• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.391-392
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• 2012

In these days, the desire for the precise and tiny displays in mobile application has been increased strongly. Currently, laser displays ranging from large-size laser TV to mobile projectors, are commercially available or due to appear on the market [1]. In order to achieve a mobile projectors, the semiconductor laser diodes should be used as a laser source due to their size and weight. In this presentation, the continuous etch characteristics of Pd and AlGaN/GaN superlattice for the fabrication of blue laser diodes were investigated by using inductively coupled $CHF_3$ and $Cl_2$ -based plasma. The GaN laser diode samples were grown on the sapphire (0001) substrate using a metal organic chemical vapor deposition system. A Si-doped GaN layer was grown on the substrate, followed by growth of LD structures, including the active layers of InGaN/GaN quantum well and barriers layer, as shown in other literature [2], and the palladium was used as a p-type ohmic contact metal. The etch rate of AlGaN/GaN superlattice (2.5/2.5 nm for 100 periods) and n-GaN by using $Cl_2$ (90%)/Ar (10%) and $Cl_2$ (50%)/$CHF_3$ (50%) plasma chemistry, respectively. While when the $Cl_2$/Ar plasma were used, the etch rate of AlGaN/GaN superlattice shows a similar etch rate as that of n-GaN, the $Cl_2/CHF_3$ plasma shows decreased etch rate, compared with that of $Cl_2$/Ar plasma, especially for AlGaN/GaN superlattice. Furthermore, it was also found that the Pd which is deposited on top of the superlattice couldn't be etched with $Cl_2$/Ar plasma. It was indicating that the etching step should be separated into 2 steps for the Pd etching and the superlattice etching, respectively. The etched surface of stacked Pd/superlattice as a result of 2-step etching process including Pd etching ($Cl_2/CHF_3$) and SLs ($Cl_2$/Ar) etching, respectively. EDX results shows that the etched surface is a GaN waveguide free from the Al, indicating the SLs were fully removed by etching. Furthermore, the optical and electrical properties will be also investigated in this presentation. In summary, Pd/AlGaN/GaN SLs were successfully etched exploiting noble 2-step etching processes.

• Journal of KIISE:Software and Applications
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• v.34 no.1
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• pp.40-51
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• 2007

To improve academic achievement, the most students not only participate in regular classes but also take various extra programs such as private lessons, private institutes, and educational TV programs. In this paper, we propose a data mining approach to identify which studying methods or usual life patterns during a school vacation affect changes in the academic achievement. First, we derive various studying methods and life patterns that are thought to be affecting changes in the academic achievement during a school vacation. Second, we propose the method of transforming and analyzing data to apply them to decision trees and association rules, which are representative data mining techniques. Third, we construct decision trees and find association rules from the real survey data of middle school students. We have discovered four representative results from the decision trees. First, for students in the higher rank, there is a tendency that private institutes give a positive effect on the academic achievement. Second, for the most students, the Internet teaming sites nay give a negative effect on the achievement. Third, private lessons that have thought to be making a large impact to the achievement, however, do not make a positive effect on the achievement. Fourth, taking several studying methods in parallel nay give a negative effect on the achievement. In association rules, however, we cannot find any meaningful relationships between academic achievement and usual life patterns during a school vacation. We believe that our approach will be very helpful for teachers and parents to give a good direction both in preparing a studying plan and in selecting studying methods during a school vacation.

• Journal of Korea Port Economic Association
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• v.31 no.3
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• pp.141-153
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• 2015

This paper is an attempt to analyze the comparative advantage of Busan Port to China. For this, we use the market comparative advantage index, which is a version of the revealed comparative advantage index. The market comparative advantage index (MCA) uses trade patterns to identify the sectors in which a region has a comparative advantage, in this case by comparing Busan Port's trade profile with the world average (China). The indices are calculated at the commodity level of the HS four-digit classification. The export data used in this study are obtained from the Korea International Trade Association. Exports to China accounted for almost one third of Korean exports in 2014. There are, however, structural differences among the main export items of Busan Port. This paper, therefore, employs MCA indices to reveal the behaviors of the ten main export items, which are "HS3920-other plates/sheets/film/foil of plastics," "HS7606-aluminum plates/sheets/strip," "HS8479-unspecified machines/medical appliances," "HS8486-machines for semiconductor devices or wafers," "HS8529-parts for transmission apparatus for television," "HS8703-motor vehicles for the transport of persons," "HS8708-parts of motor vehicles," "HS9001-optical fibers," and "HS9013-liquid crystal devices." The study shows that export competitiveness of nine items increases, the exception being HS8703. However, China's import ratios of seven of the nine items for which the MCA indices go up are on the decrease, which means that it would be hard to expand the export market for these seven items, despite the higher MCA indices. Since the shares of the port's total exports to China of HS3907, HS8486, HS8529, HS9001, and HS9013 in total exports to China increase together with China's import ratio decreasing, these items may have promising export markets. MCA increases of HS7606 and HS8479 are attributable to China's lower import ratio, rather than a higher export share, so higher MCA indices do not guarantee higher export competitiveness for these items.

• Journal of the Korean Society for Library and Information Science
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• v.45 no.2
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• pp.209-228
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• 2011

Web search behavior has evolved. People now search using many diverse information devices in various situations. To monitor these scattered and shifting search patterns, an improved way of learning and analysis are needed. Traditional web search studies relied on the server transaction logs and single query instance analysis. Since people use multiple smart devices and their searching occurs intermittently through a day, a bundled query research could look at the whole context as well as penetrating search needs. To observe and analyze bundled queries, we developed a proprietary research software set including a log catcher, query bundling tool, and bundle monitoring tool. In this system, users' daily search logs are sent to our analytic server, every night the users need to log on our bundling tool to package his/her queries, a built in web survey collects additional data, and our researcher performs deep interviews on a weekly basis. Out of 90 participants in the study, it was found that a normal user generates on average 4.75 query bundles a day, and each bundle contains 2.75 queries. Query bundles were categorized by; Query refinement vs. Topic refinement and 9 different sub-categories.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.490-498
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• 2002

This study investigated the effects of the 'Meeting With Scientists' program on children's stereotypical images of scientist. To do those, 36 children of a fifth grade class participated in the program for one month. The program consisted of two main activities:(l) participating in scientists' lectures and exchanging e-mail with them; and (2) visiting web sites about scientist and science, and exchanging e-mail with scientists at the sites. The results of the study can be summarized as follows: First, after participating in the program, children showed the significant decrease of several stereotypical items, such as facial growth of hair(bald hair beard), symbols of research, and age of the scientist. Second, the most popular source of the images was the visual media at the pretest but the source was changed to the visiting and participating scientist's lecture, and internet at the posttest. The latter items appeared a significant difference between the pretest and the posttest, The results indicate that the program is effective to decrease of children's stereotypical physical image of scientist.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2A
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• pp.172-178
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• 2011

In this paper, the performance of bit interleaved of coded and modulation(BICM) module of the second generation of digital terrestrial television broadcasting system(DVB-T2) is evaluated with the help of computer simulation. The frame error rate performance is studied in AWGN, Rayleigh fading and 15% erasure channels. In addition, iterative receiver is considered that exchanges extrinsic information between the rotated demapper and the LDPC decoder. Through the simulation it is observed that under the flat fading Rayleigh channel, about 1.2dB gain at FER of $10^{-4}$ is introduced when rotated constellation and iterative demapping and decoding are employed. Under the 15% earasure channel, rotated constellation gives performance gain of about 5dB at BER of $10^{-4}$ and when IDD is applied, additional performance gain of about 3dB can be achieved.

• Korean journal of communication and information
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• v.29
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• pp.233-269
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• 2005

The purpose of the study is to explore the characteristics of lawsuits against investigative reporting programs of the broadcast media. This study proposed three research questions: (1) what were the characteristics of court derisions on the investigative reporting programs? (2) what were the reasonings on which judges rely in the lawsuits for a right of reply? (3) what were the critical issues and how the libel laws were applied in balancing between the freedom of the press and the protection of individual rights. To answer these questions, the study employed quantitative and qualitative methods analysing 35 related cases. This study revealed that investigative reporting programs must deal with the Issues of 'public figures' and 'matters of public concern' to be protected under the freedom of the press. The study also found that the broadcast media must prove legitimate public interests and the truth of the facts to prevail in a case. In 1999, the Constitutional Court of Korea held that pubic figures in libel cases must be regarded differently from private figures. In accordance with the decision, the Supreme Court has applied differing criteria for public figures in libel cases. However, courts have not set a clear definition of the public figure yet. To advocate the freedom of the press, as the results of this study indicate, TV producers and journalists should behave lawfully in the course of newsgathering and provide the opportunities of reply for their news sources.

• Korean journal of communication and information
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• v.57
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• pp.250-266
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• 2012

In neo-liberalism, the change-value of the market and of the machandise based on the individual as the consumer dominate the public sphere, and the capital power encroach on it. with the technological revolution. At the same time the public sphere as such represent the media sphere, which is more and more subordinate, and have no choice but to do to the governmental authority having political power privatized. The private usage of reason in the public sphere is carried out at the structual level. How can we call such a space in which the private usage of reason is generalized and dominant as the public sphere? And so now, we sound out the possibility of the public sphere such as a new space of the universality where the public usage of reason can be realized without any limits and with free. So, when we imagine the proletarian public sphere, in which co-exist the divers private interests, as a new public sphere capable to be constructed, we can address a question as follow. What is the caracteristic of the proletarian public sphere in modern society?, Is the public community able to be formed and realized in such space? How would have the proletarian public sphere the carateristics of the publis sphere? What is the attribute of the community that the proletarian public sphere would make, and what is its force of emancipation? The power is no longer stable and static. Rather, it is reconstructed and reorganized in the divers phases of the everyday life. It is the reason why we put on the order of the day the proletarian public sphere as alternative public space, which would be a place of divers hegemonic representation. And now, we are aware of the beginning of thses changes.

• Hwankyungkyoyuk
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• v.11 no.2
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• pp.118-129
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• 1998

This survey is made to offer the fundamental data for the establishment of practical environmental education plan based on understanding of the change of the environmental awareness of elementary school students under the longitudinal-sectional research design. In this research, the questionnaire made by Kim Jong-ki in 1988 and by Kim Hak-Bong in 1993, is amended and filled up, which is used to the 624 numbers of fifth and sixth grade students lived in Seoul, Pyungtaek and Yangjugu. This research ares are devided into 5 ares which are the environmental general, environmental pollution, living environment, environmental education and consciouness of environmental crisis to humen beings. First, it is grasped general tendency and then is compared and analyzed the level of awareness by residence, sex, grade. stsdard of living parental academic, the background variation of parental job with the status in 1988 and 1933. The results are as follows: 1) The rate of interest for environmental pollution and population is reduced but the rate of interest for animal protection is increased. 2) In spite of reinforcement of environmental education In school, the numbers of the students who became to know some information about that from the class are diminished. 3) Even if the children are aware of sewage seriousely, the numbers of the students who answer it is caused by domestic sewage are a few. 4) On the environmental education area, the various materials of the are not utilized well in a class. 5) On the environmental crisis to the human beings the rate is much increased in 1993 ttan that of 1988 environmental contamination is the important cause of the human beings' crises but now the rate is reduced again. In other variables except the environmental contamination, it is increased the that of 1993 on the war, on population it is showed a tendency of reduction. The results of this study are as follows : 1) It is supposed that the education should be done only not for the knowledge of environmental education but for the practice of that - animal breeding, field experience of the ecological destruction places. 2) The various environmental education materials such as TV, VTR are demanded to give the students proper information about that and to educate sufficently. 3) The course of fields exploration for environmental education should be prepared under cooperation of the authorities concerned. 4) It has to be groped for an epoch-making teaching method and the training and the practice of teachers in order to reform environmental pollution.

• The Korean Journal of Food And Nutrition
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• v.29 no.2
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• pp.206-217
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• 2016

This study was conducted to assess the recognition and consumption of health functional food (HFF) of the college students in the Northern Gyeonggi-do area (Republic of Korea). To accomplish this, a survey was conducted to investigate 360 college students (183 males and 177 females) regarding their general characteristics, as well as the recognition, knowledge, considerations, purchases and consumption of HFF. Most male and female students (68.9% and 61.6%, respectively) were unaware of the HFF certification mark, however, more females(58.8%) were aware of the legal HFF definition compared to males (36.6%). The HFF advertising routes for males and females were 'TV radio' (43.2% and 43.5%, respectively) and 'internet smart phones' (19.7% and 27.1%, respectively). The main factor considered for selection and the most serious problem concerning HFF by males and females were 'effectiveness' (36.1% and 43.6%, respectively) and 'hype (exaggerated advertisement)' (35.0% and 55.9%, respectively). The main purchase route by males and females was 'pharmacy' (35.2% and 27.8%, respectively). The main reason for HFF product purchase by males and females was 'health promotion' (38.8% and 29.4%, respectively) and the main reason for not purchasing an HFF product was 'no health problem'(34.8% and 36.7%, respectively). The percentage of HFF consumption was 46.0% in males and 69.8% in females. The main HFF product consumed by males and females was 'vitamin mineral' (36.9% and 43.5%, respectively). The main reason for HFF consumption by males was 'health promotion' (31.0%) and females was 'recovery from fatigue' (21.8%). The main reason for not consuming HFF by males and females was 'no health problem' (38.4% and 41.5%, respectively). These results suggest the need to provide correct information concerning HFF to college students. Based on these results, greater efforts should be made to provide meaningful information regarding factors affecting purchase and consumption patterns for college students related to the research and development of HFF in the Northern Gyeonggi-do area.