• Title/Summary/Keyword: Co-learning

Search Result 865, Processing Time 0.04 seconds

A Study of the Core Factors Affecting the Performance of Technology Management of Inno-Biz SMEs (기술혁신형(Inno-Biz) 중소기업의 기술경영성과에 미치는 핵심요인에 관한 연구)

  • Yoon, Heon-Deok;Seo, Ri-Bin
    • Journal of Technology Innovation
    • /
    • v.19 no.1
    • /
    • pp.111-144
    • /
    • 2011
  • This study is to confirm the core factors of innovative capabilities and technological entrepreneurship affecting the performance of technology management and business management of small and medium-sized enterprises (SMEs). Through the consideration about the complex natures of technological innovation affecting by multidimensional factors, this study designs the research model that innovative capabilities, the performances of technology and business management are arranged in accordance with the innovation process; input-output-outcome. To meet this research purpose, the hypothesis are set up based on the previous research studies and the research samples are selected from members of the Innovative Business (INNO-BIZ) Association, located in Seoul and Geyonggi province. As a result of regression analysis to the responses gathered from 360 firms, the performance of business management is influenced positively by the technology superiority, market growth and business profitability which are the dominant factors of performance of technology management. In addition, three sub-variables of innovative capabilities such as R&D, strategic planning and learning capability, have positive effects on both the managerial performances. Innovativeness and progressiveness of technological entrepreneurship affect both the performances positively. Moreover, the co-relation between technological entrepreneurship of an innovation leader and innovative capabilities of organizational members are identified. Lastly, technological entrepreneurship has the mediating effect on the path of leading innovative capabilities to the managerial performances. In conclusion, the research results imply that technological innovation-type firms should periodically evaluate the performance of technology management which are the output of technological innovations and the reinvestment for ultimate business success. And improving and developing innovative capabilities and technological entrepreneurship is required to continuously and consistently investing and supporting resources on technological innovations at the firm-and government-level. It is considered that these are the crucial methods for securing the technologically competitive advantage of SMEs with less resources and narrow innovation range.

  • PDF

A Study and Investigation for the Attitude about Smoking of Boys' and Girls' High School in Seoul (서울시내 남녀고교생의 흡연에 관한 태도 조사연구)

  • Sim Young Ae
    • Journal of Korean Public Health Nursing
    • /
    • v.3 no.1
    • /
    • pp.74-100
    • /
    • 1989
  • Inspite of the lots of studies on the harmfulness of cigarette smoking to the body published by many researchers since 1950, cigarette smoking people are increasing in number especially, cigarette smoking by young and women causes a serious problem. Examining the physiological motives of youth shows that, impulse which the youth want to immitate the adults, alluring curiousity, and defiant physiology of escaping from the norm of traditional groups which has been banned are cooperated well compoundly. As the period of the youth is the one which they accumulate knowledge and charactor by learning as well as the period of growth mentally, and physically they should be rightly educated about smoking before they addicted to smoking and it is desirable for us to make the youth to understand how harmfully the smoking is to effect to their growth and mental soundness simply not as a social norm which they should not smoke. The main motive of this study on the attitude of smoking by the youth is to give basic materials related on this field. For this study, 647 questionnaires were used as studying material which were able to analyze among 720 questionnaires of 2 classes of each grade of 3 high schools among the high schools of boys, girls and co-educated in Seoul from Oct. 21, 1988 through Oct. 26, 1988. Study Instrument are graded in Likert's 5 point from 40 questions which are 20 questions m affirmations and 20 questions in negations after analyzing the factors on 60 simple sentence questions which the students showed in preliminary studies. And these are systemized to be measured from 1 point which means they think smoking IS very bad to 5points which means they think smoking is really good. In these collected materials, technical statistics of frequency. percentage, average, standard deviation are used for general character and smoking attitude, $X^2-test$ for examinning Independant variables of physical. emotional, ethical and other areas pearson's coefficient of correlation for related direction and degree" and step­regression analysis for the degree of relative contribution of all variables which effect smoking attitude. The results of this study are as follows; 1. The smoking attitude of high school boys and girls showed average of 1.78 in physical area, 2.63 in emotional area, 2.61 in ethical area, 2.29 in other area respectively in a negative attitude generally also the negative attitude are expressed most strongly in physical area. I've can also say by this results that smoking is harmful to their health and further more it can be judged that this proves the youth in the period of preparation be adults have a strong curiousity in the emotional, ethical and other areas. 2. The most influential variables in each field as related factors effecting smoking attitude of the student can be explained from 13.2 in physical area the lowest experienced variables to 25.2 in emotional area the highest of degree of smoking experience. The fact that the more the smoking experienced students are increasing in number the higher tendency which accept the' smoking tells as the importance of health education about the population of latest student's smoking as important variables shown equally in each area. Those of grade, age, numbers of smoking people in house are showed meaningful in pure interrelation. Those related to the acceptance of teacher's smoking, sex, mothors education are shown meaningful in opposite interrelations. This means that the' increasing number' of smoking people in grade age, the number of smoker in family have a affirmative attitude. And people who are not interested in teacher's smoking wants to quit it, and whose mother's education is higher have a negative attitude. 3. The most negatively answered questions of the smoking attitude In physical, emotional, ethical and other areas are as belows; Firstly too much smoking is harmful to our health is 1.12 point. Secondly smoking have a ill-effect on pregnancy and embryo is 1.13 point. Thirdly smoking is harmful· to our health is 1.27 point. Fourthly smoking in crowed area with the people such as In a bus or subway should be prohibited is 1.27point. Fifthly smoking can ruin lungs is 1.31 point. And the most affirmatively answered questions are also as below; Firstly we showed smoke depending on time and place is 3.96 points. Secondly smoking is just habit is 3.83 points. Thirdly smoking people seem to be unable and deplorable is 3.69 point. Fourthly smoking should be prohibited by law is 3.56 points. Fifthly high school student's smoking is immitation of adults is 3.52 points.

  • PDF

A Study on the Competencies of Automotive Professional Engineers in Korea (자동차 신제품개발 관련 차량기술사의 전문적 업무역량 분석)

  • Kim, Joo-Young;Lim, Se-Yung
    • 대한공업교육학회지
    • /
    • v.33 no.2
    • /
    • pp.192-217
    • /
    • 2008
  • This paper investigated the perceived criticalities and patterns of Korean Professional Engineer's competency regarding the working activities of automative product development, manufacturing, etc by using questionnaires responded to the survey which were applied to the automotive professors, experts and professional engineers (vocational parties) by e/mail, etc. This research investigated the following questions: First, what are the characteristic patterns, relevancy and perceived criticalities of Korean Professional Engineer's competencies? Second, What are the ranked priority of the Korean Professional Engineers' competencies? Are there any differency for each item, sub group of job, intelectual criterior of the competencies between relevancy and perceived criticalities according to the types of vocational parties, etc.? Accoring to the results; first, Professor group showed highest points among 3 groups per each item of the competencies by vocational parties Second, Chassis design group ranked top position among the 8 sub groups by vocational parties and, third, Problem Solving Knowledge ranked highest points than any others. Korean Professional Engineers are found to be positioned as key members, leaders and managers on surveying market, product planning, designing product & components, developing component parts, establishing shop with production equipment, managing quality control & material handling, organizing relevant meetings, developing human resources by training and learning, to back up finance with law matters, cooperating with concerned parties to achieve organizational goals, and to coordinate projects. etc, identifying ethical issues and business skills in order to survive and win to be competitive in various kinds of the automotive industry battle fields.

The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM (다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형)

  • Park, Ji-Young;Hong, Tae-Ho
    • Asia pacific journal of information systems
    • /
    • v.19 no.2
    • /
    • pp.139-155
    • /
    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.

Syllabus Design and Pronunciation Teaching

  • Amakawa, Yukiko
    • Proceedings of the KSPS conference
    • /
    • 2000.07a
    • /
    • pp.235-240
    • /
    • 2000
  • In the age of global communication, more human exchange is extended at the grass-roots level. In the old days, language policy and language planning was based on one nation-state with one language. But high waves of globalizaiton have allowed extended human flow of exchange beyond one's national border on a daily basis. Under such circumstances, homogeneity in Japan may not allow Japanese to speak and communicate only in Japanese and only with Japanese people. In Japan, an advisory report was made to the Ministry of Education in June 1996 about what education should be like in the 21st century. In this report, an introduction of English at public elementary schools was for the first time made. A basic policy of English instruction at the elementary school level was revealed. With this concept, English instruction is not required at the elementary school level but each school has their own choice of introducing English as their curriculum starting April 2002. As Baker, Colin (1996) indicates the age of three as being the threshold diving a child becoming bilingual naturally or by formal instruction. Threre is a movement towards making second language acquisition more naturalistic in an educational setting, developing communicative competence in a more or less formal way. From the lesson of the Canadian immersion success, Genesee (1987) stresses the importance of early language instruction. It is clear that from a psycho-linguistic perspective, most children acquire basic communication skills in their first language apparently effortlessly and without systematic and formal instruction during the first six or seven years of life. This innate capacity diminishes with age, thereby making language learning increasingly difficult. The author, being a returnee, experienced considerable difficulty acquiring L2, and especially achieving native-like competence. There will be many hurdles to conquer until Japanese students are able to reach at least a communicative level in English. It has been mentioned that English is not taught to clear the college entrance examination, but to communicate. However, Japanese college entrance examination still makes students focus more on the grammar-translation method. This is expected to shift to a more communication stressed approach. Japan does not have to aim at becoming an official bilingual country, but at least communicative English should be taught at every level in school Mito College is a small two-year co-ed college in Japan. Students at Mito College are basically notgood at English. It has only one department for business and economics, and English is required for all freshmen. It is necessary for me to make my classes enjoyable and attractive so that students can at least get motivated to learn English. My major target is communicative English so that students may be prepared to use English in various business settings. As an experiment to introduce more communicative English, the author has made the following syllabus design. This program aims at training students speak and enjoy English. 90-minute class (only 190-minute session per week is most common in Japanese colleges) is divided into two: The first half is to train students orally using Graded Direct Method. The latter half uses different materials each time so that students can learn and enjoy English culture and language simultaneously. There are no quizes or examinations in my one-academic year program. However, all students are required to make an original English poem by the end of the spring semester. 2-6 students work together in a group on one poem. Students coming to Mito College, Japan have one of the lowest English levels in all of Japan. However, an attached example of one poem made by a group shows that students can improve their creativity as long as they are kept encouraged. At the end of the fall semester, all students are then required individually to make a 3-minute original English speech. An example of that speech contest will be presented at the Convention in Seoul.

  • PDF

Evaluation of Endothelium-dependent Myocardial Perfusion Reserve in Healthy Smokers; Cold Pressor Test using $H_2^{15}O\;PET$ (흡연자에서 관상동맥 내피세포 의존성 심근 혈류 예비능: $H_2^{15}O\;PET$ 찬물자극 검사에 의한 평가)

  • Hwang, Kyung-Hoon;Lee, Dong-Soo;Lee, Byeong-Il;Lee, Jae-Sung;Lee, Ho-Young;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
    • /
    • v.38 no.1
    • /
    • pp.21-29
    • /
    • 2004
  • Purpose: Much evidence suggests long-term cigarette smoking alters coronary vascular endothelial response. On this study, we applied nonnegative matrix factorization (NMF), an unsupervised learning algorithm, to CO-less $H_2^{15}O-PET$ to investigate coronary endothelial dysfunction caused by smoking noninvasively. Materials and methods: This study enrolled eighteen young male volunteers consisting of 9 smokers $(23.8{\pm}1.1\;yr;\;6.5{\pm}2.5$ pack-years) and 9 nonsmokers $(23.8{\pm}2.9 yr)$. They do not have any cardiovascular risk factor or disease history. Myocardial $H_2^{15}O-PET$ was performed at rest, during cold ($5^{\circ}C$) pressor stimulation and during adenosine infusion. Left ventricular blood pool and myocardium were segmented on dynamic PET data by NMF method. Myocardial blood flow (MBF) was calculated from input and tissue functions by a single compartmental model with correction of partial volume and spillover effects. Results: There were no significant difference in resting MBF between the two groups (Smokers: 1.43 0.41 ml/g/min and non-smokers: $1.37{\pm}0.41$ ml/g/min p=NS). during cold pressor stimulation, MBF in smokers was significantly lower than 4hat in non-smokers ($1.25{\pm}0.34$ ml/g/min vs $1.59{\pm}0.29$ ml/gmin; p=0.019). The difference in the ratio of cold pressor MBF to resting MBF between the two groups was also significant (p=0.024; $90{\pm}24%$ in smokers and $122{\pm}28%$ in non-smokers.). During adenosine infusion, however, hyperemic MBF did not differ significantly between smokers and non-smokers ($5.81{\pm}1.99$ ml/g/min vs $5.11{\pm}1.31$ ml/g/min ; p=NS). Conclusion: in smokers, MBF during cold pressor stimulation was significantly lower compared wi4h nonsmokers, reflecting smoking-Induced endothelial dysfunction. However, there was no significant difference in MBF during adenosine-induced hyperemia between the two groups.

Ultrastructure of Degenerating Axon Terminals in the Basal Forebrain Nuclei of the Rat following Prefrontal Decortication (이마앞겉질을 제거시킨 흰쥐 앞뇌의 바닥핵무리에서 변성축삭종말의 미세구조연구)

  • Ahn, Byung-June;Ko, Jeong-Sik;Ahn, E-Tay
    • Applied Microscopy
    • /
    • v.35 no.3
    • /
    • pp.135-152
    • /
    • 2005
  • Prefrontal cortex is a psychological and metaphysical cortex, which deals with feeling, memory, planning, attention, personality, etc. And it also integrates above-mentioned events with motor control and locomotor activities. Prefrontal cortex works as a highest CNS center, since the above mentioned functions are very important for one's successful life, and further more they are upgraded every moments through memory and learning. Many of these highest functions are supposed to be generated via forebrain basal nuclei (caudate nucleus, fundus striati nucleus, accumbens septi nucleus, septal nucleus, etc.). In this experiment, prefrontal efferent terminals within basal forebrain nuclei were ultrastructurally studied. Spraque Dawley rats, weighing $250{\sim}300g$ each, were anesthetized and their heads were fixed on the stereotaxic apparatus (experimental model, David Kopf Co.). Rats were incised their scalp, perforated a 3mm-wide hole on the right side of skull at the 11mm anterior point from the frontal O point (Ref. 13, Fig. 1), suctioned out the prefrontal cortex including cortex of the frontal pole, with suction instrument. Two days following the operations, small tissue blocks of basal forebrain nuclei were punched out, fixed in 1% glutaraldehyde-1% paraformaldehyde solution followed by 2% osmium tetroxide solutions. Ultrathin sections were stained with 1% borax-toluidin blue solution, and the stained sections were obserbed with an electron microscope. Degenerating axon terminals were found within all the basal forbrain nuclei. Numbers of degenerated terminals were largest in the caudate nucleus, next in order, in the fundus striati nucleus, in the accumbens septi nucleus, and the least in the septal nucleus. Only axospinous terminals were degenerated within the caudate nucleus and the fundus striati nucleus, and they showed the characters of striatal motor control system. Axodendritic and axospinous terminals were degenerated within the accumbens septi nucleus and the lateral septal nucleus, and they showed the characters of visceral limbic system. Prefrontal role in integrating the limbic system with the striatal system, en route basal forebrain nuclei, was discussed.

Clinical Investigation of Childhood Epilepsy (소아간질의 임상적 관찰)

  • Moon, Han-Ku;Park, Yong-Hoon
    • Journal of Yeungnam Medical Science
    • /
    • v.2 no.1
    • /
    • pp.103-111
    • /
    • 1985
  • Childhood epilepsy which has high prevalence rate and inception rate is one of the commonest problem encountered in pediatrician. In contrast with epilepsy of adult, in childhood epilepsy, more variable and varying manifestations are found because the factors of age, growth and development exert their influences in the manifestations and the courses of childhood epilepsy. Moreover epileptic children have associated problems such as physical and mental handicaps, psychologicaldisorders and learning disability. For these reasons pediatrician who deals with epileptic children experiences difficulties in making diagnosis and managing them. In order to improve understanding and management of childhood epilepsy, authors reviewed 103 cases of epileptic patients seen at pediatric department of Yeungnam University Hospital retrospectively. The patients were classified according to the type of epileptic seizure. Suspected causes of epilepsy, associated conditions of epileptic patients, age incidence and the findings of brain CT were reviewed. Large numbers of epileptic patients (61.2%) developed their first seizures under the age of 5. The most frequent type of epileptic seizure was generalized ionic-clonic, tonic, clonic seizure (49.5%), followed by simple partial seizure with secondary generalization (17.5%), simple partial seizure (7.8%), a typical absence (5.8%) and unclassified seizure (5.8%). In 83.5% of patients, we could not find specific cause of it, but in 16.5% of cases, history of neonatal hypoxia (4.9%), meningitis (3.9%), prematurity (1.9%), small for gestational age (1.0%), CO poisoning (1.0%), encephalopathy (1.0%), DPT vaccination (1.0%), cerebrovascular accident (1.0%) and neonatal jaundice (1.0%) were found, 30 cases of patients had associated diseases such as mental retardation, hyperactivity, delayed motor milestones or their combinations. The major abnormal findings of brain CT performed in 42 cases were cortical atrophy, cerebral infarction, hydrocephalus and brain swelling. This review stressed better designed classification of epilepsy is needed and with promotion of medical care, prevention of epilepsy is possible in some cases. Also it is stressed that childhood epilepsy requires multidisplinary therapy and brain CT is helpful in the evaluation of epilepsy with limitation in therapeutic aspects.

  • PDF

Product Recommender Systems using Multi-Model Ensemble Techniques (다중모형조합기법을 이용한 상품추천시스템)

  • Lee, Yeonjeong;Kim, Kyoung-Jae
    • Journal of Intelligence and Information Systems
    • /
    • v.19 no.2
    • /
    • pp.39-54
    • /
    • 2013
  • Recent explosive increase of electronic commerce provides many advantageous purchase opportunities to customers. In this situation, customers who do not have enough knowledge about their purchases, may accept product recommendations. Product recommender systems automatically reflect user's preference and provide recommendation list to the users. Thus, product recommender system in online shopping store has been known as one of the most popular tools for one-to-one marketing. However, recommender systems which do not properly reflect user's preference cause user's disappointment and waste of time. In this study, we propose a novel recommender system which uses data mining and multi-model ensemble techniques to enhance the recommendation performance through reflecting the precise user's preference. The research data is collected from the real-world online shopping store, which deals products from famous art galleries and museums in Korea. The data initially contain 5759 transaction data, but finally remain 3167 transaction data after deletion of null data. In this study, we transform the categorical variables into dummy variables and exclude outlier data. The proposed model consists of two steps. The first step predicts customers who have high likelihood to purchase products in the online shopping store. In this step, we first use logistic regression, decision trees, and artificial neural networks to predict customers who have high likelihood to purchase products in each product group. We perform above data mining techniques using SAS E-Miner software. In this study, we partition datasets into two sets as modeling and validation sets for the logistic regression and decision trees. We also partition datasets into three sets as training, test, and validation sets for the artificial neural network model. The validation dataset is equal for the all experiments. Then we composite the results of each predictor using the multi-model ensemble techniques such as bagging and bumping. Bagging is the abbreviation of "Bootstrap Aggregation" and it composite outputs from several machine learning techniques for raising the performance and stability of prediction or classification. This technique is special form of the averaging method. Bumping is the abbreviation of "Bootstrap Umbrella of Model Parameter," and it only considers the model which has the lowest error value. The results show that bumping outperforms bagging and the other predictors except for "Poster" product group. For the "Poster" product group, artificial neural network model performs better than the other models. In the second step, we use the market basket analysis to extract association rules for co-purchased products. We can extract thirty one association rules according to values of Lift, Support, and Confidence measure. We set the minimum transaction frequency to support associations as 5%, maximum number of items in an association as 4, and minimum confidence for rule generation as 10%. This study also excludes the extracted association rules below 1 of lift value. We finally get fifteen association rules by excluding duplicate rules. Among the fifteen association rules, eleven rules contain association between products in "Office Supplies" product group, one rules include the association between "Office Supplies" and "Fashion" product groups, and other three rules contain association between "Office Supplies" and "Home Decoration" product groups. Finally, the proposed product recommender systems provides list of recommendations to the proper customers. We test the usability of the proposed system by using prototype and real-world transaction and profile data. For this end, we construct the prototype system by using the ASP, Java Script and Microsoft Access. In addition, we survey about user satisfaction for the recommended product list from the proposed system and the randomly selected product lists. The participants for the survey are 173 persons who use MSN Messenger, Daum Caf$\acute{e}$, and P2P services. We evaluate the user satisfaction using five-scale Likert measure. This study also performs "Paired Sample T-test" for the results of the survey. The results show that the proposed model outperforms the random selection model with 1% statistical significance level. It means that the users satisfied the recommended product list significantly. The results also show that the proposed system may be useful in real-world online shopping store.

Spectral Band Selection for Detecting Fire Blight Disease in Pear Trees by Narrowband Hyperspectral Imagery (초분광 이미지를 이용한 배나무 화상병에 대한 최적 분광 밴드 선정)

  • Kang, Ye-Seong;Park, Jun-Woo;Jang, Si-Hyeong;Song, Hye-Young;Kang, Kyung-Suk;Ryu, Chan-Seok;Kim, Seong-Heon;Jun, Sae-Rom;Kang, Tae-Hwan;Kim, Gul-Hwan
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.23 no.1
    • /
    • pp.15-33
    • /
    • 2021
  • In this study, the possibility of discriminating Fire blight (FB) infection tested using the hyperspectral imagery. The reflectance of healthy and infected leaves and branches was acquired with 5 nm of full width at high maximum (FWHM) and then it was standardized to 10 nm, 25 nm, 50 nm, and 80 nm of FWHM. The standardized samples were divided into training and test sets at ratios of 7:3, 5:5 and 3:7 to find the optimal bands of FWHM by the decision tree analysis. Classification accuracy was evaluated using overall accuracy (OA) and kappa coefficient (KC). The hyperspectral reflectance of infected leaves and branches was significantly lower than those of healthy green, red-edge (RE) and near infrared (NIR) regions. The bands selected for the first node were generally 750 and 800 nm; these were used to identify the infection of leaves and branches, respectively. The accuracy of the classifier was higher in the 7:3 ratio. Four bands with 50 nm of FWHM (450, 650, 750, and 950 nm) might be reasonable because the difference in the recalculated accuracy between 8 bands with 10 nm of FWHM (440, 580, 640, 660, 680, 710, 730, and 740 nm) and 4 bands was only 1.8% for OA and 4.1% for KC, respectively. Finally, adding two bands (550 nm and 800 nm with 25 nm of FWHM) in four bands with 50 nm of FWHM have been proposed to improve the usability of multispectral image sensors with performing various roles in agriculture as well as detecting FB with other combinations of spectral bands.