• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2206-2217
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• 1971

Spillway and discharge channel of reservoirs require the Control of Large volume of water under high pressure. The energies at the downstream end of spillway or discharge channel are tremendous. Therefore, Some means of expending the energy of the high-velocity flow is required to prevent scour of the riverbed, minimize erosion, and prevent undermining structures or dam it self. This may be accomplished by Constructing an energy dissipator at the downstream end of spillway or discharge channel disigned to dissipated the excessive energy and establish safe flow Condition in the outlet channel. There are many types of energy dissipators, stilling basins are the most familar energy dissipator. In the stilling basin, most energies are dissipated by hydraulic jump. stilling basins have some length to cover hydraulic jump length. So stilling basins require much concrete works and high construction cost. Flip bucket type energy dissipators require less construction cost. If the streambed is composed of firm rock and it is certain that the scour will not progress upstream to the extent that the safety of the structure might be endangered, flip backet type energy dissipators are the most recommendable one. Following items are tested and studied with bucket radius, $R=7h_2$,(medium of $4h_2{\geqq}R{\geqq}10h_2$). 1. Allowable upstream channel slop of bucket. 2. Adequate bucket lip angle for good performance of flip bucket. Also followings are reviwed. 1. Scour by jet flow. 2. Negative pressure distribution and air movement below nappe flow. From the test and study, following results were obtained. 1. Upstream channel slope of bucket (S=H/L) should be 0.25<H/L<0.75 for good performance of flip bucket. 2. Adequated lip angle $30^{\circ}{\sim}40^{\circ}$ are more reliable than $20^{\circ}{\sim}30^{\circ}$ for the safety of structures.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1296-1307
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• 1997

Background : Erdosteine is a thiol derivative developed for the treatement of chronic obstructive bronchitis, including acute infective exacerbation of chronic bronchitis. Erdosteine has mucomodulating and antioxidant properties and especially exhibits excellent gastrointestinal tolerability. Methods : The study was conducted as a prospective evaluation, with 2 comparative groups orally treated with erdosteine 300mg (bid.) or ambroxol 30mg (b.i.d.) for 7 days and the design of trial was double-blind. The treatments have been assigned randomly to patients (n=80) with acute or chronic bronchitis. The primary end-point used to determine efficacy in this study was subjective symptoms including expectorating frequence, expectoration volume, expectorating difficulty, expectoration viscosity, cough intensity and dyspnea. The secondary end-points of efficacy was the result of arterial blood gas analysis and pulmonary function test. Safety was evaluated with adverse drug reactions and laboratory tests monitoring. 61 patients was included in the efficacy analysis, due to the fact that 19 patients drop-out for different reasons. The obtained values have been analyzed with paired Hest., ANOVA test., multivariate $t^2$-test, repeated measures analysis of covariance, two sample t-test, loglinear-logit model analysis, Fisher's exact test. Results : 1) There was no significant difference on demographic data and vital signs between erdosteine and ambroxol treated groups. 2) The comparison between erdosteine and ambroxol treated groups showed no significant difference in improvement of each symptom in spite of the more favorable efficacy obtained with erdosteine. No difference on the contrary was observed for arterial blood gas analysis and pulmonary function test. 3) As safety is concerned, no clinical significant changes in laboratory test and symptom were induced in erdosteine and ambroxol treated group and two patients in ambroxol treated group drop-out for adverse reactions in symptom. 4) In the evaluation of final clinical efficacy, erdosteine improved more effectively patient's overall symptoms {very good effect (11/31), good effect (12/31), moderate effect (6/31), no effect (2/31), aggravation (0/31)} than ambroxol {very good effect (6/30), good effect (14/30), moderate effect (5/30), no effect (4/30), aggravation (2/30)}. And the probability of symptomatic improvement by erdosteine compared to ambroxol was 2.5 times. (p<0.05). Conclusion : This study showed that erdosteine was clinically effective and safe drug for treatment of acute and chronic bronchitis.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.63-75
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• 2016

For safe water supply, residual chlorine has to be maintained in tap-water above a certain level from drinking water treatment plants to the final tap-water end-point. However, according to the current literature, approximately 30-60% of residual chlorine is being lost during the whole water supply pathways. The losses of residual chlorine may have been attributed to the current tendency for water supply managers to reduce chlorine dosage in drinking water treatment plants, aqueous phase decomposition of residual chlorine in supply pipes, accelerated chlorine decomposition at a high temperature during summer, leakage or losses of residual chlorine from old water supply pipes, and disappearances of residual chlorine in water storage tanks. Because of these, it is difficult to rule out the possibility that residual chlorine concentrations become lower than a regulatory level. In addition, it is concerned that the regulatory satisfaction of residual chlorine in water storage tanks can not always be guaranteed by using the current design method in which only storage capacity and/or hydraulic retention time are simply used as design factors, without considering other physico-chemical processes involved in chlorine disappearances in water storage tank. To circumvent the limitations of the current design method, mathematical models for aqueous chlorine decomposition, sorption of chlorine into wall surface, and mass-transfer into air-phase via evaporation were selected from literature, and residual chlorine reduction behavior in water storage tanks was numerically simulated. The model simulation revealed that the major factors influencing residual chlorine disappearances in water storage tanks are the water quality (organic pollutant concentration) of tap-water entering into a storage tank, the hydraulic dispersion developed by inflow of tap-water into a water storage tank, and sorption capacity onto the wall of a water storage tank. The findings from his work provide useful information in developing novel design and technology for minimizing residual chlorine disappearances in water storage tanks.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.1-11
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• 2018

It is ten years since the Good Agricultural Practices (GAP) certification system was implemented in Korea, and the government aims to acquire GAP certification up to 25% of the total agricultural areas by 2022. As of the end of 2017, 6.3% of the total cultivated area and 8.1% of the total farm households were certified, which is slower than expected. The purpose of this study was to investigate the causes of the GAP accreditation through the surveys and on site inspections of the GAP certified farmers and to propose the development plans according to the problems analysis of the current system in order to expand the GAP certification. Certified farmers recognized the need for agricultural safety and hygiene, but there were a lot of nonconformities regarding practical practices. This is due to the ambiguity of the certification standards and the wrong ways in the training method for the producers. GAP certification is slow to expand to farmers and low consumer awareness is considered a structural problem of GAP certification system, and improvement measures are needed accordingly. It is necessary to convert the state-led GAP certification system into a state-led private certification system. It is necessary for the government to focus on policy, research and follow-up management. In addition, it is necessary to establish a separate organization in the form of a contribution organization for the certification, education, and public relations. In addition, long-term plan must be established and systematically carried out. It is necessary to integrate too many certification agencies compared to the farming scale of Korea, and it is necessary to realize the application fee for realizing the financial independence of the certification body and correct certification work. In addition, inspector qualification standards should be strengthened and training system should be improved to nurture high quality inspectors. Simplified certification standards based on statutes need to be subdivided into practical action plans. In order to improve the GAP certification system, it is necessary to have a discussion through a committee composed of specialists from industry and academia, and it will be possible to contribute to the safety of the food of the people through the production of safe by drawing concrete development plans.

• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.49-56
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• 2011

To investigate the toxicological effects of ${\beta}$-glucan, we performed basic studying on ${\beta}$-glucan in Sprague-Dawley (SD) rats. Standard endpoints in this study included mortality, clinical observations, changes of body weights, analysis on food consumption, ophthalmoscopic examination, hematologic examination, serum biochemistry, analysis of organ weights, gross anatomic pathology and histopathology. No clinical signs and mortality were observed in animals treated with beta-glucan throughout the experimental period. The average body weight of each treatment groups showed similar levels at end of experiment. There were no treatment-related changes in mortality, body weights changes, food consumption, ophthalmoscopic examination. Although there were statistically significant differences between the control and treated groups in some relative and absolute organ weights, and hematological and biochemical analysis, the data were in biologically normal ranges and did not show a dose-dependent manner. In the morphological change, hepatic tissue were not showed ballooning degeneration and irregular arrangement of hepatic cell in ${\beta}$-glucan treatment groups with control group. Also, organs weights (liver, heart, kidney and stomach) and hematological indices (WBC, RBC, Hb, Hct and Platelet) did not show statistically significant differences among the experimental groups. In summary of these results, there were no changes in mortality, mean body weight, clinical signs, food consumption. There were no changes in ophthalmological examination, hematology, blood chemistry, necropsy and histopathology. In conclusion, although further investigation of glucan should be performed in the functions registered in many ancient literatures, ${\beta}$-glucan is physiologically safe and may have potential as candidate food for human health.

• Tuberculosis and Respiratory Diseases
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• v.45 no.3
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• pp.574-582
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• 1998

Background: Bronchofiberscopy is a procedure with a chance of airway irritation and it may cause pathophysiologic changes of respiratory system. So we tried to evaluate the influence of bronchofibercopy on $O_2$ saturation, ABGA and PIT by patient's basal status and procedure type. Method: $O_2$ saturation was measured every 1 minute from the left index finger tip with percutaneous oximetry. ABGA was done before and right after the bronchofiberscopy and PIT was done before and within 10 minutes after the bronchofiberscopy. Results: The mean time for bronchofiberscopy procedure was 14.5mim and $SaO_2$ maximally fall to 89.0 below 8% of the baseline after mean time of 8.4min, which was recovered at the end of the procedure. $SaO_2$ change amount was 8.4 % on Non-$O_2$ supply group, which was lower compared to 6.4 % of the $O_2$-supply group without statistically significance. Biopsy Group and BAL group showed more $SaO_2$ fall than washing only group. The level of $PaO_2$ and FEV1 of the patient didn't influence significantly on $SaO_2$ fall during the procedure. ABGA taken before and after the bronchofiberscopy showed mild fall of $PaO_2$ and mild rise of $PaCO_2$. Whereas PFT showed decrease of FEV1(P<0.05) and increase of RV without changes in airway resistance and pulmonary diffusion capacity. Comparing before and after the bronchofiberscopy, the washing group showed no significant changes on PIT, while the biopsy group and the BAL group showed increase of RV & decrease of $FEV_1$ after the bronchofiberscopy. BAL group showed more changing tendency rather than biopsy group although not statistically significant. Conclusion: Bronchofiberscopy is considered as a relatively safe procedure, but it would be better to be done with $O_2$ supply especially in the patient with low $PaO_2$ and in the case of biopsy and BAL.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.354-360
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• 2015

In recent years, Allium victorialis has been extensively used as a pharmacological agent for various diseases in the form of anti-arteriosclerotic, anti-diabetic and anti-cancer. Allium victorialis is severely affected by various fungal diseases since it naturally grow in the shady and humid environments in Korea. In this case, different types of fungicides are applied to control the fungal diseases in Allium victorialis. The present study was aimed to determine the residual characteristics of two fungicides namely tebuconazole and fludioxonil on Allium victorialis. For this study, the fungicides were drenched soil on Allium victorialis in the cultivation area Pyeongchang by the standard (two thousand fold) and double (thousand fold) dilutions. At the end of $15^{th}$, $30^{th}$ and $40^{th}$ days samples were collected for residue analysis. Residues of tebuconazole and fludioxonil were analyzed using GC/NPD (Gas Chromatography/Nitrogen Phosphorus Detector) and their recovery were found to be 108.8~119.5% and 91.3~104.8%, respectively. The method of limits of quantification for both fungicides was $0.01mg\;kg^{-1}$. Further, the results of this study shows that the residue levels of both fungicides on Allium victorialis were <$0.01{\sim}0.12mg\;kg^{-1}$ and $0.01{\sim}0.09mg\;kg^{-1}$ and their % ADI (% Acceptable Daily Intake) were 17.44% and 25.75%, respectively. Based on the results obtained in this study, we suggest that the residue levels of both of the fungicides on Allium victorialis are safe and these fungicides can also be used to control fungal diseases in Allium victorialis.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.209-220
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• 2018

Mating disruption (MD) has been widely used to effectively control Grapholita molesta in apple orchards. A simultaneous mating disruption (SMD) techniques have been developed to control both G. molesta and G. dimorpha. This study was performed to determine the practical parameters to apply the SMD technique to field conditions. To determine the application amount of SMD lures, a dispenser containing 10 mg pheromone was placed at different numbers of trees in an orchard. Application at every other tree (= one dispenser per two trees) was relatively safe to expect effective MD efficiency in both wax and polyethylene (PE) formulations. One time application at the end of March was enough to maintain a year round MD efficacy against both species. A fence treatment using food trap was applied to prevent any immigratory mated females from nearby untreated regions. To enhance the food trap by adding host-derived secondary compounds, terpinyl acetate (TA) was screened to be effective to attract females of Grapholita molesta among six compounds contained in apple fruit extracts. Among different TA concentrations, 0.05% TA treatment was the most effective to attract the adults. A mixture of TA and sugar was effective to attract and kill females and called FAKT (female attract-to-kill techniques). FAKT was treated at approximately 6 m interval at the edge of the apple orchards. The females trapped by the FAKT included mated females possessing vitellogenic oocytes. SMD supplemented with FAKT maintained the high MD efficacy and significantly suppressed leaf damage induced by the two insect pests compared to control or single SMD treatment.

• Journal of Korean Home Economics Education Association
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• v.32 no.3
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• pp.111-133
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• 2020

The purpose of this study is to analyze the contents of global citizenship education in the 2015 revision of Home Economics textbook and examine the relevance of global citizenship education in the subject of Home Economics. To this end, the contents of global citizenship education included in the 2015 revision of middle school Home Economics textbook were extracted and analyzed from the viewpoint of the UNESCO Topics and Learning Objectives (TLO), according to the procedure of the concurrent triangulation design. When the frequencies of inclusion of the 9 topics of TLOs were counted, about 54.6% of global citizenship education(GCED) content covered in the 2015 revision of Home Economics textbooks in total was related to the socio-emotional aspects. In particular, TLO 4 (Different levels of identity) showed the highest ratio, followed by TLO 5(Different communities people belong to and how these are connected) and TLO 1 (Local, national and global systems and structures). As a result of categorizing global citizenship education learning topics extracted from Home Economics textbooks of middle school by Home Economics sub-topic area, the child and family(94) area showed the greatest relevance to all learning topics. Food and nutrition(13), clothing(13), housing(15), and consumption (14) showed similar distributions of learning subjects. Child and family area is related to global citizenship education in the topics of adolescent development and its characteristics, family relations, sexual and domestic violences prevention, change in family structures and healthy families, aging society and work-family balance, and life planning and career exploration. The food and nutrition area is related to global citizenship education in the topics of nutrition and eating behavior, and adolescents' food selection and safe cooking. The topic of clothing management and recycling of clothing area, housing culture, residential space utilization, and residential life and safety of housing area, consumer life in adolescence of consumption area were related to the learning subject of global citizenship education. As such, high relations between GCED learning topics and Home Economics learning content elements were found. It is expected that the data of this study will be used as basic data for program development, class improvement, and textbook development with global citizenship education as a content element in Home Economics education.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.1
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• pp.3263-3291
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• 1974

Experimental work of grain bin was carried out to develop the methods of natural air in-bin drying and storage. The method is considered to be more economical, labour saving, and an effective countermeasure to grain loss. To examine the possibility of farm use of the grain bin and to analyze the related factors concerned with in-bin grain drying and storage, ambient air conditions (especially the change of air temperature and relative humidity) and grain quality during drying and storage periods were investigated. A laboratory model bin was constructed to investigate the effect of different forced air conditions on the drying characteristics of rice. In addition, a grain bin with 2.2m diameter and 1.8m height, considered to be the optimum size for the average Korean farm, was constructed and tested to examine the drying and storing characteristics of rice. The weather data analyzed in this study was the nine-year (from 1964 to 1972) record of air temperature and relative humidity in the Suweon area, and the thirty-year (from 1931 to 1960) record of pentad normal relative humidity and air temperature in the Seoul area. From the results of the weather data analyses, the adequate air delivery hours (which was arbitrary defined as the condition to give less than 75% relative humidity) to dry the rice during October were about nine hours (from approximately 10 A.M. to 7 P.M, ) a day, in which the average air temperature was about 15.9$^{\circ}C$ and average relative humidity was 66%. The occurence of days having three hours of such conditions was 1, 2, and 1-day within the 1st, 2nd add last 10-day periods for the month of October, respectively. Therefore, it may be considered that the weather condition in October was satisfactory for the forced natural air drying. The results of the laboratory model bin test were analyzed to obtain the drying curve and drying rate for different drying stages and grain layers in the bin corresponding to various conditions of forced natural air. A drying experiment with a prototype grain bin showed that an approximate 5 percent grain moisture gradient through a 1.6 meter grain deposit was observed after 80 hours of intermittent drying, giving an over dried zone in the lower grain layers and an extremely high grain moisture zone in the upper layers. This indicates that an effective measure should be taken to reduce this high moisture gradient. In order to investigate the drying characteristics of bulk grain in a layerturning operation a grain bin test was performed. This showed a significant improvement of uniform drying. In this test, approximate 107 hours were required to dry a depth of 1.6 meter of grain from an initial moisture content of 22.2 percent to a moisture content of 16.7 percent using an air delivery rate of 2.8 cubic meter per a minute per every cubic meter of grain. This resulted in a 2 percent moisture gradient from the top to the bottom of the bin. During storage period, till the end of June the average temperature of grain was 2~3$^{\circ}C$ higher than ambient air temperature. But during July when the grain moisture content went up slightly (less than 1 percent), the average temperature of the grain also increased to 3~5$^{\circ}C$ higher than ambient air temperature. It is therefore recommended that for safe grain storage, grain should not be stored in sheet metal bins after mid May. From the above results, in-bin rice drying and storage can be used effectively on Korean farms. It is strongly recommended that the use of grain-bin system should be implemented for farm use to improve farm drying and storage of rice.