• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.392-399
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• 2021

This study was conducted to research the status of pesticide residues in a total of 114 herbs and spices obtained from January to October 2020. 341 pesticide residues were analyzed by the multi class pesticide multiresidue methods using GC-MSMS, GC-ECD, GC-NPD, LC-MSMS, LC-PDA, and LC-CAS. As a result of analysis, 36 pesticide residues were found, and detection rate was 31.6%. Of them, seven samples were detected over Maximum Residue Limits (MRLs) and the unsuitable level in pesticide was 6.1%. The herbs and spices exceeding MRLs include coriander (2 times), mint (2 times), basil (once), rosemary (once), and boraye (once). According to an analysis of 341 pesticide residues, 22 pesticides were detected 52 times and 8 pesticides were found to exceed the MRLs. The pesticides exceeding MRLs were ingredients such as etofenprox, flufenoxuron, fluquinconazole, iprodione, lufenuron, paclobutrazol, phenthoate, and spiromesifen.

• Journal of the Korean GEO-environmental Society
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• v.20 no.5
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• pp.13-21
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• 2019

There are many cuts or natural rock slopes that remain stable for a long time in the natural environment with steep slopes ($65^{\circ}$ to $85^{\circ}$). In terms of design practice, the rock mass consisting of similar rock condition and geological structures is defined as a good continuum rock slope, and during the process of decision making angle of this rock slope, it will be important to establish the geotechnical properties estimating method of the continuum rock on the process of stability analysis in the early stages of design and construction. In this study, the stability analysis of a good continuum rock slope that can be designed as a steep slope proposed a practical method of estimating the shear strength by induced from the Hoek-Brown failure criterion, and in addition, the design applicability was evaluated through the stability analysis of steep rock slope. The existing method of estimating the shear strength was inadequate for practical use in the design, as the equivalent M-C shear strength corresponding to the H-B envelope changes sensitively, even with small variations in confining stress. To compensate for this problem, it was proposed to estimate equivalent M-C shear strength by iso-angle division method. To verify the design applicability of the iso-angle division method, the results of the safety factor and the displacement according to the change in angle of the cut slope constructed at the existing working design site were reviewed. The safety factor is FS=16~59 on the 1:0.5 slope, FS=12~52 on the 1:0.3 slope, most of which show a 10~12 percent reduction. Displacement is 0.126 to 0.975 mm on the 1:0.5 slope, 0.152 to 1.158 mm on the 1:0.3 slope, and represents an increase of 10 to 15%. This is a slightly change in normal proportion and is in good condition in terms of stability. In terms practical the working design, it was confirmed that applying the shear strength estimated by Iso-angle division method derived from the H-B failure criterion as a universal shear strength for a good continuum rock mass slope was also able to produce stable and economic results. The procedure for stability analysis using LEM (Limit Equilibrium Analysis Method) and FEM (Finite Element Analysis Method) will also be practical in the rock slope where is not distributed fault. The study was conducted by selecting the slope of study area as a good rock condition, establishing a verification for which it can be applied universal to a various rock conditions will be a research subject later on.

• The Korean Journal of Air & Space Law and Policy
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• v.34 no.1
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• pp.39-77
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• 2019

Crew members engaged in international air transportation provide work in many countries due to the nature of their work. According to the Private International Act, the place where the employee habitually carries out his/her work plays an important role in the determination of the governing law of the international labor contract (Article 28, Paragraph 2) and in the decision of international jurisdiction (Article 28, Paragraphs 3 and 4). The concept of the place where the employee habitually carries out his/her work was proposed by the EU to determine international jurisdiction and governing law. In international aviation law, the legislative purpose of the place where the employee habitually carries out his/her work is different from that of home base, which is a concept introduced for fatigue management of the crew in order to secure the aviation safety; thus the place where the employee habitually carries out his/her work and home base are not the same concept. In order to determine the place where the employee habitually carries out his/her work, following matters should be considered comprehensively; (i) where the crew starts and ends work, (ii) where the aircraft the crew is performing work on is primarily parked, (iii) where the crew is informed of the instructions and organizes his/her work activities, (iv) where the crew is obliged to reside according to the labor contract, (v) where there is an office provided by the employer and available to the crew, (vi) where the crew is obliged to be when he/she is ineligible for the work or subject to discipline. However, since all of the above items are the same as the location of the home base, it is reasonable to consider the home base as the most important factor when deciding on the place where the employee habitually carries out his/her work. In contrast, the state where the aircraft is registered (Article 17 of the Chicago Convention), should not be regarded as a place of where the employee habitually carries out his/her work. In this case, CJEU provided the first judging standard for the concept of the place where the employee engaged in international air transportation habitually carries out his/her work. It is the interpretation of the Brussels regulations which became a model -for the Korean Private International Act,- so it would be helpful to understand the concept of the place where the employee habitually carries out his/her work.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.340-347
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• 2019

We performed a safety survey on residual pesticides in dried agricultural products. A total of 110 samples of dried agricultural products distributed in Gyeonggi-do were analyzed for 263 pesticides according to multi class pesiticide multiresidue method. Ten types of pesticides were detected in 10 samples. Chlorpyrifos was detected in Ricinus communis leaves, chlorpyrifos, hexaconazole, pyridalyl in Chwinamul (wild aster), diniconazole, isoprothiolane, lufenuron in radish leaves, hexaconazole in Cirsium setidens (Korean thistle), bifenthrin, and chlorothalonil, boscalid, and pyraclostrobin in pepper leaves. The detection rate of pesticides was 9.1%, and among these samples, one was detected over Maximum Residue Limits (MRLs). In the validation study, the values of limit of detection (LOD), limit of quantitation (LOQ), coefficient of determination ($R^2$) and recovery were in the range of 0.002~0.027 mg/kg, 0.006~0.083 mg/kg, 0.9964~1.0000 and 74.8~118.9%, respectively. The Positive List System (PLS) was newly introduced as part of the safety management of residual pesticide in agricultural products in Korea in 2019. With the application of the PLS, if the MRL is not established, 0.01 mg/kg limit is applied uniformly. In spite, these of strengthened residue limits, the MRLs of dried agricultural products are still insufficient. Therefore, this study could be utilized as basic data for the setting of proper MRLs.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.5
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• pp.66-77
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• 2019

This study investigated the feasibility of wintering evergreen broad-leaf trees in the Incheon coastal area through a climate analysis. The coldest monthly mean air temperature ranged from $-2.9^{\circ}C{\sim}-1.6^{\circ}C$. The warmth index of the coastal area of Incheon ranged from $98.89^{\circ}C{\cdot}month-109.03^{\circ}C{\cdot}month$, while the minimum air temperature year ranged from $-13.9^{\circ}C{\sim}-3.6^{\circ}C$. This proved that the Incheon coastal area was not suitable for evergreen broad-leaf trees to grow as the warmth index ranges from $101.0^{\circ}C{\cdot}month{\sim}117.0^{\circ}C{\cdot}month$, and the temperature year-round is $-9.2^{\circ}C$ or higher. This suggests the coastal areas of Incheon is not suitable for the growth of evergreen broad-leaf trees, however some evergreen broad-leaf trees lived in some parts of the area. Wind speed reduction and temperature effect simulations were done using Landschaftsanalyse mit GIS program. As a result of the simulations of wind speed reduction and temperature effects affecting the evergreen broad-leaf trees, it was discovered that a coastal wind velocity of 8.6m/sec was alleviated to be 5m/sec~7m/sec when the wind reached the areas where evergreen broad-leaf trees were present. It was also discovered that species that grew in contact with buildings benefited from a temperature increase of $1.1^{\circ}C{\sim}3.4^{\circ}C$ due to the radiant heat released by the building. Simulation results show that the weather factors affecting the winter growth damages of evergreen broad-leaved trees were wind speed reduction and local warming due to buildings. The wind speed reduction by shielding and local warming effects by buildings have enabled the wintering of evergreen broad-leaved trees. Also, evergreen broad-leaved trees growing in the coastal area of Incheon could be judged to be gradually adapting to low temperatures in winter. This study reached the conclusion that the blockage of wind, and the proximity of buildings, are required for successfully wintering evergreen broad-leaf trees in the coastal area of Incheon.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.65-71
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• 2019

With regard to current Neck CT, Bismuth shielding boards are often being used to reduce exposure to superficial organs such as the thyroid. However, beam hardening often occurs near superficial organs with Bismuth shielding boards and variations in CT Number, Noise, and Uniformity values occur severely. This study looked into the usefulness of shielding boards made from aluminum and silicone that can be easily obtained and have good machinability by comparing them to the existing Bismuth shielding board. An Aluminum 7.3mm and a Silicone 21.5mm were made with shielding ratios similar to that of the Bismuth(0.06 mmPb). TLD (TLD-100) was placed on the thyroid area of the Phantom (RS-108T) and 5 doses were measured for each. To compare image quality, CT Number and Noise variations in axial images of the thyroid area in Neck CT images were compared. Also, variations in CT Number, Noise, and Uniformity were measured in the AAPM phantom images and compared. In the results, when thyroid doses for each shielding board were compared, the Bismuth shielding board showed a 14% reduction, the Silicone 21.5mm showed a 15% reduction, and the Aluminum 7.3mm showed a 13% reduction compared to the Non-Shield. Statistically, there were no significant differences in comparison with the Bismuth shielding board. In CT Number variations of thyroid area images, variations were largest for the Bismuth shielding board. With Uniformity evaluations of the AAPM phantom, the Bismuth shielding board was found unsuitable and the Aluminum 7.3mm and Silicone 21.5mm satisfied the acceptance criteria. Research results show that the Aluminum 7.3mm and Silicone 21.5mm have a similar shielding ratio to the high-priced Bismuth shielding board that is currently being used clinically and in comparison tests of CT Number attenuation coefficient variations, Noise, and Uniformity which are phantom image evaluation items, they proved to be better than Bismuth shielding boards. If various shielding boards are made using aluminum and silicone, sized appropriately for superficial organs, it would be useful in decreasing patient doses.

• Journal of Food Hygiene and Safety
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• v.34 no.2
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• pp.191-198
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• 2019

This study investigated the residual characteristics of bifenthrin and chlorothalonil in crown daisy and suggested pre-harvest residue limits (PHRLs) based on their dissipation patterns and biological half-lives. The samples for residue analysis were harvested at 0 (3 hr), 1, 3, 5, 7, 9, 11, 13, 15, 18, 22 and 26 days after treatment, and analyzed by $GC/{\mu}-ECD$ and TOF/MS. The limit of quantitation (LOQs) of bifenthrin and chlorothalonil were 0.0046 mg/kg and 0.0007 mg/kg, respectively. Recoveries ranged from $88.67{\pm}7.97%$ and $99.90{\pm}16.03%$, showing that this method is appropriate for the analysis of the pesticide residues in crown daisy. Being well within first order kinetics, the biological half-lives of the pesticide residues in crown daisy were 9.63 days for bifenthrin and 6.54 days for chlorothalonil. The PHRLs of bifenthrin and chlorothalonil were recommended as 11.70 mg/kg and 24.10 mg/kg for 26 days before harvest, respectively.

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.60-67
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• 2021

In this study we investigated pesticide residues on herbs and spices disrtibuted in the Incheon Metropolitan area. A total of 112 samples were purchased from off-line and on-line markets from January to October 2020. In accordance with the implementation of the Positive List System (PLS), the proper usage of pesticides is now being enforced. It is assumed that unregistered pesticides are being used on herbs and spices due to the low number of registered pesticides in the agricultural industry. Pesticide residue levels were not detected in 99 samples but 11 kinds of pesticides in 6 samples (13 times) exceeded the MRLs. The pesticides that were used in accordance with the PLS were Diazinon, Diethofencarb and Pyridalyl. However, unregistered pesticides were on the herbs and spices. Therefore, it is necessary to educate producers of herbs and spices on the appropriate use of pesticides. It is also necessary to establish MRLs on herbs and spices.

• Knowledge Management Research
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• v.22 no.2
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• pp.119-144
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• 2021

Recently, as competition in the market evolves from the competition among companies to the competition among their supply chains, companies are struggling to enhance their supply chain management (hereinafter SCM). In particular, as blockchain technology with various technical advantages is combined with SCM, a lot of domestic manufacturing and distribution companies are considering the adoption of blockchain-oriented SCM (BOSCM) services today. Thus, it is an important academic topic to examine the factors affecting the use of blockchain-oriented SCM. However, most prior studies on blockchain and SCMs have designed their research models based on Technology Acceptance Model (TAM) or the Unified Theory of Acceptance and Use of Technology (UTAUT), which are suitable for explaining individual's acceptance of information technology rather than companies'. Under this background, this study presents a novel model of blockchain-oriented SCM acceptance model based on the Technology-Organization-Environment (TOE) framework to consider companies as the unit of analysis. In addition, Value-based Adoption Model (VAM) is applied to the research model in order to consider the benefits and the sacrifices caused by a new information system comprehensively. To validate the proposed research model, a survey of 126 companies were collected. Among them, by applying PLS-SEM (Partial Least Squares Structural Equation Modeling) with data of 122 companies, the research model was verified. As a result, 'business innovation', 'tracking and tracing', 'security enhancement' and 'cost' from technology viewpoint are found to significantly affect 'perceived value', which in turn affects 'intention to use blockchain-oriented SCM'. Also, 'organization readiness' is found to affect 'intention to use' with statistical significance. However, it is found that 'complexity' and 'regulation environment' have little impact on 'perceived value' and 'intention to use', respectively. It is expected that the findings of this study contribute to preparing practical and policy alternatives for facilitating blockchain-oriented SCM adoption in Korean firms.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.69-79
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• 2022

The purpose of this study is to monitor the pesticide residues in frozen fruits and vegetables distributed and sold in online and offline markets in Korea. For the study, 107 samples of 34 types of frozen fruits and vegetables were examined, and a total of 341 pesticide residues were analyzed by using multiclass pesticide multi-residue methods of the Korean Food Code. As a result, pesticide residues were detected from 16 of 64 frozen fruits samples and 15 of 43 frozen vegetables samples. Conclusively, residues were detected from 31 samples in total, showing a detection rate of 29.0%. Specifically, pyridaben exceeded the Maximum Residue Limits (MRLs) based on the Positive list system (PLS) in one of the frozen radish leaves, and the violation rate was 0.9%. Detection on frozen fruits and vegetables was made 23 times for 11 types and 36 times for 21 types. In total, 28 types of pesticide residues were detected 59 times. Fungicides were detected the most in frozen fruits, while insecticides were detected the most in frozen vegetables. The most detected pesticides were the insecticide, acaricide chlorfenapyr (5) and the fungicide boscalid (5). Chlorfenapyr was detected only in frozen vegetables, and boscalid was detected in frozen fruits except one.