• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.454-459
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• 2012

To investigate heavy metals (Hg, Pb and Cd) and their potential health risks in commercial dried laver (Porphyra sp.), we collected 45 samples from the major production areas on the western and southern coasts of Korea (Hwaseong, Seocheon, Gunsan, Muan, Shinan, Jindo, Haenam, Wando, Jangheung, Goheung and Busan). The Hg, Pb and Cd concentrations were measured using inductively coupled plasma spectrometry (ICP-MS) or a mercury analyzer. The average Hg, Pb and Cd concentrations in the dried laver were $0.006{\pm}0.0017$, $0.196{\pm}0.0614$ and $0.894{\pm}0.4882$ mg/kg, respectively. Based on the 2007 Korean Public Nutrition Report, these levels are 0.02, 0.11 and 2.47% of the provisional tolerable weekly intake (PTWI) for Hg, Pb and Cd, respectively, established by the FAO/WHO. The hazard quotient (HQ) determined from the ratio of exposure and safe levels were less than 1.0. Therefore, the levels of overall exposure to Hg, Pb and Cd for dried laver were below the recommended JECFA (Joint FAO/WHO Expert Committee on Food Additives) levels, which indicate safe levels for public health.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2008.03a
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• pp.203-216
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• 2008

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.653-663
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• 2010

This study was conducted to monitor residues of 10 veterinary drugs in food products. Various veterinary drugs were examined including enrofloxacin, ciprofloxacin, norfloxacin, oxolinic acid, amoxicillin, ampicillin, oxytetracycline, tetracycline, chlortetracycline, and doxycycline in beef, pork, egg, chicken, eel, flatfish, and rockfish obtained from 6 different regions (Seoul, Incheon, Daejeon, Gwangju, Daegu, Busan). Residues were detected in 21 (6.5%) samples out of 321 samples. In particular, 2 (1.0%) livestock samples had detected residues among 203 products, and 19 (16.1%) aquaculture samples had residues detected among 118 products. The most frequently detected drug residues in aquaculture products were oxytetracycline and amoxicillin, but the levels were mostly below the MRL (Maximum Residue Limit). In only one flatfish sample, amoxicillin was found at a level higher than the MRL (0.05 mg/kg). In livestock products, residues of most veterinary drugs were not detected. But enrofloxacin was detected in 2 chicken (Korean name: Ogolgae) samples at a higher level than the MRL (0.1 mg/kg as the sum of ciprofloxacin).

• Journal of the Korean Dietetic Association
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• v.13 no.4
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• pp.389-406
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• 2007

This study was conducted to estimate the safety level of non-cooking and cooking processed foods to propose the sanitary management of foods donated to foodbanks. The time and temperature were measured and the microbial levels of aerobic plate counts (APC), coliforms, E. coli, Salmonella spp., S. aureus, B. cereus, and E. coli O157:H7 were analyzed on ten food items donated to seven foodbanks. The amount of cooked foods donated to each foodbank was about 10 to 40 servings. All foodbanks hired a supervisor and had at least one refrigerator/freezer and one temperature-controlled vehicle, but only four foodbanks had the separate offices to manage the foodbank operation. The flow of donated foods was gone through the steps; production, meal service and holding at donator, collection by foodbank, transport (or holding after transport) and distribution to recipients. After production, the levels of APC of both non-cooking and cooking processed foods were complied with the standards by Ministry of Education & Human Resources Development, and were not increased till distribution. Only the level of coliforms in dried squid & cucumber salad (1.5×$10^3$ CFU/g) was not met the standards. E. coli and other pathogens were not detected in all tested samples. The microbial levels of delivery vessels and work tables were satisfactory, but the APC levels of two of four tested serving tables (6.9×$10^3$ and 5.3×$10^3$ CFU/100$cm^2$) and the coliforms level of one (1.1×$10^3$ CFU/100$cm^2$) were over the standards. The air-borne microflora level in serving room was estimated as satisfactory. It took about 3.0 to 6.5 hours from after-production to distribution and the temperatures of donated foods were exposed mostly to temperature danger zone, which had a high potential of microbial growth. These results imply that a checklist to monitor time and temperature in each step should be provided and the employees involving foodbank operation should be properly educated to ensure the safety of donated foods.

• Earthquakes and Structures
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• v.15 no.3
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• pp.253-261
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• 2018

This article details a bridge-specific fragility method developed to enhance the seismic design and resilience of bridges. Current seismic design processes provide guidance for the design of a bridge that will not collapse during a design hazard event. However, they do not provide performance information of the bridge at different hazard levels or due to design changes. Therefore, there is a need for a supplement to this design process that will provide statistical information on the performance of a bridge, beyond traditional emphases on collapse prevention. This article proposes a bridge-specific parameterized fragility method to enable efficient estimation of various levels of damage probability for alternative bridge design parameters. A multi-parameter demand model is developed to incorporate bridge design details directly in the fragility estimation. Monte Carlo simulation and Logistic regression are used to determine the fragility of the bridge or bridge component. The resulting parameterized fragility model offers a basis for a bridge-specific design tool to explore the influence of design parameter variation on the expected performance of a bridge. When used as part of the design process, these tools can help to transform a prescriptive approach into a more performance-based approach, efficiently providing probabilistic performance information about a new bridge design. An example of the method and resulting fragility estimation is presented.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.11-18
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• 2007

A laboratory investigation was conducted to characterize the flexural fatigue behavior of high performance fiber reinforced cement mortar. Five specimens for statics flexural test and fourteen specimens for the flexural fatigue test were made based on the fiber mixing ratio. Static flexural tests were firstly performed to obtain magnitudes of static failure loads and stress levels before flexural fatigue tests. The flexural fatigue behaviors were investigated based on the stress level and fiber mixing ratio. Also, the equations for the interrelation of the flexural fatigue stress levels with the number at loading cycle were proposed.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.211-219
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• 2008

The hazard warning levels are necessary for the rational design and safety construction of underground space, as mountain and urban tunnel. Sakurai provided the hazard warning levels for assessing the stability of tunnels using the critical strain of rock mass, which is defined as a ratio between uni-axial compressive strength and the Young's modulus. The concept of critical strain guidelines is introduced in this study for the assessment of tunnel safety during excavation. Moreover, in this paper, the critical strain properties of sedimentary rock in Korea has investigated and analysed in detail by Lab. test, as the uniaxial compression tests. Finally, critical strain properties of sedimentary rock is discussed the relationship of failure strain values, uniaxial compression strengths and Young's modulus.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.821-832
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• 2008

The hazard warning levels are necessary for the rational design and safety construction of underground space, as mountain and urban tunnel. Sakurai provided the hazard warning levels for assessing the stability of tunnels using the critical strain of rock mass, which is defined as a ratio between uni-axial compressive strength and the Young's modulus. The concept of critical strain guidelines is introduced in this study for the assessment of tunnel safety during excavation. Moreover, in this paper, the critical strain properties of sedimentary rock in Korea has investigated and analysed in detail by Lab. test, as the uniaxial and triaxial compression tests. Finally, critical strain properties of sedimentary rock on uniaxial and triaxial stress condition is discussed the relationship of failure strain values, uniaxial and triaxial compression strengths, confining pressure and Young's modulus.

• Structural Engineering and Mechanics
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• v.37 no.2
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• pp.233-251
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• 2011

The seismic provisions of the current edition (2005) of the National Building Code of Canada (NBCC) differ significantly from the earlier edition. The current seismic provisions are based on the uniform hazard spectra corresponding to 2% probability of exceedance in 50 years, as opposed to the seismic hazard level with 10% probablity of exeedance in 50 years used in the earlier edition. Moreover, the current code is presented in an objective-based format where the design is performed based on an acceptable solution. In the light of these changes, an assessment of the expected performance of the buildings designed according to the requirements of the current edition of NBCC would be very useful. In this paper, the seismic performance of a set of six, twelve, and eighteen story buildings of regular geometry and with concrete moment resisting frames, designed for Vancouver western Canada, has been evaluated. Although the effects of non-structural elements are not considered in the design, the non-structural elements connected to the lateral load resisting systems affect the seismic performance of a building. To simulate the non-structural elements, infill panels are included in some frame models. Spectrum compatible artificial ground motion records and scaled actual accelerograms have been used for evaluating the dynamic response. The performance has been evaluated for each building under various levels of seismic hazard with different probabilities of exceedance. From the study it has been observed that, although all the buildings achieved the life-safety performance as assumed in the design provisions of the building code, their performance characteristics are found to be non-uniform.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.579-592
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• 2017

This study assessed the quantitative microbial risk of non-enterohemorrhagic Escherichia coli (EHEC). For hazard identification, hazards of non-EHEC E. coli in natural and processed cheeses were identified by research papers. Regarding exposure assessment, non-EHEC E. coli cell counts in cheese were enumerated, and the developed predictive models were used to describe the fates of non-EHEC E. coli strains in cheese during distribution and storage. In addition, data on the amounts and frequency of cheese consumption were collected from the research report of the Ministry of Food and Drug Safety. For hazard characterization, a doseresponse model for non-EHEC E. coli was used. Using the collected data, simulation models were constructed, using software @RISK to calculate the risk of illness per person per day. Non-EHEC E. coli cells in natural- (n=90) and processed-cheese samples (n=308) from factories and markets were not detected. Thus, we estimated the initial levels of contamination by Uniform distribution ${\times}$ Beta distribution, and the levels were -2.35 and -2.73 Log CFU/g for natural and processed cheese, respectively. The proposed predictive models described properly the fates of non-EHEC E. coli during distribution and storage of cheese. For hazard characterization, we used the Beta-Poisson model (${\alpha}=2.21{\times}10^{-1}$, $N_{50}=6.85{\times}10^7$). The results of risk characterization for non-EHEC E. coli in natural and processed cheese were $1.36{\times}10^{-7}$ and $2.12{\times}10^{-10}$ (the mean probability of illness per person per day), respectively. These results indicate that the risk of non-EHEC E. coli foodborne illness can be considered low in present conditions.