• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.194-201
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• 2017

This study was conducted to determine the valid time for accurate detection of complete blood cell count (CBC) in pig blood using an automatic blood corpuscle analyzer (Hemavet 950FS). Blood samples were collected from 34 pigs (Duroc) with a 60 kg (${\pm}3.5$) body weight. Ten specimens with CBC parameters in normal range and with no hemolysis were selected among 34 samples and used in this study. Regarding leukocytes parameters, white blood cell (WBC), neutrophil (NE), and lymphocyte (LY) counts showed a low daily variation (coefficient of variation, CV), whereas monocyte (MO), eosinophil (EO), and basophil (BA) CVs were significantly high (19.7, 56.9, and 53.3%, respectively). On the other hand, all parameters of erythrocytes and thrombocytes showed stable daily variation. All parameters of leukocytes and thrombocytes were significantly reduced as storage time passed (P<0.01 or 0.001), except for lymphocytes (P=0.535). However, no significant differences were observed in parameters of erythrocytes from blood up to 120 hours. From above results, we assert that Hemavet 950FS is useful in analyzing CBC, except for MO, EO, and BA. For accurate detection of leukocyte and thrombocyte parameters, analysis should be performed within 4 hours after blood collection when using Hemavet 950FS. On the other hand, parameters of erythrocytes could be stably detected for at least 120 hours after blood collection.

• Journal of Fisheries and Marine Sciences Education
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• v.9 no.2
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• pp.179-187
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• 1997

Doppler log and current meter are based on the measurment of the doppler effect. Ship's speed over the ground measured by means of doppler log effect of underwater ultrasonic intends to get infulence by the difference of sound velocity, the ship's course, the sea bottom inclination, the trim and tranducer installation etc. This paper investigated on the error of speed over the ground by change of the trim comparing the real speed obtained by the mile post with the speed of single beam type doppler log on the trainning ship Kyeongyangho. The results are as follows ; 1. Indicating speed of doppler log is very much greatly influenced on variation of trim, but the real speed is less affected variation by trim. 2. The range of variation and error of speed over ground are smallest when ship's trim is 2.15m trim by the stern.

• Korean Journal of Ichthyology
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• v.33 no.3
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• pp.184-190
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• 2021

Since the original description of new species, Eumicrotremus jindoensis, we confirmed the first occurrence of E. jindoensis based on a single specimen (22.3 mm SL) caught by inshore stow net at the coastal waters of Boryeong of Korea. However, our specimen slightly differed from type specimens in having more vertebrae (26 vs. 21~24), longer snout (17.4% vs. 8.1~9.1%), longer preanus length (67.5% vs. 58.0~58.3%) and shorter second dorsal fin base (15.3% vs. 20.2~20.8%). Comparing with mtDNA COI and Cytb sequences, we could not find any differences in mtDNA Cytb sequences between our specimen and type specimens, which suggest that those morphological differences may belong to local variation by habitat and environmental condition between off Jindo Island and off Boryeong in Korea. Eumicrotremus uenoi is known from the southern sea of Korea narrowly (Busan, Tongyeong, and Jeju Island), the other congeneric species (E. asperrimus, E. pacificus, and E. taranetzi) from only the eastern sea of Korea, but E. jindoensis from the central coast to southern coast of western Korea.

• Journal of Life Science
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• v.21 no.6
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• pp.901-906
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• 2011

In order to investigate the variations on the seed hardness of Pisum sativum distributed in southern area of Korean peninsula, 10 local strains (Choonseong. Ganghwa, Pocheon, Hadong, Haman, Geumneung, Yeongyang, Boseong, Gochang, Namweon), which located from $34^{\circ}26"N$ to $38^{\circ}11"N$, were selected according to their latitudes and geographical distances. The seeds of these strains were collected and their contents of mannose and galactose were analyzed. Mannose contents in the seeds were variable in the range between the highest 10.351 mg/g (Ganghwa) and the lowest 5.962 mg/g (Yeongyang). The contents of galactose were also represented remarkable differences from 7.050 mg/g (Yeongyang) to 19.314 mg/g (Hadong). The local strains were classified into 3 variation types such as the south central type (Namweon, Yeongyang, Geumneung, Gochang), the central type (Choonseong. Ganghwa, Pocheon) and the southern type (Haman, Hadong) and 1 strange strains (Boseong) according to the geographical climatic type, isopleth of warmth index and the ratio of mannose to galactose, which indicate the hardness of seeds in Leguminosae, ranged from 0.46 to 0.94. The variation types are very significant genecologically as an evidence for microevolution related to natual and artificial selection in cultivated plants.

• Journal of Navigation and Port Research
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• v.27 no.1
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• pp.81-86
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• 2003

In the paper, the power amplifier using active biasing for LDMOS MRF-21060 is designed and fabricated. Driving amplifier using AH1 and parallel power amplifier AH11 is made to drive the LDMOS MRF 21060 power amplifier. The variation of current consumption in the fabricated 5 Watt power amplifier has an excellent characteristics of less than 0.1A, whereas passive biasing circuit dissipate more than 0.5A. The implemented power amplifier has the gain over 12 dB, the gain flatness of less than $\pm$0.09dB and input and output return loss of less than -19dB over the frequency range 2.11~2.17GHz. The DC operation point of this power amplifier at temperature variation from $0^{\circ}C$ to $60^{\circ}C$ is fixed by active circuit.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.9
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• pp.1079-1086
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• 2012

In this paper, X-band 60 W Solid-State Power Amplifier with sequential control circuit and pulse width variation circuit for improve bias of SSPA module was designed. The sequential control circuit operate in regular sequence drain bias switching of GaAs FET. The distortion and efficiency of output signals due to SSPA nonlinear degradation is increased by making operate in regular sequence the drain bias wider than that of RF input signals pulse width if only input signal using pulsed width variation. The GaAs FETs are used for the 60 W SSPA module which is consists of 3-stage modules, pre-amplifier stage, driver-amplifier stage and main-power amplifier stage. The main power amplifier stage is implemented with the power combiner, as a balanced amplifier structure, to obtain the power greater than 60 W. The designed SSPA modules has 50 dB gain, pulse period 1 msec, pulse width 100 us, 10 % duty cycle and 60 watts output power in the frequency range of 9.2~9.6 GHz and it can be applied to solid-state pulse compression radar using pulse SSPA.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.9
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• pp.735-744
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• 2000

The electrical procerties and stability of ZnO-Pr$_{6}$O$_{11}$-CoO-Cr$_2$O$_3$-Er$_2$O$_3$ (ZPCCE) based varistors were investigated in the Er$_2$O$_3$content range of 0.0 to 4.0 mol%. ZPCCE ceramics containing 2.0 mol% Er$_2$O$_3$ exhibited the highest density of 5.74 g/㎤ corresponding to 99.3% of theoretical density. The varistors with 0.5 mol% and 2.0 mol% Er$_2$O$_3$exhibited a relatively satisfying nonlinearity, which the nonlinear exponent is 40.50 and 47.15, respectively and the leakage current is 2.66 $mutextrm{A}$, respectively. Under more severe d.c. stress, such as (0.80 V$_{1mA}$/9$0^{\circ}C$/12h)+(0.85 V$_{1mA}$115$^{\circ}C$/12h)+(0.90 V$_{1mA}$12$0^{\circ}C$/12h)+(0.95 V$_{1mA}$1$25^{\circ}C$12h), they showed a very excellent stability, which the variation rate of the variator voltage is -0.89% and -0.15%, the variation rate of the nonlinear coefficient is -4.67% and -3.56%, and the variation rate of leakage current is -6.02% and -19.56%, respectively. It is surely bellived that ZnO-0.5 mol% Pr$_{6}$O$_{11}$-1.0 mol% CoO-0.5 mol% Cr$_2$O$_3$-x mol% Er$_2$O$_3$(x=0.5, 2.0) based varistors will be greatly contributed to develop the advanced Pr$_{6}$O$_{11}$-based ZnO varistors in future.uture. future.uture.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.139-145
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• 2024

This paper presents the design of a voltage controlled oscillator (VCO) which is one of the key building blocks in modern wireless communication systems with small VCO gain (K_vco) variation. To compensate conventional large K_vco variation, a series varactor bank has been added to the conventional LC-tank with parallel capacitor bank array. And also, in order to achieve excellent phase noise performance while maintaining wide tuning range, a mixed coarse/fine tuning scheme(series varactor array and parallel capacitor array) is chosen. The switched varactor array bank is controlled by the same digital code for switched capacitor array without additional digital circuits. For use at a low voltage of 1.2V, the proposed current reference circuit in this paper used a current reference circuit for safety with the common gate removed more safely. Implemented in a TSMC 0.13㎛ CMOS RF technology, the proposed VCO can be tuned from 4.4GH to 5.3GHz with the K_vco (VCO gain ) variation of less than 9.6%. While consuming 3.1mA from a 1.2V supply, the VCO has -120dBc/Hz phase noise at 1MHz offset from the carrier of the 5.3 GHz.

• Journal of Korean Society of Forest Science
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• v.14 no.1
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• pp.33-38
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• 1972

This study was carried out to investigate on the variation of wood fiber dimensions of some oakwoods. Every 2 annual ring was selected for specimens from pith toward bark up to 28th annual ring on 3 species of Oak SINGALNAMOO(Quercus mongorica Fisch.), JOLCHAMNAMOO(Quercus serrata Thunb.) and KULCHAMNAMOO(Quercus variabilis Blume) which grew in Mt. Jiri. The investgated results are as follows: 1. Values of wood fiber lengths increase rapidly up to 16th annual ring, however, considerably stable at the rear part. Range of wood fiber length variations: Species Range of length(mean) CV SINGALNAMOO, $640{\sim}1,544{\mu}$($1,142.3{\mu}$), 8~16% JOLCHAMNAMOO, $592{\sim}1,600{\mu}$($1,179.6{\mu}$), 6~21% KULCHAMNAMOO, $679{\sim}1,592{\mu}$($1,298.9{\mu}$), 2~15% 2. The increment of wood fiber width and thickness by annual rings shows quite inactive contrary to the length. Range of wood fiber width: $7.6{\sim}10.0{\mu}$(mean $9.3{\mu}$) Range of wood fiber thickness: $2.0{\sim}3.2{\mu}$(mean $2.6{\mu}$) 3. There was no significance between species through their wood fiber lengths. 4. And these wood fibers believed to be valuable for pulp-wood through their fiber bonding ratio, Runkel ratio and flexibility coefficient.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.4
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• pp.73-80
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• 2013

Breakdown characteristics of air in the vertical arrangement of line conductor and plane electrode in case of combustion flame on the plane electrode are examined by the application of AC. and DC voltages to the gap. In order to investigate the effect of paraffin flame on the breakdown characteristics of air, flashover voltages are measured according to the variation of the gap length and the horizontal distance between the flame and the line conductor. As the result of the experiment, flashover voltages are substantially lowered down to 29.8% in case of the AC voltage, and 16.1% in case of the negative DC voltage, when in the presence of the flame. from 100% when in the absence of flame. Flashover voltages of air in the range of smaller than 3㎝ at the horizontal distance are increased in the proportion of the gap length and the horizontal distance in case of both AC and negative DC voltages. But before the flashover occurs, the flame is extinguished by such corona wind that is produced from the line conductor when the gap length and the horizontal distance reach to a certain degree. The effect of relative air density and the phenomenon of thermal ionization are analysed as the reduction factors of flashover voltages, due to high temperature of the flame.