• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.583-590
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• 2019

As the consumption of fresh fruits and vegetables increases, food poisoning caused by foodborne pathogen contamination is not decreasing. To prevent the contamination of produce, a quick and easy, low-cost, environmentally-safe disinfection method that does not affect produce freshness or quality is needed. This study demonstrates a new-concept, circulating-water disinfection system that purifies water by using newly developed 'LED-PS (photosensitizer)-induced ROS generation unit'. Using various types of LED-PS induced ROS generation units, we investigated the conditions for reducing the density of various pathogenic bacteria by more than 3 log CFU / mL in 1 hour. The major operational factors affecting the density reduction of the LED-PS-induced ROS generation unit were analyzed. Depending on bacteria species, the density reduction rate was varied. The effect of the units on reducing the density of Bacillus cereus and Pectobacterium carotovorum subsp. carotovorum was high, but the effect on foodborne bacteria such as Escherichia coli was relatively low. In this circulating water disinfection system, the density reduction effect tended to increase as the flow rate increased and the initial bacterial density decreased. As the amount of PS absorbed beads increased, the density reduction effect increased exponentially in some bacteria. Model 3280, a double cylindrical unit connecting two single cylindrical units, could completely sterilize more than 3 log CFU/mL of B. cereus and P. carotovorum subsp. carotovorum in 30 minutes of LED irradiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.643-647
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• 2010

Gamhongro-ju is a Korean traditional alcoholic beverage made from medicinal herbs and spices. In this study, polyphenol content and antioxidant activities of gamhongro-ju and the 8 individual herb extracts used to make the beverage were determined. Cinnamon, saposhnikovia root, clove, ginger, violet-root cromwell, licorice, citrus peel and logan (2.5 g each) were extracted with 1000 mL of 45% and 60% purified ethanol (PE), and 45% traditionally distilled ethanol (TDE). The individual herb (20 g each) was extracted with 1000 mL of 60% PE. Polyphenol content, DPPH and ABTS radical scavenging activities of the extracts were measured. In the combined herb extracts, polyphenols were significantly higher in the 45% and 60% PE extracted for 90 days than those for 30 days. In the 8 individual herb extracts, the clove extract had the highest polyphenol content (2421~2446 mg/L). ABTS $IC_{50}$ values of the combined herb extracts were lower in the 60% PE and 45% TDE extracted for 90 days than those for 30 days. In the 8 individual herb extracts, the clove and cinnamon had the lowest ABTS and DPPH $IC_{50}$ values. In the individual extracts, ginger had the lowest polyphenol content; however, it was the third in the antioxidant activity.

• The Korean Journal of Pharmacology
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• v.20 no.1 s.34
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• pp.55-65
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• 1984

Comparative effects of $PGF_{2{\alpha}}$ and ouabain on the isolated rat(Sprague-Dowley) atria were studied. The isolated rat atria were prepared for isometric myography in the isolated organ bath containing Feigen's solution perfused with 95% $O_2$ and 5% $CO_2$, and the pH of the medium was maintained at 7.4. The cumulative concentration-response relationship revealed the positive inotropic effects of both drugs with the higher potency of $PGF_{2{\alpha}}$ and the higher efficacy of ouabain. $PGF_{2{\alpha}}$ showed a positive chronotropic effect, but ouabain showed a tendency of increasing the contraction rate. In low-Ca(1.4 mM) medium, the positive inotropic and chronotropic effect of $PGF_{2{\alpha}}$(by $3{\times}10^{-8}M$) were preponderant $(p<0.05{\sim}p<0.005)$ over those of ouabain(by $3{\times}10^{-3}M$). $Ca^{++}$-addition(cumulative, to 2.8, 4.2, 5.6, and 7.0 mM) into the medium evoked the more sensitive response in the $PGF_{2{\alpha}}$ group than in the ouabain group. In low-K(2.8 mM) medium, the $PGF_{2{\alpha}}a(3{\times}10^{-8}M)$ group and the ouabain$(3{\times}10^{-3}M)$ group showed similar tensions(DT and RT) and contraction rates. And both group showed significantly(p<0.05p<0.01) higher tensions and contraction rates than those of the control group. By the cumulative addition of the $K^+$(to 4.2, 5.6, 7.0 and 8.4 mM), only the DT of the $PGF_{2{\alpha}}$ group was sustained at signifcantly$(p<0.05{\sim}p<0.01)$ higher level than the DT of the control group. The $K^+$-addition inhibited the positive inotropic effect of ouabain significantly (p<0.05). The cumulative addition of lidocaine in high concentrations $(1{\times}10^{-5}\;to\;1{\times}10^{-3}M)$ evoked no significant influence on the intropic activities of $PGF_{2{\alpha}}$ and ouabain, but significant ${\beta}$-blockade with propranolol could not inhibit the positive intropic and chronotropic effect of $PGF_{2{\alpha}}$. In conclusion, it is presumed that $PGF_{2{\alpha}}$ may have some more active mechanism of accelerating the influx of $Ca^{++}$ across the cell membrane of the isolated rat atria as compared with ouabain, and the action site may be located at the cell membrane. As a supposition which needs further investigations, it is presumed that $PGF_{2{\alpha}}$ may have its specific membrane receptors on the atrial muscle or sinus node cells.

• Journal of The Korean Association For Science Education
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• v.15 no.2
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• pp.173-184
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• 1995

The purpose of this study was to analyse the problems of 'Science Inquiry Experiment Contest(SIEC)' which was one of 8 programs of 'The 2nd Student Science Inquiry Olympic Meet(SSIOM)'. The results and conclusions of this study were as follows: 1. It needs to reconsider the role of practical work within science experiment because practical work skills form one of the mainstays in current science. But the assessment of students' laboratory skills in the contest was made little account of. It is necessary to remind of what it means to be 'good at science'. There are two aspects: knowing and doing. Both are important and, in certain respects, quite distinct. Doing science is more of a craft activity, relying more on craft skill and tacit knowledge than on the conscious application of explicit knowledge. Doing science is also divided into two aspects, 'process' and 'skill' by many science educators. 2. The report's and checklist's assessment items were overlapped. Therefore it was suggested that the checklist assessment items were set limit to the students' acts which can't be found in reports. It is important to identify those activities which produce a permanent assessable product, and those which do not. Skills connected with recording and reporting are likely to produce permanent evidence which can be evaluated after the experiment. Those connected with manipulative skills involving processes are more ephemeral and need to be assessed as they occur. The division of student's experimental skills will contribute to the accurate assess of student's scientific inquiry experimental ability. 3. There was a wide difference among the scores of one participant recorded by three evaluators. This means that there was no concrete discussion among the evaluators before the contest. Despite the items of the checklists were set by preparers of the contest experiments, the concrete discussions before the contest were necessary because students' experimental acts were very diverse. There is a variety of scientific skills. So it is necessary to assess the performance of individual students in a range of skills. But the most of the difficulties in the assessment of skills arise from the interaction between measurement and the use. To overcome the difficulties, not only must the mark needed for each skill be recorded, something which all examination groups obviously need, but also a description of the work that the student did when the skill was assessed must also be given, and not all groups need this. Fuller details must also be available for the purposes of moderation. This is a requirement for all students that there must be provision for samples of any end-product or other tangible form of evidence of candidates' work to be submitted for inspection. This is rather important if one is to be as fair as possible to students because, not only can this work be made available to moderators if necessary, but also it can be used to help in arriving at common standards among several evaluators, and in ensuring consistent standards from one evaluator over the assessment period. This need arises because there are problems associated with assessing different students on the same skill in different activities. 4. Most of the students' reports were assessed intuitively by the evaluators despite the assessment items were established concretely by preparers of the experiment. This result means that the evaluators were new to grasp the essence of the established assessment items of the experiment report and that the students' assessment scores were short of objectivity. Lastly, there are suggestions from the results and the conclusions. The students' experimental acts which were difficult to observe because they occur in a flash and which can be easily imitated should be excluded from the assessment items. Evaluators are likely to miss the time to observe the acts, and the students who are assessed later have more opportunity to practise the skill which is being assessed. It is necessary to be aware of these problems and try to reduce their influence or remove them. The skills and processes analysis has made a very useful checklist for scientific inquiry experiment assessment. But in itself it is of little value. It must be seen alongside the other vital attributes needed in the making of a good scientist, the affective aspects of commitment and confidence, the personal insights which come both through formal and informal learning, and the tacit knowledge that comes through experience, both structured and acquired in play. These four aspects must be continually interacting, in a flexible and individualistic way, throughout the scientific education of students. An increasing ability to be good at science, to be good at doing investigational practical work, will be gained through continually, successively, but often unpredictably, developing more experience, developing more insights, developing more skills, and producing more confidence and commitment.

• Journal of The Korean Association For Science Education
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• v.32 no.1
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• pp.15-29
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• 2012

The purpose of this study was to investigate the educational factors on career choice of science-gifted students to science and technology bound universities and the difference of perception in regards to group factors. In addition, this study aimed to examine the effects of science-gifted education and critical events in relation to career choice to science and technology bound universities. For the study, 104 university freshmen, 75 males and 29 females, were sampled from UNIST (Ulsan National Institute of Science and Technology), that many science high school graduates entered this year. The survey was conducted with questionnaires to do with the perceptions concerning career choice and educational factors that cause them to choose such career directions. The educational factors on career choice to science and technology bound universities were classified as 3 main categories such as educational environment factor (teaching-learning factor), human factor, attitude towards science factor and the subcategories within each category. The research findings are as follows: First, the factors were closely connected with each other and 'the project centered classes' were highly interrelated with other educational environment factors such as 'the experiment activity and environment for the activity' and 'influence of teachers (professors).' Second, the female students and graduates of the science high school were more positively influenced by the educational environment and human factors on their decision for career than male students and graduates of the general high school. Third, this research found that historical scientific knowledge, perception of scientists' social status and job applications in the science field gave less influence rather than other factors on their decision for career. As a result of examining critical events for science-gifted education in relation to career choice to science and technology bound universities, numerous students mentioned that the extracurricular science activities such as science camps and field trips gave significant effects on students' career choices to science and engineering fields.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.2
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• pp.41-74
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• 2020

The monetary penalties system inherently has efficiency as DNA. In the event that administrative measures to recover unfair profits from businesses that violate the law, deprive business licenses, or order to suspend business, infringe the interests of ordinary consumers, a system that can achieve the same effect through financial sanctions. It is a monetary penalties. In addition, it is convenient for the government because it takes effect only by the administrative agency's unilateral imposition order compared to the trial process, which takes a long time and huge cost to prove the illegality. However, it is questionable whether procedural legitimacy is well established in Korea's aviation monetary penalties. Compared to foreign legislation, Korea's aviation monetary penalties system need to be improved. This paper was for the purpose of studying the improvement direction of the monetary penalties system disposed of in the Korean aviation field. This study suggests the direction by examining the US system, which is an aviation advanced country, in the aviation safety area. The research was conducted with the intention of exploring the direction as follows: First, the characteristics of the Federal Aviation Administration (FAA) aviation administrative sanctions and the US aviation penalty system will be outlined. Furthermore, with the recent paradigm shift in aviation safety management, this paper tried to look at new trends that focus on autonomous reporting of aviation safety as a proactive and preventive measure in conventional post-airline accident management administration, focusing on various systems including ASAP. This article also reviewed the formal process for imposing monetary penalties adopted by the FAA. Based on the above review, this paper also looked at ways to improve the reporting system for aviation safety in Korea.

• Journal of Korean Home Economics Education Association
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• v.21 no.3
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• pp.45-64
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• 2009

The purpose of this study was to develope issue-centered teaching learning process plan for environment-friendly housing education and to apply it to the housing section of Technology Home Economics in a middle school. PRO-CON cooperative group model was used for the teaching learning process plans of 2-session lessons according to the ADDIE model. In the development stage, 7 activity materials and 20 teaching learning materials (4 reading texts, 12 pictures and photos, & 5 moving pictures) were developed for 2-session lessons. The plans applied to the 7 classes, 222 students, in the third grade of the G middle school in Gyeonggi-do during July 10th-17th, 2008. The results showed that the final pro-con was influenced by the rationals of juries' pro-con of each team and the representative's discussion besides one's environmental perspective. The intention to implement environment-friendly housing activities was significantly increased between before and after the lessons. The contents, methods, goals, and process of the 2-session lessons were evaluated over medium to somewhat higher levels. Those evaluations except methods and general satisfaction with the lessons were differed by sex, students' and their families' interests in environments but not by the type of housing. These results might support that pro-con cooperative group model of controversial issues on parking lot would be appropriate to environment-friendly housing lessons and could apply to broad issues on housing and various schools in other areas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.592-603
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• 2014

We developed various recipes of turmeric powder (Curcuma longa L.) added to milk bread and assessed the individual effects of seven ingredients [milk ($X_1$), turmeric powder ($X_2$), bread improver ($X_3$), fresh yeast ($X_4$), butter ($X_5$), sugar ($X_6$), and salt ($X_7$)] as well as the 2-way interaction effects of the ingredients on the sensory characteristics of breads using fractional factorial design method. The center and end points of each component were determined via literature review and multiple test baking. Seven trained sensory test panels evaluated the outside appearance (OA), inside appearance (IA), and flavor & texture (FT) of 38 breads using 46 items of sensory evaluation. Findings are as follows: for the OA, $X_1$ (P<0.05) and $X_4$ (P<0.0001) exhibited significant individual effects, whereas $X_1*X_7$, $X_2*X_5$, $X_3*X_6$, and $X_4*X_6$ indicated significant interaction effects (P<0.05). For the IA, $X_1$ (P<0.0001), $X_4$ (P<0.0001), $X_6$ (P<0.05), $X_2*X_4$ (P<0.05), and $X_3*X_6$ (P<0.01) showed individual and interaction effects, respectively. For the FT, $X_1$ and $X_2$ showed the most significant individual effect (P<0.0001), followed by $X_4$, $X_5$ and $X_6$ (P<0.05) in descending order. $X_4*X_7$ indicated the only significant interaction effect. We computed the magnitudes of the 2-way interaction effects of the ingredients with a distinct emphasis. Model equations predicting the levels of the ingredient effects on the breads were also provided via regression analyses. In summation, $X_4$ appeared to be the most significant component affecting the sensory characteristics based on its individual and 2-way interaction effects. Further, $X_6$, $X_1$, $X_2$, and $X_5$ indicated both individual and interaction effects. $X_3$ and X7 showed only interaction effects. The center point effect appeared to be unequivocal for whole sensory characteristics. Findings of the present study may provide insights into the selection of ingredients to derive an optimal model for turmeric powder-added bread using the response surface method hereafter.

• Archives of design research
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• v.16 no.3
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• pp.201-210
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• 2003

The world is preparing another unseen war, that is, the cultural war of digital economy which will dominate the new millenium. As the “contents”, which are composed of various ingredients of media, gain vitality, the developed nations are in preparation of the war with the “cultural industry” weapons. The digital economic experts say that the left out nations will become economic colony in the new millenium age. The most important characteristics of cultural industry is the unity of creativity and culture which is all the more improved on the basis of the culture created upon knowledge. This leads to competition between nations or regions, and to survive one has to develop the industrial structure through cognition of its own cultural value. Furthermore, it is not a short-term development and investment of cultural products but a study on the method to graft the cultural value to the industry itself. The multi-media period does not accept an independent medium, and the contents products are becoming the leading industry since il is proved that they last semi-permanently in the digital world. The victory lies in the quality and quantity of the contents as the high ability and variety of the technology of media advance in accordance to the market principles. Since the culture, science and economy are becoming one complex structure, all nations of the world are trying the evolve a unique design of their on culture on the basis of the global universality. In consequence, we should excavate a uniqueness from our cultural heritage and develop into a korean design which will be recognized in the world market. The value of our cultural property should not only be used as academic and research purposes but should be re-evaluated with modem view, recognized as the core element that decides the quality of life and developed into exclusive designs. The korean designs represent the mould concept of our people which evolves from the mould or shape alphabet of Korea To meet the requirements of the changing world and in preparation of the cultural competitive age, it is never too early to make a data on the korean designs through their analysis and evaluation.

• Journal of Science Education
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• v.37 no.3
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• pp.434-445
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• 2013

The purpose of this study is to aid the teaching strategy for the teacher by investigating the preconception of the earthquake for 4th grade students in elementary school before learn the curriculum. For this, 31 grade students who lived in Seongnam in Gyeonggi province were interviewed with the questionnaire. The following is the findings. On the definition of an earthquake, 64.9% of the students had scientific conception. On the question of 'what happens on the ground when there is an earthquake', 59.2% of the students responded shaking or cracking of the earth, ground, things or building. On the question of 'what a person should do when there is an earthquake', most of the students responded by more than two answers. In contrast, on the causes of an earthquake, there were the largest percentage (35.3%) students who answered they didn't know. Except for one student, there were no students had talked about scientific conception. On the question of 'what happens below when there is an earthquake', 26.3% of the students responded they didn't know. On the place where an earthquake occurs rather frequently, 22.2% of the students mentioned an island. On the reason, 39.9% of the students responded they didn't know and there were no students with scientific answers. This study showed 4th grade students had scientific conception on the definition of an earthquake, and they had many experience interaction with external environment on 'what happens on the ground when there is an earthquake', 'the place where an earthquake occur rather frequently'. However the students had relatively small experience on the causes of an earthquake, on 'what happens below the ground when there is an earthquake', and earthquake-prone areas. Based on this study, additional research must be conducted on science in which the students' preconceptions is investigated to connect back to curriculum development. In addition, consideration must be given on how to integrate the thinking processes of students during the curriculum development process.