• Korean Journal of Clinical Laboratory Science
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• v.40 no.1
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• pp.1-5
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• 2008

Thirty two of bathroom water samples from public bathroom in Seoul areas were examined using acid-fast staining, Lowenstein-Jensen (L-J) medium culture and PCR-restriction fragment length polymorphism (PCR-RFLP). In 6.25% (2/32) bathroom water samples, acid-fast bacilli were detected by AFB stain, and in 21.9% (7/32) bathroom water samples, acid fast bacilli grew on L-J media. Of them, six acid-fast bacilli were identified as Mycobacterium avium, and the other AFB as Mycobacterium szulgai by PCR-RFLP. These results are suggested that accidental nontuberculosis mycobacterial infection to a weakness person will be possible in public area.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.725-733
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• 2014

16 water treatment plants(WTPs) in Jeju province were investigated to evaluate the corrosivity of tap water. In addition, the impacts of lime and carbon dioxide on LI changes at ES WTP were analyzed. The average of LI in Jeju tap was -1.78 which was similar to that of in-land multi-regional WTPs. The recommended process to improve LI of ES WTP which has high corrosivity(i.e., LI = -2.61) was to combine lime and carbon dioxide with the dosages of 20 mg/L and 5 mg/L respectively to meet LI of -1.0 ~ 0. pH was confirmed to be a major water quality parameter that determined LI based on the correlation results among LI and water quality parameters. Precaution on turbidity increase by lime addition should given to minimize particle breakthrough in the distribution system. Turbidity increase can be controlled by the addition of lime prior to filters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.1-9
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• 2000

This paper presents the error performance of 16 star-QAM with diversity reception in microcell systems in the presence of additive white Gaussian noise(AWGN) and cochannel interference. The differential detection of 16 star-QAM is split into phase detection and amplitude detection. This technique can reduce the degradation of error performance which is due to fading and the complexity of receiver. Diversity reception is proposed to improve the degradation of error performance due to fading. Equal gain and maximal ratio combinings were adopted for the phase detection and the amplitude detection, respectively. The performance of 16 star-QAM was evaluated for various of Rician factor K, maximum Doppler frequency f_DT, signal to cochannel interference ratio and diversity branch L.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.312-316
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• 1999

I-V characteristics of Praseodymium-based ZnO varistor doped with $Nd_2O_3$ in the range 0.0-2.0mol% sintered at 130$0^{\circ}C$ and 135$0^{\circ}C$ were investigated. In the all sides, ZnO varistors sintered at $1300^{\circ}C$ exhibited much better varistor characteristics than that at 135$0^{\circ}C$. All ZnO varistors doped with $Nd_2O_3$ sintered at $1300^{\circ}C$ exhibited good varistor characteristics but particularly ZnO varistor doped with l.Omol% $Nd_2O_3$ exhibited the best characteristics, which the nonlinear is 65.2 and the leakage current is 4.5pA. It is estimated that ZnO varistor doped with l.Omol% $Nd_2O_3$ will begin to be sufficiently used as basic composition to fabricate a good varistor.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.685-694
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• 2018

In this paper, we designed and fabricated the frequency mixer, which is the core parts of high frequency head in Ku-band tracking radar. To overcome the problem of single-ended and single-balanced resistive structure, we designed the fine-line structure with balanced mixer, to generate IF signal without distortion in L-band, after receiving the RF signal of the Ku-band. The prototype mixer showed a Noise Figure Max of 6.823dB, Gain of 4.1598~4.676dB and Band Pass of 61MHz in 5 Ku-band samples frequency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.67-76
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• 2000

In this paper, a low noise amplifier has been developed, which is operating at L-band i.e., 1525-1575 MHz. By using resistive decoupling circuits, the resistor dissipates undesired signal in low frequency band. By adopting this design method the stability of the LNA is increased and the input impedance matching is improved. The LNA consists of the low noise GaAs FET ATF-10136 and the internally matched VNA-25. The low LNA is fabricated by both the RP circuit and the self-bias circuits in an aluminum housing. As a result, the characteristics of the LNA implemented show more than 32 dB in gain, lower than 0.5 dB in noise figure, 18.6 dBm output gain in 1 dB gain compression point.

• Journal of Astronomy and Space Sciences
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• v.21 no.1
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• pp.1-10
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• 2004

We present BV CCD photometry of metal-rich globular cluster M71. Based on our color-magnitude diagram (CMD), we derive the distance to M71 using a sample of Hipparcos subdwarfs of similar metallicity. Our distance modulus is (m - M)v = 13.46(${\pm}0.17$. CMD comparison was also made between M71 and 47 Tuc. We confirm that there exists a significant age differonce(> 2 billion years) in spite of their Similarity in metallicity.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.523-530
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• 1999

This paper presents the on -line techniques of SHE-PvVI\I for GTO current source converter. The look-up t table is linearized with this proposed method so that the tum-on/off periods of the GTO switches can be c computed in real-time for any modulation index. This allows the rapid and continuous regulation of the DC O output current while producing the sinusoidal AC input current waveform and unity power factor. The l linearized S}lE-PW~I technique and the high power factor control scheme are Prolxlsed and their‘ performance i is tested analytically. The validity of this proposed technique is well verified through the simulation and e experimental results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.419-421
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• 2009

The freezing point would be different as the atmospheric pressure and humidity change. So if we can measure the transparency of ice, it should be easy that we approximate a freezing process and estimate the density of ice. This paper presents the method for estimating the transparency of ice in images. First, ice images are mapped to the $CIEL^*a^*b^*$ color space, and we make a new index for the ice transparency by using the average of $L^*$ and RMS(Root Mean Square) Contrast. In this case, the new index is better than the other existing method, i.e, Weber contrast, and Michelson contrast.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.5
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• pp.703-712
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• 2009

The principal objective of this study was to supply basic material determine basic information regarding effective health promotion regimens for elderly women via a comparative survey of health status by aging age between elderly women (=70 y) and college women. The subject groups of elderly women (=70 y) and college women were selected and surveyed from March to October, 2008, in the Seoul area. The average age of the elderly women assessed in this study was $78.64{\pm}7.30$, the average height was $147.07{\pm}5.72$ cm, and the average weight was $50.47{\pm}7.44$ kg. As compared with college women, a higher percentage of elderly women ate breakfast regularly, but the elderly women also experienced difficulties in chewing due to dentures, and therefore ate their meals with large quantities of liquids, and usually ate their meals within 10 minutes. The majority of elderly women suffered from at least one disease, and the most common symptom reported was hypertension (25%). 52.2% of elderly women and 47.8% of college women reported that they exercised 1~2 times per week. They reported that their favorite exercise was light exercise, such as jogging and athletics (73.1%). As compared with college women, the smoking rate was lower among elderly women, but some of the elderly women were long-time smokers or alcoholics. The differences in red blood cells counts, Hb, hematocrit, and MCV of the between elderly women and college women were significant. In addition, but the MCH and MCHC were higher in elderly women compared with college women and the total cholesterol of elderly woman ($175.62{\pm}38.89$ mg/dL) was significantly lower compared with college woman ($186.13{\pm}28.19$ mg/dL). TG ($127.89{\pm}51.25$ mg/dL) and LDL-cholesterol ($120.51{\pm}32.88$ mg/dL) of elderly woman were significantly higher than TG ($79.71{\pm}40.9$ 6mg/dL) and LDL-cholesterol($103.78{\pm}22.94$ mg/dL) of college woman (p<0.05). The levels of HDL-cholesterol ($58.78{\pm}12.90$ mg/dL) in the college women was significantly higher than the HDLcholesterol levels ($48.17{\pm}13.79$ mg/dL) of the elderly women (p<0.05). Serum vitamin C levels in elderly women were significantly higher than those of college women (p<0.05), whereas no significant difference was detected between the two groups. Consequently, it can be concluded that the appropriate education programs for dietary habits and health promotion are necessary for a healthier life. Additionally, it is necessary for individuals to precisely determine precisely their own health status, and develop appropriate dietary programs for themselves.