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Studies on absorption of ammonium, nitrate-and urea-N by Jinheung and Tongil rice using labelled nitrogen (중질소(重窒素)를 이용(利用)한 진흥(振興)과 통일(統一)벼의 암모니움, 질산(窒酸) 및 요소태(尿素態) 질소(窒素)의 흡수특성(吸收特性) 연구(硏究))

  • Park, Hoon;Seok, Sun Jong
    • Korean Journal of Soil Science and Fertilizer
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    • v.10 no.4
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    • pp.225-233
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    • 1978
  • Uptake and distribution of labelled urea, $NH{_4}^+$, and $NO{_3}^-$ by Tongil and Jinheung rice grown with each nitrogen source until ear formation stage under water culture system were as follows. 1. When the previous nitrogen source was same as one tested the uptake rate ($mg^{15}N/g$ d.w. root 2hrs, at $28^{\circ}C$ light) was great in the order of $NH_4$ >urea> $NO_3$ and higher (especially $NH_4$) in Tongil than in Jinheung. Rate limiting step (slowest) seems to be exist at R (root)${\rightarrow}$LS(leaf sheath) for urea, LS${\rightarrow}$LB(leaf blade) for $NH_4$ and M(medium)${\rightarrow}$R for $NO_3$. The fast step of translocation appeare to be at M${\rightarrow}$R for urea R${\rightarrow}$LS for $NH_4$ and LS${\rightarrow}$LB for $NO_3$. 2. The uptake rate of $NH_4$ by the urea-fed plant increased almost linearly from $18^{\circ}C$ via $28^{\circ}C$ to $38^{\circ}C$ in Tongil ($Q_{10}$=1.21 and 1.32 respectively) while no change in Jinheung ($Q_{10}$=0.99 and 1.00 respectively). It decreased by 12% in Jinheung under dark but uo change in Tongil. 3. The uptake rate of nitrogen source by different source-fed plant was great in the order of $NH_4{\rightarrow}^{15}NO_3$ $NO_3{\rightarrow}^{15}NH_4$, $urea{\rightarrow}^{15}NO_3$ and higher (especially $NH_4{\rightarrow}^{15}NO_3$) in Tongil. In the case of $urea{\rightarrow}^{15}NH_4$ it was same in $NH_4{\rightarrow}^{15}NO_3$ for Tongil and slightly lower than that in $NO_3{\rightarrow}^{15}NH_4$ for Jinheung. It was lower (especially Tongil) in $NH_4{\rightarrow}^{15}NO_3$ than in $NH_4{\rightarrow}^{15}NH_4 $ 4. The uptake rate (in $NH_4{\rightarrow}^{15}NO_3$) was higher during 15 minutes than during 2 hours and always higher in Tongil. 5. $^{15}N$ excess % and content in each part, and uptake rate of root seems to have their own significance relatling with metabolism and translocation respectively. The change of nitrogen nutritional environment and source preference of varieties were discussed in relation to field condition and efficient use of nitrogen fertilizer.

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Open Skies Policy : A Study on the Alliance Performance and International Competition of FFP (항공자유화정책상 상용고객우대제도의 제휴성과와 국제경쟁에 관한 연구)

  • Suh, Myung-Sun;Cho, Ju-Eun
    • The Korean Journal of Air & Space Law and Policy
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    • v.25 no.2
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    • pp.139-162
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    • 2010
  • In terms of the international air transport, the open skies policy implies freedom in the sky or opening the sky. In the normative respect, the open skies policy is a kind of open-door policy which gives various forms of traffic right to other countries, but on the other hand it is a policy of free competition in the international air transport. Since the Airline Deregulation Act of 1978, the United States has signed an open skies agreement with many countries, starting with the Netherlands, so that competitive large airlines can compete in the international air transport market where there exist a lot of business opportunities. South Korea now has an open skies agreement with more than 20 countries. The frequent flyer program (FFP) is part of a broad-based marketing alliance which has been used as an airfare strategy since the U.S. government's airline deregulation. The membership-based program is an incentive plan that provides mileage points to customers for using airline services and rewards customer loyalty in tangible forms based on their accumulated points. In its early stages, the frequent flyer program was focused on marketing efforts to attract customers, but now in the environment of intense competition among airlines, the program is used as an important strategic marketing tool for enhancing business performance. Therefore, airline companies agree that they need to identify customer needs in order to secure loyal customers more effectively. The outcomes from an airline's frequent flyer program can have a variety of effects on international competition. First, the airline can obtain a more dominant position in the air flight market by expanding its air route networks. Second, the availability of flight products for customers can be improved with an increase in flight frequency. Third, the airline can preferentially expand into new markets and thus gain advantages over its competitors. However, there are few empirical studies on the airline frequent flyer program. Accordingly, this study aims to explore the effects of the program on international competition, after reviewing the types of strategic alliance between airlines. Making strategic airline alliances is a worldwide trend resulting from the open skies policy. South Korea also needs to be making open skies agreements more realistic to promote the growth and competition of domestic airlines. The present study is about the performance of the airline frequent flyer program and international competition under the open skies policy. With a sample of five global alliance groups (Star, Oneworld, Wings, Qualiflyer and Skyteam), the study was attempted as an empirical study of the effects that the resource structures and levels of information technology held by airlines in each group have on the type of alliance, and one-way analysis of variance and regression analysis were used to test hypotheses. The findings of this study suggest that both large airline companies and small/medium-size airlines in an alliance group with global networks and organizations are able to achieve high performance and secure international competitiveness. Airline passengers earn mileage points by using non-flight services through an alliance network with hotels, car-rental services, duty-free shops, travel agents and more and show high interests in and preferences for related service benefits. Therefore, Korean airline companies should develop more aggressive marketing programs based on multilateral alliances with other services including hotels, as well as with other airlines.

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Study of Animation 3-Dimensional Motion Picture (애니메이션 입체 영화에 대한 연구)

  • Min, Kyung-Mi
    • Cartoon and Animation Studies
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    • s.9
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    • pp.127-142
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    • 2005
  • Not only in Korea but throughout the entire world millions of people are in contact with images. Images have become a medium through which to transmit anything from simple visualizations of moving images to knowledge and information. The age of the internet has arisen thanks to scientific development, and the internet generation's acquisition of information is continuously becoming faster. The spectators, ufo must choose amongst the excessive amount of available information, are changing along with it just as quickly. The method of visual transmission has changed to match the demands of the fast-changing pace of the new generation. In order to receive an instantaneous selection amongst much information, the primary requisite is attracting one's attention, and then presenting a corresponding feeling of satisfaction. The early stages of film arose from the desire to capture one's actual situation as it realty is. Unsatisfied with the still picture, people developed the motion picture. Research has succeeded in reproducing 3-dimensional images more realistic than the actual image we perceive as a result of the difference in visual perspective of both eyes and their response to rays of light From color film to 3-dimensional pictures, people enjoy the magnificent results of this. All fields within the category of film are continuously studying the human desire to pursue their visual side, namely the pursuit of visual images with a maximum sense of reality. The images that millions of people around the world see now are flat. The screen's depth and optical illusions effectively give a sense of reality while conveying information. However, although the flat screen is able to create a sense of depth using the different visual perspective of each eye for the realization of a cubic effect, there are limitations. Entering the 21s1 century, there is a quickly-arising branch within the field of image media which seeks to overcome these limitations Although 3-dimensional images began in films, entering the latter half of the 20th century, due to development of 3-dimensional images using the mediums of the animation field, cellular phones, advertisement screens, television etc., without restriction is designated as 'image.'. With research having started around 1900 and continuing for over 100 years, we are now able to witness the popularization of 3-dimensional films happening before our very eyes. Within our own country, we can frequently see them at amusement parks and museums. In the future, through the popularization of HDTV etc., there is a good outlook for practical use of 3-dimensional images in televisions with advanced picture qualify as well as in other areas. Together with the international current, research on 3-dimensional films has been activated in Korea and is rising as a main current in the film industry. Within this context, the contents and understanding of 3-dimensional images must keep in step with the pace of technical advancements. In order to accelerate of development of film contents to keep in pace with technical developments, this dissertation presents the techniques and technical aspects of future developments, and shows the need to prepare in advance to make the field grow- and thereby avoid having a lack of experts and being conquered by other nations in the field - rather than only advancing the technical aspects and importing the contents. This dissertation aims to stimulate interest and continual research by progressive-thinking people related to the film industry. Part II looks into the definition and types of 3-dimensional motion pictures, the terminology, the fundamentals of image formation, current market fluctuations, and looks into 3-dimensional techniques which can be borrowed and introduced in 3-dimensional animations. Part III concerns 3-dimensional animated films. It analyzes 3-dimensional production techniques while using the introduction of specific animation techniques in the 2004 production Lee Sun Shin and Nelson - Naval Heroes 3-dimensional animation produced in 2004 by Clay & Puppet Stop-Motion Animation & Computer Graphic. Original Korean title: 해전영웅 이순신과 넬슨. as an example, and it also looks into how current film techniques used in animations can be applied in 3-dimensional films. Additionally, the actual stages of the various fields of 3-dimensional animations are presented. Given the current direction and advancement of 3-dimensional films making use of animations and the possible realization of this field, the author plans to weigh the development of this yet unexploited new market Not looking at the current progress of the field, but rather the direction of the hypothetical types of animation techniques, the author predicts the marketability and possibility of development of each area.

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Experimental Study of Flip-Bucket Type Hydraulic Energy Dissipator on Steep slope Channel (긴구배수로 감세공의 Filp Bucket형 이용연구)

  • 김영배
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.13 no.1
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    • pp.2206-2217
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    • 1971
  • Spillway and discharge channel of reservoirs require the Control of Large volume of water under high pressure. The energies at the downstream end of spillway or discharge channel are tremendous. Therefore, Some means of expending the energy of the high-velocity flow is required to prevent scour of the riverbed, minimize erosion, and prevent undermining structures or dam it self. This may be accomplished by Constructing an energy dissipator at the downstream end of spillway or discharge channel disigned to dissipated the excessive energy and establish safe flow Condition in the outlet channel. There are many types of energy dissipators, stilling basins are the most familar energy dissipator. In the stilling basin, most energies are dissipated by hydraulic jump. stilling basins have some length to cover hydraulic jump length. So stilling basins require much concrete works and high construction cost. Flip bucket type energy dissipators require less construction cost. If the streambed is composed of firm rock and it is certain that the scour will not progress upstream to the extent that the safety of the structure might be endangered, flip backet type energy dissipators are the most recommendable one. Following items are tested and studied with bucket radius, $R=7h_2$,(medium of $4h_2{\geqq}R{\geqq}10h_2$). 1. Allowable upstream channel slop of bucket. 2. Adequate bucket lip angle for good performance of flip bucket. Also followings are reviwed. 1. Scour by jet flow. 2. Negative pressure distribution and air movement below nappe flow. From the test and study, following results were obtained. 1. Upstream channel slope of bucket (S=H/L) should be 0.25<H/L<0.75 for good performance of flip bucket. 2. Adequated lip angle $30^{\circ}{\sim}40^{\circ}$ are more reliable than $20^{\circ}{\sim}30^{\circ}$ for the safety of structures.

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Ecophysiological Interpretations on the Water Relations Parameters of Trees(VII) - Measurement of Water Flow by the Heat Pulse Method in a Larix leptolepis Stand - (수목(樹木)의 수분특성(水分特性)에 관(關)한 생리(生理)·생태학적(生態學的) 해석(解析)(VII) - Heat pulse법(法)에 의한 낙엽송임분(林分)의 수액류속(樹液流速) 계측(計測) -)

  • Han, Sang Sup;Kim, Sun Hee
    • Journal of Korean Society of Forest Science
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    • v.82 no.2
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    • pp.152-165
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    • 1993
  • This is the basic study in order to know the amount of transpirational water loss in a Larix leptorepis stand by a heat pulse method. Especially this study has been measured and discussed the diurnal and seasonal trends of heat pulse velocity by changes of radiation, temperature and humidity, differences of heat pulse velocity by direction and depth in stem, differences of heat pulse velocity by dominant, codominant and suppressed trees, diurnal change of heat pulse velocity by change of leaf water potential, sap flow path way in sapwood by dye penetration and amount of daily and annual transpiration in a tree and stand. The results obtained as follows : 1. Relation between heat pulse velocity(V) and sap flow rate(SFR) was established as a equation of SFR=1.37V($r=0.96^{**}$). 2. The sap flow rate presented in the order of dominant, codominant and suppressed tree, respectively. The daily heat pulse velocity was changed by radiation, temperature and vapor pressure deficit. 3. The heat pulse velocity in individual trees did not differ in early morning and in late night, but had some differed from 12 to 16 hours when radiation was relatively high. 4. The heat pulse velocity and leaf water potential showed similar diurnal variation. 5. The seasonal variation of heat pulse velocity was highest in August, but lowest in October and similar value of heat pulse velocity in the other months. 6. The heat pulse velocity in stem by direction was highest in eastern, but lowest in southern and similar velocity in western and northern. 7. The difference of heat pulse velocity in according to depths was highest in 2.0cm depth, medium in 1.0cm depth, and lowest in 3.0cm depth from surface of stem. 8. The sap flow path way in stem showed spiral ascent turning right pattern in five sample trees, especially showed little spiral ascent turning right in lower part than 3m hight above ground, but very speedy in higher than 3m hight. 9. The amount of sap flow(SF) was presented as a equation of SF=1.37AV and especially SF in dominant tree was larger than in codominant or suppressed tree. 10. The amount of daily transpiration was 30.8ton/ha/day and its composition ratio was 83% at day and 17% at night. 11. The amount of stand transpiration per month was largest in August(1,194ton/ha/month), lowest in May (386ton/ha/month). The amount of stand transpiration per year was 3,983ton/ha/year.

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Determination of optimum fertilizer rates for barley reflecting the effect of soil and climate on the response to NPK fertilizers (기상(氣象) 및 토양조건(土壤條件)으로 본 대맥(大麥)의 NPK 시비적량결정(施肥適量決定))

  • Park, Nae Joung;Lee, Chun Soo;Ryu, In Soo;Park, Chun Sur
    • Korean Journal of Soil Science and Fertilizer
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    • v.7 no.3
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    • pp.177-184
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    • 1974
  • An attempt was made to determine simple and the most reasonable fertilizer recommendation for barley utilizing the present knowledge about the effect of soil and climatic factors on barley response to NPK fertilizer in Korea and establishing the critical contents of available nutrients in soils. The results were summarized as follows. 1. The relationships between relative yields or fertilizers rates for maximum yields from quadratic response curves and contents of organic matter, available $P_2O_5$, exchangeable K in soils were examined. The trend was more prospective with relative yields because of smaller variation than with fertilizer rates. 2. Since the relationship between N relative yields and organic matter contents in soils was almost linear over the practical range, it was difficult to determine the critical content for nitrogen response by quadrant methods. However, 2.6%, country average of organic matter content in upland soils was recommended as the critical point. 3. There showed a trend that average optimum nitrogen rater was higher in heavy texture soils, colder regions. 4. The critical $P_2O_5$ contents in soil were 96 or 118 ppm in two different years, which were very close to the country average, 114 ppm of $P_2O_5$ contents in upland soils. The critical K content in soil was 0.32 me/100g, which was exactly coincident to the country average of exchangeable K in upland soils. 5. According to the contents of avaiiable $P_2O_5$ and exchangeable K, several ranges were established for the purpose of convenience in fertilizer recommendation, that is, very low, Low, Medium, High and very High. 6. More phosphate was recommended in the northern region, clayey soils, and paddy soils, whereas less in the southern region and sandy soils. More potash was recommended in the northern region and sandy soils, whereas less in the southern region and clayey soils. 7. The lower the PH, the more fertilizers were recommended. However, liming was considered to be more effective than increas in amount of fertilizers.

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A THREE-DIMENSIONAL FEM COMPARISON STUDY ABOUT THE FORCE, DISPLACEMENT AND INITIAL STRESS DISTRIBUTION ON THE MAXILLARY FIRST MOLARS BY THE APPLICATION OF VAR10US ASYMMETRIC HEAD-GEAR (비대칭 헤드기어의 적용시 상악제 1 대구치에 나타나는힘과 변위 및 초기 응력분포에 관한 3차원 유한요소법적 연구)

  • Kim, Jong-Soo;Cha, Dyung-Suk;Ju, Jin-Won;Lee, Jin-Woo
    • The korean journal of orthodontics
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    • v.31 no.1 s.84
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    • pp.25-38
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    • 2001
  • The purpose of this study was to compare the force, the displacement and the stress distribution on the maxillary first molars altered by the application of various asymmetric head-gear. For this study, the finite element models of unilateral Cl II maxillary dental arch was made. Also, the finite element models of asymmetric face-bow was made. Three types of asymmetric face-bow were made : each of the right side 15mm, 25mm and 35mm shorter than the left side. We compared the forces, the displacement and the distribution of stress that were generated by application of various asymmetric head-gear, The results were as follows. 1. The total forces that both maxillary first molars received were similar in all groups. But the forces that mesially positioned tooth received were increased as the length of the outer-bow shortened, and the forces that normally positioned tooth received were decreased as the length of the outer-bow shortened. 2. In lateral force comparison, the buccal forces that normally positioned tooth received were increased as the length of the outer-bow shortened, and the buccal fortes that mesially positioned tooth received were decreased as the length of the outer-bow shortened. Though the net lateral force moved to the buccal side of normally positioned tooth as the length of the outer-bow shortened, both maxillary first molars received the buccal force. That showed 'Avchiai Expansion Effect' 3. The distal forces, the extrusion forces and the magnitudes of the crown distal tipping that mesially positioned tooth received were increased as the length of the outer-bow shortened, and the forces that normally positioned tooth received were decreased as the length of the outer-bow was shortened. 4. The magnitude of the distal-in rotation that normally positioned tooth received were increased as the length of the outer-bow was shortened. But, mesially positioned tooth show two different results. For the outer-bow 15mm shortened, mesially positioned tooth showed the distal-in rotation, hut for the outer-bow 25mm and 35mn shortened, mesially positioned tooth showed the distal-out rotation. Thus, the turning point exists between 15mm and 25mm. 5. This study of the initial stress distribution of the periodontal ligament at slightly inferior of the furcation area revealed that the compressive stress in the distobuccal root of the normally positioned tooth moved from the palatal side to the distal side and the buccal side successively as the length of the outer-bow shortened. 6. This study of the initial stress distribution of the periodontal ligament at slightly inferior of the furcation area revealed that the magnitudes of stress were altered but the total stress distributions were not altered in the mesiobuccal root and the palatal root of normally positioned tooth, and also three roots of mesially positioned tooth as the length of the outer-bow shortened.

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Memory Organization for a Fuzzy Controller.

  • Jee, K.D.S.;Poluzzi, R.;Russo, B.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1041-1043
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    • 1993
  • Fuzzy logic based Control Theory has gained much interest in the industrial world, thanks to its ability to formalize and solve in a very natural way many problems that are very difficult to quantify at an analytical level. This paper shows a solution for treating membership function inside hardware circuits. The proposed hardware structure optimizes the memoried size by using particular form of the vectorial representation. The process of memorizing fuzzy sets, i.e. their membership function, has always been one of the more problematic issues for the hardware implementation, due to the quite large memory space that is needed. To simplify such an implementation, it is commonly [1,2,8,9,10,11] used to limit the membership functions either to those having triangular or trapezoidal shape, or pre-definite shape. These kinds of functions are able to cover a large spectrum of applications with a limited usage of memory, since they can be memorized by specifying very few parameters ( ight, base, critical points, etc.). This however results in a loss of computational power due to computation on the medium points. A solution to this problem is obtained by discretizing the universe of discourse U, i.e. by fixing a finite number of points and memorizing the value of the membership functions on such points [3,10,14,15]. Such a solution provides a satisfying computational speed, a very high precision of definitions and gives the users the opportunity to choose membership functions of any shape. However, a significant memory waste can as well be registered. It is indeed possible that for each of the given fuzzy sets many elements of the universe of discourse have a membership value equal to zero. It has also been noticed that almost in all cases common points among fuzzy sets, i.e. points with non null membership values are very few. More specifically, in many applications, for each element u of U, there exists at most three fuzzy sets for which the membership value is ot null [3,5,6,7,12,13]. Our proposal is based on such hypotheses. Moreover, we use a technique that even though it does not restrict the shapes of membership functions, it reduces strongly the computational time for the membership values and optimizes the function memorization. In figure 1 it is represented a term set whose characteristics are common for fuzzy controllers and to which we will refer in the following. The above term set has a universe of discourse with 128 elements (so to have a good resolution), 8 fuzzy sets that describe the term set, 32 levels of discretization for the membership values. Clearly, the number of bits necessary for the given specifications are 5 for 32 truth levels, 3 for 8 membership functions and 7 for 128 levels of resolution. The memory depth is given by the dimension of the universe of the discourse (128 in our case) and it will be represented by the memory rows. The length of a world of memory is defined by: Length = nem (dm(m)+dm(fm) Where: fm is the maximum number of non null values in every element of the universe of the discourse, dm(m) is the dimension of the values of the membership function m, dm(fm) is the dimension of the word to represent the index of the highest membership function. In our case then Length=24. The memory dimension is therefore 128*24 bits. If we had chosen to memorize all values of the membership functions we would have needed to memorize on each memory row the membership value of each element. Fuzzy sets word dimension is 8*5 bits. Therefore, the dimension of the memory would have been 128*40 bits. Coherently with our hypothesis, in fig. 1 each element of universe of the discourse has a non null membership value on at most three fuzzy sets. Focusing on the elements 32,64,96 of the universe of discourse, they will be memorized as follows: The computation of the rule weights is done by comparing those bits that represent the index of the membership function, with the word of the program memor . The output bus of the Program Memory (μCOD), is given as input a comparator (Combinatory Net). If the index is equal to the bus value then one of the non null weight derives from the rule and it is produced as output, otherwise the output is zero (fig. 2). It is clear, that the memory dimension of the antecedent is in this way reduced since only non null values are memorized. Moreover, the time performance of the system is equivalent to the performance of a system using vectorial memorization of all weights. The dimensioning of the word is influenced by some parameters of the input variable. The most important parameter is the maximum number membership functions (nfm) having a non null value in each element of the universe of discourse. From our study in the field of fuzzy system, we see that typically nfm 3 and there are at most 16 membership function. At any rate, such a value can be increased up to the physical dimensional limit of the antecedent memory. A less important role n the optimization process of the word dimension is played by the number of membership functions defined for each linguistic term. The table below shows the request word dimension as a function of such parameters and compares our proposed method with the method of vectorial memorization[10]. Summing up, the characteristics of our method are: Users are not restricted to membership functions with specific shapes. The number of the fuzzy sets and the resolution of the vertical axis have a very small influence in increasing memory space. Weight computations are done by combinatorial network and therefore the time performance of the system is equivalent to the one of the vectorial method. The number of non null membership values on any element of the universe of discourse is limited. Such a constraint is usually non very restrictive since many controllers obtain a good precision with only three non null weights. The method here briefly described has been adopted by our group in the design of an optimized version of the coprocessor described in [10].

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Analysis of Twitter for 2012 South Korea Presidential Election by Text Mining Techniques (텍스트 마이닝을 이용한 2012년 한국대선 관련 트위터 분석)

  • Bae, Jung-Hwan;Son, Ji-Eun;Song, Min
    • Journal of Intelligence and Information Systems
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    • v.19 no.3
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    • pp.141-156
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    • 2013
  • Social media is a representative form of the Web 2.0 that shapes the change of a user's information behavior by allowing users to produce their own contents without any expert skills. In particular, as a new communication medium, it has a profound impact on the social change by enabling users to communicate with the masses and acquaintances their opinions and thoughts. Social media data plays a significant role in an emerging Big Data arena. A variety of research areas such as social network analysis, opinion mining, and so on, therefore, have paid attention to discover meaningful information from vast amounts of data buried in social media. Social media has recently become main foci to the field of Information Retrieval and Text Mining because not only it produces massive unstructured textual data in real-time but also it serves as an influential channel for opinion leading. But most of the previous studies have adopted broad-brush and limited approaches. These approaches have made it difficult to find and analyze new information. To overcome these limitations, we developed a real-time Twitter trend mining system to capture the trend in real-time processing big stream datasets of Twitter. The system offers the functions of term co-occurrence retrieval, visualization of Twitter users by query, similarity calculation between two users, topic modeling to keep track of changes of topical trend, and mention-based user network analysis. In addition, we conducted a case study on the 2012 Korean presidential election. We collected 1,737,969 tweets which contain candidates' name and election on Twitter in Korea (http://www.twitter.com/) for one month in 2012 (October 1 to October 31). The case study shows that the system provides useful information and detects the trend of society effectively. The system also retrieves the list of terms co-occurred by given query terms. We compare the results of term co-occurrence retrieval by giving influential candidates' name, 'Geun Hae Park', 'Jae In Moon', and 'Chul Su Ahn' as query terms. General terms which are related to presidential election such as 'Presidential Election', 'Proclamation in Support', Public opinion poll' appear frequently. Also the results show specific terms that differentiate each candidate's feature such as 'Park Jung Hee' and 'Yuk Young Su' from the query 'Guen Hae Park', 'a single candidacy agreement' and 'Time of voting extension' from the query 'Jae In Moon' and 'a single candidacy agreement' and 'down contract' from the query 'Chul Su Ahn'. Our system not only extracts 10 topics along with related terms but also shows topics' dynamic changes over time by employing the multinomial Latent Dirichlet Allocation technique. Each topic can show one of two types of patterns-Rising tendency and Falling tendencydepending on the change of the probability distribution. To determine the relationship between topic trends in Twitter and social issues in the real world, we compare topic trends with related news articles. We are able to identify that Twitter can track the issue faster than the other media, newspapers. The user network in Twitter is different from those of other social media because of distinctive characteristics of making relationships in Twitter. Twitter users can make their relationships by exchanging mentions. We visualize and analyze mention based networks of 136,754 users. We put three candidates' name as query terms-Geun Hae Park', 'Jae In Moon', and 'Chul Su Ahn'. The results show that Twitter users mention all candidates' name regardless of their political tendencies. This case study discloses that Twitter could be an effective tool to detect and predict dynamic changes of social issues, and mention-based user networks could show different aspects of user behavior as a unique network that is uniquely found in Twitter.

A High Quality Rice Variety "Cheongcheongjinmi" Adaptable to Low Nitrogen Fertilizer Application (질소 소비료적성 고품질 벼 신품종 "청청진미")

  • Cho, Young-Chan;Oh, Myung-Kyu;Choi, Im-Soo;Kim, Yeon-Gyu;Kim, Myeong-Ki;Hwang, Hung-Goo;Hong, Ha-Cheol;Jeong, O-Young;Choi, In-Bae;Choi, Yong-Hwan;Jeon, Yong-Hee;Lee, Jeom-Ho;Lee, Jeong-Heui;Lee, Jeong-Il;Shin, Young-Seop;Kim, Jeong-Ju;Kim, Ki-Jong;Baek, Man-Kee;Roh, Jae-Hwan
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.654-659
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    • 2009
  • "Cheongcheongjinmi" is a new japonica rice variety developed from a cross between Iri401 and Ilpumbyeo by the rice breeding team of National Institute of Crop Science, RDA. This variety is suitable for ordinary season culture of low level nitrogen application. Heading date of "Cheongcheongjinmi" is August 17, 4 days later than that of Sobibyeo in plain areas. It has culm length of 82 cm, and relatively semi-erect pubescent leaf blade and slightly tough culm tolerant to lodging with good canopy architecture. This variety has 13 tillers per hill, 126 spikelets per panicle and 90.2% of ripened grains. "Cheongcheongjinmi" showed lower spikelet fertility than Sobibyeo when exposed to cold stress. This variety showed slower leaf senescence and lower viviparous germination compared to Sobibyeo during the ripening stage. "Cheongcheongjinmi" is susceptible to blast disease, bacterial blight, virus diseases and planthoppers. The dried plant weight, total nitrogen and RuBisCO activity of "Cheongcheongjinmi" were higher than those of Sobibyeo in low level nitrogen application. The milled rice of "Cheongcheongjinmi" exhibits translucent, clear non-glutinous endosperm and medium short grain. It shows lower protein and amylose contents than those of Sobibyeo, and better palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this cultivar is about 5.10 MT/ha at low level nitrogen application of ordinary season culture in local adaptability test for three years. Especially, "Cheongcheongjinmi" has better milling properties such as the percentage of whole grain in milled rice and milling recovery of whole grain, respectively than those of Sobibyeo. "Cheongcheongjinmi" would be adaptable to middle plain areas and middle-western coastal areas of Korea.