• The Journal of Engineering Geology
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• v.28 no.3
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• pp.411-429
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• 2018

Daeyoung mine (also called "Daema mine") produced gold and silver from mainly gold- and silver-bearing quartz veins. The mine tailings are a waste hazard, but most of the tailings were swept away or dispersed throughout the area around the mine long before the tailing dump areas were transformed into agricultural land. Soil liner and protection facilities, such as retaining walls, were constructed in the mine area to prevent the loss of tailings. The content of the tailings is 3,424.41~3,803.61 mg/kg, which exceeds the safety standard by a factor of 45. In addition, contamination was detected near agricultural areas and in the sediments in downstream drainage channels. A high level of As contamination was concentrated near the waste tailings yard; comparaable levels were detected in agricultural areas close to streams that ran through the waste dump yard, whereas the levels were much lower in areas far from the streams. The contamination in stream sediments showed a gradual decrease with distance from the mine waste yard. Based on these contamination patterns, we concluded that there are two main paths that affect the spread of contaminants: (1) loss of mine waste, and (2) the introduction of mine waste into agricultural areas by floods after transportation by streams. The agricultural areas contaminated by mass inflow of mine waste can act as contamination sources themselves, affecting other agricultural areas through the diffusion of contaminants. At present, although the measured effect in minimal, sediments in streams are contaminated by exposed mine waste and surface liners. It is possible for contaminants to diffuse or spread into nearby areas if heavy elements trapped in soil grains in contaminated agricultural areas leach out as soil solution or contaminant particles during diffusion into the water supply.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.111-116
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• 1994

The role of $Ca^{2+}$/calmodulin-dependent protein kinase II in the increase of myofilament $Ca^{2+}$ sensitivity by agonist and GTP was investigated in rabbit mesenteric ${\alpha}-toxin$ permeabilized artery. $0.3{\mu}M\;Ca^{2+}$ increased myosin light chain phosphorylations monotonically. $10\;{\mu}M$ norepinephrine and $10\;{\mu}M$ GTP potentiated increase of myosin light chain phosphorylations by $0.3{\mu}M\;Ca^{2+}$, which reaches a peak at 5 min and gradually declines to the $Ca^{2+}$ alone level at 20 min. At the early phase (1 min), $10\;{\mu}M$ KN 62, the inhibitor of $Ca^{2+}$/calmodulin-dependent protein kinase II , decreased myosin light chain phosphorylation levels by $10\;{\mu}M$ norepinephrine and $10\;{\mu}M$ GTP in the presence of $0.3{\mu}M\;Ca^{2+}.\;However\;10\;{\mu}M$ KN-62 did not affect the myosin light chain phosphorylations by $10\;{\mu}M$ norepinephrine and $10\;{\mu}M$ GTP in the presence of $0.3{\mu}M\;Ca^{2+}$ at the peak (5 min) and plateau phases (20 min). From these results, the role of $Ca^{2+}$/calmodulin-dependent protein kinase II may be different depending on time, which may play a role in increase of myofilamint $Ca^{2+}$ sensitivity by norepinephrine and GTP resulting from increase of myosin light chain phosphorylations at the early phase. However, at plateau phase, $Ca^{2+}$/calmodulin-dependent protein kinase II may not be involved in the increase of myofilament $Ca^{2+}$ sensitivity by norepinephrine and GTP in rabbit mesenteric ${\alpha}-toxin$ permeabilized artery.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.247-257
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• 2014

Assessment for operator's dermal and inhalation exposure to acetamiprid during cultivation of water melon in greenhouse was carried out. For dermal exposure measurement, whole body dosimetry (WBD) was performed as the first trial in Korea. WBD consists of cotton/polyester outer clothes and cotton inner clothes. Hand exposure was measured by washing of nitrile gloves and hands while head exposure was monitored by face/neck wipe technique. Inhalation exposure was monitored with personal air sampling pumps and IOM sampler (glass fiber filter). Analytical limit of quantitation was 2.5 ng/mL. Good reproducibility (C.V < 8.7%), linearity ($R^2$ > 0.99) and recovery (70~119%) were obtained. Field recovery of acetamiprid was 77~95%. During mixing/loading, hand exposure of acetamiprid was about 10 times ($229.7{\mu}g$) more than that of application case ($20.9{\mu}g$). During application, total dermal exposure was $1207.4{\mu}g$. Exposure of lower legs was $1132.1{\mu}g$, which is 93.8% of the total dermal exposure. Inhalation exposure during mixing/loading and application was not detected. Margin of safety (MOS) was calculated for risk assessment using male Korean average body weight (70 kg) and acceptable operator exposure level ($124{\mu}g/kg/day$) to give 140, suggesting that health risk of operator during treatment of acetamiprid for water melon in greenhouse could be safe.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.131-138
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• 2018

In this study, we investigated the trend of technological development in major countries related to the propulsion equipment of railway vehicles. The propulsion system is the main equipment of electric vehicles. A lot of time and investment are required in order to ensure the development of technology. Therefore, developed countries have maximized their effort to develop technologies with safety, reliability, and convenience of maintenance. They have also done their utmost to prevent technology transfer to other countries after the development of new technologies. For example, Toshiba of Japan developed a new 3,300V/1,500 A class IGBT power device, but was reluctant to export it to foreign countries in order to protect this technology. In this study, we analyzed the patents applied for related to propulsion control systems and presented the direction of development during the technical development of these systems. The patent analysis of the core technologies was conducted using the Thomson Innovation DB. We examined the number of patents applied for by country, year and major applicant. As a result of the analysis, it was found that the proportion of patent applications per country was in the order of China, 48%, Europe 16.6%, and the United States 14.9%. The patent situation of the top 10 principal applicants revealed that (the top three were?) ABB 14%, GE 13%, and CRRC 12%. At the same time, we also conducted a qualitative analysis of the level of technical development by evaluating such factors as the influence index, quotation, market securing power and citation. Based on the result of the patent analysis, we presented the direction of technical development of the propulsion control equipment of railway vehicles. Based on the analysis results, it was found that domestic applicants considerably reduced their efforts to protect their patents from foreign companies. Nowadays, most of the electric motors used in Korea are induction motors. In advanced countries, permanent magnet electric motors are employed in new railway lines. Therefore, intensive investment is needed in new developments.

• Journal of Nutrition and Health
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• v.53 no.1
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• pp.54-67
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• 2020

Purpose: This study examined the relationship between job stress, attributes of health functional food (HFF) selection, and consumption values for information technology (IT) workers, and analyzed the factors influencing the selection of HFF to improve health by making the right choice of HFFs. Methods: Three hundred forty IT workers in Gyeonggi area participated in the study. The participants were divided into low or high job stress group. The differences in participants' general characteristics, attributes of HFF selection, and HFF consumption values were investigated, and the mediating effects of HFF consumption values on the relationship between job stress levels and the HFF selection attributes were analyzed. Results: Job stress levels were high in those IT workers with a length of service < 5 years (p = 0.013). The group with lower job stress levels had a higher tendency to consider the ingredients contained in HFF products (p < 0.001), and their efficacy (p = 0.047). They also showed greater emotional value for a sense of security from consuming HFFs to stay healthy (p = 0.047). The group with higher job stress levels had greater epistemic value in that their choice of HFFs differentiated them from the other workers (p = 0.036). Higher job stress was associated with less consideration of the intrinsic attributes such as ingredients and efficacy of the HFF selection attributes (p = -0.113), emotional value of the HFF consumption values (p = -0.136), and the functional value such as practicality, price, and safety (p = -0.134). The job stress level influenced the intrinsic attributes through the functional and emotional values, demonstrating that the functional and emotional values had appropriate mediating effects on the relationship between job stress levels and intrinsic attributes. Conclusion: Education needs to be provided for workers to relieve job stress and improve the functional and emotional values, which contributes to choosing the appropriate HFFs.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.311-318
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• 2010

U. S. NRC Regulation Guide 1.52 regulating ESF ACS in nuclear power plants has been revised to revision 3. To apply reduction of operability test time, allowance of alternative challenge agents for in-place leak test of HEPA filters, and upgrade of Methyl Iodide penetration acceptance criterion in activated carbon performance test suggested in Reg. Guide 1.52(Rev.3) on Yonggwang units 5 and 6 ESF ACSes, technical feasibility study was carried out with on-site experiments as well as experiments with a lab-scale model. It was confirmed that the moisture in the system returned to the level before the test in 1 or 4 days even though the moisture was removed during the operability test lasting more than 10 hours. Therefore, it is appropriate to perform monthly operability test in 15 minutes just long enough to check the operability of equipment. To change challenge material for in-place HEPA filter leak test, size of aerosol, production rate, and leak detection capability were compared for DOP and PAO. It was concluded that PAO can be substituted for DOP in nuclear power plants. The upgrade of Methyl Iodide penetration acceptance criterion from 0.175 % to 0.5 % in active carbon filter bed deeper than 4 inches was to conform to the change of activated carbon performance test method to ASTM D3803(1989). It was confirmed that Methyl Iodide penetration acceptance criterion of 0.5 % under $30^{\circ}C$, relative humidity 95 % condition was conservatively good enough for testing performance of active carbon insitu. The licence change of Yonggwang units 5 and 6 has been completed based on this study.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.49-61
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• 2017

The study was conducted for safety evaluation of 208 kinds of residue pesticides on 200 dried agricultural products, which are distributed in Gwangju. The method of monitoring was the second of Multi Class Pesticide Multi-residue Methods in Korean Food Code, and GC-ECD, GC-NPD, GC-MSD, and LC-MS/MS were used as evaluation equipment to analyze. The residue level in pesticides were 15.5% (31 of 200 samples) and 4 samples exceeded MRLs. 4.5 mg/kg of pyraclostrobin (MRL; 3.0 mg/kg) was detected in red pepper, 1.49 mg/kg of chlorpyrifos (MRL; 0.13 mg/kg) in daikon leaves, 38.26 mg/kg of pyridalyl (MRL; 0.25 mg/kg) in pepper leaves, 0.98 mg/kg of chlorpyrifos (MRL; 0.05 mg/kg), respectively. Pesticides were found on the 15 samples among the 21 samples of red pepper which is a fruit vegetable, and this resulted in high detection rate of 71%. In addition, pesticides were detected on chwinamul, shitake, siler divaricata, daikon leaves and others within MRLs. The frequent detected kinds of pesticides were insecticide (47.6%), fungicide (33.3%), acaricide (14.3%), nematicide (4.8%) in the order named, and pesticides were methoxyfenozide > pyraclostrobin > azoxystrobin, chlorantraniprole > novaluron, trifloxystrobin in frequent order.

• Korean Security Journal
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• no.34
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• pp.89-113
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• 2013

Travel by airplane using airport in globalized modern society is familiar to our life but such airport can be a target of terrorists who would threaten our safety. However, aviation terrorism which is represented by 9.11 terror gives horror beyond our imagination to modern people. Since the first airplane hijacking in Peru in 1931 happened, security organization in each nation has taken various prevention measures to block aviation terrorism. The most realistic measures to prevent aviation terrorism would be security check activity to control approach of terrorist that passengers on airplane and cargos are checked to find out dangerous article like explosive etc. But security check activity in Korea shifted to security check activity focused on private security for efficiency of airport operation differently from security check activity in advanced countries where public interests is strengthened according to risk of terror after 9.11 system. That is, since Incheon airport opened in March 2001, security check system focused on the police was changed. Now Incheon international airport Corporation instructs and supervises security check job and private security personnel are in charge of actual security check activity. But this check system has limitation in blocking terror activity by terrorists which is systematized and intelligent as time passes due to deteriorated job satisfaction of private security personnel and confusing supervising system. Accordingly, it is suggested to introduce risk management skill which is one of management strategy of private corporation for security check activity to prevent terror activity. With this skill, risk factors of aviation terror are identified and analyzed regularly, and each process such as setting of priority, activity to reduce risk, and assessment of security is carried out. And it would be necessary to do efforts, for example, to properly change level of security check according to threat of terror such as to place policeman at airport security in case threat of terror is severe. On the other hand, it is necessary to establish national police organization for good communication of security check activity in field and supervising function, which can encourage systematization and specialization of aviation security job.

• Korean Security Journal
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• no.59
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• pp.37-69
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• 2019

According to viewpoints of researchers and stakeholders, various opinions can be suggested on self-governing police system. Therefore, success of Korean self-governing police system will be defending on how to balance among conflicting values such as Empowerment, Political neutrality, Financial issues, Comprehensive competence in maintaining public safety. Before the launching of self-governing police system nation-wide, the experience of Jeju provincial police will be valuable model case. In specific, enlargement of work scope of self-governing police in Jeju province which has been introduced since last year will be a useful reference. There is more pessimism about self-governing police of Jeju province so far. However, this perspective is mostly based on the issue regarding hardwares such as manpower, equipment, law and organization. Issues regarding softwares such as organizational culture, operation system and work process need more attention to evaluate self-governing police system properly. To mark the first year after enlargement of work scope of Jeju police, this study demonstrate the overall result and implications of self-governing police of Jeju province based on documents, statistics, reports and media reports. In result, several preconditions are needed to implement the self-governing police system nation-wide successfully. 1. Strengthen the link between local government and local police 2. Establish the foundation for collaboration of state and local police 3. Enhance the aspect of citizen autonomy in local level 4. Reinforcing the capability of handling situation of state and local police 5. Invigorating the inter-organizational working group to operate self-governing police system effectively. The self-governing police system is unclosed topic to discuss. After this study, in-depth studies should be followed with more resources. Particularly, additional perspective including redundancy and equity need to be considered regarding self-governing police. By getting with the changes of macroscopic trends - lowbirth and aging, the fourth industrial revolution and possible reunification of north and south Koreas - these studies should suggest the long-term blueprint of self-governing police system of Korea.

• KDI Journal of Economic Policy
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• v.30 no.1
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• pp.71-130
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• 2008

Using data from the Korean Labor & Income Panel Study (KLIPS), this study investigates private income transfers in Korea, where adult children have undertaken the most responsibility of supporting their elderly parents without well-established social safety net for the elderly. According to the KLIPS data, three out of five households provided some type of support for their aged parents and two out of five households of the elderly received financial support from their adult children on a regular base. However, the private income transfers in Korea are not enough to alleviate the impact of the fall in the earned income of those who retired and are approaching an age of needing financial assistance from external source. The monthly income of those at least the age of 75, even with the earning of their spouses, is below the staggering amount of 450,000 won, which indicates that the elderly in Korea are at high risk of poverty. In order to analyze microeconomic factors affecting the private income transfers to the elderly parents, the following three samples extracted from the KLIPS data are used: a sample of respondents of age 50 or older with detailed information on their financial status; a five-year household panel sample in which their unobserved family-specific and time-invariant characteristics can be controlled by the fixed-effects model; and a sample of the younger split-off household in which characteristics of both the elderly household and their adult children household can be controlled simultaneously. The results of estimating private income transfer models using these samples can be summarized as follows. First, the dominant motive lies on the children-to-parent altruistic relationship. Additionally, another is based on exchange motive, which is paid to the elderly parents who take care of their grandchildren. Second, the amount of private income transfers has negative correlation with the income of the elderly parents, while being positively correlated with the income of the adult children. However, its income elasticity is not that high. Third, the amount of private income transfers shows a pattern of reaching the highest level when the elderly parents are in the age of 75 years old, following a decreasing pattern thereafter. Fourth, public assistance, such as the National Basic Livelihood Security benefit, appears to crowd out private transfers. Private transfers have fared better than public transfers in alleviating elderly poverty, but the role of public transfers has been increasing rapidly since the welfare expansion after the financial crisis in the late 1990s, so that one of four elderly people depends on public transfers as their main income source in 2003. As of the same year, however, there existed and occupied 12% of the elderly households those who seemed eligible for the National Basic Livelihood benefit but did not receive any public assistance. To remove elderly poverty, government may need to improve welfare delivery system as well as to increase welfare budget for the poor. In the face of persistent elderly poverty and increasing demand for public support for the elderly, which will lead to increasing government debt, welfare policy needs targeting toward the neediest rather than expanding universal benefits that have less effect of income redistribution and heavier cost. Identifying every disadvantaged elderly in dire need for economic support and providing them with the basic livelihood security would be the most important and imminent responsibility that we all should assume to prepare for the growing aged population, and this also should accompany measures to utilize the elderly workforce with enough capability and strong will to work.