• The Korean Journal of Air & Space Law and Policy
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• v.31 no.2
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• pp.177-214
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• 2016

During more than 20 years of practice, Civil Aviation Law has experienced three times of amendments since it was enacted in 1995. But these revisions are limited to the technical level. The problems and limitations have become increasingly prominent in its implementation. Firstly, the civil aviation law is the result of interests game among several departments and some legal issues was left behind and the regulation was very vague as a result. Secondly, the process of aviation legislation is the process that the country has undergone profound changes and social transformation. The 20 years is long enough for the society to undergo tremendous changes and 1995 version of civil aviation law does not keep pace of development of economy. There was a serious lag between reality and the law. In order to actively promote the development of the aviation industry and overcome implementation issues of the Civil Aviation Law, Civil Aviation Administration of China (CAAC) initiated modification procedure the law and published new draft of Civil Aviation Law in August 2016. The spirit of this modification is to learn and absorb new achievements of domestic and foreign legislation and the International Convention on civil aviation. Furthermore, the purpose of the revision is to provide favorable policy for the development of civil aviation industry and improve aviation safety and supervision, strengthen and protection of consumer rights and interests, to enhance the safety of civil aviation activities, and promote the development of general aviation. This revision concerned to the 78 articles which are revised or deleted and 24 articles added. The highlights of the draft include but not limited to the enhancement of security management, clarification of the main responsibility for production safety. And also it added the provisions related to the construction of effective tracking capability of public air transport enterprises and license system on the transport of dangerous goods. Compared with the existing civil aviation law, the draft has made a great improvements. But there are several deficiencies and limitations in the drafts. These problems need to be supplemented and perfected through further amendments in near future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.1041-1048
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• 2016

Biofilm cells and viable but non-culturable (VBNC) state may play a role in the survival of Campylobacter jejuni under unfavorable environmental conditions. The objective of this study was to investigate the behavior of C. jejuni biofilm cells and VBNC cells on smoked duck. The transfer of C. jejuni biofilm cells to smoked duck and its ability to resuscitate from biofilm and VBNC cells on smoked duck was investigated. Transfer experiments were conducted from C. jejuni biofilm cells to smoked duck after 5 min, 1 h, 3 h, and 24 h contact at room temperature, and the efficiency of transfer (EOT) was calculated. In addition, smoked duck was inoculated with C. jejuni biofilm and VBNC cells and then stored at 10, 24, 36, and $42^{\circ}C$ to examine the cells' ability to resuscitate on smoked ducks. The 5 min contact time between C. jejuni biofilm cells and smoked duck showed a higher EOT (0.92) than the 24 h contact time (EOT=0.08), and the EOT decreased as contact time increased. Furthermore, C. jejuni biofilm cells on smoked duck were not recovered at 10, 24, and $36^{\circ}C$, and C. jejuni VBNC cells were not resuscitated at $42^{\circ}C$. Although the resuscitation of C. jejuni biofilm and VBNC cells was not observed on smoked duck, microbial criteria of C. jejuni is needed in poultry and processed poultry products due to risk of its survival and low infectious dose.

• Journal of the Korean earth science society
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• v.41 no.1
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• pp.75-91
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• 2020

The purposes of this study are 1) to develop a pre-education program for teaching the basic concepts of systems thinking and STEAM program based on systems thinking and 2) to investigate the effects of the program on middle school students' systems thinking. The subjects were 4 seventh-graders and 4 ninth-graders in a middle school located in the province of Gyeongsangbuk-do. Data related to students' systems thinking was analyzed using the rubrics developed by Hung(2008). The results were reviewed by experts to verify the validity of the rubrics and the reliability of students' system thinking. In addition, the data analyzed with the rubrics, students' awareness of systems thinking, word associations, causal maps and interviews were systematically analyzed to investigate the effects of the program on students' systems thinking. The findings of this study were as follows: First, a pre-education program and teachers' guidebook for teaching and learning the concept of systems thinking and causal maps were developed. The pre-education program consisted of familiar TV entertainment program-Infinite Challenge (Muhandojeon)-with a theme of Global Warming. Second, a STEAM education program based on systems thinking which was composed of 5 steps: Analysis-Design-Build-Assessment-Systems thinking. The major theme of the program was an air extinguisher. The developed STEAM education program had positive effects on improving middle school students' systems thinking abilities such as understanding systems, relations within a system and system generalization. Therefore, it was concluded that the STEAM program could be instrumental for cultivating students' STEAM literacy with improved systems thinking.

• Journal of The Korean Association For Science Education
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• v.38 no.4
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• pp.481-494
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• 2018

This study investigated elementary students' understanding of Earth revolution and its accompanied apparent motion of constellation in terms of spatial reasoning. We designed a set of multi-tiered constructed response items in which students described their own idea about the reason of consecutive movement of constellations for three months and drew a diagram about relative locations of the Sun, the Earth, and the constellations. Sixty-five sixth grade students from four elementary schools participated in the tests both before and after science classes on the relative movement of Earth and Moon. Their answers to the items were categorized inductively in terms of transforming frames of reference which are observed on the Earth and designed from the Space-based perspective. We analyzed those categories by the levels of spatial reasoning and depicted the change of students' levels between pre/post-tests so that we could get an idea on the preliminary developmental pathway of students' understanding of this topic. The lower anchor description was that constellations move around the Earth with geocentric perspective. Intermediate level descriptions were planar understanding of Earth movement, intuitive idea on constellation movement along with the Earth. Students with intermediate levels did not reach understanding of the apparent motion of constellations. As the upper anchor description students understood the apparent motion of constellations according to the Earth revolution and could transform their frames of reference between Earth-based view and Space-based view. The features as the case of evolutionary learning progressions and critical points of students' development for this topic were discussed.

• Journal of The Korean Association For Science Education
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• v.40 no.4
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• pp.385-398
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• 2020

This study aims to examine genetics problem-solving processes of high school students with different learning approaches. Two second graders in high school participated in a task that required solving the complicated pedigree problem. The participants had similar academic achievements in life science but one had a deep learning approach while the other had a surface learning approach. In order to analyze in depth the students' problem-solving processes, each student's problem-solving process was video-recorded, and each student conducted a think-aloud interview after solving the problem. Although students showed similar errors at the first trial in solving the problem, they showed different problem-solving process at the last trial. Student A who had a deep learning approach voluntarily solved the problem three times and demonstrated correct conceptual framing to the three constraints using rule-based reasoning in the last trial. Student A monitored the consistency between the data and her own pedigree, and reflected the problem-solving process in the check phase of the last trial in solving the problem. Student A's problem-solving process in the third trial resembled a successful problem-solving algorithm. However, student B who had a surface learning approach, involuntarily repeated solving the problem twice, and focused and used only part of the data due to her goal-oriented attitude to solve the problem in seeking for answers. Student B showed incorrect conceptual framing by memory-bank or arbitrary reasoning, and maintained her incorrect conceptual framing to the constraints in two problem-solving processes. These findings can help in understanding the problem-solving processes of students who have different learning approaches, allowing teachers to better support students with difficulties in accessing genetics problems.

• Journal of Aquaculture
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• v.8 no.3
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• pp.195-207
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• 1995

In order to study the embryonic development and hatching of wild long shanny, Stichaeus grigorjewi, were caught with the gill nets in the East Sea of Korea, and stocked at indoor tanks to induce natural spawning in February 25, 1994 and February 16 to 24, 1995. They were already matured when stocked, and average body length (50.66 cm) and body weight (1,192.74 g) of 57 females and average body length (48.62 cm) and body weight (612.58g) of 43 males were recorded. Before stocking, they were inserted with identification tags(ID tags) in the dorsal muscle, and spawning was traced by the portable reader (Destron/lDl Ltd.) Forty females among 57 spawned successfully in the average of 4 days after stocking. Females spawned almost all eggs contained in the ovaries at one time in the form of an egg mass and averaging 227,200 eggs Per egg mass. The egg mass was oval in shape, translucent milky in color, 20.32cm long axis and 14.57cm short axis in size, and 803.7g in weight. Male parents guarded their egg masses and circulated water with the tail part of the body. Fertilized egg was spherical in shape, and their average diameter was 1.54 mm. Each egg had a containing single oil globule, and it's average diameter was 0.37 mm. The average water temperature was $13.2^{\circ}C$ and incubation times after fertilization were 5 hours 25 minutes up to 2-cell stage, 13 hours up to morula stage, and 66 hours 35 minutes up to embryo formation stage. Hatching rate was approximately 10 percent in 368 hours 50 minutes after fertilization, and approxionateoly 90 percent of eggs were hatched in 425 hours 30 minutes after fertilization.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.3
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• pp.225-235
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• 2009

A common procedure of restoration of endodonticlly treated tooth with fiber-reinforced post is followed by core build-up after post cementation. However, this technique is complex and time-consuming. The aim of this study was to compare fracture strength of premolar, restored with various methods of core fabrications on fiber-reinforced posts and casting metal restoration. Forty five freshly extracted human mandibular premolars were obtained and devided into 5 groups acconding to the type of post and methods of core build-up. In Group A, D.T. $Light-post^{(R)}$ were cemented with $DUO-LINK^{TM}$ and then $LIGHT-CORE^{TM}$ was used for core restoration. In Group B, D.T. $Light-post^{(R)}$ and $DUO-LINK^{TM}$ were used for cementing in the postspace, and $DUO-LINK^{TM}$ was used again for core restoration. In Group C, $Light-post^{(R)}$ bonding and the core build-up were performed simultaneously by using $DUO-LINK^{TM}$. In Group D, $LuxaPost^{(R)}$ was bonded by using $LuxaCore^{(R)}-Dual$. Again, $LuxaCore^{(R)}-Dual$ was used for core restoration. In Group E, $LuxaPost^{(R)}$ bonding and the core build-up were performed simultaneously by using $LuxaCore^{(R)}-Dual$. Axial reduction was formed parallelly as possible and 45 degree bevel was made at buccal occlusal surface. Crowns were fabricated and cemented. Each tooth was embedded in self-curing acrylic resin to the level of 2mm below the CEJ. Specimens were fixed on universal testing machin such that the axis of the tooth was at 45 degree inclination to the horizontal plane, and compressive force was applied at a crosshead speed of 1mm/min until failure occurred. The mean fracture strength was the highest in group A followed by descending order in group B, D, E and C. However, there were no statistically significant differences between groups with regard to the fracture strength. The type of the post or build-up methods of the core does not seem to influence the fracture strength.

• Sleep Medicine and Psychophysiology
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• v.14 no.2
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• pp.86-91
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• 2007

Background: Actigraphy is a reliable and valid method for assessing sleep in normal, healthy populations, but it may be less reliable and valid for detecting disturbed sleep in patients. In this study, we attempted to assess the utility of actigraphy in the estimation of sleep quality in patients with obstructive sleep apnea syndrome (OSAS), a major sleep disorder. Method: We analyzed the data of patients who underwent polysomnography (PSG) and actigraphy simultaneously for one night at the Center for Sleep and Chronobiology, Seoul National University Hospital from November 2004 to March 2006. Eighty-nine subjects with OSAS alone and 21 subjects with OSAS and periodic limb movement disorder (PLMD) were included for final data analyses between groups. Polysomnographic and actigraphic data were also compared. Results: In subjects with mild OSAS (RDI<15), modretae ($15{\leq}RDI$<30), and OSAS with PLMD, PSG and actigraphy did not show significant difference in total sleep time and sleep efficiency. However in severe ($30{\leq}RDI$) OSAS subjects, PSG and actigraphy showed significant difference in total sleep time and sleep efficiency. In all patients, no correlations were found between sleep parameters from PSG and from those using actigraphy. Conclusions: We suggest that in severe OSAS patients, PSG is the diagnostic tool. In mild and moderate cases, actigraphy might be used as a screening tool.

• Korean Journal of Social Welfare
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• v.68 no.2
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• pp.107-130
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• 2016

This study is aimed at the exploratory research on the influence of the obligation of extension of the retirement age on the baby boom generation. The basic question of this study is about which of the baby boom generation can get how much benefit according as the extension of the retirement age becomes compulsory. The extension of the retirement age is the system that can be applied to regular full-time workers. Accordingly, this study is intending to analyze the characteristics of the workers having a high likelihood for benefits from extension of the retirement age by tracing the economic activity state and labor history of the baby boomers. For this purpose, this study looked into the change of the economic activity state by age cohort of the male baby boomers based on the data for the Korea Labor Panel's 4th(2001) & 17th(2014)year. Using Survival analysis, this study also analyzed who will continue to remain as a regular full-time wage earner. As the result of the analysis, it was found that the more the cohort ages of baby boomers increased, the smaller the probability of remaining as a regular full-time wage earner, and the group who can get benefits from extension of the retirement age was predicted to account for only 11.4% level among the baby boomers. In addition, the result showed that there was a high likelihood of getting more benefits from extension of the retirement age when the baby boomers worked for the government-invested institution, corporate bodies, and government organizations rather than working for private enterprises. Thus, it can be safely said that there might appear a generational conflict due to extension of the retirement age in that such jobs coincide with the ones favored by the rising generation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.3
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• pp.53-63
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• 2017

With increasing the importance of venture startup in the national economy, a trend shows that the government's policy support for venture startup is not only strengthened, but also entrepreneurial enthusiasm is increasing. In order for this trend to continue as an ongoing phenomenon, not a temporary phenomenon, venture startups should continue to grow with survival competitiveness. In this respect, there is a time when it is necessary to study the factors affecting the success of venture startups more than ever. There is a limit to seeing main factors, which affect the entry into the growth stage with survival competitiveness for the success of venture startups, as only 'entrepreneur capacity' and 'differentiation strategy' claimed by existing previous studies. As a more fundamental factor, entrepreneurial behavior is important in terms of opportunity discovery and opportunity utilization, but research into this falls short of expectations. This study is intended to look into success factors of venture startup. To achieve this, a survey was empirically carried out to CEOs in 100 small and medium venture startups through AHP analysis. The results are as follows. As stated above, entrepreneurship of success factors in venture startups is considered most critical, followed by innovation, economics, and technology. And 'entrepreneur's competency', 'positive entrepreneurial motivation', 'creative technology utilization', and 'continuous investment in technical development' are considered most critical for 'entrepreneurship', 'innovation', 'technology', and 'economics' as sub-factors, respectively. Consequently, entrepreneur's entrepreneurship that has been required in general startups is a critical factor to be also in common required in venture startups. This means that they can secure the competitiveness of venture startup along with continuous investment support in business startup with a positive mindset and their own technological competence as innovators to overcome the risk and uncertainty of business startup as entrepreneurship that marks the start of a new enterprise.