• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.39-46
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• 2015

A outdoor termination installed at the outdoor substation is required to connect undergroud cables and overhead transmission lines. The joint box for AC transmission system is already developed and widely used to interconnect overhead and undergroud systems. But the development of the joint box for DC transmission system was only introduced from China and Japan, but theire developemnt staus and core technologies were not fully reported. In order to implement HVDC systems connecting ovehead transmission lines and undergroud cables, a outdoor termination should be developed, but the detailed specifications and information of this device were not reported. It is estimated that the development of the joint box for DC environment has some technical obstacles including insulating materials, electric field mitigation, thermal temperature rise, and space charge accumuations. Among this, the most important one is the DC elctrical insualtion design. Therefore, in order to investigate the DC elctrical insualton design of outdoor termination, the design of AC slip-on type outdoor termination is reffered, and DC electric field analysis performed to verify the possiblity of application of AC joint box into DC joint box. Especially for DC electric field analysis, temperature rise of insualting materials of a joint box was considered, because the conductivity of materials could be changed due to temperature rise. Furthermore, DC electric field analysis considering transinet state, and polarity reversal state were also investigated to verify which state is the most severe condition for the DC joint box. From the simualtion resulsts, it was shown that the value and the position of maximum electric field was obtained comparing AC state, DC state without temperaure rise, and DC state with temperaure rise. And it was confimred that severe DC electric field was observed considing temperaure rise. Finally, in order to reduce DC eletric field intensifation, different configuration of the joint box was applied and it was not possible to obtain satisfactory results. It means that the slight change of configuration of AC joint box was not the suitable soluton for DC joint box. It is essential to establish novel DC insulaton design skills and method for DC joint box to commercialze this product in the near future.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.11-17
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• 2003

As a pan of a study on effective use of seafood processing by-products, such as cuttle bone as a calcium source, we examined on the kind of organic acid (acetic acid and lactic acid), reaction concentration (mole ratio of calcium to mole of organic acid), reaction temperature $(20\~60^{\circ}C)$ and reaction time (6$\~$24 hours) as reaction conditions for the solubility improvement of cuttle bone powder. The high soluble cuttle bone powder was also prepared from the optimal reaction conditions and partially characterized. From the results on examination of reaction conditions, the high soluble cuttle bone powder was prepared with 0.4 in mole ratio of a calcium to mole of a acetic acid at room temperature for 12 hours, Judging from the patterns of IR and X-ray diffraction, the main component of the high soluble cuttle bone powder was presented as a form of calcium acetate, and a scanning electron micrograph showed an irregular form. The soluble calcium content in the high soluble cuttle bone powder was $5.3\%$ and it was improved about 1,380 times compared to a raw cuttle bone powder. For the effective use of the high soluble cuttle bone powder as a material for a functional improvement in processing, it should be used after the calcium treatment at room temperature for about 1 hour in tap water or distilled water. from these results, we concluded that it is possible to use the high soluble cut시e bone powder as a material for a functional improvement in processing.

• (The)Study of the Eastern Classic
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• no.37
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• pp.377-410
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• 2009

In the East Asian Confucianism society, Hakmun was aimed to bring human beings and nature into harmony, and to explore a unity between knowledge and conducts. For example, Neo-Confucianism aspired they could explain the human existence and society through a single concept of Iki(理氣, the basic principles and the atmospheric force of nature). In this philosophy, humanics and natural sciences had not been differentiated at all. The East-West cultural interchanges at the beginning of modernity caused a crack in the traditional academic concepts. Through the Hundred Days of Reform(變法自疆運動, a movement of Strenuous Efforts through Reforming the Law), the Western Affairs Movement(洋務運動) in China, Meiji Restoration(明治維新) in Japan, or Innovation Movements(開化運動) and the Patriotic Enlightenment Movement(愛國啓蒙運動) in Korea, the traditional meanings of Hakmun was degraded while it became a target of the criticism of the enlightenment movements. Accordingly, East Asians' perception of Hakmun rapidly began to change. Although there had been the Silhak(實學, practical science) movement in Korea, which tried to differentiate its conceptualization of Hakmun from that of Neo-Confucianism during the 18th and 19th century, the fundamental shift in meaning occurred with the influx of the modern Western culture. This change converted the ultimate objective of Hakmun as well as its methods and substances. The separation of humanics and natural sciences, rise in dignity of the technological sciences, and subdivision of learning into disciplines and their specialization were accelerated during the Korean enlightenment period. The inflow of the modern western science, humanized thought, and empiricism functioned as mediators in these phase and they caused an irreversible crack in the traditional academic thoughts. Confronting the western mode of knowledge, however, the East Asian intellectuals had to explain their new learning by using traditional terms and concepts; modification was unavoidable when they tried to explain the newly imported knowledge and concepts. This presentation focuses on the traditional concepts of 'gyeogchi'(格致, extending knowledge by investigating things) and 'gungni'(窮理, investigation of principles), pervasively used in philosophy, physics and many other fields of study. These concepts will mark the key point with which to trace changes of knowledge and to understand the way how the concept of Hakmun was converted into a modern one.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.104-115
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• 1992

The rice culture techniques included 'Jodosukyungbeob'(旱稻水耕法 : culture techniques of early-ripening paddy rice), 'Mandosukyungbeob' (晩稻水耕法) : culture techniques of late-Ripening paddy rice 'Handobeob'(旱稻＆lt;山稻＆gt;法 : culture techniques of upland rice), 'Myojongbeob'(苗種法 : culture techniques of paddy rice by transplanting), 'Kunangbeob'(乾秧法 : culture techniques of rice by transplanting which rears seeding in dry paddy) and 'Sudogunpanongbeob'(水稻乾播農法 : culture techniques of paddy rice seeding in dry field). Especially, 'Kunangbeob' and 'Sudogunpanongbeob' were originally developed in Korea as seen in 1600s(Kyoungje : 經濟) and early 1800s (Yoji : 要旨). In 'Jodosukyungbeob' it took 9 days for seed dipping, water-sprouting and prevent damage by birds, each for 3 days in China, but in Korea seed dipping in water took 3 days and the rest of the procedures were flexibly established. In matured soils, practices were fall plowing right after harvest, recognition of effective tillering and additional fertilization use of human manure, and stimulation of sprouting by lime application. The unique culture techniques adequate for Korean situations were practiced, which included weed control after draining accurately for 3 to 4 times, draining at mid season for improving wind and drought tolerance, rice harvesting at appropriate time for preventing grain shattering, and seeding in rows. 'Mandosukyungbeob' was improved techniques contrast to those of China, and the major contents were selection of proper varieties, good stand establishment by seeding high rates, induction of vigorous tillers, and adoption of 'Jokjongbeob'(足種法 : seeding method by foot). Also, one of the most prominent rice cultures by our ancestors was 'Kunpanongbeob' that was systemized form habitual practice of Pyongan Province. The unique technique actualized was 'Hando [旱稻(山稻)]' culture technique which was the combinations of 'Jokjongbeob', root stimulation method, and disaster-tolerant mixture cropping with adoptation of variety theory, although it was originated from China. The transplanting techniques has come before 'Jikseol'($\ulcorner$直說$\lrcorner$) and its merits were sufficiently realized. However, this method was basically prohibited from the early Chosun dynasty because extremely bad harvest was expected under drought conditions and insufficient conditions of water storage. But, it was permitted in the areas that contained water all the times and in case of large-scale farming especially. Most of rice culture was transplanted in the end of the Chosun dynasty because transplanting was continuously spreaded in the three southern provinces of Korea. Under these circumstances, transplanting technique was improved from the early to the end of the Chosun dynasty by weed control, fertilizing, water management, and quadratic transplanting. Based on these techniques, agricultural productivity was improved 5 times by that time. 'Kunpanongbeob' was created and developed properly for Korean conditions that is dry in early season and flooding in late season. This was successively developed and established into transplanting technique of nursery seedling.

• Journal of Agricultural Extension & Community Development
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• v.7 no.1
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• pp.155-166
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• 2000

When the marcher visited Korea in fall 1994, he was shocked to see high rise apartment buildings around the capitol region including Seoul and Suwon, resulting from rising demand of housing because of urban migration followed by second and third industrial development. After 6 years in March 2000, the researcher witnessed more apartment buildings and vinyl house complexes, one of the evidences of continued economic progress in Korea. Korea had to receive the rescue finance from International Monetary Fund (IMF) because of financial crisis in 1997. However, the sign of recovery was seen in a year, and the growth rate of Gross Domestic Products (GDP) in 1999 recorded as high as 10.7 percent. During this period, the Korean government has been working on restructuring of banks, enterprises, labour and public sectors. The major directions of government were; localization, reducing administrative manpower, limiting agricultural budgets, privatization of public enterprises, integration of agricultural organization, and easing of various regulations. Thus, the power of central government shifted to local government resulting in a power increase for city mayors and county chiefs. Agricultural extension services was one of targets of government restructuring, transferred to local governments from central government. At the same time, the number of extension offices was reduced by 64 percent, extension personnel reduced by 24 percent, and extension budgets reduced. During the process of restructuring, the basic direction of extension services was set by central Rural Development Administration Personnel management, technology development and supports were transferred to provincial Rural Development Administrations, and operational responsibilities transferred to city/county governments. Agricultural extension services at the local levels changed the name to Agricultural Technology Extension Center, established under jurisdiction of city mayor or county chief. The function of technology development works were added, at the same time reducing the number of educators for agriculture and rural life. As a result of observations of rural areas and agricultural extension services at various levels, functional responsibilities of extension were not well recognized throughout the central, provincial, and local levels. Central agricultural extension services should be more concerned about effective rural development by monitoring provincial and local level extension activities more throughly. At county level extension services, it may be desirable to add a research function to reflect local agricultural technological needs. Sometimes, adding administrative tasks for extension educators may be helpful far farmers. However, tasks such as inspection and investigation should be avoided, since it may hinder the effectiveness of extension educational activities. It appeared that major contents of the agricultural extension service in Korea were focused on saving agricultural materials, developing new agricultural technology, enhancing agricultural export, increasing production and establishing market oriented farming. However these kinds of efforts may lead to non-sustainable agriculture. It would be better to put more emphasis on sustainable agriculture in the future. Agricultural extension methods in Korea may be better classified into two approaches or functions; consultation function for advanced farmers and technology transfer or educational function for small farmers. Advanced farmers were more interested in technology and management information, while small farmers were more concerned about information for farm management directions and timely diffusion of agricultural technology information. Agricultural extension service should put more emphasis on small farmer groups and active participation of farmers in these groups. Providing information and moderate advice in selecting alternatives should be the major activities for consultation for advanced farmers, while problem solving processes may be the major educational function for small farmers. Systems such as internet and e-mail should be utilized for functions of information exchange. These activities may not be an easy task for decreased numbers of extension educators along with increased administrative tasks. It may be difficult to practice a one-to-one approach However group guidance may improve the task to a certain degree.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.2
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• pp.65-74
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• 1972

A local rice variety, Jinheung and newly bred IR667-Suwon 214 were grown in $5m^2$ concret pot with two spacings and two nitrogen levels and their ripening structure and its function were comparatively investigated to elucidate the causes of unusually low ripened grain ratio of IR667 lines. The following differences between two varieties were found. 1. Though IR667 had much lower ripened grain ratio (64%) than Jinheung (85%) grain yield(790 kg/10a) of IR667 was higher than that (760 kg/10a) of Jinheung. 2. Number of ripined grain per net assimiration rate (NAR) at 10 days after heading was a little higher in IR667 (6,490) than in Jinheung (6,360) consiting to lower grain weight ($29.9{\times}10^{-3}g$) in IR667 than $31.2{\times}10^{-3}g$ of Jinheung. But number of total grain per NAR was much higher (10,530) in IR667 than 7,290 of Jinheung indicating that it was the probable cause of low ripened grain ratio of IR667. 3. Extinction coeificient (K) was 0.115 in IR667 and 0.200 in Jinheung, thus IR667 could construct greater ripening structure per unit area. 4. Number of grain per LAI was decreased with increasing LAI at heading and the decreasing rate was similar for both IR667 and Jinheung. 5. Critical leaf area index at which crop growth rata (CGR) is maximum was 6.5 for IR667 and 5.2 for Jinheung. Below 5.2 of LAI net assimilation rate was always higher an Jinheung throughout the growing season. 6. The estimated optimum leaf area index having maximum grain yield was 7.4 for IR667 and 6.2 for Jinheung at 10 days after heading. However, actual leaf area index was 6.2 for IR-667 and 4.7 for Jinheung and these were even below critical leaf area index. 7. The decrease of LAI during ripening period was great in IR667 but photosynthesis per $m^2$ was decreased more rapidly in Jinheung. 8. Net assimilation rate (NAR) decreased with the increase of LAI at any time of ripening period. The decreasing rate of NAR with the increase of LAI was greater in IR667 with ripening. The greater decreasing rate of NAR in IR667 seemed to be attributed to low photosynthetic activity and high respiratory loss due to the requirement of higher optimum temperature of ripening. 9. Grain yield-ripened grain ratio curve showed less contribution of dry matter yield after heading to grain yield in IR667 than in Jinheung due to unfavorable ripening environment(specialy air temperature) indicating that yield of IR667 could most effectively increased through the improvement of ripening environment.

• 한국지구물리탐사학회:학술대회논문집
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• 2002.09a
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• pp.139-162
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• 2002

Since weak zones or geological lineaments are likely to be eroded, weak zones may develop beneath rivers, and a careful evaluation of ground condition is important to construct structures passing through a river. Dc resistivity surveys, however, have seldomly applied to the investigation of water-covered area, possibly because of difficulties in data aquisition and interpretation. The data aquisition having high quality may be the most important factor, and is more difficult than that in land survey, due to the water layer overlying the underground structure to be imaged. Through the numerical modeling and the analysis of case histories, we studied the method of resistivity survey at the water-covered area, starting from the characteristics of measured data, via data acquisition method, to the interpretation method. We unfolded our discussion according to the installed locations of electrodes, ie., floating them on the water surface, and installing at the water bottom, since the methods of data acquisition and interpretation vary depending on the electrode location. Through this study, we could confirm that the dc resistivity method can provide the fairly reasonable subsurface images. It was also shown that installing electrodes at the water bottom can give the subsurface image with much higher resolution than floating them on the water surface. Since the data acquired at the water-covered area have much lower sensitivity to the underground structure than those at the land, and can be contaminated by the higher noise, such as streaming potential, it would be very important to select the acquisition method and electrode array being able to provide the higher signal-to-noise ratio data as well as the high resolving power. The method installing electrodes at the water bottom is suitable to the detailed survey because of much higher resolving power, whereas the method floating them, especially streamer dc resistivity survey, is to the reconnaissance survey owing of very high speed of field work.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.468-478
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• 2004

It is essential in various application areas of data mining and bioinformatics to effectively retrieve the occurrences of interesting patterns from sequence databases. For example, let's consider a network event management system that records the types and timestamp values of events occurred in a specific network component(ex. router). The typical query to find out the temporal casual relationships among the network events is as fellows: 'Find all occurrences of CiscoDCDLinkUp that are fellowed by MLMStatusUP that are subsequently followed by TCPConnectionClose, under the constraint that the interval between the first two events is not larger than 20 seconds, and the interval between the first and third events is not larger than 40 secondsTCPConnectionClose. This paper proposes an indexing method that enables to efficiently answer such a query. Unlike the previous methods that rely on inefficient sequential scan methods or data structures not easily supported by DBMSs, the proposed method uses a multi-dimensional spatial index, which is proven to be efficient both in storage and search, to find the answers quickly without false dismissals. Given a sliding window W, the input to a multi-dimensional spatial index is a n-dimensional vector whose i-th element is the interval between the first event of W and the first occurrence of the event type Ei in W. Here, n is the number of event types that can be occurred in the system of interest. The problem of‘dimensionality curse’may happen when n is large. Therefore, we use the dimension selection or event type grouping to avoid this problem. The experimental results reveal that our proposed technique can be a few orders of magnitude faster than the sequential scan and ISO-Depth index methods.hods.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.5
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• pp.25-33
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• 2011

This work proposes a skinny-type 10b 50MS/s 0.13um CMOS three-step pipeline ADC for CIS applications. Analog circuits for CIS applications commonly employ a high supply voltage to acquire a sufficiently acceptable dynamic range, while digital circuits use a low supply voltage to minimize power consumption. The proposed ADC converts analog signals in a wide-swing range to low voltage-based digital data using both of the two supply voltages. An op-amp sharing technique employed in residue amplifiers properly controls currents depending on the amplification mode of each pipeline stage, optimizes the performance of op-amps, and improves the power efficiency. In three FLASH ADCs, the number of input stages are reduced in half by the interpolation technique while each comparator consists of only a latch with low kick-back noise based on pull-down switches to separate the input nodes and output nodes. Reference circuits achieve a required settling time only with on-chip low-power drivers and digital correction logic has two kinds of level shifter depending on signal-voltage levels to be processed. The prototype ADC in a 0.13um CMOS to support 0.35um thick-gate-oxide transistors demonstrates the measured DNL and INL within 0.42LSB and 1.19LSB, respectively. The ADC shows a maximum SNDR of 55.4dB and a maximum SFDR of 68.7dB at 50MS/s, respectively. The ADC with an active die area of 0.53$mm^2$ consumes 15.6mW at 50MS/s with an analog voltage of 2.0V and two digital voltages of 2.8V ($=D_H$) and 1.2V ($=D_L$).

• The Korean Journal of Pharmacology
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• v.25 no.1
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• pp.53-58
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• 1989

For several years, we investigated the pharmacological action of several substances isolated from Buxus microphylla var koreana Nakai, which had been used as folk remedies of malaria and venereal disease. Cyclobuxine $D(C_{25}H_{42}ON_2)$, a steroidal alkaloid, exerted an antiinflammatory action, hypotensive and bradycardic effects in rats. In the present study, we isolated alkaloid from the acetone-insoluble fraction of the strong bases of this plants. This alkaloid $(C_{25}H_{38}ON_2)$ was identified as a steroidal alkaloid contained a cyclopropane ring by physical and chemical methods. It is a derivative of cyclobuxine D and named cyclobuxine E. We examined the effect of cyclobuxine E on the contractile response induced by acetylcholine and two distinct types of potassium-activated calcium channels in an intestinal smooth muscle of the rat. Cyclobuxine E inhibited significantly the Ach-induced contraction. The isolated longitudinal muscle from the rat duodenum was immersed calcium-depleted potassium depolarizing solution. Ten minutes after, 1.8 mM $CaCl_2$ was added to muscle bath and elicited a biphasic increase in muscle tension. Cyclobuxine E produced an appreciable inhibition of both components of the mechanical response. In addition, Cyclobuxine E introduced at a point when the tonic response had reached its maximum level, caused the muscle to exhibit a rapid loss of tension. Based on these experimental results, we proposed the possibility that the inhibitory action of cyclobuxine E on the isolated rat duodenum may be due to inhibiting the transmembrane fluxes of calcium ion in potassium-activated calcium channels.