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Enhancing Technology Learning Capabilities for Catch-up and Post Catch-up Innovations (기술학습역량 강화를 통한 추격 및 탈추격 혁신 촉진)

  • Bae, Zong-Tae;Lee, Jong-Seon;Koo, Bonjin
    • The Journal of Small Business Innovation
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    • v.19 no.2
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    • pp.53-68
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    • 2016
  • Motivation and activities for technological learning, entrepreneurship, innovation, and creativity are driving forces of economic development in Asian countries. In the early stages of technological development, technological learning and entrepreneurship are efficient ways in which to catch up with advanced countries because firms can accumulate skills and knowledge quickly at relatively low risk. In the later stages of technological development, however, innovation and creativity become more important. This study aims to identify a) the factors (learning capabilities) that influence technological learning performance and b) barriers to enhancing innovation capabilities for the creative economy and organizations. The major part of this study is related to learning capabilities in the post-catch-up era. Based on a literature review and observations from Korean experiences, this study proposes a technological learning model composed of various influencing factors on technological learning. Three hypotheses are derived, and data are collected from Korean machine tool manufacturers. Intense interviews with CEOs and R&D directors are conducted using structured questionnaires. Statistical analysis, such as correlation and ANOVA are then carried out. Furthermore, this study addresses how to enhance innovation capabilities to move forward. Innovation enablers and barriers are identified by case studies and policy analysis. The results of the empirical study identify several levels of firms' learning capabilities and activities such as a) stock of technology, b) potential of technical labor, c) explicit technological efforts, d) readiness to learn, e) top management support, f) a formal technological learning system, g) high learning motivation, h) appropriate technology choice, and i) specific goal setting. These learning capabilities determine firms' learning performance, especially in the early stages of development. Furthermore, it is found that the critical factors for successful technological learning vary along the stages of technology development. Throughout the statistical and policy analyses, this study confirms that technological learning can be understood as an intrinsic principle of the technology development process. Firms perform proactive and creative learning in the late stages, while reactive and imitative learning prevails in the early stages. In addition, this study identifies the driving forces or facilitating factors enhancing innovation performance in the post catch-up era. The results of the preliminary case studies and policy analysis show some facilitating factors such as a) the strategic intent of the CEO and corporate culture, b) leadership and change agents, c) design principles and routines, d) ecosystem and collaboration with partners, and e) intensive R&D investment.

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Determination of methamphetamine, 4-hydroxymethamphetamine, amphetamine and 4-hydroxyamphetamine in urine using dilute-and-shoot liquid chromatography-tandem mass spectrometry (시료 희석 주입 LC-MS/MS를 이용한 소변 중 메스암페타민, 4-하이드록시메스암페타민, 암페타민 및 4-하이드록시암페타민 동시 분석)

  • Heo, Bo-Reum;Kwon, NamHee;Kim, Jin Young
    • Analytical Science and Technology
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    • v.31 no.4
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    • pp.161-170
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    • 2018
  • The epidemic of disorders associated with synthetic stimulants, such as methamphetamine (MA) and amphetamine (AP), is a health, social, legal, and financial problem. Owing to the high potential of their abuse and addiction, reliable analytical methods are required to detect and identify MA, AP, and their metabolites in biological samples. Thus, a dilute-and-shoot liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) was developed for simultaneous determination of MA, 4-hydroxymethamphetamine (4HMA), AP, and 4-hydroxyamphetamine (4HA) in urine. Urine sample ($100{\mu}L$) was mixed with $50{\mu}L$ of mobile phase consisting of 0.4 % formic acid and methanol and $50{\mu}L$ of working internal-standard solution. Aliquots of $8{\mu}L$ diluted urine was injected into the LC-MS/MS system. For all analytes, chromatographic separation was performed using a C18 reversed-phase column with gradient elution and a total run time of 5 min. The identification and quantification were performed by multiple reaction monitoring (MRM). Linear least-squares regression was conducted to generate a calibration curve, with $1/x^2$ as the weighting factor. The linear ranges were 2.0-200, 1.0-800, and 10-2500 ng/mL for 4HA and 4HMA, AP, and MA, respectively. The inter- and intraday precisions were within 6.6 %, whereas the inter- and intraday accuracies ranged from -14.9 to 11.3 %. The low limits of quantification were 2.0 ng/mL (4HA and 4HMA), 1.0 ng/mL (AP), and 10 ng/mL (MA). The proposed method exhibited satisfactory selectivity, dilution integrity, matrix effect, and stability, which are required for validation. Moreover, the purification efficiency of high-speed centrifugation was clearly higher than 6-15 % for QC samples (n=5), which was higher than that of the membrane-filtration method. The applicability of the proposed method was tested by forensic analysis of urine samples from drug abusers.

Early histological change in hard tissue from orthodontic force placed on microscrews in ovariectomized rats (난소 적출 백서에 식립된 마이크로스크류에 교정력 부여 시 나타난 초기 경조직 변화에 관한 연구)

  • Lee, Dea-Seung;Chang, Moon-Jung;Lee, Jin-Woo
    • The korean journal of orthodontics
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    • v.36 no.2 s.115
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    • pp.103-113
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    • 2006
  • Most elderly women experience a decrease in their bone density due to a deficiency of calcium intake, ovariectomy, or menopause. This study evaluated the usability of the microscrew as a skeletal anchorage system in these orthodontic treatment cases, using rats as a research group. The 4 month old sprague-dawley species rats were divided into two groups, the OS (Ovariectomy Screw), and the SS (Sham operation Screw) group. In both the OS and SS groups, microscrews were implanted into the palatal bone between the upper molar teeth and two upper incisors were retracted using NETE coil spring with 75 g of force. After 3days, the again after 7 days, 7 rats in each group were sacrificed. Three days before they were sacrificed, Alizarin red S was intraperitoneally injected, and their maxillary bone, tibia and blood from their hearts were taken. The components of the extracted blood were biochemically analyzed and non-decalcified grinding resin sections for maxillary bone and tibia were made. The sections were examined with a polarization microscope, and fluorescent microscope. Smaller concentrations of Ca and P, the inorganic substances closely related to bone density, were found in the extracted blood of the OS group. Both OS and SS groups showed a possibility of bone remodeling with a high concentration of ALP after 7 days. An increase in bone density on the tension and compression sides of the microscrew and the tension side of the tooth for both OS and SS groups was confirmed with a polarization microscope. However, the bone density of the pressure side of the tooth and apical side was decreased. More deposits of Alizarin red S in the bone after 7 days rather than 3 days seen with a fluorescent microscope suggested the existence of new bone formation.

A Study on the Change of AIDS Knowledge and Sexual Behavior among Middle and High School Students through AIDS Prevention Education (중고등학생의 에이즈 예방교육(豫防敎育)을 통한 에이즈 지식(知識)과 성의식(性意識) 변화(變化)에 관(關)한 연구(硏究))

  • Kwon, Kwan-Woo;Lee, Kyoung-Mu;Kim, Joung-Soon
    • Journal of the Korean Society of School Health
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    • v.12 no.1
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    • pp.109-129
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    • 1999
  • AIDS is worldwide problem. It has threatens societies and is potentially a big problem among youth. UNAIDS has warned that collective global responses are necessary; with half of the newly infected being children and young people in 1998, educating youth below age 24 is essential. Because of both their unexpected, strong sexual activities and an easjer tendency to change their behavior than adults, UNAIDS emphasizes the importance of prevention education for youth. In Korea, 4 cases of HIV infection have officially been reported among high school students. Considering the potential seriousness of HIV infection among youth, the Korean AntiAIDS Federation (KAAF) began an education programme for Korean youth (middle & high school pupils) as one intervention method in 1993. The purpose of this study is to evaluate the impact of the education programs performed and to develop a better programme. The intervention method used in this study was mainly a lecture in a big or small auditorium or through broadcasting systems using audio-visual teaching aids. The period of this survey was from Nov. 10 to Dec. 26. in 1998. The subjects surveyed were 792 pupils who were sampled from 12 different middle and high schools in Seoul by a two-stage cluster sampling. Self-recording the structured questionnaire was used for data collection. Data were analyzed by using a paired t-test to compare the knowledge difference before and after the interrention method. A chi-square test to compare the consciousness difference between pre-post-education results was used, and an ANOVA was ased to compare the knowledge difference among the selected groups. Major results of this study are summarized as follows: (1) AIDS knowledge significantly changed after AIDS prevention education. (2) The direct lecture in a big or small auditorium is more effective than an indirect lecture through a broadcasting system or through audio-visual teaching aids. (3) Those who had not seen obscene materials (e.g. pornography films, magazines etc.) acguired much more knowledge than others after AIDS prevention education. (4) Those who had no girlfriend/or boyfriend acquired much more knowledge than the others after AIDS prevention education. (5) As to the attitudes toward chastity, more girls than boys and students who had not seen obscene materials rather than those who already had were liable to support the state ment: "all should remain chase" and their consciousness on "being chaste" changed much more than that of others after intervention. (6) As to the individual evaluation of lectures, 23.1% shows "very good", 44.1% "good", 26.9% "normar" '-' thus, the positive evaluation was to 94.2%. The negative response was 5.8%. (7) As to the desire for AIDS education sponsored by KAAF in the future, more than 90.5% showed a positive reaction. (8) As to the educators in future education methods, pupils wanted lecturers from outside their schood. (9) Students from vocational high schools have seen obscene materials much more than other groups and the percentage of those who had a girlfriend/or boyfriend was higher than that of the others as wello. (10) 90% of those who watched obscene materials responded that they experienced these materials while at middle school and 100% before reaching the second grade of high school. (11) The number of boys who have experienced obscene materials is twice as many as that of girls. (12) The percentage of boys who have a girlfriend is much higher than the percentage of girls who have a boyfriend. (13) Among those who have friends of the opposite sex, 11.1% say that they hare had sexual contact and 20.8% hare experienced kissing and caressing.

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Effect of Breed, Age, Season, Parity and Mating Type on Boar Semen Characteristics and Fertilizing Capacity (종모돈의 정액성상과 번식성적에 미치는 품종, 연령, 계절, 산차 및 교배방법의 영향)

  • Jeon, Y.M.;Yun, H.j.;Lee, J.K.;Son, Y.G.;Kang, K.;Park, C.S.
    • Korean Journal of Animal Reproduction
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    • v.24 no.2
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    • pp.209-216
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    • 2000
  • This study was carried out to investigate the effects of breed, age of boar, season, parity and mating system on boar semen characteristics and fertilizing capacity. A total of 4181 sows and 199 boars of Durocs (D), Landraces (L), and Yorkshires (Y) were used for this experiment at Darby Artificicial Insemination Center from 1996 through 1999. Semen volume per ejaculate was largest in Landrace (266.8 $m\ell$), followed by Yorkshire, and was smallest in Duroc. Sperm motility did not show significant differences among the above breeds. Sperm concentration was lowest in Landrace (4.7$\times$10$^{9}$ sperm/$m\ell$) and was highest in Duroc (5.7$\times$10$^{9}$ sperm/$m\ell$). Semen volume per ejaculate according to the age of boars was largest at the age of 2 years, followed by the age of 4 and 3 years, and was smallest at the age of I year. Semen volume per ejaculate according to the season in boars was largest in winter (228.6 $m\ell$), followed by autumn and summer, and was smallest in spring. Sperm concentration was highest in spring (5.9$\times$10$^{9}$ sperm/$m\ell$), followed by summer and winter, and was lowest in autumn. The average litter weight at birth did not show any differences according to the mating type. But the number of pigs born alive per litter was largest (9.5 pigs) in the natural mating + artificial insemination group, followed by the artificial insemination group (9.2 pigs), and was smallest (8.9 pigs) in the natural mating group (P<0.01). The average litter weight at birth and number of pigs born alive per litter did not show any differences between the natural mating and artificial insemination. The L (♀)$\times$Y (♂) and L (♀)$\times$L (♂) matings show $\varepsilon$ d higher average litter weight at birth and number of pigs born alive per litter than the Y (♀) $\times$ Y (♂) and Y (♀) $\times$ L (♂) matings. The pigs in the 2~6th parities had higher average litter weight at birth and number of pigs born alive per litter than those in the 1 st and 7~9th parities.

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Patients with brain metastases the usefulness of contrast-enhanced FLAIR images after delay (뇌전이 환자의 조영 증강 후 지연 FLAIR 영상의 유용성)

  • Byun, Jae-Hu;Park, Myung-Hwan;Lee, Jin-Wan
    • Korean Journal of Digital Imaging in Medicine
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    • v.16 no.1
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    • pp.13-19
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    • 2014
  • Purpose: FLAIR image is beneficial for the diagnosis of various bran diseases including ischemic CVS, brain tumors and infections. However the border between the legion of brain metastasis and surrounding edema may not be clear. Therefore, this study aims to investigate the practical benefits of delayed imaging by comparing the image from a patient with brain metastasis before a contrast enhancement and the image 10 minutes after a contrast enhancement. Materials and methods: Of the 92 people who underwent MRI brain metastases in suspected patients 13 people in three patients there is no video to target the 37 people confirmed cases, and motion artifacts brain metastases in our hospital June-December 2013, 18 people measurement position except for the three incorrect patient (male: 11 people, female: 7 people, average age: 60 years) in the target, test equipment, 3.0T MR System (ACHIEVA Release, Philips, I was 8ChannelSENSE Head Coil use Best, and the Netherlands). TR 11000 ms, TE 125 ms, TI2800 ms, Slice Thickness 5 mm, gap 5 mm, is a Slice number 21, the parameters of the 3D FFE, T2 FLAIR variable that was used to test, TR 8.1 ms, TE 3.7 ms, Slice number 240 I set to. The experiment was conducted by acquiring the FLAIR prior to contrast enhancement (heretofore referred to as Pre FLAIR), and acquiring the 3D FFE CE five minutes after the contrast enhancement, and recomposing the images in an axial plane of S/T 3mm, G 0mm (heretofore referred to as MPR TRA CE). Using the FLAIR 10 minutes after the contrast enhancement (heretofore referred to as Post FLAIR) and Pi-View, a retrospective study was conducted. Using MRIcro on the image of a patient confirmed for his diagnosis, the images before and after the contrast media, as well as the CNR and SNR of the MPR TRA CE images of the lesion and the site absent of lesion were compared and analyzed using a one-way analysis of variance. Results: CNR for Pre FLAIR and Post FLAIR were 34.35 and 60.13, respectively, with MPR TRA CE at 23.77 showing no significant difference (p<0.050). Post-experiment analysis shows a difference between Pre FLAIR and Post FLAIR in terms of CNR (p<0.050), but no difference in CNR between Post FLAIR and MPR TRA CE (p>0.050), indicating that the contrast media had an effect only on Pre FLAIR and Post FLAIR. The SNR for the normal site Pre FLAIR was 106.43, and for the lesion site 140.79. Post FLAIR for the normal site was 107.79, and for the lesion site 167.91. MPR TRA CE for the normal site was 140.23 and for the lesion site 183.19, showing significant difference (p<0.050), and post-experiment analysis shows that there was a difference in SNR only on the lesion sites for Pre FLAIR and Post FLAIR (p<0.050). There was no difference in SNR between the normal site and lesion site for Post FLAIR and MPR TRA CE, indicating no effect from the contrast media (p>0.050). Conclusions: This experiment shows that Post FLAIR has a higher contrast than Pre FLAIR, and a higher SNR for lesions, It was not not statistically significant and MPR TRA CE but CNR came out high. Inspection of post-contrast which is used in a high magnetic field is frequently used images of 3D T1 but, since the signal of the contrast medium and the blood flow is included, this method can be diagnostic accuracy is reduced, it is believed that when used in combination with Post FLAIR, and that can provide video information added to the diagnosis of brain metastases.

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Computerized Multiple 15-hue tests for Quantifying Color Vision Acuity (색각 능력의 정량적 평가를 위한 전산화된 다중 15-색상 배열 검사법)

  • Ko S.T.;Hong S.C.;Choi M.J.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3 s.61
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    • pp.321-331
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    • 2000
  • Multiple 15-hue tests were designed and implemented on a PC in the study so as to quickly and quantitatively evaluate color vision acuity. Difficulty of the test was control)ed by the value of CDBACC (color difference between adjacent color chips) calculated using a CIELAB formula. The multiple 15-hue tests consist of eight of the hue tests (test 3-10) and three of the basic color (red, green, blue) tests (test 11-13). The 15 colors used for the hue tests were specified by the 15 color coordinates that were located at a constant distance (d = 2. 3. 5. 7, 10, 20, 30. 40) from white reference in the CIE chromaticity coordinate system and were separated by a constant color difference (CDBACC = 0.75, 1.1, 1.8. 2.5. 3.5. 7.5. 11, 14) from the adjacent chips. The color coordinates for the 15 chips for the basic color tests were the same as those of the 15 points spaced equally by a constant color difference (6.87 for the green color test. 7.27 for the red color test, 7.86 for the blue color test) from the white reference along the axis of red, green and blue. Thirty normal subjects who were not color blind were taken to undergo the multiple 15-hue tests. It was observed that most of the subjects correctly arranged color chips for the tests with CDBACC greater than 5, whereas no one correctly answered for those with CDBACC less than 2. Rapid changes in the number of the subjects correctly arranged took place when CDBACC of the tests was between 2 and 4.5. In the basic color tests, unlike the hue tests having similar values of CDBACC, it was seen that the subjects arranged color chips even less correctly. It was found that JNCD (just noticeable color difference) - a measure of color vision acuity was about 3 in average for the subjects. The JNCD was chosen as the value of the CDBACC of the test for which about $50\%$ of the subjects failed to successfully arrange color chips. ERCCA (error rate of color chips arrangement) for the test with CDBACC the same as the JNCD was shown to be about $20\%$. It is expected that the multi 15-hue tests implemented on a PC in the study will be an economical tool to quickly and quantitatively evaluate color vision acuity and, accordingly, the tests can be used for early diagnosis to massive potential patients suffering from diseases (ex. diabetes, glaucoma) which may induce changes in color vision acuity.

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Financial Fraud Detection using Text Mining Analysis against Municipal Cybercriminality (지자체 사이버 공간 안전을 위한 금융사기 탐지 텍스트 마이닝 방법)

  • Choi, Sukjae;Lee, Jungwon;Kwon, Ohbyung
    • Journal of Intelligence and Information Systems
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    • v.23 no.3
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    • pp.119-138
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    • 2017
  • Recently, SNS has become an important channel for marketing as well as personal communication. However, cybercrime has also evolved with the development of information and communication technology, and illegal advertising is distributed to SNS in large quantity. As a result, personal information is lost and even monetary damages occur more frequently. In this study, we propose a method to analyze which sentences and documents, which have been sent to the SNS, are related to financial fraud. First of all, as a conceptual framework, we developed a matrix of conceptual characteristics of cybercriminality on SNS and emergency management. We also suggested emergency management process which consists of Pre-Cybercriminality (e.g. risk identification) and Post-Cybercriminality steps. Among those we focused on risk identification in this paper. The main process consists of data collection, preprocessing and analysis. First, we selected two words 'daechul(loan)' and 'sachae(private loan)' as seed words and collected data with this word from SNS such as twitter. The collected data are given to the two researchers to decide whether they are related to the cybercriminality, particularly financial fraud, or not. Then we selected some of them as keywords if the vocabularies are related to the nominals and symbols. With the selected keywords, we searched and collected data from web materials such as twitter, news, blog, and more than 820,000 articles collected. The collected articles were refined through preprocessing and made into learning data. The preprocessing process is divided into performing morphological analysis step, removing stop words step, and selecting valid part-of-speech step. In the morphological analysis step, a complex sentence is transformed into some morpheme units to enable mechanical analysis. In the removing stop words step, non-lexical elements such as numbers, punctuation marks, and double spaces are removed from the text. In the step of selecting valid part-of-speech, only two kinds of nouns and symbols are considered. Since nouns could refer to things, the intent of message is expressed better than the other part-of-speech. Moreover, the more illegal the text is, the more frequently symbols are used. The selected data is given 'legal' or 'illegal'. To make the selected data as learning data through the preprocessing process, it is necessary to classify whether each data is legitimate or not. The processed data is then converted into Corpus type and Document-Term Matrix. Finally, the two types of 'legal' and 'illegal' files were mixed and randomly divided into learning data set and test data set. In this study, we set the learning data as 70% and the test data as 30%. SVM was used as the discrimination algorithm. Since SVM requires gamma and cost values as the main parameters, we set gamma as 0.5 and cost as 10, based on the optimal value function. The cost is set higher than general cases. To show the feasibility of the idea proposed in this paper, we compared the proposed method with MLE (Maximum Likelihood Estimation), Term Frequency, and Collective Intelligence method. Overall accuracy and was used as the metric. As a result, the overall accuracy of the proposed method was 92.41% of illegal loan advertisement and 77.75% of illegal visit sales, which is apparently superior to that of the Term Frequency, MLE, etc. Hence, the result suggests that the proposed method is valid and usable practically. In this paper, we propose a framework for crisis management caused by abnormalities of unstructured data sources such as SNS. We hope this study will contribute to the academia by identifying what to consider when applying the SVM-like discrimination algorithm to text analysis. Moreover, the study will also contribute to the practitioners in the field of brand management and opinion mining.

An Investigation on Expanding Co-occurrence Criteria in Association Rule Mining (연관규칙 마이닝에서의 동시성 기준 확장에 대한 연구)

  • Kim, Mi-Sung;Kim, Nam-Gyu;Ahn, Jae-Hyeon
    • Journal of Intelligence and Information Systems
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    • v.18 no.1
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    • pp.23-38
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    • 2012
  • There is a large difference between purchasing patterns in an online shopping mall and in an offline market. This difference may be caused mainly by the difference in accessibility of online and offline markets. It means that an interval between the initial purchasing decision and its realization appears to be relatively short in an online shopping mall, because a customer can make an order immediately. Because of the short interval between a purchasing decision and its realization, an online shopping mall transaction usually contains fewer items than that of an offline market. In an offline market, customers usually keep some items in mind and buy them all at once a few days after deciding to buy them, instead of buying each item individually and immediately. On the contrary, more than 70% of online shopping mall transactions contain only one item. This statistic implies that traditional data mining techniques cannot be directly applied to online market analysis, because hardly any association rules can survive with an acceptable level of Support because of too many Null Transactions. Most market basket analyses on online shopping mall transactions, therefore, have been performed by expanding the co-occurrence criteria of traditional association rule mining. While the traditional co-occurrence criteria defines items purchased in one transaction as concurrently purchased items, the expanded co-occurrence criteria regards items purchased by a customer during some predefined period (e.g., a day) as concurrently purchased items. In studies using expanded co-occurrence criteria, however, the criteria has been defined arbitrarily by researchers without any theoretical grounds or agreement. The lack of clear grounds of adopting a certain co-occurrence criteria degrades the reliability of the analytical results. Moreover, it is hard to derive new meaningful findings by combining the outcomes of previous individual studies. In this paper, we attempt to compare expanded co-occurrence criteria and propose a guideline for selecting an appropriate one. First of all, we compare the accuracy of association rules discovered according to various co-occurrence criteria. By doing this experiment we expect that we can provide a guideline for selecting appropriate co-occurrence criteria that corresponds to the purpose of the analysis. Additionally, we will perform similar experiments with several groups of customers that are segmented by each customer's average duration between orders. By this experiment, we attempt to discover the relationship between the optimal co-occurrence criteria and the customer's average duration between orders. Finally, by a series of experiments, we expect that we can provide basic guidelines for developing customized recommendation systems. Our experiments use a real dataset acquired from one of the largest internet shopping malls in Korea. We use 66,278 transactions of 3,847 customers conducted during the last two years. Overall results show that the accuracy of association rules of frequent shoppers (whose average duration between orders is relatively short) is higher than that of causal shoppers. In addition we discover that with frequent shoppers, the accuracy of association rules appears very high when the co-occurrence criteria of the training set corresponds to the validation set (i.e., target set). It implies that the co-occurrence criteria of frequent shoppers should be set according to the application purpose period. For example, an analyzer should use a day as a co-occurrence criterion if he/she wants to offer a coupon valid only for a day to potential customers who will use the coupon. On the contrary, an analyzer should use a month as a co-occurrence criterion if he/she wants to publish a coupon book that can be used for a month. In the case of causal shoppers, the accuracy of association rules appears to not be affected by the period of the application purposes. The accuracy of the causal shoppers' association rules becomes higher when the longer co-occurrence criterion has been adopted. It implies that an analyzer has to set the co-occurrence criterion for as long as possible, regardless of the application purpose period.

Effects of Green Tea Powder on the Disorders of Lipid Metabolism and Hepatic Functions in Rats treated by 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) (녹차가 다이옥신계 TCDD(2,3,7,8-tetrachlorodibenzo-p-dioxin)에 노출된 흰쥐의 지질대사 및 간 독성물질대사에 미치는 영향)

  • Lee, Joon-Ho;Kim, Hyun-Sook;Hwang, Seok-Youn
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.9
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    • pp.1185-1193
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    • 2006
  • This study investigated the effects of green tea on the disorders of lipid metabolism, oxidative system and hepatic functions induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), using adult male rats (SD) for 3 weeks. These 36 animals were divided into four groups. TCDD ($50{\mu}g/kg$ BW) was intraperitoneally injected at the beginning of experiment. Green tea powder was added 1% or 3% levels in basal diets respectively. Relative weights of thymus were decreased about one-third of control group, but those of liver, brain and testis were significantly increased in rats treated TCDD. Neutrophill% and lymphocyte% by TCDD treatment was improved by green tea diets. In liver functional enzyme, elevation of glutamic oxaloacetic transaminase (GOT) and alkaline phosphatase (ALP) activities due to TCDD treatment was lowered by green tea diets. The concentrations of serum and liver lipids were significantly increased by TCDD treatment, however, those of serum and liver triglyceride tended to decrease by green tea diets. Fecal lipid excretion was increased in rats fed green tea diets. Especially, fecal total cholesterol level was significantly elevated by 3% green tea diets. The activities of superoxide dismutase (SOD) were increased in rats fed 3% green tea diets. Increment of benzphetamine N-demethylase (BPND) activity by TCDD treatment was declined by 1% green tea diets. These results indicate that green tea can exert improving effects on liver lipid accumulation and unfavorable hepatic functions, and elevate antioxidation.