• Hwankyungkyoyuk
• /
• v.7 no.1
• /
• pp.1-17
• /
• 1994

This study was performed to determine appropriate teaching-learning and evaluation methods for Environmental Studies. To promote the relevance of our study to the needs of the schools and concerned educational communities of environmental education, we reviewed related literature, conducted questionnaire surveys, interviewed related teachers and administrator, held meetings with experts, and field-tested our findings. For selecting and developing teaching-learning methods of Environmental Studies, findings of educational research in general are considered. moreover, principles of environmental education, general aim of environmental education, orientations of environmental education, and developmental stages of middle school students in educational psychology were attended. In addition, relevance to the purpose of the Environmental Studies curriculum, appropriateness for value inquiry as well as knowledge inquiry, small group centered class organization, social interaction centered teaching-learning process, regional environmental situation, significance of personal environment, evaluation methods of Environmental Studies, multi- and inter-disciplinary contents of the Environmental Studies textbook, suitability to the evaluation methods of Environmental Studies, and emphasis on the social interaction in teaching-learning process were regarded. It was learned the Environmental Studies can be taught most effectively in via of holding discussion sessions, conducting actual investigation, doing experiment-practice, doing games and plate, role-playing and carrying out simulation activities, and doing inquiry. These teaching-learning methods were field-tested and proved appropriate methods for the subject. For selecting and developing evaluation method of Environmental Studies, such principles and characteristics of Environmental Studies as objective domains stated in the Environmental Studies curriculum, diversity of teaching-learning organization, were appreciated. We categorized nine evaluation methods: the teacher may conduct questionnaire surveys, testings, interviews, non-participatory observations; they may evaluate student's experiment-practice performances, reports preparation ability, ability to establish a research project, the teacher may ask the students to conduct a self-evaluation, or reciprocal evaluation. To maximize the effect of these methods, we further developed an application system. It considered three variables, that is, evaluates, evaluation objectives domains, and evaluation agent, and showed how to choose the most appropriate methods and, when necessary, how to combine uses of different methods depending on these variables. A sample evaluation instrument made on the basis of this application system was developed and tested in the classes. The system proved effective. Pilot applications of the teaching-learning methods and evaluation method were made simultaneously; and the results and their implications are as follows. Discussion program was applied in a lesson dealing with the problems of waste disposal, in which students showed active participation and creative thinking. The evaluation method used in this lesson was a multiple-choice written test for knowledge and skills. It was shown that this evaluation method and device are effective in helping students' revision of the lesson and in stimulating their creative interpretations and responces. Pupils showed great interests in the actual investigation program, and this programme was proved to be effective in enhancing students' participation. However, it was also turned out that there must be pre-arranged plans for the objects, contents and procedures of survey if this program is to effective. In this lesson, non-participatory observation methods were used with a focus on the attitudes of students. A scaled reported in general description rather than in grade. Experiment-practice programme was adopted in a lesson for purifying contaminated water and in this lesson, instruction objectives were properly established, the teaching-learning process was clearly specified and students were highly motivated. On the other hand, however, it was difficult to control the class when some groups of students require more times to complete their experiment, and sometimes different results. As regards to evaluation, performance observation test were used for assessing skills and attitudes. If teachers use well-prepared Likert scale, evaluation of all groups within a reasonablely short period of time will be possible. The most effective and successful programme in therms of students' participation and enjoyment, was the 'ah-nah-bah-dah-market' program, which is kind of game of the flea market. For better organized program of this kind, however, are essential, In this program, students appraise their own attitudes and behavior by responding to a written questionnaire. In addition, students were asked to record any anecdotes relating to self-appraisal of changes on one's own attitudes and behaviours. Even after the lesson, students keep recording those changes on letters to herself. Role-playing and simulation game programme was applied to a case of 'NIMBY', in which students should decide where to located a refuse dumping ground. For this kind of programme to e successful, concepts and words used in the script should be appropriate for students' intellectual levels, and students should by adequately introduced into the objective and the procedures of the lessons. Written questionnaire was used to assess individual students' attitudes after the lesson, but in order to acquire information on the changes of students' attitudes and skills, pre-test may have to be made. Doing inquiry programme, in which advantages in which students actually investigated the environmental influence of the areas where school os located, had advantages in developing students' ability to study the environmental problems and to present the results of their studies. For this programme to be more efficient, areas of investigation should be clearly divided and alloted to each group so that repetition or overlap in areas of study and presentation be avoided, and complementary wok between groups bee enhanced. In this programme, teacher assessed students' knowledge and attitudes on the basis of reports prepared by each group. However, there were found some difficults in assessing students' attitudes and behaviours solely on the grounds of written report. Perhaps, using a scaled checklist assessing students' attitudes while their presentation could help to relieve the difficulties.

• Food Science of Animal Resources
• /
• v.27 no.3
• /
• pp.320-328
• /
• 2007

This study was conducted to determine the effect of pH adjustment and the addition of cryoprotectants on the quality characteristics of chicken breast surimi. We prepared surimi from Alaska pollack, as a the control, by two time washing times and the addition of cryoprotectants. Different preparations of surimi were manufactured by adjusting to pH 11.0 and the addition of different addition cryoprotectants during frozen storage (T1 : 5% sorbitol and 0.3% polyphosphate, T2: 4% sugar, 5% sorbitol and 0.3% polyphosphate, and T3: 2% salt, 4% sugar, 5% sorbitol and 0.3% polyphosphate). The moisture content was significantly lower in the control and T3 samples. The crude protein content was increased with storage times. The crude protein was higher in the control. The water-holding capacity, myofibrillar protein and shear force were significantly higher in T3 than other surimi samples. All gel characteristics were significantly higher in the control and T3 than other surimi samples. pH 11.0 adjusted chicken breast surimi had greater lightness than the control, and T3 samples had the highest lightness and whiteness. Sensory evaluations were significantly higher in the control and T3 than the other samples. The gel, and physical characteristics and sensory evaluation of T3 were similar to the control. T3 samples had superior color and pH than the control Alaska pollack surimi.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.s02
• /
• pp.34-44
• /
• 1989

The stability of rice cultivation in Korea is largely depended on climatic conditions, especially, low temperature at the period of early growth stage and after heading. The improvement of cold tolerant varieties and appropriate cultural practices in rice are very effective to minimize the cold damage. This paper is summarized the mechanism and counterplans of cold injury of rice plants. The paddy area having commonly cold injury in Korea is approximately 15, 522ha in 1,709 sites on the national scale. The cold damage at seedling stage in nursery bed appeared to poor germination, leaf discoloration, dead seedlings and seedling rot ect.. At the vegetative stage, the decreased tiller number due to poor rooting and the delayed heading caused by slow growth and panicle differentiation are commonly showed. The cold injury at early reproductive stage appeared to the degeneration of spikelets and rachis - branches, while that at meiosis stage showed to increased sterility due to poor development of pollen and shortened panicle length with delaying heading, therefore the grain yield is largely decreased. The cold damage at heading and ripening stages showed to poor pollination and fertilization, low panicle exsertion, poor grain filling and finally grain quality became low. To minimize the cold injury to rice plants by low temperature, following counterplans would be recommonded ; Improvement of the cold toelrant rice varieties for the regions of midmountains and alpines. Raising healthy seedlings at upland nursery beds and by using of growth regulators such as ABA, Fuchiwang and Tachiace. Soil improvement and organic matter application to reduce cold damage by increasing water and fertilizer holding capacities in the paddy field having commonly cold water and in the place where cold damage is regularly occurred. Appropriate fertilization for raising healthy rice plants to tolerate under low temperature condition. Water management to increase water temperature in the paddy such as depth watering, round channels and polyethylene tubes around the field. Establishment of the optimum cultivation time of rice based on minimum, mean and maximum temperatures at different regions with appropriate rice varieties.

• Food Science of Animal Resources
• /
• v.25 no.2
• /
• pp.141-148
• /
• 2005

This study was conducted to evaluate physicochemical and textural properties, and antimicrobial effects of low-fat comminuted sausages manufactured with sodium lactate $(3.3\%,\;SL)$ and various levels $(0.1\~0.3\%)$ of grapefruit seed extract (GSE, DF-100) during refrigerated storage for 10 weeks. Low-fat comminuted sausages (LFCS) has pH ranges of $6.09\~6.26,\;74\~76\%$ moisture, $<3\%\;fat,\;16\~17\%$ protein. The addition of SL $(3.3\%)$ and GSE with various levels $(0.1\~0.3\%)$ didn't impair water holding capacity (WHC), vacuum purge (VP) and Hunter color values (L, a, b). LFCS containing SL $(3.3\%)$ increased hardness and chewiness, whereas most TPA values were not affected by the addition of various levels $(0.1\~0.3\%)$ of GSE. LFCS containing $0.2\%\;or\;0.3\%$ GSE retarded the microbial growth of Listeria monocytogenes(LM). The addition of $0.3\%$ GSE in LFCS showed similar antimicrobial effect to $3.3\%$ SL, which kept $10^3 CFU/g$ until 10 weeks of refrigerated storage. Yellowness, VP and cohesiveness tended to be increased with increased storage time. These results indicated that the addition of $0.3\%$ GSE as a replacer for synthetic particularly paI1icuiarly inhibited the microbial growth of LM, resulting in antimicrobial effect similar to those of $3.3\%$ SL treatment without quality defects.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.11 no.1
• /
• pp.1598-1603
• /
• 1969

A field expeperiment has been conducted in order to explore possibilities of efficient and economical irrigation methods for the rice cultivation through which irrigation water may be saved and rice paddies may keep water for longer period of time, resulting in an increased yield of rice. Some of the major findings from the experimentation are summarized in the following. 1. There is slightly significant difference among experimental plots in the weight of rice straw. 2. The 9cm-lined plot proves to be the best in terms of the thickness. In this connection, however, it seems to by 3cm. 3. The wheat straw-lined plot is found superior in yield. However, this may be resulted in by the application of more fertilizer, and how long the plot could be durable may be problematic. Since every two or three years the straw-lining work has to be done, more labour may be required of the plot. 4. It would be inappropriate to expect any meaningful experimental results for the first year, since surface soil and deep soil are mixed up in the course of work. There is not observed any meaningful difference in the number of ears per stalk and in the number of grains per ear. However, in the lined plots, the number of tillers is slightly increased. 5. Irrigation has been applied by means of ordinary method after lining. When irrigation is applied at the interval of five to six days, irrigation water is saved by 44.9 per cent in the case of 9cm-lined plot, 39.7 per cent in the case of 6 cm-lined plot, and 36.3 percent in the case of 3 cm-lined plot. 6. An increased yields arenoted in the wheat straw-lined plot by 23.8 per cent, in the 9 cm-lined plot by 20.1 per cent, in the 3 cm-lined plot by 12 per cent. and in the case of vinyl-lined plot by 12.5 per cent. 7. The rate of maturity of grains is proved better, and the husking rate also found better(75%), that is, the quality of rice grains is improved.

• Korean Journal of Poultry Science
• /
• v.8 no.2
• /
• pp.91-114
• /
• 1981

This research was carried out from July to August, 1981, to analyse the true state of management, the skill of production, the structure of consciousness about the selected 294 poultry$.$farms, and to know about their bottlenecks and suggestions. The results obtained were as follows: 1. As for manager's ages, 31 to 45 years old men rate was 67.76%. upper 50years old men 15.94%. 2. 79.9% of farm omen possess attainments equal to or higher than those of upper secondary school graduates. 3. In poultry farming career of the investigated person, layer chicken industry was longer than broiler. 4. Occupations of farm owners before. doing poultry farming were farmers(32.35%), company employees, civil servants and soldiers, etc. 5. 58.62% of the person ran only poultry farming and the rest of them held the additional office of a farmer and a public officer. 6. There were many people who made a speciality of poultry farming holding additional jobs as dairy farming, cultivating crops, gardening, etc. 7. 42.35% of the person began poultry farming with under 1,000 layer chickens. And the rate of the ones with 1,000-2,000 broilers for the first time consisted 40.95% 8. Present breeding scale was that the rate of the farmers having 5,000-10,000 layer chickens was 37.13% and the ones having 5,000-10,000 broilers 38.32%. 9. The rate of the person supplying self-labor was 23.16%, the person having 1.3 employees 51.47% and the ones having under 20 employees 1.47%. 10. 74.26% of the poultry farms used very good quality of baby chicks. 11. The rate of the farms which used chicken feed making the point of the quality of it was 65.47% and the ones which bought it on credit 26.62%. 12. 65.47% bought feed directly from factories and 26.62% bought it from commercial agents. 13. The rate of the layer chicken farms paying for feed in cash was 19.39% and the broiler farms 32.74%. Most of the farms bought feed on credit by 30-60 days. 14. They bought the medicine for chicken from animal drug stores or veterinary hospitals. 15. The rate of the person posting up accounts roughly was 47.52% and that of the ones doing them detaily was 43.57%, 40% did not do them because of bother and only 21.22% had their own cashbooks.

• Journal of Animal Science and Technology
• /
• v.47 no.5
• /
• pp.837-850
• /
• 2005

This study was conducted to investigate the changes of quality characteristics on seasoned pork with Korean traditional 4 types seasoning such as soybean sauce(T1); Kimchi sauce(T2); pickled shrimps sauce(T3); onion sauce(T4). The seasoned samples were aged at 10±1℃ for 13 days. The results obtained were as follows; Except for T2, pH of treatments were significantly decreased(P<0.05) as aging period increased. Salinity(%) and saccharinity(%) of seasoned meat were tended to increased during aging period. Thiobarbituric acid reactive substances(TBARS) were increased significantly during storage in all treatment(P<0.05). T4 showed the highest TBARS among the all treatment groups. Volatile basic nitrogen(VBN) values of all treatments were significantly increased(P<0.05) as storage period increased. There were no significant differences in water holding capacity(WHC) among the all treatments, and those values were not changed by the passage of storage days. Shear force values of all treatments were tended to decreased by the passage of storage days. In surface color, the values of L*, a* and b* showed a tendency of increasing value along the storage days. The values of a* and b* of T2 were significantly higher than other treatments during aging period(P<0.05). In inner color, a* and b* values of T2 were significantly higher than those of other treatments during aging period(P<0.05). In the sensory evaluation of cooked meat, T3 treatment resulted in lower score in aroma, flavor, tenderness, juiciness and overall acceptability. The number of total plate counts and Lactobacilli spp. tended to increase with storage in all treatments group. The numbers of Escherichia coli were not changed by the passage of storage time.

• Journal of Animal Science and Technology
• /
• v.45 no.5
• /
• pp.835-840
• /
• 2003

Two hundreds and twenty three pork carcasses of commercial breeds were studied for comparing to technical quality characteristics of pork identified by National Pork Producers Council(NPPC) scale. pH and conductance(C) were taken in 1(pH$_1$, C$_1$), 3(pH$_3$, C$_3$), 6(pH$_6$, C$_6$) and 24hr(pHu, Cu) postmortem on 4~5th thoracic vertebrae. Visual color and CIE value were estimated in longissimus dorsi(LD) muscle in 24hr postmortem on the two sites(4~5th thoracic vertebrae and last vertebrae) using National Pork Producers Council(NPPC) scale and color difference meter. Significant differences were observed in pH$_1$, pHu, Cu, CIE L$^{*}$ value, water holding capacity(WHC) and juiciness at all scales(p〈0.05). But, pH and CIE L$^{*}$value were considerably affected by postmortem time and measuring site. NPPC scale was highly related with CIE L$^{*}$(R$^2$=0.77) and WHC(R$^2$=0.66), and moderately related with C$_{u}$(R$^2$=0.59) and pH$_{u}$(R$^2$=0.54), and poorly related with pH$_3$(R$^2$=0.32), pH$_6$(R$^2$=0.28) and C$_1$～C$_6$(R$^2$=0.03~0.18).

• Journal of Food Hygiene and Safety
• /
• v.33 no.3
• /
• pp.168-175
• /
• 2018

The use of microwave-assisted extraction and an acid-base clean-up process to determine the amount of methylmercury (MeHg) in marine products was suggested in order to improve the complicated sample preparation process. The optimal conditions for microwave-assisted extraction was developed by using a 10% NaCl solution as an extraction solution, setting the extraction temperature at $50^{\circ}C$, and holding for 15 minutes to extract the MeHg in marine products. A NaOH solution was selected as a clean-up substitute instead of L-cysteine solution. Overall, 670 samples of marine products were analyzed for total mercury (Hg). Detection levels were in the range of $0.0006{\sim}0.3801{\mu}g/kg$. MeHg was analyzed and compared using the current food code and the proposed method for 49 samples which contained above 0.1 mg/kg of Hg. Detection ranges of methylmercury followed by the Korea Food Code and the proposed method were $75.25(ND{\sim}516.93){\mu}g/kg$ and $142.07(100.14{\sim}244.55){\mu}g/kg$, respectively. The total analytical time of proposed method was reduced by more than 25% compared with the current food code method.

• Food Science of Animal Resources
• /
• v.23 no.2
• /
• pp.128-136
• /
• 2003

This study was peformed to evaluate physico-chemical and textural properties, and shelf-life effect of low-fat functional sausages(LFFS) manufactured with sodium lactate(SL), lac color and various molecular weights of chitosans(low=1.5 kDa, medium=30∼40 kDa and high=200 kDa) during storage at 4$^{\circ}C$ for 8 weeks. LFFS had a pH range of 6.39∼6.50, 76∼78% moisture, <2% fat, 14∼15% protein. The combination of SL and low molecular weight(MW) of chitosan improved water holding capacity(WHC), however those of SL and medium MW of chitosan reduced WHC. Vacuum purge(VP) reduced with increased MW of chitosans during refrigerated storage. The addition of chitosans reduced the lightness and yellowness, but increased the redness values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm. LFFS containing SL and medium MW of chitosan increased most texture profile analysis(TPA) values, as compared to controls with 75 and 150 ppm. The addition of SL in LFFS retarded the microbial growth for Listeria monocytogenes, however no synergistic effect with the addition of chitosans were observed. E coli O157:H7 and Salmonella typhimurium reduced during refrigerated storage, regardless of SL and chitosan treatments. Increased storage time increased values for VP, yellowness and textural properties. These results indicated that the combination of SL and various MW of chitosans affected the functional and textural properties, and inhibited the microbial growth for LM effectively. In addition, 0.5% lac color as a replacer for sodium nitrite improved the color development, resulting in similar hunter color values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm.