• Journal of Environmental Science International
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• v.23 no.4
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• pp.737-742
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• 2014

This study aimed for evaluating the applicability of the two stage dual media filtration system in field water treatment plant. The field plant of two stage and dual media filtration system was operated for 2 months. Average iron concentrations of the settled water, existing filtered water and second stage filtered water was 0.041 mg/L, 0.007 mg/L and 0.005 mg/L, respectively. Removal efficiency of iron concentration in the second stage is appropriately 35% more than in existing filtered water. Also removal efficiency of residual chlorine in the dual media filtration system is relatively 42.3% more than in existing filtered water due to adsorption of activated carbon, but the removal of ammonia nitrogen by adsorption is insufficient. Average concentrations of THM and chloroform in the settled water are 0.033 mg/L, 0.026 mg/L, respectively and in existing filtered water are 0.023 mg/L and 0.023 mg/L. Average concentrations of THM and chloroform in the dual media filtration system are 0.008 mg/L and 0.013 mg/L. Therefore removal efficiency of THM concentration in second stage is more than 66.4% in existing filtrated water. Also removal efficiency of chloroform in the dual media filtration system is more than 50.0% in existing filtered water because of the adsorption of activated carbon. In this case backwashing period in dual stage system is 4~5 days, but in existing filtration system is 1~2 days.

• Human Ecology Research
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• v.51 no.3
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• pp.355-370
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• 2013

The purpose of this study is to investigate the nature of work-family compatibility in the everyday experiences of dual-earner families. By comprehensively describing how dual-earner families manage daily life, this study shows their current situations. In particular, this study overcomes the limitations of previous studies using the phenomenological research methods. Previous studies partially dealt with the problems of dual-earner couples, such as the role conflict of wives and husbands. However, this study broadly demonstrates how wives and husbands as independent individuals manage their lives by working together for a living. Participants were 6 males and 6 females, who lived in Gwangju metropolitan city. Data were collected through in-depth interviews and analyzed using the method of Stevick-Colaizzi-Keen in Moustakas (1994). The results of this study display that dual-earner couples work for a living, but work is the driving force in their life. Family provides dual-earner couples with a stable life, but their stable life is possible by social support like the assistance of a mother-in-law. Dual-earner couples consider work and family as the essential axis of life, thus they give the same value on work and family. Even though dual-earner couples have a difficult time educating their children because of long working hours and coming home late, they positively combine work and family meeting the needs of self-improvement. Therefore, it is necessary to create a working environment that provides enough time for housework and childcare.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.116-126
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• 2008

This paper describes the Dual-band WLAN transmitter with 2.4[GHz], 5[GHz]. Dual-band WLAN transmitter was designed at 2.4[GHz] and 5[GHz]. The Dual-band WLAN transmitter has a amplifier which operate at 2.4[GHz] and 5[GHz] frequency and two VCO(Voltage Controlled Oscillator) or VCO has a wide scope of frequency. these problem cause a size and a power consumption, The Dual-band WLAN transmitter module was proposed to solve these. the transmitter was designed to get output signals of IEEE 802.11a's 5.8[GHz] band signal using frequency multiplication way or to act a amplifier about the 2.4[GHz] band signal of IEEE 802.11b/g, according to inputed frequency and bias voltage that a eve using single transmission block. The output spectrum get the improved specification of ACPR of 4[dB], 6[dB], 16[dB] at +11[MHz], +20[MHz], +30[MHz] offset of center frequency compared to no linearization, was satisfied to transmit spectrum mask of IEEE 802.11a wireless Lan.

• Journal of Society of Preventive Korean Medicine
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• v.15 no.1
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• pp.117-130
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• 2011

Objectives : This study was performed to investigate the status of dual medical license holders who have both the medical doctor (MD) and the Korean medicine doctor (KMD) license in Korea, and provide basic data for developing the cooperational strategy between conventional western medicine and traditional Korean medicine. Methods : The questionnaires on the general characteristics and working status were developed and administered for both dual license holders and medical students with MD or KMD license. The data of 187 persons were collected and analyzed. Results : Mean age of dual medical license holders is $42.28{\pm}6.54$ and most of them are male(86.0%). 75.2% of them obtained MD license first. However among the students who had MD or KMD license, 73.7% had KMD license. The mean time for obtaining the additional license was $10.11{\pm}4.905$ year. Forty nine dual license holders are opening both medical clinic and Korean medicine clinic. Conclusions : To promote the role of dual license holders for collaborating traditional Korean medicine and western medicine, developing an integrative medical curriculum should be enhanced, and the studies investigating the practice characteristics, and self-consciousness of dual license holders are required.

• Communications of the Korean Mathematical Society
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• v.27 no.4
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• pp.653-664
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• 2012

We study the abstract structure of the automorphism group of the ternary self-dual code of length 8 and give its convenient presentation by generators.

• Journal of the Chungcheong Mathematical Society
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• v.31 no.2
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• pp.269-280
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• 2018

We study self-dual codes over Galois rings using the building-up construction method. In the construction, the existence of an antiorthogonal matrix is very important. In this study, we examine the existence problem of an antiorthogonal matrix over Galois rings.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.129-132
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• 2000

This paper describes how to Implement dual band GSM hand set varying single band GSM phone. The idea can be extended to Triple mode design. Multiband design is important for global roamming and Baseband setup planning. Here H/W and SW issues are briefly described

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.623-624
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• 2012

• Korean Journal of Mathematics
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• v.13 no.1
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• pp.51-59
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• 2005

Let (M, $g$) be a compact oriented self-dual 4-dimensional Einstein manifold with positive sectional curvature. Then we show that, up to rescaling and isometry, (M, $g$) is $S^4$ or $\mathbb{C}\mathbb{P}_2$, with their cannonical metrics.

• Communications of the Korean Mathematical Society
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• v.10 no.3
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• pp.541-544
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• 1995

In [1], Ahmad has given a characterization of prime dual ideals in bounded commutative BCK-algebras. The aime of this paper is to show that Theorem of [1] holds without the commutativity.