• Title/Summary/Keyword: second-order system

Search Result 3,286, Processing Time 0.033 seconds

Development of Assay Methods for Enterotoxin of Escherichia coli Employing the Hybridoma Technology (잡종세포종기법을 이용한 대장균의 장독소 측정법 개발)

  • Kim, Moon-Kyo;Cho, Myung-Je;Park, Kyung-Hee;Lee, Woo-Kon;Kim, Yoon-Won;Choi, Myung-Sik;Park, Joong-Soo;Cha, Chang-Yong;Chang, Woo-Hyun;Chung, Hong-Keun
    • The Journal of the Korean Society for Microbiology
    • /
    • v.21 no.1
    • /
    • pp.151-161
    • /
    • 1986
  • In order to develop sensitive and sepcific assay methods for E. coli heat labile enterotoxin(LT) hybridoma cell lines secreting LT specific monoclonal antibody were obtained. LT was purified from cell lysate of E. coli O15H11. The steps included disruption of bacteria by French pressure, DEAE Sephacel ion exchange chromatography, Sephadex G200 gel filtration, and second DEAE Sephacel ion exchange chromatography, successively. Spleen cells from Balb/c mice immunized with the purified LT and $HGPRT^{(-)}$ plasmacytomas, $P3{\times}63Ag8.V653$ were mixed and fused by 50% (w/v) PEG. Hybrid cells were grown in 308 wells out of 360 wells, and 13 wells out of them secreted antibodies reacting to LT. Among these hybridoma cell 1G8-1D1 cell line was selected since it had produced high-titered monoclonal antibody continuously. By using culture supernatant and ascites from 1G8-1D1 cells the monoclonal antibody was characterized, and an assay system for detecting enterotoxigenic E. coli was established by double sandwich enzyme-linked immunosorbent assay (ELISA). The following results were obtained. 1. Antibody titers of culture supernatant and ascites from 1G8-1D1 hybridoma cells were 512, and 102, 400, respectively by GM1-ELISA and its immunoglobulin class was IgM. 2. The maximum absorption ratio of 1G8-1D1 cell culture supernatant to LT was 90% at $300\;{\mu}g/ml$ of LT concentration. LT concentration shown at 50% absorption ratio was $103.45{\mu}g$ and the absorption ratio was decreased with tile reduction of LT concentration. This result suggests that monoclonal antibody from 1G8-1D1 hybridoma cell bound with LT specifically. 3. The reactivities of 1G8-1D1 cell culture supernatant to LT and V. cholerae enterotoxin(CT) were 0.886 and 0.142(O.D. at 492nm) measured by the GM1-ELISA, indicating 1G8-1D1 monoclonal antibody reacted specifically with LT but not with CT. 4. The addition of 0.1ml of ascites to 0.6mg and 0.12mg of LT decreased the vascular permeability factor to 41% and 44% respectively, but it did not completely neutralize LT. 5. By double sandwich ELISA using monoclonal antibody, as little as 75ng of the purified LT per ml could be detected. 6. The results by assay of detecting LT in culture supernatants of 14 wild strains E. coli isolated from diarrhea patients by the double sandwich ELISA were almost the same level as those by reverse passive latex agglutination.

  • PDF

The Effect of Creative Problem-Solving Instruction Model on the Creativity and Environment-Awareness in Elementary Practical Arts Environmental Education (초등실과 환경단원의 창의적 문제해결수업이 아동의 창의성 및 환경의식에 미치는 효과)

  • 최청림;정미경
    • Journal of Korean Home Economics Education Association
    • /
    • v.15 no.4
    • /
    • pp.115-132
    • /
    • 2003
  • The purpose of this study is aimed at giving proof that helps the elementary practical arts education system accomplish as the effects are turned out experimentally. Two classes of the sixth grade of J elementary school in Dae-gu have been selected in order to be experimented. One was chosen as an experimental group, the other was done as a comparative group. The creative-problem-solving learning-model was applied to the experimental group, and the traditional way of teaching was applied to the comparative group. For four classes of the sixth grades, ‘chapter 8: Making with recycled materials’ was proceeded as the content. Then. tests about the way of environmental awareness and creativity were carried out twice. After that, the results of pre and after-test in the comparative and experiment groups were compared using the t-test method. Following the analysis of the data collected in this study. the following major observations were obtained: First, children who were educated the creative problem-solving in a practical arts education achieved higher scores than before. Therefore, it turns out that the CPS method is an effective way to improve the environmental awareness in children. It showed that it included lots of daily habits connected with daily life and it made the intention to carry out the environment-preservation stronger and children´s attitude towards the environment improved. Moreover, making with recycled materials was used to solve an environmental problem, affecting in a positive way in our life. It also made the positive recognition about the environment. Second. the application of the creative problem-solving class of the practical arts education can make positive results to children. It helped children to have more interest in the environment around them. Children´s fluency, flexibility and originality in their ideas were improved as much as possible while they were solving problems. Consequently, the application of the creative problem-solving class model of elementary practical arts environmental education lets children expand environment consciousness and creativity.

  • PDF

The Maize with Multiple Ears and Tillers (MET) III. Developmental Habit and Morphology of the Tillers (다얼성 옥수수 연구 III. 분얼발생의 습성 및 형태)

  • Choe, Bong-Bo;Lee, Hee-Bong;Lee, Won-Koo;Kang, Kwon-Kyoo;Jong, Seung-Keun
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.34 no.1
    • /
    • pp.23-29
    • /
    • 1989
  • In order to investigate developmental habit and morphology of maize tillers, time and location of tiller development. number of tillers per plant, tiller angle, height and diameter of tillers and root systems of tillers were examined under field condition for maize with tillers. Materials used were mostly from Korean local lines and a few lines from other countries were also included for comparison. The time of the first tiller development was about 18 to 20 days after emergence when planted on May in Yusong. The second tiller appeared about 4 to 5 days after the first tiller appeared. The tiller number per plant varied with lines and hybrids and ranged from two to ten. The location of tiller development was usually basal nodes of the main stem. Each tiller appeared to have its own root system. The angle between tillers and main stem was variable depending upon the maizes and the tiller angle could be classified into three categories. The height of tillers was also variable and seemed to be under genetic control. The most productive tillers were found among the Korean local derivatives.

  • PDF

A Legislative Study on Cultural HeritageBetween 1945 and 1960 - Focused on the Cultural Heritage Protection Act Legislated in 1962 - (1945~1960년 문화재 관련 입법 과정 고찰 - 1962년 문화재보호법 전사(前史) 관련 -)

  • Kim, Jongsoo
    • Korean Journal of Heritage: History & Science
    • /
    • v.52 no.4
    • /
    • pp.78-103
    • /
    • 2019
  • The Conservation Decree of the Chosun Treasures Historic and Natural Monuments (hereinafter referred to as the Conservation Decree), which was enacted during the Japanese colonial period, was preserved in accordance with the provisions of article No. 100 of the constitutional law. However, legislative attempts were made to replace the Conservation Decree during the US military administration and early Korean Government. The first attempt was about the National Treasures Historic and Natural Monuments which were brought in by the Legislative Assembly of South Chosun (1947) during the US military administration. The second was a bill by the government for preservation of historical interests (1950), which was submitted to the National Assembly on March 15, 1950 (the so-called Preservation Act (1950)). These two bills were amended and supplemented on the basis of the existing contents of the Conservation Decree. Afterwards, from 1952 to 1960, the legislation of the Cultural Heritage Protection Act (1959) and the Cultural Heritage Bill (1960) were subsequently introduced and enacted. The government's attempt to enact such a cultural property bill was aimed at the legislature to replace the preservation order system that had been in effect since the Japanese colonial period. However, due to the political situation at the time, these laws did not reach final legislation. In October 1960, the government enacted the Regulations for the Preservation of Cultural Property, which was an administrative edict that was promulgated and enacted in November. This was the first official cultural property decree introduced by the Korean government. With the enactment and promulgation of the Cultural Heritage Protection Act in January 1962, Korea's judicial cultural property legislation was established, based on the Korean government's unremitting efforts and experience in legislation of cultural property. In that context, the Cultural Heritage Protection Act is a historical product. The Cultural Heritage Protection Act, which was enacted in 1962, is known to emulate or transplant Japan's Cultural Heritage Protection Act (1950). It was not fully recognized that it was an extension of the Korean government's legislative process of cultural property during the period of 1945-1960. Therefore, it is important to examine the legislative process of cultural property from 1945 to 1960 to understand the background of enacting the Cultural Heritage Protection Act in 1962 along with the establishment of the Korean Cultural Property Law.

A Study on the Legislative Conception of Terror of the Advanced European Nations (유럽 선진국의 법제적 테러 개념에 관한 고찰)

  • Kwon, Jeong-Hun;Kim, Tae-Hwan
    • Korean Security Journal
    • /
    • no.15
    • /
    • pp.29-50
    • /
    • 2008
  • Many countries throughout the world have enacted laws on terrorism in the light of the changes that time has brought to them, geographical features, cultural values, and environmental elements. Especially some advanced European nations prescribe the definition of terrorism, the purpose of terrorism, the behavior of terrorism, and the types of crimes related to terrorism and so on for the following reason that it is more vital for the authorities concerned to investigate and punish terrorists after the rise of terrorism. In this regard, this paper analyzes legislative countermoves against terrorists of advanced countries such as France, Germany, and England and through this sheds light on the need of future anti-terrorism bills. The legislative basic guidelines directly to manipulate future terrors based on theories derived from this study could be summarized as follows. In the first place, providing laws on direct investigative power and harsher punishment to those involved in terrorism is a prerequisite for social security and thus the presidential directive of the state anti-terrorism action guidelines just deals with administrative measures without any effective response to terrorism. Hence it is urgent to make anti-terrorism bill concerning investigation and punishment of terrorists. In the second place, it is associated with the objectives of terror. The expression "all sorts of" stated in Korean law is so quite unclear that it can not fulfill the required conditions for naming it "crime". Comprehending provisoes of the crime that meets the purpose of the terrorists is necessary in order to investigate and inflict punishment on them. Therefore, it is advisable to establish specific and precise principles such as political, social, ideological, and religious purpose of terrorists in the bill. In the third place, to meet the flow of times of technicalization, informatization, such provisoes as destruction of electronic data system, crimes related to nuclear materials, purchases of weapons by terrorists, tax administration for prohibition of sale, and arson should be considered in terror bill. In the fourth place, nonselective attack toward unspecified individuals has become a serious issue in our society. Terrorists leave poisonous foods or beverages to crowded place or dump toxic chemicals into river intentionally. Therefore more strict regulations must be included in terror bill to prevent possible terrorist attacks.

  • PDF

Pattern of Pusan Station Shopping District(II) (부산역(釜山驛) 상점가(商店街)의 패턴(II))

  • Kim, Won-Kyung
    • Journal of the Korean association of regional geographers
    • /
    • v.5 no.2
    • /
    • pp.47-117
    • /
    • 1999
  • This study concern with the pattern of Pusan Station shopping district within Pusan City, Korea, one of the special functioned shopping district within Pusan City. This paper will serve as a part of series studies which attempt to clarify the internal structure of Pusan as a whole. Part(II) of this study deals with the functions including living related, restaurants and others. The pattern of floors, size of shops, street corners and widths of streets were also analysed. The results are as follows: 1. In terms of numbers of firms in living related function, Pusan Station shopping district is the $7{\sim}8th$ ranked central place among nine the highest centers within Pusan City. Pusan Station shopping district has not much promoted vertical spatial differentiation comparatively, and also it's intensity of land use is the lower among nine the highest centers. It is presented that intimate relationship between intensity of vertical land use and classes of central places within the city. The ratio of inns and hotels in Pusan Station shopping district is third ranked in Pusan City. And the size of inns and hotels in this area is the most largest among the nine highest ranked central places within Pusan City. These presented that the traditional characteristics of station area as a special functioned shopping district. Inns and hotels mainly located along the narrower and back street. And it forms agglomerated areas or 'an alley of inns' at the inner parts of blocks, some like a 'hidden flower'. In Korea, 'alley' means that an area of specialization gains the prestige, traditionally. 2. Restaurants mainly locate along the narrower and back streets. And agglomerated areas of restaurants coincide with the agglomerated area of drinking places. It shows that these two kinds of functions need the same locational conditions. The ratio of Chinese restaurants is the highest in the Pusan Station shopping district. It's due to the agglomerated area these kinds of restaurants at the 'China town'. 3. Pusan Station shopping district has been formed along the streets within the residential areas. It's means that this shopping district now at the initial or middle growth era in development stage of shopping areas. 4. In general, wholesales and light manufacturing are located at peripheries within shopping district. But in Pusan Station shopping district, it dose not appear these spatial pattern. It shows that this area is lower ranked central place and not much progressed in spatial differentiation. 5. Particular firms which customers and workers have stayed more longer period of time are located at the far from the first floor. This vertical spatial differentiation is similar to the horizontal sequences. 6. Firms which have more ability of rental payment are located at street comers such as banks and pharmacies. In Pusan Station shopping district commercial facilities could not invade into the second third floors at narrower streets and first floor of back streets, still now.

  • PDF

Yongdoseo(龍圖墅) and Guimunwon(龜文園) which Applied a Sangsu(象數) Principle on Garden Composition (상수(象數) 원리를 정원구성에 적용한 용도서(龍圖墅)와 귀문원(龜文園))

  • Hong, Hyoung-Soon
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.30 no.2
    • /
    • pp.119-129
    • /
    • 2012
  • Yongdoseo and Guimunwon are described in "Bokgeo(卜居, fixabode)" of "Sanlimkyengje(山林經濟)" written by Manseon Hong. This record is a unique garden conceptual idea applying the principles of Hetu(河圖) and Luoshu(洛書), fanciful gardens which have not been actually constructed. Here, two garden types were concretely described respectively, however the underlying meaning therein cannot be apprehended without exact understanding about Sangsu studies. Therefore, the purpose of this study is to illuminate the meaning contained in Garden illustration and the historical meaning of landscape therein through considering this text. To achieve the purpose of this study, the writer and the compiler who are the background of this writing and the outline of Sangsu studies were investigated. Also, the principles of Saengsu(生數), Seongsu(成數), Yin Yang(陰陽), Four Bodies(四象), Palgwedo(八卦圖), etc. which are in Hetu and Luoshu were considered. The result of this study went through this research process is summarized as follows. First, Hetu Luoshu are conceptual definitions which wholly abstracted the basic propositions of Sangsu philosophy such as the universe change principle, etc., while Yongdoseo and Guimunwon can be said to be operational definitions which apply those as garden composition principle, enabling to experience the meaning contained therein concretely and explain it in a replicable way. This attempt is a unique example, unprecedented in Chinaas well. Second, as a livingspace, garden was selected as a means to concretize operational definitions about the meaning of Hetu Luoshu, and as the property to reproduce the bearings concept, the location and the number, etc. of Hetu Luoshu, Taegukjeong(太極亭), Shipjagak(十字閣), Dondae(墩臺), well, pond as well as various kinds of trees were used. Third, the main motif of Yongdoseo and Guimunwon is the relation between Apriority(先天) and Posterior(後天), and the relation between Constitution(體) and Use(用) of Hetu and Luoshu respectively. That is, Yongdoseo planted evergreen trees such as Shipjangcheong(十長靑) in order to symbolize the universe creation principle which Hetu stands for, i.e. silent, harmonious, orderly and win-win image. In Guimunwon, flowering trees(花木) and fruit trees(果木) were planted freely to express the change of Posterior which Luoshu stands for, thatis, dynamic, disharmonious, disorderly, incompatible(相剋) and changing image. The effects intended to be attained through such planting were, 'freshness and cheerfulness(淸爽)' of Yongdoseo and 'splendidness' of Guimunwon respectively. Sangsu studies based on Hetu and Luoshu is a unique thinking system to the Orient which came from the accumulated wisdom of several scholars from various schools through a long period since ancient times. Therefore, the concept and the theory thereof are profound and huge, and its viewpoints of interpretation are diverse. It is a limit of this study that more in-depth and various consideration was not performed. As a further research project, more empirical study of Orientalism such as Sangsu studies, etc. inherent in Traditional Garden is necessary.

Numerical Analysis of Unstable Combustion Flows in Normal Injection Supersonic Combustor with a Cavity (공동이 있는 수직 분사 초음속 연소기 내의 불안정 연소유동 해석)

  • Jeong-Yeol Choi;Vigor Yang
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2003.05a
    • /
    • pp.91-93
    • /
    • 2003
  • A comprehensive numerical study is carried out to investigate for the understanding of the flow evolution and flame development in a supersonic combustor with normal injection of ncumally injecting hydrogen in airsupersonic flows. The formulation treats the complete conservation equations of mass, momentum, energy, and species concentration for a multi-component chemically reacting system. For the numerical simulation of supersonic combustion, multi-species Navier-Stokes equations and detailed chemistry of H2-Air is considered. It also accommodates a finite-rate chemical kinetics mechanism of hydrogen-air combustion GRI-Mech. 2.11[1], which consists of nine species and twenty-five reaction steps. Turbulence closure is achieved by means of a k-two-equation model (2). The governing equations are spatially discretized using a finite-volume approach, and temporally integrated by means of a second-order accurate implicit scheme (3-5).The supersonic combustor consists of a flat channel of 10 cm height and a fuel-injection slit of 0.1 cm width located at 10 cm downstream of the inlet. A cavity of 5 cm height and 20 cm width is installed at 15 cm downstream of the injection slit. A total of 936160 grids are used for the main-combustor flow passage, and 159161 grids for the cavity. The grids are clustered in the flow direction near the fuel injector and cavity, as well as in the vertical direction near the bottom wall. The no-slip and adiabatic conditions are assumed throughout the entire wall boundary. As a specific example, the inflow Mach number is assumed to be 3, and the temperature and pressure are 600 K and 0.1 MPa, respectively. Gaseous hydrogen at a temperature of 151.5 K is injected normal to the wall from a choked injector.A series of calculations were carried out by varying the fuel injection pressure from 0.5 to 1.5MPa. This amounts to changing the fuel mass flow rate or the overall equivalence ratio for different operating regimes. Figure 1 shows the instantaneous temperature fields in the supersonic combustor at four different conditions. The dark blue region represents the hot burned gases. At the fuel injection pressure of 0.5 MPa, the flame is stably anchored, but the flow field exhibits a high-amplitude oscillation. At the fuel injection pressure of 1.0 MPa, the Mach reflection occurs ahead of the injector. The interaction between the incoming air and the injection flow becomes much more complex, and the fuel/air mixing is strongly enhanced. The Mach reflection oscillates and results in a strong fluctuation in the combustor wall pressure. At the fuel injection pressure of 1.5MPa, the flow inside the combustor becomes nearly choked and the Mach reflection is displaced forward. The leading shock wave moves slowly toward the inlet, and eventually causes the combustor-upstart due to the thermal choking. The cavity appears to play a secondary role in driving the flow unsteadiness, in spite of its influence on the fuel/air mixing and flame evolution. Further investigation is necessary on this issue. The present study features detailed resolution of the flow and flame dynamics in the combustor, which was not typically available in most of the previous works. In particular, the oscillatory flow characteristics are captured at a scale sufficient to identify the underlying physical mechanisms. Much of the flow unsteadiness is not related to the cavity, but rather to the intrinsic unsteadiness in the flowfield, as also shown experimentally by Ben-Yakar et al. [6], The interactions between the unsteady flow and flame evolution may cause a large excursion of flow oscillation. The work appears to be the first of its kind in the numerical study of combustion oscillations in a supersonic combustor, although a similar phenomenon was previously reported experimentally. A more comprehensive discussion will be given in the final paper presented at the colloquium.

  • PDF

A Study on contents related to geography in "Myriad Things"(萬物門) of $Miscellaneous$ $Explanations$ $of$ $Seongho$(星湖僿說) (성호사설 '만물문(萬物門)'의 지리 관련내용 고찰)

  • Sohn, Yong-Taek
    • Journal of the Korean Geographical Society
    • /
    • v.47 no.1
    • /
    • pp.60-78
    • /
    • 2012
  • The main objective of this study is to conduct subnational population projections of Korea based on a Myriad Things" (萬物門), which is part of Seongho's representative work entitled $Miscellaneous$ $Explanations$ $of$ $Seongho$ (星湖僿說), has been in this paper in order to understand Seongho's "thinking on geography". To do so, contents related to geography were selected and these were discussed and interpreted in terms of the classification system of today's geographical knowledge. Following is the result of this research. First, information on astronomical geography and natural geography such as uplift, tornado, structure of soil, and the $yut$ board as well as humangeographical topics such as wild $ginseng$, cigarettes, hot pepper, traditional fruits and nuts (chestnuts, jujubes, and persimmons), Goryeo paper (Korean paper), mulberry trees, cotton plants, natural dye, policy about horses, magnetic compass needles, and farming implements for rice transplantation are mentioned in "Myriad Things" in relation to geography. Second, the depth of information described varies from topic to topic, but the topics on tornado and magnetic compass needles, horses, wild ginseng, traditional fruits and nuts, and $yut$ board are described in depth and in detail. Third, authenticity of the contents on these topics are "true" insofar as bibliographical information and citations are provided for support. Fourth, these topics reflect the interests and circumstances that are related to the "economic improvement of common people's livelihood" in those days, such as agriculture, crops, and transportation of goods. Fifth, the bibliography and citations explaining all instances reveal that China (Qing) is a great civilization of the advanced world and that the scholarship of Joseon relied on and accepted it. Sixth, except for horse raising and management, farming implements for rice transplantation, sericulture, and natural dying of cloth, most of the topics are useful even today. In short, theres is a profound aspect to the content that makes it possible to estimate the "geographical thinking". In general, the focus of the content of this book directly linked to the practical agricultural economy of the common people.

  • PDF

A Study on Stage of Concern, Level of Use, Innovation Configuration, and Intervention demand of Teachers in Culinary Practice Education (조리실습 교육에 대한 교사의 관심도, 실행 수준, 실행 형태 및 지원 요구도 조사)

  • Park Eun-Sook;Kim Young-Nam
    • Journal of Korean Home Economics Education Association
    • /
    • v.18 no.3 s.41
    • /
    • pp.41-60
    • /
    • 2006
  • The system of teaching culinary practice needs drastic modification to catch up with dietary life and education curriculum changes. To reflect such changes, it is necessary to instill a strong will and interest as well as educational environment improvement in teachers. In this sense, this study researched the teachers' stages of concerns, levels of use, innovation configuration, and intervention demands, based on the CBAM(Concerns Based Adoption Method) developed by Hord et. al. For the survey, 500 questionnaires sent by mail and 187 were analyzed by SPSS/win 10.0 program. The results are summarized as follows. 1) The teachers stages of concerns on culinary practice is assessed to be in the lowest level of perceptual stage, which indicates a state of indifference. 2) In terms of the levels of use, routine use was the highest, followed by refinement use, integrated use, research use, and reinvent use in descending order. Mechanical use posted the lowest level. Even though the stages of concern showed the beginning stage, the Level of use was relatively high. 3) About the innovation configuration, approximately 30% of the teachers were not accomodate the culinary practice referred to the 7th National Education Curriculum. 4) According to the intervention demands on culinary practice education, it was found that teachers generally wanted more interventions in every component. Among the intervention components, the highest demand was on the support for facility. Demand on the financing is the second highest. Teachers in the level of routine use demanded more information and materials supply and individual encouragement, but teachers in the level of preparation needed study opportunity for training on operation skills more.

  • PDF