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The Influential Factor Analysis in the Technology Valuation of The Agri-Food Industry and the Simulation-Based Valuation Analysis (농식품 산업의 기술평가 영향요인 분석과 시뮬레이션 기반 기술평가 비교)

  • Kim, Sang-gook;Jun, Seung-pyo;Park, Hyun-woo
    • Journal of Technology Innovation
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    • v.24 no.4
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    • pp.277-307
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    • 2016
  • Since 2011, DCF(Discounted Cash Flow) method has been used initiatively for valuating R&D technology assets in the agricultural food industry and recently technology valuation based on royalties comparison among technology transfer transactions has been also carried out in parallel when evaluating the technology assets such as new seed development technologies. Since the DCF method which has been known until now has many input variables to be estimated, sophisticated estimation has been demanded at the time of technology valuation. In addition, considering more similar trading cases when applying sales transaction comparison or industry norm method based on information of technology transfer royalty, it is an important issue that should be taken into account in the same way in the Agri-Food industry. The main input variables used for technology valuation in the Agri-Food industry are life cycle of technology asset, the financial information related to the Agri-Food industry, discount rate, and technology contribution rate. The latest infrastructure building and data updating related to technology valuation has been carried out on a regular basis in the evaluation organization of the Agri-Food segment. This study verifies the key variables that give the most important impact on the results for the existing technology valuation in the Agri-Food industry and clarifies the difference between the existing valuation result and the outcome by referring the support information that is derived through the latest input information applied in DCF method. In addition, while presenting the scheme to complement fragment information which the latest input data just influence result of technology valuation, we tried to perform comparative analysis between the existing valuation results and the evaluated outcome after the latest of reference data for making a decision the input values to be estimated in DCF. To perform these analyzes, it was first selected the representative cases evaluated past in the Agri-Food industry, applied a sensitivity analysis for input variables based on these selected cases, and then executed a simulation analysis utilizing the key input variables derived from sensitivity analysis. The results of this study is to provide the information which there are the need for modernization of the data related to the input variables that are utilized during valuating technology assets in the Agri-Food sector and for building the infrastructure of the key input variables in DCF. Therefore it is expected to provide more fruitful information about the results of valuation.

Development of a Detection Model for the Companies Designated as Administrative Issue in KOSDAQ Market (KOSDAQ 시장의 관리종목 지정 탐지 모형 개발)

  • Shin, Dong-In;Kwahk, Kee-Young
    • Journal of Intelligence and Information Systems
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    • v.24 no.3
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    • pp.157-176
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    • 2018
  • The purpose of this research is to develop a detection model for companies designated as administrative issue in KOSDAQ market using financial data. Administration issue designates the companies with high potential for delisting, which gives them time to overcome the reasons for the delisting under certain restrictions of the Korean stock market. It acts as an alarm to inform investors and market participants of which companies are likely to be delisted and warns them to make safe investments. Despite this importance, there are relatively few studies on administration issues prediction model in comparison with the lots of studies on bankruptcy prediction model. Therefore, this study develops and verifies the detection model of the companies designated as administrative issue using financial data of KOSDAQ companies. In this study, logistic regression and decision tree are proposed as the data mining models for detecting administrative issues. According to the results of the analysis, the logistic regression model predicted the companies designated as administrative issue using three variables - ROE(Earnings before tax), Cash flows/Shareholder's equity, and Asset turnover ratio, and its overall accuracy was 86% for the validation dataset. The decision tree (Classification and Regression Trees, CART) model applied the classification rules using Cash flows/Total assets and ROA(Net income), and the overall accuracy reached 87%. Implications of the financial indictors selected in our logistic regression and decision tree models are as follows. First, ROE(Earnings before tax) in the logistic detection model shows the profit and loss of the business segment that will continue without including the revenue and expenses of the discontinued business. Therefore, the weakening of the variable means that the competitiveness of the core business is weakened. If a large part of the profits is generated from one-off profit, it is very likely that the deterioration of business management is further intensified. As the ROE of a KOSDAQ company decreases significantly, it is highly likely that the company can be delisted. Second, cash flows to shareholder's equity represents that the firm's ability to generate cash flow under the condition that the financial condition of the subsidiary company is excluded. In other words, the weakening of the management capacity of the parent company, excluding the subsidiary's competence, can be a main reason for the increase of the possibility of administrative issue designation. Third, low asset turnover ratio means that current assets and non-current assets are ineffectively used by corporation, or that asset investment by corporation is excessive. If the asset turnover ratio of a KOSDAQ-listed company decreases, it is necessary to examine in detail corporate activities from various perspectives such as weakening sales or increasing or decreasing inventories of company. Cash flow / total assets, a variable selected by the decision tree detection model, is a key indicator of the company's cash condition and its ability to generate cash from operating activities. Cash flow indicates whether a firm can perform its main activities(maintaining its operating ability, repaying debts, paying dividends and making new investments) without relying on external financial resources. Therefore, if the index of the variable is negative(-), it indicates the possibility that a company has serious problems in business activities. If the cash flow from operating activities of a specific company is smaller than the net profit, it means that the net profit has not been cashed, indicating that there is a serious problem in managing the trade receivables and inventory assets of the company. Therefore, it can be understood that as the cash flows / total assets decrease, the probability of administrative issue designation and the probability of delisting are increased. In summary, the logistic regression-based detection model in this study was found to be affected by the company's financial activities including ROE(Earnings before tax). However, decision tree-based detection model predicts the designation based on the cash flows of the company.

Design and Analysis of Online Advertising Expenditure Model based on Coupon Download (쿠폰 다운로드를 기준으로 하는 온라인 광고비 모델의 설계 및 분석)

  • Jun, Jung-Ho;Lee, Kyoung-Jun
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.1-19
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    • 2010
  • In offline environment, unlike traditional advertising model through TV, newspaper, and radio, online advertising model draws instantaneous responses from potential consumers and it is convenient to assess. This kind of characteristics of Internet advertising model has driven the growth of advertising model among various Internet business models. There are, conventionally classified, CPM (Cost Per Mile), CPC (Cost Per Click), and CPS (Cost Per Sales) models as Internet advertising expenditure model. These can be examined in manners regarding risks that stakeholders should stand and degree of responsibility. CPM model that is based on number of advertisement exposure is mechanically exposed to users but not actually recognized by users resulting in risk of wasted expenditure by advertisers without any advertising effect. While on aspect of media, CPS model that is based on conversion action is the most risky model because of the conversion action such as product purchase is determined by capability of advertisers not that of media. In this regard, while there are issue of CPM and CPS models disadvantageously affecting only one side of Internet advertising business model value network, CPC model has been evaluated as reasonable both to advertisers and media, and occupied the largest segment of Internet advertising market. However, CPC model also can cause fraudulent behavior such as click fraud because of the competition or dishonest amount of advertising expenditure. On the user aspect, unintentionally accessed advertisements can lead to more inappropriate expenditure from advertisers. In this paper, we suggest "CPCD"(Cost Per Coupon Download) model. This goes beyond simple clicking of advertisements and advertising expenditure is exerted when users download a coupon from advertisers, which is a concept in between CPC and CPS models. To achieve the purpose, we describe the scenario of advertiser perspective, processes, participants and their benefits of CPCD model. Especially, we suggest the new value in online coupon; "possibility of storage" and "complement for delivery to the target group". We also analyze the working condition for advertiser by a comparison of CPC and CPCD models through advertising expenditure simulation. The result of simulation implies that the CPCD model suits more properly to advertisers with medium-low price products rather than that of high priced goods. This denotes that since most of advertisers in CPC model are dealing with medium-low priced products, the result is very interesting. At last, we contemplate applicability of CPCD model in ubiquitous environment.

Assessment of Carsington Dam Failure by Slope Stability and Dam Behavior Analyses (사면안정 해석과 댐 거동분석을 통한 Carsington Dam 파괴의 고찰)

  • 송정락;김성인
    • Proceedings of the Korean Geotechical Society Conference
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    • 1991.10a
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    • pp.87-102
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    • 1991
  • It has been reported that the failure of Carsington Dam in Eng1and occured due to the existence of a thin yellow clay layer which was not identified during the design work, and due to pre-existing shears of the clay layer. The slope stability analyses during the design work, which utilized traditional circular arc type failure method and neglected the existence of the clay layer, showed a safety factor of 1.4. However, the post-failure analyses which utilized translational failure mode considering the clay layer and the pre-existing shear deformation revealed the reduction of safety factor to unity. The post-failure analysis assumed 10。 inclination of the horizontal forces onto each slice based on the results of finite element analyses. In this paper, Bishop's simplified method, Janbu method, and Morgenstern-Price method were used for the comparison of both circular and translational failure analysis methods. The effects of the pre-existing shears and subsquent movement were also considered by varying the soil strength parameters and the pore pressure ratio according to the given soi1 parameters. The results showed factor of safefy 1.387 by Bishop's simplified method(STABL) which assumed circular arc failure surface and disregarding yellow clay layer and pre-failure material properties. Also the results showed factor of safety 1.093 by Janbu method(STABL) and 0.969 by Morgenstern-Price method(MALE) which assumed wedge failure surface and considerd yellow clay layer using post failure material properties. In addition, dam behavior was simulated by Cam-Clay model FEM program. The effects of pore pressure changes with loading and consolidation, and strength reduction near or at failure were also considered based on properly assumed stress-strain relationship and pore pressure characteristics. The results showed that the failure was initiated at the yellow clay layer and propagated through other zones by showing that stress and displacement were concentrated at the yel1ow clay layer.

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A Study on Development of Prototype Test Train Design in G7 Project for High Speed Railway Technology (G7 고속전철기술개발사업에서의 시제차량 통합 디자인 개발)

  • 정경렬;이병종;윤세균
    • Archives of design research
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    • v.16 no.4
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    • pp.185-196
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    • 2003
  • The demand for an environment-friendly transportation system, equipped with low energy consumption, and low-or zero-pollution has been on the increase since the beginning of the World Trade Organization era. Simultaneously, the consistent growth of high-speed tram technology, combined with market share, has sparked a fierce competition among technologically-advanced countries like France, Germany, and Japan in an effort to keep the lead in high-speed train technology via extensive Research and development(R&D) expenses. These countries are leaders in the race to implement the next-generation transportation system, build intercontinental rail way networks and export the high-speed train as a major industry commodity. The need to develop our own(Korean) 'high-speed train' technology and its core system technology layouts including original technology serves a few objectives: They boost the national competitive edge; they develop an environmental friendly rail road system that can cope with globalization and minimize the social and economic losses created by the growing traffic-congested delivery costs, environment pollution, and public discomforts. In turn, the 'G7 Project-Development of High Speed Railway Technology' held between 1996 and 2002 for a six-year period was focused on designing a domestic train capable of traveling at a speed of 350km/h combined and led to the actual implementation of engineering and producing the '2000 high-speed train:' This paper summarizes and introduces one of the G7 Projects-specifically, the design segment achievement within the development of train system engineering technology. It is true that the design aspect of the Korean domestic railway system program as a whole was lacking when compared with the advanced railroad countries whose early phase of train design emphasized the design aspect. However, having allowed the active participation of expert designers in the early phase of train design in the current project has led to a new era of domestic train development and the implementation of a way to meet demand flexibly with newly designed trains. The idea of a high-speed train in Korea and its design concept is well-conceived: a faster, more pleasant, and silent based Korean high-speed train that facilitates a new travel culture. A Korean-type of high-speed train is acknowledged by passengers who travel in such trains. The Korean high-speed prototype train has been born, combining aerodynamic air-cushioned design, which is the embodiment of Korean original design of forehead of power car minimized aerodynamic resistance using a curved car body profile, and the improvement of the interior design with ergonomics and the accommodation of the vestibule area through the study of passenger behavior and social culture that is based on the general passenger car.

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A Microcomputer-Based Data Acquisition System (Microcomputer를 이용(利用)한 Data Acquisition System에 관(關)한 연구(硏究))

  • Kim, Ki Dae;Kim, Soung Rai
    • Journal of Biosystems Engineering
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    • v.7 no.2
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    • pp.18-29
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    • 1983
  • A low cost and versatile data acquisition system for the field and laboratory use was developed by using a single board microcomputer. Data acquisition system based on a Z80 microprocessor was built, tested and modified to obtain the present functional system. The microcomputer developed consists of 6 kB ROM, 5 kB RAM, 6-seven segment LED display, 16-Hex. key and 8 command key board. And it interfaces with an 8 channel, 12 bits A/D converter, a microprinter, EPROM programmer for 2716, and RS232C interface to transfer data between the system and HP3000 mini-computer manufactured by Hewlett Packard Co., A software package was also developed, tested, and modified for the system. This package included drivers for the AID converter, LED display, key board, microprinter, EPROM programmer, and RS232c interface. All of these programs were written in 280 assembler language and converted to machine codes using a cross assembler by HP3000 computer to the system during modifying stage by data transferring unit of this system, then the machine language wrote to the EPROM by this EPROM programmer. The results are summarized as follows: 1. Measuring program developed was able to control the measuring intervals, No. of channels used, and No. of data, where the maximum measuring speed was 58.8 microsec. 2. Calibration of the system was performed with triangle wave generated by a function generator. The results of calibration agreed well to the test results. 3. The measured data was able to be written into EPROM, then the EPROM data was compared with original data. It took only 75 sec. for the developed program to write the data of 2 kB the EPROM. 4. For the slow speed measurements, microprinter instead of EPROM programmer proved to be useful. It took about 15 min. for microprinter to write the data of 2 kB. 5. Modified data transferring unit was very effective in communicating between the system and HP3000 computer. The required time for data transferring was only 1~2 min. 6. By using DC/DC converting devices such as 78-series, 79-series. and TL497 IC, this system was modified to convert the only one input power sources to the various powers. The available power sources of the system was DC 7~25 V and 1.8 A.

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Comparative Study on the Nurses' Job Satisfaction between the Oriental Medicine Ward and the General Ward (한방병동과 일반병동 간호사의 직무만족도의 비교연구)

  • Byun, Chang-Ja;Choi, Sang-Soon;Paik, Seung-Nam;Lee, Mi-Aie
    • Journal of Korean Academy of Nursing Administration
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    • v.1 no.1
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    • pp.97-111
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    • 1995
  • In our society today, a variety of medical caring system, along with a scientific development in the area of oriental medical science plus national demand, has increased the augmentation and the opening of oriental wards and hospitals (Han Bang), which has come to create an additional requirement of nursing activity at oriental medicine wards should be different from that of the general wards or the same as the other. In view of this, various studies need to be made in this connection. The purpose of this study is to comprehend the number of nurses who want to work at oriental medicine wards and measure job satisfaction in nursing as compared with those working at general wards so as to provide basic materials for future assignment and supplementary training for the nurses. An attempt was made to contribute toward nursing administration on the one hand improving nursing training course on the other hand. A total of 72 nurses currently working at two oriental medicine hospitals available in Seoul and 82 general nurses were selected for this study using the questionaire from December 1993 to January 1994. An instrument for the study was based on the measurement of work satisfaction developed by Paula L. Stamps including 37 questions complemented by Kim for revision (1993) and 14 questions regarding general characteristics and oriental medicine wards. The instrument to test dependability showed Cronbach's=0.7711. The collected data have been processed by computer package SPSS. General characteristics of the two groups and the matters involved in oriental medicine wards were calculated into real figure and percentage an similarities between the two groups were analyzed by t-test and F-test according to the characteristics of variables. The comparative test on work satisfaction among the two groups including general characteristics and work factors were conducted by t-test and F-test. The major findings as a result of the study are as follows : 1. As general characteristics, age group of $26{\sim}30$ years are more than any segment of age. As to marital status, the number of those in single status is slightly higher than the married. Approximately 80% of them are graduates of nursing schools and nursing colleges. They are mostly in service for one to three years. There is no significant difference between the two groups. 2. The number of those who want to work at oriental medicine wards represents 40.3% against 58.4%, being in favor of general wards. 3. The reason for service at oriental medicine wards is that "there is room for potential research" which happened to rank first, followed by "easy job," "good working atmosphere" and "growing interest in oriental medicine." 4. Work satisfactions among nurses who work at oriental medicine wards prove greater than that of nurses who work at general wards. 5. Work satisfaction between the two groups by work factors is reflected with significant difference statistically on task requirement, interaction and doctor-nurse relationships. 6. The general charcateristics and the work satisfaction by work factors prove that there are significant difference in age, marital status, education and the period of work. They tend to be more satisfied with the work as they grow in age. Significant differneces are found in the work factors such as autonomy, adiministration and professional job in the relationship with doctor-nurse. As to marital status, the married are more satisfied than the unmarried. There are significant differneces in the factors respecting administration and doctor-nurse college graduates are highly satisfied with task requirement. However, satisfaction with the professional level has proven the highest degree for those having master degree. The period of work and satisfaction : There are significant differneces in task requirement, administration, interactions, professional level and doctor-nurse relationships. As a general rule, the degree of satisfactions is in proportion to the lengrh of service. The following conclusions are drawn based on the fndings mentioned above. Even though the work satisfaction of the nurse who work at oriental medicine ward is relatively high, it is desired that personal consultation be given as to disposition of nurses when they are assigned to oriental medicine wards. It is also recommended that lectures on oriental medicine be conducted through supplementary training and/or basic nursing course in order that they may be motivated for ingenious activities with an increasing sense of self-esteem which will eventually enhance positive changes for the patients who are in need of oriental medicine nursing and for the medical teams. In addition, joint reseaches involvingclinical care and education should be in constant process for unique and scientific development for those who are subject to oriental medicine nursing care.

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The Landscape Organization of the Dodong-SeoWon in the Aesthetics of Moderation (중용(中庸)의 미학으로 살핀 도동서원(道東書院)의 경관짜임)

  • Rho, Jae-Hyun;Shin, Byung-Chul
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.30 no.4
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    • pp.44-55
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    • 2012
  • This study is to interpret how landscape aesthetic characteristics of moderation, which is the point of human-oriented neo-confucianism vision, are projected to the landscape organization of a Dodong-SeoWon, known for its overflow to neo-confucianism grounds and standards among domestic SeoWon. The aspects of neo-confucianism discussion in the shape of Dodong-SeoWon with the beauty of from and contents dominating the landscape of Dodong-SeoWon different from constructive completeness as 7 external and internal landscape organization including placement, circulation, setting, vista, fencing, naming, and decoration are as follows. The left direction of Dodong-SeoWon, part of external organization, is the result of landscape organization that emphasized the stage of moderation through the unification of man and nature by naturalizing natural direction to human-oriented directions. Important aspects to rule external orders and standards of Dodong-SeoWon are principles of one classes based on ranks and bilateral symmetry that is the unity of setting and circulation landscape organization from penetrating the spirit of moderation with no bias. By securing territoriality by fencing the unity of verticality and horizontality, the landscape organization to reach moderation is expressed. Meanwhile, Suwoloo(水月樓) perceived on the floor of central assembly hall, the formation of time frame from roof piles of Hwanjumun(喚主門) as well as pilars of Jungjeongdang(中正堂), and rime link method inducing visual balance and openness through segment, combination, and others are vista organization that show the ideality of unique neo-confucianism building. Also as part of landscape organization contents. semantically, building name including arrangement from Taegukdoseol, ideological naming following the name of Ssanggye-SeoWon, which is the former body, the name of the hall symbolizing the transfer of neo-confucianism enlightenment, impartiality with no bias, as well as Geoinjae(居仁齋) and Geoijae(居義齋) based on olympic, are also results of applying neo-confucianism standards. Additionally. the SeoHoe(瑞花) expressing the change of IleumIlyang(一陰一陽) on the stylobate of Jungjeongdang, Saeho(細虎) which goes up and down, as well as Simul made of four dragons, are artistic expression of the moderation that symbolizes the harmony of ying and yang with no exceeding or insufficiency. Humorous and unique rocks and stones evenly arranged in all spots of Dodong-SeoWon are to promote anti-strict organization by offsetting the image and external order of the lecture hall as strict as it is, and this is very ironic as it is the other landscape organization in different dimension as well as the expression of moderation.

A comparative study between Korea and the USA on the development process in retail trade & its changing locations (소매업의 발달과정과 입지 변화에 관한 한.미 비교 연구)

  • Jeon, Kyung-Sook
    • Journal of the Korean association of regional geographers
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    • v.6 no.2
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    • pp.21-40
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    • 2000
  • The retail trades in many countries have changed recently according to the high quality, diversification, and marked individuality of consumer needs. Under the continually competing system of the WTO agreement, corporations based in the USA and the EU try to raise their market share in other countries so it is inevitable for Korean retail enterprises to compete with them. This paper is aimed at contributing to the efficient growth for Korean retail trade from the analysis of the development process in retail trade and its changing locations comparing Korea and the USA. Retailers in the USA have practiced diversified marketing strategies considerably in order to survive in a rapidly changing retailing environment. American retailing, which has the most advanced marketing system in the world, has been of growing concern to marketing strategies in Korea. The following is a brief summary of this study. 1. Speedy and higher quality consumption is needed in accordance with the great increase in the single-family household and the female labor force participation both in Korea and in the USA. Senior citizens have become a new consumer group due to the aging population. In the future the retail trade will switch over to diversified retail formats and internet shopping as countries are transformed into information and communication societies. 2. In Korea, the former retail system characterized by markets and department stores has been greatly changed since the late 1980s with emphasis on high quality and convenience in consumption behaviors, with large domestic enterprises and foreign distribution corporations participating in Korean retailing. In the USA, retailing mergers and takeovers by major retails, bankruptcies, and extra-large shopping centers have emerged since the late 1980s. Recently, the USA retailing formats have been changed from the lower price-oriented discount types to the large scale theme parks. Much emphasis was put on entertainment, resorts, and convention centers. On the other hand, non-store types, such as the internet shopping, the CATV shopping, as well as catalog and mail-order sales are drastically increasing, although the proportion of their sales is low up to now. 3. In Korea, most of the retail facilities are concentrated in Seoul and the Metropolitan Region, and the distribution ratio of facilities came to 52% in 1997. The periodic markets, traditional markets which open on a periodic basis, are located mainly in Chollanam-do and Kyungsangbuk-do. The large-sized discount stores have expanded their locations to the over-crowded apartment complexes in new towns, located in the Metropolitan Region, and the large provincial cities, unlike the suburban locations in the USA. Therefore we needed to give attention to the locational relations in retail facilities between Seoul & the Metropolitan Region and rural settlement areas. In the USA, urban areas grew quickly with the development of the automobile in the 1920s, and the location of stores changed from a dispersed style centering around rural areas to a centralized one in urban areas. There is an accelerated growth for suburban areas, which have grown rapidly since 1950. As the membership warehouse clubs were introduced in the 1970s, the decentralization of location was more intensified. On the other hand, inner cities were revitalized by rearranging existing facilities to cope with suburban areas. And the location-free virtual retailing & TV shopping are also growing every year. 4. In view of the above, the continuous and desirable development devices in Korean retail trade are summarized as follows: First, the countermeasures against economies of scale, increase in retailing sales, and rise of a employment percentage in retailing are in need. Second, a scheme of lowering the proportion of food retail sales, and increasing a ratio of durable goods sales need to be worked out. Third, the original ideas are needed to apply positively information, communication and technology to retailing, to graft the traditional types on modem ones based on the social culture. Fourth, strategies are needed to strengthen the competitiveness of our retail trade through cooperation and chains of smaller retailers, the large enterprises participating in the distribution industry. Fifth, in order to realize the above, the retail industry, the administration, and the academic world should support the retail segment with concern and a practical strategy plan.

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Selectivity of Bleaching Herbicides Caused by Physiological Differences between Rice and Barnyardgrass (벼와 피의 생리적(生理的) 차이(差異)에 의한 백화형(白化型) 제초제(除草劑)의 선택성(選擇性))

  • Na, J.Y.;Kim, J.S.;Kim, T.J.;Cho, K.Y.;Pyon, J.Y.
    • Korean Journal of Weed Science
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    • v.12 no.2
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    • pp.89-101
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    • 1992
  • In this study, various physiological and biochemical experiments were conducted to know whether the selectivity between rice and barnyardgrass treated with bleaching herbicides containing diphenyl ether compounds was also partly based on their basic physiological proterties such as peroxidation ability, membrane stability or antioxidant system. It seemed to be partly based on the differences of their physiological characteristics that barnyardgrass was commonly more susceptible to most of the bleaching herbicides than rice. The scenescence of intact leaf segment was more rapid in barnyardgrass than in rice, indicating that barnyardgrass is weak at early stage. Also pigment metabolic ability, antioxidant enzyme activities(peroxidase, catalase, superoxide dismutase, glutathione reductase) and antioxidant content (tocopherol, ascorbic acid, glutathione, carotenoids) were lower in barnyardgrass on the basic of fresh weight. However, lipoxygenase activity and the content of unsaturated fatty acid which is vulnerable to oxygen radicals were higher in barnyardgrass, suggesting that barnyardgrass seedling bave a properties easy to be peroxidized. The differences of PPIX (protoporphyrin IX) or carotenoid content, which are the primary substances inducing herbicide activity, were not related to the selectivity between rice and barnyardgrass.

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