• The KIPS Transactions:PartD
• /
• v.11D no.6
• /
• pp.1221-1230
• /
• 2004

In mobile environments, the locations of moving objects such as vehicles, airplanes and users of wireless devices continuously change over time. For efficiently processing moving object information, the database system should be able to deal with large volume of data, and manage indexing efficiently. However, previous research on indexing method mainly focused on query performance, and did not pay attention to update operation for moving objects. In this paper, we propose a novel moving object indexing method, named ACAR-Tree. For processing efficiently frequently updating of moving object location information as well as query performance, the proposed method is based on fixed grid structure with auxiliary R-Tree. This hybrid structure is able to overcome the poor update performance of R-Tree which is caused by reorganizing of R-Tree. Also, the proposed method is able to efficiently deal with skewed-. or gaussian distribution of data using auxiliary R-Tree. The experimental results using various data size and distribution of data show that the proposed method has reduced the size of index and improve the update and query performance compared with R-Tree indexing method.

• Environmental and Resource Economics Review
• /
• v.20 no.4
• /
• pp.859-882
• /
• 2011

Since two oil crises in the 1970s, Korea has actively engaged in overseas E&P projects to increase energy diversity as well as its self-development rate of energy resources. Korea's energy self-development rate, an index that indicates the ratio of resources acquired through overseas development compared to direct imports. Currently, Korea is conducting a total of 180 promising overseas oil development projects in 36 countries as of the end of 2010. By now, it has secured a reserve of around 1.63 billion barrels and production of around 176 thousand barrels of oil per day. The self-development rate for oil rose from 2.8% in 2006 to 7.4% in 2010. Not content with these remarkable successes, the korean government is planning to raise its self-development rate in oil to 25% by 2019, by promoting the active participation of Korean companies in overseas oil development projects. This paper is concerned with estimation of the required amount of government subsidies that includes loans and financial support through state-controlled banking institutions in order to reach the target 25% rate by 2019. The estimation results shows that government subsidies of at least 268 million dollars are needed for the current rate of 7.4% in oil. However, the amount sharply increases up to 1.25 billion dollars in 2019 when domestic oil demand rises to 1.02 billion barrels.

• School Mathematics
• /
• v.16 no.4
• /
• pp.691-708
• /
• 2014

In general, the intuitive knowledge that can use in mathematics problem solving is one of the important knowledge to teachers as well as students. So, this study is aimed to analyze the elementary preservice teachers' intuitive knowledge in relation to intuitive and counter-intuitive problem solving. For this, I performed survey to use questionnaire consisting of problems that can solve in intuitive methods and cause the errors by counter-intuitive methods. 161 preservice teachers participated in this study. I got the conclusion as follows. preservice teachers' intuitive problem solving ability is very low. I special, many preservice teachers preferred algorithmic problem solving to intuitive problem solving. So, it's needed to try to improve preservice teachers' problem solving ability via ensuring both the quality and quantity of problem solving education during preservice training courses. Many preservice teachers showed errors with incomplete knowledges or intuitive judges in counter-intuitive problem solving process. For improving preservice teachers' intuitive problem solving ability, we have to develop the teacher education curriculum and materials for preservice teachers to go through intuitive mathematical problem solving. Add to this, we will strive to improve preservice teachers' interest about mathematics itself and value of mathematics.

• Journal of Embryo Transfer
• /
• v.31 no.1
• /
• pp.19-25
• /
• 2016

This study was conducted to evaluate the effects of type of culture media (BM, G2, OS, TCM, and MEM) on B6D2F1 mice oogenesis. In the present study, B6D2F1/CrljOri $F_1$ mice were utilized in order to maximize oogenesis. Also we used TCM-199, Dulbecco's medified Eagle's medium (DMEM), embryo culture medium (Fertilization medium, Cleavage medium, Blastocyst medium), G series medium and One step medium. In vitro maturation was highest in BM followed by the order of OS, MEM, TCM and G2 ($90{\pm}2.8%>88{\pm}3.2%>85{\pm}4.9%>78{\pm}10.2%>64{\pm}7.7%$, respectively). To note, the G2 group was statistically different compared to other groups (p<0.05). On the other hand the fertilization rate was highest in the G2 group followed by BM, OS, TCM, and MEM ($87{\pm}7.2%>85{\pm}6.9%>74{\pm}14.0%>71{\pm}13.8%>2{\pm}1.4%$, respectively). The MEM group was significantly lower compared to other groups (p<0.05). The developmental rate was highest in the OS group followed by the G2 group and the BM group albeit no statistical significance was noted ($73{\pm}11.6%>71{\pm}9.2%>66{\pm}10.4%$). Of note, all cells of the TCM and MEM groups were died during embryonic development. The zona hatched rate ($51{\pm}9.8%$ vs. $50{\pm}9.1%$ vs. $47{\pm}7.2%$ for BM, G2, and OS respectively) and attached rate ($45{\pm}12.3%$ vs. $38{\pm}16.1%$ vs. $37{\pm}11.5%$ for BM, G2, and OS respectively) were not different amongst groups. No difference was found in total cell numbers ($74{\pm}13.9$ vs. $64{\pm}9.2$ vs. $76{\pm}6.7$ for BM, G2, and OS respectively), ICM cell numbers ($20{\pm}1.9$ vs. $14{\pm}1.8$ vs. $15{\pm}2.1$), TE cell numbers ($55{\pm}12.5$ vs. $49{\pm}10.7$ vs. $61{\pm}5.9$), % ICM ($30{\pm}2.8%$ vs. $24{\pm}7.0%$ vs. $22.8{\pm}2.2%$) and ICM:TE ratio ($1:2{\pm}0.5$ vs. $1:3.1{\pm}0.8$ vs. $1:3.1{\pm}0.5$) amongst groups. In summary, these results can provide fundamental data to maximize culture condition for in vitro fertilization on B6D2F1 mice.

• Archives of design research
• /
• v.17 no.1
• /
• pp.25-36
• /
• 2004

The purpose of this study is to analyse and interpret the way of differentiated expression and changing creative trend following 5-day workweek which has been recently adopted. For this aim 11 pieces of distinctive advertising text were analysed. The criteria for selection of analysing text were relativeness with 5-day workweek and cognitive inconsistency. These texts were negative phrases, exaggerated expression, and excessively humorous appeals. The study revealed the followings: First, 5-day workweek concerned advertising texts were considered as high attention getting and successful in stimulating advertising audiences' curiosity by using the elements opposing the value and belief system formed in the existing audience. Second, consumption-driving lifestyle was found in most expressions for credit cards advertising. Third, hedonic need-oriented lifestyle was typical in young consumer products category. Fourth, family centered lifestyle emphasized meaning of rest and solidarity of family.

• Journal of Broadcast Engineering
• /
• v.15 no.1
• /
• pp.122-132
• /
• 2010

AT-DMB system has been developed to increase data rate up to double of conventional T-DMB in the same bandwidth while maintaining backward compatibility. The AT-DMB system adopted hierarchical modulation which adds BPSK or QPSK signal as enhancement layer to existing DQPSK signal. The enhancement layer signal should be small enough to maintain backward compatibility and to minimize the coverage loss of conventional T-DMB service coverage. But this causes the enhancement layer signal of AT-DMB susceptible to fading effect in transmission channel. A turbo code which has improved error correction capability than convolutional code, is applied to the enhancement layer signal of the AT-DMB system for compensating channel distortion. However there is a need for other solutions for better reception of AT-DMB signal in receiver side without increasing transmitting power. In this paper, we propose adaptive array antenna system with Eigen-space beamforming algorithm which benefits beamforming gain along with diversity gain. We analyzed the reception performances of AT-DMB system in indoor and mobile environments when this new smart antenna system and algorithm is introduced. The computer simulation results are presented along with analysis comments.

• 대한공업교육학회지
• /
• v.31 no.2
• /
• pp.64-82
• /
• 2006

This study investigated what effects multiple intelligence, through which the diverse intelligence abilities of a learner are identified, has on technological problem solving ability according to sex. And it was carried out to present a way to reduce the gap between boys and girls in technological problem solving ability. The subject was 833 middle school students in the third grade (boys: 423, girls: 410) whose schools are located in a megalopolis or more large area. And the instruments developed by Yong-Lyn Moon(2001) and in CRESST(1998) were used. The results of this study are as follows. First, it appeared that there were statistically meaningful differences at six items in multiple intelligence between boys and girls. The six items were bodily-kinesthetic intelligence, logical-mathematical intelligence, naturalistic intelligence, musical intelligence, interpersonal intelligence, and introspective intelligence. Second, in technological problem solving ability, it appeared that boys and girls showed statistically meaningful differences at self-regulation and problem solving strategy. Third, it appeared that logical-mathematical intelligence, linguistic intelligence, introspective intelligence, and natural intelligence had an effect on boys in the way of self-regulation and logic-mathematical intelligence, introspective intelligence, naturalistic intelligence, and linguistic intelligence did on girls. Fourth, it appeared that logical-mathematical intelligence, musical intelligence, and bodily-kinesthetic intelligence had an effect on boys in the way of problem solving ability and linguistic intelligence and musical intelligence had on girls. Fifth, it appeared that logical-mathematical intelligence did an effect on both sexes in drawing up the understanding of contents. On the basis of the results of this study, the area related to multiple intelligence directly or indirectly should be developed in the course of designing the primary and secondary curriculums to reduce the gap between boys and girls in multiple intelligence. With these efforts, the scholastic attainments gap caused by the difference of multiple intelligence will be overcome.

• 대한공업교육학회지
• /
• v.33 no.1
• /
• pp.134-148
• /
• 2008

In this study, a survey was conducted to determine the understanding by teachers at KIPO-funded high schools of the specialized training of invention patent personnel. The subjects were 4 high schools and 126 copies of questionnaires were collected for analysis. The results of this study are as follows. First, teachers understand that it is particularly important to provide a specialized training for students so that they can more effectively adapt to the changes in their lives. They also consider basic job skills training, moral education and job readiness training as equally important. Second, they recognize the necessity for a specialized training of invention patent personnel. Third, they think that redundant teachers arising from the reform of the curriculum for specialized training should be provided with minor training. Fourth, they think that the reform of the curriculum for specialized training should consider the following aspects: the development of a curriculum for invention patent-specialized high schools, the strengthening of administrative financial supports, the creation of a consensus among those involved for the success of the specialized training, the development of textbooks and materials, and the consideration of the future prospects and current conditions of the invention patent industry. Fifth, they think that the successful operation of specialized high schools requires the consideration of the following factors: users' understanding, conformance, selection & concentration and uniqueness.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.10
• /
• pp.2105-2112
• /
• 2009

Recently RFID system has been adopted in various fields rapidly. However, we ought to solve the problem of privacy invasion that can be occurred by obtaining information of RFID Tag without any permission for popularization of RFID system To solve the problems, it is Ohkubo et al.'s Hash-Chain Scheme which is the safest method. However, this method has a problem that requesting lots of computing process because of increasing numbers of Tag. Therefore, We suggest the way (process) satisfied with all necessary security of Privacy Protection Shreme and decreased in Tag Identification Time in this paper. First, We'll suggest the SP-Division Algorithm seperating SPs using the Performance Measurement consequence of each node after framing the program to create Hash-Chain Calculated table to get optimized performance because of character of the grid environment comprised of heterogeneous system. If we compare consequence fixed the number of nodes to 4 with a single node, equal partition, and SP partition, when the total number of SPs is 1000, 40%, 49%, when the total number of SPs is 2000, 42%, 51%, when the total number of SPs is 3000, 39%, 49%, and when the total number of SPs is 4000, 46%, 56% is improved.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.6
• /
• pp.4040-4047
• /
• 2015

The purpose of this study was to analyze a change in Post-traumatic Stress Disorder (PTSD) level and the continuity of the effects in music therapy by applying short-term music therapy program in fire fighters with Post-traumatic Stress (PTS). Forty two fire fighters in 3 districts were randomly assigned to experimental group (21 subjects) and control group (21 subjects). Music therapy was applied in totally 10 sessions by two sessions (120 minutes) a day for 5 days. PTS level was measured immediately after the end of program, after 4 weeks, and after 12 weeks. As a result, PTS level has significantly decreased into $8.90{\pm}4.55$ from $26.52{\pm}2.32$ right after the music therapy program(p<0.05). And the effect was shown to be continued significantly up to after 4 weeks($11.95{\pm}4.57$) and after 12 weeks($13.76{\pm}5.62$)(p<0.05). As a result of research, it is considered that the music therapy is effective approach for reduction in PTS as for fire fighters who belong to the group with high risk of PTSD. Accordingly, the application of regular program for managing fire fighters' mental health is understood to likely to contribute to enhancing the field service competence.