• Korean Journal of Agricultural Science
• /
• v.48 no.4
• /
• pp.739-751
• /
• 2021

The thawing process is usually essential for imported pork because this product is typically distributed frozen. Consumers prefer fresh pork because discoloration, nutrient spills, and microbial contamination are high during the thawing process. The illegal act of selling frozen pork by disguising it as fresh pork through various methods can occur for the benefit of the difference in the sales price. However, there is some difficulty in securing systematic and objective data, as sensory tests are generally performed on imported pork. In the experiment conducted here, the electrical conductivity and dielectric properties of pork neck and pork belly products were measured. The amounts of change before and after freezing were compared through a statistical analysis, and a new method for determining frozen meat was proposed based on the analysis results. The weight was reduced compared to that before freezing due to the outflow of drips from the thawing process, but there was no difference in the drip loss level due to the thawing method. Vacuum packaging was found to lead to more drip loss than regular packaging, but the difference was not statistically significant. Frozen pork neck meat can be determined by measuring the electrical conductivity in the lean parts and the dielectric characteristic in the fatty parts. Frozen pork belly is determined by measuring the dielectric constant of the part closest to the outer fat layer.

• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.4
• /
• pp.423-430
• /
• 2023

One recent notable method for real-time elimination of ionospheric errors in geodetic applications is the Predicted Global Ionosphere Map (PGIM). This study analyzes the level of accuracy achievable when applying the PGIM provided by the Center for Orbit Determination of Europe (CODE) to the Korean Peninsula region. First, an examination of the types and lead times of PGIMs provided by the International GNSS Service (IGS) Analysis Center revealed that CODE's two-day prediction model, C2PG, is available approximately eight hours before midnight. This suggests higher real-time usability compared to the one-day prediction model, C1PG. When evaluating the accuracy of PGIM by assuming the final output of the Global Ionosphere Map (GIM) as a reference, it was found that on days with low solar activity, the error is within ~2 TECU, and on days with high solar activity, the error reaches ~3 TECU. A comparison of the errors introduced when using PGIM and three solar activity indices-Kp index, F10.7, and sunspot number-revealed that F10.7 exhibits a relatively high correlation coefficient compared to Kp-index and sunspot number, confirming the effectiveness of the prediction model.

• The Plant Pathology Journal
• /
• v.40 no.2
• /
• pp.218-224
• /
• 2024

Plants are treasure trove of novel compounds that have potential for antifungal chemicals and drugs. In our previous study, we had screened plant extracts obtained from more than eight hundred plant materials collected in Korea, and found that butanol fraction of the Actinostemma lobatum were most potent in suppressing growth of diverse fungal pathogens of plants. Here in this study, we describe further analysis of the butanol fraction, and summarize the results of subsequent antifungal activity test for the sub-fractions against a selected set of plant pathogenic fungi. This line of analyses allowed us to identify the sub-fractions that could account for a significant proportion of observed antifungal activity of initial butanol fraction from A. lobatum. Further analysis of these sub-fractions and determination of structure would provide the shortlist for novel compounds that can be a lead to new agrochemicals.

• Nuclear Engineering and Technology
• /
• v.56 no.4
• /
• pp.1431-1440
• /
• 2024

The study aimed to develop a laser-based distance meter (LDM) to improve water surface identification for clinical MeV electron beam dosimetry, as inaccurate water surface determination can lead to imprecise positioning of ionization chambers (ICs). The LDM consisted of a laser ranging sensor, a signal processing microcontroller, and a tablet PC for data acquisition. I₅₀ (the water depth at which ionization current drops to 50 % of its maximum) measurements of electron beams were performed using six different types of ICs and compared to other water surface identification methods. The LDM demonstrated reproducible I₅₀ measurements with a level of 0.01 cm for all six ICs. The uncertainty of water depth was evaluated at 0.008 cm with the LDM. The LDM also exposed discrepancies between I₅₀ measurements using different ICs, which was partially reduced by applying an optimum shift of IC's point of measurement (POM) or effective point of measurement (EPOM). However, residual discrepancies due to the energy dependency of the cylindrical chamber's EPOM caused remained. The LDM offers straightforward and efficient means for precision water surface identification, minimizing reliance on individual operator skills.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.2
• /
• pp.169-178
• /
• 2011

BACKGROUND: This study aimed to estimate the measurement uncertainty associated with determination of cadmium and lead from tomato paste by ICP/MS. The sources of measurement uncertainty (i.e. sample weight, final volume, standard weight, purity, molecular weight, working standard solution, calibration curve, recovery and repeatability) in associated with the analysis of cadmium and lead were evaluated. METHODS AND RESULTS: The guide to the expression of uncertainty was used for the GUM (Guide to the expression of Uncertainty in Measurement) and Draft EURACHEM/CITAC (EURACHEM: A network of organization for analytical chemistry in Europe/Co-Operation on International Traceability in Analytical Chemistry) Guide with mathematical calculation and statistical analysis. The uncertainty components were evaluated by either Type A or Type B methods and the combined standard uncertainty were calculated by statistical analysis using several factors. Expected uncertainty of cadmium and lead was $0.106{\pm}0.015$ mg/kg (k=2.09) and $0.302{\pm}0.029$ mg/kg (k=2.16), on basis of 95% confidence of Certified Reference Material (CRM) which was within certification range of $0.112{\pm}0.007$ mg/kg for cadmium (k=2.03) and $0.316{\pm}0.021$ mg/kg for lead (k=2.01), respectively. CONCLUSION(s): The most influential components in the uncertainty of heavy metals analysis were confirmed as recovery, standard calibration curve and standard solution were identified as the most influential components causing uncertainty of heavy metal analysis. Therefore, more careful consideration is required in these steps to reduce uncertainty of heavy metals analysis in tomato paste.

• Journal of Korea Water Resources Association
• /
• v.36 no.3 s.134
• /
• pp.385-398
• /
• 2003

The concept of the effective storage ratio has been suggested to determine the size of detention pond by the previous researchers. The 11 pump - pond facilities in Dongdu-chun city were selected to analyze the critical duration for design rainfall and the storage ratio for each rainfall duration in this study It has been then found that the criteria of the maximum storage ratio is not reasonable for determining the size of detention pond because the difference of storage ratio with respect to each rainfall duration is too small. Moreover, since the size of pond compared with the pump capacity is not always big enough, the pump should be frequently operated, which may result in pump failure. Thus, the pond should be sufficiently sized to prevent the possibility of the pump failure due to frequent operation. According to the analyses for changing pump capacity, it has been found that if the function of the pond compared with the pump is concentrated, determining the size of pond based on the storage ratio is operationally feasible for even small basin. Thus, an improved procedure based on the storage ratio for determining the size of detention pond in small basin has been suggested. The results by the proposed procedure considering pump switching frequency may lead to reasonable pump operation. A simple linear programming model has been also adopted to figure out the relationship between pump capacity and pond size. It has been shown that the determination lot the size of detention pond based on conventional hydrologic flood routing in pond is feasible for only urban districts not rural areas.

• Journal of the Korea Society for Simulation
• /
• v.16 no.2
• /
• pp.27-35
• /
• 2007

When sensor networks are deployed in open environments, all the sensor nodes are vulnerable to physical threat. An attacker can physically capture a sensor node and obtain the security information including the keys used for data authentication. An attacker can easily inject false reports into the sensor network through the compromised node. False report can lead to not only false alarms but also the depletion of limited energy resource in battery powered sensor networks. To overcome this threat, Fan Ye et al. proposed that statistical on-route filtering scheme(SEF) can do verify the false report during the forwarding process. In this scheme, the choice of a security threshold value is important since it trades off detection power and energy, where security threshold value is the number of message authentication code for verification of false report. In this paper, we propose a fuzzy rule-based system for security threshold determination that can conserve energy, while it provides sufficient detection power in the SEF based sensor networks. The fuzzy logic determines a security threshold by considering the probability of a node having non-compromised keys, the number of compromised partitions, and the remaining energy of nodes. The fuzzy based threshold value can conserve energy, while it provides sufficient detection power.

• Journal of the Korean Chemical Society
• /
• v.40 no.12
• /
• pp.724-732
• /
• 1996

The organic precipitate flotation using Cu(II)-pyrrolidinedithiocarbamate complex as a coprecipitant was studied for the preconcentration and determination of trace Cd, Pb, Bi and Co in several water samples. Experimental conditions such as pH of solution, amounts of Cu(II) and ammonium pyrrolidinedithiocarbamate(APDC), stirring time, the type and amount of surfactant, etc. were optimized for the effective flotation of analytes. After 3.0 mL of 1,000 ${\mu}g/mL$ Cu(II) solution was added to 1.00 L water sample, the pH of the solution was adjusted to 2.5 with HNO3 solution. Trace amounts of analytes were coprecipitated by adding 2.0% APDC solution. And the precipitates were flotated onto the surface of solution with the aid of nitrogen gas and sodium lauryl sulfate. The floats were collected from mother liquor, and filtered through the micropore glass filter by suction. The precipitates were dissolved with 4 mL conc. HNO3, and then diluted to 25.00 mL with deionized water. The analytes were determined by graphite furnace atomic absorption spectrophotometry. This flotation technique was applied to the analysis of some water samples, and the 90 to 120% of recoveries were obtained from the spiked samples, this procedure could be concluded to be simple and applicable for the trace element analysis in various kinds of water.

• The Journal of KAIRB
• /
• v.4 no.1
• /
• pp.16-22
• /
• 2022

Purpose: The traditional ethical study only suggests a blurred insight on the research using medical big data, especially in this rapid-changing and demanding environment which is called "4th Industry Revolution." Current institutional/ethical issues in big data research need to approach with the thoughtful insight of past ethical study reflecting the understanding of present conditions of this study. This study aims to examine the ethical issues that are emerging in recent health care big data research. So, this study aims to survey the public perceptions on of health care big data as part of the process of public discourse and the acceptance of the utility and provision of big data research as a subject of health care information. In addition, the emerging ethical challenges and how to comply with ethical principles in accordance with principles of the Belmont report will be discussed. Methods: Survey was conducted from June 3th August to 6th September 2020. The online survey was conducted through voluntary participation through Internet users. A total of 319 people who completed the survey (±5.49%P [95% confidence level] were analyzed. Results: In the area of the public's perspective, the survey showed that the medical information is useful for new medical development, but it is also necessary to obtain consents from subjects in order to use that medical information for various research purposes. In addition, many people were more concerned about the possibility of re-identifying personal information in medical big data. Therefore, they mentioned the necessity of transparency and privacy protection in the use of medical information. Conclusion: Big data on medical care is a core resource for the development of medicine directly related to human life, and it is necessary to open up medical data in order to realize the public good. But the ethical principles should not be overlooked. The right to self-determination must be guaranteed by means of clear, diverse consent or withdrawal of subjects, and processed in a lawful, fair and transparent manner in the processing of personal information. In addition, scientific and ethical validity of medical big data research is indispensable. Such ethical healthcare data is the only key that will lead to innovation in the future.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.1
• /
• pp.226-230
• /
• 2007

The purpose of this study was to analyze harmful heavy metals and residual pepsticides in 30 kinds of oriental medical materials. This study was carried out on 32 samples with 30 kinds of Oriental medical materials. The GC-ECD(Varian, CP-3800) was used to analyze residual pepsticides. ICP-OES(Varian, Vista-MPX) was used to analyze lead, arsenic, cadmium. Mercury was analyzed by amalgamation method. Arsenic was detected less than 3(mg/kg) in 21 samples and was not detected 11 samples. Lead was detected less than 5(mg/kg) in 25 samples and was not detected 7 samples. Mercury was detected less than 0.2(mg/kg) in 12 samples and was not detected 20 samples. Cadmium was detected more than 0.3(mg/kg) in 3 samples was detected less than 0.3(mg/kg) in 17 samples and was not detected 12 samples. A few residual pepsticides was detected, but all residual pepsticides was safe.