• Economic and Environmental Geology
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• v.32 no.1
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• pp.63-72
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• 1999

In order to examine the contamination levels of trace elements in stream sediments in the Chungnam coal mine area, stream sediment and water samples were collected and analyzed for trace elements. The pH of stream water was neutral or weak-alkaline and the mobility of metal in stream sediments was supposed to be low. From the result of cluster analysis, non-polluted sampling stations can be distinguished from polluted sampling stations influenced by mining activities. The trace element concentrations in sediments from non-polluted zone were considered to be the natural backround concentrations of this area. The trace element concentrations in sediment samples from the mining area were higher than those from non-polluted area, and contaminated area of enriched trace element levels need to be properly managed. From the results of discriminant and regression analyses, concentrations of Cd, Cu, Pb AND zN and predicted values of Be, Mo, and Ni in Chungnam coal mine area were found to be lower than those in metal mining areas in Korea.

• Journal of Environmental Health Sciences
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• v.42 no.3
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• pp.224-233
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• 2016

Objectives: The purpose of this study was to evaluate the relationship between residential surroundings, such as a power plant, steel mill and petrochemical facilities, and urinary arsenic concentrations in Chungcheongnam-do Province, Korea. Methods: Stratified by fish consumption and residential district, median and maximum block sampling was applied. A total of 346 spot urine samples were speciated for $As^{5+}$, $As^{3+}$, monomethylarsonic acid(MMA), dimethylarsonic acid (DMA) and arsenobetaine (AsB). Exposure assessment was based on questionnaires including data on sex, age, current tobacco use, fish consumption, type of water consumed, and occupational category. Results: Urinary $As^{5+}+As^{3+}+MMA+DMA$ concentrations of people living in the vicinity of a power plant ($GM=50.39{\mu}g/g$) were 61% higher than those of people living in the inland area according to median block sampling. Urinary $As^{5+}+As^{3+}+MMA+DMA+AsB$ concentrations of people living in the vicinity of industrial complex area were higher than those of people living in the inland area according to block sampling by median and maximum. Conclusion: Urinary arsenic concentrations of people living in vulnerable areas such as around industrial complexes, especially power plants, were higher than those of people living in an inland area.

• Economic and Environmental Geology
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• v.25 no.2
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• pp.145-151
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• 1992

In order to study the optimum depth for the soil geochemical exploration in the area which is affected by agricultural activities and waste disposal of metal mine, the soil samples were sampled from the B layer of residual soil and vertical 7 layers up to 250 cm in the rice field and 3 layers up to 90 cm in the ordinary field. They were analyzed for Au, As, Cu, Pb and Zn by AAS, AAS-graphite furnace and ICP. To investigate the proper depth for the soil sampling in the contaminated area, the data were treated statistically by applying correlation coefficient, factor analysis and trend analysis. It is conclude that soil geochemical exploration method could be applied in the farm-land and a little contaminated area. The optimum depth of soil sampling is 60 cm in the ordinary field, and 150~200 cm in the rice field. Soil sampling in the area of a huge mine waste disposal is not recommendable. Plotting of geochemical map with factor scores as a input data shows a clear pattern compared with the map of indicater element such as As or Au. The second or third degree trend surface analysis is effective in inferring the continuity of vein in the area where the outcrop is invisible.

• Communications for Statistical Applications and Methods
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• v.17 no.1
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• pp.9-16
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• 2010

The sampling design for the spatial population studies needs a model assumption of a dependent relationship, where the interesting parameters can be the population mean, proportion and area. We know that the study of an interested spatial population, which is stratified by a geographical condition or shape, and the degree of distort of an estimation area is much useful. In light of this, if auxiliary information of the target variable such as wasted area contaminated by some material and the degree of distribution of animal or plants is available, then the spatial estimator might be improved through the calibration procedure. In this research, we propose the calibration procedure for the spatial stratified sampling in which we consider the one and two-dimensional auxiliary information.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.71-76
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• 2021

Digital decimation filters are used in various digital signal processing systems using ADCs, including digital communication systems and sensor network systems. When the sampling rate of digital data is reduced, aliasing occurs. So, an anti-aliasing filter is necessary to suppress aliasing before down-sampling the data. Since the anti-aliasing filter has to have a sharp transition band between the passband and the stopband, the order of the filter is very high. However, as the order of the filter increases, the complexity and area of the filter increase, and more power is consumed. Therefore, in this paper, we propose two types of decimation filters, focusing on reducing the area of the hardware. In both cases, the complexity of the circuit is reduced by applying the required down-sampling rate in two times instead of at once. In addition, CIC decimation filters without a multiplier are used as the decimation filter of the first stage. The second stage is implemented using a CIC filter and a down sampler with an anti-aliasing filter, respectively. It is designed with Verilog-HDL and its function and implementation are validated using ModelSim and Quartus, respectively.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.827-830
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• 2003

This paper proposes an area-efficient FIR filter architecture for sampling rate conversion of hi-fi audio data. Sampling rate conversion(SRC) block converts audio data sampled at 96KHz down to 48KHz sampled data and vice versa. 63-tap FIR filter coefficients have been synthesized that gives 100dB stop band attenuation and 5.2KHz transition bandwidth. Time-shared filter architecture requires only one multiplier and accumulator for 63-tap filter operation. This results in huge hardware saving of up to 10~19 times smaller compared with traditional FIR structure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.10
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• pp.4940-4957
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• 2019

Compared with the localization methods in the static sensor networks, node localization in dynamic sensor networks is more complicated due to the mobility of the nodes. Dynamic Sampling Localization Algorithm Based on Virtual Anchor (DSLA) is proposed in this paper to localize the unknown nodes in dynamic sensor networks. Firstly, DSLA algorithm predicts the speed and movement direction of nodes to determine a sector sampling area. Secondly, a method of calculating the sampling quantity with the size of the sampling area dynamically changing is proposed in this paper. Lastly, the virtual anchor node, i.e., the unknown node that got the preliminary possible area (PLA), assists the other unknown nodes to reduce their PLAs. The last PLA is regarded as a filtering condition to filter out the conflicting sample points quickly. In this way, the filtered sample is close to its real coordinates. The simulation results show that the DSLA algorithm can greatly improve the positioning performance when ensuring the execution time is shorter and the localization coverage rate is higher. The localization error of the DSLA algorithm can be dropped to about 20%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.442-448
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• 2009

Bacteriological examination of a 12,700 ha area within Jaranman Saryangdo area, located in Jaran bay and Saryangdo island, was conducted with 35 fixed (designated areas and adjacent areas) seawater sampling stations between January 2006 and December 2008. According to results, the geometric mean range and the estimated 90th percentile range of fecal coliform counts in sea water samples collected in the designated area were <1.8-2.4 and <1.8-8.6 MPN/100mL, respectively. The estimated 90th percentile range of fecal coliform counts in sea water samples collected from 6 sampling stations in the adjacent areas were 6.1-34.6 MPN/100mL. Based on these results, bacteriological water quality of the designated areas in the Jaranman. Saryangdo area meet the NSSP (National Shellfish Sanitation Program) guidelines for approved area. The bacteriological sea water quality in Jaranman.Saryangdo area has been shown to be favorable at all investigated sampling stations except for July and August which coincided with heavy rainfall. In fact, the bacteriological water quality was not affected if rainfall was less than 30 mm rainfall. However, the degree of bacteriological contamination increased rapidly and the water quality exceeded approved NSSP guidelines set for rainfall above 60 mm.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.351-359
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• 2004

Velocity-type repisratory air flow transducer measures dynamic pressure converted from air velocity based on the we1l-known Bernoulli's principle. It requires multiple velocity sampling holes on the flow plane. Measurement error theoretica1ly estimated by computer simulation was demonstrated to significantly reduce by unequally locating the velocity sampling holes. The flow plane was divided into multiple equi-area rings and the sampling holes were located on the circles also equally dividing each ring's area, which decreased measurement error down to 1/5 of the simple equi-radius ring division method. Also, less than 1 ％ relative error was estimated with 4 or more sampling holes. The present technique was less sensitive by <1/2 to the velocity profile change compared to the euqi-radius sampling. Therefore, the present unequal distance velocity sampling technique should be of great use to design the structure of the velocity-type respiratory air flow transducer.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.89-98
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• 2002

This study was taken in general hospital, hotel, shopping center, underground cafe, school, house, for the purpose of investigating the distribution of indoor radon concentration in urban area, by E-PERM which approved U.S. EPA, between August and November 1999. There are two sampling Places were exceed 148 ㏃/㎥(4 pCi/L; U.S EPA remedial level), difference mean is 24.0㏃/㎥ when compared with underground vs. aboveground indoor radon concentration in the same building and ratio is 1.6, so underground area is higher than aboveground (p<0.05). Influencing factors were examined. They related to the location of sampler(detector) open or near the door is lower radon concentration than inside portion, which explains probably open area has better ventilated air and dilutes indoor radon concentration. Temperature has a negative relationship (p<0.05) with indoor radon concentration and relative humidity has a positive (p<0.05) Simultaneously to investigate water radon concentration, collected piped-water and the results were very low, which is the same in piped-water concentration other countries. In conclusion, underground indoor radon concentration is higher than aboveground. Concentration was related to sampling spot, open portion is lower than inside. Higher the temperature, lower the indoor radon concentrations. On the other hand higher the relative humidity, higher the indoor radon concentrations. Indoor radon concentration is influenced by sampling point, temperature, relative humidity.