• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.59-66
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• 2024

In this paper, the method to design the antenna, which is suitable for an impulse-like waveform radiation, is presented. In general, the impulse-like waveform has its spectrum of around sub GHz bandwidth and the antenna should be properly designed for not only operating wide-bandwidth also reflecting the time domain characteristics for near-zone impulse radar applications. In this regard, Vivaldi antenna has been designed and characterized in terms of short-pulse radiating aspects in the time domain and verified by measured results. The designed antenna has shown to be operating within wide-bandwidth and to be stable for the input impedance from 1.8 to more than 10GHz. The far-zone radiating waveform has been investigated on each plane at the interval of 30degree and the designed antenna has shown to be a directive characteristic. It can be seen that those results proposed are widely applicable to the near area sensing applications such as ground-penetrating radar.

• The Korean Journal of Pesticide Science
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• v.7 no.4
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• pp.264-270
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• 2003

To control effectively and safely Phytophthora root rot caused by Phytophthora capsici on tomato in hydroponic culture, tank-mixing method was considered with two pesticides, metalaxyl copper oxychloride 50% WP and dimethomorph dithianon 38% WP. Forty days after transplanting of tomato seedlings, 4 mL of sporangia of P. capsici (about 25 sporangi/mL) per plot was inoculated around tomato plant roots, and at 5 days after inoculation, the pesticides tank-mixed at three dilution levels, 12,500, 25,000 and 50,000, were drenched 1, 2 or 3 times per plot on the culture cube every 15 days for metalaxyl copper oxychloride 50% WP and every 10 days for dimethomorph dithianon 38% WP. During the drenching period, the residue levels of metalaxyl and dimethomorph in hydroponic culture solution were similar to the initial levels but the level of dithianon was drastically decreased from one day after tank-mixing. In tomato drenched with metalaxyl copper oxychloride 50% WP, metalaxyl was detected $0.02\sim0.04$ mg/kg in all diluted plots. Dimethomorph was detected $0.012\sim0.021$, $0.001\sim0.006$ and $0.001\sim0.003$ mg/kg in 12,500, 25,000 and 50,000 times diluted plots, respectively, while dithianon was detected 0.005, 0.003 mg/kg in 12,500 and 50,000 times diluted plots, respectively. The detection levels of three pesticides were far below compared with the levels of Korean MRLs. Incidences of Phytophthora root rot were not found in all the plots, but phytotoxic responses were recognized in the 12,500 times diluted plots of both pesticides. Based on the above results, the drenching of the culture solution tank-mixed with these pesticides could be recommended as a very safe and effective method to control Phytophthora root rot in tomato in hydroponic culture.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.258-268
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• 2014

The test method of aerobic transformation in soil has established based on international test guideline (OECD TG 307). And then, the case study was conducted with [$^{14}C$]butachlor. Butachlor is commonly used herbicide in Korea. [$^{14}C$]Butachlor was treatrd $6.83mgKg^{-1}$ in loamy soil. The treated soil was incubated in flow-through system for 60 days. The mass balance of applied radioactivity (AR) ranged from 91.1 to 95.5% and from 93.0% to 97.7% for non-sterile and sterile soils, respectively. In non-sterile soil, the concentration of [$^{14}C$]butachlor was declined from 94.4% AR at 0 day to 8.4% AR at 60 days after treatment. 2-Chloro-2',6'-diethylacetanilide was the major degradation product detected in soil extract. The calculated $DT_{50}$ and $DT_{90}$ of butachlor were 10.4 days and 34.6 days, respectively. $^{14}CO_2$ and non-extractable soil residue were increased up to 3.5% and 43.5% AR at 60 DAT. There is no significant decrease of the [$^{14}C$]butachlor through the incubation period in sterile soil.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.281-287
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• 2020

The purpose of this study is to examine whether the effect of service satisfaction regarding the accessibility of child care services varies between dual-earner and single-earner families. In particular, we conducted the analysis by dividing the service accessibility into sub-areas. The study sample consisted of 267 parents living in Seoul and Gyeonggi region. As a result of the analysis, accommodation in use time and affordability influenced satisfaction in the single-earner families, and information acquisition and acceptability in the dual-earner families. For single-earner families, the more convenient the use time of the childcare institution and the less the service cost burden, the higher the satisfaction. The dual-earner families had higher satisfaction levels if it was easier to obtain information about the childcare centers and weaker the religious characteristics of the childcare centers. Based on the research results, it is necessary to differentiate the burden of cost and provide more flexible operation of childcare service operating hours. In addition, it is necessary to devise a policy method to increase the transparency of information to childcare institutions.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.350-356
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• 2012

Performance of proficiency testing and the validation of analytical method was included a scheme of quality assurance in analytical chemistry laboratory to monitor a laboratory's performance abilities and produce consistently reliable data. This study was assessed the applicability of proficiency testing scheme proposed for analytical laboratories of pesticide product in domestic. The validation of analytical methods, stability and homogeneity for formulated pesticide products (emulsifiable concentrate) of emamectin benzoate and lufenuron was confirmed for the proficiency testing. The z-score of 33 participation laboratories for emamectin benzoate were that the numbers of outlier were 2 laboratories (6.0%), z-score outside the range from -3 to 3 designated "unaccptable" were 2 laboratories and z-score in the ranges -2 to -3 and 2 to 3 designated "questionable" were 3 laboratories (9.0%). Three laboratories (9.0%) showed the z-score designated "questionable" for lufenuron. The additional proficiency testing for various product types will be needed to establish the scheme of quality control.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.367-380
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• 2013

In this study, sub-indicators, and thematic mid-indexes to evaluate the water use characteristics were selected through historical data analysis and factor analysis, and consisted of the subject approach framework. And the integrated index was developed to evaluate water use characteristics of the watershed. Using developed index, the water use characteristics were assessed for 812 standard basins with the exception for North Korea using data of 1990 to 2007 from the relevant agencies. A sensitivity analysis is conducted for this study to determine the proper way through various normalization and weighting methods. To increase the objectivity of developed index, the history of the damage indicators are excluded in the analysis. In addition, in order to ensure its reliability, results from index with and without consideration of the damage history were compared. Also, the index is also applied to real data for 2008 Gangwon region to verify its field applicability. Through the validation process this index confirmed the adequacy for the indicators selection and calculation method. The results of this study were analyzed based on the spatial and time vulnerability of the basin's water use, which can be applied to various parts such as priority decision-making for water business or policy, mitigations for the vulnerable components of the basin, and supporting measures to establishment by providing relevant information about it.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.597-607
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• 2023

Purpose: The Ministry of Employment and Labor has been working hard to ensure the safety of workers due to heavy rain during natural disasters as the responsible ministry in charge of preventing industrial accidents and health problems for workers. Accordingly, the Ministry of Employment and Labor intends to analyze actual cases of responding to heavy rain disasters and suggest ways to improve the response system. Method: An emergency response system implemented to respond to heavy rain disasters with an internal expert group composed of those in charge of disaster work at headquarters, local government offices, and Korea Occupational Safety and Health Agency, and an external expert group composed of professors, consulting representatives, and disaster managers from other ministries. Contents on self-inspection by industry, workplace inspection, use of serious siren, safety management and restoration work guidance were reviewed. Result: First of all, it is necessary to check the regular contact system from time to time, and it is also necessary to prepare and distribute detailed self-checklists for each industry. In addition, it is necessary to check the implementation of self-inspection when inspecting workplaces, and it seems necessary to have measures to increase the readability of information notified through serious disaster sirens. In addition, since safety work is done in the form of a contract, it seems necessary to prepare specific safety guidelines. Conclusion: In order to protect the lives of workers due to seasonal harm and risk factors, unlike the passive coping methods of the past, abnormal weather should not be regarded as an unexpected situation, and it should be actively and preemptively responding beyond the conventional framework.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.656-664
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• 2023

Purpose: The Ministry of Employment and Labor manages disasters based on the standard manual for risk management of large-scale human accidents in workplaces when large-scale disasters such as fires and collapses occur in workplaces. We are going to check the standard manual currently in operation and suggest improvement plans for the insufficient items. Method: Accordingly, the standard manual was checked together with internal and external experts in the disaster management manual and disaster management staff at headquarters and local government offices, and items to be improved were identified with priority. Result: In case of a collapse accident, it is necessary for the Ministry of Public Administration and Security to accurately present the selection criteria in order to eliminate the controversy over the selection of the disaster management department. In addition, it seems necessary to supplement the details of the disaster safety communication network operation and evacuation guidelines. Conclusion: In the future, in order to improve the disaster management system that meets the public's eye level, it is expected to prepare a standard manual for risk management of large-scale human accidents in workplaces that guarantees the lives and safety of workers through the collection of opinions from experts in the relevant field, disaster management personnel, and the general public.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.806-814
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• 2023

Purpose: According to the Occupational Safety and Health Act of the Ministry of Employment and Labor, in order to prevent industrial accidents, the right to stop work must be exercised in the event of an imminent danger. This study conducted a fact-finding survey on whether employers fulfilled the right to suspend work in the workplace when an imminent danger, such as a typhoon, was encountered. Method: For two days from August 9 to October, when the impact of Typhoon Khanun No. 6 was significant, it was confirmed by wire whether or not the work suspension was carried out at the workplace, and the subjects of the survey were 1,649 construction sites, 830 manufacturing sites, and 278 other industries, for a total of 2,757 sites. Result: As a result of the fact-finding survey, 56% (1,555 locations) on August 9th and 77% (2,142 locations) on August 10th carried out full or partial work suspension. In particular, on August 10, when the typhoon landed, 40% of all workplaces completely stopped work. Conclusion: Through this study, it was confirmed that the right to suspend work by employers is being used in actual workplaces. In the future, when there is an imminent danger, in addition to the right to suspend work, flexible and telecommuting, working hour adjustments, etc. must be actively used to ensure the safety of workers and protect their lives.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.304-307
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• 2005

Multiresidue method was set up for the simultaneous determination of various residual pesticides in potatoes and carrots, which was analyzed by gas chromatography-electron capture detector/nitrogen phosphorus detector. Method consisted with acetone/acetonitrile (9 : 1) extraction and dichloromethane partition, followed by florisil cartridge purification with hexane/dichloromethane/acetonitrile (50 : 45 ; 5) elution. Among 197 pesticides (194 kinds) spiked to food materials, 143 and 155 pesticides were recovered over 70% on potatoes and carrots, respectively. Nineteen pesticides including bromacil, cyproconazole, were not detected in water and sample matrices. Matrix components may affect the low detections of 25 pesticides such as benfuracarb, bitertanol from potatoes and 16 pesticides such as bitertanol, carbosulfan from Carrots. Some pesticides including dichlobenil, fluoroimide and iprodione were highly detected from one or both matrices even though they were not detected from water.