• Journal of Radiation Protection and Research
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• v.24 no.3
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• pp.171-184
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• 1999

In this paper, using statistical theory the basic concepts and the formulars of lower limit of detection were deasribed. Assuming that risks of 5% are acceptable (95% confidence level), lower limits of detection were calculated on the measuring apparatus for alpha, beta and gamma nuclides. Also, on the basis concepts of lower limit of detection, the MDA values were calculated for the radionuclides detected easily in the environment. These results make it possible to evaluate confidence limits on the radioanalytical results in the environmental sample.

• Journal of KIISE:Software and Applications
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• v.31 no.3
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• pp.379-386
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• 2004

Video segmentation is a fundamental task in video indexing and it includes two kinds of shot change detections such as the abrupt transition and the gradual transition. The abrupt shot boundaries are detected by computing the image-based distance between adjacent frames and comparing this distance with a pre-determined threshold value. However, the gradual shot boundaries are difficult to detect with this approach. To overcome this difficulty, we propose the method that detects gradual transition in the MPEG compressed video using the HMM (Hidden Markov Model). We take two different HMMs such as a discrete HMM and a continuous HMM with a Gaussian mixture model. As image features for HMM's observations, we use two distinct features such as the difference of histogram of DC images between two adjacent frames and the difference of each individual macroblock's deviations at the corresponding macroblock's between two adjacent frames, where deviation means an arithmetic difference of each macroblock's DC value from the mean of DC values in the given frame. Furthermore, we obtain the DC sequences of P and B frame by the first order approximation for a fast and effective computation. Experiment results show that we obtain the best detection and classification performance of gradual transitions when a continuous HMM with one Gaussian model is taken and two image features are used together.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1618-1631
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• 1994

In this paper, in-process chatter detection methodology which utilizes nondimensional characteristic variables is introduced. To obtain nondimensional chatter detection indexes which are constant regardless of the cutting conditions during machining with the same tool and workpiece material, both the cutting forces and accelerations are measured and processed in time and frequency domain. The indexes are calculated from the present and past value of the acceleration and cutting force signals in time and frequency domain. The chatter is identified when these chatter detection indexes are bigger than the threshold which is decided by preliminary experiments. The experiment shows that these indexes works very well in-process chatter detection.

• Journal of fish pathology
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• v.9 no.2
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• pp.169-176
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• 1996

An indirect double antibody enzyme-linked immunosorbent assay (ELISA) was developed for rapid detection of a new virus isolated from abnormally swimming salmonid fish, RVS (Retrovirus of salmonid). Results using brain tissue homogenates, and infected cell cultures are described. The sensitivity of the methods is $10^{2.6}$ $TCID_{50}/100{\mu}l$ of the examined cell culture fluid. The specificity was confirmed by the ELISA inhibition test and virological examinations. Viral antigen could be detected in artificially infected fish tissue homogenates. The assay will allow the diagnosis of RVS-infected fish within a day.

• Analytical Science and Technology
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• v.14 no.1
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• pp.64-71
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• 2001

In this paper, the formula of lower limit of detection considering the measuring time of sample and background was derived using the basic concepts of lower limit of detection. Among parameters affecting the determination of MDA value, the MDA values were calculated with variation of amount of sample and measuring time of sample and background. The results of adequate division between the measuring time of sample and that of background studied in this research make it possible to evaluate confidence limits on the radio analytical results in the environmental sample.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.5
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• pp.465-470
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• 2010

This paper proposes an adaptive video watermarking algorithm according to bit detection rate of watermark in MPEG2 system. The watermark strength is adaptively applied as BER(bit error rate) of watermark extracted from decoded frame for motion compensation. Watermark insertion uses a frequency spread spectrum method. A realtime watermark extraction is done directly in the DCT domain during MPEG decoding. The experimental simulations show that PSNR(peak signal to noise ratio) results 31.5dB for a fixed watermark strength and 33.dB for an adaptive watermark strength. Also average BER is 0.126 and less than 0.2 avaliable value.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.107-114
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• 2007

Islanding of PV systems occurs when the utility grid is removed but the PV systems continue to operate and provide power to local loads. Islanding is one of the serious problems in an electric power system connected with dispersed power sources. This can present safety hazards and the possibility of damage to other electric equipments. In the passive method, the voltage and frequency of PCC are measured and it determines islanding phenomena if their values excess the allowed limits. If the real and reactive power of RLC load and those of the PV system are closely matched, islanding phenomena can't be detected by the passive methods. Several active methods were proposed to detect islanding operation in the region where the passive method can not detect it. The most effective method is SFS method which was suggested by Sandia National Laboratory. In this paper, a new islanding detection method using automatic phase-shift is proposed and its validity is verified through the simulation and experimental results.

• Korean journal of food and cookery science
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• v.19 no.2
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• pp.241-253
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• 2003

Changes in chemical, microbiological quality of pan fried oak mushroom and meat, soy sauce glazed hair tail and roasted dodok in wrap packaging, top sealing, vacuum packaging were evaluated during storage 25$^{\circ}C$, 4$^{\circ}C$, -18$^{\circ}C$ for 5 days. The results were as follows: 1) The cases of chilled and frozen storage, there were small increases in the pH from the first day, with no differences between the different packaging methods, with the exception of the vacuum packaging, which was lower. The pH and Aw of the roasted dodok were lower than those of the other foods. The Aw for all three foods at room temperature significantly decreased in the wrap packaging and top sealing on day one, but the rate of reduction was lower when in chilled storage. The VBN increased with increasing length of storage, and temperatures, but the rate of increase was lower in the top sealing and vacuum packaging. The VBN of roasted dodok was considerably lower than with the other foods. The POV increased significantly on the first day or room temperature storage and the rate or increase was low in chilled End frozen storages, and in the vacuum packaging. 2) SPC of the roasted dodok at room temperature increased significantly within five days of storage. but was inhibited within five days in the vacuum packaging with chilled storage. The SPC of the soy sauce glazed hair tail was low in the top sealing and vacuum packaging when in chilled storage. The coliform of the pan fried oak mushroom and meat. on the fifth day of room temperature storage, was close to hazardous conditions for the wrap packaging. From the third day of chilled storage, few coliform were detected in the pan fried oak mushroom and meat, or the soy sauce glazed hair tail, but not in the vacuum packaging, within five days, for all three foods in frozen storage. The S. spp. had exceeded the standard in the wrap packaging and top sealing with the pan fried oak mushroom and meat on the third day at room temperature, but was not detected in the vacuum packaging within five days, and exceeded the standard in the wrap packaging on the fifth day of chilled storage. S. spp. was not detected in the soy sauce glazed hair tail within five days at all storage temperatures. S. spp. was not detected in the roasted dodok within five days of chilled and frozen storage, but was detected from the third day in the wrap packaging. and the fifth in the top sealing, at room temperature, which exceeded the standard. Sal. spp., V parahaemolyticus, E. coli O157:H7, L. monocytogenes were not detected. 3) The Aw was found to be influenced by storage temperature, period and packaging method, while the VBN was significantly influenced by the storage temperature and period. Regarding the SPC, the pan fried oak mushroom and meat was affected by the storage temperature and period, while the soy sauce glazed hair tail was influenced by the packaging method and storage period. The roasted dodok's microbiological quality was influenced by the method of packaging. The chemical, microbiological quality of home-delivered meals were preserved to be five days in the vacuum packaging, at. chilled and frozen storage.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.500-506
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• 2017

Kimchi cabbage is one of the four major vegetable crops in Korea. The total annual production of kimchi cabbage, the main material of kimchi, was 20,559 tons in 2015. Kimchi cabbage is one of the majer crops produced by farmers which accounts for about 80% of the total leaf vegetable production in Korea. As the consumption of environmental-friendly agricultural products increases, food safety is one of the major public health concerns. We analyzed the biological hazards of kimchi cabbage produced by two types of cultivation methos such as organic farming and conventional farming using various culture media and microscopy. A total of 432 samples were analysed for presence of sanitary indicator microorganisms (aerobic plate count, coliform count, yeast & mold) and food-borne pathogens (Staphylococcus aureus, environmental Listeria, Bacillus cereus). The population of sanitary indicating microorganisms and food borne pathogens was under 5 Log CFU/g in all tested samples. The results of total microorganism numbers of leaf surface showed a positive correlation to those of soil samples. Additionally, we examined chemical factors such as pesticide residues and heavy metals in soil samples. All tested samples did not shown contamination levels higher than the standard limit.

• Applied Biological Chemistry
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• v.21 no.3
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• pp.185-192
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• 1978

Three herbicides including nitrofen, alachlor and butachlor f?ere applied to farm soils of oil-bearing crops rape, soybean and paddy rice and their residual levels in the soil and seeds were determined by ECD-attached gas chromatograph without hydrolysis. Applied herbicides were decreased abruptly 2 weeks after application and slowly thereafter, reaching below 10% level while the extent of disappearance varied depending on the herbicides, crops and soil conditions. The herbicides were not detected at all in the seeds of tested crops within the detection limit of the analytical methods employed.