• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.407-411
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• 1999

Studies have been carried out on the fabrication of PPy/GC and PPy/Pt electrode modified with polypyrrole film and determination of Cr(VI) by using 3-electrode system with modified electrodes. Modified electrodes were able to easily fabricated by cyclic voltammetry scanned from +1.0V to -1.0V(vs. Ag/AgCl) at 50 mV/sec. Film thickness could be controlled at same condition by the number of cycling up to 26 times. Reduction behaviour of Cr(VI) at PPy/GC electrode could be seen at wide potential ranges from +0.6V to -0.5V(vs. Ag/AgCl), and maximum reduction peak potential of the ion was observed at -0.25V(vs.Ag/AgCl). Calibration graph at its potential was linear from 0.1 ppm to 80.O ppm. Slope factor and relative coefficient were 1.75 mA/ppm and 0.998, respectively. Reduction behaviour of Cr(VI) at PPy/Pt electrode was similar to PPy/GC electrode, Calibration graph was linear from l.0 ppm to 60.0 ppm. Slope factor and relative coefficient were 0.5mA/ppm and 0.923, respectively. But PPy/GC modified electrode had about 3 times higher sensitivity than PPy/Pt modified electrode. Reduction behaviour of Cu(II), As(IlI), Pb(II), and Cd(II) couldn't be seen at PPy/GC electrode,Its metals had not lnterfered with Cr (VI) determination.

• Journal of Radiation Protection and Research
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• v.27 no.3
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• pp.155-164
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• 2002

Methodology to evaluate the effective doses to adults undergoing various diagnostic x-ray examinations were established by Monte Carlo simulation of the x-ray examinations. Anthropomorphic mathematical phantoms, the MIRD5 male phantom and the ORNL female phantom, were used as the target body and x-ray spectra were produced by the x-ray spectrum generation code SPEC78. The computational procedure was validated by comparing the resulting doses to the results of NRPB studies for the same diagnostic procedures. The effective doses as well as the organ doses due to chest, abdomen, head and spine examinations were calculated for x-rays incident from AP, PA, LLAT and RLAT directions. For instance, the effective doses from the most common procedures, chest PA and abdomen AP, were 0.029 mSv and 0.44 mSv, respectively. The fact that the effective dose from PA chest x-ray is far lower than the traditional value of 0.3 mSv(or 30 mrem), which results partly from the advances of technology in diagnostic radiology and partly from the differences in the dose concept employed, emphasizes necessities of intensive assessment of the patient doses in wide ranges of medical exposures. The methodology and tools established in this study can easily be applied to dose assessments for other radiology procedures; dose from CT examinations, dose to the fetus due to examinations of pregnant women, dose from pediatric radiology.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.6
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• pp.117-125
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• 2007

Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system. It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system. Therefor, this paper, consists of an isolated DC-DC converter to boost the fuel cell voltage 380[VDC] and a PWM inverter with LC filter to convent the DC voltage to single-phase 220[VAC]. Expressly, The fuel cell system which it proposes DC-DC the efficient converter used PWM the phase transient control law and it depended to portion resonance ZVS switching, loss peek voltage and electric current of realization under make schedule, switching frequency anger and the switch reduction. And mind benevolence it sprouted 2 in stop circuit and it added and a direct current voltage and the electric current where the ingredient is reduced in load side ripple stable under make whom it will be able to supply. Besides the efficiency of 92[%]is obtained over the wide output voltage regulation ranges and load variations. Also, under make over together the result leads simulation and test, the propriety confirmation.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.34-45
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• 2002

This study was carried out to investigate the diversity and frequency of ectomycorrhizal fungi by cutting levels in Quercus acuta and Pinus densiflora stands from June to October, 2001. The obtained results from investigation were as follows, 1. The total of fungi found during the surveyed periods were 50 species, 30 genus, 15 families. The fungi belonged to Agaricales(37 species, 18 genus, 7 families), Aphllophorales(7 species, 6 genus, 3 families), Auriculariales(1 species, 1 genus, 1 families) and Gasteromycetes(5 species, 5 genus, 4 families), Basidiomycota. 2. The total number of putative ectomycorrhizal fruiting bodies were 137 individuals, 22 species, 10 genus, 5 families, 79 individuals, 10 species, 6 genus, 3 families at strip-cutting area of Pinus densiflora stand, 24 individuals, 9 species, 5 genus, 4 families at strip-cutting area of Quercus acuta stand and 25 individuals, 10 species, 4 genus, 3 families at spacing cutting area of Quercus acuta stand. 3. Tylropilus neofelleus had high host specificity associated with Chamaecyparis obtusa, while Amanita pseudoporphyria had relatively wide host ranges compared to other ectomycorrhizal fungi. 4. The results analyzed by Correlation coefficients showed that relative humidity and precipitation were major enviromental factors to affect the distribution of ectomycorrhizal fruiting bodies.

• Journal of muscle and joint health
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• v.3 no.2
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• pp.166-176
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• 1996

This is a study through survey with the purpose of analysing of treatment cost for arthritis. Treatment cost can be devided Into two characteristics, one is the direct cost and the other is the indirect cost. Direct cost contains fees of medical treatment Including cost of self treatment & purchsing price of herb durg. On the other hand indirect cost means the using money of tansportation, lodging charge & labor-losing-time cost. For the succession of medical treatment of chronic diseases patients have to control themselves to go shopping around for the cure remeadies. And also it is important that the cost for unefficient or probably hamful folk remeadies should be reduced in order to distribute appropriatively the limited financial resources. As the result of this study, the fees for self treatment & herb drug are two times as much as those of regural medical treatment. Within the direct cost, there are the mean cost of regural medical treatment 59,630 won/mon., self-treatment 42,790 won/mon., and herb drug 78,380won/mon. therefore total mean direct cost is 180,800won per month. Moreover patients intermittently pay the cost of prostheses If folk remedies, these are added to the direct cost as above mentioned. Attributes of folk remedies are various from cure & analgesics to nutrients and their virtues as medicine are not clear in view of scientific knowledge. But 56% of arthritis patients have ever been experienced folk remedies. the cost for these remedies has wide ranges from 40,000 won to 1,000,000won. Total mean indirect cost including the transfortation fee, lodging charge & labor-losing-time cost has the range from 82,825won/month to 106,150won/month. Among these cost, labor-losing-time cost has a mojority because the waiting times are too long for seeing a doctor. In conclusion those patients having arthritis have a large burden against the treatment cost for continuous care. Therefore health professional should make effort to guide the patient to determine themselves informed choice about the treatment process.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.6
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• pp.353-360
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• 2010

The Kyunggi Bay in mid-west of Korea is a relatively large estuarine system that connects the Han River system with Yellow Sea. Due to macro-tidal range of more than 8 m, the urban estuary shows deep tidal channels and wide tidal flats. Since last 30 years, the coastal development is undergoing, yielding noticeable change in environment. Particularly the tidal flat dynamics are generally accepted as being related with tidal residual flows in this area (Kim et al., 2009). We have estimated the annual variation and vertical structure of residual currents with one-year long observed flows in two major tidal channels of Kyunggi Bay. The moving average method and tidal current harmonic analysis yield nearly the same results on residual flow. The residual flow in Jangbong channel ranges from 20 cm/s in summer to 30 cm/s in winter. It is noticeable that the residual flow in Jangbong channel is flood dominant throughout the year, while the flow in Seokmo channel is ebb-dominant residual flow with current speed range of 20-40 cm/s. Due to the baroclinic response of relatively shallow estuary, significant reduction of energy in bottom layers have been observed, indicating the importance of residual circulation to the tidal flat behavior.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.659-663
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• 1999

Gametogenesis, reproductive cycle, condition factor, and meat weight rate of the surf clam, Tresus Keenae were studied by histological observations and morphometric data based on the samples which have been collected from the south coast of Korea, from January 1995 to February 1996. The annual ranges of the mean seawater temperature and specific gravity in habitat of the surf clam were $4.9\~24.9^{\circ}C$ and 1.0210$\~$1.0266, respectively. Monthly changes in the condition factor showed in a wide range from 0.2381 to 0.2827, began to increase in January and reached the first maximum (0.2827) in April. And then the value rapidly decreased in June, thereafter, reached the second peak (0.2812) in August. The condition factor of this species showed the two peaks, and gonadal development reached sexually mature and ripe conditions during the period of these two peaks. The meat weight rate ranged from $38.0\%$ to $46.4\%$, and its change showed a similar tendency with the condition factor. The reproductive cycle of this species can be divided into five successive stages: in both sex, multiplicative (December to January, July to August), growing (January to February, September to October), mature (February to April, September to November), spawning (April to June, September to November), and degenerative and resting stage (May to July, November to January).

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.124-130
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• 2007

The purposes of this study were (1) to analyze price sensitivity, (2) to define the range of acceptable prices for each foreign segment, and (3) to provide a price model for Korean traditional restaurants. From October to November, 2006, a total of 781 foreigners responded to individual surveys. Statistical analyses on the survey data were performed using descriptive statistics and Price Sensitivity Measurement (PSM). Major findings from the study are as follows: First, the ranges of the acceptable prices were $98$\sim$$130 for fine dining/gourmet restaurants, $70$\sim$$90 for theme/ambience restaurants, $40$\sim$$60 for popular/family restaurants, and $18$\sim$$30 for convenience/fast food restaurants. Second, the convenience/fast food restaurants showed the highest price sensitivity. Third, a low stress level and wide range of the acceptable price were observed for the fine dining/gourmet restaurants, suggesting that the price sensitivity of the fine dining/gourmet restaurants was quite low. Finally, the price sensitivity indicated by the Japanese was higher than by the other groups. In consequence, the research findings suggest that the managers of the Korean traditional restaurants should strategically plan prices by understanding different customers' price sensitivity within and between customer segments. Through additional research, marketers can compare perceptions of specific brands, the competition, and variations within a product line.

• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.193-200
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• 2010

Current rose cultivars are all composed of heterozygous genome due to long history of out crossing including interspecific hybridization. It has been adapted by artificial selection and crossing by breeders that mainly based on the crossing with fertile pollen derived from inter- or intra-specific hybridization. Pollen viability and germination ability tests provide valuable information for the designing of parentage for more successful breeding efficacy. In this study, we tested the pollen viability and germination ability in seven rose cultivars to find any relationship among several factors including pollen size, ploidy levels, and crossing compatibility. The pollen viability showed wide ranges from 39% 'Pinocchio' as minimum to 82% 'Scarlet Mimi' as maximum, whereas pollen germination rate were from 1% 'Mini Rosa' to 41% 'Scarlet Mimi' as a highest. Pollen size ranged from 41.3 to $45.4{\mu}m$ in large sized pollen and 30.7 to $37.4{\mu}m$ in small sized pollen. The mean diameter of large sized pollen is approximately 10-40% bigger than that of small sized pollen. There are positive relationships among ploidy level, total chromosome length, and pollen size. Crossing list showed that seed setting ratio and seed germination were related to pollen viability, pollen germination, and ploidy level.

• Food Science and Preservation
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• v.12 no.4
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• pp.344-349
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• 2005

Microwave-assisted process (MAP) was applied to extract antioxidant-related components from Thymus quinquecostatus var. japonica Hara. Microwave power(2,450 MHz, $0{\sim}160$ W) and extraction time($1{\sim}5\;min$) were used as independent variables($X_i$) for central composite design to yield 10 different extraction conditions. Response surface methodology was applied to predict optimum extraction conditions for dependent variables of extracts, such as total yield, total phenolics, flavonoid, and electron donation ability depending on different powers and extraction times of MAP. Determination coefficients($R^2$) of regression equations for dependent variables were higher than 0.93 excluding that of total phenolics, and microwave power was predicted more influential than extraction time in MAP (p<0.05). The optimal extraction time for each dependent variable was ranged from 3.36 to 4.97 min, but microwave power showed wide ranges depending on variables. The superimposed contour maps for maximized dependent variables illustrated extraction conditions of 64 to 100 W in microwave power and 2.9 to 4.0 min in extraction time.