• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.1
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• pp.25-33
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• 2010

The matching condition at a perforated wall with vertical slits involves the permeability parameter, which can be calculated by two different methods. One expresses the permeability parameter in terms of energy dissipation coefficient and jet length at the perforated wall, being advantageous in that all the related variables are known, but it gives wrong result in the limit of long waves. The other expresses the permeability parameter in terms of friction coefficient and inertia coefficient, giving correct result from short to long waves, but the friction coefficient should be determined on the basis of a best fit between measured and predicted values of such hydrodynamic coefficients as reflection and transmission coefficients. In the present study, an empirical formula for the friction coefficient is proposed in terms of known variables, i.e., the porosity and thickness of the perforated wall and the water depth. This enables direct estimation of the friction coefficient without invoking a best fit procedure. To obtain the empirical formula, hydraulic experiments are carried out, the results of which are used along with other researchers' results. The proposed formula is used to predict the reflection and transmission coefficients of a curtain-wall-pile breakwater, the upper part of which is a curtain wall and the lower part consisting of a perforated wall with vertical slits. The concurrence between the experimental data and calculated results is good, verifying the appropriateness of the proposed formula.

• Analytical Science and Technology
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• v.23 no.2
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• pp.196-204
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• 2010

In this study, the following concentrations of some PAHs (Polycyclic Aromatic Hydrocarbons) were investigated; [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, indeno(1,2,3-c,d)pyrene] in processed foods (n=165) and cooked meats (n=45) and established the analytical method by characteristics of processed foods. The methodology involved extraction (alkali digestion, liquid-liquid extraction, microwave extraction), clean-up on Sep-Pak Florisil Cartridges and determination by HPLC/FLD (High Performance Liquid Chromatography/Fluorescence Detector). The recovery of overall method for 8 PAHs spiked into these products ranged from 92 to 103%. The mean level of detected foods was found to be benzo(b)fluoranthene $0.9\;{\mu}g/kg$ in smoked salmon, benzo(b)fluoranthene $1.0\;{\mu}g/kg$, benzo(k)fluoranthene $0.3\;{\mu}g/kg$, benzo(a)pyrene $0.9\;{\mu}g/kg$ in dried banana, benzo(b)fluoranthene $0.2\;{\mu}g/kg$, benzo(k)fluoranthene $0.1\;{\mu}g/kg$, benzo(a)pyrene $0.2\;{\mu}g/kg$ in smoked chicken, benzo(b)fluoranthene $1.3\;{\mu}g/kg$, benzo(k)fluoranthene $0.3\;{\mu}g/kg$, benzo(a)pyrene $0.9\;{\mu}g/kg$ in charcoal grilled pork, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.379-386
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• 1997

Recombinant plasmid, pBKH4, containing NPT II and P35S-BcHSP17.6 was constructed by ligation of Bum H I -digested pBKSl-l and BcHSP 17.6 (thermotolerance gene) 6om pBLH4. The tobacco leaf disc was cocultivated with transformed Agmbacterium tumefaciens bearing pBKH4 for 24 hours and transformed shoots were selected on MS-n/B medium containing $100\;{\mu\textrm{g}}/ml$ of kanamycin. Heat-killing temperature of Nicotima tabacum was $50^{\circ}$ for >15min, and transformed tobacco plants with BcHSP17.6 cDNA exhibited thermotolerance at the heat-killing temperature. The transgenic plants were analyzed by Southern blot hybridization with the probe of ${\alpha}^{_32}P$ labelled BcHSP17.6 cDNA. Transcription and expression level of BcHSP17.6 cDNA were also continued by Northern blot analysis and Ouchterlony double immunodiffusion assay. In this study, we suggest that the BcHSP17.6 cDNA introduced to tobacco plant is related to thenuoto-lerance and 17.6-kD LMW HSP acts as a protector from heat damage in plants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.197-202
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• 1999

This study was conducted to evaluate the dry matter yield, quality and utilization of nutrients of crabgrass (Digitaria sanguinalis L.) dominant swards as a roughage sources. Dry matter yield of stages, chemical composition, DM digestibility was obserbed, and DM intake, digestibility and utilization of nitrogen and energy by Korean native goats was determined. Average DM yield of crabgrass dominant swards was obtained 8,473kg/ha, and average contents of CP, NDF, ADF and lignin was 13.0%, 74.1%, 38.6% and 10.4%, respectively. DM intake by Korean native goats was lower for crabgrass dominant swards than for sown grass swards(P>0.05). Digestibility of DM, celluar constituents, NDF and ADF by Korean native goats was significantly lower for crabgrass dominant swards than for sown grass swards(P<0.05). Utilization of nitrogen and energy by Korean native goats was significantly lower for crabgrass dominant swards than for sown grass sward(P<0.05). Above the results, although crabgrass dominant swards was lower than in DM yield, digestibility, and utilization of N and energy, but the DM yield of crabgrass dominant swards was obtained 8,471kg/ha without fertilizer. Therefore it appears that crabgrass dominant swards have a potential to provide roughage sources.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.323-328
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• 2004

The development of group-specific tissue probability maps (TPM) provides a priori knowledge for better result of cerebral tissue classification with regard to the inter-ethnic differences of inter-subject variability. We present sequential procedures of group-specific TPM and evaluate the age effects in the structural differences of TPM. We investigated 100 healthy volunteers with high resolution MRI scalming. The subjects were classified into young (60, 25.92+4.58) and old groups (40, 58.83${\pm}$8.10) according to the age. To avoid any bias from random selected single subject and improve registration robustness, average atlas as target for TPM was constructed from skull-stripped whole data using linear and nonlinear registration of AIR. Each subject was segmented into binary images of gray matter, white matter, and cerebrospinal fluid using fuzzy clustering and normalized into the space of average atlas. The probability images were the means of these binary images, and contained values in the range of zero to one. A TPM of a given tissue is a spatial probability distribution representing a certain subject population. In the spatial distribution of tissue probability according to the threshold of probability, the old group exhibited enlarged ventricles and overall GM atrophy as age-specific changes, compared to the young group. Our results are generally consistent with the few published studies on age differences in the brain morphology. The more similar the morphology of the subject is to the average of the population represented by the TPM, the better the entire classification procedure should work. Therefore, we suggest that group-specific TPM should be used as a priori information for the cerebral tissue classification.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.61-72
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• 2002

In this parer, a new harmonic imaging technique is Proposed and evaluated experimentally. In the Proposed method. a weighted chirp signal with a hanning window is transmitted. The RF samples obtained on each array element are individually compressed by correlating with the reference signal defined as the 2nd harmonic component($2f_0$) of a transmitted chirp signal generated in a square-law system. The correlator output will then consist of the compressed version of the $2f_0$ component generated in tissue and the crosscorrelation sequence of the fundamental($f_0$) and 2f$_{0}$components. The Proposed method uses the compressed $2f_0$ component to form an image. for which the crosscorrelation term should be suppressed below at least -50dB. The Proposed method has two process, 2f$_{0}$-correlation and $2f_0$-correlation(PI) . $2f_0$-correlation can successfully eliminate the $f_0$ component with a single transmit-receive events and therefore is more efficient than the conventional Pulse inversion method in terms of the frame rate. 2i)-correlation(Pl) Performs pulse compression after applying pulse inversion method for the 2nd harmonic image with high resolution and SNR. Another advantage of the proposed method is that the SNR of 2nd harmonic imaging can be improved without limitation by increasing the duration of the chirp signal. The proposed method was verified through both the computer simulations and actual experiments .ts .

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.435-441
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• 1998

We examined effects of interleukin $1{\alpha}$ ($IL1{\alpha}$) and phorbol 12, 13 dibutyrate (PDB), an activator of protein kinase C, on mRNA for Prostaglandin H synthase (PGHS) and prostanoid production in cultured ovine meningeal fibroblasts. Immuno- and morphologically-identified fibroblasts were derived from cerebral cortex and white matter from fetal lambs (approximately 120 days gestation) and grown to confluence on glass coverslips in 12 well plates. Levels of prostaglandin $F_{2{\alpha}}$ and the stable hydrolysis product of prostacyclin (i.e., $6-keto-PGF_{1{\alpha}}$) were determined using enzyme immunoassay. Relative amounts of mRNA were determined by in situ hybridization using ovine cDNA for PGHS1. $IL1{\alpha}$ (10 ng/ml) increased mRNA levels over baseline by $62{\pm}19%$ (p＜0.05) at 60 min., $37{\pm}12%$ (NS) at 120 min., and $36{\pm}18%$ (NS) at 240 min (n=12). Levels of $6-keto-PGF_{1{\alpha}}$ were $148{\pm}18%$ pg/ml during baseline, $246{\pm}41%$ pg/ml at 60 min., $248{\pm}40%$ pg/ml at 120 min., and $259{\pm}62%$ pg/ml at 240 min (all p＜0.05) (n=12). $PGF_{2{\alpha}}$ was increased although it wasn't statistically significant. However, $IL1{\alpha}$ decreased $PGE_2$ level significantly (all p＜0.05). PDB $(10^{-6}M)$ increased mRNA levels over baseline by $25{\pm}6%$ after 30 min., $40{\pm}6%$ after 60 min., and $20{\pm}8%$ after 90 min. (n=9) (all p＜0.05). Levels of $6-keto-PGF_{1{\alpha}}$ were $200{\pm}43%$ pg/ml during baseline, $202{\pm}43%$ pg/ml after 30 min. (NS), $268{\pm}58%$ pg/ml after 60 min. (p＜0.05), and $296{\pm}60%$ pg/ml after 90 min. (p＜0.05) (n=9). Levels of $PGF_{2{\alpha}}$ were $178{\pm}26%$ pg/ml during baseline, $300{\pm}30%$ pg/ml after 30 min., $299{\pm}35%$ pg/ml after 60 min., and $355{\pm}32%$ pg/ml after 90 min (all p＜0.05) (n=6). Actinomycin-D (1 mg/ml) prevented increases in mRNA, $6-keto-PGF_{1{\alpha}}$, and $PGF_{2{\alpha}}$ at 60 min. for both $IL1{\alpha}$ and PDB. We conclude that cerebral fibroblasts are avid producers of prostanoids, and that enhanced production of PGHS is responsible for augmented $PGF_{2{\alpha}}$ and prostacyclin production in the presence of an activator of protein kinase C and for decreased $PGE_2$ and increased prostacyclin production in the presence of $IL1{\alpha}$.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.89-96
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• 1982

The purpose of this study is to identify the phases of four different types, low-copper lathe cut (Type II, class 1) and spherical (Type II, class 2) amalgam alloys which are made by Caulk company and high copper Dispersalloy (Type II, class 3) made by Johnson & Johnson and Tytin (Type I, class 2) made by S.S. White and to determine the Vickers hardness number on the individual phase and four different types of dental amalgam. After each amalgam alloy and Hg measured exactly by the balance was triturated by the mechanical amalgamator (De Trey), the triturated mass was inserted into the cylindrical metal mold which was 4 mm in diameter and 12mm in height and was pressed by the Instron Universal Testing machine (Model 1125) at the speed of 1mm/minute with 143$kg/cm^2$ according to the A.D.A. Specification No. 1. The Specimen removed from the mold, mounted and stored in the room temperature for 7 days. The speciman was polished with the emery paper from #220 to #1200 and finally on the polishing cloth with 0.3 and 0.05 um $Al_2O_3$ powder suspended in water. And then each specimen was etched by Allan's method and washed with Sodium Bisulfinite for 30 seconds. Finally differentiation and metallography on each phase were obtained by using metallographical microscope (Versamet, Union) and microhardness was obtained by using microhardness tester (MVH-2, Torsee). The results were as follows: 1. In the low-copper amalgam, the ${\gamma}$, ${\gamma}_1$ and ${\gamma}_2$ phase were observed and in the high-copper amalgam, the ${\gamma}$, ${\gamma}_1$. ${\epsilon}$ and ${\eta}$ phases were observed but ${\gamma}_2$ phase was not observed. 2. Among the microhardness of each amalgam phase measured under pressing a vickers diamond indenter with 2.0gm load for 30 seconds, e phase has the highest V.H.N (314 ${\pm}$ 20), and in low-copper amalgam 12 phase has the lowest V.H.N. (29${\pm}$1) and ${\eta}$ phase which was observed in high-copper amalgam has 230${\pm}$13 V.H.N and this phase is considerd to contribute to strengthen the handness in amalgam. 3. The V.H.N. measured under pressing a Vickers diamond indenter with 300.0gm load for 30 seconds in low-copper amalgam was lower than that of high-copper amalgam.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.2 s.2
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• pp.223-235
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• 1993

This study associates with socio-economic status in a slice section area of Chicago metropolitan to get spatial patterns of urban windows. GSIS(Geo-spatial Information System) has been monitored with several statistic methods, and geo-spatial map presentations. From the grouping analysis, the result displays that most suburban town have high income values, such as Elmhurst, Melrose Park, North Lake(Income ranges between $25,000${\sim}$30,000 : 1980 Sensus data). The factors produced form both analyses of SAS and BMDP are socio-ethnic, economic, hispanic, black, life expectancy, and multiple car ownership. In the study area the socio-ethnic factor is striking, and is composed of nine out of the fourteen varialbles. Geo-spatial 3-D mapping represents a socio-economic configuration of the study area. The high income value areas are Elmhurst and North Lack, and a spot between Belmont Ave. and the Lake Shore. Economic configuration is a vital importance of socio-economic activities in the urban areas. In the study area a minimum average income level is about $4,364 and maximun is $30,311.

• Tuberculosis and Respiratory Diseases
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• v.58 no.1
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• pp.25-30
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• 2005

Background : An insertion-deletion polymorphism of angiotensin converting enzyme (ACE) gene has been shown to be associated with enzyme activity levels of ACE. Reported results that have been mutually contradictory about asthmatic hypersensitiveness and occurrence according to ACE gene insertion (I)/deletion (D) polymorphism. Also, the involvement of the ACE genes as the genetic basis of bronchial asthma is currently controversy. We investigated whether there was any association between polymorphisms of the ACE genes and airway hyper-responsiveness in chronic obstructive pulmonary disease (COPD). Methods : A total of 100 patients with COPD were enrolled in this study. The ACE genotypes were determined in all subjects by polymerase chain reaction. Pulmonary function test including bronchodilator response (BDR), methacholine bronchial provocation test (MBPT) were done in those patients. Airway hyper-responsiveness include any findings of positive BDR or MBPT. Results : In COPD patients, the ACE genotype distribution did not differ significantly among groups of patients with severities of COPD, and with or without airway hyper-responsiveness. Conclusions : These results suggest that polymorphisms of the ACE gene may not be associated with airway hyper-responsiveness, development and severity of COPD.