• Water for future
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• v.28 no.6
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• pp.147-158
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• 1995

The purpose of this study is to establish a method of estimating the daily urban water demand using statistical model. This method will be used for the development of the efficient management and operation of the water supply facilities. The data used were the daily urban water use, the population, the year lapse and the weather conditions such as temperature, precipitation, relative humidity, etc. Kwangju city was selected for the case study area. The raw data used in this study were rearranged either by month or by season for the purpose of analysis, and the statistical analysis was applied to the data to obtain the regression model. As a result, the multiple linear regression model was developed to estimate the daily urban water use based on the seather condition. The regression constant and the model coefficients were determined for each month of a year. The accuracy of the model was within 3% of average error and within 10% of maximum error. The developed model was found to be useful to the practical operation and management of the water supply facilities.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.561-566
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• 2008

Two experiments were conducted to evaluate nutritive value of cell mass from lysine production (CMLP) as a protein supplement for ruminants. In each experiment, animals were fed a diet containing 40% of forages and 60% of concentrates, mainly composed of rice straw and ground corn, respectively, to meet the maintenance requirements, and the diets were formulated to supply equal amounts of energy and nitrogen among treatments. In order to investigate the effect of CMLP on ruminal fermentation (Experiment 1), three Korean native goats weighing $26.1{\pm}1.4kg$ were allotted into individual cages with a $3{\times}3$ Latin square design. Each animal was fed one of three protein sources (CMLP, soybean meal (SBM), and urea). Rumen pH, bacterial and fungal counts, volatile fatty acid concentrations and acetate to propionate ratio were not significantly different among treatments. Concentration of propionate, however, was higher in SBM treatment (14.1 mM) than in CMLP (8.7 mM) or urea (9.3 mM) treatments. There was significantly more branch-chain volatile fatty acid production in CMLP (1.9 mM) and SBM (1.8 mM) treatments than in urea (1.3 mM) treatment. The number of protozoa was the highest in urea treatment, followed by CMLP and SBM treatment with significant differences. A metabolic trial (Experiment 2) was conducted to measure in vivo nutrient digestibility and nitrogen retention in Korean native goats fed CMLP and SBM. Two heavy ($35.0{\pm}1.2kg$) and two light ($25.0{\pm}0.9kg$) Korean native goats, caged individually, were used in this experiment. A heavy and a light animal were paired and supplemented with either CMLP or SBM. The animals fed CMLP showed a trend of lower total tract digestibility in all the nutrients measured; however, there was no statistical significance except for digestibility of ether extract. Nitrogen digestibility of CMLP was estimated to be about 7% units lower than that of SBM. There was a tendency for lower nitrogen retention in CMLP treatment (35.9%) compared to SBM treatment (42.3%). In summary, CMLP can be a good protein source for ruminant animals from nutritional and economic perspectives and may replace some, if not all, of SBM in a diet without losing nitrogen utilization efficiency. Further research is warranted for investigating the effect of CMLP fed with easily fermentable forage and the effective level of CMLP for replacing SBM.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.5
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• pp.492-501
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• 2013

In this paper, a multi polarization reconfigurable microstrip antenna that can be used selectively for four polarizations(vertical polarization, horizontal polarization, right hand circular polarization, left hand circular polarization) at the S-band is presented. The proposed antenna consists of four PIN diodes and a microstrip patch with a cross slot and a circular slot and is fed by utiliting electromagnetic coupling between the microstrip patch and the feed line. The proposed antenna has a DC bias network to supply DC voltage to each PIN diode and the polarization can be determined by controlling the ON /OFF states of four PIN diodes. The fabricated antenna has a VSWR below 2 in the vertical polarization(3.17~3.21 GHz), the horizontal polarization(3.16~3.20 GHz), the left hand circular polarization (3.08~3.19 GHz), and the right hand circular polarization(3.10~3.2 GHz) frequency bands. The designed antenna has the cross polarization level higher than 20 dB, a gain over 5 dBi for the linear polarization states, and 3 dB axial ratio bandwidth wider than 50 MHz in the circular polarization states.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.550-556
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• 2016

Groundwater heat pump (GWHP) systems must consider phenomena such as clogging to improve system efficiency and maintenance. In this study, we evaluated the prokaryotic diversity in a boring slime sample obtained at a depth of 10 m, which represented an undisturbed sample not affected by aquifer drawdown. Bacteria belonging to the phyla Proteobacteria (20.8%), Acidobacteria (18.8%), Chloroflexi (16.9%), and Firmicutes (10.2%) were found. Additionally, 144 species were identified as belonging to the genus Koribacter. Archaeal phyla were detected including Thaumarchaeota (42.8%), Crenarchaeota (36.9%), and Euryarchaeota (17.4%) and the class level comprised the miscellaneous Crenarchaeota group (MCG), Finnish forest soil type B (FFSB), and Thermoplasmata, which collectively accounted for approximately 69.4% of the detected Archaea. Operational taxonomic units (OTUs) were analyzed to reveal 3,565 bacterial and 836 archaeal OTUs, with abundances of 7.81 and 6.68, and richnesses of 5.96E-4 and 2.86E-3, respectively. The distribution of the groundwater microbial community in the study area showed a higher proportion of non-classified or unidentified groups compared to typical communities in surface water and air. In addition, 135 (approx. 1.9%) reads were assigned to a bacterial candidate associated with clogging.

• Environmental and Resource Economics Review
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• v.16 no.1
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• pp.27-63
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• 2007

Using the CGE model, this paper investigates economic impacts of a shortage in crude oil resulting from voluntary export restraints, OPEC's agreement of a cut in oil production, and/or a storing on speculation. Unlike most previous studies considering oil price as the unpredictable variable, this study constructs the model to determine the oil price endogenously under the condition of an insufficient supply of crude oil. According to IEA's extraordinary steps for a shortage of crude oil, we investigate an economic impact of 7~12% shortage below the level of business as usual. The results show that oil price soars by 17.3~33.5%, the rate of economic growth falls by 0.52~0.96%p, and the consumer price index(CPI) rises by 0.8~1.51%p. These results imply that increasing in 1%p of oil price results in decreasing in 0.03%p of economic growth and increasing in 0.045%p of consumer price index. The production of electricity declines because of the increase in production cost. A shortage of crude oil has an effect on sources of electricity. Most reduction in electricity generation occurs from the reduction in the thermal power generation which is highly dependent on crude oil. The shortage of crude oil causes demand for petroleum to significantly decline but demand for coal and heat to increase because of the substitution effect with petroleum. Demand for gas rise in the first year but falls from the second year.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.1
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• pp.126-142
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• 2016

This paper presents a wide-frequency-range, low-power transceiver with an automatic impedance-matching calibration for TV-white-space (TVWS) application. The wide-range automatic impedance matching calibration (AIMC) is proposed for the Drive Amplifier (DA) and LNA. The optimal $S_{22}$ and $S_{11}$ matching capacitances are selected in the DA and LNA, respectively. Also, the Single Pole Double Throw (SPDT) switch is integrated to share the antenna and matching network between the transmitter and receiver, thereby minimizing the systemic cost. An N-path filter is proposed to reject the large interferers in the TVWS frequency band. The current-driven mixer with a 25% duty LO generator is designed to achieve the high-gain and low-noise figures; also, the frequency synthesizer is designed to generate the wide-range LO signals, and it is used to implement the FSK modulation with a programmable loop bandwidth for multi-rate communication. The TVWS transceiver is implemented in $0.13{\mu}m$, 1-poly, 6-metal CMOS technology. The die area of the transceiver is $4mm{\times}3mm$. The power consumption levels of the transmitter and receiver are 64.35 mW and 39.8 mW, respectively, when the output-power level of the transmitter is +10 dBm at a supply voltage of 3.3 V. The phase noise of the PLL output at Band 2 is -128.3 dBc/Hz with a 1 MHz offset.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.68-78
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• 2000

In Korea, food balance sheet and national nutrition survey have been conducted in parallel by Central Government for several decades. However, the gap between the two statistics became larger to reach an intolerable level in recent years, likely due to the limitation of dietary survey method in spite of the drastic change in dietary habits after industrialization and urbanization during last three decades. The currently available data from national nutrition survey was optimized by taking in to account of the food balance sheet. Adjusted consumption data for individual food items during the period of 1991-95 were given in tabular forms for groups of cereals potatoes sugars & sweets, legumes, nuts & seeds, fruits, vegetables, meats, eggs, dairy products oils & fats and fishery foods. Conversion factors of processed foods including wheat products, soybean products, Kimchi and dairy products into their raw materials were tentatively proposed. Great differences between supply data and intake data of food commodities were pointed out to be likely due to the seasonal variation and ignorance of processed foods and dining-out in the national nutrition survey. It is recommended to utilize these optimized food intake data as the nationally-representative one until new data from the national health and nutrition survey undertaken after modified procedures since 1998 are obtained and verified in future.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.4
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• pp.443-451
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• 2010

This paper describes a fully integrated CMOS low-IF mobile-TV RF tuner for Band-III T-DMB/DAB applications. All functional blocks such as low noise amplifier, mixers, variable gain amplifiers, channel filter, phase locked loop, voltage controlled oscillator and PLL loop filter are integrated. The gain of LNA can be controlled from -10 dB to +15 dB with 4-step resolutions. This provides a high signal-to-noise ratio and high linearity performance at a certain power level of RF input because LNA has a small gain variance. For further improving the linearity and noise performance we have proposed the RF VGA exploiting Schmoock's technique and the mixer with current bleeding, which injects directly the charges to the transconductance stage. The chip is fabricated in a 0.18 um mixed signal CMOS process. The measured gain range of the receiver is -25~+88 dB, the overall noise figure(NF) is 4.02~5.13 dB over the whole T-DMB band of 174~240 MHz, and the measured IIP3 is +2.3 dBm at low gain mode. The tuner rejects the image signal over maximum 63.4 dB. The power consumption is 54 mW at 1.8 V supply voltage. The chip area is $3.0{\times}2.5mm^2$.

• Journal of the Korean Geographical Society
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• v.49 no.4
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• pp.615-632
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• 2014

This study aims to explore 'bluffing', one of the most important topics in order to ensure the objectivity, validity, reliability of scoring of constructed-response items. The author identifies the conception of bluffing, and classifies major types of bluffing on the basis of previous studies on the theoretical level. Next, the author analyzes empirically the bluffing strategies and types of learners on key terms of Korean Geography subject. Compared with the existing research reports, the result of this study shows a significantly lower average bluffing score. On the other hand, it is consistent in results of previous studies reported that average bluffing score is similar between genders and that those students who got highest grades did least bluffing. Actually bluffing types are classified into four categories: 'repeating the question' type, 'depending on a well-known or existing knowledge' type, 'applying some basic concepts regardless of understanding' type, and 'inducing scorer's basic beliefs' type. Some comments and suggestions are as follows. First, it is necessary to continue researches of the relations among bluffing and age, gender, grade, intelligence and learning styles. Second, it is required for scorers who score constructed-response items to develop and supply the scoring guide including analysis contents of bluffing types and cases, and increase opportunity for training. Third, we need to inquire the domain-specific bluffing types in geography subject based on the generalizable sample size.

• Speech Sciences
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• v.10 no.3
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• pp.7-27
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• 2003

Esophageal Speech uses the esophageal air during phonation. Fluent esophageal speakers frequently intake air in oral communication, but unskilled esophageal speakers are difficult with swallowing lots of air. The purpose of this study was to investigate the difference of acoustic characteristics of vowel and consonants production according to the speech proficiency level in esophageal speech. 13 normal male speakers and 13 male esophageal speakers (5 unskilled esophageal speakers, 8 skilled esophageal speakers) with age ranging from 50 to 70 years old. The stimuli were sustained /a/ vowel and 36 meaningless two syllable words. Used vowel is /a/ and consonants were 18 : /k, n, t, m, p, s, c, $C^{h},\;k^{h},\;t^{h},\;p^{h}$, h, I, k', t', p', s', c'/. Fundermental frequency (Fx), Jitter, shimmer, HNR, MPT were measured with by electroglottography using Lx speech studio (Laryngograph Ltd, London, UK). 36 meaningless words produced by esophageal speakers were presented to 3 speech-language pathologists who phonetically transcribed their responses. Fx, Jitter, HNR parameters is significant different between skilled esophageal speakers and unskilled esophageal speakers (P<.05). Considering manner of articulation, ANOVA showed that differences in two esophageal speech groups on speech proficiency were significant; Glide had the highest number of confusion with the other phoneme class, affricates are the most intelligible in the unskilled esophageal speech group, whereas in the skilled esophageal speech group fricatives resulted highest number of confusions, nasals are the most intelligible. In the place of articulation, glottal /h/ is the highest confusion consonant in both groups. Bilabials are the most intelligible in the skilled esophageal speech, velars are the most intelligible in the unskilled esophageal speech. In the structure of syllable, 'CV+V' is more confusion in the skilled esophageal group, unskilled esophageal speech group has similar confusion in both structures. In unskilled esophageal speech, significantly different Fx, Jitter, HNR acoustic parameters of vowel and the highest confusions of Liquid, Nasals consonants could be attributed to unstable, improper contact of neoglottis as vibratory source and insufficiency in the phonatory air supply, and higher motoric demand of remaining articulation due to morphological characteristics of vocal tract after laryngectomy.