• Title/Summary/Keyword: Population dynamics

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Weeds on Rice Paddy Field of Jeonnam Western Region (전남지역 벼 재배방법에 따른 잡초 발생 특성)

  • Im, Il-Bin;Im, Bo-Hyeok;Park, Jea-Hyeon;Jang, Jeong-Han;Im, Min-Hyeok;Lee, In-Yong
    • Weed & Turfgrass Science
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    • v.4 no.4
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    • pp.295-307
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    • 2015
  • Surveys of weed species in paddy fields were conducted to identify weed occurrence on July 2013. Total 237 sites of paddy fields in 9 City/Gun, Jeonnam Provinces in Korea were investigated. From the survey, 45 weed species in 18 families were identified and classified to 33 annuals and 15 perennials. Based on the occurrence ratio, the most weed species belonged to Poaceae (9 species) and 8 and 4 weed species belonged to Cyperaceae and Scrophulariaceae, respectively. These 21 weed species in the most four families accounted for 46% of total weed occurrence. The most dominant weed species in Korean paddy fields were Echinochloa spp. (18.5%), followed by Monochoria vaginalis (12.3%), Lemna perpusilla (8.2), Eleocharis kuroguwai (5.2%) and Scirpus juncoides (5.2%). The most dominant weed species in machine transplanting paddy fields were Echinochloa spp. (14%), followed by Monochoria vaginalis (12%) and in water seeded rice paddy fields were Echinochloa spp. (25%), followed by Monochoria vaginalis (11%). This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in paddy fields.

A STUDY FOR THE CURRICULUM DEVELOPMENT OF SOCIAL WORK IN KOREA (한국 사회사업교과과정 개발을 위한 연구)

  • Nam, Sae-Jin
    • Korean Journal of Social Welfare
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    • v.1
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    • pp.51-71
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    • 1979
  • During last five years several workshops and seminars among social work educators, in and out country, has taken place. In those gatherings there has been, criticism on American model on which curriculum of social work in Korea has mainly based, and many proposals which most developing countries should consider and adopt for developing their own curriculums. The proposals could be summarized as follows; 1. Specification of developmental functions of social work should be made so that the curriculum could involve. It also must come from own societal needs and own national development task. 2. Social work should participate and make contribution to plan and solve the main social problems in own countries. 3. Clarification of educational objective in undergraduate level should be made and one of them must be related to the first professional degree. 4. There should be the courses which provide the content of macro level participation. How much of the proposals are reflected in the current curriculum of Korea? What are the problems Korean social work education has been faced in connection with reflecting the proposals? What kinds of task we should or could perform in order to adopt the proposals? These are the questions which deserved to be studied. The followings are the answers to the questions; 1. The new courses such as social welfare policy and planning, Social Development, Population Dynamics and Family Planning, Social problems, Special Issues in Social Welfare, etc, are placed in the curriculum. 2. Though the new courses are added the courses of case work, group work, and community organization are strongly remained it means that integrative method is not quite adopted and that conflicts are taking place between new and old fashion. 3. Fieldwork placement policy has been changes from concurrent to block and from social work method oriented to social problem oriented. 4. There are lack of integration among the all courses, of consistency between pre and post courses and connection among the related courses. 5. Establishment of image of social worker with B, A. degree should be urgently taken place. It can't be done by social work field alone but by cooperation with all the forces related to the social work practice. 6. B. A. graduate should have a common base of knowledge and competence. It could be come from the clear and specified objectives of undergraduate level education. And agreement among the member schools on the objectives can call on the fundamental similarities in each curriculums. Different programs from one school to another can be tolerated as long as there are fundamental similarities among the schools. Basic concepts and framework of social work should be kept clearly. It is a slow and long process to make social work recognized as a profession in the developing countries. Korea can't be and exception. Failure of having social work be indegenous can't be the reason to refuse an change the basic concepts of social work. One of he most important task which social work education in Korea must achieve in the near future is to establish the minimum requirement courses in the curriculum. Social work field, on the other hand, must find the positions for the social works in the various settings and institute. Clear role and image of social worker can be obtained by doing that.

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Dominance and Distribution of Weed Occurrence on Hot Pepper, Soybean, Maize, and Chinese Cabbage Fields of Gyeongbuk Province (경북지역 고추, 콩, 옥수수, 배추밭의 잡초종 발생 분포와 우점 양상)

  • Kim, Sang Kuk;Kim, Hak Yoon
    • Weed & Turfgrass Science
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    • v.4 no.2
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    • pp.95-103
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    • 2015
  • In this study, we surveyed the distribution pattern and dominance of weeds occurred in four summer crop fields, hot pepper, soybean, maize, and Chinese cabbage in Gyeongbuk province. The weeds were summarized as 32 family and 132 species in hot pepper field, 31 family and 116 species in soybean field, 37 family 134 species in maize field, finally 35 family and 170 species in Chinese cabbage field. Among these weeds occurred in the four summer crop fields, the compositae was commonly dominant family, it occupied 17.4% in hot pepper field, 18.1% in soybean field, 11.9% in maize field, and 16.5% in Chinese cabbage field. The major five families including compositatae, graminae, polygonaceae, convolvulaceae and cruciferae were occupied 43.2% in hot pepper field, 47.4% in soybean field, 42.5% in maize field, and 43.5% in Chinese cabbage field, respectively. Furthermore, the most dominant weed in the hot pepper, soybean, maize, and Chinese cabbage fields was Portulaca oleracea, Digitaria ciliaris, and Rorippa palustris, respectively. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in food crop fields of Gyeongbuk province.

Impact Analysis of Tributaries and Simulation of Water Pollution Accident Scenarios in the Water Source Section of Han River Using 3-D Hydrodynamic Model (3차원 수리모델을 이용한 한강 상수원구간 지류영향 분석 및 수질오염사고 시나리오 모의)

  • Kim, Eunjung;Park, Changmin;Na, Mijeong;Park, Hyeon;Kim, Bogsoon
    • Journal of Korean Society on Water Environment
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    • v.34 no.4
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    • pp.363-374
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    • 2018
  • The Han River serves as an important water resource for the city of Seoul, Korea and in the neighboring metropolitan areas. From the Paldang dam to the Jamsil submerged weir, the 4 water intake stations that are located for the Seoul metropolitan population were under review in this study. Therefore the water quality management in this section is very important to monitor, analyze and review to rule out any safety concerns. In this study, a 3-D hydrodynamic model, EFDC (Environmental Fluid Dynamics Code), was applied to the downstream of the Paldang Dam in the Han River, which is about 23 km in length, to determine issues related to water resource management. The 3-D grid was composed of 2,168 horizontal grids and three vertical layers. In this case, the hydrodynamic model was calibrated and verified with an observed average daily water surface elevation, water temperature and flow rate data for 3 years (2013~2015). The developed EFDC model proved to reproduce the hydrodynamics of the Han River well. The composition ratios of the noted incoming flows at the monitored intake stations for 3 years and their flow patterns in the river were analyzed using the validated model. It was found that the flow of the Wangsuk Stream depended on the Paldnag dam discharge, and it was noted that the composition ratios of the stream at the intake stations changed accordingly. In a word, the Wangsuk Stream moved mainly along the right bank of the Han River under the condition of a normal dam flow. As can be seen, when the dam discharge rate was low, the incidence of lateral mixing was often seen. The scenario analyses were also conducted to predict the transport of conservative pollutants as in the case of a chemical spill accident. Generally speaking, when scenarios were applied, the arrival time and concentration of pollutants at each intake station was thus predicted.

Distributional characteristics of phytoplankton and nutrient limitation during spring season in Jinhae Bay (춘계 진해만에서 식물플랑크톤 증식과 제한영양염 분포특성)

  • Son, Moonho;Kim, Dongseon;Baek, Seung Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3345-3350
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    • 2014
  • We investigated to assess the relationships between the major nutrients and phytoplankton dynamics during the spring season in 2010 and 2011 at 23 stations in Jinhae Bay, Korea. The bay is divided into four different zones based on pollutant sources and geographical characteristics. Nutrient limitation (>80%) was significant in Zone II, which is located in central bay and is influenced by the water well mixed from outer bay. The limited nutrient was followed in Zone III and IV that was occupying between 17% and 83%. However, the low levels are being kept below 35% in Zone I, which is characterized by the semi-enclosed eutrophic area of Masan and Haegam bays. Based on the PCA (principle component analysis) analysis, the nitrogen (N) sources in 2010 were particularly dominant and it may be due to the water mixing and wastewater formed from bottom layers and sewage. In 2011, major nutrients including nitrogen, silicon and phosphorus were dominant in the bay and are supplied by the river discharge after rainfalls with low salinity conditions. In particular, the N nutrients being supplied in 2010 are correlated with pennate diatoms Pseudo-nitzchia spp. and is not related to the phytoplankton population densities in 2011. The present study suggests that N sources play an important role in the proliferation of diatom, and the rapid nutrient uptakes by them are potential nutrient limitation factors in the bay.

The Pigments Variation of Phytoplankton in the Seomjin and Yeongsan River estuary (섬진강과 영산강 하구의 식물플랑크톤 기원 색소분포 변동)

  • Jeon, Hyeji;Lee, Eugene;Son, Moonho
    • Journal of Marine Life Science
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    • v.5 no.2
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    • pp.99-106
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    • 2020
  • To investigate effect of variation in physiochemical conditions due to river discharge on phytoplankton, field surveys were conducted in the Seomjin and Yeongsan River estuaries from April to November 2016. The concentrations of DIN and DSi in Seomjin River estuary were gradually low as distance from upstream. On the other hands, the concentrations of DIN and DSi in Yeongsan River estuary were critically high at upstream, due to which is characterized as semi-enclosed eutrophic area. A total of 12 phytoplankton pigments were analyzed, and the distribution of each taxa was investigated using indicator for each phytoplankton taxa. Fucoxanthin, an indicator pigment of diatoms, showed an average of 0.61±1.00 ㎍ l-1 and 0.76±1.22 ㎍ l-1 in the Seomjin and Yeongsan River estuaries, respectively. Concentration of fucoxanthin was more than twice that of other pigments except chlorophyll a., indicating that diatoms were dominant taxa. Peridinin, an indicator pigment of dinoflagellate, showed some similar tendency to the microscopic observation, but mismatch results were also present, indicating a technical limitation of pigment analysis. Chlorophyll b, alloxanthin, and zeaxanthin, which are indicator pigments of green algae, cryptomonads, and cyanobacteria, were detected in both estuaries even though those taxa were not detected in microscopic observation. This indicates that the two estuaries were affected by freshwater species. Here, we can suggest that phytoplankton composition in estuary was directly influenced by the inflow from upstream. In particular, the phytoplankton population dynamics in Yeongsan River estuary was greatly associated with a large-scale artificial dyke, especially in summer rainy season. On the other hands, the seasonal and horizontal distribution of phytoplankton in Seomjin River estuary has changed along the salinity gradients and inflow-related changes.

Two Economic Crises, Unemployment, Working Poor, and Gender: Explaining the Dynamics of the Risk Patterns of Suicide in South Korea (두 번의 경제위기와 실업, 노동빈곤, 그리고 젠더: 한국 자살 위험양식의 역동적 변화에 대한 시론)

  • Moon, Dasuel;Chung, Haejoo
    • 한국사회정책
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    • v.25 no.4
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    • pp.233-263
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    • 2018
  • This study sought to identify gender-specific mechanisms of increased suicide rates during economic crises in South Korea. In order to address research aims, we focused on two international economic crises: IMF financial crisis in 1997, and international recession in 2008. This study provides three main findings. First, different mechanisms increased suicide rates during the two economic crises. Particularly, the high level of unemployment raised suicide rates during the 1997 IMF while the high level of working poor in the 2008 recession. Second, suicidal risk patterns for men and women differed at each period. The 1997 crisis which mostly affected full-time permanent workers had had relatively greater impacts on men suicide, whereas the 2008 crisis which affected precarious workers had done on women suicide. Finally, our finding indicated that these gender-specific risk patterns had been derived from the gendered labour market and male-friendly social policy. Placing women at the periphery of the labor market and using them as a buffer in times of crisis, governments failed to protect them from their economic difficulties. Suicide is fundamental and important public health and social problems. These findings suggest that the national suicide prevention strategy should pay attention to the social determinants of suicide through gendered as well as population health perspectives.

A Comparative Pedagogical Approach to Lifelong Education: Possibilities and Limitations (평생교육의 비교교육학적 접근: 가능성과 한계)

  • Choi, DonMin
    • Korean Journal of Comparative Education
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    • v.28 no.3
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    • pp.291-307
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    • 2018
  • As the value of lifelong learning becomes important, states are making efforts to build a system of lifelong learning. According to this tendency, this paper intends to compare the participation rate of lifelong learning, learning outcomes, learning support infrastructure, support of learning expenses, and recognition of lifelong learning. For the comparative pedagogical approach, Bray and Thomas' cubes such as geographical / regional level, non - geographical demographic statistics, social and educational aspects were utilized. The participation rate of lifelong learning in Korea is 34.4% in 2017, which is lower than the OECD average of 46%. The competency scores of Korean adults were lower than the OECD national averages of the PIAAC survey which measured adult competence, language ability, numeracy, and computer-based problem solving ability. In order to recognize prior learning, EU countries have developed EQFs to evaluate all non-formal and informal learning outcomes, while Korea recognizes qualification as a credit banking credit under the academic credit banking system. International comparisons of lifelong learning can be used as an important tool for diagnosing the actual conditions of lifelong learning in a country and establishing future lifelong learning policies. Therefore, it is necessary to maintain that the comparative pedagogical approach of lifelong learning differs according to the historical context, socioeconomic characteristics, and population dynamics, including the formation process and characteristics of modern countries.

Methods of Regulating Migration Processes in EU Countries

  • Hamova, Oksana;Dergach, Anna;Pikulyk, Oksana;Zolotykh, Irina;Diachenko, Kateryna
    • International Journal of Computer Science & Network Security
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    • v.21 no.3
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    • pp.257-265
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    • 2021
  • Modern methods of regulating migration processes in EU states include a wide variety of adapted, transformed under the sway of globalization tools in order to influence the movement of human capital within the European space. The main purpose of the regulatory policy on migration flows is the redistribution of professionally competent professionals between different spheres of life. Herewith, the determining factor in the effectiveness of such distribution is a rational combination of stimulating and disincentive levers of influence on the movement of citizens of different EU countries and taking into account the motives of such mobility. Modernization of migration management approaches can be a major economic, social, political and cultural progress of European countries. The purpose of the research is to conduct a detailed analysis of existing practices of migration flow management, in particular their stimulation or containment, and to outline key migration trends formed under the influence of multicomponent approaches to migration regulation, transformation of regulatory legislation and changing priorities of modern society. The research methods: statistical-analytical method; ARIS method; method of tabular, graphical and analytical modeling; comparative analysis; systematization, generalization. Results. Current pan-European methods of regulating migration processes are insufficiently adapted to the multinational socialeconomic space; consequently, there are some disparities in the distribution of migrants between EU countries, although the overall dynamics of migration is positive. Fluctuations in the population of European countries during 2000-2019 and trends in the transformation of social-economic space confirm the insufficient level of influence of current methods of regulating migration flows. Along with this, the presence of a characteristic asymmetry in the distribution of migrants requires a greater focus on the modernization of regulatory instruments, in particular, the regulatory mechanism for managing migration processes. As a result of the conducted study, further prospects for the implementation of alternative methods of regulating migration processes in EU states have been outlined; the current and projected limits for increasing the level of observance of migrants' rights at the European level have been clarified through the adoption of appropriate regulatory acts; effective solutions for intensifying the influx of high-quality labor resources from different countries to EU have been identified. The research results can be used to study methods of regulating migration processes in the countries in the global dimension.

Agro-ecosystem Diversity and Integrated Mite Pest Management in Fruit Orchards: A Review and Future Prospect (농업생태계 다양성과 과수원 응애류 해충 종합관리: 이론적 고찰과 미래 전망)

  • Kim, Dong-soon
    • Korean journal of applied entomology
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    • v.60 no.1
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    • pp.49-61
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    • 2021
  • Integrated mite management provided a basic direction to early the fruit tree IPM. The early IPM concept was based on incorporation of the biological control for mite pests with the existing chemical control compatibly. Since then, the hypotheses and mechanisms of the interaction between species diversity and pest population dynamics have provided a broader understanding of mite-centered pest management in fruit tree ecosystems. Based on the principle of the ecosystem, biological control and pest management through habitat modification or manipulation are developing to the concept of agro-ecological engineering. In particular, the natural enemy diversity is dynamically changed according to the different cultivation environment in the management of mite pests, and the species composition of phytophagous mites is also changed by the environment for orchard management. This paper reviews the biological control of mites, which was the basis of apple IPM, and also re-examines the topics of species diversity and pest management, predacious mite diversity in relation to mite control and the change of species composition of mite pests in the sight of ecological engineering. Finally, we suggest a strategy for biological control of spider mites in apple orchards in Korea.