• Journal of Information Processing Systems
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• v.18 no.6
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• pp.741-754
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• 2022

Openstack is widely used as a representative open-source infrastructure of the service (IaaS) platform. The Openstack Identity Service is a centralized approach component based on the token including the Memcached for cache, which is the in-memory key-value store. Token validation requests are concentrated on the centralized server as the number of differently encrypted tokens increases. This paper proposes the practical Byzantine fault tolerance (PBFT) blockchain-based Openstack Identity Service, which can improve the performance efficiency and reduce security vulnerabilities through a PBFT blockchain framework-based decentralized approach. The experiment conducted by using the Apache JMeter demonstrated that latency was improved by more than 33.99% and 72.57% in the PBFT blockchain-based Openstack Identity Service, compared to the Openstack Identity Service, for 500 and 1,000 differently encrypted tokens, respectively.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.383-385
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• 2022

텍스트 요약(Text Summarization)은 자연어 처리(NLP) 분야의 주요 작업 중 하나이다. 높은 정확성을 보이는 문서 요약 딥 러닝 모델을 만들기 위해서 대용량 학습 데이터가 필요한데, 대용량 데이터 전처리 과정에서 처리 시간, 메모리 관리 등과 같은 문제가 발생한다. 본 논문에서는 대규모 병렬처리 플랫폼 Apache Spark 를 사용해 추상 요약 딥 러닝 모델의 데이터 전처리 과정을 개선하는 방법을 제안한다. 실험 결과 제안한 방법이 기존 방법보다 데이터 전처리 시간이 개선된 결과를 보이고 있다.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.67.1-67.1
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• 2021

We use Sloan Digital Sky Survey, Large Sky Area Multi-Object Fibre Spectroscopic Telescope, and Apache Point Observatory Galactic Evolution Experiment data to analyze the kinematic and chemical properties of stellar members in Sagittarius(Sgr) tidal streams. Using distances, positions, proper motions, and angular momenta of stars around the Sgr streams, we gather clean sample of Sgr member stars. We find that the leading arm has different chemical, kinematic, orbital characteristics from those of the trailing arm and the remnant of Sgr. In particular, the leading arm shows relatively lower eccentricity distribution than the trailing arm, suggesting their origin may differ or they have experienced different dynamical evolution, which is in somewhat mystery.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.208-210
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• 2008

정형 정보를 저장하는 대표적인 수단인 Microsoft Excel과 Database 간 상호변환에 있어서 다양한 방법들 중 Web을 기반으로 하는 변환 기술은 활용도가 매우 높을 것이다. 특히 많은 자료가 엑셀로 관리되는 경우 데이터 중복의 문제가 발생하며 DB를 통한 통합관리는 사용자 편의성 측면에서 높은 필요성을 갖는다. 본 논문은 이런 문제를 해결하기 위한 방안으로 POI를 이용한 변환 기법을 소개한다.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.193-202
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• 2024

As companies specialize, they use more modern applications, but they still rely on legacy systems and data access is limited by data silos. In this paper, we propose the Fabricator system, a design system for metadata based on Data Fabric that plays a key role in the data orchestration layer consisting of three layers: Sources Engine, Workload Builder, and Data Fabric Ingestion, thereby achieving meaningful integration of data and information. Provides useful insights to users through conversion. This allows businesses to efficiently access and utilize data, overcoming the limitations of legacy systems.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.645-653
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• 1999

Introduction : Although myocardial ischemia tends to occur more frequently than can he documented in ventilated patients, it has not been well studied on the factors related to the occurrence of the ischemia. Methods : To investigate the related factors to ischemia development, a prospective study was done in 95 cases with consecutive 73 patients who had received mechanical ventilation(MV) in MICU. In addition to 24 h holter monitoring, echocardiogram, electrolytes, cardiac enzymes, hemodynamic, and gas exchange measurements were done within 24 h after initiation of MV in 69 cases. The measurements were repeated at weaning period in 26 cases. The ischemia was defined by the ST segment changes; up-sloping depression more than 1.5 mm or down-sloping or horizontal depression more than 1.0 mm from isoelectric baseline for 80 ms following J point. Results : Twelve patients(12.6% in 95 cases) developed ischemia in total. The incidence of ischemia development showed an increased tendency in the initial 24 hr after MV (15.9%) and in patients with left-sided heart failure found by echocardiogram (18.2%) compared with that of the weaning period (3.8%) and patients without heart failure (10.9%) (P=0.12, P=0.09, in each). There were no differences in APACHE III score, baseline ECG findings, electrolytes abnormalities, use of inotropics or bronchodilators, presence of sepsis or shock, mode of ventilation, and survival rate according to the development of ischemia. Maximal heart rates and mean arterial pressure also were not different between patients with ($137.2{\pm}30.9/min$, $82.5{\pm}15.9$ mm Hg) and without ischemia ($l29.5{\pm}29.7/min$, $83.8{\pm}17.6$ mm Hg). Conclusion : Although the incidence of myocardial ischemia was 12.6% in total, there were no clinically predictable factors to the development of ischemia during mechanical ventilation.

• Journal of The Korean Society of Clinical Toxicology
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• v.15 no.1
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• pp.11-16
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• 2017

Purpose: The association of hypoalbuminemia with 30-day in-hospital mortality in patients with organophosphate insecticide poisoning (OPI) was studied. Methods: This retrospective cohort study was conducted between January 2006 and November 2013 in the emergency department (ED) after OPI poisoning. A Kaplan-Meier 30-day survival curve and the log-rank test were used to analyze patients stratified according to serum albumin levels on ED admission (hypoalbuminemia or normo-albuminemia). Independent risk factors including hypoalbuminemia for 30-day mortality were determined by multivariate Cox regression analysis. Results: A total of 135 patients were included. Eighty-eight (65%) patients were male and the mean age was $57.3{\pm}17.0$ years. Serum albumin, mean arterial pressure, and Glasgow coma scale score were significantly higher in the survival group than the non-survival group. APACHE II score was significantly lower in the non-survival group than the survival group. The mortality of the hypoalbuminemia group (serum albumin <3.5 g/dl) was 68.8%, while that of the normo-albuminemia group (serum albumin ${\geq}3.5g/dl$) was 15.1%. The area under the ROC curve of the serum albumin level was 0.786 (95% CI, 0.690-0.881) and the APACHE II score was 0.840 (95% CI, 0.770-0.910). Conclusion: Hypoalbuminemia is associated with 30-day mortality in patients with OPI poisoning.

• Journal of KIISE
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• v.44 no.1
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• pp.84-94
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• 2017

Recently, the importance of velocity, one of the characteristics of big data (5V: Volume, Variety, Velocity, Veracity, and Value), has been emphasized in the data processing, which has led to several studies on the real-time stream processing, a technology for quick and accurate processing and analyses of big data. In this paper, we propose a Squall framework using Time-triggered Message-triggered Object (TMO) technology, a model that is widely used for processing real-time big data. Moreover, we provide a description of Squall framework and its operations under a single node. TMO is an object model that supports the non-regular real-time processing method for certain conditions as well as regular periodic processing for certain amount of time. A Squall framework can support the real-time event stream of big data and micro-batch processing with outstanding performances, as compared to Apache storm and Spark Streaming. However, additional development for processing real-time stream under multiple nodes that is common under most frameworks is needed. In conclusion, the advantages of a TMO model can overcome the drawbacks of Apache storm or Spark Streaming in the processing of real-time big data. The TMO model has potential as a useful model in real-time big data processing.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.1
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• pp.23-34
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• 2010

As the number of user increases according to the improvement of the network, the multi-thread schemes are used to process the service requests of several users who are connected simultaneously. The static thread pool scheme has the problem of occupying a static amount of system resources. On the other hand, the dynamic thread pool scheme can control the number of threads according to the users' requests. However, it has disadvantage that this scheme cannot react to the requests which are larger than the maximum value assigned. In this paper, a web server using a learning-based dynamic thread pool scheme is suggested, which will be running on a server programming of a multi-thread environment. The suggested scheme adds the creation of the threads through the prediction of the next number of periodic requests using Auto Regressive scheme with the web server apache worker MPM (Multi-processing Module). Unlike previous schemes, in order to set the exact number of the necessary threads during the unchanged number of work requests in a certain period, K-Nearest Neighbor algorithm is used to learn the number of threads in advance according to the number of requests. The required number of threads is set by comparing with the previously learned objects. Then, the similar objects are selected to decide the number of the threads according to the request, and they create the threads. In this paper, the response time has decreased by modifying the number of threads dynamically, and the system resources can be used more efficiently by managing the number of threads according to the requests.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.895-901
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• 2007

Currently the advancement of the computer and the Internet sees the direction of studying freely to do, it does not receive not to be, the student the environment it will be able to study oneself it is doing the direct help of the teacher and to be possible. Plan and it embodied the high school information society which it follows in 7th curriculum and the WBI of computer subject from the dissertation which it sees. In order to improve the qualify of curriculum ultimately, it endeavored. Territory it analyzes a subject contents first, especially it surveys, foundation it hardens, the actual training semester and pure with studying of self-evaluation do to become accomplished, studying oneself to sleep the possibility of doing own lead studying which is the possibility of studying spontaneously and integrated textbook studying in same tine it does to be with they are composing of the education paradigm the flag for a problem solving ability and an originality accident. In this dissertation used the php, Apache web server and the DBMS used the MySQL. To program member joining, the information society and computer curriculum take a course and test, it questions and, it is composed to data mourge. After taking a course, simultaneously lecturing a paper and online instruction, set up a foundation and quering that gratify one's curiosity thus it will be able to digest a study in once.