activity against SBC were showed higher ($r^2=SBC{\gg}RBC$) than that of RBC. In CoMFA models, steric field on the activity was more influenced than electrostatic field. And in case of CoMSIA models, the influence of CoMSIA field on the activity against RBC and SBC was differ from each other but the influence of H-bond donor field was same to the two fungi. It is revealed that the selectivity factor with CoMFA model on the fungicidal activity between the two fungi was caused on the difference of steric field. Therefore, it is predicted that the large steric field with meta- and para-substituents on the N-phenyl ring will be improved to the fungicidal activity with SBC.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.113-119
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• 1997

Purpose : Radical gastrectomy is main treatment of gastric cancer. But the result is not satisfactory with surgery alone. Most of pattern of failure remain locoregional recurrence. To improve 5 year survival postoperative chemotherapy with or without radiotherapy has been used. We analyzed patients with stage III and IV stomach cancer who had radical operation and received postoperative radiation therapy combined with or without chemotherapy retrospectively. Material and Method : From March 1985 to June 1993, 68 patients treated with curative resection and received postoperative adiuvant radiotherapy with 36Gy or more were evaluated. Median age was 60 years(range 28-66 yrs) . Patients were followed from 3 to 133 months with median follow up of 48 months. Thirty seven patients had non signet ring adenocarcinoma, 29 signet ring cell, 2 other cell. Patients with stage IIIA, IIIB, IV disease were 19, 25 and 24 respectively Chemotherapy was given to all patients except two. Results : Five-year overall survival and disease-free survival rate were 36.6% and 33.6%, respectively. Prognostic factor affecting survival were assessed. High ratio of jnvolved/dissected Iymph node, signet ring histology showed Poor Prognosis with statistical significance. Presence of residual tumor after surgery, stageIV. split course of radiation therapy, age, number of involved Iymph node, number of Iymph node dissection and grade of tumor affected survival without statistical significance, Type of chemotherapy did not affect survival. Recurrence was documented in 34 patients. High recurrence was seen in omentum and peritoneum with 23.5%, and remnant stomach, anastomosis site, A-loop and I-loop had also high recurrence with 13.2%. In field locoregional recurrence was 20.7% and total distant metastases were 39.7%. Total intraabdominal failure was 47.1% and extraabdominal failure was 13.2%. Treatment toxicity was considered to be acceptable. 22.1% of patients had grade 3 and only 1 patient had grade 4 leukopenia. Six Patients(8.8%) had weigh loss more than 10%. Conclusion : Treatment toxicity was acceptable with combined treatment with chemotherapy and radiotherapy. Locoregional recurrence was relatively low compared to distant failure with addition of irradiation. Peritoneal and omental seeding was high Five-rear surival was increased with combined modality. Radiation may eradicate minimal residual disease and improve survival, To evaluate role of radiation Prospective randomized study employing chemotherapy alone and chemotherapy plus radiation is necessary. Futhermore to reduce intraabdominal failure, role of intraabdominal chemotherapy in addition to combined chemotherapy plus radiation has to be explored.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.219-230
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• 2021

BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

• Journal of the Korean Magnetics Society
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• v.12 no.6
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• pp.206-211
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• 2002

We have constructed a new kind of magnetic motion capture sensor based on the pulse magnetic field method. 3-orthogonal magnetic pulse fields were generated in turns only one period of sinusoidal waveform using 3-orthogonal magnetic dipole coils, ring counter and analog multiplier. These pulse magnetic fields were measured with 3-orthogonal search coils, of which induced voltages by the x-, y-, and l-dipole sources using S/H amplifier at the time position of maximum induced voltage. Using the developed motion capture sensor, we can measure position of sensor with uncertainty of ${\pm}$0.5％ in the measuring range from ${\pm}$0.5 m to ${\pm}$1.5 m.

• Communications of the Korean Mathematical Society
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• v.20 no.3
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• pp.427-436
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• 2005

Let (R, m) be a 2-dimensional regular local ring with algebraically closed residue field R/m. Let K be the quotient field of R and v be a prime divisor of R, i.e., a valuation of K which is birationally dominating R and residually transcendental over R. Zariski showed that there are finitely many simple v-ideals $m=P_0\;{\supset}\;P_1\;{\supset}\;{\cdotS}\;{\supset}\;P_t=P$ and all the other v-ideals are uniquely factored into a product of those simple ones. It then was also shown by Lipman that the predecessor of the smallest simple v-ideal P is either simple (P is free) or the product of two simple v-ideals (P is satellite), that the sequence of v-ideals between the maximal ideal and the smallest simple v-ideal P is saturated, and that the v-value of the maximal ideal is the m-adic order of P. Let m = (x, y) and denote the v-value difference |v(x) - v(y)| by $n_v$. In this paper, if the m-adic order of P is 2, we show that $O(P_i)\;=\;1\;for\;1\;{\leq}\;i\; {\leq}\;{\lceil}\;{\frac{b+1}{2}}{\rceil}\;and\;O(P_i)\;=2\;for\;{\lceil}\;\frac{b+3}{2}\rceil\;{\leq}\;i\;\leq\;t,\;where\;b=n_v$. We also show that $n_w\;=\;n_v$ when w is the prime divisor associated to a simple v-ideal $Q\;{\supset}\;P$ of order 2 and that w(R) = v(R) as well.