• Journal of information and communication convergence engineering
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• v.8 no.4
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• pp.387-392
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• 2010

This study focuses on improving MIMO-OFDM systems by combining a wireless communication architecture known as vertical BLAST(bell laboratories layered space-time) or V-BLAST and STTC(space time trellis coding). In this paper, the combination is done by introducing STTC in each V-BLAST layer. Moreover, this architecture uses multiple antennas that are grouped into small number of antennas which makes it less complex to decode by decoding every group. Whereas, in traditional V-BLAST, all the antennas form one group and they are decoded together at the receiver, therefore, this increases the complexity as the number of antennas is getting high. We compare the bit error rate performance of this system with MIMO-OFDM that uses convolutional coding instead of STTC. Under the same spectral efficiency, the simulation results prove that joining V-BLAST with STTC improves MIMO-OFDM systems performance.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.1-5
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• 2011

In recent years, worldwide production of solar wafers increased rapidly. Therefore, the solar wafer technology in the developed countries already has become an industry, and related industries such as solar wafer manufacturing equipment have developed rapidly. In this paper we propose the color classification method of the polycrystalline solar wafer that needed in manufacturing equipment. The solar wafer produced in the manufacturing process does not have a uniform color. Therefore, the solar wafer panels made with insensitive color uniformity will fall off the aesthetics. Gaussian mixture models (GMM) are among the most statistically mature methods for clustering and we use the Gaussian mixture models for the classification of the polycrystalline solar wafers. In addition, we compare the performance of the color feature vector from various color space for color classification. Experimental results show that the feature vector from YCbCr color space has the most efficient performance and the correct classification rate is 97.4%.

• Journal of Korean Library and Information Science Society
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• v.52 no.4
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• pp.103-126
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• 2021

This study aims to propose a plan to restructure libraries as a complex space for education and culture for 19 public libraries belonging to the Chungcheongnam-do Office of Education. For the purpose of this, case surveys and user surveys of complex facilities of domestic and foreign public institutions were conducted. Based on the findings, a space restructuring strategy was suggested by dividing the library space into the following ways: a space to learn (a comprehensive data room, a theme data inquiry room, a future classroom, a blended learning center, a STEAM training room, and an online lecture learning room), a space to express (a foyer, a maker room, a digital media creation room and an online lecture production room), a space to share (a club room, a group study room, a well-being complex culture space, a convenient living space, rest area, and a browsing area), and a space to enjoy (a performance-thought playground, infant and child archives, a digital virtual experience room, a specialized alcove room, and an outdoor reading room). In addition, a restructuring model of public libraries belonging to the Office of Education was proposed, such as a leading model, a basic model, a joint model, and a minimum model, in consideration of the size of the building, the size of the library, and the level of service and space.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.40.4-40.4
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• 2020

Kyung Hee university invented the Transformable Reflective Telescope (TRT) for optical experiment and education. The TRT kit can transform into three optical configurations from Newtonian to Cassegrain to Gregorian by exchanging the secondary mirror. We designed the Ebert-Fastie spectrograph as an extension of the TRT kit. The primary mirror of the TRT kit serves as both collimator and camera lens, and the reflective grating as the dispersing element is placed along the optical axis of the primary mirror. We designed and fabricated the grating holder and the source units using 3D printer. Baffle was also fabricated to suppress the stray light, which was reduced by 83%. The spectrograph can observe the optical wavelength range (4000Å~7000Å). Measured resolving power (R=λ/Δλ) was ~700 with slit width of 0.18mm. The spectrograph is optimized for f/24, and the spectral pixel scale is 0.49Å/pixel with Canon 550D detector. We present the sample spectra of discharged Ne, Ar and Kr gases. The flexible setting and high performance make this spectrograph a useful tool for education and experiment.

• Korean Institute of Interior Design Journal
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• v.15 no.2 s.55
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• pp.99-107
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• 2006

People with visual impairments are difficult to go to education facility by themselves, because of their limited visual ability, orientation, and usability field, so they prefer dormitories. Those dormitories playa role in living space, education, communication and culture function. Therefore those facilities planned more user centered design, since they are influenced by user actability and their values. User centered designs that match between the user and space are understood as well as their characteristics and behavior. Especially for understanding their activity, observation is conducted about their behavior in dormitories. Thus the purpose of this study is suggested to be a basic source that planning about residential facility for people with visual impairments through interview and observation investigation by analysis that they resident in space motion and performance.

• Steel and Composite Structures
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• v.30 no.4
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• pp.315-325
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• 2019

Double skin composite walls offer structural and economic merits over conventional reinforced concrete counterparts in terms of higher capacity, greater stiffness, and better ductility. This paper investigated the axial behavior of double skin composite walls with steel truss connectors. Full-scaled tests were conducted on three specimens with different height-to-thickness ratios. Test results were evaluated in terms of failure mode, load-axial displacement response, buckling loading, axial stiffness, ductility, strength index, load-lateral deflection, and strain distribution. The test data were compared with AISC 360 and Eurocode 4 and it was found that both codes provided conservative predictions on the safe side.

• Journal of The Korean Association of Information Education
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• v.12 no.1
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• pp.41-48
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• 2008

Current performance evaluation of the natural science section mainly focuses on teacher evaluation, which causes slow feedback on the evaluation result and little evaluation on colleagues due to limits of time and space. In addition, report performance evaluation, which is a main target of the evaluation in the natural science section, is conducted mostly based on records of experiments and observation without any systematic forms. Such performance evaluation cannot meet expectation on the evaluation for a self-adjustment through instant feedback on the evaluation result and improvement of motivation through sharing common performance standard. Therefore, the study here completes an experiment/research report through information sharing and discussion among colleague learners based on the web and uses it for colleague or teacher evaluation. In addition, it is intended to recognize needs of learners and develop a performance evaluation system that can provide learners with appropriate feedback through the result.

• Journal of the Korean Institute of Educational Facilities
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• v.12 no.5
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• pp.25-34
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• 2005

The Educational Cultural Center for Students is a new mixed-cultural space which made around 1997 for students' education of humanism and talent with the 7th revision of educational course. This Educational Cultural Center for Students is different to the existing one because the subject of the culture is students who make creation and performance by themselves while the former ones were for seeing, hearing and feeling things. There are seven Educational Cultural Center for Students all over the country and will be built more in the future. Comparing to the former Educational Cultural Centers for Students, functional rooms in the Educational Cultural Centers for Students are an outdoor performance room, a large performance room, a small performance room of performance facility, a gallery of display facility, a gymnasium, a swimming pool, a fitness room, a table-tennis room of physical facility, a library and a reading room of a book facility, and a group room, a computer room, a singing room, a billiard room, an art room, a musical room, a dancing room, a manner room, a playing room, a cultural lecture room and a seminar room of a interest-activity facility. The result of analyzing the usage frequency is that a performance room has the highest frequency and a display room, a musical room, a music appreciation room and a physical room follow the frequency order. But this frequency does not fit for all area. By place and social situations, the frequency and space organization may be changed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.1
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• pp.31-41
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• 2018

The purpose of this study is to look at the difference between the importance and the satisfaction with respect to government startup aid programs perceived by entrepreneurs to improve the effectiveness of government startup aid policy and verify the causal relationship between startup aid project and business performance. In this respect, this study aims to look at the impact of entrepreneurs' perceived satisfaction over government startup aid programs on startup business performance. Major study findings from this study are as follows. First, as a result of testing statistical significance of the difference between importance and satisfaction in startup education, facility/space, consulting, or fund support field, respectively in start-up assistance project, it appeared that there was a significant difference in all fields. In addition, fund support was the field that showed the biggest difference between importance and satisfaction. Second, the results of IPA (importance-performance analysis), which displays relative importance and performance of start-up assistance project on four quadrants so that entrepreneurs can evaluate which start-up assistance projects they think important and which projects they are satisfied with by themselves are as follows. Let us summarize the distribution of start-up assistance project on four quadrants in the first place. Facility/space support project is distributed in the 1st quadrant that requires ongoing maintenance; start-up funding program in the 2nd quadrant that requires concentrated improvement; consulting support project in the 3rd quadrant that requires limited use at low priority; and start-up education support project in the boundary between the 3rd quadrant that requires limited use and the 4th quadrant that requires rejection against unnecessary items. Third, the results from multiple regression analysis to identify the impact of satisfaction with government startup aid programs over business performance are as follows. As a result of analyzing the influence relationship between government startup aid program and financial performance, it appeared that satisfaction with facility/space had a positive (+) impact on financial performance. This suggests that the higher the satisfaction with facility/space, the higher the financial performance. As a result of analyzing the influence relationship between start-up assistance project and non-financial performance, it appeared that satisfaction with startup education had a positive (+) impact on non-financial performance. This suggests that the higher the satisfaction with startup education, the higher the non-financial performance.

• Research in Mathematical Education
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• v.9 no.1 s.21
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• pp.25-45
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• 2005

Background Phenomenography suggests that more variation is associated with wider ways of experiencing phenomena. In the discipline of mathematics, broadening the 'lived space' of mathematics learning might enhance students' ability to solve mathematics problems Aims The aim of the present study is to: 1. enhance secondary school students' capabilities for dealing with mathematical problems; and 2. examine if students' conception of mathematics can thereby be broadened. Sample 410 Secondary 1 students from ten schools participated in the study and the reference group consisted of 275 Secondary 1 students. Methods The students were provided with non-routine problems in their normal mathematics classes for one academic year. Their attitudes toward mathematics, their conceptions of mathematics, and their problem-solving performance were measured both at the beginning and at the end of the year. Results and conclusions Hierarchical regression analyses revealed that the problem-solving performance of students receiving non-routine problems improved more than that of other students, but the effect depended on the level of use of the non-routine problems and the academic standards of the students. Thus, use of non-routine mathematical problems that appropriately fits students' ability levels can induce changes in their lived space of mathematics learning and broaden their conceptions of mathematics and of mathematics learning.