• Child Studies in Asia-Pacific Contexts
• /
• v.6 no.2
• /
• pp.59-72
• /
• 2016

We examined the relationship between the extent of Facebook usage and social well-being with consideration of cyberbullying involvement using a person-oriented approach. Survey data were collected from a sample of 312 secondary students from Grades 7 and 8 in Hong Kong. Levels of cyberbullying involvement, Facebook usage and perceived social support were investigated. Participants were classified into three clusters based on the different levels of Facebook usage and cyberbullying victimization through cluster analyses (i.e., frequent Facebook user/noncyberbullied victim, frequent Facebook user/cyberbullied victim, and uninvolved). Our results showed that frequent Facebook users who are cyberbullied tend to engage in cyberbullying perpetration significantly more than the frequent Facebook users who are not cyberbullied, even when the latter reported higher Facebook usage. This result provides some support for the idea that cyberbullying victimization has additional value on top of the level of usage in explaining one's participation in cyberbullying perpetration. As expected, frequent Facebook users who were not cyberbullied reported the highest perceived social support among the three groups. What is even more interesting is the equal level of perceived social support found between the cyberbullied victims and the uninvolved. Our results suggest that, although limiting adolescents' Internet use might reduce their risks of being involved in cyberbullying, it might also take away the potential benefits they could get from interacting with the online community. Benefits of using the person-oriented approach in the study of cyberbullying are discussed.

• The Mathematical Education
• /
• v.51 no.4
• /
• pp.415-427
• /
• 2012

This study investigated the perception and utilization about computer of beginning secondary mathematics teachers by utilization frequency of computer. To increase utilization frequency of computer in school mathematics, our finding shows that beginning secondary mathematics teachers should have an interest in computer utilization and perceive computers as an important tool for mathematics learning. In addition, they are likely to use more frequently computer under the condition that computers have sufficient class materials and supplement their shortcomings that have derived less usage in math classes. Therefore, future studies have to investigate not only how to develope textbooks and run after-school classes but also how to make creative discretional activities by computer, which makes computers more useful for teacher training. In sum, the results of case studies for computer usability should be released to motivate computer utilization and increase mathematical thinking ability.

• Journal of Korea Multimedia Society
• /
• v.22 no.10
• /
• pp.1187-1198
• /
• 2019

In this study, we propose a new $PM_{10}$ forecasting model for Seoul region using DNN(Deep Neural Network) and secondary data. The previous numerical and Julian forecast model have been developed using primary data such as weather and air quality measurements. These models give excellent results for accuracy and false alarms, but POD is not good for the daily life usage. To solve this problem, we develop four secondary factors composed with primary data, which reflect the correlations between primary factors and high $PM_{10}$ concentrations. The proposed 4 models are A(Anomaly), BT(Back trajectory), CB(Contribution), CS(Cosine similarity), and ALL(model using all 4 secondary data). Among them, model ALL shows the best performance in all indicators, especially the PODs are improved.

• English Language & Literature Teaching
• /
• v.12 no.4
• /
• pp.139-157
• /
• 2006

As the Communicative Approach has become the norm in foreign language teaching, the objectives of teaching English in school have changed radically in Korea. The focus in high school English textbooks has shifted from mere mastery of structures to communicative proficiency. This paper will study five polysemous words which appear in twelve high school English textbooks used in Korea. The twelve text books are incorporated into a single corpus and analyzed to classify the usage of the selected words. Then the usage of each word was compared with that of three other corpora based sources: the BNC(British National Corpus) Sampler, ICE Singapore(International Corpus of English for Singapore) and Collins COBUILD learner's dictionary which is based on the corpus, "The Bank of English". The comparisons carried out as part of this study will demonstrate that Korean text books do not always supply the full range of meanings of polysemous words.

• The Korean Society of Law and Medicine
• /
• v.11 no.1
• /
• pp.117-143
• /
• 2010

Along with the development of digital technologies, the information obtained during the medical procedures was working as a source of valuable assets. Especially, the secondary use of personal health information gives the ordeal to privacy protection problems. In korea, the usage of personal medical information is basically regulated by the several laws in view of general and administrative Act like Medicine Act, Public institutions' personal information protection Act, Information-Network Act etc. There is no specific health information protection Act. Health information exchange program for the blood donor referral related with teratogenic drugs and contagious disease and medical treatment reporting system for income tax convenience are the two examples of recently occurred secondary use of health information in Korea. Basically the secondary use of protected health information is depend on the risk-benefit analysis. But to accomplish the minimal invasion to privacy, we need to consider collection limitation principle first. If the expected results were attained with alternative method which is less privacy invasive, we could consider the present method is unconstitutional due to the violation of proportionality rule.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2003.10a
• /
• pp.133-138
• /
• 2003

The prediction of protein secondary structure has been an important bioinformatics tool that is an essential component of the template-based protein tertiary structure prediction process. It has been known that the predicted secondary structure information improves both the fold recognition performance and the alignment accuracy. In this paper, we describe several novel ideas that may improve the prediction accuracy. The main idea is motivated by an observation that the protein's structural information, especially when it is combined with the evolutionary information, significantly improves the accuracy of the predicted tertiary structure. From the non-redundant set of protein structures, we derive the 'potential' parameters for the protein secondary structure prediction that contains the structural information of proteins, by following the procedure similar to the way to derive the directional information table of GOR method. Those potential parameters are combined with the frequency matrices obtained by running PSI-BLAST to construct the feature vectors that are used to train the support vector machines (SVM) to build the secondary structure classifiers. Moreover, the problem of huge model file size, which is one of the known shortcomings of SVM, is partially overcome by reducing the size of training data by filtering out the redundancy not only at the protein level but also at the feature vector level. A preliminary result measured by the average three-state prediction accuracy is encouraging.

• Journal of Engineering Education Research
• /
• v.13 no.2
• /
• pp.38-42
• /
• 2010

It is necessary for lower grade students to study the correct usage of tools as a base of the technical education for dismantling and assembling various machines. However, enough understanding has not been obtained though the usage of these tools when training first grade students. So, we started to develop a teaching text and materials within the students' practice curriculum based on the dismantling and assembly of all-terrain vehicle [ATV]'s, which is a very motivating for lower grade students. This practice makes the student learn both how to use the tools and the steering mechanism of cars through the dismantling and assembling of the ATV. It is possible to not only have the student learn about the knowledge obtained through the practice, but also they also acquire wider and deeper knowledge through making the text and teaching materials for the practice. The textbook and secondary educational materials of this practice curriculum were created in cooperation with a fifth grade student as part of their graduation research. As a result, an effective teaching and learning text and secondary educational material regarding manufacturing practice could be developed from the student's point of view. Making a teaching text and materials is effective for promoting the study and experience of engineering.

• The Journal of the Korea Contents Association
• /
• v.14 no.7
• /
• pp.395-406
• /
• 2014

This research observes how an adolescent's usage of social network services is related with media use time, and also tries to verify how a parent's participation in acting to limit usage time serves as a mediating effect. For this analysis, data from The Korean Information Society Development Institute [Korea Media Panel Research] was used, being a survey conducted on 1,572 students from primary to secondary and high schools nationwide. The subjects' gender in the final analysis was 818 male students and 754 female students. In addition, primary school students consisted of 672 individuals, 416 were from secondary and 484 from high schools. To verify the appropriateness of the model proposed in this research, analyzed through the structural equation, using social network services(SNS) was not shown to have an effect on media usage time. However, there was an indirect effect from the use of alternative activities. In addition, the parent's limitation of usage showed no effect on media use time. This research attempts to identify the reasons why parents' limiting the usage time, along with alternative activities, do not have any significant effect in reducing media usage time in this era of smart media evolution. Further, this research hopes to suggest meaningful and political implications for the nation and society to understand and resolve media addiction.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.3 no.1
• /
• pp.78-82
• /
• 2014

Power Transformers with more than one secondary winding are not uncommon in industrial applications. But new classes of applications where very large number of independent secondaries are used are becoming popular in controlled converters for medium and high voltage applications. Cascade H-bridge medium voltage drives and Pulse Step Modulation (PSM) based high voltage power supplies are such applications. Regulated high voltage power supplies (Fig. 1) with 35-100 kV, 5-10 MW output range with very fast dynamics (${\mu}S$ order) uses such transformers. Such power supplies are widely used in fusion research. Here series connection of isolated voltage sources with conventional switching semiconductor devices is achieved by large number of separate transformers or by single unit of multi-secondary transformer. Naturally, a transformer having numbers of secondary windings (~40) on single core is the preferred solution due to space and cost considerations. For design and simulation analysis of such a power supply, the model of a multi-secondary transformer poses special problem to any circuit analysis software as many simulation softwares provide transformer models with limited number (3-6) of secondary windings. Multi-Secondary transformer models with 3 different schemes are available. A comparison of test results from a practical Multi-secondary transformer with a simulation model using magnetic component is found to describe the behavior closer to observed test results. Earlier models assumed magnetising inductance in a linear loss less core model although in actual it is saturable core made-up of CRGO steel laminations. This article discusses a more detailed representation of flux coupled magnetic model with saturable core properties to simulate actual transformers very close to its observed parameters in test and actual usage.

• Resources Recycling
• /
• v.28 no.4
• /
• pp.3-14
• /
• 2019

Lead is one of the common non-ferrous metals used in modern industry. The usage of lead continues to increase and has risen from 5 million tonnes per year worldwide in the 1970s to 11 million tonnes in the 2010s. In principle lead is virtually 100 % recyclable as an element without loss of quality. The recycling of lead scrap reduces the energy consumption and environmental burden, comparing to the primary metal production. Therefore production of secondary lead from scrap has been steadily growing and at present it meets approximately 60 % of usage worldwide. Lead scrap (mainly lead-acid battery) is smelted in primary and secondary smelter. Most secondary lead smelting were performed in a shaft-type furnace (blast furnace), rotary furnace and reverberatory furnace. The lead bullion is either cast into ingots and re-melted in refining kettles or refining is performed on the hot lead bullion immediately after production. This work provides an overview of the primary lead production and recycling process.