• Title/Summary/Keyword: Clustering Effect

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Gene Expression Profiling of the Rewarding Effect Caused by Methamphetamine in the Mesolimbic Dopamine System

  • Yang, Moon Hee;Jung, Min-Suk;Lee, Min Joo;Yoo, Kyung Hyun;Yook, Yeon Joo;Park, Eun Young;Choi, Seo Hee;Suh, Young Ju;Kim, Kee-Won;Park, Jong Hoon
    • Molecules and Cells
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    • v.26 no.2
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    • pp.121-130
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    • 2008
  • Methamphetamine, a commonly used addictive drug, is a powerful addictive stimulant that dramatically affects the CNS. Repeated METH administration leads to a rewarding effect in a state of addiction that includes sensitization, dependence, and other phenomena. It is well known that susceptibility to the development of addiction is influenced by sources of reinforcement, variable neuroadaptive mechanisms, and neurochemical changes that together lead to altered homeostasis of the brain reward system. These behavioral abnormalities reflect neuroadaptive changes in signal transduction function and cellular gene expression produced by repeated drug exposure. To provide a better understanding of addiction and the mechanism of the rewarding effect, it is important to identify related genes. In the present study, we performed gene expression profiling using microarray analysis in a reward effect animal model. We also investigated gene expression in four important regions of the brain, the nucleus accumbens, striatum, hippocampus, and cingulated cortex, and analyzed the data by two clustering methods. Genes related to signaling pathways including G-protein-coupled receptor-related pathways predominated among the identified genes. The genes identified in our study may contribute to the development of a gene modeling network for methamphetamine addiction.

The Effect of Ethanol on the Physical Properties of Neuronal Membranes

  • Bae, Moon-Kyoung;Jeong, Dong-Keun;Park, No-Soo;Lee, Cheol-Ho;Cho, Bong-Hye;Jang, Hye-Ock;Yun, Il
    • Molecules and Cells
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    • v.19 no.3
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    • pp.356-364
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    • 2005
  • Intramolecular excimer formation of 1,3-di(1-pyrenyl) propane(Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to evaluate the effect of ethanol on the rate and range of lateral and rotational mobilities of bulk bilayer structures of synaptosomal plasma membrane vesicles (SPMVs) from the bovine cerebral cortex. Ethanol increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the SPMVs. Selective quenching of both DPH and Py-3-Py by trinitrophenyl groups was used to examine the range of transbilayer asymmetric rotational mobility and the rate and range of transbilayer asymmetric lateral mobility of SPMVs. Ethanol increased the rotational and lateral mobility of the outer monolayer more than of the inner one. Thus ethanol has a selective fluidizing effect within the transbilayer domains of the SPMVs. Radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py was used to examine both the effect of ethanol on annular lipid fluidity and protein distribution in the SPMVs. Ethanol increased annular lipid fluidity and also caused membrane proteins to cluster. These effects on neuronal membranes may be responsible for some, though not all, of the general anesthetic actions of ethanol.

Genome Wide Expression Analysis of the Effect of Woowhangchongshim-won on Rat Brain Injury

  • Kim, Bu-Yeo;Lim, Se-Hyun;Kim, Hyun-Young;Kim, Young-Kyun;Lim, Chi-Yeon;Cho, Su-In
    • The Journal of Internal Korean Medicine
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    • v.30 no.3
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    • pp.594-603
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    • 2009
  • Objectives : ICH breaks down blood vessels within the brain parenchyma, which finally leads to neuronal loss, drugs to treat ICH have not yet been established. In this experiment, we measured the effect of Woowhangchongshim-won (WWCSW) on intracerebral hemorrhage (ICH) in rat using microarray technology. Methods : We measured the effect of WWCSW on ICH in rat using microarray technology. ICH was induced by injection of collagenase type IV, and total RNA was isolated. Image files of microarray were measured using a ScanArray scanner, and the criteria of the threshold for up- and down-regulation was 2 fold. Hierarchical clustering was implemented using CLUSTER and TREEVIEW program, and for Ontology analysis. GOSTAT program was applied in which p-value was calculated by Chi square or Fisher's exact test based on the total array element. Results : WWCSW-treatment restored the gene expression altered by ICH-induction in brain to the levels of 76.0% and 70.1% for up- and down-regulated genes, respectively. Conclusion : Co-regulated genes by ICH model of rat could be used as molecular targets for therapeutic effects of drug including WWCSW. That is, the presence of co-regulated genes may represent the importance of these genes in ICH in the brain and the change of expression level of these co-regulated genes would also indicate the functional change of brain tissue.

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Effect of Multiple Copies of Cohesins on Cellulase and Hemicellulase Activities of Clostridium cellulovorans Mini-cellulosomes

  • Cha, Jae-Ho;Matsuoka, Satoshi;Chan, Helen;Yukawa, Hideaki;Inui, Masayuki;Doi, Roy H.
    • Journal of Microbiology and Biotechnology
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    • v.17 no.11
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    • pp.1782-1788
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    • 2007
  • Cellulosomes in Clostridium cellulovorans are assembled by the interaction between the repeated cohesin domains of a scaffolding protein (CbpA) and the dockerin domain of enzyme components. In this study, we determined the synergistic effects on cellulosic and hemicellulosic substrates by three different recombinant mini-cellulosomes containing either endoglucanase EngB or endoxylanase XynA bound to mini-CbpA with one cohesin domain (mini-CbpAl), two cohesins (mini-CbpA12), or four cohesins (mini-CbpAl234). The assembly of EngB or XynA with mini-CbpA increased the activity against carboxymethyl cellulose, acid-swollen cellulose, Avicel, xylan, and com fiber 1.1-1.8-fold compared with that for the corresponding enzyme alone. A most distinct improvement was shown with com fiber, a natural substrate containing xylan, arabinan, and cellulose. However, there was little difference in activity between the three different mini-cellulosomes when the cellulosomal enzyme concentration was held constant regardless of the copy number of cohesins in the cellulosome. A synergistic effect was observed when the enzyme concentration was increased to be proportional to the number of cohesins in the mini-cellulosome. The highest degree of synergy was observed with mini-CbpAl234 (1.8-fold) and then mini-CbpAl2 (1.3-fold), and the lowest synergy was observed with mini-CbpAl (1.2-fold) when Avicel was used as the substrate. As the copy number of cohesin was increased, there was more synergy. These results indicate that the clustering effect (physical enzyme proximity) of the enzyme within the mini-cellulosome is one of the important factors for efficient degradation of plant cell walls.

Visual Model of Pattern Design Based on Deep Convolutional Neural Network

  • Jingjing Ye;Jun Wang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.2
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    • pp.311-326
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    • 2024
  • The rapid development of neural network technology promotes the neural network model driven by big data to overcome the texture effect of complex objects. Due to the limitations in complex scenes, it is necessary to establish custom template matching and apply it to the research of many fields of computational vision technology. The dependence on high-quality small label sample database data is not very strong, and the machine learning system of deep feature connection to complete the task of texture effect inference and speculation is relatively poor. The style transfer algorithm based on neural network collects and preserves the data of patterns, extracts and modernizes their features. Through the algorithm model, it is easier to present the texture color of patterns and display them digitally. In this paper, according to the texture effect reasoning of custom template matching, the 3D visualization of the target is transformed into a 3D model. The high similarity between the scene to be inferred and the user-defined template is calculated by the user-defined template of the multi-dimensional external feature label. The convolutional neural network is adopted to optimize the external area of the object to improve the sampling quality and computational performance of the sample pyramid structure. The results indicate that the proposed algorithm can accurately capture the significant target, achieve more ablation noise, and improve the visualization results. The proposed deep convolutional neural network optimization algorithm has good rapidity, data accuracy and robustness. The proposed algorithm can adapt to the calculation of more task scenes, display the redundant vision-related information of image conversion, enhance the powerful computing power, and further improve the computational efficiency and accuracy of convolutional networks, which has a high research significance for the study of image information conversion.

Managerial Implication of Trails in the Teabaeksan National Park Derived from the Analysis of Visitors Behaviors Using Automatic Visitor Counter Data (탐방객 자동 계수기 데이터를 활용한 태백산국립공원 탐방로 탐방 행태 분석 및 관리 방안 제언)

  • Sung, Chan Yong;Cho, Woo;Kim, Jong-Sub
    • Korean Journal of Environment and Ecology
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    • v.34 no.5
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    • pp.446-453
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    • 2020
  • This study built a model to predict the daily number of visitors to 18 trails in the Taebaeksan National Park using the auto-counter system data to analyze the factors affecting the daily number of visitors to each trail and classified the trails by visitors' behaviors. Results of the multiple regression models with the daily number of visitors of the 18 trails indicated that the events, such as the National Foundation Day celebration of Snow Festival, affected the number of visitors of all of the 18 trails and were the most critical factor that determined the daily number of visitors to the Taebaeksan National Park. The long-holidays of three days or longer and other national holidays also affected the daily number of visitors to the trails. Precipitation had a negative impact on the number of visitors of trails where the intention of most visitors was for sightseeing or camping instead of hiking, whereas had no significant impacts on the number of visitors of trails where many visitors intended for hiking. It indicated that visitors who intended for hiking went ahead hiking even if the weather was poor. The effects of temperature had a positive effect on the number of visitors who intended for hiking but a negative effect on the number of visitor to the trails near Danggol Plaza where the Snow Festival was held in each winter, suggesting that the impact of the Snow Festival was the deterministic factor for trail management. Results of K-mean clustering showed that the 18 trails of the Taekbaeksan National Park could be classified into three types: those affected by the Snow Festival (type 1), those that have sightseeing points and so were visited mostly by non-hikers (type 2), and those visited mostly by hikers (type 3). Since visitor behaviors and illegal actions differ according to the trail type, this study's results can be used to prepare a trail management plan based on the trail characteristics.

Analysis of shopping website visit types and shopping pattern (쇼핑 웹사이트 탐색 유형과 방문 패턴 분석)

  • Choi, Kyungbin;Nam, Kihwan
    • Journal of Intelligence and Information Systems
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    • v.25 no.1
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    • pp.85-107
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    • 2019
  • Online consumers browse products belonging to a particular product line or brand for purchase, or simply leave a wide range of navigation without making purchase. The research on the behavior and purchase of online consumers has been steadily progressed, and related services and applications based on behavior data of consumers have been developed in practice. In recent years, customization strategies and recommendation systems of consumers have been utilized due to the development of big data technology, and attempts are being made to optimize users' shopping experience. However, even in such an attempt, it is very unlikely that online consumers will actually be able to visit the website and switch to the purchase stage. This is because online consumers do not just visit the website to purchase products but use and browse the websites differently according to their shopping motives and purposes. Therefore, it is important to analyze various types of visits as well as visits to purchase, which is important for understanding the behaviors of online consumers. In this study, we explored the clustering analysis of session based on click stream data of e-commerce company in order to explain diversity and complexity of search behavior of online consumers and typified search behavior. For the analysis, we converted data points of more than 8 million pages units into visit units' sessions, resulting in a total of over 500,000 website visit sessions. For each visit session, 12 characteristics such as page view, duration, search diversity, and page type concentration were extracted for clustering analysis. Considering the size of the data set, we performed the analysis using the Mini-Batch K-means algorithm, which has advantages in terms of learning speed and efficiency while maintaining the clustering performance similar to that of the clustering algorithm K-means. The most optimized number of clusters was derived from four, and the differences in session unit characteristics and purchasing rates were identified for each cluster. The online consumer visits the website several times and learns about the product and decides the purchase. In order to analyze the purchasing process over several visits of the online consumer, we constructed the visiting sequence data of the consumer based on the navigation patterns in the web site derived clustering analysis. The visit sequence data includes a series of visiting sequences until one purchase is made, and the items constituting one sequence become cluster labels derived from the foregoing. We have separately established a sequence data for consumers who have made purchases and data on visits for consumers who have only explored products without making purchases during the same period of time. And then sequential pattern mining was applied to extract frequent patterns from each sequence data. The minimum support is set to 10%, and frequent patterns consist of a sequence of cluster labels. While there are common derived patterns in both sequence data, there are also frequent patterns derived only from one side of sequence data. We found that the consumers who made purchases through the comparative analysis of the extracted frequent patterns showed the visiting pattern to decide to purchase the product repeatedly while searching for the specific product. The implication of this study is that we analyze the search type of online consumers by using large - scale click stream data and analyze the patterns of them to explain the behavior of purchasing process with data-driven point. Most studies that typology of online consumers have focused on the characteristics of the type and what factors are key in distinguishing that type. In this study, we carried out an analysis to type the behavior of online consumers, and further analyzed what order the types could be organized into one another and become a series of search patterns. In addition, online retailers will be able to try to improve their purchasing conversion through marketing strategies and recommendations for various types of visit and will be able to evaluate the effect of the strategy through changes in consumers' visit patterns.

A Methodology of Customer Churn Prediction based on Two-Dimensional Loyalty Segmentation (이차원 고객충성도 세그먼트 기반의 고객이탈예측 방법론)

  • Kim, Hyung Su;Hong, Seung Woo
    • Journal of Intelligence and Information Systems
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    • v.26 no.4
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    • pp.111-126
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    • 2020
  • Most industries have recently become aware of the importance of customer lifetime value as they are exposed to a competitive environment. As a result, preventing customers from churn is becoming a more important business issue than securing new customers. This is because maintaining churn customers is far more economical than securing new customers, and in fact, the acquisition cost of new customers is known to be five to six times higher than the maintenance cost of churn customers. Also, Companies that effectively prevent customer churn and improve customer retention rates are known to have a positive effect on not only increasing the company's profitability but also improving its brand image by improving customer satisfaction. Predicting customer churn, which had been conducted as a sub-research area for CRM, has recently become more important as a big data-based performance marketing theme due to the development of business machine learning technology. Until now, research on customer churn prediction has been carried out actively in such sectors as the mobile telecommunication industry, the financial industry, the distribution industry, and the game industry, which are highly competitive and urgent to manage churn. In addition, These churn prediction studies were focused on improving the performance of the churn prediction model itself, such as simply comparing the performance of various models, exploring features that are effective in forecasting departures, or developing new ensemble techniques, and were limited in terms of practical utilization because most studies considered the entire customer group as a group and developed a predictive model. As such, the main purpose of the existing related research was to improve the performance of the predictive model itself, and there was a relatively lack of research to improve the overall customer churn prediction process. In fact, customers in the business have different behavior characteristics due to heterogeneous transaction patterns, and the resulting churn rate is different, so it is unreasonable to assume the entire customer as a single customer group. Therefore, it is desirable to segment customers according to customer classification criteria, such as loyalty, and to operate an appropriate churn prediction model individually, in order to carry out effective customer churn predictions in heterogeneous industries. Of course, in some studies, there are studies in which customers are subdivided using clustering techniques and applied a churn prediction model for individual customer groups. Although this process of predicting churn can produce better predictions than a single predict model for the entire customer population, there is still room for improvement in that clustering is a mechanical, exploratory grouping technique that calculates distances based on inputs and does not reflect the strategic intent of an entity such as loyalties. This study proposes a segment-based customer departure prediction process (CCP/2DL: Customer Churn Prediction based on Two-Dimensional Loyalty segmentation) based on two-dimensional customer loyalty, assuming that successful customer churn management can be better done through improvements in the overall process than through the performance of the model itself. CCP/2DL is a series of churn prediction processes that segment two-way, quantitative and qualitative loyalty-based customer, conduct secondary grouping of customer segments according to churn patterns, and then independently apply heterogeneous churn prediction models for each churn pattern group. Performance comparisons were performed with the most commonly applied the General churn prediction process and the Clustering-based churn prediction process to assess the relative excellence of the proposed churn prediction process. The General churn prediction process used in this study refers to the process of predicting a single group of customers simply intended to be predicted as a machine learning model, using the most commonly used churn predicting method. And the Clustering-based churn prediction process is a method of first using clustering techniques to segment customers and implement a churn prediction model for each individual group. In cooperation with a global NGO, the proposed CCP/2DL performance showed better performance than other methodologies for predicting churn. This churn prediction process is not only effective in predicting churn, but can also be a strategic basis for obtaining a variety of customer observations and carrying out other related performance marketing activities.

Stereo Vision-based Visual Odometry Using Robust Visual Feature in Dynamic Environment (동적 환경에서 강인한 영상특징을 이용한 스테레오 비전 기반의 비주얼 오도메트리)

  • Jung, Sang-Jun;Song, Jae-Bok;Kang, Sin-Cheon
    • The Journal of Korea Robotics Society
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    • v.3 no.4
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    • pp.263-269
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    • 2008
  • Visual odometry is a popular approach to estimating robot motion using a monocular or stereo camera. This paper proposes a novel visual odometry scheme using a stereo camera for robust estimation of a 6 DOF motion in the dynamic environment. The false results of feature matching and the uncertainty of depth information provided by the camera can generate the outliers which deteriorate the estimation. The outliers are removed by analyzing the magnitude histogram of the motion vector of the corresponding features and the RANSAC algorithm. The features extracted from a dynamic object such as a human also makes the motion estimation inaccurate. To eliminate the effect of a dynamic object, several candidates of dynamic objects are generated by clustering the 3D position of features and each candidate is checked based on the standard deviation of features on whether it is a real dynamic object or not. The accuracy and practicality of the proposed scheme are verified by several experiments and comparisons with both IMU and wheel-based odometry. It is shown that the proposed scheme works well when wheel slip occurs or dynamic objects exist.

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Land-cover Change detection on Korean Peninsula using NOAA AVHRR data (NOAA AVHRR 자료를 이용한 한반도 토지피복 변화 연구)

  • 김의홍;이석민
    • Spatial Information Research
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    • v.4 no.1
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    • pp.13-20
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    • 1996
  • This study has been on detection of land-cover change on Korean peninsula (including the area of north Korean territory) between May of 1990 year and that of 1995 year using NOAA AVHRR data. It was necessary that imagery data should be registered to each other and should not be deviated much in seasonal variation in order to recognize land - cover change. Atmosphic effect such as clould and dirt was erased by maximum NDVI(Normalized Difference Vegetation Index) method the equation of which was as following $$NDVI(i,j,d)=\frac{ch2(j,j,d)-ch1(i,j,d)}{ch2(i,j,d)+ch1(i.j,d)}$$ Each image of maximum NDVI of '90 year and '95 year was c1assifed onto 8 categories ,using iso-clustering method each of which was water, wet barren and urban, crop field, field, mixed vegetation, shrub, forest and evergreen.

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