• Journal of Korean Society on Water Environment
• /
• v.35 no.1
• /
• pp.19-27
• /
• 2019

The purpose of this study is to evaluate the water quality and phytoplankton community in Bukhan River which account for 44.4 % of the total inflow into Lake Paldang, using multivariate statistical techniques (i.e., correlation analysis, principal component analysis (PCA)/factor analysis (FA)). Water samples were collected from March to November 2015 and the following parameters measured; water temperature, pH, DO, EC, SS, BOD, Chl-a, COD, TN, $NO_3-N$, $NH_3-N$, TP, DTP, $PO_4-P$, and phytoplankton community. The water quality of the main stream and the tributaries were not significantly different apart from the relatively high concentration of BOD, COD and nutrients recorded in MH. The highest cell density of Stephanodiscus hantzschii and Merismopedia glauca dominated phytoplankton was observed in PD. Based on the correlation analysis, total phytoplankton and cyanophyceae were highly correlated with BOD, COD and nutrients. PCA/FA resulted in four main factors accounting for 82.240 % of the total variance in the water quality dataset. The group of component 1 (TN, DTN, DO, $NO_3-N$, water temperature) and component 2 ($PO_4-P$, T-P, DTP, SS) were classified as nutrient element factor whereas component 3 (Chl-a, COD, BOD, $NH_3-N$, pH) was related to organic substances. Hence, the identification of the main potential environmental pollution factors in Bukhan River will help policy makers make better and more informed decisions on how to improve the water quality.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.28 no.1
• /
• pp.27-36
• /
• 2020

The study was compared for growth and yield of cherry tomato (Lycopersicon esculentum var. cerasiforme) crops as affected by various homemade liquid fertilizer (LF), commonly applied in the environmentally friendly farmhouses. LF treatment included UT (untreatment, water), OC (oil cake), BF (bone+fish meal), FA (fish amino meal), SO (sesame oil meal), and SF (starfish). Seasonal pH and EC in SO- and SF-LF rapidly decreased at 30 days after the storage, which were the highest EC of 0.6 - 0.8 dS/m, followed by BF-LF with 0.4 dS/m EC. T-N concentration in LF was the highest on the SF (0.0062%), followed by SO (0.0059%) and BF materials (0.0030%), which were all the great for the K concentration in the LF. P and Ca concentrations were the highest on the FA-LF, with the highest Mg concentration observed on the vegetable SO-LF. Soil EC was the highest on the SF-LF plots of 0.74 dS/m, with no significant differences between the treatments observed on the macro-nutrient concentrations in the soil and leaf. Leaf dry weight, leaf temperature, stem diameter, and plant height were investigated at once per 15 days. UT-LF reduced the leaf dry weight at all the measurement time while the plant height was low at an initial measurement but increased and similar to the other homemade LF treatments at a later measurement. Fruit yield and average fruit weight were the lowest on the UT-LF plots at 75 days after fertigation. Fruit diameter was increased by the BF-LF and SF-LF, with the highest fruit soluble solid contents and fruit coloring observed on the FA-LF. BF-LF maintained high fruit firmness.

• Korean Journal of Environmental Agriculture
• /
• v.17 no.1
• /
• pp.65-69
• /
• 1998

In order to evaluate the utility of bituminous coal fly ash, gypsum, oyster shell as soil amendments, aadic clayloam paddy soils with low calaum content were amended in the upper 15㎝ with amendments, and then Chinese cabbage was cultivated under plastic film house. Amendments treated were, in metric tons per hectare, i) none(Check) ; ii) 80 fly ash(FA) ; iii) 4 shell(SH) ; iv) 56 fly ash+24 gypsum (FG) ; v) 40 fly ash+24 gypsum+0.8 shell(FGS). On the whole, soil chemical properties were improved by amendments treatments. Amongst treatments, FA prominently neutralized soil pH and increased contents of Av. $P_2O_5$, Ex. K, and Av. B in soils. Besides, it showed the highest ratio in bacteria/fungi and (bacteria+actinomycetes)/fungi. FGS also affected the neutralization of soil pH and the increment of Ex. Mg. Amendments plants appeared alkaline damages only at early growing stage, but showed positive responses in fresh weight yields : 23% for FGS : 21% for FG : 19 18% for SH. At harvesting, leaves both of FA and FGS plants had higher values in contents of N, P, K, Ca, Mg, Fe, Mn, Zn, B, reduang-sugar, and vitamin-C than of others. In especial, Check plants appeared the heart rot symptoms owing to calaum defiaency differently from amendments plants. Taken together, FGS was an effective combination enable to maximize the utility of fly ash, gypsum, shell as soil amendments, espeaally in cabbage yield and quality.

• Journal of Biomedical Engineering Research
• /
• v.27 no.5
• /
• pp.203-209
• /
• 2006

The aim of this study is to investigate the feasibility of ex vivo MR diffusion tensor imaging technique in order to observe the diffusion-contrast characteristics of human gastric tissues. On normal and pathologic gastric tissues, which have been fixed in a polycarbonate plastic tube filled with 10% formalin solution, laboratory made 3D diffusion tensor Turbo FLASH pulse sequence was used to obtain high resolution MR images with voxel size of $0.5{\times}0.5{\times}0.5mm^3\;using\;64{\times}32{\times}32mm^3$ field of view in conjunction with an acquisition matrix of $128{\times}64{\times}64$. Diffusion weighted- gradient pulses were employed with b values of 0 and $600s/mm^2$ in 6 orientations. The sequence was implemented on a clinical 3.0-T MRI scanner(Siemens, Erlangen, Germany) with a home-made quadrature-typed birdcage Tx/Rx rf coil for small specimen. Diffusion tensor values in each pixel were calculated using linear algebra and singular value decomposition(SVD) algorithm. Apparent diffusion coefficient(ADC) and fractional anisotropy(FA) map were also obtained from diffusion tensor data to compare pixel intensities between normal and abnormal gastric tissues. The processing software was developed by authors using Visual C++(Microsoft, WA, U.S.A.) and mathematical/statistical library of GNUwin32(Free Software Foundation). This study shows that 3D diffusion tensor Turbo FLASH sequence is useful to resolve fine micro-structures of gastric tissue and both ADC and FA values in normal gastric tissue are higher than those in abnormal tissue. Authors expect that this study also represents another possibility of gastric carcinoma detection by visualizing diffusion characteristics of proton spins in the gastric tissues.

• Korean Journal of Radiology
• /
• v.19 no.6
• /
• pp.1161-1171
• /
• 2018

Objective: The aim of this study was to investigate diffusion tensor (DT) imaging-derived properties of benign oligemia, true "at risk" penumbra (TP), and the infarct core (IC) during the first 3 hours of stroke onset. Materials and Methods: The study was approved by the local animal care and use committee. DT imaging data were obtained from 14 rats after permanent middle cerebral artery occlusion (pMCAO) using a 7T magnetic resonance scanner (Bruker) in room air. Relative cerebral blood flow and apparent diffusion coefficient (ADC) maps were generated to define oligemia, TP, IC, and normal tissue (NT) every 30 minutes up to 3 hours. Relative fractional anisotropy (rFA), pure anisotropy (rq), diffusion magnitude (rL), ADC (rADC), axial diffusivity (rAD), and radial diffusivity (rRD) values were derived by comparison with the contralateral normal brain. Results: The mean volume of oligemia was $24.7{\pm}14.1mm^3$, that of TP was $81.3{\pm}62.6mm^3$, and that of IC was $123.0{\pm}85.2mm^3$ at 30 minutes after pMCAO. rFA showed an initial paradoxical 10% increase in IC and TP, and declined afterward. The rq, rL, rADC, rAD, and rRD showed an initial discrepant decrease in IC (from -24% to -36%) as compared with TP (from -7% to -13%). Significant differences (p < 0.05) in metrics, except rFA, were found between tissue subtypes in the first 2.5 hours. The rq demonstrated the best overall performance in discriminating TP from IC (accuracy = 92.6%, area under curve = 0.93) and the optimal cutoff value was -33.90%. The metric values for oligemia and NT remained similar at all time points. Conclusion: Benign oligemia is small and remains microstructurally normal under pMCAO. TP and IC show a distinct evolution of DT-derived properties within the first 3 hours of stroke onset, and are thus potentially useful in predicting the fate of ischemic brain.

• Rapid Communication in Photoscience
• /
• v.1 no.1
• /
• pp.19-20
• /
• 2012

Novel star-shaped imide compounds containing electron-donating triphenylamine and/or electron-withdrawing bis(trifluoromethyl)phenyl side groups were synthesized via a two-step process. First, 3,6-dibromo-benzene-1,2,4,5-tetracarboxylic acid (2B4BA) was reacted with 4-aminophenyl (diphenylamine) (ATPA) or 3,5-bis(trifluoromethyl)aniline (6FA) by imide reaction. Then, Suzuki coupling reaction was carried out on these compounds with 4-(N,N-diphenylamino)-1-phenyl boronic acid (BTPA) or 3,5-bis(trifluoromethyl)phenyl boronic acid (6FBB), resulting in 3,6-bis[4-(diphenylamino)phenyl]-N,N'-bis[4-(diphenylamino) phenyl]-pyromellitimide (TPTPPI), 3,6-bis[3,5-bis(trifluoro methyl) phenyl]-N,N'-bis[3,5-bis(trifluoromethyl) phenyl]-pyro mellitimide (6F6FPI) or 3,6-bis[4-(diphenylamino)phenyl]-N,N'-bis[3,5-bistrifluoromethyl)phenyl]-pyromellitimide (6FTPPI). The imide compounds obtained were characterized by NMR, FT-IR, DSC, TGA, melting point analyzer, EA, and solubility measurements. In addition, their optical and electrical properties were evaluated by fluorescence spectroscopy, UV-vis spectroscopy, and cyclic voltammetry (CV). 6F6FPI exhibited deep blue emission (443 nm), along with high $T_m$ ($382^{\circ}C$) and relatively high $T_g$ ($148^{\circ}C$).

• Steel and Composite Structures
• /
• v.26 no.4
• /
• pp.501-511
• /
• 2018

Concrete-filled steel tubular (CFT) columns are commonly used in engineering structures and always subjected to torsion in practice. This paper is thus devoted to investigate the mechanical behavior of circular CFT columns under pure torsion.3D finite element models based on reasonable material constitutive relation were established for analyzing the load-strain ($T-{\gamma}$) curves of circular CFT columns under pure torsion. The numerical simulation indicated that local bulking of the steel tube in CFT columns was prevented and the shear strength and ductility of the core concrete were significantly improved due to the confinement effect between the steel tube and the core concrete. Based on the results, formulas to predict the torsional ultimate bearing capacity of circular CFT columns were proposed with satisfactory correspondence with experimental results. Besides, formulas of composite shear stiffness and the overall process of the $T-{\gamma}$ relation of circular CFT columns under pure torsion were proposed.

• Journal of Korean Library and Information Science Society
• /
• v.3
• /
• pp.1-31
• /
• 1976

If Y'ational developments are depend on the dex-elopment of regional >ociety and de~.elopment of regional society are rely on intellcctual delrelopment of members of regional society, going abreas! oi economic capacity. Estnhlis!l:r,ent of libraries as a treasure-house of mental resources and its Jet-elopment are inevit-able and important. But in every respect :f modern libraries are not equipped with contemporary devclij;!~i:c:\ulcornert of society. One c~i the resolving problems, like this, opening the door of the liI~-,\ulcornerr:~fa-c ilities, as one object, which located in every regional areas, u.9ng the existing facilities, the width of the library services mus: I)c opened. I-' ;- I n,> study is aimed at like the following: 1. is analysizing the situation ~vhich the library facilities of one ti:u~:sa!~d five hundred and fifty nine located here and there ir, Ii.;~-ui:gij~opkr ovince in Korea and s i s t ~t.l lousand seven hundred aid tliirl:~ six village libraries, for connecting as a library networks. 2. Tl\ulcornerc ivhole libraries in Kyungbook province and dividing into four ::arts as a Daegu, Phohang, Ahndong and Kimchun area as a transportation area, school area and resources area which exhibiting the view-point of helping-net~vorksl ike the following,

• Membrane and Water Treatment
• /
• v.13 no.5
• /
• pp.245-257
• /
• 2022

Water quality characteristics and their spatial variations in the Nakdong River were statistically analyzed by multivariate techniques including correlation analysis, CA, and FA/PCA based on water quality parameters for 17 sites over 2017-2019, yielding PI values for primary factors. Site 10 indicated the highest parameter concentrations, and results of pearson's correlation analysis suggest that non-biodegradable organic matter had been distributed on the site. Five clusters were identified in order of descending pollution levels: I (Ib > Ia) > II (IIa > IIb) > III. Spatial variations started from sub-cluster Ib in which Daegu city and Geumho-river are joined. T-P, PO4-P, SS, COD, and TOC corresponded to VF 1 and 2, which were found to be principal components with strong influence on water quality. Sub-cluster Ib was strongly influenced by NO3-N and T-N compared to other clusters. According to the PIs, water quality pollution deteriorated due to non-biodegradable organic matter, nitrogen- and phosphorus-based nutrient salts in the middle and lower reaches, illustrating worsening water pollution due to inflows of anthropogenic sources on the Geumho-river, i.e., sewage and wastewater, discharged from Site 10, at which there is a concentration of urban, agricultural, and industrial areas.

• The Magazine of the IEIE
• /
• v.24 no.9
• /
• pp.91-98
• /
• 1997

Text-to-Speech(WS) technology has been attracting a lot of interest among speech engineers because of its own benefits. Namely, the possible application areas of talking computers, emergency alarming systems in speech, speech output devices for speech-impaired, and so on. Hence, many researchers have made significant progresses in the speech synthesis techniques in the sense of their own languages and as a result, the quality of current speech synthesizers are believed to be acceptable to normal users. These are partly why the MPEG group had decided to include the WS technology as one of its MPEG-4 functionalities. ETRI has made major contributions to the current MPEG-4 775 appearing in various MPEG-4 documents with relatively minor contributions from AT&T and NW. Main MPEG-4 functionalities presently available are; 1) use of original prosody for synthesized speech output, 2) trick mode functions for general users without breaking synthesized speech prosody, 3) interoperability with Facial Animation(FA) tools, and 4) dubbing a moving/anlmated picture with lip-shape pattern informations.