• International Journal of Highway Engineering
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• v.16 no.2
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• pp.11-18
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• 2014

PURPOSES : This study aims to develop a strength test method for irregularly shaped concrete block paver. METHODS : Ten (10) different types of concrete block pavers including porous and dense blocks were tested for strength capacities. Destructive and non-destructive methods were used to develop a strength test method for irregularly shaped concrete block paver. The flexural strength evaluation was conducted in accordance to KS F 4419, while compressive strength was conducted with a 45.7mm-diameter core specimen. The impact echo test method was used to evaluate the elastic modulus. Finally, regression analysis was used to investigate the relationship between flexural strength, compressive strength and elastic modulus based on their corresponding test results. RESULTS : The flexural strength of the tested block pavers ranged from 4MPa to 10MPa. At 95% confidence level, the coefficients of determination between compressive-flexural strength relationship and compressive strength-elastic modulus relationship were 0.94 and 0.84, respectively. These coefficients signified high correlation. CONCLUSIONS : Using the test method proposed in this study, it will be easier to evaluate the strength of irregularly shaped concrete block pavers through impact echo test and compressive test, instead of the flexural test. Relative to the flexural strength requirement of 5MPa, the minimum values of compressive strength and elastic modulus, as proposed, are 13.0MPa and 25.0GPa, respectively.

• Journal of Environmental Science International
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• v.20 no.1
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• pp.25-34
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• 2011

The new empirical static model was constructed on the basis of dimension analysis to predict the pressure drop according to the operating conditions. The empirical static model consists of the initial pressure drop term (${\Delta}P_{initial}$) and the dust mass number term($N_{dust}=\frac{{\omega}_0{\nu}_f}{P_{pulse}t}$), and two parameters (dust deposit resistance and exponent of dust mass number) have been estimated from experimental data. The optimum injection distance was identified in the 64 experimental data at the fixed filtration velocity and pulse pressure. The dust deposit resistance ($K_d$), one of the empirical static model parameters got the minimum value at d=0.11m, at which the total pressure drop was minimized. The exponent of dust mass number was interpreted as the elasticity of pressure drop to the dust mass number. The elasticity of the unimodal behavior had also a maximum value at d=0.11m, at which the pressure drop increased most rapidly with the dust mass number. Additionally, the correlation coefficient for the new empirical static model was 0.914.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.10
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• pp.4577-4581
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• 2016

Objective: The aim of this study was to assess thyroid function in breast cancer patients exposed to therapeutic external beam radiation. The focus was on possible progressive changes and any relationships between the incidence of primary hypothyroidism, the time required to become hypothyroid, and factors such as chemotherapy, hormonotherapy and immunotherapy. Materials and Methods: Seventy females undergoing 3D conformal and IMRT radiation therapy for breast cancers were enrolled in a non-randomized prospective study. The patients was divided into two groups: those after mastectomy or breast conserving surgery (BCS) were irradiated to a scar of the chest wall/breast and the ipsilateral supraclavicular and the axillary areas (supraclavicular radiotherapy group - SC-RT group - 32 patients) and the control group receiving adjuvant chest wall/breast RT only (BCT group - 38 patients).The total doses were 50.0 to 70 Gy in 5 to 7 weeks. The median follow-up term was 24 months (range, 1-40 months). Thyroid function was evaluated by measuring thyroid stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3) levels. The minimum, maximum and mean thyroid gland doses for 20 Gy (V20) were calculated for all patients. Results: Statistically significant results were obtained for the SC-RT group. Two yearsa fter the end of RT the chance of an event was increased in 6% of the population (p=0.009) in the SC-RT group. In the BCT group no significance was noted. No statistically significant differences were found for V20, chemio-, immunotherapy and hormonotherapy or Ki67 values (p=0.12). No significant results were obtained for development of hypothyroidism and clinical factors (age, thyroid volume, treatment modalities). Conclusion: Radiotherapy is associated with a higher incidence of thyroid toxicity in breast cancer patients. Routine thyroid function monitoring should be recommended in such cases.

• Journal of Korean Neurosurgical Society
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• v.58 no.2
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• pp.119-124
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• 2015

Objective : We compared the clinical and radiographic outcomes of stand-alone polyetheretherketone (PEEK) cage and Zero-Profile anchored spacer (Zero-P) for single level anterior cervical discectomy and fusion (ACDF). Methods : We retrospectively reviewed 121 patients who underwent single level ACDF within 2 years (Jan 2011-Jan 2013) in a single institute. Total 50 patients were included for the analysis who were evaluated more than 2-year follow-up. Twenty-nine patients were allocated to the cage group (m : f=19 : 10) and 21 for Zero-P group (m : f=12 : 9). Clinical (neck disability index, visual analogue scale arm and neck) and radiographic (Cobb angle-segmental and global cervical, disc height, vertebral height) assessments were followed at pre-operative, immediate post-operative, post-3, 6, 12, and 24 month periods. Results : Demographic features and the clinical outcome showed no difference between two groups. The change between final follow-up (24 months) and immediate post-op of Cobb-segmental angle (p=0.027), disc height (p=0.002), vertebral body height (p=0.033) showed statistically better outcome for the Zero-P group than the cage group, respectively. Conclusion : The Zero-Profile anchored spacer has some advantage after cage for maintaining segmental lordosis and lowering subsidence rate after single level anterior cervical discectomy and fusion.

• 한국해양학회지
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• v.5 no.2
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• pp.41-51
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• 1970

Periodic characters of water temperature in the regions of the Mishima and the Okinoshima were derived through the analysis of the five days interval data during 1914 to 1970 mainly. In terms of ten days mean temperatures, annual variation function of the Mishima region, Korea Strait, is F($\theta_d$)=17.45-5.34 cos $\theta_d$-3.77 sin $\theta_d$+0.62 sin $2\theta_d$ -0.52 sin $3\theta_d$, where $\theta_d$=$\frac{\pi}{18}$(d-2), d is the order of ten days period 1 to 36. And in the region of Okinoshima, Tsushima Strait, we find F($\theta_d$)=18.88-5.39 cos $\theta_d$-3.60 sin $\theta_d$+0.52 sin $2\theta_d$. The annual mean temperature is 17.4$^{\circ}C$ in the Mishima region, 18.9$^{\circ}C$ in the Okinoshima region, and the amplitudes of annual variation functions are 7$^{\circ}C$ in both regions with minimum temperature in the middle ten days of February, maximum in the middle ten days of August. The long term variations of surface water temperature with 12 5 years period were observed in the annual mean temperature, monthly mean temperatures and the fixed day temperatures of every year. In addition to these, relatively short term variations were also found significant periods of 3 years, 4 years and 2 years, respectively.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.346-352
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• 2017

In this study, we analyzed environmental factors including annual fruit growth and meteorological conditions in Suwon area from 2000 to 2014 to develop and verify a fruit width prediction model in 'Fuji' apple. The 15-year average of full bloom data was April 28 and that of fruit development period was 181 days. The fruit growth until 36 days after full bloom followed single sigmoid curve. The environmental factors affecting fruit width were BIO2, precipitation in September, the average of daily maximum and minimum temperature in April, minimum temperature in August, and growing degree days (GDD) in April. Among them, the model was constructed by combining BIO2 and precipitation in September, which are not cross-correlated with each other or, with other factors. And then, the final model was selected as 19.33095 + (5.76242 ${\times}$ BIO2) - (0.01891 ${\times}$ September precipitation) + (2.63046 ${\times}$ minimum temperature in April) which was the most suitable model with AICc of 92.61 and the adjusted $R^2$ value of 0.53. The model was compared with the observed values f rom 2000 to 2014. As a result, the mean difference between the measured and predicted values of 'Fuji' apple fruit width was ${\pm}2.9mm$ and the standard deviation was 3.54.

• The Plant Pathology Journal
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• v.35 no.2
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• pp.149-155
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• 2019

The antimicrobial activity of acetone, hexane, dichloromethane, and methanol extracts from leaves, stems, immature green fruits, and red fruits of tomato plants was examined against six phytopathogens. The minimum inhibitory concentration (MIC) of the acetonic extracts from these four plant parts was lower than that of the other solvents. Among the acetonic extracts, tomato leaves had a lower MIC than the other tomato parts. The acetonic extract from tomato leaves was therefore selected as a source of antimicrobial substances. The acetonic extract from tomato leaves inhibited mycelial growth of Fusarium oxysporum f. sp. lycopersici, Glomerella cingulata, and Rhizoctonia solani. Mycelial growth of R. solani treated with acetone extract from leaves showed more susceptibility than the other phytopathogens. Using 0.31 mg/ml of the acetonic extract from leaves, mycelial growth of R. solani on days 1, 2, and 3 decreased by 50.0, 52.1, and 64.0%, respectively, compared with acetone solvent treatment. The antimicrobial compounds effective against R. solani were identified as linolenic acid and caffeic acid by bioautography and GC-MS. These two compounds were used to treat six phytopathogens to confirm their antimicrobial activities. Linolenic acid inhibited mycelial growth of R. solani, while caffeic acid showed only slight antimicrobial activity. Results indicated that we propose extracts from tomato leaves which included antimicrobial compounds may provide a new lead in the pursuit of new biological sources of agrochemical candidates.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.167-176
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• 1995

A study on phytoplankton community was carried out from June, 1992 to May, 1993 at selected stations in Hoedong Reservoir. The phytoplankton are identified as 176 taxa including 5 phylum, 67 genera. The important species in this reservoir were Asterionella formosa, C meneghiniana, Dictyosphaerium plilchellum, Fragilaria crotonensis, Melosira distans, M grantulata, M. granulata var. angustissima, M. granulate var. angntissima f. spirdis, Micractinium pussillum, Microcystis aeruginosa, Pundorina morn, Pediastrum boryanum, P. duplex, Peridinium sp., Scenedesmus quadriauda, Synedra acus, S. rumpens and S. ulna. The causative species of water bloom were identified as Microcystis aeruginsa, Trahellomonas hispida, Ceratium hirwdinella, Peridinium sp., Melosira italica, Staurastrum dorsidentiferum var. onatum in the area. During the study periods standing crcps of phytoplankton were maximum in August, 1992 and minimum in December 1992. The species dominance index and diversity index were ranged 24.7-99.9, 0.001-3.06, respectively. Key Words : phytoplankton community, causative species of water bloom, standing crops. dominance index, species diversity index.

• Bulletin of the Korean Mathematical Society
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• v.50 no.6
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• pp.2021-2026
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• 2013

Let G = (V,E) be a graph. A function $f:V{\rightarrow}\{-1,+1\}$ defined on the vertices of G is a signed total dominating function if the sum of its function values over any open neighborhood is at least one. The signed total domination number of G, ${\gamma}^s_t(G)$, is the minimum weight of a signed total dominating function of G. In this paper, we study the signed total domination number of generalized Petersen graphs P(n, 2) and prove that for any integer $n{\geq}6$, ${\gamma}^s_t(P(n,2))=2[\frac{n}{3}]+2t$, where $t{\equiv}n(mod\;3)$ and $0 {\leq}t{\leq}2$.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.321-323
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• 2006

A combination of thymol and sodium bisulfate was found to be an effective biocidal agent against strains of Burkholderia cepacia and of Xanthomonas maltophilia that were found in the space shuttle water system. Potassium iodide (KI), the biocidal agent used in the past, had a minimum inhibitory concentration (MIC) of 50,000 ppm against the two B. cepacia (541 STS-81 and 1119 STS-91) strains, whereas that of thymol and sodium bisulfate was 2,400 and 950 ppm, which was 21 and 53 times lower than that of KI for B. cepacia, respectively. The MIC value for the combination of thymol and sodium bisulfate was 4 times lower than that for thymol or sodium bisulfate alone against B. cepacia (541 STS-81, 1119 STS-91) or Pseudomonas cepacia (ATCC 31941). The fractional inhibitory concentration (FIC) of the combination of thymol and sodium bisulfate for all organisms tested was less than 0.5, indicating a strong synergistic effect.