• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.807-813
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• 2008

The gate-biases of the Doherty power amplifier are controlled to improve the linearity performance. The linearity improvement mechanism of the Doherty amplifier is the harmonic cancellation of the carrier and peaking amplifier at the output power combining point. However, it is difficult to cancel the harmonic power for the broader power range because the condition for cancelling is varied by power. For the linearity improvement, we have explored the linearity characteristic of the Doherty amplifier according to the input power and gate biases of the carrier and peaking amplifier. To extend the region of harmonic power cancellation, we have injected the proper gate bias to the carrier and peaking amplifier according to the input power levels. To validate the linearity improvement, the Doherty amplifier is designed using Eudyna 10-W PEP GaN HEMT EGN010MKs at 2.345 GHz and optimized to achieve a high linearity and efficiency at an average output power of 33 dBm, backed off about 10 dB from the $P_{1dB}$. In the experiments, the envelope tracking Doherty amplifier delivers a significantly improved adjacent channel leakage ratio performance of -37.4 dBc, which is an enhancement of about 2.8 dB, maintaining the high PAE of about 26 % for the WCDMA 1-FA signal at an average output power of 33 dBm. For the 802.16-2004 signal, the amplifier is also improved by about 2 dB, -35 dB.

• Journal of Korean Home Economics Education Association
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• v.32 no.1
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• pp.89-105
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• 2020

This study aimed at analyzing the clothing management units of technology and home economics textbooks in terms of their contents related to Education for Sustainable Development(ESD). The inquisitive tendency of the textbooks was also examined adopting the modified Romey's method, because it is known as an important factor in increasing student's class participation in sustainable clothing management and inducing practical behavior. First, the learning contents of clothing management unit were analyzed according to the social/political/cultural, environmental, and economic perspectives of ESD. As a result, ESD contents from social/political/cultural perspectives (safety, and health and food), environmental perspectives (natural resources, energy, and environmental problem), and the economic perspectives (sustainable production and consumption) were identified, with a heavy focus on environmental perspective. Secondly, Romey's inquisitive content analysis method was modified to analyze texts, pictures/charts, and learning activities of the clothing management unit. In all textbooks, facts and definitions were the dominant types of contents, which means less opportunities for development of inquiry ability. In conclusion, the ESD contents of the clothing management unit are inclined to the environmental perspective, and it is necessary that textbook development would need to be balanced between three perspectives. Also, future textbook authors will need to improve the inquisitive tendency of the textbooks to encourage student participation in class and induce practical application in real life.

• Journal of Korean Medical classics
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• v.11 no.2
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• pp.114-134
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• 1998

The conception of pyo(標) bon(本) joong(中) in the part of woongihak(運氣學) of negeong(內徑) one of the important thing that decides the relation between six gi(六氣) and samyum and samyang(三陰三陽) or between each other's of samyum and samyang itself, it says that the relation of Pyo-rce(表裏). So this conception from the ancient times have been used to explain the theory of meridian(經絡) and organs(五臟六腑) and in other important field of oriental medicine - Sanghannon(傷寒論), it became basis of explanation of pcthoiogical principles in the system of six kyung(六徑). At first, the subject or this study is limited to the rament of $\ll$Somun(素問)$\gg$ in order to find the accurate and original meanings of pyo(標) bon(本) joong(中). And the meanings are studied by the way of expanding it's meaning with basic conceptions of woongihak(運氣學) and astronomy included in negeong(內徑). In this study, the results are summarized as the followings. 1. The contents of - the 68th chapter of negeong(內徑), concerning pyo(標) and joong(中) come under chogi(初氣) and joonggi(中氣) of the same chapter, after consideration of astronomical knowledge. And they become active during the period that last about 30days, a haft of one step(一步) of kaekgi(客氣). 2. Bon(本) as a kind of six gi(六氣) that is revealed from internal principle of something, that is to say Ohhaeng(五行), comes mainly under the kaekgi(客氣) of woongihak(運氣學) with the meaning of 'sign' is thai the specific properties of six gi(六氣) are revealed to our sight, so we can feel that through the change of nature, Joong(中) is the other property hidden in the inside of six gi(六氣), that is a portion of original nature(本性) like the bon(本). 3. The relation of pyo(標) and bon(本) is like that bctween the principle hidden inside in all things(理) and it's expression into the real world(氣) also similar to thai of yumyang(陰陽) and ohhaeng(五行). Therefore bon(本), though it means one of the six gi(六氣), hale the property of ohhaeng(五行) and pyo(標) is revealed, with an appearance of samyum-samyang(三陰三陰). 4. pyo(標) and joong(中) are also the both sides of yum(陰) and yang(陰) that revealed under the change of yumyang-ohhaengl(陰陽五行) in the nature. For example, if the one is yang(陰), the other is yum(陰). In the process that the change of all things is revealed out, first the property of pyo(標) appears strongly and then that of joong(中) appears comparatively weakly. But, in spite of the inhibitive relation of yumyang(陰陽), pyo(標) and joong(中) promote each other. 5. Under the course of change. It happens according to the bon(本), the property of ohhaeng(五行) in the case of soyang(少陽) and taeyum(太陰), because the effect of moisture(濕) and fire(火) that makes hyung(形) and gi(氣) is very strong in the universe. In the case of taeyang(太陽) and soyum(少陰), it happens according to the bon(本) and pyo(標) because they hare the polarity of water and fire(火水), at the same time, are not separated each other. In the case of yangmeong(陽明) and gualyum(厥陰), the change appears only according to the joong(中), but not strongly because the phase of yangmeong(陽明) and gualyum(厥陰) is a lull phase processing to the next one.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.72-80
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• 2015

Purpose Serum estradiol ($E_2$) measurement is requested for diagnosing menstrual cycles, ovulation induction, infertility, and menopause. $E_2$ is measured using several methods and kits including radioimmunoassay (RIA) and chemiluminescece immunoassay (CLIA). The purpose of this study was to evaluate quality of these methods and to compare them with each other. Materials and Methods Seven radioimmunoassay kits and two CLIA methods were included in the analysis. Using standard samples and patient samples, intra-assay precision, inter-assay precision, correlation between other methods, sensitivity, and recovery rate were evaluated. Results For all tested kits and methods, coefficients of variance (CVs) of intra-assay precision test were 10.9~13.6% in low-level samples and less than 10% in medium and high-level samples. CVs of inter-assay precision test were 10.8~12.3% in low-level samples and less than 10% in medium and high-level samples with all tested kits and methods. Recovery rates were $92.7{\pm}12.4%$ for SIEMENS, $101.4{\pm}18.4%$ for DIAsource, $95.1{\pm}11.5%$ for AMP, $108.4{\pm}18.5%$ for BECKMAN COULTER, $104.2{\pm}13.5%$ for BECKMAN COULTER Ultra Sensitive, $101.3{\pm}11.6%$ for CIS Bio, and $93.1{\pm}13.2%$ for MP kits. Sensitivity was 7.5, 6.2, 5.7, 6.2, 5.3, 4.5, and 5.5 pg/mL for SIEMENS, DIAsource, AMP, BECKMAN COULTER, BECKMAN COULTER Ultra Sensitive, CIS Bio, and MP kits, respectively. The measurement by MP kit was slightly higher than those by other kits in low-level samples, and the measurement by E170 was slightly higher than those of other kits in medium and high-level samples. In the measurement of standard sample for external quality control, SIEMENS kit produced relatively lower values whereas E170, Architect, and MP kits produced relatively higher values compared with other kits. Conclusion All tested kits for $E_2$ measurement have satisfactory performance for clinical use. However, correlation between kits should be considered when test kits are to be changed, because some pairs of kits do not have correlations with each other.