• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.244-250
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• 1983

This study was carried out to analyst the damage due to the brown planthopper, Nilapalvata lugens Stal, at different stages(maximum tillering, booting, heading, and milking) of rice. The results are as follows: The population density of the migrating and the first generations of the brown planthoppers seemed not to be large enough to cause significant effects on the plant height and the number of tillers, while the second and the third generations caused significant reduction in 1000 grain weight(Yl) and the filled grain percentage$(Y_2)$. They were very closely related to the population density(X) of tile second generation of the BPH; $$Y1(g)=25.602-0.0213X(r=-0.5205^{**})$$ $$Y2(\%)=76.97-0.1370X(r=-0.4820^{**})$$ The relationship between rice yield (Yg) and the accumulated total density (X) of BPH per hill by the time of harvest; $$Y(g)=24.694-0.0576X(r=-0.6959^{**})$$ Since the source of the outbreak BPH is the first generation, it nay conclude that the detailed information on the population status of the first generation; density, age components, ratio of the brachypterous form, are very important in relation to management of the pest.

• Korean journal of applied entomology
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• v.5_6
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• pp.19-26
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• 1968

Results obtained from the observation of 1,000 matured resting conidia of Pyricularia oryzae CAV. were as fellows. The percentage of a condium conitaining was 95.5, while that of a multinucleate conidium was 4.5. Formation of the three-celled mature conidium containing a nucleus in each cell, which was derived from the immatured conidium, could be recognized. Chromosomes could be observed in the conidium when the nuclear division took place. The number of chromosomes was n=3, 4, 5 or 6 but rile majority was 5. The nucleus was moved into the germ-tube from the conidium by following ways: (a) a resting nucleus divided into two nuclei in the conidium and one of them was moved into the germ-tube. The other nucleus remained in the conidium (43 per cent): (b) a nucleus was moved into the germ-tube from the conidium without nuclear division (57 Per cent). The appressorium without a nucleus was abundantly observed when stain was made. However, tile number of a mononucleate appressorium was 476 out of 500 appressoria which had nuclear sap. On the ground of this experiment, we could support the conidium of blast fungus contained mononucleus and also homokaryon seemed to b: appealed on the conidia even though those were multilocular. As the results, it could be concluded that use of inoculum derived from single spore isolate was reasonable for any experiments in the rice blast fungus.

• Korean journal of applied entomology
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• v.5_6
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• pp.27-32
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• 1968

The larval instar of Scintillatrix djingischani OBENBERGER WES determined by measuring the head width of the larvae, some of which were bred in the room and the other collected in orchards during four years(1963-1966). Their growth ratio and variation were also studied. 1) The variation curve of the head width of the Iarvae distinctly appeared to be seven (7) curves, which seemed to have lived to be over seven(7) instars after six(6) times of molting. 2) In general, tile larvae live out to be 6-7 instar. Those pupated at 6th instar seem to over winter in tissue from November as matured. And those pupated in late Spring or early Summer after over wintering in canbium seem to be at 7th instar. 3) The standard deviation of the head width tends to grow larger except at 1st and 7th instar, while the coefficient of variation tends to decrease according as the number of instar increases. The growth ratio was found to decrease according as the number of instar increase except at 1 at and 2 nd instar. 4) To the growth of tee larval head width of this insect, Games and Campbell's formula was more applicable than Dyar's. 5) From the activties of larvae it is presumed that those bred in the year over winter in phelloderm or canbium at the 2 nd-3 rd instar, and the matured (2 year old) emerge the next year after over wintering in cambium or tissue at the 5th or 6th instar.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.9
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• pp.73-80
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• 2004

In this paper, we present the cell resequencing buffer to solve the cell sequence integrity problem of the Cyclic banyan network that is a high-performance fault-tolerant cell switch. By offering multiple paths between input ports and output ports, using the deflection self-routing, the Cyclic banyan switch offer high reliability, and it also solves congestion problem for the internal links of the switch. By the way, these multiple paths can be different lengths for each other. Therefore, the cells departing from an identical source port and arriving at an identical destination port can reach to the output port as the order that is different from the order arriving at input port. The proposed cell resequencing buffer is a hardware sliding window mechanism. to solve such cell sequence integrity problem. To calculate the size of sliding window that cause the prime cost of the presented device, we analyzed the distribution of the cell delay through the simulation analyses under traffic load that have a nonuniform address distribution that express tile Property of traffic of the Internet. Through these analyses, we found out that we can make a cell resequencing buffer by which the cell sequence integrity is to be secured, by using a, few of ordinary memory and control logic. The cell resequencing buffer presented in this paper can be used for other multiple paths switching networks.

• Journal of Radiation Protection and Research
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• v.28 no.2
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• pp.109-116
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• 2003

Based on the necessity to evaluate the activation products inventory during decommissioning lot domestic nuclear power plants, a preliminary estimation of the activation products inventory for Kori unit 1, which is getting close to the end of lifetime, was carried out with ANISN and ORIGEN2 code. In order to calculate neutron nux using ANISN code, the reactor was divided into 9 zones from core to bioshield concrete for radial direction. Also :he cross-section of main nuclides were calibrated with neutron flux in the reactor pressure vessel(RPV) region. The results showed that 95 % of tile total radioactivity in RPV from reactor shutdown to 10 years came from the nuclides of $^{55}Fe,\;^{59}Ni,\;^{63}Ni\;and\;^{60}Co$. And the total radioactivity with cooling of more than 50 years after decommissioning was no more than 0.2 % of at the time of shutdown. Considering the weight of RPV is 210 tons, the total radioactivity of RPV reached to $5.25{\times}10^{6}GBq$ at shutdown time. As compared with the total radioactivity of bioshield concrete at reactor shutdown time, the radioactivity after tooling more than 10 years was below 1 %.

• Journal of Radiation Protection and Research
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• v.30 no.1
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• pp.17-25
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• 2005

Since the safety of nuclear power plant has been becoming a big social issue the exposure dose of radiation for workers has been one of the important factors concerning the safety problem. The existing calculation methods of radiation dose used in the planning of radiation work assume that dose rate does not depend on the location within a work space thus the variation of exposure dose by different work path is not considered. In this study, a modified numerical method was presented to estimate the exposure dose during radiation work in radwaste storage considering the effects of the distance between a worker and sources. And a new numerical algorithm was suggested to search the optimal work path minimizing the exposure dose in pre-defined work space with given radiation sources. Finally, a virtual work simulation program was developed to visualize the exposure dose of radiation doting radiation works in radwaste storage and provide the capability of simulation for work planning. As a numerical example, a test radiation work was simulated under given space and two radiation sources, and the suggested optimal work path was compared with three predefined work paths. The optimal work path obtained in the study could reduce the exposure dose for the given test work. Based on the results, tile developed numerical method and simulation program could be useful tools in the planning of radiation work.

• Hwankyungkyoyuk
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• v.19 no.1 s.29
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• pp.1-13
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• 2006

This study was aimed to explore the level of awareness of Korean teachers and college students towards sustainable development(SD) and education for sustainable development(ESD). A survey was conducted to understand the present status of awareness of SD and ESD among 317 college students and 625 teachers in Korea from April to May of 2005. The questionnaire included items asking whether they heard about terms such as sustainability or sustainable development, the source of information on SD, the level of understanding or the urgent task for SD in Korea. It also included questions about experiences in participating in or conducting ESD, the need for ESD, important areas in and the modality for ESD and the willingness to participate in ESD. The results showed that the level of awareness on SD among teachers was low compared to college students, who have a relatively high level of access on SD issues through textbooks and classes in high school. Interestingly, most of college students replied that they never received any ESD, even though they learned SD in class. Both the teacher and student group thought that tile priority of sustainable development should be an 'environment-related' area in the social, economical and environmental perspectives. Most of the students and teachers considered the concept of SD as 'pursuing the balance between environmental protection and economic development.' Some of the teachers recognized the concept of sustainable development in the paradigm of continuous economic development. Both groups responded that the urgent task related to sustainable development is 'environmental protection' and the 'reduction of poverty.' On the other hand, they had experiences in teaching related to natural resources, gender equity, health, human rights, climate changes and other SD issues in class, but not under the name of ESD. They also emphasized 'critical thinking and problem solving & decision-making' in education. Most of the students and teachers responded that it was needed to carry out ESD, and that the way of life for SD would be the priority. It is suggested that various pedagogy and modalities according to various target groups should be considered in providing ESD. It is necessary to use more effective strategies for ESD rather than just introducing the concept of SD. Also, it is needed to review the ESD practices of teachers and improve the quality of education within the scope of ESD.

• Korean Journal of Human Ecology
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• v.3 no.1
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• pp.88-99
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• 2000

This study was perfomed to search for how properties of the starch viscosity appear in different qualities, when acetic acid is added. For this study, corn starch which belongs to A-type. Potato starch to B-type. and sweet potato starch to C-type were chosen as an experimental material. which was added to acetic acid controlled as pH 4.0, 4.5, and 5.0 at the time of before and after heating. After that, the viscosity properties of each starch was analyzed using Amylogram and Brookfield viscometer. As a result. the viscosity was shown high in an order of potato. sweet potato, and corn starch. According to addition of acetic acid. tile viscosity appeared to be low. The viscosity differences of before and after heating when the acid is added were shown as follows : Amylogram shows that the lower the pH is. the lower the viscosity is when the acid is added before-heating. In case the acid is added before-heating, gelatinization temperature, consistency and setback was increased. but breakdown decreased. In case the acid is added after-heating, the viscosity goes down at soon as it is added meanwhile consistency and setback was decreased. but breakdown increased. Such properties of the viscosity show a conspicuous variation in an order of potato. sweet Potato. and corn starch. Brookrield viscometer shows that the lower the apparent viscosity is. the lower pH is at the time of before-heating when the acid is added. In case of after-heating, when the acid is added. the apparent viscosity shows a higher inclination than that of before-heating in corn starch and sweet potato starch.

• Journal of Korea Water Resources Association
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• v.39 no.2 s.163
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• pp.89-98
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• 2006

To evaluate the pipe failure impact, current methodologies consider only a broken pipe as the impacted area. However, these approaches are accurate if the broken pipe is the only area isolated from tile system. Depending on the number and locations of on-off valves, more pipes which are adjacent to a broken pipe may be isolated. Using the concept of Segment suggested by Walski, the methodology evaluating the pipe failure impact incorporated with on-off valve locations has been suggested by Jun. However, a segment cannot account for all possible pipe failure impacted areas since it does not consider additional failures, namely the network topological failure and the hydraulic pressure failure. For this reason, a methodology which can consider the network topology and hydraulic pressure limitation as well as on-off valve locations is suggested. The suggested methodology is applied to a real network to verify its applicability As results, it is found that a single pipe failure can affect huge areas depending on the configuration of on-off valves and the network topology. Thus, the applicability of the suggested methodology for evaluating the pipe failure impacts on a water distribution network is proved.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.542-548
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• 2005

Chemical components and physiological activities Bamboo (Phyllostachys bambusoides Starf) extracts obtained by burning, dry heating or extracting with water or 70% ethanol and were investigated. Contents of soluble solid and total phenolic compounds were highest in the ethanol extract. Contents of polyphenols such as catechin, chlorogenic acid, caffeic acid, 3-hydroxy benzoic acid and ferulic acid were determined. Free sugars consisted of galactose, glucose, fructose, and sucrose. Organic acids including citric, tartaric, malic, succinic, and acetic acid were present in the bamboo extracts. Antioxidant activities of dry heat and ethanol extracts were higher than those of BHA or ${\delta}-tocopherol$. Nitrite- scavenging effect of extracts ranged from 84.7 to 99.6% at pH 1.2 ana 3.0. Tyrosinase-inhibitory activity was higher in the water extract, and SOD-like and ACE-inhibitory activity were highest in tile dry kent extract. Antimicrobial activities of the bamboo extracts were strong against Bacillus subtilis, Escherichia coli O157, and Staphylococcus aureus.