• Journal of KIISE:Information Networking
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• v.32 no.3
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• pp.279-290
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• 2005

Recently, as the serious damage caused by DDoS attacks increases, the rapid detection and the proper response mechanisms are urgent. However, existing security mechanisms do not effectively defend against these attacks, or the defense capability of some mechanisms is only limited to specific DDoS attacks. In this paper, we propose a detection architecture against DDoS attack using data mining technology that can classify the latest types of DDoS attack, and can detect the modification of existing attacks as well as the novel attacks. This architecture consists of a Misuse Detection Module modeling to classify the existing attacks, and an Anomaly Detection Module modeling to detect the novel attacks. And it utilizes the off-line generated models in order to detect the DDoS attack using the real-time traffic. We gathered the NetFlow data generated at an access router of our network in order to model the real network traffic and test it. The NetFlow provides the useful flow-based statistical information without tremendous preprocessing. Also, we mounted the well-known DDoS attack tools to gather the attack traffic. And then, our experimental results show that our approach can provide the outstanding performance against existing attacks, and provide the possibility of detection against the novel attack.

• Applied Biological Chemistry
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• v.6
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• pp.15-24
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• 1965

The mackerels, Scomber japonicus (HOUTTYN), for this study were caught by purse sein net in Korea. In this paper, the seasonal variations of the oil content and Vitamin A concentration in oil in different parts of the mackerel, the distribution of the Vitamin A of viscera of that and physical and chemical constants of oil were discussed. The results are summarized as follows: 1. In the beginning of June, the liver weight increased rapidly and reached the maximum. In this period, the gonad weight was also maximum. It seemed that this phenomenon has influenced on the nutritional and physiological aspects of the spawning stage. 2. The Vitamin A concentration of liver oil reached the maximum value in the middle of July. In the most case, it was proportinate to the oil content in liver inversely. 3. The Vitamin A concentration of pyloric caeca oil reached the maximum Value in the late of July. It showed the tendency of being proportionate to the oil content in pyloric caeca inversely. And the Vitamin A concentration of intestine oil reached maximum value in the beginning of July. 4. The distribution average ratio of Vitamin A in liver, pyloric caeca, intestine, stomach and contents of stomach and gonad to the total Vitamin A in whole viscera were 60.8, 29.4, 5.7, 2.2, and 1.9 percentage. The seasonal variation of the distribution of Vitamin A in pyloric caeca to the amount of total Vitamin A in whole viscera was proportionate to that of liver inversely. 5. It seemed that there were no any corelation between the Vitamin A content and seasonal variation of the physical and chemical constants of viscera oil. But when the Vitamin A concentration was high, the refractive index, the amount of unsaponifiable matter and iodine value of viscera oil were also high. 6. On the extracting vitamin oil of viscera of mackerel, it is the most suitable period from the end of May to the middle of October. The liver, pyloric caeca and intestine of mackerel are valuable and the other parts of vicera are worthless as vitamin oil resources. It is probable that the whole viscera oil could also be utilized as vitamin-rich oil, if it were concentrated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.125-130
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• 2008

This study analyzed the growth, seed quality, and yield of major early-maturing soybean cultivars by comparing them in order to utilize the research results in the selection of early-maturing soybean cultivars in multi-cropping farms in the Southern area. This field trial was conducted at Naju region (latitude $35^{\circ}04'N$, longitude $126^{\circ}54'E$), Jeonnam, with planting on June 15. The maturing date for Keunol-kong and Hwaseong-put-kong was found to be around September 12, which was earlier than other cultivars. Thus, there were advantages to introducing a cropping system as well as having good seed quality and high yield. On the other hand, the maturing date for Saeol-kong and Sinrok-kong was found to be around September 20, which was a little bit late; however, the seed quality of the cultivars was good and they had a high yield. Therefore, if we want to sow the following crops of soybeans around mid-September, Keunol-kong and Hwaseong-put-kong are advantageous, while for the seeding around late September, Saeol-kong and Sinrok-kong would be good. This study was also performed to identify the limitation time for early harvesting by reviewing seed quality and yield of major early-maturing soybean cultivars according to early harvesting. When harvesting Keunol-kong on September 6, which was six days earlier than the optimal harvesting time (September 12), there was no difference in seed weight, yield, or seed quality than those of the harvested at the optimum maturing time. As for Saeol-kong, when harvesting on September 18, which was six days earlier than the optimal harvesting time (September 24), there was no difference in seed weight, yield, or seed quality than those of the harvested at the optimum maturing time. Therefore, the stable limitation time for early harvesting of Keunol-kong and Saeol-kong was concluded to be six days earlier than the optimal harvesting time.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.207-216
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• 2004

This study was carried out to select the promising forage crops for forage production in paddy field of NLRI, RDA, Suwon from 1999 to 2001. The species of forage crop used in this experiment were barley(3 varieties), wheat(2), rye(3) and Italian ryegrass(IRG, 3). Stages of heading, milk and yellow ripe of barley were 1 May, middle May and late May, respectively. In milk to yellow ripe stage, dry matter(DM) and total digestible nutrient(TDN) yield of barley were $7.30{\sim}9.58$ MT and $4.75{\sim}6.24$ MT per ha, and Albori was the most promising variety among the barley. The growth of wheat was a little late compared to that of barley. but it seemed to be crop having higher forage yield and nutritive value. In milk to yellow stage, DM and TDN yield of wheat were $8.17{\sim}10.82$ MT and $5.33{\sim}7.31$ MT per ha. Heading stage of rye was 27 to 29 April, and it seemed to be suitable for harvest at heading to flowering stage because of heavy lodging after flowering. In flowering stage, DM and TDN yield of rye were 10.18 and 6.03 MT per ha. Heading stage of early maturing IRG was 7 May and it seemed to be good for harvest at flowering stage of middle May in cropping system. In flowering stage, DM and TDN yield of early type IRG were 4.48 and 2.96 MT per ha. The results demonstrated that the promising forage crops for forage production in paddy. field were rye and barley(Albori) in Middle region, and rye harvesting at early May was recommended when considered middle May of rice transplanting period, and rye and barley considered late May of rice planting period. Also early maturing and high yielding IRG variety was strongly needed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.245-252
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• 2004

Experiment was carried out to find the fertilizing effects of 8 different application rates of swine compost fermented with sawdust(SCS) including Chemical fertilizer(CF) on forage yield and soil chemical characteristics of mixed pastures sown in Sep. 1993 at National Livestock Research Institute, RDA., in Suwon during low years. It was arranged in a randomized complete block design with three replicates. Dry matter yield were shown at similar among treatments except Control and $50\%$ SCS of standard amount plot. In botanical composition, the legume and weeds percentages of each treatment were increased as advancing year. The final year's legume percentage were high in line with SCS fertilizing plots($39\%{\sim}43\%$), SCS + CF plots($30\%{\sim}41\%$) and CF plot($32\%$). In productions of TDN, NE and crude protein yield, SCS or SCS($75\%$) + CF($25\%$) were nearly same comparing those of CF, respectively. Phosphate, potassium, magnesium contents and K/(Ca + Mg) except calcium contents of those SCS fertilizing plots in plant were generally high with comparing CF. Those contents were proportional according to the fertilizing amount These result indicate the possibility to substitute chemical fertilizer for SCS($75\%$, 25ton/ha) + CF, $25\%$) as manure-N 210 kg/ha, but might be considered accumulation phosphate in the soil.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.203-213
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• 1985

The in situ posture of anterior body of Metagonimus yokogawai was observed in experimental metagonimiasis of dog. The metacercariae were collected from naturally infected sweetfish by peptic digestion; a total of 8 dogs was orally infected with 10,000 metacercariae respectively. Two dogs were killed on 3 days, 9 days, 4 weeks and 10 weeks after the infection. The postures of worms in histological section of small intestine and of whole worms collected from the fixed intestinal mucosa were examined by light and scanning electron microscope. The results were summarized as follows: 1. The recovery rates of worms were 42.6% on 3 days, 55.0% on 9 days, 33.2% on 4 weeks and 9. 8% on 10 weeks after the infection respectively. 2. In histological sections of small intestine, most of worms were found at intervillous spaces as ovoid sections of posterior body. However, many worms, especially in 3 day-old worms, revealed protruded anterior body in glandular lumens of crypt. Some sections of anterior body were bifurcated or sacculated. 3. The worms collected from fixed intestinal mucosa under dissecting microscope exhibited a variety of postures. Many worms showed flat shapes with a concavity or curvatures. However, in many worms, the anterior body made a single or multiple protrusions. 4. By SEM observation of protruded anterior body, a longitudinal groove was found. 5. The frequency of worms with protruded anterior body decreased in 9 days, 4 weeks and 10 weeks than in 3 day-old worms. The above findings indicated that the anterior body of juvenile and adult M. yokogawai protruded to lumens of glandular crypt by folding their lateral portions to make a reversible tubelike structure. Frequent multiple protrusions were considered to be made to adapt the microniche of glandular crypts of dog intestine.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.185-198
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• 2016

Korea has put in significant efforts to increase the number of wildlife crossings between fragmented habitats to prevent loss of biodiversity and to encourage the habitat connectivity in Korea. However, there is a lack of biological data on the effect of vegetation structure in these wildlife crossings and guidelines for design and management of wildlife crossing structures in Korea. Therefore, we selected ground beetle assemblages as model organisms to compare the effect of vegetation structure in wildlife crossings, i.e. bare ground- and shrub-type corridors, in agro-forested landscapes. For this study, 4,207 ground beetles belonging to 33 species were collected through pitfall trapping along the northern forest-corridor-southern forest transects from late April to early September in 2015. Dominant species, abundance, and species richness of ground beetles were significantly higher in the shrub-type corridors than the bare ground-type corridors. Also, the species composition of bare ground-type corridor was significantly different compared to the other habitats such as shrub-type corridor and forests. Similarly, environmental variables were also influenced by vegetation management regimes or trap locations. Collectively, our study clearly indicates that the movement of forest associated ground beetles between forest patches can increase as the vegetation in wildlife crossings becomes complex. Although further studies are needed to verify this, there are indications that the current wildlife crossings that comply with the guidelines may be unfriendly to the movement of ground dwelling arthropods as well as ground beetles. To enhance the ecological function of wildlife crossings, the guidelines need to be rectified as follows: 1) Shrubs or trees should be planted along the corridor verges to provide refuge or movement paths for small mammals and ground dwelling arthropods, and 2) Open spaces should be provided in the middle of the corridors to be used as a path for the movement of large mammals.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.196-206
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• 2012

Studies of seasonal changes in $C_3/C_4$ mixed communities are rare, particularly in Asian summer monsoon climate zones. In our present study, seasonal changes in the profile and coverage of $C_3$ and $C_4$ plants were investigated in 2009 in Haenam, Yeongdong and Cheorwon regions of South Korea (all at different latitudes). The aim was to estimate the impacts of temperature and sunshine duration on species composition and transition timing of the $C_3$ and $C_4$ plants. From our results, the number of $C_3$ plants was found to increase from early spring to mid-May, and then decrease again until September in the Haenam and Yeongdong regions, but continuously increase from early spring to September in the Cheorwon region under relatively low summer temperatures. On the other hand, the number of $C_4$ plants increased from June or July to September in all three regions. These seasonal changes in species number and ratio have a direct impact upon species diversity which is highest when there are no dominant species. The relative coverage and relative summed dominance ratio (SDR') of the $C_3$ plants decreased from spring to autumn, but increased for the $C_4$ plants during this time in an exponential fashion with increasing accumulated temperature and sunshine duration. The transition timing from $C_3$ to $C_4$ plants occurred when the sum of sunshine duration for the days with daily mean temperature above $5^{\circ}C$ was 1017 hrs for the SDR'.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.222-224
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• 1975

Three strains of common carp, i. e. , Israeli carp, red-and-white, and golden strains, were stocked in the same pond, and their growth rates were compared with following results: From August 12 to November 21 in 1975, fingerlings of the three strains of common carp, Cyprinus carpo, each weighing about 0.5 g with total length of 2 to 3 cm, were stocked. The pond had an area of $316m^2$ with a mean water depth of 55cm, and the bottom was covered with a 20 to 30 cm thick layer of silt containing a considerable amount of decaying organic materials. Feed given was prepared with equal amounts of fish meal and polished barley, of which, in addition, $10\%$ green grass and $1\%$ table salt were mixed together when prepared into paste feed using a chopper after boiling the barley. Total protein content of the feed was $34.9\%$ in dry state with $5\%$ moisture content. Total feed given was 30.08 kg calculated in dry state to produce 20.588 kg of the common carp fingerlings, thus the feed coefficient being 1.51. By strains, the harvested Israeli carp ranged 98 to 311g each with a mean weight of $172.69g(100\%)$, red-and-white strain 15 to 318g with mean of $104.1g(60.3\%)$, and the golden strain 30 to 268g with mean of $128.7g(74.6\%)$. During the rearing season mean water temperature was $23.9^{\circ}C$ and the assumed main growth period with the water temperature above $15^{\circ}C$ was, upto the end of October, for 80 days with a mean water temperature of $23.9^{\circ}C$. Taking this main growth period as the basis for growth rate analysis, the mean daily increments, expressed as the attained body weight in times of the starting weight, become 1.075786 times (or the Israeli strain, 1.06901 times for the red-and-white strain, and 1.07185 times for the golden strain.

• Journal of Korean Society of Forest Science
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• v.23 no.1
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• pp.1-8
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• 1974

The seed quality testing for Korean white pine (Pinus koraiensis), their pre-germination and embryo growing process were investigated and the abnormal embryo groups were discriminated by the use of soft X-ray photograph. The study results were as follows ; 1. The embryo reflection was clearly observed for air dried seeds (moisture content was 6.3%) at 30 sec, stratificated seeds at 60 sec (moisture content 24.0-36.0%) and immature seed (moisture content 41.0-64.0%) at 90sec., then the photographing variation for soft X-ray was the radiographing distance at 42cm focus M, voltage 19.5 K.V.P. and Ampere 8 mA. By the above result, the radiographing time for discriminating the embryo reflection was increased by the increase of moisture content in the seeds. 2. The embryo reflection could be clearly observed from the last ten days of June and the embryo length ratio to endosperm length was growing to 65% at the first ten days of September. By the result obtained the soft X-ray photograph was thought to be effective method for the study of inner morphology of seeds. 3. The clear reflection seeds for embryo and endorsperm were observed to 69.7% and the seeds were practically germinated to 75.2% The difference in number between the discriminated seeds by the soft X-ray photograph and the practically germinated seeds was only 6%. According to this results, the soft X-ray photograph was thought to be a effective methods for the germination diagnosis in the shortest time and with the exactness comparatively. 4. Because of the possibility of clearness for observation of pre-germination process, the soft X-ray photograph could be used for the study on the physiology of seed germination. 5. The frequency of abnormal embryos was observed of total 4.4% and their types and subtypes could be classified into twenty groups. Among these groups, single abnormal embryo type was divided into eight subtypes and observed of 2.0 percent, twin embryo was six subtypes and 1.8 percent, triple embryo was five subtypes and 0.5 percent, and inverse type was 0.12 percent.