• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.224-232
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• 2017

In this study, we investigated the disease, insect damage, growth, and yield characteristics of sorghum and foxtail millet in an organic paddy-upland rotation system at Anseong-si Gyeonggi province, Korea, in 2016. Seven varieties of sorghum and foxtail millet are used in this study. A rotational upland field and continuously cropped upland field were compared in order to establish an optimum cultural method and to select the best sorghum and foxtail varieties for a paddy-upland rotation system. The incidence rate of major diseases was higher for sorghum than for foxtail millet. Moktaksusu (22.8%) had the highest incidence rate among sorghum varieties. Hwanggeumchal (7.0%) had the highest incidence rate among foxtail millet varieties. DS202 (89.3%) was the most severely damaged by Ostrinia furnacalis larva, which is the main pest of sorghum and maize. The weed numbers, and the weed fresh and dry weights were lower in the rotational upland field than in the continuously cropped upland field. Futhermore, the number of weed plants decreased by 42% and the dry weight of weeds decreased by 33% in the rotational upland field compared to the continuously cropped upland field. The culm length of sorghum and foxtail millet were 7.9 cm, and 3.4 cm longer, respectively, in the rotational upland field than in the continuously cropped upland field. The average yield of sorghum per 10 a increased by 90% in the rotational upland field compared to continuously cropped upland field. However, there was no significant difference between the rotational upland field and the continuously cropped upland field for foxtail millet. The most suitable varieties for a paddy-upland rotation system were judged to be Hwanggeumchal, Donganmae, and DS202 for sorghum, and Samdachal, Samdamae, Dahwangmae for foxtail millet.

• Korean Journal of Environmental Agriculture
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• v.31 no.4
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• pp.318-327
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• 2012

BACKGROUND: For Non-Point Source(NPS) loads reduction, pollutant loads need to be quantified for major farming methods. The objective of this study was to evaluate impacts of farming methods on NPS pollutant loads from a paddy rice field during the growing season. METHODS AND RESULTS: The height of drainage outlet, amount of fertilizer, irrigation water quality were considered as farming factors for scenarios development. The control was derived from conventional farming methods and four different scenarios were developed based combination of farming factors. A field scale model, CREAMS-PADDY(Chemicals, Runoff, and Erosion from Agricultural Management Systems for PADDY), was used to calculate pollutant nutrient loads. The data collected from an experimental plot located downstream of the Idong reservoir were used for model calibration and validation. The simulation results agreed well with observed values during the calibration and validation periods. The calibrated model was used to evaluate farming scenarios in terms of NPS loads. Pollutant loads for T-N, T-P were reduced by 5~62%, 8~37% with increasing the height of drainage outlet from 100 mm of 100 mm, respectively. When amount of fertilizer was changed from standard to conventional, T-N, T-P pollutant loads were reduced by 0~22%, 0~24%. Irrigation water quality below water criteria IV of reservoir increased T-N of 9~65%, T-P of 9~47% in comparison with conventional. CONCLUSION(S): The results indicated that applying increased the height of drainage after midsummer drainage, standard fertilization level during non-rainy seasons, irrigation water quality below water criteria IV of reservoir were effective farming methods to reduce NPS pollutant loads from paddy in Korea.

• Journal of Engineering Education Research
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• v.12 no.1
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• pp.3-16
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• 2009

The purpose of this study is to prepare diverse measures to enhance the utilization of national authorized qualification. The detail objectives of this study are first, to re-establish the utilization scope and range of national authorized qualification through analysis of advance research and theory in various fields of learning on the function of qualification; and second, to set the direction to strengthen the utilization of national authorized qualification. Based on discussions on the various fields of learning on the function of qualification, this study divided the utilization scope of qualification into personal utilization for the benefit of the qualification acquirer him or herself and public utilization for the social and economic benefits. And according to this distinction, we prepared measures to strengthen the utilization of national authorized qualification. First of all, as a way to strengthen personal utilization of the national authorized qualification, we prepared measures to enhance accessibility and facilitate further improvement. As a means to enhance accessibility, we proposed restriction on setting the application condition, diversification of qualification authorization method, facilitation of partial qualification system and minimization of expense required to acquire qualification. Also for the further improvement, we proposed creation of job-level centered grade system and development of job-level centered qualification item by stage. For strengthening the public utilization of national authorized qualification, we come up with ways of strengthening flexibility, transparency, public trust and compatibility. As a way to strengthen flexibility, we proposed establishment of qualification demand monitoring system, expansion of direct participation of users on qualification management, establishment of qualification expiration period and its renewal. For the strengthening of transparency, we proposed to build general qualification information system and to utilize qualification recommendation system. To strengthen public trust, we proposed to strengthen the management of qualification management regulation, secure independency, establish internal audit system and strengthen post management of national authorized qualification. And lastly, we suggested that compatibility comparison standard between qualification and qualification level standard be developed for the strengthening of compatibility.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.200-207
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• 2019

The movement distance and home range size of Pelophylax chosenicus were identified in the rice paddy and ecological park as alternative habitats from July to November 2017. A total of 39 frogs were tracked by radio tracking method. As a result, the average move distance in the population of rice paddy was 11.7 ± 1.9 m (n = 64) and the population of ecological park was 24.7 ± 4.3 m (n = 39). The move distance between the two populations was significantly different. The mean MCP of the population of rice paddy was 181.2 ± 110.8 m² (n = 11) and the population of ecological park was 416.1 ± 276.2 m² (n = 10), but there was no significant difference. The population area of rice paddy was 4,160 m² (Kernel density 95%) and the core area was 1,080 m² (Kernel density 50%). The population area (Kernel density 95%) of ecological park was 5,391 m² and the core area (Kernel density 50%) was 736 m². This study shows that it is appropriate to construct the area of alternative habitat for P. chosenicus at least 1.33 ha, and it is more advantageous for the ecological park to be constructed than the paddy field with high development pressure and human interference. If the rice paddies were to be abandoned for several years, or to be used traditional farming methods, such as refraining from using agricultural machinery and chemicals, they could be used as alternative habitat for P. chosenicus.

• Journal of Food Hygiene and Safety
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• v.6 no.1
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• pp.1-12
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• 1991

Fischer 344 rats aged six weeks were diYided into four groups and group 1, 2, and 3 of rats were given an intraperitoneal injection of diethylnitrosamine at 200 mg/kg body weight and group 4 was given saline alone. Two weeks after beginning of the experiment, group 1 and 2 of rats were begun to feed on diets containing 0.02% 2-acetylaminofluorene as a promoter for four weeks. Three weeks after beginning of the experiment, all groups were performed partial hepatectomy. During the last two weeks, group 1 and 3 of rats were received subcutaneously 3 consecutive weekly doses of iron dextran at 0.125 ml/100 g body weight. Subcutaneous injection of iron dextran resulted in hepatic siderosis in group 1 and 3 of rats. Pre neoplastic nodules were identified histopathologically by two markers, resistance to exogenous iron accumulation and glutathione S-transeferase placental form (GST-P) activity, while early carcinogen induced foci were hardly resistant to iron accumulation and though a few lesions were identified, it could hardly be distincted from normal hepatocytes of surroundings. However, GST-P positive nodules as well as foci were clearly distincted from normal hepatic cells of surroundings. In the quantitative analysis of carcinogen-induced nodules and foci, more lesions were detected by immunohistochemical method for GST-P than by prussian blue staining for resistant to iron accumulation. It is concluded that immunohistochemical marker for GST-P is more sensitive and reliable than iron-resistance marker, and that iron-resistance is not useful marker for early detection of carcinogen-induced hepatic lesions.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.270-279
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• 2005

It is important to understand and evaluate the environmental impacts of rice cultivation for developing environmentally-friendly agriculture because rice is main crop in Korea and rice cultivation have both functions of water pollution and purification with environmental and cultivation conditions. This paper presents the evaluation of nitrogen impact by rice cultivation on water system. A simple protocol was proposed to assess the potential amount of nitrogen outflow from paddy field and most of parameters affect on the nitrogen outflow from paddy field such as the amount of fertilizer application, water balance, the quality and quantity of irrigation water, soil properties, nitrogen turnover in the soil and cultivation method were considered. To develop the protocol, coefficients for parameters affected nitrogen turnover and outflow were gotten and summarized by comparison and analysis of all possible references related, and by additional experiments at field and laboratory. And potential amount of nitrogen input and output by water in paddy field were estimated with the protocol at the conditions of the nitrogen contents of irrigation water, amount of fertilizer application, and irrigation methods. Where irrigation water was clean, below 1.0 mg $L^{-1}$ of nitrogen concentration, rice cultivation polluted nearby watershed. At the conditions of 2.0 mg $L^{-1}$ of nitrogen concentration, 110 kg $ha^{-1}$ of nitrogen fertilizer application and flooding irrigation, rice cultivation had water pollution function, but it had water purification function with intermittent irrigation. At the conditions of 3.0 mg $L^{-1}$ of nitrogen concentration and 110 kg $ha^{-1}$ of nitrogen fertilizer application, rice cultivation had water purification function, but that had water pollution function with 120 kg $ha^{-1}$ of nitrogen application. Where irrigation water was polluted over 6.0 mg $L^{-1}$ of nitrogen, it was evaluated that rice cultivation had water purifying effect, even though the amount of nitrogen application was 120 kg $ha^{-1}$.

• Journal of Life Science
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• v.16 no.6
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• pp.1060-1065
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• 2006

Non-invasive evaluation of liver function in animal models remains a challenge. Hepatoscintigraphy provides information about changes in liver size and shape, and enables to understand general liver function. Futhermore it is readily used to diagnosis complications of liver transplantation like hepatitis, rejections and biliary complications. In this study, we investigated the usefulness of evaluating the liver function in miniature pigs with $^{99m}Tc-Tin$ colloid and $^{99m}Tc-DISIDA$ which are the most commonly used radiopharmaceuticals in human medicine. In result, $^{99m}Tc-Tin$ colloid was uptaked in lung, liver, gastric wall and kidney in miniature pigs. And $^{99m}Tc-DISIDA$ showed continuous uptake images of heart, lung, liver, gallbladder and duodenum, and it was similar to human's. Therefore we could conclude $^{99m}Tc-Tin$ colloid would not be suitable for evaluating hepatic function because of it's nonspecific affinity, however $^{99m}Tc-DISIDA$ scintigraphy would be an effective method for detecting hepatobiliary function in miniature pigs.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.3
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• pp.273-285
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• 2009

Statement of problem: The aim of dental research is to advance scientific knowledge and leads to improvement in the treatment and prevention of dental disease. Utilizing an effective research design and adequate statistical methods are essential procedures ensuring that the results of researches are based on evidences. A research should utilize proper statistical methods without statistical errors; Otherwise, it could adversely affect clinical practice and future research. Purpose: This study was made to investigate the statistical methods used in the Journal of Korean Academy of Prosthodontics (JKAP) and then to assess them for the statistical errors. Material and methods: Among the total of 399 articles in the JKAP published from 2000 to 2006, 292 articles using statistics were reviewed. The validity of the statistical methods used in them were assessed using a checklist based on the guideline for statistical reporting in the uniform requirements for manuscripts submitted to biomedical journals by International Committee of Medical Journal Editors. The checklist consisted of three categories of statistical errors: 1) Unspecified computer statistical packages, 2) Inadequate description of statistical methods, 3) Misuse of statistical terms. Then, the results were compared between the Korean version and the English version in the JKAP. Results: Among the 212 articles using statistics in the Korean version, 115 articles (54%) and among the 80 articles using statistics in the English version, 47 articles (59%) were shown to have unspecified computer statistical packages without statistically significant difference (P = .66). Likewise, 101 articles (48%) in the Korean version and 25 articles (31%) in the English version were shown to have the inadequate description of statistical methods without statistically significant difference (P = .09). However, 114 articles (54%) in the Korean version and 19 articles (24%) in the English version were shown to have the misuse of statistical terms with statistically significant difference (P = .01). Conclusion: Some of the articles in the JKAP had inadequate statistical validity, given the statistical errors identified in this assessment. Hence, dental researchers should be more careful when it comes to describing and applying statistical methods.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.295-300
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• 2015

Purpose: The aim of this study was to evaluate the shear bond strength between Ni-Cr alloy and composite resin using universal adhesive systems coMPared to conventional method using metal primers. Materials and methods: For this study, a total of 120 cast commercial Ni-Cr alloy (Vera Bond 2V) disks were embedded in acrylic resin, and their surfaces were smoothed with silicon carbide papers and airborne-particle abrasion. Specimens of each metal were divided into 6 groups based on the combination of metal primers (Metal primer II, Alloy primer, Metal & Zirconia primer, MKZ primer) and universal adhesive systems (Single Bond Universal, All Bond Universal). All specimens were stored in distilled water at $37^{\circ}C$ for 24 hours. Shear bond strength testing was performed with a universal testing machine at a cross head speed of 1 m/min. Data (MPa) were analyzed using one-way ANOVA and the post hoc Tukey's multiple comparison test (${\alpha}$=.05). Results: There were significant differences between Single Bond Universal, All Bond Universal, Metal Primer II and Alloy Primer, MKZ Primer, Metal & Zirconia Primer (P<.001). Conclusion: Universal Adhesive system groups indicated high shear bond strength value bonded to Ni-Cr alloy than that of conventional system groups using primers except Metal Primer II. Within the limitations of this study, improvement of universal adhesive systems which can be applied to all types of restorations is recommended especially non-precious metal alloy. More research is needed to evaluate the effect of silane inclusion or exclusion in universal adhesive systems.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.169-179
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• 2004

The purpose of this study was to discriminate clinically and radiographically among the three groups of dentigerous cysts studied. First, Group I, involved area of dentigerous cyst was successive permanent tooth area beneath deciduous tooth. Second, Group II, involved permanent molar area, and the last, Group III involved maxillary anterior supernumerary tooth area. The author observed and compared the clinico-radiographic features of 49 cases of Group I, 36 cases of Group II, and 15 cases of Group III of dentigerous cyst and this observation and comparison had been done by based on the charts and panoramic films. The obtained results were as follows: 1. The cases of Group I were 29 cases and, those of Group II were 36 and those of Group III were 15. 2. The incidence of dentigerous cyst is high in first decade. In Group I, before first decade and early first decade was 87.8%, in Group II and Group III, was discovered more lately. 3. The frequency of dentigerous cyst is 2.5 times higher in male than in female. 4. The sequence of chief complaint was swelling(50%), routine examination(32%), and pain(9%). 5. When considering the type of the cyst, lateral type is many most in Group I (71.4%) and central type is many most in Group II (94.4%) and Group III (100%). 6. The most size of dentigerous cyst was 2 crown size in Group I, 1 crown size in Group II, above of 4 crown size in Group III. 7. Almost involved teeth showed displacement and some tooth of displaced teeth showed delayed root development and dilaceration of root. 8. The most many response of alveolar bone was buccal bone expansion in Group I (67.3%), no bone expansion in Group II(66.7%) and palatal bone expansion in Group III (60.0%). 9. The percentage of involved teeth were as follows : The mandibular third molar was 31% and many most. The mandibular second premolar was 30%. Mesiodens of maxillary anterior area was 15%. The maxillary canine was 8%. The mandibular first premolar was 5%. 10. In the Group I, causes suggesting of dentigeous cyst are pulpotomized deciduous tooth(59.2%), severe dental caries of deciduous tooth, untreated traumatic history on the deciduous tooth etc. 11. The treatment method of dentigerous was marsupialization in 61.2% of cases of Group I and that was enucleation in 61.1% of cases of Group II and in 80.0% of cases of Group III.