• The KIPS Transactions:PartB
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• v.8B no.2
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• pp.173-182
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• 2001

본 논문에서는 투과형 토머그래피 영상재구성을 위하여 EM 알고리즘을 사용하는 경우에 발생하는 문제점을 해결할 수 있는 방안을 제시한다. 일반적으로 토머그래피 영상재구성과 같은 다-차원의 모수 추정인 경우에서는 그것의 페널티 함수의 헤이지안행렬의 역행렬 차수가 매우 높기 때문에 그것을 직접적으로 계산할 수 없다. 이러한 문제점을 해결하기 위하여 PEMG-1 알고리즘을 제안한다. 이 알고리즘은 페널티 함수를 사용하는 그래디언트 형태의 알고리즘인데 이것은 Lange(1995)과 Green(1990)의 알고리즘에서 지적된 문제점을 동시에 해결할 수 있다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3694-3702
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• 1999

OSL algorithm has an advantage that repeated algorithm is easily derived, even though penalty function which has a complicated transcendental function. In order to solve this problem, we suggested MPEMG algorithm. However, though this algorithm extend convergence rate of smoothing constant, it include the problem that is not faster than OSL algorithm in the convergence rate increasing penalized log-likelihood. Accordingly, in this paper, we will suggest SMOSLG digital image restoration algorithm which is fast in the convergence rate as well as extend convergence region of smoothing constant. And also we will study the usefulness of algorithm suggested through digital image simulation.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.293-302
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• 2013

So far, DW(data warehouse) of hospital has been used as tool for analyzing patient-focused data. However, EMR(Electronic Medical Record) is established these days, so informal data which is record and video record could be useful to get some information for patient remedy, not as DW data. This study claims that need of establishing treatment-focused DW, not for hospital administration-focused DW which has been used lots of hospital DW. Also we discussed how CDW can be applied for real medication situation. At last, we deduct a relation past record of sick and wounded patient as Thesaurus searching method by real hospital data for establishing base of early-treatment system.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.313-320
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• 2000

PEM algorithm cannot expend repeated algorithm, if penalty function is transcendental function. However, OSL algorithm has an advantage that repeated algorithm is easily derived, even though penalty function which has a complicated transcendental function. In spite of this advantage, this algorithm is restricted in convergence region of smoothing constant which increase penalized log-likelihood, so we cannot get the optimal image restoration because it cannot provide us with a various smoothing constant value for the digital image restoration. In this paper, in order to resolve the disadvantage of OSL algorithm, we would like to suggest the algorithm with smoothing constant enlarge the tolerance limit range of convergence and to find not only properties of its convergence but also usefulness of suggested algorithm through digital image simulation.

• KIISE Transactions on Computing Practices
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• v.24 no.1
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• pp.24-32
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• 2018

This paper proposes a Big Data system for energy Big Data which is aggregated in real-time from industrial and public sources. The constructed Big Data system is based on Hadoop and the Spark framework is simultaneously applied on Big Data processing, which supports in-memory distributed computing. In the paper, we focus on Big Data, in the form of heat energy for district heating, and deal with methodologies for storing, managing, processing and analyzing aggregated Big Data in real-time while considering properties of energy input and output. At present, the Big Data influx is stored and managed in accordance with the designed relational database schema inside the system and the stored Big Data is processed and analyzed as to set objectives. The paper exemplifies a number of heat demand plants, concerned with district heating, as industrial sources of heat energy Big Data gathered in real-time as well as the proposed system.

• Journal of Digital Convergence
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• v.11 no.6
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• pp.103-112
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• 2013

Traditional method of establishing prediction model is usually using formal data stored in Data Base. However, nowadays advent of "smart" era brought by ground-breaking development of communication system makes informal data to dominate overall data, such 80% in total. Therefore, conventional method using formal data as establishing predicting model would be untrustworthy means in present. In other words, it is indispensible to make prediction model credible including informal data(SNS, image, video) and semi-formal data(log data). In this study, we increase credibility of predicting model adapting Bigdata method and comparing reliability of conventional measurement to real-data.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.155-164
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• 2016

In this paper, we investigate and analyze big data platform published at home and abroad. The results had a problem with personal information security on each platform. In particular, there was a vulnerability in the encryption of personal information stored in big data representative of HBase NoSQL DB that is commonly used for big data platform. However, data encryption and decryption cause the system load. In this paper, we propose a method of encryption with HBase, encryption and decryption systems, and methods for applying the personal information management system (PMIS) for each step of the way and big data platform to reduce the load on the network to communicate. And we propose a new big data platform that reflects this. Therefore, the proposed Big Data platform will greatly contribute to the activation of Big Data used to obtain personal information security and system performance efficiency.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.201-210
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• 2014

Recently, the more complicated with the elements made of information system, the more dangerous in migration them. So it is need to accomplish information system migration systematically. According to the movement of public institution, a large scale of information system migration is in processing and will be made. In this paper, I would like to suggest the use of migration solution in order to speed & effect information system migration process. This will be provided the pursuit function of information system movement, movement location pursuit in real time, monitoring function through the situation room, separation migration possibility on the basis of business attribute. Therefore, if you use the suggested solution, it will be decreased trial and error & minimized the movement time.

• Journal of Industrial Convergence
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• v.20 no.4
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• pp.31-37
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• 2022

Research on what factors affect the success of the movie market is very important for reducing risks in related industries and developing the movie industry. In this study, in order to find out the degree of correlation of independent variables that affect movie performance, a survey was conducted on film experts using the AHP method and the importance of each measurement factor was evaluated. In addition, we hypothesized that factors derived from big data related to search portals and SNS will affect the success of movies due to the increase in the spread and use of smart phones. And a prediction model that reflects both the expert survey information and big data mentioned above was proposed. In order to check the accuracy of the prediction of the proposed model, it was confirmed that it was improved (10.5%) compared to the existing model as a result of verification with real data.Therefore, it is judged that the proposed model will be helpful in decision-making of film production companies and distributors.