• Korean Journal of Culture and Social Issue
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• v.12 no.1
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• pp.103-128
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• 2006

The present study investigated individuals' perception of important social issues in Korea. Based on previous research(Hahn, 1994; Hahn & Kang, 2000), a checklist containing 370 social issues was created. This checklist was administered to 1600 Koreans(812 college students, 788 adults) residing in 5 regional areas in Korea during the period of December 2004 and February 2005. Data were analyzed by the respondents' age, sex, and residing areas, and findings were compared to those of the two previous studies conducted in 1994 and 1999. Major findings of the study are as follows. First, across the three surveys, over 50% of the respondents consistently indicated the following four items as important social issues in the Korean society: political corruption, environmental pollution, the education system that is driven too much for college entrance, employment difficulty for local college graduates. Second, more than 50% of the respondents in the current survey indicated the following 12 items as important social issues that must be resolved: high unemployment rate, political corruption, environmental pollution, education system, overall difficulty of getting jobs, the nation's distrust in politics, hardships of life among the working classes, political incompetence, people with defective personal credit standings, employment difficulty for local college graduates, political instability, corruption of public servants. Third, analyses on the top 30 social issues across the three surveys revealed a positive and significant rank-order correlation for a five-year period(i.e., 1994-1999, 1999-2004), but not for a ten-year period(i.e., 1994-2004). Implications of the study and directions for future research are discussed.

• Computational Structural Engineering
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• v.7 no.3
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• pp.95-103
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• 1994

The safety related components in the nuclear power plant should be designed to withstand the seismic load. Among these components the integrity of reactor internals under earthquake load is important in stand points of safety and economics, because these are classified to Seismic Class I components. So far the modelling methods of reactor internals have been investigated by many authors. In this paper, the dynamic behaviour of reactor internals of Yong Gwang 1&2 nuclear power plants under SSE(Safe Shutdown Earthquake) load is analyzed by using of the simpled Global Beam Model. For this, as a first step, the characteristic analysis of reactor internal components are performed by using of the finite element code ANSYS. And the Global Beam Model for reactor internals which includes beam elements, nonlinear impact springs which have gaps in upper and lower positions, and hydrodynamical couplings which simulate the fluid-filled cylinders of reactor vessel and core barrel structures is established. And for the exciting external force the response spectrum which is applied to reactor support is converted to the time history input. With this excitation and the model the dynamic behaviour of reactor internals is obtained. As the results, the structural integrity of reactor internal components under seismic excitation is verified and the input for the detailed duel assembly series model could be obtained. And the simplicity and effectiveness of Global Beam Model and the economics of the explicit Runge-Kutta-Gills algorithm in impact problem of high frequency interface components are confirmed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.420-436
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• 2016

The purpose of this study was to identify the status of task performance and working conditions for nutrition teachers in order to determine new ways to improve the current nutrition system and increase job satisfaction among teachers. From the 14th of July to the 26th of September 2014, email questionnaires were distributed to and collected from 311 nutrition teachers nationwide, including teachers at elementary, middle, and high schools. The results are as follows. First, over 90% of nutrition teachers indicated that their work was demanding. In particular, 63.5% of nutrition teachers at high schools worked more than 40 hours of overtime per month. Second, 73% of nutrition teachers provided nutrition education, but the percentage significantly decreased at upper levels of school. Nutrition teachers had difficulties teaching due to the absence of standard teaching materials and a lack of time due to excessive work. Teachers also wanted 30 hours of job training once per year during their vacation organized by the regional Department of Education. Third, around half of the nutrition teachers considered that promotion and transfer professions are necessary for systematic foodservice and education. An additional allowance was demanded by nutrition teachers at schools that serve two or three meals per day. Considering the results, alleviating the workload of nutrition teachers and more time preparing nutrition classes for student are required. Fair evaluation of job performance that considers work conditions of nutrition teachers should be considered.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.229-246
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• 2023

The bitterling (Cyprinidae, Acheilongnathinae) is a temperate freshwater fish with a unique spawning symbiosis with host mussels. Female bitterlings use their extended ovipositors to lay eggs on the gills of mussels through the mussel's exhalant siphon. In the present study, in April of 2020, we investigated spawning frequencies and patterns of three bitterling fish species in host mussel species in the Nakdong River basin (Hoecheon). During field surveys, a total of four bitterling and three mussel species were found. We observed bitterling's spawning eggs/larvae in the three mussel species: Anodonta arcaeformis(proportion spawned: 45.5%), Corbicula fluminea(12.1%), and Nodularia douglasiae (45.2%). The number of bitterlings' eggs/larvae per mussel ranged from 1 to 58. Using our developed genetic markers, we identified the eggs/larvae of each bitterling species in each mussel species (except for A. macropterus): A. arcaeformis (spawned by Acheilognathus yamatsutae), C. fluminea (A. yamatsutae and Tanakia latimarginata), and N. douglasiae (A. yamatsutae, Rhodeus uyekii, and T. latimarginata). Approximately 57.6% of N. douglasiae mussel individuals had eggs/larvae of more than one bitterling species, suggesting that interspecific competition for occupying spawning grounds is intense. This is the first report on bitterling's spawning events in the Asian clam C. fluminea from Korea; however, it should be ascertained whether bitterling's embryo undergoes successful development inside the small mussel and leaves as a free-swimming juvenile. In addition, the importance of its conservation as a new host mussel species for bitterling fishes needs to be studied further.