• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.7
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• pp.81-88
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• 2004

In case of mechanical down tilting, a horizontal pattern is distorted and beam width widens whenincreasing tilt angle, which causes an expansion of hand off region and burden base station equipment. In contrast, electrical down tilting has advantage that horizontal HPBW is kept constant with down tilting. In this paper, based on a phased array technology, dual polarized base station antenna with electrical down tilting was developed at 800MHz band. The antenna has down tilting range of 0$^{\circ}$ to 14$^{\circ}$, and 15㏈i gain. We use stacked microstrip patch as a radiated element and apply balanced feed technique to improve isolation between ports and discrimination of cross polarization. The effect of electrical down tilting was verified by field test.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.1
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• pp.39-45
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• 2000

Two experiments were conducted to determine the ileal digestibility of the amino acids contained in linseed meal using the regression technique and then applying the values obtained, in a growth trial, using growing-finishing pigs. For the digestibility trial, four $20{\pm}0.5kg$ crossbred $(Yorkshire{\times}Landrace{\times}Beijing\;Black)$ barrows were fitted with simple T-cannula in the terminal ileum. After recovery, the barrows were fed one of four experimental diets according to a $4{\times}4$ Latin Square design. The pigs were fed corn-soybean meal based diets supplemented with 0, 25, 50 or 75% linseed meal. For the growth trial, 80 crossbred $(Yorkshire{\times}Landrace{\times}Beijing\;Black)$ growing pigs $(20.2{\pm}1.5kg)$ were fed corn-soybean meal diets supplemented with 0, 5, 10 or 15% linseed meal. Five pens (2 gilts and 2 castrates) were assigned to each treatment. With the exception of leucine, the digestibility coefficients for the indispensible amino acids declined as the level of linseed meal in the diet increased. There was a good agreement between the amino acid digestibilities for lysine, methionine, threonine and tryptophan determined using the regression technique and amino acid digestibilities previously published for linseed meal. During both the growing (20-49 kg) and finishing (49-95 kg) periods, the addition of linseed meal decreased average daily gain and feed conversion in a linear manner (p<0.05). Feed intake was not significantly different among treatments. The overall results suggest that linseed meal can be used at levels of between 5 and 10% in diets fed to growing-finishing pigs provided that the diet has been balanced for digestible amino acids.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.369-375
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• 2000

Two experiments were conducted to determine the apparent ileal digestibility of the amino acids contained in peanut meal using the regression technique and then applying the values obtained, in a growth trial, using growing-finishing pigs. For the digestibility trial, four 20 kg crossbred (Yorkshire${\times}$Landrace${\times}$Beijing Black) barrows were fitted with simple T-cannula in the terminal ileum. After recovery, the barrows were fed one of four experimental diets according to a $4{\times}4$ Latin Square design. The pigs were fed corn-soybean meal based diets supplemented with 0, 25, 50 or 75% peanut meal. For the growth trial, 200 crossbred (Yorkshire${\times}$Landrace${\times}$Beijing Black) growing pigs (20.9 kg) were fed corn-soybean meal diets supplemented with 0, 5, 10, 15 or 20% peanut meal. Five pens (4 gilts and 4 castrates) were assigned to each treatment. With the exception of arginine, histidine and phenylalanine, the digestibility coefficients for the indispensible amino acids declined as the level of peanut meal in the diet increased. There was a good agreement between the amino acid digestibilities for lysine, methionine, threonine and tryptophan determined using the regression technique and amino acid digestibilities previously published for peanut meal. During both the growing (21-54 kg) and finishing (54-99 kg) periods, the addition of peanut meal decreased average daily gain (p=0.01) and feed conversion in a linear manner (p<0.05). Feed intake was not significantly different among treatments. The overall results suggest that peanut meal can be used at levels up to 15% in diets fed to growing-finishing pigs provided that the diet has been balanced for digestible amino acids.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.521-527
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• 2000

Two experiments were conducted to determine the ileal digestibility of the amino acids contained in cottonseed meal using the regression technique and then applying the values obtained, in a growth trial, using growing-finishing pigs. For the digestibility trial, four 20 kg crossbred ($Yorkshire{\times}Landrace{\times}Beijing$ Black) barrows were fitted with simple T-cannula in the terminal ileum. After recovery, the barrows were fed one of four experimental diets according to a $4{\times}4$ Latin Square design. The pigs were fed com-soybean meal based diets supplemented with 0, 25, 50 or 75% cottonseed meal. For the growth trial, 128 crossbred ($Yorkshire{\times}Landrace{\times}Beijing$ Black) growing pigs (21 kg) were fed com-soybean meal diets supplemented with 0, 4, 8 or 12% cottonseed meal. Four pens (4 gilts and 4 castrates) were assigned to each treatment. The digestibility coefficients for the indispensible amino acids declined as the level of cottonseed meal in the diet increased. There was good agreement between the amino acid digestibilities for methionine, threonine and tryptophan determined using the regression technique and amino acid digestibilities previously published for cottonseed meal. However, for lysine, the value of 67% ileal digestibility obtained in the present experiment was higher than most previously published estimates which ranged from 42 to 73%. During both the growing (21-43 kg) and finishing (43-84 kg) periods, the addition of cottonseed meal decreased average daily gain and feed conversion in a linear manner (p<0.05). Feed intake was not significantly different between treatments. The overall results suggest that cottonseed meal can be used at levels of up to 8% in diets fed to growing-finishing pigs provided that the diet. has been balanced for digestible amino acids.

• Journal of Power Electronics
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• v.12 no.2
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• pp.276-284
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• 2012

AC/AC power conversion is widely used to feed AC loads with a variable voltage and/or a variable frequency from a constant voltage constant frequency power grid or to connect critical loads to an unreliable power supply while delivering a very balanced and accurate sinusoidal voltage system of constant amplitude and frequency. The load specifications will clearly impose the requirements for the inverter stage of the power converter, while wider ranges of choices are available for the rectifier. This paper investigates the utilization of a buck-type current source rectifier as the active front-end stage of an AC/AC converter for applications that require an adjustable DC-link voltage as well as elimination of the low-frequency common mode voltage. The proposed solution is to utilize a combination of two or more zero current vectors in the Space Vector Modulation (SVM) technique for Current Sources Rectifiers (CSR).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.s01
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• pp.98-114
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• 1988

This study was conducted to investigate the status and prospects of seed quality researches in rapeseed. Rapeseed Quality was mainly related to oil and protein content, fatty acid composition and glucosinolate content. Hence, breeding for improvement of rapeseed Quality has been emphasized as follows: 1) inheritance mode, 2) investigation of germplasm, 3) establishment of analysis technique, 4) establishment of selection method, 5) idealization of cultural technique. The oil quality is determined by its fatty acids. Fatty acids have been determined by gas chromatography. To improve oil quality was emphasized for zero erucic acid, the highest possible linoleic acid and the lowest possible linolenic acid content. Rapeseed meal is not considered as top quality feed ingredient although it has higher protein content and well-balanced amino acid composition. This is mainly because of the presence of considerable amounts of glucosinolates. Thus the reduction of glucosinolate content in rapeseed meal is of great importance. In breeding for meal quality, low glucosinolate lines (plants) were selected and analyzed by gas chromatography and UV-spectrophotometer. Current problems and future researches of rapeseed quality in Korea are 1) improvement of researcher's number and facilities, 2) depression of animal feeding trials, 3) unsatisfied relationship between research and manufacturing and products field, 4) improvement of fertility for yellow and thin seed coat lines crossed between mustard and rapeseed, 5) establishment of new rapid analysing system for rapeseed quality.

• The Journal of Fisheries Business Administration
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• v.16 no.1
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• pp.91-124
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• 1985

Mariculture is contrasted with inland aqua-culturing fisheries. It is defind as the Industry of rearing Aquaorganism in limited coastal area relatively shallow in depth. Then, It's coming into being realization of Mariculture in it is long in history that Mariculture was realized in Korea. But it is from the early part of 1960s, that this industry has normally developed. Owing to 200 miles economy-zone problems of coastal countries, the development of deep sea fishing was limited, so the Korean Government has now appreciated the importance of cultured industries in the field of coastal fisheries. And the Korean Mariculture the output of which was only 18, 000 M/T in '60s attained 540, 000M/T in 1980s, has now occupied its relative importance in Korean Fisheries Industry. So the purpose of this report is to suggest the prospect of technical development of mariculture in the future of Korea, through the analysis of the various problems that affect upon the individual management '||'&'||' fishing ground utilization, along with the appreciation of "how to extend of those technical innovation" and "how the fishermen's technique level is extended at this stage. According to this study, the result is summarized as follows. First, Maricultural technique is classified into 8 sub-techniques as follows, as shown in fig. 1.Fig. 1. The Formation structure of mariculture technique Second, the change of technical method of mariculture in coastal area of Korea has made as 5 stages; 1) Scattering of culturing organism 2) Culturing by putting stone and installing bamboo 3) Culturing by installing rope and seeding 4) Culturing of putting objectives in cages 5) Culturing fish by feed Third, the maricultural fisheries of Korea has about 70 years long in history. It began from 1910s. But at that time there was no special technique in aquaculture and its technique was confined in searching out the object of species. The species was laver, oyster ect.Forth, although realization of mariculture in Korea has been long time, it is of late from 1960s that this has been industrial with normal development, and its technique of mariculture has mainly has developed from 1970s. Its result not only contributed to the high growth in Korean ecconomy along with the well balanced development between industires, but also it played a great role for the resolution of nation's food problem. Especially maricultural production has shown its sustained annual increase of 13.8% during the last 20 years. So the portion of mariculture among total fisheries stucture was extended from 4.1% in the early 1960s to 22.4% in 1980s.Fifth, it could be safely said that such development in maricultural field is resulted from the activity of aquacultural institutes such as Fisheries Reseach '||'&'||' Development production of major kinds such as Oyster, Sea-mustard, and Laver etc. As well as in the innovation of aquaculturing method with synthetic fiber utilization. FRDA has played important role in the efficient propargation of new aquacultural technique.Sixth, as for the change in aquaculture structure and its during period between 1970s and 1980s, the private management participation shown 25% increase from household number of 45, 173 to 56, 268 in total number. And in the respect of the management scale, of their management decreased, while it showed an increase in relative large scale management, the increase over 3 employees compared with other fisheries field between '70s and 80s. This must be an major trait to be recorded, Now the data above mentioned are shown as in table 1 and 2.Table 1. The maricultural fishing ground development situation in 982.Table 2. The mariculture management as seen in the employmnet size in high seasion.Owing to the technical innovation, of the mariculture in coastal area new income of fishermen increased and it also is true that the number of fishermen participating in its industrialization increased. But the problem being from now on is the self-discharge of the destruction fishing ground considered resulted from rapid expansion in aquaculture industry and the preventive system of sentility of fishing ground. sentility of fishing ground.