• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.293-300
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• 2016

Traditional databases exploit a record-based model, where the attributes of a record are placed contiguously in a slow hard disk to achieve high performance. On the other hand, for read-intensive data analysis systems, the column-based compressed database has become a proper model because of its superior read performance. Currently, flash memory SSD is largely recognized as the preferred storage media for high-speed analysis systems. This paper introduces a compressed column-storage model and proposes a new index and its data management scheme for a high-capacity data warehouse system. The proposed index management scheme is based on the asymmetric index duplication and achieves superior search performance using the master index and compact index, particularly for large read-mostly databases. In addition, the data management scheme contributes to the read performance and high reliability by compressing the related columns and replicating them in two mirrored SSD. Based on the results of the performance evaluation under the high workload conditions, the data management scheme outperforms the traditional scheme in terms of the search throughput and response time.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.3
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• pp.73-82
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• 2022

Auto-scaling is one of the most important functions for cloud computing technology. Even if the number of users or service requests is explosively increased or decreased, system resources and service instances can be appropriately expanded or reduced to provide services suitable for the situation and it can improves stability and cost-effectiveness. However, since the policy is performed based on a single metric data at the time of monitoring a specific system resource, there is a problem that the service is already affected or the service instance that is actually needed cannot be managed in detail. To solve this problem, in this paper, we propose a method to predict system resource and service response time using a multivariate time series analysis model and establish an auto-scaling policy based on this. To verify this, implement it as a custom scheduler in the Kubernetes environment and compare it with the Kubernetes default auto-scaling method through experiments. The proposed method utilizes predictive data based on the impact between system resources and response time to preemptively execute auto-scaling for expected situations, thereby securing system stability and providing as much as necessary within the scope of not degrading service quality. It shows results that allow you to manage instances in detail.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.14-17
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• 2009

본 연구에서는 장대교량에서 케이블의 장력을 간편하게, 그리고 자동적으로 추정할 수 있는 저비용 무선장력계측시스템을 개발하였다. 개발된 시스템은 크게 비용이 저렴하고 설치 및 관리가 용이한 무선 기반 하드웨어와 케이블에서 계측된 가속도 데이터로부터 장력을 자동으로 추정하여 주는 내장 (Embedded) 자동화 소프트웨어로 구성된다. 저비용 무선 기반 하드웨어는 연산능력을 가진 무선계측유닛과, 계측 신호개선을 위한 신호처리보드, 그리고 상용 MEMS 가속도계로 구성되었으며, 내장 자동화 소프트웨어는 계측된 신호의 주파수 분석을 위한 FFT 모듈, 케이블의 푸리에 스펙트럼으로부터 고유진동수를 자동으로 추출하기 위한 자동 피크 추출(Peak-picking) 알고리즘 모듈, 그리고 추출된 고유진동수를 활용하여 케이블의 장력을 추정하는 진동법 모듈로 구성되었다. 개발된 시스템의 검증을 위하여, 사장교의 케이블 축소모델을 제작하고 케이블 모델에 다양한 장력과 새그를 주어 진동실험을 수행하였다. 실험 결과, 개발된 시스템은 케이블 모델의 주파수응답스펙트럼으로부터 고유진동수를 정확하게 추정하였으며, 장력과 새그의 크기에 상관없이 매우 정확한 장력을 추정하였다.

• Annual Conference on Human and Language Technology
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• 2014.10a
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• pp.242-246
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• 2014

웹을 비롯한 다양한 곳에서 기하급수적으로 증가하고 있는 문서들로 인해, 자연어 텍스트로부터의 지식추출의 중요성이 점차 커지고 있다. 이 연구에서는 한국어로 작성된 자연어 텍스트로부터의 시간 정보 추출을 위해 개발된 시스템을 소개하고, 직접 구축한 한국어 데이터셋에 대한 성능 분석을 제공한다. 이 시스템은 사람이 직접 작성한 규칙들에 기반하여 작동하지만, 질의응답시스템 등에 적용될 수 있는 수준의 성능으로 향상시키기 위해 기계학습 기반의 시스템으로 업그레이드하는 등의 작업을 계속할 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.61-65
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• 2003

In this paper, we analysed the standardized techniques for radio frequency identification systems. RFID system is to carry data in suitable transponders, generally known as tags, and to retrieve data, by machinable means, at a suitable time and place to satisfy particular application needs. The paper has discussed on international standardization trends and its techniques and provided with understanding the technical regulations for activating and harmonizing internationally domestic RFID industries.

• Journal of Digital Contents Society
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• v.15 no.3
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• pp.413-423
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• 2014

Recently, cloud computing has been affecting academic information system buildup. When university academic affairs information system is designed with cloud computing, it is very important to estimate the adequate processing capacity for the cloud computer taking into account a waste of resources and the quality of service. Cloud computer's processing capacity to meet the quality of service expected by users should be predicted based on users' transaction patterns and resource requirements characteristics. In this paper, we analyze actual traffic patterns occurring in university academic affairs business and propose a method to calculate the optimal processing capacity for cloud computer to satisfy the given average response time. To justify our research, we apply the research results to a real university academic affairs business case and obtain the optimal processing capacity for the integrated academic affairs business.

• 한국어정보학회:학술대회논문집
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• 2016.10a
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• pp.119-121
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• 2016

최근 사람과 컴퓨터가 대화를 하는 채팅시스템 연구가 활발해지고 있다. 컴퓨터가 사람의 말에 적절한 응답을 하기 위해선 그 의미를 분석할 필요가 있다. 발화에 대한 의미 분석의 기본이 되는 연구로 감정분석과 화행분석이 있다. 그러나 이 둘은 서로 밀접한 연관이 있음에도 불구하고 함께 분석하는 연구가 시도되지 않았다. 본 연구에서는 Long Short-term Memory(LSTM)를 이용하여 대화체 문장의 감정과 화행, 서술자를 동시에 분석하는 통합 대화 분석모델을 제안한다. 사랑 도메인 데이터를 사용한 실험에서 제안 모델은 감정 58.08%, 화행 82.60%, 서술자 62.74%의 정확도(Accuracy)를 보였다.

• Annual Conference on Human and Language Technology
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• 2016.10a
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• pp.119-121
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• 2016

최근 사람과 컴퓨터가 대화를 하는 채팅시스템 연구가 활발해지고 있다. 컴퓨터가 사람의 말에 적절한 응답을 하기 위해선 그 의미를 분석할 필요가 있다. 발화에 대한 의미 분석의 기본이 되는 연구로 감정분석과 화행분석이 있다. 그러나 이 둘은 서로 밀접한 연관이 있음에도 불구하고 함께 분석하는 연구가 시도 되지 않았다. 본 연구에서는 Long Short-term Memory(LSTM)를 이용하여 대화체 문장의 감정과 화행, 서술자를 동시에 분석하는 통합 대화 분석모델을 제안한다. 사랑 도메인 데이터를 사용한 실험에서 제안 모델은 감정 58.08%, 화행 82.60%, 서술자 62.74%의 정확도(Accuracy)를 보였다.

• Journal of Digital Contents Society
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• v.10 no.3
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• pp.395-400
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• 2009

The wide spread of the Internet service has brought in web GIS development. But, there are problems of the user access latencies, the network traffic, and the server overload in Internet Geographic Information System because spatial data are transferred in large volumes. In this paper, I propose a cache algorithm on client side to solve the above problems. The proposed algorithm demonstrates the performance improvement over known studies by utilizing unit time and spatial proximity. In addition, this paper conducts a performance evaluation to measure the improvement in algorithm efficiency and analyzes the results of the performance evaluation. When spatial data queries are conducted, according to our performance evaluation, hit rate has been improved over the existing algorithms.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.3
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• pp.130-139
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• 2016

A frequency of earthquake occurrence in the Republic of Korea is increasing over the past few decades. In this situation, an importance of earthquake prevention comes to the fore because the earthquake does damage to structures and causes severe damage of human life. For the earthquake prevention, a real-time vibration measurement for structures is important. As an example, the United States of America and Japan have already been monitoring real-time earthquake acceleration for the important structures and the measured acceleration data has been managed by forming database. This database could be used for revising the seismic design specifications or predicting the damage caused by earthquake. In Korea, Earthquake Recovery Plans Act and Enforcement Regulations are revised and declared lately. Ministry of Public Safety and Security is constructing a integrated management system for the measured earthquake acceleration data. The purpose of this research is to develop a real-time vibration monitoring and analysis system for structures which links to the integrated management system. The developed system contains not only a monitoring function to show real-time acceleration data but also an analysis system to perform fast fourier transform, to obtain natural frequency and earthquake magnitude, to show response spectrum and power spectrum, and to evaluate structural health. Additionally, this system is designed to be able to link to the integrated management system of Ministry of Public Safety and Security. It is concluded that the developed system can be useful to build a safety management network, minimize maintenance cost of structures, and prevention of the structural damage due to earthquake.