• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.141-151
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• 2022

Wireless earphones are products that are consumed together with smart devices (mobile phones, etc), and there is no twisting and convenience compared to general earphones. However, due to the lack of information on the quality of wireless earphones, consumers tend to purchase products based on brand awareness, and manufacturers deliver information to consumers based on different standards for each product due to the lack of standards for measurement methods for quality evaluation. In particular, the playback time of wireless earphones is a factor that can directly affect consumers' purchases, so it is necessary to prepare a standardized test method to properly measure it. This paper introduces the current status of wireless earphones and related standard trends, and proposes a method for measuring the audio playback time of wireless earphones developed through this. In addition, this measurement method will be proposed as an international standard (IEC) after being established as the national standard, the Korean Industrial Standard (KS).

• International Journal of Highway Engineering
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• v.20 no.3
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• pp.39-46
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• 2018

PURPOSES: This study is to estimate nondestructive strength equation based on probability for bridges using field test data. METHODS : In this study, a series of the field inspection and the test have been performed on 297 existing bridges, in order to evaluate the bridges, based on the test results of the in-depth inspection, and the estimated strengths by means of the nondestructive strength equations are analyzed and compared with results of the core specimen strengths. RESULTS : According to results of analyses, In case of standard design compressive strength of concrete is 18MPa, 21MPa, similar reliability of RILEM equation were 0.89~0.90, but in case of standard design compressive strength of concrete is 35MPa, 40MPa were 0.4~0.56. According to standard design compressive strength of concrete is 40MPa, similar reliability of ultrasonic pulse velocity method equation were 0.56. CONCLUSIONS :RILEM equation had high similar reliability than other equation in case of standard design compressive strength of concrete is 18MPa, 21MPa, but had low similar reliability than other equation in case of standard design compressive strength of concrete is 35MPa, 40MPa. and ultrasonic pulse velocity method equation had low similar reliability than other equation in case of standard design compressive strength of concrete is 40MPa.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.174-180
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• 2014

Standard weather data available to greenhouse environmental design are limited in most regions of the country. So, instead of using standard weather data, in order to find the method to build design weather data for greenhouse heating and cooling, design outdoor weather conditions were analyzed and compared by TAC method and frequency analysis using climatological normal and thirty years from 1981 to 2010 hourly weather data provided by KMA and standard weather data provided by KSES. Average TAC values of outdoor temperature, relative humidity and insolation using thirty years hourly weather data showed a good agreement with them using standard weather data. Therefore, in regions which are not available standard weather data, we suggest that design outdoor weather conditions should be analyzed using thirty years hourly weather data. Average of TAC values derived from every year hourly weather data during the whole period can be established as environmental design standards, and also minimum and maximum of them can be used as reference data.

• Journal of Internet Computing and Services
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• v.7 no.4
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• pp.1-10
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• 2006

We are studying international standard about the software quality evaluation. The software quality has been more important on users and developers. In this paper, first, we study international tendency of the inside and outside of the country in software quality evaluation for evaluating the software quality objectively and quantitatively, Second, we notify a new direction for software quality standard of inside and outside of country. Third, we study on the testing method of software reliability for making use of the software reliability growth model. Fourth, we spread method about standard of the software quality evaluation, fifth, we research into the international standard ISO/IEC 9126 and ISO/IEC 25000 series for evaluation of software quality testing, and we propose to the application plan of software quality testing.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.87-93
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• 2013

In this research, a new methodology to perform building energy analysis using Industry Foundation Classes (IFC) standard has been studied. With the help of Archicad 14 modeling software, a 3D test model is generated and then exported to IFCXML format. A ruby code program retrieves the building information from the resulting IFCXML file using Nokogiri library. An INP file is created and gets ready for next energy analysis step. DOE 2.2 program analyzes the INP file and gives a detailed report of the energy cost of the building. Case study shows when using the IFC standard method, the Interoperability of the energy analysis is greatly improved. The main stream 3D building modeling software supports IFC standard. DOE 2.2 is able to read the INP file generated by IFC file. This means almost any 3D model created by main stream modeling software can be analyze in terms of energy cost Thus, IFC based energy analysis method has a promising future. With the development and application of IFC standard, designers can do more complex and easy-to-run energy analysis in a more efficient way.

• Journal of Korea Multimedia Society
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• v.15 no.9
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• pp.1102-1111
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• 2012

In this paper, we propose a robust watermarking method against geometric attack even though the watermarked image is partially damaged. This method consists of standard image normalization which transforms any image into a predefined standard image and embedding watermark in DCT domain of standard normalized image using spread spectrum technique. The proposed standard image normalization method has an improvement over existing image normalization method, so it is robust to partial damage and geometric attack. The watermark embedding method using spread spectrum technique also has a robustness to image losses such as blurring, sharpening and compressions. In addition, the proposed watermarking method does not need an original image to detect watermark, so it is useful to public watermarking applications. Several experimental results show that the proposed watermarking method is robust to partial damage and various attacks including geometric deformation.

• Herbal Formula Science
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• v.19 no.1
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• pp.175-182
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• 2011

Objectives : This study was performed to compare the differences between decoctions extracted by different extraction method and extraction time. Methods : Decoctions were prepared with pressed or non-pressed extraction conditions for 60, 120 and 180min. The yields of extracts, sugar contents, hydrogen ion concentrations(pH), the contents of reference compounds in Yukmijihwang-tang(Liuweidihuang-tang) were investigated. Results : The yields and the dissolved solid content containing sugar content of decoctions were more in pressed extraction method than unpressed extraction method, and they tended to be increased as extraction time increased. The pH values of decoctions methods did not show significant differences between pressed and unpressed extraction methods or extraction times. Most of reference compounds showed higher contents in pressed extraction method than unpressed extraction method and their contents were augmented according to increase of extraction time. The content of paeonol was decreased when extracted in more than 120min with pressed extraction method and tended to be decreased as extraction time increased in unpressed extraction method. Conclusions : The pressed extraction with long extraction time could be useful for decoction of Yukmijihwang-tang(Liuweidihuang-tang). However, another ingredients possible to decrease in such condition need to be considered to determine suitable extraction condition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.11
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• pp.1217-1227
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• 2012

There are several antenna calibration methods, so-called 3-Antenna Method, Standard Site Method, and Standard Antenna Method which measure the antenna gains or antenna factors. These methods yield the free space or quasi free space antenna gains in only the frequency domain. In this paper, an antenna calibration method using the time domain in the open area test site is discussed. The reflected waves due to the ground are traced in the time domain. After they are removed by the time gating function of network analyzer, the free space transmission coefficient $S_{21}$ is extracted. Such a way is applied to the broad band horn antenna ranging 1 GHz to 18 GHz, and the free space gains are obtained by Friis transmission equation. The method is checked by Standard Site Method in open area test site. The results show comparatively good agreement except for 18 GHz.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.187-191
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• 2008

This study focuses on applying performance-based design to construction standard in building construction. First, it realizes situation and issues of standard specification in building construction, deduces the need factors for establishing performance-based construction standard, and then, it proposes the application of performance standard. The required stages for deducing performance-based construction standard consist of dividing building parts, deducing required functions, performance items and performance requirement and deciding a method of performance evaluation. Through these stages, performance-based design process is deduced.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.73.2-73.2
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• 2016

We present the results of KaVA SgrA* observation together with Takahagi(32m), Yamaguchi(32m) and Nobeyama(45m) telescopes at 22 and 43GHz, respectively. In early 2014, G2 cloud was expected to encounter with SgrA* and to make a significant flux variation, but it has not been measured yet. So it's worth to check our amplitude calibration method to confirm if we have a missing flux caused by uncertainty in measuring it. We have tested both a standard method using system noise temperature(Tsys) with antenna gain information, and a template method in order to calibrate antenna gain using nearby maser source. As a result, we found that the latter method is useful for antennas which have inaccurate gain information or poor Tsys measurements, and is especially effective for sources at low elevation like SgrA*. In addition, the comparison shows that the amplitude calibration by standard method can be improved up to 10% with a correction factor using a template method. This result implies we can get more accurate flux from a standard method when any maser source not exists around target.