• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.758-766
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• 2008

To evaluate homologue patterns and removal efficiency before and after water treatment, the concentrations of dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were determined in 122 samples from 42 drinking water treatment plants throughout Japan over a two year period. The mean concentrations and toxic equivalent (TEQ) values of dioxins in raw and treated waters were 60.24 pg/L (0.14 pg-WHO-TEQ/L) and 4.15 pg/L (0.016 pg-WHO-TEQ/L), respectively. The dioxins contribution ratio of drinking water in relation to dioxins tolerable daily intake (TDI, 4 pg-TEQ/kg/day) was 0.016%. The mean TEQ removal rate of dioxins by drinking water treatment was over 88%. However, the mean removal rate of 2, 3, 7, 8-TeCDF (tetrachlorodibenzofuran) by water treatment in the 122 samples was minus 17%. Therefore, to identify which process affected the level of 2, 3, 7, 8-TeCDF, the removal efficiencies at both the advanced and conventional water treatment plants were investigated. For the TEQ removal rate across the processes, the dioxin congeners, TeCDF and non-ortho-PCBs remarkably indicated minus values after chlorination in both the advanced and conventional water treatments plant. From this study, the level of 2, 3, 7, 8-TeCDF was found to be increased as a result of chlorination.

• Economic and Environmental Geology
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• v.42 no.3
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• pp.195-206
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• 2009

We investigated natural background and enrichment characteristics and predicted geochemical disaster for stream sediments in the Hamyang-Sancheong area. Stream sediments samples were collected 95 ea in study area. The stream sediments were well known that had not possibility of contamination effect and represented drainage basins. We got the major and hazardous elements concentrations by XRF, ICP-AES and NAA analysis methods. Acid decomposition for the ICP-AES has been used $HClO_4$ and HF with $200^{\circ}C$ heating at 1st and after that $HClO_4$ HF and HCl with $200^{\circ}C$ heating at 2nd stage. We could know the characteristics that concentration of Cu and Co decreased when concentration of $SiO_2$ increased in correlation analysis. The enrichment factor of the stream sediments was below 2 in study area. This result indicated that study area belonged to moderate enrichment. The stream sediments of Hamyang area were enriched in order of Pb>Th>Cr>V>Co>Cu and those of Sancheong area were enriched in order of Pb>Th>Cr>Co>V>Cu. The enrichment factor(E.F.) of the Pb, Cr, Co and V was similar between Hamyang and Sancheong area. The enrichment factor of the Th was higher in Hamyang area and that of the Cu was higher in Sancheong area. The enrichment factor of the Pb was highly enriched in all study area than earth crust mean. But we could know that study area was not exposed to the pollution of the Pb through the tolerable level.

• Journal of Environmental Science International
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• v.17 no.1
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• pp.57-66
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• 2008

The frequency analysis and the probability plot were applied to heavy metal contents of soils collected from the Goseong Cu mine area as a statistic method for the determination of the threshold value which was able to partition a population comprising largely dispersed heavy metal contents into the background and the anomalous populations. Almost all the heavy metal contents of soil showed a positively skewed distributions and their cumulative percentage frequencies plotted as a curved lines on logarithmic probability plot which represent a mixture of two or more overlapping populations. Total Cu, Pb and Cd data and extractable Cu and Pb data could be partitioned into background and anomalous populations by using the inflection in each curve. The others showed a normally distributed population or an largely overlapped populations. The threshold values obtained from replotted frequency distributions with the partitioned populations were Cu 400 mg/kg, Pb 450 mg/kg and Cd 3.5 mg/kg in total contents and Cu 40 mg/kg and Pb 12 mg/kg in extractable contents, respectively. The thresholds for total contents are much higher than the tolerable level of soil pollution proposed by Kloke(Cu 100 mg/kg, Pb 100 mg/kg, Cd 3 mg/kg), but those for extractable contents are not exceeded the worrying level of soil pollution proposed by Ministry of Environment(Cu 50 mg/kg, Pb 100 mg/kg). When the threshold values were used as the criteria of soil pollution in the study area, $9{\sim}19%$ of investigated soil population was in polluted level. The spatial distributions of heavy metal contents greater than threshold values showed that polluted soils with heavy metals are restricted within the mountain soils in the vicinity of abandoned mines.

• The Korean Journal of Community Living Science
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• v.26 no.4
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• pp.661-673
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• 2015

This study examines the effects of a low-calorie raw juice diet on the level of serum ferritin in adults and analyzes nutrient intake from the diet. There were significant differences between juices; the highest calorie was provided by pear juice, highest crude protein, vitamin A, and vitamin B2 levels were from green Juice 1; and highest vitamin C and vitamin B1 levels were from fruit juices. The ratio of estimated energy requirements (EER) for the participants was 56.2% from the raw juice diet. The percentages of recommended intake (RI) from the raw juice diet of protein (57.9%), dietary fiber (19.1%), niacin (6.2%), calcium (0.1%), and magnesium (0.2%) were lower than 75%. However, those of RI of vitamin A, vitamin B1, vitamin B2, vitamin B6, and vitamin C were 1796.5%, 7481.7%, 1915.5%, 30858.7%, and 7500%, respectively, exceeding the tolerable upper intake level (UL) for vitamin A, vitamin B6, and vitamin C. There were significant decreases in weight, the body mass index (BMI), body fat mass, and skeletal muscle mass in males and females. After the diet program, serum iron and SOD (superoxide dismutase) showed significant decreases, whereas RBC, hemoglobin, hematocrit, and serum ferritin showed significant increases. There were negative correlations between serum ferritin and weight and between serum ferritin and skeletal muscle mass for all participants. There were negative correlations between serum ferritin and skeletal muscle mass for males and between serum ferritin and body fat mass for females. These results suggest that a raw juice diet can supplement a regular diet to prevent excess or deficient nutrient intake.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.3
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• pp.119-126
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• 2003

The size of low voltage level conductor cables can be installed with a long length just like a aviation field, shall be determined for considering the ampacity of cable and the drop of voltage for the power system. Therefore, The size of the conductor cables may be larger one for considering the tolerable voltage drop comparatively, although the allowable ampacity of the conductor cables may have a margin in comparison with the rated full load current In this case, the conductor cables' allowable ampacity will be very larger than the rated full load current and the generated heat of the conductor will be relatively downed. The conductor cables' alternating current resistance corrected with the maximum allowable temperature of the conductors, has been applied on the general formula for the calculating the voltage drop in determinating the size of low voltage level conductor cables, and the resistance is larger than the resistance corrected with the actual temperature of the conductor cables. This paper was studied for the purpose of the conductor resistance corrected with the actual temperature rise of the conductor and address the economic design formula so that this studies shall minimize the errors which can be occurred in comparison with the general formula and which can be applied in design work for determining the size of low voltage level conductor cables.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.768-772
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• 2006

To assess the dietary exposure to 3-monochloropropane-1,2-diol (3-MCPD) from soy sauces, the levels of 3-MCPD in commercial soy sauces were analyzed with gas chromatography/mass spectrometry. Sixty nine out of the 72 soy sauces tested contained a level of 3-MCPD below $0.3\;{\mu}g/g$, the maximum limit in Korea. The average concentration of the 72 samples was $0.080\;{\mu}g/g$ and the highest concentration was $3.131\;{\mu}g/g$. On the basis of the consumption data, 3-MCPD concentration and body weight, the estimated daily exposures to 3-MCPD were ranged from 0.037 to $0.146\;{\mu}g/kg$ body weight (bw)/day for 95th percentile exposed population groups. Our estimated daily exposures are significantly lower than the provisional maximum tolerable daily intake (PMTDI) of $2\;{\mu}g/kg$ bw/day, which was established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA).

• ETRI Journal
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• v.40 no.2
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• pp.167-179
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• 2018

This paper proposes an IEEE 802.15.4m compliant TV white-space orthogonal frequency-division multiplexing (TVWS)-(OFDM) radio frequency (RF) transceiver that can be adopted in advanced metering infrastructures, universal remote controllers, smart factories, consumer electronics, and other areas. The proposed TVWS-OFDM RF transceiver consists of a receiver, a transmitter, a 25% duty-cycle local oscillator generator, and a delta-sigma fractional-N phase-locked loop. In the TV band from 470 MHz to 698 MHz, the highly linear RF transmitter protects the occupied TV signals, and the high-Q filtering RF receiver is tolerable to in-band interferers as strong as -20 dBm at a 3-MHz offset. The proposed TVWS-OFDM RF transceiver is fabricated using a $0.13-{\mu}m$ CMOS process, and consumes 47 mA in the Tx mode and 35 mA in the Rx mode. The fabricated chip shows a Tx average power of 0 dBm with an error-vector-magnitude of < 3%, and a sensitivity level of -103 dBm with a packet-error-rate of < 3%. Using the implemented TVWS-OFDM modules, a public demonstration of electricity metering was successfully carried out.

• The Journal of the Acoustical Society of Korea
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• v.6 no.3
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• pp.43-51
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• 1987

In this work an implementation of SAW based serial type AWQPSK modulator is studied. The SAW AWQPSK modulator consisting of input apodized IDT and output uniform IDT with center frequency of 20 MHz and bit rate of 4MHz has been designed and fabricated on $YZ-LiNbO_3$ substrate. Measured center frequency and null-to-null bandwidth are 20MHz, respectively. The sidelobe suppression is achieved 60dB below the peak mainlobe level. Measured responses meet the theoretical values with tolerable amount of deviation. SAW-based modulator simplifies the implementation of AWQPSK which uses complex pulse shape as a baseband pulse.

• Journal of Nutrition and Health
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• v.27 no.4
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• pp.356-367
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• 1994

The purpose of this study was to investigate the dietary compliance and related variables in NIDDM patients. One hundred and fourteen patients at two hospitals in Seoul were interviewed and height, body weight, family history and postprandial blood glucose were analyzed statistically along with the dietary practices. 1) When the degree of dietary compliance was expressed as Tunbridge score, 75% was grouped as satisfactory, 9.7% as Tolerable, and 14.9% belonged to Hopeless group. 2) Calorie intake of the subjects was lower then RDA. Carbohydrate, fat, and protein contributed each 60 : 22 :18. When SFA was used 1, the relative ratio of PUFA : MUFA : SFA was 0.8 : 1.2 : 1. 3) The mean score of knowledge test on diet therapy was 5.6$\pm$2.9 out of possible 12.0 points. 4) Age had significant positive correlation with duration of diabetes(p<0.001), and significant negative correlation with scores of knowledge test on diet therapy was observed(p<0.001). 5) The difference of actual and prescribed calorie intake had positive correlation with PP2 blood glucose level(p<0.05), and significant negative correlation with age(p<0.05). 6) Statiscally significant variables on the practice of diet therapy were the present body weight, protein and carbohydrate intake, age, and sex.

• Nutritional Sciences
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• v.6 no.1
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• pp.48-52
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• 2003

The Dietary Reference Intakes (DRI's) are new nutrient intake standards that are being set for the United States and Canada. There are currently four types of DRI's: Estimated Average Requirements (EAR), Recommended Dietary Allowances (RDA), Adequate Intakes (AI), and Tolerable Upper Intake Levels (UL). The EAR is the nutrient intake that would be adequate for about half the population, while intake at the RDA should be adequate for 97-98% of the population. When the data are insufficient to set an EAR and RDA, then an AI is set. The UL is the highest intake level that does not pose a risk of adverse effects. The EAR, AI, and UL may be used to assess intakes of both individuals and of groups of people. For individuals, the EAR is used to calculate the probability that intake is inadequate, the AI is used to decide if the probability of inadequacy is low, and the UL is used to determine if a risk of excess intake is present. For groups. the EAR is used to estimate the prevalence of inadequacy, the AI is used to decide if the prevalence of inadequacy is low, and the UL is used to estimate the prevalence of excessive intakes. Because this approach to setting and applying nutrient standards is new, research recommendations include improving estimates of risk, improving dietary data, and improving statistical methods.