• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.415-422
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• 2018

Lycorma delicatula, known as spotted lanternfly, is a planthopper native to Southeast Asia, including Vietnam, India and South China. This species damages local fruit trees and has spread rapidly in South Korea in recent years. The purpose of this study is to present the methods and estimation results pertaining to the risk of invasive species like Lycorma delicatula. We used a partial budget (PB) method to assess direct income reduction of farm households and a partial equilibrium (PE) model to examine social welfare change from the outbreak of Lycorma delicatula. We also estimated the future economic impacts of Lycorma delicatula under various climate scenarios considering habitat suitability. As climate change progresses, domestic ecosystems are expected to become increasingly vulnerable to pest outbreaks leading to further economic damage. We believe that this study can be a base to evaluate efficiency of the national pest control and quarantine system.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.318-326
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• 2016

Two phosphate solubilizing bacteria, Pantoea rodasii PSB-11and Enterobacter aerogenes PSB-12, were isolated from button mushroom compost and employed to assess their synergistic effect in liquid medium and on growth of green gram plants by single and co-inoculation of the strains. Co-inoculation of two strains was found to release the highest content of soluble phosphorus ($521{\mu}g\;ml^{-1}$) into the medium, followed by single inoculation of Pantoea strain ($485{\mu}g\;ml^{-1}$) and Enterobacter strain ($470{\mu}g\;ml^{-1}$). However, there was no significant difference between single inoculation of bacterial strain and co-inoculation of two bacterial strains in terms of phosphorous release. The highest pH reduction, organic acid production and glucose consumption was observed in the E. aerogenes PSB-12 single inoculated culture medium rather than those of co-inoculation. According to the plant growth promotion bioassay, co-inoculated mung bean seedlings recorded 10.6% and 10.7% higher shoot and root growth respectively compared to the control. Therefore, in concluding, co-inoculation of the strains P. rodasii and E. aerogenes displayed better performance in stimulating plant growth than inoculation of each strain alone. However, being short assessment period of the present study, we recommend in engaging further works under field conditions in order to test the suitability of the strains to be used as bio-inoculants.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.8-14
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• 2020

According to the statistics provided by Korean Maritime Safety Tribunal for the year 2018, the majority of marine accidents in the past four years have occurred in fishing boats and small-sized boats. Negligent behavior resulting from not looking outside and non-compliance with navigation laws are the primary reasons behind ship collisions. Although safety education and training are reinforced to prevent such accidents, they still occur frequently. Hence, technical methods are continuously being developed to reduce ship collisions caused by human cause. The objective of this study is to reduce ship collisions by employing the WAVE communication system, which has short transmitting and receiving periods that can be incorporated for high-speed small-sized vessels. In this study, the suitability of the communication range was examined, and the appropriate range and timing for avoidance motion were accordingly selected, and a control algorithm based on the same was thereby designed. Consequently normal operation of the collision avoidance system was verified by connecting and simulating the proposed WAVE communication router-controller-steering equipment.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.4
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• pp.300-308
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• 2009

In a pursuit of the development of alternative mobile power sources with a high energy density, a planar and air-breathing PEMFCs with a new type of hydrogen cartridge which uses onsite $H_2$ generated from sodium borohydride ($NaBH_4$) hydrolysis have been investigated for use in advanced power systems. Two types of $H_2$ generation through $NaBH_4$ hydrolysis are available: (1) using organic acids such as sulphuric acid, malic acid, and sodium hydrogen carbonate in aqueous solution with solid $NaBH_4$ and (2) using solid selected catalysts such as Pt, Ru, CoB into the stabilized alkaline $NaBH_4$ solution. It might therefore be relevant at this stage to evaluate the relative competitiveness of the two methods mentioned above. The effects of flow rate of stabilized $NaBH_4$ solution, MEA (Membrane Electrode Assembly) improvement, and type and flow control of the catalytic acidic solution have been studied and the cell performances of the planar, air-breathing PEMFCs using $NaBH_4$ has been measured from aspects of power density, fuel efficiency, energy density, and fast response of cell. In our experiments, planar, air-breathing PEMFCs using $NaBH_4$ achieved to maximum power density of 128mW/$cm^2$ at 0.7V and energy efficiency of 46% and has many advantages such as low operating temperature, sustained operation at a high power density, compactness, the potential for low cost and volume, long stack life, fast star-up and suitability for discontinuous operation.

• The Journal of Engineering Geology
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• v.30 no.1
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• pp.1-15
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• 2020

The Mohr-Coulomb model is mainly used in evaluating the behavior of the ground in numerical analyses of domestic ground excavation. This study analyzes its limitations and compares its numerical results with the hyperbolic model, a model that closely follows actual ground behavior during excavation. Recent applications of the Mohr-Coulomb model in Korea have tended to impose arbitrary special boundary conditions to control the problem of excessive heaving of the ground excavation surface. This adjustment only controls the size of the heaving of the excavation surface, implying that the ground behavior is distorted from the actual behavior. This study compares results from the hyperbolic model (hardening soil model) and the Mohr-Coulomb model, and confirms that the hyperbolic model provides both a more-suitable solution to the problem of heaving during excavation and the actual stress-strain behavior. In numerical analyses of ground excavation, the hyperbolic model is expected to give results consistent with the actual ground behavior.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.342-348
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• 2013

In this paper, the evaluation method for the responsivity and noise characteristics of an infrared thermal imaging camera was presented. Signal transfer function and noise equivalent temperature difference of the infrared thermal imaging camera were obtained by using a differential mode blackbody that is able to control the temperature difference ${\Delta}$T between an infrared target and its background. And we verified the suitability of our evaluation method through comparison between the found noise equivalent temperature difference and the specification of the camera. In addition, the difference of 0.01 K of the two noise equivalent temperature differences calculated from with and without nonuniformity correction suggests that the nonuniformity correction is essential process for the evaluation of the infrared thermal imaging camera.

• Korean Journal of Clinical Pharmacy
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• v.28 no.3
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• pp.224-229
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• 2018

Background: The patients receiving hematopoietic stem cell transplantation (HSCT) are known to have a high incidence of breakthrough nausea and vomiting due to the conditioning regimen. The purpose of this study was to evaluate the adequacy of antiemetic therapy for breakthrough nausea and vomiting in patients receiving HSCT and to propose an effective treatment regimen. Methods: We retrospectively reviewed the electronic medical records of 109 adult patients. The collected data were used to identify (1) antiemetic and dosing regimens prescribed for controlling breakthrough nausea and vomiting, (2) the rate of patients who developed breakthrough nausea and vomiting, and (3) the percent of antiemetics prescribed on the day of symptom onset. Based on the National Comprehensive Cancer Network guideline, we assessed the suitability of antiemetics for breakthrough nausea and vomiting, and prescription timing. Results: All patients were prescribed pro re nata antiemetics. About 40.0%, 41.4%, and 18.6% of patients were using one, two, and three or more additional drugs for breakthrough nausea and vomiting, respectively. The most frequently administered drugs were intravenous metoclopramide (43.8%) and granisetron patch (36.2%). Breakthrough nausea and vomiting occurred in 87 patients (79.1%) and they developed symptoms 320 cases. About 220 cases (68.8%) were treated with additional antiemetics on the day of symptom onset and the rate of symptom resolution was only 10.3% (9 patients). Conclusion: The breakthrough nausea and vomiting in patients receiving HSCT occurred very frequently and was hard to control, thus requiring more rapid and aggressive treatments.

• Journal of Preventive Medicine and Public Health
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• v.40 no.5
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• pp.351-362
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• 2007

Objectives: The present study was intended to assess the mental health of nurses working for university hospitals and to establish which factors determine their mental health. Methods: Self-administered questionnaires were given to 1,486 nurses employed in six participating hospitals located in Daejeon City and Chungnam Province between July 1 st and August 31st, 2006. The questionnaire items included sociodemographic, job-related, and psychosocial factors, with job stress factors (JCQ) as independent variables and indices of mental health status (PWI, SDS and MFS) as dependent variables. For statistical analysis, the Chi-square test was used for categorical variables, with hierarchical multiple regression used for determining the factors effecting mental health. The influence of psychosocial and job-related factors on mental health status was assessed by covariance structure analysis. The statistical significance was set at p<0.05. Results: The factors influencing mental health status among subject nurses included sociodemographic characteristics such as age, number of hours of sleep, number of hours of leisure, and subjective health status; job-related characteristics such as status, job satisfaction, job suitability, stresses such as demands of the job, autonomy, and coworker support; and psychosocial factors such as self-esteem, locus of control and type A behavior patterns. Psychosocial factors had the greatest impact on mental health. Covariance structure analysis determined that psychosocial factors affected job stress levels and mental health status, and that the lower job stress levels were associated with better mental health. Conclusions: Based on the study results, improvement of mental health status among nurses requires the development and application of programs to manage job stress factors and/or psychosocial factors as well as sociodemographic and job-related characteristics.

• Water for future
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• v.24 no.1
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• pp.83-92
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• 1991

The purpose of this paper is to estimate river maintenance water of the main gauging stations in Geum river watershed. The estimation methods of river maintenance water are classified into two categories : views of supply and demand. The definition of river main-tenance water in this paper, is the maximum value between mean drought flow and environmental conserving flow. In order to estimate river maintenance water, the mean drought flow estimated at the upstream of the Daecheong Dam but the downstream of the Daecheong Dam estimated mean drought flow and water quality control flow use of QUAL2E Model. In result, a mean drought flow showed large value at the Gong ju and Gyu am station as the downstream of the Daecheong Dam. The river maintenance water is 33.82$m^3$/sec at the Gong ju station, 51.51$m^3$/sec at the Gyu am station. Therefore, an estimation of the river maintenance water in the Geum River watershed concluded suitability which is determined mean drought flow.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.391-402
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• 2017

Lactic acid bacteria (LAB) are widely used as starter culture in food fermentation due to their harmless entity and health beneficial properties along with the ability to change texture, aroma, flavor and acidity of food products. In this study, five different LAB (FB003, FB058, FB077, FB081, and FB111) isolated from different Korean traditional fermented foods, assigned to Lactobacillus plantarum, Pediococcus pentosaceus, Weissella viridescens, Lactobacillus sakei, and Leuconostoc mesenteroides, respectively, on the basis of their physiological properties and 16S rRNA sequence analysis, to use as fermentation starter and check their ability to fasten the ripening time as well as the overall optimization in the fermentation condition. To check their suitability as starters, their safety, acid and bile tolerance, NaCl and temperature resistance, susceptibility to common antibiotics, and antimicrobial activities were determined. Squid jeotgal samples were prepared by adding $10^8CFU/g$ of each strain in different samples, which were then kept for fermentation at $4^{\circ}C$ and checked for their antioxidant activities at 0, 7, 15, and 21-day intervals. The samples fermented with FB003 and FB077 displayed the highest antioxidant activity. This study revealed two effective starter cultures (FB003, FB077) for squid jeotgal fermentation, which presented increased functionalities. The results of this study will lead to the development of novel industrial-scale production avenues for jeotgal preparation, and offer new insights into the prevention and control of chronic diseases.