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A Study on the Revitalization of BIM in the Field of Architecture Using AHP Method (AHP 기법을 이용한 건축분야 BIM 활성화 방안 연구)

  • Kim, Jin-Ho;Hwang, Chan-Gyu;Kim, Ji-Hyung
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.5
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    • pp.473-483
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    • 2022
  • BIM(Building Information Modeling) is a technology that can manage information throughout the entire life cycle of the construction industry and serves as a platform for improving productivity and integrating the entire construction industry. Currently, BIM is actively applied in developed countries, and its use at various overseas construction sites is increasing This is unclear. due to air shortening and budget savings. However, there is still a lack of institutional basis and technical limitations in the domestic construction sector, which have led to the lack of utilization of BIM. Various activation measures and institutional frameworks will need to be established for the early establishment of these productive BIMs in Korea. Therefore, as part of the research for the domestic settlement and revitalization of BIM, this study derived a number of key factors necessary for the development of the construction industry through brainstorming and expert surveys using AHP techniques and analyzed the relative importance of each factor. In addition, prior surveys by a group of experts resulted in 1, 3 items in level, 2, 9 items in level, and 3, 27 items in level, and priorities analysis was performed through pairwise comparisons. As a result of the AHP analysis, it was found that the relative importance weight of policy aspects was highest in level 1, and the policy factors in level 2 and the cost-based and incentive system introduction factors were considered most important in level 3. These findings show that the importance of the policy guidance or institutions underlying the activation of BIM rather than research and development or corporate innovation is relatively high, and that the preparation of policy plans by public institutions should be the first priority. Therefore, it is considered that the development of a policy system or guideline must be prioritized before it can be advanced to the next activation stage. The use of BIM technologies will not only contribute to improving the productivity of the construction industry, but also to the overall development of the industry and the growth of the construction industry. It is expected that the results of this study can provide as useful information when establishing policies for activating BIM in central government, relevant local governments, and related public institutions.

Application of Greenhouse Climate Management Model for Educational Simulation Design (교육용 시뮬레이션 설계를 위한 온실 환경 제어 모델의 활용)

  • Yoon, Seungri;Kim, Dongpil;Hwang, Inha;Kim, Jin Hyun;Shin, Minju;Bang, Ji Wong;Jeong, Ho Jeong
    • Journal of Bio-Environment Control
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    • v.31 no.4
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    • pp.485-496
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    • 2022
  • Modern agriculture is being transformed into smart agriculture to maximize production efficiency along with changes in the 4th industrial revolution. However, rural areas in Korea are facing challenges of aging, low fertility, and population outflow, making it difficult to transition to smart agriculture. Among ICT technologies, simulation allows users to observe or experience the results of their choices through imitation or reproduction of reality. The combination of the three-dimension (3D) model and the greenhouse simulator enable a 3D experience by virtual greenhouse for fruits and vegetable cultivation. At the same time, it is possible to visualize the greenhouse under various cultivation or climate conditions. The objective of this study is to apply the greenhouse climate management model for simulation development that can visually see the state of the greenhouse environment under various micrometeorological properties. The numerical solution with the mathematical model provided a dynamic change in the greenhouse environment for a particular greenhouse design. Light intensity, crop transpiration, heating load, ventilation rate, the optimal amount of CO2 enrichment, and daily light integral were calculated with the simulation. The results of this study are being built so that users can be linked through a web page, and software will be designed to reflect the characteristics of cladding materials and greenhouses, cultivation types, and the condition of environmental control facilities for customized environmental control. In addition, environmental information obtained from external meteorological data, as well as recommended standards and set points for each growth stage based on experiments and research, will be provided as optimal environmental factors. This simulation can help growers, students, and researchers to understand the ICT technologies and the changes in the greenhouse microclimate according to the growing conditions.

Cation Content of Salt-Tolerant and -Susceptible Cultivars and Its Inheritance in Rice (벼 내염성 및 비내염성 품종들의 양이온함량과 그의 유전)

  • Won, Yong-Jae;Heu, Mun-Hue;Koh, Hee-Jong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.1
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    • pp.1-8
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    • 1992
  • This study was conducted to obtain the basic information on salt-tolerance of rice cultivars in relations with growth retardation and cation content. As the salt-level increased, less retardation in plant height and dry weight were shown in salt-tolerant than salt-susceptible rice cultivars. Salt tolerant cultivars showed lower N $a^{+}$ and higher $K^{+}$ content and lower N $a^{+}$ / $K^{+}$ ratio at each salt-levels than salt-susceptible ones, while there were no significant differences in $Ca^{++}$ and $Mg^{++}$ content. At the tillering stage, the plant height and dry weight of the salt-treated plots were significantly correlated with N $a^{+}$ and $K^{+}$ content and N $a^{+}$ / $K^{+}$ ratio, implying that N $a^{+}$ and $K^{+}$ content could be an indicator of salt-tolerance of a rice cultivar. There were no tiller-depending differences in cation content in all cultivars. N $a^{+}$ content and N $a^{+}$ / $K^{+}$ ratio in leaves were lower at the top and higher at the bottom. In three $F_1$ hybrids between salt tolerant parent Pokkali and three salt susceptible parents, plant height, dry weight, $K^{+}$ content and N $a^{+}$ / $K^{+}$ ratio were similar to those of Pokkali parent, while N $a^{+}$ content was intermediate of the parents. So, it seemed that salt tolerance is dominant over salt susceptibility. In $F_2$ of Pokkali/wx817 cross, genetic segregation of plant height, dry weight, $K^{+}$ content and N $a^{+}$ / $K^{+}$ ratio varied continuously and was biased onto Pokkali side, while that of N $a^{+}$ content showed normal distribution with intermediate mode. Broad-sense heritability of the characters ranged from 0. 604 to 0. 811. Genotypic and phenotypic correlation coefficients among them were relatively high.fficients among them were relatively high.h.h.

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Studies on the Chilling Injury of Rice Seedlings III. Possibility of Low-Temperature Hardening (수도의 유묘기 냉해에 관한 연구 III. 유묘의 저온경화 가능성 검토)

  • Kwon, Y.W.;Ahn, M.B.;Oh, Y.J.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.24 no.3
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    • pp.21-25
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    • 1979
  • To evaluate the possibility of hardening of rice seedlings to chilling injury by low temperature conditioning for improvement of nursery temperature management a chilling sensitive new variety Tongil from Indica \times Japonica cross and a chilling tolerant Japonica variety Jinheung were reared by the 3rd leaf-stage in a day $30^{\circ}C/night\; 20^{\circ}C$ growth chamber, and were subjected to temperature conditioning for hardening against chilling injury for 6 days. Then the seedlings conditioned and unconditioned were chilled in a day and night $8^{\circ}C$ chamber for 2, 4, 6, or 8 days long and returned to the day and night $30^{\circ}C/night\; 20^{\circ}C$ condition for development of chilling injuries. Survival rate after chilling injury development of the variety Tongil showed distinct effect of hardening, i. e. the unhardened-25 % survival, the hardened by a gradual drop of temperature regime $(30^{\circ}C/20^{\circ}C\rightarrow24^{\circ}C/14^{\circ}C\rightarrow18^{\circ}C/12^{\circ}C\rightarrow8^{\circ}C)4 -59% survival and the hardened. by repeated brief exposure (4hrs. to 6hrs.) to $8^{\circ}C$ shock-89% survival against chilling of $8^{\circ}C$ for 4 days long. The variety Jinheung survived even against 8 days chilling at $8^{\circ}C$ C, but the discoloration rate of leaves due to chilling showed noticeably the hardening effect as repeated shock was much better than the gradually lowering temperatures.

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Deep Learning Approaches for Accurate Weed Area Assessment in Maize Fields (딥러닝 기반 옥수수 포장의 잡초 면적 평가)

  • Hyeok-jin Bak;Dongwon Kwon;Wan-Gyu Sang;Ho-young Ban;Sungyul Chang;Jae-Kyeong Baek;Yun-Ho Lee;Woo-jin Im;Myung-chul Seo;Jung-Il Cho
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.25 no.1
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    • pp.17-27
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    • 2023
  • Weeds are one of the factors that reduce crop yield through nutrient and photosynthetic competition. Quantification of weed density are an important part of making accurate decisions for precision weeding. In this study, we tried to quantify the density of weeds in images of maize fields taken by unmanned aerial vehicle (UAV). UAV image data collection took place in maize fields from May 17 to June 4, 2021, when maize was in its early growth stage. UAV images were labeled with pixels from maize and those without and the cropped to be used as the input data of the semantic segmentation network for the maize detection model. We trained a model to separate maize from background using the deep learning segmentation networks DeepLabV3+, U-Net, Linknet, and FPN. All four models showed pixel accuracy of 0.97, and the mIOU score was 0.76 and 0.74 in DeepLabV3+ and U-Net, higher than 0.69 for Linknet and FPN. Weed density was calculated as the difference between the green area classified as ExGR (Excess green-Excess red) and the maize area predicted by the model. Each image evaluated for weed density was recombined to quantify and visualize the distribution and density of weeds in a wide range of maize fields. We propose a method to quantify weed density for accurate weeding by effectively separating weeds, maize, and background from UAV images of maize fields.

Importance-Satisfaction Analysis of Users of Gochang Jayeonmadang Project (고창 자연마당 조성사업 이용자의 중요도·만족도 분석)

  • Jin Pyo Hong;Yun Jin Shim;Jung Won Sung;Kyeong Cheol Lee;Hyeong keun Kweon;Hui Jae Yun
    • Journal of Practical Agriculture & Fisheries Research
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    • v.25 no.1
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    • pp.5-13
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    • 2023
  • This study was conducted to identify items that should be considered in order to increase user satisfaction in the Jayeonmadang project by analyzing the importance and satisfaction targeting Gochang Jayeonmadang users. As a result of analysis on the importance and satisfaction of Gochang Jayeonmadang users focusing on 20 items in 6 fields, Overall, it was analyzed that they were not satisfied as they were important. In order to increase user satisfaction of Gochang Jayeonmadang, maintenance such as 'cleanliness and hygiene', 'water quality', 'vegetation growth', and 'facility management' should be carefully reflected from the planning and design stage, and careful attention should be paid even after the project. In addition, emphasis should be placed on enhancing the user convenience, such as 'accessibility', 'space layout and utilization efficiency', and 'convenience of route'. And, when promoting the Jayeonmadang project, the purpose of the project should be actively promoted to local residents to raise the residents' awareness of the importance of biodiversity in the city.

A Study on the Meaning and Strategy of Keyword Advertising Marketing

  • Park, Nam Goo
    • Journal of Distribution Science
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    • v.8 no.3
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    • pp.49-56
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    • 2010
  • At the initial stage of Internet advertising, banner advertising came into fashion. As the Internet developed into a central part of daily lives and the competition in the on-line advertising market was getting fierce, there was not enough space for banner advertising, which rushed to portal sites only. All these factors was responsible for an upsurge in advertising prices. Consequently, the high-cost and low-efficiency problems with banner advertising were raised, which led to an emergence of keyword advertising as a new type of Internet advertising to replace its predecessor. In the beginning of 2000s, when Internet advertising came to be activated, display advertisement including banner advertising dominated the Net. However, display advertising showed signs of gradual decline, and registered minus growth in the year 2009, whereas keyword advertising showed rapid growth and started to outdo display advertising as of the year 2005. Keyword advertising refers to the advertising technique that exposes relevant advertisements on the top of research sites when one searches for a keyword. Instead of exposing advertisements to unspecified individuals like banner advertising, keyword advertising, or targeted advertising technique, shows advertisements only when customers search for a desired keyword so that only highly prospective customers are given a chance to see them. In this context, it is also referred to as search advertising. It is regarded as more aggressive advertising with a high hit rate than previous advertising in that, instead of the seller discovering customers and running an advertisement for them like TV, radios or banner advertising, it exposes advertisements to visiting customers. Keyword advertising makes it possible for a company to seek publicity on line simply by making use of a single word and to achieve a maximum of efficiency at a minimum cost. The strong point of keyword advertising is that customers are allowed to directly contact the products in question through its more efficient advertising when compared to the advertisements of mass media such as TV and radio, etc. The weak point of keyword advertising is that a company should have its advertisement registered on each and every portal site and finds it hard to exercise substantial supervision over its advertisement, there being a possibility of its advertising expenses exceeding its profits. Keyword advertising severs as the most appropriate methods of advertising for the sales and publicity of small and medium enterprises which are in need of a maximum of advertising effect at a low advertising cost. At present, keyword advertising is divided into CPC advertising and CPM advertising. The former is known as the most efficient technique, which is also referred to as advertising based on the meter rate system; A company is supposed to pay for the number of clicks on a searched keyword which users have searched. This is representatively adopted by Overture, Google's Adwords, Naver's Clickchoice, and Daum's Clicks, etc. CPM advertising is dependent upon the flat rate payment system, making a company pay for its advertisement on the basis of the number of exposure, not on the basis of the number of clicks. This method fixes a price for advertisement on the basis of 1,000-time exposure, and is mainly adopted by Naver's Timechoice, Daum's Speciallink, and Nate's Speedup, etc, At present, the CPC method is most frequently adopted. The weak point of the CPC method is that advertising cost can rise through constant clicks from the same IP. If a company makes good use of strategies for maximizing the strong points of keyword advertising and complementing its weak points, it is highly likely to turn its visitors into prospective customers. Accordingly, an advertiser should make an analysis of customers' behavior and approach them in a variety of ways, trying hard to find out what they want. With this in mind, her or she has to put multiple keywords into use when running for ads. When he or she first runs an ad, he or she should first give priority to which keyword to select. The advertiser should consider how many individuals using a search engine will click the keyword in question and how much money he or she has to pay for the advertisement. As the popular keywords that the users of search engines are frequently using are expensive in terms of a unit cost per click, the advertisers without much money for advertising at the initial phrase should pay attention to detailed keywords suitable to their budget. Detailed keywords are also referred to as peripheral keywords or extension keywords, which can be called a combination of major keywords. Most keywords are in the form of texts. The biggest strong point of text-based advertising is that it looks like search results, causing little antipathy to it. But it fails to attract much attention because of the fact that most keyword advertising is in the form of texts. Image-embedded advertising is easy to notice due to images, but it is exposed on the lower part of a web page and regarded as an advertisement, which leads to a low click through rate. However, its strong point is that its prices are lower than those of text-based advertising. If a company owns a logo or a product that is easy enough for people to recognize, the company is well advised to make good use of image-embedded advertising so as to attract Internet users' attention. Advertisers should make an analysis of their logos and examine customers' responses based on the events of sites in question and the composition of products as a vehicle for monitoring their behavior in detail. Besides, keyword advertising allows them to analyze the advertising effects of exposed keywords through the analysis of logos. The logo analysis refers to a close analysis of the current situation of a site by making an analysis of information about visitors on the basis of the analysis of the number of visitors and page view, and that of cookie values. It is in the log files generated through each Web server that a user's IP, used pages, the time when he or she uses it, and cookie values are stored. The log files contain a huge amount of data. As it is almost impossible to make a direct analysis of these log files, one is supposed to make an analysis of them by using solutions for a log analysis. The generic information that can be extracted from tools for each logo analysis includes the number of viewing the total pages, the number of average page view per day, the number of basic page view, the number of page view per visit, the total number of hits, the number of average hits per day, the number of hits per visit, the number of visits, the number of average visits per day, the net number of visitors, average visitors per day, one-time visitors, visitors who have come more than twice, and average using hours, etc. These sites are deemed to be useful for utilizing data for the analysis of the situation and current status of rival companies as well as benchmarking. As keyword advertising exposes advertisements exclusively on search-result pages, competition among advertisers attempting to preoccupy popular keywords is very fierce. Some portal sites keep on giving priority to the existing advertisers, whereas others provide chances to purchase keywords in question to all the advertisers after the advertising contract is over. If an advertiser tries to rely on keywords sensitive to seasons and timeliness in case of sites providing priority to the established advertisers, he or she may as well make a purchase of a vacant place for advertising lest he or she should miss appropriate timing for advertising. However, Naver doesn't provide priority to the existing advertisers as far as all the keyword advertisements are concerned. In this case, one can preoccupy keywords if he or she enters into a contract after confirming the contract period for advertising. This study is designed to take a look at marketing for keyword advertising and to present effective strategies for keyword advertising marketing. At present, the Korean CPC advertising market is virtually monopolized by Overture. Its strong points are that Overture is based on the CPC charging model and that advertisements are registered on the top of the most representative portal sites in Korea. These advantages serve as the most appropriate medium for small and medium enterprises to use. However, the CPC method of Overture has its weak points, too. That is, the CPC method is not the only perfect advertising model among the search advertisements in the on-line market. So it is absolutely necessary that small and medium enterprises including independent shopping malls should complement the weaknesses of the CPC method and make good use of strategies for maximizing its strengths so as to increase their sales and to create a point of contact with customers.

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STUDIES ON THE DIMORPHISM AND FERTILITY OF PERSICARIA JAPONICA (MEISSNER) GROSS ET NAKAI (Persicaria Japonica (MISSNER) Gross et Nakai의 이형화와 수정력에 관한 연구)

  • HARN, Chang Yawl
    • Journal of Plant Biology
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    • v.3 no.1
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    • pp.1-15
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    • 1960
  • HARN, Chang Yawl : Studies on the dimorphism and Fertility of Persicaria japonica (MEISSNER) Gross et Nakai. Kor Jour. Bot. 3(I) 1-15 1960 Numerous investigations, since the works of DARWIN, have been made regarding the heterostylous plants by JOST (1907), CORRENS (1924), LAIBACK (1924), LEWIS (1943), and many others. Studies on the heterostylous Polygomum, however, were not reported except for the buckwhent, Fagopyrum esculentum, which was investigated by SCHOCH-BODMER (1930), EAST (1934), FROLOVA & Co-Workers (1946), MORRIS (1947, 1951) TATEBE (1949, 1951, 1953), present author (1957), and others. It is because no heterostylous species, besides buckwheat, have been known to exist in the Polygonum family. The author, during his studies on both heterostylism and fertility of Polygonaceae, has found that the species, persicaria japonica (Meissner) Gross et Nakai, is not diecious as has been known in taxonomy, but in reality beterostylous both morphologically and physiologically. It was found that this plant, regarded by taxonomist, as a male plant setting no seed, actually set seed (botanical fruit) when legitimate combination was made. Since his brief report on the dimorphic phenomens of this plant in 1956, the author's further research on the manner of fertilization has revealed that this species is a peculiar type whose dimorphism has undergone extreme specialization structurally and physiologically, the short-styled individual behaving in nature as a male plant and the long-styled individual, as female, whereas in controllled pollination the plant shows highly differentiated typical dimorphism. When compared with the other dimorphous species of this family, F. esculentum and P. sentiosa. it has been clarified that these three species differ in the degree of differentiation of their dimorphism morphologically and physiologically. That is, P. japonica has developed such a high specialization as to mislead the taxonomists, while P. senticosa shows almost no noticeable difference between long- and shortstyled individuals retaining most of the inherent physiological character cmmon to the genus except for the fact that it has two forms of flowers. F. esculentum appears to have taken the intermediate position in every respect. The result obtained in the present experiment are summarized as follows: 1) P. japonica has two kinds of individuals, one long style-short stamened; the other, short style-long stamened. The floral structure of this plants shows typical characteristics of dimorphic heterostylism. The differentiation between the two forms of flower has proceeded so highly both in primary and secondary difference of flower structure that this may be regarded as the most specialized form of dimorphism. 2) The differences of floral structure between the long and short styled individuals are remarkable compared with the other dimorphic species of the family. 3) The stamens of long styled plants show the sign of deteriolation whereas those of the short styled flower are well-developed. 4) When legitimate combinations are made, both L- and S-styled individuals are fertilized well and set seed (fruit), while in the illegitimate combination no fertilization and seed setting occur. Physiologically this species exhibits the typical behavior of dimorphic plants. 5) The self-fertile character, so common in other species of the other non-heterostyle Polygonum family, has disappeared completely. 6) Under natural conditions, no or few seed setting is observed in short styled individuals that behave as if they were male plants. 7) In hand pollination, the combination of both $L{\times}S$ and $S{\times}L$ alike yield relatively good fertility and seed-formation, the behavior of short styled individuals in artificial pollination differing remarkably from that in nature. 8) Under controlled pollination, $L{\times}S$ combination sets far more seed than in the combination of $S{\times}L$. In the S-styled individuals, the fertilized flower has the tendency of its seed more readily falling off in every stage of seed development than in the L-styled individuals. 9) The behaviors of pollen tubes just parallels the results of fertility test. That is, in the illegitimate combination, L-selfed, $L{\times}L$, S-selfed, and $S{\times}S$, the growth of pollen tubes is checked in the style, while in legitimately combined $L{\times}S$ and $S{\times}L$, the pollen tubes grow well reaching the ovaries within 40-50 minutes after pollination. The response of short styled individuals, known as male plant among taxonomists, is identical, as far as behavior fo pollen tube growth and fertilization are concerned, to that of long styled individuals, the so-called female plant. 10) The pollen grains from the short-styled plants are complete and fertile, whereas 70% of those of L-styled are found to be abortive, i.e., empty contents. 11) The remaining 30% of pollen of L-plant shows varied degree of stainability when stained with iron-aceto-carmine......mostly light red, while the pollen grains of S-style individuals are dark brown indicating complete fertility and viability. 12) The abundance of sterile pollen in L-styled and the nature of seed-dropping which occurs in S-styled individuals appear to be the main causes why the short styled individuals bear no seed in nature. Under controlled legitimate union, $S{\times}L$, the careful and elaborate pollination would give the S-styoled flowers the opportunities to receive the fertile pollens, though few in number, from L-styled plant, thus enabling S-plant to bear seed. 13) This species is not dioecious as is regarded by taxonomists, but typical dimorphic plant which has so highly specialized in floral structures and funcitons that the long-styled plant behaves just like a female individual; and the short-styled, like a male.

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Effect of Feeding Whole Crop Barley Silage- or Whole Crop Rye Silage based-TMR and Duration of TMR Feeding on Growth, Feed Cost and Meat Characteristics of Hanwoo Steers (청보리 사일리지 TMR 또는 청호밀 사일리지 TME 급여 및 급여기간이 거세 한우의 증체, 사료비 및 육질특성에 미치는 효과)

  • Jin, Guang Lin;Kim, Jong-Kyu;Qin, Wei-Ze;Jeong, Jun;Jang, Sun-Sik;Sohn, Yong-Suk;Choi, Chang-Won;Song, Man-Kang
    • Journal of Animal Science and Technology
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    • v.54 no.2
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    • pp.111-124
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    • 2012
  • Feeding trial was conducted with 80 Hanwoo steers (7.5 months of age, 204.4 kg body weight) for 680 days from growing period to late fattening period to examine the feeding value of whole crop barley silage TMR (BS-TMR) and whole crop rye silage TMR (RS-TMR) on body gain, feed cost, slaughter characteristics and quality characteristics of $longissimus$ $dorsi$ muscle. Dietary treatments were conventional separate feeding of concentrate and rice straw (control), feeding BS TMR up to middle fattening period and same diet as for control during late fattening period (BS-TMR I), feeding BS-TMR for whole experimental period (BS-TMR II), feeding RS TMR up to middle fattening period and same diet as for control during late fattening period (RS-TMR I) and RS TMR for whole experimental period (RS-TMR II). Sixteen castrated calves were assigned to each treatment (4 pens, 4 heads per pen). Pens in each treatment were randomly distributed. Feeding both BS silage TMR and RS silage TMR slightly increased body gain of Hanwoo steers at the stages of growing and early fattening, and increased (P<0.0001) at middle fattening compared to feeding control diet while control diet tended to increase body gain at late fattening stage compared to feeding BS-TMR I, BS-TMR II and RS-TMR I diets. Total body gain was slightly increased in Hanwoo steers fed both I and II for BS and RS TMR compared to that in control diet. Feed cost per kg gain per head was relatively low in the Hanwoo steers fed silage TMRs to that fed control diet. Carcass weight, back fat thickness and $longissimus$ $dorsi$ area of Hanwoo steers tended to increase but lowered (P<0.047) yield index by feeding silage TMRs. Feeding BS TMR slightly decreased marbling score but no difference was found in the number of head over grade 1 between diets. Control diet tended to improve yield grade compared to silage TMRs. Chemical composition, water holding capacity, drip loss, cooking loss and pH, color and fatty acid composition of $longissimus$ $dorsi$ were not affected by experimental diets and feeding duration of silage TMRs. Shear force, however, was increased (P<0.046) by silage TMRs without difference between them compared to control diet. Based on the results of the current study, BS TMR and RS TMR could improve body gain and reduce feed cost without deteriorating meat quality compared to separate feeding of concentrate and rice straw. Overall feeding value was similar between BS TMR and RS TMR.

Status and Prospect of Herbicide Resistant Weeds in Rice Field of Korea (한국 논에서 제초제 저항성잡초 발생 현황과 전망)

  • Park, Tae-Seon;Lee, In-Yong;Seong, Ki-Yeong;Cho, Hyeon-Suk;Park, Hong-Kyu;Ko, Jae-Kwon;Kang, Ui-Gum
    • Korean Journal of Weed Science
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    • v.31 no.2
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    • pp.119-133
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    • 2011
  • Sulfonylurea (SU)-resistant weeds include seven annual weeds such as Monochoria vaginalis, Scirpus juncoides and Cyperus difformis, etc., and three perennial weeds of Scirpus planiculmis, Sagittaria pigmaea and Eleocharis acicularis as of 2010 since identification Monochoria korsakowii in the reclaimed rice field in 1998. The Echinochloa oryzoides resistant to acetyl CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibitors has been confirmed in wet-direct seeding rice field of the southern province, Korea in 2009. In the beginning of occurrence of SU-resistant weeds the M. vaginalis, S. juncoides and C. difformis were rapidly and individually spreaded in different fields, however, theses resistant weeds have been occurring simultaneously in the same filed as time goes by. The resistant biotype by weed species demonstrated about 10- to 1,000-fold resistance, base on $GR_{50}$ (50% growth reduction) values of the SU herbicides tested. And the resistant biotype of E. oryzoides to cyhalofop-butyl, pyriminobac-methyl, and penoxsulam was about 14, 8, and 11 times more resistant than the susceptible biotype base on $GR_{50}$ values. In history of paddy herbicides in Korea, the introduction of SU herbicides including besulfuron-metyl and pyrazosulfuron-ethyl that control many troublesome weeds at low use rates and provide excellent crop safety gave farmers and many workers for herbicide business refreshing jolt. The products and applied area of SU-included herbicides have been rapidly increased, and have accounted for about 69% and 96%, respectively, in Korea. The top ten herbicides by applied area were composed of all SU-included herbicides by 2003. The concentrated and successive treatment of ACCase and ALS inhibitors for control of barnyardgrass in direct-seeded rice led up to the resistance of E. oryzoides. Also, SU-herbicides like pyrazosulfuron-ethyl and imazosulfuron which are effective to barnyardgrass can be bound up with the resistance of E. oryzoides. The ALS activity isolated from the resistant biotype of M. korsakowii to SU-herbicides tested was less sensitive than that of susceptible biotype. The concentration of herbicide required for 50% inhibition of ALS activity ($I_{50}$) of the SU-resistant M. korsakowii was 14- to 76-fold higher as compared to the susceptible biotype. No differences were observed in the rates of [$^{14}C$]bensulfuron uptake and translocation. ALS genes from M. vaginalis resistant and susceptible biotypes against SU-herbicides revealed a single amino acid substitution of proline (CCT), at 197th position based on the M. korsakowii ALS sequence numbering, to serin (TCT) in conserved domain A of the gene. Carfentrazone-ethyl and pyrazolate were used mainly to control SU-resistant M. vaginalis by 2006, the early period, in Korea. However, the alternative herbicides such as benzobicyclone, to be possible to control simultaneously the several resistant weeds, have been developing and using broadly because the several resistant weeds have been occurring simultaneously in the same filed. The top ten herbicides by applied area in Korea have been occupied by products of 3-way mixture type including herbicides with alternative mode of action for the herbicide resistant weeds. Mefenacet, fentrazamide and cafenstrole had excellent controlling effects on the ACCase and ALS inhibitors resistant when they were applied within 2 leaf stage.