• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.184-191
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• 2000

Gametogenesis and the reproductive cycle of the marsh clam, Corbicula leana(Prime} were investigated monthly Hyongsan estuary, Korea from January to December 1998 by histological observation. C. leana had separate sexes, and oviparous. The gonads were located between the sub-region of mid-intestinal gland in visceral cavity and reticular cennective tissue. The ovary and testis were composed of a number of ovarian and testicular tubules, respectively, Mature oocytes were characterized by germinal vesicles with nucleoli and their sizes ranged $70\;to\;80{\mu}m$ in diameter. A number of mesenchymal tissues and pigment granular cells were distributed in the growing oocytes and spermatocytes during early developmental stages. With the further development of gonad, these tissuse and cells gradually disappeared. The monthly changes in the fatness index were closely related to reproductive cycle. Minimun size for sexual maturity was reached over 10.0 mm in shell length. The reproductive cycle could be classified into 6 stages : multiplicative (March to April): early growing and growing (May to June), mature (July to August), spent (September), degenerative (October) and recovery (November to February).

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.5
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• pp.542-546
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• 2008

Recently dual-port SDRAM (DPSDRAM) architecture tailored for dual-processor based mobile embedded systems has been announced where a single memory chip plays the role of the local memories and the shared memory for both processors. In order to maintain memory consistency from simultaneous accesses of both ports, every access to the shared memory should be protected by a synchronization mechanism, which can result in substantial access latency. We propose two optimization techniques by exploiting the communication patterns of target applications: lock-priority scheme and static-copy scheme. Further, by dividing the shared bank into multiple blocks, we allow simultaneous accesses to different blocks thus achieve considerable performance gain. Experiments on a virtual prototyping system show a promising result - we could achieve about 20-50% performance gain compared to the base DPSDRAM architecture.

• Journal of Korea Multimedia Society
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• v.9 no.2
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• pp.215-225
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• 2006

Binary images, such as cartoon character images, text images and signature images, which consist of two values with black and white have more difficulties inserting imperceptible secret data than color images. Steganography using binary cover images is not easy to satisfy requirements for both the imperceptibility of stego images and a high embedding rate of secret data at the same time. In this paper, we propose a scheme that can get both the high quality of stego images and a high embedding rate by supplementing the advantages of previous research. In addition, the insertion of the proposed method changes only existing pixels of the imperceptible position and can embed the secret data of [$log_2(mn+1)-2$] bits in a block with size of $m{\times}n$.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.534-537
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• 2002

An agarase gene from Bacillus cereus ASK202 was expressed in high levels by E. coli BL21(DE3)/pEBA1 using pET28a(+) vector system with the inducible T7 promoter in the presence of isopropyl- ${\beta}$ -thiogalactopyranoside. The open reading frame encodes 761 amino acid residues with a calculated molecular weight of 83,300 daltons and a potential signal peptide about 36 amino acid residues at the N-terminus. E. coli BL21(DE3)/pEBA1 produce 1280 unit/ ${\ell}$ of agarase. The optimum physical condition for the agarase activity was pH 5.6, and $40^{\circ}C$, respectively. The agarase activity was stable up pH $4.0{\sim}9.0$ and $4{\sim}40^{\circ}C$. The km and maximum rate of metabolism for agar were 0.068mg/$m{\ell}$ and 0.094mg/$m{\ell}{\cdot}min$, respectively.

• 한국해양학회지
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• v.4 no.1
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• pp.1-8
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• 1969

Phytoplankton samples, collected about twenty day interval on May of 1967, at same twenty-one stations located in the north-eastern Korea Strait were examined in an attempt to determine the specific distribution and abundance of phytoplankton. Water bottle samples preserved with neutralized formula were used for the phytoplankton study. In May, water temperature and salinity show both lower at the sea of Korea side than that of Japan side, and both indicate gradually higher to the sea of Japan side. Fourty-six species of diatoms and three species of dinoflagellates in early May, and thirty-six species of diatoms and six species of dinoflagellates in the May were detected. Among them thirty species of diatoms and two species of dinoflagellates were appeared commonly in both cruise. Chaetoceros curvisetus and Rhizosolenia castracanei were wide distributed species, and Leptocylindrus danicus was the most numerous species at this sea in May. In generally, the sea of Korea side was more rich in species and numbers of phytoplankton.

• Korean Journal Plant Pathology
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• v.13 no.4
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• pp.215-218
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• 1997

The environmental factors affecting maturity of pseudothecia overwintered in iufected leaves by Mycosphaserella nawae was investigated. The pseudothecia in the overwinteringinfected leaves were matured at the end of April when the average temperature was $14^{\circ}C$ and precipitation was enough. Pseudothecia initiation was preceded by the fungal biomass development in a given host. The maturity of the pseudothecia from the leaves defoliated in early October was earlier and higher than those defoliated in November of the previous year. Pseudothecia development was also positively affected by low temperature. The maturity time, as determined by percentage of matured pseudothecia out of prematured ones, was also 20 days earlier, and the rate of maturity was higher for the leaves overwintered in door, than for those kept in greenhouse. We have providedevidence that the conidia play a significant role in the epidemiology of this pathogen. Many pseudothecia were developed in the leaves infected by artificially inoculated conidia and maturation rate of the pseudothecia was not different from that of the typical symptom by ascospores infection of Mycosphaerella nawae.

• Research in Plant Disease
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• v.7 no.2
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• pp.120-122
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• 2001

The powdery mildew of broad bean (Vicia faba) extensively occurred in farmers' fields in Changseon-myon, Namhae-gun, Gyeongsangnam-do, Korea in 2001. Both sides of the leaves and stems were covered with white fungal spores and mycelia, and then the leaves and stems colored brown and dark brown and eventually died. Conidia and conidiophores were formed on the lesion. Conidia were cylindric, 29~45$\times$13~23 um (av, 36~18 um) in size and born singly on the conidiophore. Fibrosin bodies were not observed. Conidiophores were straight with 3-4 cylindric cells and 51~100$\times$6~10 um (av.70$\times$8 um) in size. Foot cell was 28~53$\times$7~10 um (av,39$\times$8 um) in size. Appressorium was a lobed type. Cleistothecia were not formed. This is the first report on powdery mildew of broad bean caused by Oidium sp. in Korea.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.135-139
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• 1994

In the year 1992/93 leucocytozoonosis could be first diagnbosed in 87 chickens of 4 chicken farms in Honam districts. The diagnosis was confirmed by detection of the blood merozoites or gametocytes and histological finding of the schizonts from various organs with some clinical signs. Cases of leucocytozoonosis only occurred from the end of June to the middle of September. Artificial infection could be observed by means of inoculation of infected blood merozoites. The schizonts were found in the liver and cardiac muscle of the different chickens recovered from the natural infection, respectively, in September and next February. Thus the relapse or long-term infection in cold seasons might be possible. The unique gametocyte antigen polypeptide was 50.1 kD.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.141-146
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• 1998

In order to determine the optimmum harvest time of Citrus unshiu Marc. var. miyagawa and C. unshiu Marc. var. okitsu produced in Cheju, citrus fruits sampled at packing houses or harvested directly on citrus tree in south and north area of Cheju were analyzed. The fruits were grown in size till middle of October, and soluble solids were increased continuously after that. The fruits size were different by positional directions on the tree, the quality of citrus fruits in central southern positions on the tree was good for fresh fruit consumptions. Compared with only the quality of citrus fruits as a factor of soluble solids, total sugar, pH, and color index, the optimum harvest time were supposed to be reasonable at late of November for C. unshiu Marc. var. okitsu, and at early of December for C. unshiu Marc. var. miyagawa. The results obtained from citrus fruits sampled at packing houses were supposed to be not suitable for determing the optimum harvest time, because of storage after harvest at ordinary harvesting time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.300-304
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• 1991

Several experiments were conducted to elucidate a possibility of sweet sorghum, sugar beet and sugar cane as the resources of bio-energy which were collected from Philipine, India, Japan and Gene -bank in Korea. The experiments were carried out in Chinju, Korea from 1986 to 1988. When sweet sorghum cultivars were taken from 70 to 118 days after sowing on May 20, 1988 upto heading stage, the sugar content of stem was 6 to 14% and yielded 4 to 10ton per l0a in terms of the total fresh weight of plant. Sugar beet root contained 9.2 to 19.8% in sugar producting 3,542 to 6. 397kg per l0a. Meanwhile. the sugar content in stem of sugar cane was 15.2 to 16.7% and final growth the late October in this particular region. Particularly, F1 hybrid cultivar(s-l) of sweet sorghum could be harvested twice in a year. The alcohol quantity obtained from the juice of sweet sorghum was 180$\ell$ per l0a and was increased as sowing date was earlier. The results suggested that it would be possible to utilize the sugar crops as bio-energy resources using improved cultural methods and effective fermentation techniques.