• Journal of Korea Society of Digital Industry and Information Management
• /
• v.6 no.3
• /
• pp.19-29
• /
• 2010

A marketing model is changed from a customer acquisition to customer retention and it is being moved to a way that enhances the quality of customer interaction to add value to our customers. Such personalization is emerging from this background. The Web site is accelerate the adoption of a personalization, and in contrast to the rapid growth of data, quantitative analytical experience is required. For the automated analysis of large amounts of data and the results must be passed in real time of personalization has been interested in technical problems. A recommendation algorithm is an algorithm for the implementation of personalization, which predict whether the customer preferences and purchasing using the database with new customers interested or likely to purchase. As recommended number of users increases, the algorithm increases recommendation time is the problem. In this paper, to solve this problem, a recommendation system based on clustering and dimensionality reduction is proposed. First, clusters customers with such an orientation, then shrink the dimensions of the relationship between customers to low dimensional space. Because finding neighbors for recommendations is performed at low dimensional space, the computation time is greatly reduced.

• Journal of Powder Materials
• /
• v.16 no.1
• /
• pp.43-49
• /
• 2009

Titanium carbides are widely used for cutting tools and grinding wheels, because of their superior physical properties such as high melting temperature, high hardness, high wear resistance, good thermal conductivity and excellent thermal shock resistance. The common synthesizing method for the titanium carbide powders is carbo-thermal reduction from the mixtures of titanium oxide($TiO_2$) and carbon black. The purpose of the present research is to fabricate nano TiC powders using titanium salt and titanium hydride by the mechanochemical process(MCP). The initial elements used in this experiment are liquid $TiCl_4$(99.9%), $TiH_2$(99.9%) and active carbon(<$32{\mu}m$, 99.9%). Mg powders were added to the $TiCl_4$ solution in order to induce the reaction with Cl-. The weight ratios of the carbon and Mg powders were theoretically calculated. The TiC and $MgCl_2$ powders were milled in the planetary milling jar for 10 hours. The 40 nm TiC powders were fabricated by wet milling for 4 hours from the $TiCl_4$+C+Mg solution, and 300 nm TiC particles were obtained by using titanium hydride.

• Journal of Korea Multimedia Society
• /
• v.21 no.8
• /
• pp.952-959
• /
• 2018

Clustering is one of the most fundamental algorithms in machine learning. The performance of clustering is affected by the distribution of data, and when there are more data or more dimensions, the performance is degraded. For this reason, we use a stacked auto encoder, one of the deep learning algorithms, to reduce the dimension of data which generate a feature vector that best represents the input data. We use k-means, which is a famous algorithm, as a clustering. Sine the feature vector which reduced dimensions are also multi dimensional, we use the Euclidean distance as well as the cosine similarity to increase the performance which calculating the similarity between the center of the cluster and the data as a vector. A deep clustering networks combining a stacked auto encoder and k-means re-trains the networks when the k-means result changes. When re-training the networks, the loss function of the stacked auto encoder and the loss function of the k-means are combined to improve the performance and the stability of the network. Experiments of benchmark image ad document dataset empirically validated the power of the proposed algorithm.

• Journal of Agricultural Extension & Community Development
• /
• v.11 no.1
• /
• pp.175-189
• /
• 2004

There are many assertions related to biotechnology and genetically modified organisms(GMOs). Some experts have asserted that GM foods could be dangerous and that there is no reliable evidence that have been demonstrated safe through appropriate tests, and the others asserted these foods are as safe and nutritions as their conventional counterparts. The objectives of this study was to study an societal implications of biotechnology and GMOs in agriculture. To keep the balance in mind the researcher examined not only usefulness but also harmfulness of GMOs, along with the developmental process of biotechnology industry. It was observed that basically, multinational corporations developed GMOs to maximize their profit, and strengthened their control on agriculture and food through GMOs, as observed in alliance among big multinational corporations' food chain cluster and systems. Under the situation, farmers were losing their status as independent producer and were becoming propertied labor for multinational corporation through contract farming. If these trends continuous in the future, multinational corporations will have the control of genetic resources, these may bring about reduction of bio-diversity, thus may lead the opposite direction to eco-friendly agriculture. If multinational corporations' tendency to suppress the latent harmfulness for the profit continuous further, this may lead the degradation phase of farming and agriculture, thus leading negative socio-economic effects as well as culture and religion.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.4
• /
• pp.9-16
• /
• 2015

Quick and safe message transmission is an important research topic of vehicular ad hoc networks (VANET). Most studies assume that the periodic broadcast of beacon-frames between vehicles increases the safety of the driver. In this paper, we propose a medium access control (MAC) protocol and location-based clustering for the VANET to support reliable data transfer. In our proposal, the cluster heade (CH) manage the access and allocate the resources of the node. Our proposal uses simulation to confirm the reduction of the transmission delay and the collision rate of the signal.

• Biomolecules & Therapeutics
• /
• v.24 no.5
• /
• pp.552-558
• /
• 2016

Severe complications associated with EV71 infections are a common cause of neonatal death. Lack of effective therapeutic agents for these infections underlines the importance of research for the development of new antiviral compounds. In the present study, the anti-EV71 activity of norwogonin, oroxylin A, and mosloflavone from Scutellaria baicalensis Georgi was evaluated using a cytopathic effect (CPE) reduction method, which demonstrated that all three compounds possessed strong anti-EV71 activity and decreased the formation of visible CPEs. Norwogonin, oroxylin A, and mosloflavone also inhibited virus replication during the initial stage of virus infection, and they inhibited viral VP2 protein expression, thereby inhibiting viral capsid protein synthesis. However, ribavirin has a relatively weaker efficacy compared to the other drugs. Therefore, these findings provide important information that will aid in the utilization of norwogonin, oroxylin A, and mosloflavone for EV71 treatment.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.15 no.5
• /
• pp.205-214
• /
• 2020

With the recent development of hardware and software technology, interest in the development of wearable devices is increasing. In particular, wearable devices require algorithms suitable for low-power and low-capacity embedded devices. Among them, there is an increasing demand for a signal compression algorithm that reduces communication overhead, in order to increase the efficiency of storage and transmission of electrocardiogram (ECG) signals requiring long-time measurement. Because normal beats occupy most of the signal with similar shapes, a high rate of signal compression is possible if normal beats are represented by a template. In this paper, we propose an algorithm for determining the normal beat template using the template cluster and Pearson similarity. Also, the template is expressed effectively as a few vertices through linear approximation algorithm. In experiment of Datum 234 of MIT-BIH arrhythmia database (MIT-BIH ADB) provided by Physionet, a compression ratio was 33.44:1, and an average distribution of root mean square error (RMSE) was 1.55%.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.7
• /
• pp.3112-3127
• /
• 2018

Since time series clustering is performed without prior information, it is used for exploratory data analysis. In particular, clusters of time series with similar shapes can be used in various fields, such as business, medicine, finance, and communications. However, existing time series clustering algorithms have a problem in that time series with different shapes are included in the clusters. The reason for such a problem is that the existing algorithms do not consider the limitations on the size of the generated clusters, and use a dimension reduction method in which the information loss is large. In this paper, we propose a method to alleviate the disadvantages of existing methods and to find a better quality of cluster containing similarly shaped time series. In the data preprocessing step, we normalize the time series using z-transformation. Then, we use piecewise aggregate approximation (PAA) to reduce the dimension of the time series. In the clustering step, we use density-based spatial clustering of applications with noise (DBSCAN) to create a precluster. We then use a modified K-means algorithm to refine the preclusters containing differently shaped time series into subclusters containing only similarly shaped time series. In our experiments, our method showed better results than the existing method.

• The Plant Pathology Journal
• /
• v.34 no.2
• /
• pp.93-103
• /
• 2018

Leaf blotch of wheat caused by Bipolaris sorokiniana is a major constraint to wheat production, causing significant yield reduction resulting in severe economic impact. The present study characterizes to determine and compare pathogenic variability exist/not based on components of leaf blotch disease development and level of aggressiveness due to agroclimatic condition of B. sorokiniana in wheat. A total of 169 virulent isolates of B. sorokiniana isolated from spot blotch infected leaf from different wheat growing agroclimate of Bangladesh. Pathogenic variability was investigated on a susceptible wheat variety 'kanchan' now in Bangladesh. A clear evidence of positive relationship among the components was recorded. From hierarchical cluster analysis five groups were originating among the isolates. It resolved that a large amount of pathogenic diversity exists in Bipolaris sorokiniana. Variation in aggressiveness was found among the isolates from different wheat growing areas. Most virulent isolates BS 24 and BS 33 belonging to High Ganges River Flood Plain agro-climatic zones considered by rice-wheat cropping pattern, hot and humid weather, high land and low organic matter content in soil. Positive relationship was found between pathogenic variability and aggressiveness with agro-climatic condition.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.4
• /
• pp.83-90
• /
• 2012

In e-commerce systems that deal with a large number of items, the function of personalized recommendation is essential. Collaborative filtering that is a successful recommendation algorithm, suffers from the sparsity, cold-start, and scalability restrictions. Additionally, this work raises a new flaw of the algorithm, inconsistent performance of recommendation. This is also not measurable by the current MAE-based evaluation that does not consider the deviation of prediction error, and furthermore is performed independently of precision and recall measurement. To evaluate the collaborative filtering comprehensively, this work proposes an extended evaluation model that includes the current criteria such as MAE, Precision, Recall, deviation, and applies it to cluster-based combined collaborative filtering.