• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.89-98
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• 2023

Currently, no guidelines exist regarding the maximum residues of pesticides in edible oil which is a processed food commonly consumed in Korea. This lack of guidelines hinders the evaluation of the safety of edible oil in terms of pesticide contamination. In this study, an analysis method based on heat distillation and GC-MS/MS was established by optimizing the extraction and purification procedure for 68 pesticides. Important variables in the thermal distillation procedure included heating temperature and time, and we found the nitrogen flow rate as a mobile phase and the type of dissolving solvent were not considerably affected. The determination coefficient (R²) of the residual pesticide was 0.99 or higher, and the quantitative limit (LOQ) was 0.01-0.02 mg/L. The average recovery rate (n=5) was 66.1-120.0% and the relative standard deviation was lower than ±10% when 68 pesticides were spiked at concentrations of 0.01-0.02, 0.1, and 0.5 mg/L. In addition, the within-laboratory precision was less than ±11%, meeting the Korea Food and Drug Safety Evaluation Institute's Guidelines on Standard Procedures for Preparing Food Testing Methods (2016). Therefore, the test method developed in this study can be used as a test method for managing the safety of the residual pesticide concentration in edible oil.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.5
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• pp.353-362
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• 2016

Thermal barrier coating (TBC) is an essential element consisting of a super-alloy base and ceramic coating designed to achieve long operational time under a high temperature and pressure environment. However, the top coat of TBC can be delaminated at certain temperatures with long operation time. As the delamination of TBC is directly related to the blade damage, the coupling status of the TBC should be assured for reliable operation. Conventional studies of nondestructive evaluation have been made for detecting generation of thermally grown oxide (TGO) or qualitatively evaluating delamination in TBC. In this study, the ultrasonic C-scan method was developed to obtain the damage map inside TBC by estimating the delamination in a quantitative way. All specimens were isothermally degraded at $1,100^{\circ}C$ with different time, having different partial delamination area. To detect partial delamination in TBC, the C-scan was performed by a single transducer using pulse-echo method with normal incidence. Partial delamination coefficients of 1 mm to 6 mm were derived by the proportion of the surface reflection signal and flaw signal which were theoretical signals using Rogers-Van Buren and Kim's equations. Using the partial delamination coefficients, the partial delamination maps were obtained. Regardless of the partial delamination coefficient, partial delamination area was increased when degradation time was increased in TBC. In addition, a decrease in partial delamination area in each TBC specimen was observed when the partial delamination coefficient was increased. From the portion of the partial delamination maps, the criterion for delamination was derived.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.41-53
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• 2015

In meteorological field, many researchers have tried to develop micro scale weather analysis modules for providing real-time weather information service in the metropolitan area. This effort enables us to cope with various economic and social harms coming from serious change in the micro meteorology of a metropolitan area due to rapid urbanization such as quantitative expansions in its urban activity, growth of population, and building concentration. The accuracy of the micro scale weather analysis modules (MSWAM) directly related to usefulness and quality of the real-time weather information service in the metropolitan area. This paper design a evaluation system along with verification tools that sufficiently accommodate spatio-temporal characteristics of the outputs of the MSWAM. For this we proposes a test for the equality of mean vectors of the output series of the MSWAM and corresponding observed time series by using a spectral analysis technique. As a byproduct, a time series cluster analysis method, using a function of the test statistic as the distance measure, is developed. A real data application is given to demonstrate the utility of the method.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.476-491
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• 2016

Purpose: This study investigated consumers' perception of food safety and risk from foodborne illness and consumption pattern of meat and processed meat products in Korea. Methods: A quantitative survey was performed by trained interviewers, surveying 1,500 adults who were randomly selected from six major provinces in Korea. Results: Most of the respondents reported foodborne illness risk related to the consumption of raw meat but not related to heated meat and processed meat products. As respondents perceived the risk of food poisoning from raw meat, the purchase and intake decreased (p<0.001). Most of the respondents considered a low possibility of foodborne illness at home. Seventy-seven percent of the respondents thought that bacteria and virus are the main causes of foodborne illness. Improper storage practice (40.7%) and unsafe food material (29.3%) were the main risk factors contributing to foodborne illness. Perception and practice of food safety was significantly different by the residency area. The most preferred meat, processed meat, and processed ground meat products were pork (58%), ham (31.1%), and pork cutlet (40.4%), respectively. The most preferred cooking method was roasting, regardless of the type of meat, but the second preference for cooking method was significantly affected by the type of meat (p<0.001): stir-fried pork, beef with seasoning, fried-chicken and boiled duck. Frequency of eating out was 0.75/day on weekdays and 0.78/day on weekends at the mainly Korean BBQ restaurant. Conclusion: The results of this study could be used to develop science-based education materials for consumer and the specific guideline of risk management of meat and processed meat products.

• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.535-550
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• 2016

Objective: To enhance user experience of the product by using "wow" materials and parts, a framework for participatory emotional design and evaluation was proposed and validated through a case study in this paper. Background: Customers in recent days value a product which provides new feeling and images they want to get while interacting with it beyond its function, quality, and usability. Since the product consists of various parts and materials, "wow" materials and parts which can affect the customer's feeling and emotions are the essential components for changing the user experience. Method: A framework for participatory and human sensibility ergonomic design was considered and applied on developing the aesthetically and emotionally affecting glass panels of changing colors. Design experts defined a target market for this multicolor glass panels and modified the existing designing goal. Constraints for this design modification were identified by market trend research and consulting with the company which owns the technology for checking out its feasibility. The company developed and provided prototype samples as well as their competing materials. Quantitative and qualitative evaluation of the emotional quality was conducted to validate whether the design goal was achieved successfully. Results: The target market for the developing materials was defined as finishing for the buildings. The designing goal was set as to feed new visual sensation of clean and colorful images. The emotional quality of two different types of multicolor glass panels and an ordinary unicolor panel were evaluated quantitatively with semantic differential method. Results showed that the emotion of the subjects for the multicolor glass panels can be abstracted into two dimensions; named 'colorfulness' and 'harmony'. It was found that the developed samples got higher scores in emotional quality for both dimensions compared to the ordinary one. Age was found to be a significant factor for evaluating the emotional quality of colorfulness. Conclusion and Applications: The proposed framework is a valid approach for enhancing the user experience of the product by participatory design of emotional materials and parts. This framework can be applied easily on the emotional design and evaluation of different materials and components.

• Korean journal of food and cookery science
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• v.17 no.2
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• pp.129-138
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• 2001

In this study, development of the pine needle flavor oils and their application to foods, especially to traditional Korean foods, were investigated. The pine needle flavor oils were prepared by the autoclaving method, and their volatile flavor components(VFCs) were determined by capillary gas chromatographic method The major flavor components of the pine noddle flavor oil were a -pinene 31.1%, pentane 9.8%, tricyclene 7.5%, camphene 6.8%, hexanal 6.2%, propane 6.0%, ${\beta}$-pinene 5.6%, limonene 3.9%. The acceptability of the pine needle flavor oils, sensory evaluation including a preference test and quantitative descriptive analysis(QDA), of the pine needle flavor oil, a sesame oil, and a blended oil (pine needle flavor oil : sesame oil 50 : 50 v/v) was carried out. The blended oil and sesame oil showed much higher preference scores than the pine needle flavor oil, and blended oil was almost as acceptable as sesame oil(P ＜ 0.05). The results seem to indicate that blended oil can be used as a unique substitution for sesame oil in some foods, especially in some traditional Koran food.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.263-268
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• 2019

Methanol is a toxic alcohol used in various products such as antifreeze, detergent, disinfectant and industrial solvent. In the human body, methanol is oxidized to formaldehyde and formic acid, which can lead to metabolic acidosis, optic nerve impairment, and death. In this study, the methanol levels in detergents (n=191) and rinse aids (n=13) were analyzed by gas chromatography-headspace-mass spectrometry (GC-HS-MS). Limit of detection was 1.09 mg/kg, accuracy and precision were 91.1-97.9% and <10%, and it was suitable for quantitative analysis. This analysis method was simple and fast with a higher recovery rate than the conventional MFDS (Ministry of Food and Drug Safety) method of diluting the sample in water and putting it in a headspace vial.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.863-871
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• 2018

Existing vulnerability analysis tools are prone to missed detections, incorrect detections, and over-detection, which reduces accuracy. In this paper, cross-checking based on a vulnerability detection method using static and dynamic analysis is proposed, which develops and manages safe applications and can resolve and analyze these problems. Risks due to vulnerabilities are computed, and an intelligent vulnerability detection technique is used to improve accuracy and evaluate risks under the final version of the application. This helps the development and execution of safe applications. Through incorporation of tools that use static analysis and dynamic analysis techniques, our proposed technique overcomes weak points at each stage, and improves the accuracy of vulnerability detection. Existing vulnerability risk-evaluation systems only evaluate self-risks, whereas our proposed vulnerability risk-evaluation system reflects the vulnerability of self-risk and the detection accuracy in a complex fashion to evaluate relative. Our proposed technique compares and analyzes existing analysis tools, such as lists for detections and detection accuracy based on the top 10 items of SANS at CWE. Quantitative evaluation systems for existing vulnerability risks and the proposed application's vulnerability risks are compared and analyzed. We developed a prototype analysis tool using our technique to test the application's vulnerability detection ability, and to show that our proposed technique is superior to existing ones.

• Journal of the Korea Institute of Building Construction
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• v.24 no.5
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• pp.565-575
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• 2024

This research was initiated to establish quality standards and testing methods for fine dust in aggregates, a component currently not regulated under the Korean Industrial Standards(KS) KS F 2527 for Concrete Aggregates. With limited existing research and no definitive quality or testing standards for fine dust, this study sought to provide a quantitative analysis of fine dust in aggregates and to set forth quality standards based on the dust content through a concrete performance evaluation. The experimental findings showed that the primary chemical constituents of the fine dust were aluminum oxide(Al₂O₃), iron oxide(Fe₂O₃), and silicon dioxide(SiO₂). It was observed that increasing levels of fine dust in the aggregates led to higher values of the fine dust index(Al₂O₃+Fe₂O₃). This escalation in the fine dust index corresponded with an increase in the unit water content of the concrete and a consequent decline in compressive strength. Based on these observations, a maximum allowable limit for the fine dust index in aggregates was proposed at 23%. This limit was derived from the correlation between fine dust content and a 15% reduction in compressive strength of standard concrete specimens. The proposed evaluation method for the fine dust index based on its content in aggregates is expected to enhance concrete performance and ensure structural stability. This contribution to the field addresses a significant gap in the standards and provides a foundation for further research and standardization in the construction materials industry.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.30-36
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• 2015

Purpose Whole body bone scan, which makes up a largest percentage of nuclear medicine tests, has high sensitivity and resolution about bone lesion like osteomyelitis, fracture and the early detection of primary cancer. However, any standard for valuation has not yet been created except minimum factor. Therefore, in this study, we will analysis the method which show a quantitative evaluation index in whole body bone scan. Materials and Methods This study is conducted among 30 call patients, who visited the hospital from April to September 2014 with no special point of view about bone lesion, using GE INFINIA equipment. Enumerated data is measured mainly with patient's whole body count and lumbar vertabrae, and the things which include CNR (Contrast to Noise ratio), SNR (Signal to Noise ratio) are calculated according to the mean value signal and standard deviation of each lumbar vertabrae. In addition, the numerical value with the abdominal thickness is compared to each value by the change of scan speed and tissue equivalent material throughout the phantom examination, and compared with 1hours deleyed value. Completely, on the scale of ten, 2 reading doctors and 5 skilled radiologists with 5-years experience analysis the correlation between visual analysis with blind test and quantitative calculation. Results The whole body count and interest region count of patients have no significant correlation with visual analysis value throughout the blind test(P<0.05). There is definite correlation among CNR and SNR. In phantom examination, Value of the change was caused by the thickness of the abdomen and the scan speed. And The poor value of the image in the subject as a delay test patient could be confirmed that the increase tendency. Conclusion Now, a standard for valuation has not been created in whole body bone scan except minimum factor. In this study, we can verify the significant correlation with blind test using CNR and SNR and also assure that the scan speed is a important factor to influence the imagine quality from the value. It is possible to be some limit depending on the physiology function and fluid intake of patient even if we progress the evaluation in same condition include same injection amount, same scan speed and so on. However, that we prove the significant evaluation index by presenting quantitative calculation objectively could be considered academic value.