• Journal of Communications and Networks
• /
• v.13 no.4
• /
• pp.367-376
• /
• 2011

In this paper, we propose self-organizing schemes for the initial configuration of the neighbor cell list (NCL), maintenance of the NCL, and physical cell identifier (PCI) allocation in heterogeneous networks such as long term evolution systems where lower transmission power nodes are additionally deployed in macrocell networks. Accurate NCL maintenance is required for efficient PCI allocation and for avoiding handover delay and redundantly increased system overhead. Proposed self-organizing schemes for the initial NCL configuration and PCI allocation are based on evolved universal terrestrial radio access network NodeB (eNB) scanning that measures reference signal to interference and noise ratio and reference symbol received power, respectively, transmitted from adjacent eNBs. On the other hand, the maintenance of the NCL is managed by adding or removing cells based on periodic user equipment measurements. We provide performance analysis of the proposed schemes under various scenarios in the respects of NCL detection probability, NCL false alarm rate, handover delay area ratio, PCI conflict ratio, etc.

• The Korean Journal of Archival Studies
• /
• no.56
• /
• pp.183-212
• /
• 2018

The study aimed at exploring a direction of development of the conceptual model for organizing public digital records. First, it started with reviewing the possibility of item-oriented records and archival organization, then analyzed RIC-CM developed by ICA EGAD. Second, it investigated the hierarchies of the classes and descriptive information applied to public digital records, as well as showed the necessities of transition from paper-based model to digital-based one. Based on these, it studied to seek possibilities for organizing public digital records not by record groups but by items. Finally, this study proposed the direction of development of the next generation conceptual model for organizing public digital records.

• Journal of the Korean Society of Safety
• /
• v.33 no.6
• /
• pp.77-84
• /
• 2018

Report documents of industrial and occupational accidents have continuously been accumulated in private and public institutes. Amongst others, information on narrative-texts of accidents such as accident processes and risk factors contained in disaster report documents is gaining the useful value for accident analysis. Despite this increasingly potential value of analysis of text information, scientific and algorithmic text analytics for safety management has not been carried out yet. Thus, this study aims to develop data processing and visualization techniques that provide a systematic and structural view of text information contained in a disaster report document so that safety managers can effectively analyze accident risk factors. To this end, the risk factor map using text mining and self-organizing map is developed. Text mining is firstly used to extract risk keywords from disaster report documents and then, the Self-Organizing Map (SOM) algorithm is conducted to visualize the risk factor map based on the similarity of disaster report documents. As a result, it is expected that fruitful text information buried in a myriad of disaster report documents is analyzed, providing risk factors to safety managers.

• Journal of People, Plants, and Environment
• /
• v.24 no.6
• /
• pp.651-662
• /
• 2021

Background and objective: This study identifies whether children's planning-organizing executive function can be significantly classified and predicted by home environment quality and wealth factors. Methods: For empirical analysis, we used the data collected from the 10th Panel Study on Korean Children in 2017. Using machine learning tools such as support vector machine (SVM) and random forest (RF), we evaluated the accuracy of the model in which home environment factors classify and predict children's planning-organizing executive functions, and extract the relative importance of variables that determine these executive functions by income group. Results: First, SVM analysis shows that home environment quality and wealth factors show high accuracy in classification and prediction in all three groups. Second, RF analysis shows that estate had the highest predictive power in the high-income group, followed by income, asset, learning, reinforcement, and emotional environment. In the middle-income group, emotional environment showed the highest score, followed by estate, asset, reinforcement, and income. In the low-income group, estate showed the highest score, followed by income, asset, learning, reinforcement, and emotional environment. Conclusion: This study confirmed that home environment quality and wealth factors are significant factors in predicting children's planning-organizing executive functions.

• Tuberculosis and Respiratory Diseases
• /
• v.62 no.6
• /
• pp.540-544
• /
• 2007

The patient is a 62-year-old man with known diabetes mellitus who presented with a two-weeks-history of dyspnea, cough, and fever. He was diagnosed with a lung abscess in the right upper lobe and was treated with intravenous antibiotics. The patient's clinical and radiological findings improved within seven days after medical treatment. However, newly developed ground-glass opacity and infiltrations were observed in the right lower lung. Fourteen days after admission, the patient's symptoms and imaging finding became aggravated despite trestment with susceptible antibiotics for lung abscess. Trans-bronchial lung biopsy (TBLB) was performed in the lateral basal segment of the right lower lobe of the lung. A histologic photomicrograph showed organizing pneumonia, also called bronchiolitis obliterans with organizing pneumonia(BOOP), that became more definite as the terminal bronchioles and alveoli became occluded with masses of inflammatory cells and fibrotic tissue. The clinical symptoms and radiograph findings resolved quickly with prednisone treatment. We report a case of secondary organizing pneumonia diagnosed after TBLB following lung abscess treatment and provide a review of the literature.

• Journal of Korea Water Resources Association
• /
• v.51 no.5
• /
• pp.383-393
• /
• 2018

The regional frequency analysis is the method which uses not only sample of target station but also sample of neighborhood stations in which are classified as hydrological homogeneous regions. Consequently, identification of homogeneous regions is a very important process in regional frequency analysis. In this study, homogeneous regions for regional frequency analysis of precipitation were identified by the self-organizing map (SOM) which is one of the artificial neural network. Geographical information and hourly rainfall data set were used in order to perform the SOM. Quantization error and topographic error were computed for identifying the optimal SOM map. As a result, the SOM model organized by $7{\times}6$ array with 42 nodes was selected and the selected stations were classified into 6 clusters for rainfall regional frequency analysis. According to results of the heterogeneity measure, all 6 clusters were identified as homogeneous regions and showed more homogeneous regions compared with the result of previous study.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.3D
• /
• pp.347-356
• /
• 2009

This paper is described clustering analysis of traffic characteristics-based highway classification in order to deviate from methodologies of existing highway functional classification. This research focuses on comparing the clustering techniques performance based on the total within-group errors and deriving the optimal number of cluster. This research analyzed statistical clustering method (Hierarchical Ward's minimum-variance method, Nonhierarchical K-means method) and Kohonen self-organizing maps clustering method for highway characteristic classification. The outcomes of cluster techniques compared for the number of samples and traffic characteristics from subsets derived by the optimal number of cluster. As a comprehensive result, the k-means method is superior result to other methods less than 12. For a cluster of more than 20, Kohonen self-organizing maps is the best result in the cluster method. The main contribution of this research is expected to use important the basic road attribution information that produced the highway characteristic classification.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06a
• /
• pp.325-327
• /
• 2012

스마트 홈은 단순한 가정 내 네트워크 연결이 아닌 주택(건물)내의 정보 기술 요소를 구현하는 토털 홈 정보 제어 시스템 서비스, 솔루션을 총칭한다. 현재는 언제, 어디서, 어떤 기기로건 인터넷에 접속할 수 있는 유비쿼터스(Ubiquitous) 시대이자, 개별 사물들이 인터넷에 연결되어 스스로 필요한 정보를 주고받게 될 시대가 도래함에 따라 사람들의 주요 생활공간에서도 활용도가 점차 커지는 것이다. 수시로 변화하는 상황에 적응하며 정확도가 높은 스마트 서비스의 제공을 위해서는 사용자의 의도에 부합하는 Semantic-Context 정보생성을 위한 SOM(Self-Organizing Map)추론 방식의 알고리즘과 정보의 의미화로 다양한 서비스를 지원할 수 있는 인프라 대비 최대 서비스가 요구된다. 이에 따라 본 논문에서는 스마트 홈에서 이종 가전기기들의 상황정보를 센서 데이터로부터 추출하여 사용자 맞춤형 서비스를 제공하기 위한 SOM 추론 기반의 스마트 홈을 설계한다.

• Journal of Korea Multimedia Society
• /
• v.18 no.8
• /
• pp.943-949
• /
• 2015

A reader usually spends a lot of time browsing and searching word meaning in a dictionary, internet or smart applications in order to find the unknown words. In this paper, we propose a method to compensate this drawback. The proposed method introduces a vocabulary upon recognizing a word or group of words that was captured by a smart phone camera. Through this proposed method, organizing and editing words that were captured by smart phone, searching the dictionary data using bisection method, listening pronunciation with the use of speech synthesizer, building and editing of vocabulary stored in database are given as the features. A smart phone application for organizing English words was established. The proposed method significantly reduces the organizing time for unknown English words and increases the English learning efficiency.

• Communications for Statistical Applications and Methods
• /
• v.10 no.2
• /
• pp.507-517
• /
• 2003

Self-organizing map (SOM) has been developed mainly by T. Kohonen and his colleagues as a unsupervised learning neural network. Because of its topological ordering property, SOM is known to be very useful in pattern recognition and text information retrieval areas. Recently, data miners use Kohonen´s mapping method frequently in exploratory analyses of large data sets. One problem facing SOM builder is that there exists no sensible criterion for evaluating goodness-of-fit of the map at hand. In this short communication, we propose valid evaluation procedures for the Kohonen SOM of any size. The methods can be used in selecting the best map among several candidates.