• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2326-2332
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• 2016

In this paper, the proposed small size PLL works stable with the discrete loop filter which is controlled by voltage controlled oscillator's output signal. A switch controlled loop filter is introduced into the proposed PLL instead of a conventional $2^{nd}$-order loop filter. Those three switches are controlled by the very high frequency output signal of voltage controlled oscillator. The switches are also controlled by UP/DN signals and 'on/off' depending the presence of UP/DN signals. A negative feedback functioned capacitor with a switch does make it possible to integrate the PLL into a single chip. The proposed PLL works stably even though a total of small 180pF capacitor used in the discrete loop filter. The proposed PLL has been designed with a 1.8V supply voltage, 0.18um multi - metal and multi - poly layer CMOS process and proved by Hspice simulation.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.99-105
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• 2014

A reference spur suppressed PLL with two-symmetrical loops without changing the bandwidth which is optimized to suppress phase noise and reduce locking time has been designed. The principle of suppressing a reference signal spur is to stabilize the input voltage of voltage controlled oscillator (VCO). The proposed PLL consists of a phase-frequency detector(PFD) which has two outputs, two charge pumps(CP), two loop filters(LF), a divider and a VCO which has two inputs. Simulation results with $0.18{\mu}m$ CMOS process show that the reference spur is approximately suppressed to 1/2 of the reference spur in a conventional PLL. Even though there is a 5% process variation in the magnitude of R and C, the simulation result shows that the reference spur is still suppressed to 1/2 of the reference spur in a conventional PLL. The power consumption is 6.3mW at the power supply of 1.8V.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.4 no.1
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• pp.25-29
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• 1968

The effect of differences in grain size on the initial growth of seedlings was studied in rice with two leading varieties of Jaekun and Nongkwang. The grains were classified into three classes of large, medium and small size by their specific gravity. The results observed at seedling stage are summarized as follows. 1. Higher percentage of seeds with larger size was observed to be normally developed into sound seedlings comparing with those with small seeds. This suggests the more effective maintainance of seedings. 2. Seedlings from larger seeds also showed higher values in the number of roots, leaves and tillerings where no varietal difference was observed. 3. Varietal speciality led to the lorger coleoptile of Nongkwang variety, with rather longer plant, than that of Jaekun, while higher value in coleoptile length was observed at the seedlings from larger seeds. 4. Thus larger seeds and the Aariety Nongkwang yielded heavier dry matter of upper part. These trends appeared more clearly at the late seedling stage. 5. There was constant decrease in the dry matter weight per unit coleoptile length until the seedling-selfsupportingstage while after this stage abrupt increase was observed. Seedlings from larger seeds showed higher value in the dry matter weight per unit coleoptile until this stage, thought the differences became insignificant after this stage. And no varietal difference was found.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.784-794
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• 1996

In this papre, the design and the fabrication of the surface mountable voltage controlled oscillator is described for local oscillator in PCS(WACS/TDMA) handset. The VCO employs two silicon bipolar transistors of $f_{gamma}$ of 4 GHz as active devices. These are asembled to form the VCO on the 4 layer PCB of the size $12{\times}10mm$which provides the strip line resonator at the third layer. The fabricated VCO shows tuning rage over 50 MHz, phase noise -100 dBc/Hz at the 100 kHz frequency offset, and 0 dBm output power with the consumption of 22 mA at 3V. It is belived that the size will be more reduced by employing 1005 chip components and that the current consumption will be improved by employing transistors of higher $f_{gamma}$.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.94-98
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• 1990

Seven varieties of soybeans (Paldal, Danyeob, Jangbaek, Baegun, Jangyeobkong and 2 cultivars of Local 1 and Local 2) were investigated to compare the germination properties and cooking rate. The growth rate of soybean sprout roots was slower for larger size of soybeans. A 100% of germination was obtained for Danyeobkong and Paldalkong. Local 1 and Local 2 were lowest, 47% and 31%, respectively in germination ratio. The hardness of cooked soybeans measured by the maximum cutting force of cotyledon showed that Local 2 was softer and Danyeobkong was harder than other varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.245-251
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• 1985

Distributions of seed weight were investigated with different seed sized peanut varieties planted at the same time, and germination and field emergence percentage, growth, and seed yield were compared among three seed sizes of four peanut genotypes. Field performance also was carried out to evaluate the effects of cotyledon removal on growth and yields in field with large and small seed-sized peanut varieties. The variation of seed weight of large seed-sized was wider than small seed-sized peanut variety. The larger seed showed the higher percent germination after 3 days cold treatment in laboratary and field emergence. The growth was not different with their sizes, while seed yield was related to seed size in small seed-sized genotypes. The growth of peanut such as main stem, internodes, and total branches was affected significantly by cotyledon removal, although the differences were not obvious after podding time, and in small seed-sized variety Oltangkong, the yields was decreased by cotyledon removal but not in large seed-sized variety.

• The Korean Journal of Mycology
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• v.28 no.2
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• pp.88-92
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• 2000

Substrate improvement, maturation period and method of pinheading promotion were investigated to establish the culture method of Lyopyllum ulmarium which could obtained high yield in the short culture period. Rice bran+wheat bran (10%+10%) combination was selected from various additives, which showed vigorous growth of fruit body and high yield (133.8 g/850 cc). Oyster shells powder substance increased yield to 155.5 g per 850 cc capacity bottle. The suitable method for pinheading promotion was to stand the bottle reversely. The number of fruit bodies per 850 cc capacity bottle in this method was 27.2 stipes and bunch formation was good. When the maturation period of mycelium culture was 15 days to 30 days, pinheading period was 10 days. But when the maturing mycelium was 30 to 45 days, yield per 850 cc bottle was 148.2 g.

• Korean Journal of Medicinal Crop Science
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• v.2 no.1
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• pp.32-37
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• 1994

This experiment was conducted to obtain the basic information for the increase ofgermination percent by the seed diameter, specific gravity, different grain filling period and stratification in Bupleurum falcatum seeds. The seed size of B.falcatum ranged from 2.0 to 3.9mm in diameter, The large seed showed the higher germinability, The optimum specific gravity of salt selection for seed screening was 1.05 resulting in screening out seeds with high germinability over 70%.The seeds needed grain filling period for 60 days or longer after flowering to keep high germinability The optimum period of stratification treatment to promote seed germination was about 80 days.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.443-448
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• 2001

This study was carried out to obtain the basic informations on the characteristics of gametophytes formation and microspore germination in Astragalus membranaceus Bunge. Pollen mother cells passed through meiosis when the flower bud length reaches around 3.5 mm, thus creating the tetrad when it is 4.0 mm long. Pollen attains full growth when the bud is about 10.0 mm long and the anther is found to dehisce when the length of tate bud reach around 12.0 mm. Embryo sac develops at a similar speed as pollen did and it attains its full growth when the bud is about 10-12 mm long. After being stored at 4$^{\circ}C$ or -4$^{\circ}C$, the pollen maintained its germination ability to almost full extent by the 30th day after store. However, the germination rate at room temperature (23~28$^{\circ}C$) decreased below 3％ by the 3rd day of storage and so did the germination speed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.3
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• pp.274-282
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• 1998

This study deals with sinking resistance for purse seine, in the case of different d/l, ratio of twine diameter and leg length. Experiments carried out on the six types simplified reduced model seines which were made of knotless netting. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two -ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cm for seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. Experiments were measured in the observation channel of a flume tank at the static conditions Sinking motion was recorded by the two sets TV-camera for VTR which were placed in top and side of the model seine, and reading coordinate carried out by the video digitization system. An analysis were calculated out by simultaneous differential equations for numerical method by Runge - Kutta - Gill sub - routine. The results obtained were as follows: 1. Average sinking speed of seine of seine margin was fastest for Ⅵ seine followed by V, IV, III, II and I seines. 2. The coefficient of resistance for a seine wall was depended upon the ratio of d/l : KD =0.081 (d/l )-0.5 3. The coefficient of resistance for netting bundle was not depended upon the ratio of d/l :CR = 0.91 (), d : Twine diameter, l : Leg length, : Density of netting materals, $\omega$ : Density of water