• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.185-188
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• 2009

Purpose: Standard of retests were discrepant and inconsistent due to inaccuracy and lack of standardization within normal range limit of tumor marker test. To enhance the standardization of retests set standard value below normal range and the Order Communication System Quality Control (OCS QC) program was put in place. This program enables managing the results within lower limit of normal range which were used for tumor marker test in Health Center. Materials and Methods: At present the tumor marker study for AFP, CEA, CA19-9, CA125, and PSA included outpatients in Asan Medical Center from February to March, 2009. The standard value was obtained by using the percentage of CV of Inter Assay according to the normal range of each tumor test. The results were confirmed by using the OCS QC program via formatted assessment of screening test such as test items, standard value and medical department. The number of out-of-range results within plus and minus 30 percents regarding the five primary items of tumor marker test was assessed. The next step was to obtain the number of AFP, CEA, and CA125 according to the ratio of comparison between prior and post test result, 60%, 50%, and 40% within normal range, respectively. In addition, set standard value below normal range. Results: The first screening test with percentage of sample number was resulted between 30%-40% and the second one was AFP 26.1%, CEA 18.9%, CA19-9 17.3%, CA125 18.7%, and PSA 21.0% obtained screening percentage of average 20 percents. The limited value of retest was AFP less than 5.0 and more than 10.0, CEA less than 1.0 and more than 3.0, CA19-9 less than 10.0 and more than 30.0, and PSA less than 1.0 and more than 2.0 to set and the number of retest was obtained by applying to the limited value of retest to screening percentage of average 20 percents For two months, the number of retest was AFP 0, CEA 15, CA19-9 3, CA125 2, and PSA 5. Conclusions: Through using the OCS QC program in establishing the standard of retest systemically, there appeared to be reduced discrepancy among the examiners and to be expected improvement in relation to the error of results.

• Journal of Intelligence and Information Systems
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• v.22 no.2
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• pp.81-96
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• 2016

As the internet has become widespread and easy to access everywhere, it is common for people to search information via online search engines such as Google and Naver in everyday life. Recent studies have used online search volume of specific keyword as a measure of the internet users' attention in order to predict disease outbreaks such as flu and cancer, an unemployment rate, and an index of a nation's economic condition, and etc. For stock traders, web search is also one of major information resources to obtain data about individual stock items. Therefore, search volume of a stock item can reflect the amount of investors' attention on it. The investor attention has been regarded as a crucial factor influencing on stock price but it has been measured by indirect proxies such as market capitalization, trading volume, advertising expense, and etc. It has been theoretically and empirically proved that an increase of investors' attention on a stock item brings temporary increase of the stock price and the price recovers in the long run. Recent development of internet environment enables to measure the investor attention directly by the internet search volume of individual stock item, which has been used to show the attention-induced price pressure. Previous studies focus mainly on Dow Jones and NASDAQ market in the United States. In this paper, we investigate the relationship between the individual investors' attention measured by the internet search volumes and stock price changes of individual stock items in the KOSDAQ market in Korea, where the proportion of the trades by individual investors are about 90% of the total. In addition, we examine the difference between industries in the influence of investors' attention on stock return. The internet search volume of stocks were gathered from "Naver Trend" service weekly between January 2007 and June 2015. The regression model with the error term with AR(1) covariance structure is used to analyze the data since the weekly prices in a stock item are systematically correlated. The market capitalization, trading volume, the increment of trading volume, and the month in which each trade occurs are included in the model as control variables. The fitted model shows that an abnormal increase of search volume of a stock item has a positive influence on the stock return and the amount of the influence varies among the industry. The stock items in IT software, construction, and distribution industries have shown to be more influenced by the abnormally large internet search volume than the average across the industries. On the other hand, the stock items in IT hardware, manufacturing, entertainment, finance, and communication industries are less influenced by the abnormal search volume than the average. In order to verify price pressure caused by investors' attention in KOSDAQ, the stock return of the current week is modelled using the abnormal search volume observed one to four weeks ahead. On average, the abnormally large increment of the search volume increased the stock return of the current week and one week later, and it decreased the stock return in two and three weeks later. There is no significant relationship with the stock return after 4 weeks. This relationship differs among the industries. An abnormal search volume brings particularly severe price reversal on the stocks in the IT software industry, which are often to be targets of irrational investments by individual investors. An abnormal search volume caused less severe price reversal on the stocks in the manufacturing and IT hardware industries than on average across the industries. The price reversal was not observed in the communication, finance, entertainment, and transportation industries, which are known to be influenced largely by macro-economic factors such as oil price and currency exchange rate. The result of this study can be utilized to construct an intelligent trading system based on the big data gathered from web search engines, social network services, and internet communities. Particularly, the difference of price reversal effect between industries may provide useful information to make a portfolio and build an investment strategy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1180-1187
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• 2006

We Studied the method of structuring the sign system for pedestrians in the underground space by investigating and analyzing the sign system at Tae-jon Underground Commercial Area in Korea by 1) classifying the signs by types and comparing their numder for each type in sections, 2) classiflying the signs by the points of installation, types, functions and contents of information and comparing their numbers, 3) classifying the signs by their height and comparing by the points of installation, and 4) classifying the signs by their points of installation finding patterns. As a result, we found out that the current pedestrian signs in Tae-jon Underground Commercial Area could by classified into those installted with a certain regularity and those concentrated in at certain points. We also found out that there were many problems with the current signs system. The big gap of the type and numble of the signs, concentration of the signs at the gate (entrance), and the big gap of the function of the signs by their points of installation. And the gap of the signs by the number of installation is big between the North side and the South side. Most of signs concentrated in the South side show the problems of installation attached by the types and quantity of information. We suggest that type of information has consistency by posting of signs, at the same time, the necessary information should be offered in order for the pedestrians to easily recognize as they more in the Underground space.

• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.27-32
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• 2014

A doppler shift is generated by moving a transmitter or receiver operated in communication systems. The doppler frequency shift between a transmitter and a receiver or the frequency offset present in transceivers must be removed to get the wanted system performance. FTS is used for preventing an accident from operating abnormally and for guaranteeing public protection. A launching vehicle's initial velocity is very fast in order to escape the earth and the amount of doppler shift is large. Recently many studies to adopt the next generation FTS are ongoing. To introduce new FTS, the effects of doppler shift on the performance of the new FTS must be studied. In this paper the doppler effect caused by launching vehicle's velocity affecting the performance of FTS receiver is investigated into two cases, one is for EFTS as a digital FTS and the other is for FTS using a tone signal. Noncoherent DPSK and noncoherent CPFSK are considered as the modulation methods of EFTS. In the cases of the doppler frequency shift of 200Hz present in EFTS using noncoherent DPSK and noncoherent CPFSK are simulated. Simulation results show that $E_b/N_o$ of 0.5dB deteriorates in the region of near BER of about $10^{-5}$ in RS coding. And there is no performance variation in $E_b/N_o$ or $E_b/N_o$ is worsened about 0.1dB in the same BER region for the case of using convolutional and BCH coding. Quadrature detector used in FTS using tone signals is not influenced by the doppler frequency shift.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.7
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• pp.143-148
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• 2020

Recently, web services have been expanded to various areas with the evolution of cloud environment. Whenever a user accesses a web service, the user's log information is stored in the web server. This log information is used as data to analyze the user's web service tendencies and is also used as important data to track the user's system access when a security problem in the system occurs. Currently, most web servers manage user log information in a centralized manner. When user log information is managed in a centralized manner, it is simple in the side of operation, but has a disadvantage of being very vulnerable to external malicious attacks. In the case of centralized management, user log information stored in the web server can be arbitrarily manipulated by external attacks, and in severe cases, the manipulated information can be leaked. In this case, it not only decreases the trust of the web service, but also makes it difficult to trace the source and cause of the attack on the web server. In order to solve these problems, this paper proposes a new method of managing user log information in a cloud environment by applying blockchain technology as an alternative to the existing centralized log management method. The proposed method can manage log information safely from external attacks because user log information is distributed and stored in blockchain on a private network with cloud environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1623-1636
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• 2009

A currently domestic governmental R&D business is early to 100. And this is each managed individually in 15 professional organizations of research and management by characteristics of a business. For this Reason, A redundant investment issue regarding national R&D occurs, and an issue regarding efficiency of R&D investment by insufficiency of systematic R&D research project and result management is continuously raised. Ministry of Education Science and Technology establishing National Science & Technology Information Service(NTIS) in order to solve these issues. NTIS is the national R&D Portal System which can support efficiency of research and development to result utilization in planning of national research and development. As data of the same meaning are named particularly in each organizations, and that made to different data types, It is an issue to be difficult to achieve high level qualify, accuracy of integrated data in case of integration of distributed data like NTIS In this paper We consider integrated DB constructions and Information Linking of R&D Participants/Projects/Results information in a NTIS system for data qualify Improvement, and then We analyze the cause of the data quality problem, and we propose the improvement plan for data quality elevation of NTIS system.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.3
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• pp.113-120
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• 2018

In this study, we proposed a monitoring system for identifying and handling faulty sensing stream data on manufacturing equipments where low-cost sensors can be safely used. Low cost sensors will lessen the cost of implementing distributed monitoring system, but suffer from sensor noises and inaccurate sensed data. Therefore, a distributed monitoring system with low cost sensors should identify faulty signal data as either of sensor fault or machine fault, and filter out faulty signals from sensing fault. To this end, we adopted a fourier transform based diagnostic approach mixed with a weighed moving averaging method, in order to identify faulty signals. We measured how effective our approach is and found out our approach can filter out one-third faulty signals from our experimental environment. In addition, we attached wireless communication modules to reduce sensor and network installation cost. To handle massive sensor data efficiently, we employed unstructured data format with NoSQL based database.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.605-610
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• 2018

The purpose of this paper is to develop evaluation methods in order to apply effective problem-based learning (PBL). To observe the effectiveness of a PBL system on learners and to comprehend the learning process of a PBL application, analysis of reflective journals and an evaluation questionnaire completed by participants (n=68) were used. The participants of the study were recruited from Hankyong National University students who undertook first-year Creative Engineering Design. A total of four problems for the PBL-based lectures were designed and applied to 12 weeks of PBL lectures. The participants completed reflective journals upon completion of each PBL problem-based activity; upon completion of the last PBL problem, participants completed and submitted a PBL system class-evaluation questionnaire. Also the participants completed an evaluation questionnaire at each step of the instructional procedures for each PBL problem-based activity. The findings of the research show that the participants increased their comprehension of PBL systems, their understanding of lecture content and of cooperative learning, and improved their self-reflection, authentic experience, creative problem-solving skills, communication skills, documentation skills, presentation skills, observational skills, and evaluation skills. The participants described how learning through PBL increased their confidence, satisfaction, and sense of achievement, compared to the previous semester.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.97-106
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• 2020

Due to the rapid development and dissemination of 5G communication and IoT technologies, there are increasing demands for big data analysis techniques and service systems. In particular, explosively growing demands on AI technology adoption are also causing high competitions to take advantages of machine/deep-learning models to extract novel values from enormously collected data. In order to adopt AI technology to various research and application domains, it is necessary to prepare high-performance GPU-equipped systems and perform complicated settings to utilze deep learning models. To relieve the efforts and lower the barrier to utilize AI techniques, AIaaS(AI as a service) platform is attracting a great deal of attention as a promising on-line service, where the complexity of preparation and operation can be hidden behind the cloud side and service developers only need to utilize the high-level AI services easily. In this paper, we propose an AIaaS system which can support the creation of AI services based on Docker and OpenFaaS from the registration of models to the on-line operation. We also describe a case study to show how AI services can be easily generated by the proposed system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.1102-1107
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• 2004

Fingerprint Recognition System is made up of Off-line treatment and On-line treatment; the one is registering all the information of there trieving features which are retrieved in the digitalized fingerprint getting out of the analog fingerprint through the fingerprint acquisition device and the other is the treatment making the decision whether the users are approved to be accessed to the system or not with matching them with the fingerprint features which are retrieved and database from the input fingerprint when the users are approaching the system to use. In matching between On-line and Off-line treatment, the most important thing is which features we are going to use as the standard. Therefore, we have been using “Delta” and “Core” as this standard until now, but there might have been some deficits not to exist in every person when we set them up as the standards. In order to handle the users who do not have those features, we are still using the matching method which enables us to make up of the spanning tree or the triangulation with the relations of the spanned feature. However, there are some overheads of the time on these methods and it is not sure whether they make the correct matching or not. Therefore, I would like to represent the more correct matching algorism in this paper which has not only better matching rate but also lower mismatching rate compared to the present matching algorism by selecting the line segment connecting two minutiae on the same ridge and furrow structures as the reference point.